The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This work faces the problem of frequency deviation in microgrid systems. The considered microgrid includes renewable energy sources such as wind and solar photovoltaic. As long as these sources provide an irregular power supply or there is a sudden change in the system load, the power system frequency deviates. In order to compensate such deviations, alternative, conventional energy sources should...
Consensus based distributed robust adaptive finite-time secondary voltage control is designed for inverter-based islanded AC microgrids. The design combines decentralized local states information with the states of the neighboring distributed generators with directed communication topology. Robust control algorithms are used locally for each distributed generator to deal with uncertainty. Lyapunov...
Autonomous microgrid planning is a Mixed-Integer Non Convex decision problem that requires to consider investments in both distribution and generation capacity and represents significant computation challenges. We proposed in a previous publication a deterministic Second-Order Cone (SOC) relaxation of this problem that made it computationally tractable for real-size cases. However, this problem is...
Microgrid is a cluster of distributed (renewable) generation sources, storage units and loads, which, when controlled in an optimal fashion, can improve both the quality of the local power supply as well as the performance of the overall power distribution system. In this paper we present a robust control methodology for microgrids that can cope with uncertainties introduced by intermittent renewable...
With the implementation of distributed generations, microgrid has become an important entity in the modern power systems. A grid-connected microgrid can participate in multiple electricity markets with different time scale to procure energy and self-schedule its internal generation resources to serve its demand. In a medium-term operation horizon (weekly, monthly or longer time span), the decision...
Accurate sizing of power reserve (PR) due to inaccurate forecast of both renewable energy sources (RES) and load demand in a microgrid can provide substantial cost reductions. This paper proposes two strategies to dispatch the PR into different power generators. The first one uses only micro gas turbine (MGT). The second one uses MGTs plus PV based active generators (AGs). The latter enables the RES...
The uptake of high penetrations of renewable energy in microgrids is curtailed by concerns that their intermittency may cause the system to become unstable. The classic approach of small-signal stability analysis may lead to overly optimistic conclusions, because it implicitly assumes that the intermittency is small-signal in nature. Instead, LMI techniques from robust controls can be used to provide...
Levels of electricity access in sub-Saharan Africa are low with large populations living far from existing electricity infrastructure. This has led to interest in decentralized electrification solutions like microgrids, which can reach remote communities more quickly. To address a lack of capital to deploy these projects, governments have sought private investment in the sector. Studies have found...
This work considers the optimal long term pumped storage capacity problem for a microgrid equipped with a Wind Farm (WF), Interruptible Loads (IL), transmission line to a main grid and Pump Storage (PS). Typically, the WF is operated according to wind speed to charge PS and supply electrical power to satisfy the load demands. A linear model is established to describe the system dynamics of the central...
This paper presents the effects of Photovoltaic (PV) location on losses of the distribution system. The optimal location of PV is determined by using Particle Swarm Optimization (PSO) implemented in MATLAB-OpenDSS environment. IEEE 34-node test feeder is employed to verify the feasibility and effectiveness of the developed method. Once the optimal location is determined the challenge still remains...
This paper proposes a novel control strategy for coordinated operation of networked Microgirds (MGs) in a distribution system. The distribution network operator (DNO) and each MG are considered as distinct entities with individual objectives to minimize the operation costs. It is assumed that both the dispatchable and nondispatchable distributed generators (DGs) exist in the networked MGs. In order...
This paper proposes a method to optimally operate microgrids under conditions of uncertainty introduced by renewable energy sources, under both grid connected and islanded mode. Uncertainty is quantified with probability distribution and confidence levels are used to establish likelihood of forecast error. The optimization problem is formulated as a quadratic programming problem and the optimality...
We describe an adapted robust control technique for analyzing microgrid stability under the uncertainty of renewable sources and loads. Two realistic case studies are presented to demonstrate the method's effectiveness as a tool for system design and analysis. Results show that the method is able to provide a non-trivial lower bound for the minimum damping ratio of the system, and can find the unstable...
In this paper, different control strategies are presented for primary frequency regulation in a diesel-photovoltaic-supercapacitor hybrid power generation system. Firstly, a classical control approach is proposed as a reference. Then, a robust control design based on H∞ control theory is applied to the studied system. Starting from given certain desired performances, Linear Matrix Inequalities (LMI)...
We present an extension of a model predictive control approach for microgrid energy management. We take into account electricity costs, power consumption, generation profiles and power and energy constraints. Uncertainty due to variations in the environment (wind speed), failures and subsequent repairs of the generator, as well as battery lifespan limitations are taken into consideration. Simulation...
Microgrids have been explored as active cells capable of providing enhanced control schemes towards a more secure, reliable and efficient operation of LV distribution networks or MV networks when aggregated in a multi-microgrid. These structures, within the smart grid concept, rely on a communications infrastructure that introduces uncertainty in the data exchange process. In this paper such uncertainty...
A self-validated computing (SVC) method, based on affine arithmetic (AA) is proposed in this paper to solve the optimal power flow (OPF) problem for microgrids with renewable sources of variable generation. In the AA-based OPF formulation, all the state and control variables are presented in affine form, to represent the variable load, and wind and solar generation. Hence, the OPF model becomes an...
The uncertainty discrepancy between distributed wind generation and local load demand brings an interesting and important challenge to daily schedule and control policy design in microgrid. This paper proposes a look-ahead dispatch framework for matching stochastic supply and demand with optimal control of distributed storages and minimal use of wind curtailment and load shedding. A stochastic programming...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.