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Descriptions
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BEng, BSc and MSc projects within Electrical Systems at Vattenfall
BEng, BSc & MSc projects
To the department Electrical Systems within Vattenfall Technology we are looking for students who are interested in performing thesis (diploma, BSc or MSc projects). You will join a team of competence on electrical components and systems for thermal power plants and wind farms. During your project period you can work at one of our locations in Odense, Copenhagen or Aalborg.
>> Full description
Deadline:
Regarding the planning Vattenfallneed your application the 5th of January 2012 for performing project stay in the 2012 spring semester.
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CET contact: Esben Larsen |
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Development of Experimental Test Bench for Evaluating Control Algorithms for VSC 3 weeks course (can be extended to a MSc project)
Project Scope: The objective of the project is to develop an experimental test bench for evaluating different control algorithms for VSC. The diagram of the proposed experimental test bench is shown in the figure below.
Fig. 1 Diagram of the proposed test bench
Tasks:
• Understanding of the DSP controller, interface board, Danfoss VSC
• Basic DSP programming
• Communication between DSP and VSC via the in-house interface board
>> Full description
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Contact: Qiuwei Wu & Ranjan Sharma |
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Dynamic equivalent distribution model for analysis of elec-tric energy systems with large penetration of wind power MSc project
Description: The objective of the project is to develop a dynamic equivalent model, which can be freely distributed among interested parties. The model should not include confidential data from the real system, but still reflect key properties of the Bornholm system, e.g. response to system events etc. Furthermore it could be examined to which extend the Bornholm system (and the established generic model) represents other real distribution systems.
>> Full description
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Contact: Rodrigo Garcia, Guang-Ya Yang & Jacob Østergaard |
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Comparing Thermal Modelling and Measurements with Thermography for a 15kVA Synchronous Machine MSc project
Description: In this project a 15kVA synchronous machine will be modelled thermally using analytical methods and finite element analysis. The results from the thermal model will be compared to experimental measurements using thermo-couplings. The results of these will also be compared to thermography using a thermal imaging camera.
>> Full description
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Contact: Bogi Bech Jensen |
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Design, Construction and Testing of a Small-Scale Synchronous Generator MSc project
Description: The student will design, build and test a synchronous generator for use in the small-scale steam turbine setup, which is used for teaching in electrical engineering. This project combines theoretical design and analysis with practical building and testing.
>> Full description
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Contact: Bogi Bech Jensen |
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Implementation of a test setup based on voltage source converter for grid interaction studies MSc project
Description: The project student will setup a VSC to be directly plugged-in to the power amplifier. The control of the VSC (for e.g. a control representing a full scale wind turbine) will be imple-mented in Matlab and communicated to the VSC via dSPACE. The dSPACE real-time control environment allows easy prototyping of controllers within the SIMULINK environ-ment and downloading of these controllers to dedicated Digital Signal Processor (DSP) based systems for implementation.
>> Full description
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Contacts: Qiuwei Wu, Ranjan Sharma & Seung Tae Cha |
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Dynamic Modelling of Diesel Generators in the Bornholm Power System
BSc project
Description: The project is intended to develop the dynamic model for the diesel generators in the Bornholm power system. The modelling work will be comprised of modelling diesel engine, speed controller and automatic voltage regulator (AVR) for the diesel generators. Full description
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Contacts: Germán Claudio Tarnowski , Qiuwei Wu & Seung Tae Cha |
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Comparison of FRA measurements in different transformers to measure the series resistance variation of the transformer from 10Hz to 3kHz MSc project
Description: Several measurements have been performed in 11 wind turbine and park transformers for offshore wind farm applications. The recommended nine end-to-end measurements for monitoring purposes from each transformer should be compared against each other to find trends of resonant frequencies ranges and shapes. Recent work has been done on FRA monitoring and automatic assessment of transformers, as well as in-depth analysis of FRA measurements for modelling purposes.
