Design of 35 kJ/s 25 kV capacitor charging power supply for pulsed power systems

In many modern pulsed power systems traditional power supplies have been replaced by high frequency switching power supplies. These power supplies offer light weight, smaller sizes, and improved efficiencies over traditional power supplies and are suitable for high voltage pulsed power systems. In this paper, a 35 kJ/s 25 kV capacitor charging power supply with a 3-phase resonant inverter and air-insulated transformers is proposed. This capacitor charger greatly improves the stability and maintenance of the conventional power supplies with single phase inverters and oil-insulated transformers. The structural characteristics and experimental results are presented, taken from a laboratory prototype rated at 35 kW, input voltage of 3-phase 380 V, output charging voltage of 25 kV, and operating at 20 kHz. The measured power factor and efficiency at full load are about 90% and the constant output current is about 2.8 A.