A battery management system applied to a new energy electric vehicle of A00 level

Abstract

The application discloses a kind of new battery management systems applied to A00 grade new energy electric vehicle new type, including main control daughter board and MOS daughter board, the MOS daughter board is fixed on assembly support, the main control daughter board is fixed on MOS daughter board by copper stud, the main control daughter board is constituted by AFE chip, MCU module, power module, CAN module, wake-up module, EEPROM module and FLASH module, the MOS daughter board is constituted by charging MOS, discharging MOS, shunt, DCDC pre-charging MOS, DCDC MOS and heating MOS;The application is under the monitoring of high-power management system, the whole vehicle DCDC module continuously outputs 12V low-voltage power supply to central control platform, reduces battery pack cost, integrates the traditional PDU function in battery pack to management system, simultaneously reduces the assembly complexity of battery pack, improves the whole vehicle safety, built-in power battery output short-circuit protection function, can prevent the whole vehicle safety hazard caused by external short circuit.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, specifically to a battery management system for A00-class new energy electric vehicles. Background Technology

[0002] A Battery Management System (BMS) is a high-power power management system used in lithium-ion battery packs. It provides power and 12V functional power to the vehicle, and also performs functions such as overcharge protection, over-discharge protection, thermal runaway protection, single-cell failure protection, temperature failure protection, heating protection, heat preservation protection, low-voltage sleep protection, timed wake-up protection, charging wake-up protection, short-circuit protection, storage and export of historical fault information, control of two external relays, CAN 2.0 communication, and uses fast-switching MOS for vehicle pre-charging strategy. Currently, A00-class new energy electric vehicles mainly use BMS to control on-board relays for charging and discharging protection. The battery pack has many discrete components and insufficient integration. The failure of a single component requires the entire pack to be repaired, resulting in a heavy after-sales burden for the vehicle. Conventional low-power management systems are mainly used in two-wheeled electric vehicles, with lower charging and discharging power and no CAN communication module, making it impossible to interact with other ECUs.

[0003] Therefore, we propose a battery management system for A00-class new energy electric vehicles. Summary of the Invention

[0004] The purpose of this invention is to provide a battery management system for A00-class new energy electric vehicles to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a battery management system for A00-class new energy electric vehicles, comprising a main control sub-board and a MOS sub-board. The MOS sub-board is fixed on an assembly bracket, and the main control sub-board is fixed to the MOS sub-board by copper studs. The main control sub-board consists of an AFE chip, an MCU module, a power module, a CAN module, a wake-up module, an EEPROM module, and a FLASH module. The MOS sub-board consists of a charging MOS, a discharging MOS, a shunt, a DC-DC pre-charge MOS, a DC-DC MOS, and a heating MOS. The main control sub-board and the MOS sub-board are connected and communicate via internal wiring harnesses.

[0006] Preferably, the main control board is electrically connected to the low-voltage wiring harness and battery sampling wiring harness of the battery pack.

[0007] Preferably, the MOS subboard is electrically connected to the power harness of the battery pack.

[0008] Preferably, the mounting bracket is an existing device.

[0009] Preferably, the management system connects to the vehicle through the following steps:

[0010] 1) Connect the management system input "B-" to the negative terminal of the power battery;

[0011] 2) Connect the management system output "P-" to the vehicle power negative connection;

[0012] 3) Connect the management system's "DCDC output -" to the vehicle's DC-DC negative connection;

[0013] 4) Connect the management system's "Heating Output -" to the heating film;

[0014] 5) Connect the management system to the vehicle's low-voltage wiring harness.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] This invention occupies less space, has higher reliability, and lower cost, reducing the overall vehicle cost. The vehicle does not require an external 12V lead-acid battery. Under the monitoring of the high-power management system, the vehicle's DC-DC module continuously outputs 12V low-voltage power to the central control platform, reducing battery pack costs. The traditional PDU function within the battery pack is integrated into the management system, simultaneously reducing the assembly complexity of the battery pack and improving overall vehicle safety. The built-in power battery output short-circuit protection function can prevent vehicle safety hazards caused by external short circuits. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall architecture of the management system of the present invention;

[0018] Figure 2 This is a circuit diagram of the MCU module of the present invention;

[0019] Figure 3 This is a schematic diagram of the AFE sampling circuit of the present invention;

[0020] Figure 4 This is a circuit diagram of the CAN module of the present invention;

[0021] Figure 5 This is a circuit diagram of the charging / discharging MOS circuit of the present invention;

[0022] Figure 6 The circuit diagram of the DC-DC output loop of the present invention is shown. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1-6 As can be seen, the present invention provides a technical solution: a battery management system for A00-class new energy electric vehicles, including a main control sub-board and a MOS sub-board. The MOS sub-board is fixed on an assembly bracket, and the main control sub-board is fixed to the MOS sub-board by copper studs. The main control sub-board consists of an MCU module, an AFE chip circuit, a power module, a CAN module, a wake-up module, an EEPROM module, and a FLASH module. The MOS sub-board consists of a charge / discharge MOS, a shunt, a DC-DC output circuit, and a heating MOS. The main control sub-board and the MOS sub-board are connected and communicate through internal wiring harnesses. The main control sub-board is electrically connected to the low-voltage wiring harness and battery sampling wiring harness of the battery pack, and the MOS sub-board is electrically connected to the power wiring harness of the battery pack.

