Browsing by Author "Barati, Masoud"
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Item A Novel Demand Response Management Model to Reduce Smart Grid Costs(2017) Ahmadian, Saeed; Malki, Heidar A.; Barati, MasoudDRM means leveling demand curve based on electricity prices. Indeed, using variable price rates, electricity consumers are encouraged to use electricity in periods with cheap electricity price ranges. Therefore, total system cost would decrease efficiently. Motivations: To model dynamics between electricity end-users and utility companies. To present a model with simple implementation on smart households. To reduce electricity production costs and to maximize social welfare.Item An Integrated Approach to Maximize Efficiency and Reliability of Grid Connected Distributed Energy Sources(2014-12) Kotti, Radhakrishna; Shireen, Wajiha; Malki, Heidar A.; Cline, Raymond E., Jr.; Provence, Robert S.; Barati, MasoudThe emergence of local-generation as a technically sound solution for the reliability concerns of the existing power grid has lead in recent times to the concept of microgrid. The microgrid is a network of low-voltage (LV) interconnected loads and distributed-energy resources (DERs) with clearly-defined electrical boundaries. The distributed generation majority rely on either photovoltaic (PV) or wind turbines producing imperfectly-predictable variable power, making it harder for the system operators to match generation and load at every instant. This has created a significant interest in optimal grid integration and control of DER units in terms of efficiency maximization and cost minimization by implementing maximum power point tracking (MPPT) control. A new scanning method of MPPT control for grid-connected PV systems is proposed and studied. This technique displays high tracking efficiency with low tracking time. The control tracks the global maxima under partial shading conditions and provides a non-oscillatory response under steady-state operation. The performance of the proposed control is compared with perturb and observe (P&O) and incremental conductance (INC) control under varying operating conditions. The simulation and experimental results clearly prove the effectiveness of the proposed MPPT control. For wind energy conversion systems (WECS) a new adaptive sensor-less MPPT control is proposed. The controller overcomes the trade-off between step size and tracking accuracy, providing a fast tracking response along with avoiding the inconsistent generator-converter efficiency problems. The performance of the proposed control is validated through simulation and experimental results in comparison with P&O MPPT control under varying wind conditions. The DERs are connected to the microgrid with the help of power electronics interface such as AC-DC, DC-DC and DC-AC converters. The DC-DC and DC-AC converters are coupled with the help of large electrolytic capacitors. The reliability of the system is maximized by reducing the required DC link capacitance and replacing the electrolytic capacitors with high cost and reliable film capacitors. A new DC link reduction control to reduce the required DC link capacitance is proposed. The performance of the proposed control is validated through simulation results for grid connected PV and WECS under reduced DC link capacitance.Item An Optimization Framework for Resilience-based Power Grid Restoration(2018-08) Abbasi, Saeedeh; Lim, Gino J.; Lee, Taewoo; Peng, Jiming; Barati, Masoud; Vipulanandan, CumaraswamyPower outage is a terrible consequence of an extreme event that affects a wide range of consumers including homes, hospitals, and commercial industries. An extreme event such as a hurricane, windstorm or earthquake can disrupt power grids located in open areas. In a power grid, transmission lines are the most vulnerable equipment and their damage usually results in a cascading failure of the whole network. Although a power system should be strengthened in advance to withstand these events, having a plan to restore the failed power grid is essential. Emergency generation units play an important role in a restoration process; these pre-located units are called black start (BS) units. The restoration process with BS units is conducted through a parallel restoration over independent sections within a network. Appropriate sectionalization provides a more resilient power system against a long outage. Assessing and optimizing the resilience of a power system could improve the quality of the restoration process. To achieve this resilient power system, a mathematical model is presented to maximize the system’s resiliency while planning a restoration process. The system resiliency is measured through an innovative resilience vector. As a result, the restoration would be performed quickly to satisfy all critical demands. The model is a mixed integer programming (MIP), which is decomposed to a bi-level model where it can be solved in the lower complexity. Rather than the bi-level programming, a mathematical programming with equilibrium constraints (MPEC) approach is applied to solve the model. The comparison between the results of both methods demonstrates the high efficiency of bi-level programming solution methodology in a large-scale case. A pre-emptive goal programming (PEP) method also supports the solution methodologies to take care of multiple terms with different scales and priorities