Power-on and power-off circuit of high-voltage direct-current servo system

Abstract

The invention belongs to the technical field of aircraft electric actuation systems, and particularly relates to a power-on and power-off circuit of a high-voltage direct-current servo system, which comprises a dual-redundancy power supply selection circuit, a power-on slow start circuit and a motor bus capacitor discharge circuit. According to the invention, a dual-redundancy selection design is adopted, one path of voltage meeting requirements is judged to be adopted through two paths of aircraft high-voltage direct-current power supplies, a control signal is generated, and a power-on slow start circuit is controlled to charge a motor bus capacitor based on a boost start mode; and meanwhile, a motor bus capacitor discharge circuit is also arranged to discharge electric energy in a motor bus capacitor during power-off. According to the invention, self-adaptive airplane dual-redundancy power supply selection is realized on the whole, the impact current of the high-voltage direct-current servo system can be controlled when the high-voltage direct-current servo system is powered on, the electric energy of the motor bus capacitor can be quickly discharged when the high-voltage direct-current servo system is powered off, and the safety of the high-voltage system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft electric actuation systems, and in particular relates to an upper and lower power circuit of a high-voltage direct current servo system. Background Art

[0002] With the development of avionics, the control of aircraft rudders has shifted from traditional hydraulic control to electric drive control. To ensure the mission reliability of the electric actuation system, the electric actuation system usually uses dual redundant power supply, and to improve the working efficiency of the DC servo system and reduce the size and weight of the DC servo system, the aircraft power supply has been increased from the initial tens of volts to hundreds of volts. However, when the high-voltage DC servo system is powered on, the charging of the motor bus capacitor will cause the high-voltage power supply system to short-circuit instantly, causing a large current impact on the aircraft power supply system. In addition, when the power is turned off, the energy of the bus capacitor must be discharged as soon as possible. Therefore, in order to meet the power requirements of the aviation high-voltage DC servo system, it is necessary to specially design the power-on and power-off circuits of the aviation high-voltage DC servo system. Summary of the invention

[0003] In view of this, the present invention provides a power-on and power-off circuit of a high-voltage DC servo system, which can adaptively provide dual-redundancy power supply, and can meet the requirement that the impact current of the high-voltage DC servo system when powered on is less than the impact current requirement of the aircraft high-voltage power supply system, and can quickly discharge the electric energy of the motor bus capacitor when powered off so that the voltage of the bus capacitor quickly drops to a safe voltage range.

[0004] The specific technical scheme of the present invention is:

[0005] A power-on and power-off circuit of a high-voltage DC servo system, comprising a dual-redundancy power supply selection circuit, a power-on slow start circuit, and a motor bus capacitor discharge circuit;

[0006] The input control signal of the dual-redundancy power supply selection circuit is the aircraft high-voltage DC power supply, and the output high-voltage DC gating signal is used as the input control signal of the power-on slow start circuit;

[0007] The high-voltage DC power supply input end of the power-on slow start circuit is connected to the aircraft high-voltage DC power supply, and based on the high-voltage DC gating signal, a high-voltage DC power supply end of the dual-redundancy power supply selection circuit is selected as the power supply, and the power supply is transmitted to the motor bus capacitor discharge circuit and the motor bus capacitor in a slow start manner;

[0008] The motor bus capacitor discharge circuit is connected to the motor bus capacitor and can discharge the electric energy of the motor bus capacitor when the aircraft high-voltage DC power supply is powered off.

[0009] Further, the dual-redundancy power supply selection circuit includes a diode V1, a diode V2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C1, a voltage regulator tube V3, an operational amplifier D1, an NMOS tube Q1 and an NMOS tube Q2;

[0010] The operational amplifier D1 includes D1A and D1B;

[0011] The dual-redundancy power supply selection circuit combines the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft through V1 and V2, divides the voltage through R1 and R2, and outputs the VCC power supply after being stabilized by the voltage regulator tube V3. The VCC power supply serves as the working power supply of D1; R5 and R12 are connected to the reverse input end of D1A as the sampling resistors of the first high-voltage DC power supply, and the resistors R6 and R13 are connected to the positive input end of D1A as the sampling resistors of the second high-voltage DC power supply. The operational amplifier D1A is a hysteresis comparator. When the first high-voltage DC power supply When the source voltage is higher than the second high-voltage DC power supply, D1A outputs a low level, otherwise, D1A outputs a high level; the voltage comparison signal output by D1A is input to the voltage follower D1B via R9, and after being driven by D1B, is input to the inverter circuit composed of resistors R8, R10, R3 and Q1, and the second pin of Q1 is used as the first high-voltage DC power supply selection signal; the first high-voltage DC power supply selection signal is input to the inverter circuit composed of R11, R4 and Q2, and the second pin of Q2 is used as the second high-voltage DC power supply selection signal.

