中文摘要：

电晕是输电线路设计和运行中面临的重要问题之一。文中通过实验测量和模拟计算，得到了不同气压湿度下的正直流电晕起始电压和电晕离子电流。计算结果和实验结果吻合较好。电晕起始电压随气压下降、湿度升高而减小，其主要原因分别为有效电离系数增大导致的电离区域的扩大和高场强区域内碰撞电离能力的增强。当直流电压和电晕起始电压的比值一定时，电晕离子电流也随气压下降、湿度升高而减小。电晕离子电流和直流电压、电晕起始电压关系式中的系数C随湿度升高而减小。当气压降低，C随湿度下降的斜率增大。湿度一定时，C和相对空气密度近似成反比。正离子迁移率是影响C变化的主要因素。

英文摘要：

Corona is one of important problems in the design and operation of transmission lines. It was obtained through experiment and simulation that positive DC corona inception voltage and corona ion current under different air pressure and humidity conditions. Calculated results are in good agreement with experimental ones. Corona inception voltage decreases as air pressure is lowered or humidity is raised. It is mainly due to the enlargement of ionization zone and strengthening of collisional ionization intensity respectively as a result of the increase of effective ionization coefficient. Corona ion current also decreases with the fall of pressure or rise of humidity when the ratio of DC voltage to corona inception voltage is equal. The coefficient C, in the relationship among corona ion current, DC voltage and corona inception voltage, declines with the increase of humidity. The decreased rate of C with humidity becomes larger as pressure is reduced. An approximately inversely proportional relationship exists between C and relative air density at constant humidity. The variation of C is principally associated with the positive ion mobility.