High performance adjustable speed induction motor drive system uses auto-tuning sensorless vector control

In recent years, advanced system integration technologies for high performance adjustable speed drives have attracted interest for many applications. These drives use induction motors with a voltage source current controlled three-phase PWM inverter that uses IGBT and vector control. To obtain sensorless control, these systems require measurement of the induction's exact stator and rotor circuit parameters while operating under different load conditions. However, it is difficult to get sufficient steady state speed regulation accuracy or dynamic speed settling time for wide ranges and large load torque disturbances. To solve these feasibility problems, a simple and practical automatic tuning method that measures and estimates the exact stator and rotor circuit parameters of induction motor was developed. An extensive description of this system are presented.