阅读说明：本技术 无位置传感器电机驱动方法、永磁同步电机和存储介质 (Position sensorless motor driving method, permanent magnet synchronous motor, and storage medium ) 是由 赵贝石 罗薛 何资 毕磊 毕超 于 2020-05-27 设计创作，主要内容包括：本发明提供了一种无位置传感器电机驱动方法、永磁同步电机和存储介质,先是接收对逆变器输出电流采样得到的a相电流和b相电流,并对a相电流和b相电流进行Clarke变换,分别得到对应的α轴电流和β轴电流；再接收上一个采样时刻的α轴参考电压以及β轴参考电压,根据预设采样时刻内所有的α轴电流、β轴电流、α轴参考电压以及β轴参考电压得到转子位置角以及转子速度；最后根据α轴电流、β轴电流、转子位置角、预设d轴参考电流以及预设q轴参考电流生成逆变器控制信号,并将控制信号发送至逆变器。本发明通过一系列运算准确地得到转子位置角以及转子转速,对于电机参数变化具有强鲁棒性,可实现宽调速范围下的高性能电机驱动控制。(The invention provides a position-sensorless motor driving method, a permanent magnet synchronous motor and a storage medium, wherein a phase a current and a phase b current obtained by sampling an output current of an inverter are received, and the phase a current and the phase b current are subjected to Clarke conversion to respectively obtain corresponding alpha-axis current and corresponding beta-axis current; receiving the alpha-axis reference voltage and the beta-axis reference voltage at the last sampling moment, and obtaining a rotor position angle and a rotor speed according to all the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage in the preset sampling moment; and finally, generating an inverter control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, the preset d-axis reference current and the preset q-axis reference current, and sending the control signal to the inverter. The invention can accurately obtain the rotor position angle and the rotor rotating speed through a series of operations, has strong robustness to the parameter change of the motor, and can realize the high-performance motor drive control in a wide speed regulation range.)

1. A position-sensor-less motor driving method is characterized by comprising the following steps:

receiving a phase-a current and a phase-b current obtained by sampling an output current of an inverter, and performing Clarke transformation on the phase-a current and the phase-b current to respectively obtain a corresponding alpha-axis current and a corresponding beta-axis current;

receiving an alpha-axis reference voltage and a beta-axis reference voltage at the last sampling moment, and obtaining a rotor position angle and a rotor speed according to all the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage in a preset sampling moment;

and generating a control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current, and sending the control signal to the inverter to realize the drive control of the motor.

2. The position sensorless motor driving method according to claim 1, wherein the step of obtaining a rotor position angle and a rotor speed from all of the α -axis current, the β -axis current, the α -axis reference voltage, and the β -axis reference voltage at a preset sampling timing comprises:

taking all the alpha-axis currents and all the alpha-axis reference voltages in a preset sampling moment as the input of a preset alpha-axis estimation formula to obtain a first alpha-axis estimation component, and taking all the beta-axis currents and all the beta-axis reference voltages in the preset sampling moment as the input of a preset beta-axis estimation formula to obtain a first beta-axis estimation component;

according to the rotor speed at the last sampling moment, filtering the first alpha axis estimation component and the first beta axis estimation component to obtain a corresponding second alpha axis estimation component and a second beta axis estimation component after filtering;

inputting the second alpha axis estimation component and the second beta axis estimation component into a preset inverse triangle calculation formula to obtain a first rotor position angle;

and inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling moment.

3. The position-sensor-less motor driving method of claim 2, wherein the preset α -axis estimation formula is:

wherein, T_FFor the estimation window corresponding to the preset sampling instant α_αIs a predetermined parameter, is a parameter related to the sampling time, F_α(t) the first α axis estimate component at time t, when i_α(t – T_F(+) andmiddle T-T_F+<At 0, there is i_α(t – T_F+ ) = 0,= 0；

The preset beta axis estimation formula is as follows:

wherein, α_βFor preset parameters, F_β(t) the first β axis estimate component at time t, when i_β(t – T_F(+) andmiddle T-T_F+<At 0, there is i_β(t – T_F+) = 0,= 0。

4. The position sensor-less motor driving method according to claim 2, wherein the step of filtering the first α -axis estimation component and the first β -axis estimation component according to the rotor speed at the last sampling time to obtain corresponding filtered second α -axis estimation component and second β -axis estimation component comprises:

feeding back the rotor speed at the last sampling moment to a filter, and fixing the delay range of the filter;

and filtering the first alpha axis estimation component and the first beta axis estimation component through the filter to obtain a second alpha axis estimation component and a second beta axis estimation component after filtering.