in the objective function of the model. The model is analyzed by 6- and 118-bus IEEE standard test systems. Sectionalization of a transmission network has a close association with partitioning a graph (i.e., the lines are considered as edges and grid buses are the same as graph nodes). The graph partitioning problem (GPP) is formulated as a MIP model to minimize the amount of dis-joint edges so that well connected sections can be formed. Therefore, the proposed restoration model is combined with the GPP model. In this order, the sectionalization constraints are replaced with GPP constraints while the GPP objective is added to the model’s objective. The new GPP-based restoration model is examined for both 6- and 118-bus case studies and the results are compared with the first sectionalization approach. The analysis of advantages and disadvantages for the first and second restoration models is currently under work. Both proposed deterministic models are solved under the assumption of a given status for the transmission network after disruption; however, it is rarely possible to have a precise prediction on the post-status of a transmission network following an extreme weather. Hence, the post-status of transmission lines can be considered as a source of uncertainty. In this study, a robust optimization model is provided to take care of this uncertainty. The proposed robust model is a scenario-based model of the GPP-based model. These scenarios are prepared based on simulated hurricane wind speeds and the fragility profile of transmission lines. Furthermore, the worst-case model against all realization of the grid post-status is provided. The result on 118-bus test system gives a reliable solution for all realization of the scenarios with a narrow band in objectives performance measures. Dealing with large network-structured systems such as a power system is difficult. For this reason, a parallel processing is recommended by partitioning the network; which can facilitate the process by reducing the size of the target network at each moment. The common partitioning criterion is modularity while considering another metric beside it is beneficial to the result. The final chapter of the dissertation addresses the undirected network partitioning challenges in the vulnerability of the partitions via maximization of edge-connectivity and modularity. The edge-connectivity is a graph metric, which represents the robustness of the sub-networks and its optimization, enhance the robustness of the partitions. The problem is formulated as a bi-objective maximization model. The results on multiple random test cases of different sizes are analyzed to demonstrate the model’s performance.Item Arc Flash Mitigation: Overview of Codependent System Studies Relevant to IEEE Standard 1584(2015-05) Mainsah, Nyuykighan Karl Marvin; Shireen, Wajiha; Charlson, Earl J.; Barati, Masoud; Lim, Jung-UkAccidents due to arc flash events are currently of special interest in the electrical power industry. These events often result in serious injuries, deaths, equipment damage, facility shutdowns, lawsuits, and penalties. Risk assessments are usually performed by the power systems engineer during the design phase to mitigate the effects of potential arc flash occurrences. The objective of this thesis is to demonstrate the significance of arc flash hazard risk assessments implemented during the installation of electrical power equipment. This thesis presents a synopsis of the main industry design standards and codes that govern the design of electrical distribution systems in commercial and industrial facilities. Simulations were performed for a case study using SKM Power Tools to demonstrate the interpretation and practical application of these standards and codes. Electrical studies and analyses were performed on the model, and recommendations were provided to address the mitigation of potential arc flash incidents throughout the electrical network of the case study.Item Disaster Management of Power System Restoration(2017) Abbasi, Saeedeh; Barati, Masoud; Lim, Gino J.A multi-objective model is formulated to plan for a parallel restoration. An iterative optimization algorithm is introduced to solve the proposed model.Item Implementation of Adaptive Protection Scheme for Microgrid using IEC 61850 Communication Protocol(2017-08) Shah, Rikesh Prakashkumar; Shireen, Wajiha; Rajashekara, Kaushik; Han, Zhu; Barati, MasoudThe existing electrical power system is experiencing radical changes in parallel with the growing integration of Distributed Energy Resources (DER) such as Photovoltaic (PV), Wind Turbine Generators, Fuel Cell etc. DERs with locally connected loads create subsystems within the main grid which are termed as microgrids. As microgrid becomes an important part of the distribution system, issues and challenges arising from its implementation should be addressed. Amongst many such issues such as voltage regulation, phase balance, reactive power control, stability etc., protection is a major challenge for the microgrid. In view of the issues related to microgrid protection, this thesis discusses the inadequacy of the conventional protection scheme, fault behavior of inverter interfaced DERs, and impact on the coordination of relays. The thesis also proposes the adaptive protection algorithm to be applied with extensive IEC 61850 communication protocol between Microgrid Central