Control range analysis method of capacitor voltage balancing control based on virtual loss difference resistance model

In order to obtain an effective control range analysis method of different capacitor voltage balancing control strategies, this paper proposes a control range analysis method based on virtual loss difference resistance model. In this paper, the virtual loss difference resistance model is established on the submodules of cascaded converters. The control ranges of several conventional capacitor voltage balancing control strategies are analyzed according to the virtual loss difference resistance model. The value of the virtual loss difference resistance of the corresponding submodule is calculated based on STATCOM topology. Besides, the control range of the submodule capacitor voltage is analyzed. A simulation model is established in MATLAB/Simulink, and a conventional capacitor balancing control is applied in the simulation to verify the proposed analysis method. The simulation results have verified the correctness and the effectiveness of the proposed control range analysis method.