5. The position sensorless motor driving method according to claim 2, wherein the preset phase-locked loop formula includes a preset rotor speed calculation formula and a preset rotor position angle calculation formula, and the step of inputting the first rotor position angle and the rotor position angle at the previous sampling time into the preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling time includes:

inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset rotor rotating speed calculation formula to obtain the rotor rotating speed;

and inputting the rotor rotating speed and the rotor position angle at the last sampling moment into a preset rotor position angle calculation formula to obtain the rotor position angle at the current sampling moment.

6. The position sensorless motor driving method according to claim 5, wherein the preset rotor rotation speed is calculated by the formula:

wherein, Delta theta_e[k]Is the difference between the first rotor position angle at the present moment and the rotor position angle at the last sampling moment, Delta theta_e[k-1]Is the difference between the first rotor position angle at the last sampling instant and the rotor position angles at the last two sampling instants, ω_e[k-1]For the rotor speed at the last sampling instant, K_{p_PLL}And K_{i_PLL}Controlling a parameter for a controller;

the preset rotor position angle calculation formula is as follows:

wherein T is the sampling period of the control system,is the rotor speed at the present moment,the rotor position angle at the last sampling instant.

7. The position sensor-less motor driving method of claim 1, wherein the step of generating the control signal based on the α -axis current, the β -axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current comprises:

according to the rotor position angle, performing Park transformation on the alpha-axis current and the beta-axis current to respectively obtain corresponding d-axis current and q-axis current;

obtaining a current alpha-axis reference voltage and a current beta-axis reference voltage at the current sampling moment according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current;

and taking the current alpha axis reference voltage and the beta axis reference voltage as the input of a preset SVPWM (space vector pulse width modulation) algorithm to generate the control signal.

8. The position-sensor-less motor driving method of claim 7, wherein the step of obtaining the present α -axis reference voltage and the present β -axis reference voltage at the present sampling time based on the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current comprises:

taking the d-axis current and a preset d-axis reference current as the input of a preset d-axis current controller to obtain a d-axis reference voltage;

the q-axis current and a preset q-axis reference current are used as the input of a preset q-axis current controller to obtain a q-axis reference voltage;

and according to the rotor position angle, carrying out Park inverse transformation on the d-axis reference voltage and the q-axis reference voltage to respectively obtain the corresponding current alpha-axis reference voltage and current beta-axis reference voltage.

9. A permanent magnet synchronous motor, comprising: a memory, a processor, and a motor driver stored on the memory and executable on the processor, the motor driver configured to implement the steps of the position sensorless motor drive method of any one of claims 1 to 8.

10. A storage medium having stored thereon a motor driver, which when executed by a processor implements the steps of the position sensor-less motor driving method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of motors, in particular to a position sensor-free motor driving method, a permanent magnet synchronous motor and a storage medium.

Background

The permanent magnet synchronous motor has the advantages of high power density, high dynamic performance, simple structure, high reliability and the like, and along with the continuous improvement of the performance of the rare earth permanent magnet material, the maturity of the control technology of the permanent magnet synchronous motor, the permanent magnet synchronous motor has wide application in the high-precision control fields of numerical control machines, robots, electric vehicles, aerospace and the like, and in the fields of fans, pumps, compressors and the like.

The existing permanent magnet synchronous motor generally uses a hall device, a rotary transformer or an encoder as an angle sensor to obtain the position of a rotor. However, these angle sensors add additional cost and reduce the reliability of the overall system. Therefore, a position sensorless driving method of the permanent magnet synchronous motor becomes significant. The traditional position-sensor-free technology uses a sliding mode controller to estimate the back electromotive force of the permanent magnet synchronous motor under a two-phase static coordinate system according to a motor model. However, in the above-mentioned technology without position sensor, when the permanent magnet synchronous motor is in a low speed region, the rotor position angle and the rotor speed of the motor cannot be accurately estimated, and it is difficult to achieve good control over the driving system of the motor. In addition, when the motor parameters are greatly changed, the control performance of the whole control system is reduced.

Disclosure of Invention

The invention mainly aims to provide a position sensor-free motor driving method, a permanent magnet synchronous motor and a storage medium, and aims to solve the technical problem that a position sensor-free motor driving system is difficult to realize good control when the existing motor runs at a low speed, and simultaneously increase the robustness of the system to the change of motor parameters.

In order to achieve the above object, the present invention provides a position sensor-less motor driving method, comprising the steps of:

receiving a phase-a current and a phase-b current obtained by sampling an output current of an inverter, and performing Clarke transformation on the phase-a current and the phase-b current to respectively obtain a corresponding alpha-axis current and a corresponding beta-axis current;

receiving an alpha-axis reference voltage and a beta-axis reference voltage at the last sampling moment, and obtaining a rotor position angle and a rotor speed according to all the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage in a preset sampling moment;

and generating a control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current, and sending the control signal to the inverter to realize the drive control of the motor.

