A method for managing the electric quantity of a low-voltage battery module of a new energy vehicle

Abstract

This invention relates to a method for managing the power of a low-voltage battery module in a new energy vehicle, belonging to the field of vehicle battery technology. The method includes the following steps: 1. Determine the new energy vehicle mode and decide whether to supply power to an external load and / or charge the low-voltage battery module via the main charging / discharging circuit; 2. In parked and locked mode, determine the SOC threshold of the low-voltage battery module and decide whether to supply power to the external load through a small-current discharge circuit; 3. Attempt to wake up the vehicle and decide whether to proceed to step 4 or step 5; 4. The main charging / discharging circuit replenishes the low-voltage battery module; 5. The low-voltage battery module enters a power-locked state and switches to a deep sleep mode; 6. Upon receiving an external wake-up signal, the low-voltage battery module is charged, and the current is monitored to determine whether to maintain charging or proceed to step 7; 7. Continue to attempt to wake up the vehicle. If the power management module responds, return to step 6; otherwise, continue to maintain the deep sleep mode. This invention ensures safer operation of new energy vehicles.

Description

Technical Field

[0001] This invention belongs to the field of vehicle battery technology, specifically relating to a method for managing the power of a low-voltage battery module in a new energy vehicle. Background Technology

[0002] Low-voltage battery modules have always played a crucial role in automobiles. They supply power to core electrical equipment such as the starter motor and ignition system during engine startup, and also power various electrical devices within the vehicle when the engine is stopped or running at low speed. Currently, with the development of new energy vehicles, low-voltage battery modules in these vehicles are increasingly used to power control modules such as the PKE / RKE system and anti-theft modules when the vehicle is parked and locked. Because new energy vehicles require significantly less power for starting compared to traditional gasoline vehicles, the power requirements for low-voltage battery modules are lower. Therefore, the capacity of low-voltage battery modules in new energy vehicles is generally smaller. Furthermore, even when the vehicle is parked and locked, the low-voltage battery still needs to power other modules within the vehicle. Over time, this can easily lead to over-discharge, which can damage the active materials of the electrodes, causing them to lose their responsiveness and resulting in irreversible damage to the battery module.

[0003] Therefore, in order to avoid deep discharge of low-voltage battery modules, it is necessary to manage their power to ensure safer and more efficient operation of new energy vehicles. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a method for managing the power of low-voltage battery modules in new energy vehicles, thereby avoiding deep discharge of low-voltage battery modules and ensuring safer operation of new energy vehicles.

[0005] The technical solution is as follows:

[0006] A method for managing the power of a low-voltage battery module in a new energy vehicle involves setting up a main charging / discharging circuit and a low-current discharging circuit between the low-voltage battery module and the load, which are controlled to be turned on or off by a power management module, and performing the following steps:

[0007] Step 1: Determine whether the new energy vehicle is in operating mode or parked and locked mode. If the new energy vehicle is in operating mode, the power management module controls the main charging and discharging circuit to supply power to the external load and / or charge the low-voltage battery module. Otherwise, proceed to the next step.

[0008] Step 2: When the new energy vehicle is in the parking and locking mode, check whether the SOC of the low-voltage battery module is lower than the charging threshold or the locking threshold. The charging threshold is greater than the locking threshold. If the SOC of the low-voltage battery module is not lower than the charging threshold, power is supplied to the external load through a small current discharge circuit. If the SOC of the low-voltage battery module is lower than the charging threshold but higher than the locking threshold, proceed to step 3. If the SOC of the low-voltage battery module is lower than the locking threshold, proceed to step 5.

[0009] Step 3: The low-voltage battery module attempts to wake up the new energy vehicle. If the wake-up is successful, proceed to step 4; if the wake-up fails, proceed to step 5.

[0010] Step 4: The low-voltage battery module sends a request for recharge to the power management module, and the main charging and discharging circuit recharges the low-voltage battery module.

[0011] Step 5: The low-voltage battery module enters the power-lock state and switches to deep sleep mode. The power management module controls the main charging and discharging circuit and the small current discharging circuit to not output externally and proceeds to step 6.

[0012] Step 6: After receiving an external wake-up signal, the power management module closes the main charging and discharging circuit to charge the low-voltage battery module, and monitors the current of the low-voltage battery module after a certain period of time to see if it is greater than the charging judgment threshold. If it is greater than the charging judgment threshold, the main charging and discharging circuit is maintained to charge the low-voltage battery module; if it is not greater than the charging judgment threshold, proceed to step 7.

[0013] Step 7: Continue to try to wake up the new energy vehicle. If the power management module responds, return to step 6. If there is no response, control the low-voltage battery module to continue to maintain deep sleep mode.

[0014] Furthermore, the power management module includes an MCU and an AFE chip (analog front-end chip). The AFE chip is responsible for detecting the voltage and current of each cell in the low-voltage battery module. The MCU controls the closing and opening of the main charging and discharging circuit and the small current discharge path, and calculates the real-time SOC value of the low-voltage battery module based on the data detected by the AFE chip.

