Double-control protection type high-voltage control circuit

Abstract

The application provides a double-control protection type high-voltage control circuit, which comprises a double-control unit, a processing unit and a double-pole double-throw relay K1 for controlling high-voltage connection and disconnection connected in sequence, the double-control unit comprises a control unit A and a control unit B connected in communication, the control unit A and the control unit B separately control one pole of the coil of the double-pole double-throw relay K1, the processing unit comprises an inverter capable of receiving the output control signal of the double-control unit, the output signal of the inverter controls the double-pole double-throw relay K1 through input to a MOS tube, and the processing unit further comprises a feedback signal detection circuit connected with the control unit. The application changes the voltage on both sides of the relay coil through two different control units, ensures that the relay works in a reasonable range and the reliability of long-term operation, and the two control units can separately control one pole of the relay coil, can rapidly disconnect the control signal after a fault, and ensures the safety of high-voltage connection and disconnection.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage control technology in energy storage battery management systems, and specifically relates to a dual-control protection type high-voltage control circuit. Background Technology

[0002] In automated equipment, relay output control enables low-voltage control of high-voltage systems, thereby driving the operation of external high-voltage equipment. However, in current energy storage battery systems, the control of the main negative relay and main positive relay is typically achieved through single-point control by the Battery Control Unit (BCU). If a short circuit occurs in the BCU control circuit or the CPU program malfunctions during control, the relays will fail to disconnect properly, leading to over-discharge or over-charge of the battery system. This can ultimately result in irreversible battery failure or even explosion. Summary of the Invention

[0003] The purpose of this invention is to address the above-mentioned problems by providing a dual-control protection high-voltage control circuit that can quickly disconnect the control signal after a fault, ensuring the safety of high-voltage switching and guaranteeing the reliability and safety of the relay during long-term operation.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions:

[0005] A dual-control protection high-voltage control circuit includes a dual-control unit, a processing unit, and a double-pole double-throw relay K1 for controlling high-voltage access and disconnection, connected in sequence. The dual-control unit includes control unit A and control unit B, which are communicatively connected. Control unit A and control unit B each independently control one pole of the coil of double-pole double-throw relay K1. The processing unit includes an inverter that can receive the control signal output from the dual-control unit. The output signal of the inverter is input to a MOSFET to control double-pole double-throw relay K1. The processing unit also includes a feedback signal detection circuit connected to the control unit. This invention changes the voltage across the relay coil using two different control units, ensuring that the relay operates within a reasonable range and maintains reliable long-term operation. The two control units can independently control one pole of the relay coil, enabling rapid disconnection of the control signal in case of a fault. Furthermore, the data from the two control units can be exchanged in real time, achieving mutual information sharing and preventing the relay from failing to disconnect properly when malfunctioning, which could lead to overcharging or over-discharging of the battery pack, resulting in irreversible faults or even explosions.

[0006] Furthermore, control unit A outputs a control signal to inverter D1, which in turn outputs a level signal to MOSFET V2. By controlling the state of MOSFET V2, the level state of pin 1 of the double-pole double-throw relay K1 is controlled. When control unit A outputs a low-level control signal, inverter D1 outputs a high-level signal, driving MOSFET V2 to conduct, thus making pin 1 of the double-pole double-throw relay K1 low. When control unit A outputs a high-level control signal or no signal, inverter D1 outputs a low-level signal. In this case, MOSFET V2 is cut off, leaving pin 1 of the double-pole double-throw relay K1 floating, and the relay cannot function properly.

[0007] Furthermore, the processing unit also includes a dual-frequency non-retrievable monostable multivibrator D3 connected to the control unit B, wherein the dual-frequency non-retrievable monostable multivibrator D3 has a reset function.

[0008] Furthermore, the control signal output by the control unit B is connected to the inverter D2 and the dual-frequency non-retrievable monostable multivibrator D3. The inverter D2 and the dual-frequency non-retrievable monostable multivibrator D3 output level signals to the MOSFET. By controlling the state of the MOSFET, the level state of pin 12 of the double-pole double-throw relay K1 is controlled.

