Motor control system

Abstract

The utility model provides a motor control system. The motor control system comprises a first switching device, an energy storage device and a switching power supply. The first end of the first switching device is connected with the anode of the battery pack, the second end of the first switching device is connected with the first end of the energy storage device, and the second end of the energy storage device is connected with the cathode of the battery pack; the switching power supply is connected in parallel to two ends of the energy storage device; and the switching power supply is used for supplying power to a control circuit in the motor control system through the energy storage device and discharging the energy storage device under the condition that the first switching device is disconnected. According to the motor control system, the switching power supply is added in the motor control system, and when the first switching device is switched off, the energy accumulated in the energy storage device is used for supplying power to the control circuit in the motor control system through the switching power supply, so that waste of the energy in the energy storage device is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric drive technical field, especially motor control system. BACKGROUND

[0002] The motor control system mainly includes a motor controller and a control circuit. The motor controller is an integrated circuit that converts the electrical energy stored in the power battery into the electrical energy required by the driving motor to control the driving motor.

[0003] When the motor controller is powered on, the control circuit is powered by the battery pack. However, when the motor controller is powered off, the control circuit needs to be powered by other power sources. SUMMARY

[0004] To solve the above problems, the motor control system provided by the embodiments of the present application uses a switching power supply to power the control circuit with the energy storage device as a power source, fully utilizes the electrical energy stored in the energy storage device, and avoids wasting the electrical energy in the energy storage device.

[0005] The embodiments of the present application disclose the following technical solutions:

[0006] The motor control system provided by the embodiments of the present application includes a first switching device, an energy storage device, and a switching power supply.

[0007] The first end of the first switching device is used to connect the positive electrode of the battery pack, the second end of the first switching device is connected to the first end of the energy storage device, and the second end of the energy storage device is used to connect the negative electrode of the battery pack.

[0008] The switching power supply is connected in parallel across the energy storage device.

[0009] The switching power supply is used to power the control circuit in the motor control system with the energy storage device as a power source when the first switching device is disconnected.

[0010] Optionally, the switching power supply includes a transformer, a switching tube, and a first rectifier circuit.

[0011] The first end of the primary winding of the transformer is connected to the first end of the energy storage device, and the second end of the primary winding of the transformer is grounded through the switching tube.

[0012] The first secondary winding of the transformer is connected to the first rectifier circuit, and the output end of the first rectifier circuit is used to power the control circuit.

[0013] Optionally, the switching power supply further includes a second rectifier circuit and a switching power supply control chip.

[0014] The second secondary winding of the transformer is connected to the second rectifier circuit, and the output end of the second rectifier circuit is used to power the switching power supply control chip.

[0015] The output of the switching power supply control chip is connected to the switching transistor to control its switching state.

[0016] Optionally, the motor control system may also include: a sampling circuit and a voltage divider circuit;

[0017] A voltage divider circuit is connected in parallel across the energy storage device;

[0018] The input terminal of the sampling circuit is connected to the voltage output terminal of the voltage divider circuit, and the output terminal of the sampling circuit is connected to the motor controller.

[0019] The motor controller is used to obtain the state of the first switching device based on the sampling voltage of the sampling circuit.

[0020] Optionally, the voltage divider circuit includes N resistors connected in series; where N is an integer greater than or equal to 2.

[0021] The first terminal of the first resistor is connected to the positive terminal of the energy storage device, and the second terminal of the Nth resistor is connected to ground.

[0022] The input terminal of the sampling circuit is connected to the first terminal of the Nth resistor.

[0023] Optionally, the switching power supply further includes: a first diode;

[0024] The anode of the first diode is connected to the output terminal of the second rectifier circuit, and the cathode of the first diode is connected to the power supply terminal of the switching power supply control chip.

[0025] The first terminal of the Nth resistor is connected to the power supply terminal of the switching power supply control chip.

[0026] Optionally, the motor control system may also include: a pre-charging circuit;

[0027] The pre-charging circuit is connected in parallel across the first switching device; wherein, the pre-charging circuit includes a second switching device and a pre-charging resistor connected in series.

[0028] Optionally, the first rectifier circuit includes a second diode, the anode of which is connected to the first secondary winding of the transformer, and the cathode of which is used to connect to the control circuit.

