九相电机不平衡供电性能分析

Analysis of nine-phase induction motor under unbalanced supply

针对"电机本体故障或逆变器故障等因素的影响,电机的各相实际电压不可能完全平衡,在不平衡供电下,电机的性能(定子电流和转矩脉动等)也会发生一定的改变"的问题,研究了多相集中整距绕组感应电机在不平衡供电下的性能,并以一台九相电机为研究对象,对其在不平衡供电下进行了Ansoft仿真,并分析了电压不平衡对定子电流和转矩脉动的影响。研究结果表明,电压不平衡的方式不同,对电机性能的影响也不尽相同;不平衡电压的幅值与相位变化将主要影响故障相的定子电流和相位,对非故障相的影响较轻,但将同时产生较大的转矩脉动,随着不平衡程度的增大,脉动也增大,且不平衡相位产生的脉动将大于不平衡幅值产生的脉动。

The motor is supplied by an inverter,which may be excepted to be well-balanced.However a voltage mismatch is measured between phases on the experimental system which would influence the performance of motor.Aiming at this problem,the multi-phase concentrated full-coil winding induction motor was analyzed under unbalanced supply.A finite element analysis was used to calculate and analyze a nine phase motor under unbalanced supply,and the performances was compared.The results indicate that the performance of multi-phase induction motor under unbalanced supply will be different from balanced supply,especially in the phase current and the torque ripple.It will produce positive sequence voltage and negative sequence voltage which will influence the phase current and torque ripple.