“日盲”紫外电晕探测系统定标

Calibration for SBUV Corona Detection System

"日盲"紫外电晕探测是电力设备检修与维护的主要手段之一。为了提供更为准确和客观的评价依据,需要对"日盲"紫外电晕探测系统进行辐亮度定标,从而确定目标辐亮度与增益控制电压、系统输出灰度值之间的关系。为此构建了由高稳定氘灯光源、积分球、光纤光谱仪等组成的定标装置。采用可溯源美国NIST的紫外标准氘灯对光纤光谱仪进行光谱辐照度标定,并以光纤光谱仪作为标准探测器对电晕探测系统进行定标。通过实验拟合出ICCD增益控制电压与系统增益之间的关系曲线,并给出了系统的标定方程。随后进行了三组不同增益的验证实验,实验结果表明在线性区内辐亮度推算值与测量值之间的最大相对误差为6.11%,均方根为3.22%。经分析,文中所采用的系统定标方案的不确定度为9.1%,基本可以满足了"日盲"紫外电晕探测系统的需求。此外,不同增益条件下的系统响应特性可以为"电晕"探测过程中进行自动增益调整算法的设计提供参考依据。

Corona detection via spectral rang in Solar Blind Ultraviolet （SBUV） is an efficient method for power system maintenance. It is necessary to implement luminance calibration for SBUV detection system to ensure the test results’ reliability, including object luminance vs. gain control voltage and object luminance vs. gray level of the image. The calibrating system was established, which mainly consists of high stable deuterium lamp, integral ball and fiber optic spectrometer. A calibrated ultraviolet deuterium lamp which can be traced back to the American NIST was adopted to calibrate the fiber optic spectrometer, which was used as calibrated detector to calibrate the corona detection system. The relative curve between ICCD gain control voltage and system gain was fitted from the test results and the calibration equation of system was also given. Three experiments with different gain level were implemented to validate the equation. Test results show that the maxim luminance relative error between calculated value and measured value is 6.11% and the Root Mean Square （RMS） is 3.22% when ICCD works in its linear area. Analysis of the calibration scheme shows the uncertainty is 9.1%. It can satisfy the precision requirements of corona detection system. The response characteristics under deferent gain levels of detection system can also be used as a reference in designing auto-gain adjustment algorithm for corona detection.