Distribution System Reliability And Distribution Terminal Unit Optimal Configuration

As an important basis energy for the development of the national economy, electricity plays a significant role in the promotion of economic development and social progress. With the rapid growth of the economy and the popularity of information technology, people are increasingly dependent on electricity, and our need for power supply reliability have become increasingly demanding in recent years. Electricity companies are paying more and more attention to improve the distribution power supply reliability and customer satisfaction.There are many means to improve distribution power supply reliability, in which the fundamental way is to establish a strong distribution network structure. By rational planning and layout of disconnect switches and contact switches, distribution power supply reliability can be further improved. By the cascade with intelligent power distribution equipment, the fault can be isolated and non-fault region can be recovered automatically. With the development of distribution automation technology, distribution automation systems based on communication systems, distribution terminal unit and distribution master can greatly improve the reliability and operational levels of the distribution network.This paper discusses the basic theory of distribution reliability analysis and basic method of reliability calculations. Factors that influent distribution reliability are summarized including network structure, combination of distribution switches, configuration of distribution terminal unit, distribution network fault handing mode and so on. Secondly, distribution automation system architecture and functions, distribution network fault handing mode under distribution automation environment is detailed discussed. The functional requirements and functional configuration of distribution terminal unit are analyzed. By combining distribution network fault location, fault isolation, and recovery processes, the impacts that distribution automation and distribution terminal unit make to distribution network supply reliability is analyzed.By distribution network structure simplified and features extraction, considering the different distribution terminal configuration effects on distribution network reliability calculation, a distribution network reliability assessment method faced with distribution switches and distribution terminal unit under distribution automation environment is proposed based on FMEA. A specific example is used to verify the reasonableness of the method. Besides, quantitative analysis is made to compare the effectiveness that those factors make to improve distribution network reliability, including network structure, combination of distribution switches, configurations of distribution terminal.A distribution terminal unit optimal configuration idea and practical method that considering distribution phased development requirement is proposed, by exploring relationship between distribution power supply reliability and number of terminal unit under different network structures. This method is proposed to effectively solve problems such as how to deploy distribution terminal unit under different network structures, and its progressive development issues. A numerical example demonstrates the method is reasonable and practical to guide the planning process for distribution automation and distribution terminal unit.