Full description
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Contacts: Joachim Holbøll, Andrzej Holdyk & Iván Arana |
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Analysis of FRA measurements on cable and implementation of models for high frequency studies MSc project
Description: Several FRA measurements have been performed in laid and drummed submarine cables for offshore wind farm applicatios. The measurements from each cable should be compared against each other to find trends of resonant frequencies ranges and shape. Recent work has been done on FRA measurements on cables as well as modelling based on these measurements. Full description
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Contacts: Joachim Holbøll, Andrzej Holdyk & Iván Arana |
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Comparison of recommended FRA measurements in different type, rating and size transformers MSc project
Description: Several FRA measurements have been performed in laid and drummed submarine cables for offshore wind farm applicatios. The measurements from each cable should be compared against each other to find trends of resonant frequencies ranges and shape. Recent work has been done on FRA measurements on cables as well as modelling based on these measurements. Full description
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Contacts: Joachim Holbøll, Andrzej Holdyk & Iván Arana |
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Study of scenario reduction technique for microgrid applications MSc project
Description: The increasing penetration of distributed resources in power system brings theoretical as well as practical problems to the power engineers worldwide. These generations, such as micro-turbines, wind turbines, photovoltaic, fuel-cells, are interconnected to the distribution system via point of common coupling (PCC) for power delivery. The variability and intermittency of renewable generations brings out challenges to secure the power and energy balances both in short term and long term. Microgrid is proposed as a means to integrate the distributed resources as a whole for both power and heat supply. Looking from the grid side, Microgrid is acting as a controllable load where the behavior is regulated and predictive, while within the microgrid, control strategies are required to synergise both the energy resources and the demand-side. The study of stochastic nature of renewable resources and demands is necessary to enhance the Microgrid operation and control.
The stochastic behavior of renewable resources is normally represented by statistical scenarios. However, due to the volatility of the output from renewable resources as well as electricity, heat and cooling demand, huge number of scenarios can be derived based on the combined information from forecasting and historical data. It is computationally very expensive to study all the possible scenarios for microgrid operation. Therefore, it is ideal to have certain techniques which can reduce the scenarios to a limited number while not losing the generalization of the solution. Theoretically, the reduction method requires the considerations both on scenarios aggregation via evaluating a certain mathematical distance, and the probability of occurrence. This project aims to study the possibilities of using optimisation techniques to aid scenario reduction and provide a set of scenarios can be further used for microgrid operation studies
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Contacts: Guang-Ya Yang & Jacob Østergaard |
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Converter Filter Design – Accounting for Incremental Permeability of the Inductor Core MSc project
Description: When converters for high power applications are designed output filters have to be used to limit the harmonic currents acceptable level. These levels are described in standards called grid codes. Filters for high voltages and high currents are made of power components containing parasitic components that influence the filter characteristic. In addition the permeability of the inductor core, which is of importance to the filter characteristic, depends on the frequency and magnitude of the current.
Full description
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Contacts: Tonny W. Rasmussen & Bogi Bech Jensen |
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System Identification for Determining Modal Characteristics of the Power System MSc project
Description: Normally, small-signal stability analysis is conducted using tools from linear system analysis and the basic assumption is hence that the power system with sufficient accuracy can be represented by its linearized equivalent. Provided that this assumption is not violated, linear analysis offers powerful tools to reveal important properties of the system dynamics. If the linear approximation is not sufficiently accurate the linear analysis can neglect to reveal im-portant dominant behavior in the system. Hence, the results should always be closely evalu-ated and compared with responses from the non-linear system to ensure that the system can in fact be considered linear. Full description
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Contact: Thyge Knüppel |
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Measurement of transfer function for a power IGBT Special Course 10 point
Description: When IGBT is stacked in order to increase the blocking voltage the switching can be controlled in an analogue manner. To design such an analogue active gate driver information of the transfer function is needed. As this is not given in the datasheet a measurement has to be made. A laboratory test bench has to be made for the measurement. Full description
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Contact: Tonny W. Rasmussen |
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Developing and investigation of a diode clamped three level inverter-leg with passive Undeland snubber MSc project
Description: When converters for high power has to be designed each IGBT has a voltage limit of U = 6.5kV as maximum. Higher voltages are needed, so a series connection of several IGBTs is needed. This can be done with a diode clamped three level inverter leg. The principle is known from GTO inverters. Full description
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Contact: Tonny W. Rasmussen |
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Laboratory investigation of PWM and hysteresis control of a synchronous generator with a boost converter MSc project
Description: When the power level of wind turbine increases synchronous generators will be used. The variably speed is still needed and a simple converter for speed control and rectifying should be used. In the project a passive rectifier and a boost converter are given. Two possibly modulation strategies has to be investigated, PWM modulation and hysteresis modulation has to be compared.
