A zero-power sleep circuit system based on BMS and relay control

Abstract

This utility model discloses a zero-power sleep circuit system based on BMS and relay control, relating to the field of battery management system technology. The zero-power sleep circuit system includes a power battery, a battery management system, a charging relay, a discharging relay, a power supply relay, a three-position self-resetting rotary switch, and a first isolated DC / DC converter. The charging relay is electrically connected to the charging line of the power battery, and the discharging relay is electrically connected to the discharging line of the power battery. The power supply relay is connected in series with the first isolated DC / DC converter and in parallel with the three-position self-resetting rotary switch. When the three-position self-resetting rotary switch is rotated to the upper position, the battery management system controls the discharging relay, charging relay, and power supply relay to disconnect, and the first isolated DC / DC converter and the battery management system are in a stopped state. This zero-power sleep circuit system achieves a complete logic for power-down control operation, preventing circuit system failures.

Description

Technical Field

[0001] This utility model belongs to the field of battery management system technology, specifically relating to a zero-power sleep circuit system based on BMS and relay control. Background Technology

[0002] With the continuous development of electronic devices, the requirements for the safety, stability, and reliability of battery systems are becoming increasingly stringent. Battery Management Systems (BMS) are primarily used for real-time monitoring of electric vehicle battery parameters, fault diagnosis, SOC estimation, range estimation, short-circuit protection, leakage detection, display and alarm functions, and charging / discharging mode selection. Existing battery systems have some shortcomings in power control; for example, the logic of power-down control operations is not sufficiently robust, which can easily lead to battery system malfunctions, affecting the normal use of equipment and potentially causing safety hazards. Utility Model Content

[0003] The purpose of this invention is to provide a zero-power sleep circuit system based on BMS and relay control that is simple in structure and reasonably designed to solve the above problems.

[0004] This utility model achieves the above objectives through the following technical solutions:

[0005] A zero-power sleep circuit system based on BMS and relay control includes a power battery, a battery management system, a charging relay, a discharging relay, a power supply relay, a three-position self-resetting rotary switch, and a first isolated DC / DC converter. The charging relay is electrically connected to the charging line of the power battery, and the discharging relay is electrically connected to the discharging line of the power battery. The power supply relay is connected in series with the first isolated DC / DC converter, and the first isolated DC / DC converter is electrically connected to the battery management system. The power supply relay is connected in parallel with the three-position self-resetting rotary switch. The three-position self-resetting rotary switch is used to control the working state of the battery management system. The battery management system is used to control the opening and closing states of the charging relay, the discharging relay, and the power supply relay respectively. When the three-position self-resetting rotary switch is rotated to the upper position, and the battery management system controls the discharging relay, the charging relay, and the power supply relay to disconnect respectively, the first isolated DC / DC converter and the battery management system are in a stopped working state.

[0006] As a further optimization of this utility model, the power battery includes a lithium battery.

[0007] As a further optimization of this utility model, when the three-position self-reset rotary switch is rotated to the power-on position, the power supply relay is short-circuited, and the power battery is used to power up the battery management system through the power supply relay and the first isolated DC / DC in sequence. The short-circuit duration of the power supply relay is a first set duration.

[0008] As a further optimization of this utility model, the first isolated DC / DC converter is electrically connected to the battery management system via diode D2.

[0009] As a further optimization of this utility model, the battery management system is connected to the power battery through a sampling line, which is used to collect the voltage of the power battery. A temperature probe is installed on the power battery, and the temperature probe is electrically connected to the battery management system.

[0010] As a further optimization of this utility model, the zero-power sleep circuit system also includes a pre-charge relay, which is electrically connected in series with a pre-charge resistor, and the pre-charge relay and the charging relay are connected in parallel. The battery management system is also used to control the opening and closing state of the pre-charge relay. When the pre-charge relay is closed, both the discharge relay and the charging relay are open, and the power battery pre-charges the pre-charge resistor through the pre-charge relay.

[0011] As a further optimization of this utility model, the zero-power sleep circuit system also includes a second isolated DC / DC converter and an external power supply, wherein the external power supply is electrically connected to the battery management system through the second isolated DC / DC converter.

