Efficiency optimal control in braking process for linear metro

In this paper, a new approach is proposed that increases the power efficiency in braking process for linear induction motor (LIM) drive. Based on the steady-state performance equations of the LIM, the establishment of equations to quantify the power loss in braking process can be deduced. In order to reduce the pump promotes voltage in regenerative braking and decrease the energy loss of linear metro system at the same time, a complex braking control algorithm based on regenerative braking and DC energy-consuming braking, combined with vector control strategy to drive the LIM, is proposed. This algorithm allows the pump promotes voltage in braking process of LIM drive to be restrained without braking resistor while keeping a good dynamic response. The simulated results presented show the validity of the proposed complex braking control method.