温度对直流电压下油纸绝缘空间电荷特性的影响

油纸绝缘是直流输电设备的主要绝缘材料,其空间电荷特性变化会引起局部电场发生畸变,从而影响材料的介电强度,降低直流输电设备的运行可靠性和稳定性.使用电声脉冲法( PEA)测量装置,分析油纸绝缘中空间电荷的注入、迁移、消散规律,搭建试验平台,通过升压试验获得试品空间电荷注入的参考电压,然后对试品加3 kV的直流电压,分别在15℃、30℃、50℃温度下对油纸介质的空间电荷的特性进行分析.试验结果证明:在不同条件下发生空间电荷的注入,温度会对去压时空间电荷的消散产生很大的影响;温度会影响油纸绝缘介质内电场的大小和分布,使空间电荷严重畸变电场,引起绝缘的进一步破坏.

Temperature Effect on DC Voltage Space Charge Characteristics of Oil-paper Insulation

Oil-paper insulation is the main insulation material for DC power transmission equipment, the space charge characteristics change may lead to local electric field distortion, thus affecting the dielectric strength, reduce the reliability and stability of the DC transmission equipment. This paper, based on the measuring device of the electro-acoustic pulse method （PEA）, explore the law of oil-paper insulation of the space charge injection, migration and dissipation. And build a test platform, get the reference voltage through the step-up test, then the test sample 3 kV DC voltage in 15 ℃, 30 ℃, 50 ℃ temperature of the oil paper at the space charge characteristics were analyzed. The test results prove that： under different conditions, space charge injection, space charge dissipation of temperature will have a huge impact when the voltage receded; temperature will affect the oil-paper insulation of the electric field in the insulating distribution, space charge serious distortion of the electric field, caused medium size and further destruction of the insulating medium.