Novel architecture for integrated wide area protection and control

Abstract

This paper firstly reviews the recent development in power system protection, with special attention paid to the wide-area and integrated protection, in order to look into future development of protection and control system for smart grids. The paper then mainly reports on the design of a novel architecture for the integration of protection and control for wide area power network. The concept of integrated wide area protection and control is introduced, in which a hierarchically coordinated system, supported by the specially designed real-time synchronized wide area communication network, provides the protection and control for wide area or regional power substations/plants and their associated power network. Within the architecture a specially designed integrated wide area protection and control information platform receives real-time synchronized data from the communication network to support the integration of protection and control at wide area/regional level. The data received from the platform includes the static, dynamic, transient measurement and the states of circuit breakers etc., valuable information is extracted from the data and allocated to various specially designed computation algorithms in the platform to perform advanced functions of protection and control for the power network. In the platform, the sets of data that need to be transferred and their transferring speed depend on application, for example, slow for contingency analysis, near real time for monitoring and real time for control or protection. On the other hand, the information is stored in a hierarchical manner instead of centralized one, which is comprised with the hierarchical protection and control system. Equipped with the latest high speed synchronized communication technology, integrated with the advanced protection techniques and the latest developments in control system, the system offers not only fast protection, but also complete control of entire power network. It also offers a potential for merging the so called three line of defence into a unified system to more effectively ensure the reliable and safety operation of power grids. Within the architecture a cloud computing system is specially designed to implement a number of secondary functions for substations and power networks, such as the wide area fault location, fault line selection, power quality monitoring, protection settings, etc. The extended functions also include the equipment monitoring, life cycle and operation management. With the proposed cloud, the architecture of future substation equipment can be reshaped to provide a flexible framework for building interactive grid and improve the reliability and security of power grid.