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P. Palensky

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Evolving day-ahead predictions into intraday reality

Journal article (2027) - Kutay Bölat, Peter Palensky, Simon H. Tindemans
Accurate intraday forecasts are essential for power system operations, complementing day-ahead forecasts that gradually lose relevance as new information becomes available. This paper introduces a Bayesian updating mechanism that converts fully probabilistic day-ahead forecasts into intraday forecasts without retraining or re-inference. The approach conditions the Gaussian mixture output of a conditional variational autoencoder-based forecaster on observed measurements, yielding an updated distribution for the remaining horizon that preserves its probabilistic structure. This enables consistent point, quantile, and ensemble forecasts while remaining computationally efficient and suitable for real-time applications. Experiments on household electricity consumption and photovoltaic generation datasets demonstrate that the proposed method improves forecast accuracy up to 25% across likelihood-, sample-, quantile-, and point-based metrics. The largest gains occur in time steps with strong temporal correlation to observed data, and the use of pattern dictionary-based covariance structures further enhances performance. The results highlight a theoretically grounded framework for intraday forecasting in modern power 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. ...
Journal article (2026) - Weijie Xia, Gao Peng, Chenguang Wang, Peter Palensky, Eric Pauwels, Pedro P. Vergara
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. ...
Journal article (2026) - Alfan Presekal, Ioannis Semertzis, Himanshu Goyel, Peter Palensky, Alexandru Stefanov
Cyber attacks on power grids are imminent and potentially have a severe impact, as evidenced by the cyber attacks in Ukraine in 2015, 2016, and 2022. In response to this challenge, machine learning-based Intrusion Detection Systems (IDS) have become more prevalent as a potential mitigation owing to their alignment with the latest advances in artificial intelligence. However, existing anomaly detection methods for power grid Operational Technology (OT) are often inadequate, as they primarily focus on detecting power grid physical anomalies at the later attack stages and suffer from the scarcity of available data for supervised machine learning. To address these limitations, we propose a novel semi-supervised IDS specifically for digital substations of the power system. The proposed detection method identifies the distinctive distance similarity of digital substation OT communication traffic using a Convolutional Neural Network and Chebyshev distance of packet payloads, and Kolmogorov-Smirnov of packets’ interarrival time using Fast Fourier Transform amplitude. Subsequently, these traffic features are combined into a vector and classified using a novel hybrid semi-supervised Self-Organizing Map (SOM) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN). Results indicate that the proposed method can identify zero-day attacks and achieve accuracy and F1 above 95%. ...
Journal article (2026) - Zhisheng Xiong, Bo Zeng, Peter Palensky, Pedro P. Vergara
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%. ...
Cyber attacks targeting Intelligent Electronic Devices (IEDs) in digital substations can disrupt power system operation, causing equipment damage, instability, cascading failures, and even a blackout. Cyber–Physical Power System (CPPS) datasets are critically needed to develop novel methods for the detection and prevention of cyber attacks on digital substations. In this paper, a novel CPPS dataset is proposed for cyber security of digital substations, including real-time power system measurements, i.e., electromagnetic transient three-phase voltages and currents, communication network traffic, and virtual IED resource metrics. Various scenarios are simulated on an IEC 61850-compliant testbed consisting of Real-Time Digital Simulator (RTDS) and physical and virtual IEDs in hardware-in-the-loop configuration. The dataset contains different operating conditions and cyber attack scenarios, i.e., normal operation, single-phase-to-ground fault, network reconnaissance, resource exhaustion, and IEC 61850 Generic Object-Oriented Substation Event (GOOSE) and Sampled Values (SV) injection attacks. This work aims to provide the research community with a comprehensive and high-fidelity dataset to be used for the design and testing of novel methodologies to increase the cyber security of power grids. ...