[0025] Furthermore, the management system connects to the vehicle through the following steps:

[0026] 1) Connect the management system input "B-" to the negative terminal of the power battery;

[0027] 2) Connect the management system output "P-" to the vehicle power negative connection;

[0028] 3) Connect the management system's "DCDC output -" to the vehicle's DC-DC negative connection;

[0029] 4) Connect the management system's "Heating Output -" to the heating film;

[0030] 5) Connect the management system to the vehicle's low-voltage wiring harness.

[0031] It should be noted that:

[0032] ① During the pre-charging of the high-voltage system capacitors of the entire vehicle, the MCU... Figure 5 The DSG sends a PWM signal to control the three fast switches of MOS (Q30, Q34, and Q25) in the 502 module, which in turn control the fast switch of the discharge MOS (Q35, etc.) to pre-charge the capacitors of the vehicle's high-voltage system. Pre-charging is complete when the current through the sampling resistor in the 501 module is less than 250A. The MCU then stops sending PWM signals, and the DSG outputs 15V to close Q30, turn off Q34, close Q25, and turn off the discharge MOS (Q35, etc.) to begin discharging. Compared to the traditional method of pre-charging using high-power resistors, this method occupies less space, has higher reliability, and lower cost.

[0033] ② When discharging to an external load, the power battery outputs power through the charging and discharging MOS. When the AFE sampling circuit detects that any cell in the battery pack is below the set threshold, the MCU sends a control 501 to the DSG output as 0V. At this time, Q30 is turned off, Q34 is turned on, Q25 is turned off, and the discharge MOS such as Q35 is turned off, stopping the power output to the outside.

[0034] ③ When charging the power battery, the charger sends a PWM signal through the MCU in the 503 circuit, which controls the three MOS transistors Q28 / Q29 / Q30 via the CHG pin to quickly close the charging MOS transistor Q36 for pre-charge. The judgment method is the same as that for the discharge pre-charge mode. Finally, the charging MOS transistor closes. Additionally, when the AFE sampling circuit detects that any cell in the battery pack is higher than a set threshold, the MCU controls the CHG output to 0V, and simultaneously the discharge MOS control terminal outputs 0V. Then, the charging / discharging MOS transistors disconnect, stopping external power input.

[0035] ④ The management system supports power control of the vehicle-mounted DC-DC module. The management system always keeps the DC-DC module in the MCU_PreCtrl pre-charge MOS circuit, and pre-charges the DC-DC capacitor through a small-power resistor on the management system; when the MCU detects that the 12V constant input changes from 0V to above 10V (this invention determines this by detecting the 12V output voltage of the DC-DC), the MCU controls the switching of the MCU_Ctrl pin circuit, engaging the main DC-DC MOS and disengaging the DC-DC pre-charge MOS.

[0036] ⑤ The management system has a built-in 204 heating circuit. The MCU outputs a high-level heating signal to drive the Q27N-MOS in the 204 heating circuit to close, thus providing power to the heating element and preheating the power battery. Once the battery temperature rises, charging of the power battery is initiated. By controlling the switching of the Q27N-MOS at different stages, the management system supports the charging and heat preservation of the power battery, cyclically heating the power battery to ensure that it is at a suitable temperature before driving.

[0037] ⑥ The management system has a built-in short-circuit protection hardware circuit. When the management system detects a short circuit in the main power output P+ / P-, the current sampled by the 501 sampling resistor is greater than the set threshold. Then, the charging / discharging MOS output is quickly cut off to ensure the safety of the vehicle's functions.

[0038] ⑦ The management system has a built-in 201 wake-up circuit. In sleep mode, the management system has a built-in 201 timed wake-up circuit. The 201 timed wake-up circuit uses the MCU microcontroller to wake up every 2 hours based on the YI crystal oscillator signal to monitor the battery pack status.

[0039] ⑧ The management system has a built-in 205 total voltage detection function. By controlling the Q23 N-MOS in the 205 circuit to close and pull it low to 0V through a high-level input, the Q21 P-MOS is turned on, realizing total voltage detection, judging the voltage status of the external terminals of the charging / discharging MOS, and realizing the MOS adhesion detection function.

[0040] ⑨ The management system has a built-in CAN module, which enables communication with the vehicle motor controller, charger, instrument cluster, MP5, etc., to achieve real-time online monitoring and alarm display of faults; it can also interact during charging and discharging to achieve soft cut-off in case of fault, ensuring normal cut-off and opening of charging / discharging MOS, and ensuring forced cut-off of MOS without load.

[0041] ⑩ The management system has a built-in 8MB FLASH module to realize a complete record of historical faults, storing 500 historical fault records and data at the time of the fault, which facilitates fault troubleshooting and data analysis when a fault occurs.

