Past seminars at IEA in 2022
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Torsdag 16/6 kl 13:00, KC M:IEA
Master's thesis presentation
Simulation of Transformer Inrush Currents and their Impact on the Grid
Juan de la Peña Toledo
This MSc Thesis's main objective is to determine the impact of transformer inrush
currents in the grid and develop a tool that helps E.ON Energidistribution AB evaluate
transformer sizing. The motivation of E.ON is to have a more precise way to estimate the
energization consequences of increasing the transformer size in the grid, since currently
is being used a rule of thumb that relates the transformer size to the short-circuit
capacity of the bus at which the transformer is connected.
An adequate study of the causes and consequences of the inrush current phenomenon is
conducted to determine the duration and magnitude of undesired disturbances. Python
3.9 is used to design simplified transformer models based on banks of three single-phase
units due to substantial limitations of more advanced alternatives. PSCAD and Matlab
Simscape Electrical, two superior transient analysis software, are used to verify the
results of test simulations. The non-linearity of the differential system of equations
required numerical methods and the utilization of the Trapezoidal Rule of Integration
and the Newton Raphson Method.
Then, different strategies are considered potential alternatives to estimate the voltage
dip at the surrounding grid, which is the primary concern for E.ON. For the grid analysis
part, a limited version of PSS/E (PSS/E Xplore) software is used as it is the tool
that E.ON uses for steady-state and short-circuit calculations. All the strategies are
compared and evaluated for a hypothetical energization of a distribution transformer
in a reduced network correspondent to the ¨ Öland island. Some results coincide with
historical data from a similar distribution network, but on-site measurements or dynamic
grid studies must validate the results. The in-built Python API of PSS/E allows
automating the process and incorporating it with the rest of the program.
Supervisors: Olof Samuelsson (IEA), Imran Maqbool (IEA), Omar Juarez Moreno (E.ON)
Examiner: Jörgen Svensson (IEA)
Torsdag 16/6 kl 10:30, KC M:IEA
Master's thesis presentation
Latency Aware and Event-Based Wireless Control for Cloud-Fog Automation
The development seen within industrial automation in recent years enables the emergence of
manufacturing sites which utilises technology for improved productivity, quality and safety. Increased
communication demands introduced by Industry 4.0 has motivated the development of
cloud-fog automation; a technique characterised by wireless communication between the lower
levels of the automation pyramid. Specifically this gives rise to the need for efficient wireless
communication between I/O devices and controllers.
The thesis presents findings from an investigation of wireless control and communication performance.
A cascaded IMC based PID controller structure is developed to control a time-critical
motion system. Various communication protocols and control algorithms are considered to examine
the performance behavior. The results indicate that UDP based protocols, compared to
TCP based protocols, are a promising candidate for the target purpose. However, by manipulating
the control algorithm sampling interval, TCP communication yields almost equivalent results.
An exploration of event-based control results in an algorithm that achieves communication reductions
of over 80%. Given a consciously chosen sampling interval, control performances comparable
to those of the corresponding time-based system can be maintained. The research indicates that
wireless control has the potential to accomplish control performances equal to those found in
Presentation language: English
The work has been carried out at ABB Corporate Research, Västerås.
Supervisors: Zhibo Pang, Alf Isaksson, ABB, Gunnar Lindstedt, IEA
Examiner: Ulf Jeppsson, IEA
Tuesday 14/6 kl 15:30, KC M:IEA
Master's thesis presentation
A modular switching system as a flexible charging solution for a logistics terminal
Logistics terminals in Sweden can accommodate up to over 100 trucks from 3.5 ton to over 20 ton of gross vehicle weight (GVW). The ambition to move road transport from fossil fuels to electric energy requires that almost all these trucks are fully electric. One of the biggest challenges with making them fully electric is to charge them. Being commercial vehicles, they are usually operated daytime and the operation gives very little time for charging. Thus, it has to be assumed that most of the charging has to be made at the logistics terminal, and most of that nighttime. The power needed for nighttime charging is relatively low, in the 10s of kW, with a few exceptions for trucks that deliver and pick-up goods during the evening or night. During the day, the trucks that drive the longest routes will consume more power than the provided nighttime charge and will have to be charged during the day as well. To not waste valuable time the charging time has to be low, thus the needed charging power provided will be in the 100s of kW.
