阅读说明：本技术 基于zynq的多电机直接转矩控制系统及其控制方法 (ZYNQ-based multi-motor direct torque control system and control method thereof ) 是由 席小鹭 赵雪峰 任强 周林 田炜 于 2019-10-14 设计创作，主要内容包括：本发明公开了基于ZYNQ的多电机直接转矩控制系统及其控制方法,所述系统包括SoC模块、PWM逆变器模块和电机模块；所述SoC模块包括PS和PL两部分,PS端包括ARM双核处理器、存储模块、外部接口模块；PL端为FPGA,包括可编程逻辑单元和DSP运算单元,所述FPGA内部包括可编程逻辑单元实现的电机位置解码模块、监测保护模块、PWM脉冲产生模块、模数转换模块、PATA-16接口转换模块,以及可编程逻辑单元和DSP运算单元实现的DTC算法模块；将各功能模块合理分配在PS和PL端,实现四电机直接转矩控制,提高集成化、减小体积、减少成本、利于通信。(The invention discloses a ZYNQ-based multi-motor direct torque control system and a control method thereof, wherein the system comprises an SoC module, a PWM inverter module and a motor module; the SoC module comprises a PS part and a PL part, and the PS end comprises an ARM dual-core processor, a storage module and an external interface module; the PL end is an FPGA which comprises a programmable logic unit and a DSP operation unit, and the FPGA internally comprises a motor position decoding module, a monitoring protection module, a PWM pulse generation module, an analog-to-digital conversion module, a PATA-16 interface conversion module and a DTC algorithm module which are realized by the programmable logic unit and the DSP operation unit; all functional modules are reasonably distributed at PS and PL ends, direct torque control of four motors is realized, integration is improved, the size is reduced, the cost is reduced, and communication is facilitated.)

1. A multi-motor direct torque control system based on ZYNQ is characterized by comprising an SoC module, a PWM inverter module and a motor module; the SoC module is a ZYNQ chip and comprises a PS part and a PL part, wherein the PS end comprises an ARM dual-core processor, a storage module and an external interface module, and the ARM dual-core processor comprises a control processing module and a rotating speed ring module; the PL end is an FPGA which comprises a programmable logic unit and a DSP operation unit, the FPGA comprises a motor position decoding module, a monitoring protection module, a PWM pulse generation module, an analog-to-digital conversion module and a PATA-16 interface conversion module which are realized by the programmable logic unit, and a DTC algorithm module which is realized by the programmable logic unit and the DSP operation unit, and the DTC algorithm module comprises a coordinate conversion module, a torque flux linkage estimation module, a torque loop module and a flux linkage module; the motor module comprises a motor and a motor encoder;

each function module of the PL end independently generates IP and is uniformly packaged into an AXI4-Lite interface, and the PS end is connected with the PL end through an on-chip high-speed bus AXI 4-Lite; the motor position decoding module is connected with a motor encoder, the monitoring protection module and the PWM pulse generation module are connected with the PWM inverter module, and the analog-to-digital conversion module is connected with a sampling resistor on a three-phase circuit connected between the PWM inverter module and the motor through a linear isolation optocoupler; the motor position decoding module, the monitoring protection module and the analog-to-digital conversion module are sequentially connected with the coordinate conversion module, the torque flux linkage estimation module, the torque ring module or flux linkage module and the PWM pulse generation module, and the motor position decoding module is simultaneously sequentially connected with the rotating speed ring module and the torque ring module.

2. The ZYNQ-based multi-motor direct torque control system as claimed in claim 1 further comprising a power module connected to the SoC module, the PWM inverter module and the motor module, respectively.

3. The ZYNQ-based multi-motor direct torque control system in accordance with claim 1 wherein said speed loop module, torque loop module, flux linkage module include speed, torque, flux linkage comparison and PID adjustments, respectively.

4. The multi-motor direct torque control system based on ZYNQ is characterized in that the ZYNQ chip is Xilinx ZYNQ7020, and the ARM dual-core processor module is a Cortex-A9ARM core.

