Study on the Influence of Drive Strategies on the Loss in AC Permanent Magnet Motor
|School||Harbin Institute of Technology|
|Course||Motor and electrical|
|Keywords||AC permanent magnet motor Sine wave drive square wave drive iron loss rotor current loss|
With the development of computer technology, power electronics technology and manufacturing process of permanent magnetic materials and new methods of control theory, AC permanent motor servo technology in recent years develops very quickly and gradually replaces the DC servo system into the mainstream. Loss of motor is an important factor in motor design. Nowadays, a lot of study is carried out by researchers domestic and abroad, but is limited by some specific condition. In fact, Loss of motor is different with different control strategies. In this paper, an inverter is designed, and the AC permanent magnet motor loss with different control strategies is analyzed.Firstly, two mathematical models of AC permanent magnet motor are set up, vector control strategy and square wave drive control strategy are discussed in details. An inverter plat is designed that includes control system based on TMS320F2812 and IGBT drive system. This plat’s protection function is as follows: over-current , over-voltage, temperature etc, and it also has general position port and max232 serial communication .Also the current and speed closed loop program is given which includes sine wave drive and square wave drive. These works make next analysis possible.Secondly, with the help of the finite element model (FEM) software, iron loss, rotor eddy current loss and copper loss are studied, and simulation results discloses regularity of iron loss and rotor eddy loss. The influence of motor output and regularity also is analyzed. The result indicates that in the same conditions the motor loss with square wave drive is greater than that with sine wave drive when the motor windings are three phases, star connection and no centre point.Finally, the losses of a AC permanent magnet motor with different control strategies is tested, and the results show the relationship between copper loss, iron loss ,rotor eddy current losses and different control strategies. The test results approve that the FEM results is correct.