Evaluation of power losses in power electronic converters for industrial applications: comparison among hard switching, ZVS and ZVS-ZCS converters

摘要

A comparison among hard switching (HS), zero voltage switching (ZVS) and zero voltage switching zero current switching (ZVS-ZCS) converters is proposed. For high voltage (400-800V), high power (from 5 to 50 kVA) applications, where IGBTs are predominantly used, the maximum operating switching frequency for hard switching IGBT converters is 20 kHz. To reduce the size of the passive components used in the power converter, such as inductors, capacitors and transformers and thus the power converter cost, the switching frequency must be increased. This purpose is against the efficiency of the converter, because the switching losses increase with the switching frequency. Power converters controlled by other techniques such as ZVS or ZVS-ZCS are able to operate up to 100 kHz in a power range up to a few tenth of kVA. For the analysis of the three power converters, a simplified simulation tool has been developed. A comparison, through simulation results, of these power converters for an industrial application of 30 kVA output power, with different load conditions has been carried out.