多相感应电机转子磁场定向矢量控制策略

针对多相感应电机正弦供电时铁芯利用率低、输出转矩小的问题,通过分析多相电机的磁动势分布和谐波磁场对电机气隙磁密和轭部磁密的影响,提出基于谐波电流注入的转子磁场定向矢量控制方法.通过注入满足一定比例和相位关系的各次谐波电流,优化气隙磁密和轭部磁密为平顶波,并在一台九相集中整距绕组感应电机上进行实验验证.结果表明:在保持气隙磁密幅值、轭部磁密幅值和定子铜耗与基波供电分别相等的条件下,可以有效地提高电机输出转矩和电机效率;同时系统在低速下具有良好的动态响应和带载起动能力,适合应用于低速大转矩场合.

Rotor field oriented control strategy of multiphase induction motor

To solve the problem of low core utilization and low torque for multiphase induction motor with sinusoidal power supply,rotor filed oriented control(RFOC) for multiphase induction motors with harmonic currents injection was proposed based on the analysis of the influences of harmonics injection to flux densities and magnetic motive force(MMF) distribution.Harmonic currents with certain percentage and phase relationship were injected to optimize the air-gap and yoke flux densities for flat-topped waves.Taking a nine phase concentrated winding induction motor for example,the proposed theory was validated.The results show that multiphase concentrated winding induction motors with harmonic currents injection can improve the torque and efficiency,keeping the amplitudes of the tooth flux density and yoke flux density as well as the stator copper loss unchanged.The system is suitable for low-speed and high-torque applications due to the capacities of well dynamic response and starting load at low speed.