Space Vector Modeling And Power Loss Analysis Of Asynchronous Motor Under Complex Asymmetric Operation

Motor as the most important grid load, has been a large electricity consumption, and80%of all kinds of motors in our country are0.55～200kw of asynchronous motors. Asynchronous motors running in the field or mine, due to the long-term working in harsh environment, often have a variety of open-phase faults, lead to the motors running in asymmetric status. Asynchronous motors often achieve speed regulation energy-saving control and motor soft-start/soft-switching control through phase-control AC voltage regulation technology. It can be considered that motors run in a complex combination of symmetry and asymmetry operating statuses under this technology. Therefore, it is very necessary to study power losses changes of asynchronous motors running in asymmetric statuses.This thesis mainly researches on power losses changes under constant torque load, including input power, output power, iron loss, stator copper loss, rotor copper loss, mechanical loss and stray loss. Furthermore, on account of both of mechanical loss changes and stray loss changes very small, they are considered as constant values. For a variety of asynchronous motor asymmetric operating statuses, dynamic mathematical models based on space vector coordinate system were established and calculation methods of all kinds of power losses are given, especially applicable to the calculation method of motor iron loss under the asymmetric operation. Then conduct MATLAB simulations according to those models and Fourth-order Runge-Kutta method, and obtain power losses changes of asynchronous motors running in a variety of asymmetric statuses and phase-control AC voltage regulation according to The simulation results and calculation methods of power losses. The thesis further compares and analyses them. Finally, experimental platform is builded, and the measured data demonstrate the correctness of the simulation results and the rationality of the analysis.