The Concept of Modulation

The purpose of this chapter is to gently introduce the concept of modulation in the power electronics domain. The reason for the use of the word “gentle” is that in most power electronics text books and courses, modulation is directly introduced in the context of power electronic converters, without a background as to why modulation is recommended. For this purpose, we take help from basic signal processing and communications, where some very basic examples can be presented to describe the process of modulation. Though the applications are drastically different, there is a common obstacle that modulation in both domains is trying to accomplish - how can a low frequency signal be put through a “process”, and extracted at the end with minimal distortions. In the case of communications, the process is transmission over long distances, while in power electronics, it is shaping an output voltage or current in a desired form for an application.