Research on high-precision data acquisition and SOC calibration method for power battery

A high-precision data acquisition system which is used for parameters measurement of the power batteries was designed and the measuring result can be used as the calibration benchmark of battery management system (BMS). This system consists of the wide-range data acquisition device (lower device) and the configurable monitoring interface (upper device). The monitoring interface based on virtual instruments has the function of signal processing, monitoring and calibrating the battery dynamic parameters including the current, voltage, temperature, state-of-charge (SOC) and so on. With error constitution theory and error analysis of the systematic construction, it got the error analysis and modification method of the whole system including the sensor, data acquisition channel and virtual instrumentspsila software. Combining the method with hardware and software modification, this system achieves a high accuracy. Besides, calibration method for SOC of different power batteries in hybrid electric vehicles (HEV) is proposed on the basis of high-accuracy data acquired. Testing result shows that the system designed is able to calibrate the BMS accurately.