[0012] Furthermore, in the dual-redundancy power supply selection circuit: when the voltage of the first high-voltage DC power supply is higher than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is high level, and the second high-voltage DC power supply selection signal is low level; conversely, when the voltage of the first high-voltage DC power supply is lower than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is low level, and the second high-voltage DC power supply selection signal is high level, and the two selection signals are mutually exclusive.

[0013] Further, the power-on slow start circuit includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a voltage regulator tube V5, a voltage regulator tube V7, a PMOS tube Q3, a PMOS tube Q5, a transistor Q4, a transistor Q6, a diode V4, and a diode V6;

[0014] The power-on slow start circuit performs slow start power-on on the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft respectively; the first high-voltage DC power supply and the first high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of R15, R16, R17, R18, C2, C3, V5, Q3 and Q4; the second high-voltage DC power supply and the second high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of R19, R20, R21, R22, C4, C5, V7, Q5 and Q6.

[0015] Furthermore, in the power-on slow start circuit: when the first high-voltage DC power supply selection signal is at a high level, Q4 is turned on so that Q3 is slowly turned on, and the first high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through Q3 and V4, and the second high-voltage DC power supply selection signal is at a low level, Q6 is turned off so that Q5 is turned off, and the second high-voltage DC power supply is disconnected; when the second high-voltage DC power supply selection signal is at a high level, Q6 is turned on so that Q5 is slowly turned on, and the second high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through Q5 and V6, and the first high-voltage DC power supply selection signal is at a low level, Q4 is turned off so that Q3 is turned off, and the first high-voltage DC power supply is disconnected.

[0016] Furthermore, the motor bus capacitor discharge circuit includes a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C6, a voltage regulator tube V9 and a PMOS tube Q7;

[0017] In the motor bus capacitor discharge circuit: when the high-voltage DC power supply is input to the motor bus capacitor, the motor bus capacitor is charged. At the same time, the high-voltage DC power supply is input to the motor bus capacitor discharge circuit and connected to the source of Q7 and the motor bus capacitor via V8 and R23. The gate-source voltage of Q7 cannot meet the conduction condition of Q7, and Q7 is cut off, which does not affect the charging and normal operation of the motor bus capacitor. After the high-voltage DC servo system ends normal operation, the first high-voltage DC power supply and the second high-voltage DC power supply are turned off, and the high-voltage DC power supply input to the motor bus capacitor discharge circuit is disconnected. The electric energy of the motor bus capacitor during normal operation is not discharged, and the voltage of the motor bus capacitor is added to the gate-source end of Q7 after passing through R24, R25 and V9. At this time, Q7 is turned on, and the electric energy of the motor bus capacitor is discharged through Q7 and the power resistor R26, and the terminal voltage of the motor bus capacitor drops to a safe voltage.

[0018] Beneficial effects of the present invention:

[0019] The present invention proposes a power-on and power-off circuit for an aviation high-voltage DC servo system. The power-on and power-off circuit can adapt to dual-redundant power supply of an aircraft, and can make the impact current of the high-voltage DC servo system controllable when it is powered on, so as to avoid the aircraft power supply system and high-voltage components such as motor bus capacitors in the high-voltage DC servo system being damaged by large impact currents. When the power is turned off, the electric energy of the motor bus capacitor can be quickly discharged so that the voltage of the bus capacitor drops to a safe voltage range, thereby improving the safety of the high-voltage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a circuit principle block diagram of the upper and lower power circuits of a high-voltage DC servo system in a specific implementation manner of the present invention;

[0022] Figure 2 It is a principle block diagram of a dual-redundancy power supply selection circuit in a specific implementation mode of the present invention;

[0023] Figure 3 It is a principle block diagram of a power-on slow start circuit in a specific implementation manner of the present invention;

[0024] Figure 4 It is a principle block diagram of the motor bus capacitor discharge circuit in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0026] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0027] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0028] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0029] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0030] In one embodiment of the present invention, a power-on and power-off circuit of a high-voltage DC servo system is provided. Figure 1 , including a dual-redundancy power supply selection circuit, a power-on slow start circuit, and a motor bus capacitor discharge circuit;