Assuming all charging will be done from the logistics terminal, the terminal will need to be able to provide both slow charge (in the 10s of kW) and fast charge (in the 100s of kW). A desired system would be a flexible system which provides charging in different power levels at different charging spots, matching the charging power needed of each individual truck charging at any given time. Instead of providing the maximum number of charging power at each charging spot a modular charger with a switch system would provide the terminal with such a flexible system.
Finally, considering a logistics terminals limited available area, a conventional approach with charging poles and cables is undesirable. As the poles and cables create an unnecessary com- plex environment to navigate and run the risk of being damaged, the modular system which this project discusses uses Elonroads electric road system, an electric road rail on the ground.
This project is thus composed to investigate a modular charger with a switch system us- ing Elonroads technology and to provide a small scale prototype proving the concept as a solution.
Supervisors: Mats Alaküla (IEA), Kim Malmberg Svedmark (Elonroad)
Examiner: Olof Samuelsson (IEA)
Tuesday 14/6 kl 10:30, KC M:IEA
Master's thesis presentation:
ERS on Öresundsbron
Electric Road Systems is a promising technology to reduce the cost of electric road transport. Öresundsbron has a traffic flow that is much higher than what is needed for ERS to brake even compared to the use of a system of static fast chargers. In particular, the traffic that commutes daily, sometimes several time daily, is of interest since it would benefit from ERS on parts of the Öresund bridge, the island and the tunnel that connects Sweden and Denmark.
The bridge has also electric power supply in several systems, supplied from both the Danish and Swedish side. Some of these supplies are used for the trains running the bridge, some for lighting and ventilation.
This MSc thesis project is intended to gather data and knowledge under what conditions and with what possible alterations of the power supply that an installation of ERS on (parts of) Öresundsbron could be profitable.
Supervisors: Bengt Hergart (Öresundsbron), Andreas Jälmarstål (Öresundsbron), Mats Alaküla (IEA), Per Löfberg (Innovation Skåne)
Måndag 13/6 kl 15:30, KC M:IEA
Master's thesis presentation
Congestion Management of EV Charging in Distribution Networks
The societal integration of electric vehicles (EVs) imposes several challenges on the
electrical grid, where congestion and overcurrents through related components are
of focus for this thesis. Active network management through control systems is one
flexible solution to this problem, and in the project Active Network Management
for All (ANM4L), a congestion management algorithm utilizing PI controllers has
been developed. It has the possibility to control the active power (P) of the network
by curtailing the charging power for the active EVs when overcurrents are detected.
The focus of this paper is to evaluate the effectiveness of the ANM algorithms performance
in achieving congestion management, by comparing with an uncontrolled
scheduling and a decentralized tariff-based scheduling. The purpose of the latter is to
investigate the potential for congestion management without aggregator involvement
and to minimize the charging costs for the EV owners by scheduling all charging to
low-cost hours. The test network was designed without consideration of extensive
EV charging, illustrating a present day network which might have been dimensioned
decades ago. The maximum number of actively allowed EV units in the network was
led by the ANM controlled scheduling at 53%, followed by the uncontrolled (37%)
and tariff-based (24%) scheduling. This illustrates the future network and societal
constraint in terms of EV integration. For the ANM implementation, two prioritization
schemes were implemented. In a 10-bus low voltage test network with 11
kW home-charging stations, the ANM algorithm proved to be efficient in alleviating
the network constraints whilst maintaining the EV owners energy demands when
owners with the highest instantaneus power consumption experienced the highest
curtailment. The tariff-based scheduling on its own proved to severely stressful on
the network due to simultaneous tariff activation, but was in combination with the
ANM algorithm able to alleviate network congestion. Total charging costs were reduced
by 36 percent, although 10 percent of EVs were not able to fulfill their charging
requirements, indicating difficulties in societal adaptation in contrast to monetary
lucrativeness in future implementations.
