The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, a communication-assisted protection scheme is proposed for medium voltage dc (MVDC) distribution networks. MVDC grids are applicable for connection between microgrids, upgrading the transmission capacity of ac lines by the conversion to dc, and integration of renewable energy systems to the distribution grids. However, protection issues are one of the main challenges in the development...
Currently, the standards used to calculate the short circuit (SC) current ignore the contribution of DC systems to the SC current when short-circuit faults occur in an AC systems. With the rapid development of High Voltage Direct Current systems (HVDC), it has become important to determine whether the contribution of the HVDC system can be ignored when calculating the SC current. This study investigates...
Security-constrained optimal power flow (SCOPF) and security-constrained unit commitment (SCUC) problems are necessary tools to system operators for operational planning and near-to-real-time operation. The solution time of these problems are challenging mainly due to their inherent large size. Previous studies have shown that relatively few of those problems' constraints serve to enclose their feasible...
Paying for load reductions results in a market, where the amount of resources sold is less than the amount of resources bought. To resolve this imbalance, ISOs must allocate the cost of compensating demand response to those who benefit from reduced LMPs. Current cost allocation methods are based on each energy buyer's load share. In an uncongested network, this results in a “fair” allocation of costs,...
Contingencies of transformers in a multi-unit substation may affect life of healthy units severely due to overloads. This paper proposes a novel demand response (DR) and dynamic thermal rating (DTR) based optimization model for efficient capacity utilization and life management of transformers during contingencies. The model opts for the optimal combination of corrective actions among load curtailment...
Power network segmentation has many applications in the operation of power systems. The context of segmentation changes with the application. With the introduction of competition and associated modes of transaction, network segmentation with reference to congestion became a necessity. This paper proposes a methodology to solve network segmentation problem in wholesale competition environment so that...
This paper proposes a comprehensive solution methodology for the pricing difficulty when Lagrange multipliers are not unique. A linear optimization model is proposed to solve the congestion-related pricing difficulty. The objective function of the model is set to be minimizing the congestion surplus. In addition, an incentive-based allocation approach is incorporated in the solution procedure for...
Traditional methods of planning investment in Wind Energy Conversion Systems (WECS) focus on selecting sites that individually display the maximum total extractable wind energy. However, cost penalties associated with the uncertainty in Wind Power Production (WPP) may be non-negligible. This paper proposes a more holistic methodology to find the near optimal investment in WECS considering capital...
Prediction of power generated from renewable energy resources such as solar photo-voltaic (PV) is a crucial task for stabilization of grids with high renewable penetration levels. Short-term prediction of these resources allow for preemptive regulation of injected power fluctuations. In this paper, a new algorithm based on dictionary learning for prediction of solar power fluctuations is introduced...
In modernizing the electricity grid, distributed energy resources (DERs) can play an important role in accommodating intermittent energy sources, assisting system operation and the transition to a smart grid. Proper aggregation and coordination of the available DER units is required to provide flexibility to meet regular demand from the distribution system operator (DSO). By considering both their...
With the increasing integration of doubly-fed induction generator (DFIG) based large wind farms, their impact on power system static and dynamic behavior is an issue of interest. Large wind farms are usually connected to grids using relatively long transmission lines or cables (weak grids). Therefore, the wind farm stable operation in weak grids must be researched. This paper proposes an adaptive...
This paper describes generic models of photovoltaic (PV) systems developed for implementation in Western Electric Coordinating Council (WECC) base cases. The scope encompasses both transmission-connected, central station PV plants and distributed PV systems. These models were added to the WECC Approved Dynamic Model Library in March of 2014.
As more Smart Grid technologies (e.g., distributed photovoltaic, spatially distributed electric vehicle charging) are integrated into distribution grids, static distribution simulations are no longer sufficient for performing modeling and analysis. GridLAB-D is an agent-based distribution system simulation environment that allows fine-grained end-user models, including geospatial and network topology...
Vehicle to Grid (V2G) service is being considered as a new value proposition for Plug-in Electric Vehicles (PEV). V2G service can be provided using unidirectional or bidirectional power flow and the control may be centralized or autonomous. V2G may be able to provide load following, balancing, or frequency regulation services which in the energy markets are described as one or a combination of regulation...
Accurate information about dynamic states is important for efficient control and operation of a power system. This paper compares the performance of four Bayesian-based filtering approaches in estimating dynamic states of a synchronous machine using PMU data. The four methods are Extended Kalman Filter, Unscented Kalman Filter, Ensemble Kalman Filter, and Particle Filter. The statistical performance...
Solar is the fastest growing source of renewable electricity in the U.S. The anticipated PV proliferation brings integration challenges on system volt/var performance at the utility scale. One of the greatest challenges is to maintain desirable feeder voltages in utility distribution networks. The intermittent PV generation causes more frequent operation of volt/var control (VVC) devices to alleviate...
The electromagnetic transient (EMT) simulation of a large-scale power system consumes so much computational power that parallel programming techniques are urgently needed in this area. For example, realistic-sized power systems include thousands of buses, generators, and transmission lines. Massive-thread computing is one of the key developments that can increase the EMT computational capabilities...
The prospects of Electric Vehicles (EVs) in providing clean transportation and supporting renewable electricity is widely discussed in sustainable energy forums worldwide. The battery storage of EVs could be used to address the variability and unpredictability of electricity produced from renewable energy sources like wind in power systems. The EV batteries could be used to charge during periods of...
This paper presents a methodology for developing an adequacy assessment of the generating and storing mix capacity in nearly-Zero Energy Residential Buildings (nZEB). The adequacy of a given generating and storing mix will be quantified by means of a set of reliability indices obtained by adapting the traditional reliability techniques employed in power systems. The analysis will use a Montecarlo...
This paper proposes a real-time Energy Management System (EMS) for a low voltage (LV) Microgrid (MG). The system operation consists in solving the Unit Commitment (UC) and Economic Load Dispatch (ELD) simultaneously for 24 hours ahead at every 15-minute period. This operation is formulated as a multi-objective optimization problem where the minimization of operational cost, total emissions and power...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.