Islanded microgrids have low inertia due to large penetration of non-inertial inverter based power sources. Such systems are prone to instability due to a higher rate of change of frequency (RoCoF) and large peak freq...
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Islanded microgrids have low inertia due to large penetration of non-inertial inverter based power sources. Such systems are prone to instability due to a higher rate of change of frequency (RoCoF) and large peak frequency deviation in case of a sudden load change or generation loss. This paper proposes a novel fast frequency control method for an islanded microgrid comprised of both inverter based distributed generators (DGs) and synchronous generators (SGs). The frequency controller estimates the power imbalance during the transient and compensates for it through a battery energy storage system (BESS). For the estimation of the power imbalance, an approximated linear model of the microgrid is developed considering multiple SGs operating in parallel. To transfer the compensated power from BESS to SGs, and also to maintain the state of charge (SoC) of the BESS, a SoC balancing control method is presented which is implemented by controlling the biased frequency of the SGs. The performance of the proposed frequency control method is verified using Typhoon real-time hardware-in-the-loop simulator.
Nowadays a large amount of data is originated by complex systems, such as social networks, transportation systems, computer and service networks. These systems can be modeled by using graphs and studied by exploiting ...
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Nowadays a large amount of data is originated by complex systems, such as social networks, transportation systems, computer and service networks. These systems can be modeled by using graphs and studied by exploiting graph metrics, such as betweenness centrality (BC), a popular metric to analyze node centrality of graphs. In spite of its great potential, this metric requires long computation time, especially for large graphs. In this paper, we present a very fast algorithm to compute BC of undirected graphs by exploiting clustering. The algorithm leverages structural properties of graphs to find classes of equivalent nodes: by selecting one representative node for each class, we are able to compute BC by significantly reducing the number of single-source shortest path explorations adopted by Brandes' algorithm. We formally prove the graph properties that we exploit to define the algorithm and present an implementation based on Scala for both sequential and parallel map-reduce executions. The experimental evaluation of both versions, conducted with synthetic and real graphs, reveals that our solution largely outperforms Brandes' algorithm and significantly improves known heuristics.
This paper focuses on the development of a new revised Desired Compensation Adaptive Law (DCAL). DCAL is a model-based adaptive control strategy consisting of three main parts: (i) an adaptive feedforward term, (ii) a...
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This paper focuses on the development of a new revised Desired Compensation Adaptive Law (DCAL). DCAL is a model-based adaptive control strategy consisting of three main parts: (i) an adaptive feedforward term, (ii) a linear PD feedback term, and (iii) a nonlinear compensation term. In order to deal with highly nonlinear dynamic systems characterized by their abundant uncertainties and parameters variations, we propose to revise the original DCAL control law by adopting adaptive feedback gains depending on the system state errors. Besides, DCAL controller is known for its robustness against measurement noise thanks to its desired compensation design, but a large amount of external disturbances are still not compensated by such a design. Therefore, the proposed DCAL with adaptive gains (DCAL-AG) is extended with a sliding-based term to further improve its robustness and the overall performance. A model-based robust adaptive feedback controller appropriate to the control of nonlinear systems in real-time applications is thereby obtained. To demonstrate the improvements brought by the proposed control strategy, numerical simulations have been conducted on a Delta-link parallel robot named T3KR in a "Pick-and-Throw" application task at different operating conditions. Copyright (C) 2022 The Authors.
Edge Intelligence is a synergy that seems to be imperative to conclude the convergence of the Edge Computing and Internet of Things to support intelligent application very close to end users. IoT has pervaded our dail...
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ISBN:
(纸本)9781665491532
Edge Intelligence is a synergy that seems to be imperative to conclude the convergence of the Edge Computing and Internet of Things to support intelligent application very close to end users. IoT has pervaded our daily life by making things, interconnected through the Internet, smarter, distributed and more autonomous. The emerging development of intelligent applications in IoT has now started to gain significant attention. Cloud provides many benefits to IoT devices, including high-performance computing, a storage infrastructure, processing and analysis of large-scale data giving to IoT the opportunity to be robust, smart and self-configuring. The forthcoming emergence of Edge AI will extend the capabilities of the `legacy' IoT, its potentials, the number of devices and the volumes of data. However, Cloud technologies face some accessibility challenges when providing services to end-users. For instance, mobile clients can move among different places, yet require Cloud services with minimum cost and short response time. The unstable connection between Cloud and mobile devices is expected to prevent providers from achieving the optimal performance. To cope with these limitations, we aspire that Edge AI converged with IoT environments materializes the desired AI-led distributed and ubiquitous intelligence in real computing systems. We then need additional effort to establish and deliver the convergence of Edge AI and IoT in formatting the future Intelligent IoT. The Intelligent IoT is envisioned to involve numerous autonomous & distributed computing and AI-driven entities capable of understanding their internal status (context), the status of their environment and peers (collaborative context) and take timely optimized actions to efficiently serve modern applications, like tactile internet and augmented AI-led gaming.
