一种适用于交直流混合架空线路的故障保护方法OA

After a fault occurs in the AC/DC hybrid overhead lines,the fault characteristics are complex,and the pro-tection adaptability on both the DC and AC sides will be affected to varying degrees.To solve the problems of insuffi-cient adaptability and even failure of AC/DC protection under the above scenarios,the correlation characteristics of measured current in DC and AC lines under different fault scenarios are analyzed in this paper.On this basis,a high-sensitivity start-up criterion is constructed by means of the aggregated quantity of current at the DC-side neutral point at first.Then,the Hausdorff distance is introduced to measure the waveform similarity of measured current in AC/DC lines.Finally,an identification criterion for the fault between AC and DC systems is established based on the difference in AC/DC current similarity under different fault scenarios,thereby formulating a complete protection scheme.The pro-posed protection method was tested on a constructed simulation platform.Results show that it can effectively identify the inter-system and non-inter-system faults,and it can also be exported within 5 ms after the fault.