Multi-split motor driver

Abstract

The invention provides a multi-split motor driver, and the motor driver comprises a capacitor board which is used for carrying out the rectification and filtering of an input voltage, and generating a high-voltage DC voltage for supplying power to a plurality of power boards; the control board is used for communicating with an upper computer, and a core board is arranged on the control board; the core board is used for performing voltage protection, current protection and temperature protection on the motor driver and the permanent magnet synchronous motor, sampling a rotor position signal of the permanent magnet synchronous motor, generating a PWM control signal based on the rotor position signal and a control instruction, and transmitting the PWM control signal to the power board; each power board is provided with an intelligent power module, and the power boards are used for supplying power to the intelligent power modules; and the intelligent power module is used for converting the high-voltage direct-current voltage into a three-phase alternating-current voltage by taking the PWM control signal as a driving signal so as to drive the permanent magnet synchronous motor to rotate. The multi-split motor driver provided by the embodiment of the invention can meet the requirement of driving a plurality of motors.

Description

Technical Field

[0001] The present invention relates to the technical field of motor driving, and in particular to a one-to-many motor driver. Background Art

[0002] In recent years, with the continuous development of electric drive related technologies, electric drive platforms have become the mainstream technical route for various large-scale equipment. Traditional actuators such as hydraulic cylinders and mechanical drive axles have gradually been replaced by electric actuators. Faced with a large number of electric actuators in equipment, it is necessary to carry out research on multi-motor drive technology. The patent with publication number CN118413132A proposes a motor drive circuit for electric car doors, which uses a microcontroller unit (MCU) as the main control chip to drive two H-bridge drive modules, thereby realizing the drive of two DC motors. However, in application scenarios with a large number of motors, the number of motor drivers required to achieve motor drive through a one-to-two motor driver is large, which occupies a large structural space and is costly.

[0003] Patent publication number CN117499175A proposes a multi-motor synchronous control method based on a heterogeneous TSN and EtherCAT network. In this method, an industrial computer serves as the host controller, and each motor driver is connected to the bus as a communication node. The host controller issues control commands via the bus. However, the large number of communication nodes leads to a high bus load. Furthermore, the communication delay between the host computer and each motor driver is long, resulting in a slow system response. Conventional DSPs or single-chip microcomputers have limited hardware resources and can only meet the needs of driving one or two motors, making them difficult to use for a wider range of motors. Summary of the Invention

[0004] In view of the above problems, an embodiment of the present invention provides a one-to-multiple motor driver to solve the problems in the prior art of requiring a large number of motor drivers to realize motor driving, a high bus load rate, and a slow system response speed.

[0005] In a first aspect, an embodiment of the present invention provides a one-to-multiple motor driver, characterized in that the motor driver comprises:

[0006] A capacitor board is provided with a rectifier and filter module for rectifying and filtering the input voltage to generate a high-voltage DC voltage to power multiple power boards. The input voltage is a DC input voltage or a three-phase AC input voltage;

[0007] A control board is used to communicate with the host computer, and a core board is provided on the control board;

[0008] The core board is used to perform voltage protection, current protection and temperature protection on the motor driver and the permanent magnet synchronous motor, and is also used to sample the rotor position signal of the permanent magnet synchronous motor, generate a pulse width modulation (PWM) control signal based on the rotor position signal and a control instruction, and transmit the PWM control signal to the power board; the control instruction includes a target position instruction, a target speed instruction or a target current instruction;

[0009] The multiple power boards, each of which is provided with an intelligent power module, the power board is used to convert the high-voltage DC voltage into a low-voltage DC voltage to power the intelligent power module;

[0010] The intelligent power module is used to convert the high-voltage DC voltage into a three-phase AC voltage using the PWM control signal as a driving signal to drive the permanent magnet synchronous motor to rotate. Each intelligent power module corresponds to a permanent magnet synchronous motor.

[0011] In one possible implementation, the core board is specifically used to sample the voltage signal, current signal and temperature signal at the rising edge of each synchronization signal. When at least one of the voltage sampling value, current sampling value and temperature sampling value reaches the protection threshold, the operation is stopped, an alarm message is generated, and the alarm message is sent to the host computer.

