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A Novel Approach to Simulating the Performance of Autonomous Inflow Control Devices
Full text linkImproving the efficiency of oil recovery is a crucial necessity in the current energy landscape. The widespread adoption of advanced wells, equipped with Autonomous Inflow Control Devices (AICDs), represents a leading strategy for this purpose. However, the absence of a predefined and straightforward option for modeling advanced wells in dynamic multiphase flow simulators like OLGA® poses a significant challenge. To address the issue, this paper proposes a novel approach based on developing a mathematical model derived from experimental data characterizing the AICD behavior. The Algebraic Controller option in OLGA is then leveraged to integrate the AICD effects into the simulation seamlessly. The proposed methodology undergoes rigorous testing on the PUNQ-S3 reservoir model as a benchmark case study with Water Alternating Gas (WAG) injection. Results demonstrate that AICD has a better water reduction rate of 36.3% and 3.7% compared to OPENHOLE and ICD. This result also indicates the accurate modeling and simulation of AICD performance in the software, showcasing the effectiveness of the developed mathematical model. Comparative analyses of advanced wells with different Flow Control Devices (FCDs) underscore the conclusion that AICDs significantly enhance oil recovery efficiency, thereby maximizing profit and minimizing the carbon footprint
Policy Domains and the Speakers' Gender in ParlaMint-DK 4.1
Full text linkIn this paper, we describe the ParlaMint-DK 4.1 corpus, which consists of the Danish parliament speeches from 2014 to 2022 annotated with 20 general policy domains mapped to the codebook of the Comparative Agendas Project. The policy domains were added to the speeches semiautomatically using the agenda titles under which the speeches occurred. In the paper, we also account for how some of the linguistic annotations of the corpus were improved using the Text Tonsorium and present some of our previous studies on parliament data. We also describe novwl investigations, based on the policy domain annotations in ParlaMint-DK aimed at determining which domains are most frequently addressed in the speeches, and the frequency by which policy areas are debated by female and male politicians during the various governments covered by the corpus
Model Disambiguation Technology in MWORKS.Sysplorer
Full text linkModelica models exhibit excellent cross-platformcompatibility (they can be compiled and simulated on anyplatform supporting Modelica). However, experiments haverevealed that simulation results of the same Modelica modelmay vary across different platforms (under identicalsimulation algorithm configurations). The root cause ofsuch discrepancies lies in model translation uncertaintyintroduced by improper modeling practices, such asinsufficient initial constraints or ambiguous statevariables selection. Different Modelica tools may havedifferent translation strategies. Therefore, modeldisambiguation should be performed to ensure consistentsimulation results. It can be addressed by three parties:through language improvements, such as the proposal ofrelevant annotations, by vendor tools; and by the modelersthrough manual intervention. This paper presents a modeldisambiguation technology in MWORKS.Sysplorer that enablesmodelers to automatically correct model text based ontranslation information, eliminating uncertainties andensuring model portability across Modelica platforms
Modiator - A Web App for Modelica Simulation
Full text linkThe Modelica language (www.modelica.org) has become a defacto standard for systems modeling and many tools exist.This paper describes certain modern enhancements and astatic web app implementation called Modiator (ModelicaInstant Simulator). It allows an improved immediatefirst-time user experience since the web app is availablein seconds and simulations can be done directly in thebrowser. State of the art numerical solvers from theSundials suite have been compiled into WebAssembly. TheModelica model is translated into Javascript code usingtechniques such as sorting, tearing, index reduction, stateselection, etc. A subset of Modelica is supported with someextensions, for example, support for self-modifying models.This paper also presents the Fluid1D and Model3D libraries
Introducing the NewLib Library and its application to multi-level, large-scale solar field models
Full text linkSolar thermal technology is a promising solution fordecarbonizing heat production in industrial applicationsand district heating networks. When combined with heatstorage and advanced control strategies, it can cover asignificant share of heat demands. However, designing andoptimizing such systems is complex due to their dynamicbehavior and the interplay of multiple physical phenomena.To better understand and design these systems, modelingtools are essential.Modelica is particularly well-suited for this purpose. AtNewheat, large scale solar thermal field models have beendeveloped in the Modelica language using the Dymolaenvironment. These models represent the thermal andhydraulic behavior of a solar thermal field at twodifferent levels of complexity. Each is designed fordifferent project phases-fast simulations for early-stagefeasibility studies and slower but more detailedsimulations for the engineering phase.To assess the accuracy of both models, comparisons withmeasured data on an operational solar plant were performed.Results indicate that both models achieve high thermalaccuracy, with errors of less than 4% in annual heatproduction. On the hydraulic side, the detailed modelprovides more precise results than the simplified one. Themain drawback of this model being slow simulations in caseof very complex solar field layouts.Moving forward, these models will support variousapplications and enable scalable modeling of complex solarthermal systems, adapting to different project phases andrequirements
An Open-Source Industrial-Grade Collection of Renewable Energy Source Generic Models in Modelica Language
