Current compensation method and device, motor controller and storage medium

文档序号：326027 发布日期：2021-11-30 浏览：15次中文

阅读说明：本技术 一种电流补偿方法、装置、电机控制器及存储介质 (Current compensation method and device, motor controller and storage medium ) 是由陈俊桦洪伟鸿王豪浩周超彭国彬于 2021-08-31 设计创作，主要内容包括：本申请适用于电机技术领域,提供一种电流补偿方法、装置、电机控制器及存储介质,根据分别在第一有效矢量和第二有效矢量的持续时间内采样得到的两个母线电流,获得v相比较值时刻的相电流；根据第k周期的uvw相比较值和电流控制时刻的转子角度及第k-1周期的电流控制时刻的转子角度,获得第k周期的uvw相比较值时刻的转子角度；根据母线电压和abc相比较值,获得第二有效矢量；根据第二有效矢量的持续时间、第二零矢量的持续时间、v相比较值时刻的相电流、第二有效矢量和uvw相比较值时刻的转子角度,获得电流控制时刻的相电流,可以达到电流延时补偿效果,提高电流控制性能,降低电流谐波。(The application is applicable to the technical field of motors, and provides a current compensation method, a current compensation device, a motor controller and a storage medium, wherein phase current at the moment of a v comparison value is obtained according to two bus currents which are respectively obtained by sampling in the duration time of a first effective vector and a second effective vector; obtaining a rotor angle at the time of the uvw comparison value of the kth period according to the uvw comparison value of the kth period, the rotor angle at the current control time and the rotor angle at the current control time of the k-1 period; obtaining a second effective vector according to the bus voltage and the abc comparison value; and obtaining the phase current at the current control moment according to the duration of the second effective vector, the duration of the second zero vector, the phase current at the v comparison value moment and the rotor angle at the uvw comparison value moment, so that the current delay compensation effect can be achieved, the current control performance is improved, and the current harmonic is reduced.)

1. A method of current compensation, comprising:

based on the uvw comparison value of the k-th period, obtaining phase current of a v comparison value moment of the k-th period according to two bus currents sampled in the duration of the first effective vector and the second effective vector of the k-th period respectively, wherein the uvw comparison value is obtained by the abc comparison value in a numerical descending order;

obtaining a rotor angle at the time of the uvw comparison value of the kth period according to the uvw comparison value of the kth period, the rotor angle at the current control time and the rotor angle at the current control time of the k-1 period;

obtaining a second effective vector of the k period according to the bus voltage of the k period and the abc comparison value;

obtaining the phase current at the current control time of the kth period according to the duration of the second effective vector of the kth period, the duration of the second zero vector, the phase current at the v comparison value time and the rotor angle at the uvw comparison value time of the second effective vector;

and the k period and the k-1 period are two adjacent half carrier periods, and k is an integer greater than 1.

2. The current compensation method of claim 1, wherein if the k-th period is a falling edge period, the calculation formula of the rotor angle at the moment of comparing the uvw of the k-th period with the value is:

θu＝θ(k)-Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k)-Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k)-Tw/Tsh*[θ(k)-θ(k-1)]

if the k-th period is a rising edge period, the calculation formula of the rotor angle at the time of the uvw comparison value of the k-th period is as follows:

θu＝θ(k-1)+Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k-1)+Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k-1)+Tw/Tsh*[θ(k)-θ(k-1)]

wherein θ u, θ v, and θ w respectively indicate a rotor angle at the u-comparison time, the v-comparison time, and the w-comparison time of the k-th cycle, θ (k) indicates a rotor angle at the current control time of the k-th cycle, θ (k-1) indicates a rotor angle at the current control time of the k-1-th cycle, Tu, Tv, and Tw respectively indicate a u-comparison value, a v-comparison value, and a w-comparison value of the k-th cycle, and Tsh indicates a half-carrier cycle.

3. The current compensation method of claim 1, wherein obtaining the phase current at the current control time of the kth cycle based on the duration of the second effective vector of the kth cycle, the duration of the second zero vector, and the rotor angle at the time when the phase current is compared to the second effective vector and the uvw of the kth cycle comprises:

obtaining phase current under a synchronous rotating coordinate system at the moment of the v comparison value of the k period according to the phase current under the two-phase static coordinate system at the moment of the v comparison value of the k period and the rotor angle at the moment of the v comparison value;

according to the second effective vector in the two-phase stationary coordinate system of the kth period and the rotor angle at the moment of comparing the value vw, obtaining a second effective vector in the synchronous rotating coordinate system of the kth period;

obtaining phase current under the synchronous rotating coordinate system at the w comparison value moment of the k period according to the duration of the second effective vector of the k period, the phase current under the synchronous rotating coordinate system at the v comparison value moment;

and obtaining the phase current in the synchronous rotating coordinate system at the current control time of the k-th period according to the duration of the second zero vector of the k-th period and the phase current in the synchronous rotating coordinate system at the w comparison value time.

4. The current compensation method according to claim 3, wherein the formula for calculating the phase current in the synchronous rotating coordinate system at the time of the v-phase comparison value of the k-th cycle is:

id(θv)＝iα(Tv)*cos(θv)+iβ(Tv)*sin(θv)

iq(θv)＝iβ(Tv)*cos(θv)-iα(Tv)*sin(θv)

the calculation formula of the second effective vector in the synchronous rotating coordinate system of the k-th period is as follows:

ud(T2)＝uα(T2)*cos(θT2)+uβ(T2)*sin(θT2)

uq(T2)＝uβ(T2)*cos(θT2)-uα(T2)*sin(θT2)

θT2＝(θv+θw)/2

the phase current calculation formula under the synchronous rotation coordinate system at the w comparison value moment of the k-th period is as follows:

the phase current calculation formula under the synchronous rotation coordinate system at the current control time of the k-th period is as follows:

wherein id (θ v) and iq (θ v) respectively represent a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the v-comparison value timing of the k-th cycle, i α (Tv) and i β (Tv) respectively represent an α -axis component and a β -axis component of the phase current in the two-phase stationary coordinate system at the v-comparison value timing of the k-th cycle, and θ v represents a rotor angle at the v-comparison value timing of the k-th cycle;

ud (T2) and uq (T2) respectively represent a d-axis component and a q-axis component of the second effective vector in the synchronous rotating coordinate system of the k-th period, u α (T2) and u β (T2) respectively represent an α -axis component and a β -axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, and θ w represents a rotor angle at the time of w phase comparison of the k-th period;

id (θ w) and iq (θ w) respectively represent a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the time of w comparison of the k-th period, T2 represents the duration of the second effective vector of the k-th period, Ld and Lq respectively represent a d-axis component and a q-axis component of the inductance of the motor in the synchronous rotating coordinate system, R represents the resistance of the motor, ω e represents the electrical angular velocity of the motor, and ψ f represents the flux linkage of the motor;

5. The current compensation method of claim 1, wherein obtaining the phase current at the current control time of the kth cycle based on the duration of the second effective vector of the kth cycle, the duration of the second zero vector, and the rotor angle at the time when the phase current is compared to the second effective vector and the uvw of the kth cycle comprises:

obtaining an average voltage vector under the two-phase static coordinate system of the kth period according to the duration of the second effective vector of the kth period, the duration of the second zero vector and the second effective vector under the two-phase static coordinate system;

obtaining an average voltage vector under a synchronous rotating coordinate system of the kth period according to the average voltage vector under the two-phase static coordinate system of the kth period, a rotor angle at the moment of comparing a value v and a rotor angle at the moment of controlling current;

and obtaining the phase current in the synchronous rotating coordinate system at the current control time of the k period according to the phase current in the synchronous rotating coordinate system at the v comparison value time of the k period, the duration of the second effective vector, the duration of the second zero vector and the average voltage vector in the synchronous rotating coordinate system.