[0012] In one possible implementation, the core board is specifically used to sample and calculate the position of the rotor position signal at the rising edge of each synchronization signal to obtain rotor position information; based on the rotor position information, position loop calculation, speed loop calculation, current loop calculation and space vector pulse width modulation (SVPWM) calculation are performed in sequence to generate a PWM control signal.

[0013] In a possible implementation, a synchronization signal is generated at a peak and a trough of a PWM triangular carrier wave.

[0014] In a possible implementation, synchronization signals of different permanent magnet synchronous motors have a configurable phase difference.

[0015] In a possible implementation, the control board and the host computer implement communication and transmission via Ethernet communication, serial port communication, or controller area network (CAN) communication.

[0016] In a possible implementation, the core board includes a field programmable gate array (FPGA) chip, a crystal oscillator, a Flash memory, and a double data rate synchronous dynamic random access memory (DDR SDRAM).

[0017] In a possible implementation, a soft start circuit is further provided on the capacitor plate, and the soft start circuit is used to avoid a large current impact during a startup process.

[0018] In one possible implementation, the motor driver further includes a first auxiliary power board, a second auxiliary power board, and a control power board, and the capacitor board is further used to supply power to the first auxiliary power board and the second auxiliary power board;

[0019] The first auxiliary power supply board is used to convert the high-voltage DC voltage into a low-voltage DC control voltage to power the driver board and the soft start circuit;

[0020] The second auxiliary power board is used to convert the high-voltage DC voltage into a first low-voltage DC voltage to supply power to the control power board;

[0021] The control power supply board is used to convert the first low-voltage DC voltage into a second low-voltage DC voltage to power the control board and the position feedback device.

[0022] In a possible implementation, the position feedback device is a rotary transformer or an absolute encoder.

[0023] In the technical solution provided by the embodiment of the present invention, a one-to-multiple motor driver is designed based on an FPGA chip. The FPGA chip has rich hardware resources and fast program execution speed, which can meet the needs of driving multiple motors. This enables one motor driver to control multiple motors at the same time, reducing the number of motor drivers required for the electric drive platform and reducing the size of the motor driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A connection diagram of a one-to-multi-motor driver provided by an embodiment of the present invention.

[0025] Figure 2 A timing diagram of a motor driver provided by an embodiment of the present invention.

[0026] Figure 3 A schematic diagram of a synchronization signal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more clear and understandable, the present invention is further described below with reference to the accompanying drawings and specific embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] Figure 1 A connection diagram of a one-to-multiple motor driver provided by an embodiment of the present invention is shown in FIG. Figure 1As shown, the motor driver includes a capacitor board, a control board, a core board, and multiple power boards. The capacitor board is equipped with a rectifier and filter module, which is used to rectify and filter the input voltage to generate a high-voltage DC voltage to power the multiple power boards. The input voltage can be DC or AC. The rectifier and filter module includes busbar capacitors and a three-phase rectifier bridge. The DC input voltage is 450V to 750V DC, and the AC input voltage is 380V ± 15%. A control board is used to communicate with the host computer. A core board is provided on the control board, and the control board and the core board are connected through an inter-board connector; the core board is used to perform voltage protection, current protection and temperature protection on the motor driver and the permanent magnet synchronous motor, and is also used to sample the rotor position signal of the permanent magnet synchronous motor, generate a pulse width modulation (PWM) control signal based on the rotor position signal and the control instruction, and transmit the PWM control signal to the power board; multiple power boards, each of which is provided with an intelligent power module, the power board is used to convert high-voltage DC voltage into low-voltage DC voltage to power the intelligent power module; the intelligent power module is used to use the PWM control signal as the drive signal to convert the high-voltage DC voltage into a three-phase AC voltage to drive the permanent magnet synchronous motor to rotate, and each intelligent power module corresponds to a permanent magnet synchronous motor.

