STM32-based power-on slow start protection circuit

Abstract

The utility model discloses a power-on slow start protection circuit based on STM32, and belongs to the technical field of alternating current servo drivers. The circuit comprises a power-on slow start control circuit, a dynamic electric slow start circuit and a bus capacitance circuit. After the dynamic electricity is powered on, firstly, a bus capacitor is charged through a current-limiting resistor in the dynamic electricity slow starting circuit, meanwhile, the bus voltage is detected in real time, and when the bus voltage reaches starting voltage, a control module sends out a PRON control signal to a direct-current relay in the power-on slow starting control circuit. After a direct-current relay in the dynamic electricity slow start circuit receives a start signal of the power-on slow start control circuit, a normally open contact of the direct-current relay is closed, a current-limiting resistor is bypassed, and all power currents pass through the contact of the direct-current relay. The peripheral circuit is simple in structure, the design cost of system hardware is reduced, the power-off protection function is improved, the reliability of the system is improved, the domestication requirement of devices is met, and the special requirement of military equipment for the servo driver is met.

Description

A power-on soft-start protection circuit based on STM32 Technical Field

[0001] This invention relates to the field of AC servo driver technology, specifically to a power-on soft-start protection circuit based on STM32. Background Technology

[0002] AC servo drives are widely used in various automatic control systems, such as machine tools and robots in civilian fields, and also have extensive applications in the military field, such as artillery servo systems, fire control systems, radar, and illumination devices. During use, abnormal input power to the drive may occur due to cable installation problems, insulation damage, or circuit breaker tripping. If fault detection and protection are not performed, the current flowing through the power device will rise sharply in a short period of time, causing damage to the power device.

[0003] Therefore, it is necessary to design an input voltage detection and protection circuit for the AC servo driver to prevent damage and failure caused by short circuit overcurrent. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a power-on soft-start protection circuit based on STM32.

[0005] This invention is achieved through the following technical solution:

[0006] A power-on soft-start protection circuit based on STM32 is disclosed. The circuit includes a power-on soft-start control circuit, a power-on soft-start circuit, and a bus capacitor circuit. The power-on soft-start control circuit generates a relay control signal in the power-on soft-start circuit. The power-on soft-start circuit controls the direction of power current flow. The bus capacitor circuit is used for instantaneous power failure protection.

[0007] The power-on soft-start control circuit has the following connections: pin 1 of optocoupler B1 is connected to the first end of resistor R2; the second end of resistor R2 is connected to the first end of resistor R1; the second end of resistor R1 is connected to the relay control signal PR_ON; pin 2 of optocoupler B1 is connected to control ground M; pin 4 of optocoupler B1 is connected to power supply 1P15; pin 2 of optocoupler B1 is connected to the first end of resistor R3; the second end of resistor R3 is connected to the first end of capacitor C1; the first end of capacitor C1 is connected to the first end of resistor R4; the second end of capacitor C1 is connected to power supply ground 1M15; the second end of resistor R4 is connected to power supply ground 1M15; and the first end of resistor R4 is connected to the base of NPN transistor V2. The NPN transistor V2 emitter is connected to power ground 1M15, the NPN transistor V2 collector is connected to pin 3 of transistor V1, pin 3 of transistor V1 is connected to pin 2 of DC relay K1, pin 2 of transistor V1 is connected to pin 1 of DC relay K1, pin 1 of DC relay K1 is connected to the first end of resistor R6, the second end of resistor R6 is connected to power supply 1P15, the first end of resistor R5 is connected, the second end of R5 is connected to pin 2 of transistor V1 and pin 1 of DC relay K1, pins 3 and 5 of DC relay K1 are connected to power supply DC24V+, and pins 3 and 5 of DC relay K1 are connected to DC24V+_RELAY.

[0008] The power electric soft start circuit receives the DC24V+_RELAY signal. Pins 3, 4, 5, and 6 of the DC relay K2 are engaged. Pin 1 of the DC relay K2 is connected to the DC24V+_RELAY signal. Pin 1 of the DC relay K2 is connected to the DC24V-_RELAY signal. Pins 3 and 5 of the DC relay K2 are connected to the first terminals of resistors R7 and R8 and pin 4 of rectifier module N1. Pins 4 and 6 of the DC relay K2 are connected to the second terminals of resistors R7 and R8 and P600. Pin 5 of rectifier module N1 is connected to M600. Pin 1 of rectifier module N1 is connected to M600.

[0009] After the DC540V power supply is powered on, the bus capacitor is first charged through the current-limiting resistor in the power supply soft start circuit. The first terminal of capacitor C2 in the bus capacitor circuit is connected to the first terminals of capacitors C3, C4, and C5, P600, and the first terminal of resistor R9. The second terminals of capacitors C2, C3, C4, C5, and resistor R9 in the bus capacitor circuit are connected to the first terminals of capacitors C6, C7, C8, C9, and resistor R10. The second terminals of capacitors C6, C7, C8, C9, and resistor R10 are connected to M600.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] This invention utilizes a DC relay to build a soft-start circuit, integrating the soft-start circuit, bus capacitor circuit, and relay control circuit together. The external circuit structure is simple, reducing the system hardware design cost, improving the power failure protection function, increasing system reliability, realizing the requirement of domestic component production, and meeting the special requirements of military equipment for servo drives. Attached Figure Description

[0012] Figure 1 is a schematic diagram of a power-on soft-start protection circuit based on STM32 according to the present invention.

