Demonstrative study of control system for distribution system with distributed generation

When the volume of the distributed generation (DG) is increased, the voltage variation may occur in the distribution line. To keep the distribution line voltage for smooth power supply, a research project ldquoDemonstrative Project on Power Network Technologyrdquo was carried out from 2004 to 2008 under the research contract with the New Energy and Industrial Technology Development Organization (NEDO). In the project, control devices and a centralized control system to keep the distribution line voltage properly were developed and demonstrated. In this paper, demonstration tests to keep the voltage of the distribution line were carried out by use of static var compensator (SVC) and loop balance controller (LBC). Then, the required capacity of the control devices were estimated analytically. As a result, an optimal selection of the control device and the control method is considered according to the penetration ratio of the DG.