Improvement of Stabilization Time by Information Exchange Between Dispersed Generators in Local-network under Islanding

Abstract

According to the deregulation of the electric power market and the improvement of small generators, the electricity supply by the dispersed generators (DG) is very attractive for both utilities and consumers. However, because of various types of DGs with small rating, the introduction of DG in a power distribution system increases the complexity of system operation. We propose on-line information exchange between DGs to facilitate autonomous operation of the distribution system. This paper evaluates the improvement of reliability of such system by the on-line information exchange between DGs.
The large scale introduction of DGs might allow the power supply to the distribution system to be continued even if it is isolated from the upper system. We discuss the effect of information exchange on the system stability under islanding after the upper system failure. The analysis is performed in terms of instantaneous values calculated by using PSCAD/EMTDC. As a result, it is revealed that the transient stability improves when a DG with fast response speed and DG with slow speed exchange the information on inverse power flow to the network.