[0029] The second rectifier circuit includes a third diode. The anode of the third diode is connected to the second secondary winding of the transformer, and the cathode of the third diode is connected to the power supply terminal of the switching power supply control chip.

[0030] Optionally, the switching power supply may further include a first filter circuit and a second filter circuit;

[0031] The input terminal of the first filter circuit is connected to the cathode of the second diode, and the output terminal of the first filter circuit is used to power the control circuit in the motor controller.

[0032] The input of the second filter circuit is connected to the cathode of the third diode, and the output of the second filter circuit is used to power the switching power supply control chip.

[0033] Optionally, the switching power supply also includes a snubber circuit;

[0034] The absorption circuit is connected in parallel across the two ends of the primary winding of the transformer.

[0035] Optionally, the motor control system may also include: an inverter circuit;

[0036] The inverter circuit is connected in parallel across the two ends of the energy storage device, and the output of the inverter circuit is used to connect to the motor.

[0037] This application provides a motor control system, comprising: a first switching device, an energy storage device, and a switching power supply; a first terminal of the first switching device is connected to the positive terminal of a battery pack, a second terminal of the first switching device is connected to the first terminal of the energy storage device, and a second terminal of the energy storage device is connected to the negative terminal of the battery pack; an input terminal of the switching power supply is connected to the first terminal of the energy storage device; the switching power supply is used to supply power to the control circuit in the motor control system through the energy storage device when the first switching device is disconnected. The motor control system provided in this application uses the energy storage device as a power source to supply power to the control circuit of the motor control system when the energy storage device is disconnected from the battery pack, fully utilizing the electrical energy stored in the energy storage device, avoiding waste of electrical energy in the energy storage device, and also discharging the energy storage device to improve the safety of the motor controller. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of a motor control system provided in an embodiment of this application;

[0040] Figure 2 This is a schematic diagram of another motor control system provided in an embodiment of this application;

[0041] Figure 3 This is a schematic diagram of another motor control system provided in an embodiment of this application;

[0042] Figure 4 This is a schematic diagram of another motor control system provided in an embodiment of this application;

[0043] Figure 5 This is a schematic diagram of the structure of a motor control system provided in an embodiment of this application;

[0044] Figure 6 This is a schematic diagram of another motor control system provided in an embodiment of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0046] The terms "first" and "second," etc., used in the specification and claims of this utility model are used to distinguish different objects, not to describe a specific order of the objects. For example, "first rectifier circuit" and "second rectifier circuit," etc., are used to distinguish different rectifier circuits, not to describe a specific order of the rectifier circuits.

[0047] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0048] To facilitate understanding of the technical solutions of this application, the application scenarios of the embodiments of this application will be described below. The embodiments of this application do not specifically limit the specific form of the energy storage device, such as a capacitor, inductor, or supercapacitor. For ease of understanding, the application scenarios of this application will be described below using a capacitor as an example.

[0049] In electric vehicle applications, the vehicle's battery powers the motor controller, which in turn controls the motor to move according to set directions, speeds, angles, and response times. The motor controller includes a large capacitor; when the controller is powered off, the energy stored in the capacitor poses a safety hazard, thus reducing the controller's safety.

[0050] Therefore, this application provides a motor control system. By introducing a switching power supply into the motor control system, and disconnecting the capacitor from the battery pack (powering off the motor controller), the energy in the capacitor is used to power the control circuit in the motor control system, making full use of the energy accumulated in the capacitor. When the switching device is connected to the capacitor (powering on the motor controller), the energy in the battery pack can be avoided from being wasted.

[0051] The solution of this application will be described below in conjunction with other embodiments.

[0052] See Figure 1 This figure is a schematic diagram of the structure of a motor control system provided in an embodiment of this application;

[0053] like Figure 1 As shown, the motor control system includes: a first switching device K1, an energy storage device 110, and a switching power supply 120;

[0054] The first terminal of the first switching device K1 is used to connect to the positive terminal of the battery pack Udc+, and the second terminal of the first switching device K1 is connected to the first terminal of the energy storage device 110. The second terminal of the energy storage device 110 is used to connect to the negative terminal Udc- of the battery pack.