[0012] As a further optimization of this utility model, the zero-power sleep circuit system also includes a CAN communication connector, which is electrically connected to the battery management system.

[0013] As a further optimization of this utility model, the zero-power sleep circuit system also includes a fuse, and the power battery is connected to the fuse.

[0014] The present invention has at least the following beneficial effects: The zero-power sleep circuit system based on BMS and relay control provided by the present invention, during the power-down control process, uses the battery management system to control the discharge relay, charging relay and power supply relay to disconnect, so that the main circuit of the power battery is completely isolated from the external load. That is, the first isolation DC / DC and the battery management system are in a stopped working state, so that the entire system circuit is completely de-energized and in a zero-power state, effectively avoiding battery system failure and having a high safety factor;

[0015] Moreover, during the power-on process, by operating the three-position self-reset knob switch to the power-on position and holding it for a certain period of time, the battery management system begins to control the power supply relay to disconnect. At the same time, it controls the charging relay and the discharging relay to disconnect. The first isolated DC / DC and the battery management system are in a stopped working state to ensure stable power-on.

[0016] In addition, by using the pre-charging operation of the pre-charging resistor, the discharge relay and charging relay are not directly closed when the system is powered on, which would cause the capacitor in the circuit to generate a huge surge current, potentially damaging the relay contacts, fuses, electronic components on the circuit board, etc., thus ensuring the safety of the circuit system.

[0017] Furthermore, based on this circuit system, the battery management system controls the discharge relay and the power supply relay so that when the power battery charge is too low, the first isolation DC / DC and the battery management system can be stopped in time, the entire system circuit is completely de-energized and in a zero-power state. When the system is woken up, an external power supply is used to perform an emergency wake-up operation on the power battery, while providing emergency power to the battery management system to ensure that the system is not damaged or malfunctions. Attached Figure Description

[0018] Figure 1 This is a system diagram of a zero-power sleep circuit based on BMS and relay control according to this utility model.

[0019] In the diagram: 1. Power battery; 2. Battery management system; 3. Pre-charge relay; 4. Discharge relay; 5. Charging relay; 6. Pre-charge resistor; 7. Power supply relay; 8. First isolation DC / DC converter; 9. Second isolation DC / DC converter; 10. Diode D2; 11. Diode D1; 12. Fuse; 13. Hall current sensor; 14. Temperature probe; 15. Three-position self-resetting rotary switch; 16. Discharge positive terminal; 17. Charging positive terminal; 18. External power supply; 19. CAN communication connector; 20. Charging negative terminal; 21. Discharge negative terminal. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] like Figure 1As shown, this utility model provides a zero-power sleep circuit system based on BMS and relay control, including a power battery 1, a battery management system 2, a charging relay 5, a discharging relay 4, a power supply relay 7, a three-position self-resetting rotary switch 15, and a first isolated DC / DC converter 8. The power battery 1 includes a lithium battery. The charging relay 5 is electrically connected to the charging line of the power battery 1, and the discharging relay 4 is electrically connected to the discharging line of the power battery 1. The power supply relay 7 is connected in series with the first isolated DC / DC converter 8, and the first isolated DC / DC converter 8 is electrically connected to the battery management system 2. The power supply relay 7 is connected in parallel with the three-position self-resetting rotary switch 15. The three-position self-resetting rotary switch 15 controls the working state of the battery management system 2. The battery management system 2 controls the opening and closing states of the charging relay 5, the discharging relay 4, and the power supply relay 7 respectively. When the three-position self-resetting rotary switch 15 is rotated to the upper position, the battery management system 2 controls the discharging relay 4, the charging relay 5, and the power supply relay 7 to disconnect, thus completely isolating the main circuit of the power battery 1 from the external load. The first isolation DC / DC8 and the battery management system 2 are in a stopped state, making the entire system circuit completely de-energized and in a zero-power state. This avoids the risk of overheating and fire caused by continuous discharge due to circuit faults when the power battery 1 is used in equipment such as vehicles that are parked for a long time without being de-energized. The zero-power state of the entire circuit system can effectively eliminate such hidden dangers. In addition, the zero-power state can reduce the side reaction of slow chemical reactions in the power battery 1 caused by long-term energization, even in a low-power state, which leads to capacity decay. This reduces the battery aging rate. Moreover, after the system is de-energized, the power supply to high-voltage components such as the battery management system 2 and the first isolation DC / DC8 is completely cut off. When maintenance personnel touch the circuit, there is no need to worry about electric shock. Therefore, through the above-mentioned perfect power-down control logic, battery system failures are effectively avoided, resulting in a high safety factor.