Optionally, the step of obtaining the rotor position angle and the rotor speed according to all the α -axis current, the β -axis current, the α -axis reference voltage, and the β -axis reference voltage at a preset sampling time includes:

taking all the alpha-axis currents and all the alpha-axis reference voltages in a preset sampling moment as the input of a preset alpha-axis estimation formula to obtain a first alpha-axis estimation component, and taking all the beta-axis currents and all the beta-axis reference voltages in the preset sampling moment as the input of a preset beta-axis estimation formula to obtain a first beta-axis estimation component;

according to the rotor speed at the last sampling moment, filtering the first alpha axis estimation component and the first beta axis estimation component to obtain a corresponding second alpha axis estimation component and a second beta axis estimation component after filtering;

inputting the second alpha axis estimation component and the second beta axis estimation component into a preset inverse triangle calculation formula to obtain a first rotor position angle;

and inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling moment.

Optionally, the preset α -axis estimation formula is:

wherein, T_FFor the estimation window corresponding to the preset sampling instant α_αIs a predetermined parameter, is a parameter related to the sampling time, F_α(t) the first α axis estimate component at time t, when i_α(t – T_F(+) andmiddle T-T_F+<At 0, there is i_α(t – T_F+ ) = 0,= 0；

The preset beta axis estimation formula is as follows:

wherein, α_βFor preset parameters, F_β(t) the first β axis estimate component at time t, when i_β(t – T_F(+) andmiddle T-T_F+<At 0, there is i_β(t – T_F+) = 0,= 0。

Optionally, the step of filtering the first α -axis estimation component and the first β -axis estimation component according to the rotor speed at the last sampling time to obtain a corresponding filtered second α -axis estimation component and second β -axis estimation component includes:

feeding back the rotor speed at the last sampling moment to a filter, and fixing the delay range of the filter;

and filtering the first alpha axis estimation component and the first beta axis estimation component through the filter to obtain a second alpha axis estimation component and a second beta axis estimation component after filtering.

Optionally, the preset phase-locked loop formula includes a preset rotor speed calculation formula and a preset rotor position angle calculation formula, the step of inputting the first rotor position angle and the rotor position angle at the last sampling time into the preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling time includes:

inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset rotor rotating speed calculation formula to obtain the rotor rotating speed;

and inputting the rotor rotating speed and the rotor position angle at the last sampling moment into a preset rotor position angle calculation formula to obtain the rotor position angle at the current sampling moment.

Optionally, the preset rotor speed calculation formula is:

wherein, Delta theta_e[k]Is the difference between the first rotor position angle at the present moment and the rotor position angle at the last sampling moment, Delta theta_e[k-1]Is the difference between the first rotor position angle at the last sampling instant and the rotor position angles at the last two sampling instants, ω_e[k-1]For the rotor speed at the last sampling instant, K_{p_PLL}And K_{i_PLL}Controlling a parameter for a controller;

the preset rotor position angle calculation formula is as follows:

wherein T is the sampling period of the control system,is as followsThe rotational speed of the rotor at the previous moment,the rotor position angle at the last sampling instant.

Optionally, the step of generating a control signal according to the α -axis current, the β -axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current includes:

according to the rotor position angle, performing Park transformation on the alpha-axis current and the beta-axis current to respectively obtain corresponding d-axis current and q-axis current;

obtaining a current alpha-axis reference voltage and a current beta-axis reference voltage at the current sampling moment according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current;

and taking the current alpha axis reference voltage and the beta axis reference voltage as the input of a preset SVPWM (space vector pulse width modulation) algorithm to generate the control signal.

Optionally, the step of obtaining a current α -axis reference voltage and a current β -axis reference voltage at a current sampling time according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current includes:

taking the d-axis current and a preset d-axis reference current as the input of a preset d-axis current controller to obtain a d-axis reference voltage;

the q-axis current and a preset q-axis reference current are used as the input of a preset q-axis current controller to obtain a q-axis reference voltage;

and according to the rotor position angle, carrying out Park inverse transformation on the d-axis reference voltage and the q-axis reference voltage to respectively obtain the corresponding current alpha-axis reference voltage and current beta-axis reference voltage.

In addition, to achieve the above object, the present invention also provides a permanent magnet synchronous motor, including: a memory, a processor, and a motor driver stored on the memory and executable on the processor, the motor driver when executed by the processor implementing the steps of the position sensor-less motor driving method as described above.

Further, to achieve the above object, the present invention also provides a computer-readable storage medium having stored thereon a motor driver, which when executed by a processor, implements the steps of the position-sensor-less motor driving method as described above.