[0055] The first switching device K1 can be a controlled switching device. For example, in one possible implementation, the first switching device K1 can be a relay switch.

[0056] The energy storage device 110 can be at least one of a capacitor, an inductor, and a supercapacitor. For ease of understanding, the following embodiments will use capacitor C1 as an example to describe the motor control system.

[0057] The switching power supply 120 is connected in parallel across the energy storage device 110.

[0058] In one possible implementation, the second terminal of the energy storage device 110 is grounded, the first input terminal of the switching power supply 120 is connected to the first terminal of the energy storage device 110, and the second input terminal is connected to ground. It should be understood that the second terminal of the energy storage device 110 is grounded, and the second input terminal of the switching power supply 120 is at the same potential as ground.

[0059] The switching power supply 120 is used to supply power to the control circuit in the motor control system by using the energy storage device 110 as a power source when the first switching device K1 is turned off, and to discharge the energy storage device 110.

[0060] It should be noted that the control circuit in a motor control system may include a motor controller chip, optocouplers, operational amplifiers, communication circuits, and drive circuits for power devices.

[0061] In this embodiment, the switching power supply 120 can convert the voltage across the energy storage device 110 into a voltage suitable for the control circuit. Then, when the first switching device K1 is turned off, it converts the voltage across the energy storage device 110 into the voltage required by the control circuit to power the control circuit.

[0062] For example, the output voltage of the switching power supply 120 can be a commonly used DC voltage such as 5V, 12V and 24V. This embodiment does not limit the output voltage of the switching power supply.

[0063] In this embodiment, when the first switching device K1 is open, the voltage across the energy storage device is converted into the voltage required by the control circuit to power the control circuit. Compared to the method of discharging the energy storage device through a discharge resistor in related technologies, this embodiment fully utilizes the energy accumulated in the energy storage device when the first switching device K1 is open, avoiding waste of energy in the energy storage device; when the first switching device K1 is closed, the energy in the battery pack is used to power the control circuit, avoiding waste of energy in the battery pack. When the energy storage device is a capacitor or supercapacitor, the capacitor or supercapacitor can be discharged while utilizing the electrical energy in the energy storage device, improving the safety of the motor controller.

[0064] In addition, this embodiment omits the discharge resistor, thereby saving the heat dissipation space required due to the heat generated by the discharge resistor, which helps to reduce the size of the motor controller.

[0065] See Figure 2 The figure is a schematic diagram of another motor control system provided in an embodiment of this application.

[0066] This application describes a specific implementation of a switching power supply in a motor control system.

[0067] like Figure 2 As shown, the switching power supply 200 includes a transformer T, a switching transistor Q1, and a first rectifier circuit 210;

[0068] The first end of the primary winding of transformer T is connected to the first end of capacitor C1, and the second end of the primary winding of transformer T is grounded through switch Q1; the first secondary winding of transformer T is connected to the first rectifier circuit 210, and the output of the first rectifier circuit 210 is used to supply power to the control circuit.

[0069] The first rectifier circuit 210 converts the AC signal output from the first secondary side of the transformer T into a DC signal. The first rectifier circuit 210 can be any one or a combination of a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier circuit, and a voltage doubler rectifier circuit.

[0070] For example, when the first rectifier circuit 210 is a half-wave rectifier circuit, the anode of the diode is connected to one end of the first secondary winding, and the cathode of the diode is connected to the control circuit.

[0071] In this embodiment, the operating state of the switching power supply is controlled by the switching transistor Q1, namely, the switching power supply being turned on and off.

[0072] For example, in this embodiment, the switch Q1 can be a metal-oxide-semiconductor field-effect transistor (MOSFET). The gate of switch Q1 is connected to the primary winding of transformer T, and the drain of switch Q1 is grounded through resistor R8. In practical applications, the switching on and off of switch Q1 is controlled by a pulse width modulation (PWM) signal, thereby controlling the switching power supply.

[0073] It should be understood that in this embodiment, the voltage across capacitor C1 can be stepped down using transformer T, and the stepped-down voltage can be used to power the control circuit of the motor control system. When the first switching device K1 is turned off, the switching power supply converts the voltage across capacitor C1 into the voltage required by the control circuit to power the control circuit.