6. The current compensation method of claim 5, wherein the formula of calculating the phase current in the synchronous rotation coordinate system at the time of the v-phase comparison value of the k-th cycle is:

id(θv)＝iα(Tv)*cos(θv)+iβ(Tv)*sin(θv)

iq(θv)＝iβ(Tv)*cos(θv)-iα(Tv)*sin(θv)

the calculation formula of the average voltage vector in the two-phase stationary coordinate system of the k-th period is as follows:

uα(avg)＝T2*uα(T2)/(T2+T02)

uβ(avg)＝T2*uβ(T2)/(T2+T02)

the calculation formula of the average voltage vector in the synchronous rotating coordinate system of the k-th period is as follows:

ud(avg)＝uα(avg)*cos(θavg)+uβ(avg)*sin(θavg)

uq(avg)＝uβ(avg)*cos(θavg)-uα(avg)*sin(θavg)

θavg＝[θv+θ(k)]/2

the formula for calculating the phase current in the synchronous rotating coordinate system at the current control time of the k-th period is as follows:

wherein id (θ v) and iq (θ v) respectively represent a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the v-comparison value timing of the k-th cycle, ia (Tv) and i β (Tv) respectively represent an α -axis component and a β -axis component of the phase current in the two-phase stationary coordinate system according to the v-comparison value timing of the k-th cycle, and θ v represents a rotor angle at the v-comparison value timing of the k-th cycle;

u α (avg) and u β (avg) respectively represent an α -axis component and a β -axis component of the average voltage vector in the two-phase stationary coordinate system of the k-th period, u α (T2) and u β (T2) respectively represent an α -axis component and a β -axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, T2 represents a duration of the second effective vector of the k-th period, and T02 represents a duration of the second zero vector of the k-th period;

ud (avg) and uq (avg) respectively represent a d-axis component and a q-axis component of an average voltage vector in a synchronous rotating coordinate system of the k-th period, and theta (k) represents a rotor angle at the current control time of the k-th period;

id (k) and iq (k) respectively represent d-axis components and q-axis components of phase currents in the synchronous rotating coordinate system at the current control timing of the k-th cycle, Ld and Lq respectively represent d-axis components and q-axis components of inductances of the motor in the synchronous rotating coordinate system, R represents a resistance of the motor, ω e represents an electrical angular velocity of the motor, and ψ f represents a flux linkage of the motor.

7. The current compensation method according to any one of claims 1 to 6, wherein the obtaining of the phase current at the time of the comparison value of v for the k-th cycle based on the two bus currents sampled within the duration of the first and second valid vectors of the k-th cycle, respectively, based on the comparison value of uvw for the k-th cycle comprises:

obtaining an abc comparison value of the k period according to the amplitude and the phase angle of the target voltage vector of the k period;

and sorting the abc comparison values of the k period according to numerical descending order to obtain the uvw comparison value of the k period.

8. A current compensation apparatus, comprising:

the first phase current obtaining unit is used for obtaining phase current at the v comparison value moment of the k period according to two bus currents which are respectively obtained by sampling in the duration time of a first effective vector and a second effective vector of the k period based on the uvw comparison value of the k period, and the uvw comparison value is obtained by the abc comparison value according to numerical value descending order;

the rotor angle acquisition unit is used for acquiring the rotor angle at the uvw comparison value moment of the kth period according to the uvw comparison value of the kth period, the rotor angle at the current control moment and the rotor angle at the current control moment of the kth-1 period;

the effective vector calculation unit is used for obtaining a second effective vector of the k period according to the bus voltage of the k period and the abc comparison value;

the second phase current obtaining unit is used for obtaining the phase current at the current control time of the k-th period according to the duration of the second effective vector of the k-th period, the duration of the second zero vector, the phase current at the v comparison value time, and the rotor angle at the comparison value time of the second effective vector and uvw;

and the k period and the k-1 period are two adjacent half carrier periods, and k is an integer greater than 1.

9. A motor controller comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the current compensation method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the current compensation method according to any one of claims 1 to 7.

Technical Field

The present application belongs to the field of motor technology, and in particular, to a current compensation method, device, motor controller, and storage medium.

Background

The single bus current detection technology is a technology for reducing the cost of a current sensor. The single-bus current detection only detects the bus current on a direct current bus in the motor controller, and determines the correlation between the bus current and the phase current of the motor according to the switching state of a three-phase bridge arm of the inverter, so as to estimate the phase current of the motor. The single-bus current detection method only needs one current sensor, so that the cost is greatly reduced. Motor phase current reconstruction based on a single bus current detection technology provides a solution for a low-cost motor vector control system. In the reconstruction process of the motor phase current, the bus current needs to be continuously sampled twice to be converted into two-phase current and calculate the third phase current.

Since the bus current sampling action needs to be completed within the duration of two effective voltage vectors, and the effective vector output in the motor operation process continuously changes, the bus current sampling time is variable relative to the carrier period. In the technical field of low switching frequency control or high-speed motor control, the change range of the electrical angle of the motor in a carrier period is enlarged, so that the influence of switching action on a current waveform is obviously increased. In a single carrier period, due to the action voltage vector change, the current change presents a stage change characteristic and harmonic waves are increased, the accuracy of current sampling is obviously affected by the change of the bus current sampling time, and a single bus current sampling value can deviate from a current fundamental value. Furthermore, the current delay effect is difficult to estimate due to variations in the bus current sampling instants. The existing single-bus current detection technology is difficult to effectively process current sampling in the technical scope of low switching frequency control or high-speed motor control, so that the current control performance is reduced, and the current harmonic wave is increased.

Disclosure of Invention

The embodiment of the application provides a current compensation method and device, a motor controller and a storage medium, and aims to solve the problems that current sampling is difficult to effectively process in the scope of low switching frequency control or high-speed motor control technology, so that the current control performance is reduced and the current harmonic wave is increased in the existing single-bus current detection technology.

A first aspect of an embodiment of the present application provides a current compensation method, including:

obtaining a second effective vector of the k period according to the bus voltage of the k period and the abc comparison value;

and the k period and the k-1 period are two adjacent half carrier periods, and k is an integer greater than 1.

A second aspect of an embodiment of the present application provides a current compensation apparatus, including:

the effective vector calculation unit is used for obtaining a second effective vector of the k period according to the bus voltage of the k period and the abc comparison value;

and the k period and the k-1 period are two adjacent half carrier periods, and k is an integer greater than 1.

