The Research Of High-Reliability Distribution Network With The Flexible Looped Network Control Device

With the rapid development of economy, the customers’demand for high-reliability and high-quality power is rising. In the power system, distribution network is connected to the user directly, which plays an important role in power system reliability. Restricted by the level of distribution automation technology, the traditional open-loop distribution network is difficult to provide high-reliability electric power. The close-loop distribution network can improve the power supply reliability effectively, but it has the problems of high short circuit current and electromagnetic loop network. With the development of flexible DC technology, the AC/DC hybrid distribution network can connect the power grid in different areas, limit short circuit capacity and avoid the emergence of electromagnetic loop network, which can improve the power supply reliability clearly.This paper introduces an improved method of minimum cut sets. This method puts forward the load point’s common-mode minimum cut sets,and considers the influence of the isolation device and the contact switch. This paper discusses the advantages and disadvantages of the traditional close-loop distribution network, and introduces the basic structure and application of the Flexible Looped Network Control Device in closed-loop distribution network. Then this paper figures out the main circuit failure rate of the Flexible Looped Network Control Device based on MMC. Taking advantage of the method of Markov Process and the existing distribution network reliability algorithm, this paper accomplishes the distribution network reliability evaluation with the Flexible Looped Network Control Device. This paper gives comprehensive analysis and comparison about several high-reliability connection modes using RBTS Bus 2 system, and discusses the performance of the close-loop distribution network using the Flexible Looped Network Control Device. At last, this paper uses the software to evaluate geographical system connection diagram of one region in our country about power supply reliability and short circuit current, which provides reference for the reconstruction and construction of high reliability distribution network in China.