五桥臂逆变器-双异步电机调速系统的零矢量交错模型预测控制

五桥臂逆变器-双异步电机调速系统采用模型预测控制相比于传统的矢量控制具有更好的动态性能,易于实现系统的全局性能优化,但却存在稳态性能差、计算量大难以实现、无法消除公共桥臂开关动作需求限制等问题。对此,提出一种零矢量交错模型预测控制(ZVI-MPC)方法,将空间矢量的概念与矢量合成原理引入到模型预测中,在一个采样周期中对每台逆变器均作用两个电压矢量(一个非零矢量和一个零矢量),利用无差拍理论计算两逆变器的非零矢量作用时间,结合公共桥臂开关需求,调节各矢量作用时间并按照零矢量交错原则进行开关状态分布,以避免出现公共桥臂开关动作需求冲突。该方法在任意采样周期内只需考虑12种有效矢量组合,大大减少预测控制计算量。仿真和实验结果表明采用零矢量交错模型预测控制,两台电机可独立稳定运行,且均具有良好的动静态性能,相比于传统模型预测控制方法,本文所提方法稳态性能更理想,且计算量显著减小,易于实现。

Model Predictive Control Based on Zero Vectors Interleave for Dual Induction Motor Drives System Fed by Five-Leg Inverter

Compared to the conventional vector control, a five-leg inverter-dual asynchronous motor speed control system using model predictive control can achieve better dynamic performance and multiple objects optimization. However, it has some disadvantages, such as poor steady state performance, large amount of calculation, and limitation for switching requirements of the common leg, and so on. This paper proposes a model predictive control method based on zero vector interleave, where the space vector and its synthesis are introduced. In this control method, two voltage vectors including one non-zero vector and one zero vector are employed for each inverter in a sampling period. According to the dead-beat principle, the duty cycles of non-zero vectors for both inverters are adjusted to achieve zero vectors interleaved, which can avoid switching action demand conflict of the public bridge legs. Only 12 valid vector combinations are considered in every sampling period, reducing the calculation of predictive control significantly. Simulation and experimental results show that both induction motors operate independently and stably with good steady state/dynamic performance. Compared to the conventional model predictive control method, the propose method has better steady state performance and simplified calculation.