A third aspect of embodiments of the present application provides a motor controller, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the current compensation method of the first aspect of embodiments of the present application when executing the computer program.

A fourth aspect of embodiments of the present application provides a computer-readable storage medium, which stores a computer program, which when executed by a processor implements the steps of the current compensation method according to the first aspect of embodiments of the present application.

In the current compensation method provided in the first aspect of the embodiment of the present application, based on a uvw comparison value obtained by descending the abc comparison value in the k-th period according to the numerical value, a phase current at a v comparison value time in the k-th period is obtained according to two bus currents sampled within the duration of a first effective vector and a second effective vector in the k-th period, respectively; obtaining a rotor angle at the time of the uvw comparison value of the kth period according to the uvw comparison value of the kth period, the rotor angle at the current control time and the rotor angle at the current control time of the k-1 period; obtaining a second effective vector of the k period according to the bus voltage of the k period and the abc comparison value; the phase current at the current control moment of the kth period is obtained according to the duration of the second effective vector of the kth period, the duration of the second zero vector, the phase current at the moment of the v comparison value and the rotor angle at the moment of the comparison value of the second effective vector and uvw, so that the current delay compensation effect can be achieved, and the current control error caused by the sampling error of the bus current is reduced, thereby improving the current control performance, reducing the current harmonic wave, and being applicable to the technical field of low switching frequency control or high-speed motor control.

It is understood that the beneficial effects of the second to fourth aspects can be seen from the description of the first aspect, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a motor controller provided in an embodiment of the present application;

FIG. 2 is a table of calculation formulas of three-phase comparison values of a target voltage vector in six sectors of a space vector plane according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a triangular carrier, a waveform of a PWM signal, and a bus current in a half-carrier period according to an embodiment of the present disclosure;

FIG. 4 is a first flowchart of a current compensation method according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a triangular carrier, a waveform of a PWM signal, and a bus current in a half-carrier period after an abc phase sequence is redefined as provided in an embodiment of the present application;

fig. 6 is a schematic diagram of a relationship between a current change and a switching action time (i.e., a uvw comparison time) in a half-carrier period according to an embodiment of the present application;

FIG. 7 is a second flowchart of a current compensation method according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a rotor angle, voltage and current acquisition timing sequence within a half-carrier period according to an embodiment of the present disclosure;

FIG. 9 is a third flowchart illustrating a current compensation method according to an embodiment of the present disclosure;

FIG. 10 is a fourth flowchart illustrating a current compensation method according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of a current compensation device provided in an embodiment of the present application;

fig. 12 is a schematic structural diagram of a motor controller according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

The embodiment of the application provides a current compensation method, which can be executed by a processor of a motor controller when a corresponding computer program is run, and is used for obtaining phase current at the current control moment according to the phase current at the current sampling moment obtained based on a current sampling technology in the motor control process, so that the current delay compensation effect can be achieved, and the current control error caused by the bus current sampling error is reduced, thereby improving the current control performance, reducing the current harmonic wave, and being applicable to the technical field of low switching frequency control or high-speed motor control.

In application, the motor controller can be applied to an air conditioner, a fan and a washing machine and is used for driving and controlling the motor of the air conditioner, the fan and the motor of the washing machine, and the motor controller can be specifically a frequency converter.

As shown in fig. 1, a schematic diagram of a motor controller is exemplarily shown;

the motor controller comprises a processor, a current sensor and an inverter;

the current sensor is electrically connected with the negative electrode of the direct current bus and is used for detecting bus current on the direct current bus, and the current sensor is exemplarily shown in fig. 1 to be realized by a sampling resistor which is connected in series on the negative electrode of the direct current bus;

the first input end of the inverter is electrically connected with the positive pole of the direct current bus, the second input end of the inverter is electrically connected with the negative pole of the direct current bus, the six controlled ends of the inverter are electrically connected with the processor, the three output ends of the inverter are respectively electrically connected with the three phase current and phase voltage input ends of the motor, the inverter exemplarily shown in fig. 1 includes three-phase bridge arms (a-phase bridge arm, b-phase bridge arm and c-phase bridge arm), each of which includes two switching tubes (an upper switching tube and a lower switching tube), input ends of the upper switching tubes of the three-phase bridge arms are connected in common to constitute a first input end of the inverter, output ends of the lower switching tubes of the three-phase bridge arms are connected in common to constitute a second input end of the inverter 3, a controlled end of each switching tube constitutes one controlled end of the inverter, and an output end of the upper switching tube and an input end of the lower switching tube of each phase bridge arm are connected in common to constitute one output end of the inverter;

the processor is configured to:

acquiring target phase voltages (a-phase voltage, b-phase voltage and c-phase voltage) required to be applied to a stator according to a target rotor speed required to be reached by a motor so as to generate corresponding target phase currents (a-phase current ia, b-phase current ib and c-phase current ic) at the stator;

a Space Vector Pulse Width Modulation (SVPWM) method is adopted to determine a target voltage Vector according to a rotor angle and a target phase voltage, a three-phase comparison value is obtained through a comparison value calculation method based on the SVPWM method according to a target voltage Vector amplitude and a phase angle, then a triangular carrier is adopted to compare with the three-phase comparison value obtained through calculation, a generated Pulse Width Modulation (PWM) signal for driving a switching tube of a corresponding phase is generated, the on-off states of six switching tubes of a three-phase bridge arm of an inverter are controlled, and therefore three-phase voltages are output to a motor.

Controlling the on-off states of six switching tubes of a three-phase bridge arm of the inverter according to the PWM signals, so that the actual voltage of the bus voltage acting on the stator is equivalent to the target phase voltage, correspondingly, the actual current of the bus current acting on the stator is equivalent to the target phase current, and further the stator generates a corresponding magnetic field to drive the rotor to rotate at the target rotor speed;

in order to improve the control precision of the motor, the bus current on the direct current bus needs to be acquired through a current sensor to obtain the magnitude of the bus current on the direct current bus, so that the magnitude of the actual phase current applied to the stator can be estimated based on the magnitude of the bus current, and by comparing the actual phase current with the target phase current, the target phase current may be adjusted based on a deviation between the actual phase current and the target phase current, and based on the adjusted target phase current, the adjusted target phase voltage can be obtained, the adjusted target voltage vector can be determined by combining a space vector pulse width modulation method, and generating an adjusted pulse width modulation signal according to the adjusted target voltage vector, controlling the on-off states of six switching tubes of a three-phase bridge arm of the inverter according to the adjusted pulse width modulation signal, and finally realizing feedback control on the motor.

In application, the switch tube has a function of turning on or off under the trigger of an electrical signal (PWM signal), and is used to play a role of an electronic switch, and specifically may be an Insulated Gate Bipolar Transistor (IGBT), a triode (Bipolar Junction Transistor, BJT), a Field Effect Transistor (FET), a Thyristor (Thyristor), or the like, where the IGBT is a composite fully-controlled voltage-driven power Semiconductor device composed of a Bipolar Transistor and an Insulated Gate Field Effect Transistor, and has advantages of both a high input impedance of the Insulated Gate Field Effect Transistor and a low on-state voltage drop of the Bipolar Transistor, and the FET may be a Metal-Oxide Semiconductor Field Effect Transistor (MOS-FET for short).

