High-voltage lithium battery BMS power supply circuit

Abstract

The invention relates to the technical field of power battery processing, discloses a high-voltage lithium battery BMS power supply circuit. The voltage of a high-voltage node of a high-voltage lithium battery is reduced via a voltage stabilizing tube, the high-voltage node is connected with three NPN triodes, the collector, emitter and base electrodes of the first triode are connected with the high-voltage node, the input end of a voltage stabilizing chip and the emitter electrode of the second triode respectively, the collector and base electrodes of the second triode are connected with thehigh-voltage node and the emitter electrode of the third triode respectively, the collector electrode of the third triode is connected with the high-voltage node, a first resistor is connected betweenthe base electrode of the third triode and the high-voltage node, and the first resistor is adjusted so that a current passing the first resistor reaches a predetermined value, and a BMS power supplycurrent output by the voltage stabilizing chip reaches a predetermined value. According to the invention, the voltage is reduced to the predetermined 60V via a triode amplification circuit, the voltage is reduced via a DC-DC voltage stabilizing power supply, and the power consumption, battery loss and cost are reduced at the same time.

Description

technical field [0001] The invention relates to the technical field of power battery processing, in particular to a high-voltage lithium battery BMS power supply circuit. Background technique [0002] The battery management system (BMS) is the link between the battery and the user, and the main object is the secondary battery. Secondary batteries have the following disadvantages, such as less energy storage, discrete problems in series-parallel use, safety in use, and difficulty in estimating battery power. The performance of the battery is very complex, and the characteristics of different types of batteries are also very different. BMS mainly monitors the state of the battery, improves the utilization rate of the battery, prevents the battery from overcharging and discharging, and prolongs the service life of the battery. The power supply of BMS comes from the lithium battery itself. The lithium battery will inevitably generate power consumption, and the battery will be ...

AI Technical Summary

Problems solved by technology

Secondary batteries have the following disadvantages, such as less stored energy, discrete problems in series and parallel use, safety in use, and difficulty in estimating battery power, etc.

[0005] 2. Because the LDO step-down chip has a low withstand voltage, when multiple strings of lithium batteries have high voltage, it is necessary to use the triode amplification principle to reduce the voltage to below 30V, and then supply power to the MCU follow-up circuit through the LDO

[0007] The three traditional BMS power supply methods have the following disadvantages. The power consumption of the first type can be as small as 5uA, but the withstand voltage can only be about 30V; the power consumption of the second type can also be 10uA, but the power supply The current is very small, the higher the voltage, the smaller the current, but you can increase the power of the amplifying transistor to increase the current; the third type can achieve 10uA when the supply voltage is below 60V, and the power consumption will increase to 1mA when the voltage exceeds 60V

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