Considering the complexity of the geographical surroundings and the height of 10 kV distribution line, the impact of trees on the lightning performance can not be ignored. A model of lightning position judgment and ov...Considering the complexity of the geographical surroundings and the height of 10 kV distribution line, the impact of trees on the lightning performance can not be ignored. A model of lightning position judgment and overvoltage calculation based on the concept of striking distance is built. With the theory of orthogonal test, the main factors of trees' influence on lightning performance are figured out. The results indicate that the location of trees is the main factor. In practical engineering, suitable management of vegetation can improve the lightning performance and reduce the lightning failure of 10 kV distribution line.展开更多
In an offshore wind farm,a high‐voltage switchgear interruption in an offshore substation creates a high‐frequency,high‐amplitude overvoltage that can cause severe electromagnetic interference problems in the intel...In an offshore wind farm,a high‐voltage switchgear interruption in an offshore substation creates a high‐frequency,high‐amplitude overvoltage that can cause severe electromagnetic interference problems in the intelligent electronic device.To address this issue,mathematical models,vector fitting and finite element method were used to build an integrated electromagnetic disturbance conduction model,whose accuracy was verified by large current interruption tests.Through the simulation of a typical offshore wind farm's single‐phase grounding fault interruption process,the electromagnetic disturbance characteristics and the impact of the ground position are obtained.The results show that during the fault interruption process of phase B grounded,the dominant frequency of disturbance voltage can reach 4.34 MHz,and the amplitude can reach 1.12 kV.The ground grid has a large impact on the interference voltage,which can reach a maximum value of 2.28 kV under specific conditions.The disturbance voltage in the fault process mainly comes through the current transformer,while during the interruption process,it mainly comes through the ground grid.The authors provide a method to establish the integrated electromagnetic disturbance simulation model,which can improve the accuracy of the electromagnetic disturbance conduction process simulation of intelligent components.展开更多
文摘Considering the complexity of the geographical surroundings and the height of 10 kV distribution line, the impact of trees on the lightning performance can not be ignored. A model of lightning position judgment and overvoltage calculation based on the concept of striking distance is built. With the theory of orthogonal test, the main factors of trees' influence on lightning performance are figured out. The results indicate that the location of trees is the main factor. In practical engineering, suitable management of vegetation can improve the lightning performance and reduce the lightning failure of 10 kV distribution line.
基金National Key R&D Program of China,Grant/Award Number:2017YFB0902400。
文摘In an offshore wind farm,a high‐voltage switchgear interruption in an offshore substation creates a high‐frequency,high‐amplitude overvoltage that can cause severe electromagnetic interference problems in the intelligent electronic device.To address this issue,mathematical models,vector fitting and finite element method were used to build an integrated electromagnetic disturbance conduction model,whose accuracy was verified by large current interruption tests.Through the simulation of a typical offshore wind farm's single‐phase grounding fault interruption process,the electromagnetic disturbance characteristics and the impact of the ground position are obtained.The results show that during the fault interruption process of phase B grounded,the dominant frequency of disturbance voltage can reach 4.34 MHz,and the amplitude can reach 1.12 kV.The ground grid has a large impact on the interference voltage,which can reach a maximum value of 2.28 kV under specific conditions.The disturbance voltage in the fault process mainly comes through the current transformer,while during the interruption process,it mainly comes through the ground grid.The authors provide a method to establish the integrated electromagnetic disturbance simulation model,which can improve the accuracy of the electromagnetic disturbance conduction process simulation of intelligent components.
