Course content

Course objective: Pervasive proliferation of non-linear and time-varying loads and distributed generation make the power system operate under conditions that are substantially different from traditional sinusoidal ones. This calls for advanced compensation equipment and coordinate operation to improve power quality and efficient use of resources. Power electronics is the best candidate solution, provided that the use of any device is based on a proper understanding of the complexity of the new scenario. The aim of the course is to provide a theoretical background to correctly approach the problem of reactive, harmonic and unbalance compensation, in the context of the power theory debate still open today. Syllabus: -Introduction -Correct definition of the compensation problem. Evaluation of distributed/centralized and average/instantaneous compensation. -Characteristics, potential and limitations of different types of compensation systems: passive/active, fixed/regulated, series/shunt compensators. -General capabilities of voltage source converters for instantaneous compensation. Multifunctional inverters -Discussion of the following reactive power compensating devices: *Static Var Compensator (SVC): Principle of operation, configuration and control capabilities *Static Compensator (STATCOM): Principle of operation, configuration and control capabilities. -Historical review of the main power theories for electric networks operating under non-ideal conditions. -Presentation of the updated discussion in the scientific community.

Learning outcome

Knowledge: After completing the course, the student shall: - have a solid theoretical understanding of the main power theories and the respective methodological approaches. - be able to identify the differences between the theories debated in the scientific community and evaluate their performance in relevant cases.- develop new insights into the power/current definitions under distorted grid conditions - have the capability to assess the need for compensation in the context of power quality and stability of the modern power network. - have gained a solid knowledge of the compensation capabilities and limitations of the following compensation technologies: passive elements (C, L), line commutated compensators (SVC) and actively controlled compensators (VSC/Multifunctional inverters, Active Filters) - be able to identify the most suitable compensation tools for new grid conditions/topologies. Skills: After completing the course, the student shall be able to: - formulate properly the compensation problem and its goals for a given network/grid condition in order to decide about the most appropriate technology or combination of technologies. - design and implement control algorithms for compensation systems aimed at reactive, harmonic and unbalance compensation in the electric network. - implement them by simulations and/or experimental tests - write a scientific paper on a particular case study related to compensation of non-idealities in electric networks (at a level suitable for submission to an international conference). General competence: After completing the course, the student shall: - have acquired an overview of the historical development of power theories with respect to the technical development of the power system - have developed a critical thinking on the theoretical debate on power theories that is ongoing in the scientific community and be able to discuss the main concepts with leading international experts in the field. - have achieved a comprehensive overview of power electronic systems and corresponding configurations that can be utilized for power quality improvement in electric power systems.

Learning methods and activities

The course will be based on introductory lectures to most relevant power theories and presentation of compensation systems, as well as on discussion of selected papers. Part of lectures will be reserved for colloquia and presentations by the PhD candidates. The student will have assigned a main topic and will have to prepare the presentation/discussion of that topic according to a schedule that will be provided at the beginning of the course. For that, each student will be referred to relevant material, but also be invited to deepen his/her understanding by identifying additional scientific sources worth of discussion. An in-plenum discussion with all participants will be fostered following each presentation. The course will include guest lectures by international experts and encourage the scientific debate between them and the PhD students. The exam will consist of the preparation of a scientific paper in IEEE format, which should reflect the knowledge acquired during the course and where such knowledge will be implemented by the student using his/her PhD research topic as platform for the discussion . The course is given every second year.

Further on evaluation

The final assessment is based on an oral exam, which includes the discussion of the paper prepared and submitted by the PhD student in advance, in addition to questions on the course content.

Specific conditions

Recommended previous knowledge

TTK4105 Control Engineering or equivalent courses.

Required previous knowledge

TET4190 Power Electronics, TET4180 Electric Power System Stability or equivalent courses.

Admission to the Doctoral Program in Electrical Power Engineering is required to take this course. PhD-students from other doctoral programs can be enrolled in this course on request.

Course materials

A selection of IEEE papers and other journal articles will be used as reference for discussions and fundamental definitions. The two following books will be also used, when relevant: - "The instantaneous Power Theory and Applications to Power Conditioning" by Akagi, Hirofumi / Watanabe, Edson Hirokazu / Aredes, Mauricio, - "Understanding FACTS," N G Hingorani and L Gyugyi, IEEE Press, 2000