P. Palensky
Please Note
319 records found
1
The living forecast
Evolving day-ahead predictions into intraday reality
Network topology optimization (NTO) via busbar splitting can mitigate transmission grid congestion and reduce redispatch costs. However, solving this mixed-integer nonlinear problem for large-scale systems in near-real-time is currently intractable with existing solvers. Machine learning (ML) approaches have emerged as a promising alternative, but they have limited generalization to unseen topologies, varying operating conditions, and different systems, which limits their practical applicability. This paper formulates NTO for congestion management considering linearized AC power flow, and proposes a graph neural network (GNN)-accelerated approach. We develop a heterogeneous edge-aware message passing GNN to predict effective nodes for busbar splitting actions as candidate NTO solutions. The proposed GNN captures local flow patterns, improves generalization to unseen topology changes, and enhances transferability across systems. Case studies show up to 104 × speed-up, delivering AC-feasible solutions within one minute and a 2.3% optimality gap on the GOC 2000-bus system. These results demonstrate a significant step toward near-real-time NTO for large-scale systems with topology and cross-system generalization.
To develop an optimal operational scheme for distribution networks capable of addressing asymmetric uncertainties associated with renewable energy and load demands, this paper presents a confidence level-based information gap decision theory (CL-IGDT) framework. Building on IGDT, the proposed framework utilizes the confidence level to capture the asymmetric characteristics of uncertainties and maximize the risk-averse capability of the solution in a probabilistic manner. To facilitate such probabilistic consideration, the imprecise Dirichlet model is employed to construct the ambiguity sets of uncertainties. Consequently, a two-stage robust optimal operation model for distribution networks using CL-IGDT is developed. An iterative method is proposed to solve the model and determine the upper and lower bounds of the objective function. Case study demonstrates that the proposed approach yields a more robust and statistically optimized solution with required accuracy compared to existing methods, contributing to a reduction in first-stage cost by 0.84%, second-stage average cost by 6.7%, and significantly increasing the reliability of the solution by 8%.
Demand Response as a Competitiveness Lever for Zero-Emission Industrial Electrification
A Dutch Refinery Case Study
Deep electrification of energy-intensive industry increases exposure to volatile electricity prices and, in the Dutch context, disproportionately high grid tariffs. This paper quantifies the techno-economic value of multi-purpose demand response (DR) for a theoretical 500 MW zero-emission oil refinery in Pernis, the Netherlands, modeled as a coupled electricity-hydrogen multi-energy system. A linear programming model cooptimizes hourly dispatch and capacity sizing of battery storage, hydrogen storage, and electrolyzers, minimizing opportunity, operational, and annualized investment costs over a full simulation year. Results show that DR reduces total annual costs by 24 - 27% relative to the no-flexibility baseline. Grid connection capacity (GCC) emerges as the dominant cost lever: reducing GCC from 500 MW to 204 MW yields an additional instant saving of 73 M€/yr, making optimized DR the most cost-effective zero-emission design.
Power systems with increasing integration of power electronic converters are characterized by low inertia, limited short-circuit support, and fast dynamic behavior, making them vulnerable to active power imbalances. Under such conditions, frequency excursions and rapid change in rates of change of frequency (RoCoF) can threaten system stability. Although power electronic interfaced (PEI) units can provide fast frequency support (FFS), their uncoordinated operation may lead to inefficient or even adverse control actions. This paper proposes a coordinated optimization framework for the FFS in multi-area-energy systems incorporating MMC-based HVDC links, electrolyzers, and wind turbines. The framework optimally tunes the control actions of all participating resources to minimize frequency deviations across interconnected areas, while enabling effective sharing of active power imbalances through HVDC links. The integration of wind turbines as additional fast-acting resources is explicitly investigated, highlighting their role in improving the initial frequency response. The proposed approach is validated on a modified multi-energy HVDC system using RMS simulations in DIgSILENT PowerFactory, with the optimization problem solved by the mean-variance mapping optimization (MVMO) algorithm. Simulation results demonstrate that coordinated utilization of HVDC links, electrolyzers, and wind turbines significantly enhances frequency performance, improving RoCoF, reducing frequency nadir, and achieving better steady-state recovery under severe disturbance scenarios.
Electric Vehicles (EVs) offer substantial flexibility for grid services, yet large-scale, uncoordinated charging can threaten voltage stability in distribution networks. Existing Reinforcement Learning (RL) approaches for smart charging often disregard physical grid constraints or have degraded performance for complex, large-scale tasks, limiting their scalability and real-world applicability. This paper introduces a physics-informed (PI) RL algorithm that integrates a differentiable power flow model and voltage-based reward design into the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm, enabling RL to better scale to a large number of EVs and deliver real-time voltage support while meeting EV user demands. The resulting PI-TD3 algorithm achieves faster convergence, improved sample efficiency, and reliable voltage magnitude regulation under uncertain and overloaded conditions. Benchmarks on the IEEE 34-bus and 123-bus networks show that the proposed PI-TD3 outperforms both model-free RL and optimization-based baselines in grid constraint management, user satisfaction, and economic metrics, even as the system scales to hundreds of EVs. These advances enable robust, scalable, and practical EV charging strategies that enhance grid resilience and support the operation of distribution networks.
