A power supply circuit for a motor driver

Abstract

The utility model belongs to the technical field of electronic circuit, disclose a power supply circuit for motor driver, include: rectifier filter circuit, high pressure alarm circuit, low pressure alarm circuit, high voltage discharge does not report alarm circuit, shutdown discharge circuit, switching power supply circuit and reference voltage reference circuit, rectifier filter circuit is used for converting three -phase AC 220V input voltage into 310V DC voltage and gives motor driver power supply after, high pressure alarm circuit, the input of low pressure alarm circuit is connected with the output of rectifier filter circuit, and the output is connected with the controller, is used for high pressure alarm and low pressure alarm to the output voltage of rectifier filter circuit, high voltage discharge does not report alarm circuit, the input of shutdown discharge circuit is connected with the output of rectifier filter circuit, and the output is connected with the brake resistance, reference voltage reference circuit is used for to high pressure alarm circuit, low pressure alarm circuit output reference voltage. The utility model can improve the safety of power supply circuit of motor driver.

Description

Technical Field

[0001] This utility model belongs to the field of electronic circuit technology, and specifically relates to a power supply circuit for a motor driver. Background Technology

[0002] A motor driver is a power electronic device that connects a controller (such as an MCU, PLC, or microcontroller) to a motor. Its core function is to receive low-voltage control signals (such as speed, direction, and position commands) from the controller and convert high-voltage power (such as AC 220V or DC 24V) from the grid or power supply into drive signals that the motor can recognize. This enables precise control of the motor's speed, torque, direction, and position, while protecting the motor and control system from overload, overcurrent, and overvoltage faults. Motor drivers have wide applications in various fields, especially in industrial applications such as water treatment and the power industry where flow and air volume adjustments are required. They are also used in CNC machine tools, cranes, robots, and other equipment requiring speed control and energy saving.

[0003] However, existing power supply circuits are inadequate in terms of versatility, safety, stability, and reliability, which affects the operational stability of motor drivers. Utility Model Content

[0004] This utility model overcomes the shortcomings of existing power supply circuits in terms of versatility, safety, stability and reliability. The technical problem to be solved is to provide a power supply circuit for motor drivers that has good versatility, strong anti-interference ability and enhanced safety.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a power supply circuit for a motor driver, including: a rectifier and filter circuit, a high voltage alarm circuit, a low voltage alarm circuit, a high voltage discharge non-alarm circuit, a power-off discharge circuit, a switching power supply circuit, and a reference voltage reference circuit. The rectifier and filter circuit is used to convert the three-phase AC220V input voltage into a 310V DC voltage to power the motor driver. The input terminals of the high-voltage alarm circuit and the low-voltage alarm circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the controller. They are used to provide high-voltage and low-voltage alarms for the output voltage of the rectifier and filter circuit. The input terminals of the high-voltage discharge non-alarm circuit and the power-off discharge circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the braking resistor. The input terminal of the switching power supply circuit is connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the input terminal of the reference voltage reference circuit. It is used to output the stepped-down DC voltage to power the reference voltage reference circuit, the high-voltage discharge non-alarm circuit, and the power-off discharge circuit. The reference voltage reference circuit is used to output a reference voltage to the high-voltage alarm circuit and the low-voltage alarm circuit.

[0006] The rectifier and filter circuit is a full-wave rectifier circuit, including a three-phase silicon bridge rectifier BG1, resistors YM1, YM2, and YM3, a fuse F1, a relay switch K1, resistors RM1 and RM2, and electrolytic capacitors C53, C54, and C55. Resistors YM1, YM2, and YM3 are respectively placed between two phases of the three-phase AC 220V input voltage. The three AC input terminals of the three-phase silicon bridge rectifier BG1 are respectively connected to one phase of the three-phase AC 220V input voltage. The positive DC output terminal is connected to the positive 310V DC voltage after passing through the fuse F1 and the relay switch, and the negative DC output terminal is connected to the negative 310V DC voltage and then grounded. Electrolytic capacitors C53, C54, and C55 are connected in parallel between the positive and negative 310V DC voltage terminals.

