Soft Starting of Induction Motor with Torque Control

This paper presents a simple technique based on stator flux estimation to control the electromagnetic torque of the induction motor during soft starting. The inherent problems related to pure integration of the back electromagnetic force to estimate the stator flux are minimized using the low pass filter approach. The experimental results are showed and compared with usual current control technique. The obtained results validate the proposed technique showing its viability in applications where the objective is to fit the induction motor torque profile during starting or stopping according to the load torque.