[0029] In an embodiment of the present invention, the core board is specifically used to sample the voltage signal, current signal and temperature signal at the rising edge of each synchronization signal. When at least one of the voltage sampling value, current sampling value and temperature sampling value reaches the protection threshold, the operation is stopped, an alarm message is generated, and the alarm message is sent to the host computer.

[0030] In an embodiment of the present invention, the core board is specifically used to sample and calculate the rotor position signal at the rising edge of each synchronization signal to obtain rotor position information; based on the rotor position information, the position loop calculation, speed loop calculation, current loop calculation and space vector pulse width modulation (SVPWM) calculation are performed in sequence to generate a PWM control signal.

[0031] Specifically, the control command includes a target position command, a target speed command, or a target current command. Permanent magnet synchronous motors have three control modes: position mode, speed mode, and current mode. In position mode, the manually set target rotor position is input into the position loop, which calculates and outputs the target speed command. The target speed command is input into the speed loop, which calculates and outputs the target current command. In speed mode, the manually set target speed is input into the speed loop, which calculates and outputs the target current command. In current mode, the target current command is generated based on the manually set target current.

[0032] Figure 2 A timing diagram of a motor driver provided by an embodiment of the present invention, such as Figure 2 As shown, a synchronization signal is generated once at the peak and trough of the PWM triangle carrier wave, that is, a synchronization signal is generated once when the counter of the PWM triangle carrier wave reaches zero and a synchronization signal is generated once when the counter reaches the maximum value. In this embodiment of the present invention, by generating two synchronization signals within one cycle, the core board can update the PWM count value twice within one cycle, thereby optimizing the motor control effect.

[0033] like Figure 2 As shown, the temperature protection process, current protection process, voltage protection process, and PWM control process are executed in parallel in terms of timing, and the various links in each process are executed in series in terms of timing. The temperature protection process includes temperature sampling and overheat protection, the current protection process includes current sampling and overcurrent protection, the voltage protection process includes voltage sampling and overvoltage protection, and the PWM control process includes position sampling, position solution, position loop calculation, velocity loop calculation, current loop calculation, and SVPWM calculation. The completion signal of the current link serves as the start signal for the next link. For example, in the temperature protection process, the temperature sampling link and the overheat protection link are executed in series. After the temperature sampling link is completed, the completion signal of the temperature sampling link serves as the start signal for the overheat protection link, and the overheat protection link is entered. In the embodiments of the present invention, the characteristics of the field programmable gate array (FPGA) chip are utilized to execute multiple processes in parallel in terms of timing, thereby improving control efficiency.

[0034] In an embodiment of the present invention, a motor driver including four power boards and four permanent magnet synchronous motors is described as an example. In this case, the motor driver is a one-to-four motor driver. The four power boards include a first power board, a second power board, a third power board, and a fourth power board. The four permanent magnet synchronous motors are a first permanent magnet synchronous motor, a second permanent magnet synchronous motor, a third permanent magnet synchronous motor, and a fourth permanent magnet synchronous motor. A first intelligent power module is provided on the first power board, and the first intelligent power module is used to drive the first permanent magnet synchronous motor; a second intelligent power module is provided on the second power board, and the second intelligent power module is used to drive the second permanent magnet synchronous motor; a third intelligent power module is provided on the third power board, and the third intelligent power module is used to drive the third permanent magnet synchronous motor; and a fourth intelligent power module is provided on the fourth power board, and the fourth intelligent power module is used to drive the fourth permanent magnet synchronous motor.

[0035] Figure 3 A schematic diagram of a synchronization signal provided by an embodiment of the present invention, such as Figure 3As shown, there is at least one configurable phase difference (i.e., T) between the synchronization signals of different permanent magnet synchronous motors, the synchronization signal of the first permanent magnet synchronous motor leads the synchronization signal of the second permanent magnet synchronous motor by a phase difference, the synchronization signal of the second permanent magnet synchronous motor leads the synchronization signal of the third permanent magnet synchronous motor by a phase difference, and the synchronization signal of the third permanent magnet synchronous motor leads the synchronization signal of the fourth permanent magnet synchronous motor by a phase difference.

