Optimal Efficiency Control of Linear Induction Motor Drive for Linear Metro

In this paper, a new approach is proposed that minimizes the total copper and iron losses in variable speed and/or thrust force linear induction motor (LIM) drive. This method is based on a LIM model that considering the end effect and attraction force. For a given speed and load this model allows the establishment of equations to quantify copper and iron losses, and the relationship between stator field and torque currents for minimum total loss can be deduced. Based on these equations, a loss minimization control algorithm, combined with vector control mode to drive the LIM, is proposed. This algorithm allows the electromagnetic losses in a variable speed and thrust force LIM drive to be decreased while keeping a good dynamic response. The simulated results presented show that it is possible to improve the efficiency of LIM drive keeping a good dynamic response.