阅读说明：本技术 电机拍频抑制方法及系统、电传动控制系统、存储介质 (Motor beat frequency suppression method and system, electric transmission control system and storage medium ) 是由 梅文庆 胡亮 甘韦韦 文宇良 胡仙 贾岩 付翔宇 杜凯冰 吕永灿 于 2019-10-31 设计创作，主要内容包括：本发明提供一种电机拍频抑制方法及系统、电传动控制系统、存储介质,所述方法包括：实时采集电传动控制系统的中间电压和电机电流；提取中间电压的交流分量和直流分量；根据中间电压的交流分量和直流分量计算静态拍频补偿系数；提取表征电机拍频电流幅值指标的电机电流拍频分量；采用搜索算法,通过在线迭代寻优获得使得电机电流拍频分量最小的动态拍频补偿系数；基于动态拍频补偿系数和静态拍频补偿系数获得拍频补偿系数,利用拍频补偿系数对给定转矩或者给定转矩对应的给定转差进行补偿。本发明实现在中间电压存在二倍电网频率的脉动分量的电传动控制系统中,抑制直流交流脉动对电机产生的拍频现象,有效降低电机损耗、发热及噪声问题。(The invention provides a motor beat frequency suppression method and system, an electric transmission control system and a storage medium, wherein the method comprises the following steps: collecting the intermediate voltage and the motor current of an electric transmission control system in real time; extracting an alternating current component and a direct current component of the intermediate voltage; calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage; extracting a motor current beat frequency component representing a motor beat frequency current amplitude index; a search algorithm is adopted, and a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum is obtained through online iterative optimization; and obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient. The invention realizes that the beat frequency phenomenon of direct current and alternating current pulsation on the motor is inhibited in the electric transmission control system with the intermediate voltage having the pulsation component with the frequency of twice the power grid, and the problems of motor loss, heating and noise are effectively reduced.)

1. A method for suppressing beat frequency of a motor, comprising:

collecting the intermediate voltage and the motor current of an electric transmission control system in real time;

extracting an alternating current component and a direct current component of the intermediate voltage;

calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage;

extracting a motor current beat frequency component representing a motor beat frequency current amplitude index;

a search algorithm is adopted, and a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum is obtained through online iterative optimization;

and obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

2. The motor beat frequency suppression method according to claim 1, wherein the static beat frequency compensation coefficient is calculated from the ac component and the dc component of the intermediate voltage by using the following static beat frequency compensation coefficient function:

wherein, χ_statIs a static beat frequency compensation coefficient and is,is an intermediate voltage U_dOf medium alternating current component, U_dcIs an intermediate voltage U_dOf (d) a direct current component, k_ampIs the correction factor, ω_netIs the rotation angular frequency of the single-phase alternating current.

3. The motor beat frequency suppression method according to claim 1, wherein said extracting a motor current beat frequency component that characterizes a motor beat frequency current magnitude indicator comprises:

performing FFT analysis on the a-phase motor current or the b-phase motor current in a static abc coordinate system;

extracting characteristic frequency |2 ω_net-ω_sI is the corresponding amplitude of the beat frequency component of the motor current, wherein, omega_netIs the rotation angular frequency, omega, of a single-phase alternating current_sIs the stator rotational angular velocity.

4. The motor beat frequency suppression method according to claim 1, wherein said extracting a motor current beat frequency component that characterizes a motor beat frequency current magnitude indicator comprises:

under a synchronous dq-axis rotating coordinate system, extracting frequency of 2 omega from d-axis motor current and q-axis motor current_netComprises an alternating current component of 2 times the grid voltage frequency in the d-axis current and an alternating current component of 2 times the grid voltage frequency in the q-axis current, wherein ω is_netIs the rotation angular frequency of the single-phase alternating current;

calculating the effective value of the alternating current component with 2 times of grid voltage frequency in the d-axis current and the effective value of the alternating current component with 2 times of grid voltage frequency in the q-axis current;

and solving the mean square sum root of the two effective values to obtain the beat frequency component of the motor current.