In application, a comparison value calculation method based on the SVPWM method is described in detail as follows:

if the amplitude of the target voltage vector is Ur and the phase angle is θ 1, the calculation method of the modulation factor m1 is as follows:

wherein Udc is the bus voltage;

if theta 1 is greater than 0 and theta 1 is not greater than 1/3 x pi, the target voltage vector is located in a first sector of the space vector plane, and an angle theta m relative to the first sector is equal to theta 1;

if theta 1 is greater than 1/3 and theta 1 is less than or equal to 2/3, the target voltage vector is located in a second sector of the space vector plane, and the angle theta m relative to the second sector is theta 1-1/3;

if theta 1 is greater than 2/3 and theta 1 is less than or equal to 3/3, the target voltage vector is located in a third sector of the space vector plane, and the angle theta m relative to the third sector is theta 1-2/3;

if theta 1 is greater than 3/3 and theta 1 is less than or equal to 4/3, the target voltage vector is located in a fourth sector of the space vector plane, and the angle theta m relative to the fourth sector is theta 1-3/3;

if theta 1 is greater than 4/3 and theta 1 is less than or equal to 5/3, the target voltage vector is located in a fifth sector of the space vector plane, and the angle theta m relative to the fifth sector is theta 1-4/3;

if theta 1 is greater than 5/3 and theta 1 is less than or equal to 2, the target voltage vector is located in a sixth sector of the space vector plane, and an angle theta m relative to the sixth sector is theta 1-5/3;

and calculating the duration ratio Tm1 and Tm2 of the two effective vectors in the carrier period based on m1 and thetam:

wherein Tm is the maximum value of the carrier counter, that is, the maximum carrier cycle count value;

the calculation method of the duration ratio Tm0 of the zero vector comprises the following steps:

Tm0＝0.5*(1-Tm1-Tm2)*Tm

as shown in fig. 2, an exemplary calculation formula table showing three-phase comparison values of a target voltage vector in six sectors of a space vector plane; wherein, the comparison value of the phase a at the carrier falling edge is DDA0, and the comparison value of the carrier rising edge is DUA 0; the comparison value of the phase b at the carrier falling edge is DDB0, and the comparison value of the carrier rising edge is DUB 0; the comparison value of the c phase at the carrier falling edge is DDC0, and the comparison value at the carrier rising edge is DUC 0. In the symmetric sampling mode, the comparison value of the carrier falling edge is the same as the comparison value of the carrier rising edge, that is, DDA0 ═ DUA0, DDB0 ═ DUB0, and DDC0 ═ DUC 0.

In application, based on a single bus current sampling mode of SVPWM, in a half-carrier period, the voltage output by an inverter is divided into four sections, and when the half-carrier period is a carrier falling edge period, the four sections of voltage output by the inverter are respectively: first zero vector → first significant vector → second zero vector; when the half-carrier period is the carrier rising edge period, the four sections of voltages output by the inverter are respectively as follows: second zero vector → second significant vector → first zero vector.

As shown in fig. 3, a schematic diagram illustrating a triangular carrier wave, a waveform of a PWM signal, and a bus current in a half-carrier period is illustrated as an example; wherein Ta, Tb, and Tc are comparison values of abc, Tsh is a half-carrier period, waveforms of the a-phase, the b-phase, and the c-phase are waveforms of PWM signals output to a three-phase arm of the inverter, idc is a bus current, T1 is a duration of the first effective vector, T2 is a duration of the second effective vector, and Tad1 and Tad2 are two times of bus current sampling times.

In application, the single-bus current sampling technology is used for respectively sampling bus currents in the duration of two adjacent effective vectors (namely a first effective vector and a second effective vector) and estimating corresponding motor phase currents. The relationship between the bus current sampling and the phase current and space voltage vector is:

if the output voltage at the bus current sampling moment is the space voltage vector 100, the bus current idc is equal to the a-phase current ia;

if the output voltage at the bus current sampling moment is the space voltage vector 110, the bus current idc is equal to the negative c-phase current-ic;

if the output voltage at the bus current sampling moment is a space voltage vector 101, the bus current idc is equal to the negative b-phase current-ib;

if the output voltage at the bus current sampling moment is a space voltage vector 010, the bus current idc is equal to the b-phase current ib;

if the output voltage at the bus current sampling moment is the space voltage vector 011, the bus current idc is equal to the negative a-phase current-ia;

if the output voltage at the bus current sampling time is the space voltage vector 001, the bus current idc is equal to the c-phase current ic.

As shown in fig. 4, an embodiment of the present application provides a current compensation method, including the following steps S401 to S406:

step S401, according to the amplitude and the phase angle of the target voltage vector of the k-th period, an abc comparison value of the k-th period is obtained.

In application, the abc comparison values include an a comparison value, a b comparison value and a c comparison value, which can be obtained by a comparison value calculation method based on the SVPWM method according to the magnitude and phase angle of the target voltage vector.

And S402, sequencing the abc comparison values of the k period according to numerical value descending order to obtain a uvw comparison value of the k period.

In application, the uvw comparison value includes a u comparison value, a v comparison value and a w comparison value, and the u comparison value, the v comparison value and the w comparison value are obtained by sorting and renaming the a comparison value, the b comparison value and the c comparison value according to a descending numerical order (i.e. according to a descending numerical order), for example, if the descending numerical order of the a comparison value, the b comparison value and the c comparison value is: if the a comparison value is greater than the b comparison value and is greater than the c comparison value, the renamed a comparison value is a u comparison value, the b comparison value is a v comparison value, and the c comparison value is a w comparison value; if the numerical values of the comparison value a, the comparison value b and the comparison value c are in descending order: c compare > b compare > a compare, then the renamed a compare is w compare, b compare is v compare, c compare is u compare.

Step S403, regarding the duration between the starting time of the kth period and the comparison value time of u as the duration of the first zero vector of the kth period;

step S404, the duration between the u comparison value time and the v comparison value time of the k period is used as the duration of the first effective vector of the k period;

step S405, taking the duration between the v comparison value time and the w comparison value time of the k period as the duration of the second effective vector of the k period;

step S406 is to use the duration between the w comparison time and the ending time of the k-th cycle as the duration of the second zero vector of the k-th cycle.

In application, based on a uvw comparison value obtained after numerical descending sorting and renaming of abc comparison values, a first zero vector, a first effective vector, a second effective vector and a second zero vector in a half-carrier period are redefined, and the redefinition is specifically defined as follows:

the first zero vector is output voltage from the starting time of the half-carrier period to the time before the u comparison value time, and the duration time of the first zero vector is the duration time between the starting time of the half-carrier period and the u comparison value time;

the first effective vector is output voltage from the time of the u comparison value to the time of the v comparison value, and the duration of the first effective vector is the duration between the time of the u comparison value and the time of the v comparison value;

the second effective vector is the output voltage from the v comparison value moment to the w comparison value moment, and the duration of the second effective vector is the duration between the v comparison value moment and the w comparison value moment;

the second zero vector is the output voltage during the w comparison value time and the end time of the half carrier period, and the duration of the second zero vector is the duration between the w comparison value time and the end time of the half carrier period.

