This article covers aspects of synchronous generation that affect the design and operation of distribution networks. Of special concern are the limitations imposed by voltage, current and other constraints at various points in the network when generation is connected at selected locations. In a distribution system, individual generator capacity is small in comparison with the distribution supply capacity. This generation can range from a few hundred kilowatts to over 50 megawatts. As
the capacity increases, the technical design considerations, particularly feeder loading and voltage conditions become more critical.
For the purposes of definition in this article:
• small generators are those with a capacity of less than 1MW
• medium sized generators have a capacity of between 1-5MW
• large generators have a capacity in excess of 5MW
A synchronous generator driven by a prime mover affects the dynamics of the power system and is often part of an industrial co-generation process. Prime movers for synchronous machines are typically steam turbine, water turbine or reciprocating engine. Synchronous generators that are part of wind generation schemes are isolated from the distribution feeders by converter systems and are not considered further.
Synchronous Generation in Distribution Systems