Experimental verification of winding switching technique to enhance maximum speed operation of surface mounted permanent magnet machines

Flux weakening is an inevitable requirement in the operation of variable speed permanent magnet (PM) machines for high-speed applications due to inverter voltage limits. A new winding switching technique is experimentally validated in this study that can extend the speed range of such PM machines. A drive topology is proposed that utilises two current regulated voltage source inverters to control the machine in a dual inverter fed configuration before transitioning into an open winding configuration after winding switching. The proposed drive topology extends the constant torque region of the machine and boosts its maximum output power capability. Complete experimental results are provided to demonstrate the effectiveness of the proposed machine drive system for continuous operation over the entire speed range.This research was jointly supported by the 'BK21PLUS program' through the National Research Foundation of Korea funded by the Ministry of Education and the 'Human Resources Program' in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), which is funded by the Ministry of Trade, Industry and Energy, Republic of Korea (20154030200730)