1 code implementation • 20 Apr 2024 • Ignasi Ventura Nadal, Jochen Stiasny, Spyros Chatzivasileiadis
This paper introduces the first natural step to remove the barriers for using PINNs in time-domain simulations: it proposes the first method to integrate PINNs in conventional numerical solvers.
no code implementations • 20 Mar 2024 • Simon Stock, Davood Babazadeh, Christian Becker, Spyros Chatzivasileiadis
The BPINN combines the advantages of Physics-informed Neural Networks (PINNs), such as inverse problem applicability, with Bayesian approaches for uncertainty quantification.
no code implementations • 12 Feb 2024 • Petros Ellinas, Rahul Nellikath, Ignasi Ventura, Jochen Stiasny, Spyros Chatzivasileiadis
Finally, for the first time, we tackle the problem of bounding an NN function without a priori knowledge of the output domain.
no code implementations • 10 Jan 2024 • Jochen Stiasny, Spyros Chatzivasileiadis
We find that this error estimate highly correlates with the NN's prediction error and that increasing the order of the IRK method improves this estimate.
no code implementations • 6 Oct 2023 • Agnes M. Nakiganda, Catherine Cheylan, Spyros Chatzivasileiadis
Training Neural Networks able to capture the topology changes of the power grid is one of the significant challenges towards the adoption of machine learning techniques for N-k security computations and a wide range of other operations that involve grid reconfiguration.
no code implementations • 18 Jun 2023 • Samuel Chevalier, Ilgiz Murzakhanov, Spyros Chatzivasileiadis
Our contributions achieve a speedup that can exceed 100x and allow higher degrees of verification flexibility.
1 code implementation • 23 Mar 2023 • Rahul Nellikkath, Spyros Chatzivasileiadis
Machine learning algorithms, especially Neural Networks (NNs), are a valuable tool used to approximate non-linear relationships, like the AC-Optimal Power Flow (AC-OPF), with considerable accuracy -- and achieving a speedup of several orders of magnitude when deployed for use.
no code implementations • 21 Mar 2023 • Rahul Nellikkath, Andreas Venzke, Mohammad Kazem Bakhshizadeh, Ilgiz Murzakhanov, Spyros Chatzivasileiadis
However, using EMT simulations or Reduced-order models (ROMs) to accurately determine the ROA is computationally expensive.
no code implementations • 17 Mar 2023 • Jochen Stiasny, Baosen Zhang, Spyros Chatzivasileiadis
To accelerate these simulations, we propose a simulator -- PINNSim -- that allows to take significantly larger time steps.
no code implementations • 15 Mar 2023 • Jochen Stiasny, Spyros Chatzivasileiadis
Comparing the prediction of PINNs to the solution of conventional solvers, we find that PINNs can be 10 to 1000 times faster than conventional solvers.
no code implementations • 4 Jan 2023 • Sarthak Gupta, Ali Mehrizi-Sani, Spyros Chatzivasileiadis, Vassilis Kekatos
According to non-incremental control rules, such as the one mandated by the IEEE Standard 1547, the reactive power setpoint of each DER is computed as a piecewise-linear curve of the local voltage.
no code implementations • 22 Dec 2022 • Simon Stock, Jochen Stiasny, Davood Babazadeh, Christian Becker, Spyros Chatzivasileiadis
Bayesian Physics-Informed Neural Networks (BPINNs) combine the advantages of Physics-Informed Neural Networks (PINNs), being robust to noise and missing data, with Bayesian modeling, delivering a confidence measure for their output.
no code implementations • 21 Dec 2022 • Rahul Nellikkath, Spyros Chatzivasileiadis
For safety-critical systems such as power systems, this places a major barrier for their adoption.
no code implementations • 17 Nov 2022 • Sarthak Gupta, Vassilis Kekatos, Spyros Chatzivasileiadis
This task of optimal rule design (ORD) is challenging as Volt/VAR rules introduce nonlinear dynamics, and lurk trade-offs between stability and steady-state voltage profiles.