[0074] When the first switching device K1 is a relay switch, the relay switch may stick together, affecting the safety and reliability of the motor controller. Therefore, this embodiment provides another motor control system, the corresponding structural diagram of which is shown below. Figure 3 As shown.

[0075] like Figure 3 As shown, the motor control system also includes a voltage divider circuit 310 and a sampling circuit 320;

[0076] In this circuit, voltage divider circuit 310 is connected in parallel across capacitor C1; the input terminal of sampling circuit 320 is connected to the voltage output terminal of voltage divider circuit 310, and the output terminal of sampling circuit 320 is connected to motor controller. The motor controller is used to obtain the state of the first switching device K1 based on the sampled voltage from sampling circuit 320.

[0077] In one possible implementation, the voltage divider circuit 310 can be composed of N (N≥2) resistors connected in series. The first terminal of the first resistor is connected to the positive terminal of capacitor C1, and the second terminal of the Nth resistor is connected to ground. The input terminal of the sampling circuit 320 is connected to the first terminal of the Nth resistor. It should be noted that the resistance values ​​of the resistors in the voltage divider circuit 310 can be equal or unequal. This embodiment does not limit the resistance values ​​of the resistors in the sampling circuit 320.

[0078] For example, the voltage divider circuit 310 consists of four resistors (R2, R3, R4, and R5) connected in series. The first terminal of R2 is connected to the positive terminal of capacitor C1, the second terminal of R5 is grounded, and the input terminal of the sampling circuit 320 is connected to the first terminal of R5.

[0079] The output of the sampling circuit 320 is connected to the motor controller. The motor controller determines the state of the first switching device K1 based on the sampling voltage of the sampling circuit 320, thereby preventing the first switching device K1 from being stuck and improving the safety and reliability of the motor controller.

[0080] See Figure 4 This figure is a schematic diagram of another motor control system provided in this embodiment.

[0081] like Figure 4 As shown, in this motor control system, the switching power supply control chip U1 and the sampling circuit share a voltage divider circuit. The first end of R5 in the voltage divider circuit can also be connected to the power supply terminal VDD of the switching power supply control chip U1 to supply power to the switching power supply control chip U1, so that the switching power supply can complete self-starting when the first switching device K1 is closed.

[0082] In addition, the VREF terminal of the switching power supply control chip U1 is connected to ground via capacitor C7, the FB terminal is connected to ground via resistor R11, the switching power supply output voltage Vout1 is connected to the FB terminal via resistor R12; the CS terminal is connected to ground via resistor R10; the reference voltage Vref acquired at the VREF terminal is connected to the RC / CT terminal via resistor R6, the RT / CT terminal is grounded via capacitor C2; and the GND terminal is connected to ground.

[0083] It should be understood that the switching power supply control chip U1 uses the output voltage Vout1 of the first rectifier circuit, the reference voltage Vref, and the drain current MOS_S of the switching transistor Q1 to generate a PWM signal, which is a mature technology and will not be elaborated here.

[0084] For example, the switching power supply control chip U1 used in this embodiment can be a power IC chip of Texas Instruments (TI), model UCC28C42.

[0085] In this embodiment, the sampling circuit and the switching power supply control chip U1 share a voltage divider circuit, which can reduce circuit design costs and reduce circuit complexity.

[0086] See Figure 5 The figure is a schematic diagram of the structure of a motor control system provided in this embodiment.

[0087] like Figure 5As shown, the switching power supply 500 in the switching power supply control system includes a transformer T, a first rectifier circuit 510, a second rectifier circuit 520, a first diode D1, and a switching power supply control chip U1.

[0088] The transformer T includes a primary winding, a first secondary winding, and a second secondary winding. The first secondary winding is connected to the control circuit via a first rectifier circuit 510, and the output voltage of the first rectifier circuit 510 is Vout1. The second secondary winding is connected to the anode of a first diode D1 via a second rectifier circuit 520. The cathode of the first diode D1 is connected to the VDD terminal of the switching power supply control chip U1, and the output voltage of the second rectifier circuit 520 is Vout2.

