In this paper, the building thermal dynamic characteristics are introduced in the community microgrid (MG) planning model. The proposed planning model is formulated as a mixed integer linear programming (MILP) which s...
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ISBN:
(纸本)9781728149318
In this paper, the building thermal dynamic characteristics are introduced in the community microgrid (MG) planning model. The proposed planning model is formulated as a mixed integer linear programming (MILP) which seeks to determine the optimal deployment strategy for various distributed energy resources (DER). The objective is to minimize the annualized cost of community MG, including investment cost in DER, operation cost for dispatchable fuel-generators (DFG), energy storage system (ESS) degradation cost, energy purchasing and peak demand charge at PCC, customer discomfort cost due to the room temperature deviation and load curtailment cost. Given the slow thermal dynamic characteristics of buildings, the heating, ventilation and air-conditioning (HVAC) system in the proposed model is treated as a demand side management (DSM) component, whose dispatch commands are provided by the central MG controller. Numerical results based on a community MG comprising of 20 residential buildings demonstrate the effectiveness of the proposed planning model and the benefits of introducing the building thermal dynamic model.
This paper performs optimal sizing of the distributed energy resources (DERs) of an islanded microgrid test system to minimize the generation cost. Two fossil fueled generators, two wind turbines and three fuel cells ...
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ISBN:
(纸本)9781728134567
This paper performs optimal sizing of the distributed energy resources (DERs) of an islanded microgrid test system to minimize the generation cost. Two fossil fueled generators, two wind turbines and three fuel cells are the DERs involved to be sized for the minimization of generation cost. Utilization percentage shows the maximum usage of DERs in obtaining the minimal value of objective function. Grey Wolf Optimizer (GWO), its modified version (MGWO) and MGWO amalgamated with particle swarm optimization (PSO), sine cosine algorithm (SCA) and crow search algorithm (CSA) to perform the optimization. A comparative study is then made to prove the efficiency of the proposed hybrid MGWOCSA among the four other optimizers used and also among those available in literature.
The current electric grid is transitioning through increasing penetration of distributed energy resources (DERs), which include intermittent renewable generation resources on the distribution side. Both the monitoring...
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ISBN:
(纸本)9781728121369
The current electric grid is transitioning through increasing penetration of distributed energy resources (DERs), which include intermittent renewable generation resources on the distribution side. Both the monitoring and control of DERs require extensive data-exchange and communication networks. These networks lead to cyber vulnerabilities and risks of new kinds of cyberattacks that may be extremely destructive for power system operations. Although current standards, such as IEEE Std. 1547-2018, do not discuss cybersecurity measures for DERs, cybersecurity controls should be developed for securing DER systems at the device level, communications level, and applications level. This paper discusses the current industry's best practices related to DER cybersecurity and proposes recommended functionalities for improving the cybersecurity posture of DERs, specifically at the device/distribution level. These practical recommendations have been discussed and verified with the industry through a DER cybersecurity working group.
Differential expression analysis of RNA sequencing (RNA-seq) data typically relies on reconstructing transcripts or counting reads that overlap known gene structures. We previously introduced an intermediate statistic...
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Differential expression analysis of RNA sequencing (RNA-seq) data typically relies on reconstructing transcripts or counting reads that overlap known gene structures. We previously introduced an intermediate statistical approach called differentially expressed region (DER) finder that seeks to identify contiguous regions of the genome showing differential expression signal at single base resolution without relying on existing annotation or potentially inaccurate transcript assembly. We present the derfinder software that improves our annotation-agnostic approach to RNA-seq analysis by: (i) implementing a computationally efficient bump-hunting approach to identify DERs that permits genome-scale analyses in a large number of samples, (ii) introducing a flexible statistical modeling framework, including multi-group and timecourse analyses and (iii) introducing a new set of data visualizations for expressed region analysis. We apply this approach to public RNA-seq data from the Genotype-Tissue Expression (GTEx) project and BrainSpan project to show that derfinder permits the analysis of hundreds of samples at base resolution in R, identifies expression outside of known gene boundaries and can be used to visualize expressed regions at base-resolution. In simulations, our base resolution approaches enable discovery in the presence of incomplete annotation and is nearly as powerful as feature-level methods when the annotation is complete. derfinder analysis using expressed region-level and single base-level approaches provides a compromise between full transcript reconstruction and feature-level analysis.
The transition towards a cyber-physical energy system (CPES) entails an increased dependency on valid data. Simultaneously, an increasing implementation of renewable generation leads to possible control actions at ind...
