67 citations · 187 across the 18 of their papers we have counts for
19 papers · 1 filter
Influence of Controller Tuning on Cascaded Flexibility Provision with Feedback Optimization
Irina Zettl, Florian Klein-Helmkamp, Florian Schmidtke +2
The coordination of a large number of flexibility-providing units across various grid layers requires innovative control concepts. This is needed, e.g., to allow active distributio…
Adaptive Tuning of Online Feedback Optimization for Process Control Applications
Marta Zagorowska, Lukas Ortmann, Giuseppe Belgioioso +1
Online Feedback Optimization leverages properties of optimization algorithms to develop controllers for systems with limited model availability, which is often the case in process…
Tuning a Cascaded Online Feedback Optimization Controller for Provision of Distributed Flexibility
Irina Zettl, Florian Klein-Helmkamp, Florian Schmidtke +2
Coordinating a high number of flexibility providing units (e.g. to provide ancillary services for the transmission system) across various grid layers requires new control concepts.…
Hierarchical Provision of Distribution Grid Flexibility with Online Feedback Optimization
Florian Klein-Helmkamp, Irina Zettl, Florian Schmidtke +2
Utilizing distribution grid flexibility for ancillary services requires the coordination and dispatch of requested active and reactive power to a large number of distributed energy…
Tuning and Testing an Online Feedback Optimization Controller to Provide Curative Distribution Grid Flexibility
Lukas Ortmann, Fabian Böhm, Florian Klein-Helmkamp +3
Due to more volatile generation, flexibility will become more important in transmission grids. One potential source of this flexibility can be distribution grids. A flexibility req…
Tuning of Online Feedback Optimization for setpoint tracking in centrifugal compressors
Marta Zagorowska, Lukas Ortmann, Alisa Rupenyan +2
Online Feedback Optimization (OFO) controllers steer a system to its optimal operating point by treating optimization algorithms as auxiliary dynamic systems. Implementation of OFO…
Providing Curative Distribution Grid Flexibility Using Online Feedback Optimization
Florian Klein-Helmkamp, Fabian Böhm, Lukas Ortmann +5
Distribution grid flexibility is discussed as a possible measure in curative system operation, yielding a need for an efficient and robust coordination mechanism for the joint flex…
Deployment of an Online Feedback Optimization Controller for Reactive Power Flow Optimization in a Distribution Grid
Lukas Ortmann, Christian Rubin, Alessandro Scozzafava +3
Optimization is an essential part of power grid operation and lately, Online Optimization methods have gained traction. One such method is Online Feedback Optimization (OFO) which…
From droop to optimality: The potential of volt/var control for power distribution grid enhancement
Jonas G. Matt, Lukas Ortmann, Saverio Bolognani +1
When high amounts of active power are injected into power distribution grids, the overall power flow is limited because voltages reach their upper acceptable limits. Volt/var contr…
Online Feedback Optimization of Compressor Stations with Model Adaptation using Gaussian Process Regression
M. Zagorowska, M. Degner, L. Ortmann +4
Online Feedback Optimization is a method used to steer the operation of a process plant to its optimal operating point without explicitly solving a nonlinear constrained optimizati…
Subtransmission Grid Control via Online Feedback Optimization
Lukas Ortmann, Jean Maeght, Patrick Panciatici +2
The increasing electric power consumption and the shift towards renewable energy resources demand for new ways to operate transmission and subtransmission grids. Online Feedback Op…
Real-time Curative Actions for Power Systems via Online Feedback Optimization
Lukas Ortmann, Gianni Hotz, Saverio Bolognani +1
Curative or remedial actions are the set of immediate actions intended to bring the power grid to a safe operating point after a contingency. The effectiveness of these actions is…
Real-time Projected Gradient-based Nonlinear Model Predictive Control with an Application to Anesthesia Control
Sophie Hall, Lukas Ortmann, Miguel Picallo +1
Medical drug infusion problems pose a combination of challenges such as nonlinearities from physiological models, model uncertainty due to inter- and intra-patient variability, as…
Adaptive Real-Time Grid Operation via Online Feedback Optimization with Sensitivity Estimation
Miguel Picallo, Lukas Ortmann, Saverio Bolognani +1
In this paper we propose an approach based on an Online Feedback Optimization (OFO) controller with grid input-output sensitivity estimation for real-time grid operation, e.g., at…
Automated Insulin Delivery for Type 1 Diabetes Mellitus Patients using Gaussian Process-based Model Predictive Control
Lukas Ortmann, Dawei Shi, Eyal Dassau +3
The human insulin-glucose metabolism is a time-varying process, which is partly caused by the changing insulin sensitivity of the body. This insulin sensitivity follows a circadian…
Non-convex Feedback Optimization with Input and Output Constraints
Verena Häberle, Adrian Hauswirth, Lukas Ortmann +2
In this paper, we present a novel control scheme for feedback optimization. That is, we propose a discrete-time controller that can steer the steady state of a physical plant to th…
Experimental Validation of Fully Distributed Peer-to-Peer Optimal Voltage Control with Minimal Model Requirements
Lukas Ortmann, Alexander Prostejovsky, Kai Heussen +1
This paper addresses the problem of voltage regulation in a power distribution grid using the reactive power injections of grid-connected power inverters. We first discuss how pure…
Experimental Validation of Feedback Optimization in Power Distribution Grids
Lukas Ortmann, Adrian Hauswirth, Ivo Caduff +2
We consider the problem of controlling the voltage of a distribution feeder using the reactive power capabilities of inverters. On a real distribution grid, we compare the local Vo…
Gaussian Process-Based Model Predictive Control of Blood Glucose for Patients with Type 1 Diabetes Mellitus
Lukas Ortmann, Dawei Shi, Eyal Dassau +3
The insulin sensitivity (IS) of the human body changes with a circadian rhythm. This adds to the time-varying feature of the glucose metabolism process and places challenges on the…