163 research outputs found
Recommended from our members
Robust cloud motion estimation by spatio-temporal correlation analysis of irradiance data
Storage Size Determination for Grid-Connected Photovoltaic Systems
In this paper, we study the problem of determining the size of battery
storage used in grid-connected photovoltaic (PV) systems. In our setting,
electricity is generated from PV and is used to supply the demand from loads.
Excess electricity generated from the PV can be stored in a battery to be used
later on, and electricity must be purchased from the electric grid if the PV
generation and battery discharging cannot meet the demand. Due to the
time-of-use electricity pricing, electricity can also be purchased from the
grid when the price is low, and be sold back to the grid when the price is
high. The objective is to minimize the cost associated with purchasing from (or
selling back to) the electric grid and the battery capacity loss while at the
same time satisfying the load and reducing the peak electricity purchase from
the grid. Essentially, the objective function depends on the chosen battery
size. We want to find a unique critical value (denoted as ) of the
battery size such that the total cost remains the same if the battery size is
larger than or equal to , and the cost is strictly larger if the
battery size is smaller than . We obtain a criterion for evaluating
the economic value of batteries compared to purchasing electricity from the
grid, propose lower and upper bounds on , and introduce an efficient
algorithm for calculating its value; these results are validated via
simulations.Comment: Submitted to IEEE Transactions on Sustainable Energy, June 2011; Jan
2012 (revision
Optimal Voltage Regulation of Unbalanced Distribution Networks with Coordination of OLTC and PV Generation
Photovoltaic (PV) smart inverters can regulate voltage in distribution
systems by modulating reactive power of PV systems. In this paper, an
optimization framework for optimal coordination of reactive power injection of
smart inverters and tap operations of voltage regulators for multi-phase
unbalanced distribution systems is proposed. Optimization objectives are
minimization of voltage deviations and tap operations. A novel linearization
method convexifies the problem and speeds up the solution. The proposed method
is validated against conventional rule-based autonomous voltage regulation
(AVR) on the highly-unbalanced IEEE 37 bus test system. Simulation results show
that the proposed method estimates feeder voltage accurately, voltage deviation
reductions are significant, over-voltage problems are mitigated, and voltage
imbalance is reduced.Comment: IEEE Power and Energy Society General Meeting 201
Recommended from our members
Distributed energy storage system scheduling considering tariff structure, energy arbitrage and solar PV penetration (vol 205, pg 1384, 2017)
On the Evaluation of Plug-in Electric Vehicle Data of a Campus Charging Network
The mass adoption of plug-in electric vehicles (PEVs) requires the deployment
of public charging stations. Such facilities are expected to employ distributed
generation and storage units to reduce the stress on the grid and boost
sustainable transportation. While prior work has made considerable progress in
deriving insights for understanding the adverse impacts of PEV chargings and
how to alleviate them, a critical issue that affects the accuracy is the lack
of real world PEV data. As the dynamics and pertinent design of such charging
stations heavily depend on actual customer demand profile, in this paper we
present and evaluate the data obtained from a node charging network
equipped with Level chargers at a major North American University campus.
The data is recorded for weeks starting from late . The result
indicates that the majority of the customers use charging lots to extend their
driving ranges. Also, the demand profile shows that there is a tremendous
opportunity to employ solar generation to fuel the vehicles as there is a
correlation between the peak customer demand and solar irradiation. Also, we
provided a more detailed data analysis and show how to use this information in
designing future sustainable charging facilities.Comment: Accepted by IEEE Energycon 201
- …