Magnus Callavik

Learn More
Existing mechanical HVDC breakers are capable of interrupting HVDC currents within several tens of milliseconds, but this is too slow to fulfill the requirements of a reliable HVDC grid. HVDC breakers based on semiconductors can easily overcome the limitations of operating speed, but generate large transfer losses, typically in the range of 30 percent of(More)
State estimation (SE) for bulk power systems is traditionally formulated and executed as one integrated problem in a control center energy management system. This simultaneous approach may present challenges when the concerned network consists of different types of systems operated by different entities (independent system operator, transmission system(More)
This paper will briefly describe a new Intelligent Electronic Device (IED) containing integrated control, protection and communication elements for small hydro power plant. This joint project aims to set-up two small hydro pilot installations at two Swedish utilities. The concept requirements and project results will be discussed along with results from a(More)
This paper briefly describes some work done in a project to develop a new Intelligent Electronic Device (IED) containing integrated control, protection, monitoring and communication elements for small hydropower plants. The requirements from two Swedish Electric Power Utilities in this joint project result in two small hydro power-plant pilot-installations.(More)
This paper introduces the concepts of platformless DC connections of offshore wind turbines. First, the paper describes the possible and preferred wind turbine drivetrain arrangements capable of producing sufficiently high DC voltage. Then, the electrical system designs appropriate for the platformless DC architectures are discussed. After that, the(More)
There is a growing interest in applications of HVDC grids in many parts of the world. Comparing with individual HVDC links, HVDC grids can provide flexible energy transfers among multiple converter stations, improved system reliability, and reduced investment cost, etc. In particular, an offshore HVDC grid will allow the aggregation and delivery of power(More)
  • 1