A new volt/VAR control for distributed generation

The worldwide concern about the environments and the moves to dramatically increase the use of renewable energy for the generation of electricity has led to significant emphasis on distributed generation. Distributed generation brings many benefits to both of system operators and consumers, however, there are several difficulties and problems involved when connecting it into the local distribution system. Conventionally, a gird connected distributed generator is controlled using either constant power factor mode or constant VAR control mode. The voltage at the connection point is not monitored so that the generator terminal voltage may exceed the statutory limits. This causes concern for system operators and distributed generator operators. Therefore, new control methods are required when operating the distributed generator in parallel with the grid. In this paper, a new volt/VAR control scheme is proposed. This control strategy provides support to the voltage regulation in distribution system while maximizing the active power generation from the distributed generator. The paper presents results from simulation studies of the impact of connecting such a generator to the voltage profile along a distribution feeder.