Parallel inverters with high frequency pulse dc link

A parallel inverter based on the duty cycle extended active clamp forward mode inverter with high frequency pulse DC link is proposed. The circuit topology, steady principle, control strategy of three-state discrete pulse modulation hysteresis current, current-sharing, criterions of the key circuit parameters of the parallel inverters are investigated. The parallel inverter is constitute of the N duty cycle extended active clamp forward mode high frequency pulse DC link inverter modules with common outer voltage regulator and separately inner current regulator. A designed and developed prototype for 3 kVA 27VDC/115V400HzAC parallel inverter has excellent performances such as small bulk, lower weight, high conversion efficiency, high steady precision, fast dynamic response, wide range input voltage, good output voltage waveforms, good current-sharing effect, strong ability for different nature load, and strong over-load and short-circuit ability. The parallel inverter can be used in large power inversion fields.