5. The ZYNQ-based multi-motor direct torque control system as claimed in claim 1, characterized in that the storage module comprises a DDR module and a Flash module, the DDR module is used for high-speed data caching of functional modules at PL end, and the Flash module is used for storing operation programs, configuration parameters, motor states or system operation states.

6. The ZYNQ-based multi-motor direct torque control system in accordance with claim 1 wherein said external interface module comprises Uart interface, CAN interface and ethernet interface; the CAN interface is connected with a CAN transceiver, the Ethernet interface is connected with an internal gigabit MAC, is connected with an external gigabit PHY through RGMII, and is connected with the Ethernet through a signal transformer.

7. The ZYNQ-based multi-motor direct torque control system as claimed in claim 1, wherein the PATA-16 interface conversion module is connected with a peripheral industrial Ethernet module, and the industrial Ethernet module selects LAN9295 as a bridge piece of an EtherCAT slave station controller.

8. The ZYNQ-based multi-motor direct torque control system as claimed in claim 1, wherein the control processing module is used for coordinating and controlling the task scheduling of each functional module; the motor position decoding module is used for acquiring the information of the rotating speed, the position and the torque of the motor.

9. A control method of a ZYNQ-based multi-motor direct torque control system according to any one of claims 1 to 8, characterized in that the control method comprises:

the external interface module receives the given rotating speed omega', the actual rotating speed omega of the motor output by the motor position decoding module is compared and PID regulated in the rotating speed loop module and output to the rotating speed loop moduleConstant torque Te'; a, B two-phase current is converted into a voltage analog signal by using a sampling resistor, and the current measured by an analog-to-digital conversion module is I after passing through a linear isolation optocoupler_a，I_b. The two feedback quantities are processed by a coordinate transformation module and a torque flux linkage estimation module to obtain an actual torque Te and an actual flux linkage psi_sAnd a phase angle θ; the given torque Te' is compared with the actual torque Te and the given flux linkage psi_s' with the actual flux linkage psi_sAfter comparison and PID adjustment are carried out in the torque loop module and the magnetic chain loop module respectively, the signals are input into the PWM pulse generation module, the PWM pulse generation module controls the on-off of an IGBT power tube of the PWM inverter, and the direct current voltage is inverted and output into three-phase alternating current voltage to act on the motor.

10. The control method of a ZYNQ-based multi-motor direct torque control system according to claim 9, further comprising: the DTC algorithm module can simultaneously realize 4-path DCT control algorithms, namely the FPGA can perform direct torque control on four motors in parallel.

Technical Field

The invention relates to the technical field of motor control, in particular to a ZYNQ-based multi-motor direct torque control system and a control method thereof.

Background

At present, control algorithms for asynchronous motors or synchronous motors include a Variable Voltage Variable Frequency (VVVF) control algorithm, a space vector control (FOC) algorithm and a Direct Torque Control (DTC) algorithm. The VVVF control method has simple circuit and strong universality, basically solves the problem of smooth speed regulation of the asynchronous motor, but has unsatisfactory dynamic control effect; the FOC control method theoretically well solves the problem of alternating current torque control, the dynamic and static performances are excellent, but the FOC algorithm needs to decouple the stator current and perform complex mathematical operation, the requirement on a selected control operation platform is high, the cost is generally high, meanwhile, the FOC control depends on parameters of a controlled motor, and if the input actual motor parameters have large deviation, an ideal control effect is difficult to achieve; the direct torque control algorithm is characterized in that the flux linkage and the torque are comprehensively controlled by taking the torque as a core, the change of a rotating coordinate is not needed in the algorithm, the voltage and the current of a stator of the motor are simply detected, the flux linkage and the torque of the current motor are estimated by means of an instantaneous space vector theory, a PWM (pulse width modulation) signal is controlled by a PID (proportion integration differentiation) regulator, the on-off state of an inverter is directly controlled, higher torque dynamic performance can be obtained, and the direct torque control algorithm is more suitable for a large-inertia motion control system needing quick torque response.

