KTH is the largest technical university in Sweden. Education and research cover a broad spectrum within natural sciences and engineering, as well as architecture, industrial engineering and management, urban planning, work science and environmental engineering. There are circa 12,000 full-year undergraduate students, 1,400 postgraduate students and 3,100 employees.
The School of Electrical Engineering conducts research and education on the highest international level in Electric Power Engineering, Fusion and Space Plasma Physics, Telecommunications, and Networks, Information and Control Systems (NICS).
The scientific and technical activities of the Division of Electric Power Systems cover development and application of methods for analysis, simulation, and control of electric and integrated energy systems. The research activities in this division are divided into three subject areas, namely, power system dynamics and control, electricity markets and production planning, and power system network planning.
Voltage Source Converters (VSC) can rapidly and independently control both active and reactive power. Furthermore, in a VSC-based Multi-Terminal DC Transmission Systems (MT-DCTS), the converters are functioning as ideal current sources in the DC-side (thereby parallel connections of several DC terminals should not pose any technical difficulties), and the change of the DC power direction is implemented by DC current reversal. Due to these characteristics, it is believed that by utilizing VSC-based MT-DCTS in a bulk power system, there is a great possibility of enhancing operational flexibility and controllability of the bulk power transmission, integrating large scale renewable energy sources at different locations, and future expansion flexibility.
From an economic, technical and research point of view, this project will mostly focus on the following questions and challenges:
With modern technology—for example Voltage Source Converters (VSC)—it is possible to build Multi-Terminal DC Transmission Systems (MT-DCTS), i.e., high voltage direct current systems that at several points connect to one or more alternating current systems. The controllability of the new technology is believed to provide great possibilities of enhancing the flexibility of the bulk power transmission system, which will improve the conditions for efficient electricity trading, improve reliability, facilitate integration of large-scale renewable energy sources at different locations, and increase the possibilities for future expansion of the system.
This project will study MT-DCTS both from a technical and from an economical point of view. The research will mostly focus on the following questions and challenges:
- The topologies of MT-DCTS.
- How should the hybrid AC-DC system be optimally operated concerning N-1 criterion (or other probabilistic methods,) congestion management, electrical losses and electricity markets?
- Derivation of control strategies for converters to keep the DC power balance and to fulfill the hybrid AC-DC system requirements. What are the advantages and disadvantages of using local and remote information, respectively, for these control strategies?
- What is the impact of adding primary frequency control signals in converters on the hybrid AC-DC system operation?
- How can the primary frequency control between the asynchronous AC systems connected by MT-DCTS be coordinated?
Applicants should have a completed academic degree on master`s level in Electrical Engineering, Engineering Physics or a related field. Furthermore, good oral and written communication skills in English are required. To address its varied work, KTH aims to employ a diversity of talent and thus welcomes applicants who will add to the variety of the University, especially as concerns its gender structure.
Form of employment: Time limited.
Start date: According to agreement.
The salary follows the directions provided by KTH. The position includes 20% departmental duties.
Application deadline: May, 9th 2011
Employers reference number: E-2011-0193
The application shall include a CV, a brief statement on why the applicant wishes to pursue PhD studies, contact information to three references, the degree certificate, and official transcripts of records.
The application should quote the reference number above and be sent by email to: firstname.lastname@example.org
in pdf format (only), with all documents merged into one single pdf-file, and with the reference number in the subject field.
Or, if electronic submission is impossible, to:
KTH School of Electrical Engineering
Att: Katharine Hammar
Osquldas väg 10
SE – 100 44 Stockholm
Mehrdad Ghandhari, Docent
Phone: +46 8 790 7758,