Principles of electrical design of permanent magnet generators for direct drive renewable energy systems

Abstract: The objective of this chapter is to discuss the electromagnetic design of direct drive generators for renewable energy generation. It starts with a look at the requirements of these generator systems. Next, it discusses the main material choices and topology choices with their advantages and disadvantages. Then, as an example, the electromagnetic design of a 3 MW 15 rpm permanent magnet (PM) generator for a direct drive wind turbine is discussed. Next, it gives scaling laws that make it possible to estimate the size of direct drive generators. Finally, a number of issues that need further investigation are discussed.

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