Optimization of Detection Accuracy of Closed-Loop Optical Voltage Sensors Based on Pockels Effect

Abstract

The influence of optical parameters on the performance of closed-loop optical voltage sensors (OVSs) based on Pockels effect is analyzed and a control algorithm is proposed to suppress the nonlinearity caused by the unideal parameters of optical devices for optimizing the detection precision of OVSs. First, a quantified model of the feedback phase demonstrates how the optical parameters of optical devices (including light source, polarizer, 45° fusion point, Faraday rotator and half-wave plate) result in the nonlinearity of closed-loop OVSs. Then, the parameter indexes of different optical devices are put forward to instruct the manufacturing process of the optical system. Furthermore, a closed-loop control algorithm is investigated to improve the measurement accuracy of nonlinear OVSs considering the unideal parameters. The experiment results indicate that additional bias caused by undesirable optical parameters is obviously decreased so that the measurement accuracy of OVSs satisfies the demand of IEC60044-3 for 0.1 level measurement accuracy, which verifies the effectiveness and correctness of the methods for suppressing the impact of unideal optical parameters on OVSs.

Real-Time Polarimetric Optical High-Voltage Sensor Using Phase-Controlled Demodulation

“…Among the few studies that have already realized the potential of modern control in the theoretical and experimental analysis of OVSs, we can cite the following: [11], [14], [18], [19]. Essentially, the purpose of the OVS described in Fig.…”

“…Essentially, the purpose of the OVS described in Fig. 1 is to measure the V s (t), according to (11). However, V π s can vary with temperature, causing inaccuracies in this measurement procedure.…”

“…As with the OVSs described above, where waveplates were employed, the elimination of any such devices is desirable for simplifying the system, improving temperature stability and achieving insensitivity to light wavelength. Moreover, since such waveplates are separated from the sensor crystal, angular misalignments between their axes are usually unavoidable and lead to additional measurement errors [11]. To solve this problem, Li and Zeng [12] presented a classic BGO crystal-based arrangement, without the extra λ/4 waveplate: the crystal was cut in such a manner that, from two internal total reflections, a relative phase shift of π/2 between the p and s polarizing components (generated by the Fresnel reflection coefficients) was produced.…”

Vibration Characteristics of Quartz Crystal and Analysis of System Error in Fiber Optic Voltage Sensor

“…In practical applications, quartz crystal deformation is easily affected by the environment, such as ambient temperature and external vibration. However, the research on OVS mainly focuses on thermal induced error [11][12][13][14][15][16][17] at present. There are little reports on the vibration performance of RFOVS system.…”

Practical Adaptation of a Low-Cost Voltage Transducer with an Open Feedback Loop for Precise Measurement of Distorted Voltages

“…In industry, voltage measurements are usually performed using electrical devices or optical sensors, using contact or contactless measurement methods [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Each of these methods has its advantages and disadvantages depending on the measured voltage type (alternating current (AC), or direct current (DC), or AC and DC), voltage amplitude and slope, frequency, and temperature.…”