Fault current limiter solution trials in Britain

British network operator Western Power Distribution is trialling the EDGE-FCLi fault current limiting device.

The EDGE-FCLi with a response time of less than 200µs – about 1,000 times quicker than conventional mechanical methods – is expected to have the potential to play a key role with increasing connections of distributed energy resources and bi-directional flows on the network.

By stopping the current flowing quickly when a fault occurs, the device will reduce the risk of large electrical currents which could damage equipment and result in power outages.

The device, which has been developed in partnership with Israeli current limiting specialist GridON, has been installed on the University of Warwick campus, where high current levels are generated through a combined heat and power generator.

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Dan Hardman, Innovation a Networks Engineer who is looking after the project for WPD, says that although this is not the first fault limiter, it is one of the first power electronic fault limiters in the UK.

“We are getting more and more distributed generation connected to the grid. If you keep increasing the amount of generation, the current that flows under fault conditions can exceed the rating of the grid, causing damage to equipment and ultimately affecting power supplies,” he comments.

“If there is a fault, this device can detect the fault using clever electronics and opens itself to break the circuit. It acts very quickly to disconnect the fault current. We are testing these functionalities of the device now in our trial to see if they are successful or not.”

The utility says that in order to enable a scalable and long term path for new distributed connections, the fault current contribution from new generators needs to be reduced to near zero.

Some generation sources such as inverter-based solar contribute little fault current but synchronous ones such as combined heat and power contribute significant fault current.

The trial will last for at least a year and, if proven successful, the technology could potentially be used at other locations across the network.