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ISBN:
(纸本)9788394625375
The transition towards a cyber-physical energy system (CPES) entails an increased dependency on valid data. Simultaneously, an increasing implementation of renewable generation leads to possible control actions at individual distributed energy resources (DERs). A state estimation covering the whole system, including individual DER, is time consuming and numerically challenging. This paper presents the approach and results of implementing a simplified state estimator onto an embedded system for improving DER monitoring. The implemented state estimator is based on numerically robust orthogonal factorization and used on a set of state equations of a generic wind turbine generator (WTG). The simplified state estimator is tested by simulating a generic WTG model and evaluated based on its execution time and estimation accuracy. Results show its fast execution time, its accuracy in handling normal measurement error and its ability to provide reliable data in the case of gross errors in the set of measurements.
In this paper, an integrated and modular control design is developed for distributed energy resources (DERs) to stabilize power systems and minimize effects of load variations and intermittent generation. Traditionall...
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ISBN:
(纸本)9781509021826
In this paper, an integrated and modular control design is developed for distributed energy resources (DERs) to stabilize power systems and minimize effects of load variations and intermittent generation. Traditionally, the droop control of each generator (or virtual power plant) works as a local feedback loop to track frequency during load disturbance, whereas automatic generation control (AGC) calculates control signals and sends them to each generator with the goal of matching the total generation and load in the overall system. The droop control and the AGC work separately, therefore the two controls often conflict each other. The proposed design enables us to modularly synthesize an integrated control for each of the DERs by using both local and wide-area measurements so that the controls work together in enhancing stability and performance of the power system. The design methodology admits the full nonlinear power flow equations, and it results in a data-driven control that in real-time takes into account the nonlinear power flow interactions (in terms of current angle measurements) and adaptively adjusts parameters of the controls that operate the DERs. The design framework uses the concept of passivity-short systems to analyze individual DERs and quantify their dynamic responses in such a way that the resulting system-wide implementation becomes plug-and-play. Simulations are done to demonstrate the effectiveness of the proposed methodology and design.
The paper deals with the asymptotic description of a diffraction pattern similar to the classical Weyl–Van der Pol phenomenon (the Weyl–Van der Pol formula). The latter arises in the problem of diffraction of waves ...
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Greater penetration of Distributed Energy Resources (DERs) in power networks requires coordination strategies that allow for self-adjustment of contributions in a network of DERs, owing to variability in generation an...
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ISBN:
(纸本)9781538609439
Greater penetration of Distributed Energy Resources (DERs) in power networks requires coordination strategies that allow for self-adjustment of contributions in a network of DERs, owing to variability in generation and demand. In this article, a distributed scheme is proposed that enables a DER in a network to arrive at viable power reference commands that satisfies the DERs local constraints on its generation and loads it has to service, while, the aggregated behavior of multiple DERs in the network and their respective loads meet the ancillary services demanded by the grid. The Net-load Management system for a single unit is referred to as the Local Inverter System (LIS) in this article. A distinguishing feature of the proposed consensus based solution is the distributed finite time termination of the algorithm that allows each LIS unit in the network to determine power reference commands in the presence of communication delays in a distributed manner. The proposed scheme allows prioritization of Renewable Energy Sources (RES) in the network and also enables auto-adjustment of contributions from LIS units with lower priority resources (non-RES). The methods are validated using hardware-in-the-loop simulations with Raspberry PI devices as distributed control units, implementing the proposed distributed algorithm and responsible for determining and dispatching real-time power reference commands to simulated power electronics interface emulating LIS units for demand response.
Reactive power management is one of the imperative ancillary services provided by TSO (Transmission System Operator). This reactive power imbalance mainly occurs at transmission levels, and TSO pays generators for man...
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ISBN:
(纸本)9781538609439
Reactive power management is one of the imperative ancillary services provided by TSO (Transmission System Operator). This reactive power imbalance mainly occurs at transmission levels, and TSO pays generators for managing reactive power. DSO (Distribution System Operator), DER (Distributed Energy Resources), and DG (Distributed Generators) cannot take part in this provision to TSO due to regulations, specifically in Italy. The paper discusses the needs for reactive power management, and comparison of different existing compensation techniques. It talks about the regulatory restrictions, and some proposals for changes, for participation in ancillary market. The paper then discusses about the use of DER as an aggregated virtual power plant to serve as reactive power compensation technique.
We describe a method for estimating a probability density function when some of the sufficient statistics are known. The general form of the PDF is within the exponential family and is known as the exponentially embed...
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We describe a method for estimating a probability density function when some of the sufficient statistics are known. The general form of the PDF is within the exponential family and is known as the exponentially embedded family. Using the proposed estimator new approaches to choosing features from a set of possible features become available, with the error metric being the Kullback-Liebler distance. Applications to subset selection in the context of multipath estimation as well as linear regression for machine learning are used to illustrate the practical utility of the method.
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