Battery management system based on co-processor and solid-state relay

Abstract

The invention discloses a battery management system based on a co-processor and a solid-state relay. The system is a novel battery management system which is low in power consumption and high in estimation accuracy of the state of charge (SOC) of a battery. The battery management system based on the co-processor and the solid-state relay is based on an MC9S12XE single-chip microcomputer, and capable of monitoring working state parameters of the battery, estimating the SOC of the battery accurately, and achieving insulation monitoring, fault grading alarming and equalization management of the battery. The battery management system based on the co-processor and the solid-state relay comprises a main control board, a current collecting board and a voltage collecting board, wherein the current collecting board and the voltage collecting board are connected with the main control board, the main control board is connected with a master positive terminal of high voltage and a master negative terminal of the high voltage through high voltage connectors to achieve the insulation monitoring of the high voltage, the main control board is connected with the relay through a power driving connector, the current collecting board enables SOC estimation of the battery to be achievable by combination of the co-processor and a main processor, the current collecting board is connected with a current sensor through a current signal connector, the current sensor is arranged between the relay and the master negative terminal of the high voltage, the voltage collecting board collects voltage signals through an operational amplifier chip, and power supply of the operational amplifier chip is controlled by the solid-state relay.

Description

technical field [0001] The invention relates to a battery management system, in particular to a battery management system based on a coprocessor and a solid state relay. Background technique [0002] As the main power source of electric vehicles, the performance of batteries will directly affect the promotion of electric vehicles. The battery management system not only needs to monitor the working status of the battery in real time, but also needs to balance the inconsistency of the cycled battery, so as to prevent the battery from overcharging and over-discharging, so as to improve the cycle life of the battery. [0003] At present, a lot of research has been done on the battery management system at home and abroad. For example, the intelligent management system of General Motors of the United States can realize the status monitoring of single batteries and has a balancing function. The products of domestic companies such as Yineng, Ligao, Guantuo and Mogong have also been...

AI Technical Summary

Problems solved by technology

[0006] Chinese patent CN101141076A connects the voltage detection unit to the auxiliary power supply or the battery unit through a contact relay to determine whether the circuit of the voltage detection unit is abnormal when starting or stopping; the battery voltage is measured by using the number of battery unit relays corresponding to the total number of battery units This acquisition method needs to cycle on and off the battery unit relay, which affects the life of the relay. In addition, due to the different voltage drop of the relay, the accuracy of the voltage acquisition corresponding to the battery will also decrease.

[0007] Chinese patent CN102064568A adopts the LTC6802 coprocessor to collect the battery voltage and output the equalization control signal, and exchange data with the main controller through the SPI bus. However, this processing method cannot solve the problem of improving the accuracy of the SOC

[0010] The second is battery voltage acquisition with low power consumption and high precision. At present, the acquisition of battery voltage is mainly divided into two categories, one is chip-based voltage acquisition, and the other is the use of analog switches or solid state relays to cycle the voltage. Acquisition, the former acquisition method leads to a relatively large self-consumption power when the battery management system is in a non-working state, which affects the driving range of the electric vehicle battery. The latter method uses switches, and the voltage drop of each switch is different. , which affects the high-precision acquisition of the battery voltage, and reduces the reliability of the battery management system due to the switching back and forth of the switch

Images