基于老化因子的变压器绝缘状态分析

为进一步研究变压器扩展德拜等效电路对变压器绝缘介质老化的影响规律,提出利用回复电压极化谱特征量建立变压器扩展德拜等效电路,并通过分析等效电路参数对回复电压极化谱的影响,获得变压器绝缘介质老化情况。通过仿真和实例分析的结果表明:大时间常数的极化支路反映变压器绝缘纸的老化情况;小时间常数的极化支路反映变压器绝缘油的老化情况。在此基础上,结合等效电路参数提出老化因子K_L,以此来定量分析变压器绝缘状态,并获得老化因子与变压器绝缘状态之间的内在联系。当K_L位于区间[0, 10],变压器绝缘状态良好;当K_L位于区间[10, 30],变压器绝缘状态一般;当K_L位于区间[30, ∞],变压器绝缘状态老化严重。

Analysis of insulation state of transformer based on aging factor

For further studying effect of extended Debye equivalent circuit on insulation medium aging of transformer, the extended Debye equivalent circuit of transformer was built using the characteristic of return voltage polarization spectrum. By analysis of equivalent circuit parameters' effect on return voltage polarization spectrum, the insulation medium aging of transformer was obtained finally. The simulation and examples analysis results showed that: polarization branch with large time constant reflected the aging of insulation paper in the transformer; polarization branch with small time constant reflected the aging of insulation oil in the transformer. Based on equivalent circuit parameters, aging factor (K_L) was defined to analyze insulation state of transformer. The intrinsic relationship between the aging factor and insulation state of transformer was obtained. The analysis results demonstrated that insulation state of transformer was good when K_L in range between [0, 10]; Insulation state of transformer was general when K_L in range between [10, 30]; Insulation state of transformer was aged seriously when K_L in range between [30, ∞].