[0013] Figure 2 is a schematic diagram of the power-on soft start control circuit according to an embodiment of the present invention.

[0014] Figure 3 is a schematic diagram of the power electric soft start circuit according to an embodiment of the present invention.

[0015] Figure 4 is a schematic diagram of the bus capacitor circuit according to an embodiment of the present invention.

[0016] Figure 5 is a flowchart of the power-off control in the enabled state according to an embodiment of the present invention.

[0017] Figure 6 is a flowchart of the power-off control under normal conditions according to an embodiment of the present invention.

[0018] Figure 7 is a flowchart of the power outage (power is restored immediately after power outage) control process under normal conditions according to an embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings:

[0020] When the power supply is powered on, the bus capacitor is first charged through the current-limiting resistor in the power supply soft start circuit. At the same time, the bus voltage is monitored in real time. When the bus voltage reaches the starting voltage, the control module sends a PR_ON control signal to the DC relay in the power supply soft start control circuit. After receiving the starting signal from the power supply soft start control circuit, the normally open contact of the DC relay in the power supply soft start circuit closes, bypassing the current-limiting resistor, and all power current flows through the contacts of the DC relay. By monitoring the bus voltage in real time and controlling the high and low levels of the PR_ON signal, the contacts of the DC relay in the power supply soft start circuit are controlled.

[0021] The schematic diagram of the STM32-based power-on soft-start protection circuit is shown in Figure 1. The circuit includes a power-on soft-start control circuit, a power soft-start circuit, and a bus capacitor circuit.

[0022] The power-on soft-start control circuit is shown in Figure 2. Pin 1 of optocoupler B1 is connected to the first terminal of resistor R2. The second terminal of resistor R2 is connected to the first terminal of resistor R1. The second terminal of resistor R1 is connected to the relay control signal PR_ON. Pin 2 of optocoupler B1 is connected to control ground M. Pin 4 of optocoupler B1 is connected to power supply 1P15. Pin 2 of optocoupler B1 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the first terminal of capacitor C1. The first terminal of capacitor C1 is connected to the first terminal of resistor R4. The second terminal of capacitor C1 is connected to power ground 1M15. The second terminal of resistor R4 is connected to power ground 1M15. The first terminal of resistor R4 is connected to the NPN single... The base of transistor V2 is connected to the ground, the emitter of NPN transistor V2 is connected to power supply ground 1M15, the collector of NPN transistor V2 is connected to pin 3 of transistor V1, pin 3 of transistor V1 is connected to pin 2 of DC relay K1, pin 2 of transistor V1 is connected to pin 1 of DC relay K1, pin 1 of DC relay K1 is connected to the first end of resistor R6, the second end of resistor R6 is connected to power supply 1P15, the first end of resistor R5 is connected, the second end of R5 is connected to pin 2 of transistor V1 and pin 1 of DC relay K1, pins 3 and 5 of DC relay K1 are connected to power supply DC24V+, and pins 3 and 5 of DC relay K1 are connected to DC24V+_RELAY.

[0023] The power-on soft start circuit is shown in Figure 3. When the DC24V+_RELAY signal from the power-on soft start control circuit is received, pins 3, 4, 5, and 6 of the DC relay K2 are energized. Pin 1 of the DC relay K2 is connected to the DC24V+_RELAY signal, and pin 1 of the DC relay K2 is connected to the DC24V-_RELAY signal. Pins 3 and 5 of the DC relay K2 are connected to the first terminals of resistors R7 and R8 and pin 4 of rectifier module N1. Pins 4 and 6 of the DC relay K2 are connected to the second terminals of resistors R7 and R8 and P600. Pin 5 of rectifier module N1 is connected to M600, and pin 1 of rectifier module N1 is connected to M600.

[0024] After the DC540V power supply is powered on, the bus capacitor is first charged through the current-limiting resistor in the power supply soft start circuit. The bus capacitor circuit is shown in Figure 4. The first terminal of capacitor C2 in the bus capacitor circuit is connected to the first terminals of capacitors C3, C4, and C5, P600, and the first terminal of resistor R9. The second terminals of capacitors C2, C3, C4, C5, and resistor R9 in the bus capacitor circuit are connected to the first terminals of capacitors C6, C7, C8, C9, and resistor R10. The second terminals of capacitors C6, C7, C8, C9, and resistor R10 are connected to M600.

[0025] When the power supply is powered on, the bus capacitor is first charged through the current-limiting resistor in the power supply soft start circuit. Simultaneously, the bus voltage is monitored in real time. When the bus voltage reaches the starting voltage, the control module sends a PR_ON control signal to the DC relay in the power supply soft start control circuit. Upon receiving the start signal from the power supply soft start control circuit, the normally open contact of the DC relay in the power supply soft start circuit closes, bypassing the current-limiting resistor, and all power current flows through the contacts of the DC relay. By monitoring the bus voltage in real time and controlling the high and low levels of the PR_ON signal, the contacts of the DC relay in the power supply soft start circuit are controlled.