Electricity Consumption Profiles (ECPs) are crucial for operating and planning power distribution systems, especially with the increasing number of low-carbon technologies such as solar panels and electric vehicles. Traditional ECP modeling methods typically assume the availability of sufficient ECP data. However, in practice, the accessibility of ECP data is limited due to privacy issues or the absence of metering devices. Few-shot learning (FSL) has emerged as a promising solution for ECP modeling in data-scarce scenarios. Nevertheless, standard FSL methods, such as those used for images, are unsuitable for ECP modeling because (1) these methods usually assume several source domains with sufficient data and several target domains. However, in the context of ECP modeling, there may be thousands of source domains, e.g., households with a moderate amount of data, and thousands of target domains, e.g., households that ECP are required to be modeled. (2) Standard FSL methods usually involve cumbersome knowledge transfer mechanisms, such as pre-training and fine-tuning. To address these limitations, this paper proposes a novel FSL framework that integrates Transformers with Gaussian Mixture Models (GMMs) for ECP modeling. The proposed approach is fine-tuning-free, computationally efficient, and robust even with extremely limited data. Results show that our method can accurately restore the complex ECP distribution with a minimal amount of ECP data (e.g., only 1.6% of the complete domain dataset) and outperforms state-of-the-art time series modeling methods in the context of ECP modeling.
Digital substations, which replace traditional analog infrastructure, are essential to power grid operation but are facing growing vulnerability to cyber attacks. Existing anomaly detection in substation communication requires labeled datasets for supervised training and fails to incorporate temporal characteristics, which cannot detect unknown persistent attacks. Setting arbitrary thresholds for outlier detection leads to high false positives and low detection rates. This paper addresses cyber security challenges related to IEC 61850 Generic Object Oriented Substation Event (GOOSE) protocol within digital substations. We propose a novel unsupervised Transformer-based Distribution Fitting Anomaly Detection (TF-DiFAD) method for time series GOOSE frames with a robust thresholding technique. Deep packet inspection is used to extract features from GOOSE frames, which are processed through the proposed TF-DiFAD model. TF-DiFAD combines the deep learning transformer model with statistical distribution fitting techniques to accurately detect anomalous GOOSE frames. Specifically, reconstruction errors are generated using a state-of-the-art transformer model. A novel model-agnostic solution is applied for setting anomaly thresholds and calculating anomaly probabilities. The Kolmogorov-Smirnov test is employed to select the best-fitting distribution for these errors. TF-DiFAD is benchmarked against other state-of-the-art models using two distinct test datasets, demonstrating superior performance. The results indicate that TF-DiFAD detects anomalies with Receiver Operating Characteristics Area Under Curve (ROC AUC) scores of 96.84% and 95.73% respectively for both datasets.
The expansion of offshore wind power plants (OWPP) necessitates power system studies of wind power plant due to large number of interfaced converters in wind turbine. The traditional detailed model of wind farms although provides high fidelity but leads to computational complexity and long simulation time. Due to this, simplified equivalent modeling approaches such as the single-machine (SM) equivalent model are commonly adopted in the system studies. This approach considers similar wind incident on all turbines and ignores the losses due to collector cables which is unsuitable due to the complexity and scaling of the network. However, the suitability of such equivalent representation for large OWPPs under multiple-event scenarios remains insufficiently examined in the existing literature. Therefore, this paper investigates the dynamic suitability of a single-machine and multi-machine equivalent model for a 400 MW HVDC-connected OWPP in DIgSILENT PowerFactory. Both aggregated models are examined against each other and the detailed WPP under sequential event scenarios. The comparison is performed based on the RMS dynamic response as well as quantitative performance metrics such as root mean square error (RMSE) and fit percentage. The results indicate that the SM equivalent model only captures the dominant dynamic behavior and reduces the computation time by 84%, whereas the multi-machine model provides an improved accuracy for transient response with a reduction of computation time by 77%.
Rapidly expanding Electric Vehicle (EV) adoption necessitates robust, large-scale charging strategies to meet global decarbonization targets. Traditional methods, such as heuristics and mathematical programming-based approaches, struggle to scale effectively and adapt to EV dispatch’s complexity, uncertainty, and variability. Reinforcement Learning (RL) offers a promising alternative due to its ability to handle complex optimization problems, process substantial real-time data, and learn continuously without explicit retraining for every scenario. This study proposes a novel end-to-end RL framework that leverages the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm, enhanced by Graph Neural Networks (GNN), to capture spatial interactions among charging nodes. A key contribution is integrating a safety layer designed to ensure grid stability, preserve EV charging requirements, and enforce power limits. The RL agent was trained and evaluated using real EV charging sessions, offering a realistic assessment of its performance. The results indicate that the proposed method can efficiently coordinate large fleets of EVs, ensuring stable power grid operation and fair distribution of charging resources.