Full description
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Contact: Tonny W. Rasmussen |
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Developing of active hybrid gate driver for series connecting of power IGBTs MSc project
Description: When converters for high power has to be designed each IGBT has a voltage limit of U = 6.5kV as maximum. Higher voltages are needed, so a series connection of several IGBTs is needed. This connection raises the problem that the IGBTs have to share the voltage among them. This sheering of voltage is needed in both the stationary situation when the converter is not switching and in dynamic case when the IGBT switch between on and off state. Previous projects led to a possible solution. Full description
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Contact: Tonny W. Rasmussen |
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Laboratory investigation of a MMC, (Modular Multilevel Converter), and the need of current limiting inductance and filter topology MSc project
Description: When converters for high power has to be designed each IGBT has a voltage limit of U = 6.5kV as maximum. Higher voltages are needed for the converter and a solution is to use a MMC converter. See the figure below. Due to small nonsymmetrical voltage in the module peak, current appear to recharge the modules.
How precise can the module voltages be controlled and how large must the reactor be? The multi level techniques create a voltage with a nice shape, how small and simple can the filter be? Full description
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Contact: Tonny W. Rasmussen |
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Investigation and design of passive and active snubber circuit for inverter leg with power IGBTs MSc project
Description: When inverter legs are switching state, switching loss appears with voltage across the IGBT and current in the IGBT at the same time. Passive snubber circuits have been developed in the past. Here the loss is moved from the IGBT to a snubber resistor. In active snubber circuits the resistor is replaced with an active part that move the loss back to the DC side. Different solutions have different loss and an investigation is needed. This has to be compared with a circuit without snubbers.
Full description
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Contact: Tonny W. Rasmussen |
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Investigation and design of active snubber circuit for inverter leg with power IGBTs MSc project
Description: When inverter legs are switching state, switching loss appears with voltage across the IGBT and current in the IGBT at the same time. Passive snubber circuits have been developed in the past. Here the loss is moved from the IGBT to a snubber resistor. In active snubber circuits the resistor is replaced with an active part that move the loss back to the DC side. The free wheeling diode in the active circuit is used in an unusual way, which gives the subject for investigation in this project.
Full description
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Contact: Tonny W. Rasmussen |
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Modeling & Analysis of Grid-Connected Wind Turbine MSc project
Background: Installed wind generation capacity in Bornholm island has now exceeded 30 MW, with another 20 MW estimated to be installed in near future. Further, within the next 16 years the Danish government is likely to enact a national renewable portfolio, which will result in significantly more wind generation capacity development in coming years and penetration levels that will exceed 50%.
Wind power generation is vital to Danish national energy policy, and system operators must be able to accommodate variable generation while maintaining system reliability. Such variable nature of the underlying wind resource does pose new problems for electric power system operators and sets new challenges for the control of power systems.
It is therefore necessary to know the consequences of dynamic interaction between wind turbine and power systems. This project should discuss the dynamic wind turbine models for power system stability studies. It should focuses on the modelling issues concerning the turbine interaction with the power system, i.e. what phenomena of a turbine/farm need to be modelled and in what degree of accuracy e.g. in case of studying grid contingencies. Full description
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Contact: Jacob Østergaard |
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Sweep frequency response measurements and analysis in medium voltage cables in laboratory and field conditions Special Course 30 point
Description: The objective of this project is to measure two different kinds of MV cables with dedicated SFRA equipment, FRAX-101 in lab and field conditions. First a single phase cable will be measured at DTU, then a spare three phase cable will be measure in a warehouse of DONG Energy and then the measurements will be done in Nysted, an offshore wind farm in the south of Denmark.
