A motor-friendly and efficient resonant DC-link converter

Parasitic high frequency (HF) phenomena for adjustable speed drives (ASD) fed by inverters with fast switching semiconductors are well known in literature. Although many advantages rise when using higher switching frequencies, like lower motor harmonics and audible noise, feeding the electrical machine through long cables lead to high voltage overshoots at motor terminals due to cable-motor impedance mismatch. Another important aspect in power converter design represents the efficiency, which has to be as high as possible. In this paper two topologies of resonant DC-link converter proving in the same time high efficient and motor-friendly are analyzed. Principle of operation are discussed together with control strategy and design. Motor-friendly characteristics are presented. Finally, simulations and measurements back up the reliability of chosen topology.