Research on the Battery Internal Impedance Measuring Instrument

摘要

The realization of on-line monitoring to internal resistance of single cell is important to improve the safe operation of DC system and to increase the reliability and autoimmunization level of power systems. The current internal resistance measuring methods, such as density method, open-circuit voltage method, DC discharge method are compared and analyzed while their advantages and disadvantages are presented. The AC method, a new method to measure internal resistance of single cell is introduced, especially on its operating principle and the design of hardware and software. The internal resistance measuring instruments based on the AC method have been put into operation in many substations. Field applications have proved that the instrument has the advantages of high-precision, strong anti-interference capability, a high degree of automation, and be capable to realize on-line monitoring.