[0036] It should be noted that the phase difference refers to the phase difference between the rising edges of different synchronization signals, or the phase difference between the falling edges of different synchronization signals, and does not refer to the phase difference between the rising edge of one synchronization signal and the falling edge of another synchronization signal. In other words, there is at least one configurable phase difference between the rising edges of the synchronization signals of different permanent magnet synchronous motors, or there is at least one configurable phase difference between the falling edges of the synchronization signals of different permanent magnet synchronous motors.

[0037] In an embodiment of the present invention, by setting a phase difference between the synchronization signals of different permanent magnet synchronous motors, there is a corresponding delay in the opening time of the drive bridge arms corresponding to different permanent magnet synchronous motors, thereby avoiding electromagnetic interference caused by the simultaneous opening of the drive bridge arms of multiple permanent magnet synchronous motors.

[0038] In an embodiment of the present invention, a phase difference is set by a host computer, and the phase difference is less than a preset threshold. For example, the preset threshold is 1 / 60000s. Communication between the control board and the host computer is achieved through Ethernet communication, serial communication, or Controller Area Network (CAN) communication. In actual applications, the preset threshold can be set based on motor control requirements, which is not limited in the embodiment of the present invention.

[0039] In the present embodiment, the core board is the minimum system required for the FPGA chip to run the program, and its functions are relatively fixed. The core board includes the FPGA chip, crystal oscillator, Flash memory, and Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM). The core board is connected to the control board via an inter-board connector. The core board can be connected to different control boards according to actual application requirements to achieve different control functions.

[0040] In the embodiment of the present invention, a soft start circuit is further provided on the capacitor board, and the soft start circuit is used to avoid a large current impact during the startup process.

[0041] In an embodiment of the present invention, the motor driver further includes a first auxiliary power board, a second auxiliary power board, and a control power board, and the capacitor board is also used to supply power to the first auxiliary power board and the second auxiliary power board. The first auxiliary power board is used to convert the high-voltage DC voltage into a low-voltage DC control voltage to supply power to the drive board and the soft start circuit; the second auxiliary power board is used to convert the high-voltage DC voltage into a first low-voltage DC voltage to supply power to the control power board; and the control power board is used to convert the first low-voltage DC voltage into a second low-voltage DC voltage to supply power to the control board and the position feedback device. The position feedback device is a rotary transformer or an absolute encoder, and the position feedback device is used to collect the rotor position signal of the permanent magnet synchronous motor.

[0042] like Figure 1 As shown, different line colors represent different connection methods. Blue lines represent electrical connections via AC voltage, green lines represent electrical connections via high-voltage DC voltage, yellow lines represent electrical connections via low-voltage DC voltage, red lines represent data connections, and black lines represent communication connections. Specifically, the red lines between the control board and the first power board, the second power board, the third power board, and the fourth power board represent PWM control signals, the red lines between the control board, the position feedback device, and the permanent magnet synchronous motor represent rotor position signals, and the red lines between the control board and the drive board represent drive control signals, which are used to control the drive circuit on the drive board.

[0043] In an embodiment of the present invention, the drive board controls the drive circuit in response to a drive control signal. The drive circuit includes an indicator light drive circuit, a fan drive circuit, and a brake drive circuit. The drive board is electrically connected to the indicator light via the indicator light drive circuit for driving the indicator light; electrically connected to the fan via the fan drive circuit for driving the fan; and electrically connected to the brake via the brake drive circuit for driving the brake. The indicator light is used to indicate the drive control status of the permanent magnet synchronous motor by the intelligent power module. When the drive control status is normal, the green light is constantly on; when the drive control status is in abnormal mode, the red light is constantly on. The fan is used to dissipate heat for the motor driver, and the brake is used to brake the permanent magnet synchronous motor. The drive control status refers to whether the intelligent power module can normally drive the permanent magnet synchronous motor, that is, the state of the blue line between the intelligent power module and the permanent magnet synchronous motor.