[0026] Power outages can be mainly divided into three states:

[0027] When the driver is powered off while enabled, and the MCU receives a signal that the external power supply voltage has dropped to DC 300V, the MCU controls the disconnection of the DC relay contacts in the control circuit. When the bus voltage drops to DC 350V, the driver triggers an undervoltage alarm, and the driver needs to be powered on again to operate. The control flow is shown in Figure 5.

[0028] When the driver is powered off without being enabled, and the MCU receives a signal that the external power supply voltage has dropped to DC 300V, the MCU controls the disconnection of the DC relay contacts in the control circuit. When the voltage drops to DC 350V, the driver will first report an undervoltage fault, and then self-reset. The driver can then operate without needing to reapply control power. The control flow is shown in Figure 6.

[0029] When the driver is powered off and then powered on again in an unenabled state, the MCU receives a signal that the external power supply voltage has dropped to DC 300V. The MCU then disconnects the DC relay contacts in the control circuit. At this point, the voltage is detected to be DC 430V, and a voltage signal is sent to the MCU. After a 1-second software delay, the MCU closes the DC relay contacts in the control circuit. Once the normally open relay contacts are closed, the driver can operate without requiring a re-application of control power. The control flow is shown in Figure 7.

[0030] In summary, the present invention provides a power-on soft-start protection circuit based on STM32, which has a simple control circuit, reduces costs, and achieves 100% domestic production of components.

[0031] In summary, these are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. All equivalent variations and modifications made in accordance with the shape, structure, features and spirit described in the claims of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A power-on soft-start protection circuit based on STM32, characterized in that: The circuit includes a power-on soft start control circuit, a power-on soft start circuit, and a bus capacitor circuit. The power-on soft start control circuit generates a relay control signal in the power-on soft start circuit; the power-on soft start circuit controls the direction of power current flow; and the bus capacitor circuit is used for instantaneous power failure protection.

2. The power-on soft-start protection circuit based on STM32 according to claim 1, characterized in that: The power-on soft-start control circuit has the following connections: pin 1 of optocoupler B1 is connected to the first end of resistor R2; the second end of resistor R2 is connected to the first end of resistor R1; the second end of resistor R1 is connected to the relay control signal PR_ON; pin 2 of optocoupler B1 is connected to control ground M; pin 4 of optocoupler B1 is connected to power supply 1P15; pin 2 of optocoupler B1 is connected to the first end of resistor R3; the second end of resistor R3 is connected to the first end of capacitor C1; the first end of capacitor C1 is connected to the first end of resistor R4; the second end of capacitor C1 is connected to power supply ground 1M15; the second end of resistor R4 is connected to power supply ground 1M15; and the first end of resistor R4 is connected to the base of NPN transistor V2. The NPN transistor V2 emitter is connected to power ground 1M15, the NPN transistor V2 collector is connected to pin 3 of transistor V1, pin 3 of transistor V1 is connected to pin 2 of DC relay K1, pin 2 of transistor V1 is connected to pin 1 of DC relay K1, pin 1 of DC relay K1 is connected to the first end of resistor R6, the second end of resistor R6 is connected to power supply 1P15, the first end of resistor R5 is connected, the second end of R5 is connected to pin 2 of transistor V1 and pin 1 of DC relay K1, pins 3 and 5 of DC relay K1 are connected to power supply DC24V+, and pins 3 and 5 of DC relay K1 are connected to DC24V+_RELAY.

3. The power-on soft-start protection circuit based on STM32 according to claim 2, characterized in that: The power electric soft start circuit receives the DC24V+_RELAY signal. Pins 3, 4, 5, and 6 of the DC relay K2 are engaged. Pin 1 of the DC relay K2 is connected to the DC24V+_RELAY signal. Pin 1 of the DC relay K2 is connected to the DC24V-_RELAY signal. Pins 3 and 5 of the DC relay K2 are connected to the first terminals of resistors R7 and R8 and pin 4 of rectifier module N1. Pins 4 and 6 of the DC relay K2 are connected to the second terminals of resistors R7 and R8 and P600. Pin 5 of rectifier module N1 is connected to M600. Pin 1 of rectifier module N1 is connected to M600.

4. The power-on soft-start protection circuit based on STM32 according to claim 3, characterized in that: After the DC540V power supply is powered on, the bus capacitor is first charged through the current-limiting resistor in the power supply soft start circuit. The first terminal of capacitor C2 in the bus capacitor circuit is connected to the first terminals of capacitors C3, C4, and C5, P600, and the first terminal of resistor R9. The second terminals of capacitors C2, C3, C4, C5, and resistor R9 in the bus capacitor circuit are connected to the first terminals of capacitors C6, C7, C8, C9, and resistor R10. The second terminals of capacitors C6, C7, C8, C9, and resistor R10 are connected to M600.

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