As shown in fig. 5, a schematic diagram illustrating a triangular carrier, a waveform of a PWM signal, and a bus current in a half-carrier period after redefining an abc phase sequence is exemplarily shown; where Tu, Tv, and Tw are uvw comparison values, Tsh is a half-carrier period, u-phase, v-phase, and w-phase waveforms are waveforms of PWM signals output to a three-phase arm of the inverter, idc is a bus current, T1 is a duration of the first effective vector, and T2 is a duration of the second effective vector.

In application, in the application of controlling a high-power motor, the switching frequency of the inverter is limited, that is, low switching frequency control needs to be realized. In addition, in the field of high-speed motor control, the degree of change in current phase within a single PWM period is large, and therefore, the equivalent switching frequency within the motor electrical period is reduced. In the above two applications, harmonic components in the current increase due to a decrease in the switching frequency of the inverter, and the influence of the switching operation on the current waveform cannot be ignored.

As shown in fig. 6, a schematic diagram of a relationship between a current variation in a half-carrier period and a switching action time (i.e., a uvw comparison time) in a low switching frequency control category is exemplarily shown; wherein Tu, Tv and Tw are uvw comparison values, Tsh is a half carrier period, Tad1 is a current sampling time, and iu is a sampled bus current. In fig. 6, the u-phase current can be approximately changed by a broken line in a half-carrier period, and each broken line range is the action range of different voltage vectors. The slopes of the current change line segments under the action of different voltage vectors are different. Taking the current sampling time Tad1 between the u-phase comparison value Tu and the v-phase comparison value Tv as an example, assuming that the sampled bus current is equal to the u-phase current iu, it can be known that the sampled current iu at this time will deviate from the sinusoidal fundamental wave of the u-phase current at the current sampling time Tad1, thereby causing the subsequent current control effect to be reduced. In addition, because the sampling position is influenced by the occurrence moment of the carrier comparison action (namely the moment of the uvw comparison value), the uvw comparison value is continuously changed in the operation process of the motor, and therefore, the influence degree of the current sampling by the harmonic wave is different in the operation process of the motor, and the uncertainty of current control is increased.

As shown in fig. 7, based on the redefined uvw phase sequence, the current compensation method provided in the embodiment of the present application further includes the following steps S701 to S704:

step S701, based on the uvw comparison value in the k-th cycle, obtaining a phase current at the v comparison value moment in the k-th cycle according to two bus currents sampled within the duration of the first effective vector and the second effective vector in the k-th cycle, respectively.

In application, according to a single bus current detection technology, based on a uvw phase sequence, a first bus current is sampled within the duration of a first effective vector, a second bus current is sampled within the duration of a second effective vector, and the two bus current sampling moments need to be close to a carrier comparison action moment between the two bus current sampling moments on the basis of meeting the time required by sampling, namely a v comparison value moment. And performing motor phase current reconstruction and coordinate transformation on the first bus current and the second bus current to obtain phase current under a two-phase static coordinate system, wherein the phase current is used as the phase current at the moment of comparing the v phase value.

In one embodiment, step S701 includes:

based on a single bus current detection technology, obtaining phase current in a three-phase stationary coordinate system of the kth period according to a first bus current sampled in a first effective vector of the kth period and a second bus current sampled in the duration of a second effective vector of the kth period;

and performing coordinate transformation on the phase current in the three-phase stationary coordinate system of the k-th period to obtain the phase current in the two-phase stationary coordinate system of the k-th period as the phase current at the v comparison value moment of the k-th period.

In one embodiment, the formula for the phase current at the time of the comparison of v for the k-th cycle is:

iα＝ia

where ia and i β respectively represent the α -axis component and the β -axis component of the phase current in the two-phase stationary coordinate system of the k-th cycle (i.e., the α -axis component and the β -axis component of the phase current in the two-phase stationary coordinate system at the time of the v-phase comparison value of the k-th cycle), and ia, ib, and ic represent the phase current in the three-phase stationary coordinate system of the k-th cycle.

Step S702, obtaining the rotor angle at the time of the uvw comparison value of the k-th period according to the uvw comparison value of the k-th period, the rotor angle at the current control time and the rotor angle at the current control time of the k-1-th period.

In application, the rotor angle at the uvw comparison time of the k-th period includes a rotor angle at the u comparison time, a rotor angle at the v comparison time, and a rotor angle at the w comparison time, and can be calculated according to the uvw comparison of the k-th period, the rotor angle at the current control time of the k-th period, and the rotor angle at the current control time of the k-1-th period. Rotor angle means the angle within the electrical period in which the d-axis of the magnetic pole of the rotor permanent magnet is pointing. The rotor angle can be calculated by the induction signal of an angle sensor or a speed sensor arranged on the motor, and can also be calculated by a rotor speed estimation technology based on no position sensor.

In one embodiment, if the k-th period is a falling edge period, the calculation formula of the rotor angle at the moment when the uvw of the k-th period is compared with the value is as follows:

θu＝θ(k)-Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k)-Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k)-Tw/Tsh*[θ(k)-θ(k-1)]

if the k-th period is a rising edge period, the calculation formula of the rotor angle at the time of the uvw comparison value of the k-th period is as follows:

θu＝θ(k-1)+Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k-1)+Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k-1)+Tw/Tsh*[θ(k)-θ(k-1)]

As shown in fig. 8, an exemplary diagram illustrating the timing of the rotor angle, voltage and current acquisition during a half-carrier period is shown; wherein θ (k) represents a rotor angle at a current control time of a k-th cycle, θ (k-1) represents a rotor angle at a current control time of the k-1-th cycle, θ u, θ v, and θ w represent rotor angles at a u-comparison value time, a v-comparison value time, and a w-comparison value time of the k-th cycle, respectively, ia and i β represent an α -axis component and a β -axis component of a phase current in the two-phase stationary coordinate system of the k-th cycle, respectively, u α (T1) and u β (T1) represent an α -axis component and a β -axis component of a first effective vector in the two-phase stationary coordinate system of the k-th cycle, respectively, and u α (T2) and u β (T2) represent an α -axis component and a β -axis component of a second effective vector in the two-phase stationary coordinate system of the k-th cycle, respectively.

Step 703, obtaining a second effective vector of the k-th period according to the bus voltage of the k-th period and the abc comparison value.

In application, in the current delay compensation calculation, the voltage loaded to the motor between the bus current sampling time and the current control time needs to be acquired. As shown in fig. 5, the bus current sampling time is first passed through the duration T2 of the second active vector, and then passed through the duration T02 of the second zero vector to the current control time. The second effective vector relates to the sector in which the target voltage vector lies in the space vector plane, i.e. to the magnitude of the abc comparison value.

In application, in the SVPWM category, the second effective vector may be calculated according to a relationship between a duty ratio of the abc comparison value and the bus voltage, and when the bus current sampling time is in a first half carrier period (that is, a falling edge period) and a second half carrier period (that is, a rising edge period), the calculation methods of the second effective vector are different.

