Institute of Sustainable Energy, Universiti Tenaga Nasional, Kajang 43000, Malaysia.
Institute of Power Engineering, Universiti Tenaga Nasional, Kajang 43000, Malaysia.
Sensors (Basel). 2021 Nov 2;21(21):7292. doi: 10.3390/s21217292.
The color of transformer oil can be one of the first indicators determining the quality of the transformer oil and the condition of the power transformer. The current method of determining the color index (CI) of transformer oil utilizes a color comparator based on the American Society for Testing and Materials (ASTM) D1500 standard, which requires a human observer, leading to human error and a limited number of samples tested per day. This paper reports on the utilization of ultra violet-blue laser at 405- and 450-nm wavelengths to measure the CI of transformer oil. In total, 20 transformer oil samples with CI ranging from 0.5 to 7.5 were measured at optical pathlengths of 10 and 1 mm. A linear regression model was developed to determine the color index of the transformer oil. The equation was validated and verified by measuring the output power of a new batch of transformer oil samples. Data obtained from the measurements were able to quantify the CI accurately with root-mean-square errors (RMSEs) of 0.2229 for 405 nm and 0.4129 for 450 nm. This approach shows the commercialization potential of a low-cost portable device that can be used on-site for the monitoring of power transformers.
变压器油的颜色可以是判断变压器油质量和电力变压器状况的首要指标之一。目前，测定变压器油颜色指数（CI）的方法是采用基于美国材料试验协会（ASTM）D1500 标准的色标比较器，这种方法需要人工观测，因此存在人为误差，而且每天只能检测有限数量的样本。本文报告了利用 405nm 和 450nm 波长的紫外-蓝光激光来测量变压器油的 CI。总共对 20 个 CI 范围在 0.5 到 7.5 之间的变压器油样本进行了 10mm 和 1mm 光程的测量。建立了一个线性回归模型来确定变压器油的颜色指数。通过测量新一批变压器油样本的输出功率对该方程进行了验证和确认。测量得到的数据能够准确地量化 CI，对于 405nm 的 RMSE 为 0.2229，对于 450nm 的 RMSE 为 0.4129。这种方法展示了低成本便携式设备的商业化潜力，这种设备可以在现场用于监测电力变压器。
