Photonic Voltage Transducer with Lightning Impulse Protection for Distributed Monitoring of MV Networks

Grzegorz Fusiek,Pawel Niewczas

doi:10.3390/s20174830

Abstract

The design, construction and characterization of a photonic voltage transducer with a lightning impulse protection for distributed measurements on medium voltage (MV) networks (11 kV) was presented in this paper. The sensor prototype, comprising a combination of a piezoelectric transducer and a fibre Bragg grating (FBG) as a core optical sensing element, and a dedicated lightning protection device comprising a set of reactive components, was evaluated through laboratory testing and its performance was assessed based on the accuracy requirements specified by the relevant industry standards. It was demonstrated that the sensor has the potential to meet the accuracy requirements for the 3P protection and 0.2 metering classes specified by the IEC 60044-7. The device successfully underwent lightning impulse withstand tests, satisfying the safety requirements applicable to 11 kV networks as specified by the standard. The usage of an FBG as a photonic sensing component enables the multiplexing of multiple such sensors to provide the distributed measurement of voltage along a power network.

Highlights

Electricity distribution networks are a key element of the wide-area power system
The IEC 60044 standard is being replaced by the new IEC 61869 standard, the equivalent part 7 of the new standard is not available at the time of writing of this paper, and the document forecast publication date is currently set to December 2022 [22]
While data samples from both systems can be acquired at the same time and synchronized, the acquisition of the sensor and reference signals starts at different moments each time the software controlling acquisition is started, causing a random phase displacement between the acquired signals

Summary

Introduction

Electricity distribution networks are a key element of the wide-area power system. Among the various problems related to the electrical network functionality and stability, there are different types of faults that can be either temporary, causing no damage to the electrical equipment and leading to temporary power outages, or permanent, causing the failure of the system equipment and leading to blackouts with durations sometimes reaching several hours [2]. 50–90% of faults in overhead distribution systems, after a short delay (below 3 min) the network can operate normally [2,3]. Lightning events cause temporary faults on distribution networks with less than 20% of lightning strikes causing permanent damage [2,3,4]. In the majority of cases, when the lightning event occurs, the equipment insulation can be damaged due to the high current surge in the line that generates large voltage impulses—often leading to flashovers unless the equipment was protected with surge arresters [2] or is furnished with sufficient insulation that meets the relevant industry standards [5]

Methods

Findings

Discussion

Conclusion