全周期无轴承开关磁阻发电机的设计

Design of a Full-period Bearingless Switched Reluctance Generator

分析全周期发电模式下无轴承开关磁阻发电机(bearingless switched reluctance generator,BSRG)的悬浮机理和发电原理,利用等效磁路法推导全周期BSRG的一相磁场储能表达式。考虑到全周期BSRG的控制方式和主、悬浮绕组的电流波形,将两套绕组电流等效为方波;再根据机电能量转换原理,积分得到了利用方波电流峰值表示的平均转矩和平均悬浮力表达式。结合输出功率与平均转矩的关系,推导出了全周期BSRG的主体尺寸计算公式。利用平均悬浮力设计样机最大径向负载要求,并通过绕组峰值电流与气隙磁密的关系计算绕组的匝数。最后,基于所提方法设计了一台实验样机,并通过有限元仿真验证了所提方法的正确性。

The principles of suspension and generation of a bearingless switched reluctance generator（BSRG） for full-period generating mode were introduced in the paper.The expression of one phase magnetic field energy for the full-period BSRG was derived using an equivalent magnetic-circuit method.Based on the control strategy and winding current waveforms of the full-period BSRG,the currents in two kinds of windings were equivalent to two square waveforms.Then the average torque and radial force expressions,represented by the peak values of two square currents,were gained using an integral of the corresponding derivative of the magnetic field energy,respectively.Combining with the relationship between average torque and electromagnetic power,the computational formula of main body for the full-period BSRG can be obtained.The design requirement of the maximal radial load can be gotten with the average radial force expression.The number of turns of two windings may be calculated with the relationship between peak values of square currents and magnetic flux density in the gap,respectively.Finally,a prototype was designed with the method presented in the paper;and the finite element analysis verified this design method for the full-period BSRG.