In one embodiment, if the k-th period is a falling edge period, the second valid vector is calculated as follows:

if the values of the abc comparison values are descending a comparison value > b comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > a comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > c comparison value > a comparison value, the second valid vector is:

uα(T2)＝-2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending c comparison value > b comparison value > a comparison value, the second valid vector is:

uα(T2)＝-2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending c comparison value > a comparison value > b comparison value, the second valid vector is:

if the values of the abc comparison values are descending a comparison value > c comparison value > b comparison value, the second valid vector is:

where u α (T2) and u β (T2) respectively denote an α -axis component and a β -axis component of the second effective vector in the two-phase stationary coordinate system of the k-th cycle, and Udc denotes a bus voltage of the k-th cycle.

In one embodiment, if the k-th period is a rising edge period, the second effective vector is calculated as follows:

if the values of the abc comparison values are descending a comparison value > b comparison value > c comparison value, the second valid vector is:

uα(T2)＝2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending b comparison value > a comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > c comparison value > a comparison value, the second valid vector is:

if the values of the abc comparison values are descending c comparison value > b comparison value > a comparison value, the second valid vector is:

if the values of the abc comparison values are descending c comparison value > a comparison value > b comparison value, the second valid vector is:

if the values of the abc comparison values are descending a comparison value > c comparison value > b comparison value, the second valid vector is:

uα(T2)＝2*Udc/3，uβ(T2)＝0；

Step S704, obtaining the phase current at the current control time of the k-th period according to the duration of the second effective vector, the duration of the second zero vector, the phase current at the v comparison value time, and the rotor angle at the comparison value time of the second effective vector and uvw of the k-th period.

In application, based on a mathematical model of the permanent magnet motor, the action interval of the second effective vector and the second zero vector is subjected to linearization processing, and the current at the current control moment is calculated by taking the bus current sampling moment as a starting point.

As shown in fig. 9, in one embodiment, step S704 includes the following steps S901 to S904:

step S901 obtains a phase current in a synchronous rotating coordinate system at the v-comparison time of the k-th cycle according to a phase current in a two-phase stationary coordinate system at the v-comparison time of the k-th cycle and a rotor angle at the v-comparison time.

In application, according to phase currents obtained by a bus current sampling technology, a d-axis current id (theta v) and a q-axis current iq (theta v) in a synchronous rotation coordinate system at the moment of comparing values of v are calculated.

In one embodiment, the formula for calculating phase currents id (θ v) and iq (θ v) in the synchronous rotating coordinate system at the time of comparing v in the k-th period is as follows:

id(θv)＝iα(Tv)*cos(θv)+iβ(Tv)*sin(θv)

iq(θv)＝iβ(Tv)*cos(θv)-iα(Tv)*sin(θv)

where id (θ v) and iq (θ v) respectively represent a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the v-comparison time of the k-th cycle, i α (Tv) and i β (Tv) respectively represent an α -axis component and a β -axis component of the phase current in the two-phase stationary coordinate system at the v-comparison time of the k-th cycle, and θ v represents a rotor angle at the v-comparison time of the k-th cycle.

And S902, obtaining a second effective vector in the synchronous rotating coordinate system of the kth period according to the second effective vector in the two-phase static coordinate system of the kth period and the rotor angle at the moment of comparing the values with vw.

In application, the voltages in the action interval of the second effective vector are subjected to coordinate transformation, and a d-axis voltage ud (T2) and a q-axis voltage uq (T2) in a synchronous rotating coordinate system are obtained, wherein theta T2 is a central angle in the duration T2 of the second effective vector.

In one embodiment, the calculation formula of the second effective vector in the k-th period of the synchronous rotating coordinate system is as follows:

ud(T2)＝uα(T2)*cos(θT2)+uβ(T2)*sin(θT2)

uq(T2)＝uβ(T2)*cos(θT2)-uα(T2)*sin(θT2)

θT2＝(θv+θw)/2

wherein ud (T2) and uq (T2) respectively represent a d-axis component and a q-axis component of the second effective vector in the synchronous rotating coordinate system of the k-th period, u α (T2) and u β (T2) respectively represent an α -axis component and a β -axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, and θ w represents a rotor angle at the time of w phase comparison value of the k-th period.

Step S903, obtaining the phase current in the synchronous rotating coordinate system at the w comparison value moment of the k period according to the duration of the second effective vector of the k period, the phase current in the synchronous rotating coordinate system at the v comparison value moment.

In application, according to a motor state equation, a d-axis current id (theta w) and a q-axis current iq (theta w) in a synchronous rotation coordinate system at the time of w comparison are calculated by a sampling current id (theta v) and a current iq (theta v) at the time of v comparison.

In one embodiment, the phase current calculation formula in the synchronous rotating coordinate system at the time of the w comparison value of the k-th period is as follows:

where id (θ w) and iq (θ w) respectively denote a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the time of w comparison of the k-th period, T2 denotes a duration of the second effective vector of the k-th period, Ld and Lq respectively denote a d-axis component and a q-axis component of the inductance of the motor in the synchronous rotating coordinate system, R denotes the resistance of the motor, ω e denotes the electrical angular velocity of the motor, and ψ f denotes the flux linkage of the motor.

Step S904, obtaining the phase current in the synchronous rotating coordinate system at the current control time of the k-th period according to the phase current in the synchronous rotating coordinate system at the comparison time of the duration of the second zero vector of the k-th period and w.

In application, because the voltage is zero in the zero vector action interval, the current at the current control moment is calculated through the current at the bus current sampling moment, and the current compensation effect is realized.

In one embodiment, the phase current calculation formula in the synchronous rotation coordinate system at the current control time of the k-th cycle is as follows:

where id (k) and iq (k) respectively represent the d-axis component and the q-axis component of the phase current in the synchronous rotating coordinate system at the current control time of the k-th cycle, and T02 represents the duration of the second zero vector of the k-th cycle.

As shown in fig. 10, in one embodiment, step S704 includes the following steps S1001 to S1004:

step S1001 obtains a phase current in a synchronous rotation coordinate system at the v-comparison time of the k-th cycle from a phase current in a two-phase stationary coordinate system at the v-comparison time of the k-th cycle and a rotor angle at the v-comparison time.

In application, step S1001 is the same as step S901 in the embodiment corresponding to fig. 9, and is not described here again.

Step S1002, obtain an average voltage vector in the two-phase stationary coordinate system of the kth period according to the duration of the second effective vector of the kth period, the duration of the second zero vector, and the second effective vector in the two-phase stationary coordinate system.

In application, the average values u alpha (avg) and u beta (avg) of the voltage between the bus current sampling time and the current control time are calculated, namely the average action effect of the second effective vector and the second zero vector.

In one embodiment, the calculation formula of the average voltage vector in the two-phase stationary coordinate system of the k-th period is as follows:

uα(avg)＝T2*uα(T2)/(T2+T02)

uβ(avg)＝T2*uβ(T2)/(T2+T02)

where u α (avg) and u β (avg) denote an α -axis component and a β -axis component of the average voltage vector in the two-phase stationary coordinate system of the k-th period, respectively, u α (T2) and u β (T2) denote an α -axis component and a β -axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, respectively, T2 denotes a duration of the second effective vector of the k-th period, and T02 denotes a duration of the second zero vector of the k-th period.