[0007] The high-voltage alarm circuit includes resistors R35, R27, and R29, an electrolytic capacitor C67, a voltage comparator U6C, and an optocoupler O7. One end of resistor R35 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of the voltage comparator U6C. The inverting input terminal of the voltage comparator U6C is grounded after passing through resistor R27 and electrolytic capacitor C67 connected in parallel. The output terminal of the voltage comparator U6C is connected to the negative input terminal of the optocoupler O7. The positive input terminal of the optocoupler O7 is connected to the positive terminal of the power supply through resistor R29. The positive output terminal of the optocoupler O7 is connected to the controller for outputting a high-voltage alarm signal, and the negative output terminal is grounded.

[0008] The low-voltage alarm circuit includes resistors R40, R42, R38, and R43, an electrolytic capacitor C10, a voltage comparator U19D, a transistor T13, and an optocoupler O23. One end of resistor R40 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the non-inverting input of voltage comparator U19D. The non-inverting input of voltage comparator U19D is grounded via resistor R42 and electrolytic capacitor C10 connected in parallel. The inverting input of voltage comparator U19D is connected to the reference voltage output of the reference voltage reference circuit. The voltage comparator U19D is connected to the input terminal via resistor R43. The output terminal is also connected to the base of transistor T13 and the positive terminal of the 15V power supply via resistors R39 and R38. The base of transistor T13 is grounded via resistor R41, the emitter is grounded, and the collector is connected to the negative input of optocoupler O23. The positive input of optocoupler O23 is connected to the positive terminal of the 15V power supply via resistor R36 and diode DL4. The positive output of optocoupler O23 is connected to the controller for outputting a low-voltage alarm signal, and the negative output is grounded.

[0009] The power supply circuit for a motor driver further includes a resistor R37. One end of the resistor R37 is connected to the collector of the transistor T13, and the other end is connected to the positive terminal of the power supply via the coil of the relay switch K1. The relay switch K1 is located at the power output terminal of the rectifier filter circuit.

[0010] The high-voltage discharge non-alarm circuit includes resistors R144, R142, R147, R148, R143, and R145, a voltage comparator U20A, an insulated-gate bipolar transistor T6, a MOSFET gate driver U7, and capacitors C55, C113, C114, and C112. One end of resistor R144 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20A. The inverting input terminal of voltage comparator U20A is grounded after being connected in parallel with resistors R142, C55, and C113. The non-inverting input terminal of voltage comparator U20A is connected to the reference voltage output by the reference voltage reference circuit via resistor R147. The output terminal of voltage comparator U20A is connected to the non-inverting input terminal via resistor R148, and the output terminal is also connected to the positive terminal of a 15V power supply via resistor R143. The output terminal is also connected to the MOSFET gate driver U7. The input terminal of the gate driver U7 is connected; the output terminal of the MOSFET gate driver U7 is connected to the gate of the insulated gate bipolar transistor T6 via resistor R145. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R146. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D23. The two ends of the diode D23 are connected to a braking resistor.

[0011] The power-off discharge circuit includes resistors R139, R141, R120, R136, R137, R143, and R145, an electrolytic capacitor C110, a voltage comparator U20B, an insulated-gate bipolar transistor T3, and a MOSFET. Gate driver U19, capacitors C110, C111, C51, and C53; one end of resistor R139 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20B; the inverting input terminal of voltage comparator U20B is grounded via a parallel connection of Zener diode D22, resistor R141, capacitors C110 and C111; the non-inverting input terminal of voltage comparator U20B is connected via resistor R136 to one end of rectifier diodes D13, D19, and D20; the other ends of rectifier diodes D13, D19, and D20 are respectively connected to one phase of the three-phase AC 220V input voltage; the output terminal of voltage comparator U20B is connected to the input terminal of MOSFET gate driver U19; MOSFET The output terminal of the gate driver U19 is connected to the gate of the insulated gate bipolar transistor T3 via resistor R138. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R140. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D21. The two ends of the diode D21 are connected to a braking resistor.

