Using Astute HV Monitoring To Target Maintenance
Published 16 Mar 2021
HV Montioring Of Cables & Switchgear
Astute® HV Service
Failure of your high-voltage switchgear and cabling could cost millions in repairs, replacements and fines. But most cable failures don’t happen in a flash – they can be predicted from warning signs, most notably partial discharge (PD).
By watching your cables and switchgear, EA Technology’s Astute® HV service can alert you to suspicious spikes and pinpoint which parts of your HV system should be investigated.
The below case study shows how a major UK utility company decided to keep a cautious eye on their HV assets by using the EA Technology Astute® HV monitoring service through continuously partial discharge monitoring.
Background
Our client is a major UK utility company that owns and operates electrical networks supplying 1.4 million customers. As such, they are responsible for maintaining electrical assets and repairing faults in a safe and prompt manner. Failure to do so can cause supply interruptions, which is costly to our client and frustrating for their customers.
Most electrical asset failures are not instantaneous but develop slowly over time. These failures can be predicted by searching for distinct signatures, most prominently, partial discharge (PD).
PD is commonly caused by the breakdown of asset insulation, which leads to electrical currents propagating through the insulation, which further deteriorates insulation; this is a cyclic process which inevitably leads to faults. With the right equipment installed, PD can be detected, and failures can be avoided before they cause unplanned outages.
EA Technology specialises in producing and managing hardware that monitors PD in high voltage networks. The Astute HV Monitoring® system is a comprehensive monitoring package that includes:
- Astute HV Monitoring® hardware
- A software platform to manage asset monitoring
- Remote monitoring by EA Technology
- Expert interpretation of results
- Automatic email and text alerts
- Advice from experts in the field
One large HV substation owned by our client had a history of PD activity and asked EA Technology to investigate.
Our Approach
The substation in question was home to a very large, and ageing switchboard (with 50 panels/circuits). To investigate the suspected PD, an Astute HV Monitoring® system was installed to monitor every panel of the switchboard. In total, over 150 sensors were installed to pinpoint the exact location of the faulty equipment.
The data collected by the sensors triggered automatic alarms and were subsequently analysed by our expert data team remotely. Our team identified four panels that showed clear signs of PD and were in instant need of intervention. The PD signals for these panels are shown in the graph overleaf. This information was passed on to our client in a timely fashion, who took action to investigate this further.
Entering HV substations known to house defects poses many risks. Therefore, before investigating the faults, the Astute HV Monitoring® dashboard was used to view recent data as part of the risk assessment on entering the substation.
Astute HV Monitoring Dashboard
The panels identified by the monitoring system were targeted to be investigated individually. It was immediately evident that the old insulation had broken down; this is shown in the figure above. The centre of the wooded insulator displays scorched burning marks, which is indicative of PD activity.
Degraded insulation, leading to partial discharge
The faulty insulators were promptly replaced with modern, high-density polyethylene insulation, as shown in the figure below. With the monitoring devices still in place, data was continuously collected and analysed to evaluate if the PD issue was solved. The results showed healthy ultrasonic readings with no signs of PD.
Client Benefits
The Astute HV Monitoring® system was successfully deployed to identify 4 specific panels (out of a total of 50) at risk of future faults. This allowed our client to prioritise the maintenance of their assets, ultimately saving time and money, and ensuring a reliable electricity supply for the thousands of customers connected to this substation.
Average ultrasonic readings activity of the four suspect panels
Now that the monitoring system is in place, our client can rest assured that any future PD-related issues will automatically be detected and raised before assets fail. The exact cost savings for such catastrophic asset failures is difficult to estimate, but regulatory financial penalties for supply interruptions can reach hundreds of thousands of pounds for a single occurrence.
Astute HV Diagram
About EA Technology
EA Technology’s mission is to promote the development of resilient, accessible, low cost energy networks globally, accelerating the transition to energy decarbonisation.
EA Technology is a specialist in asset management solutions for owners and operators of electrical assets. Headquartered in the UK, our operations and customers are global with four regional offices around the world. We originated in 1966 as a groundbreaking research and development organisation serving the electricity industry.
We are committed to providing our customers with innovative products and services, consultancy and training which deliver tangible benefits for their businesses enabling them to create safer, stronger and smarter networks for today and the future.
We work with many clients on a long-term basis to safeguard their power networks. We can advise on strategy and implementation solutions using a range of products, providing an ongoing service to ensure the reliability of equipment, together with highly trained customers’ staff in specialist areas. Our software helps our customers to manage their assets to achieve maximum life and reduce costs.
Thorne & Derrick
Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage voltage power systems:
- Slip-on Cable Terminations
- Cold-shrink Cable Terminations
- Heat-shrink Cable Terminations
- Cable Joints – Heat & Cold-shrink
- Separable Connectors (Euromold)
- Surge Arresters & Switchgear/Transformer Bushings
Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV
Further Reading
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Astute HV Monitoring Brochure
Size: 1.06 MB
