Minimising the impact of disturbances in future highly-distributed power systems

It is expected that future power systems will require radical distributed control approaches to accommodate the significant expansion of renewable energy sources and other flexible grid devices. It is important to rapidly and efficiently respond to disturbances by, for example: utilising adaptive, wide-area protection schemes; proactive control of available grid resources (such as managing the fault level contribution from converter-interfaced generation) to optimise protection functionality; and taking post-fault action to ensure protection stability and optimal system operation. This paper analyses and highlights the protection functions which will be especially important to minimising the impact of disturbances in future power systems. These functions include: fast-acting wide-area protection methods using Phasor Measurement Units (PMUs); adaptive and “self-organising” protection under varying system conditions; protection with distributed Intelligent Electronic Devices (IEDs); enhanced fault ride-through; and pattern recognition based schemes. In particular, the paper illustrates how the increased availability of measurements and communications can enable improved protection functionality within distribution systems, which is especially important to accommodate the connection of highly-distributed generation at medium- and low-voltages.