[0031] The input control signal of the dual-redundancy power supply selection circuit is the aircraft high-voltage DC power supply, and the output high-voltage DC gating signal is used as the input control signal of the power-on slow start circuit;

[0032] The high-voltage DC power supply input end of the power-on slow start circuit is connected to the dual-redundancy aircraft high-voltage DC power supply, and based on the high-voltage DC gating signal, a high-voltage DC power supply end of the dual-redundancy power supply selection circuit is selected as the power supply, and the power supply is transmitted to the motor bus capacitor discharge circuit and the motor bus capacitor in a slow start manner;

[0033] The motor bus capacitor discharge circuit is connected to the motor bus capacitor and can discharge the electric energy of the motor bus capacitor when the aircraft high-voltage DC power supply is powered off.

[0034] In this embodiment, if Figure 2As shown, the dual-redundancy power supply selection circuit includes a diode V1, a diode V2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C1, a voltage regulator tube V3, an operational amplifier D1, an NMOS tube Q1 and an NMOS tube Q2;

[0035] The operational amplifier D1 includes D1A and D1B;

[0036] In this embodiment, the first pin of the diode V1 and the first pin of R5 are connected to the first high-voltage DC power supply, the first pin of the diode V2 and the first pin of R6 are connected to the second high-voltage DC power supply, the first pin of R3 and the second pin of the NMOS tube are connected to the first high-voltage DC power supply selection signal, and the first pin of R4 and the second pin of the NMOS tube are connected to the first high-voltage DC power supply selection signal.

[0037] The dual-redundancy power supply selection circuit of this embodiment combines the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft through diodes V1 and V2, divides the voltage through resistors R1 and R2, and stabilizes the voltage through a voltage regulator V3 to output a VCC power supply as the working power supply of the operational amplifier D1; resistors R5 and R12 are connected to the reverse input terminal of the operational amplifier D1A as sampling resistors of the first high-voltage DC power supply, and resistors R6 and R13 are connected to the positive input terminal of the operational amplifier D1A as sampling resistors of the second high-voltage DC power supply. The operational amplifier D1A is a hysteresis comparator. When the voltage of the first high-voltage DC power supply is higher than that of the second high-voltage DC power supply, D1A outputs a low level, otherwise, D1A outputs a high level; the voltage comparison signal output by D1A is input to the voltage follower D1B through resistor R9, and is driven by D1B and input to the resistors R8 and R13 after being driven by D1B. The inverter circuit is composed of R10, R3 and NMOS tube Q1, and the second pin of NMOS tube Q1 is used as the first high-voltage DC power supply selection signal; the first high-voltage DC power supply selection signal is input to the inverter circuit composed of resistors R11, R4 and NMOS tube Q2, and the second pin of NMOS tube Q2 is used as the second high-voltage DC power supply selection signal; the function of the dual-redundancy power supply selection circuit is that when the voltage of the first high-voltage DC power supply is higher than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is high level and the second high-voltage DC power supply selection signal is low level; conversely, when the voltage of the first high-voltage DC power supply is lower than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is low level and the second high-voltage DC power supply selection signal is high level, and the two selection signals are mutually exclusive.

[0038] In this embodiment, if Figure 3As shown, the power-on slow start circuit includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a voltage regulator tube V5, a voltage regulator tube V7, a PMOS tube Q3, a PMOS tube Q5, a transistor Q4, a transistor Q6, a diode V4, and a diode V6;

[0039] The first pins of the resistor R15, the capacitor C2, and the voltage regulator tube V5 are connected to the first high-voltage DC power supply, and the third pin of the PMOS tube Q3 are connected to the first high-voltage DC power supply. The first pin of the resistor R17 is connected to the first high-voltage DC power supply selection signal. The first pins of the resistor R19, the capacitor C4, and the voltage regulator tube V7 are connected to the third pin of the PMOS tube Q5. The first pin of the resistor R21 is connected to the second high-voltage DC power supply selection signal. The second pins of the diodes V4 and V6 are connected to the motor bus capacitor.