5. The motor beat frequency suppression method according to claim 1, wherein the search algorithm is a gradient descent method, and a dynamic beat frequency compensation coefficient that minimizes a motor current beat frequency component is obtained by online iterative optimization using the gradient descent method, specifically:

and continuously adjusting the value of the dynamic beat frequency compensation coefficient in the concave function by adopting a gradient descent method based on the concave function characteristics of the motor current beat frequency component and the dynamic beat frequency compensation coefficient, and searching and acquiring the dynamic beat frequency compensation coefficient which enables the motor current beat frequency component to be minimum.

6. A motor beat frequency suppression method according to claim 5, wherein said concave function is represented in discrete form as follows:

ΔIp[k-1]＝Ip[k-1]-Ip[k-2]；

in the formula, x_dyn[k]To control the dynamic beat compensation coefficient at the kth time of the cycle,%_dyn[k-1]To control the dynamic beat frequency compensation coefficient at the k-1 th moment of the cycle, alpha is the search step length, I_p[k]To control the beat component of the motor current at the kth moment of the cycle, I_p[k-1]To control the beat frequency component of the motor current at time k-1 of the cycle, Δ Ip [ k-1 ]]Is the difference value of the beat frequency components of the motor current corresponding to the beat frequency compensation coefficients at the K-1 th moment and the K-2 th moment, epsilon is a set limit value and is a positive number, K₁、K₂The gradient descent coefficients are all positive.

7. The motor beat frequency suppression method according to claim 1,

compensating coefficient x of dynamic beat frequency_{dyn_optimal}And static beat frequency compensation coefficient x_statAdding to obtain a beat frequency compensation coefficient x_comp＝χ_{dyn_optimal}+χ_statCompensating coefficient x for beat frequency_compCompensated to a given torque T_e ^*Or a given torque T_e ^*Corresponding given slip ω_sip ^*Upper, i.e. T_e ^*(ω_sip ^*)o_tptimal＝T_e ^*(ω_sip ^*)+χ_comp。

8. A motor beat suppression system for implementing the motor beat suppression method according to any one of claims 1 to 7, comprising:

the acquisition unit is used for acquiring the intermediate voltage and the motor current of the electric transmission control system in real time;

a filtering unit for extracting an alternating current component and a direct current component of the intermediate voltage;

the beat frequency current extraction unit is used for extracting a motor current beat frequency component representing a motor beat frequency current amplitude index;

the static compensation unit is used for calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage;

the dynamic compensation unit is used for obtaining a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum by adopting a search algorithm and performing online iterative optimization;

and the compensation feedback unit is used for obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

9. An electric drive control system comprising a memory and a processor, the memory having stored thereon a computer program which, when executed by the processor, implements a motor beat frequency suppression method as claimed in any one of claims 1 to 7.

10. A storage medium having stored thereon a computer program which, when executed by one or more processors, implements a motor beat suppression method as claimed in any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of variable flow control, in particular to a motor beat frequency suppression method and system, an electric transmission control system and a storage medium.

Background

The electric drive control system formed by a single-phase rectifier, a three-phase inverter and an alternating current motor is one of the most common systems of an alternating current-direct current voltage type frequency converter and mainly comprises a single-phase rectifier, a middle direct current supporting capacitor, a three-phase inverter and an alternating current motor, wherein the single-phase rectifier is a single-phase diode uncontrolled rectifier or a single-phase PWM four-quadrant rectifier, a middle direct current loop is mainly a middle direct current supporting capacitor, and the capacitance value of the middle direct current supporting capacitor is C_dAs shown in fig. 1, an intermediate dc loop of an electric transmission control system formed by a conventional single-phase rectifier, a three-phase inverter and an ac motor is provided with an LC hardware filter loop for filtering out a dc voltage 2 times grid voltage pulsating component, but the LC hardware filter loop is limited by space volume, weight and cost considerations of a converter, so that the electric transmission control system formed by the single-phase rectifier, the three-phase inverter and the ac motor without the LC hardware filter loop as shown in fig. 2 may be adopted, and the LC filter hardware loop is omitted. Is different from the traditional single-phase crossing-direct-alternating system (when an LC hardware filter loop is provided, the intermediate voltageIs stable and has no fluctuation condition), under the condition of no LC hardware filter loop, the intermediate voltage has a pulsating component with 2 times of the network voltage frequency.

