Analysis and Simulation on Looped Network Controllers for Distribution Network

Distribution networks generally operate in radial way although they are designed in closed loop way. When a looped network occurs in order to transfer loads, there are many technical risks, which may have negative impact upon stability and safety of a distribution network. The capability of traditional voltage regulation is very limited, whereas various schemes based on power electronics technology are powerful, but complicated and uneconomical. A novel scheme of a looped network controller taking advantage of thyristors and arrestors, etc., is put forward together with its control. An equivalent simulation system, which is obtained by simplifying an actual distribution network, is established, as a result simulation and analysis are carried out. The results of the study show that the proposed scheme is simple, easy to implement and has negligible impact upon distribution relays. This new scheme can limit efficiently the closed loop surge current during the load transfer operation and deal with distribution network faults properly. Therefore, it can be recommended as a new scheme and method to improve the reliability of distribution network.