Control Algorithm Design Of AC-Side Traction Converter With DC-Link Lightweight

This paper was supported in part by the Sub-Project of the National Key Technology Support Program of China "Simulation Research on Optimization Control Strategy for CRH3Traction Drive System" under Grant2009BAG12A05-10.In order to realize the DC-link lightweight of CRH3high speed Electric Multiple Units (EMU), the compensation control algorithm of AC-side traction converter was studied and analyzed in detail which can provide theoretical support for engineering optimization design of high-speed railway train.DC-link lightweight mainly consists of LC resonance filter circuit cancellation and DC-link capacitor minimization. In this paper, the characteristic of AC-side traction converter without LC resonance filter circuit was analyzed and the mechanism and distribution of harmonics were derived. Then the dual-closed loop harmonic suppression algorithm with N times notch filter (NF) and harmonic compensation proportional resonant (PR) controller was proposed. The outer voltage loop control with N times notch filter was adopted to eliminate the ripple components of DC-link voltage without affecting the dynamic performance of the whole control system. The inner current loop control with harmonic compensation PR controller was used to realize zero steady-state error control for alternating current signal and eliminate the low-order harmonics of the line current.Secondly, the mechanism of DC-link voltage ripple was derived in the paper and the influence of two-cascading AC-side traction converter with carrier phase-shifting technology on DC-link ripple and capacitor minimization was analyzed in quantity and quality respectively. Theoretical analysis and simulation results show that DC-link voltage ripple can be reduced by carrier phase-shifting on the basis of traditional DC-link capacitor design method, and then the capacitor minimization could be realized further.Finally, hardware in the loop experiment platform with dSPACE simulator and TMS320F2812controller was set up. The main circuit model of AC-side traction converter was built and the DSP control programming of traction converter with DC-link lightweight was completed on the platform. The validity and effectiveness of the control algorithm were both proved by the simulation and experiment results.