Theoretical Calculation Of Surface Electric Field And Analysis Of Electromagnetic Environment On The Shaped Wire

The distribution and demand of energy resources are relatively uneven,so the large-capacity long-distance HVDC transmission engineerings are necessary.For the selection of overhead transmission lines,the shaped wire has larger transmission capacity and higher strength than traditional round stranded wire,it is increasingly used in engineering.For many years,the studys on distributed electric field and electromagnetic environment of transmission lines have never stopped.But the wires are always regarded as smooth surface in the study,and such method must cause a large error in the calculation.This paper focuses on the influence of the pattern on the surface of the line on the electric field and corona,and further predicts the electromagnetic environment caused by the line corona,which has certain guiding significance for the design and construction of the line.This paper focuses on the electric field influence and corona character of the shaped wire's surface detail,and predicts the electromagnetic environment caused by the shaped wire's corona,which has certain guiding significance for the design and construction of the shaped wire.Firstly,according to the special surface geometry of the shaped wire,a semi-numerical method for accurately calculating the surface electric field is proposed.On the basis of verifying the correctness,the method is applicated to the traditional round stranded wire and the results is equally effective.As a comparison,the electric field distributions of shaped wire and round strand wire are considered,and the influences of wire radius and the number of outermost aluminum wires on the surface field strength is considered.Finally,the electric field distribution calculation method of the split wires is extended by the single type wire.Secondly,the corona voltage of shaped wire is calculated by the known electric field distribution.On the basis of understanding the basic mechanism of gas discharge and the criterion of corona,and the most corona direction amounts to the electric field strength maximum direction.When the surface electric field maximum of shaped wire is constant,the corona voltage can be obtained by simple calculation.Further,the effects of shaped wire itself factors and external environmental factors on the corona voltage is discussed.Finally,the corona discharge of shaped wire is inevitable,and the radio interference and audible noise caused by the total electric field increase need to be considered in the circuit design stage.Therefore,this paper analyzes the variation law of the shaped wire from the above aspects,the influences of the wire cross section,the number of splits,the split pitch,the wire height and the distance between the two poles on the combined electric field,radio interference and audible noise of the shaped wire are discussed,and some generally applicable conclusions are obtained.