A relay driving circuit with multiple protections for inter-box equalization

Abstract

The application discloses a relay driving circuit with multiple protections and used for inter-box balance, which comprises a PACK circuit body, wherein the PACK circuit body comprises an MCU, a relay driving power supply control circuit, a relay trigger signal circuit, a relay attraction delay circuit and a self-locking control circuit, a self-locking detection circuit, an attraction comparison signal control circuit, a safety protection module and a communication module; after the relay attraction signal is sent by the MCU, the relay attraction delay circuit and the self-locking control circuit wait for the LOCK output signal of the self-locking detection circuit through a delay circuit; the PACK circuit body is arranged to introduce negative feedback in a control loop, to realize circuit interlocking through feedback signals, so as to avoid faults; a fuse is arranged in a conduction loop to reduce the severity of faults; the communication and control signals of the MCU are combined to output, so that multiple protections of the relay control are realized, and the system safety and reliability are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of large-capacity battery energy storage, and particularly relates to a relay driving circuit used for inter-box balancing and having multiple protections. BACKGROUND

[0002] With the development of the large-capacity battery energy storage industry, high-voltage battery systems will inevitably be used in the design of large battery energy storage systems, that is, multiple boxes are connected in series. In order to maintain the consistency of the batteries in each box, balancing technology will be used to balance the power difference of each box. Because each box is connected in series, the voltage relative to the same reference point will be very different, and the use of relays with physical isolation characteristics is the mainstream choice in the industry during balancing. However, because each balancing circuit of each box needs to be equipped with a pair of relays for switching of the balancing circuit, there will be dozens of relays in a battery cluster that need to be coordinated on and off, and once there is a disturbance and false triggering, it may cause multiple boxes to be directly connected in parallel, resulting in a short circuit, thereby reducing the safety and reliability of the system. Therefore, we need to propose a relay driving circuit used for inter-box balancing and having multiple protections to solve the above problems. SUMMARY

[0003] The purpose of the present application is to provide a relay driving circuit used for inter-box balancing and having multiple protections, which can introduce negative feedback in the control loop, interlock the circuit through the feedback signal, and avoid the occurrence of faults; increase a fuse in the conduction loop to reduce the severity of the fault; combine the output of the communication and control signals of the MCU to realize multiple protection of the relay control, greatly improve the safety and reliability of the system, and solve the problems raised in the background technology.

[0004] To achieve the above purpose, the application adopts the following technical scheme:

[0005] A relay driving circuit used for inter-box balancing and having multiple protections, comprising a PACK circuit body, wherein the PACK circuit body comprises an MCU, a relay driving power supply control circuit, a relay trigger signal circuit, a relay pull-in delay circuit and a self-locking control circuit, a self-locking detection circuit, a pull-in comparison signal control circuit, a safety protection module and a communication module, one end of the relay driving power supply control circuit, the relay trigger signal circuit, the relay pull-in delay circuit and the self-locking control circuit, the self-locking detection circuit and the communication module is connected with the MCU, the other end of the self-locking detection circuit is connected with one end of the pull-in comparison signal control circuit, the other end of the pull-in comparison signal control circuit is connected with a connection terminal, and the connection terminal is connected with a battery box through the safety protection module.

[0006] The relay drive power supply control circuit is used to release the self-locking signal when switching the channel; the relay trigger signal circuit transmits the control signal to the self-locking detection circuit in advance after the MCU sends the relay opening signal, so that the self-locking detection circuit sends the self-locking signal COM before the relay is attracted; the relay attraction delay circuit and the self-locking control circuit wait for the output signal LOCK of the self-locking detection circuit through the delay circuit after the MCU sends the relay attraction signal; the self-locking detection circuit includes two input signals RELAY_SIG and COM, and the self-locking action is completed by comparing the order of the RELAY_SIG and COM signals after the relay receives the attraction instruction, so as to ensure that other box relays cannot be attracted again at the same time period after one box relay is attracted; the attraction comparison signal control circuit cooperates with the output signal LOCK of the self-locking detection circuit to determine whether the COM outputs or inputs the 12V signal.

[0007] Preferably, the relay drive power supply control circuit includes Q2, Q4, resistor R6 and resistor R13, the Q2 is set as a PMOS tube, the Q4 is set as an NMOS tube, one end of the Q2 is connected with one end of the Q4, two ends of the resistor R6 are connected with two ends of the Q2 respectively, the other end of the Q2 is connected with a 12V voltage, two ends of the resistor R13 are connected with two ends of the Q4 respectively, one end of the resistor R13 is connected with a resistor R9, and one end of the resistor R9 is connected with a POWER end of the MCU.

