|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1999 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1998 : ¥1,400,000 (Direct Cost : ¥1,400,000)
In the present sub-transmission and distribution systems of a power system, numerous voltage regulators such as On-Load Tap-Changing (OLTC) transformers exist and work independently based on their different control indices (local voltage indices) to regulate individual voltages. Such a distributed control scheme is thought to be reliable due to its maintainability, fault tolerant characteristic, and so on. However, there are some problems that the control actions tend to increase and that the controls may accelerate voltage collapse in heavily loading conditions.
In this project, we investigates the control problem of numerous voltage regulators from the viewpoints of the control efficiency and the stability of a whole system, and then develop a new control method based on autonomous decentralized control scheme to coordinate numerous controls. A control index (system index) is developed for the total system optimal control, which will be computed independently in each distributed controller through exchanging information among nearby controllers. Based on the system index together with the local voltage index, each controller regulates its target voltage, where the freedom exists about how to use these two indices depending on the policy of system operation. Therefore, fuzzy control scheme is adopted to retain the advantageous features of the existing local voltage controllers.
Furthermore, this report examines control problems concerning FACTS devices in order for the future application of the proposed control scheme not only to the distribution systems but also to the transmission systems, while some analysis methods for this purpose are developed.