Experimental results of the current-source PWM inverter fed induction motor drive with an open-loop stator current control

In this paper the control of the current-source PWM inverter fed induction motor drive is discussed. The vector control system of the induction motor is realized in a rotor flux oriented reference frame, where only the measured angular rotor speed and the dc link current are needed for motor control. Methods to damp the stator current oscillations and to compensate the capacitive currents drawn by the load filter are presented. The proposed methods operate in an open-loop manner and can be realized without measurement of any electrical variable. With the presented open-loop control methods the motor current sensors can be totally eliminated since the stator current measurements are not needed either for protection in the current source inverter fed drives. The proposed control methods are realized using a single-chip Motorola MC68HC916Y1 microcontroller. The experimental tests show excellent performance in both steady state and transient conditions.