阅读说明：本技术 一种半集中式开绕组电机驱动系统的控制方法 (Control method of semi-centralized open winding motor driving system ) 是由 王伟 田伟杰 程明 于 2021-04-13 设计创作，主要内容包括：本发明公开一种半集中式开绕组电机驱动系统的控制方法,控制方法包括以下步骤：电机驱动系统由三台逆变器向两台开绕组直线电机供电；利用硬件电路测量两台电机的三相电流以及母线电压并通过PARK变换计算出实际dq轴电流；通过直线电机速度调节器计算得驱动系统所需的推力F-e～*；根据推力需求F-e～*,结合每台电机的实际参数给电机分配q轴电流指令；计算两台电机运行所需要的dq轴电压；分配两台电机的电压需求给三台逆变器输出；利用空间矢量调制方法将逆变器输出电压指令调制成占空比指令；结合两台电机的运行状况对零序电压进行分配。本发明控制方法通过驱动多电机系统运行,并提高系统的直流母线电压利用率,实现系统扩速。(The invention discloses a control method of a semi-centralized open winding motor driving system, which comprises the following steps: the motor driving system supplies power to the two open-winding linear motors by three inverters; measuring three-phase currents and bus voltages of the two motors by using a hardware circuit, and calculating actual dq axis current through PARK conversion; calculating the thrust F required by the driving system through a linear motor speed regulator e * (ii) a According to thrust requirement F e * Distributing a q-axis current instruction to the motors by combining the actual parameters of each motor; calculating dq axis voltages required by the operation of the two motors; distributing the voltage requirements of the two motors to the three inverters for output; using space vector tonesModulating an inverter output voltage command into a duty ratio command by the manufacturing method; and distributing the zero sequence voltage by combining the operating conditions of the two motors. The control method of the invention drives the multi-motor system to operate, improves the direct current bus voltage utilization rate of the system and realizes the speed expansion of the system.)

1. A control method of a semi-centralized open-winding motor driving system is characterized by comprising the following steps:

s1, the motor driving system supplies power to the two open-winding linear motors by three inverters, and the two linear motors are rigidly connected;

s2, measuring three-phase current and bus voltage of two motors by using hardware circuit, calculating actual dq axis current by PARK conversion, and calculating operation angle (theta) of two motors by using grating ruler_Ι，θ_ΙΙ) And speed;

s3, calculating the thrust required by the driving system through a linear motor speed regulator

S4 according to the thrust requirementDistributing a q-axis current instruction to the motors by combining the actual parameters of each motor;

s5, calculating dq axis voltages required by the operation of the two motors;

s6, distributing the voltage requirements of the two motors to the three inverters for output;

s7, modulating the inverter output voltage command into a duty ratio command by using a space vector modulation method;

and S8, distributing the zero sequence voltage according to the running conditions of the two motors.

2. The control method of a semi-centralized open-winding motor driving system according to claim 1, wherein in S3:

v,v^*actual and reference speeds, k, of the drive system, respectively_{p_v},k_{i_v}Respectively, the proportionality coefficient and the integral coefficient of the speed regulator.

3. The control method of a semi-centralized open-winding motor driving system according to claim 2, wherein in S4:

τ_sis the polar distance psi of the linear motor_{f1_Ι}Is the permanent magnet flux linkage of the first motor_{f1_ΙΙ}Is the permanent magnet flux linkage of the second motor.

4. The control method of a semi-centralized open-winding motor driving system according to claim 3, wherein in the step S5:

x ═ I or II

i_{d_x},i_{q_x},Actual dq-axis current and reference dq-axis current, u, respectively, of motor x_{d_Ι},u_{q_Ι},u_{d_ΙΙ},u_{q_ΙΙ}For the voltage requirement of motor x, k_{p_d_v},k_{i_d_v},k_{p_q_v},k_{i_q_v}Respectively, the proportionality coefficient and the integral coefficient of the dq-axis current regulator of motor x.

