BMS system power supply unit and electric vehicle

Abstract

This invention relates to the field of electric vehicle technology, providing a BMS system power supply device and an electric vehicle. The BMS system power supply device includes a power conversion module and a wake-up module. The first input terminal of the power conversion module is connected to the electric vehicle's power battery, and the output terminal is connected to the electric vehicle's BMS system. It converts the output voltage of the power battery to supply power to the BMS system, enabling the BMS system to manage the power battery. The output terminal of the wake-up module is connected to the second input terminal of the power conversion module, used to control the operating state of the power conversion module. The wake-up module is powered by the electric vehicle's low-voltage battery. This invention can reduce wear and tear on the power battery, improve its lifespan, and simultaneously, the power conversion module can replenish power to the low-voltage battery, maximizing its power supply time.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle technology, and particularly relates to a BMS system power supply device and an electric vehicle. Background Technology

[0002] In pure electric new energy vehicles, the high-voltage power battery accounts for about half of the total vehicle cost, making it an extremely important component. If the high-voltage power battery becomes depleted, it will cause irreversible damage to the battery, or even lead to battery failure, resulting in significant losses.

[0003] Therefore, pure electric vehicles are generally equipped with a BMS (Battery Management System) to manage the power battery. The BMS system cannot operate continuously with power; if it does, it will continuously degrade the battery, affecting its lifespan. If the vehicle is not used for a long period, it may even cause battery failure. To reduce this degradation, a wake-up device is currently used to control the power converter to periodically power on the BMS system, allowing it to periodically monitor and manage the power battery. However, in existing technology, because the wake-up device is powered by the power battery and remains powered continuously from the date the vehicle leaves the factory, this increases the degradation of the power battery. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a BMS system power supply device and an electric vehicle to reduce the power battery wear caused by the BMS system wake-up device in the electric vehicle.

[0005] A first aspect of the present invention provides a power supply device for a BMS system, comprising:

[0006] Power conversion module and wake-up module;

[0007] The first input terminal of the power conversion module is connected to the power battery of the electric vehicle, and the output terminal is connected to the BMS system of the electric vehicle. It is used to convert the output voltage of the power battery to supply power to the BMS system so that the BMS system can manage the power battery.

[0008] The output terminal of the wake-up module is connected to the second input terminal of the power conversion module to control the working state of the power conversion module;

[0009] The wake-up module is powered by the low-voltage battery of the electric vehicle.

[0010] Optionally, the operating states of the power conversion module include an on state and an off state;

[0011] The wake-up module is used to control the power conversion module to be in the on state every first preset time interval, and to control the power conversion module to be in the off state after the power conversion module has been in the on state for a second preset time interval.

[0012] The first preset duration is longer than the second preset duration.

[0013] Optionally, the output of the power conversion module is also connected to the low-voltage battery via a relay, and the on / off state of the relay is controlled by hardwired control of the electric vehicle.

[0014] When the power conversion module is in the ON state, the relay closes, and the power conversion module is also used to charge the low-voltage battery.

[0015] The relay disconnects when the power conversion module is in the off state.

[0016] Optionally, the output terminals of the power conversion module include a positive output terminal and a negative output terminal, with the positive output terminal connected to the positive terminal of the low-voltage battery and the negative output terminal connected to the negative terminal of the low-voltage battery.

[0017] The relay is connected between the positive output terminal and the positive terminal of the low-voltage battery;

[0018] Alternatively, the relay is connected between the negative output terminal and the negative terminal of the low-voltage battery.

[0019] Optionally, the wake-up module includes:

[0020] Conversion circuit, timing switch circuit and auxiliary management chip;

[0021] The input terminal of the conversion circuit is connected to the low-voltage battery, and the output terminal is connected to the input terminal of the timing switch circuit, which is used to convert the voltage output by the low-voltage battery.

[0022] The output of the timing switch circuit is connected to the power supply pin of the auxiliary management chip for timing to turn on or off; when the timing switch circuit is on, the auxiliary management chip is powered on and outputs a control signal to control the working state of the power conversion module.

[0023] Optionally, the output terminals of the conversion circuit include a first output terminal and a second output terminal, and the timing switch circuit includes a first switching transistor, a second switching transistor, and a clock chip;

[0024] The first output terminal is connected to the drain of the first switching transistor through the first diode, the source of the first switching transistor is connected to the auxiliary management chip, and the gate of the first switching transistor is connected to the drain of the second switching transistor through the second diode.

