Compound control algorithm based on a novel topology of current compensation apparatus

This paper theoretically analyzes the compound control apparatus for current quality compensation which is designed as differentiation cascaded H bridge type with two modules: fundamental-frequency module and high-frequency module. The detection algorithm calculates the harmonic current and fundamental-frequency current of the load current which serve as the command current. For the purpose of eliminating the steady periodic error of system and improving the tracking accuracy of the compensation current, PI and repetitive controller in parallel is introduced as a advanced current control method. A detailed analysis and design for the high-frequency module is presented based on frequency characteristic and steady state. A 10kV system simulation model based on PSCAD/EMTDC is built to analyze the control strategy. Finally, the experimental results illustrate that the proposed control strategy is feasible and provide a reference for the 10kV industrial apparatus.