Operation and Control of Renewable Energy Systems

Chapter 2Power Electronic Converters

2.1 Types of Power Electronic Converters

In order to utilize the power generated by various renewable energy sources, power electronic converters are essentially required. Many renewable resources such as wind are intermittent in nature and require power electronic circuits to maintain frequency and voltage at the desired level. In addition, the present trend is to use variable-speed wind turbine with pitch control. Similarly, the power generated by photovoltaic conversion is dc and must be converted to ac before it can be utilized in the existing system. Moreover, due to the intermittent nature of power generation in renewable energy systems, energy storage is required to maintain balance between generation and load. Energy is generally stored in batteries, which requires PE for control. The function of power electronics in renewable energy systems is to convert energy generated by renewable energy sources to be used in power grid with maximum possible efficiency and minimum cost. Thus, power electronic converters in the form of ac-dc-ac, dc-dc-ac or dc to ac are commonly used in renewable energy systems and are briefly described in this chapter. Power converters for renewable energy systems integration present a more complex system compared to stand-alone system. It is therefore important to study PE converters from the point of view of their application in renewable energy systems.

2.2 Power Semiconductor Devices

Power electronic converters ...