Intermediate voltage U due to the output characteristics of a single-phase rectifier_dOften consists of two parts, one part being a dc component U_dcA part being a pulsating componentComponent of pulsationThe ripple frequency of (2) is twice the grid frequency, i.e. 2 times the single-phase ac input. At the moment, because the intermediate direct-current loop still contains a pulsating component with twice grid frequency, the pulsating intermediate voltage can directly supply power to the alternating-current motor through the three-phase voltage type inverter, and if the three-phase voltage type inverter is not effectively controlled, the phenomena of unbalanced three phases of current, increased torque pulsation and the like of the alternating-current motor, namely beat frequency phenomenon can be caused; especially when the three-phase inverter outputs a frequency omega_sAnd the frequency 2. omega. of the pulsating component of the intermediate voltage_netWhen the phases are close to each other, the beat frequency phenomenon is more serious, even a small voltage ripple component can also cause larger beat frequency current and beat frequency torque, and the phenomenon can cause extra loss, heat generation and noise of the motor, reduce the running performance of the motor and influence the overall stability of the system.

The existing methods for suppressing and eliminating beat frequency phenomena can be divided into two categories, namely hardware methods and software methods: the hardware method is to use a hardware LC filter loop (as shown in figure 1) to filter out the pulsating component of the DC bus voltage, thus fundamentally solving the beat frequency phenomenon; the software method for eliminating beat frequency phenomenon mainly comprises the following steps: a single period control method, a feedforward compensation method, a feedback compensation method, a frequency compensation method and the like. Due to the problems of complex control precision and digital realization, the application range of the first three methods is limited, and the inhibition parameters can not be optimized online in real time. Therefore, the research on the simple and practical technical scheme of online beat frequency suppression in the electric transmission control system of the single-phase rectifier, the three-phase inverter and the alternating current motor has important theoretical and practical significance.

Disclosure of Invention

The invention aims to provide a motor beat frequency suppression method and system, an electric transmission control system and a storage medium, which solve the problem of motor current three-phase imbalance caused by fluctuating intermediate voltage in the electric transmission control system and realize beat frequency suppression.

In a first aspect, the present invention provides a method for suppressing beat frequency of a motor, including:

collecting the intermediate voltage and the motor current of an electric transmission control system in real time;

extracting an alternating current component and a direct current component of the intermediate voltage;

calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage;

extracting a motor current beat frequency component representing a motor beat frequency current amplitude index;

a search algorithm is adopted, and a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum is obtained through online iterative optimization;

and obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

Furthermore, the static beat frequency compensation coefficient is calculated according to the alternating current component and the direct current component of the intermediate voltage by adopting the following static beat frequency compensation coefficient function:

wherein, χ_statIs a static beat frequency compensation coefficient and is,is an intermediate voltage U_dOf medium alternating current component, U_dcIs an intermediate voltage U_dOf (d) a direct current component, k_ampIs the correction factor, ω_netIs the rotation angular frequency of the single-phase alternating current.

Further, the extracting the motor current beat frequency component representing the motor beat frequency current amplitude index includes:

performing FFT analysis on the a-phase motor current or the b-phase motor current in a static abc coordinate system;

extracting characteristic frequency |2 ω_net-ω_sI is the corresponding amplitude of the beat frequency component of the motor current, wherein, omega_netIs the rotation angular frequency, omega, of a single-phase alternating current_sIs the stator rotational angular velocity.

Further, the extracting the motor current beat frequency component representing the motor beat frequency current amplitude index includes:

under a synchronous dq-axis rotating coordinate system, extracting frequency of 2 omega from d-axis motor current and q-axis motor current_netComprises an alternating current component of 2 times the grid voltage frequency in the d-axis current and an alternating current component of 2 times the grid voltage frequency in the q-axis current, wherein ω is_netIs the rotation angular frequency of the single-phase alternating current;

calculating the effective value of the alternating current component with 2 times of grid voltage frequency in the d-axis current and the effective value of the alternating current component with 2 times of grid voltage frequency in the q-axis current;

and solving the mean square sum root of the two effective values to obtain the beat frequency component of the motor current.

