Search results for "Microgrid"
showing 10 items of 83 documents
Nonlinear droop control for minimum power losses operation in islanded microgrids
2017
In this work, a modified primary regulation technique is proposed to control one of the inverter interfaced units feeding an islanded microgrid. The proposed approach employs an off-line minimum losses Optimal Power Flow, OPF, to extract a lookup table for the composition of the droop curve. Simulations prove that generators reach an operating point that corresponds to a minimum loss operation for the relevant power flow distribution. Since OPF has been implemented with frequency and voltage dependent models, the results of the modified droop are stable and also energy efficient. Further studies will address further analysis on systems showing different R/X ratio and modeling of more genera…
An execution, monitoring and replanning approach for optimal energy management in microgrids
2011
abstract This work develops a new approach for optimal energy management of electrical distribution ‘smart-grids’. Optimality aims at improving sustainability through the minimization of carbon emissions and atreducing production costs and maximizing quality. Input data are the forecasted loads and productionsfrom renewable generation units, output data are a set of control actions for the actuators. Theconsidered electrical distribution system includes storage units that must be considered over a 24 h timeinterval, to consider an entire charge and discharge cycle. The objectives for the optimal management ofdistributed (renewables and not) generation are technical, economical and environme…
Overgrid: A Fully Distributed Demand Response Architecture Based on Overlay Networks
2017
In this paper, we present Overgrid, a fully distributed peer-to-peer (P2P) architecture designed to automatically control and implement distributed demand response (DR) schemes in a community of smart buildings with energy generation and storage capabilities. As overlay networks in communications establish logical links between peers regardless of the physical topology of the network, the Overgrid is able to apply some power balance criteria to its system of buildings, as they belong to a virtual microgrid, regardless of their physical location. We exploit an innovative distributed algorithm, called flow updating, for monitoring the power consumption of the buildings and the number of nodes…
Review on photovoltaic based active generator
2015
An active generator has the capacity to support frequency control and instantaneous power balance. The grid operator adjusts the power dispatch of generators according to power demand fluctuations. Photovoltaic (PV) based active generators can be used as load following generators in the same manner as other power dispatch generators. This new type of distribution system, based on active generator(s), needs new innovative management and operation strategies for increasing the penetration of intermittent renewable energy systems. The considered PV based active generator has three units, i.e., PV array, battery storage and super capacitor. In this review paper, the management and operation app…
A parametric study on unbalanced three phase islanded microgrids with inverter interfaced units
2013
In this paper, the solution of the power flow for unbalanced three phase microgrids systems is proposed. The study aims at the integration of inverter interfaced units using the control law used for primary voltage and frequency regulation, so as to take into account possible small variations of these parameters to account for sudden load changes. The proposed study deals with unbalanced systems which is the typical case of small distribution systems and shows how the power losses term varies as the regulators parameters vary as well, thus showing that these are sensitive parameters that could have an important role in optimal management of such systems.
Optimal power flow based on glow worm-swarm optimization for three-phase islanded microgrids
2014
This paper presents an application of the Glowworm Swarm Optimization method (GSO) to solve the optimal power flow problem in three-phase islanded microgrids equipped with power electronics dc-ac inverter interfaced distributed generation units. In this system, the power injected by the distributed generation units and the droop control parameters are considered as variables to be adjusted by a superior level control. Two case studies with different optimized parameters have been carried out on a 6-bus test system. The obtained results showed the effectiveness of the proposed approach and overcomes the problem of OPF in islanded microgrids showing loads unbalance.
Flexible power converters for the fault tolerant operation of Micro-Grids
2010
The progressive penetration level of Distributed Generation (DG) is destined to cause deep changes in the existing distribution networks no longer considered as passive terminations of the whole electrical system. A possible solution is the realization of small networks, namely the Micro-Grids, reproducing in themselves the structure of the main production and distribution of the electrical energy system. In order to gain an adequate reliability level of the microgrids the individuation and the management of the faults with the goal of maintaining the micro-grid operation (fault tolerant operation) is quite important. In the present paper flexible power converters and a companion control al…
A multi-agent system reinforcement learning based optimal power flow for islanded microgrids
2016
In this paper, a distributed intelligence algorithm is used to manage the optimal power flow problem in islanded microgrids. The methodology provides a suboptimal solution although the error is limited to a few percent as compared to a centralized approach. The solution algorithm is multi-agent based. According to the method, couples of agents communicate with each other only if the buses where they are located are electrically connected. The overall prizing system required for learning uses a feedback from an approximated model of the network. Based on the latter, a distributed reiforcement learning algorithm is implemented to minimize the joule losses while meeting operational constraints…
Independent energetic grids for a smart island: Model and design of a microgrid for a small Italian island
2016
Unlike many Italian peninsular areas, which are increasingly turning to a diverse supply of renewable resources to generate electricity, Italian not-interconnected small islands continue to rely on oil for their electricity and other energy needs (e.g. transports). Small-scale electricity systems, that are not connected to a larger electricity grid, are usually more expensive. The present paper proposes the functional design of an innovative Smart Grid which allows changing an Italian small not-interconnected island, Pantelleria, into a smart island, towards a more sustainable energy model. In detail, a techno-economic feasibility study is performed in order to design a Smart Grid at Pantel…
A new architecture for Smart Contracts definition in Demand Response Programs
2019
The present paper shows the possibility to use a smart contract for defining a distributed Demand Response mechanism. The use of the blockchain and smart contracts for the Demand Response mechanism allows the creation of an automatic system, where network users can communicate with the DSO to provide their flexibility. The blockchain ensures that the same information is shared among the users of the grid, while preserving user privacy. The DSO notifies the request to increase or reduce the load in a given period of the day using channels, a native abstraction of Hyperledger Fabric. The smart contract computes the support provided by each user to fulfill the requested load adaptation and aut…