Distributed Control Approaches for Power Systems

Abstract

The energy industry is undergoing through a reconstruction from a monopolistic electricity market to a more open and transactive one. The next ­generation grid is a level playing field in terms of electricity transactions, where all customers have an equal opportunity. The emerging concepts of electricity prosumers are expected to have a significant impact on the retail electricity market. As a result, there is an urgent need to control the interactions among numerous consumers and pro­sumers. The existing control approaches can be divided into three categories, namely, centralized control, decentralized control, and distributed control. The majority of existing literature focuses on the centralized control. In most cases, the dedicated communication links are required to ex­change data between the central controller and the local agents. The centralized control approaches are suitable for relatively small­-scale systems without reconstructing the existing communication and control networks. However, as the number of consumers and prosumers are increasing to hun­dreds of thousands, there are some technical barriers on the centralized control-­based economic operations such as heavy computation burden and single point of failure. The decentralized control is an intermediate solution to address the above mentioned challenges. The overall objective is to maximize the benefits of local agents and there is no guarantee that the decisions made by each local agents can contribute to the global optimal decision of the entire system. The distributed control has the potential to solve the economic operation problems of multiple consumers and prosumers. Lo­cal agents can share information through two-­way communication links in order to find the global optimal decision. Application of distributed control methods in power system increase system’s scalability, alleviate monopoly and monopsony, improve the privacy and distribute computational load among various entities.