Intelligent Fault Detection in Aerial Bunched Cables Using Partial Discharge Monitoring

Abstract

Aerial Bunched Cable (ABC) is an innovative over- head power distribution system that uses insulated conductors bundled together, typically supported by a messenger wire. Unlike traditional bare conductor systems, ABC offers improved safety, reliability, and reduced power theft. It is particularly suitable for urban areas, congested spaces, and regions with challenging terrain. The use of ABC contributes to bettervoltageregulationandlowermaintenancerequirementsinpower distributionnetworks.Despitetheenhancedsafetyandreliability offered by ABC systems compared to traditional overhead lines, theyremainvulnerabletoinsulationdegradationovertime duetoenvironmentalandmechanicalstress.Earlydetection of such faults is crucial to prevent major failures and system outages. This project aims to develop a monitoring system that detects leakage current generated by partial discharge activityin aerial bunched cables. The leakage current produced due to insulationdeteriorationisfirstsensedandthenamplifiedusingan AD620instrumentationamplifier,whichisdesignedtoaccurately measure very small signals in electrically noisy environments. Theamplifiedsignalisthenprocessedbyamicrocontroller and evaluated against predefined threshold levels to determine abnormal conditions associated with insulation degradation. A communicationmoduleisincorporatedtotransmitreal-timefault alerts to a mobile application, enabling remote monitoring of the cable condition. Unlike traditional fault detection methods that relyoncomplexandcostlyprotectionschemessuchasdifferential protection, the proposed system provides a cost-effective and real-time monitoring solution specifically designed for ABC net- works.Themethodologyintegratesprecisionsignalamplification, microcontroller-based signal processing, and wireless communi- cation to provide continuous monitoring of the cable insulation condition. By enabling timely maintenance interventions, this solution significantly improves the operational reliability, safety, and maintainability of medium-voltage overhead distribution systems employing aerial bunched cables.

Introduction

The text discusses a Partial Discharge (PD) Monitoring System for Aerial Bunched Cables (ABCs) designed to detect early insulation degradation in overhead power distribution networks. ABCs are widely used because they provide improved safety, reduced power theft, and better reliability compared to traditional bare conductors. However, their insulation can deteriorate over time due to thermal stress, moisture, environmental aging, and electrical overstress.

One of the earliest signs of insulation damage is partial discharge, which is a localized electrical breakdown inside the insulation that gradually weakens it and may eventually cause cable failure. Detecting PD at an early stage is important for preventive maintenance and avoiding unexpected power system failures.

The proposed system detects PD by monitoring the leakage current generated during insulation degradation. Since these leakage currents are extremely small, the system uses an AD620 instrumentation amplifier to amplify the weak signals before processing them with an Arduino-based microcontroller. The AD620 is suitable because of its high precision, high input impedance, low noise, and adjustable gain.

The amplified signal is continuously monitored by the microcontroller. If the leakage current exceeds a predefined threshold, the system identifies it as a potential insulation fault and activates warning mechanisms such as LEDs, buzzers, or GSM notifications to alert maintenance personnel. The system operates in two stages:

1. Setting Mode – The user sets the threshold leakage current value through push buttons, and the selected value is displayed on an LCD.
2. Monitoring Mode – The microcontroller continuously measures and compares leakage current values against the threshold to identify abnormal conditions.

The methodology uses a non-intrusive monitoring technique by sensing leakage current through the messenger conductor of the cable without interfering with the main power conductors. Signal conditioning circuits reduce electrical noise and ensure safe input to the microcontroller ADC.

The literature review highlights previous studies on PD monitoring, insulation aging, leakage current detection, neural-network-based prediction methods, and sensor-based techniques such as Rogowski coils. Existing approaches often rely on expensive or offline testing systems, whereas the proposed design aims to provide a low-cost, real-time, and practical monitoring solution.

Simulation and hardware experiments showed that the system successfully distinguishes between safe and faulty operating conditions. Under normal conditions, leakage current stays below the threshold and no alert is triggered. When insulation degradation causes leakage current to exceed the threshold, the system accurately detects the fault and activates warning indicators.

Conclusion

Intelligent Fault Detection in Aerial Bunched Cables Using Partial Discharge Monitoring is presented as an effective approach for identifying insulation degradation in overhead distributionsystemsbyobservingleakagecurrentvariations associated with partial discharge activity. Aerial bunched ca- bles are widely used in modern power distribution networks due to their safety and reliability; however, environmental conditions,aging,andmechanicalstresscangraduallyweaken thecableinsulationandleadto partialdischarge, which is an early indicator of potential faults. To monitor this condition, the leakage signal obtained from the messenger conductor is processed using a precision amplification circuit based on the AD620 Instrumentation Amplifier. Because the leakage currents produced during partial discharge events are extremely small, the AD620 instrumentation amplifier is used to accurately amplify these weak signals while maintaining high noise immunity and signal stability. The amplified signal isthensuppliedtoamicrocontroller,whereitisconvertedinto digital form using an analog-to-digital converter and contin- uously analyzed in real time. The microcontroller compares the measured leakage current with a predefined threshold value that represents the safe operating condition of the cable insulation. When the measured current remains below this threshold, the system indicates normal operation; however, if the leakage current exceeds the predefined limit, the system identifies it as a possible insulation fault caused by partial discharge activity. In such situations, warning indicators such asLEDs or buzzersare activated,and faultinformation canbe transmitted through a communication module to alert mainte- nance personnel.

References

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Copyright

Copyright © 2026 Prof. Ashna Joseph, Prof. Elezabeth Paul, Sreeranjini V A, Athira Lal, Ajay Jojo, P S Sachin. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.