Improving Power Grid Interconnections for System Stability

For most of the last century, generators stabilised the grid as a by-product of producing energy. Today, we are building assets that stabilise the grid without producing energy at all. That shift identifies the binding constraint. Electricity system transition is no longer constrained by renewable resource availability. It is constrained by deliverability and operability. In inverter-dominated systems under rapid load growth, the binding constraints are: - transmission and major substation capacity - system strength, fault levels, frequency and voltage control - connection and commissioning throughput - secure operation under worst-day conditions - execution pace across networks and system services Generation capacity remains necessary. On its own, it no longer delivers firm supply or supports large new loads. Historically, synchronous generators supplied energy and stability together. Inertia, fault current, voltage support, and controllability were implicit. As synchronous plant retires, these services must be provided explicitly. Stability shifts from physics-led to control-led. System behaviour becomes more sensitive to modelling accuracy, protection coordination, control settings, and real-time visibility. Curtailment is not excess energy. It is a deliverability or security constraint. When transmission and substations lag generation, congestion and curtailment rise. Independent analysis shows that delay increases prices and emissions by extending reliance on higher-cost thermal generation. Distribution networks are no longer passive. They now host distributed generation, storage, EV charging, and large loads at the edge of transmission. Voltage control, protection coordination, hosting capacity, and connection throughput now constrain both decarbonisation and industrial growth. Firming is a hard requirement. Batteries provide fast frequency response and contingency arrest. They do not provide multi-day energy and do not replace networks or system strength in weak grids. Demand response reduces peaks. It cannot be relied upon for system-wide security under stress. Execution speed is critical. Slow delivery increases congestion duration, curtailment exposure, reserve requirements, and reliance on ageing plant. These effects flow directly into costs, emissions, and reliability. This is why electricity bills can rise even when average wholesale prices fall. Costs are driven by peak demand, contingencies, and security, not average energy. Large digital and industrial loads are transmission-scale, continuous, and failure-intolerant. They increase contingency size and correlation risk. At that scale, loads do not connect to the grid, they shape it. Supporting growth requires time-to-power, transmission and substation capacity in load corridors, explicit system strength and fault levels, operable firming under worst-day conditions, scalable connection and commissioning, and early procurement of long lead time HV equipment. #energy

"One of the key ways to make energy systems more reliable is by maximizing flexibility — improving how well the system can adapt in real time to changes in supply and demand. The more flexible the system, the better it can handle sudden demand spikes in the event of extreme weather, such as cold snaps or heat waves, or respond to supply disruptions such as plant outages. Improving flexibility includes upgrading aging infrastructure. Much of the U.S. grid was built decades ago under different demand patterns. Modernizing the grid — by updating substations and transmission equipment, deploying advanced sensors and incorporating advanced transmission technologies (ATTs), for example — can reduce failure rates during extreme heat and cold. These technologies help operators detect problems quicker, reroute power if equipment is damaged and restore service fast. Modernization not only improves reliability but also reduces expensive emergency interventions and lowers long-term maintenance costs. Increasing grid capacity, both through deployment of ATTs and building regional and interregional transmission lines, can reduce the risk of a local weather event turning into a widespread outage. Creating a more interconnected grid allows regions to share power during shortages. Having this greater transmission capacity also help keep prices down by allowing lower-cost electricity to reach areas facing higher demand. Demand-side management options can help ease pressure on the system during extreme weather events. These include encouraging customers and large users to reduce or shift electricity use during peak periods in exchange for lower bills or leveraging distributed energy resources to help prevent shortages. Systems that rely too much on a single fuel are more vulnerable to disruption. Diversification across energy sources and technologies helps reduce the risk of issues related to fuel shortages, infrastructure failures and localized weather impacts. Finally, policy is also critical. It’s vital that incentives are properly aligned with modern needs for flexibility and preparedness. This can help utilities make system investments that really work in extreme weather and minimize costs to consumers in both the short and the long run." Kelly Lefler World Resources Institute https://lnkd.in/e5syqXQp

