1,721,037 research outputs found
Dual-loop generalized predictive control method for two-phase three-wire railway active power quality controller
No full textOne of the most challenging topics in electric railway networks (ERNs) is power quality (PQ) problems caused by single-phase feeding of time-varying and high-power locomotives. During previous years, many techniques and compensators have been offered to alleviate these problems. Railway active power quality controller (RAPQC) is considered as one of the most efficient approaches. Due to the time-variant, uncertainty and distorted features of ERNs, the controlling of RAPQCs has always been a substantial concern to experts. This paper presents, a new robust control system for two-phase three-wire RAPQC (ThRAPQC) based on generalized model predictive control integrated with modified instantaneous reactive power theory (GMPC-MIRP). A dual-loop balancing system has been adopted in the proposed control system to equalize the active powers of traction power substation (TPSS) adjacent feeders, compensate reactive powers and suppress harmonic simultaneously. The performance of the proposed method in comparison with the conventional Fryze-Buchholz-Depenbrock (FBD)-based current strategy together with hysteresis current controller (FBD-HCC) has been evaluated through the detailed simulations and Opal-RT 5600-based laboratory setup results. The fast response, high precision, lower fluctuation in reference current tracking and high capability of working in distorted conditions are the outstanding privileges of the proposed method that are confirmed by the output results
Monte Carlo BEV Users Simulation to Assess the Charging Stations Usage in Highway
No full textCar electrification is necessary to reduce Green-house Gasses(GHGs). Italy is behind the European Union average by both vehicle and charging infrastructure spread. The infrastructure planning needs to keep up with the expected growth of Electric Vehicles (EVs). This paper proposes a model based on Monte Carlo simulation of user charging behavior. The model tries to solve the dimensioning problem from the perspective of the policymaker in a high-demand scenario. It allows the assessment of the minimum number of charging ports for a specific service level. The case study of Al Milan-Bologna, an important highway section in Italy is shown
The Evolution of Railway Power Supply Systems Toward Smart Microgrids: The concept of the energy hub and integration of distributed energy resources
No full textIn recent years, the achievement of sustainable energy systems has become one of the foremost challenges of experts around the world. In this context, the reduction of energy consumption while providing optimum power flow to the end users is a substantial challenge in various fields of generation, transmission, and distribution. Environmental concerns like global greenhouse gas emissions and other problems related to fossil fuels, together with deficiency of resources, are other significant aspects
A-day-ahead photovoltaic power prediction based on long short term memory algorithm
No full textIn recent years, Photovoltaic System (PV) have been installed in parking lots in order to provide the green energy to Electric vehicles (EVs). Energy Synchronizing between PV generations and EVs demand is a function of different variables, and it is very challenging. Having an accurate prediction of PV generation helps to ease the complexity of this problem. Although various Machine Learning (ML) techniques have been applied and resulted well, traditional ML approaches need years of history of PV generations to make an accurate prediction. In many cases, parking lots or the houses recently equipped by PV panels, and this information is not available. Therefore, the primary motivation of this work is to build a reliable deep learning forecasting model based on Long Short Term Memory (LSTM) architecture in order to make a short-term prediction based on the limited previous observation. The proposed model is applied to a month of the PV power generation data and resulted in the promising accuracy with the Mean Absolute Percentage Error (MAPE) value of 0.028
Increasing transportation sustainability from scratch: Small city context
No full textReshaping transportation offer in metropolitan and suburban areas plays a fundamental role in complying with environmental commitment. A sustainable public transportation system is crucial to reduce air pollution and the overall environmental impact of transportation sector, going beyond mere displacement solutions offered. This paper presents how to implement a sustainable transportation solution starting from green shift investments in a small citizen centre. Two new bus lines were examined and planned to adapt the actual service to a potentially-evolving demand. Electric vehicle types were selected to compare full-electric with hydrogen traction systems. Moreover, particular attention was paid to the energy supply chain through Well-To-Tank analysis. Battery vehicles appear to be preferred, at the moment, when reliance on the national grid is prevailing showing affordable costs 1.8 €/km, +0.5 €/km with respect to the actual Diesel operations. However, also hydrogen energy vector resulted a competitive choice. Uncertainty in the market demand plays a great role and if reduced progressively, it allows to recover the heavy investments, given the high cost of ownership of 2.8 €/km. The research is enriched by the collaboration of a managerial representative of Arriva Italia, operator of local public transportation and an exponent of the scientific community