[0022] In this configuration, when the three-position self-resetting rotary switch 15 is rotated to the power-on position, it must be held for 3 seconds, and the battery management system 2 must receive a power-off signal for 3 seconds. Only after this signal has lasted for 3 seconds will the battery management system 2 begin to control the power supply relay 7 to disconnect, and simultaneously control the charging relay 5 and the discharging relay 4 to disconnect. The first isolated DC / DC 8 and the battery management system 2 are then in a stopped state. It should be noted that holding the switch for 3 seconds is to ensure operational reliability and avoid accidental misoperation. If the three-position self-resetting rotary switch 15 is rotated to the power-on position for only 0.5 seconds, it indicates that the system may have been triggered accidentally by vibration or accidental contact, and the system will not perform a power-off operation. In other embodiments, the time could be 4 seconds, 4.5 seconds, 5 seconds, etc., and is not limited here.

[0023] It should be noted that, Figure 1 The positive discharge terminal 16 and negative discharge terminal 21 are used to connect to external electrical equipment, enabling the power battery 1 to provide power to these devices. The positive charging terminal 17 and negative charging terminal 20 are used to connect to an external power source, enabling the external power source to charge the power battery 1. The positive and negative terminals are connected accordingly.

[0024] It should be noted that the control logic of this circuit system during power-on control is as follows: When the three-position self-resetting rotary switch 15 is rotated to the power-on position, the power supply relay 7 is short-circuited. The power battery 1 is used to power up the battery management system 2 sequentially through the power supply relay 7 and the first isolated DC / DC 8. The short-circuit duration of the power supply relay 7 is a first set duration. The first set duration is 3 to 4 seconds, preferably 3 seconds. During these 3 seconds, when the three-position self-resetting rotary switch 15 is rotated to the power-on position, its contacts directly "short-circuit" the two ends of the power supply relay 7. By bypassing the coil control circuit of the power supply relay 7 through a physical wire, the main contacts of the power supply relay 7 are forced to close, thereby enabling the battery management system 2 to be powered on. After 3 seconds, the three-position self-resetting rotary switch 15 is released.

[0025] Among them, such as Figure 1 As shown, the first isolation DC / DC 8 is electrically connected to the battery management system 2 through diode D111. Diode D111 prevents reverse current flow. That is, when the isolation DC / DC 8 outputs a stable voltage, diode D111 allows current to flow forward to the battery management system 2. However, if the voltage reverses due to some reason (such as power fluctuations, faults, etc.), diode D111 will block the reverse current, thus protecting the battery management system 2 from damage by reverse voltage and improving the reliability and stability of the system.

[0026] For example, the battery management system 2 is connected to the power battery 1 via a sampling line. The sampling line is used to collect the voltage of the power battery 1. The power battery 1 is equipped with a temperature probe 14, which is electrically connected to the battery management system 2.

[0027] The zero-power sleep circuit system also includes a pre-charge relay 3, which is electrically connected in series with a pre-charge resistor 6, and the pre-charge relay 3 is connected in parallel with the charging relay 5. The battery management system 2 is also used to control the opening and closing state of the pre-charge relay 3. When the pre-charge relay 3 is closed, the discharge relay 4 and the charging relay 5 are both open, and the power battery 1 pre-charges the pre-charge resistor 6 through the pre-charge relay 3.