[0009] Furthermore, the duration of the output level signal pulse of the dual-frequency non-retrievable monostable multivibrator D3 is determined by the RC frequency converter composed of resistor R7 and capacitor C2.

[0010] Furthermore, when the control signal output by control unit B is low, the dual-frequency non-retrievable monostable multivibrator D3 outputs a high-level pulse to drive MOSFET V10 to conduct and ground, causing MOSFET V8 to conduct. The startup power supply VCC_H2 is input to pin 12 of the double-pole double-throw relay K1 through the anti-reverse diode V5, making pin 12 of the double-pole double-throw relay K1 high. At the same time, the inverter D2 outputs a high-level signal to MOSFET V6, driving MOSFET V6 to conduct and ground, causing MOSFET V3 to conduct. The power supply VCC_H1 is input to pin 12 of the double-pole double-throw relay K1 through the anti-reverse diode V5, and pin 12 of the double-pole double-throw relay K1 remains high. When pin 12 of the double-pole double-throw relay K1 remains at a high level and pin 1 is at a low level, the double-pole double-throw relay K1 will activate, its double-pole double-throw switch will switch positions, high voltage HV_I will be connected to high voltage HV_O, and the feedback signal REY_FB-N will be at a low level and received by the control unit B, thus determining that the relay has activated normally and the high voltage has been connected normally.

[0011] Furthermore, when the control unit B outputs a high-level control signal or no output signal, the dual-frequency non-retrievable monostable multivibrator D3 is at a low level, the MOSFET V10 is in the off state, and pin 12 of the double-pole double-throw relay K1 is in a floating state. Simultaneously, the inverter D2 outputs a low-level signal, the MOSFET V6 is in the off state, and pin 12 of the double-pole double-throw relay K1 is in a floating state, preventing the double-pole double-throw relay K1 from functioning properly. When pin 12 of the double-pole double-throw relay K1 is in a floating state, or when pin 1 of the double-pole double-throw relay K1 is in a floating state, the double-pole double-throw relay K1 does not operate. Its double-pole double-throw switch returns to its initial position, and the high voltage HV_I cannot be connected to the high voltage HV_O. The feedback signal is high and received by the control unit B, thus determining whether the relay is open or not operating, and whether the high voltage has been properly disconnected or not connected.

[0012] Furthermore, the voltage of the power supply VCC_H1 is lower than that of the startup power supply VCC_H2. By switching the relay power supply, the relay can be kept in a low-power state to ensure that it does not overheat and to guarantee the reliability of its long-term operation.

[0013] Furthermore, control unit A and control unit B communicate and exchange data via serial port, and / or SPI, and / or CAN. Through serial communication, control unit A and control unit B achieve data exchange and mutual information sharing, thereby enabling real-time monitoring and control of the relay's status.

[0014] Furthermore, the control signals output by the control unit are connected to the power supply through pull-up resistors.

[0015] Compared with existing technologies, the advantages of this invention are:

[0016] 1. This invention uses a double-pole double-throw relay to smoothly connect and disconnect high voltage on one side, and to provide real-time feedback on whether the high voltage is properly connected and disconnected on the other side, ensuring that the control unit can monitor the on / off state of the high voltage in real time;

[0017] 2. The relay coil is controlled by two independent control units, which is beneficial to ensure that the relay can still be disconnected normally through the other control unit in the event of failure of one control unit, thus ensuring the safety of high voltage switching.

[0018] 3. The relay adopts a high-voltage pulse drive and medium-voltage maintenance function design, which can reduce the power consumption of the relay coil, prevent the relay from overheating during long-term energization, and prevent the contact from sticking, thus shortening the service life of the relay and ensuring the reliability and safety of the relay in long-term operation.

[0019] 4. The two independent control units communicate via serial port to achieve data exchange and information sharing, thereby enabling real-time monitoring and control of the relay status;

[0020] 5. This invention is designed with a feedback signal detection circuit, which is connected to the control unit, and can detect the high voltage on / off state of the relay in real time, so as not to cause loss of control.