Finally the results will be analysed and a RLC model will be created using Matrix Fitting Toolbox, from The Vector Fitting Web Site. Full description
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Contacts: Joachim Holbøll & Iván Arana Aristi |
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Algorithme for electric vehicle charging BSc/MSc project
Description: With their battery capacity, electric vehicles can play an important role in future integration of more renewable energy sources in the electric power system. If the charging is controlled in relation with the immediate energy balance of the system, problems like electricity overflow can be avoided.
One way of doing this is by charging the batteries when there is plenty of energy, and otherwise disconnect the charger; or even let energy flow from the battery back into the system when there is an energy deficit. The price of electricity can be used to signal this to the vehicle, and previous projects in this field have shown a great potential for this control method.
In this project, the aim is to design an algorithm that can make the decision in or near the vehicle to charge, disconnect, or discharge the battery into the system. In its most simple form, the decision can simply to be to charge when the price is below a certain threshold and otherwise not. However, other parameters must be taken into account to achieve an optimal result, such as the user’s requirements for the state of charge at a certain time, the expected development of the electricity price, and physical limitations like maximum charging current, and present and maximum battery capacity.
The following subtasks are outlined for the project:
• Analysis of the overall setup, i.e. price-based control of
electricity demand
• Analysis of functional requirements and boundary
conditions for the algorithm. Mathematical expression of
the optimization problem
• Design of different algorithms
• Simulation of algorithm performance, using realistic
market data
• Implementation on a microcontroller platform. Test
using realistic market data
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| Contact: Jacob Østergård |
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Assessment of frequency measurement techniques to be used in future intelligent energy systems MSc project
Description: The term Intelligent Energy Systems (IES) is used about the vision of a future energy system that incorporates a large share of renewable energy sources into a highly automated, flexible and reliable system.
An example of IES technology is a household appliance that reacts intelligently to varying system conditions, which can be determined by measuring the AC frequency of the system. Depending on the specific application, the frequency measurement must meet different requirements, and in this project, it is investigated how different algorithms meet these requirements. In addition, the algorithms are implemented and tested on a microcontroller platform to evaluate the performance.
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| Contact: Phil Douglass |
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Vacuum breaker modelling for time domain simulations in PSCAD
Special Course 10-15 point
Description: The objective of this project is to develop a generic model of a three phase vacuum circuit breaker for electromagnetic transient simulation in PSCAD.
This project is in cooperation with DONG Energy; hence a contact person from DONG will participate in meetings and assist with suggestions and data throughout the project. Full description
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Contacts: Joachim Holbøll & Iván Arana Aristi |
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Resonances in breaker-transformer-cable systems Special Course 10-15 point
Description: The objective of this project is to simulate resonances in a breaker-transformer-cable systems by means of state of the art models in PSCAD.
The breaker model will be developed by the parallel project “Vacuum breaker modelling for time domain simulations in PSCAD”.
The transformer model will be created, based on variable frequency measurements and an available code developed by SINTEF to create a synthesized electrical network using the vector fitting technique.
The cable model will be created based on the geometrical and electrical properties of the cable, using the “Frequency dependant (phase) model”.
This project is in cooperation with DONG Energy; hence a contact person from DONG will participate in meetings and assist with suggestions and data throughout the project. Full description
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Contacts: Joachim Holbøll & Iván Arana Aristi |
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Protection systems modelling in PSCAD Special course 10-15 point
Description: The objective of this project is to implement a protection system in PSCAD. Here different models of current transformers, voltage transformer, faults, relays and tripping signals are expected to be used.
