A novel optimal control method of grounding impedance for distribution system

On basis of Peterson-coil automatic tuning system, a novel IGBT optimal control method of grounding impedance for distribution system is presented in this paper. When the operation of distribution system is normal, the IGBT module is off, the zero sequence voltage with system frequency will be low; when a single-phase grounding fault occurs, the IGBT module is on, the Peterson-coil is put into operation, the grounding capacitive current can be compensated, the fault arc can thus be extinguished instantaneously. The simulation is carried out using the software MATLAB, theory analysis and simulation results show that the presented method has quick compensation speed and wide adjustment range, the inductor-current can be continuously adjusted, the grounding fault current can be compensated effectively.