[0089] It should be understood that the first rectifier circuit 510 is used to convert the AC signal output from the first secondary side of the transformer T into a DC signal; the second rectifier circuit 520 is used to convert the AC signal output from the second secondary side of the transformer T into a DC signal. Both the first rectifier circuit 510 and the second rectifier circuit 520 can be any one of a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier circuit, and a voltage doubler rectifier circuit.

[0090] For example, when the first rectifier circuit 510 is a half-wave rectifier circuit, the anode of the second diode is connected to one end of the second secondary winding, and the cathode of the second diode is connected to the control circuit of the motor control system; when the second rectifier circuit 520 is a half-wave rectifier circuit, the anode of the third diode is connected to one end of the second secondary winding, the cathode of the third diode is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the VDD terminal of the switching power supply control chip U1.

[0091] In this embodiment, by adding a first diode D1 to the switching power supply, when the first switching device K1 is closed, the first terminal of R5 in the voltage divider circuit supplies power to the switching power supply control chip U1; after the switching power supply is started, the second secondary winding supplies power to the switching power supply control chip U1, thereby reducing the complexity of the circuit design.

[0092] See Figure 6 The figure is a schematic diagram of another motor control system provided in this embodiment.

[0093] like Figure 6 As shown, the motor control system also includes a pre-charging circuit 610, and the switching power supply includes a first filter circuit 620, a second filter circuit 630, and an absorption circuit 640.

[0094] (1) The pre-charging circuit 610 is connected in parallel across the first switching device K1; wherein, the pre-charging circuit 610 includes a second switching device K2 and a pre-charging resistor R1 connected in series.

[0095] When the charging controller needs to be activated, the second switching device K2 is first closed, and the capacitor C1 is charged through the pre-charging resistor R1; when the voltage across the capacitor C1 is equal to the voltage across the battery pack, the second switching device K2 is opened, and the first switching device K1 is closed.

[0096] In this embodiment, the pre-charging circuit 610 is used to charge the capacitor C1 of the motor controller to prevent the first switching device K1 from sticking or being damaged due to large current, thereby improving the safety and reliability of the motor controller.

[0097] (2) In the switching power supply, the input terminal of the first filter circuit 620 is connected to the output terminal of the first rectifier circuit, and the output terminal of the first filter circuit 620 is used to supply power to the control circuit in the motor controller; the input terminal of the second filter circuit 630 is connected to the output terminal of the second rectifier circuit, and the output terminal of the second filter circuit 630 is used to supply power to the switching power supply control chip U1.

[0098] The first filter circuit 620 and the second filter circuit 630 can both be any one of a low-pass filter, a high-pass filter, a band-pass filter, a band-stop filter, and a notch filter.

[0099] For example, both the first filter circuit 620 and the second filter circuit 630 are RC low-pass filters. In the first filter circuit 620, the first terminal of capacitor C4 is connected to the cathode of the second diode D2, and the second terminal of C4 is connected to ground; the resistor RL in the first filter circuit 620 is connected in parallel across capacitor C4; in the second filter circuit 630, the first terminal of capacitor C5 is connected to the cathode of the third diode D3, and the second terminal of C5 is connected to ground; the resistor R9 in the second filter circuit 630 is connected in parallel across capacitor C5.

[0100] In this embodiment, the first filter circuit 620 and the second filter circuit 630 are used to filter out the ripple in the output voltage of the first rectifier circuit and the second rectifier circuit, respectively, thereby improving the stability and reliability of the motor controller. In addition, the first filter circuit 620 and the second filter circuit 630 can also extend the service life of the motor controller.

[0101] (3) In the switching power supply, the absorption circuit 640 is connected in parallel to both ends of the primary winding of the transformer T.

[0102] The absorption circuit 640 can be any one of the following: RC absorption circuit, RCD absorption circuit, LD buffer circuit, and lossless absorption circuit.

[0103] For example, the absorption circuit 640 is an RCD absorption circuit. The first end of the resistor R7 in the RCD absorption circuit is connected to the first end of the primary winding, the second end of R7 is connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is connected to the second end of the primary winding, and the capacitor C3 is connected in parallel across the two ends of the resistor R7.

[0104] In this embodiment, the absorption circuit 640 absorbs and suppresses interference from high-frequency signals. The absorption circuit can reduce the electromagnetic interference and noise level inside the motor control system, thereby improving the stability and reliability of the motor controller.