[0015] Furthermore, the main charging and discharging circuit includes a MOSFET, a sampling resistor, and a relay. The MOSFET is connected to the control signal and the drive power supply. The relay is connected to the external load, the low-voltage battery module, and the MOSFET output, respectively. The MOSFET output passes through the sampling resistor to complete the feedback of the control signal. The control signal passes through the MOSFET to control the relay to open and close, thereby controlling the external load to charge the low-voltage battery module through the main charging and discharging circuit.

[0016] Furthermore, the low-current discharge circuit includes a current sensor, an overcurrent protector, a sampling resistor, a MOSFET, and a driver chip. The current sensor and the MOSFET are connected in series between the external load and the low-voltage battery module. There are two MOSFETs, with their drains connected together, their gates connected to the driver chip, and their sources connected to the current sensor and the low-voltage battery module, respectively. The current sensor controls whether the control signal is connected to the driver chip through the overcurrent protector. The control signal controls the switching on and off of the MOSFET through the driver chip, thereby controlling the external load to charge the low-voltage battery module through the low-current discharge circuit, and completing the back-check through the sampling resistor.

[0017] Furthermore, when the main charging / discharging circuit or the low-current discharging circuit is working, it does not accept external wake-up signal input.

[0018] Furthermore, in step 6, the external wake-up signal includes a power-on wake-up signal or a hardware switch signal.

[0019] Furthermore, the "certain time" mentioned in step 6 is 1-5 minutes.

[0020] Beneficial effects:

[0021] 1) This invention uses MCU and AFE chips to judge the status of new energy vehicles and combines SOC value to control the management of charging and discharging. It can effectively avoid irreversible damage to low-voltage battery modules caused by deep discharge, and ensure safer operation of new energy vehicles.

[0022] 2) The circuit is simple and easy to manage, which can significantly improve the lifespan of low-voltage battery modules. Attached Figure Description

[0023] Figure 1 This is a flowchart of the method of the present invention;

[0024] Figure 2 This is the logic circuit diagram of the present invention;

[0025] Figure 3 This is the logic circuit diagram of the main charging and discharging circuit of the present invention;

[0026] Figure 4 This is the logic circuit diagram of the low-current discharge circuit of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit it. Terms such as "upper," "lower," "front," "rear," "left," "right," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the purpose of describing the invention. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0028] like Figure 1 The method for managing the power of a low-voltage battery module in a new energy vehicle is shown. A main charging / discharging circuit and a low-current discharging circuit, controlled by a power management module, are set up between the low-voltage battery module and the load, and the following steps are performed:

[0029] Step 1: Determine whether the new energy vehicle is in operating mode or parked and locked mode. If the new energy vehicle is in operating mode, the power management module controls the main charging and discharging circuit to supply power to the external load and / or charge the low-voltage battery module. Otherwise, proceed to the next step.

[0030] Step 2: When the new energy vehicle is in the parking and locking mode, check whether the SOC of the low-voltage battery module is lower than the charging threshold or the locking threshold. The charging threshold is greater than the locking threshold. If the SOC of the low-voltage battery module is not lower than the charging threshold, power is supplied to the external load through a small current discharge circuit. If the SOC of the low-voltage battery module is lower than the charging threshold but higher than the locking threshold, proceed to step 3. If the SOC of the low-voltage battery module is lower than the locking threshold, proceed to step 5.

[0031] Step 3: The low-voltage battery module attempts to wake up the new energy vehicle. If the wake-up is successful, proceed to step 4; if the wake-up fails, proceed to step 5.

[0032] Step 4: The low-voltage battery module sends a request for recharge to the power management module, and the main charging and discharging circuit recharges the low-voltage battery module.

[0033] Step 5: The low-voltage battery module enters the power-lock state and switches to deep sleep mode. The power management module controls the main charging and discharging circuit and the small current discharging circuit to not output externally and proceeds to step 6.

[0034] Step 6: After receiving an external wake-up signal, including a jump-start wake-up signal or a hardware switch signal, the power management module closes the main charging and discharging circuit to charge the low-voltage battery module. After 1-5 minutes, it monitors the current of the low-voltage battery module to see if it is greater than the charging judgment threshold. If it is greater than the charging judgment threshold, the main charging and discharging circuit continues to charge the low-voltage battery module. If it is not greater than the charging judgment threshold, proceed to step 7.

[0035] Step 7: Continue to try to wake up the new energy vehicle. If the power management module responds, return to step 6. If there is no response, control the low-voltage battery module to continue to maintain deep sleep mode.

[0036] The power management module includes an MCU and an AFE chip. The AFE chip is responsible for detecting the voltage and current of each cell in the low-voltage battery module. The MCU controls the closing and opening of the main charging and discharging circuit and the small current discharge path, and calculates the real-time SOC value of the low-voltage battery module based on the data detected by the AFE chip.

