A New Method of Insulation Detection on Electric Vehicles Based on a Variable Forgetting Factor Recursive Least Squares Algorithm

The lithium-ion batteries of an electric vehicle belong to a high-voltage direct-current system. insulation performance vehicles is very important for their safe operation. To solve the problems slow response and poor estimation accuracy resistance under complex working conditions, real-time detection method based on variable forgetting factor least squares algorithm proposed in this paper. Based low-frequency signal injection considering influence Y capacitor, corresponding circuit model mathematical reflected wave voltage are established, linearized by first-order Taylor expansion. By analyzing parameter identification setting appropriate shutdown criteria, with designed quickly accurately estimate capacitance. experimental test results show that can track changes capacitance condition noise interference root mean square error resistor within 0.012.