Problems of deployment of RC switching elements in distribution MV networks for improving reliability of power supply

This paper deals with the problems of deployment modern remote-controlled (RC) switching elements in electrical distribution MV networks. These advanced elements contribute to improved reliability of operation of electrical networks as they enable operative reaction to resulting situation within the network and to secure modifications to its configuration in such manner that any possible interruption of power supply is reduced to minimum. That leads to increase in revenues concerning power supply. That modernization is considerably expensive, so close attention is paid to selection of new elements and place of their position. The use of methods of multi-criteria analysis is suitable for this decision-making. The new approach to the issue of multi-criteria decision making in the field of RC switching elements there is the application of methods not only on a single type of elements as in the past, yet the selection of variants comprising various types of elements, which is more convenient for electrical power engineering as, for example, modernisation of a certain part of the network is mostly associated with installation of several types of elements. In principle, this methodology called "elements combination" is based on evaluation in two steps. The first step shall be associated with selection of an optimum variant for all switching elements together in accordance with set of criteria. We use CDA multi-criteria method for this. This method is one of many methods which fall into the multi-criteria analysis (MCA). This first decision making stage will provide us with possible variants (elements) sorted with respect to convenience of their replacement regardless of the implication, for which type of switching elements on higher level (recloser, remote-controlled switch disconnector, intelligent disconnector) it should be replaced in ideal case. Following step is based on creating new criterial matrix, which contains all evaluated variants (switching elements) again. However, there are evaluated according to another criteria respecting not only suitability of replacement (determinate in the first step), yet especially the amount and nature of consumption (behind the element), the frequency of operations with element and spared annual costs. This criteria matrix is subsequently solved using a standard mathematic apparatus, which includes several methods of MCA. After solution of mentioned matrix we will get the final order of old switching elements most suitable to replacement for elements of higher-level. Descibed methodology is here applied to specific decision making task from the field of electrical power engineering. This task is based on determination of optimum order for replacement of section switches with various remote-controlled switching elements in overhead lines of the North Moravian region in the Czech republic.