1 code implementation • 14 Nov 2022 • Samuel Chevalier, Spyros Chatzivasileiadis
This paper develops for the first time, to our knowledge, a tractable neural network verification procedure which incorporates the ground truth of the non-linear AC power flow equations to determine worst-case neural network performance.
no code implementations • 23 Oct 2022 • Ilgiz Murzakhanov, Sarthak Gupta, Spyros Chatzivasileiadis, Vassilis Kekatos
The IEEE 1547 Standard for the interconnection of distributed energy resources (DERs) to distribution grids provisions that smart inverters could be implementing Volt/VAR control rules among other options.
no code implementations • 18 Sep 2022 • Vladimir Dvorkin, Samuel Chevalier, Spyros Chatzivasileiadis
Gas network planning optimization under emission constraints prioritizes gas supply with the least CO$_2$ intensity.
no code implementations • 13 Sep 2022 • Robert I. Hamilton, Jochen Stiasny, Tabia Ahmad, Samuel Chevalier, Rahul Nellikkath, Ilgiz Murzakhanov, Spyros Chatzivasileiadis, Panagiotis N. Papadopoulos
To do so, we demonstrate that the Power Transfer Distribution Factors (PTDF) -- a physics-based linear sensitivity index -- can be derived from the SHAP values.
1 code implementation • 24 Jul 2022 • Ilgiz Murzakhanov, Gururaj Mirle Vishwanath, Vemalaiah Kasi, Garima Prashal, Spyros Chatzivasileiadis, Narayana Prasad Padhy
Algorithms that adjust the reactive power injection of converter-connected RES to minimize losses may compromise the converters' fault-ride-through capability.
1 code implementation • 14 Mar 2022 • Jochen Stiasny, Samuel Chevalier, Rahul Nellikkath, Brynjar Sævarsson, Spyros Chatzivasileiadis
Deep decarbonization of the energy sector will require massive penetration of stochastic renewable energy resources and an enormous amount of grid asset coordination; this represents a challenging paradigm for the power system operators who are tasked with maintaining grid stability and security in the face of such changes.
no code implementations • 21 Oct 2021 • Lars Herre, Pierre Pinson, Spyros Chatzivasileiadis
The proposed probabilistic reserve procurement allows restricted reserve providers to enter the market, thereby increases liquidity and has the potential to lower procurement costs in power systems with high shares of variable renewable energy sources.
no code implementations • 21 Oct 2021 • Alyssa Kody, Samuel Chevalier, Spyros Chatzivasileiadis, Daniel Molzahn
Nonlinear power flow constraints render a variety of power system optimization problems computationally intractable.
1 code implementation • 12 Oct 2021 • Alicia Alarcón Cobacho, Eléa Prat, Daniel Vázquez Pombo, Spyros Chatzivasileiadis
Continuous flexibility markets have the advantage of allowing more liquidity, which can be critical in the earlier stages of such markets, and can be operated closer to real-time, thereby enabling a better use of the latest forecasts; but, by design, they also result to a lower social welfare compared to auction-based markets.
1 code implementation • 6 Oct 2021 • Rahul Nellikkath, Spyros Chatzivasileiadis
This paper introduces, for the first time to our knowledge, physics-informed neural networks to accurately estimate the AC-OPF result and delivers rigorous guarantees about their performance.
no code implementations • 30 Jun 2021 • Jochen Stiasny, Samuel Chevalier, Spyros Chatzivasileiadis
In order to drastically reduce the heavy computational burden associated with time-domain simulations, this paper introduces a Physics-Informed Neural Network (PINN) to directly learn the solutions of power system dynamics.
2 code implementations • 28 Jun 2021 • Rahul Nellikkath, Spyros Chatzivasileiadis
Physics-informed neural networks exploit the existing models of the underlying physical systems to generate higher accuracy results with fewer data.
1 code implementation • 25 Jun 2021 • Jochen Stiasny, Georgios S. Misyris, Spyros Chatzivasileiadis
Physics-informed neural networks are different: they incorporate the power system differential algebraic equations directly into the neural network training and drastically reduce the need for training data.
