Power SystemsA critical societal System that, in the case of GW-scale gri... have traditionally relied on Fault CurrentThe unusually elevated Current which flows in the event of a... as a key means for identifying that a disruptive and potentially dangerous FaultA disruptive and potentially dangerous event occurring in a ... has occurred. For example, when a short circuit occurs, a very high flow of CurrentA flow of charged particles, usually electrons, in an electr... – or the Fault Current – occurs that can damage equipment and/or cause fires. To prevent this, the sections of the grid that are experiencing Fault conditions must be quickly disconnected.
To recognise such Fault conditions, the PowerElectrical represents rate at which Energy is transferred th... SystemA set of Components that are formally related together by a ... has traditionally relied on the presence of Synchronous GeneratorsA Generation Plant which is directly connected to the Power ..., which are capable of injecting large amounts of Current during a Fault, allowing it to be more easily detected. Relatively low-cost devices, such as circuit breakers or fuses, then disconnect the relevant part of the System experiencing the Fault.
By contrast, insufficient Fault Current can occur where large concentrations of Inverter Based Resources (IBR)A diverse range of Energy Resources that, unlike many conven... are deployed, and especially where the proportion of Synchronous Generation is also in decline. Due to the inherent constraints of IBR technologies, the amount of Current typically produced under Fault conditions cannot significantly exceed the normal rating of the device without causing damage. This may result in traditional overcurrent protection devices being unable to detect and prevent Faults due to the absence of sufficient Fault Current. While the Current may stay below levels that are dangerous to equipment, it may still produce other dangerous conditions such as increased exposure to live electrical equipment or local power quality issues.