Grid-Forming Inverters: Quietly Solving a Crisis We Don’t Talk About As renewables scale, one thing is quietly disappearing from our grids: Inertia. Spinning turbines in coal, gas, and hydro plants used to stabilize frequency. But inverter-based solar and storage don’t provide that naturally. Enter Grid-Forming Inverters (GFIs), not just feeding power, but actively supporting the grid. ✅ Create voltage and frequency reference — no need to follow others ✅ Provide virtual inertia for smoother post-fault recovery ✅ Enable black start capability (restart a dead grid) ✅ Stabilize weak grids — vital for remote and developing regions In short: they help solar + BESS act like conventional generation and that changes everything. 📊 A few numbers to keep in mind: • Australia targets 80% of new inverters to be grid-forming by 2035 • Systems with over 60% inverter-based generation become unstable without GFIs • IRENA notes that with >60% inverter-based generation, systems without GFIs face serious stability risks 🔍 Curious how others are integrating GFIs into their systems? Let’s exchange notes — strategy, challenges, and lessons learned. #GridStability #RenewableEnergyTech #SolarAndStorage #PowerSystemsInnovation

Lessons from the North Macedonia Grid Blackout On 18 May 2025, North Macedonia faced one of Europe’s most significant grid incidents, a total loss of its 110 kV network after cascading transformer trips from overvoltage. The 400 kV grid stayed up, but the lower system collapsed. The ENTSO-E investigation is a masterclass in voltage control, protection coordination, and reactive power planning. What Happened: • During a low-load spring night, lightly loaded 400 kV lines produced excess capacitive reactive power. • With no reactors, SVCs, or STATCOMs online, voltages spiked near 450 kV. • Several 400/110 kV transformers tripped on overvoltage protection, progressively isolating the 110 kV grid until complete separation at 04:59 CEST. • The incident was classified as ICS Scale 3, ENTSO-E’s highest severity level. The Response • MEPSO activated its restoration plan within minutes. • Disconnecting interconnectors to KOSTT and EMS normalized voltages. • Full restoration finished by 07:47, with trading resuming shortly after. The Real Drivers: 1. Reactive Power Imbalance: Seasonal low-load nights in South-East Europe often cause overvoltages from line charging. With no dynamic reactive devices online, operators rely on tap changes and manual switching, an unsustainable approach. 2. Protection Philosophy: Transformer overvoltage protection isn’t standard in most European TSOs. MEPSO added it in 2023 to handle recurring overvoltages, a decision that protected equipment but worsened grid separation. 3. SCADA & Data Visibility: A UPS failure in April disabled MEPSO’s SCADA historian, limiting situational awareness and post-event analysis. It didn’t trigger the blackout, but it hindered coordination. Lessons: a) Reactive power control isn’t optional, it’s core system stability infrastructure. b) Protection design must match system conditions, not generic standards. c) Data availability is as critical as breakers and relays during crises. d) Market mechanisms and physical grid operations are more intertwined than ever. Looking Ahead The final ENTSO-E report is expected to: • Recommend mandatory reactive devices (reactors, SVCs) in low-load zones. • Establish regional voltage-control protocols under SO GL / NC ER. • Strengthen Operational Planning Data Environment (OPDE) visibility and coordination standards. One overlooked point: MEPSO lacked automatic voltage load shedding, relying on manual DSO coordination, a fragile last line of defense. My Take: This wasn’t just a blackout, it was a timely reminder of how voltage stability risks are evolving. Europe’s grids are becoming more reactive-power-dominated, data-driven, and interconnected. The real question isn’t if we’ll see more of these incidents, but how prepared we’ll be next time. #PowerSystems #GridStability #ReactivePower #VoltageControl #SystemProtection #ENTSOE

