MODELLING AND MINIMIZING OF HIGH-FREQUENCY LEAKAGE CURRENTS IN ADJUSTABLE SPEED DRIVES

摘要

Today, adjustable speed drives (ASDs) manufacturers use high-speed switching devices such as the insulated gate bipolar transistors (IGBTs) to achieve higher efficiency, low weight, and small size. However, the advent of fast power devices has produced several unexpected problems, such as premature deterioration of ball bearing and high levels of electromagnetic emissions, caused by flowing of parasitic capacitive currents known as common mode (CM) currents. In order to evaluate these leakage currents, a suitable model of the ASD is obtained by identification of the high-frequency spreading paths. The authors first carry out simulations using the proposed model and compare the results with experimental one. They then propose two methods of reduction of the CM currents in the ASD system.