Supervisors: Olof Samuelsson and Martin Lundberg (IEA), Liang Du (Temple University)
Examiner: Jörgen Svensson, IEA
Måndag 13/6 kl 13:15, KC M:IEA
Master's thesis presentation
Automatic control of electronic push brake system on a bike trailer
According to the German Regulation on the approval of road vehicles, trailers for bicycles
in Germany have to be equipped with push brakes, if the total weight exceeds
40 kg. Hence, in this thesis, an investigation is done about the possibility to integrate
electronic push brakes on an existing trailer made by Thule. By applying a concept
developing process, this investigation aims to build a full-scale mock-up, that can be
used as a proof of concept. The problem is divided into four sub-problems; brakes,
manipulation of brakes, sensors, and electronics. Concerning the brakes, the results
show that the pre-existing disc brakes on the trailer, which are provided to be used
for running, are strong enough to meet the legislation. Regarding the manipulation
of brakes, the final concept presented in this thesis is a lead screw-based concept
for transferring rotational- to translational motion. The concept uses stepper motors
for position control of the lead screw which allows for controlling the braking
torque. The results show that this concept enables the disc brakes to produce enough
torque to meet the legislation. Lastly, for the sensor model, an accelerometer was
considered. The idea was to sense a brake event based on the acceleration data and
the brake correspondingly on the trailer. However, even though the result indicates
that it is possible to sense break events, this approach introduced control problems
and the conclusion is that another sensor measuring force between the bicycle and
trailer is needed.
The work has been carried out at Thule, Hillerstorp.
Supervisors: Joakim Persson and Hannes Olaison, Thule, Gunnar Lindstedt, IEA
Assistant supervisor: Anders Robertsson, Reglerteknik LTH
Examiner: Mats Alaküla, IEA
Fredag 10/6 kl 10:30, KC M:IEA
Master's thesis presentation
Evaluation of Energy Harvesting from Door Closer and Solutions for Assisted Opening
A door closer is a device that closes a door in a controlled manner after
it has been opened. This can be beneficial for many reasons, for example
security purposes, to prevent energy waste and to live up to fire regulations.
This thesis project focuses on the possibilities of using a door closer that has
replaced the hydraulic braking typically used in these devices with an electric
generator. The goal is to have the door closer power added functionality
without connecting the door to an external power source. More specifically,
this thesis has studied the possibility of harvesting energy from the movements
of a swing door to power assisted opening. Unlike an automated door, an
assisted opening would only supply some helping opening force to weaker
The main goal of this thesis was to study and test the energy efficiency of
the electromechanical door closer. This was done through a series of tests on
three different prototypes. By measuring the energy in different parts of the
system, as well as the energy required to open the door, the energy efficiency
of the system could be determined. Furthermore, a comparison between the
results from energy harvesting tests and the results from the assisted opening
tests was made. Another objective was to test and analyze the possibilities
of energy harvesting during opening. After testing and analyzing the data,
a use case was made for the assisted opening, including when and how much
the door should assists and how the door should identify a user with the need
It was concluded that a similar amount of energy could be harvested from
all prototypes but at differing closing times. Furthermore, it was determined
that powering one automatic opening required many more manual openings.
It was demonstrated that while assisted opening required less energy, it was
necessary for the system to be able to differentiate between users in need of
assistance and average.
Based on the results, a solution for how the assisted opening should be implemented
was suggested. The solution was evaluated in an user experience
test. It was found that while the assistance was appreciated, one common
criticism was that it was too difficult to trigger the assisted opening. While it
would be optimal from a user experience perspective to have the door closer
assist every time, this is not possible energy-wise with the current system.