Step S1003, obtaining an average voltage vector in the synchronous rotation coordinate system of the k-th period according to the average voltage vector in the two-phase stationary coordinate system of the k-th period, the rotor angle at the v-comparison value time, and the rotor angle at the current control time.

In application, the voltage average values u alpha (avg) and u beta (avg) are subjected to coordinate transformation to obtain a d-axis voltage average value ud (avg) and a q-axis voltage average value uq (avg) in a synchronous rotation coordinate system.

In one embodiment, the calculation formula of the average voltage vector in the synchronous rotating coordinate system of the k-th period is as follows:

ud(avg)＝uα(avg)*cos(θavg)+uβ(avg)*sin(θavg)

uq(avg)＝uβ(avg)*cos(θavg)-uα(avg)*sin(θavg)

θavg＝[θv+θ(k)]/2

wherein ud (avg) and uq (avg) respectively represent a d-axis component and a q-axis component of the average voltage vector in the synchronous rotating coordinate system of the k-th cycle, and θ (k) represents a rotor angle at the current control time of the k-th cycle.

Step S1004, obtaining the phase current in the synchronous rotating coordinate system at the current control time of the k-th period according to the phase current in the synchronous rotating coordinate system at the v-comparison time of the k-th period, the duration of the second effective vector, the duration of the second zero vector, and the average voltage vector in the synchronous rotating coordinate system.

In application, according to a motor state equation, d-axis current id (k) and q-axis current iq (k) in a synchronous rotation coordinate system corresponding to the current control time are calculated.

In one embodiment, the formula for calculating the phase current in the synchronous rotating coordinate system at the current control time of the k-th cycle is as follows:

where id (k) and iq (k) respectively represent a d-axis component and a q-axis component of the phase current in the synchronous rotating coordinate system at the current control timing of the k-th cycle, Ld and Lq respectively represent a d-axis component and a q-axis component of the inductance of the motor in the synchronous rotating coordinate system, R represents the resistance of the motor, ω e represents the electrical angular velocity of the motor, and ψ f represents the flux linkage of the motor.

In application, the embodiment corresponding to fig. 10 provides a simplified current compensation method, and the difference from the embodiment corresponding to fig. 9 is that in the current delay compensation calculation of S1002, the current control time current can be calculated by averaging the voltages in the action interval of the second effective vector and the action interval of the second zero vector and only solving the motor state equation once, so that the calculation process is simplified, and the current control efficiency of the motor can be effectively improved.

In application, the k-th period and the k-1-th period are two adjacent half carrier periods, k is an integer greater than 1, the k-th period may be a current half carrier period, and the corresponding k-1-th period may be a last half carrier period.

The embodiment of the present application further provides a current compensation device, which is applied to a motor controller and is used for executing the steps in the foregoing method embodiments. The device may be a virtual appliance (virtual appliance) in the motor controller, run by a processor of the motor controller, or the motor controller itself.

As shown in fig. 11, a current compensation apparatus 100 provided in the embodiment of the present application includes:

the first phase current obtaining unit 101 is configured to obtain, based on a uvw comparison value of a kth period, a phase current at a v comparison value moment of the kth period according to two bus currents sampled within durations of a first effective vector and a second effective vector of the kth period, respectively;

a rotor angle obtaining unit 102, configured to obtain a rotor angle at the uvw comparison value time of the kth period according to the uvw comparison value of the kth period, the rotor angle at the current control time of the k-1 period, and the rotor angle at the current control time of the kth period;

an effective vector calculation unit 103, configured to obtain a second effective vector of the k-th cycle according to the bus voltage of the k-th cycle and the abc comparison value;

and a second phase current obtaining unit 104, configured to obtain the phase current at the current control time of the k-th period according to the duration of the second effective vector of the k-th period, the duration of the second zero vector, the phase current at the v comparison value time, and the rotor angle at the comparison value time of the second effective vector and uvw.

In one embodiment, the current compensation device further comprises:

a comparison value obtaining unit, configured to obtain an abc comparison value of a k-th cycle according to an amplitude and a phase angle of a target voltage vector of the k-th cycle;

the phase sequence mapping unit is used for sequencing the abc comparison values of the kth period according to numerical descending order to obtain a uvw comparison value of the kth period;

a first time acquisition unit, configured to use a duration between a start time of a kth period and a time of the u-comparison value as a duration of a first zero vector of the kth period;

a second time acquisition unit, configured to use a duration between a u-comparison value time and a v-comparison value time of a k-th cycle as a duration of the first valid vector of the k-th cycle;

a third time acquisition unit, configured to use a duration between a v comparison value time and a w comparison value time of a k-th cycle as a duration of a second valid vector of the k-th cycle;

and a fourth time acquisition unit for taking the duration between the w comparison value time and the end time of the k-th period as the duration of the second zero vector of the k-th period.

In one embodiment, the first phase current obtaining unit includes:

the current sampling subunit is used for obtaining the phase current in the three-phase stationary coordinate system of the k period according to the first bus current sampled in the first effective vector of the k period and the second bus current sampled in the duration of the second effective vector of the k period based on a single bus current detection technology;

and the coordinate conversion subunit is used for performing coordinate conversion on the phase current in the three-phase stationary coordinate system of the k-th period to obtain the phase current in the two-phase stationary coordinate system of the k-th period as the phase current at the v comparison value moment of the k-th period.

In one embodiment, the coordinate conversion unit is configured to calculate the phase current at the time of the v-phase comparison value of the k-th cycle according to the following formula:

iα＝ia

In one embodiment, the rotor angle obtaining unit is configured to:

if the k-th period is a falling edge period, calculating the rotor angle at the moment of the uvw comparison value of the k-th period according to the following calculation formula:

θu＝θ(k)-Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k)-Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k)-Tw/Tsh*[θ(k)-θ(k-1)]

if the k-th period is a rising edge period, calculating the rotor angle at the moment of the uvw comparison value of the k-th period according to the following calculation formula:

θu＝θ(k-1)+Tu/Tsh*[θ(k)-θ(k-1)]

θv＝θ(k-1)+Tv/Tsh*[θ(k)-θ(k-1)]

θw＝θ(k-1)+Tw/Tsh*[θ(k)-θ(k-1)]

In one embodiment, the valid vector calculation unit is configured to calculate the second valid vector by:

if the k-th period is a falling edge period, the calculation method of the second effective vector is as follows:

if the values of the abc comparison values are descending a comparison value > b comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > a comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > c comparison value > a comparison value, the second valid vector is:

uα(T2)＝-2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending c comparison value > b comparison value > a comparison value, the second valid vector is:

uα(T2)＝-2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending c comparison value > a comparison value > b comparison value, the second valid vector is:

if the values of the abc comparison values are descending a comparison value > c comparison value > b comparison value, the second valid vector is:

