EPE Association: EPE 2009 - Subtopic 15-3 - LS: 'Power Electronics for Power Systems (III)'

EPE 2009 - Subtopic 15-3 - LS: 'Power Electronics for Power Systems (III)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 15: 'Transmission and Distribution of Electrical Energy' > EPE 2009 - Subtopic 15-3 - LS: 'Power Electronics for Power Systems (III)'

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   Control of multi-terminal VSC-HVDC transmission for offshore wind power
By Jun LIANG, Oriol GOMIS-BELLMUNT, Janaka EKANAYAKE, NICHOLAS JENKINS [View]
[Download]

Abstract: Voltage source converter multi-terminal HVDC transmission (MTDC) for the connection of large offshore wind farms to the terrestrial grid is investigated. The voltage-current characteristics of converters for MTDC are presented. A control system for a four-terminal HVDC system is designed and simulated under both normal and abnormal operating conditions.

   LVDC CUSTOMER-END INVERTER OPERATION IN SHORT CIRCUIT
By Pasi NUUTINEN, Pasi PELTONIEMI, Pasi SALONEN, Pertti SILVENTOINEN [View]
[Download]

Abstract: Short-circuit protection devices applied to customer-end network protection today require multiple times the nominal current to operate within the required time limits. A three-phase 400 VAC distribution network supplies sufficient short-circuit current in customer-end faults, and reaching the required protection time poses no problems. When a Low-Voltage Direct Current (LVDC) network is used to supply a DC/AC inverter at the customer, the short-circuit currents depend, in practice, only on the inverter, because the DC network services several customers and can thus feed multiple times the current required at one customer. This paper discusses customer-end inverter operation, current supply capability, and current limiting in short-circuit. The paper presents three options for short-circuit protection in different inverter structures, makes a brief comparison between them, and proposes the best solution for every structure.

   New Transformerless STATCOM Topology for Compensating Unbalanced Medium-Voltage Loads
By Hassan MOHAMMADI PIROUZ, Mohammad TAVKOLI BINA [View]
[Download]

Abstract: Cascaded multi-level converters have some noticeable advantages such as high reliability, efficient fault management capability, simple structure, and adaptability with different power levels. Furthermore, these converters could be connected to medium-voltage networks without an isolating transformer. However, the voltage balancing of the DC capacitors is a highly challenging task particularly in harmonically polluted and unbalanced systems. To overcome this problem, a new cascaded converter based on two level half-bridge modules for shunt compensators is proposed in this paper. The control algorithm of the compensator and its configuration are designed and optimized in order to achieve an efficient performance in unbalanced systems. This makes it possible to compensate the currents produced by the electric traction system as a popular of medium voltage unbalanced load properly.

EPE 2009 - Subtopic 15-3 - LS: 'Power Electronics for Power Systems (III)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 15: 'Transmission and Distribution of Electrical Energy' > EPE 2009 - Subtopic 15-3 - LS: 'Power Electronics for Power Systems (III)'
	[return to parent folder]

	Control of multi-terminal VSC-HVDC transmission for offshore wind power By Jun LIANG, Oriol GOMIS-BELLMUNT, Janaka EKANAYAKE, NICHOLAS JENKINS	[View] [Download]
Abstract: Voltage source converter multi-terminal HVDC transmission (MTDC) for the connection of large offshore wind farms to the terrestrial grid is investigated. The voltage-current characteristics of converters for MTDC are presented. A control system for a four-terminal HVDC system is designed and simulated under both normal and abnormal operating conditions.

	LVDC CUSTOMER-END INVERTER OPERATION IN SHORT CIRCUIT By Pasi NUUTINEN, Pasi PELTONIEMI, Pasi SALONEN, Pertti SILVENTOINEN	[View] [Download]
Abstract: Short-circuit protection devices applied to customer-end network protection today require multiple times the nominal current to operate within the required time limits. A three-phase 400 VAC distribution network supplies sufficient short-circuit current in customer-end faults, and reaching the required protection time poses no problems. When a Low-Voltage Direct Current (LVDC) network is used to supply a DC/AC inverter at the customer, the short-circuit currents depend, in practice, only on the inverter, because the DC network services several customers and can thus feed multiple times the current required at one customer. This paper discusses customer-end inverter operation, current supply capability, and current limiting in short-circuit. The paper presents three options for short-circuit protection in different inverter structures, makes a brief comparison between them, and proposes the best solution for every structure.

	New Transformerless STATCOM Topology for Compensating Unbalanced Medium-Voltage Loads By Hassan MOHAMMADI PIROUZ, Mohammad TAVKOLI BINA	[View] [Download]
Abstract: Cascaded multi-level converters have some noticeable advantages such as high reliability, efficient fault management capability, simple structure, and adaptability with different power levels. Furthermore, these converters could be connected to medium-voltage networks without an isolating transformer. However, the voltage balancing of the DC capacitors is a highly challenging task particularly in harmonically polluted and unbalanced systems. To overcome this problem, a new cascaded converter based on two level half-bridge modules for shunt compensators is proposed in this paper. The control algorithm of the compensator and its configuration are designed and optimized in order to achieve an efficient performance in unbalanced systems. This makes it possible to compensate the currents produced by the electric traction system as a popular of medium voltage unbalanced load properly.