Operating Area Extension of Surface Mounted Permanent Magnet Motor by LC Network

The maximum operable speed of a surface mounted permanent magnet motor is determined by the maximum available motor terminal voltage. In the conventional drive system using a three-phase voltage source inverter, the higher maximum motor terminal voltage can be obtained by boosting the DC link voltage such as a boost converter or Z-source inverter. However, all the devices and circuit should be redesigned because of the higher isolation length. This paper proposes the drive method for a surface mounted permanent magnet motor using a LC power network. LC network is placed between the motor terminal and the output terminal of inverter. The maximum operable speed in the proposed drive system is higher than that in the conventional drive system while keeping the same rated torque. The design method of LC network and the system analysis are presented. The effectiveness of the proposed method is verified by the experimental results.