The current and voltage transformer models will be developed by the parallel project “Inductive instrument transformers modelling in PSCAD”.
Several fault and relay models are available in PSCAD, however if necessary logical gates can be used to create desired protection systems and control algorithms.
This project is in cooperation with DONG Energy; hence a contact person from DONG will participate in meetings and assist with suggestions and data throughout the project. Full description
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Contacts: Joachim Holbøll & Iván Arana Aristi |
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Modelling of switching transients in Nysted Offshore Wind Farm
BSc/MSc project
Background & Objective: In 2007 field measurements were done in Nysted Offshore Wind Farm, where three GPS synchronized measuring systems were built and used for simultaneous measurements at three different locations in the wind farm.
Several switching events were realized and recorded, but some of the data has not benne analyzed yet.
The student is expected to analyze some of the information regarding one/several switching events, where the radial circuit breaker was opened to de-energize a radial of wind turnines under production.
The important phenomenon to analyze is the disconnection of a radial with several operating wind turbines, and create a model of a fixed- speed wind turbine (incl. capacitor bank) with fault-right-through capabilities, in a simulation tool to reproduce the measurements and compare discrepancies. Full description
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| Contact: Iván Arana Aristi |
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Inductive instrument transformers modelling in PSCAD
Special Course 10-15 point
Description: The objective of this project is to simulate current transformers and voltage transformers in PSCAD.
The current and voltage transformer will be modelled using standard models in PSCAD like JA or Lucas, with the available information from a real protection system. The main idea here is to use limited real data from a commercial voltage and current transformer and verify the capabilities of the protection system regarding current, voltage and frequency limitations.
This project is in cooperation with DONG Energy; hence a contact person from DONG will participate in. Full description
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| Contacts: Joachim Holbøll & Iván Arana Aristi |
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Power feedback at oil rig BEng/BSc project
Description: The purpose of this project is to develop and analyze an electric system where braking energy from drawworks at an oil rig can be absorbed in the oil rig’s AC system instead of as today being dumped in resistors which include losses.
The power generation of an oil rig consists of a 6.6 kV network with 4 ea 2650 kW generating sets, diesel driven and running 900 RPM. The operation is performed with two to four generators connected to the switchboard, depending on the operation and the load.
Main power consumption is the Drawworks with 4 ea 862 kW AC motors each controlled by a 4 quadrant AC drive. The AC drives are supplied by DC (approx 930 V DC nominal) via 24 pulse diode bridges.
The braking power is obtained via a separate bridge connected to each AC drive and resistors connected to the DC bus. The Drawworks load and braking capabilities shall be safe with the operation of two to four generators connected. Full description
Industrial collaboration: Maersk Contractors, att. Ib Larsen
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| Contact: Tonny Wederberg Rasmussen |
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Generic distribution network model for analysis of electric energy systems with substantial wind power penetration BSc/MSc project
Background: Bornholm is a Danish island situated south of Sweden with more than 27,000 customers. The Bornholm distribution system has many of the characteristics known from other Danish distribution systems. With respect to area, load and population Bornholm corresponds to roughly 1% of Denmark. The peak load is 55 MW. The distribution system is connected to the 132 kV grid via a 63 MVA offshore cable. The installed wind power is 30 MW and in 2007 the wind power covered 30% of the load, which is above the Denmark average wind power penetration. The Bornholm distribution system is used in several student and research projects at CET.
Full description
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Contacts: Jacob Østergaard & John Eli Nielsen |
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Analysis of Wind Power Expansion in a Distribution Grid MSc project
Background: Bornholm is a Danish island situated south of Sweden with more than 27,000 customers. The Bornholm distribution system has many of the characteristics known from other Danish distribution systems. With respect to area, load and population Bornholm corresponds to roughly 1% of Denmark. The peak load is 55 MW. The distribution system is connected to the 132 kV grid via a 63 MVA offshore cable. The installed wind power is 30 MW and in 2007 the wind power covered 30% of the load, which is above the Denmark average wind power penetration. Full desription
Industrial collaboration: Østkraft A/S
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Contacts: Jacob Østergaard & John Eli Nielsen |
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Visualization of power system state information Bsc project
The objective of the project is to design and develop software for visualization of streaming measurement data from the power system.