Furthermore, the search algorithm is a gradient descent method, the dynamic beat frequency compensation coefficient which enables the beat frequency component of the motor current to be minimum is obtained by adopting the gradient descent method through online iterative optimization, and the method specifically comprises the following steps:

and continuously adjusting the value of the dynamic beat frequency compensation coefficient in the concave function by adopting a gradient descent method based on the concave function characteristics of the motor current beat frequency component and the dynamic beat frequency compensation coefficient, and searching and acquiring the dynamic beat frequency compensation coefficient which enables the motor current beat frequency component to be minimum.

Further, the concave function is represented in discrete form as follows:

ΔIp[k-1]＝Ip[k-1]-Ip[k-2]；

in the formula, x_dyn[k]To control the dynamic beat compensation coefficient at the kth time of the cycle,%_dyn[k-1]To control the dynamic beat frequency compensation coefficient at the k-1 th moment of the cycle, alpha is the search step length, I_p[k]To control the beat component of the motor current at the kth moment of the cycle, I_p[k-1]To control the beat frequency component of the motor current at time k-1 of the cycle, Δ Ip [ k-1 ]]Is the difference value of the beat frequency components of the motor current corresponding to the beat frequency compensation coefficients at the K-1 th moment and the K-2 th moment, epsilon is a set limit value and is a positive number, K₁、K₂The gradient descent coefficients are all positive.

Further, the dynamic beat frequency compensation coefficient χ is adjusted_{dyn_optimal}And static beat frequency compensation coefficient x_statAdding to obtain a beat frequency compensation coefficient x_comp＝χ_{dyn_optimal}+χ_statCompensating coefficient x for beat frequency_compCompensated to a given torque T_e ^*Or a given torqueCorresponding given slip ω_sip ^*Upper, i.e. T_e ^*(ω_sip ^*)_otptimal＝T_e ^*(ω_sip ^*)+χ_comp。

In a second aspect, the present invention further provides a motor beat frequency suppression system, configured to implement the motor beat frequency suppression method, where the system includes:

the acquisition unit is used for acquiring the intermediate voltage and the motor current of the electric transmission control system in real time;

a filtering unit for extracting an alternating current component and a direct current component of the intermediate voltage;

the beat frequency current extraction unit is used for extracting a motor current beat frequency component representing a motor beat frequency current amplitude index;

the static compensation unit is used for calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage;

the dynamic compensation unit is used for obtaining a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum by adopting a search algorithm and performing online iterative optimization;

and the compensation feedback unit is used for obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

In a third aspect, the present invention further provides an electric drive control system, including a memory and a processor, where the memory stores a computer program, and the computer program, when executed by the processor, implements the motor beat frequency suppression method.

In a fourth aspect, the present invention further provides a storage medium having a computer program stored thereon, where the computer program, when executed by one or more processors, implements the motor beat suppression method.

The invention provides a motor beat frequency suppression method and system, an electric transmission control system and a storage medium, which realize the suppression of beat frequency phenomenon (the motor current beat frequency component is reduced to the minimum) generated by direct current and alternating current (DC/AC) pulsation on a motor in an AC/DC type electric transmission control system with the intermediate voltage having the pulsation component of twice grid frequency, effectively reduce the problems of motor loss, heating and noise, and improve the running performance of the motor and the system stability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an electric drive control system consisting of a conventional single-phase rectifier + three-phase inverter-AC motor;

FIG. 2 is a schematic diagram of an electric transmission control system consisting of a single-phase rectifier, a three-phase inverter and an alternating current motor without an LC hardware filter loop;

FIG. 3 is a schematic diagram of an application of a motor beat frequency suppression method according to an embodiment of the present invention;

fig. 4 is a flowchart of a motor beat frequency suppression method according to an embodiment of the present invention;

fig. 5 is a flowchart of step S4 according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a principle of extracting a beat frequency component of a motor current in a stationary abc coordinate according to an embodiment of the present invention;

fig. 7 is another flowchart of step S4 according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a principle of extracting a beat frequency component of a motor current under a synchronous dq-axis rotating coordinate system according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a gradient descent method according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a motor beat frequency suppression system according to a second embodiment of the present invention;

fig. 11 is a block diagram of a motor beat frequency suppression system according to a second embodiment of the present invention.