[0008] Preferably, the relay trigger signal circuit includes Q1, Q5, resistor R7, resistor R15 and resistor R10, two ends of the resistor R7 are connected with two ends of the Q1 respectively, the connection end of the resistor R7 and the Q1 is connected with one end of the Q5, two ends of the resistor R15 are connected with the other two ends of the Q5 respectively, and one end of the resistor R10 is connected with the connection end of the resistor R15 and the Q5.

[0009] Preferably, the relay attraction delay circuit and the self-locking control circuit include an electric controller RELAY, Q6 and Q7, the electric controller RELAY is connected in parallel with D1, one end of the electric controller RELAY is connected with the other end of the Q1, the other end of the electric controller RELAY is connected with one end of the Q6, the other two ends of the Q6 are connected with a resistor R16 and a capacitor C4 respectively, two ends of the capacitor C4 are connected with two ends of the Q7, two ends of the Q7 are connected with a resistor R11 and a resistor R18 respectively, the other end of the Q7 is connected with a resistor R14, one end of the resistor R18 is connected with one end of the resistor R14, and one end of the resistor R11 and the other end of the resistor R14 are connected with the MCU.

[0010] Preferably, the self-locking detection circuit comprises U1A, U1B, a delay circuit and D2, one end of the U1B is connected with one pin of the U1A through the resistor R20, the U1A is connected with the NPN type Q3 at two pins, one end of the Q3 is connected with one pin of the U1A through the resistor R12, the other pin of the Q3 and the three pin of the U1A are connected with the delay circuit, one end of the delay circuit is connected with the relay attraction delay circuit and the self-locking control circuit through the D2.

[0011] Preferably, the delay circuit comprises the resistor R1, the resistor R2, the resistor R3, the capacitor C2 and the capacitor C3, the resistor R1, the resistor R2 and the resistor R3 are connected in series, one end of the capacitor C2 is connected between the resistor R1 and the resistor R2, one end of the capacitor C3 is connected between the resistor R2 and the resistor R3, the other end of the capacitor C3 and the capacitor C2 is grounded.

[0012] Preferably, the attraction comparison signal control circuit comprises D3, Q8 and Q9, one end of the D3 is connected with the connection terminal, the other end of the D3 is connected with one end of the Q8, the other two ends of the Q8 are connected with the resistor R27, the connection end of the Q8 and the resistor R27 is connected with one end of the Q9, the other two ends of the Q9 are connected with the resistor R29 and the capacitor C5 in parallel, the connection end of the capacitor C5 and the resistor R19 is connected with the self-locking detection circuit through the resistor R28.

[0013] Preferably, the safety protection module comprises two fuses F, one end of the two fuses is connected with the control switch, one end of the control switch is connected with the connection terminal, the other end of the two fuses is connected with the positive and negative poles of the battery box.

[0014] Preferably, the communication module comprises the external communication terminal comprising two pins, the pin of the MCU comprises the TX pin and the RX pin, the two pins of the external communication terminal are connected with the TX pin and the RX pin respectively.

[0015] Preferably, the plurality of PACK circuit bodies are provided, and the same pins between the connection terminals on the plurality of PACK circuit bodies are connected by wires.

[0016] Compared with the prior art, the relay driving circuit for balancing between boxes and having multiple protections has the following advantages:

[0017] 1, the present application through MCU, relay drive power control circuit, relay trigger signal circuit, relay pull-in delay circuit and self-locking control circuit, self-locking detection circuit, pull-in comparison signal control circuit, safety protection module and communication module, can introduce negative feedback in control loop, through feedback signal interlocking circuit, to avoid the occurrence of failure; In the on loop increase fuse, to reduce the severity of the fault; In combination with the output of MCU communication and control signal, to realize the multiple protection of relay control, greatly improve the system safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 for the circuit diagram of the present application;

[0019] Figure 2 for the MCU and communication module connection circuit diagram of the present application;

[0020] Figure 3 for the circuit diagram of the present application relay drive power control circuit;

[0021] Figure 4 for the circuit diagram of the present application relay trigger signal circuit, relay pull-in delay circuit and self-locking control circuit;

[0022] Figure 5 for the circuit diagram of the present application self-locking detection circuit

