A method of speed sensorless vector control of parallel-connected dual induction motors by a single inverter with a rotor flux control

A purpose of this paper is to present the speed-sensorless vector control method of parallel-connected dual induction motors fed by a single inverter. This system may be unstable when the ratings of each induction motor are different and an extremely unbalanced load for both motors is added. Then we suggest a control method that the system can be stable in this condition. According to this method, the rotor flux is directly controlled to be constant by a rotor flux control though it isn??t controlled in an ordinary system.