BMS main control board power supply protection circuit and system based on multistage redundancy

Abstract

The invention provides a BMS main control board power supply protection circuit and system based on multistage redundancy, and relates to the field of power supply protection. The BMS main control board power supply protection circuit based on multistage redundancy comprises a main power supply module, the positive electrode and the negative electrode of the main power supply module are connected with a BMS main control board and a standby power supply module, when the BMS main control board works normally, power is supplied through the external input main power supply module, and meanwhile, an MOS switch of the standby power supply module is turned on in a PWM mode. According to the BMS main control board power supply protection circuit and system based on multi-level redundancy, zero-interruption switching is achieved, the switching delay of a main power source and a standby power source is smaller than or equal to 10 ms and is better than the 50 ms requirement of the national standard GB / T 34131-2023, long-time buffering power supply is achieved, a super capacitor module supports the main control board to continuously operate for 5 minutes or longer, 90% of short-time fault scenes are covered, and the service life of the main control board is prolonged. And the situation that the relay is cut off with current due to sudden breakpoint of the system is avoided, so that the effect of prolonging the service life of the main loop relay is achieved.

Description

Technical Field

[0001] This invention relates to the field of power supply protection technology, specifically to a power supply protection circuit and system for a BMS main control board based on multi-level redundancy. Background Technology

[0002] Traditional BMS main control board power supply has the following defects: power failure risk: when the main power supply is interrupted due to voltage fluctuations, short circuits or line faults, the BMS main control board will directly crash, resulting in the failure of battery status monitoring and the loss of operation process data because it cannot be stored in time. The current status cannot be reported to the upper-level equipment in time due to power failure, and in severe cases, there is even a risk of thermal runaway.

[0003] Redundancy mechanism is lacking: The existing solution only provides power to the MCU and does not cover the entire power supply link of the main control board. When the external power supply suddenly stops or becomes unstable, if the system is in a charging or discharging state, the relays in the main circuit may be cut off due to current, which will affect the safety of the system and the service life of the relays.

[0004] Unable to monitor external power supply status: When the external power supply is abnormal, the BMS main control board lacks the ability to diagnose dynamic faults in the external power supply and execute corresponding processing actions because it cannot supply power normally at this time. Summary of the Invention

[0005] The purpose of this invention is to provide a power supply protection circuit and system for a BMS main control board based on multi-level redundancy, which solves the problems mentioned in the background art.

[0006] Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a power supply protection circuit for a BMS main control board based on multi-level redundancy, comprising a main power supply module, wherein the positive and negative terminals of the main power supply module are connected to the BMS main control board and a backup power supply module.

[0008] Furthermore, when the BMS main control board is working normally, it is powered by the external main power module, and the backup power module MOS switch is turned on via PWM. The backup power module status detection module monitors the status change of the backup power voltage. As the supercapacitor voltage is gradually raised, the PWM duty cycle gradually increases. Finally, when the supercapacitor is charged to the same level as the supply voltage, the PWM duty cycle is locked at 100%.

[0009] Furthermore, when the BMS main control board detects an abnormality in the power supply status of the main power module, it automatically switches to the backup power module for power supply. At the same time, it records and reports the power supply abnormality information locally and sends a request to disconnect the relay to the PCS or the upper-level equipment. When the main circuit is not charging or discharging, the relay is then disconnected.

[0010] Furthermore, the BMS then sets the PWM duty cycle of the backup power supply module switch to 0% to safely power off.

[0011] Furthermore, if the main power module returns to normal during this period, the BMS main control board will cancel the alarm and report the status to the superior device. Simultaneously, the backup power supply current will be charged to normal through the main control board's power-on process.

[0012] This invention provides a power supply protection circuit and system for a BMS main control board based on multi-level redundancy. It has the following beneficial effects:

[0013] This BMS main control board power supply protection circuit and system, based on multi-level redundancy, features zero-interruption switching: the main and backup power supply switching delay is ≤10ms, which is better than the 50ms requirement of the national standard GB / T 34131-2023; long-term buffer power supply: the supercapacitor module supports the main control board to run continuously for ≥5 minutes, covering 90% of short-term fault scenarios; and extended service life of the main circuit relays: it avoids the relays from being cut off with current due to sudden system interruption, thereby extending the service life of the main circuit relays. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the power supply protection circuit for the BMS main control board based on multi-level redundancy according to the present invention;

[0015] Figure 2 This is a schematic diagram of the power-on process on the BMS main control board of the present invention;

[0016] Figure 3 This is a schematic diagram of the power supply diagnosis and protection process executed by the BMS main control board of the present invention. Detailed Implementation

[0017] 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.