[0044] In the technical solution provided by the embodiment of the present invention, a one-to-multiple motor driver is designed based on an FPGA chip. The FPGA chip has rich hardware resources and fast program execution speed, which can meet the needs of driving multiple motors. This enables one motor driver to control multiple motors at the same time, reducing the number of motor drivers required for the electric drive platform and reducing the size of the motor driver.

[0045] In the embodiment of the present invention, the rotor position signals and speed signals between multiple motors are transmitted through the hardware circuit inside the FPGA chip, which avoids communication delays, improves the response speed of multi-motor synchronous control, improves the control efficiency of multiple motors, and solves the problem of large communication delay in the prior art when the upper computer sends position instructions or speed instructions to each motor driver.

[0046] In the embodiment of the present invention, a resolver position calculation solution using soft decoding is adopted, eliminating the need for expensive decoding chips and reducing the cost of a single machine.

[0047] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A multi-motor driver, characterized in that: The motor driver comprises: A capacitor board is provided with a rectifier and filter module for rectifying and filtering the input voltage to generate a high-voltage DC voltage to power multiple power boards. The input voltage is a DC input voltage or a three-phase AC input voltage; A control board is used to communicate with the host computer, and a core board is provided on the control board; The core board is used to perform voltage protection, current protection and temperature protection on the motor driver and the permanent magnet synchronous motor, and is also used to sample the rotor position signal of the permanent magnet synchronous motor, generate a pulse width modulation (PWM) control signal based on the rotor position signal and a control instruction, and transmit the PWM control signal to the power board; the control instruction includes a target position instruction, a target speed instruction or a target current instruction; The multiple power boards, each of which is provided with an intelligent power module, the power board is used to convert the high-voltage DC voltage into a low-voltage DC voltage to power the intelligent power module; The intelligent power module is used to convert the high-voltage DC voltage into a three-phase AC voltage using the PWM control signal as a driving signal to drive the permanent magnet synchronous motor to rotate. Each intelligent power module corresponds to a permanent magnet synchronous motor.

2. The motor driver according to claim 1, wherein: The core board is specifically used to sample the voltage signal, current signal and temperature signal at the rising edge of each synchronization signal. When at least one of the voltage sampling value, current sampling value and temperature sampling value reaches the protection threshold, the operation is stopped, an alarm message is generated, and the alarm message is sent to the host computer.

3. The motor driver according to claim 1, wherein: The core board is specifically used to sample and calculate the position of the rotor position signal at the rising edge of each synchronization signal to obtain rotor position information; based on the rotor position information, position loop calculation, speed loop calculation, current loop calculation and space vector pulse width modulation (SVPWM) calculation are performed in sequence to generate a PWM control signal.

4. The motor driver according to claim 2 or 3, characterized in that: A synchronization signal is generated at the peak and trough of the PWM triangle carrier wave.

5. The motor driver according to claim 1, wherein: The synchronization signals of different permanent magnet synchronous motors have a configurable phase difference.

6. The motor driver according to claim 1, wherein: The control board and the host computer realize communication transmission through Ethernet communication, serial communication or controller area network (CAN) communication.

7. The motor driver according to claim 1, wherein: The core board comprises a field programmable gate array (FPGA) chip, a crystal oscillator, a Flash memory and a double rate synchronous dynamic random access memory (DDR SDRAM).

8. The motor driver according to claim 1, wherein: A soft start circuit is also provided on the capacitor plate, and the soft start circuit is used to avoid large current impact during the startup process.

9. The motor driver according to claim 8, characterized in that: The motor driver further comprises a first auxiliary power board, a second auxiliary power board and a control power board, and the capacitor board is further used to supply power to the first auxiliary power board and the second auxiliary power board; The first auxiliary power supply board is used to convert the high-voltage DC voltage into a low-voltage DC control voltage to power the driver board and the soft start circuit; The second auxiliary power board is used to convert the high-voltage DC voltage into a first low-voltage DC voltage to supply power to the control power board; The control power supply board is used to convert the first low-voltage DC voltage into a second low-voltage DC voltage to power the control board and the position feedback device.

10. The motor driver according to claim 9, characterized in that: The position feedback device is a rotary transformer or an absolute encoder.

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