EPE Association: EPE 2019 - LS5d: Grids Monitoring and Stability

EPE 2019 - LS5d: Grids Monitoring and Stability
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2019 - LS5d: Grids Monitoring and Stability

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   A Comparative Study on Damping Methods of Virtual Synchronous Generator Control
By Jia LIU [View]
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Abstract: Grid-tied inverters adopting virtual synchronous generator (VSG) control can provide frequency support for the power grid in a similar way to conventional synchronous generators. However, virtual inertia emulation also introduces an oscillatory mode. Various damping methods capable to assign closed-loop poles are proposed in the literature. In this paper, theoretical analyses and experimental results are presented to compare these methods, in respect of dynamic response and ripple attenuation ability.

   APPLICATION OF S-TRANSFORM FOR VOLTAGE DIPS DETECTION AND ANALYSIS IN MODERN DISTRIBUTION GRIDS
By Aleksandar STANISAVLJEVIC [View]
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Abstract: The paper addresses the problem of fault detection and analysis in modern distribution grids, using an algorithm based on Stockwell transform (S-transform). The FFT and the Standard RMS were implemented for comparison of results with the ST method. Modified IEEE model of 13-bus test system with high level of distributed generation was used for testing of presented methods in Matlab/Simulink simulation environment. Methods are implemented in laboratory using advanced, dSpace based setup that includes modified industrial converters and distribution grid emulator. Also, real grid measurement results of voltage disturbances obtained on two different voltage levels are used for further testing of presented methods and confirmation of results obtained in simulations and on the laboratory setup.

   Impact of converter control parameters on the high-frequency resonance stability of a wind-farm connected to an ac grid
By Mebtu BEZA [View]
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Abstract: The transient stability of a wind-farm connected to an ac grid depends on the control settings of the involved converters, the grid resonances and the system's operating conditions. This paper focuses on investigating the impact of converter control algorithms on possible high-frequency resonance interactions that could endanger the overall stability of these kinds of systems. Mainly, two control strategies namely the conventional cascade control structure, consisting of an inner current-control loop and various outer-loop controls, and the immediate voltage control structure, which does not include a current-control loop, are compared. The impact of control parameters for both methods will be investigated as well. For this purpose, the ac-side input admittance of a wind-turbine converter is derived for the two control strategies and passivity-based frequency-domain analysis is used to assess their impact on system stability. Finally, the analytical findings are verified through detailed time-domain simulations and recommendations to increase system stability are given accordingly.

   Tuning of Droop Parameters Using Virtual Capacitor Control to Improve Voltage Dynamics
By Kosei SHINODA [View]
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Abstract: This paper proposes a new approach to tuning voltage droop parameters in an MMC-based multi-terminal HVDC system. Using the new degree of freedom offered by the virtual capacitor control, the transient behavior of the DC voltage can be improved without adverse effects on the connected AC grids.

EPE 2019 - LS5d: Grids Monitoring and Stability
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2019 - LS5d: Grids Monitoring and Stability
	[return to parent folder]

	A Comparative Study on Damping Methods of Virtual Synchronous Generator Control By Jia LIU	[View] [Download]
Abstract: Grid-tied inverters adopting virtual synchronous generator (VSG) control can provide frequency support for the power grid in a similar way to conventional synchronous generators. However, virtual inertia emulation also introduces an oscillatory mode. Various damping methods capable to assign closed-loop poles are proposed in the literature. In this paper, theoretical analyses and experimental results are presented to compare these methods, in respect of dynamic response and ripple attenuation ability.

	APPLICATION OF S-TRANSFORM FOR VOLTAGE DIPS DETECTION AND ANALYSIS IN MODERN DISTRIBUTION GRIDS By Aleksandar STANISAVLJEVIC	[View] [Download]
Abstract: The paper addresses the problem of fault detection and analysis in modern distribution grids, using an algorithm based on Stockwell transform (S-transform). The FFT and the Standard RMS were implemented for comparison of results with the ST method. Modified IEEE model of 13-bus test system with high level of distributed generation was used for testing of presented methods in Matlab/Simulink simulation environment. Methods are implemented in laboratory using advanced, dSpace based setup that includes modified industrial converters and distribution grid emulator. Also, real grid measurement results of voltage disturbances obtained on two different voltage levels are used for further testing of presented methods and confirmation of results obtained in simulations and on the laboratory setup.

	Impact of converter control parameters on the high-frequency resonance stability of a wind-farm connected to an ac grid By Mebtu BEZA	[View] [Download]
Abstract: The transient stability of a wind-farm connected to an ac grid depends on the control settings of the involved converters, the grid resonances and the system's operating conditions. This paper focuses on investigating the impact of converter control algorithms on possible high-frequency resonance interactions that could endanger the overall stability of these kinds of systems. Mainly, two control strategies namely the conventional cascade control structure, consisting of an inner current-control loop and various outer-loop controls, and the immediate voltage control structure, which does not include a current-control loop, are compared. The impact of control parameters for both methods will be investigated as well. For this purpose, the ac-side input admittance of a wind-turbine converter is derived for the two control strategies and passivity-based frequency-domain analysis is used to assess their impact on system stability. Finally, the analytical findings are verified through detailed time-domain simulations and recommendations to increase system stability are given accordingly.

	Tuning of Droop Parameters Using Virtual Capacitor Control to Improve Voltage Dynamics By Kosei SHINODA	[View] [Download]
Abstract: This paper proposes a new approach to tuning voltage droop parameters in an MMC-based multi-terminal HVDC system. Using the new degree of freedom offered by the virtual capacitor control, the transient behavior of the DC voltage can be improved without adverse effects on the connected AC grids.