EPE Association: EPE 2017 - LS4f: Grid Issues

EPE 2017 - LS4f: Grid Issues
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 05: Renewable Energy Power Systems > EPE 2017 - LS4f: Grid Issues

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   Compensating the Rotating Mass Kinetic Energy in Grids including High Shares of Renewables
By Pasi PELTONIEMI [View]
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Abstract: The growing number of renewable energy production plants have caused a problem that conventionalinertia response to frequency variations has reduced. As a consequence the amplitude and frequency offrequency variations has grown. Renewable power plants such as wind and solar PV do not inherentlyrespond to the frequency variations. However, also renewable energy systems (RES) can take part onthe frequency regulation by including such controls to the system. In the current day power grid theconnected rotating synchronousmass, that is the inertia, represents certain amount of kinetic energy. Thisenergy can be replaced by synthetic inertia of RES, but the main questions are what kind of dynamics arerequired from the energy sources and are they capable of executing the required performance. Anotherissue is how different energy sources should take part in the frequency regulation. This paper focuseson the available kinetic energy in a grid where power production is based mostly on renewables. Keytechnologies investigated include wind, solar, and battery energy storages. As a result kinetic energiesfor each technology is calculated for small island environment that is assumed to operate independently.

   Flexible operation of parallel grid-connecting converters under unbalanced grid voltage
By Jinghang LU [View]
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Abstract: According to the European grid code, grid-connecting converters should always be connected to the grid under grid voltage unbalance. However, grid voltage unbalance severely affects the stable operation of the converters and leads to the various power issues, such as active power oscillation, DC-link voltage ripple, and overloading. Moreover, under grid voltage unbalance, the active power delivery ability is decreased due to the converter's current rating limitation. In this paper, a thorough study on the current limitation of the grid-connecting converter under grid voltage unbalance is conducted. In addition, based on the principle that total output active power should be oscillation free, a coordinated control strategy is proposed for the parallel grid-connecting converters. The case study has been conducted to demonstrate the effectiveness of this proposed control strategy.

   Modular Multilevel Parallel Converter based Split Battery System (M2B) for Stationary Storage Applications
By Arthur SINGER [View]
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Abstract: A novel battery energy storage system (BESS) based on an enhanced modular multilevel converter (M2C) with the ability to switch its modules in parallel is being presented. Compared to a full-bridge M2C equipped with batteries as energy storage elements on its submodules, the losses are reduced by 20\%. The raise in efficiency is thoroughly explained as well as its reliability. Its high efficiency, its fail-safety and its fast response time to load jumps makes the M2B especially suitable for peak shaving and other stationary storage applications which are illustrated by current use cases.

   Multisampled-Capacitor-Voltage Active Damping for Parallel Interleaved Grid Connected Voltage Source Converters with LCL Filter
By Javier SAMANES [View]
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Abstract: Parallel interleaved converters for high power renewable energy systems present stability issues at theLCL resonance frequency. A multisampled measurement and filtering strategy is proposed to stabilizethe system based on the capacitor voltage derivative active damping, overcoming its limitations for lowswitching power converters. The effects of the delays on the stability of the active damping strategywould be analysed. The solution developed is robust against grid inductance variations, ensuring thefulfilment of the stringent harmonic grid codes.

EPE 2017 - LS4f: Grid Issues
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 05: Renewable Energy Power Systems > EPE 2017 - LS4f: Grid Issues
	[return to parent folder]

	Compensating the Rotating Mass Kinetic Energy in Grids including High Shares of Renewables By Pasi PELTONIEMI	[View] [Download]
Abstract: The growing number of renewable energy production plants have caused a problem that conventionalinertia response to frequency variations has reduced. As a consequence the amplitude and frequency offrequency variations has grown. Renewable power plants such as wind and solar PV do not inherentlyrespond to the frequency variations. However, also renewable energy systems (RES) can take part onthe frequency regulation by including such controls to the system. In the current day power grid theconnected rotating synchronousmass, that is the inertia, represents certain amount of kinetic energy. Thisenergy can be replaced by synthetic inertia of RES, but the main questions are what kind of dynamics arerequired from the energy sources and are they capable of executing the required performance. Anotherissue is how different energy sources should take part in the frequency regulation. This paper focuseson the available kinetic energy in a grid where power production is based mostly on renewables. Keytechnologies investigated include wind, solar, and battery energy storages. As a result kinetic energiesfor each technology is calculated for small island environment that is assumed to operate independently.

	Flexible operation of parallel grid-connecting converters under unbalanced grid voltage By Jinghang LU	[View] [Download]
Abstract: According to the European grid code, grid-connecting converters should always be connected to the grid under grid voltage unbalance. However, grid voltage unbalance severely affects the stable operation of the converters and leads to the various power issues, such as active power oscillation, DC-link voltage ripple, and overloading. Moreover, under grid voltage unbalance, the active power delivery ability is decreased due to the converter's current rating limitation. In this paper, a thorough study on the current limitation of the grid-connecting converter under grid voltage unbalance is conducted. In addition, based on the principle that total output active power should be oscillation free, a coordinated control strategy is proposed for the parallel grid-connecting converters. The case study has been conducted to demonstrate the effectiveness of this proposed control strategy.

	Modular Multilevel Parallel Converter based Split Battery System (M2B) for Stationary Storage Applications By Arthur SINGER	[View] [Download]
Abstract: A novel battery energy storage system (BESS) based on an enhanced modular multilevel converter (M2C) with the ability to switch its modules in parallel is being presented. Compared to a full-bridge M2C equipped with batteries as energy storage elements on its submodules, the losses are reduced by 20\%. The raise in efficiency is thoroughly explained as well as its reliability. Its high efficiency, its fail-safety and its fast response time to load jumps makes the M2B especially suitable for peak shaving and other stationary storage applications which are illustrated by current use cases.

	Multisampled-Capacitor-Voltage Active Damping for Parallel Interleaved Grid Connected Voltage Source Converters with LCL Filter By Javier SAMANES	[View] [Download]
Abstract: Parallel interleaved converters for high power renewable energy systems present stability issues at theLCL resonance frequency. A multisampled measurement and filtering strategy is proposed to stabilizethe system based on the capacitor voltage derivative active damping, overcoming its limitations for lowswitching power converters. The effects of the delays on the stability of the active damping strategywould be analysed. The solution developed is robust against grid inductance variations, ensuring thefulfilment of the stringent harmonic grid codes.