Torque-angle-oriented control of induction machines

Two independent control inputs can be applied to an induction machine at any moment. A common characteristic among conventional control methods is that they seek to keep the flux amplitude constant so that the induction machine has control characteristics similar to those of a dc machine. In this paper, a vector control scheme based torque angle is discussed. It is shown that by keeping the torque angle constant or regulating it in an appropriate manner, dynamic performance similar to those of traditional fixed-flux-level vector control methods can be achieved with lower energy consumption and simpler operation. Objectives such as maximum efficiency, maximum power factor, or maximum torque per amp can be achieved readily in steady state under this control.