多方向实车振动路谱对电池容量和阻抗特性影响的试验研究

The characteristic parameters of power battery influenced by vibration will interfere the state estimation precision, and there is no unified test specification at present. Therefore, an experimental research method based on multi-directional real road spectrum is proposed to analyze the capacity and impedance of battery module. The necessity of using real road spectrum is discussed through analyzing the domestic and foreign battery vibration test standards and specifications. The three-directional acceleration sensors and the data acquisition system are used to obtain the multi-directional vibration signal of the battery pack under the intensified road condition. The concentration frequency section with highly energy distribution is selected for piecewise fitting by calculating the power spectrum density estimation of the original data, and the random vibration curve suitable for general shaker is constructed. The discharge test system under vibration conditions is built, in which the battery modules are applied with the installation form and preload in the actual vehicle, the standard charge-discharge and pulse characteristic tests under vibration conditions are carried out. The results show that there is obvious energy loss and sensitivity direction when the road excitation is transmitted to the battery pack, and the vibration acceleration of the pack is less than 2g and the energy is concentrated in the range of f<50 Hz. The intensified road vibration has no obvious effect on the discharge capacity of the power battery, while it will cause the increase of DC internal resistance by no more than 10% in this experiment. The research results will provide a basis for state estimation and fault diagnosis of power battery considering vibration factors.