In the figure:

ψ^*motor flux (stator or rotor flux)

T_e ^*-given torque

ω_sip ^*-given slip

T_e ^*(ω_sip ^*)_otptimalGiven torque or given slip after superposition of beat compensation coefficients

i_a-a-phase motor current

i_b-b-phase motor current

i_c-c-phase motor current

i_d-motor stator d-axis current

i_q-motor stator q-axis current

ω_s-stator rotational angular velocity

ω_r-rotor rotational angular velocity

ω_net-angular frequency of rotation of single-phase alternating current

θ_eSynchronous rotation of stator frequency

PWM-pulse width modulation

Sa、S_b、S_c-a switch state.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

The motor beat frequency suppression method and system, the electric transmission control system and the storage medium provided by the invention are applied to the electric transmission control system of the existing single-phase rectifier, three-phase inverter and alternating current motor, and as shown in figure 3, the single-phase cross-current network voltageFlows into a single-phase rectifier, generates an intermediate voltage U between the single-phase rectifier and a three-phase inverter_dThe output of the single-phase rectifier flows into the three-phase inverter, the output of the three-phase inverter flows into the alternating current motor IM, and the intermediate voltage U of the electric transmission control system is acquired in real time_dAnd motor current for extracting AC component of intermediate voltage(including amplitude and phase) and DC component, calculating static beat frequency compensation coefficient and calculating dynamic beat frequency compensationThe coefficient is based on the existing motor control unit and PWM modulation unit, and the beat frequency compensation coefficient chi of the invention is introduced_compSuperimposed on the given torqueOr a given torqueCorresponding given slip ω_sip ^*And motor beat frequency suppression is realized.

Example one

The embodiment provides a motor beat frequency suppression method, as shown in fig. 4, including:

step S1, collecting the intermediate voltage U of the electric transmission control system in real time_dAnd motor current (at least two phases);

step S2, extracting the AC component of the intermediate voltage(including amplitude and phase) and DC component U_dc；

Step S3, calculating static beat frequency compensation coefficient x according to the alternating current component and the direct current component of the intermediate voltage_stat；

Specifically, the static beat frequency compensation coefficient is calculated by adopting the following static beat frequency compensation coefficient function:

wherein, χ_statIs a static beat frequency compensation coefficient and is,is an intermediate voltage U_dOf medium alternating current component, U_dcIs an intermediate voltage U_dOf (d) a direct current component, k_ampIs the correction factor, ω_netIs the rotation angular frequency of the single-phase alternating current.

Step S4, extracting electricity representing beat frequency current amplitude index of motorBeat frequency component I of electromechanical current_p；

Specifically, as shown in fig. 5 and 6, the step S4 includes:

step 41, in a static abc coordinate system, a-phase motor current i is subjected to_aAnd b-phase motor current i_bPerforming FFT analysis;

step 42, extracting characteristic frequency |2 ω_net-ω_sI is the corresponding amplitude of the beat frequency component of the motor current, wherein, omega_netIs the rotation angular frequency, omega, of a single-phase alternating current_sIs the stator rotational angular velocity.