The invention provides a position-sensorless motor driving method, a permanent magnet synchronous motor and a storage medium, wherein the method comprises the steps of receiving a phase-a current and a phase-b current obtained by sampling an output current of an inverter, and performing Clarke transformation on the phase-a current and the phase-b current to respectively obtain corresponding alpha-axis current and beta-axis current; receiving the alpha-axis reference voltage and the beta-axis reference voltage at the last sampling moment, and obtaining a rotor position angle and a rotor speed according to all the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage in a preset sampling moment; and generating a control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, the preset d-axis reference current and the preset q-axis reference current, and sending the control signal to the inverter to realize the drive control of the motor.

The invention receives the a-phase current and the b-phase current obtained by sampling the output current of the inverter, performs a series of coordinate transformation and data calculation on the a-phase current and the b-phase current, accurately obtains the position angle of the rotor and the rotating speed of the motor, and has strong robustness on the parameter change of the motor, thereby realizing the high-performance motor drive control in a wide speed regulation range.

Drawings

FIG. 1 is a schematic diagram of an apparatus in a hardware operating environment according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart illustrating a method for driving a sensorless motor according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a module according to an embodiment of the method for driving a position sensorless motor of the present invention;

fig. 4 is a detailed flowchart of the steps of obtaining the rotor position angle and the rotor speed according to all the α -axis current, the β -axis current, the α -axis reference voltage, and the β -axis reference voltage at a preset sampling time in the position sensorless motor driving method according to the present invention;

fig. 5 is a flowchart illustrating a step-refined flow of obtaining a current α -axis reference voltage and a current β -axis reference voltage at a current sampling time according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current in the position-sensorless motor driving method according to the present invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, fig. 1 is a schematic terminal structure diagram of a hardware operating environment according to an embodiment of the present invention.

The terminal of the invention is a device which can be a permanent magnet synchronous motor and can also be other motors with storage functions.

As shown in fig. 1, the terminal may include: a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Wherein a communication bus 1002 is used to enable connective communication between these components. The user interface 1003 may include a Display screen (Display), an input unit such as a Keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface, a wireless interface. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1005 may be a high-speed RAM memory or a non-volatile memory (e.g., a magnetic disk memory). The memory 1005 may alternatively be a storage device separate from the processor 1001.

Optionally, the terminal may further include a camera, a Wi-Fi module, and the like, which are not described herein again.

Those skilled in the art will appreciate that the terminal structure shown in fig. 1 is not intended to be limiting and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

In the terminal shown in fig. 1, the network interface 1004 is mainly used for connecting to a backend server and performing data communication with the backend server; the user interface 1003 mainly includes an input unit such as a keyboard including a wireless keyboard and a wired keyboard, and is used to connect to the client and perform data communication with the client; and the processor 1001 may be configured to call up a motor driver stored in the memory 1005 and perform the following operations:

receiving a phase-a current and a phase-b current obtained by sampling an output current of an inverter, and performing Clarke transformation on the phase-a current and the phase-b current to respectively obtain a corresponding alpha-axis current and a corresponding beta-axis current;

receiving an alpha-axis reference voltage and a beta-axis reference voltage at the last sampling moment, and obtaining a rotor position angle and a rotor speed according to all the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage in a preset sampling moment;

and generating a control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current, and sending the control signal to the inverter to realize the drive control of the motor.

Further, the processor 1001 may call the motor driver stored in the memory 1005, and also perform the following operations:

taking all the alpha-axis currents and all the alpha-axis reference voltages in a preset sampling moment as the input of a preset alpha-axis estimation formula to obtain a first alpha-axis estimation component, and taking all the beta-axis currents and all the beta-axis reference voltages in the preset sampling moment as the input of a preset beta-axis estimation formula to obtain a first beta-axis estimation component;

according to the rotor speed at the last sampling moment, filtering the first alpha axis estimation component and the first beta axis estimation component to obtain a corresponding second alpha axis estimation component and a second beta axis estimation component after filtering;

inputting the second alpha axis estimation component and the second beta axis estimation component into a preset inverse triangle calculation formula to obtain a first rotor position angle;

and inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling moment.

Further, the processor 1001 may call the motor driver stored in the memory 1005, and also perform the following operations:

feeding back the rotor speed at the last sampling moment to a filter, and fixing the delay range of the filter;

and filtering the first alpha axis estimation component and the first beta axis estimation component through the filter to obtain a second alpha axis estimation component and a second beta axis estimation component after filtering.

Further, the processor 1001 may call the motor driver stored in the memory 1005, and also perform the following operations:

inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset rotor rotating speed calculation formula to obtain the rotor rotating speed;

and inputting the rotor rotating speed and the rotor position angle at the last sampling moment into a preset rotor position angle calculation formula to obtain the rotor position angle at the current sampling moment.

