830 / 2019-04-29 21:00:05

High-Order Sliding Mode Control of Modular Multilevel Matrix Converter in Fractional Frequency Offshore Wind Power System

Modular multilevel matrix converter,fractional frequency offshore wind power system,sliding mode control,nonlinear control

The Modular Multilevel Matrix Converter (M3C) is a high-power high-voltage direct AC/AC power converter topology which is suitable for low frequency power transmission and distribution systems, such as offshore wind power integration, long-distance FFTS and subsea electric system. But it has obvious non-linear characteristics, complex system structure, high model order and complex control task. Based on the analysis of vector control, this paper proposes a high-order sliding mode control (SMC) strategy combining linear sliding mode with non-singular terminal sliding mode to control a high-order nonlinear system. According to the simulation results of the output waveform quality and power characteristics, the M3C has a better performance under SMC than PI control. The control strategy proposed in this paper can quickly and simply control high-order nonlinear strongly coupled systems, which provides ideas for the stability control of power systems.