1,720,990 research outputs found
Application of solid-state transformers in a novel architecture of hybrid AC/DC house power systems
Full text linkThe ongoing diffusion of solid-state DC/DC converters makes possible a partial migration of electric power systems from the present AC paradigm to a future DC scenario. In addition, the power demand in the domestic environment is expected to grow considerably, for example, due to the progressive diffusion of electric vehicles, induction cooking and heat pumps. To face this evolution, the paper introduces a novel electric topology for a hybrid AC/DC smart house, based on the solid-state transformer technology. The electric scheme, voltage levels and converters types are thoroughly discussed to better integrate the spread of electric appliances, which are frequently based on internal DC buses, within the present AC distribution networks. Voltage levels are determined to guarantee high safety zones with negligible electric risk in the most exposed areas of the house. At the same time, the developed control schemes assure high power quality (voltage stability in the case of both load variations and network perturbations), manage power flows and local resources according to ancillary services requirements and increase the domestic network overall efficiency. Dynamic simulations are performed, making use of DIgSILENT PowerFactory software, to demonstrate the feasibility of the proposed distribution scheme for next-generation smart houses under different operating conditions
Remote islanded distribution networks supplied by BESS integrated PV generation units
No full textIn some countries, electrical distribution lines have to cross areas where the installation cost could be very high and carrying out maintenance could become extremely difficult (e.g. desert areas). As a result, frequent power disconnections and blackout heavily affect the quality of supply of end-users. Oppositely, the renewable energy sources exploitation in supplying portions of the distribution network during system disconnections is very interesting, both for reducing fossil fuel use and as backup power generator. In case the islanded local electrification makes use of discontinuous and unpredictable energy sources such as photovoltaic, a Battery Energy Storage System is required to regulate the system, supplying power balance and voltage stability. In the paper, a stand-alone distribution network, corresponding in size to a typical Libyan oasis-village, has been developed and analysed. A photovoltaic generator locally supplies the islanded network, while an integrated BESS provides the daily energy balance and the system stability. The research examines the effectiveness of the proposed control strategy, developed with the scope of coordinating the role of both the solar generation and the energy storage system in facing active and reactive power requirements of the connected loads. Specific algorithms are introduced to define the optimal electrical operating condition in terms of voltage and frequency. Power system simulations demonstrate the control strategy strengths in terms of stability and time of response. Quality of supply, evaluated in terms of frequency deviations and voltage profiles, remains considerably high also considering different scenarios and introducing quick load variations. Finally, a brief investigation on integrating photovoltaic, storage and traditional generators (making use of fossil fuels) is presented
Optimal Management of Battery-Integrated Renewable Energy Communities for Providing Energy Flexibility Services
No full textThis paper examines the challenges and opportunities in the European energy sector, with a particular focus on Italy, in light of the ongoing energy crisis and policies aimed at transitioning to renewable sources. Utilizing an optimization-based approach, the study analyzes innovative methodologies to manage the complexities of the current energy system. Specifically, it investigates the crucial role of communication between distribution system operators and renewable energy communities in maximizing mutual benefits and addressing the challenges posed by the energy crisis. The findings of this study could provide valuable insights for the development of effective energy policies, guiding the transition towards a more sustainable and efficient energy system in Europe
A novel methodology for the management of distribution network based on neutral losses allocation factors
No full textOptimal Dispatch of PV Inverters in Multi-Phase Low Voltage Active Distribution Networks
No full textA novel optimal PhotoVoltaic (PV) inverter dispatch scheme is proposed in this paper which combines the active power curtailment and reactive power control schemes in order to simultaneously determine the optimal active and reactive power set points of residential PVs. The non-convexity of resultant AC optimal power flow model, caused by the inherent power balance constraints and selective inclusion of PV systems through binary variables, is handled by leveraging the cheap semi-definiteprogramming and sparsity-promoting-regularization approaches. The application of proposed methodology on a low-voltage test distribution network shows that recurrent technical issues of these networks such as voltage rise and voltage unbalance can be successfully mitigated as well as significant reduction in active power losses can also be achieved
Convexified OPF in Multiphase Low Voltage Radial Distribution Networks including Neutral Conductor
No full textCentralized OPF in Unbalanced Multi-Phase Neutral Equipped Distribution Networks Hosting ZIP Loads
Full text linkAssessing the frequency support provided by DFIG wind turbines according to current standards
No full textNowadays, wind turbines commonly installed in new plants include a power converter. This allows these generators to operate in a variable speed range with the aim of maximizing the primary source exploitation. On the other hand, the presence of a converter implies a partial decoupling from the grid. Several studies have been carried out to enhance the ability of wind turbines in supporting frequency stability in the case of network events, and some grid codes recently include these regulating functions as required specifications. This work presents a novel control system applied to a Doubly Fed Induction Generator to make it compliant with present Italian standards. In order to characterize the role of wind turbines in supporting network frequency, several simulations have been carried out in the DIgSILENT PowerFactory environment. Main advantages and disadvantages are identified and discussed, depending on both the wind turbine operating conditions and the characteristics of the required stabilizing contribution
Bus injection relaxation based OPF in multi-phase neutral equipped distribution networks embedding wye- and delta-connected loads and generators
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