EPE Association: EPE 2011 - LS2b: Topic 16: HVDC and STATCOM

EPE 2011 - LS2b: Topic 16: HVDC and STATCOM
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 16: Power electronics in transmission and distribution > EPE 2011 - LS2b: Topic 16: HVDC and STATCOM

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   Control of a Modular Multilevel Converter-based HVDC transmission system
By Diego SOTO, T. C. GREEN [View]
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Abstract: This paper proposes a novel control scheme to regulate the capacitor voltages in a multi modular converter (MMC) topology which is suitable for HVDC transmission systems. The scheme is based on the use of the active positive sequence current component, to maintain balance between the AC-side and DC-side powers, and the active and reactive negative sequence components, to exchange energy from the capacitors of one phase to those of another phase. The latter equalizes the stored energy amongst the valves and it is useful during asymmetrical AC system faults, or during fast system disturbances, which generally charge/discharge capacitors of each valve in a very different way. Performance of the proposed controller is tested on an example HVDC system which comprises an MMC inverter and an MMC rectifier station connected via a DC-link cable. The MMC topology considered is a standard three-phase bridge and uses H-bridge modules to implement converter valves. Compared to the standard MMC, which uses half-bridge modules, the H-bridge MMC offers the capability to ride-through DC system faults.Proposals are verified through detailed simulations of the example system under fault conditions. This includes: a three-phase to ground fault, a single-phase to ground fault and a pole-to-pole fault on the DC-link. Results confirm the converter capability to ride-though not only AC system faults but also DC system faults. However, system functionality is limited by the capacity of cell capacitors to store/deliver energy during the fault. Nevertheless, an H-bridge MMC HVDC terminal, even with a small storage capacity (20 ms at rated power), is still able to manage severe AC and DC system outages without assistance of auxiliary elements (e.g. break resistor, fault current limiter).

   Loss Comparison of Different Sub-Module Implementations for Modular Multilevel Converters in HVDC Applications
By Tomas MODEER, Staffan NORRGA, Hans-Peter NEE [View]
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Abstract: This paper presents a loss calculation and comparison between different submodule topologies andsemiconductor choices for a Modular Multilevel Converter in a 1:1GW, 320kV HVDC application.

   Power Quality Analysis of a Static Synchronous Compensator (STATCOM) Connected to a High Voltage Transmission Network
By Aitor LAKA, Jon Andoni BARRENA, Francisco Javier CHIVITE-ZABALZA, Miguel Angel RODRIGUEZ-VIDAL [View]
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Abstract: This paper analyses the voltage harmonic content at the Point of Common Coupling (PCC) and at the Voltage Source Converter (VSC) output in a STATCOM application by using a calculation tool, also discussed in the paper. Subsequently, a parameter sensitivity analysis is carried out taking into account the variation of key parameters such as the line length, the shunt transformer impedance, the capacitor bank connection and the effect of a given filter, for instance a LC type filter. The harmonic content at the (PCC) obtained when 24 and quasi 48 pulse modulation techniques are used, is calculated and subsequently compared against the stringent Spanish power quality legislation.

EPE 2011 - LS2b: Topic 16: HVDC and STATCOM
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 16: Power electronics in transmission and distribution > EPE 2011 - LS2b: Topic 16: HVDC and STATCOM
	[return to parent folder]

	Control of a Modular Multilevel Converter-based HVDC transmission system By Diego SOTO, T. C. GREEN	[View] [Download]
Abstract: This paper proposes a novel control scheme to regulate the capacitor voltages in a multi modular converter (MMC) topology which is suitable for HVDC transmission systems. The scheme is based on the use of the active positive sequence current component, to maintain balance between the AC-side and DC-side powers, and the active and reactive negative sequence components, to exchange energy from the capacitors of one phase to those of another phase. The latter equalizes the stored energy amongst the valves and it is useful during asymmetrical AC system faults, or during fast system disturbances, which generally charge/discharge capacitors of each valve in a very different way. Performance of the proposed controller is tested on an example HVDC system which comprises an MMC inverter and an MMC rectifier station connected via a DC-link cable. The MMC topology considered is a standard three-phase bridge and uses H-bridge modules to implement converter valves. Compared to the standard MMC, which uses half-bridge modules, the H-bridge MMC offers the capability to ride-through DC system faults.Proposals are verified through detailed simulations of the example system under fault conditions. This includes: a three-phase to ground fault, a single-phase to ground fault and a pole-to-pole fault on the DC-link. Results confirm the converter capability to ride-though not only AC system faults but also DC system faults. However, system functionality is limited by the capacity of cell capacitors to store/deliver energy during the fault. Nevertheless, an H-bridge MMC HVDC terminal, even with a small storage capacity (20 ms at rated power), is still able to manage severe AC and DC system outages without assistance of auxiliary elements (e.g. break resistor, fault current limiter).

	Loss Comparison of Different Sub-Module Implementations for Modular Multilevel Converters in HVDC Applications By Tomas MODEER, Staffan NORRGA, Hans-Peter NEE	[View] [Download]
Abstract: This paper presents a loss calculation and comparison between different submodule topologies andsemiconductor choices for a Modular Multilevel Converter in a 1:1GW, 320kV HVDC application.

	Power Quality Analysis of a Static Synchronous Compensator (STATCOM) Connected to a High Voltage Transmission Network By Aitor LAKA, Jon Andoni BARRENA, Francisco Javier CHIVITE-ZABALZA, Miguel Angel RODRIGUEZ-VIDAL	[View] [Download]
Abstract: This paper analyses the voltage harmonic content at the Point of Common Coupling (PCC) and at the Voltage Source Converter (VSC) output in a STATCOM application by using a calculation tool, also discussed in the paper. Subsequently, a parameter sensitivity analysis is carried out taking into account the variation of key parameters such as the line length, the shunt transformer impedance, the capacitor bank connection and the effect of a given filter, for instance a LC type filter. The harmonic content at the (PCC) obtained when 24 and quasi 48 pulse modulation techniques are used, is calculated and subsequently compared against the stringent Spanish power quality legislation.