Further, the processor 1001 may call the motor driver stored in the memory 1005, and also perform the following operations:

according to the rotor position angle, performing Park transformation on the alpha-axis current and the beta-axis current to respectively obtain corresponding d-axis current and q-axis current;

obtaining a current alpha-axis reference voltage and a current beta-axis reference voltage at the current sampling moment according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current;

and taking the current alpha axis reference voltage and the beta axis reference voltage as the input of a preset SVPWM (space vector pulse width modulation) algorithm to generate the control signal.

Further, the processor 1001 may call the motor driver stored in the memory 1005, and also perform the following operations:

taking the d-axis current and a preset d-axis reference current as the input of a preset d-axis current controller to obtain a d-axis reference voltage;

the q-axis current and a preset q-axis reference current are used as the input of a preset q-axis current controller to obtain a q-axis reference voltage;

and according to the rotor position angle, carrying out Park inverse transformation on the d-axis reference voltage and the q-axis reference voltage to respectively obtain the corresponding current alpha-axis reference voltage and current beta-axis reference voltage.

The specific embodiment of the apparatus is substantially the same as the following embodiments of the position sensorless motor driving method, and will not be described herein again.

Referring to fig. 2, fig. 2 is a schematic flow chart illustrating a method for driving a sensorless motor according to an embodiment of the present invention. The position-sensorless motor driving method provided by the embodiment comprises the following steps:

step S10, receiving a-phase current i obtained by sampling inverter output current_a[k]And b-phase current i_b[k]And performing Clarke transformation on the a-phase current and the b-phase current to respectively obtain corresponding α axis currents i_α[k]And β Axis Current i_β[k]；

The position sensorless motor driving method provided in this embodiment may be applied to a permanent magnet synchronous motor, and specifically, please refer to fig. 3, where fig. 3 is a schematic structural diagram of a module according to an embodiment of the position sensorless motor driving method of the present invention, and the method mainly includes an inverter, a current sampling module, a dc power supply, a permanent magnet synchronous motor, and a controller. The inverter outputs voltage to the permanent magnet synchronous motor to drive the motor to work, the current sampling module is arranged to sample two-phase stator current output by the inverter and feed back a sampling result to the controller, the controller outputs a corresponding control signal to the inverter according to the sampling result, and the inverter is controlled to change the output voltage of the motor, so that the drive control of the motor is realized. The position-sensorless motor driving method provided in this embodiment may also be applied to motors with other topologies, and is not limited specifically herein.

In this embodiment, the current sampling time is set as the kth cycle, and the sampled a-phase current i is received at the current sampling time_a[k]And b-phase current i_b[k]And performing coordinate transformation on the circuit, preferably, the coordinate transformation on the a-phase current and the b-phase circuit is realized by using Clarke transformation. Clarke transformation is a coordinate transformation method for transforming each physical quantity based on a 3-axis stator stationary coordinate system into a 2-axis stator stationary coordinate system.

Step S20, receiving the α axis reference voltage of the last sampling timeAnd β axis reference voltageObtaining a rotor position angle theta according to all α axis currents, β axis currents, α axis reference voltages and β axis reference voltages in a preset sampling moment_e[k]And rotor speed;

receiving the α -axis reference voltage of the last sampling time, namely the k-1 th periodAnd β axis reference voltageIt should be understood that when k is 1, there is no corresponding α axis reference voltage and β axis reference voltage, and it is not necessary to receive these two parameters, which are considered to be 0. furthermore, the α axis reference voltage and the β axis reference voltage at the last sampling time are based on the a-phase current, the b-,And calculating a preset d-axis current instruction and a preset q-axis current instruction.

In this embodiment, the preset sampling time is set as the first n sampling times, and the rotor position angle θ is calculated according to the four existing parameters of the first n sampling times, that is, the α axis current, the β axis current, the α axis reference voltage, and the β axis reference voltage_e[k]And rotor speed ω_e[k]It should be understood that when n is 3, the α -axis current at the first 3 times is i_α[k]，i_α[k-1]，i_α[k-2]β Axis Current at the first 3 moments is i_β[k]，i_β[k-1]，i_β[k-2]The α axis reference voltage at the first 3 moments is，，The β axis reference voltage at the first 3 moments is，，It is easy to understand that the rotor position angle is an important parameter in motor control, the accuracy of the rotor position angle has an important influence on the full play of the motor performance, many practical problems encountered in motor drive control are related to the angle error of the rotor position angle of the motor, and the rotor rotating speed makes the method also applicable to the rotating speed closed-loop motor drive control.

