Improved control strategy for three-phase AC choppers under induction motor load

Abstract EN

This paper presents a modified control strategy for controlling three-phase ac chopper under induction motor load.

This modified strategy is known as Extinction Angle Control (EAC).

This new strategy is compared with the Modified Phase Angle Control (MPAC) and Symmetrical Angle Control (SAC) to demonstrate its superior performance.

These strategies are based on varying the stator ac voltage to control the speed of three-phase induction motor.

The proposed strategy is characterized by a higher power factor and a better total harmonic distortion compared with the other two strategies over the normal operating arrange.

Performance evaluation of the motor under the different switching strategies is demonstrated.

The simulation of the system is carried out using PSIM computer program.

The simulation results are compared with the experimental results obtained from a laboratory prototype.

The levels of harmonics in the supply currents and power factor are evaluated for different control strategies.