风速突变工况下永磁风力发电机静态偏心磁场分析

为了研究风速突然变化对永磁风力发电机主轴的电磁力作用,特别是在已发生一定的主轴偏心的情况下风速突变对主轴的影响,利用数学表达式和仿真对气隙磁场进行了计算和分析。根据发电机气隙偏心故障时气隙磁场变化的特点,计算气隙磁导和磁场密度,并利用ANSOFT MAXWELL软件建立永磁风力发电机的二维模型,分析电流变化引起的电磁力及其对主轴的作用。仿真结果表明:风速突变引起的电流变化影响永磁风力发电机气隙磁密。转子偏心使发电机转子产生沿偏心方向的磁拉力,风速突变时转子收到的不平衡磁拉力比正常风速运行更大。

Analysis of static eccentric magnetic field of permanent magnet wind generator under wind speed mutation

In order to study the effect of sudden changes in wind speed on the electromagnetic force of the rotor of the permanent magnet wind generator,especially in the case of a certain rotor eccentricity,the magnetic field of the air gap is calculated and analyzed by using the mathematical expression and simulation.The air gap magnetic conductance and magnetic field density are calculated according to the characteristics of air gap magnetic field when the air gap eccentricity fault of generator occurs.The two-dimensional model of permanent magnet wind generator is established by ANSOFT MAXWELL software,and the electromagnetic force caused by the current variation and its effect on the main shaft are analyzed.The simulation results show that the change of winding current caused by the wind speed change affects the air gap magnetic flux density of permanent magnet wind turbine generator.The rotor eccentricity produces magnetic force along the direction of eccentricity,when the wind speed abruptly changes,the unbalanced magnetic pull of the rotor is larger than the normal speed.