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Wind systems connected to a three-phase voltage grid often experience unbalanced voltage conditions, due to differences in the loads in the grid. This issue is particularly important in wind energy conversion systems (WECS) that use the doubly fed induction generator (DFIG). Therefore, it is important to take into account unbalanced conditions when coupling the wind generator with the grid, especially...
Smart grids are becoming practical nowadays with their integrated, complex and communicative architecture. The addition of renewable energy sources, control automation, information and communication technologies (ICT), advanced monitoring and protection and smart metering has further increased the complexity. Next generation smart grid will act as an interactive energy web with multi-way communication,...
A fuzzy logic controller is proposed to perform the functions of supplementary inertial and frequency control in wind turbine generating units. Expert knowledge governing the performance of the proposed fuzzy logic approach for frequency support in this study is expressed by a set of fuzzy rules extracted from a common symmetrical rule table widely used in the literature. A sample multi-machine power...
This paper introduces an enhanced Genetic Algorithm (GA) that uses the concept of sensitivity analysis to develop an encoding strategy for improving the computational efficiency of the search process. The objective is to determine the optimal placement of distributed energy resources (DERs) with minimum generation cost. Locational Marginal Price (LMP) is employed as an indicator to quantify the need...
In this paper, we propose a decision model for multiobjective power management of a generic MicroGrid (MG). The concept of Nash Bargaining Solution (NBS) from game theory is used by the central MG control unit to dispatch different resources within the MG. Using NBS, the MG is guaranteed to reach a solution on the Pareto-front of the multiobjective power management optimization problem. This solution...
Increasing penetration of photovoltaics (PV) into the electric grid necessitates accurate intra-hour solar irra-diance forecasting. The authors have previously developed a low cost all-sky imaging system at the University of Texas at San Antonio. The SkyImager hardware is designed around a Raspberry Pi single board computer (SBC) with a fully programmable, high resolution Pi Camera, housed in an all-weather...
The increasing number and types of energy resources and prosumers has complicated the operation in microgrid greatly. Such problem becomes a hard-to-solve or even impossible-to-solve for traditional mathematical algorithms without necessary approximation. However, modern heuristic optimization techniques have proven their efficiency and robustness in complex non-linear, non-convex and large-size problems...
This paper proposes a new model to allocate reserve costs among the involved players, considering the characteristics of the several entities, and the particular circumstances at each moment. The proposed model is integrated in the Multi-Agent Simulator of Competitive Electricity Markets (MASCEM), which enables complementing the multi-agent simulation of diverse electricity market models, by including...
Isolated microgrids are prone to large frequency and voltage deviations, due to limited generation capacity, finite generation inertia, and possibly including large portions of dynamic loads. They require effective security-constrained power management methods, which operate the system optimally, while satisfying the security constraints. Region-based security assessment is popular for real-time security-constrained...
Daily load variation and intermittence of renewable generation may sometime cause transmission congestion in modern power system. As a result, cheap generation cannot be fully dispatched and in extreme condition involuntary load shedding will be enforced. In this paper, an intelligent parallel scheduling method using optimal transmission switching (OTS) and batteries is proposed to mitigate transmission...
Network equivalence is useful for electrical market analysis in large power networks. Generation shift factors (GSF)-based bus clustering methods have been used for network equivalence to analyze the impact of changes in transactions between operating areas or congestion zones on transmission line flows. However, GSFs are sensitive to the location change of slack generator. Equivalent networks based...
This paper presents an optimization methodology based on tabu search to solve a unconstraint voltage regulators allocation problem in power distribution networks. The main objective is to find a balance between costs related to system planning and the fulfillment of power quality indexes. Analysis of the voltage profile and the objective function are carried out in the MATLAB environment for a typical...
Power systems are vulnerable to extreme contingencies (like an outage of a major generating substation) that can cause significant generation and load loss and can lead to further cascading outages of other transmission facilities and generators in the system. Some cascading outages are seen within minutes following a major contingency, which may not be captured using only the dynamic simulation of...
Secure high-speed communication is required to ensure proper operation of complex power grid systems and prevent malicious tampering activities. In this paper, artificial neural networks with temporal dependency are introduced for false data identification and mitigation for broadcasted IEC 61850 SMV messages. The fast responses of such intelligent modules in intrusion detection make them suitable...
This paper presents a two stage error detection technique for a power system time series data. It implements a local similarity method to isolate an anomalous time series data, and further applies a window scanning technique to detect instances of inconsistent data segments. The requirement for few parameter definitions and small computation time makes this technique attractive for data error detection...
There is an increase interest for islanding operation of distributed generators (DG) due to economical and technical reasons. However, the control strategy applied to the DG is different for grid connected and islanding conditions, which demands identifying the DG connection status. This paper presents a methodology for detecting the DG connection status. The methodology is able to detect the occurrence...
Voltage control and reactive power management are two critically important criteria for ensuring quality power delivery and system stability in the grid. As the two issues are coupled, they have been generally tackled simultaneously. In this paper, we utilize the concept of stochastic game modeling from game theory to develop a novel algorithm to solve the multi-objective optimization (MOO) problem...
This paper is motivated by infeasibilities in look-ahead economic dispatch with significant wind integration; such infeasibilities result from transmission line constraints that cannot be satisfied within a security constrained economic dispatch. Thus, constraint relaxation is necessary to achieve the dispatch decisions and market solution. The acceptable relaxation margin is determined by assessing...
The growing installation of phasor measurement units (PMUs) provide grid operators wide-area situational awareness while introducing additional vulnerabilities to power systems from the cyber security point of view. This paper presents an online method to detect ongoing contingencies in the system and bad data injection on its PMU network. To do so, the principal component analysis is applied to leverage...
This paper establishes stochastic model of plug-in electric vehicle (PEV) charging and derives the probabilistic description of the electricity needs from EV charging for one charging station at any hour of a day. Three key variables are used to characterize the stochastic behavior of EV charging: starting time of charging, state of charge (SOC), and total number of charging EVs. The electricity needs...
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