At present, DSP or ARM is mainly used for realizing a direct torque control system, the DSP, the ARM, the DSP and the ARM are used as a main controller, an external AD sampling module, a fault protection module, a driving and isolating module and the like are connected, the size is large, the cost is high, the difficulty is large, especially when a direct torque is needed to control a multi-path motor, the size of the whole control system is larger, the cost is higher, the realization difficulty is larger, and the bandwidth limitation of a chip level easily influences the torque response speed, so that the direct torque control effect is influenced.

Disclosure of Invention

Technical problem to be solved

Based on the problems, the invention provides a ZYNQ-based multi-motor direct torque control system and a control method thereof, which realize the integration of direct torque control and drive of multiple motors, have higher integration level, smaller volume and lower cost and are more beneficial to communication.

(II) technical scheme

Based on the technical problem, the invention provides a ZYNQ-based multi-motor direct torque control system, which comprises an SoC module, a PWM inverter module and a motor module; the SoC module is a ZYNQ chip and comprises a PS part and a PL part, wherein the PS end comprises an ARM dual-core processor, a storage module and an external interface module, and the ARM dual-core processor comprises a control processing module and a rotating speed ring module; the PL end is an FPGA which comprises a programmable logic unit and a DSP operation unit, the FPGA comprises a motor position decoding module, a monitoring protection module, a PWM pulse generation module, an analog-to-digital conversion module and a PATA-16 interface conversion module which are realized by the programmable logic unit, and a DTC algorithm module which is realized by the programmable logic unit and the DSP operation unit, and the DTC algorithm module comprises a coordinate conversion module, a torque flux linkage estimation module, a torque loop module and a flux linkage module; the motor module comprises a motor and a motor encoder;

each function module of the PL end independently generates IP and is uniformly packaged into an AXI4-Lite interface, and the PS end is connected with the PL end through an on-chip high-speed bus AXI 4-Lite; the motor position decoding module is connected with a motor encoder, the monitoring protection module and the PWM pulse generation module are connected with the PWM inverter module, and the analog-to-digital conversion module is connected with a sampling resistor on a three-phase circuit connected between the PWM inverter module and the motor through a linear isolation optocoupler; the motor position decoding module, the monitoring protection module and the analog-to-digital conversion module are sequentially connected with the coordinate conversion module, the torque flux linkage estimation module, the torque ring module or flux linkage module and the PWM pulse generation module, and the motor position decoding module is simultaneously sequentially connected with the rotating speed ring module and the torque ring module.

Furthermore, the system also comprises a power supply module, wherein the power supply module is respectively connected with the SoC module, the PWM inverter module and the motor module.

Further, the rotating speed ring module, the torque ring module and the flux linkage ring module respectively comprise comparison and PID adjustment of rotating speed, torque and flux linkage.

Preferably, the ZYNQ chip is Xilinx ZYNQ7020, and the ARM dual-core processor module is a Cortex-A9ARM core.

Further, the storage module comprises a DDR module and a Flash module, the DDR module is used for caching high-speed data of each functional module at the PL end, and the Flash module is used for storing an operation program, configuration parameters, a motor state or a system operation state.

Further, the external interface module comprises a Uart interface, a CAN interface and an ethernet interface; the CAN interface is connected with a CAN transceiver, the Ethernet interface is connected with an internal gigabit MAC, is connected with an external gigabit PHY through RGMII, and is connected with the Ethernet through a signal transformer.

Further, the PATA-16 interface conversion module is connected with a peripheral industrial Ethernet module, and the industrial Ethernet module selects LAN9295 as a bridge piece of the EtherCAT slave station controller.

Further, the control processing module is used for coordinating and controlling task scheduling of each functional module; the motor position decoding module is used for acquiring the information of the rotating speed, the position and the torque of the motor.