[0021] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0022] Figure 1 This is a circuit diagram of the dual-control protection type high-voltage control circuit of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, a dual-control protection high-voltage control circuit includes a dual-control unit, a processing unit, and a double-pole double-throw relay K1 for controlling high-voltage access and disconnection, connected in sequence. The dual-control unit includes control unit A and control unit B, which are communicatively connected. Control unit A and control unit B each independently control one pole of the coil of double-pole double-throw relay K1. The processing unit includes an inverter that can receive control signals output from the control unit. The output signal of the inverter is input to a MOSFET to control double-pole double-throw relay K1. The processing unit also includes a feedback signal detection circuit connected to the control unit. This invention changes the voltage across the relay coil using two different control units, ensuring the relay operates within a reasonable range and maintains reliable long-term operation. The two control units can independently control one pole of the relay coil, enabling rapid disconnection of the control signal after a fault. Furthermore, the data from the two control units can be exchanged in real time, allowing for mutual information sharing and preventing the relay from failing to disconnect properly when malfunctioning, thus preventing overcharging or over-discharging of the battery pack and potentially leading to irreversible faults or even explosions.

[0025] In this embodiment, control unit A outputs a control signal to inverter D1, and inverter D1 outputs a level signal to MOSFET V2 to control the state of MOSFET V2, thereby controlling the level state of pin 1 of the double-pole double-throw relay K1.

[0026] The control signal output by control unit B is connected to inverter D2 and dual-frequency non-retrievable monostable multivibrator D3 with reset function. Inverter D2 and dual-frequency non-retrievable monostable multivibrator D3 output level signals to MOSFETs to control the state of MOSFETs, thereby controlling the level state of pin 12 of double-pole double-throw relay K1. Specifically: The dual-frequency non-retriggerable monostable multivibrator D3 outputs a level signal to MOSFET V10, controlling the state of MOSFET V10. When MOSFET V10 is turned on, it causes MOSFET V8 to turn on. The starting power supply VCC_H2, after voltage division and regulation, is input to pin 12 of double-pole double-throw relay K1 via anti-reverse diode V5, and pin 12 of double-pole double-throw relay K1 is at a high level. The inverter D2 outputs a level signal to MOSFET V6, controlling the state of MOSFET V6. When MOSFET V6 is turned on, it causes MOSFET V3 to turn on. The power supply VCC_H1, after voltage division and regulation, is input to pin 12 of double-pole double-throw relay K1 via anti-reverse diode V5, and pin 12 of double-pole double-throw relay K1 remains at a high level. When MOSFET V10 is in the off state, pin 12 of double-pole double-throw relay K1 is floating; when MOSFET V6 is in the off state, pin 12 of double-pole double-throw relay K1 is floating.

[0027] In this embodiment, the duration of the output level signal pulse of the dual-frequency non-retrievable monostable multivibrator D3 is determined by the RC frequency converter composed of resistor R7 and capacitor C2.

[0028] The specific control process in this embodiment is as follows:

[0029] Control unit A outputs a control signal REY1_EN-N, which is connected to the power supply VCC_LV via pull-up resistor R1. When control unit A outputs a low-level control signal REY1_EN-N, it is input to pin 2 of inverter D1. Pin 4 of inverter D1 then outputs a high-level signal, which, through current-limiting resistor R2, is input to the gate of NMOS transistor V2, controlling V2 to conduct. This causes pin 1 of relay K1 to be low. In this embodiment, inverter D1 is a 74LVC1G04, NMOS transistor V2 is a 2N7002, and power supply VCC_LV is a +5V DC power supply.

[0030] Control unit B outputs control signal REY2_EN-N, which is connected to pin 2 of inverter D2 and pin 1 of dual-frequency non-retrievable monostable multivibrator D3 with reset function, and is connected to power supply VCC_LV via pull-up resistor R9; pins 2 and 16 of monostable multivibrator D3 are connected to power supply VCC_LV, pins 8 and 14 are grounded, and resistor R7 and capacitor C2 are connected between pins 15 and 14 to form an RC frequency converter, pin 3 is connected to the gate of NMOS transistor V6, and pin 13 is connected to the gate of NMOS transistor V10.