Based on the findings of this thesis, proposals for future studies and improvements
Supervisors: Sara Roos and Martin Englund at the company, Gunnar Lindstedt, IEA
Examiner: Ulf Jeppsson IEA
Onsdag 8/6 kl 10:30, KC M:IEA
Master's thesis presentation
Enhancement and Verification of Motion Profile Design Tool
Robots and other machines utilised in industries are using servo motors that need precise, well
defined and controlled motions. Often are these motions to move to a precise point with a exact
velocity. Motion profiles provides the physical motion information for such a precise motion as well
as the graphical interpretation on how it would move in terms of position, velocity and acceleration.
The motion profile is used by the servo controller to determine which power level should be used
to drive the motor.
This Master Thesis aim to improve an existing tool for calculating motion profiles for servo motors
used in the manufacturing industry by implementing features to calculate more advanced motion
profiles. These new features include motion profile with non-zero jerk in the beginning and end
points, motion profiles focusing on velocity changes and motion profiles where the focus is on
position changes. The final step in this Master Thesis project is to show the strength of designing
motion profiles using this tool by comparing it to a motion profile created using Beckhoff motion
profile designer run on a setup resembling a real application.
All the goals of the Master Thesis were achieved. The new features were motion profiles with the
option of non-zero jerk in the beginning and at the end of the acceleration and deceleration motion,
motion profiles with predefined initial velocity, initial position and end velocity as well as a motion
profiles with a predefined initial velocity, initial position and end position. The comparison with a
motion profile from Beckhoff showed that with our tool a smaller servo motor could drive a bigger
load faster and still be within its limits.
The work has been carried out at Tetra Pak AB, Lund.
Supervisors: Tobbe Bengtsson, Tetra Pak, Gunnar Lindstedt, IEA
Examiner: Ulf Jeppsson IEA
(Presentation in Swedish)
Måndag 30/5 kl 10:30, KC M:IEA
Master's thesis presentation
General SCADA Application for Water and Wastewater Treatment
The average swede uses 140 liters of water every day. This combined with the usage in industry
means that Swedish municipal water treatment plants produce approximately 900 billion
liters of clean and safe drinking water every year. This does not include the fact that all water
flowing to a treatment plant needs to be treated before being sent back out in to the environment.
These facts hint at what a huge scale these processes operate at. Furthermore this needs
to happen every hour of every day, 365 days a year. So how can these processes be monitored
to ensure that everything works as intended and any problems are found and resolved as quickly
as possible? With the help of a Supervisory Control And Data Acquisition (SCADA). In simple
terms a SCADA is a way to supervise and manage a process.
Kentima is a Swedish company located in Staffanstorp, Skåne, Sweden. They specialise in developing
and selling products for the automation and security sector. One of the software sold
by Kentima is WideQuick. WideQuick is a software suite which enables the creation of Human
Machine Interfaces (HMI) and SCADA solutions. It is on the behalf of Kentima that this thesis
was started as they want to expand their services with a specialised SCADA for the water and
The scope of this thesis is to lay the foundation for a general SCADA solution that can quickly
and easily be adapted to function with any water and wastewater facility. The requirements
for the functionality of this were generated through academic research. This was complemented
with interviews from customers active in the field of water and wastewater with varying responsibilities,
such as system integrators. The combination of the latest academic research with the
knowledge from people in the industry was thought to give the best possible application. This is
because it would give a good balance between the best practices from the academic world along
with the practices that are actually used in the industry.
As mentioned earlier the thesis lays the foundation of project. This includes a navigation bar
to navigate between different processes. An object library to represent different objects in the
process. As well as object control, analysis and overview. The thesis will explain how this was
achieved and the reasoning behind the choices made. After the application was build it was then
demonstrated to both the company and the customers. This was to get their input and feedback
on what looks good, what needs to changed and to inspire things to be developed in the future.
The final part of the thesis will primarily discuss the feedback from the customers. It will also
lay out suggestions on things to be developed in the future to complement the project into a
complete SCADA application for the water and wastewater industry.
The work has been carried out at Kentima AB, Staffanstorp.