A method of controlling a ZYNQ-based multi-motor direct torque control system, the method comprising:

the external interface module receives the given rotating speed omega ', the actual rotating speed omega of the motor output by the motor position decoding module is compared and PID regulated in the rotating speed loop module, and the given torque Te' is output; a, B two-phase current is converted into a voltage analog signal by using a sampling resistor, and the current measured by an analog-to-digital conversion module is I after passing through a linear isolation optocoupler_a，I_b. The two feedback quantities are processed by a coordinate transformation module and a torque flux linkage estimation module to obtain an actual torque Te and an actual flux linkage psi_sAnd a phase angle θ; the given torque Te' is compared with the actual torque Te and the given flux linkage psi_s' with the actual flux linkage psi_sAfter comparison and PID adjustment in the torque loop module and the magnetic chain loop module respectively, PWM pulses are inputAnd the PWM pulse generation module controls the on-off of an IGBT power tube of the PWM inverter, inverts the direct-current voltage and outputs the inverted direct-current voltage into three-phase alternating-current voltage and acts on the motor.

Further, the control method further includes: the DTC algorithm module can simultaneously realize 4-path DCT control algorithms, namely the FPGA can perform direct torque control on four motors in parallel.

(III) advantageous effects

The technical scheme of the invention has the following advantages:

(1) according to the invention, the ZYNQ chip is adopted, the ARM, the FPGA and the DSP are integrated in the SoC, compared with the scheme that the ARM and the DSP are connected with each module externally, the integration is higher, the volume is reduced, the cost is reduced, in addition, the communication bottleneck can not occur through the on-chip bus AXI4-Lite communication, the communication speed is higher, the anti-jamming capability is stronger, and the embedded Linux operating system is carried in the ARM carried by the ZYNQ chip, the system design is simplified, the difficulty of software development is reduced, and the expansibility of the system is improved;

(2) in the invention, each functional module is reasonably distributed at PS and PL ends of a ZYNQ chip, the parallel execution capability of an FPGA, the floating point operation capability of a DSP and the control task scheduling capability and the algorithm capability of an ARM are fully exerted, the control bandwidth and the operation speed of the whole system are improved, and thus the direct torque control effect of multiple motors is ensured;

(3) because the DTC algorithm relates to multiple floating point operations, if the DTC algorithm is realized by pure logic, a lot of logic unit resources are consumed, the difficulty is high, and the stability is not good; therefore, the MAC multiplier in the DSP operation unit is used for time division multiplexing, the result is quickly and accurately obtained, the calculated amount of ARM is greatly reduced, the control bandwidth of the whole machine is improved, the existing resources are fully utilized, and a 4-path DCT control algorithm can be realized theoretically, namely, the direct torque control can be performed on four motors in parallel through the FPGA; the DTC control system of the multi-path motor is greatly simplified, and the realization difficulty of the DTC control of the multi-path motor is reduced;

(4) in the invention, each function module of the FPGA is encapsulated into an independent IP module, so that the function module can be transplanted more conveniently;

(5) the ARM has abundant peripheral interfaces, and the FPGA has better expandability, so that the FPGA can be widely applied to various fields of electric vehicle control, industrial control, automatic production lines and the like;

(6) the invention can record the system running state and the motor state such as bus voltage, bus current, actual torque, actual rotating speed, motor efficiency obtained by calculation and the like in real time through the Flash module so as to be used for big data analysis, provide guidance for driving of a driver and improve the motor efficiency.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

FIG. 1 is a system block diagram of an embodiment of the present invention;

FIG. 2 is a schematic diagram of a two-way direct torque control method according to an embodiment of the present invention;

fig. 3 is a resource utilization table and a resource utilization bar chart of the PL side in the two direct torque control algorithms according to the embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The invention discloses a ZYNQ-based multi-motor direct torque control system, which comprises an SoC module, a PWM inverter module, a motor module and a power module, wherein the SoC module is Xilinx ZYNQ7020 and comprises two parts, namely PS and PL, the PS end comprises an ARM dual-core processor module with low power consumption, namely a Cortex-A9 dual ARM core, a storage module and an external interface module, the PL end is an FPGA and comprises 106K programmable logic units, 220 DSP operation units and 4 mode clock managers (MMCM);

the ARM dual-core processor comprises a rotating speed ring module and a control processing module; the FPGA comprises a motor position decoding module, a monitoring protection module, a PWM pulse generation module, an analog-to-digital conversion module, a PATA-16 interface conversion module and a DTC algorithm module, wherein the motor position decoding module, the monitoring protection module, the PWM pulse generation module, the analog-to-digital conversion module and the PATA-16 interface conversion module are realized by a programmable logic unit, the DTC algorithm module is realized by a DSP operation unit and comprises a coordinate conversion module, a torque flux linkage estimation module, a torque loop module and a magnetic loop module.