And step S30, generating a control signal according to the alpha-axis current, the beta-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current, and sending the control signal to the inverter to realize the drive control of the motor.

In this embodiment, after obtaining the rotor position angle, a control signal is generated according to α axis current, β axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current, and as an implementation scheme, the control signal is S_a[k]、S_b[k]、S_c[k]And the control signals are sent to the inverter to respectively control three bridge arms of the inverter to output three-phase stator voltages, so that the driving control of the motor is realized.

The embodiment receives the a-phase current and the b-phase current obtained by sampling the output current of the inverter, performs a series of coordinate transformation and data calculation on the a-phase current and the b-phase current, accurately obtains the position angle of the rotor and the rotating speed of the rotor, has strong robustness on the parameter change of the motor, and can realize high-performance motor drive control in a wide speed regulation range.

Further, referring to fig. 4, fig. 4 is a detailed flow chart illustrating steps of obtaining a rotor position angle and a rotor speed according to all the α -axis current, the β -axis current, the α -axis reference voltage, and the β -axis reference voltage at a preset sampling time in the sensorless motor driving method according to the present invention. The step of obtaining the rotor position angle and the rotor speed according to the alpha-axis current, the beta-axis current, the alpha-axis reference voltage and the beta-axis reference voltage comprises:

step S21, taking all the alpha axis currents and the alpha axis reference voltages in a preset sampling moment as the input of a preset alpha axis estimation formula to obtain a first alpha axis estimation component, and taking all the beta axis currents and the beta axis reference voltages in a preset sampling moment as the input of a preset beta axis estimation formula to obtain a first beta axis estimation component;

step S22, filtering the first alpha axis estimation component and the first beta axis estimation component according to the rotor speed at the last sampling moment to obtain a corresponding second alpha axis estimation component and a second beta axis estimation component after filtering;

step S23, inputting the second alpha axis estimation component and the second beta axis estimation component into a preset inverse triangle calculation formula to obtain a first rotor position angle;

and step S24, inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling moment.

It is easily understood that, in this embodiment, the α -axis reference voltage and the β -axis reference voltage are generated at the previous sampling time, that is, the α -axis reference voltage and the β -axis reference voltage at the k-1 sampling time, and there is a case that when k is 1, it is not necessary to obtain the α -axis reference voltage and the β -axis reference voltage at the previous sampling time, and it is considered that they take the value of 0.

It should be understood that when n is 3, the α axis current at the first 3 times is i_α[k]，i_α[k-1]，i_α[k-2]β Axis Current at the first 3 moments is i_β[k]，i_β[k-1]，i_β[k-2]The α axis reference voltage at the first 3 moments is，，The β axis reference voltage at the first 3 moments is，，。

In this embodiment, an α axis estimation formula is also preset, α axis current and α axis reference voltage at the first n moments are used as inputs of a preset α axis estimation formula, and a first α axis estimation component F is obtained through calculation_α[k]Specifically, the α axis estimation rule is presetThe formula is as follows:

wherein, T_FFor the estimation window corresponding to the preset sampling instant α_αIs a predetermined parameter, is a parameter related to the sampling time, F_α(t) the first α axis estimate component at time t, when i_α(t – T_F(+) andmiddle T-T_F+<At 0, there is i_α(t – T_F+ ) = 0,= 0；

In this embodiment, an β axis estimation formula is also preset, β axis current and β axis reference voltage at the first n moments are used as inputs of a preset β axis estimation formula, and a first β axis estimation component F is obtained through calculation_β[k]Specifically, the preset β axis estimation formula is as follows:

wherein, α_βFor preset parameters, F_β(t) the first β axis estimate component at time t, when i_β(t – T_F(+) andmiddle T-T_F+<At 0, there is i_β(t – T_F+) = 0,= 0。

The first α axis estimation component and the first β axis estimation component are obtained through the above steps, and it should be understood that the preset α axis estimation formula and the preset β axis estimation formula are solution formulas of a continuumα axis sampling current, β axis sampling current, α axis reference voltage command and β axis reference voltage command of n time moments obtain αβ axis estimation component F of current time moment_α[k]F_β[k]. The present embodiment is not particularly limited herein. In addition, the value range of n is 3-50.

And after the first alpha axis estimation component and the first beta axis estimation component are obtained, inputting the two estimation components into a filter, and performing smooth filtering on the estimation components according to the rotor speed at the last sampling moment to obtain a second alpha axis estimation component and a second beta axis estimation component. In this embodiment, an inverse trigonometric calculation formula is also preset, and the second α axis estimation component and the second β axis estimation component are used as inputs of the inverse trigonometric calculation formula to obtain the first rotor position angle. Specifically, the preset inverse triangle calculation formula is as follows:

wherein the content of the first and second substances,the component is estimated for the second α axis at the current time,the component is estimated for the second β axis at the current time.

