Current source inverter drive speed sensor-less vector controlled induction motor

A rotor speed sensor-less system is proposed for a field oriented controlled (vector controlled) current source inverter-fed induction motor drive system. In the system, the rotor speed is expected from the d component of the stator voltage υ_1d, and PWM switching patterns of the current source inverter are derived from the vector control algorithm as the real time current vectors. An experimental system by applying the expected speed algorithm was composed. The test results with the sensor-less vector control algorithm have been found satisfactory at the transient and the normal operating conditions. In this paper, experimental results of the variable speed driving condition and on the four quadrant-operation at the constant torque drive by the laboratory prototype are presented