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. ...
Journal article (2026) - Dong Liu, Juan S. Giraldo, Peter Palensky, Pedro P. Vergara
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. ...
Journal article (2026) - Cesar Diaz-Londono, Stavros Orfanoudakis, P.P. Vergara Barrios, P. Palensky, Fredy Ruiz, Giambattista Gruosso
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. ...
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. ...
Journal article (2026) - Dong Liu, Sander Timmerman, Yu Xiang, Ensieh Hosseini, Peter Palensky, Pedro P. Vergara
To correct outdated and incomplete topologies in low-voltage distribution networks (LVDNs) using only voltage magnitude measurements, a data-driven approach is developed by integrating machine learning algorithms with correlation analysis. Similar to existing data-driven topology identification and correction methods, the proposed approach exploits smart meter data to infer topology information. However, unlike many conventional approaches that require repeated preprocessing, multiple data sources, or separate procedures for different topology elements, it provides a unified framework that consistently uses the same up-to-date voltage magnitude dataset across all processing stages. Specifically, switch states are identified via supervised learning, while user–feeder connections and customer phase labels are refined using a modified hierarchical clustering algorithm. To address the similarity among smart meter data induced by distributed photovoltaic (PV) systems, a time-based data selection strategy is incorporated into the correlation analysis. The feasibility and robustness of the proposed approach are validated using modified real-world LVDNs and multiple incomplete smart meter datasets collected from customers in the Netherlands. The results demonstrate that the proposed approach can effectively mitigate the impact of PV-induced similarity on phase identification and improve topology correction performance. Although the approach is designed for topology correction rather than full topology reconstruction, the corrected topology improves network observability and supports distribution system operators in load balancing and PV integration. ...
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. ...
Conference paper (2026) - S. Orfanoudakis, B. Elders, P. Palensky, P.P. Vergara Barrios
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. ...
Conference paper (2026) - A. Presekal, V. Rajkumar, H. Goyel, N. Cibin, P. Palensky, J. Godefrooi, A. Ştefanov
The increasing digitalization of power grids has introduced cyber security vulnerabilities. One of the vulnerabilities is related to the IEC 61850 Generic Object Oriented Substation Event (GOOSE) protocol for time-critical communication between Intelligent Electronic Devices (IEDs). This protocol lacks built-in message integrity and authentication mechanisms, making it susceptible to cyber attacks, e.g., spoofing. To address these vulnerabilities, IEC 62351-6:2020 recommends the usage of a Hash-based Message Authentication Code (HMAC). However, implementing this security measure in existing brownfield digital substations is challenging due to the lack of compatible commercial devices and is economically expensive. Therefore, this research proposes and evaluates a cost-effective cyber security enhancement using commodity hardware, e.g., Raspberry Pi, to implement HMAC-based message authentication for ensuring GOOSE message integrity and authentication in brownfield digital substations with respect to stringent time requirements for the operation of protective relays. The proposed solution ensures message integrity and authentication while maintaining compliance with standard requirements. Validation is performed using real commercial IEDs in a real-time Hardware-in-the-Loop (HIL) architecture, demonstrating that the solution meets substation time requirements. This approach provides a feasible and immediate cyber security enhancement for brownfield digital substations without requiring significant infrastructure changes. ...
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. ...