Finally, the first rotor position angle and the rotor position angle theta of the last sampling moment are compared_e[k – 1]Inputting the current position angle theta of the rotor into a preset phase-locked loop calculation formula to obtain the rotor position angle theta at the current sampling moment_e[k]。

The embodiment accurately estimates the real-time rotor position angle and the rotor rotating speed of the motor in the mode, has strong robustness to the parameter change of the motor, and can realize the high-performance motor drive control in a wide speed regulation range.

Further, the step of filtering the first α -axis estimation component and the first β -axis estimation component according to the rotor speed at the previous sampling time to obtain a corresponding filtered second α -axis estimation component and second β -axis estimation component includes:

step S221, feeding back the rotor speed of the last sampling moment to a filter, and fixing the delay range of the filter;

step S222, filtering the first α -axis estimation component and the first β -axis estimation component by the filter to obtain a second α -axis estimation component and a second β -axis estimation component after filtering.

In this embodiment, after obtaining the first α -axis estimated component and the first β -axis estimated component, the rotor speed ω at the previous sampling time is first sampled_e[k-1]Feeding back into the filter, fixing the delay range of the filter, preferably in dependence on the rotor speed ω_e[k-1]The filter fixed delay is in the range of 35 ° to 55 °.

Inputting the first α axis estimation component and the first β axis estimation component into a filter according to the rotor speed at the previous moment, and filtering the first α axis estimation component and the first β axis estimation component to obtain a second α axis estimation component and a second β axis estimation component after filtering, specifically, the second α axis estimation component and the second β axis estimation component can be obtained by calculating according to the following formulas:

wherein T is the system sampling period, omega_e[k-1]Is the rotor speed at the last sampling instant,the component is estimated for the second α axis at the previous sampling instant,the component is estimated for the second β axis at the previous sampling instant,the component is estimated for the first α axis at the current time,the component is estimated for the first β axis at the current time.

In this embodiment, the first α -axis estimation component and the first β -axis estimation component are filtered in the above manner to obtain smoother data, that is, the second α -axis estimation component and the second β -axis estimation component, so as to reduce the influence of sampling interference and make the angle more accurate.

Further, the step of inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle and the rotor speed at the current sampling moment includes:

step S241, inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset rotor rotating speed calculation formula to obtain the rotor rotating speed;

and step S242, inputting the rotor rotating speed and the rotor position angle at the last sampling moment into a preset phase-locked loop calculation formula to obtain the rotor position angle at the current sampling moment.

In this embodiment, the preset phase-locked loop formula includes a preset rotor rotation speed calculation formula, and it is easily understood that the rotor rotation speed is a rotation speed corresponding to the rotation frequency of the rotor and its supporting system, and is an important parameter reflecting the operation state of the motor. Inputting the first rotor position angle and the rotor position angle at the last sampling moment into a preset rotor rotation speed calculation formula, and calculating to obtain the rotor rotation speed omega_e[k]Specifically, the preset rotor speed calculation formula is as follows:

wherein, Delta theta_e[k]Is the difference between the first rotor position angle at the present moment and the rotor position angle at the last sampling moment, Delta theta_e[k-1]Is the difference between the first rotor position angle at the last sampling instant and the rotor position angles at the last two sampling instants, ω_e[k-1]For the rotor speed at the last sampling instant, K_{p_PLL}And K_{i_PLL}Parameters are controlled for the controller.

In this embodiment, the preset phase-locked loop formula includes a rotor position angle calculation formula, the rotor speed and the rotor position angle at the previous sampling time are input into the preset rotor position angle calculation formula, and the rotor position angle at the current sampling time is obtained, specifically, the preset rotor position angle calculation formula is:

wherein T is the sampling period of the control system,is the rotor speed at the present moment,the rotor position angle at the last sampling instant.

In the embodiment, the real-time rotor position angle and the rotor rotating speed of the motor are accurately estimated, and the motor has strong robustness to the parameter change of the motor, so that the high-performance motor drive control in a wide speed regulation range is realized.

Further, the step of generating a control signal according to the α -axis current, the β -axis current, the rotor position angle, a preset d-axis reference current, and a preset q-axis reference current includes:

step S31, according to the rotor position angle, performing Park transformation on the α axis current and the β axis current to respectively obtain corresponding d axis current i_d[k]And q-axis current i_q[k]；

Step S32, obtaining a current alpha-axis reference voltage and a current beta-axis reference voltage at the current sampling moment according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current;

step S33, using the current α axis reference voltage and the β axis reference voltage as input of a preset SVPWM modulation algorithm, and generating the control signal.

