Implementation and Experimental Tests of a Management System for MV/LV Distribution Grids
The continuous monitoring of network power flows and the remote control of Distributed Generators... more The continuous monitoring of network power flows and the remote control of Distributed Generators and Energy Storage Systems are the essential elements to allow a full exploitation of Renewable Energy Sources and their real integration in distribution networks. Thus in the paper a management system is presented for load flow monitoring in MV/LV distribution network. Moreover, on the basis of calculated power flows, the management system is able to send control commands to DGs and ESSs, to vary their power production or power factor or eventually to disconnect them in order to maintain the network stability. The proposed solution was really implemented in the MV network of Ustica Island, developing a dedicated Supervisory Control And Data Acquisition system. Different experimental tests were performed to verify the management system performances. To emulate the case of power flow inversion due to an increase of distributed generated power an on-field distributed generator emulator was assembled in a mobile station and it was connected to a generic point of the low voltage network.
Realizzazione di un banco di misura e di un modello in Simulink per la ricerca e la caratterizzazione di reti di accoppiamento per la trasmissione di segnali su cavi di media tensione
Experimental EMF characterization of a secondary substation
This paper presents the results of the experimental EMC characterization of a new medium/low volt... more This paper presents the results of the experimental EMC characterization of a new medium/low voltage (MV/LV) secondary substation, which was developed in the framework of the research project "NEW CAB ELARC". It has two MV/LV transformers, with total rated power of 1000 kVA. To perform the experimental characterization, firstly an analysis was performed of the Italian and European standards recommendations. Different approaches were highlighted and the most appropriate procedures were identified for the measurement of the magnetic fields emissions, at power systems frequency (50 Hz) in steady-state conditions. A dedicated test lab was set up for the secondary substation characterization. The measurement results showed that, thanks to the chosen layout, the emissions of the substation under test are lower than those of typical substations of the same power.
A back to back method for the temperature rise test of prefabricated substations: A case study
In this work a back to back method is presented which allows to develop heating tests of prefabri... more In this work a back to back method is presented which allows to develop heating tests of prefabricated secondary substations with a limited number of supplying equipment (an induction regulator and a capacitor bank). The proposed method makes use of the transformer tap changers to create a voltage difference on the medium voltage side. In this way, only an adjunctive low voltage supply is needed. With the proposed test system, the heating tests are developed on a 1000 kVA prefabricated substation. Thanks to the experimental tests, the class of enclosure of the substation and the operating temperature and resistance of the power transformers are determined, according to the recommendations of the standards EN 62271-202 and EN 60076-2. Beside the traditional tests prescribed by the standards, a thermographic analysis of the substation under test is also performed. The simplicity of this analysis suggests its usefulness as pre-compliance test, which can be also performed in manufacturer laboratories.
A fuel cell powered autonomous surface vehicle: The Eco-SWAMP project
International Journal of Hydrogen Energy, Jun 1, 2021
Abstract Autonomous surface vehicles are becoming consolidated robotic tools for marine, coastal ... more Abstract Autonomous surface vehicles are becoming consolidated robotic tools for marine, coastal and inland surveys. Autonomous surface vehicles are usually equipped with electronic instruments to perform remotely controlled or autonomous geo-morphological, biological, chemical, physical analyses and data collection. Actually, well-established solutions provide battery power but the research focuses on introducing a fuel cell to decrease the environmental impact meanwhile increasing the cruising range. In this paper, the design of the Eco-SWAMP, a fuel cell powered autonomous surface vehicle, is presented starting from its battery-powered version, the SWAMP prototype. The experimental power consumption profile of the SWAMP during four missions is analysed to define the primary energy sources ratings of the Eco-SWAMP. After a commercial choice of primary sources, power management algorithms are designed and compared in MATLAB/Simulink environment by simulation results. The proposed procedure can be easily applied to any autonomous marine vehicle.
The aim of this paper is to develop a complete model of a power-line communication (PLC) system o... more The aim of this paper is to develop a complete model of a power-line communication (PLC) system operating on a medium-voltage (MV) network. The core-shield configuration was chosen for signal transmission in the power cables. In order to validate the developed model experimental, the medium-voltage network of the Favignana island was used to carry out detailed testing. The transmission was performed between two transformer substations in the presence of mains voltage (i.e., 24 kV). ST7540 FSK power-line transceivers, together with capacitive coupling interfaces, were used for the transmission and the reception of the communication signal. The correlation between the experimental measurements and the simulation results would appear to validate the use of the developed model for the analysis of MV transmission channels.
