Mixed-Integer-Linear-Programming-Based Energy Management System for Hybrid PV-Wind-Battery Microgrids: Modeling, Design, and Experimental Verification

Abstract

Abstract-Microgrids are energy systems that aggregate distributed energy resources, loads and power electronics devices in a stable and balanced way. They rely on energy management systems to schedule optimally the distributed energy resources. Conventionally, many scheduling problems have been solved by using complex algorithms that, even so, do not consider the operation of the distributed energy resources. This paper presents the modeling and design of a modular energy management system and its integration to a grid-connected battery-based microgrid. The scheduling model is a power generation-side strategy, defined as a general mixed-integer linear programming by taking into account two stages for proper charging of the storage units. This model is considered as a deterministic problem that aims to minimize operating costs and promote self-consumption based on 24-hour ahead forecast data. The operation of the microgrid is complemented with a supervisory control stage that compensates any mismatch between the offline scheduling process and the real time microgrid operation. The proposal has been tested experimentally in a hybrid microgrid at the Microgrid Research Laboratory in Aalborg University.

A fast time-frequency response based differential spectral energy protection of AC microgrids including fault location

“…The distribution system consists of four distributed generation (DG) units, (DG 1, DG 2, DG 3 and DG 4) each of which is a 9 MW, 575 V, 60 Hz DFIG based wind farm [23], and are connected to the distribution system at buses E, B, C and D through 10.5 MVA, 575v/ 22.9 kV transformers T r2 , T r3 , T r4 and T r5 , respectively. In addition to the GCM of operation of the microgrid, an energy storage (battery bank) [20] is installed at the point of common coupling, i.e., bus ' A' , so as to formulate a viable microgrid in IM of operation. The details regarding the network parameters are specified in the Appendix.…”

Online Energy Management Systems for Microgrids: Experimental Validation and Assessment Framework

“…In the case of the ESS, the non-interactive operation is activated when the battery in the ESS reaches its maximum limits of charge, which is defined by the manufacturers as a threshold voltage value V th . Under this condition, the reference of the inner current controller is defined by an outer battery voltage controller, which keeps the battery voltage in a constant level [19]. This charging stage is known as Constant-Voltage charger mode and is highly recommended for ensuring an appropriate charge of the battery [33].…”

“…Seamless transitions between operational modes can be achieved by setting the initial conditions of the inactive controllers to the current value of the reference current. Interested readers may refer to [18], [19], [39] for detailed information about the different control loops.…”

“…Accordingly, the energy management system of the MG (MG-EMS) establishes the reference commands for DER/loads controllers to make the whole system operate optimally, not only considering the current MG behavior, but also economical and technical constraints, environmental conditions, and external requirements [18], [19]. To do that, the MG-EMS usually performs a short-term scheduling process for operation, which uses input parameters and profiles involving the prediction of available resources subjected to uncertainties [20].…”

Optimization Models for Islanded Micro-Grids: A Comparative Analysis between Linear Programming and Mixed Integer Programming

“…This method ensures computational efficiency and guarantees a global solution (while the pure MINLP provides with only local ones). Because the MINLP models are often transformed to the MILP problems to facilitate model solving and to guarantee the local solution, some researchers have started to develop pure MILP model without the need for Benders decomposition application [14]. A simplified representation of the power units applied to the optimization of energy power flow of limited systems, like for example a single battery storage [15] or a combination of renewables and storage [16], can be based on Linear Programming (LP).…”