With the simply modified Auto-sequentially Commutated Inverter (ASCI) and its Pulse Width Modulation (PWM) control technique, a current source inverter capable of producing sinusoidal output voltage and current, fast regulation against abrupt load change is developed. The PWM control technique and the capacitor bank connected to the inverter terminals as a function of filter are used for sinusoidal output voltage and current. Fast response of the inverter output voltage is accomplished by using the circulating current control techque, which is made by the current PWM. By the modelling and simulation of the proposed inverter, its characteristics and control loop design guide are obtained. An 3.75kw induction motor and resistors are used for the load of the proposed inverter. As a result, fast response and sinusoidal output voltage and current is obtained, which verifies that the circulating current controlled CSI is suitable for driving an ac motor at fixed speed and UPS application.