[0040] When the power-on slow start circuit of this embodiment is working, the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft are respectively powered on slowly. The first high-voltage DC power supply and the first high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of resistors R15, R16, R17, R18, capacitors C2, C3, voltage regulator tube V5, PMOS tube Q3, and transistor Q4; the second high-voltage DC power supply and the second high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of resistors R19, R20, R21, R22, capacitors C4, C5, voltage regulator tube V5, PMOS tube Q5, and transistor Q6; when the first high-voltage DC power supply selection signal is high level, the transistor Q6 The transistor Q4 is turned on, causing the PMOS transistor Q3 to be turned on slowly. The first high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through the PMOS transistor Q3 and the diode V4. At this time, since the second high-voltage DC power supply selection signal is at a low level, the transistor Q6 is turned off, causing the PMOS transistor Q5 to be turned off, and the second high-voltage DC power supply is disconnected. Similarly, when the second high-voltage DC power supply selection signal is at a high level, the transistor Q6 is turned on, causing the PMOS transistor Q5 to be turned on slowly. The second high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through the PMOS transistor Q5 and the diode V6. At this time, since the first high-voltage DC power supply selection signal is at a low level, the transistor Q4 is turned off, causing the PMOS tube Q3 to be turned off, and the first high-voltage DC power supply is disconnected.

[0041] like Figure 4As shown, the motor bus capacitor discharge circuit includes a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C6, a voltage regulator tube V9 and a PMOS tube Q7; the first pins of the resistor R25 and the diode V8 are connected to the second pins of the diodes V4 and V6, and the first pins of the resistors R23, R24, the voltage regulator tube V9, the capacitor C6 and the third pin of the PMOS tube Q7 are connected to the motor bus capacitor.

[0042] The motor bus capacitor discharge circuit of this embodiment functions as follows: when the high-voltage DC power supply is input to the motor bus capacitor, the motor bus capacitor is charged. At the same time, the high-voltage DC power supply is input to the motor bus capacitor discharge circuit, and is connected to the source of the PMOS tube Q7 and the motor bus capacitor via the diode V8 and the current limiting resistor R23. At this time, since the gate-source voltage of the PMOS tube Q7 cannot meet the conduction condition of the PMOS tube Q7, the PMOS tube Q7 is cut off, which does not affect the charging and normal operation of the motor bus capacitor. After the high-voltage DC servo system is normally operated, the first high-voltage DC power supply and the second high-voltage DC power supply are turned off, that is, the high-voltage DC power supply input to the motor bus capacitor discharge circuit is disconnected. Since the electric energy of the motor bus capacitor is not discharged during normal operation, the voltage of the motor bus capacitor is added to the gate-source end of the PMOS tube Q7 after the voltage-dividing resistors R24 and R25 and the voltage regulator tube V9. At this time, the PMOS tube Q7 is turned on, and the electric energy of the motor bus capacitor is discharged via the PMOS tube Q7 and the power resistor R26, and the terminal voltage of the motor bus capacitor can be rapidly reduced to a safe voltage.

[0043] The power-on and power-off circuits of the high-voltage DC servo system of this embodiment realize adaptive aircraft dual-redundancy power supply selection, which can make the impact current of the high-voltage DC servo system controllable when it is powered on, and can quickly discharge the electrical energy of the motor bus capacitor when it is powered off, thereby improving the safety of the high-voltage system.

[0044] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A power-on and power-off circuit of a high-voltage DC servo system, characterized in that: It includes a dual-redundancy power supply selection circuit, a power-on slow start circuit, and a motor bus capacitor discharge circuit; The input control signal of the dual-redundancy power supply selection circuit is the aircraft high-voltage DC power supply, and the output high-voltage DC gating signal is used as the input control signal of the power-on slow start circuit; The high-voltage DC power supply input end of the power-on slow start circuit is connected to the aircraft high-voltage DC power supply, and based on the high-voltage DC gating signal, a high-voltage DC power supply end of the dual-redundancy power supply selection circuit is selected as the power supply, and the power supply is transmitted to the motor bus capacitor discharge circuit and the motor bus capacitor in a slow start manner; The motor bus capacitor discharge circuit is connected to the motor bus capacitor and can discharge the electric energy of the motor bus capacitor when the aircraft high-voltage DC power supply is powered off.