[0025] The second output terminal is connected to the gate of the second switching transistor through the first resistor, and the source of the second switching transistor is connected to the interrupt pin and the power supply pin of the clock chip, respectively.

[0026] A second resistor is also connected between the drain and gate of the first switching transistor;

[0027] A third resistor is also connected between the interrupt pin and the power supply pin of the clock chip.

[0028] Optionally, the conversion circuit includes:

[0029] Voltage divider resistors, Zener diodes, electrolytic capacitors, and voltage regulator chips;

[0030] The voltage divider resistor and the Zener diode are connected in series to form a series branch. One end of the series branch closest to the voltage divider resistor is connected to the low-voltage battery, and the other end is grounded.

[0031] The first output terminal is drawn from the midpoint of the series connection between the voltage divider resistor and the Zener diode.

[0032] An electrolytic capacitor is connected in parallel with a Zener diode. One end of the electrolytic capacitor is connected to the ground pin of the Zener chip, and the other end is connected to the voltage input pin of the Zener chip. The voltage output pin of the Zener chip leads out to the second output terminal.

[0033] A second aspect of the present invention provides an electric vehicle, including a power battery, a low-voltage storage battery, a BMS system, and a BMS system power supply device as described above.

[0034] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows:

[0035] The BMS system power supply device provided in this embodiment of the invention includes a power conversion module and a wake-up module. The power conversion module converts the output voltage of the power battery to supply power to the BMS system, enabling the BMS system to manage the power battery. The wake-up module controls the operating state of the power conversion module and is powered by the low-voltage battery of the electric vehicle. Compared to the prior art where the wake-up module is powered by the power battery, changing the wake-up module to be powered by the low-voltage battery significantly reduces the wear and tear on the power battery and improves its lifespan. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the power supply device for the BMS system provided in an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the power supply device for the BMS system provided in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the wake-up module provided in an embodiment of the present invention;

[0040] Figure 4 This is an example diagram of an electric vehicle provided in an embodiment of the present invention. Detailed Implementation

[0041] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0042] To illustrate the technical solution described in this invention, specific embodiments are described below.

[0043] In pure electric new energy vehicles, the high-voltage power battery accounts for about half of the total vehicle cost, making it an extremely important component. If the high-voltage power battery becomes depleted, it will cause irreversible damage, even leading to battery failure, resulting in significant losses for the entire vehicle. Therefore, pure electric vehicles are generally equipped with a Battery Management System (BMS) to manage the power battery, and include a corresponding monitoring power supply (including a timed wake-up module and a power conversion module). This monitoring power supply has a timed self-wake-up function, and upon wake-up, it supplies power to the BMS system, allowing the BMS system to detect power battery information and report it to the backend monitoring system. In existing technology, because this monitoring power supply is provided by the power battery and is continuously powered from the date the vehicle leaves the factory, it increases the wear and tear on the power battery.

[0044] To reduce wear and tear on the power battery, see [link / reference] Figure 1 As shown, this embodiment of the invention provides a BMS system power supply device, the device 10 including:

[0045] Power conversion module 11 and wake-up module 12.

[0046] The first input terminal of the power conversion module 11 is connected to the power battery of the electric vehicle, and the output terminal is connected to the BMS system of the electric vehicle. It is used to convert the output voltage of the power battery to supply power to the BMS system so that the BMS system can manage the power battery.

[0047] The output terminal of the wake-up module 12 is connected to the second input terminal of the power conversion module, and is used to control the operating state of the power conversion module. The wake-up module 12 is powered by the low-voltage battery of the electric vehicle.

[0048] In this embodiment of the invention, since the wake-up module 12 needs to periodically wake up the power conversion module 11 to ensure the BMS system is periodically powered on, the wake-up module 12 requires uninterrupted power supply from the date of manufacture. In the prior art, the wake-up module 12 is usually powered by the electric vehicle's power battery, leading to increased wear and tear on the power battery and shortening its lifespan. Therefore, this embodiment of the invention replaces the wake-up module 12 with power from the electric vehicle's low-voltage battery to eliminate the wear and tear on the power battery caused by the wake-up module 12. Although the wake-up module 12 still causes wear and tear on the low-voltage battery, it is cheaper and easier to replace than the power battery, which is more in line with the user's interests.

