Bushfire Mitigation: How ‘Pulse’ Technology Cuts the Sparks During Fault Testing

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Bushfires

The other day I was reading an article on bushfire mitigation that described how automatic circuit reclosers are the most common form of distribution protection equipment. Automatic circuit reclosers were invented more than 70 years ago, and they represented a major advance in overhead protection. They do not, however, sufficiently reduce the risk of igniting a fire.

Faults will always occur on an electricity network, whether above or below ground, and managing faults to minimize the production of sparks and arcs is essential to mitigate the risk of fires.

Every time a fault occurs, a recloser attempts to reclose, sending the full fault current through the network. If the fault is permanent, sparks are generated at the site of the fault for each reclose attempt. For this reason, networks correctly suspend reclosing in areas such as forests and bush that are prone to fires when it is especially dry outside.

Tweaks to the design of reclosers have occurred over the years, but most do not significantly reduce either arcs or sparks when closing into a fault. Importantly, closing into a fault not only exacerbates the risk of fires, but it damages network assets when the full force of the fault is repeatedly banged into the system.

Since 2008, however, a unique, patented approach to reclosing has been available that dramatically reduces fire risk during reclosing by using 95% less energy when testing for a fault. It’s called PulseClosing® Technology, and it lets through only 5% of the fault current when determining whether a fault is transient or permanent. The recloser only recloses if the fault is cleared. Here’s a video illustrating the difference in sparks produced by conventional reclosing and when using PulseClosing Technology. By using just 5 % of the fault current, the likelihood of damaging network assets is significantly reduced, and the fewer sparks that are generated also dramatically reduces the risk of starting a fire.

Importantly, nearly 60% of all network fires result from asset failure, so using PulseClosing Technology not only reduces the risk of a fire at an actual fault (during testing), but the risk of a fire from asset failure is also reduced.

I’d be interested in your thoughts on bushfire mitigation strategies in the Comments section below.

Spécialiste

Jason Lander

Date de publication

septembre 19, 2018