【摘要】 提出一种新颖的基于转矩预测控制+快速空间矢量调制算法的三电平中点钳位式逆变器供电的异步电动机直接转矩控制方案。系统中首先使用转矩预测控制算法得到所需施加的定子参考电压矢量,然后基于非正交60°坐标系,利用空间矢量脉宽调制算法选择基本矢量合成所需的参考电压矢量,该算法在基本矢量的选取和作用时间计算方面十分简单。针对电机运行时有功功率的输出导致直流侧电容电压失衡问题,采用先预测、后控制的方式稳定中点电位。仿真结果验证了该控制算法的可行性,三电平直流侧中点电位不平衡、输出电压dv/dt得到了有效地抑制,并获得良好的电机动态和稳态调速特性。更多还原

【Abstract】 In this paper, a novel scheme based on predictive control and fast space vector pulse width modulation algorithm for the direct torque control (DTC) system of an induction machine fed by three-level DCMLI is proposed. In the system, the reference stator-voltage space vector is obtained by the predictive control algorithm firstly, then a space vector pulse width modulation (SVPWM) algorithm based on non-orthogonal 60° coordinate is used for the synthesizing of reference voltage vector with the basic vectors, which could easily obtain the desired vectors and calculate their dwelling time. Aimed to the capacitor voltage unbalance resulted by active power output in the motor operation, the control of neutral-point potential is implemented by predicting first and controlling next. Simulation results verify the feasibility of the proposed control scheme, the neutral-point potential unbalance and the dv/dt of output voltage are restrained effectively. Well dynamic and steady state performance of induction machines are obtained for the DTC schemes.更多还原