[0049] As can be seen, the BMS system power supply device 10 provided in this embodiment of the invention includes a power conversion module 11 and a wake-up module 12. The power conversion module 11 is used to convert the output voltage of the power battery to supply power to the BMS system, so that the BMS system can manage the power battery. The wake-up module 12 is used to control the working state of the power conversion module, and the wake-up module 12 is powered by the low-voltage battery of the electric vehicle. Compared with the prior art where the wake-up module 12 is powered by the power battery, by changing the wake-up module 12 to be powered by the low-voltage battery, the wear and tear on the power battery is greatly reduced, and the life of the power battery is improved.

[0050] Optionally, the operating states of the power conversion module 11 include an on state and an off state.

[0051] The wake-up module 12 is used to control the power conversion module 11 to be in the on state at first preset intervals, and to control the power conversion module 12 to be in the off state after the power conversion module 11 has been in the on state for a second preset interval. The first preset interval is longer than the second preset interval.

[0052] In this embodiment of the invention, the wake-up module 12 has a timing function, which can control the power conversion module 11 to turn on at regular intervals. After the power conversion module 11 is turned on, it converts the output voltage of the power battery to supply power to the BMS system, so that the BMS system can collect information from the power battery.

[0053] Optionally, for BMS system power supply devices considering positive and negative polarity connections, see [link to relevant documentation]. Figure 2 As shown.

[0054] The output of the power conversion module 11 is also connected to the low-voltage battery via a relay 13, the on / off state of which is controlled by hardwired control of the electric vehicle.

[0055] When the power conversion module 11 is in the ON state, the relay 13 is closed, and the power conversion module 11 is also used to charge the low-voltage battery.

[0056] When the power conversion module 11 is in the off state, the relay 13 is disconnected.

[0057] Optionally, the output terminals of the power conversion module 11 include a positive output terminal and a negative output terminal. The positive output terminal is connected to the positive terminal of the low-voltage battery, and the negative output terminal is connected to the negative terminal of the low-voltage battery.

[0058] Relay 13 is connected between the positive output terminal and the positive terminal of the low-voltage battery.

[0059] Alternatively, relay 13 can be connected between the negative output terminal and the negative terminal of the low-voltage battery.

[0060] In this embodiment of the invention, considering the small capacity of the low-voltage battery, prolonged use of the low-voltage battery to power the wake-up module 12 would lead to battery depletion, affecting the normal operation of other vehicle functions. Therefore, this embodiment connects the output of the power conversion module 11 to the low-voltage battery. When the power conversion module 11 is in operation, its output voltage is higher than the low-voltage battery voltage, enabling it to charge the low-voltage battery. Simultaneously, since the low-voltage battery and the wake-up module 12 are connected in parallel, the power conversion module 11 can also directly power the wake-up module 12, thereby ensuring the normal operation of the low-voltage battery.

[0061] A relay 13 is connected between the output terminal of the power conversion module 11 and the low-voltage battery (as provided in the embodiment of the invention). Figure 2 In this circuit, relay 13 is connected between the positive output terminal and the positive terminal of the low-voltage battery. When the power conversion module 11 is working, relay 13 is closed, allowing the power conversion module 11 to charge the low-voltage battery and supply power to the wake-up module 12. When the power conversion module 11 is in standby mode, relay 13 is open, preventing the low-voltage battery from directly supplying power to the BMS through this path.

[0062] Optionally, in this embodiment of the invention, in order to further reduce the standby power consumption of the wake-up module 12, the wake-up module 12 adopts a low-power circuit design, and the circuit structure is described below. Figure 3 As shown.

[0063] Optionally, the wake-up module 12 includes:

[0064] The system comprises a conversion circuit, a timing switch circuit, and an auxiliary management chip. The input of the conversion circuit is connected to the low-voltage battery, and its output is connected to the input of the timing switch circuit, used to convert the voltage output from the low-voltage battery. The output of the timing switch circuit is connected to the power supply pin of the auxiliary management chip, used for timing-based on / off switching. When the timing switch circuit is on, the auxiliary management chip powers on and outputs a control signal to control the operating state of the power conversion module.

[0065] Optionally, the conversion circuit includes:

[0066] The system consists of a voltage divider resistor R1, a Zener diode D1, an electrolytic capacitor CD1, and a voltage regulator chip V1. The voltage divider resistor R1 and the Zener diode D1 are connected in series to form a series branch. One end of the series branch closest to the voltage divider resistor R1 is connected to the low-voltage battery, and the other end is grounded. The midpoint of the series connection between the voltage divider resistor R1 and the Zener diode D1 is the first output terminal. The electrolytic capacitor CD1 is connected in parallel with the Zener diode D1. One end of the electrolytic capacitor CD1 is connected to the ground pin GND of the voltage regulator chip V1, and the other end is connected to the voltage input pin Vin of the voltage regulator chip V1. The voltage output pin Vout of the voltage regulator chip V1 is the second output terminal.

