Search results for "Grid"

Fundamental Analysis of Grid-Forming Converters Enhanced with Feedforward Controls

2022

The grid-forming control for power converters can be enhanced by proper feedforward terms included in the active power control loop. Two basic structures are identified, the feedforward angle and the feedforward frequency. The formal analysis of the transfer functions reveals a structural similarity. The two schemes exhibit however a fundamental difference in their transient capabilities. The grid-forming controls are characterized with the introduction of two specific factors, for the direct assessment of the inertia and the damping which can be provided by the grid-forming converter. The sensitivity analysis of the two feedforward schemes indicates that the enhancement of the transient pe…

FLEXIBILITY OPTIMISATION PLATFORMS FOR ENERGY MANAGEMENT OF SMART POWER SYSTEMS

A Comparison between RMS and EMT Grid-Forming Implementations in MATLAB/Simscape for Smart Grids Dynamics

2022

The article presents a comparison between phasor RMS and EMT models for grid-forming converters. The specific aspects related to the implementation in Simscape Electrical of MATLAB/Simulink are discussed for both RMS and EMT time-domains. The comparison between the different implementations is performed with the simulation of two widely studied grid-forming schemes, the virtual synchronous machine and the power-synchronization control. The simulation-based comparison examines transient phenomena with different characteristics and time scales, including frequency transients, phase jumps and short-circuit events. Specific indications regarding limitations and suitability of grid-forming model…

Predictions in Resilient Hybrid AC/DC Grids Leveraged by an Interoperable and Secure ICT Platform

2022

Power systems are undergoing a significant change and the main elements to address the new challenges is the new key-role played by the distribution grid and its transformation into a smart grid. While the distribution grid has traditionally operated with alternating current (AC), nowadays most devices operate with DC internally, and most distributed renewable resources generate power in DC. Furthermore, storage components, such as batteries and supercapacitors, have a DC character. DC seems to be the one of the most promising candidates to avoid stranded investments and to guarantee incredible saving for the community in Europe, making the transition to a fully decarbonised energy system a…

The possibility of applying combined heat and power microgrid model for industrial parks. A case study for Dong Nam industrial park in Vietnam

2023

Microgrid systems that combine cooling, heating and power (CHP) with distributed cogeneration units and renewable energy sources are a practical way to meet the growing need for energy, and industrial parks have enormous potential for the development of integrated electrical and thermal systems. This paper presents a microgrid CHP model and evaluates the possibility of developing the model in the Dong Nam industrial park in Ho Chi Minh City, Vietnam. HOMER software was used to evaluate the effectiveness of the model.

REGULATION DROOP COEFFICIENTS IN ISLANDED MICROGRIDS

In this thesis, a novel non-linear droop control is proposed. The droop curve is generated as a piecewise linear curve from the optimized operating points of the system under consideration for different values of the supplied load. For each Optimal Power Flow (OPF), the droop coefficients are generated and these create small piecewise linear parts of the final droop curve. The operation is constrained by frequency and voltage limits. It is well known that the load flow problem solution can provide infinite operating points if the generators set point is not fixed. For each loading condition, the solution to the OPF problem outputs a single solution. Such solution, in case of microgrids with…

Demand Response Pricing Strategies for Islanded Microgrids

2013

In this paper, Time of Use and Critical Peak Pricing policies are designed and their effects on optimized operation is evaluated. For this purpose, an optimal operation algorithm is employed and the relevant production costs are derived. As far as the Time of Use policy is concerned, such costs are observed to be different in two time intervals of the day, due to the loads changing effect and the production of renewable energy. Whereas in the Critical Peak Pricing Policy, a peak time interval is identified to set up different pricing rates. The optimization algorithm used to carry out the work described above minimizes the microgrid's energy losses, the production costs and the Green House …

A Simulation Study for Assessing the Minimum Number of V2G Recharge Points in Favignana

2022

Issues related to the stability of non-interconnected grids are of high relevance given the increasing presence of renewable sources in the power generation system. In order to ensure adequate levels of system's reliability, it is necessary to find new methods to ensure the stability of the electric grid. The present work proposes a methodology for the definition of the minimum number of Vehicle-to-Grid (V2G) charging points that would allow the integration of 1 MW of photovoltaic power in the power grid of the Italian island of Favignana, electrically disconnected from the continental grid. Primary frequency regulation simulations are carried out in Matlab/Simulink environment for differen…

Optimal energy management in the smart grid

2017

In this chapter, the problem of energy management in smart grids is outlined. Optimized energy management is considered here as the operation of energy and power flow control in the aim of attaining minimum cost or minimum power losses while meeting technical constraints. Of course, according to the type of energy system in which such operation is carried out, the meaningful variables and objectives in the problem may largely change. As the extension of the system increases, the influence of the physical behaviour of the electrical power lines takes a more important role. Power electronics takes instead an increasing influence, as the dimension of the power system decreases although Kirchho…

Challenges in Energy Systems for the Smart- Cities of the Future

2012

In the last years the European Union has actively promoted the renewable energies and the Combined Heat and Power (CHP) also for residential and tertiary buildings. The exploitation of renewable sources and cogeneration seems hampered by the regulatory wall that prohibit for residential, tertiary and commercial buildings the constitution of users clusters. In fact, the unification up to a threshold value of some tens of kVA, at least, can facilitate the installation of renewable energy power plants as solar PV modules or CHP systems (cogeneration) or CCHP systems (tri-generation), overcoming technical and economical barriers and combining several load profiles. The actual distribution syste…