The streaming data comes from Phasor Measurement Units (PMU), which measure frequency, voltage and currents with accurate time stamping of each measurement, which makes real-time comparison of data from separate PMU’s possible. This data can be used to assess the state of the power system and various forms of visualizations of the data can simplify this assessment. For extended use of the streaming data an alarm system could be implemented, so that when a measurement exceeds a defined range, the event would be registered and the alarm visualized on a monitor. The visualization software would be useful in control rooms to detect and prevent events that could lead to faults, such as blackouts. Full description
Company collaboration: Energinet.dk
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Contacts: Friđrik Rafn Ísleifsson & Jacob Østergaard |
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Using Artificial Intelligence Techniques to Automate Electric Power Systems Restoration Bsc project
The objective of this project is to design and implement an electric power fault detection and restoration system using artificial intelligence techniques in particular software agents.
Software Agents is an advanced technology which combines capabilities of artificial intelligence (e.g. reasoning, learning and optimization), distributed computing (e.g. modularity, reliability, no single point of failure) and communication (e.g. high level dialogue based conversation). Software systems implemented using this technology consists of independent components (agents) which can communicate and cooperate with each other to achieve goal of the system. These components are proactive and autonomous, which means they always keep sensing (taking inputs) from the out side world and atomically react to any relevant change in a purposeful manner.
Full description
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Contact: Jacob Østergaard |
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Identification and Classification of events in electric power systems
PMU related project (PMU = Phasor Measurement unit) Msc project
Description: Electric Power systems are highly non-linear systems that operate in constantly changing environment where loads, generator output and other key operating parameters change continually. The changes in the load or generator output are most of the time of small scale, but there occur though occasionally changes that are of larger scale. Such large scale changes could for example be caused by a loss of transmission line, loss of a consumption area or a loss of production unit.
When such severe disturbance/event occurs in electric power system, the system response following the disturbance could contain information about the system characteristics and system parameters such as the inertia constant, short circuit capacity and etc. It is therefore of interest to identify those large scale events in PMU measurement data so the system responses can be used in offline analysis of the system behavior.
The objective of this project is to identify large disturbances/events in the available PMU data at Centre for Electric Technology (CET). In order to fulfill this objective the students must go through the following:
1. Analyze how the occurrence of specific events appears in a PMU data set.
2. Develop/select an appropriate method for detection of those events.
3. Test the method by implementing it into search algorithm that analyses the
available measurements.
Full description
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Contact: Hjörtur Jóhannsson |
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Control and Monitor Design for Power Balance during System Islanding Operation BSc project
Description: You are supposed to design a controller which can coordinate loads and generators inside a small power system, in order to balance the power after being islanded from grid according to your control strategy; meanwhile, you are required to design a monitor panel which can visualize or record the islanding process by displaying critical parameters.
Further information: Full description • EU More MicroGrids
Cooperation with: Østkraft
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Contact: Jacob Østergaard |
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Optimal Planning of High Voltage Distribution Network - a practical case study BSc project
Description: This project aims at developing an optimal expansion plan for a practical high voltage distribu-tion network in Denmark, based on the outcome of previous research.
