1,720,975 research outputs found
Real-time monitoring and control system for Trieste University Campus electrical distribution grid
No full textThe growing integration needs in the electrical systems are increasingly demanding more control also on the distribution network. This can be satisfied by introducing advanced control on the small and medium distribution grid sites and, in general, introducing electronic devices for voltage and power-flow control. All these concepts are commonly summarized with the Smart Grid term and putting the emphasis on system management through the Micro Grid paradigm. In this context the distribution network of a university campus, with one connection point to the distribution network, can be an interesting test bed. In this paper the status and the evolution of the Trieste University Campus distribution network is presented, showing also the adopted technical solutions
Cold Ironing Integration in City Port Distribution Grids: Sustainable electrification of port infrastructures between technical and economic constraints
No full textIn the near future, a strong development in port infrastructures is expected in response to the ecological transition. At the same time, tight environmental requirements in city ports make compulsory new actions for site decarbonization. These two aspects are forcing toward a port electrification, where renewable energy resources and storage systems can increase port sustainability in accordance with the green deal
The Control and Monitoring System on a Medium Voltage AC Distribution Grid: Device Implementation and Calibration Procedure
No full textSeveral new functionalities are enabled by information and telecommunication technologies, even in the control systems of electrical distribution grids. As a matter of fact, the digital transformation of the energy sector will interest future electrical distribution systems. Among expected advantages, Renewable Energy Sources generation and enhanced environmental compatibility will match new services to optimize the grid functioning. Indeed, control and monitoring systems on a distribution grid can ensure an easier management of all the services that consumers, producers and prosumers provide to the network. Basing on these important potentialities, the paper presents technical details of a distribution network monitoring and control device based on a processor of the large and common x86 family and a real-time Linux operating system. The device is suitable for integrating all Information and Communication Technologies (ICTs) commonly adopted in high performance digital energy control systems
Enhanced partial frequency variation starting of hydroelectric pumping units: Model based design and experimental validation
Full text linkThe hydroelectric pumped storage is one of the most sustainable solutions to store electrical energy for optimizing the grid operation. However, the pump motor starting may constitute a significant issue for the power plant. Indeed, the motor's large power and the long power lines (needed for connecting remotely located plants to the grid) may prevent a direct-on-line start. On the other hand, constraints as spaces availability in the powerhouse, and time and cost availability (especially for revamping projects) limit the feasibility of other starting methods. In this paper, a novel starting method is proposed for the revamping of a hydroelectric power plant (HPP), where a synchronous machine is used to drive the pump. On the basis of the power plant characteristics, an enhanced version of the synchronous starting with partial frequency variation is proposed, leading to the creation of a startup sequence capable of being integrated into the existing excitation control systems’ software (of both the generator and the motor installed in the power plant). Such Enhanced Partial Frequency Variation (EPFV) starting method combines the advantages of back-to-back starting method to the ones of asynchronous starting, without requiring additional equipment in respect to a conventional direct-on-line start solution. This is enabled by the model-based design approach here applied, which allows to determine the correct set of parameters and variables’ thresholds required for the machine startup, taking into account the specific characteristics of the HPP in study. The developed starting sequence, implemented into the real HPP by using the capabilities of the existing digital excitation control systems, allowed the correct starting of the motor. This is demonstrated by experimental data obtained during the 5MVA motor starting tests. The results also prove the effectiveness of the model-based design approach in enabling the definition of the pump starting sequence, as well as validating the mathematical model used for the sequence design
Evolution of the Trieste Port: A real-time system for a coordinated cold ironing
