Determination of the Relevant Time Periods for Intra-Day Distribution System Minimum Loss Reconfiguration

The recent trends towards enhancing distribution system automation and the development of microgrids are making the perspective of applying intra-day reconfigurations more and more appealing. This paper formulates and applies a comprehensive rule-based approach to determine the configuration with minimum losses during time for a distribution system with time-varying load and local generation patterns. The results of the optimization carried out for successive time periods are used to develop an original procedure for determining the timings of the intra-day reconfiguration by taking into account the ranking of the best configurations and the persistence in time of these configurations. The objective function used depends on a parameter called cost ratio, that is, the ratio between the cost of the energy losses per kWh and the cost of performing a switching operation. A specific indicator (called objective assessment ratio) is introduced in order to quantify the convenience of performing intra-day reconfiguration with respect to maintaining during the day the same configuration leading to the lowest daily energy losses. The results obtained on two classical test systems and on a real distribution network are included, comparing the outcomes of the proposed approach with the results obtained from other methods.