[0067] Optional, timing switch circuit:

[0068] The system includes a first switching transistor Q1, a second switching transistor Q2, and a clock chip. The first output terminal is connected to the drain of the first switching transistor Q1 via a first diode D2. The source of the first switching transistor Q1 is connected to an auxiliary management chip. The gate of the first switching transistor Q1 is connected to the drain of the second switching transistor Q2 via a second diode D3. The second output terminal is connected to the gate of the second switching transistor Q2 via a first resistor R4. The source of the second switching transistor Q2 is connected to both the interrupt pin INT and the power supply pin VDD of the clock chip. A second resistor R3 is also connected between the drain and gate of the first switching transistor Q1. A third resistor R5 is also connected between the interrupt pin INT and the power supply pin VDD of the clock chip.

[0069] In this embodiment of the invention, the wake-up module 12 operates as follows:

[0070] The low-voltage battery inputs 24V, which is divided by resistor R1 and Zener diode D1. Since Zener diode D1 is a 12V regulator and electrolytic capacitor CD1 is connected in parallel with it, the voltage Ucd1 across electrolytic capacitor CD1 is 12V. This voltage is connected in one path to voltage regulator chip V1, converting the 12V level to 5V to power timing chip U2. The other path is connected to diode D2 and MOSFET Q1 to power auxiliary management chip U1. Q1 is typically a P-channel MOSFET, which acts as a switch. The purpose of choosing Q1 is to utilize its switching function so that Q1 is turned off when wake-up module 12 is in standby mode. This de-energizes auxiliary management chip U1 (flyback circuit control chip) during standby, thus eliminating the losses caused by the flyback circuit in wake-up module 12 during standby, significantly reducing standby power consumption.

[0071] The device controlling the on / off state of Q1 is the timing clock chip U2. Specifically, the control method is as follows: When the wake-up module 12 is in standby mode, the interrupt pin INT of the clock chip U2, due to the external 5V and pull-up resistor R5, keeps the source (S) of the MOSFET Q2 (generally an N-channel MOSFET) at 5V. Since the gate of Q2 is also connected to the external 5V in series with resistor R4, the gate of Q2 is also at 5V, so Q2 is off at this time. Because Q2 is off, the gate-source of Q1 cannot be charged, so Q1 is also off. Therefore, the power supply pin of U1 cannot be powered, the flyback circuit cannot work, and losses are reduced.

[0072] The timing chip U2 starts timing from the standby time of the wake-up module 12. When the wake-up time is up, the interrupt pin INT of the timing chip outputs a low level. At this time, the source (S) of Q2 is low, so 5V charges the gate and source of Q2 through R4, turning Q2 on. The cathode of diode D3 is pulled low to GND. At this time, capacitor CD1 (12V) can charge the gate and source of Q1 through D2, R3, and D3, turning the drain and source of Q1 on. Capacitor CD1 supplies power to U1 through D2 and Q1. At this time, the wake-up module 12 wakes up and starts working normally.

[0073] This completes the process from standby to wake-up. When standby is needed, the interrupt pin INT of the timer chip U2 outputs a high level, so Q2 and Q1 are both turned off, the power supply to U1 is disconnected, and the wake-up module 12 enters sleep mode. Standby power consumption calculation: Vin*(Vin-12) / R1=24*12 / 3600=80mW.

[0074] Based on the above, the BMS system power supply device provided in this embodiment of the invention reduces the power battery loss to 0W by changing the wake-up module 12 to be powered by a low-voltage battery. Simultaneously, through low-power circuit design of the wake-up module 12, the power loss to the low-voltage battery can be controlled to <80mW. Furthermore, the wake-up module 12 has self-wake-up or wake-up functions, maintaining battery monitoring. The output of the power conversion module 11 is connected in parallel with the low-voltage battery, enabling charging of the low-voltage battery. By adding a relay 13 between the output of the power conversion module 11 and the low-voltage battery, the relay 13 is disconnected when the wake-up module 12 is in standby mode, eliminating the power loss to the low-voltage battery from the BMS system.

