高速电机因其功率密度高、体积重量小、工作效率高等明显优势,受到越来越广泛的关注.高效稳定的驱动系统是充分发挥高速电机优异性能关键所在,该文主要从控制策略、转角估算以及功率拓扑设计等方面,分别分析高速电机驱动技术的难点,并总结归纳国内外当前研究成果,之后对高速电机驱动技术及其发展趋势进行总结展望.

Maximum torque per ampere (MTPA) control strategy is widely used in permanent magnet synchronous motor (PMSM) control systems because it can maximize the role of the inner permanent magnet synchronous motor (IPMSM) reluctance torque so that the motor efficiency can reach the highest. The control performance of the traditional MTPA control strategy applied to IPMSM is greatly affected by nonlinear factors such as parameter variation and magnetic circuit saturation. To solve the above problems, this paper proposes to construct a d'q' coordinate system rotating synchronically with the current vector, using the method of coordinate tracking to realize the real-time self-searching MTPA working point with i(d)(')= 0 control. The scheme is simulated on a 2830W / 3000rpm IPMSM, the control performance of the proposed method is verified, and the control effect of the self-searching MTPA working point is realized.

高速永磁同步电机驱动系统具有电磁时间常数小、高速区载波比低的特征,加剧了电流纹波,影响系统效率、振动噪声和电磁干扰.为降低高速永磁同步电机的电流纹波,基于SiC-MOSFET/Si-IGBT混合型逆变器设计了一种改进型低损耗空间矢量调制算法.首先,通过调整零电压矢量的生成方式和各功率器件的开关动作时序,将大部分开关动作转移至低损耗的SiC-MOSFET中,并为高损耗的Si-IGBT提供零电压开关条件,降低了逆变器损耗,提高了驱动系统的效率和可用开关频率,逆变器开关频率的提高有效降低了电机电流纹波.其次,对该算法作用时的电流纹波特性进行深入分析,在此基础上提出一种变开关频率模式的最优交轴电流纹波峰值调制算法以优化交轴电流纹波性能.然后,根据预测的交轴电流纹波峰值实时调整载波频率,通过削峰填谷的方式对交轴电流纹波进行平均,在不增加开关损耗的条件下,分散开关能量、降低转矩脉动、改善振动噪声和电磁兼容性能.所提方案的优势在于:较于传统型逆变器,逆变器开关损耗降低、效率提高,可进一步提升开关频率以改善电流纹波;较于传统空间矢量调制算法,改进了电压矢量的生成方式,并利用载波频率这一新增自由度分散能量,降低了交轴电流纹波.最后,通过仿真与实验对所提出算法的有效性进行了验证.

Due to its quick response and strong robustness, direct torque control (DTC) system of permanent magnet synchronous motor (PMSM) is widely used in the field of higher response performance. However, the performance of conventional DTC still needs to be explored. Some factors have a great influence on the stability of the system such as: large torque ripple, stator resistance voltage drop, the disadvantage of integral method and nonlinear factors. In order to improve inhere problems above of conventional DTC, this paper uses the mathematical model in dq-frame to observe the flux linkage, and puts forward the definition of "stator flux line". Based on these, an improved torque control algorithm of high-speed motor based on flux decoupling is proposed. The simulation results on a 7.5kW/2400rpm PMSM verified the proposed control scheme has good performance in low speed-region and the algorithm can suppress the torque and flux ripple of the control system to a certain extent.