Full text linkIn a context of massive penetration of Renewable EnergySources (RES) in the grid, it is of prime importance forTransmission System Operator (TSO) to correctly representthese components in their day-to-day dynamic simulationsused to assess system stability, both in operational andplanning situations. Well-parametrized genericPower Electronics Interfaced Resources (PEIR) models haveemerged as a viable option for TSOs for large-scalestability situations, and are largely available incommercial power system software. However, despite previousefforts in the open-source community, especially in theModelica one, there is a lack of a complete, up-to-date,and industrial-grade library. This paper presents thecurrent status of the Dynaωo Modelica library for standardPEIR models that tries to fill this gap. The library’sarchitecture and content, the implementation choices, andalready existing industrial usages of the models arepresented in detail, alongside validation cases and results
Dynamic modelling of an Ammonia to Power application at high efficiency using a solid oxide fuel cell system
Full text linkAmmonia is a promising zero carbon and sustainable hydrogencarrier that can be used as a fuel in solid oxide fuelcells (SOFC) by offering advantages related to the ease ofstorage and the possibility of being used directly withoutan external reformer. In this study, a Modelica-baseddynamic model of an 'Ammonia to Power' (A2P) system wasdeveloped by integrating ammonia decomposition kinetics,electrochemical reactions, all the system-level componentsand the main control loops. A novel Balance of Plant (BoP)configuration is proposed, featuring a five-way heatexchanger that recovers waste heat primarily using the fuelstream as the thermal energy vector instead of air. Themodel evaluates transient responses to operationalperturbations, the behavior of the different control loops,and recirculation percentage rates to optimize systemperformance. Efficiency is calculated as the ratio of thepower output from the SOFC to the power derived from thefresh ammonia line
Efficient Training of Physics-enhanced Neural ODEs via Direct Collocation and Nonlinear Programming
Full text linkWe propose a novel approach for training Physics-enhancedNeural ODEs (PeN-ODEs) by expressing the training processas a dynamic optimization problem. The full model,including neural components, is discretized using ahigh-order implicit Runge-Kutta method with flippedLegendre-Gauss-Radau points, resulting in a large-scalenonlinear program (NLP) efficiently solved bystate-of-the-art NLP solvers such as Ipopt. Thisformulation enables simultaneous optimization of networkparameters and state trajectories, addressing keylimitations of ODE solver-based training in terms ofstability, runtime, and accuracy. Extending on a recentdirect collocation-based method for Neural ODEs, wegeneralize to PeN-ODEs, incorporate physical constraints,and present a custom, parallelized, open-sourceimplementation. Benchmarks on a Quarter Vehicle Model and aVan-der-Pol oscillator demonstrate superior accuracy,speed, generalization with smaller networks compared toother training techniques. We also outline a plannedintegration into OpenModelica to enable accessible trainingof Neural DAEs
VDCWorkbench: A Vehicle Dynamics Control Test & Evaluation Library for Model and AI-based Control Approaches
Full text linkThe ability to systematically compare and evaluate diversecontrol strategies is essential for the development ofeffective control algorithms in autonomous driving. Thiscontribution presents the VDCWorkbench Modelica Library, aunified platform designed to support the development,testing, validation and verification of vehicle dynamicscontrollers and energy management strategies. The presentedlibrary is an extension of the IEEE VTS Motor VehicleChallenge 2023 models and offers multi-physical componentmodeling, including a hybrid energy storage system (fuelcell & hydrogen tank and battery with aging model), as wellas vehicle dynamics control for autonomous driving researchprojects. Two path-following approaches are featured: anopen-loop lateral controller with a static inversion of asingle-track model, and a closed-loop state-dependentgeometric path-following controller with static controlallocation. The library may also serve as the foundationfor development of vehicle control methods, such astwo-degree-of-freedom control approaches concepts. Oneexample is given for this combination of a feedforwardcontroller with residual reinforcement learning, where alearned agent improves the performance of the open loopcontroller. The entire library will be released as opensource on GitHub in September 2025
Quasi-Periodic Feedforward Control Based on Inverse Model Tabled FFT
Full text linkMitigating periodic oscillations (e.g. in rotating systems)is a common control engineering problem. Fast FourierTransform (FFT)-based methods are well-suited forrespective analysis. While FFT algorithms inherently assumesignal periodicity, rotating systems often exhibit trueperiodic behavior (e.g., shaft rotation frequencies). Usingangle-sampled data rather than time-sampled data allowsdirect analysis of oscillations relative to rotationalcycles, which is particularly useful for tracking unbalanceor periodic external excitation in rotating assemblies.Modelica provides several built-in resources to addressthese challenges. First of all, inverse models have thepotential to derive an ideal control signal in time domain.For periodic disturbances, this ideal control is likely tobe approximated well by a periodic, i.e.Fourier-transformable signal. Modelica is an appropriatemodel environment to store and retrieve tabled FFT datadepending on operating conditions such as rotational speed.In a real-time application, synthesizing control signalsfrom precomputed Fourier tables offers a practicalalternative to executing potentially complex inverse modelsonline, reducing computational effort and systemcomplexity. The paper demonstrates this approach using theexample of mitigating oscillations induced by an internalcombustion engine in a hybrid automotive power train