No full textThe continuous growing in environment requirements combined with the proximity of ports to city centers make it necessary to take actions in favor of the site de-carbonization. Therefore the electrical distribution grid of port needs to be analyzed and renewed for reducing the CO2 equivalent mass produced. This goal can be reached by using an integrated monitor systems in order to impose a desired power-flow and proper voltages on the different grid nodes. Not only the possibility of supervising the grid but also some notable functionalities are enabled by these innovative systems: for example cold ironing hubs, electrical vehicle recharge hubs, optimization of power generation and storage functionality. In this paper, the Port of Trieste is taken as case of study and possible evolution scenarios will be presented using a mathematical model of the medium voltage power system. Particularly, an innovative real-time hierarchical monitor system architecture will be discussed, while a patched Linux PC will be presented as possible monitor device implementation
A coordinated voltage and reactive power control architecture for large PV power plants
Full text linkThe increasing presence of nonprogrammable renewable energy sources (RES) forces towards the development of new methods for voltage control. In the case of centralized generation, the hierarchical regulation or secondary voltage regulation (SVR) is guaranteed by coordinated voltage and reactive power controls in transmission systems. This type of regulation loses effectiveness when the generation becomes distributed and based on small and medium sized generators. To overcome this problem, it is important that also distributed generators, typically based on RES, participate in the voltage regulation. By starting from the methodologies already applied, this work wants to present a new method for involving distributed generators in SVR. The novelty is given by the application of an existing methodology to the new configuration of electrical grids characterized by a relevant distributed generation. The aim is to control the distributed generators (DGs) as coordinated sources of reactive power for conveniently supporting the voltage regulation. In this paper, a real large photovoltaic (PV) plant is considered. The power plant is composed of several PV generators connected through a distribution network. With the algorithm proposed, the set of generators can be treated as a single traditional power plant that can participate in the hierarchical voltage regulation. The reactive power of each single generator is coordinated in a way similar to the SVR used in several national systems
Comparison Between Ring and Radial Configurations of the University of Trieste Campus MV Distribution Grid
Full text linkDistribution systems are being pushed towards smarter architectures, management strategies, and controls. To develop new platforms and algorithms for distribution systems management, the University of Trieste is using its medium voltage MW-scale ring distribution system as a demonstrator. In addition to the installation of a real-time monitoring system, power system studies and analyses are required. The paper presents and compares some results concerning the power system operation in both closed (normal operation) and open (post fault operation) configurations, where the latter are identified by means of a quantitative dependability analysis. In particular, the voltage profile, the currents, and the losses in the system are studied, evaluating the impact of faults capable of opening the ring
Dependability Analysis of a Digital Excitation Control System
No full textThe synchronous generators' excitation is usually regulated by means of a real-time digital control system, while other apparatuses are dedicated to secondary functions (e.g human machine interface, remote control unit, logic and control functions). A performance increase and a cost reduction can be achieved by integrating all the functions into a single platform. However, this requires assessing the dependability performance of the control systems currently in use, to set a base benchmark for future evaluations. In this paper, the quantitative dependability analysis of a digital excitation control system is performed, by using as a case study a real system installed in a hydroelectric power station. Two configurations are analyzed, and their dependability performance are compared
Electrical storage in distribution grids with renewable energy sources
No full textElectric storage brings significant benefits to the electric systems by counteracting the strong constraint that the generated power has to be instantaneously balanced by load. This paper analyses the prospect of the introduction of a storage device into a small distribution grid considered as an energy hub
Open Source Hardware in the Loop Real-time Simulation of Zonal DC systems
No full textThe development of innovative flexible power systems (e.g. DC grids, zonal distributions, hierarchical controlled grids, microgrids) involves the introduction of new active devices. The control and management of these devices is ensured only in presence of a distributed and performing data communication network. To properly operate the grid, each device must be thus the active interface to the other controlled systems. The test of these complex controlled configurations represents a challenge to be faced. In this regard, Hardware-In-the-Loop platforms are effective in the testing activity. The paper proposes a methodology to model a zonal DC system, whose simulation is performed in RTAI (Real Time Application Interface), an open source real-time operating system. The correct functioning of open source system is proven by comparing experimental-live transients and HIL simulation outputs. Such a verification testifies the potentiality of the described approach
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