Protection Unit and relays. A small laboratory based microgrid was setup to prove the proposed algorithm.Item Integrated Microgrid Expansion Planning and Policy Making under Uncertainty in Power Electricity Market(2018-05) Khayatian, Aida; Lim, Gino J.; Feng, Qianmei; Lee, Taewoo; Barati, Masoud; Pan, MiaoAn interconnected microgrid is a group of Distributed Energy Resources (DER) with the ability to operate in a grid connected mode. DERs include nondispatchable renewable generation such as wind and solar units as well as small scale dispatchable resources such as diesel generators, microturbines, and energy storage The penetration of microgrids to the energy portfolio across the world has been steadily increasing over the past few years. Several studies have predicted that this trend will continue in the future leading to large scale integration of microgrids into energy networks, which poses several principle challenges to be addressed. First, deploying a microgrid on the main-grid depends on estimated profits for potential power investors in the electricity capacity market. Hence, there is a clear need for quantitative analysis tools that can help power investors in assessing monetary benefits of investment on microgrids in this competitive market. To address this need, this proposal proposes a mathematical model to help power investors to decide if they should invest in a microgrid installation. The proposed model integrates microgrid expansion planning with the conventional generation and transmission planning to study the potential advantages of the grid-connected microgrid system. Accordingly, the model provides an appropriate market price signal for power investors to determine the size, time, and type of new power resources required to satisfy reliability requirements and operation cost optimization. Second, the power investors, in particular, face a number of important challenges in terms of uncertainties such as load growth and component power outage. To incorporate the uncertain parameters into the optimization model, a two-stage stochastic optimization approach is proposed. The objective of the model is to maximize the expected revenue from power companies, while ensuring the cost-effectiveness and reliability of the power system under those uncertain factors. The proposed model is solved based on Benders decomposition. Computational experiments are conducted on two IEEE-6 and -118 bus test systems to analyze the effectiveness of the proposed approach. Several further issues are of interest. The first issue is how to design an interconnected microgrid with intermittent renewable resources such that the resulting network is stable. To maintain the stability of such a network, this study presents some policies to be implemented in advance. These policies will provide insights for the power investors to design an interconnected microgrid having more renewable resources while ensuring the reliability of the network under these fluctuations or other obstacles. The second issue is the power planning problem with these uncertain factors is a large scale problem. Further study is needed to overcome the computational efforts. Finally, new regulations and policies have been implemented for power system network. It will be interesting to incorporate the new policies in the assessment of microgrid's benefits. Moreover, recent hurricanes prove that our electric utilities as critical infrastructures are very vulnerable to extreme weather events. Therefore, there is a severe need for an alternative strategy to mitigate and adapt to the risks of these events. First, this study analyzes and simulates the high-impact low-probability events such as hurricanes on the power systems resiliency using hierarchical analytical process. Using this quantitative analysis, the proposed framework is suggested to enhance the resiliency by efficiently deploying the microgrids into power systems.Item Microgrid expansion planning and policy making in the electricity market(2017) Khayatian, Aida; Barati, Masoud; Lim, Gino J.Item Optimal Location of PV Powered Smart Charging Facilities With Energy Storage for Electric Vehicles(2016-08) Umeano, Michael O.; Shireen, Wajiha; Han, Zhu; Pan, Miao; Barati, Masoud; Lim, Jung-UkIncreasing charging facilities to service electric vehicles (EVs) and Plug-in Hybrid Electric Vehicles (PHEVs) leads to increased stress on the existing electric grid. PV integrated charging stations (PVCS) supplemented with energy storage have provided promising results in reducing dependency on the electric grid for charging PHEVs. Despite advances in power electronics used to interface PVCS with the grid, random charging patterns, structural contingencies and intermittency of solar energy creates the inevitable issue of random power penetration and adoption to/from the grid. To maximize the benefits of PVCS they should be integrated into the distribution network at optimum locations. A well planned and operated PVCS would provide several benefits to the distribution network such as reduction in power losses, voltage regulation and reactive power support. This paper proposes a new method for optimally siting PV powered PHEV charging facilities with energy storage in a distribution network under stress due to heavy penetration of PHEVs. The performance of the proposed heuristic method is demonstrated through a case study using an IEEE 30-bus system.