信号相关在测量蓄电池内阻相位差方面的应用

Application of Signal Correlation Principle in Measurement of Phase Difference of Battery Internal Resistance

为更好地解决目前蓄电池内阻巡检仪在相位差测量方面存在的不足,引入了信号相关原理。通过得到蓄电池的响应电压信号和注入交流信号的互相关函数以及两信号的自相关函数,对两者相位差的计算进行理论推导,利用快速傅里叶变换(FFT)实现计算相位差的算法并嵌入到单片机中,结合蓄电池组的选通情况,将奇数节蓄电池和偶数节蓄电池分别处理,从而解决在相位差测量方面的不足,最终得到两者的正确相位差,为单体电池内阻计算提供正确的依据。经仿真分析和试验测量数据验证,采用该方案实现的内阻巡检仪可在线实时监测各节蓄电池与注入交流信号的相位差,为蓄电池的内阻计算提供正确依据,测量结果稳定精确。

In order to better solve the shortcomings of current battery internal resistance detector in phase difference measurement,the signal correlation principle is introduced. By obtaining the cross-correlation functions of the response voltage signal and the injected AC signal of the battery and the auto-correlation functions of each signal,the calculation of the phase difference between the two signals is theoretically deduced,and the algorithm of calculating the phase difference is realized by using FFT. Embedded in the MCU,combined with the selection of batteries,odd batteries and even batteries are processed separately,so as to solve the shortcomings of phase difference measurement,and finally get the correct phase difference between them,which provides the correct basis for the calculation of internal resistance of individual batteries. The simulation analysis and experimental data validate that the internal resistance patrol instrument based on this scheme can monitor the phase difference between each battery and the injected AC signal online and in real time,which provides the correct basis for the calculation of the internal resistance of the battery,and the measurement results are stable and accurate.