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15 pages, 860 KiB

Open AccessFeature PaperArticle

A Novel Compact dq-Reference Frame Model for Inverter-Based Microgrids

by Carlos A. Macana, Eduardo Mojica-Nava, Hemanshu R. Pota, Josep M. Guerrero and Juan C. Vasquez

Electronics 2019, 8(11), 1326; https://doi.org/10.3390/electronics8111326 - 11 Nov 2019

Cited by 4 | Viewed by 5330

The development and the experimental validation of a novel dynamic model of an islanded three-phase Inverter-based Microgrid (IMG) is presented in this paper. The proposed model reproduces the relevant system dynamics without excessive complexity and enough accuracy. The dynamics of the IMG are captured with a compact and scalable dynamic model, considering inverter based distributed generators with d-current droop primary and proportional resonant inner controllers. The complete development of the model, the practical assumptions, and the accurate proportional power sharing of the primary control technique are shown. The accuracy performance was verified in experiments performed at the Aalborg Intelligent Microgrids Laboratory for an islanded IMG case. Full article

(This article belongs to the Special Issue Design, Modeling and Control of Power Electronic Converters for/in Renewable Energy Systems)

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17 pages, 1091 KiB

Open AccessFeature PaperArticle

Experiments on a Real-Time Energy Management System for Islanded Prosumer Microgrids

by Carlos A. Macana, Hemanshu R. Pota, Quanyan Zhu, Josep M. Guerrero and Juan C. Vasquez

Electronics 2019, 8(9), 925; https://doi.org/10.3390/electronics8090925 - 23 Aug 2019

Cited by 5 | Viewed by 4090

Abstract

This paper presents an experimental demonstration of a novel real-time Energy Management System (EMS) for inverter-based microgrids to achieve optimal economic operation using a simple dynamic algorithm without offline optimization process requirements. The dynamic algorithm solves the economic dispatch problem offering an adequate stability performance and an optimal power reference tracking under sudden load and generation changes. Convergence, optimality and frequency regulation properties of the real-time EMS are shown, and the effectiveness and compatibility with inner and primary controllers are validated in experiments, showing better performance on optimal power tracking and frequency regulation than conventional droop control power sharing techniques. Full article

(This article belongs to the Special Issue Energy Management Based on Internet of Things)

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12 pages, 3009 KiB

Open AccessArticle

A Prototype of an Electromagnetic Induction Sensor for Non-Destructive Estimation of the Presence of Corrosive Chemicals Ensuing Concrete Corrosion

by Kabir A. Mamun, Ravin N. Deo, F. R. Islam, Hemanshu R. Pota, Aneesh A. Chand, Kushal A. Prasad and Aisake Cakacaka

Sensors 2019, 19(9), 1959; https://doi.org/10.3390/s19091959 - 26 Apr 2019

Cited by 7 | Viewed by 5020

Abstract

The corrosion of steel reinforcement in concrete often leads to huge unbudgeted expenses for maintaining, monitoring and renovating an infrastructure. This is mainly due to the presence of salts or chemical chlorides that pose a danger to the concrete structures. The determination of the existence of these corrosive salts is vital for defining the service life of concrete. This research looked at developing an electromagnetic induction (EMI) sensor for the detection of corrosive salts. The first design adopted a single-loop coil (SLC) concept, and the second was based on a multiple-loop coil (MLC) one using copper wire. Tests were conducted on these two techniques, and with the results obtained, the latter seemed more promising; thus, a prototype sensor was developed using the MLC concept. As this new prototype sensor was able to detect the manifestation of chemical contents in a concrete structure, it could be used as a non-destructive evaluation (NDE) technique for the detection of corrosive chemicals in concrete and has the further possibility of detecting corrosion in concrete. Full article

(This article belongs to the Section State-of-the-Art Sensors Technologies)

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15 pages, 803 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Islanding Detection of Synchronous Distributed Generator Based on the Active and Reactive Power Control Loops

by Reza Zamani, Mohamad-Esmail Hamedani-Golshan, Hassan Haes Alhelou, Pierluigi Siano and Hemanshu R. Pota

