A Research Of Fast Faulted Line-Section Location Method For Distribution System Based On Fault Indicators

The rapid development of social economy, reliability of power supply is required more higher. However, the distribution network has high failure rate, long outage time and low reliability of power supply. It couldn’t meet the needs of the electric power users. But the existing fault location methods are complicated, and the effect of loction isn’t obvious. Evenmore, the equipment cost is high, it can’t promote in large area.Therefore, this paper studies the fault location method based on cheap fault indicator according to remote transmission function of new fault indicator. The main research is as follows:1. In this paper, a new fault location method for distribution system based on the directed graph is proposed. By applying actuating signals of fault indicators received from master station, the bus-branch incidence matrix and branch current vector are built, and they are multiplied to fast determine the location of faulted line sections.2. It introduces the fault indicator with directional information which could be applied in the fault location. It just uploads the trigger information when the fault current and reference line current in the same direction according to the detection of fault indicator. Then locate the fault section. It sloves fault location when distribution systems itegrated with distributed generation and closed-loop work in the fault situation.3. It also studies the fault-tolerant mechanism of fault indicator when distribution network in fault and normal state. By using the basic positioning results, the situation of distribution network are grouped, and the fault current vector are built of groups according to the reverse progress. And then contact ratio analysis with the actuating signals of fault indicators received from master station. Determine the precise fault section according to the value of the contact ratio index.The proposed method theory is rigorous and simple principle. No need of normalization processing and subnet splitting, uploading less information, it can locate fault position of complex distribution systems integrated with distributed generation and work in situation of multiple faults with close-loop control. It has better fault-tolerant capacity when a few of fault indicators in a state of misoperation and refuse to action. And it can identify whether there is a fault happens in distribution network, and then accurately locate fault section.In the paper, the correct-ness and applicability are proved by KCL theory. And a large amount extremely complicated simulations on a typical suburban and urban distribution network system are carried on. In addition, it also compared with the existing mature locating methods according to simulation. The results show that proposed method can be used in practice, which has a great prospect in application.