A critical challenge in modern grid stability is that inverter-based resources (IBRs) are often “black boxes” to utilities and system operators. Inverter manufacturers and plant developers understandably hesitate to disclose proprietary control strategies, leaving operators with limited visibility into internal dynamics. The problem is further compounded by the fact that IBRs can switch among multiple control modes, which are typically unknown to operators yet can exhibit dramatically different dynamic behaviors. In the final days of 2025, we were excited to learn that our paper on black-box IBR modeling was accepted by IEEE Transactions on Smart Grid. In this work, we develop a comprehensive data-driven framework that uses only terminal measurements to discover unknown control modes and learn continuous-time models that accurately capture IBR dynamics under each mode. By leveraging physics-inspired deep learning, the proposed approach addresses four major challenges in a unified way: 🚀 High-Order Nonlinear Representation Using only terminal measurements, the framework provides a general learning approach for characterizing arbitrary high-order nonlinear dynamics of IBRs. It is not tied to any specific control paradigm and can cover anything from power/voltage/current control loops to virtual synchronous machines (VSMs) and phase-locked loops (PLLs). 🚀 Continuous-Time Modeling Unlike most data-driven methods built on discrete-time models (e.g., RNNs, LSTMs, Transformers), our approach learns continuous-time state-space models (differential-algebraic equations). This enables seamless integration of the learned IBR models into standard power-system time-domain simulations with arbitrary numerical integration schemes and step sizes. 🚀 Discovery of Unknown Control Modes A physics-inspired deep unsupervised learning mechanism automatically identifies distinct control modes from historical disturbance data and learns separate state-space models that represent the dynamics associated with each mode. 🚀 Robustness to Noise and Uncertainty Inspired by Kalman filtering, the learning architecture explicitly accounts for system uncertainties and measurement noise, both of which are ubiquitous in real-world grid systems and data. It ensures the method’s robust performance in practical settings. The examples in the paper demonstrate how the proposed framework can learn accurate time-domain models of fully black-box IBRs and deliver highly accurate long-horizon predictions of their responses to grid disturbances, e.g., subsynchronous oscillations caused by PLL interactions in weak grids. See details here: https://lnkd.in/eFd5CU4e #PowerSystem #SmartGrid #InverterBasedResources #RenewableEnergy #PowerElectronics #Control #PowerSystemStability #PowerSystemModeling #PowerSystemSimulation #SystemIdentification #DataDriven #MachineLearning #DeepLearning #ArtificialIntelligence #PhysicsInformed #IEEETransactionsOnSmartGrid

🔌 Grid operators are implementing various strategies to manage the declining inertia caused by the increased penetration of variable generation (VG) resources, such as wind and solar. These strategies fall into three main categories: maintaining inertia, providing more response time, and enhancing fast frequency response. To maintain inertia, operators can ensure that a mix of synchronous generators is online to exceed critical inertia levels. Additionally, synchronous renewable energy sources and synchronous condensers can be deployed to provide inertia. To provide more response time, operators can reduce contingency sizes and adjust underfrequency load shedding (UFLS) settings. Finally, enhancing fast frequency response involves leveraging load resources, extracting wind kinetic energy, and dispatching inverter-based resources to improve the grid's ability to respond to frequency changes. 🍃 Extracted wind kinetic energy refers to the capability of wind turbines to provide fast frequency response (FFR) by utilising the kinetic energy stored in their rotating blades. This approach can be particularly effective in addressing the challenges posed by declining inertia in power systems with high wind penetration. By extracting kinetic energy, wind turbines can respond rapidly to frequency deviations, thereby helping to stabilise the grid. This method can be used in conjunction with other resources to enhance overall system reliability and maintain frequency within acceptable limits. 💡 High deployment of variable generation (VG) resources can be effectively managed by combining extracted kinetic energy from wind turbines and increasing output from curtailed wind plants. The figure below illustrates that when these two strategies are combined, they significantly mitigate frequency decline. The simulation shows that relying solely on extracted kinetic energy results in frequency falling below UFLS (underfrequency load shedding), while using only FFR barely avoids UFLS. However, when both methods are applied together, the frequency decline is minimal, demonstrating that these approaches can serve as viable alternatives to traditional inertia and primary frequency response from conventional generators. #gridmodernization #stability #gridforming #powerelectronics #renewables #cleanenergy #solidstate

