EPE Association: EPE 2017 - LS3a: Micro-grids

EPE 2017 - LS3a: Micro-grids
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 06: Grids and Smart Grids > EPE 2017 - LS3a: Micro-grids

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   Beat Frequency Oscillation Analysis for Parallel DC-DC Converters Based on Crossed Frequency Output Impedance Matrix Model
By Xiaolong YUE [View]
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Abstract: The interaction of power electronic converters in a microgrid can introduce system instability and power quality issues. Existing investigations focus on interactions either in low frequency regions, such as the constant power load, or in very high frequency regions like electro-magnetic interference. However, interactions of power converters around their switching frequency range are not included. In fact, the interaction of dc-dc converters with different switching frequencies can introduce beat frequency oscillation in certain cases. Since additional frequency component (beat frequency) is generated, traditional impedance concept is no longer the tool for beat frequency oscillation analysis and new models need to be developed. In this paper, a crossed frequency output impedance matrix model is proposed to describe the terminal characteristics of a dc-dc converter around its switching frequency range. A high frequency equivalent circuit model for the converter is then developed to predict the beat frequency oscillation that results from the interaction of two parallel dc-dc converters with different switching frequency. Finally, several design guidelines are proposed to limit the beat frequency oscillation in the parallel system. Experimental results validate the accuracy and effectiveness of the proposed prediction method and design guidelines.

   Decentralized Control of a Microgrid
By Simon ROUND [View]
[Download]

Abstract: Microgrid systems provide benefits to strong, weak and remote power grids. Using multiple sources with differing characteristics and native constraints makes it a challenge to control the microgrid. Compared to the traditional central controller approach, a decentralized microgrid controller architecture has benefits including resiliency to asset and communication failures, which are experimentally verified in the paper. A reactive power proportional sharing algorithm is presented and experimentally proven.

   Use of Data-Mining for Non-Invasive Harmonic Signature Recognition in Micro-Grids: A Preliminary Approach applied to Residential Areas with PV Converters
By Daniel SIEMASZKO [View]
[Download]

Abstract: The future of distribution networks tends more and more to include computational power, embedded intelligence and smart metering on the high voltage level as well as the low voltage micro-grids. Several hardware solutions were developed to implement the so-called smart grids with measurement devices delivering data about the state of networks on various levels. This work introduces the use of a specific electric signature based on harmonic response of power converters in order to be able to get information in a non-invasive manner. A simulated residential grid with several loads and PV converters has been run real-time with one micro second sampled data, for being able to retrieve information through data mining methods.

   Voltage dips detection in a microgrid with distributed generation for grid-tie inverter protection purposes
By Aleksandar STANISAVLJEVIC [View]
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Abstract: The paper addresses the problem of fault detection in an unbalanced microgrid with distributedgenerators, using algorithms based on harmonic estimation: Wavelet Transform (WT), Fast FourierTransform (FFT) and Reduced Fast Fourier Transform (RFFT). Simulations were carried out in theMATLAB/SimPowerSystems environment. Modified IEEE13 bus system with distributed generationwas used. Experimental verification was done in the Laboratory for Power Electronics of the Facultyof Technical Sciences on advanced setup with grid emulator and modern hardware using modifiedindustrial converters and advanced control circuit. The algorithms were evaluated as part of the gridtieinverter protection scheme for 6 types of faults. It was shown that wavelet with Daubechies with 4filter coefficients has not performed as expected, as it was not able to successfully detect voltagedips. On the other hand, algorithms based on Fourier transformation (FFT and RFFT) successfullydetected voltage dips.

EPE 2017 - LS3a: Micro-grids
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 06: Grids and Smart Grids > EPE 2017 - LS3a: Micro-grids
	[return to parent folder]

	Beat Frequency Oscillation Analysis for Parallel DC-DC Converters Based on Crossed Frequency Output Impedance Matrix Model By Xiaolong YUE	[View] [Download]
Abstract: The interaction of power electronic converters in a microgrid can introduce system instability and power quality issues. Existing investigations focus on interactions either in low frequency regions, such as the constant power load, or in very high frequency regions like electro-magnetic interference. However, interactions of power converters around their switching frequency range are not included. In fact, the interaction of dc-dc converters with different switching frequencies can introduce beat frequency oscillation in certain cases. Since additional frequency component (beat frequency) is generated, traditional impedance concept is no longer the tool for beat frequency oscillation analysis and new models need to be developed. In this paper, a crossed frequency output impedance matrix model is proposed to describe the terminal characteristics of a dc-dc converter around its switching frequency range. A high frequency equivalent circuit model for the converter is then developed to predict the beat frequency oscillation that results from the interaction of two parallel dc-dc converters with different switching frequency. Finally, several design guidelines are proposed to limit the beat frequency oscillation in the parallel system. Experimental results validate the accuracy and effectiveness of the proposed prediction method and design guidelines.

	Decentralized Control of a Microgrid By Simon ROUND	[View] [Download]
Abstract: Microgrid systems provide benefits to strong, weak and remote power grids. Using multiple sources with differing characteristics and native constraints makes it a challenge to control the microgrid. Compared to the traditional central controller approach, a decentralized microgrid controller architecture has benefits including resiliency to asset and communication failures, which are experimentally verified in the paper. A reactive power proportional sharing algorithm is presented and experimentally proven.

	Use of Data-Mining for Non-Invasive Harmonic Signature Recognition in Micro-Grids: A Preliminary Approach applied to Residential Areas with PV Converters By Daniel SIEMASZKO	[View] [Download]
Abstract: The future of distribution networks tends more and more to include computational power, embedded intelligence and smart metering on the high voltage level as well as the low voltage micro-grids. Several hardware solutions were developed to implement the so-called smart grids with measurement devices delivering data about the state of networks on various levels. This work introduces the use of a specific electric signature based on harmonic response of power converters in order to be able to get information in a non-invasive manner. A simulated residential grid with several loads and PV converters has been run real-time with one micro second sampled data, for being able to retrieve information through data mining methods.

	Voltage dips detection in a microgrid with distributed generation for grid-tie inverter protection purposes By Aleksandar STANISAVLJEVIC	[View] [Download]
Abstract: The paper addresses the problem of fault detection in an unbalanced microgrid with distributedgenerators, using algorithms based on harmonic estimation: Wavelet Transform (WT), Fast FourierTransform (FFT) and Reduced Fast Fourier Transform (RFFT). Simulations were carried out in theMATLAB/SimPowerSystems environment. Modified IEEE13 bus system with distributed generationwas used. Experimental verification was done in the Laboratory for Power Electronics of the Facultyof Technical Sciences on advanced setup with grid emulator and modern hardware using modifiedindustrial converters and advanced control circuit. The algorithms were evaluated as part of the gridtieinverter protection scheme for 6 types of faults. It was shown that wavelet with Daubechies with 4filter coefficients has not performed as expected, as it was not able to successfully detect voltagedips. On the other hand, algorithms based on Fourier transformation (FFT and RFFT) successfullydetected voltage dips.