[0031] When the control signal REY2_EN-N output by control unit B is low, pin 13 of the dual-frequency non-retrievable monostable multivibrator D3 with reset function will output a high-level pulse. The duration of the pulse is determined by the RC frequency converter composed of resistor R7 and capacitor C2. This high-level pulse will drive NMOS transistor V10 to conduct, causing voltage divider resistor R10 to ground, thus turning on PMOS transistor V8. At this time, the power supply VCC_HV2, after passing through voltage divider resistors R8 and R10 and Zener diode V9, will input the regulated voltage to pin 12 of relay K1 through anti-reverse diode V5, thereby making pin 12 of relay K1 present a high level. Diodes V5 and V7 are selected from BAV70W, monostable multivibrator D3 is selected from 74HCT221, NMOS transistor V10 is selected from 2N7002, PMOS transistor V8 is selected from BSP171, Zener diode V9 is selected from MM3Z16VT1G, resistor R7 is selected from 100K, capacitor C2 is selected from 4.7uF, voltage divider resistors R8 and R10 are 22K, and power supply VCC_HV2 is selected from +24V DC power supply.

[0032] When pin 1 of relay K1 is low and pin 12 is high, relay K1 will be energized and begin operation, and its double-pole double-throw switch will switch positions. At this time, pin 4 of relay K1 will switch to pin 5, and high voltage HV_I will be connected to high voltage HV_O. A varistor protection element R5 and a high-voltage capacitor C1 and resistor R6 will be added between high-voltage HV_I and HV_O. Simultaneously, pin 9 of relay K1 will switch to pin 8. Before the switch, the feedback signal REY_FB-N is obtained by dividing the power supply VCC_HV2 using voltage divider resistors R11 and R12, so the feedback signal REY_FB-N is high at this time. After the switch, the feedback signal REY_FB-N is pulled down, and the feedback signal REY_FB-N is low. The level change of this feedback signal REY_FB-N is received and acquired by control unit B, thereby determining whether the relay has operated normally. The relay K1 is selected as SR2M-V23047-A1024-A501, the varistor R5 is selected as B72650M0141K072, the high voltage capacitor C1 is selected as 4.7nF / 2kV, the resistor R6 is 47Ω, and the voltage divider resistors R11 and R12 are 100K and 15K respectively.

[0033] After the control signal REY2_EN-N output from control unit B is low, monostable multivibrator D3 outputs a high-level pulse, causing relay K1 to start normally. Simultaneously, the REY2_EN-N signal is also input to pin 2 of inverter D2, causing pin 4 of inverter D2 to output a high-level signal, which is input to the gate of NMOS transistor V6, controlling V6 to conduct and ground, thus causing PMOS transistor V3 to conduct. At this time, the power supply VCC_HV1, after passing through voltage divider resistors R3 and R4 and Zener diode V4, inputs the regulated voltage to pin 12 of relay K1 via anti-reverse diode V5, thereby maintaining pin 12 of relay K1 at a high level. The NMOS transistor V6 is a 2N7002, the PMOS transistor V3 is a BSP171, the Zener diode V4 is an MM3Z16VT1G, the voltage divider resistors R3 and R4 are 22KΩ and 10KΩ respectively, and the power supply VCC_HV1 is a +15V DC power supply.

[0034] When pin 12 of relay K1 remains high and pin 1 is low, the relay will remain in the conducting state. At this time, because the voltage of the power supply VCC_HV1 is smaller than that of the starting power supply VCC_HV2, the current flowing through the coil of relay K1 is reduced, which can effectively reduce the coil power consumption and prevent the relay from being in a long-term conducting state and causing the contacts to stick together, thus protecting the relay.

