High-Voltage Charging Power Supply Based on an LCC-Type Resonant Converter Operating at Continuous Conduction Mode

This article describes the design, implementation, and testing of a 2.0-kW high-voltage rep-rate charging power supply based on an non-isolated inductor-capacitor-capacitor (LCC)-type resonant converter operating at continuous conduction mode, which provides a constant charging current with high control accuracy/efficiency. The design of the proposed capacitor charging power supply (CCPS) has been carried out in such a way that to be a low cost, simpler, compact, and efficient driver for the miniature pulsed plasma sources (PF-3J: 10 kV, 84 nF, 48 nH, and PF-225: 15 kV, 2 μF, 50 nH), operating at repetitive discharges with the following specifications: 20 kV, 2.0 kW, and maximum pulse repetition rate up to 50 Hz. In order to understand the required conditions of such a power converter toward the functional stability, a detailed theoretical study of, and the design considerations along with the simplified design equations taken for, the proposed converter are discussed from a practical viewpoint. Due to the use of a fast complex programmable logic device (CPLD) controller, the synchronization of the start of the leg switching voltage with the moment of zero-current detection was observed at the switching frequency of 125 kHz. The functional stability of the CCPS at repetitive discharge mode was verified via operation at low and high frequencies. The results of diagnostics successfully confirmed the accurate performance of the control and sampling circuits for the moderate repetition rate of 0.5 Hz with the repeatability of about 0.1%. Finally, the developed rep-rate high-voltage charging power supply was shown to be very reliable, even under faulty operating conditions in the system.