Determination of the relevant periods for intraday distribution system minimum loss reconfiguration

Abstract

Summary The recent trends toward enhancing distribution system automation and the development of microgrids are making the perspective of applying intraday 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 periods are used to develop an original procedure for determining the timings of the intraday 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 kilowatthour 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 intraday 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. Copyright © 2014 John Wiley & Sons, Ltd.

Heuristic optimization of electrical energy systems: Refined metrics to compare the solutions

“…However, the number Y could be so high to make the generation of the configurations (with a graph-search algorithm) practically intractable. For example, the real distribution network shown in [61] has N = 207 nodes, B = 213 branches and S = 1 supply point, resulting in L = 7 open branches for each radial network, and in Y = 151,641,612 possible radial configurations. For larger networks the situation is even more extreme.…”

“…Without loss of generality, the minimum losses problem addressed here is based on a single loading condition. More generally, with the diffusion of distributed resources in the distribution systems, the problem is formulated by considering the evolution in time of generation and demand patterns, assessing the losses on a given time interval, also with the possibility of determining an optimal set of network configurations for intra-day time periods [61]. The concepts introduced in this paper can be directly applied to the results of these more detailed problem formulations.…”

Multi-Objective Distribution Network Reconfiguration Based on Pareto Front Ranking

“…The power losses R yh I 2 yh are calculated by solving at each time step h a power flow based on the backward-forward sweep method [23], particularly suitable for radial distribution networks.…”

“…jb is not changed, otherwise it is changed. The change depends on the integer or binary representations: 2 In addition, a last-resource large number of iterations N (a) For the integer encoding strategies, rounding the velocity results to integer values is considered in [31] and the enhanced integer coded PSO method [32] has been used to minimize the total branch losses by maintaining the radial network structure and without violating the constraints. In these cases, the change can be implemented by searching for a feasible configuration represented by the integer coding used, for example adjacent to the configuration that has to be changed.…”

“…In the analysis of electrical distribution systems with reconfigurable structure and radial operation, for large networks the number of possible radial network configurations (calculated from the Kirchhoff's matrix tree theorem) may be so high to make exhaustive search of all the possible radial configurations practically infeasible. As such, many deterministic and probability-based methods have been exploited to find out the configurations leading to pseudo-optimal solutions for a given objective function or for multi-objective functions [1][2][3]. In particular, multi-objective approaches have been applied to address distribution system reconfiguration by taking into account the trade-off among conflicting objectives.…”