5. The method for controlling a semi-centralized open-winding motor driving system according to claim 4, wherein the step S6 specifically includes the steps of:

s61, unifying the voltage requirements of the two motors to the same coordinate system;

gamma is the angle difference between two motors, gamma is theta_Ι-θ_ΙΙ，u_{d_ΙΙ},u_{q_ΙΙ},u′_{d_ΙΙ},u′_{q_ΙΙ}The voltage requirements of the motor I before and after transformation are met;

s62, determining a voltage distribution mode according to different motor combinations and calculating required voltage;

calculating an identification variable l₁,l₂Respectively as follows:

according to l₁And l₂The relationship between the two voltage vectors and the angle difference alpha between the two voltage vectors of the motor determine three voltage distribution modes, and the following conditions are respectively met:

mode 1, the condition is satisfied: l₁≤l₂The common voltage points are:

mode 2, the condition is satisfied: (l)₁>l₂)&[(0°≤α≤90°)or(270°≤α≤360°)]The common voltage points are:

mode 3, the condition is satisfied: (l)₁>l₂)&[90°<α<270°]The common voltage points are:

and calculating the voltage output requirements of three inverters by combining three voltage distribution modes:

6. the method according to claim 5, wherein the step S8 specifically includes:

s81, calculating zero sequence voltage requirements u of the two motors by using the transfer function of the PR regulator_{0_Ι},u_{0_ΙΙ}；

K_p,K_iProportional coefficient and resonance coefficient of the PR regulator; omega_cIs the cutoff frequency of the PR adjuster; omega₀Is the resonant frequency of the PR adjuster;

s82, converting the zero sequence voltage requirements of the two motors into a zero sequence duty ratio instruction T_{0_Ι},T_{0_ΙI}；

u_dcIs a dc bus voltage; t is_sIs a PWM control period;

s83, calculating a duty ratio instruction after zero sequence voltage suppression adjustment;

for | T_{0_Ι}| is greater than | T_{0_ΙΙ}|：

For | T_{0_Ι}Less than | T_{0_ΙΙ}|：

Wherein:

T_{m_1},T_{m_2},T_{m_3}three-phase duty cycle before zero sequence modulation; t'_{m_1},T′_{m_2},T′_{m_3}Respectively the three-phase duty cycle after zero-sequence modulation.

Technical Field

The invention relates to the field of motor control, in particular to a control method of a semi-centralized open-winding motor driving system.

Background

When the end windings of the motor are opened, an inverter needs to be added to each end. In the whole motor driving system, the addition of the inverter can lead to the increase of the hardware cost of the driving system, the increase of the volume and the failure probability of the driving system and the influence on the safety and the reliability of the system.

At present, in order to solve the adverse effect caused by excessive inverters, at the present stage, there are two main control topologies for reducing the number of switching tubes: one is the control of driving multiple motors by a single inverter, and the other is the control of two motors with five bridge arms. For a control topology of driving multiple motors by a single inverter, a large number of switching tubes can be omitted, but the operation conditions among multiple motors are required to be extremely similar. For the situation that the operating conditions of the two motors are greatly different, the control topology can generate large circulation currents, and the control performance can be extremely reduced. For the topology of five bridge arms and double motors, one phase winding of the two motors shares the same bridge arm, so that a part of switching tubes can be omitted, and the topology is suitable for different running conditions of the two motors. At present, no relevant research is available on the proposed semi-centralized open-winding motor driving topology and the cooperative control strategy.

Disclosure of Invention

The invention aims to provide a control method of a semi-centralized open-winding motor driving system, which is used for driving a multi-motor system to operate, improving the voltage utilization rate of a direct-current bus of the system and realizing the speed expansion of the system; the hardware cost of the multi-motor open winding driving system is reduced; the system volume of the multi-motor open winding driving system is reduced; the fault probability of the multi-motor open winding driving system is reduced, and the safety and the reliability of the system are improved.

The purpose of the invention can be realized by the following technical scheme:

a control method of a semi-centralized open-winding motor driving system comprises the following steps:

s1, the motor driving system supplies power to the two open-winding linear motors by three inverters, and the two linear motors are rigidly connected;

s2, measuring three-phase current and bus voltage of two motors by using hardware circuit, calculating actual dq axis current by PARK conversion, and calculating operation angle (theta) of two motors by using grating ruler_I，θ_ΙΙ) And speed;

s3, calculating the thrust F required by the driving system through a linear motor speed regulator_e ^*；

S4 according to the thrust requirement F_e ^*Distributing a q-axis current instruction to the motors by combining the actual parameters of each motor;

s5, calculating dq axis voltages required by the operation of the two motors;

s6, distributing the voltage requirements of the two motors to the three inverters for output;

s7, modulating the inverter output voltage command into a duty ratio command by using a space vector modulation method;

and S8, distributing the zero sequence voltage according to the running conditions of the two motors.