[0042] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A battery management system for A00-class new energy electric vehicles, characterized in that: The system includes a main control sub-board and a MOS sub-board. The MOS sub-board is fixed on an assembly bracket, and the main control sub-board is fixed to the MOS sub-board using copper studs. The main control sub-board consists of an AFE chip, an MCU module, a power module, a CAN module, a wake-up module, an EEPROM module, and a FLASH module. The MOS sub-board consists of a charging MOS, a discharging MOS, a shunt, a DC-DC pre-charge MOS, a DC-DC MOS, and a heating MOS. The main control sub-board and the MOS sub-board are connected and communicate via an internal wiring harness. The system also includes a management method. (1) When the high voltage system capacitor of the whole vehicle is pre-charged, the MCU sends a PWM signal through the DSG to control the three MOS fast switches Q30 / Q34 / Q25 in the circuit 502 to control the discharge MOS fast switch to pre-charge the high voltage system capacitor of the whole vehicle. When the current value through the sampling resistor in the circuit 501 is less than 250A, the pre-charge is completed, the MCU stops sending the PWM signal, the DSG outputs 15V to control Q30 to close, Q34 to turn off, Q25 to close, and the discharge MOS to turn off for discharge; (2) When discharging to an external load, the power battery outputs power through the charging and discharging MOS. When the AFE sampling circuit detects that any cell in the battery pack is below the set threshold, the MCU sends the DSG output in the control circuit 501 to 0V. At this time, Q30 is turned off, Q34 is closed, Q25 is turned off, the discharge MOS is disconnected, and the power output to the outside is stopped. (3) When charging the power battery, the charger sends a PWM signal through the MCU in circuit 503 to control the three MOS fast switches Q28 / Q29 / Q30 through the CHG pin to control the charging MOS Q36 to close quickly for pre-charging. The judgment method is the same as the discharge pre-charging method. Finally, the charging MOS is closed. In addition, when the AFE sampling circuit detects that any cell in the battery pack is higher than the set threshold, the MCU controls the CHG output to 0V, and at the same time the discharge MOS control terminal outputs 0. Then the charging / discharging MOS is disconnected, and the external power input is stopped. (4) The management system supports power control of the vehicle-mounted DCDC module. The management system always keeps the DCDC module in the MCU_PreCtrl pre-charge MOS circuit and pre-charges the DCDC capacitor through the small power resistor on the management system. When the MCU detects that the 12V constant power input changes from 0V to more than 10V, the MCU controls the switching of the MCU_Ctrl pin circuit, energizes the main DCDC MOS, and disconnects the DCDC pre-charge MOS. (5) The management system has a built-in heating circuit 204. The MCU outputs a high-level heating signal to drive the Q27N-MOS in the heating circuit 204 to close, and conducts the output to the heating element to realize the preheating of the power battery. When the battery temperature rises, the power battery is charged again. By controlling the switching of Q27N-MOS at different stages, the management system supports the charging and heat preservation of the power battery, and cyclically heats the power battery to ensure that the power battery is at a suitable temperature before driving. (6) The management system has a built-in short-circuit protection hardware circuit. When the management system detects a short circuit in the main power output P+ / P-, the sampling resistor in circuit 501 collects a current greater than the set threshold, and then quickly cuts off the charging / discharging MOS output to ensure the safety of the whole vehicle function. (7) The management system has a built-in wake-up circuit 201. In the sleep state, the management system has a built-in wake-up circuit 201. The wake-up circuit 201 is activated by the MCU microcontroller according to the YI crystal oscillator signal every 2 hours to monitor the battery pack status. (8) The management system has a built-in total voltage detection function. By closing Q23 N-MOS in the high-level input control circuit 205 and pulling it low to 0V, Q21 P-MOS is turned on, realizing total voltage detection, judging the voltage status of the external terminal of the charging / discharging MOS, and realizing the MOS adhesion detection function. (9) The management system has a built-in CAN module to enable communication with the vehicle motor controller, charger, instrument cluster and MP5, and to realize real-time online monitoring and alarm display of faults; and can interact during charging and discharging to realize soft cut-off in case of fault, ensuring normal cut-off and opening of charging / discharging MOS, and ensuring that MOS is forcibly cut off without load; (10) The management system has an 8MB FLASH module built in, which realizes the full record of historical faults, stores 500 historical faults and fault data, and facilitates fault investigation and data analysis when a fault occurs.

2. The battery management system for A00-class new energy electric vehicles according to claim 1, characterized in that: The main control board is electrically connected to the low-voltage wiring harness and battery sampling wiring harness of the battery pack.

3. The battery management system for A00-class new energy electric vehicles according to claim 2, characterized in that: The MOS subboard is electrically connected to the power harness of the battery pack.

4. A battery management system for A00-class new energy electric vehicles according to claim 2, characterized in that: The management system connects to the vehicle through the following steps: 1) Connect the "B-" input to the management system and the negative terminal of the power battery; 2) Connect the management system output "P-" to the vehicle power negative connection; 3) Connect the management system's "DCDC output -" to the vehicle's DC-DC negative connection; 4) Connect the management system's "Heating Output-" to the heating film; 5) Connect the management system to the vehicle's low-voltage wiring harness.

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