The distribution network operated by Dong Energy is diversified in voltages levels and network topologies due to historic reasons. A research have found out that using selected, limited volt-age levels and topologies, optimal expansion plan in terms of construction costs, transmission losses and etc for the distribution network in general can be achieved through comparison studies. In this project, the expansion plan for a specific distribution network is to be studied. The conclusion from the previous research is to be used and validated in this project. Strong indus-trial support is available for this project. Full description
Background and Reference: Optimal Design of High-level Distribution grid
Industrial Partner: Dong Energy S&D
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Contact: Jacob Østergaard |
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Power generation system for grid isolated operation MSc project
Description: The high availability of power supply will be achieved as follows:
• Basic load (ERP) will be supplied from two wind turbines rated 850 kW;
• The energy storage system will act as a dump load during periods with high wind and the filter for transients caused by short time wind variations. Furthermore, the energy storage will, as the back-up source, also provide reactive power and stabilise voltage and frequency in the system. That means it will be possible to provide the 50Hz reference from the battery, and when desynchronising with the grid the system will do so seamlessly. This in effect allows black start operation. For maximum efficiency, the battery should operate around a set-point determined over time based upon wind velocities and of course operating modes/load following etc. (drop). The VRB can be sized to provide a 1 to 1 active power to VAR ratio. The reactive power consumption of each wind turbine will be limited by addition of capacitors. The system operation shall be based on charging the VRB to approx. 65% and allow it to swing around this level. This is the most optimal way to operate the battery storage. Possible excess of electric energy should be either used for extra production of hydrogen, or dumped;
• The operation of the wind turbines will be backed by a diesel generating set rated 350 kW, which will act as the power frequency regulator and back-up power supply during periods with wind energy based power generation less than ERP's immediate power demand (260 - 318 kW). The diesel generating set will also provide reactive power to the wind turbines and stabilise voltage in the system; Surplus electrical energy produced in the system shall be dumped, e.g. in an electrical boiler connected to the district heating system or an electrolyser producing hydrogen and oxygen.
PDF version
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Contact: Arne Hejde Nielsen |
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Optimised electric power and heat generation for local combined heating and power plant including solar heating system MSc project
Description: Brædstrup Totalenergianlæg A/S is a local combined heating and power plant which supplies the consumers of the town Brædstrup with heat and delivers electric power to the public power network. As a supplement to the natural gas-based heat production Brædstrup Totalenergianlæg has initiated a large-scale solar heating system of 8,000 m2 solar heating. The plant which is expected to be put into operation in the middle of 2007 has been projected to produce approx 10% of the total heat generation – or approx 4,000 MWh per year.
The solar heating system adds new complexity to the optimisation of the plant’s operation, and the development of a systematic method to optimise the operation of the plant is therefore necessary. The challenge is to optimise the power and heat generation and not least the profit of electricity sale – now including the compulsory solar heating generation. The objective of the project is to develop a method for this optimisation. Full description
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Contact: Jacob Østergaard |
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Advanced modelling and simulation of frequency controlled loads BSc project
Description: This goal of the project is to model and investigate thermostatically controlled loads, such as water heaters, electric heating and fridges, with varying temperature set points (upper/lower lim-its). The model shall be developed and implemented in a numeric simulation tool and should take into account the complex dynamics of the aggregated load.
In electric power systems, there are hundreds and thousands of thermostatically controlled loads, which is turned on and off in cycles according to their temperature set points. The effect of dynamically varying temperature set points, e.g. controlled by the power system frequency, can enable such loads as a frequency controlled reserve to help maintain system frequency.
In order to identify and study the properties of such reserve in the power system, modelling of aggregated loads is needed.
The project will be part of a larger project with other students and industrial collaboration. The student can choose a variety of simulation software, such as MATLAB, Excel or DIgSILENT to carry out this project. More detailed information will be given by the supervisors upon the beginning of the project. Full description
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Contact: Jacob Østergaard |
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Probabilistic Load Flow Considering Intermittency of Wind Generation in System Planning MSc project
Description: Traditional deterministic method for power system planning and operation analysis is no longer adequate for today’s fast changing power industries. Uncertainties have appeared and are appearing in many aspects of power systems, such as time, location and amount of power transactions and new load and generation characteristics. Particularly, the intermittence of wind generation has added more uncertainness into power system operation and planning. Given these uncertainties, there is therefore a need to develop new methods to address various uncertainties in power system operation and planning.
This project aims at developing a Probabilistic Load Flow program for power system planning and operation analyses, with special focus of modelling the intermittency of wind generation. Probability models of generation units as well as wind turbines will be built. Wind and electricity load data will be obtained from practical system for the project use. A Monte Carlo simulation based probabilistic load flow program will be developed for planning analyses.
