Study on Distributed Autonomous Supply System in the Deregulation Power System

Abstract

As the world wide deregulation in the electric power industry progresses, the basic structures of future power systems should change drastically. Particularly, in power distribution systems which are the closest to the demand side in a power system, higher flexibility and higher reliability are necessary. Flexible, Reliable and Intelligent Electric eNergy Delivery System (called “FRIENDS”) which has been proposed by the authors is a new concept for a future power distribution system. The most important idea of FRIENDS is to install the new facilities called Quality Control Center (QCC) between distribution substation and customers. QCC has dispersed generators, dispersed energy storage systems and many power electronics devices. By controlling those facilities appropriately, various purposes of FRIENDS can be achieved.
In Japan, power supply reliability is kept constant in high level, however, it will be difficult to keep the reliability level because Independent Power Producers (IPP) which have uncertainty will enter more and more into the electrical market if the deregulation makes progress and the market grows. If we want to keep the same level of reliability in the present system, we will need “useless” investment for expansion of equipment though some customers do not require the high reliability level. In other words, the present system cannot adopt to the deregulation. This paper proposes a new power supply system which has some advantages with in deregulation considering FRIENDS. In this system, a power system is divided into two parts and each part manages the reliability and the power rate independently. Further, this paper proposes two methods for evaluation of the system. First, by using the concept of value of service, we propose the method which decides the quantity of facilities in QCC and indicate that this system can allow a lower level of reliability. Second, by modeling a relation between power rate and load, we consider the construction of the proposed distribution system.