一种光电式电压传感器及其温度漂移补偿方法

An optoelectronic voltage sensor and its compensation method for temperature drift

提出了一种利用发光二极管(LED)电致发光(EL)效应的光电式电压传感器,其传感单元仅由一个电阻器和两个LED组成。被测交流电压施加于一个高阻值(例如100 MΩ)的电阻器,产生μA级的泄漏电流并驱动两个LED发光,用两根塑料光纤将此光强传输至光电探测器,则通过测量光强度即可获知被测电压。选用阻值约为100 MΩ的电阻器,在室温条件下实验测量了0.2~5.5kV的工频电压,传感器输出与被测电压有效值之间存在较好的线性关系,其非线性误差低于3.1%。同时,提出并实验验证了一种利用两路光传感信号实现电压传感器输出随温度漂移的补偿方法,在5.5kV的被测电压范围及-40^+60℃的温度范围内,补偿后传感器输出的温度漂移约为±2.1%。本文的光电式电压传感器不需要额外光源,并具有结构简单、成本低等优点。

An optoelectronic voltage sensor is proposed which is based on electroluminescent （EL） effect of light emitting diode （LED）. The voltage sensing unit is mainly composed of a resistor and two LEDs. The AC voltage to be measured is applied to the resistor with a resistance of greater than 100 MΩ,and a leakage current of -μA will be produced and the two LEDs are driven. The voltage sensing signals produced by the two LEDs are transmitted to two photodetectors through two pieces of plastic optical fi- bers, and they can be obtained from the detection of light intensity. When the resistance is - 100 MΩ, 50 Hz AC voltage in the range of 0. 2--5.5 kV has been measured at room temperature. There exists a good linear relationship between measurand AC voltage and output voltage sensing signal, and the non- linear error of experimental data is less than 3.1%. A compensation method for the temperature drift of output voltage has been proposed and proved by using the experimental data obtained from two branches of sensing signals. In the temperature range of -40-60 ℃ and the measurand voltage range of 5.5 kV, the temperature drift of output sensing signal is within -4-2. 1%. Advantages of the proposed voltage sensor mainly include no need of additional light source, simple configuration, and low cost.