DC bus voltage control of large-capacity SMES converter

This paper introduces a novel multiplex voltage source converter topology based on common DC bus. Except from the excellent characters of traditional VSC, the capacity of the system can be expanded. Dual mode control is proposed to stabilize DC bus voltage, when the superconducting inductor current is between the maximum and the minimum allowable value, chopper control mode is adopted; when the current exceeds the maximum and the minimum allowable value, converter control mode is adopted. 50kW SMES system is taken for example, Matlab/Simulink simulation results indicate that dual-mode control is superior to general control for its stable power output and optimization of output current harmonics.