Electricity and Control June 2024

TRANSFORMERS, SUBSTATIONS + CABLES

A smarter, more reliable power grid Dr Ulrich Greiner, Manager Research & Development, Kries Energietechnik, TE Connectivity As the world works to manage the energy transition, the ways we generate and consume power are poised for radical change.The electrical grid that delivers this power must also change, becoming smarter to adapt to new sources of generation and maintain reliability.

Dr Ulrich Greiner, TE Connectivity.

R enewable power sources such as wind and solar introduce variability to the supply side of the equation as the power sources are not constant but intermittent (the sun does not always shine and the wind does not always blow steadily). The rise of electric vehicles, larger data centres and the general electrification of everything are increasing the demand placed on the grid as well. At the same time, the increased frequency of severe weather events raises the potential for more widespread power outages. Throughout these changes, grids must continue to deliver power reliably. When people flip a switch, they expect the lights to go on. When that doesn’t happen, consumers and regulatory bodies notice. The grid must become more flexible and resilient to handle the changes. In short, it must become smarter – it must have access to the information needed to control and deliver power safely to all customers with minimal downtime. A more transparent grid is a more resilient grid In the power industry, reliability is measured via the System Average Interruption Duration Index (SAIDI), which provides the average number of minutes an average customer in a region is without power over the course of a year. The ability to gather more information about the flow of electricity across a grid can help locate faulty wires and

reduce the time it takes to get the power back on when something goes wrong – decreasing downtime and improving reliability. Sensors provide critical information about the levels of voltage and current running through a circuit at a specific point along the line. That information can support a more resilient grid in several ways. Improved maintenance Some sensors can detect intermittent fluctuations in current that don’t trip the circuit but do indicate the potential for an outage in future. By collecting data on the accumulation of these spikes in current, electricity providers can set thresholds for alerts and repair or replace failing equipment before it causes downtime. TE Connectivity has also developed a device that can detect a partial discharge, a precursor to intermittent faults. When combined with remote signalling capabilities, these devices give electricity providers more information to help prevent faults in the first place. In addition to improving reliability, reducing the number of ground faults can reduce the chances of those faults sparking wildfires in dry climates.

Faster localisation of faults Historically, detecting faults in the distribution system has

required manual checking for notifications of faulty cir cuits in the ring main units (RMUs) or pad-mounted switchgear enclosures that sit between substations and the transformers out side houses and business es. Placing sensors called faulted circuit indicators (FCIs) on power lines can help locate problems more precisely, providing an op portunity to isolate the fault and reroute power to parts of the circuit that can safe ly receive it. Reducing the amount of time it takes to locate the fault also means workers can get on site

Monitoring the energy grid: this graphic shows where the grid can become ‘smarter’.

22 Electricity + Control JUNE 2024