[0028] After power-on, the battery management system 2 will collect the voltage and temperature data obtained in the above manner and perform self-test analysis to determine whether the functions of the power battery 1 components are normal. If normal, it will control the pre-charge relay 3 to close, and the power battery 1 will pre-charge the pre-charge resistor 6 connected in series through the pre-charge relay 3.

[0029] After pre-charging is complete, the battery management system 2 controls the discharge relay 4 and charging relay 5 to close, and then opens the pre-charge relay 3 after 1 second. If the discharge relay 4 and charging relay 5 are closed directly when the system is powered on, the capacitor in the circuit connected after the pre-charge resistor 6 is moved away from the power battery 1 will instantly generate a huge surge current, which may damage the relay contacts, fuses, electronic components on the circuit board, etc. By pre-charging the pre-charge resistor 6 first, the current is limited by the series-connected pre-charge resistor 6, allowing the capacitor in the circuit connected after the pre-charge resistor 6 is moved away from the power battery 1 to charge slowly, thus avoiding the generation of surge current.

[0030] When a system malfunctions, the battery management system 2 disconnects the corresponding relays to ensure the safety of the system circuit. It should be noted that during pre-charging, discharging, or charging, any situation exceeding the normal operating range, such as overcurrent, overvoltage, undervoltage, or overheating, constitutes a system malfunction. For example, in the case of an overcharge malfunction, the battery management system 2 will disconnect the charging relay 5; in the case of an over-discharge malfunction, it will disconnect the discharging relay 4; and in the case of a malfunction during pre-charging, it will disconnect the pre-charge relay 3. In some severe malfunctions, multiple relays may be disconnected simultaneously. For example, in the event of a severe overcurrent or short circuit malfunction, the power supply relay 7, charging relay 5, and discharging relay 4 may be disconnected to completely cut off the connection between the power battery 1 and the external circuit, ensuring the safety of the system circuit.

[0031] For example, such as Figure 1 As shown, the zero-power sleep circuit system also includes a second isolated DC / DC 9 and an external power supply 18, which is electrically connected to the battery management system 2 via the second isolated DC / DC 9.

[0032] Based on the above circuit system, the control logic during sleep and wake-up operations is as follows:

[0033] Hibernation: When the battery management system 2 detects that the power battery 1 has too low a charge (below the set threshold, such as 5% to 10% SOC), the battery management system 2 controls the discharge relay 4 to open to prevent the battery from being over-discharged and damaged. If no charging operation is detected within 1 minute, the power supply relay 7 will then be opened, causing the first isolation DC / DC 8 and the battery management system 2 to stop working. The entire circuit system loop is completely de-energized and in a zero-power state. If a charging action is detected within 1 minute, the power supply relay 7 will not be opened again to avoid system power failure.

[0034] Wake-up: The wake-up operation is performed by manually rotating the three-position self-reset knob switch 15 to the power-on position.

[0035] In other embodiments, if the power battery 1 has too low a charge and cannot be woken up by operating the three-position self-reset rotary switch 15, an external power supply 18 can be used to output a stable voltage through the second isolated DC / DC 9, which is then passed through diode D2 to perform an emergency wake-up operation on the power battery 1, while simultaneously providing emergency power to the battery management system 2. It should be noted that the voltage range of the external power supply 18 is 12–32V to ensure that the system will not be damaged or malfunction during emergency power supply.

[0036] For example, the zero-power sleep circuit system also includes a CAN communication connector 19, which is electrically connected to the battery management system 2. Figure 1 As shown, it is connected to the battery management system (BMS) 2 through the CAN_H, CAN_L and CAN_G interfaces for data transmission between the battery management system 2 and external devices. For example, the data that the battery management system 2 needs to transmit to the outside includes the voltage, current, temperature and SOC (remaining charge) of the power battery 1.

[0037] For example, the zero-power sleep circuit system also includes a fuse 12, and the power battery 1 is connected to the fuse 12. When a short circuit occurs in the main circuit of the power battery 1 or the battery management system 2 (such as relay sticking or cable damage), the current will rise sharply. The fuse 12 will melt due to overload, cutting off the circuit and preventing the lithium battery from overheating, catching fire, or the components in the battery management system 2 from burning out. That is, the fuse 12 can play the role of overcurrent protection for the circuit system.