Simulation and optimisation study of the integration of distributed generation and electric vehicles in smart residential district
No full textThis paper presents an optimisation methodology for simulating the integration of distributed generation and electric vehicles (EVs) in a residential district. A model of a smart residential district is proposed. Different charging scenarios (CS) for private cars are considered for simulating different power demand distributions during the day. Four different case studies are investigated, namely the Base Case, in which no EVs are present in the district and three study cases with different CSs. A global optimisation method based on a genetic algorithm approach was applied on the model to find the total power from PV panels installed and co-generative micro gas turbines while minimising the annual energy cost in the district for the four different scenarios. In conclusion, the results showed that the use of EVs in the district introduces considerable savings with respect to the Base Case. Moreover, the impact of the chosen CS is nearly insignificant under a purely economic perspective even if it is relevant for grid management. Additionally, the optimum amounts of installed power vary in a limited range if the distance travelled by EVs, users’ departure and arrival time change broadly
EV charging station integrated with electric railway system powering by train regenerative braking energy
No full textDuring the last years, investment in developing electric vehicles (EVs) has been increased as an important strategy by nations to reduce carbon emission and consumption of fossil fuels. On the other side, the power supplying of multitudinous EV charging stations (EVChSs) may overload the utility grid and cause indirect emissions. However, a substantial content of electric energy is generated by applying regenerative braking in electric railway systems (ERSs). Integration of ERSs and EVChSs in the strategic points, like parking areas close to ERS stations or rail freight intermodal terminals with targeted exploitation of trains regenerative braking energy (RBE) as an ancillary supply, can improve the energy efficiency in EVChSs and reduce the cost. In this paper, a new method is proposed to charge EVs by transferring RBE from ERS to EVChS taking advantage of interface power electronics converters. In the proposed strategy, a railway power flow controller (RPFC) integrated with DC/DC converter has been adopted to restore RBE. The simulation results are provided to confirm the effectiveness of the proposed strategy
Public and Micro-Mobility Transportation Modes Comparison
No full textPublic transport and electric vehicles, two-wheeled especially, are expected to constitute a major part of future sustainable transport systems in smart cities. The focus of this paper is to analyze different paradigms of mobility on a fixed route in the center of Milan. The chosen path connects Milan Central station to Milano Bovisa station, a very traffic way. The first part of the paper is based on the analysis of the two most common means of urban transport in Milan: the train and the trolley bus. The comparison is performed in terms of energy consumption, emissions, and costs. In the second part, instead, the focus has been shifted to other means of transport: electric light micro-mobility. Given the increased interest these days in both electric scooters and electric bikes, a preliminary analysis of these two means of transport is carried out. From the results, it is possible to conclude that these types of vehicles represent a sustainable alternative for getting around the city
Different penetration of electric vehicles and impact on developments in the electric grid
No full textThe world of transport is facing a great challenge with individual transport accounting for about 80% of it with cars, gradually abandoning fossil fuels and traditional engines to embrace battery powered propulsion, observing in 2030 a significant diffusion of Electric Vehicles (EVs) in Europe exceeding 40 million units. The paper examines the impact of different level of penetration of electric mobility on the electricity network and Low Voltage (LV) Distribution network and in particular, what interventions and evolutions the distribution grid will have to undergo in order to manage this new and progressively increasing load of energy. Urban and rural grid models have been studied, to underline the differences between the EVs impact on High and Low density networks. A management model for the production and consumption of electricity has been proposed to improve the critical aspects obtained from the first simulations, coupling a PV system with an Energy Storage System (ESS). Finally, a solution to exploit the public Charging Stations (CSs) where to control the local voltage variations through connected EVs is presented
Sostenere gli investimenti in energie rinnovabili in assenza di incentivi nazionali: Il caso dell’introduzione dei veicoli elettrici
No full text- …
