Advanced Dual-Probes Noncontact Voltage Measurement Approach for AC/DC Power Transmission Wire Based on the Electric Field Radiation Principle

The contact-free measurement of current and voltage technologies are key points to achieve online monitoring tasks in the modern power system, which are updated in these decades. However, ensuring accuracy and a convenient level of operation in the meanwhile is also a difficult task that needs to be solved in advance. Besides, there are unidealized situations in the process of application of existence measure methods. According to the principle of electric field radiation, this article proposes a noncontact voltage measurement approach based on three pairs of dual-probes circle measurement structures to measure the voltage of transmission wire online. Compared with the other methods, first, in this proposed approach, the sensor structure is optimized to be simple, low-cost, and easy to install and operate. Second, the potential error in the measuring process caused by the other electric field in the environment is eliminated with dual probes, and the influence of unidealized situations like off-center wire can be also avoided by calculating algorithm. Third, in no matter direct current (DC)/alternating current (AC) monitoring scenarios, with the proposed structure and methodology, the accuracy can be ensured to reach the acceptance level (below 1.63%) even when the core of the wire to be measured is in any position instead of in the center. In the final, the simulation results and circuit tests verify these advantages to encourage us to implement them in the realistic power system.