A Direct Field Oriented Induction Machine Drive with Robust Flux Estimator for Position Sensorless C - Industry Applications Conference, 1995. Thirtieth IAS Annual Meeting, IAS '95., Conference Record

The rotor flux is estirnatcd for a direct field oriented induction machine drive using a voltage-current mode algorithm, or physical based algorithm. The estimated rotor flux is used to synthesize the components of the rotation matrix, szn(@,) and cos(@,). These angles are critical in transforming the command currents to the stationary frame such tha t field orientation is maintained. The principles of rotor flux estimation are presented, followed by examination of low speed effects, parameter sensitivity, and criteria for selection of the filter time constant, T,. Computer simulation and extensive experimental results are iricluded. I. I n t r o d u c t i o n Field oriented induction machine drives are used in industry where high precision performance is required. Currently, several research efforts are directed towards establishing posit ion s e n s o d e s s field oriented induction machine drives. These drives are suited for applications where drives with encoders are not practical but high performance is essential. These areas include hazardous operating environments like the process control and chemical industries. In [l], thc authors presented a rotor flux oriented, position sensorless induction machine drive. The authors proposed a solution in which simple low pass filtering of both the back emf arid flux command is done, resulting in a robust flux estimator. Fundamentally, two advantages exist in developing a position sensorless drive using tlie estiniation approach of [l]. One, simplified control system design is employed to produce the flux estimator. Minimal time is required to tune the estimator. Two, the esti0-7803-3008-0195 $4.00