Simplified Model Predictive Thrust Control Based Arbitrary Two Voltage Vectors for Linear Induction Machines in Metro Transportation

In this paper, the model predictive thrust control (MPTC) method is applied in combination with the arbitrary two voltage vectors modulation strategy so as to acquire the more accurate modulation. Because of the huge number of possible voltage vector pairs that need to be evaluated, it may consume high calculation cost to find the best pair of voltage vectors (BPVV). So, one simplified method is proposed to avoid the tedious process of enumerating and comparing all possible cases, which can find directly the BPVV from large number of possible voltage vector pairs. Besides, the current limit is introduced into MPTC to avoid the overcurrent in dynamic transients, and the proposed search method is also effective to the case with current limit. This method has been numerically simulated and experimentally tested on a platform consisting of two coupled 3kW arc induction motors. Both simulation and experimental results show that the MPTC performance is improved by using the modulation of BPVV under different conditions, and its complexity is reduced obviously.