A novel measurement approach based on wideband excitation for frequency-coupling admittances of train converter

Abstract

ABSTRACT In order to assess the high-frequency resonance and stability issue in the electrified railway system, a novel wideband measurement approach based on multi-tone signal is developed for extracting the sampling frequency-coupling admittances (SFCAs) of train converter. By injecting a series of linearly independent wideband excitation signals, the SFCAs of train are obtained simultaneously without affecting the network impedance. Considering the frequency distribution of wideband signal, an alternating injection method based on multi-tone signal is proposed. It aims at eliminating the overlapping effects of various frequency relationships on the target coupling harmonics in the 4QC control system. With unknown network impedance, the SFCAs of train covering all the desired frequencies, even several times sampling frequency, can be captured by the proposed wideband measurement approach. Comprehensive experiments are conducted on a hardware-in-the-loop (HIL) system for validating the measurement results.