Optimal Control Strategy of Current Harmonic for Onboard Line side Converter

Abstract:

The running of line side converter of alternating current(AC) drive electric locomotive and electric multiple units will generate current harmonic, and the frequency range of the current harmonic is wide. This will easily cause resonance between the train and the power supply grid. The harmonic characteristic of line side current in ideal conditions is analyzed; the problem about harmonic performance of usual transient current control strategy for multiple line side converters is discovered through comparison. In order to solve the problem, two optimal transient current control strategies based on average current feedback and primary current feedback are proposed. The simulation analysis and the line testing verify the validity of optimal control strategy. The total harmonic distortion(THD) for primary current fall to about 1%. The line side harmonic characteristic is improved visibly, and the resonance between the train and power grid is suppressed effectively.