Bidirectional switch for a solid state tap changer

Commutation cell with bi-directional switch and high frequency switching is a basic building element of a solid state tap changer. Existing technique requires accurate current measurement and has potential hazards. Different solutions are suggested in the paper and verified by simulation and experimental study. A novel commutation technique without necessity to measure current is developed and presented. Experiments verify the simulation results. The application of such a commutation is demonstrated on 500 kVA tap changed transformer. Voltage regulation with tap changer is demonstrated too.