[0075] This invention effectively reduces standby power consumption, retaining only the losses from voltage sampling and the bleeder resistor (this can be determined based on actual needs; in extreme cases, the bleeder resistor and high-voltage sampling can be eliminated). This helps ensure the normal operation of the vehicle's power battery when the vehicle is stationary for extended periods. It also solves the problem of high power consumption in standby mode of the wake-up module, thus improving the lifespan of the power battery.

[0076] See Figure 4 As shown, this embodiment of the invention also provides a power vehicle, including a power battery, a low-voltage storage battery, a BMS system, and a BMS system power supply device as described above.

[0077] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A power supply device for a BMS system, characterized in that, include: Power conversion module and wake-up module; The first input terminal of the power conversion module is connected to the power battery of the electric vehicle, and the output terminal is connected to the BMS system of the electric vehicle. It is used to convert the output voltage of the power battery to supply power to the BMS system so that the BMS system can manage the power battery. The output terminal of the wake-up module is connected to the second input terminal of the power conversion module, and is used to control the working state of the power conversion module; wherein, the wake-up module is powered by the low-voltage battery of the electric vehicle and adopts a low-power circuit design; The wake-up module is used to control the power conversion module to be in the on state every first preset time interval, and to control the power conversion module to be in the off state after the power conversion module has been in the on state for a second preset time interval; wherein, the first preset time interval is longer than the second preset time interval. The output of the power conversion module is also connected to the low-voltage battery via a relay, and the on / off state of the relay is controlled by hardwired control of the electric vehicle. When the power conversion module is in the ON state, the relay is closed. The power conversion module is also used to charge the low-voltage battery. At the same time, the power conversion module directly supplies power to the wake-up module to ensure the normal use of the low-voltage battery. When the power conversion module is in the off state, the relay is disconnected to prevent the low-voltage battery from directly supplying power to the BMS system through this path; The wake-up module includes: Conversion circuit, timing switch circuit and auxiliary management chip; The input terminal of the conversion circuit is connected to the low-voltage battery, and the output terminal is connected to the input terminal of the timing switch circuit, for converting the voltage output by the low-voltage battery; The output terminal of the timing switch circuit is connected to the power supply pin of the auxiliary management chip for timing on or off; when the timing switch circuit is on, the auxiliary management chip is powered on and outputs a control signal to control the working state of the power conversion module.

2. The BMS system power supply device as described in claim 1, characterized in that, The output terminal of the power conversion module includes a positive output terminal and a negative output terminal. The positive output terminal is connected to the positive terminal of the low-voltage battery, and the negative output terminal is connected to the negative terminal of the low-voltage battery. The relay is connected between the positive output terminal and the positive terminal of the low-voltage battery; Alternatively, the relay is connected between the negative output terminal and the negative terminal of the low-voltage battery.

3. The BMS system power supply device as described in claim 1, characterized in that, The output terminals of the conversion circuit include a first output terminal and a second output terminal, and the timing switch circuit includes a first switching transistor, a second switching transistor, and a clock chip. The first output terminal is connected to the drain of the first switching transistor via a first diode, the source of the first switching transistor is connected to the auxiliary management chip, and the gate of the first switching transistor is connected to the drain of the second switching transistor via a second diode. The second output terminal is connected to the gate of the second switching transistor through the first resistor, and the source of the second switching transistor is connected to the interrupt pin and the power supply pin of the clock chip, respectively. A second resistor is also connected between the drain and gate of the first switching transistor; A third resistor is also connected between the interrupt pin and the power supply pin of the clock chip.

4. The BMS system power supply device as described in claim 3, characterized in that, The conversion circuit includes: Voltage divider resistors, Zener diodes, electrolytic capacitors, and voltage regulator chips; The voltage divider resistor and the Zener diode are connected in series to form a series branch. One end of the series branch near the voltage divider resistor is connected to the low-voltage battery, and the other end is grounded. The midpoint of the series connection between the voltage divider resistor and the Zener diode is led out to the first output terminal; The electrolytic capacitor is connected in parallel with the Zener diode. One end of the electrolytic capacitor is connected to the ground pin of the Zener chip, and the other end is connected to the voltage input pin of the Zener chip. The voltage output pin of the Zener chip leads out to the second output terminal.

5. An electric vehicle, characterized in that, It includes a power battery, a low-voltage storage battery, a BMS system, and a BMS system power supply device as described in any one of claims 1-4.

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