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This full paper concentrates on the results of technical and economical analyses of DC supply of low-voltage electricity appliances and application of low-voltage DC (LVDC) networks in electrification of real estates. This paper illustrates possible advantage that can be achieved by using DC voltage inside the premises. The main contribution of this paper relates to the suitability of electricity appliances for low-voltage DC and the influences of LVDC real estate distribution networks on the energy-and cost-efficiency of electricity distribution.

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Experiences from the field setup of utility grid low voltage DC (LVDC) distribution are discussed. LVDC distribution being a novel approach to public electricity distribution, a research platform is realised to enable practical studies. The goal of the setup is to combine the requirements of the fully functional LVDC system and a flexible research platform. The scope of the paper is to discuss experiences from first six months of continuous use of the setup. The paper focuses on comparing how expected and realised results meet and how the setup has been operating in real public network. On the other hand, design flaws and challenges are covered. Finally, future research tasks and the development of the setup towards LVDC smart grid are presented.

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Low-Voltage Direct Current (LVDC) distribution network is a novel approach to the LV distribution. This paper presents the practical experiences from the implementation of a field environment research platform for ±750 V LVDC electricity distribution system in actual distribution network environment. The paper illustrates the main design of the field test environment as well as the challenges encountered during the construction and commission of the platform. The main objectives in the work have been to realise a real environment test bed for the development of the LVDC technology for public electricity distribution (utility networks), to determine the major gaps in the national standardisation and in the availability of components, and to gain knowledge of the different phases of the implementation process itself.

The leading themes in the distribution network development are the cost effectiveness and system reliability. Also the requirements for reducing pollution and increasing the service quality are issues, which have led to the introduction of SmartGrids network concepts. These network solutions are mostly dependent on power electronics, applied to connection of loads, generation and storages to the independently operable low-voltage (LV) grids. One of such solutions is the low voltage DC (LVDC) distribution system, which is an interesting challenger to the AC low voltage network solutions. An often-asked question is how the shorter lifetimes of power electronics compared to the traditional network components affect on the reliability of the electricity distribution and also to its total costs. In the this paper the question about the reliability development is approached from two main points of view: The component level focusing on the reliability of power electronics based network components, and the system level concentrating on the power quality experienced by the customers and the effects of converters on the entire distribution system reliability. The question of the reliability impact of large-scale utilization of power electronics in electricity distribution is relevant, when considering the direction of the technical development in electricity distribution. This paper is especially aimed at discussing the modelling of the reliability impacts in the case of the LVDC-system.

PurposeThe purpose of this paper is to establish a methodological framework to address key issues in electricity distribution network development. The paper defines subtasks in the strategy process and presents key elements in the strategy work and long‐term network planning. The results are illustrated by a case network.Design/methodology/approachThe paper describes the methodology for cost and reliability analyses in the strategy work. The focus is on techno‐economic feasibility of certain network development technologies in the network strategy and the surveys are linked to economic regulation, specifically to reliability of supply and allowed return. The study addresses the stages of strategic decision making and compilation of investment strategies.FindingsThe strategic planning concept and methods are applicable in practice; the results have proven valuable in the long‐term business development and in discussions with the company owners. Outage costs are an essential element in the economic regulation of the business, reliability being a key driver in network planning.Research limitations/implicationsThere is no universal solution to strategic decision making, but each development task is highly case specific. This is due to diverging operating environments and targets set by the company owners; these issues strongly influence the strategy process.Practical implicationsThe work illustrates strategic planning in an actual distribution company and shows how the methodology can be applied to the strategic network development. Nevertheless, the results cannot be generalised as such, but each network has to be considered individually.Originality/valueThe proposed concept can be applied to the long‐term development of distribution networks. The results are internationally applicable, yet diverging regulatory models call for specific methodology in each country.