[0012] The switching power supply circuit is used to convert 310V DC voltage into 15V DC voltage to supply power to the reference voltage reference circuit.

[0013] The reference voltage circuit includes resistors R31, R23, and R24, a voltage source V7, an electrolytic capacitor C65, and a capacitor C61. One end of resistor R31 is connected to the positive terminal of a 15V DC voltage, and the other end is grounded through the voltage source V7. The reference terminal of the voltage source V7 is connected to its cathode through resistor R24 ​​and to its anode through resistor R23. Electrolytic capacitors C65 and C61 are connected in parallel with the voltage source V7. The cathode of the voltage source V7 outputs a 5.83V reference voltage.

[0014] Compared with the prior art, the present invention has the following advantages: This utility model provides a power supply circuit for a motor driver, including: a rectifier and filter circuit, a high-voltage alarm circuit, a low-voltage alarm circuit, a high-voltage discharge without alarm circuit, a shutdown discharge circuit, a switching power supply circuit, and a reference voltage reference circuit. It can realize the safety detection of the power system during the operation of the driver, and can not only realize high-voltage and low-voltage alarms, but also realize high-voltage discharge and shutdown discharge, thus improving the safety of the circuit. Attached Figure Description

[0015] Figure 1 A structural block diagram of a power supply circuit for a motor driver provided for an embodiment of this utility model; Figure 2 This is a circuit diagram of the rectifier and filter circuit in an embodiment of this utility model; Figure 3 This is a circuit diagram of the high-voltage alarm circuit in an embodiment of this utility model; Figure 4 This is a circuit diagram of the low-voltage alarm circuit in an embodiment of this utility model; Figure 5 This is a circuit diagram of the high-voltage discharge non-alarm circuit in this embodiment of the utility model; Figure 6 This is a circuit diagram of the power-off discharge circuit in an embodiment of this utility model; Figure 7 This is a circuit diagram of the switching power supply circuit in an embodiment of this utility model; Figure 8 This is a circuit diagram of the reference voltage reference circuit in an embodiment of this utility model. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] like Figure 1As shown in the figure, this utility model embodiment provides a power supply circuit for a motor driver, including: a rectifier and filter circuit, a high-voltage alarm circuit, a low-voltage alarm circuit, a high-voltage discharge non-alarm circuit, a shutdown discharge circuit, a switching power supply circuit, and a reference voltage reference circuit. The rectifier and filter circuit is used to convert the three-phase AC220V input voltage into a 310V DC voltage to power the motor driver. The input terminals of the high-voltage alarm circuit and the low-voltage alarm circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the controller, used to provide high-voltage and low-voltage alarms for the output voltage of the rectifier and filter circuit. The input terminal of the high-voltage discharge non-alarm circuit and the shutdown discharge circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the braking resistor. The input terminal of the switching power supply circuit is connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the input terminal of the reference voltage reference circuit, used to output a stepped-down DC voltage to power the reference voltage reference circuit, the high-voltage discharge non-alarm circuit, and the shutdown discharge circuit. The reference voltage reference circuit is used to output a reference voltage to the high-voltage alarm circuit and the low-voltage alarm circuit.

[0018] like Figure 2 As shown, in this embodiment, the rectifier and filter circuit is a full-wave rectifier circuit, including a three-phase silicon bridge rectifier BG1, resistors YM1, YM2, and YM3, a fuse F1, a relay switch K1, resistors RM1 and RM2, and electrolytic capacitors C53, C54, and C55. Resistors YM1, YM2, and YM3 are respectively disposed between two phases of the three-phase AC220V input voltage. The three AC input terminals of the three-phase silicon bridge rectifier BG1 are respectively connected to one phase of the three-phase AC220V input voltage. The positive DC output terminal is connected to the positive 310V DC voltage after passing through the fuse F1 and the relay switch K1. The negative DC output terminal is connected to the negative 310V DC voltage and then grounded. Electrolytic capacitors C53, C54, and C55 are connected in parallel between the positive and negative 310V DC voltage terminals. The rectifier and filter circuit converts three-phase AC 220V AC power into 310V DC voltage. Resistors RM1 and RM2 are connected in parallel across relay switch K1 for initial start-up conduction.

