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Scheduling of storage devices in microgrids with multiple renewable energy resources is crucial for their optimal and reliable operation. With proper scheduling, the storage devices can capture the energy when the renewable generation is high and utility energy price is low, and release it when the demand is high or utility energy price is expensive. This scheduling is a multi-step optimization problem...
A regime shift occurs when a dynamical system's state shifts from a nominal equilibrium to an alternative equilibrium. This concept is often used to describe the collapse of ecological systems, but it also appears in many engineering systems; most notably in the voltage collapse of power systems. This paper uses an information theoretic index known as the Fisher Information (FI) as a real-time statistical...
This paper presents a study of the impact of severe generation imbalance on reactive power margins. In particular, the focus of the study is the analysis of characteristics of the reactive power margins under two common strategies A) generation redispatch and B) load shedding when a significant loss of generation occurs in a power system. Simulation results show that, at some buses, Strategy A may...
Nowadays, power companies are actively promoting the construction of power quality monitoring system (PQMS). There is a vital need to deal with the large amount of data extracted from PQMS. This paper proposes a novel method of fault location estimation based on the voltage sag records of PQMS. By this method, fault position and fault resistance can be estimated by particle swarm optimization algorithm...
As the penetration of wind generation increases, the effects of ramping events on power system security become serious. In order to improve the output characteristics of wind generation, wind farms coordination control based on contribution index is proposed to ensure wind farms to respond to scheduling plan of virtual power plant (VPP). Based on the power regulation amount of wind farms, regulation...
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,...
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...
Accurate estimation of dynamic states is important for monitoring and controlling transient stability. This paper proposes an adaptive interpolation approach to improve the performance of the Extended Kalman Filter (EKF) for estimating dynamic states of a synchronous machine. This approach consists of two major steps. First, the non-linearity of state transition function and measurement function is...
Significant research has been performed to evaluate the challenges and mitigation options associated with integration of individual Wind Generation Resources (WGRs) to weaker portions of the electric grid. This paper focusses on the development of a screening approach to assess control instability issues on a weak portion of grid expected to have a cluster of wind farms connected to it. A Control...
This work aims to describe the implementation of a renewable energy based Microgrid test site facility at the University of Genova (Italy) and to depict the advanced functionalities there implemented within the national supported project Smartgen. The developed advanced Distribution Management System (DMS) is based on a Supervisory Control And Data Acquisition (SCADA) system for the remote monitoring...
Monitoring the long term voltage stability of the power grid is necessary to ensure its secure operation. In this paper, a voltage stability index that is linear with the power demand, called the M-index, based only on angles is proposed. The linearity of the M-index can be utilized to estimate the load margin directly. The linearity of the M-index is proved for the two-bus system and a method to...
System splitting is an efficient way to prevent widespread blackout. Finding proper splitting schemes for on-line application is becoming increasingly difficult due to the combinatorial explosion nature of the problem. This paper considers a new problem formulation of system splitting with priority service areas and proposes an efficient three-stage method for designing on-line system splitting. These...
In this paper, we regard the power quality evaluation method as research content. We construct the identity understanding matrix and difference understanding matrix by using the judgment matrix of analytic hierarchy process and the connection degree model of set pair analysis. Then calculate the weight of power quality indexes by utilizing the compatibility matrix method and entropy weight method...
This paper presents optimized approaches for microgrid design and allocation of energy storage units to enhance self adequacy of microgrids. Microgrids are clusters of distributed energy resources serving clusters of distributed loads either in grid connected or isolated grid modes. The self adequacy of microgrids is maximized by the optimal installment of energy storage units that can store the spilled...
The integration pattern of an electric vehicle (EV) fleet usually consists of 4 parameters including arrival time, departure time, state-of-charge and the number of integrations. Though such patterns have been widely studied in the past few years, how the EVs are dispersed in power distribution systems, are not studied yet. However, neglecting the spatial aspect of EV integration is equivalent to...
This paper presents an online clustering modeling method for large-scale photovoltaic (PV) power plants. The proposed method utilizes the defined feature distance of inverter control parameters as the clustering index to derive the equivalent PV plant model. Based on the offline parameter database and the online matching method, the feature distance weighted by online parameter sensitivity is obtained...
Enactment of stringent climate protection directives and policies for renewable energy as well as electric vehicle integration is expected to place considerable strain on system frequency stability. Decreasing share of conventional power plants and consequently the loss of readily controllable power generation, makes controlled charging of electric vehicles an attractive option for the Transmission...
The need to increase situational awareness in power systems is more evident than before. Increased power system complexity and integration of intermittent resources have contributed to the emerging need to monitor power systems in real time. Real time contingency analysis can increase situational awareness by monitoring the power system in real time and alarming the operators of the impending problems...
In this paper, detection of fault in a series compensated line during power swing is considered. Voltage and current signals contain non-fundamental componens due to fault in a series compensated line during power swing. Presence of transients due to MOV and airgap operation, sub synchronous resonance, voltage and current inversions further make the fault detection process more complex. There are...
Photovoltaic (PV) generation is increasingly prevalent throughout power distribution systems. The increased presence of this variable resource can cause adverse impacts to the system due to cloud-induced power output fluctuations. These adverse impacts can be mitigated by allowing PV inverters to absorb and provide reactive power in response to voltage swings. Additionally, properly chosen reactive...
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