For more details, please check the project description. Industrial partners will be sought for this project. Full description
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Contact: Jacob Østergaard |
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Investigation of aggregating frequency responsive loads in power system dynamic simulation MSc project
Description: This project is part of a major research project “Demand as Frequency Controlled Reserve” in CET, which investigates using electricity demands to support grid frequency during system events. The aim of this student project is to develop frequency responsive load models using Power Factory for dynamic simulation studies. Tasks of this project include, use and identify Power Factory’s capabilities in building various frequency responsive load models such as, fridges and electric heaters; develop aggregated frequency responsive load models at transmission level; system simulation studies.
For more details, please check the project description. The project will be carried out in cooperation with Ea Energianalyse. Full description
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Contact: Jacob Østergaard |
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Automatic detection and classification of incidents in the electric power system MSc project
Description: The objective of the project is to develop methods for the detection of special incidents in the electric power system based on synchronised PMU measurements of voltage and current on various locations in the grid. The mathematical tools will primarily be the Wavelet transformation, but neural networks and the Fuzzy technique may also be relevant. The methods will be tested on a large number of PMU measurements collected from the Danish transmission network for more than a year. The project will be carried out in cooperation with IMM
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Contact: Niels K. Poulsen, IMM |
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Development of an object-orientated communication system for wind turbines
Description: The objective of the project is to implement a new flexible, scalable and object-orientated communication system for a 500 kW Nordtank wind turbine located at Risø. The communication system will be based on the future communication system in the electric power system, ie the IEC61850 family of standards. The project will focus on the communication requirements of the future electric power system including an investigation of whether the turbine will be able to deliver system services and actively contribute to the future grid structure with intentional island operation.
Expected cooperation partners: Energinet.dk and Risø DTU
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Contact: Bjarne Poulsen, IMM |
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Short circuit conditions for wind turbines with full-range converters
Description: Modern wind turbines are, to an increasing extent, equipped with a full-range converter between the generator and the electric power grid. This is a challenge to the short circuit properties, as the delivery of the short circuit effect is limited by the converter. Consequently, the short circuit level may be too low to detect short circuits in the electric power grid for certain. The objective of the project is to investigate how turbines with a full-range converter may react during a fault. Simulations of the short circuit conditions have to be carried out in windfarms with a collection grid and turbines in a distribution grid respectively. Dependent on the extent, the project may include an investigation of the needs for changes in international standards within the field.
The project will be carried out in cooperation with Energi E2 and Siemens Wind Power, and will include a short stay at Siemens Wind Power.
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Contact: Tonny Wederberg Rasmussen |
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Black start after blackout in a cell divided network
Description: The objective of the project is to develop and analyse a concept that, after a system breakdown, can disconnect a grid area from the rest of the system and re-energies the grid area via local resources to re-establish the supply. Subsequently, the local grid area should be able to synchronise with the rest of the system when it has been re-established or contribute to the restoration of the rest of the system.
In cooperation with: Energinet.dk
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Contacts: Jacob Østergaard & Kai Heussen |
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Application of PMU measurements for early-warning about system breakdowns
Description: Within the last few years, a measurement principle based on the so-called Phase Measurement Units (PMUs) has been developed enabling the measurement of phase variance between various points in the transmission grid. This opens up the prospects of early warning of a system breakdown and critical operations. This knowledge can be utilised to introduce fast, corrective measures to prevent system breakdowns. An example is a future cell division of the grid where an early warning is of crucial importance for a successful transition to autonomous cell operation (intentional island operation).
The objective of the project is to investigate the possibilities of utilising the PMUs for an early warning of system breakdowns. Analyses of data collected in the Danish transmission system by PMUs will be carried out to identify and warn about critical operation.
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Contact: Arne Hejde Nielsen |
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Last updated by 12.05.2012 Responsible:
Jacob Østergaard
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