Combined Three-phase Inverters with High Frequency Pulse DC Link
A combined three-phase inverter based on the duty cycle extended active clamp forward mode inverter with high frequency pulse dc link is proposed in this paper. The three phase inverter is constituted of three same single inverter modules. The voltage-mode feed forward control strategy is introduced in the active clamp forward mode high frequency pulse DC link circuit, the three-state discrete pulse modulation (DPM) hysteresis current control strategy is introduced in the inverter. The circuit topology, steady principle, control strategy, load characteristic, criteria for the key circuit parameters of the combined three-phase inverter are deeply investigated. A designed and developed 3kVA 27VDC/200V400HzAC prototype has excellent comprehensive performances such as small bulk, lower weight, high conversion efficiency, high steady precision, wide input voltage range, low THD of output voltage, strong over-load and short-circuit ability, and strong ability with different nature load and unbalanced three-phase load.