Research on on-line monitoring method of insulation state of electric vehicle high voltage system

At present, with the development of electric vehicle technology, there are more and more high-voltage electric equipment in the whole vehicle, and the voltage level in the vehicle is also improved, so the safety of electric highvoltage is becoming more and more important. Insulation detection is one of the key high-voltage safety technologies, but most of the current detection methods in the electric vehicle insulation resistance comprehensive detection, fault location and other aspects of defects, can not meet the electric vehicle insulation detection of increasingly high requirements. For electric car high voltage safety issues, based on the insulation resistance testing carried on the thorough research as the research object, this paper proposes a low frequency injection insulation resistance online detection algorithm, and builds the equivalent model, and analysis show that the algorithm can be to conduct a comprehensive testing insulation resistance for electric vehicle, and can be for a single point of insulation fault of power battery fault point location. Experimental results show that the designed system can realize the insulation resistance detection function, and the error rate is low, the proposed algorithm is correct, and the safety performance of electric vehicles is further improved.