2. The power-on and power-off circuit of the high-voltage DC servo system according to claim 1, characterized in that: The dual-redundancy power supply selection circuit includes a diode V1, a diode V2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C1, a voltage regulator tube V3, an operational amplifier D1, an NMOS tube Q1 and an NMOS tube Q2; The operational amplifier D1 includes D1A and D1B; The dual-redundancy power supply selection circuit combines the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft through V1 and V2, divides the voltage through R1 and R2, and outputs the VCC power supply after being stabilized by the voltage regulator tube V3. The VCC power supply serves as the working power supply of D1; R5 and R12 are connected to the reverse input end of D1A as the sampling resistors of the first high-voltage DC power supply, and the resistors R6 and R13 are connected to the positive input end of D1A as the sampling resistors of the second high-voltage DC power supply. The operational amplifier D1A is a hysteresis comparator. When the first high-voltage DC power supply When the source voltage is higher than the second high-voltage DC power supply, D1A outputs a low level, otherwise, D1A outputs a high level; the voltage comparison signal output by D1A is input to the voltage follower D1B via R9, and after being driven by D1B, is input to the inverter circuit composed of resistors R8, R10, R3 and Q1, and the second pin of Q1 is used as the first high-voltage DC power supply selection signal; the first high-voltage DC power supply selection signal is input to the inverter circuit composed of R11, R4 and Q2, and the second pin of Q2 is used as the second high-voltage DC power supply selection signal.

3. The upper and lower power circuits of the high voltage DC servo system according to claim 2, characterized in that: In the dual-redundancy power supply selection circuit: when the voltage of the first high-voltage DC power supply is higher than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is high level, and the second high-voltage DC power supply selection signal is low level; conversely, when the voltage of the first high-voltage DC power supply is lower than that of the second high-voltage DC power supply, the first high-voltage DC power supply selection signal is low level, and the second high-voltage DC power supply selection signal is high level, and the two selection signals are mutually exclusive.

4. The upper and lower power circuits of the high voltage DC servo system according to claim 3, characterized in that: The power-on slow start circuit includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a voltage regulator tube V5, a voltage regulator tube V7, a PMOS tube Q3, a PMOS tube Q5, a transistor Q4, a transistor Q6, a diode V4, and a diode V6; The power-on slow start circuit performs slow start power-on on the first high-voltage DC power supply and the second high-voltage DC power supply provided by the aircraft respectively; the first high-voltage DC power supply and the first high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of R15, R16, R17, R18, C2, C3, V5, Q3 and Q4; the second high-voltage DC power supply and the second high-voltage DC power supply selection signal are input to the power switch circuit with slow start function composed of R19, R20, R21, R22, C4, C5, V7, Q5 and Q6.

5. The power-on and power-off circuit of the high-voltage DC servo system according to claim 4, characterized in that: In the power-on slow start circuit: when the first high-voltage DC power supply selection signal is at a high level, Q4 is turned on so that Q3 is slowly turned on, and the first high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through Q3 and V4, and the second high-voltage DC power supply selection signal is at a low level, Q6 is turned off so that Q5 is turned off, and the second high-voltage DC power supply is disconnected; when the second high-voltage DC power supply selection signal is at a high level, Q6 is turned on so that Q5 is slowly turned on, and the second high-voltage DC power supply is output to the motor bus capacitor as a high-voltage DC power supply through Q5 and V6, and the first high-voltage DC power supply selection signal is at a low level, Q4 is turned off so that Q3 is turned off, and the first high-voltage DC power supply is disconnected.

6. The power-on and power-off circuit of the high-voltage DC servo system according to claim 5, characterized in that: The motor bus capacitor discharge circuit includes a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C6, a voltage regulator tube V9 and a PMOS tube Q7; In the motor bus capacitor discharge circuit: when the high-voltage DC power supply is input to the motor bus capacitor, the motor bus capacitor is charged. At the same time, the high-voltage DC power supply is input to the motor bus capacitor discharge circuit and connected to the source of Q7 and the motor bus capacitor via V8 and R23. The gate-source voltage of Q7 cannot meet the conduction condition of Q7, and Q7 is cut off, which does not affect the charging and normal operation of the motor bus capacitor. After the high-voltage DC servo system ends normal operation, the first high-voltage DC power supply and the second high-voltage DC power supply are turned off, and the high-voltage DC power supply input to the motor bus capacitor discharge circuit is disconnected. The electric energy of the motor bus capacitor during normal operation is not discharged, and the voltage of the motor bus capacitor is added to the gate-source end of Q7 after passing through R24, R25 and V9. At this time, Q7 is turned on, and the electric energy of the motor bus capacitor is discharged through Q7 and the power resistor R26, and the terminal voltage of the motor bus capacitor drops to a safe voltage.

Images