A three-phase 100 kV, 200 kVA automatic repetitive charging system

Summary form only given. A three-phase 100 kV, 200 kVA repetitive charging system were designed and constructed. It consists of four main parts: L-C converter with constant current, high voltage rectification unit (included high voltage transformer and three-phase bridge rectifier), PLC (Programmable Logic Controller) control unit and IGBT (Insulated Gate Bipolar Transistor) controller. The main parameters are: the charging current of 2A, the maximum operating voltage of 100 kV and the maximum rep-rate of 100 pps. The charging technique of the L-C converter with constant current was adopted. Its fundamental principle is based on the resonance phenomenon in the circuit being composed of inductance and capacitance. The charging current is only proportional to the input voltage of charging unit and has no concern with load, so that there is no limiting current resistance or inductance in the charging circuit. As mentioned before, the main characteristics are the fast charging speed and the high charging efficiency. A PLC was used as the central part in the control unit. Before test, the operating voltage from 1 to 100 kV, the rep-rate from 1 to 100 pps and the discharge times from 1 to 10000 shots are chosen, respectively. The charging process is automatic performance. When the voltage of charging capacitor reaching the preset value, a control signal is transmitted to IGBT. Then IGBT closed, the charge stops. In reverse, the capacitor is charged. This charging system has been used not only in the rep-rate microsecond pulse accelerator, but also in the shotlife test of the rep-rate switch at 100 kV and 100 pps.