Research On Feeder Automation Key Technology Based On Adaptive Reclosure

Distribution network failure rates are high,most of which are transient failures.The application of automatic reclosing is of great significance for improving the power supply reliability of the distribution system.However,the traditional reclosing method widely used in current distribution lines has certain safety hazards.The short-circuit current generated when blindly closing in a permanent fault will have a large impact on the system,and even cause serious consequences such as cable fire and explosion.In addition,the interphase fault location and isolation schemes of the recloser and the voltage time type segmenter are widely used in the in-situ feeder automation scheme.This scheme also has multiple short-circuit impact problems during the fault processing.In response to these problems,the specific work of this paper is as follows:A novel approach of current limiting distribution line adaptive reclosing is proposed.The device can be classified into two types:a configuration probe reactor type or a configuration probe resistor type,depending on the configured probe impedance component.By analyzing several typical types of cable lines and overhead lines,the range of impedance values of the two types of the pro'be impedance components are calculated to limit the short-circuit current,and a permanent fault criterion is proposed to achieve adaptive reclosing.A permanent fault simulation model is established with PSCADIEMTDC simulation software.Studying different the probe impedance component within a suitable range of values can effectively suppress the magnetizing inrush current and is not affected by the nature of the load.It is verified that the proposed permanent fault criterion can accurately distinguish between transient faults and permanent faults.At the same time,after the input of the probe impedance component in the research range,it will not cause serious voltage sag.Based on the basic principle of the in-situ intelligent feeder automation system,the novel approach of current limiting distribution line adaptive reclosing is applied to the in-situ intelligent feeder automation system,and different application scenarios are proposed.It can be combined with the relay protection configuration of the distribution line to replace the distribution line outlet switch or branch switch with protection function.Or use it to replace the recloser in the traditional feeder automation based on mutual coordination of recloser with voltage-time type of sectionalizer.Or all the switches participating in the feeder automation on the feeder are all configured as current limiting distribution line adaptive reclosing devices.By designing the logical coordination between the switches,an in-situ intelligent feeder automation system based on multi-stage current limiting adaptive reclosing devices is realized.