Research on the design and optimization of 1.5 MW semi-direct drive permanent magnet synchronous wind turbine

Abstract

The utilization of wind energy can alleviate the problems of fossil energy shortage and environmental pollution. As the core unit of wind power generation systems, improving the design and manufacturing technology of permanent magnet synchronous generator has become the research focus of researchers. In this paper, the key design technology of direct drive permanent magnet synchronous wind turbine, especially the semi-direct drive permanent magnet synchronous wind turbine with primary gear is studied, and a 1.5 MW semi-direct drive permanent magnet synchronous wind turbine is designed. To improve the power factor of the permanent magnet synchronous generator, the reactive power compensation device and filter circuit are added to the control circuit. The results show that after adding the reactive power compensation circuit, the power factor of the circuit can reach 1. In addition, due to the filter circuit, the fifth harmonic is reduced from 5.6% to 3.9%. The scheme of closed slot is used to weaken cogging torque and resistance torque of the permanent magnet synchronous generator. To improve the utilization of permanent magnet, a T-shaped rotor pole structure is proposed in this paper and the pole arc coefficient is selected between 0.65–0.70. Through the comparative analysis of various design schemes, the design scheme of 50 poles-180 slots is determined. The temperature rise of the permanent magnet synchronous generator is calculated by the thermal network method and ANSYS finite element analysis. The results show that the temperature rise of the design scheme is within the normal working range of the motor.