In an embodiment, the valid vector calculation unit is adapted to calculate the second valid vector by:

if the k-th period is a rising edge period, the calculation method of the second effective vector is as follows:

if the values of the abc comparison values are descending a comparison value > b comparison value > c comparison value, the second valid vector is:

uα(T2)＝2*Udc/3，uβ(T2)＝0；

if the values of the abc comparison values are descending b comparison value > a comparison value > c comparison value, the second valid vector is:

if the values of the abc comparison values are descending b comparison value > c comparison value > a comparison value, the second valid vector is:

if the values of the abc comparison values are descending c comparison value > b comparison value > a comparison value, the second valid vector is:

if the values of the abc comparison values are descending c comparison value > a comparison value > b comparison value, the second valid vector is:

if the values of the abc comparison values are descending a comparison value > c comparison value > b comparison value, the second valid vector is:

uα(T2)＝2*Udc/3，uβ(T2)＝0；

In one embodiment, the second phase current acquisition unit comprises:

the first current obtaining subunit is used for obtaining the phase current in the synchronous rotating coordinate system at the v comparison value moment of the k period according to the phase current in the two-phase static coordinate system at the v comparison value moment of the k period and the rotor angle at the v comparison value moment;

the vector obtaining subunit is configured to obtain a second effective vector in the synchronous rotating coordinate system of the kth period according to the second effective vector in the two-phase stationary coordinate system of the kth period and the rotor angle at the moment of comparing the vw values;

the second current obtaining subunit is configured to obtain, according to the duration of the second effective vector in the k-th period, the phase current in the synchronous rotating coordinate system at the time of comparing the second effective vector in the synchronous rotating coordinate system with the v, the phase current in the synchronous rotating coordinate system at the time of comparing the w-th effective vector with the v-th effective vector in the k-th period;

and the third current acquisition subunit is used for acquiring the phase current in the synchronous rotating coordinate system at the current control time of the k-th period according to the duration of the second zero vector of the k-th period and the phase current in the synchronous rotating coordinate system at the w comparison value time.

In one embodiment, the second phase current acquisition unit comprises:

the first vector acquisition subunit is used for acquiring an average voltage vector in the two-phase static coordinate system of the kth period according to the duration of the second effective vector of the kth period, the duration of the second zero vector and the second effective vector in the two-phase static coordinate system;

the second vector acquisition subunit is used for acquiring an average voltage vector in a synchronous rotating coordinate system of the kth period according to the average voltage vector in the two-phase stationary coordinate system of the kth period, the rotor angle at the moment of comparing the values v and the rotor angle at the moment of controlling the current;

and the second current acquisition subunit is used for acquiring the phase current in the synchronous rotating coordinate system at the current control time of the k-th period according to the phase current in the synchronous rotating coordinate system at the v comparison value time of the k-th period, the duration of the second effective vector, the duration of the second zero vector and the average voltage vector in the synchronous rotating coordinate system.

In application, each component in the above apparatus may be a software program unit, may also be implemented by different logic circuits integrated in a processor or a separate physical component connected to the processor, and may also be implemented by a plurality of distributed processors.

The current compensation device provided by the embodiment of the application obtains the phase current at the current control moment according to the phase current at the current sampling moment obtained based on the current sampling technology, can achieve the current delay compensation effect, and reduces the current control error caused by the bus current sampling error, thereby improving the current control performance, reducing the current harmonic wave, and being applicable to the technical category of low switching frequency control or high-speed motor control.

As shown in fig. 12, an embodiment of the present application further provides a motor controller 200, including: at least one processor 201 (only one processor is shown in fig. 12), a memory 202, and a computer program 203 stored in the memory 202 and executable on the at least one processor 201, the steps in the various method embodiments described above being implemented when the computer program 203 is executed by the processor 201.

In an application, the motor controller may include, but is not limited to, a processor and a memory, and may also include the current sensor and inverter shown in fig. 1, and/or may also include a filter, a PWM driver, an analog-to-digital converter, and the like. Those skilled in the art will appreciate that fig. 12 is merely an example of a motor controller, and does not constitute a limitation of a motor controller, and may include more or fewer components than those shown, or some components in combination, or different components, for example, input-output devices, network access devices, etc. The input and output device can comprise the human-computer interaction device and can also comprise a display screen for displaying the working parameters of the motor controller. The network access device may include a communication module for the motor controller to communicate with the client.

In an Application, the Processor may be a Central Processing Unit (CPU), and the Processor may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

In application, the memory may in some embodiments be an internal storage unit of the motor controller, such as a hard disk or a memory of the motor controller. The memory may also be an external storage device of the motor controller in other embodiments, such as a plug-in hard disk provided on the motor controller, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like. The memory may also include both an internal storage unit of the motor controller and an external storage device. The memory is used for storing an operating system, an application program, a Boot Loader (Boot Loader), data, and other programs, such as program codes of computer programs. The memory may also be used to temporarily store data that has been output or is to be output.

In application, the Display may be a Thin Film Transistor Liquid Crystal Display (TFT-LCD), a Liquid Crystal Display (LCD), an Organic electroluminescent Display (OLED), a Quantum Dot Light Emitting diode (QLED) Display, a seven-segment or eight-segment digital tube, and the like.

In application, the communication module can be set as any device capable of directly or indirectly carrying out long-distance wired or wireless communication with the client according to actual needs, so that a user can control the working state of the motor by operating the client through the motor controller, and further control the working states of equipment such as an air conditioner, a fan, a washing machine and the like applied to the motor. The Communication module may provide a solution for Communication applied to the network device, including Wireless Local Area Networks (WLANs) (e.g., Wi-Fi Networks), bluetooth, Zigbee, mobile Communication Networks, Global Navigation Satellite Systems (GNSS), Frequency Modulation (FM), Near Field Communication (NFC), Infrared (IR), and the like. The communication module may include an antenna, and the antenna may have only one array element, or may be an antenna array including a plurality of array elements. The communication module can receive electromagnetic waves through the antenna, frequency-modulate and filter electromagnetic wave signals, and send the processed signals to the processor. The communication module can also receive a signal to be sent from the processor, frequency-modulate and amplify the signal, and convert the signal into electromagnetic waves through the antenna to radiate the electromagnetic waves.

It should be noted that, for the information interaction, execution process, and other contents between the above-mentioned devices/modules, the specific functions and technical effects thereof are based on the same concept as those of the embodiment of the method of the present application, and reference may be made to the part of the embodiment of the method specifically, and details are not described here.

It will be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely illustrated, and in practical applications, the above function distribution may be performed by different functional modules according to needs, that is, the internal structure of the apparatus is divided into different functional modules to perform all or part of the above described functions. Each functional module in the embodiments may be integrated into one processing module, or each module may exist alone physically, or two or more modules are integrated into one module, and the integrated module may be implemented in a form of hardware, or in a form of software functional module. In addition, specific names of the functional modules are only used for distinguishing one functional module from another, and are not used for limiting the protection scope of the application. The specific working process of the modules in the system may refer to the corresponding process in the foregoing method embodiment, and is not described herein again.

The embodiments of the present application further provide a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

Embodiments of the present application provide a computer program product, which when run on a motor controller, enables the motor controller to implement the steps in the above-described method embodiments.

The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium and can implement the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or device capable of carrying computer program code to a motor controller, a recording medium, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the modules is merely a logical division, and in actual implementation, there may be other divisions, for example, multiple modules or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or modules, and may be in an electrical, mechanical or other form.

The modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

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