Full-Size Converter Operation of Large Hydro Power Generators: Generator Design Aspects

This paper investigates the additional opportunities and aspects in the design process of large hydro power synchronous machines provided by full-size converter operation. As a matter of fact, thus far frequency converters for hydro power plants have been mainly selected to meet the demands of conventionally designed machines and of retrofit applications. The new optimization possibilities in motor-generator design given by the full-size converter operation have not yet found much attention in the literature. This paper shows how full-size converter operated hydro power synchronous machines can be designed to have smaller volumes, lower material cost and higher efficiencies than their conventional counterparts by mainly designing the motor-generator for active power only. It also discusses the trade-off between the construction volume and mass and the required mass moment of inertia of these large machines.