[0023] Figure 6 for the circuit diagram of the present application pull-in comparison signal control circuit;

[0024] Figure 7 for the multiple PACK circuit body connection circuit diagram of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] The present application provides a Figures 1-5The relay driving circuit shown is used for inter-box equalization and has multiple protections, and includes a PACK circuit body, the PACK circuit body including an MCU, a relay driving power supply control circuit, a relay trigger signal circuit, a relay pull-in delay circuit and a self-locking control circuit, a self-locking detection circuit, a pull-in comparison signal control circuit, a safety protection module and a communication module, one end of the relay driving power supply control circuit, the relay trigger signal circuit, the relay pull-in delay circuit and the self-locking control circuit, the self-locking detection circuit and the communication module being connected with the MCU, the other end of the self-locking detection circuit being connected with one end of the pull-in comparison signal control circuit, the other end of the pull-in comparison signal control circuit being connected with a connection terminal, and the connection terminal being connected with a battery box through the safety protection module; (in the figure, module 1 is the relay driving power supply control circuit, module 2 is the relay trigger signal circuit, module 3 is the relay pull-in delay circuit and the self-locking control circuit, module 4 is the self-locking detection circuit, module 5 is the pull-in comparison signal control circuit, module 6 is the safety protection module, and module 7 is the communication module).

[0027] The relay driving power supply control circuit is used for releasing the self-locking signal when switching the channel; the relay trigger signal circuit delivers the control signal to the self-locking detection circuit in advance after the MCU sends the relay opening signal, so that the self-locking detection circuit sends the self-locking signal COM before the relay is pulled in; the relay pull-in delay circuit and the self-locking control circuit wait for the output signal LOCK of the self-locking detection circuit through the delay circuit after the MCU sends the relay pull-in signal; the self-locking detection circuit contains two input signals RELAY_SIG and COM, and completes the corresponding self-locking action by comparing the order of the RELAY_SIG and COM signals after the relay receives the pull-in instruction, so as to ensure that the relays of other battery boxes cannot be pulled in at the same time period after the relay of one battery box is pulled in; the pull-in comparison signal control circuit cooperates with the output signal LOCK of the self-locking detection circuit to determine whether the COM outputs or inputs the 12V signal;

[0028] The relay driving power supply control circuit includes Q2, Q4, a resistor R6 and a resistor R13, Q2 is set as a PMOS tube, Q4 is set as an NMOS tube, one end of Q2 is connected with one end of Q4, two ends of the resistor R6 are respectively connected with two ends of Q2, the other end of Q2 is connected with a 12V voltage, two ends of the resistor R13 are respectively connected with two ends of Q4, one end of the resistor R13 is connected with a resistor R9, one end of the resistor R9 is connected with the POWER end of the MCU, when the inter-box equalization is completed, the MCU lowers the POWER pin level to turn off the 12V power supply circuit, so as to reset the self-locking detection circuit.

[0029] The relay trigger signal circuit comprises Q1, Q5, resistor R7, resistor R15 and resistor R10, two ends of the resistor R7 are connected with two ends of the Q1 respectively, and the connection end of the resistor R7 and the Q1 is connected with one end of the Q5, two ends of the resistor R15 are connected with the other two ends of the Q5 respectively, one end of the resistor R10 is connected with the connection end of the resistor R15 and the Q5, when the MCU sends the relay opening signal MCU_IO, the control signal is transmitted to the self-locking detection circuit in advance, so that the self-locking circuit can send the self-locking signal COM before the relay is attracted.

[0030] The relay attraction delay circuit and the self-locking control circuit comprise the electric controller RELAY, Q6 and Q7, the electric controller RELAY is connected in parallel with D1, one end of the electric controller RELAY is connected with the other end of the Q1, the other end of the electric controller RELAY is connected with one end of the Q6, the other two ends of the Q6 are connected with the resistor R16 and the capacitor C4 respectively, two ends of the capacitor C4 are connected with two ends of the Q7, the Q7 is connected with the resistor R11 and the resistor R18 respectively, one end of the resistor R14 is connected with the other end of the resistor R18, one end of the resistor R11 and the other end of the resistor R14 are connected with the MCU, when the MCU sends the relay attraction signal MCU_IO, the delay circuit is formed through the resistor R11 and the capacitor C4, and the output signal LOCK of the self-locking detection circuit is waited. If the LOCK is low, the relay can be normally opened; if the LOCK is high, the driving voltage of the MOS tube Q6 is pulled down, and the relay cannot be opened.

