Real-Time Validation of Power Flow Control Method for Enhanced Operation of Microgrids

Abstract

This paper describes a control methodology for electronic power converters distributed in low-voltage microgrids and its implementation criteria in general microgrid structures. In addition, a real-time simulation setup is devised, implemented, and discussed to validate the control operation in a benchmark network. Considering these key aspects, it is shown that operational constraints regarding the power delivered by sources, flowing through network branches, and exchanged at the point of connection with the main grid can generally be fulfilled by the presented control approach. The control is performed considering a cost function aiming at optimizing various operation indexes, including distribution losses, current stresses on feeders, voltage deviations. The control system allows an enhanced operation of the microgrid, specifically, it allows dynamic and accurate power flow control enabling the provision of ancillary services to the upstream grid, like the demand–response, by exploiting the available infrastructure and the energy resources. Then, the validation of the approach is reported by using a real-time simulation setup with accurate models of the power electronic converters and related local controllers, of the grid infrastructure, of the power flow controller, and of the communication network used for data exchange. It is also shown that the implemented platform allows to fully reproduce, analyze, and finally validate all the relevant steady-state and dynamic behaviors related in the considered scenario.

Generalized Control of the Power Flow in Local Area Energy Networks

“…Let K d be the selector of those voltages, among ũv , whose phasor can be controlled on the real (direct) axis, and K q the selector of those voltages that can be controlled on the imaginary (quadrature) axis. Let u d be the controllable voltage terms along the direct axis, and u q the controllable voltage terms along the quadrature axis; similarly to (7), we may express voltages ũv as…”

“…A completely different approach relies on local area energy networks (E-LANs) that aggregate the users within a microgrid and coordinate their operation to improve the electric performances, extend the grid functionalities, and allow participation of end-users to the electric market either individually or within energy communities [7].…”

Energy Management Systems for Optimal Operation of Electrical Micro/Nanogrids

“…The control and management of microgrids is dealt with in three articles focused, respectively, on power flow control, on BSSs capability of managing black start and islanding events, and on use of EV fleets as a flexible load for balancing purpose in the microgrid management system [3][4][5].…”

“…Abedini et al [3] propose an optimal power flow control method for microgrids together with its real-time validation considering a benchmark low-voltage distribution network with distributed energy resources. The control is designed considering a cost function aimed at optimizing various operation indicators, such as distribution losses, current stresses on feeders, and voltage deviations.…”

A Per-Phase Power Controller for Smooth Transitions to Islanded Operation

“…1 power control is an important feature too. For example, [19] proposes a centralized controller that issues optimal per-phase power references to distributed three-phase EPCs, achieving powerflow controllability at the point of common coupling (PCC) of a microgrid with the upstream grid. Independent power…”