The Dielectrics and Electrical Insulation Society (DEIS) is concerned with the material properties and behavior of dielectrics, particularly as applied to electrical insulation systems. The DEIS scope ranges from molecular properties and dielectric phenomena, to aging and failure modes of insulation systems for in-service assets. While perhaps not immediately apparent, the work of the DEIS is fundamental to delivering many aspects of smart grid technology. This article highlights some of the impacts DEIS research can have on the smart grid, while the companion articles report on recent advances at the forefront of dielectrics research from the recent Conference on Electrical Insulation and Dielectric Phenomena (CEIDP) 2014.
Power modules will become more and more critical to future power networks, to incorporate wind turbines and other renewables, high voltage direct current (HVDC) transmission, and other technologies associated with the Smart Grid. Since Insulated Gate Bipolar Transistor (IGBT) modules can be both turned on and off, they can be used for modular multilevel converters (MMC), which enables downsizing of converters and reduction of harmonics generation and losses. Thus, converters with IGBT modules are most common for recent HVDC systems, and the market of IGBT modules is increasing rapidly. Being the key device for Smart Grid, utmost care has to be taken in assessing the reliability of IGBT modules. A fundamental understanding of insulation failure modes and the behavior of materials used for IGBT modules is crucial for the creation of more reliable power electronics devices.
The “weakest link” of transmission and distribution grid components is mostly their insulation. The solid insulation of power cables, capacitors, post and suspension insulators, transformers, etc. is of the non-self-healing type. That is, it undergoes an irreversible aging process due to service stresses that eventually leads such components to failure.
The Low Voltage (LV) grid, particularly in urban areas of many modernized countries, is exclusively based on connections with underground power cables. Loading usually is far below their ampacity and so far, no major concerns have been raised on the condition of the LV grid. Repeated failure is the only cause for replacement. However, historical failure rates of LV cables indicate that flawless operation cannot be taken for granted. Furthermore, with the increasing penetration of de-centralized generation, an increased pressure is expected on the performance of the LV infrastructure. No methods are currently available to effectively assess cable life expectancy. This calls for an investigation into options for condition monitoring of the LV grid.