In this embodiment, after the rotor position angle is obtained, the α -phase current and the β -phase current in the two-phase stationary coordinate system are subjected to Park conversion according to the rotor position angle, so as to obtain the d-axis current and the q-axis current in the two-phase rotating coordinate system. It is readily understood that the Park variation is a coordinate transformation method for transforming the stator vector of the 2-axis stationary coordinate system to the synchronously rotating 2-axis coordinate system.

After the d-axis current and the q-axis current are obtained, the current α -axis reference voltage at the current sampling moment is obtained through calculation by using the d-axis current, the q-axis current, the rotor position angle, the preset d-axis reference current and the preset q-axis reference currentAnd current β axis reference voltageThe specific calculation method refers to the following embodiments, then, an SVPWM modulation algorithm is preset in the embodiment, the current α -axis reference voltage and β -axis reference voltage are used as the input of the SVPWM modulation algorithm, the sector where the reference voltage is located and the application time are calculated, and corresponding control signals are generated.

In the embodiment, the corresponding control signal is generated according to the rotor position angle in the above manner, so that the motor is accurately driven according to the actual condition of the motor.

Further, referring to fig. 5, fig. 5 is a schematic diagram illustrating a detailed flow of the step of obtaining the current α -axis reference voltage and the current β -axis reference voltage at the current sampling time according to the d-axis current, the q-axis current, the rotor position angle, the preset d-axis reference current, and the preset q-axis reference current in the position-sensorless motor driving method of the present invention. The step of obtaining a current alpha-axis reference voltage and a current beta-axis reference voltage at a current sampling moment according to the d-axis current, the q-axis current, the rotor position angle, a preset d-axis reference current and a preset q-axis reference current comprises:

step S321, comparing the d-axis current with a preset d-axis reference currentAs input of a preset d-axis current controller, obtaining a d-axis reference voltage；

Step S322, the q-axis current and a preset q-axis reference current are processedAs input of a preset q-axis current controller, obtaining a q-axis reference voltage；

Step S323, performing Park inverse transformation on the d-axis reference voltage and the q-axis reference voltage according to the rotor position angle, and obtaining the corresponding current α -axis reference voltage and the current β -axis reference voltage, respectively.

In this embodiment, a d-axis current controller is also preset to control the d-axis current and a preset d-axis reference currentInputting the voltage into a d-axis current controller to obtain a d-axis reference voltageSpecifically, please refer to the following formula:

wherein, K_{p_Cur}And K_{i_Cur}In order to preset the parameters of the controller,for the reference voltage of d-axis at the last sampling instant, Δ i_d[k]Presetting the difference value of d-axis reference current and d-axis current at the current moment, delta i_d[k-1]The difference between the preset d-axis reference current at the last sampling moment and the d-axis current at the last sampling moment.

In this embodiment, a q-axis current controller is also preset to control the q-axis current and a preset q-axis reference currentInputting the reference voltage into a q-axis current controller to obtain a q-axis reference voltageSpecifically, please refer to the following formula:

wherein the content of the first and second substances,for the reference voltage of q-axis at the last sampling instant, Δ i_q[k]Presetting the difference value of the q-axis reference current and the q-axis current at the current moment, delta i_q[k-1]The difference between the preset q-axis reference current at the last sampling moment and the q-axis current at the last sampling moment.

It should be understood that the rotor position angle and rotor speed estimation method of the present invention can be used in conjunction with any current controller, and is not limited to the PI controller selected in the present embodiment.

After the d-axis reference voltage and the q-axis reference voltage are obtained, according to the rotor position angle obtained in the above process, Park inverse transformation is carried out on the d-axis reference voltage and the q-axis reference voltage in the two-phase rotating coordinate system, and a current alpha-axis reference voltage and a current beta-axis reference voltage in the two-phase static coordinate system are obtained. It is easily understood that the inverse Park transform is an inverse of the Park transform, which is a coordinate transformation method for transforming the stator vector of a synchronously rotating 2-axis coordinate system to a 2-axis stationary coordinate system.

In this embodiment, the d-axis current and the q-axis current, the rotor position angle, the preset d-axis reference current and the preset q-axis reference current are substituted into a preset reference voltage formula, and then Park inverse transformation is performed on an output result to obtain a current α -axis reference voltage and a current β -axis reference voltage, so as to ensure the accuracy of the control signal generated in the subsequent step.

Furthermore, an embodiment of the present invention also provides a computer-readable storage medium, on which a motor driver is stored, which, when being executed by a processor, implements the operations of the position-sensor-less motor driving method as described above.

The specific embodiment of the computer-readable storage medium of the present invention is substantially the same as the embodiments of the position sensorless motor driving method described above, and will not be described herein again.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.