Not all electricity outages can be prevented, but we can prepare for them intelligently

A Review co-authored by Bálint Hartmann, Senior Research Fellow at BME’s Department of Electric Power Engineering, has been published in Nature Reviews Electrical Engineering. The study examines outage prevention and restoration in modern power systems.

Published in a leading forum for electrical engineering and energy research, the article, entitled ‘From electricity outage analysis and monitoring to mitigation and restoration’, provides a comprehensive overview of electricity outage management. It covers the full range of approaches, from the analysis of past outage data and the identification of grid vulnerabilities to real-time monitoring, proactive mitigation, automated grid control, and rapid restoration.

According to the authors, solutions based on measurement data, advanced sensors, artificial intelligence, grid automation, energy storage, and microgrids will all play a prominent role in future energy systems.

One of the two key findings of the study published this summer is that severe outages caused by extreme weather events pose an increasingly significant risk to power systems: the number of weather-related outages recorded between 2014 and 2023 was roughly twice that recorded between 2000 and 2009. The other is that some outages caused by small, simple faults can escalate into much more serious problems due to the complexity of the systems, through a cascading or domino effect, causing significant damage. (The February 2021 Texas power outage, for example, caused an estimated USD 195 billion in economic losses.)

As head of BME’s FASTER Research Group, Bálint Hartmann studies the topology, dynamics, and vulnerability of power systems. In earlier research on critical phenomena, he analysed empirical outage data and carried out cascading-failure simulations on realistic power grids, demonstrating that heavy-tailed distributions may arise not only from self-organised criticality but also from rare-region effects and highly optimised tolerance mechanisms. “A heavy-tailed distribution means that, although very large outages are rare, they may occur significantly more frequently than we would expect on the basis of a conventional, rapidly decaying probability distribution. Some complex systems may also exhibit so-called dragon king events: extreme events arising from an identifiable system-level mechanism and therefore predictable to some extent. The essence of optimised tolerance is that, with finite resources, it is not possible to prepare for every conceivable hazard to the same extent. If a system is optimised for the most likely disturbances, it will inevitably remain more vulnerable to other, rarer events,” Hartmann explained in response to a question from bme.hu.

An interesting example is the blackout on the Iberian Peninsula in April last year, which had several system-level contributing factors. Oscillations, deficiencies in voltage and reactive power control, rapid drops in generation, and the successive disconnection of generators jointly led to the collapse of the system. “None of these factors would necessarily have been fatal on its own, but they reinforced one another, and the failure unfolded so quickly that not even the automatic protection systems were able to prevent it,” Hartmann told bme.hu.

He added that we must accept that our systems are so complex that such incidents will happen again – the question is how we can manage the restoration effectively. One way of preparing for such events is through testing with digital twins. The Review recommends making greater use of continuous, extensive measurement, improving the processing of sensor data with artificial intelligence, running simulations and strengthening resilience.

“Resilience, however, is not merely a matter of digitalisation. Physical grid reinforcement, reserves, energy storage and advanced controls are complementary measures. 

No single technology alone can solve the problem. The key is to detect dangerous operating conditions as early as possible and to have sufficient options for intervention to ensure that a local problem does not escalate into a system-wide one.”

Asked why Hungary has not experienced a major nationwide blackout in recent decades, Hartmann said that this was partly due to the country’s strong integration into the European power system and its robust transmission connections with neighbouring countries, partly to the capabilities of MAVIR (Hungary’s transmission system operator), and perhaps also, to some extent, to good fortune.

Even so, this field of research is of strategic importance to both Hungary and BME. Developing reliable, resilient and sustainable power systems is a prerequisite for the energy transition, the integration of renewable energy sources and the secure operation of critical infrastructure.

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