Hermann Koch, Siemens, Germany
Dr.-Ing. Hermann Koch is Director of Standards and Regulations of the High Voltage Technology at Siemens. He graduated in Industrial Control Engineering at the Fachhochschule Rüsselsheim and in Electrical Engineering at the TU Darmstadt in 1979 and 1986, respectively, after also studying at New Jersey Institute of Technology, Newark, New Jersey, USA. In 1990 he received his Dr.-Ing. degree from the TU Darmstadt. Since 1991 he is working with Siemens High Voltage Division in different responsibilities.
Hermann Koch is Chairman of the IEEE PES Substations Committee. In IEC he is Secretary of SC 17C High Voltage Switchgear Assemblies, and in CIGRE member of the Strategic Advisory Group of SC B3 Substations. He has published more than 130 technical papers and holds 31 patents in the field of gas insulated technology, his area of expertise. He is engaged in studies, innovations, and R&D activities for high voltage gas insulated power transmission systems.
Prof. Sivaji Chakaravorti, Director, NIT Calicut, delivered the Distinguished Lecture Program on Oil-Paper Insulation of Transformers on 19th December 2017.
Transformers are the most expensive and most critical assets of electrical transmission and distribution system. Transformer failures could cause power outages, personal and environmental hazards and expensive rerouting or purchase of power from other suppliers. The replacement of power transformers takes time as they are generally not available off the shelf. Thus, in addition to the cost of replacement, there is a cost of power loss owing to the delay in replacement. In some cases, the failure of transformers would result into total stoppage of some critical processes, which causes additional losses. The cost of monitoring of the condition of the transformers is very much negligible when compared to the loss due to its failure. Thus, monitoring condition of transformers is imperative for utilities and industries.
In the well attended talk, the speaker portrayed how his team developed the technology to measure and reduce the moisture content in solid insulators. He clearly conveyed the message to participants about condition of insulating mediums inside a transformer with statistics taken from literature. He explained the possibilities and reasons for deterioration of insulation and its effects on performance and ageing of transformers. He stressed on different diagnostic testing methods used to test the condition of oil as well as paper insulation with merits and drawbacks, which includes both electrical and chemical based methodologies. He also shared his field experience in conducting such testing in transformers yards of different substations and generating stations in India. He concluded his talk with research opportunities in the area so that budding research engineers can work on it