ABSTRACT
This chapter describes what an inverter is, and details a single-phase square-wave inverter, a three-phase inverter, and firing angle and freewheel diode and their purposes. It shows how output of a rectifier and an inverter are controlled, and what a power converter is. The chapter details the structure of a thyristor-based converter and suggests how a converter can be used as a rectifier or as an inverter. It explains pulse width modulation (PWM), and what PWM can be used for. The chapter explores single-phase and three-phase use of inverters based on PWM, and amplitude and frequency modulation ratios. To improve the quality of the output waveform from an inverter, so that it better resembles a sinusoidal waveform, various techniques are available. If triggering occurs exactly at the zero crossing point for negative to positive voltage, the thyristor starts conducting at that moment and continues to conduct as far as it is forward biased.