Alternatively, as shown in fig. 7 and 8, the step S4 includes:

step 43, extracting the frequency of 2 omega from the d-axis motor current and the q-axis motor current in the synchronous dq-axis rotating coordinate system_netIncluding 2 times the grid voltage frequency 2 omega in the d-axis current_netOf alternating current component i_{d_ac}And 2 times the grid voltage frequency 2 omega in the q-axis current_netOf alternating current component i_{q_ac}In which ω is_netIs the rotation angular frequency of the single-phase alternating current;

step 44, calculating the 2-time grid voltage frequency 2 omega in the d-axis current_netOf alternating current component i_{d_ac}Effective value of (I)_{d_ac}And 2 times the grid voltage frequency 2 omega in the q-axis current_netOf alternating current component i_{q_ac}Effective value of (I)_{q_ac}；

Step 45, solving the root mean square sum of the two effective values to obtain a motor current beat frequency component I_p。

The motor current beat component extraction method is selected from the two implementation methods of step S4 described above, according to whether the stationary abc coordinate system or the synchronous dq-axis rotation coordinate system.

Step S5, adopting search algorithm, and optimizing the dynamic beat frequency compensation coefficient χ through online iteration_dynObtaining a dynamic beat frequency compensation coefficient chi for minimizing the beat frequency component of the motor current_dyn__optimal；

In particular, the search algorithm is preferably a gradient descent method (but not limited thereto, other mathematical search algorithms suitable for the concave function may also be suitable), by whichOnline iterative optimization dynamic beat frequency compensation coefficient chi_dynObtaining a dynamic beat frequency compensation coefficient chi for minimizing the beat frequency component of the motor current_{dvn_optimal}。

According to engineering experience, based on motor current beat frequency component I_pAnd a dynamic beat frequency compensation coefficient χ_dynThe concave function characteristic is provided, according to the mathematical theory, the dynamic beat frequency compensation coefficient chi can be continuously adjusted by adopting a gradient descent method_dynFinally, a dynamic beat frequency compensation coefficient x is obtained by searching_{dyn_optimal}So that the beat frequency component I of the motor current_pMinimum, motor current beat frequency component I_pTo a minimum value I_pAnd min is the aim of inhibiting the beat frequency current of the motor.

The meaning of the gradient descent method is: and aiming at the concave function, searching the corresponding x when the y is minimum.

The principle of the gradient descent method is shown in fig. 9, and the formula of the gradient descent method is as follows:

Δy[k-1]＝y[k-1]-y[k-2]；

x 0 is 0 (initial value)

The concave function described above is expressed in discrete form as follows:

let y be I_p[k]，x＝χ_dyn[k]，

ΔIp[k-1]＝Ip[k-1]-Ip[k-2]；

In the formula, x_dyn[k]To control the dynamic beat compensation coefficient at the kth time of the cycle,%_dyn[k-1]To control the dynamic beat frequency compensation coefficient at the k-1 th moment of the cycle, alpha is the search step length, I_p[k]To control the beat component of the motor current at the kth moment of the cycle, I_p[k-1]To control the beat frequency component of the motor current at time k-1 of the cycle, Δ Ip [ k-1 ]]The first k-1 time and the secondThe beat frequency compensation coefficient at the time of K-2 corresponds to the beat frequency component difference of the motor current, epsilon is a set limit value and is a positive number, K₁、K₂The gradient descent coefficients are positive and are set according to engineering debugging basis.

And continuously adjusting the value of the dynamic beat frequency compensation coefficient in the concave function by adopting a gradient descent method, and searching and obtaining the dynamic beat frequency compensation coefficient which enables the current beat frequency component of the motor to be minimum. Dynamic beat frequency compensation coefficient chi_{dyn_optimal}Is the final steady state value after iterative computation according to the concave function in discrete form, the steady state value is to realize | delta Ip [ k-1 ]]And the value of | < epsilon is a converged value after continuous iteration and updating.

