Search results for " grid"
showing 10 items of 358 documents
Hybrid passive and communications-based methods for islanding detection in medium and low voltage smart grids
2013
Islanding condition takes place when a distributed generator (DG) continues to power a part of the grid even if power from electric utility is no longer present. Adverse effects of islanding are power quality deterioration, grid-protection interference, equipment damage, and personnel safety hazards. For these reasons, DG systems must detect an islanding condition and immediately disconnect from the grid (anti-islanding protection). This paper proposes an hybrid solution, for both low voltage (LV) and medium voltage (MV) applications, which makes use of passive and communication-based methods for islanding detection. Among the existing communication technologies, the study is focused on pow…
A New Solution for Low-Voltage Distributed Generation Interface Protection System
2015
In this paper, a new solution is proposed for the remote monitoring and control of distributed generators (DGs) and energy storage systems (ESSs) connected to low-voltage distribution networks. The proposed system fulfills the in-force standard requirements for the connection of DGs to the utility grid. Moreover, it allows implementing some enhanced functions for the remote control of inverters of DGs and ESSs, not only in terms of disconnection but also in terms of voltage regulation and power shuttering. The proposed solution is based on a new interface protection system and a dedicated secondary substation concentrator, which allows the communication between the distributed system operat…
Development of a Coupling System for Medium Voltage Power Line Communication in the CENELEC A Frequency Band
2016
In this paper the performances of a new power line communication (PLC) coupling system for medium voltage (MV) smart grids are investigated in the CENELEC A frequency band (i.e. 3 - 95 kHz). The new coupling solution is based on the use of the capacitive divider of the voltage detecting system (VDS) as PLC coupler to the MV network. According to IEC 61243-5, VDS are worldwide used to reveal the presence of the mains voltage to ensure the safety of the operators. A proper interface circuit has been invented and patented to couple the PLC signal through the VDS. In this way no dedicated MV PLC coupler is required, thus avoiding the related costs of the coupler, of its installation, and those …
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…
Electromagnetic immunity analysis of a new interface device with power line communication for smart grid and energy storage applications
2013
An analysis of EMC standards related to smart grid devices with PLC port has been carried out and the standardization lacks have been pointed out with reference to the evaluation of electromagnetic immunity to narrowband, coming from other communication systems connected to the grid, and RF disturbances conducted disturbances, usually present in a power grid. In particular, the paper analyses the electromagnetic conducted immunity of a new interface protection device (ID) for smart grid and energy storage applications. The new ID is equipped with a measuring board, a STM32 microcontroller, for data elaboration and memorization, and a ST7580 N-PSK powerline transceiver. An experimental test …
Electric and magnetic emission in near field region and thermal behaviour of power module for photovoltaic application
2015
The new power module, characterized by high power density, miniaturization of packages and layout and high frequency switching, are increasingly used in the field of in automotive, aircraft industry and for Distributed Generation (DG) connected to smart grid. To guarantee the reliability and safety of these systems, the electromagnetic compatibility (EMC) and thermal behavior, have to be carefully considered for these appliances. This paper describes a measurement methodology to characterize the electromagnetic emissions in near field zone produced by a PM prototype and its thermal behavior. In particular, the electric and magnetic fields, in the near field region in the frequency range 9kH…
Integration of IEC 61850 MMS and IEEE 802.22 for Smart Grid Communication
2017
The reliability of Smart Grid depends on two-way communication between substation and utility. IEC 61850 is an international standard defined to ensure interoperability between Substation Automation System (SAS). IEC 61850 services are mapped on the Manufacturing Message Specification (MMS) especially for meter data management system. MMS is the OSI protocol that run over TCP/IP or OSI networks to support IEC 61850 services. Presently, the MMS uses Ethernet as the layer 2 protocol. However, for long distance communication in remote areas wireless communication is the prefered mode. The Cognitive Radio based IEEE 802.22 is next generation standard for Wireless Regional Area Network (WRAN) th…
Review of IEEE 802.22 and IEC 61850 for real-time communication in Smart Grid
2015
Real time data communication in Smart Grid is a big challenge due to its vastness and complexities. Wireless Regional Area Network (WRAN) - IEEE 802.22 permits opportunistic use of television white space (TVWS) by secondary user, if it is not being utilized by primary user. This standard has the potential to transfer big data of smart grid in real time to control center. The IEC 61850 is the standard for electrical substation automation that uses TCP/IP for data transfer among different ‘intelligent electronic devices’ (IEDs). IEC 61850 consists of different message types which belong to different performance classes that are mapped to different communication protocols. The different perfor…
Thermodynamic-based cost allocation in low-temperature thermal grids in presence of distributed energy producers
2022
Thermal grids are well-established technologies that can cover the thermal demands of buildings in a more sustainable way. The lower operating temperature will allow not only for the integration of heat produced by thermal renewable energy sources but also for the storage of surplus electricity from the grid using power to heat technologies. To ensure a wider diffusion of this technology, it is important to propose a method for the cost allocation among producers connected to the grid. In this regard, this paper proposes Exergoeconomics as a possible solution. To show the capabilities of the method, some operating scenarios are compared for a cluster of five buildings in the tertiary sector…
On thermoeconomics of energy systems at variable load conditions: integrated optimization of plant design and operation
2007
Abstract Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process an…