Supervisors: Mattias Nilsson, Kentima, Gunnar Lindstedt, IEA
Examiner: Ulf Jeppsson IEA
Monday 30/5 kl 9:00-10:00, KC4 IEA seminar room at level +2 (also on Teams)
Master's thesis presentation
"Heavy truck electrification - How will it affect the electrical grid?"
Kristin Bobeck (W) and Lisa Salvin (W)
The transport sector is facing major challenges to reduce the greenhouse gas emissions. The electrification of the freight fleet, which is an important step towards emission reduction, will result in capacity challenges in the grid. The aim of this thesis is to evaluate how the existing grid is affected by the electrification of heavy trucks and what solutions or reinforcements needs to be implemented to enable this. A case study is performed on two different logistics centres in Skåne. Charging profiles with different charging techniques are created in Matlab based on interviews with the logistics centres.
Simple charging resulted in a power peak of 39.0 MW and 10.0 MW for the respective fleets in the case of a total electrification. Planned charging resulted in power peaks of 13.2 MW and 3.0 MW, respectively. Aggregated with the existing baseload the created charging profiles are simulated on grid models in PowerFactory to observe overloading in components. The existing grid allows only 4 % respectively 7 % electrification. Different solutions to allow further electrification are evaluated and batteries is considered to be the most suitable option. This thesis concludes that planned charging reduces the load with 70 % compared to simple charging and that truck charging increases the load on the grid considerably compared to the baseload. Batteries are evaluated based on dimensioned size and cost and are considered to be a viable solution to alleviate the grid until grid reinforcement is possible. As the electrification of the society proceeds, it is important to evaluate the prerequisites of the existing grid. Implementations of further solutions such as flexibility, energy production and energy efficient vehicles are necessary to maintain a sustainable electrical network.
Supervisors: Olof Samuelsson (IEA), Alice Jansson (IEA), Håkan Skarrie (Kraftringen), Andreas Vikström (Kraftringen)
Examiner: Mats Alaküla (IEA)
Wednesday 23/2, kl 10:15, KC M:IEA and Zoom (see below)
"Solar Energy Harvesting for Outdoor Applications"
The use of solar cells as a solution for different energy harvesting applications has seen a significant growth during the last few years. With the recent advances in the power conversion efficiency and manufacturability of organic photovoltaic cells these systems can be made even cheaper and more available for consumers, opening up new ways for solar technology to be implemented into products. This report investigates how an energy harvesting system suitable for low power applications can be constructed with the use of an organic photovoltaic cell as the energy harvesting source. It also explains how this energy is sampled via a regulatory IC chip and how this all is connected via a PCB. All components were carefully evaluated, tested and assembled to form a final energy harvesting system. The report also resulted in a simulation tool that can simulate the performance of the energy harvesting system as implemented in a specific battery charging application. From these simulations it is concluded that the system is very dependent on the OPV azimuth angle. It performs well in south facing harvesting, allowing for a substantial battery charging potential, but struggles to provide charging power for a north facing OPV. However, depending on the magnitude of draining current of the battery, a north facing OPV can still provide enough charging current to be considered feasible for implementation. The report concludes that from a performance point of view, an OPV based energy harvesting system can extract enough energy to provide real value for potential future Verisure products.
The work has been carried out at Verisure AB, Malmö.
Supervisors: Nick Hackett (Verisure), Gunnar Lindstedt (IEA)
Examiner: Ulf Jeppsson (IEA)
LU Zoom meeting: https://lu-se.zoom.us/j/64583772754
Meeting ID: 645 8377 2754 (Waiting room enabled)
Thursday 17/2 kl 10:30, KC M:IEA and Zoom (see below)
"Integrated DC fast charger in an electric vehicle"
Axel von Keyserlingk
More and more electric vehicles are emerging with a nominal battery voltage higher than what most older DC fast chargers are capable of charging. This requires the vehicle manufacturers to include a high power DC to DC converter in order to be able to charge at these stations, adding cost and complexity. Instead, with only minor modifications of the traction system, the motor and inverter can be used as three parallel DC to DC converters, removing the need for an extra converter. The aim is to develop, assemble and test a low voltage system that can run at about the same current level as existing charging stations. Its performance is assessed and the measured efficiency is compared to a theoretically derived one. The results are then extrapolated to a higher voltage in order to investigate its feasibility. The system is proven to work satisfactorily at the low voltage, although with quite poor efficiency of about 80% at around 5kW charging. When increasing the voltage the efficiency seems promising.