And step S6, obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

Specifically, the dynamic beat frequency compensation coefficient chi_{dyn_optimal}And static beat frequency compensation coefficient x_statAdding to obtain a beat frequency compensation coefficient x_comp＝χ_{dyn_optimal}+χ_statCompensating coefficient x for beat frequency_compCompensating to a given torqueOr a given torqueCorresponding given slip ω_sip ^*Upper, i.e. T_e ^*(ω_sip ^*)_otptimal＝T_e ^*(ω_sip ^*)+χ_comp。

Example two

The present embodiment provides a motor beat suppression system for implementing a motor beat suppression method of an electric drive control system, as shown in fig. 9 and 10, the system including:

the acquisition unit 1 is used for acquiring the intermediate voltage and the motor current of the electric transmission control system in real time;

a filtering unit 2 for extracting an alternating current component and a direct current component of the intermediate voltage;

the beat frequency current extraction unit 3 is used for extracting a motor current beat frequency component representing a motor beat frequency current amplitude index;

the static compensation unit 4 is used for calculating a static beat frequency compensation coefficient according to the alternating current component and the direct current component of the intermediate voltage;

the dynamic compensation unit 5 is used for obtaining a dynamic beat frequency compensation coefficient which enables a beat frequency component of the motor current to be minimum by adopting a search algorithm and performing online iterative optimization;

and the compensation feedback unit 6 is used for obtaining a beat frequency compensation coefficient based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, and compensating the given torque or the given slip corresponding to the given torque by using the beat frequency compensation coefficient.

The filtering unit 2 further includes a low-pass filter for extracting the dc component and a band-pass filter or a wave limiter for extracting the ac component.

The beat frequency current extraction unit 3 is specifically configured to:

performing FFT analysis on the a-phase motor current or the b-phase motor current in a static abc coordinate system;

extracting characteristic frequency |2 ω_net-ω_sI is the corresponding amplitude of the beat frequency component of the motor current, wherein, omega_netIs the rotation angular frequency, omega, of a single-phase alternating current_sIs the stator rotational angular velocity.

Or the beat frequency current extraction unit 3 is specifically configured to:

under a synchronous dq-axis rotating coordinate system, extracting frequency of 2 omega from d-axis motor current and q-axis motor current_netComprises an alternating current component of 2 times the grid voltage frequency in the d-axis current and an alternating current component of 2 times the grid voltage frequency in the q-axis current, wherein ω is_netIs the rotation angular frequency of the single-phase alternating current;

calculating the effective value of the alternating current component with 2 times of grid voltage frequency in the d-axis current and the effective value of the alternating current component with 2 times of grid voltage frequency in the q-axis current;

and solving the mean square sum root of the two effective values to obtain the beat frequency component of the motor current.

And selecting a motor current beat component extraction mode from the two implementation modes according to a static abc coordinate system or a synchronous dq axis rotation coordinate system.

The dynamic compensation unit 5 is configured to obtain a dynamic beat frequency compensation coefficient that minimizes a beat frequency component of the motor current by using a gradient descent method and performing online iterative optimization, and specifically includes:

and continuously adjusting the value of the dynamic beat frequency compensation coefficient in the concave function by adopting a gradient descent method based on the concave function characteristics of the motor current beat frequency component and the dynamic beat frequency compensation coefficient, and searching and acquiring the dynamic beat frequency compensation coefficient which enables the motor current beat frequency component to be minimum.

The present embodiment also provides an electric drive control system, which includes a memory and a processor, where the memory stores a computer program, and the computer program is executed by the processor to implement the motor beat frequency suppression method.

The present invention also provides a storage medium having stored thereon a computer program which, when executed by one or more processors, implements the above-described motor beat suppression method.

According to the motor beat frequency suppression method and system, the electric transmission control system and the storage medium provided by the embodiment of the invention, the static beat frequency compensation coefficient is obtained by extracting the direct current component and the alternating current component of the intermediate voltage; by extracting a motor current beat frequency component, a search algorithm is adopted to iteratively optimize a dynamic beat frequency compensation coefficient; the beat frequency compensation coefficient is obtained based on the dynamic beat frequency compensation coefficient and the static beat frequency compensation coefficient, the beat frequency compensation coefficient is used for compensating the given torque or the given slip corresponding to the given torque, and the beat frequency compensation coefficient is superposed on the front-end given torque or the given slip controlled by the traditional motor, so that the current beat frequency component of the motor is minimized, and the adverse effects of the fluctuating intermediate voltage on the loss, the heating and the noise of the motor in the electric transmission control system without the LC hardware filter loop are further reduced.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.