جستجوی مقالات مرتبط با کلیدواژه "microgrids" در نشریات گروه "مواد و متالورژی"

This paper proposes a novel distributed adaptive secondary controller for microgrids (MGs) in islanded operation. To enhance the dynamic behaviour of a microgrid considering uncertainties and disturbances, the proposed controller uses a consensus-based adaptive control structure. A novel consensus protocol is proposed to restore the frequency and voltage (f &V) of a microgrid to their rated values. A Lyapunov function is presented to assure the asymptotic stability of the controller and the ultimate boundedness of the global neighborhood consensus error. The nonlinear nature of MGs has been also considered in the algorithm. Unlike other methods in this field that require complete information of distributed generators (DGs), the proposed controller requires only power droop coefficients and is independent of DGs parameters. Different simulations are conducted in MATLAB/SimPower Toolbox on a typical microgrid and under various disturbances to judge the performance of the adaptive controller. The simulation results show the effect of the proposed controller on increasing the resilience of an MG.

The proposed paper presents the DC/AC microgrid modeling using the Energy storage units and photovoltaic (PV) panels. The modal consists of a two stage power conversion. The power is supplied to the both DC and AC loads by this PV solar panels. The suitable way to explore the PV generation model is by using manufacturer datasheet. A bidirectional converter is connected to the battery storage system and dc bus. To keep the bus voltage stable, the storage system absorbs the excess power whenever generation is more and delivers power to the load when generation is less.  This system eliminates hazards of islanding by supply the local loads continuously incase of grid discontinuity. This paper emphasizes on control and stability of dc bus voltage and energy management scheme. Matlab/Simulink is used for integration of system modeling and efficiency of the system is verified by simulation.

In this paper, a control approach for enhancing the characteristics of a microgrid system is presented. This microgrid includes a PV system in its DC link beside a DC/DC convertor as the interface for connecting to the system inverter. Due to this, the dynamics of the PV system is also considered. The capability of this control system in maintaining the significant feature of system signals under non-linear load or load variation is also investigated. The secondary controller in this system is designed to not only restore the system voltage and frequency but also preserve the value of active and reactive power before and after its operation. The simulation results show the capability of this control system in maintaining the system performance.

Recently, along with the depletion of fossil fuels and growing electrical requirements, more attention has been paid on utilizing Renewable Energy Sources (RESs). The Chichest tourism complex is located 20 km far from Orumieh, Iran which has been supplied through the main distribution grid connection. But, recently the trend is to expand the share of RESs in supplying microgrids demand. Hence, this study reports the optimum investment planning for electrical expansion of grid-connected Chichest tourism complex including diesel/wind/PV/battery technologies. For the optimal planning of microgrid, an efficient simply-computational two-stage procedure is proposed. In the first stage, all of the feasible system configurations are determined using NREL’s HOMER software which is a well-known and well-established optimal modeling environment. Subsequently, in the second stage based on Analytical Hierarchy Process (AHP) and simple additive weighting (SAW) method, the best configurations for hybrid system are determined through the Expert Choice software considering economical and environmental criteria. With the aim of providing a comprehensive decision-making capability, a sensitivity analysis is performed considering relative importance of criteria. Simulation results demonstrate that for Chichest coast, the best configuration is grid/diesel/wind hybrid system as it shows a uniform behavior for different cases.