[0019] like Figure 3As shown, in this embodiment, the high-voltage alarm circuit includes resistors R35, R27, and R29, an electrolytic capacitor C67, a voltage comparator U6C, and an optocoupler O7. One end of resistor R35 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U6C. The non-inverting input terminal of voltage comparator U6C is connected to the reference voltage output by the reference voltage reference circuit. The inverting input terminal of voltage comparator U6C is grounded after passing through resistor R27 and electrolytic capacitor C67 connected in parallel. The output terminal of voltage comparator U6C is connected to the negative input of optocoupler O7. The positive input terminal of optocoupler O7 is connected to the positive terminal of the power supply through resistor R29. The positive output terminal of optocoupler O7 is connected to the controller for outputting a high-voltage alarm signal, and the negative output terminal is grounded.

[0020] Specifically, in this embodiment, R35 = 470 kΩ and R27 = 7.15 kΩ.

[0021] In this embodiment, a high-voltage alarm can be achieved through the voltage comparator U6C. When the three-phase AC220V voltage is higher than the standard voltage by 25%, the voltage at the inverting input terminal of the voltage comparator U6C is higher than the voltage at the non-inverting input terminal (5.83V reference voltage), and its output terminal outputs a low-level signal. Then, the optocoupler O7 is turned on and outputs the high-voltage alarm signal ALMH.

[0022] like Figure 4 As shown, in this embodiment, the low-voltage alarm circuit includes resistors R40, R42, R38, and R43, an electrolytic capacitor C10, a voltage comparator U19D, a transistor T13, and an optocoupler O23. One end of resistor R40 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the non-inverting input of voltage comparator U19D. The non-inverting input of voltage comparator U19D is grounded via resistor R42 and electrolytic capacitor C10 connected in parallel. The inverting input of voltage comparator U19D is connected to the reference voltage reference circuit. The reference voltage is connected; the output terminal of the voltage comparator U19D is connected to the input terminal via resistor R43, and the output terminal is also connected to the base of transistor T13 and the positive terminal of the 15V power supply via resistors R39 and R38; the base of transistor T13 is grounded via resistor R41, the emitter is grounded, the collector is connected to the negative input of optocoupler O23, the positive input of optocoupler O23 is connected to the positive terminal of the 15V power supply via resistor R36 and diode DL4, the positive output of optocoupler O23 is connected to the controller for outputting a low-voltage alarm signal, and the negative output is grounded.

[0023] Specifically, in this embodiment, R140 = 470kΩ and R142 = 15kΩ.

[0024] In this embodiment, a low-voltage alarm can be implemented through the voltage comparator U19D. When the three-phase AC220V voltage is lower than the standard voltage by 25%, the voltage at the inverting input terminal of the voltage comparator U19D (reference voltage 5.83V) is higher than that at the non-inverting input terminal, and its output terminal outputs a low-level signal. Then, the transistor T13 is cut off, causing the optocoupler O23 to be cut off, and a low-voltage alarm signal ALML is output to the outside.

[0025] Furthermore, a power supply circuit for a motor driver in this embodiment also includes a resistor R37. One end of the resistor R37 is connected to the collector of the transistor T13, and the other end is connected to the positive terminal of the power supply via the coil of the relay switch K1. The relay switch K1 is located at the power output terminal of the rectifier filter circuit.