[0037] The main charging and discharging circuit includes a MOSFET, a sampling resistor, and a relay. The MOSFET is connected to the control signal and the drive power supply. The relay is connected to the external load, the low-voltage battery module, and the MOSFET output, respectively. The MOSFET output passes through the sampling resistor to complete the feedback of the control signal. The control signal passes through the MOSFET to control the relay to turn on and off, thereby controlling the external load to charge the low-voltage battery module through the main charging and discharging circuit.

[0038] The low-current discharge circuit includes a current sensor, an overcurrent protector, a sampling resistor, a MOSFET, and a driver chip. The current sensor and the MOSFET are connected in series between the external load and the low-voltage battery module. There are two MOSFETs, with their drains connected together, their gates connected to the driver chip, and their sources connected to the current sensor and the low-voltage battery module, respectively. The current sensor controls whether the control signal is connected to the driver chip through the overcurrent protector. The control signal controls the switching of the MOSFET through the driver chip, thereby controlling the external load to charge the low-voltage battery module through the low-current discharge circuit, and completing the feedback check through the sampling resistor.

[0039] When the main charging / discharging circuit or the low-current discharging circuit is working, it does not accept external wake-up signal input.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles and spirit of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for managing the power of a low-voltage battery module in a new energy vehicle, comprising setting up a main charging / discharging circuit and a low-current discharging circuit controlled by a power management module to be turned on or off between the low-voltage battery module and the load, and performing the following steps: Step 1: Determine whether the new energy vehicle is in operating mode or parked and locked mode. If the new energy vehicle is in operating mode, the power management module controls the main charging and discharging circuit to supply power to the external load and / or charge the low-voltage battery module. Otherwise, proceed to the next step. Step 2: When the new energy vehicle is in the parking and locking mode, check whether the SOC of the low-voltage battery module is lower than the charging threshold or the locking threshold. The charging threshold is greater than the locking threshold. If the SOC of the low-voltage battery module is not lower than the charging threshold, power is supplied to the external load through a small current discharge circuit. If the SOC of the low-voltage battery module is lower than the charging threshold but higher than the locking threshold, proceed to step 3. If the SOC of the low-voltage battery module is lower than the locking threshold, proceed to step 5. Step 3: The low-voltage battery module attempts to wake up the new energy vehicle. If the wake-up is successful, proceed to step 4; if the wake-up fails, proceed to step 5. Step 4: The low-voltage battery module sends a request for recharge to the power management module, and the main charging and discharging circuit recharges the low-voltage battery module. Step 5: The low-voltage battery module enters the power-lock state and switches to deep sleep mode. The power management module controls the main charging and discharging circuit and the small current discharging circuit to not output externally and proceeds to step 6. Step 6: After receiving an external wake-up signal, the power management module closes the main charging and discharging circuit to charge the low-voltage battery module, and monitors the current of the low-voltage battery module after a certain period of time to see if it is greater than the charging judgment threshold. If it is greater than the charging judgment threshold, the main charging and discharging circuit is maintained to charge the low-voltage battery module; if it is not greater than the charging judgment threshold, proceed to step 7. Step 7: Continue to try to wake up the new energy vehicle. If the power management module responds, return to step 6. If there is no response, control the low-voltage battery module to continue to maintain deep sleep mode.

2. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: The power management module includes an MCU and an AFE chip. The AFE chip is responsible for detecting the voltage and current of each cell in the low-voltage battery module. The MCU controls the closing and opening of the main charging and discharging circuit and the small current discharge path, and calculates the real-time SOC value of the low-voltage battery module based on the data detected by the AFE chip.

3. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: The main charging and discharging circuit includes a MOSFET, a sampling resistor, and a relay. The MOSFET is connected to the control signal and the drive power supply. The relay is connected to the external load, the low-voltage battery module, and the MOSFET output, respectively. The MOSFET output passes through the sampling resistor to complete the feedback of the control signal. The control signal passes through the MOSFET to control the relay to turn on and off, thereby controlling the external load to charge the low-voltage battery module through the main charging and discharging circuit.

4. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: The low-current discharge circuit includes a current sensor, an overcurrent protector, a sampling resistor, a MOSFET, and a driver chip. The current sensor and the MOSFET are connected in series between the external load and the low-voltage battery module. There are two MOSFETs, with their drains connected together, their gates connected to the driver chip, and their sources connected to the current sensor and the low-voltage battery module, respectively. The current sensor controls whether the control signal is connected to the driver chip through the overcurrent protector. The control signal controls the switching on and off of the MOSFET through the driver chip, thereby controlling the external load to charge the low-voltage battery module through the low-current discharge circuit, and completing the back-check through the sampling resistor.

5. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: When the main charging / discharging circuit or the low-current discharging circuit is working, it does not accept external wake-up signal input.

6. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: The external wake-up signal mentioned in step 6 includes a power-on wake-up signal or a hardware switch signal.

7. The method for managing the power of a low-voltage battery module in a new energy vehicle as described in claim 1, characterized in that: The specified time in step 6 is 1-5 minutes.

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