Method of LC Parameter Selection for Metro Traction Drive System Based on Stability Analysis

The traction drive system of the subway has a negative impedance characteristic due to its main circuit load, which easily causes low frequency oscillation on the DC side. The value of the LC filter parameters of the main circuit is a key parameter affecting the stability of the system. Based on the equivalent circuit model of the subway transmission system, this paper analyzes the cause of the DC side low-frequency oscillation of the main circuit of the system. Then a mathematical model for analyzing the stability of the system is established based on the system main circuit topology with considering the system delay. In this paper, we fully discussed the relationship between the value of the main circuit filter parameter LC and the system stability. Then a method of LC parameter selection is proposed that effectively determine the boundary of the LC parameters of the main circuit of the traction drive system. Finally, taking Changsha Metro Line 2 as an example, the correctness of the method is verified by simulation analysis.