Intrinsic Parameter Estimation of Railway Traction Power System Based on Impedance Measurement

This paper proposes a method for adaptively extracting intrinsic parameters of the railway traction power system based on the wideband impedance measuring information. A wideband excitation signal is injected twice into the system at two connection points and only three pairs of voltage and current sampling signals need to be measured. Adaptive equivalent models representing the traction power supply system are established after determining the impedance characteristics of each region. The intrinsic parameters extracted are calculated from the adaptive equivalent model and the wideband impedance measurement results. The proposed method can be added to the existing measurement algorithms. It can provide accurate equivalent parameters and guidance for efficient model building. Experimental results show that the proposed method yields good parameter extraction and that it can also adapt to changes of order for various railway traction power systems.