Modeling of energy-efficient direct torque control system for traction induction motor

Abstract

A brief analysis of existing control systems for traction electric drives with induction motors has been carried out, as a result of which it has been established that vector control and direct torque control systems are the most promising. The comparative characteristic of these control systems according to different parameters of electric drive quality has shown that in energy-saving algorithms it is appropriate to use the systems of direct torque control. The work aims to simulate the electric drive with a direct torque control system, which provides the reduction of power losses in an asynchronous motor. The value of the stator winding power factor is chosen as a control action. The calculation and functional dependences between the main parameters of the control system and the induction motor are synthesized, the fulfillment of which allows reducing duce power losses. The functional diagram of the electric drive with an energy-efficient control system is given. The hardware of this control system does not differ from the currently used frequency converters. In the power channel of the frequency converter, a three-level autonomous voltage inverter with locking diodes is used. The results of modeling for electric drive with 11 kW motor, analysis of which showed the adequacy of the developed model and performance of the synthesized control system, the efficiency of the electric drive with energy-efficient control system increases to 18% compared with the classical direct torque control system.

Keywords

• induction motor
• direct torque control
• power factor
• efficiency
• simulation
• three-level
• voltage inverter