ZnS…Cu电致发光电压传感器及其温度漂移补偿

利用ZnS…Cu电致发光粉末与环氧树脂胶混合,设计制作了一种梯形电极结构的电压传感单元,实现了电致发光电压传感器输出信号的温度漂移补偿。电致发光电压传感信号通过2根塑料光纤传输到2个硅光电探测器,并选择其开路电压作为传感器的输出信号。在同一外加电压条件下,梯形电极区域内的电场分布是不均匀的,因而不同场点的发光亮度不同。通过测量梯形电极区域内2个不同发光点的发光强度随外加电压的变化,并对两路输出电压传感信号进行数据拟合与计算,可获知被测电压的有效值,并可实现对输出信号温度漂移的补偿。在-40~60℃范围内,采用上述温度漂移补偿方法测量了有效值在0.7~1.5 k V范围内的工频电压,传感器输出信号的非线性误差低于1.6%,验证了该温度漂移补偿方法的有效性。

ZnS:Cu electroluminescent voltage sensor and its temperature drift compensation

A ladder-shaped voltage sensing unit is designed and fabricated using ZnS:Cu powder and epoxy adhesive, and the temperature drift compensation of an electroluminescent voltage sensing signal is implemented. Two channels of electroluminescent voltage sensing signals are transmitted to two photo-detectors using two pieces of plastic optical fibers. Open circuit voltages of the two photo-detectors are used as output voltage sensing signals. The electric field distribution is non-uniform within the ladder-shaped electroluminescent voltage sensing unit, and thus the electroluminescent brightness is also non-uniform under a same applied voltage. AC voltage sensing signals can be obtained by measuring the electroluminescent brightness at two different positions on the ladder-shaped voltage sensing unit. The temperature drift compensation existing in output voltage sensing signal can be achieved by an optimal calculation and fitting of experimental data. 50 Hz AC voltage in the range of 0.7-1.5 kV is measured, and the nonlinear error is less than 1.6% in the range of -40-60℃. This result demonstrates the effectiveness of the proposed temperature drift compensation method.