Further, in S3:

v,v^*actual and reference speeds, k, of the drive system, respectively_{p_v},k_{i_v}Respectively, the proportionality coefficient and the integral coefficient of the speed regulator.

Further, in S4:

τ_sis the polar distance psi of the linear motor_{f1_Ι}Is the permanent magnet flux linkage of the first motor_{f1_ΙΙ}Is the permanent magnet flux linkage of the second motor.

Further, in S5:

x ═ I or II

i_{d_x},i_{q_x},Actual dq-axis current and reference dq-axis current, u, respectively, of motor x_{d_Ι},u_{q_Ι},u_{d_ΙΙ},u_{q_ΙI}For the voltage requirement of motor x, k_{p_d_v},k_{i_d_v},k_{p_q_v},k_{i_q_v}Respectively, the proportionality coefficient and the integral coefficient of the dq-axis current regulator of motor x.

Further, the S6 specifically includes the following steps:

s61, unifying the voltage requirements of the two motors to the same coordinate system;

gamma is the angle difference between two motors, gamma is theta_Ι-θ_ΙΙ，u_{d_ΙΙ},u_{q_ΙΙ},u′_{d_ΙΙ},u′_{q_ΙΙ}The voltage requirements of the motor I before and after transformation are met;

s62, determining a voltage distribution mode according to different motor combinations and calculating required voltage;

calculating an identification variable l₁,l₂Respectively as follows:

according to l₁And l₂The relation between the two voltage vectors and the angle difference alpha between the two voltage vectors of the motor determine three voltage distribution modes which respectively satisfyThe following conditions were used:

mode 1, the condition is satisfied: l₁≤l₂The common voltage points are:

mode 2, the condition is satisfied: (l)₁>l₂)&[(0°≤α≤90°)or(270°≤α≤360°)]The common voltage points are:

mode 3, the condition is satisfied: (l)₁>l₂)&[90°<α<270°]The common voltage points are:

and calculating the voltage output requirements of three inverters by combining three voltage distribution modes:

further, the S8 specifically includes:

s81, calculating zero sequence voltage requirements u of the two motors by using the transfer function of the PR regulator_{0_Ι},u_{0_ΙΙ}；

K_p,K_iProportional coefficient and resonance coefficient of the PR regulator; omega_cIs the cutoff frequency of the PR adjuster; omega₀Is the resonant frequency of the PR adjuster;

s82, converting the zero sequence voltage requirements of the two motors into zero sequence duty ratio instructionsT_{0_Ι},T_{0_ΙΙ}；

u_dcIs a dc bus voltage; t is_sIs a PWM control period;

s83, calculating a duty ratio instruction after zero sequence voltage suppression adjustment;

for | T_{0_Ι}| is greater than | T_{0_ΙΙ}|：

For | T_{0_Ι}Less than | T_{0_ΙΙ}|：

Wherein:

T_{m_1},T_{m_2},T_{m_3}three-phase duty cycle before zero sequence modulation; t'_{m_1},T'_{m_2},T'_{m_3}Respectively the three-phase duty cycle after zero-sequence modulation.

The invention has the beneficial effects that:

1. the control method of the invention drives the multi-motor system to operate, improves the direct current bus voltage utilization rate of the system and realizes the speed expansion of the system; the hardware cost of the multi-motor open winding driving system is reduced;

2. the control method reduces the system volume of the multi-motor open winding driving system; the fault probability of the multi-motor open winding driving system is reduced, and the safety and the reliability of the system are improved.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a motor drive system topology of the present invention;

FIG. 2 is a three-phase current diagram of motor I before and after the present invention is shifted;

FIG. 3 is a speed diagram of the drive system before and after a gear shift of the present invention;

fig. 4 is a graph of the output voltage of the inverter 1 before and after the gear shift of the present invention;

fig. 5 is a graph of the output voltage of the inverter 2 before and after the gear shift of the present invention;

fig. 6 is a graph of the output voltage of the inverter 3 before and after the gear shift of the present invention.

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. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to verify the effect of the invention, three permanent magnet linear motors are selected, and the parameters of the linear motors are as follows: stator phase resistance 3 omega, stator phase inductance L_d＝L_q＝L_s33.5mH, the permanent magnet flux linkage is 0.125 Wb.

