Low constant speed control of heavy haul electric locomotives based on variable parameter PI Regulator

Electric locomotives are required to operate at low constant speed when loading heavy cargo pack. A low constant speed control strategy for heavy haul locomotives based on variable parameter PI regulator is proposed in this paper. Acceleration and speed signals of the vehicle motor are obtained by a Luenberger observer, to correct parameters of the torque PI controller. And the alternating current electric locomotives adopt the indirect stator-quantities control strategy to achieve low constant speed control. Experiments are carried out on vehicles, the lowest speed of the vehicle is set at 0. 5km/h and the speed error is less than 0.1km/h. Results show that the proposed control strategy achieves intended purpose and promise application values.