交直流复合电压下棒-板电极起晕电压实验分析

为了获得复合电压作用下电极的起晕特性,在室内搭建了复合电压下无锈棒-板电极起晕特性实验平台,采用串联的复合加压方式,即一个电极上施加直流电压,另一个电极上施加交流电压,以紫外光子计数的突变作为电晕起始判据,获得了直流和交流复合电压下的电极起晕特性。同时对比了不同直流电压极性、电极加压方式和不同复合电压升压方式下电极起晕电压的特点,探究复合电压下棒电极半径和棒板间隙对电极起晕电压的影响。实验结果表明:在相同的大气条件及电极布置下,由于空间电荷影响,棒电极正直流、板电极交流加压方式下的起晕电压比棒电极交流、板电极正直流加压方式下的起晕电压高;在棒-板气隙间距0~5cm范围内,定直变交复合升压方式下,交直流分量有效值叠加后的起晕电压随着直流分量的增加而升高,定交变直方式下,该值随着交流分量的增加而下降,且交直流分量间互为线性关系。本文的研究成果可以为进一步研究复合电压作用下电极的电晕机理及起晕电压的准确预测奠定坚实基础。

Experimental Analysis on Corona Inception Voltage of Rod-Plane Air Gaps under DC and AC Composite Voltage

In order to obtain the corona characteristics of electrodes under AC and DC composite voltage, the test platform with series circuit was established by using a stainless rod to plane electrode. Herein, one electrode was applied with positive DC voltage, and the other one was applied with AC voltage. The corona criterion was the change of ultraviolet photon counting. The characteristics of the corona inception voltage were studied under two different voltage-applying modes, two kinds of DC polarity and two different voltage-elevating methods for the electrodes. The influence of rod radius and air gap on corona inception voltage was also investigated. It was found that, in the same atmospheric conditions and electrode arrangement, because of the influence of space charge, the corona inception voltage under voltage-applying mode, where rod electrode with positive DC and plate electrode with AC, was higher than that under the inverse mode. In the range of rod-plate air gap of 0~5cm, by the voltage-elevating method of fixed DC component, the corona inception voltage, which was obtained by the sum of DC and AC effective components under the composite voltage, increased with the increase of the DC component and decreased with the increase of the AC component by the other voltage-elevating method of fixed AC component. And the relationship between AC and DC components was linear. The results lay a solid foundation for further studies on the corona mechanism of electrodes and the accurate prediction of corona inception voltage under composite voltage.