High-disturbance-rejection voltage acquisition circuit for power battery cell and high-disturbance-rejection voltage acquisition method for power battery cell

Abstract

The invention discloses a high-disturbance-rejection voltage acquisition circuit for a power battery cell and a high-disturbance-rejection voltage acquisition method for the power battery cell. The high-disturbance-rejection voltage acquisition circuit comprises a voltage acquisition controller and multiple cell voltage acquisition channels. Each cell voltage acquisition channel is connected witha voltage acquisition controller through a protection circuit, a differential amplification circuit, an absolute value circuit, a filter circuit, an ADC driving circuit and an ADC circuit connected which are connected in turn and an isolator; The voltage acquisition controller provides the sampling clock for the ADC circuit of the cell voltage acquisition circuit, controls start and stop of ADC sampling and reads the ADC conversion result. The voltage acquisition controller sends synchronous signals to each acquisition channel simultaneously to control synchronous acquisition of multiple acquisition channels by using the non-cyclic scanning mode.

Description

technical field [0001] The invention relates to the field of high-precision data acquisition of a power battery, in particular to a high-disturbance immunity voltage acquisition circuit for a power battery unit and a method thereof. Background technique [0002] Under the background of energy constraints and environmental pollution, the development of electric vehicles presents an irresistible trend. The power battery is the energy source of electric vehicles, which is related to the power, safety and economy of the vehicle performance, and has become the key to restrict the development of electric vehicles. In order to ensure the reliable driving of the vehicle, the voltage of the power battery must be supervised in real time and effectively. Whether it is the supervision of power batteries or the research process of power battery performance, it is always inevitable to collect the voltage of power battery cells. In terms of power battery supervision, in order to avoid th...

AI Technical Summary

Problems solved by technology

[0004] In a multi-channel system, in order to avoid crosstalk between channels, electrical isolation must be added to the measurement circuit design, which is usually divided into two types: channel-to-channel isolation and group isolation. Commonly used multi-channel integrated chips integrate multiple channels into one chip. The group isolation method is mostly used, but the group isolation scheme still cannot completely eliminate the crosstalk problem caused by the common-mode voltage difference between ungrouped signal channels, so it is necessary to use channel-to-channel isolation

The most commonly used analog front-end methods in the past include resistance voltage division method, flying capacitor method, op amp plus MOSFET tube, etc. Among them, the resistance voltage divider method has the problem of impedance matching, and the method of op amp plus MOSFET tube is also difficult due to the on-resistance of MOSFET tube. There must be errors, and the flying capacitor method is limited by the sampling rate

In addition, the current related circuits mostly use the acquisition method of cyclic scanning, and all channels are sampled sequentially within a fixed time period, and the data is asynchronous and slow

Images