[0026] Furthermore, such as Figure 5 As shown, in this embodiment, the high-voltage discharge non-alarm circuit includes resistors R144, R142, R147, R148, R143, and R145, a voltage comparator U20A, an insulated-gate bipolar transistor T6, a MOSFET gate driver U7, capacitors C55, C113, C114, and C112. One end of resistor R144 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20A. The inverting input terminal of voltage comparator U20A is grounded after being connected in parallel with resistors R142, capacitors C55 and C113. The non-inverting input terminal of voltage comparator U20A is connected to the reference voltage output by the reference voltage reference circuit through resistor R147. The output terminal of voltage comparator U20A is connected to the non-inverting input terminal through resistor R148, and the output terminal is also connected to the positive terminal of a 15V power supply through resistor R143. The output terminal is also connected to the MOSFET gate driver U7. The input terminal of the gate driver U7 is connected; the output terminal of the MOSFET gate driver U7 is connected to the gate of the insulated gate bipolar transistor T6 via resistor R145. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R146. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D23. The two ends of the diode D23 are connected to a braking resistor.

[0027] Specifically, in this embodiment, R144 = 470kΩ and R142 = 7.5kΩ.

[0028] In this embodiment, the voltage comparator U20A can achieve high-voltage discharge without alarm. When the three-phase AC220V voltage is more than 20% higher than the standard voltage, the voltage at the inverting input terminal of the voltage comparator U20A (reference voltage 5.83V) is higher than the voltage at the non-inverting input terminal, and its output terminal outputs a low-level signal. This signal is then flipped to a high-level signal by the MOSFET gate driver U7, thereby driving the insulated gate bipolar transistor T6 to conduct, which in turn causes the braking resistor to conduct and discharge.

[0029] Furthermore, such as Figure 6 As shown, in this embodiment, the power-off discharge circuit includes resistors R139, R141, R120, R136, R137, R143, and R145, an electrolytic capacitor C110, a voltage comparator U20B, an insulated-gate bipolar transistor T3, and a MOSFET. Gate driver U19, capacitors C110, C111, C51, and C53; one end of resistor R139 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20B; the inverting input terminal of voltage comparator U20B is grounded via a parallel connection of Zener diode D22, resistor R141, capacitors C110 and C111; the non-inverting input terminal of voltage comparator U20B is connected via resistor R136 to one end of rectifier diodes D13, D19, and D20; the other ends of rectifier diodes D13, D19, and D20 are respectively connected to one phase of the three-phase AC 220V input voltage; the output terminal of voltage comparator U20B is connected to the input terminal of MOSFET gate driver U19; MOSFET The output terminal of the gate driver U19 is connected to the gate of the insulated gate bipolar transistor T3 via resistor R138. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R140. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D21. The two ends of the diode D21 are connected to a braking resistor.

[0030] Specifically, in this embodiment, R139 = 470kΩ and R141 = 20kΩ.

[0031] In this embodiment, power-off discharge can be achieved through voltage comparator U20B. When the power system is powered off, the non-inverting input voltage of voltage comparator U20B is zero, and its output terminal outputs a low-level signal. This signal is then flipped to a high-level signal by MOSFET gate driver U19, thereby driving the insulated gate bipolar transistor T3 to conduct, which in turn causes the braking resistor to conduct and discharge.

[0032] Specifically, voltage comparators U20B, U20A, U19D, and U6C can be four-channel voltage comparators LM339. MOSFET gate drivers U7 and U19 can be TPS2816. Insulated-gate bipolar transistors T3 and T6 can be IRG4BC30S. Diodes 23 and D21 can be rectifier diodes.

[0033] Furthermore, such as Figure 7 As shown, in this embodiment, the switching power supply circuit is used to convert the 310V DC voltage into multiple low-voltage DC voltages to power other components in the circuit, including a 15V DC voltage and a 5V DC voltage. The 15V DC voltage is then used to power the reference voltage circuit.

