Flux Angle Control to Improve the Efficiency of Induction Motors

Today, induction motors are widely used in the industry by electric drives. Vector control is one of the commonly used electric drives. Vector control has a good performance in heavy loads and the amount of rotor flux in these loads is the same as the nominal value. But in light loads, using vector control will result in a reduction in efficiency. In fact, in the light loads, the value of the rotor rated flux is not required. Motors are often used at a load other than the rated value. One of the factors that causes the motor to be placed in a load other than the rated load, is the oversized selection. In this paper, it will be tried to improve the induction motor efficiency, especially in light loads, by controlling the angle between the stator current and the rotor flux which is located on the d-axis (flux angle). In the proposed method, the value of the flux angle in light loads is controlled at a constant value, which is dependent on some of the motor parameters. The proposed method could be simply implemented, has a low computational burden and will considerably increase the efficiency of the induction motor in light loads.