[0031] The self-locking detection circuit comprises U1A, U1B, a delay circuit and D2, one end of the U1B is connected with one pin of the U1A through the resistor R20, the Q3 of the NPN type is connected with two pins of the U1A, one end of the Q3 is connected with one pin of the U1A through the resistor R12, the other pin of the Q3 and three pins of the U1A are connected with the delay circuit, one end of the delay circuit is connected with the relay attraction delay circuit and the self-locking control circuit through the D2.

[0032] The delay circuit comprises resistors R1, R2 and R3, a capacitor C2 and a capacitor C3, R1, R2 and R3 are connected in series, one end of the capacitor C2 is connected between R1 and R2, one end of the capacitor C3 is connected between R2 and R3, the other end of the capacitor C3 and the capacitor C2 is grounded, in the initial state, neither RELAY-SIG nor COM has a level input, when the MCU of PACK1 sends a relay attraction command, RELAY_SIG port will input a 12V signal, and COM port has no signal. The delay circuit makes the voltage at point A rise faster than that at point B, the voltage at the positive input end of the comparator is less than that at the negative input end, and the LOCK point is at a low level. U1B in turn outputs a high level, turns on Q8, and then the COM port becomes 12V. Since the MCU of PACK2 does not send a relay attraction command, PACK2's RELAY_SIG has no voltage input, and PACK2's COM port will be synchronized with PACK1's COM port voltage. At this time, the voltage at point B of PACK2 rises faster than that at point A, the voltage at the positive input end of the comparator is greater than that at the negative input end, the LOCK point is at a high level, Q22 and Q18 are turned on, and therefore the MCU of PACK2 outputs an attraction command, which cannot start the drive circuit, and the relay cannot be normally attracted. In addition, since the LOCK point is at a high level, Q14 triode is turned on, continuously pulling down the negative input end of U3A, and continuously locking the LOCK point state until the power supply is restarted and reset.

[0033] The attraction comparison signal control circuit comprises D3, Q8 and Q9, one end of D3 is connected with the connection terminal, the other end of D3 is connected with one end of Q8, resistors R27 is connected between the other two ends of Q8, one end of Q8 connected with resistor R27 is connected with one end of Q9, the other two ends of Q9 are connected with resistor R29 and capacitor C5 in parallel, the connection end of capacitor C5 and resistor R19 is connected with the self-locking detection circuit through resistor R28, if the box is the first battery box in which the relay is turned on, COM will output a 12V signal; if the box is not the first battery box in which the relay is turned on, COM will receive a 12V signal input by other boxes.

[0034] The safety protection module comprises two fuses F, one end of the two fuses is connected with a control switch, one end of the control switch is connected with the connection terminal, the other end of the two fuses is connected with the positive and negative poles of the battery box, when two box relays are attracted at the same time due to extreme abnormal conditions, the fuse in the main circuit will be blown due to the rising current caused by the short circuit of the box, preventing further damage from being expanded.

[0035] The communication module comprises external communication terminals comprising two pins, the pins of the MCU comprise a TX pin and a RX pin, the two pins of the external communication terminals are connected with the TX pin and the RX pin respectively, the MCU of the driving module keeps real-time communication with the control module, and the relay closing and opening requirements from the control module are executed in real time. The short circuit caused by the simultaneous closing of the relays of multiple boxes is prevented.

[0036] As shown in Figure 6 The PACK circuit bodies are provided with multiple connection terminals, the same pins between the connection terminals on the multiple PACK circuit bodies are connected by wires, and the multiple battery boxes are balanced for use.

[0037] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing embodiments of the present application are described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included in the protection scope of the present application.