Integrating electric vehicles (EVs) into the power grid can revolutionize energy management strategies, offering both challenges and opportunities for creating a more sustainable and resilient grid. In this context, model predictive control (MPC) emerges as a powerful tool for addressing the complexities of Grid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G) enabled demand response management. By leveraging advanced optimization techniques, MPC algorithms can anticipate future grid conditions and dynamically adjust EV charging and discharging schedules. However, no standard tools exist to evaluate novel energy management strategies based on MPC approaches. This work focuses on harnessing the potential of MPC in G2V and V2G applications by providing open-source algorithms that allow the maximization of EV flexibility and support demand response initiatives while mitigating the impact on EV battery health. Through extensive simulation and analysis, we demonstrate the efficacy of our approach in maximizing the benefits of G2V and V2G while assessing the impact on the longevity and reliability of EV batteries. Specifically, the proposed methods enable the optimization of EV charging and discharging schedules in real-time, taking into account fluctuating energy prices, grid constraints, and EV user preferences.
Centralized reinforcement learning-based voltage regulation in distribution networks is becoming increasingly difficult due to the growing penetration of distributed energy resources, high computational burden, repeated power flow calculations, and increasing privacy concerns. This paper proposes a physics-informed fully distributed reinforcement learning framework that enables autonomous voltage regulation using only local smart meter data. A Thevenin-equivalent-based local voltage estimation model and a hybrid correction mechanism are developed to support accurate local decision-making without synchronized global measurements or centralized power flow solvers. A lightweight coordination mechanism is further introduced to refine the actions of independently trained local agents. Case studies show that the proposed framework reduces voltage violations by approximately 80%, achieves performance close to that of power flow-based training environments, and achieves a training speedup of about 6×[jls-end-space/]. The results also indicate that the relaxation factors in the reward function and the coordination scaler are critical to voltage regulation efficiency, whereas the discount factor has a smaller impact. These findings demonstrate the practicality of the proposed framework for privacy-aware fully distributed voltage regulation.
We introduce a physics-informed neural network for power flow (PINN4PF) that effectively captures the nonlinear dynamics of large-scale modern power systems. The proposed neural network (NN) architecture consists of two important advancements in the training pipeline: (A) a double-head feed-forward NN that aligns with power flow (PF), including an activation function that adjusts to the net active and reactive power injections patterns, and (B) a physics-based loss function that partially incorporates power system topology information through a novel hidden function. The effectiveness of the proposed architecture is illustrated through 4-bus, 15-bus, 290-bus, and 2224-bus test systems and is evaluated against two baselines: a linear regression model (LR) and a black-box NN (MLP). The comparison is based on (i) generalization ability, (ii) robustness, (iii) impact of training dataset size on generalization ability, (iv) accuracy in approximating derived PF quantities (specifically line current, line active power, and line reactive power), and (v) scalability. Results demonstrate that PINN4PF outperforms both baselines across all test systems by up to two orders of magnitude, not only in terms of direct criteria, e.g., generalization ability, but also in terms of derived physical quantities.
Electric-vehicle smart charging requires quick decision-making under uncertainty while enforcing strict electricity grid and user requirements. Mathematical optimization becomes too slow at scale, while online reinforcement learning struggles with sparse rewards and safety. This paper proposes GNN-DT, a topology-aware Decision Transformer that combines graph neural network embeddings with sequence modeling to learn charging policies from offline trajectories. The method operates over variable numbers of vehicles and chargers without retraining. Evaluated on realistic smart charging scenarios, GNN-DT achieves near-optimal performance, reaching rewards within 5 percent of an oracle solver while using up to 10× fewer training trajectories than baseline methods. It consistently outperforms online and offline reinforcement learning approaches and generalizes to unseen fleet sizes and network topologies. Inference runs in milliseconds, making the approach suitable for real-time deployment in large-scale charging systems.
With the growing integration of Modular Multilevel Converters (MMCs) in Multi-Terminal Direct Current (MTDC) transmission systems, there is a growing need for control strategies that balance economic efficiency with robust dynamic performance. This paper presents an enhanced Optimal Power Flow (OPF)-based framework for hybrid AC-MTDC systems, incorporating a novel droop control strategy that jointly coordinates DC-voltage and AC-frequency regulation. By embedding frequency control loops into the MMCs, the method enables system-wide coordination that enhances power sharing and improves resilience under disturbances. The proposed strategy dynamically adjusts converter operating points to minimize generation costs and DC-voltage deviations, balancing economic objectives with system stability. A modified Nordic test system integrated with a four-terminal MTDC grid is used to validate the approach. Optimization is performed using Julia, while the system's dynamic performance is evaluated through electromagnetic transient simulations with the EMTP software. Case studies across multiple scenarios demonstrate that the proposed droop control achieves markedly improved frequency and voltage robustness over active power control, while incurring lower generation costs than the adaptive droop benchmark. The results highlight the ability of the proposed strategy to deliver cost-effective operation without compromising performance, offering a promising solution for the coordinated control of future hybrid AC-DC transmission networks.