High-frequency link DC-AC converter with suppressed snubber circuits-naturally commutated phase angle control with self turn-off devices

摘要

A novel approach to HF (high-frequency) link power conversion with suppressed snubber circuits which is suitable for high-power application is proposed. A new control scheme totally utilizing natural commutation phase-angle control with a self-turn-off device is proposed. The magnetic energy stored in the leakage inductance at the moment of switching is released and fed back to the DC voltage source by means of commutation overlap phenomena. Instantaneous current control on the output AC side of the cycloconverter stage is also available by applying current feedback control. When the proposed system is linked to the AC system line, an active filtering function against AC loads connected in parallel at the same AC system also becomes available.