1.1 INTRODUCTION TO POWER PROCESSING

The field of power electronics is concerned with the processing of electrical power using electronic devices [1 7]. The key element is the switching converter, illustrated in Fig. 1.1. In general, a switching converter contains power input and control input ports, and a power output port. The raw input power is processed as specified by the control input, yielding the conditioned output power. One of several basic functions can be performed [2]. In a dc-dc converter, the dc input voltage is converted to a dc output voltage having a larger or smaller magnitude, possibly with opposite polarity or with isolation of the input and output ground references. In an ac-dc rectifier, an ac input voltage is rectified, producing a dc output voltage. The dc output voltage and/or ac input current waveform may be controlled. The inverse process, dc-ac inversion, involves transforming a dc input voltage into an ac output voltage of controllable magnitude and frequency. Ac-ac cycloconversion involves converting an ac input voltage to a given ac output voltage of controllable magnitude and frequency.

Figure 1.1: The switching converter, a bask power processing block.

Control is invariably required. It is nearly always desired to produce a well-regulated output voltage, in the presence of variations in the input voltage and load current. As illustrated in Fig. 1.2, a controller block is an integral part of any power processing system.

Figure 1.2: A controller is generally required.

High efficiency is essential in any...