A multi-sine excitation signal optimization strategy for rapid measurement of battery impedance spectrum in time domain

The electrochemical impedance spectroscopy (EIS) is a non-invasive and intuitive technique to detect the state of batteries. It is widely used to assess the state of health (SOH) and state of charge (SOC) of batteries. In order to meet the needs of industrial applications, time-domain methods based on fast Fourier transform are deployed to acquire fast EIS measurement, in which multi-sine overlapped current signals are used as the excitation. In this paper, the amplitude and phase angle of the components of the multi-sine excitation are optimized. Results show that better measurement accuracy are observed after using the proposed optimization strategy.