The external interface module comprises a Uart interface, a CAN interface and an Ethernet interface, the CAN interface is connected with a CAN transceiver, the Ethernet interface is connected with an internal gigabit MAC, is connected with an external gigabit PHY through RGMII, and is connected with the Ethernet through a signal transformer; the PATA-16 interface conversion module contained in the FPGA is connected with an industrial Ethernet module of a peripheral, and the industrial Ethernet module selects LAN9295 as a bridge piece of an EtherCAT slave station controller; the abundant interfaces can be widely applied to various fields of electric automobile control, industrial control, automatic production lines and the like.

The storage module comprises a DDR module and a Flash module, the DDR module is used for caching high-speed data, the Flash module is used for storing an operation program, configuration parameters, a motor state or a system operation state and the like, such as bus voltage, bus current, actual torque, actual rotating speed and motor efficiency obtained through calculation, and the Flash module is used for analyzing big data, providing guidance for driving of a driver and improving the motor efficiency.

The motor module includes a motor and a motor encoder.

The PWM inverter module is realized by selecting a high-power IGBT, and the high-power IGBT is STGIB30M60 TS-L.

The power module comprises modules such as a rectifier, a multi-path transformer, a DC-DC (direct current-direct current), a low-dropout linear voltage regulator and the like, so that overcurrent, over-temperature and overvoltage short-circuit protection and high-low voltage isolation are realized, 5V, 3.3V or 1.2V and 600V voltages are output, and safe, stable and continuous voltages are provided for the SoC module, the external interface module and the PWM inverter module.

Each function module of the PL end independently generates IP and is uniformly packaged into an AXI4-Lite interface, data signals are cached and extracted through a DDR module, a PS end and the PL end are connected through an in-chip high-speed AXI4-Lite bus, a control processing module of the ARM dual-core processor controls data access of the DDR module and the PS end, and the connection relation among the function modules is as follows:

the power supply module is respectively connected with the SoC module, the PWM inverter module and the motor module; the motor position decoding module is connected with a motor encoder, the monitoring protection module and the PWM pulse generation module are connected with the PWM inverter module, and the analog-to-digital conversion module is connected with a sampling resistor on a three-phase circuit connected between the PWM inverter module and the motor through a linear isolation optocoupler; the motor position decoding module, the monitoring protection module and the analog-to-digital conversion module are sequentially connected with the coordinate conversion module, the torque flux linkage estimation module, the torque ring module or flux linkage module and the PWM pulse generation module, and the motor position decoding module is simultaneously sequentially connected with the rotating speed ring module and the torque ring module.

The motor position decoding module acquires the information of the rotating speed, the position and the torque of the motor; the PWM pulse generation module generates a PWM driving signal; the analog-to-digital conversion module performs analog-to-digital conversion on the acquired three-phase current; the coordinate conversion module comprises a click conversion module and a park conversion module; the rotating speed ring module, the torque ring module and the magnetic linkage ring module respectively comprise comparison and PID regulation of rotating speed, torque and magnetic linkage.

The invention relates to a multi-motor direct torque control system based on ZYNQ, which takes a two-way direct torque control method as an example, and is connected with two groups of PWM pulse generation modules, a DTC algorithm module, a PWM inverter module and a motor module which respectively correspond to each other, and is realized by the following control method as shown in figure 2:

the external interface module receives the given rotating speed omega ', the actual rotating speed omega of the motor output by the motor position decoding module is compared and PID regulated in the rotating speed loop module, and the given torque Te' is output; a, B two-phase current is converted into a voltage analog signal by using a sampling resistor, and the current measured by an analog-to-digital conversion module is I after passing through a linear isolation optocoupler_a，I_b. The two feedback quantities are processed by a coordinate transformation module and a torque flux linkage estimation module to obtain an actual torque Te and an actual flux linkage psi_sAnd a phase angle θ; the given torque Te' is compared with the actual torque Te and the given flux linkage psi_s' with the actual flux linkage psi_sComparison, PID, in Torque Ring Module, magnetic Link Module, respectivelyAfter regulation, the three-phase alternating current is input into a PWM pulse generation module, the PWM pulse generation module controls the on-off of an IGBT power tube of a PWM inverter, the direct current voltage is inverted and output into three-phase alternating current voltage, the maximum output of the three-phase alternating current is 600V, and the three-phase voltage U of 60A is obtained_a、U_b、U_cActing on the motor.

The DTC algorithm module performs floating point multiplication operation through the DSP operation unit, fig. 3 is a resource utilization table and a resource utilization column diagram of a PL end when two paths of direct torque control algorithms are realized, an LUT is a logic unit, an LUTAM is edge storage, an FF is a register, a DSP is a DSP operation unit MAC multiplier, a BUFG is a global clock network unit, and an MMCM is a mixed clock management module. The DTC algorithm relates to multiple floating point operations, if the DTC algorithm is realized by pure logic, a large amount of LUTs are consumed, the difficulty is high, and the stability is not good, so that an MAC product device of a DSP operation unit is used, time division multiplexing is carried out, the result is quickly and accurately obtained, the calculation amount of an ARM is greatly reduced, and the control bandwidth of the whole machine is improved. From the existing resource use condition, when the two DCT control algorithms run, the DSP resource occupation is 46%, therefore, theoretically, the PL terminal can realize the 4 DCT control algorithms, namely, the FPGA can carry out direct torque control on four motors in parallel.

As can be seen from the above, the multi-motor direct torque control system based on ZYNQ and the control method thereof have the following advantages:

(1) according to the invention, the ZYNQ chip is adopted, the ARM, the FPGA and the DSP are integrated in the SoC, compared with the scheme that the ARM and the DSP are connected with each module externally, the integration is higher, the volume is reduced, the cost is reduced, in addition, the communication bottleneck can not occur through the on-chip bus AXI4-Lite communication, the communication speed is higher, the anti-jamming capability is stronger, and the embedded Linux operating system is carried in the ARM carried by the ZYNQ chip, the system design is simplified, the difficulty of software development is reduced, and the expansibility of the system is improved;

(2) in the invention, each functional module is reasonably distributed at PS and PL ends of a ZYNQ chip, the parallel execution capability of an FPGA, the floating point operation capability of a DSP and the control task scheduling capability and the algorithm capability of an ARM are fully exerted, the control bandwidth and the operation speed of the whole system are improved, and thus the direct torque control effect of multiple motors is ensured;

(3) because the DTC algorithm relates to multiple floating point operations, if the DTC algorithm is realized by pure logic, a lot of logic unit resources are consumed, the difficulty is high, and the stability is not good; therefore, the MAC multiplier in the DSP operation unit is used for time division multiplexing, the result is quickly and accurately obtained, the calculated amount of ARM is greatly reduced, the control bandwidth of the whole machine is improved, the existing resources are fully utilized, and a 4-path DCT control algorithm can be realized theoretically, namely, the direct torque control can be performed on four motors in parallel through the FPGA; the DTC control system of the multi-path motor is greatly simplified, and the realization difficulty of the DTC control of the multi-path motor is reduced;

(4) in the invention, each function module of the FPGA is encapsulated into an independent IP module, so that the function module can be transplanted more conveniently;

(5) the ARM has abundant peripheral interfaces, and the FPGA has better expandability, so that the FPGA can be widely applied to various fields of electric vehicle control, industrial control, automatic production lines and the like;

(6) the invention can record the system running state and the motor state such as bus voltage, bus current, actual torque, actual rotating speed, motor efficiency obtained by calculation and the like in real time through the Flash module so as to be used for big data analysis, provide guidance for driving of a driver and improve the motor efficiency.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.