EPE Association: EPE 2015 - LS4e: HVDC and FACTS

EPE 2015 - LS4e: HVDC and FACTS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 06: Grids and Smart Grids > EPE 2015 - LS4e: HVDC and FACTS

   [return to parent folder]

   Double modulation control (DMC) for dual full H-bridge current flow controller (2FB-CFC)
By Fainan HASSAN [View]
[Download]

Abstract: Power flow control in multi-terminal DC grids can be accomplished through the connection in series of a controlled voltage source converter to a line. Having finite energy, the voltage source requires a means for either power recycling or additional source of power to regulate its voltage. An interline dual full bridge current flow controller (CFC) provides the capability to recycle power from one line to another through the voltage source in addition to controlling the power flow on either line. This paper proposes a control methodology that fulfills both control objectives. A double modulation controller (DMC) implements one modulating signal and two control signals to control the duty ratio of the converters simultaneously. The first control signal is proportional to the required reduction in the line current. The second control signal is implemented to regulate the voltage to either a set average value or to a value that is proportional to the amount of reduction in current.

   Electrical Type Tests for the Voltage Sourced Converter Valves based on Modular Multi-Level Converter
By TIANNING XU [View]
[Download]

Abstract: Though IEC 62501 was already published in 2009 to define the requirements of the electrical type testing for the Voltage Sourced Converter (VSC) valves for High Voltage Direct Current (HVDC) transmission, so far very few papers have really discussed the test methods for VSC valve nor disclosed any test results. In this paper, all the type tests required by IEC 62501 are discussed for a Modular Multi-level Converter (MMC)-based VSC HVDC valve based upon the half-bridge topology, with a method introduced for each test and the corresponding test results presented.

   Modular Multilevel Converter Based LCL DC/DC Converter for High Power DC Transmission Grids
By Ahmed ABOUSHADY [View]
[Download]

Abstract: This paper presents a modular multilevel converter (MMC) based DC/DC converter with LCL inner circuit for HVDC transmission and DC grids. Three main design challenges are addressed. The first challenge is the use of MMCs with higher operating frequency compared to common transformer-based DC/DC converters where MMC operating frequency is limited to a few hundred hertz due to core losses. The second issue is the DC fault response. With the LCL circuit, the steady state fault current is limited to a low magnitude which is tolerable by MMC semiconductors. Mechanical DC circuit breakers can therefore be used to interrupt fault current for permanent faults and extra sub-module bypass thyristors are not necessary to protect antiparallel diodes. Thirdly, a novel controller structure is introduced with multiple coordinate frames ensuring zero local reactive power at both bridges in the whole load range. The proposed controller structure is also expandable to a DC hub with multiple ports. Detailed simulations using PSCAD/EMTDC are performed to verify the aforementioned design solutions in normal and fault conditions.

   STUDY OF THE MMC CIRCULATING CURRENT FOR OPTIMAL OPERATION MODE IN HVDC APPLICATIONS
By MARIO MARCHESONI [View]
[Download]

Abstract: An exhaustive study on the circulating currents and their consequences in modular multilevel converters for HVDC applications is presented. The first part is a review of an analytical study of the converter, aimed to minimize the capacitors voltage ripple. In the second part the effects on the system efficiency are presented.

EPE 2015 - LS4e: HVDC and FACTS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 06: Grids and Smart Grids > EPE 2015 - LS4e: HVDC and FACTS
	[return to parent folder]

	Double modulation control (DMC) for dual full H-bridge current flow controller (2FB-CFC) By Fainan HASSAN	[View] [Download]
Abstract: Power flow control in multi-terminal DC grids can be accomplished through the connection in series of a controlled voltage source converter to a line. Having finite energy, the voltage source requires a means for either power recycling or additional source of power to regulate its voltage. An interline dual full bridge current flow controller (CFC) provides the capability to recycle power from one line to another through the voltage source in addition to controlling the power flow on either line. This paper proposes a control methodology that fulfills both control objectives. A double modulation controller (DMC) implements one modulating signal and two control signals to control the duty ratio of the converters simultaneously. The first control signal is proportional to the required reduction in the line current. The second control signal is implemented to regulate the voltage to either a set average value or to a value that is proportional to the amount of reduction in current.

	Electrical Type Tests for the Voltage Sourced Converter Valves based on Modular Multi-Level Converter By TIANNING XU	[View] [Download]
Abstract: Though IEC 62501 was already published in 2009 to define the requirements of the electrical type testing for the Voltage Sourced Converter (VSC) valves for High Voltage Direct Current (HVDC) transmission, so far very few papers have really discussed the test methods for VSC valve nor disclosed any test results. In this paper, all the type tests required by IEC 62501 are discussed for a Modular Multi-level Converter (MMC)-based VSC HVDC valve based upon the half-bridge topology, with a method introduced for each test and the corresponding test results presented.

	Modular Multilevel Converter Based LCL DC/DC Converter for High Power DC Transmission Grids By Ahmed ABOUSHADY	[View] [Download]
Abstract: This paper presents a modular multilevel converter (MMC) based DC/DC converter with LCL inner circuit for HVDC transmission and DC grids. Three main design challenges are addressed. The first challenge is the use of MMCs with higher operating frequency compared to common transformer-based DC/DC converters where MMC operating frequency is limited to a few hundred hertz due to core losses. The second issue is the DC fault response. With the LCL circuit, the steady state fault current is limited to a low magnitude which is tolerable by MMC semiconductors. Mechanical DC circuit breakers can therefore be used to interrupt fault current for permanent faults and extra sub-module bypass thyristors are not necessary to protect antiparallel diodes. Thirdly, a novel controller structure is introduced with multiple coordinate frames ensuring zero local reactive power at both bridges in the whole load range. The proposed controller structure is also expandable to a DC hub with multiple ports. Detailed simulations using PSCAD/EMTDC are performed to verify the aforementioned design solutions in normal and fault conditions.

	STUDY OF THE MMC CIRCULATING CURRENT FOR OPTIMAL OPERATION MODE IN HVDC APPLICATIONS By MARIO MARCHESONI	[View] [Download]
Abstract: An exhaustive study on the circulating currents and their consequences in modular multilevel converters for HVDC applications is presented. The first part is a review of an analytical study of the converter, aimed to minimize the capacitors voltage ripple. In the second part the effects on the system efficiency are presented.