🌍 Reflecting on the Future of #EnergyDistribution at the World Economic Forum 🌍 Honored to discuss at the World Economic Forum’s Clean Power Executive group last week, on the urgent steps needed to strengthen our energy distribution grid amidst today’s surge toward #electrification. As we accelerate #ElectricVehicles, #heatpumps, #industrialelectrification and #renewables, our #grid faces unprecedented strain, leading to overloads, connection delays, and stability issues. Here’s what we believe will drive meaningful change: Regulatory Shift to #Totex and the right pricing signals 💼 We must shift from rigid Capex models to Totex, allowing Distribution Grid Operators to prioritize flexible, digital investments. In Europe, the 2024 Electricity Market Design Directive is a step forward, but we need faster national implementation. On pricing, we need to move from a long term Capex, ‘cost plus’ model, to a dynamic pricing model, both in retail and wholesale markets, to signal investment needed to solve congestion at the points where it occurs.  Scaling #Flexibility Markets 🔄 Flexibility markets are a key enabler for an efficient distribution grid. They could cut grid investment needs by up to 20%, at the same time accelerating renewable rollout. First flexibility market implementations in Europe and North America show potential – now it is time to scale them. Data Accessibility 📊 Without much improved availability and quality of data in lower distribution grid voltage levels, flexibility markets, grid efficiency, shorter interconnection backlogs, and effective investment planning will be very difficult to achieve. Following progressive examples in the UK and elsewhere, we recommend data frameworks, adoption of standards, and data availability in the distribution grid to be required in all national regulations.  Addressing #PowerElectronics Challenges ⚙️ The rise of volatile solar and wind based power generation and the move to a largely power electronics controlled energy grid introduces fundamental control and stability issues. Industry-wide collaboration on technical standards and simulation of large scale inverter based grids is key to a resilient grid. We’re at a pivotal moment. Through regulatory evolution, flexible markets, robust data, and innovative tech, we can build a sustainable energy future. 🌍 #WEF2024 #EnergyTransition #SustainableEnergy

What happens when 1,500 MW of demand simply vanishes in an instant? When it comes to the grid, this isn't a success story about efficiency, it’s a reliability nightmare. When talking about large loads, there is one topic that keeps coming up over and over agin. It is the risk of "uncoordinated load loss." Just like the challenges on the generation side with IBRs, having large loads trip during disturbances is a huge risk. The possibility of having those load losses cascade is what keeps people up at night. With the size of data centers trying to interconnect growing and growing, we can no longer treat them as traditional industrial loads. They are a special class of load, and whatever we want to call them, Power Electronic Loads (PELs), High Impact Large Loads (HILLs), Power Electronic Interface Large Loads (PEILLs), etc... they don't behave like other loads. Unlike a motor or a furnace, a data center is a software-defined environment where the loads are very electronically sensitive, and in the absence of standards are going to be configured to protect the datacenter above all else. And so the recent timely report by the IEEE Standards Association | IEEE SA, the IEEE Industry Connection Report: "Review of Industry Efforts and Standards of Grid Readiness for Data Center Deployment" is an important read for those in the industry. The report highlights how important it is that we create better interconnection standard and standards for how we expect these loads to behave. Because in software, a sudden drop in traffic is usually a relief for the system. But the grid operates on the physics of inertia and frequency. A sudden large load shed triggers both frequency and voltage to spike, putting infrastructure, and potentially the whole interconnection at risk. The report calls for a harmonized performance standards, similar to what IEEE 2800 did for renewables. Specifically: ⚡ Standardized Ride-Through and other Performance Characteristic Requirements - Facilities must be able to stay connected during minor faults rather than defaulting to backup. This extends to ramp rate limits, oscillation control, voltage control, etc... ⚡ Modeling Expectations - More detailed modeling of how these power electronics behave in fault scenarios. ⚡ Reliable Validation - Testing Methods for Validating Data Center Performance. A sincere thank you to Eric Meier, Martin McEnroe, P.E., Bharat Vyakaranam, Ph.D, PE, and the MANY other individuals who authored and reviewed this whitepaper. You're doing important work! #EnergyTransition #DataCenters #GridModernization #IEEE #ElectricalEngineering #PowerSystems