[0034] Furthermore, such as Figure 8 As shown, the reference voltage reference circuit includes resistors R31, R23, and R24, a voltage source V7, an electrolytic capacitor C65, and a capacitor C61. One end of resistor R31 is connected to the positive terminal of a 15V DC voltage, and the other end is grounded through the voltage source V7. The reference terminal of the voltage source V7 is connected to its cathode through resistor R24 ​​and to its anode through resistor R23. Electrolytic capacitors C65 and C61 are connected in parallel with the voltage source V7. The cathode of the voltage source V7 outputs a 5.83V reference voltage for use by the high-voltage alarm circuit, the low-voltage alarm circuit, and the high-voltage discharge non-alarm circuit.

[0035] In summary, this utility model provides a power supply circuit for a motor driver, which can not only provide driving power to the driver, but also realize the safety detection of the power system during the operation of the driver, thereby improving the safety of the system.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A power supply circuit for a motor driver, characterized in that, include: The circuit includes a rectifier and filter circuit, a high-voltage alarm circuit, a low-voltage alarm circuit, a high-voltage discharge non-alarm circuit, a power-off discharge circuit, a switching power supply circuit, and a reference voltage reference circuit. The rectifier and filter circuit is used to convert the three-phase AC220V input voltage into 310V DC voltage to power the motor driver. The input terminals of the high-voltage alarm circuit and the low-voltage alarm circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the controller. They are used to provide high-voltage and low-voltage alarms for the output voltage of the rectifier and filter circuit. The input terminals of the high-voltage discharge non-alarm circuit and the power-off discharge circuit are connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the braking resistor. The input terminal of the switching power supply circuit is connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the input terminal of the reference voltage reference circuit. It is used to output the stepped-down DC voltage to power the reference voltage reference circuit, the high-voltage discharge non-alarm circuit, and the power-off discharge circuit. The reference voltage reference circuit is used to output a reference voltage to the high-voltage alarm circuit and the low-voltage alarm circuit.

2. The power supply circuit for a motor driver according to claim 1, characterized in that, The rectifier and filter circuit is a full-wave rectifier circuit, including a three-phase silicon bridge rectifier BG1, resistors YM1, YM2, and YM3, a fuse F1, a relay switch K1, resistors RM1 and RM2, and electrolytic capacitors C53, C54, and C55. Resistors YM1, YM2, and YM3 are respectively placed between two phases of the three-phase AC 220V input voltage. The three AC input terminals of the three-phase silicon bridge rectifier BG1 are respectively connected to one phase of the three-phase AC 220V input voltage. The positive DC output terminal is connected to the positive 310V DC voltage after passing through the fuse F1 and the relay switch, and the negative DC output terminal is connected to the negative 310V DC voltage and then grounded. Electrolytic capacitors C53, C54, and C55 are connected in parallel between the positive and negative 310V DC voltage terminals.

3. A power supply circuit for a motor driver according to claim 1, characterized in that, The high-voltage alarm circuit includes resistors R35, R27, and R29, an electrolytic capacitor C67, a voltage comparator U6C, and an optocoupler O7. One end of resistor R35 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of the voltage comparator U6C. The inverting input terminal of the voltage comparator U6C is grounded after passing through resistor R27 and electrolytic capacitor C67 connected in parallel. The output terminal of the voltage comparator U6C is connected to the negative input terminal of the optocoupler O7. The positive input terminal of the optocoupler O7 is connected to the positive terminal of the power supply through resistor R29. The positive output terminal of the optocoupler O7 is connected to the controller for outputting a high-voltage alarm signal, and the negative output terminal is grounded.

4. A power supply circuit for a motor driver according to claim 1, characterized in that, The low-voltage alarm circuit includes resistors R40, R42, R38, and R43, an electrolytic capacitor C10, a voltage comparator U19D, a transistor T13, and an optocoupler O23. One end of resistor R40 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the non-inverting input of voltage comparator U19D. The non-inverting input of voltage comparator U19D is grounded via resistor R42 and electrolytic capacitor C10 connected in parallel. The inverting input of voltage comparator U19D is connected to the reference voltage output of the reference voltage reference circuit. The voltage comparator U19D is connected to the input terminal via resistor R43. The output terminal is also connected to the base of transistor T13 and the positive terminal of the 15V power supply via resistors R39 and R38. The base of transistor T13 is grounded via resistor R41, the emitter is grounded, and the collector is connected to the negative input of optocoupler O23. The positive input of optocoupler O23 is connected to the positive terminal of the 15V power supply via resistor R36 and diode DL4. The positive output of optocoupler O23 is connected to the controller for outputting a low-voltage alarm signal, and the negative output is grounded.

