Voltage quality is the part of the power quality concept that concerns the applicability of the voltage in the outlet.
Voltage quality in the grid is regulated to ensure that electrical equipment functions as intended, and the grid is planned to satisfy requirements to voltage quality. The development of more power intensive and complex appliances with power electronics, and more renewable generation creates further voltage quality challenges, especially due to existing challenges with weak distribution grids.
SINTEF Energy Research has participated in and managed research projects related to voltage quality for more than 30 years, i.e. related to planning of distribution grids to ensure adequate voltage quality, creating the Power grids planning book (Planboka), developing guidelines for integrating distributed generation, and performing socio economic calculations concerning raising the short circuit capacity in distribution grids to improve voltage quality.
In ongoing research projects there is currently a focus on new appliances' impact on voltage quality, such as electric vehicles charging systems, appliances with power electronics, electric tools, heat pumps, and other appliances with asynchronous motors. There is also done research in the area of impact on voltage quality from distributed generations in the low voltage grid, mostly related to PV-converters. The roll out of AMI by 2019 gives utilities a great opportunity to get a complete overview over the utilization of and voltage quality in the distribution grid. Due to limitations in the measurement unit, communication, and databases, SINTEF has analyzed which data that should be measured, which who should be stored, how these can be exploited, and how data can be visualized effectively to give a complete overview over utilization and voltage quality in the grid. Due to new components in the power system there is an increased capability to regulate voltage in the grid, and current research investigates how the new regulating capabilities should be coordinated with existing regulation systems in the transmission and sub transmission grids.
SINTEF has also done research in the fields of earth fault detection and classification, testing of the interrupting capabilities of AMIs, and a host of other voltage quality related topics, which over time has resulted in a comprehensive knowledge on the subject. SINTEF has been an important actor when it comes to design of guidelines, in standardization work, and in the public debate concerning network management. SINTEF has also over time acquired a comprehensive measurement database that is used to support voltage quality related work, and has laboratory facilities available to perform advanced distribution grid studies by utilizing line models, programmable converters, DG units, etc. SINTEF has also developed an event analysis tool for measurement data, and SINTEF has excellent experience using simulation programs as a tool in voltage quality studies. Internally and through partners SINTEF also has contact with leading research communities in power system components that has an impact on voltage quality.