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Indexed by:会议论文

Date of Publication:2017-01-01

Included Journals:CPCI-S

Volume:2017-January

Page Number:1347-1352

Key Words:Electric traction PWM rectifier; inductance estimation; control system stability; dual-frequency harmonic current injection; fast Fourier transform

Abstract:Due to the nonstationary characteristic of the electric locomotives in electric traction systems, the equivalent grid impedance changes frequently, which may lead to detrimental effect on the control system of electric traction PWM rectifiers. The mathematical model of an electric traction PWM rectifier is established, and the double-loop control system is designed. An online grid inductance estimation method for the electric traction PWM rectifier based on dual-frequency harmonic current injection is accordingly proposed. 400Hz and 500Hz are selected as the frequencies of the harmonics injected into the system. Moving window fast Fourier transform (FFT) is performed to extract the amplitudes corresponding to the harmonics. The estimation values of the grid inductance can be obtained from a series of arithmetical operations. The experimental platform for the electric traction PWM rectifier is set up. Simulation and experimental results are demonstrated to verify the effectiveness of the proposed strategy.