[0105] In addition, the motor control system also includes: an inverter circuit; the inverter circuit is connected in parallel across the two ends of capacitor C1, and the output of the inverter circuit is used to connect the motor.

[0106] The inverter circuit is used to convert the direct current across capacitor C1 into alternating current to drive the motor.

[0107] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0108] The above description is merely one specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A motor control system, characterized in that, include: First switching device, energy storage device, and switching power supply; The first end of the first switching device is used to connect to the positive terminal of the battery pack, the second end of the first switching device is connected to the first end of the energy storage device, and the second end of the energy storage device is used to connect to the negative terminal of the battery pack. The switching power supply is connected in parallel across the two ends of the energy storage device; The switching power supply is used to supply power to the control circuit in the motor control system by using the energy storage device as a power source when the first switching device is disconnected.

2. The motor control system according to claim 1, characterized in that, The switching power supply includes a transformer, a switching transistor, and a first rectifier circuit; The first end of the primary winding of the transformer is connected to the first end of the energy storage device, and the second end of the primary winding of the transformer is grounded through the switching transistor. The first secondary winding of the transformer is connected to the first rectifier circuit, and the output of the first rectifier circuit is used to supply power to the control circuit.

3. The motor control system according to claim 2, characterized in that, The switching power supply also includes: a second rectifier circuit and a switching power supply control chip; The second secondary winding of the transformer is connected to the second rectifier circuit, and the output of the second rectifier circuit supplies power to the switching power supply control chip. The output terminal of the switching power supply control chip is connected to the switching transistor and is used to control the switching state of the switching transistor.

4. The motor control system according to claim 3, characterized in that, The motor control system further includes: a sampling circuit and a voltage divider circuit; The voltage divider circuit is connected in parallel across the two ends of the energy storage device; The input terminal of the sampling circuit is connected to the voltage output terminal of the voltage divider circuit, and the output terminal of the sampling circuit is connected to the motor controller. The motor controller is used to obtain the state of the first switching device based on the sampling voltage of the sampling circuit.

5. The motor control system according to claim 4, characterized in that, The voltage divider circuit includes N resistors connected in series; wherein N is an integer greater than or equal to 2. The first terminal of the first resistor is connected to the positive terminal of the energy storage device, and the second terminal of the Nth resistor is connected to ground; The input terminal of the sampling circuit is connected to the first terminal of the Nth resistor.

6. The motor control system according to claim 5, characterized in that, The switching power supply further includes: a first diode; The anode of the first diode is connected to the output terminal of the second rectifier circuit, and the cathode of the first diode is connected to the power supply terminal of the switching power supply control chip. The first end of the Nth resistor is connected to the power supply terminal of the switching power supply control chip.

7. The motor control system according to claim 6, characterized in that, The motor control system further includes: a pre-charging circuit; The pre-charging circuit is connected in parallel across the first switching device; wherein, the pre-charging circuit includes a second switching device and a pre-charging resistor connected in series.

8. The motor control system according to claim 4, characterized in that, The first rectifier circuit includes a second diode, the anode of which is connected to the first secondary winding of the transformer, and the cathode of which is connected to the control circuit. The second rectifier circuit includes a third diode, the anode of which is connected to the second secondary winding of the transformer, and the cathode of which is connected to the power supply terminal of the switching power supply control chip.

9. The motor control system according to claim 8, characterized in that, The switching power supply also includes a first filter circuit and a second filter circuit. The input terminal of the first filter circuit is connected to the cathode of the second diode, and the output terminal of the first filter circuit is used to supply power to the control circuit in the motor controller. The input terminal of the second filter circuit is connected to the cathode of the third diode, and the output terminal of the second filter circuit is used to supply power to the switching power supply control chip.

10. The motor control system according to claim 9, characterized in that, The switching power supply also includes an absorption circuit; The absorption circuit is connected in parallel across the two ends of the primary winding of the transformer.

11. The motor control system according to claim 10, characterized in that, The motor control system further includes: an inverter circuit; The inverter circuit is connected in parallel across the two ends of the energy storage device, and the output of the inverter circuit is used to connect to the motor.

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