Probabilistic Forecasting, Scenario Generation, and Optimal Control

This study presents an innovative approach to risk-aware decision-making in water resource management. We focus on a case study in the Netherlands, where risk awareness is key to water system design and policy-making. Recognizing the limitations of deterministic methods in the face of weather, energy system, and market uncertainties, we propose a scalable stochastic Model Predictive Control (MPC) framework that integrates probabilistic forecasting, scenario generation, and stochastic optimal control. We utilize Combined Quantile Regression Deep Neural Networks and Non-parametric Bayesian Networks to generate probabilistic scenarios that capture realistic temporal dependencies. The energy distance metric is applied to optimize scenario selection and generate scenario trees, ensuring computational feasibility without compromising decision quality. A key feature of our approach is the introduction of Exceedance Risk (ER) constraints, inspired by Conditional-Value-at-Risk (CVaR), to enable more nuanced and risk-aware decision-making while maintaining computational efficiency. In this work, we enable the Noordzeekanaal–Amsterdam-Rijnkanaal (NZK-ARK) system to participate in Demand Response (DR) services by dynamically scheduling pumps to align with low hourly electricity prices on the Day Ahead and Intraday markets. Through historical simulations using real water system and electricity price data, we demonstrate that incorporating uncertainty can significantly reduce operational costs—by up to 44 percentage points compared to a deterministic approach—while maintaining safe water levels. The modular nature of the framework also makes it adaptable to a wide range of applications, including hydropower and battery storage systems. ...
Conference paper (2025) - K. Bölat, T. Alskaif, P. Palensky, S. H. Tindemans
operators are required to monitor and analyze these systems, raising the challenge of integration and management of large, spatially distributed time-series data that are both high-dimensional and affected by missing values. In this work, a probabilistic entity embedding-based clustering framework is proposed to address these problems. This method encodes each PV system’s characteristic power generation patterns and uncertainty as a probability distribution, then groups systems by their statistical distances and agglomerative clustering. Applied to a multi-year residential PV dataset, it produces concise, uncertainty-aware cluster profiles that outperform a physics-based baseline in representativeness and robustness, and support reliable missing-value imputation. A systematic hyperparameter study further offers practical guidance for balancing model performance and robustness. ...
Digitalization is paving the way toward enhanced power grid operational capabilities and intelligence. The increased digitalization, however, also implies a greater risk of cyber vulnerabilities and threats. Therefore, various power systems facets such as transmission and distribution systems, digital substations, control centers, and wide-area communication networks are vulnerable to cyber-attacks. The most notable cyber-attacks on power grids are the twin attacks on the Ukrainian power grid in 2015 and 2016. These incidents clearly highlighted that cyber-attacks on power grids are an imminent threat that needs to be addressed. Keeping this in mind, this chapter provides essential knowledge of cyber-attack mitigation for cyber-physical power systems, i.e., secure communication protocols for operational technologies, penetration testing using cyber ranges and cyber-physical co-simulation, security controls, and intrusion detection and prevention systems. Among the wide-scope mitigation, artificial intelligence is highlighted as an emerging solution. This chapter presents how hybrid deep learning based on graph convolutional long short-term memory is used for anomaly detection in power system operational technology (OT) networks. Unlike traditional signature and supervised learning-based intrusion detection, the hybrid deep learning anomaly detection utilizes the OT traffic throughput. It takes advantage of the OT traffic’s deterministic and homogenous characteristics to provide a robust and flexible anomaly detection for a wide scope of cyber-attacks. The traffic anomalies are incorporated into an attack graph that aids power system operators identify and localize anomalies of active attacks on power systems in near real time. Cyber-attack case studies and cyber-physical co-simulation results are provided to demonstrate the efficiency of hybrid deep learning for anomaly detection. ...
Conference paper (2025) - Shuyi Gao, Shengren Hou, Peter Palensky, Pedro P. Vergara
Reinforcement learning (RL) has become a promising approach for optimizing the dispatch of energy storage systems (ESSs) in distributed energy systems. Utilizing linear methods in the Q-representation of RL often struggles to balance accuracy and efficiency, while neural network (NN) performs well but falls short in terms of explainability and interpretability. To address these challenges, we developed and evaluated a deep-Q-symbolic-network (DQSN) framework, which integrates a symbolic network (SN) into the deep-Q-network (DQN) architecture for optimal dispatch of ESS. We benchmarked the performance of DQSN against DQN using mixed-integer linear programming (MILP) results, focusing on algorithm convergence, training duration, and operational cost accuracy. Our findings indicate that DQSN achieves slightly superior rewards and reduced operational costs with a modest increase in training time. Additionally, while DQN demonstrates superior generalization to unseen scenarios, DQSN excels in accurately fitting training data, enabling DQSN to be a viable alternative to DQN, particularly in applications requiring explainability and interpretability. ...

Review of Current Practices, Requirements, Enabling Technologies, Data Federation and Challenges

The Digital Twins (DT) have emerged as the technology that provides capabilities to simulate and analyze cyber-physical systems’ behaviors using digital replicas. This is achieved through high-fidelity digital models, bi-directional communication and (near) real-time data exchange between physical real-world systems and DTs. Despite its capabilities of facilitating real-time monitoring, optimization, and predicting system performance, effectively leveraging DT for power system applications requires integrating data from heterogeneous sources and addressing various data related aspects. These include data modeling, exchange and interoperability. One promising concept to address these aspects is that of data federation which promotes interoperability, allowing DTs to operate autonomously, yet interact seamlessly. While various studies in literature have addressed DT applications, technologies, and challenges, a comprehensive review on the data federation aspects within power systems still needs to be investigated. This research seeks to bridge this gap by providing an in-depth review of DT practices in academia and industry, functional and non-functional requirements, and enabling technologies, with emphasis on data federation. Its role in enhancing system-wide interoperability in the power system, along with associated challenges are summarized and discussed. ...