NAERINGSPH-Nærings-phd

The electric distribution system is undergoing a profound change driven by: - Integration of distributed generation from renewable energy sources (RES) - Changes in load pattern induced by electric vehicles (EV?s), heat pumps, more power intensive electrical appliances, demand response schemes, etc. - Increased reliability requirements and voltage quality challenges - The need for renewal of ageing assets - New opportunities for more cost efficient operation facilitated by new technologies and new data (e.g. smart meters, distribution management systems, digital substations, new sensors, batteries, etc.) Grid reliability, operational efficiencies and customer services should be maintained and improved solving the new challenges and utilizing the new options. The changes that are happening are particularly significant for the electricity distribution grid, where "blind" and manual operations, along with the electromechanical components, will need to be transformed into a "smart grid". This transformation will be necessary to meet environmental targets, to accommodate a greater emphasis on demand response, and to support distributed generation, electric vehicles and storage capabilities. The Norwegian distribution networks have been developed over many years and have a relatively small amount of active elements, such as generators and demand side management. They are instead dominated by passive elements, principally uncontrolled loads. In the future, the loads will become more dynamic and controllable due to more active response from customers and the expected large introduction of electronic control and regulation systems. At the same time, the introduction of advanced metering systems (AMS, smart meters) and new sensors will provide the network owner with a lot more data. The introduction of more active elements will require new and improved methods for distribution system planning especially for the estimation of loads and generation. The optimal investments or reinvestments in the distribution system is a consequence of the capacity needed to host the expected loads and generation. Thus, good estimates of load and generation are imperative to optimize the distribution grid. The overall objective of the PhD-work is to contribute to improve distribution system planning to support the transformation of today's passive distribution networks into the expected future active distribution networks. Methods for estimation of loads and generation are especially addressed in order to find out if this can be done in a better way than with today's methods - taken in consideration the large amount of new data available for planners from the new smart meters. The main research questions addressed are: (1) What changes can be expected in the distribution system during the next decades, and what will be the consequences regarding distribution systems planning and operation? (2) Is the methodology used by DSO?s in Norway today for distributions system planning good enough or can it be improved? (3) As load and generation modelling is essential in distribution system planning and huge amount of new data becomes available by the introduction of smart meters, how can data from the new smart meters be used to make better load- and generation models for distribution system planning purposes? Should the load and generation models be probabilistic rather than deterministic as today? (4) How can probabilistic load-flow calculations be done with the availability of more stochastic load and generation models? (5) Will probabilistic models and calculations give better results than today's methods?

Det norske mellom- og lavspenningsnettet er utviklet over mange år og er en aldrende infrastruktur. Fornyelsen av nettet går relativt sakte og har en tendens til å bli utsatt av ulike årsaker. En økende andel distribuert produksjon bringer nytt initiativ og nye ideer til dette fagområdet. Eksisterende nett er svært utbredt og omfattende. Det er derfor viktig å finne en teknisk gjennomførbar og økonomisk forsvarlig overgang fra dagens til fremtidens nett. Ved en overgang må det også tas hensyn til gjeldend e fokus på miljø og fornybare ressurser. Ph.d studiet knyttes opp mot prosjektet "Optimal infrastructure for seamless integration of distributed generation " OiDG. Dette prosjektet ble startet opp i 2009 i regi av SINTEF Energiforskning.