Claims

1. A relay drive circuit for balanced use between enclosures and equipped with multiple protections, comprising a PACK circuit body, wherein the PACK circuit body includes an MCU, a relay drive power supply control circuit, a relay trigger signal circuit, a relay engagement delay circuit and self-locking control circuit, a self-locking detection circuit, an engagement comparison signal control circuit, a safety protection module, and a communication module, characterized in that: One end of the relay drive power supply control circuit, relay trigger signal circuit, relay engagement delay circuit, self-locking control circuit, self-locking detection circuit, and communication module is connected to the MCU. The other end of the self-locking detection circuit is connected to one end of the engagement comparison signal control circuit. The other end of the engagement comparison signal control circuit is connected to a connection terminal, which is connected to the battery box through a safety protection module. The relay drive power supply control circuit is used to release the self-locking signal when switching channels; the relay trigger signal circuit transmits the control signal to the self-locking detection circuit in advance after the MCU sends the relay open signal, so that the self-locking detection circuit sends the self-locking signal COM before the relay is energized; the relay energizing delay circuit and the self-locking control circuit wait for the self-locking detection circuit to output the signal LOCK after the MCU sends the relay energizing signal; the self-locking detection circuit includes two input signals RELAY_SIG and COM. After the relay receives the energizing command, it completes the corresponding self-locking action by comparing the order of the RELAY_SIG and COM signals, ensuring that when one cabinet relay is energized, other cabinet relays cannot be energized at the same time; the energizing comparison signal control circuit, together with the output signal LOCK of the self-locking detection circuit, determines whether COM outputs or inputs a 12V signal.

2. The relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The relay drive power supply control circuit includes Q2, Q4, resistor R6, and resistor R13. Q2 is a PMOS transistor, and Q4 is an NMOS transistor. One end of Q2 is connected to one end of Q4. The two ends of resistor R6 are connected to two ends of Q2 respectively. The other end of Q2 is connected to a 12V voltage. The two ends of resistor R13 are connected to two ends of Q4 respectively. One end of resistor R13 is connected to resistor R9. One end of resistor R9 is connected to the POWER terminal of the MCU.

3. The relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The relay trigger signal circuit includes Q1, Q5, resistors R7, R15 and R10. The two ends of resistor R7 are respectively connected to one end of Q1, and the connection end of resistor R7 and Q1 is connected to one end of Q5. The two ends of resistor R15 are respectively connected to the other two ends of Q5. One end of resistor R10 is connected to the connection end of resistors R15 and Q5.

4. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 3, characterized in that: The relay engagement delay circuit and self-locking control circuit include an electrical controller RELAY, Q6, and Q7. The electrical controller RELAY is connected in parallel with D1. One end of the electrical controller RELAY is connected to the other end of Q1. The other end of the electrical controller RELAY is connected to one end of Q6. The other two ends of Q6 are respectively connected to a resistor R16 and a capacitor C4. The two ends of the capacitor C4 are connected to one end of Q7. The two ends of Q7 are respectively connected to a resistor R11 and a resistor R18. The other end of Q7 is connected to a resistor R14, and one end of the resistor R18 is connected to one end of the resistor R14. One end of the resistor R11 and the other end of the resistor R14 are both connected to the MCU.

5. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The self-locking detection circuit includes U1A, U1B, a delay circuit, and D2. One end of U1B is connected to one pin of U1A through resistor R20. The second pin of U1A is connected to an NPN type Q3. One end of Q3 is connected to one pin of U1A through resistor R12. The other pin of Q3 and the third pin of U1A are both connected to the delay circuit. One end of the delay circuit is connected to the relay activation delay circuit and the self-locking control circuit through D2.

6. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 5, characterized in that: The delay circuit includes resistors R1, R2, and R3, and capacitors C2 and C3. R1, R2, and R3 are connected in series. One end of capacitor C2 is connected between resistors R1 and R2, and one end of capacitor C3 is connected between resistors R2 and R3. The other ends of capacitors C3 and C2 are grounded.

7. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The latching comparison signal control circuit includes D3, Q8, and Q9. One end of D3 is connected to a connection terminal, and the other end of D3 is connected to one end of Q8. A resistor R27 is connected between the other two ends of Q8. The connection point of Q8 and resistor R27 is connected to one end of Q9. A resistor R29 and a capacitor C5 are connected in parallel between the other two ends of Q9. The connection point of capacitor C5 and resistor R19 is connected to the self-locking detection circuit through resistor R28.

8. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The safety protection module includes two fuses F. One end of each fuse is connected to a control switch, one end of which is connected to a connection terminal. The other ends of the two fuses are connected to the positive and negative terminals of the battery box.

9. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The communication module includes an external communication terminal with two pins. The MCU has pins including a TX pin and an RX pin. The two pins of the external communication terminal are connected to the TX pin and the RX pin, respectively.

10. A relay drive circuit for balanced use between enclosures and with multiple protections as described in claim 1, characterized in that: The PACK circuit body is provided with multiple PACK circuit bodies, and the same pins between the connection terminals on the multiple PACK circuit bodies are connected by wires.

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