Power System Stability - a Distribution Network Perspective
What happened in Spain
On April 28, Europe experienced one of its largest recorded power blackouts. It began in SouthWest Spain and quickly spread to Portugal when their shared energy grid lost 15 GigaWatts of power generation, triggering a system black event.
Red Eléctrica de España has shared some initial information about the blackout, confirming that there were two generation loss events in close succession in SouthWest Spain, and that the French grid operator (EdF) opened breakers to prevent the impacts cascading beyond Spain.
The root causes and subsequent recommendations on the Spanish event will be provided in due course. This paper provides an insider’s knowledge of system blackouts that have occurred in Australia, and how Distributed Energy Resources (DER) like rooftop solar PV and batteries connected to the distribution network, can be managed to help prevent major outages from recurring.
Distribution Network Contributions to System Stability
High DER adoption is a key feature of the future of the Spanish power system. Monitoring and controlling DER in the distribution network brings both consumer and market gains. Here we show how the appropriate use of DERs, can boost overall system stability.
Emergency Backstop
The leading Australian technology and software firm, SwitchDin, understands the European story, with a focus on DERs connected to the Distribution Network. Back in 2016, South Australia experienced a statewide blackout. SwitchDin worked with the South Australian Power Network (SAPN) to build and deploy systems to help prevent the situation from occurring again. This ‘Emergency Backstop’ solution was triggered during a transmission line trip that disconnected (islanded) the state in 2022 and performed an integral role in avoiding another statewide blackout.
Over a period of five years, the solution that was developed by SwitchDin and SAPN, is now deployed across Australia. It is the culmination of a national collaboration with all Australian distribution utilities and industry. This solution can now be deployed in just a few months, enabling utility control for scalable emergency backstop needs and curtailing behind-the-meter energy export. It was developed with and for installers, and is integrated with more than 100 operation equipment manufacturers that make inverters, batteries and EV chargers. And importantly, it is based on industry standard protocols such as IEEE 2030.5 and CSIP-AUS, to ensure communication and security protocols are standardised, devices are interoperable, and data is trustworthy.
Flexible Connections
The status quo of most distribution grids is a significant underutilisation of overall power capacity in all but peak periods. But with unpredictable peak flows of distributed energy, system operators need to have the capability to temporarily curtail or disconnect these DERs during grid emergencies in order to prevent blackouts and power disruptions.
To manage this, SwitchDin developed what it terms ‘Flexible Connections’. It continuously monitors communications with upstream control infrastructure and equipment on-site, enabling increased utilisation of the infrastructure. Any faults or loss of communications trigger an immediate safe fallback to the lower limit. An initial deployment can be as simple as a single meter or a single site.
Without Flexible Connections, most power grids distribute conservative static capacity allocations to their customers, reducing the value of on-site DER to consumers, and reducing the system stability impact that DER can provide through temporarily increasing capacity.
Flexible Connections ensures the power utility is able to realise the potential of the rapid growth of distributed energy sources, whether they are rooftop solar PV systems, behind-the-meter battery installations, electric vehicle batteries, etc.
With a rapid increase in the number of battery installations now likely nationally, the system underpinning Flexible Connection can be quickly adopted to ensure these new investments are fully optimised and return benefits not just to the asset owners, but to all energy consumers nationwide.
SwitchDin DER Stack
Unlike legacy Distributed Energy Resource Management Systems (DERMS), SwitchDin’s DER Stack is low-cost and fast to implement, and can stand alone from, or integrate closely with, existing Advanced Distribution Management Systems (ADMS) installations.
The SwitchDin stack includes all elements of interoperability, cybersecurity and identity, installation and onboarding and system assurance. It covers all the critical functions needed for distribution network success.
