URSES – PMU Frequency-based Corrective Control of Future Power Systems

Electrical power systems occasionally operate close to their stability limits. In future, the increase in generation from remote renewable sources (PV and windgenerators) will intensify stability problems and accordingly, will increase the uncertainty of system reliability. Unexpected disturbances and inadequate system monitoring can cause catastrophic failures, leading to blackouts, as seen worldwide. Existing measurement and control schemes cannot cope with these problems. A common reason for the occurrence of blackouts is lack of coordinated control when the system is affected by large disturbances. In order to prevent large-scale blackouts, extensive research into new applications and radical changes in the complexity of Information and Communication Technology (ICT) is needed. In future, it is expected many fossil-fuel power stations to be replaced by bulk renewables. This raises some questions: What will be the frequency response of the future network after a large disturbance? Will traditional preventive control actions be effective enough? How can they be improved? If not, will new options involving flexible real-time corrective control of conventional and renewable generation provide better solutions?

The ultimate objective of the proposed research is to create a wide-area intelligent system, that empowers the future power grids by providing extensive synchronised information in real-time, quickly assessing system vulnerability, and performing timely corrective control actions based on system-wide considerations. This project deals with one of the most complex, and as yet unsolved, challenges incorporating measurement, control and protection aspects. The design of a new closed-loop coordinated corrective control scheme (CCS), which can be applied to eliminating frequency instabilities, cascading outages and catastrophic blackouts in existing and future networks. The new scheme is underpinned by three novel interdependent solutions. The first is for robust frequency and rate of frequency change estimation. The second is for determining and monitoring the instantaneous power imbalance and location of a disturbance. The third is for automated corrective control, consisting for example of controlled islanding and adaptive low frequency demand control supported by the optimal usage of existing generating resources and spinning reserve. The new scheme will prevent catastrophic blackouts, independent of any future network generation mix, unpredictable topology and load profile.