Multi-Node computation, also known as distributed computing, is a paradigm that allows for the efficient utilization of multiple interconnected nodes or machines to perform complex computational tasks. By dividing the...
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ISBN:
(数字)9798331528201
ISBN:
(纸本)9798331528218
Multi-Node computation, also known as distributed computing, is a paradigm that allows for the efficient utilization of multiple interconnected nodes or machines to perform complex computational tasks. By dividing the workload and distributing it across multiple nodes, multi-node computation enables parallel processing, scalability, and improved performance for a wide range of applications. HPCC systems® from LexisNexis Risk Solutions is a proven, open source solution for big data insights that can be implemented by businesses of all sizes. HPCC systems offers a consistent data-centric programming language, two processing platforms and a single, complete end-to-end architecture for efficient processing. ECL is the Enterprise Control Language designed specifically for huge data projects using the HPCC systems platform. It is extremely scalable and a powerful declarative data-processing language with native multi-processing capabilities and used for HPCC systems. Some core ECL functions, like the ones handling Learning Tree algorithms of Machine Learning Bundle are recursive in nature and hence high computational time is needed. This paper thus presents a solution to achieve optimized processing of ML learning tree algorithms in ECL through embedding python libraries. The proposed approach was tested on standard datasets and a significant decrease in computation time. For real Estate Valuation Regression dataset the computation time was reduced from 11.371 seconds to 0.886 seconds using the proposed method showing 1324% improvement with no impact on the accuracy. Random Forests are also implemented using the proposed Decision Tree method allowing the users to specify the number of decision trees to be used in the forest.
Virtual synchronous generator technology can effectively improve the anti-interference characteristics of the system frequency and bus voltage in the microgrid, and solve the problems of insufficient damping and low i...
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Virtual synchronous generator technology can effectively improve the anti-interference characteristics of the system frequency and bus voltage in the microgrid, and solve the problems of insufficient damping and low inertia of the system. However, in an islanded microgrid with multiple distributed generation, the difference in line impedance will cause local voltage deviations, which in turn leads to a series of problems, such as reducing power distribution accuracy and increasing bus voltage drop. Therefore, for the island-type microgrid multi-inverter distributed power generation parallel system, in order to solve the problem of low power distribution accuracy and large frequency oscillation caused by system parameters in virtual synchronous generator control, an improved virtual synchronous generator control algorithm based on adaptive droop coefficient is proposed in this paper, which not only eliminates the resistance component of the line impedance, makes the system impedance characteristic present a purely inductive nature, but also realises real-time adjustment of active and reactive power. While maintaining the stability of the bus voltage and system frequency, it maintains high power distribution accuracy and improves the dynamic performance and operational stability of the power grid system.
Automated detection of abnormal events in processes in realtime is an urgent and important task. To identify various kinds of anomalies, various Data Mining methods are often used. Often, to obtain high accuracy of t...
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ISBN:
(纸本)9781665426053
Automated detection of abnormal events in processes in realtime is an urgent and important task. To identify various kinds of anomalies, various Data Mining methods are often used. Often, to obtain high accuracy of the analysis, preliminary training is required using a large amount of data and representative samples. However, it is not always possible to obtain a representative sample of various kinds of anomalies from real sources. This paper proposes an approach to modeling datasets generated by distributed heterogeneous monitoring systems.
All-digital phased array radars are an emerging technology that require new data processing techniques which are scalable, rely on open-architecture software components, and do not create bottlenecks for the real-time...
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ISBN:
(数字)9798350392142
ISBN:
(纸本)9798350392159
All-digital phased array radars are an emerging technology that require new data processing techniques which are scalable, rely on open-architecture software components, and do not create bottlenecks for the real-time operation. Achieving a solution for these issues relies on heterogeneous processing and distributed software development on CPUs and FPGAs, whereby the overarching algorithm processing chain is distributed in a way that begins at the ADC of each element on an array and concludes in actionable data products. An important aspect is not only the speed of the algorithms, but the throughput of the packetized data transfer. These packets are not only routed, but they are also acted upon in a network of computing services. Here, we explore an open-source resource manager, known as Kubernetes, which connects the packetized data with computing resources on the servers, i.e., moving data in and out of server RAM to complete algorithms such as creating range-Doppler maps, as our results section shows.
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