Search

Backward-Forward Sweep is one of the most used procedures for the power flow calculation of large-scale active multiphase distribution networks. This paper introduces the decoupled network model which is suitable for the multi-threaded implementation of the Backward-Forward Sweep procedure. The main objectives of this paper are: (i) to introduce the decoupled new models of traditional and Electronically-coupled Distributed Energy Resources, (ii) to introduce the decoupled models of single-, two- and three-phase line sections, (iii) to give the detailed Unified Modeling Language diagrams of the software model and procedures, (iv) to give a detailed model and a procedure for the single-threaded power flow calculation, and (v) to give a detailed model and a procedure for the multi-threaded power flow calculation of the large-scale active multiphase distribution networks. The results show the advantage of the proposed decoupled single-threaded approach over the traditional coupled-based one – the speedup is up to 160%. Moreover, the speedup of the decoupled multi-threaded calculation of the power flow compared to the single-threaded one goes up to the 200%. This means that the decoupled multi-threaded implementation is up to 300% faster than the coupled one. These results prove that the Backward-Forward Sweep is particularly usable for the multi-threaded implementation. [ABSTRACT FROM AUTHOR]

Summary: The nature of transmission and distribution networks has drastically changed over the last several decades, due to a high penetration of electronically interfaced energy resources (EIERs). Consequently, the complexity of the operation and the management of these networks have considerably increased. This strongly affected the energy management systems and distribution management systems, especially the power flow calculation as their basic power application. Electronically interfaced energy resources can employ a wide range of control strategies that cannot be represented with traditional single‐phase bus types used for traditional alternating current machines in a symmetrical operation. Power flow is the main subject of this paper, and the main objectives are as follows: (i) to prove that the traditional bus classification—θV (slack bus), PQ, and PV—is not sufficient for an unbalanced power flow formulation and the calculation of emerging large‐scale unbalanced electric networks containing traditional alternating current machines and particularly EIERs; (ii) to introduce a new bus classification suitable for the power flow modeling and calculation of these networks; and (iii) to present a robust and accurate unbalanced power flow method based on the new bus classification and a bus type inspection principle. Numerical tests show that the developed power flow method can be successfully applied in the on‐line calculation mode of both energy management system and distribution management system dealing with large‐scale networks. [ABSTRACT FROM AUTHOR]

• Power flow calculation of large-scale networks has been changed due to the incorporation of electronically coupled energy resources. • Traditional single-threaded solutions have existed for long time for balanced large-scale networks. • Multi-threaded implementation offers significant speedup in power flow calculation. • The advanced bus type classification has been introduced in order to model more accurate control strategies of electronically coupled energy resources. The multi-threaded implementations of the power flow calculation procedures became more and more popular as they decreased calculation speeds. The multi-threaded power flow calculation with the integration of the control strategies of traditional and electronically coupled energy resources in asymmetrical states are the main subject of this paper and the main objectives are as follows: (i) to present the models of traditional and electronically coupled energy resources and to incorporate their control strategies into more accurate bus type classification, and develop the unbalanced power-flow calculation procedure, (ii) to identify which parts of the proposed algorithm could be implemented in the multi-threaded manner, (iii) based on the measured performance data, to further optimize the identified parts of the algorithm using subthreads, and (iv) to develop the multi-threaded power flow procedure for unbalanced large-scale weakly-meshed and meshed networks. These procedures were successfully tested on large-scale unbalanced weakly-meshed and meshed networks. [Display omitted]. [ABSTRACT FROM AUTHOR]