|
|
Rotor structure optimization of permanent magnet synchronous generator builtin type U |
School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150080, China |
|
|
Abstract To solve the problems of tooth harmonic with high voltage distortion and cogging torque for permanent magnet synchronous generator(PMSG), the rotor structure of U type PMSG was optimized, and the cause of cogging torque was analyzed. Taking 6 pole PMSG with 72 slots as example, the effects of magnetic pole shift and nonuniform air gap on the electromagnetic properties of PMSG were analyzed by finite element method. The influence of the position of rotor axial cooling channel on PMSG performance was also studied. The results show that the magnetic pole shift can make the phase of cogging torque periodically change. When the magnetic pole offsets 0.5 tooth distance, the corresponding cogging torque is the smallest with about 25% of the original value. The tooth harmonic content, the voltage distortion rate and the cogging torque are decreased with the increasing of eccentricity of nonuniform air gap. When the position of rotor ventilation duct is suitable, the magnetic flux density in the magnet surface with maximum degaussing risk is biggest, which shows that the demagnetization risk of permanent magnets can be reduced by the appropriate rotor vents position. For the motor, the maximum magnetic density at the minimum magnetic density surface of permanent magnetic steel is 0.331 7 T when the rotor vents are shifted 2 degrees of mechanical angle.
|
Received: 25 February 2017
|
|
|
|
|
|
|