Supervisors: Mats Alaküla (IEA), Gabriel Domingues (BorgWarner)
Examiner: Francisco Marquez (IEA)
LU Zoom meeting: https://lu-se.zoom.us/j/66694226249
Meeting ID: 666 9422 6249
Tisdag 9/2 kl 15:00, on Zoom (see below) and in KC M:IEA, Presentation av examensarbete.
"Smart charging and ancillary services in the Malmö region"
To meet Sweden's national environmental goal of 70% emissions reduction by 2030 compared to 2010 from domestic transport, electrification is considered key. However, as more chargeable vehicles are integrated into the market, shortage of capacity for charging infrastructure may arise. To remedy this, flexibility within charging infrastructure is proposed. The aim for this thesis is to estimate the progress of electrification in Sweden, as well as evaluate the potential and need for different types of flexibility concerning electric vehicle charging. A MATLAB model for a future scenario for electrification of transport is developed to assess the future need and potential for various strategies of smart charging solutions. Results indicate that a 90% reduction in peak power consumption, compared to the base case, may be obtained using solutions such as scheduling and signals from flexibility markets. Also as part of the thesis, a smart charging demonstration project performed by E.ON and Parkering Malmö is evaluated in terms of delivered power reduction and ease of operation. Assessment shows that reduction in power did take place, with varying effect. Influenced by the number of charging sessions meeting conditions for participation, relative reduction varies between 14% and 82%. The manual nature of the evaluation performed in this thesis might not be desirable for future development of the project and may induce some inaccuracy. A more automatic method using the VPP control software is proposed, but may require further studies for verification.
Handledare: Mats Alaküla (IEA), Alice Jansson (IEA), Peder Berne (E.ON Energiinfrastruktur)
Examinator: Olof Samuelsson (IEA)
LU Zoom meeting: https://lu-se.zoom.us/j/69260625569
Friday February 4, Lecture hall KC:A, Chemical Engineering building (Kemicentrum), Sölvegatan 39, Lund
Licentiate Thesis Seminar:
"Modeling of electric power systems in electric vehicles"
The market for partly or fully electrified vehicles is expanding fast. The number of sources and loads that are connected to the vehicles traction voltage systems (TVS) increase and thus also the ElectroMagnetic Compatibility (EMC) requirements on these sources and loads. These requirements should make sure that neither function nor lifetime of any source or load is severely affected by another. The EMC requirements include both Common Mode (CM) and Differential Mode (DM) voltages and currents created by the modulation of the various power electronic converters involved as well as intentional and parasitic impedances of the TVS and reach up to at least 10MHz for CM and 100kHz for DM. This paper presents a theory for the dimensioning of CM-capacitances in an Electric Machine Drive (EMD) that is confirmed by measurements on a commercial electrical Volvo truck. The conclusions point out a recommendation for selection of the CM-capacitances of the EMD vs. the CM capacitance of the Electrical traction Machine (EM). As a rule of thumb the recommendation is that the CM-capacitance of the EMD is around 50 times the CM-capacitance of the EM and mounted inside the EMD to avoid big loops of CM currents in the vehicle.
Prof. Mats Alaküla (Lund University, Lund, Sweden)
Prof. em. Hans Bangtsson (Lund University, Lund, Sweden)
Dr. Urban Lundgren (RISE - Research Institute of Sweden)
Prof. Olof Samuelsson (Lund University, Lund, Sweden)
Past seminars at IEA in previous years