ABSTRACT
A DC–AC converter is commonly known as an inverter. The input to an inverter is DC, and the output is AC. The power semiconductor devices perform the switching action, and the desired output is obtained by varying their turn-on and turn-off times. They must have controllable turn-on and turn-off characteristics. The commonly used devices are BJTs, MOSFETs, IGBTs, GTOs, MCTs, and forced-commutated thyristors. We use PSpice switches, BJTs, and IGBTs to simulate the characteristics of the following inverters: voltage-source inverters and current-source inverters. Two types of control are commonly used for varying the output of an inverter: PWM and sinusoidal pulse-width modulation (SPWM). The input current of a current-source inverter is maintained approximately constant by having a large inductor at the input side. The magnitude of this current is normally varied by a chopper with an output filter. The control can also use PWM, SPWM, and other advanced modulation techniques.
