科华蓄电池内阻检测原理-厦门科华恒盛股份有限公司——以诚信之道铸百年品牌
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科华蓄电池内阻检测原理

2018-04-17 11:16:44      点击:
由于电池内阻为毫欧级,因此采用常规的两端子测量方法测量误差较大,在此采用四端子测量方式。测量时两个端子施加一频率为
Because the internal resistance of the battery is millieu level, the conventional two terminal measurement method has great error, and the four terminal measurement method is adopted. At the time of measurement, two terminals are applied in a frequency.




精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery


的恒定交流激励电流信号,另两个端子用于测量。测量工作原理图如图1所示,响应信号是指科华蓄电池注入交流恒流源后,在其两端测出的交流电压信号。而正弦信号是经D/A产生的作为压控恒流源的输入信号。
A constant AC excitation current signal and the other two terminals are used for measurement. The working principle diagram is shown in Figure 1. The response signal is the AC voltage signal measured at both ends after the battery is injected into the AC constant current source. Sinusoidal signal is generated by D/A as the input signal of voltage controlled constant current source.












设正弦信号为:
The sine signal is set as:




精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery






(1)
(1)
科华蓄电池两端的响应电压信号为:
The response voltage signals at both ends of the battery are:




(2)
(2)




精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery
为注入科华蓄电池的交流电流和其两端响应电压信号的相位差。
The phase difference between the AC current and the voltage signals at both ends of the battery is injected.
通过模拟乘法器后有:
After the analog multiplier, there are:




精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery


K为模拟乘法器的放大系数。
K is the magnification factor of the analog multiplier.
进行低通滤波后滤掉交流成分得:
After low pass filtering, filter off the AC component:






精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery


(3)
(3)


由交流法测内阻原理得:
The principle of measuring internal resistance by AC method is obtained.




精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery


(5)
(5)
式中I为交流恒流源信号的最大值。比较(4)、(5)可得:
I is the maximum value of the AC constant current source signal. Comparison (4) and (5) can be obtained:






精确测量科华蓄电池内阻方法的研究
Study on the method of accurately measuring the internal resistance of the battery




上式中K、A、I都是已知量,而u为经过A/D采样送到单片机进行处理的采样值,所以在单片机中进行一个简单的除法运算便能得到科华蓄电池内阻了。
The K, A and I in the upper form are all known, while u is sampled by the A/D sample to the single chip processor, so a simple division operation in the single chip can get the internal resistance of the battery.