Clamped Auxiliary Resonant Snubber Soft-Switching Converter for High-Precision Applications

High dynamic and low output distortion are the key requirements of power converters in high-precision motion control. The soft-switching auxiliary resonant snubber inverter (ARSI) has the advantage of low dead-time effect is very suitable to be used in high-precision applications. However, the auxiliary switches in ARSI suffer from over-voltage problem due to the resonance between the junction capacitors of auxiliary switches and resonant inductor. Besides, all switches of natural zero-voltage switching ('NZVS+NZVS' mode) under the light load condition brings about voltage error. Thus, the clamped auxiliary resonant snubber converter (CARSC) is proposed in this paper. Extra diodes are added, which can not only reduce the voltage stress of auxiliary switches but also save the freewheeling energy for the next commutation to improve the efficiency. Moreover, all switches of auxiliary zero-voltage switching ('AZVS+AZVS' mode) is proposed to reduce the voltage error of 'NZVS+NZVS'. The experimental results demonstrate that the over-voltage problem is addressed and the loss of the proposed CARSC is reduced. Besides, the high-precision performance of CARSC is verified. The lowest THD of the output current is 0.015%. (c) 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.