🚨 Faster, Cheaper Grid Connections: Lessons from ERCOT 🚨 In 2023, FERC issued a landmark order to streamline grid interconnection, targeting the massive backlog slowing energy and storage projects. While progress is being made, the ERCOT model—dubbed connect and manage—has sparked attention as a potential game-changer for the rest of the U.S. 🔑 How ERCOT Stands Out: The connect and manage approach focuses on local grid upgrades without requiring expensive network-wide changes. -Uses market redispatch and curtailment to manage grid congestion. -Brings projects online in 3.5 years vs. 6+ years in many regions. For developers, this means less costly interconnection and faster timelines. It’s why ERCOT leads U.S. grid operators, adding 14.2 GW of capacity in 2021-2022, compared to 5.6 GW in PJM, the largest U.S. grid operator. 💡 Why This Matters: As we accelerate the energy transition, ERCOT’s model shows that easing interconnection bottlenecks doesn’t just save time—it also saves money, reduces project risks, and builds resilience into the system. 📚 FERC’s 2023 order laid the groundwork, but adopting ERCOT-inspired innovations like energy-only interconnection options and streamlined study processes could improve grid access nationwide. The path forward isn’t without challenges—operational stability and long-term transmission needs must be addressed. And the connect and manage approach may be less effective in more compressed RTOs/ISOs regions, or smaller non-RTO/ISO regions—but ERCOT’s success proves we can build a faster, more efficient grid⚡ #interconnection #transmission #ERCOT #FERC

Accelerating Clean Energy Through Collaboration ~ The Joint Transmission Interconnection Queue (JTIQ) Framework The path to a more sustainable energy future requires innovative solutions and collaboration across the energy sector. A shining example of this is the Joint Transmission Interconnection Queue (JTIQ) framework, a partnership between MISO and SPP, designed to streamline renewable energy integration and enhance grid reliability. In October 2023, the JTIQ framework gained significant momentum with a $464 million grant from the U.S. Department of Energy and $1.3 billion in utility investments, reflecting a robust financial and collaborative commitment to improving energy infrastructure. Since then, the progress has been remarkable: ~November 2024: The Federal Energy Regulatory Commission (FERC) approved the JTIQ transmission plans, paving the way for five 345-kV transmission projects along the MISO-SPP seam. These projects will enable the integration of approximately 29 GW of new renewable generation capacity and are expected to begin coming online by 2031. ~Ongoing Impact: These developments continue to address critical transmission constraints, enhance grid reliability, and promote the efficient interconnection of renewable energy resources. Why This Matters for the Entire Country The JTIQ framework’s impact extends far beyond the MISO-SPP region, shaping the energy landscape across the United States: ~JTIQ demonstrates how to overcome transmission bottlenecks, offering a scalable solution for other regions to integrate renewable energy more efficiently. ~Enhancing grid connectivity supports a stable, resilient energy network, setting a standard for modernization nationwide. ~ Production cost savings from JTIQ projects can translate to lower electricity prices for consumers, benefiting households and businesses across the country. ~The success of federal and private sector collaboration in JTIQ provides a replicable model for financing large-scale energy infrastructure. ~JTIQ highlights how Regional Transmission Organizations (RTOs) can work together to solve complex challenges, paving the way for a more unified national grid. Key Outcomes ~Unlocking vast renewable energy potential. ~Delivering billions in savings through improved grid efficiency. ~Strengthening grid resilience and supporting energy transition goals. The JTIQ framework underscores the importance of forward-thinking strategies to meet the demands of a rapidly evolving energy landscape. Together, we can build a cleaner, more reliable energy future. What are your thoughts on the progress made by the JTIQ framework, and how do you see it shaping the future of energy? Let’s discuss! #RenewableEnergy #GridInnovation #Collaboration #Leadership #Sustainability #EnergyTransition #PublicPrivatePartnerships #GridModernization #EnergyLeadership #seetheopportunityineverydifficulty