Impedance Identification Signal Excitation for Series-End Winding Motor System

At present, the study of battery impedance mainly focuses on off-line operating conditions, which cannot reflect the battery status online in real time. In this article, an online real-time battery impedance monitoring method is proposed with the traction inverter. This system allows superimposing an AC excitation signal of the desired frequency on the DC side without affecting the normal operation of the motor. Another advantage of this method is that no additional excitation device is needed. The amplitude and frequency of the signal are controlled by the motor drive system. Simulation and experiment are carried out to verify the feasibility of this novel method.