Speaker: Professor Hans Edin, Electrotechnical Systems, KTH Royal Institute of Technology, Stockholm, Sweden
Date: Friday September 9, 2022
Time: 3:00pm
Location: EIT 3151
Abstract:
High voltage direct current (HVDC) cables with extruded insulation system were introduced in 1998. Since then, this technology has been growing rapidly with many installations that are today operational at voltages up to 320 kV. With fast developments during the last few years, extruded DC cable systems for operation voltages as high as 640 kV are now commercially available. Due to the importance of DC conductivity in the distribution of electrical field across the cable insulation, a good understanding of the DC conduction physics is of key importance to the design of robust HVDC cables. Currently, crosslinked polyethylene (XLPE) is the dominating material used in the insulation system of extruded DC cables. Since XLPE includes peroxide decomposition products (PDP), understanding their role on conduction behavior of the insulation system has been of great interest. The PDP and other chemical species can move in the system through diffusion which makes the characterization of cable insulation more challenging. Besides, like other semi-crystalline polymers, morphology of the XLPE evolves with temperature and over time. These changes in the material pose challenges to their electrical characterization by requiring stringent control of parameters during preparation, storage, and measurement. In this work, electrical characterization techniques relevant to polymeric insulation materials are discussed highlighting their applications and limitations.
Biography:
Hans Edin received the M.Sc. and Ph.D. degrees in electrical engineering from the KTH Royal Institute of Technology, Stockholm, Sweden, in 1995 and 2001, respectively. He is currently a Professor with the KTH Royal Institute of Technology. Hans Edin's research primarily concerns creating new methods and new techniques for diagnosis of the electrical insulation systems in the power grid's high-voltage equipment. The methods are often based on being able to measure deviations in the characteristics of the constituent insulation materials when they are exposed to various types of electrical stresses.