Power transformers are the most complex, important and critical components of the transition and distribution power systems. Insulation system is the key component of life extension, better availability and higher reliability of a transformer. In order to achieve both decreasing operational cost and reliable service conditionbased maintenance is needed. Monitoring and diagnostic methods and tec...

Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs), the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focuse...

To practically apply vacuum insulation panels (VIPs) to buildings or home appliances, VIPs have demanded long-term lifespan with outstanding insulation performance. Service lives of VIPs enveloped with Al-foil and three-layer Al-metallized envelope are calculated. For Al-foil envelope, the service life is longer but edge conduction is too large compared with the Al-metallized envelope. To incre...

Transformers are one of the most valuable assets of power systems. Maintenance and condition assessment of transformers has become one of the concerns of researchers due to huge number of transformers has been approached to the end of their lifetimes. Transformer’s lifetime depends on the life of its insulation and the insulation’s life is strongly influenced by its moisture attraction as well....

In this paper, the thermal performance of four common insulators in two internal and external insulation systems is investigated for the ASHRAE setpoint range by applying detailed numerical simulation and Anti-Insulation phenomenon. Anti-Insulation phenomenon and consequent extra load on the HVAC system can occur following the thermal insulation of a building if proper temperature setpoint is n...

Power transformers use Kraft paper as insulation in the electrical windings present in the core, which is immersed in oil. In service, the temperature of the windings of core will go to 75C to 85C. If the transformer is over loaded, then the temperature can exceed upto 100°C causing the cellulose chains in the paper to cleave at an accelerated rate, which results in the degradation of mechanica...

Most power transformers operating in a power system possess oil-paper insulation. A serious defect of this type of insulation, which is associated with long operation time, is an increase in the moisture content. Moisture introduces a number of threats to proper operation of the transformer, e.g., ignition of partial discharges (PDs). Due to the varying temperature of the insulation system duri...

In this study, the optimum thickness of thermal insulation used to reduce heat gain and losses in buildings is investigated under dynamic thermal conditions by using the climatic conditions of Elazığ, Turkey. Numerical method based on an implicit finite difference procedure which has been previously validated is used to determine yearly cooling and heating transmission loads, yearly averaged ti...