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Popular Abstract in Swedish Denna avhandling presenterar några reglertekniska tillämpningar i elkraftsystem. Tillämpningarna är: hur likströmskablar påverkar båtrafik som använder magnetkompasser; frekvensmätning i elkraftsystem; algorithmer för datorbaserade reläskydd; koppling av aktiv last för att dämpa effektpendlingar.

This paper presents an analysis of the Ziegler-Nichols frequency response method for tuning PI controllers, showing that this method has severe limitations. The limitations can be overcome by a simple modification for processes where the time delay is not too short. By a major modification it is possible to obtain new tuning rules that also cover processes that are lag dominated.

Despite academic advances in PID controller design and development of automatic tuning procedures, there are still many PID controllers that are badly tuned, or not even tuned at all, in process industry. There are several reasons for this, but one major reason is that it is considered too time consuming to use current PID controller tuning methods. This paper presents a new tuning method that is

A recently published paper addressed the so called "PI+p" controller (i.e., a PI augmented with an additional, stable pole) and demonstrated that said controller yields interesting results particularly if tuned with the "contextual" approach, where model-based rules are used in conjunction with a relay experiment so as to provide at the same time the tuned regulator, and the tuning model. In this

This paper presents a library of (PID) controller models adopting the object-oriented approach, and written in Modelica. Peculiar to this work is that controllers are represented both as dynamic continuous-time and digital models, achieving consistence between the two and accounting for the functionalities of typical industrial implementations. This allows the designer to use realistic controllers

This paper treats controller design and tuning for systems with two input signals and two output signals in the process industry. Two design methods that can be combined to form a core in an algorithm for automatic design and tuning for the considered systems are presented. The proposed controller consists of a decoupler and a diagonal PID controller. The decoupler has the property that as little

In this article it is shown how the tuning of a loop is used to commission a closed-loop performance monitoring method. The extended prediction horizon index is used to monitor disturbance rejection properties expressed with the impulse response. The impulse response is obtained from the tuning of the loop. All parameters of the monitoring method are set by using the impulse response. The presente

We document the socioeconomics of wind power expansion in Sweden using two metrics. First, we compute the difference in socioeconomic status (SES) between residents exposed to wind power (0-2 km from the closest turbine) and those not exposed. For each site, the metric is computed ten years prior until five years after construction. When the comparison group is other residents within the same muni

Convolutional neural networks (CNNs) have made rapid progress in the last years and in fields, such as computer vision, they are considered state-of-the-art. However, CNNs are very computationally intensive. This makes them challenging to use in embedded devices such as smartphones, security cameras and cars. This thesis investigates different neural network compression techniques to see which wi

Grain-128AEAD is a stream cipher supporting authenticated encryptionwith associated data, and it is currently in round 2 of the NIST lightweight cryptostandardization process. In this paper we present and benchmark software implementations of the cipher, targeting constrained processors. The processors chosen arethe 8-bit (AVR) and 16-bit (MSP) processors used in the FELICS-AEAD framework.Both hig

https://www.lth.se/utbildning/ansoekan-och-antagning/application-for-courses-at-lth-to-be-included-in-postgraduate-education/ - 2026-09-03

This thesis investigates what mechanisms that contribute to the interaction between lateral and vertical dynamics in a fourwheeled vehicle. For this a vehicle model was derived. To capture all the essential dynamics of the vehicle, both a horizontal model and a vertical model was used. The interaction between the models turned out to be quite evident, making it possible to use the active suspensio

Event-based control is a promising concept for the design of resource-efficient feedback systems, where events such as sampling, actuation, and data transmissions are triggered reactively based on monitored control performance rather than a periodic timer. In this thesis, we investigate how sampling and communication events should be triggered to fully exploit the potential of event-based control