13,943 research outputs found
Optimized Solar Photovoltaic Generation in a Real Local Distribution Network
Remarkable penetration of renewable energy in electric networks, despite its
valuable opportunities, such as power loss reduction and loadability
improvements, has raised concerns for system operators. Such huge penetration
can lead to a violation of the grid requirements, such as voltage and current
limits and reverse power flow. Optimal placement and sizing of Distributed
Generation (DG) are one of the best ways to strengthen the efficiency of the
power systems. This paper builds a simulation model for the local distribution
network based on obtained load profiles, GIS information, solar insolation,
feeder and voltage settings, and define the optimization problem of solar PVDG
installation to determine the optimal siting and sizing for different
penetration levels with different objective functions. The objective functions
include voltage profile improvement and energy loss minimization and the
considered constraints include the physical distribution network constraints
(AC power flow), the PV capacity constraint, and the voltage and reverse power
flow constraints.Comment: To be published (Accepted) in: Proceedings of the IEEE PES Innovative
Smart Grid Technologies Conference (ISGT), Washington D.C., USA, 201
Decentralized Demand Side Management with Rooftop PV in Residential Distribution Network
In the past extensive researches have been conducted on demand side
management (DSM) program which aims at reducing peak loads and saving
electricity cost. In this paper, we propose a framework to study decentralized
household demand side management in a residential distribution network which
consists of multiple smart homes with schedulable electrical appliances and
some rooftop photovoltaic generation units. Each smart home makes individual
appliance scheduling to optimize the electric energy cost according to the
day-ahead forecast of electricity prices and its willingness for convenience
sacrifice. Using the developed simulation model, we examine the performance of
decentralized household DSM and study their impacts on the distribution network
operation and renewable integration, in terms of utilization efficiency of
rooftop PV generation, overall voltage deviation, real power loss, and possible
reverse power flows.Comment: 5 pages, 7 figures, ISGT 2018 conferenc
Application of a simplified thermal-electric model of a sodium-nickel chloride battery energy storage system to a real case residential prosumer
Recently, power system customers have changed the way they interact with public networks, playing a more and more active role. End-users first installed local small-size generating units, and now they are being equipped with storage devices to increase the self-consumption rate. By suitably managing local resources, the provision of ancillary services and aggregations among several end-users are expected evolutions in the near future. In the upcoming market of household-sized storage devices, sodium-nickel chloride technology seems to be an interesting alternative to lead-acid and lithium-ion batteries. To accurately investigate the operation of the NaNiCl2 battery system at the residential level, a suitable thermoelectric model has been developed by the authors, starting from the results of laboratory tests. The behavior of the battery internal temperature has been characterized. Then, the designed model has been used to evaluate the economic profitability in installing a storage system in the case that end-users are already equipped with a photovoltaic unit. To obtain realistic results, real field measurements of customer consumption and solar radiation have been considered. A concrete interest in adopting the sodium-nickel chloride technology at the residential level is confirmed, taking into account the achievable benefits in terms of economic income, back-up supply, and increased indifference to the evolution of the electricity market
Time-Series Analysis of Photovoltaic Distributed Generation Impacts on a Local Distributed Network
Increasing penetration level of photovoltaic (PV) distributed generation (DG)
into distribution networks will have many impacts on nominal circuit operating
conditions including voltage quality and reverse power flow issues. In U.S.
most studies on PVDG impacts on distribution networks are performed for west
coast and central states. The objective of this paper is to study the impacts
of PVDG integration on local distribution network based on real-world settings
for network parameters and time-series analysis. PVDG penetration level is
considered to find the hosting capacity of the network without having major
issues in terms of voltage quality and reverse power flow. Time-series analyses
show that distributed installation of PVDGs on commercial buses has the maximum
network energy loss reduction and larger penetration ratios for them.
Additionally, the penetration ratio thresholds for which there will be no power
quality and reverse power flow issues and optimal allocation of PVDG and
penetration levels are identified for different installation scenarios.Comment: To be published (Accepted) in: 12th IEEE PES PowerTech Conference,
Manchester, UK, 201
Financial Analysis of a Grid-connected Photovoltaic System in South Florida
In this paper the performance and financial analysis of a grid-connected
photovoltaic system installed at Florida Atlantic University (FAU) is
evaluated. The power plant has the capacity of 14.8 kW and has been under
operation since August 2014. This solar PV system is composed of two 7.4 kW
sub-arrays, one fixed and one with single axis tracking. First, an overview of
the system followed by local weather characteristics in Boca Raton, Florida is
presented. In addition, monthly averaged daily solar radiation in Boca Raton as
well as system AC are calculated utilizing the PVwatts simulation calculator.
Inputs such as module and inverter specifications are applied to the System
Advisor Model (SAM) to design and optimize the system. Finally, the estimated
local load demand as well as simulation results are extracted and analyzed.Comment: 6 Pages, IEEE PVSC 2017 Conference, Washington D.
Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration
We show how distributed control of reactive power can serve to regulate
voltage and minimize resistive losses in a distribution circuit that includes a
significant level of photovoltaic (PV) generation. To demonstrate the
technique, we consider a radial distribution circuit with a single branch
consisting of sequentially-arranged residential-scale loads that consume both
real and reactive power. In parallel, some loads also have PV generation
capability. We postulate that the inverters associated with each PV system are
also capable of limited reactive power generation or consumption, and we seek
to find the optimal dispatch of each inverter's reactive power to both maintain
the voltage within an acceptable range and minimize the resistive losses over
the entire circuit. We assume the complex impedance of the distribution circuit
links and the instantaneous load and PV generation at each load are known. We
compare the results of the optimal dispatch with a suboptimal local scheme that
does not require any communication. On our model distribution circuit, we
illustrate the feasibility of high levels of PV penetration and a significant
(20% or higher) reduction in losses.Comment: 6 pages, 5 figures
Modeling a Grid-Connected PV/Battery Microgrid System with MPPT Controller
This paper focuses on performance analyzing and dynamic modeling of the
current grid-tied fixed array 6.84kW solar photovoltaic system located at
Florida Atlantic University (FAU). A battery energy storage system is designed
and applied to improve the systems stability and reliability. An overview of
the entire system and its PV module are presented. In sequel, the corresponding
I-V and P-V curves are obtained using MATLAB-Simulink package. Actual data was
collected and utilized for the modeling and simulation of the system. In
addition, a grid- connected PV/Battery system with Maximum Power Point Tracking
(MPPT) controller is modeled to analyze the system performance that has been
evaluated under two different test conditions: (1) PV power production is
higher than the load demand (2) PV generated power is less than required load.
A battery system has also been sized to provide smoothing services to this
array. The simulation results show the effective of the proposed method. This
system can be implemented in developing countries with similar weather
conditions to Florida.Comment: 6 pages, 14 figures, PVSC 201
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