1 code implementation • 19 Jun 2021 • Yucun Lu, Ilgiz Murzakhanov, Spyros Chatzivasileiadis
With the rapid growth of renewable energy, lots of small photovoltaic (PV) prosumers emerge.
no code implementations • 4 Jun 2021 • Samuel Chevalier, Jochen Stiasny, Spyros Chatzivasileiadis
In the second approach, we model the Newton solver at the heart of an implicit Runge-Kutta integrator as a contracting map iteratively seeking a fixed point on a time domain trajectory.
1 code implementation • 31 Mar 2021 • Georgios S. Misyris, Jochen Stiasny, Spyros Chatzivasileiadis
The work proposed in this paper uses physics-informed neural networks to capture the power system dynamic behavior and, through an exact transformation, converts them to a tractable optimization problem which can be used to determine critical system indices.
no code implementations • 25 Nov 2020 • Andrea Tosatto, Georgios Misyris, Adrià Junyent-Ferré, Fei Teng, Spyros Chatzivasileiadis
With Europe dedicated to limiting climate change and greenhouse gas emissions, large shares of Renewable Energy Sources (RES) are being integrated in the national grids, phasing out conventional generation.
no code implementations • 23 Sep 2020 • Georgios S. Misyris, Andrea Tosatto, Spyros Chatzivasileiadis, Tilman Weckesser
With Denmark dedicated to maintaining its leading position in the integration of massive shares of wind energy, the construction of new offshore energy islands has been recently approved by the Danish government.
no code implementations • 12 Sep 2020 • Ilgiz Murzakhanov, Spyros Chatzivasileiadis
Distribution grids are experiencing a massive penetration of fluctuating distributed energy resources (DERs).
no code implementations • 14 Aug 2020 • Ilgiz Murzakhanov, Spyros Chatzivasileiadis
This document contains extended mathematical derivations for the communication-free and model-free algorithms that can actively control converter-connected devices, and can operate either as stand-alone or in combination with centralized optimization algorithms.
no code implementations • 19 Jun 2020 • Andreas Venzke, Guannan Qu, Steven Low, Spyros Chatzivasileiadis
This paper introduces for the first time a framework to obtain provable worst-case guarantees for neural network performance, using learning for optimal power flow (OPF) problems as a guiding example.
no code implementations • 5 Jun 2020 • Andrea Tosatto, Matas Dijokas, Danilo Obradovic, Tilman Weckesser, Robert Eriksson, Jenny Josefsson, Athanasios Krontiris, Mehrdad Ghandhari, Jacob Østergaard, Spyros Chatzivasileiadis
This paper presents two cost benefit analyses on the utilization of HVDC interconnectors in the Nordic countries: in the first we investigate the utilization of HVDC interconnectors for reserve procurement and, in the second, we assess the implementation of implicit grid losses on HVDC interconnectors in the day-ahead market.
Optimization and Control Systems and Control Systems and Control
1 code implementation • 8 Apr 2020 • Jochen Stiasny, George S. Misyris, Spyros Chatzivasileiadis
Varying power-infeed from converter-based generation units introduces great uncertainty on system parameters such as inertia and damping.
no code implementations • 17 Mar 2020 • Ilgiz Murzakhanov, Andreas Venzke, George S. Misyris, Spyros Chatzivasileiadis
This paper introduces a framework to capture previously intractable optimization constraints and transform them to a mixed-integer linear program, through the use of neural networks.
2 code implementations • 9 Nov 2019 • George S. Misyris, Andreas Venzke, Spyros Chatzivasileiadis
This work unlocks a range of opportunities in power systems, being able to determine dynamic states, such as rotor angles and frequency, and uncertain parameters such as inertia and damping at a fraction of the computational time required by conventional methods.
no code implementations • 3 Oct 2019 • Andreas Venzke, Spyros Chatzivasileiadis
This paper presents for the first time, to our knowledge, a framework for verifying neural network behavior in power system applications.
no code implementations • 31 Mar 2019 • José-María Hidalgo-Arteaga, Fiodar Hancharou, Florian Thams, Spyros Chatzivasileiadis
Security assessment is among the most fundamental functions of power system operator.
no code implementations • 4 Jun 2018 • Florian Thams, Andreas Venzke, Robert Eriksson, Spyros Chatzivasileiadis
This paper proposes a modular and highly scalable algorithm for computationally efficient database generation.
Systems and Control