Closed-loop Control of High Frequency AC PWM Inverter for Space Application

This paper presents a closed-loop controller design approach for a single-phase (1ϕ) pulse-width modulated (PWM) high frequency (HF) AC inverter, supplying the non-linear load for space application. Control challenges in HF inverter are highlighted compared with 50/60 Hz conventional inverter. Considering HF PWM inverter with resistive load, the parameters for two-loop control structure are decided to meet specific stability criteria and steady-state performance. Re-tuning of the controller is performed to support non-linear load (uncontrolled diode bridge rectifier) with trap filters. The possibility of connecting damper resistors in series with the trap filters is also explored for better control loop shaping. Analog realization of the controller is also discussed in brief. The proposed controller design is validated experimentally by transferring 0.5 kW power through a 50 V peak, 10 kHz AC system.