Specifically, fig. 1 shows a control topology according to the present invention. The embodiment of the invention discloses a control method of a semi-centralized open winding motor driving system, which comprises the following steps:

s1, supplying power to the two open-winding linear motors by the system through three inverters, wherein the two linear motors are rigidly connected;

s2, measuring the three-phase current and the bus voltage of the two motors by using a hardware circuit, and calculating the operation angle (theta) of the two motors by using a grating ruler_Ι，θ_ΙΙ) And speed.

S3, calculating the thrust required by the driving system through a linear motor speed regulator

v,v^*Actual and reference speeds, k, of the drive system, respectively_{p_v},k_{i_v}Respectively, the proportionality coefficient and the integral coefficient of the speed regulator.

S4 according to the thrust requirementAnd (3) distributing a q-axis current command to the motors by combining the actual parameters of each motor:

τ_sis the polar distance psi of the linear motor_{f1_Ι}Is the permanent magnet flux linkage of the first motor_{f1_ΙΙ}Is the permanent magnet flux linkage of the second motor.

And S5, calculating the dq axis voltage required by the operation of the two motors:

x ═ I or II

i_{d_x},i_{q_x},Actual dq-axis current and reference dq-axis current, u, respectively, of motor x_{d_Ι},u_{q_Ι},u_{d_ΙΙ},u_{q_ΙΙ}Is electricityVoltage requirement of machine x, k_{p_d_v},k_{i_d_v},k_{p_q_v},k_{i_q_v}Respectively, the proportionality coefficient and the integral coefficient of the dq-axis current regulator of motor x.

S6 distributing the voltage demands of two motors to three inverter outputs

S61, unifying the voltage requirements of the two motors to the same coordinate system:

gamma is the angle difference between two motors, gamma is theta_Ι-θ_ΙΙ，u_{d_ΙΙ},u_{q_ΙΙ},u′_{d_ΙΙ},u′_{q_ΙΙ}The voltage requirements of the motor I before and after the transformation are met.

S62, determining a voltage distribution mode according to different motor combinations and calculating the required voltage

Calculating an identification variable l₁,l₂Respectively as follows:

according to l₁And l₂The relationship between the two voltage vectors and the angle difference alpha between the two voltage vectors of the motor determine three voltage distribution modes, and the following conditions are respectively met:

mode 1, the condition is satisfied: l₁≤l₂The common voltage points are:

mode 2, the condition is satisfied: (l)₁>l₂)&[(0°≤α≤90°)or(270°≤α≤360°)]The common voltage points are:

mode 3, the condition is satisfied: (l)₁>l₂)&[90°<α<270°]The common voltage points are:

and calculating the voltage output requirements of three inverters by combining three voltage distribution modes:

s7, modulating the inverter output voltage command into a duty ratio command by using a space vector modulation method;

and S8, distributing the zero sequence voltage by combining the operation conditions of the two motors:

s81, calculating the zero sequence voltage requirement u of the two motors by using the following PR (proportional resonance) regulator transfer function_{0_Ι},u_{0_ΙΙ}：

K_p,K_iProportional coefficient and resonance coefficient of the PR regulator; omega_cIs the cutoff frequency of the PR adjuster; omega₀Is the resonant frequency of the PR modulator.

S82, converting the zero sequence voltage requirements of the two motors into a zero sequence duty ratio instruction T_{0_Ι},T_{0_ΙΙ}：

u_dcIs a dc bus voltage; t is_sIs a PWM control period.

And S83, calculating a duty ratio command after zero sequence voltage suppression regulation:

for | T_{0_Ι}| is greater than | T_{0_ΙΙ}|：

For | T_{0_Ι}Less than | T_{0_ΙΙ}|：

Wherein:

T_{m_1},T_{m_2},T_{m_3}three-phase duty cycle before zero sequence modulation; t'_{m_1},T'_{m_2},T'_{m_3}Respectively the three-phase duty cycle after zero-sequence modulation.

Fig. 2 is a three-phase current diagram of the motor i before and after the gear shift, and it can be seen that the present invention can control a multi-motor system more stably and has better performance before and after the gear shift. Fig. 3 is a speed diagram of the driving system before and after speed change, and it can be seen that the speed control of the present invention is more accurate and stable. Fig. 4, 5 and 6 are graphs of output voltages of three inverters before and after shifting, and it can be seen that the situation of shifting in the mode 1 basically matches with the proposed voltage distribution strategy.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.