[0035] Control unit B and control unit A communicate via serial port (the communication method can be, but is not limited to, serial port; other communication methods such as SPI and CAN are also acceptable) to exchange data. By outputting high and low levels through control signals REY1_EN-N and REY2_EN-N, the potential changes on both sides of the relay coil can be controlled, thereby realizing the connection and disconnection of external high voltage. The high and low levels of the feedback signal REY_FB-N are used to determine whether the external high voltage is connected and disconnected normally.

[0036] When control unit A or control unit B detects a fault, it can output a high-level signal to disconnect its own control terminal, or it can notify the other party to disconnect the control terminal via communication. As long as one party accurately disconnects the relay's control terminal, the accurate disconnection of the external high voltage can be ensured, guaranteeing high voltage safety.

[0037] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A dual-control protection type high-voltage control circuit, characterized in that, The system includes a dual-control unit, a processing unit, and a double-pole double-throw relay K1 for controlling high-voltage access and disconnection, connected in sequence. The dual-control unit includes control unit A and control unit B, which are communicatively connected. Control unit A and control unit B each individually control one pole of the coil of double-pole double-throw relay K1. The processing unit includes an inverter that receives the control signal output from the dual-control unit. The output signal of the inverter is input to a MOSFET to control double-pole double-throw relay K1. The processing unit also includes a feedback signal detection circuit connected to the control unit. The control unit A outputs a control signal to the inverter D1, and the inverter D1 outputs a level signal to the MOSFET V2. By controlling the state of the MOSFET V2, the level state of pin 1 of the double-pole double-throw relay K1 is controlled. The processing unit also includes a dual-frequency non-retrievable monostable multivibrator D3 connected to the control unit B, wherein the dual-frequency non-retrievable monostable multivibrator D3 has a reset function. The control signal output by the control unit B is connected to the inverter D2 and the dual-frequency non-retrievable monostable multivibrator D3. The inverter D2 and the dual-frequency non-retrievable monostable multivibrator D3 output level signals to the MOSFET. By controlling the state of the MOSFET, the level state of pin 12 of the double-pole double-throw relay K1 is controlled. When the control unit B outputs a low-level control signal, the dual-frequency non-retrievable monostable multivibrator D3 outputs a high-level pulse to drive MOSFET V10 to conduct and ground, causing MOSFET V8 to conduct. The power supply VCC_H2 is input to pin 12 of the double-pole double-throw relay K1 via the anti-reverse diode V5, making pin 12 of the double-pole double-throw relay K1 high-level. At the same time, the inverter D2 outputs a high-level signal to MOSFET V6, driving MOSFET V6 to conduct and ground, causing MOSFET V3 to conduct. The power supply VCC_H1 is input to pin 12 of the double-pole double-throw relay K1 via the anti-reverse diode V5, and pin 12 of the double-pole double-throw relay K1 remains high-level.

2. The dual-control protection type high-voltage control circuit according to claim 1, characterized in that, The duration of the output level signal pulse of the dual-frequency non-retrievable monostable multivibrator D3 is determined by the RC frequency converter composed of resistor R7 and capacitor C2.

3. The dual-control protection type high-voltage control circuit according to claim 1, characterized in that, When the control unit B outputs a high-level control signal or no output signal, the dual-frequency non-retrievable monostable multivibrator D3 is in a low-level state, the MOSFET V10 is in a cutoff state, and pin 12 of the double-pole double-throw relay K1 is in a floating state; at the same time, the inverter D2 outputs a low-level signal, the MOSFET V6 is in a cutoff state, and pin 12 of the double-pole double-throw relay K1 is in a floating state.

4. The dual-control protection type high-voltage control circuit according to claim 3, characterized in that, The voltage value of the power supply VCC_H1 is smaller than that of the starting power supply VCC_H2.

5. The dual-control protection type high-voltage control circuit according to claim 1, characterized in that, The control unit A and control unit B communicate and exchange data via serial port, and / or SPI, and / or CAN.

6. The dual-control protection type high-voltage control circuit according to claim 1, characterized in that, The control signals output by control unit A and control unit B are respectively connected to the power supply through pull-up resistors.

Images