Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line

Abstract

A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

Methodology and accuracy for non‐invasive detection of switching transient overvoltages from compensation coils connected to power transformers

“…In [4] an electric field sensor is based on capacitive sensors. In [5] a capacitive disk sensor around the conductor is proposed. Voltage sensing between two conductors with galvanic contact to one of them is described in [6].…”

Simulation and Test of a Contactless Voltage Measurement Method for Overhead Lines Based on Reconstruction of Integral Node Parameters

“…The basic approach of this method is to accurately restore the voltage parameters of the overhead line by the spatial E-field information captured by the contactless sensor. Therefore, the type and design of the sensor terminal, the algorithm, and model of the field-source solution will directly determine the accuracy of the entire measurement system [7].…”

Contactless Measurement of Voltage Harmonics on Low Voltage Multi-conductor Cables

“…A non-contact voltage sensor for transmission lines, based on differential voltage measurement is presented in [9]. The system is in self-integration mode circuit over a suspended common mode voltage, making this a non-grounded sensor.…”

“…Alternatively, it is possible to combine, in average sense, the results for several vz, using the calibration load and other triplet harmonics that are usually zero sequence in industrial environment, to obtain the values of cmin, cmax and cquad (9) and then v1, v2, and v3 (11).…”

“…Alternatively, it is possible to combine the results for several vz, using the calibration load and other triplet harmonics, that are usually zero sequence in industrial environment, to obtain the values of cmin, cmax and cquad (9) and then v1, v2, and v3 (11). Figure 3 shows details of the electronic circuit connected to all plate sensors such as the multiplexing capability, impedance measurement capability (through the current source Iz) and sensing/amplifying capability.…”