A Novel Constant Power Control for Series–Parallel Resonant Repetitive-Frequency Capacitor Charging Power Supply

This article presents a novel constant power (CP) control method for series–parallel resonant converters in the context of repetitive-frequency (RF) pulsed power supplies. The objective is to isolate pulsating power generated by RF operation from the power grid and enhance power supply utilization (PSU). The proposed CP control is based on the time-domain model, especially under discontinuous current mode. First, the CP model is established from the analytical correlation between the output voltage and the initial voltage of resonant capacitors. Second, real-time calculation of the charging current and power is achieved using the developed CP model, thereby improving dynamic response. Additionally, the switching frequency and duty cycle are updated based on the timely calculated output power, ensuring the desired CP charging and full isolation of pulsating power from the power grid. Finally, experimental results show the superiority of the proposed CP control method over conventional proportion-integration control methods in terms of the RF, the ac input-side power factor, and the PSU.