Application study of distributed generation

Significant distributed generation (DG) will be connected to distribution systems. As a result, the integration of this generation may change the assumptions under which the systems were designed and results in the operation situations that do not occur in a conventional system without directly connected distributed generation. Careful engineering planning for DG penetration is therefore needed. Understanding the issues related to the DG integration is required to maintain the reliability and proper operation performance of the system. Proper knowledge and engineering can result in effective DG integration in distribution systems. This paper presents the results of a project recently performed by the power company, Vattenfall, in Sweden. The project investigates potential advantages related to DG integration, and performed a series of reliability simulations to analyze how the DG integration affects the system reliability. The results of the project indicate that DG can be utilized to improve the system reliability and reduce not supplied energy. The project shows that various factors can influence the benefits of DG integration. It is of great value to take into account these influencing factors and incorporate DG into the planning process to obtain the most beneficial solution of DG penetration. The details of the reliability simulations are addressed and discussed in the paper.