[0038] Furthermore, the power battery 1 is electrically connected to the Hall current sensor 13. The Hall current sensor is installed in the circuit of the power battery 1 to monitor the current in the circuit in real time. It can accurately obtain the current value, whether it is the discharge current or the charging current of the power battery 1. The Hall current sensor 13 feeds back the monitored current data to the battery management system 2. The battery management system 2 can perform various operations based on this data, such as judging the charging and discharging state of the power battery 1 and calculating the remaining power capacity (SOC) of the power battery 1.

[0039] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A zero power sleep circuitry based on BMS and relay control, characterized by, The system includes a power battery (1), a battery management system (2), a charging relay (5), a discharging relay (4), a power supply relay (7), a three-position self-resetting rotary switch (15), and a first isolated DC / DC converter (8). The charging relay (5) is electrically connected to the charging line of the power battery (1), the discharging relay (4) is electrically connected to the discharging line of the power battery (1), the power supply relay (7) is connected in series with the first isolated DC / DC converter (8), and the first isolated DC / DC converter (8) is electrically connected to the battery management system (2). The three-position self-resetting rotary switch (15) is connected in parallel with the battery management system (2). The three-position self-resetting rotary switch (15) is used to control the working state of the battery management system (2). The battery management system (2) is used to control the opening and closing states of the charging relay (5), the discharging relay (4), and the power supply relay (7) respectively. When the three-position self-resetting rotary switch (15) is rotated to the upper position, and the battery management system (2) controls the discharging relay (4), the charging relay (5), and the power supply relay (7) to be disconnected respectively, the first isolated DC / DC (8) and the battery management system (2) are in a stopped working state.

2. A zero power sleep circuit system based on BMS and relay control according to claim 1, characterized in that, The power battery (1) includes a lithium battery.

3. A zero power sleep circuit system based on BMS and relay control according to claim 2, characterized in that, When the three-position self-reset rotary switch (15) is rotated to the power-on position, the power supply relay (7) is short-circuited, and the power battery (1) is used to power up the battery management system (2) through the power supply relay (7) and the first isolated DC / DC (8) in sequence. The short-circuit duration of the power supply relay (7) is the first set duration.

4. The zero power sleep circuit system based on BMS and relay control according to claim 3, characterized in that, The first isolated DC / DC (8) is electrically connected to the battery management system (2) through diode D1 (11).

5. A zero power sleep circuit system based on BMS and relay control according to claim 4, characterized in that, The battery management system (2) is connected to the power battery (1) via a sampling line. The sampling line is used to collect the voltage of the power battery (1). A temperature probe (14) is installed on the power battery (1), and the temperature probe (14) is electrically connected to the battery management system (2).

6. A zero power sleep circuit system based on BMS and relay control according to claim 5, characterized in that, The zero-power sleep circuit system also includes a pre-charge relay (3), which is electrically connected in series with a pre-charge resistor (6) and is connected in parallel with a charging relay (5). The battery management system (2) is also used to control the opening and closing state of the pre-charge relay (3). When the pre-charge relay (3) is closed, the discharge relay (4) and the charging relay (5) are both open, and the power battery (1) pre-charges the pre-charge resistor (6) through the pre-charge relay (3).

7. A zero-power sleep circuit system based on BMS and relay control according to claim 6, characterized in that, The zero-power sleep circuit system also includes a second isolated DC / DC (9) and an external power supply (18), the external power supply (18) being electrically connected to the battery management system (2) via the second isolated DC / DC (9).

8. A zero power sleep circuit system based on BMS and relay control according to claim 7, characterized in that, The zero-power sleep circuit system also includes a CAN communication connector (19), which is electrically connected to the battery management system (2).

9. A zero power sleep circuit system based on BMS and relay control according to claim 8, characterized in that, The zero-power sleep circuit system also includes a fuse (12), and the power battery (1) is connected to the fuse (12).

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