Energies 2018, 11(10), 2819; https://doi.org/10.3390/en11102819 - 19 Oct 2018

Cited by 47 | Viewed by 7430

Abstract

There has been a considerable importance for the islanding detection due to the growing integration of distributed generations (DGs) in the modern power grids. This paper proposes a novel active islanding detection scheme for synchronous DGs, considering two additional compensators and a positive feedback for each of active and reactive power control loops. The added blocks are designed using the small gain theorem and stability margins definition considering characteristics of open loop transfer functions of synchronous DG control loops. Islanding can be detected using the proposed method even where there is an exact match between generation and local load without sacrificing power quality. In addition, the performance of the proposed method can be retained even with high penetration of motor loads. The proposed scheme improves the stability and power quality of the grid, when the synchronous DG is subjected to the grid-connected disturbances. Furthermore, this method augments the stability margins of the system in the grid-connected conditions to enhance the disturbances ride-through capability of the system and reduce the negative impact of the active methods on the power quality. Simultaneous advantages of the proposed scheme are demonstrated by modeling a test system in MATLAB software and time-domain simulation achieved by PSCAD. Full article

(This article belongs to the Section F: Electrical Engineering)

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14 pages, 1747 KiB

Open AccessArticle

Fast Univariate Time Series Prediction of Solar Power for Real-Time Control of Energy Storage System

by Mostafa Majidpour, Hamidreza Nazaripouya, Peter Chu, Hemanshu R. Pota and Rajit Gadh

Forecasting 2019, 1(1), 107-120; https://doi.org/10.3390/forecast1010008 - 17 Sep 2018

Cited by 26 | Viewed by 7979

Abstract

In this paper, super-short-term prediction of solar power generation for applications in dynamic control of energy system has been investigated. In order to follow and satisfy the dynamics of the controller, the deployed prediction method should have a fast response time. To this end, this paper proposes fast prediction methods to provide the control system with one step ahead of solar power generation. The proposed methods are based on univariate time series prediction. That is, instead of using external data such as the weather forecast as the input of prediction algorithms, they solely rely on past values of solar power data, hence lowering the volume and acquisition time of input data. In addition, the selected algorithms are able to generate the forecast output in less than a second. The proposed methods in this paper are grounded on four well-known prediction algorithms including Autoregressive Integrated Moving Average (ARIMA), K-Nearest Neighbors (kNN), Support Vector Regression (SVR), and Random Forest (RF). The speed and accuracy of the proposed algorithms have been compared based on two different error measures, Mean Absolute Error (MAE) and Symmetric Mean Absolute Percentage Error (SMAPE). Real world data collected from the PV installation at the University of California, Riverside (UCR) are used for prediction purposes. The results show that kNN and RF have better predicting performance with respect to SMAPE and MAE criteria. Full article

(This article belongs to the Special Issue Applications of Forecasting by Hybrid Artificial Intelligent Technologies)

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21 pages, 2552 KiB

Open AccessArticle

Cyber Physical Energy Systems Modules for Power Sharing Controllers in Inverter Based Microgrids

by Carlos A. Macana, Ahmed F. Abdou, Hemanshu R. Pota, Josep M. Guerrero and Juan C. Vasquez

Inventions 2018, 3(3), 66; https://doi.org/10.3390/inventions3030066 - 11 Sep 2018

Cited by 8 | Viewed by 8215

Abstract

The Microgrids (MGs) are an effective way to deal with the smart grid challenges, including service continuity in the event of a grid interruption, and renewable energy integration. The MGs are compounded by multiple distributed generators (DGs), and the main control goals are load demand sharing and voltage and frequency stability. Important research has been reported to cope with the implementation challenges of the MGs including the power sharing control problem, where the use of cybernetic components such as virtual components, and communication systems is a common characteristic. The use of these cybernetic components to control complex physical systems generates new modeling challenges in order to achieve an adequate balance between complexity and accuracy in the MG model. The standardization problem of the cyber-physical MG models is addressed in this work, using a cyber-physical energy systems (CPES) modeling methodology to build integrated modules, and define the communication architectures that each power sharing control strategy requires in an AC-MG. Based on these modules, the control designer can identify the signals and components that eventually require a time delay analysis, communication requirements evaluation, and cyber-attacks’ prevention strategies. Similarly, the modules of each strategy allow for analyzing the potential advantages and drawbacks of each power sharing control technique from a cyber physical perspective. Full article

(This article belongs to the Special Issue Microgrids 2018)

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