[0018] like Figure 1-3 As shown, this embodiment of the invention provides a power supply protection circuit and system for a BMS main control board based on multi-level redundancy, including a main power module, the positive and negative terminals of which are connected to the BMS main control board and a backup power module.

[0019] When the BMS main control board is working normally, it is powered by the external main power module. At the same time, the backup power module MOS switch is turned on via PWM. The backup power module status detection module monitors the status changes of the backup power voltage. As the supercapacitor voltage is gradually raised, the PWM duty cycle gradually increases. Finally, when the supercapacitor is charged to the same level as the supply voltage, the PWM duty cycle is locked at 100%.

[0020] When the BMS main control board detects an anomaly in the power supply status of the main power module, it automatically switches to the backup power module. Simultaneously, it records and reports the power supply anomaly locally and sends a request to the PCS or upstream device to disconnect the relay. The relay is then disconnected only when the main circuit is no longer charging or discharging. Finally, the BMS sets the PWM duty cycle of the backup power module switch to 0% for a safe power-down. If the main power module returns to normal during this period, the BMS main control board will cancel the alarm and report the status to the upstream device. Meanwhile, the backup power supply current will be charged to normal through the main control board's power-on process.

[0021] Multi-level redundant power supply architecture

[0022] Main power supply module: The standard input voltage range is 12-36V. The specific power supply voltage value depends on the power supply of the BMS main control board and the drive voltage specifications of the drive relays.

[0023] Main power module status detection: such as Figure 1 As shown, the main power supply voltage value of the main power module is periodically sampled through the ADC1 pin of the BMS main controller.

[0024] Backup power module: Supercapacitor modules are preferred, but lithium battery modules can also be used. The maximum withstand voltage is designed to be slightly higher than the input voltage of the main power module, and the design capacity is sufficient to allow it to work independently for 5 minutes after the main power module stops supplying power.

[0025] Backup power module status detection: such as Figure 1 As shown, the power supply voltage of the backup power module is periodically sampled through the ADC2 pin of the BMS main controller.

[0026] MOS switches that support PWM control: such as Figure 1 As shown, the power of the main power module charging the backup power module is adjusted by the PWM duty cycle to prevent the backup power module from self-protecting due to excessive instantaneous charging power.

[0027] 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 power supply protection circuit for a BMS main control board based on multi-level redundancy, comprising a main power supply module, characterized in that: The positive and negative terminals of the main power module are connected to the BMS main control board and the backup power module.

2. The BMS main control board power supply protection system based on multi-level redundancy according to claim 1, characterized in that: When the BMS main control board is working normally, it is powered by the external main power module, and the backup power module MOS switch is turned on in PWM mode. The backup power module status detection module monitors the status change of the backup power voltage. As the supercapacitor voltage is gradually raised, the duty cycle of PWM gradually increases. Finally, when the supercapacitor is charged to the same level as the supply voltage, the PWM duty cycle is locked at 100%.

3. The BMS main control board power supply protection system based on multi-level redundancy according to claim 1, characterized in that: When the BMS main control board detects an abnormality in the power supply status of the main power module, it automatically switches to the backup power module for power supply. At the same time, it records and reports the power supply abnormality information locally and sends a request to disconnect the relay to the PCS or the upper-level equipment. The relay is then disconnected when the main circuit is not charging or discharging.

4. The BMS main control board power supply protection system based on multi-level redundancy according to claim 3, characterized in that: Finally, the BMS sets the PWM duty cycle of the backup power supply module switch to 0% to safely power off.

5. The BMS main control board power supply protection circuit and system based on multi-level redundancy according to claim 4, characterized in that: If the main power module returns to normal during this period, the BMS main control board will cancel the alarm and report the status to the superior device. Simultaneously, the backup power supply will be charged to normal value through the main control board's power-on process.

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