A new method for forecasting energy output of a large-scale solar power plant based on long short-term memory networks a case study in Vietnam
Electric Power Systems Research, Oct 1, 2021
Abstract This paper proposes a new model for short-term forecasting power generation capacity of ... more Abstract This paper proposes a new model for short-term forecasting power generation capacity of large-scale solar power plant (SPP) in Vietnam considering the fluctuations of weather factors when applying the Long Short-Term Memory networks (LSTM) algorithm. At first, a configuration of the model based on the LSTM algorithm is selected in accordance with the weather and operating conditions of SPP in Vietnam. Not only different structures of LSTM model but also other conventional forecasting methods for time series data are compared in terms of error accuracy of forecast on test data set to evaluate the effectiveness and select the most suitable LSTM configuration. The most suitable configuration has been selected and applied on Thanh Thanh Cong No 1 (TTC) SPP with 2 input cases: real historical weather data and forecasted weather data. The results show that second case gives a much larger Mean Absolute Percentage Error (MAPE) than that of first case (10.857% versus 3.491%). Based on above experiment, new additional features are proposed to improve the selected LSTM model precision and cope with the problem of error due to weather forecast data. The result of the application of the new prediction model for TTC solar plant indicates that the MAPE is reduced from 10.857% to 9.881%.
An innovative power line communication solution for medium voltage smart grids applications
This paper summarizes the authors research activity concerning the design, modeling and experimen... more This paper summarizes the authors research activity concerning the design, modeling and experimental characterization of a new coupling system for medium voltage (MV) narrow band power line communications (NB-PLC). The proposed solution has been patented by authors and it exploits the capacitive divider of voltage detecting systems (VDSs) normally used to reveal the mains voltage presence, thus avoiding the use of dedicated MV couplers. In the following, the modeling of the VDS capacitive divider is presented and the interface card design is described, based on simulation of the whole PLC transmission channel. Laboratory tests are also presented. Finally, the results are shown of an on-field measurement campaign, which has been carried out the MV distribution networks of the Islands of Ustica and Favignana. Transmission tests demonstrate that the proposed VDS coupling system can be effective for narrowband modulated signal transmission
Campagna di misure sulla rete elettrica dell’isola di Favignana per la caratterizzazione di reti di accoppiamento per la trasmissione di segnali su cavi di media tensione
Experimental Evaluation on Narrow Band Power Line Communication in Medium and Low Voltage Smart Grids
International Symposium on Power Line Communications and Its Applications, Mar 1, 2013
The aim of this work is to perform a feasibility study on the power line communication for the de... more The aim of this work is to perform a feasibility study on the power line communication for the development of a new generation of interface devices (IDs) for smart grid and energy storage applications. More in detail, this paper deals with one of the most important issues on this topic, which is the communication system. Among the existing communication technologies, the study is focused on power line communications (PLCs). After an analysis of the state of the art in the field, the main aspects are analyzed, concerning the open issues on the use of PLCs, especially for medium voltage (MV) and low voltage (LV) systems. In this work the use of PLC in MV-LV networks is investigated, by means of experimental tests in the case of a two-ways MV/LV communication between two secondary substations connected by a MV overhead power line by considering a ST7580 transceiver used in a new ID developed by the authors. Each substation has a by-pass connection at MV bus-bars and a MV/LV oil filled power transformer. Firstly, communication issues are presented, secondly experimental test in the presence of voltage net, i.e. 24 kV have been carried out to verify the possibility of power transformer crossing
A set of indicators for arc faults detection based on low frequency harmonic analysis
In this paper a novel set of indicators is presented for arc faults detection in electrical circu... more In this paper a novel set of indicators is presented for arc faults detection in electrical circuits. The indicators are defined starting from an experimental characterization of the arc fault phenomenon and the study of the arcing current in several test conditions, which were chosen in accordance with the UL 1699 Standard requirements. The proposed parameters are measured by means of a high resolution low frequency spectral analysis of the arcing current, which allows to achieve a good spectral resolution even with short observation windows.
High frequency modeling technique for three phase power electronics module
2015 5th International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)
Nowadays, the high integrated power electronics modules (PMs), characterized by high speed, low l... more Nowadays, the high integrated power electronics modules (PMs), characterized by high speed, low loss and hard ware miniaturization, represent a new technology that meets the emerging demands of many applications, such us vehicle and home appliance, renewable energy sources in smart grid. The integration process and the high switching speeds increase the PM electromagnetic emissions that can create electromagnetic interference (EMI) with electric/electronic devices near the PMs. For this reason, electromagnetic compatibility (EMC) have to be carefully considered, yet in the design phase, to guarantee the reliability of PM systems. In this paper a method to develop a high frequency (HF) model, useful to study EMI phenomena of a three-phase PM, is presented. The method is based on experimental measurements at the PM external pins and it allows to extract internal inductive and capacitive parasitic coupling with out the knowledge of structural and physics parameters of the device. The PM HF model, developed in the 150kHz-30MHz frequency range, has been implemented in MATLAB® environment. The method has been experimental validated comparing the frequency responses of the PM characteristics with that obtained by the model.
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Papers by Dario Di Cara