5. A power supply circuit for a motor driver according to claim 4, characterized in that, It also includes a resistor R37, one end of which is connected to the collector of transistor T13, and the other end is connected to the positive terminal of the power supply via the coil of relay switch K1. The relay switch K1 is located at the power output terminal of the rectifier filter circuit.

6. A power supply circuit for a motor driver according to claim 1, characterized in that, The high-voltage discharge non-alarm circuit includes resistors R144, R142, R147, R148, R143, and R145, a voltage comparator U20A, an insulated-gate bipolar transistor T6, a MOSFET gate driver U7, and capacitors C55, C113, C114, and C112. One end of resistor R144 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20A. The inverting input terminal of voltage comparator U20A is grounded after being connected in parallel with resistors R142, C55, and C113. The non-inverting input terminal of voltage comparator U20A is connected to the reference voltage output by the reference voltage reference circuit via resistor R147. The output terminal of voltage comparator U20A is connected to the non-inverting input terminal via resistor R148, and the output terminal is also connected to the positive terminal of a 15V power supply via resistor R143. The output terminal is also connected to the MOSFET gate driver U7. The input terminal of the gate driver U7 is connected; the output terminal of the MOSFET gate driver U7 is connected to the gate of the insulated gate bipolar transistor T6 via resistor R145. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R146. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D23. The two ends of the diode D23 are connected to a braking resistor.

7. A power supply circuit for a motor driver according to claim 1, characterized in that, The power-off discharge circuit includes resistors R139, R141, R120, R136, R137, R143, and R145, an electrolytic capacitor C110, a voltage comparator U20B, an insulated-gate bipolar transistor T3, and a MOSFET. Gate driver U19, capacitors C110, C111, C51, and C53; one end of resistor R139 is connected to the positive terminal of a 310V DC voltage, and the other end is connected to the inverting input terminal of voltage comparator U20B; the inverting input terminal of voltage comparator U20B is grounded via a parallel connection of Zener diode D22, resistor R141, capacitors C110 and C111; the non-inverting input terminal of voltage comparator U20B is connected via resistor R136 to one end of rectifier diodes D13, D19, and D20; the other ends of rectifier diodes D13, D19, and D20 are respectively connected to one phase of the three-phase AC 220V input voltage; the output terminal of voltage comparator U20B is connected to the input terminal of MOSFET gate driver U19; MOSFET The output terminal of the gate driver U19 is connected to the gate of the insulated gate bipolar transistor T3 via resistor R138. The gate of the insulated gate bipolar transistor T6 is grounded via resistor R140. The emitter of the insulated gate bipolar transistor T6 is grounded. The collector is connected to the positive terminal of the 310V DC voltage through diode D21. The two ends of the diode D21 are connected to a braking resistor.

8. A power supply circuit for a motor driver according to claim 1, characterized in that, The switching power supply circuit is used to convert 310V DC voltage into 15V DC voltage to supply power to the reference voltage reference circuit.

9. A power supply circuit for a motor driver according to claim 1, characterized in that, The reference voltage circuit includes resistors R31, R23, and R24, a voltage source V7, an electrolytic capacitor C65, and a capacitor C61. One end of resistor R31 is connected to the positive terminal of a 15V DC voltage, and the other end is grounded through the voltage source V7. The reference terminal of the voltage source V7 is connected to its cathode through resistor R24 ​​and to its anode through resistor R23. Electrolytic capacitors C65 and C61 are connected in parallel with the voltage source V7. The cathode of the voltage source V7 outputs a 5.83V reference voltage.

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