EPE Association: EPE 2016

EPE 2016 - LS3e: FACTS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 06: Grids and Smart Grids > EPE 2016 - LS3e: FACTS

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   Design and Evaluation of a Test Rig for Full-Size Grid Frequency Stabilizer Modules with Ultracapacitors
By Malte JOHN [View]
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Abstract: In order to stabilize the grid frequency in case of sudden loss of power generation, an injection of real power is needed. For this, a Static Var Compensator (SVC) can be combined with ultracapacitors, forming a grid frequency stabilizer. To prove the feasibility of this novel combination, the paper shows the realization of a 1MW class test rig for full-size modules. Single modules are tested using a second module and connecting them at their AC front-end. The control of the AC/DC and DC/DC converters is described and the performance of the test field is shown in measurement results.

   Input-Series and Output-Series High Voltage Converter with Active Balancing Circuit for N-1 Operation
By Tiago NABAIS LIMA [View]
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Abstract: An input-series/output-series converter dedicated to high power applications is presented. Theconverter is composed of plural MF transformers based on DC-DC sub-converters. The seriesconnection allows reaching input-voltage levels in the range of several tens or hundreds of kV. Thepower level can be increased by modularity, even if the size of one MF transformer is generallylimited by the size of the available magnetic cores. Each sub-converter has at its primary side a 3-Level Half-Bridge inverter that generates the MF intermediary voltage. The output circuit of each subconverteris a simple diode rectifier. The series input circuit is completed by an active balancing circuitwhich allows the N-1 operation of the installed channels with unmodified input voltage conditions.The paper presents the new topology together with the adopted control structure. The performance ofthe proposed architecture and its possible mode of operation with one or more disabled sub-convertersis verified with a small-scale demonstrator.

   Optimized design of a Hybrid-MMC and evaluation of different MMC topologies
By Viktor HOFMANN [View]
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Abstract: This paper investigates the combined use of basic cell types (half and full bridges) in a Modular Multilevel Converter in order to achieve an improved MMC performance. Based on an MMC without any additional features (only considering the power transmission capability), an optimal design is presented for additional capabilities such as DC fault ride-through capability or safe operation during reduced DC voltage. These different MMC configurations are compared to a Half and a Full Bridge MMC with regard to the total cost per transmitted power, which includes semiconductor losses and basic power electronic costs.

   Protection of Hybrid Transformers in the Distribution Grid
By Johannes BURKARD [View]
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Abstract: Due to the increasing integration of renewable energy sources and power electronic loads into the distribution grid, a deterioration of the grid power quality is expected. Consisting of a low frequency transformer and a fractionally rated power electronic converter, the hybrid transformer can be applied to ensure a high power quality by controlling voltage, current, active and reactive power dynamically. For the application ingrids with conventional grid protection infrastructure, hybrid transformers have to withstand considerable overvoltage and -current stresses during voltage surges or grid short circuits. Since the semiconductors are less robust than low frequency transformers with respect to these stresses, the effects of possiblefault scenarios and a protection concept are studied in this paper.

EPE 2016 - LS3e: FACTS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 06: Grids and Smart Grids > EPE 2016 - LS3e: FACTS
	[return to parent folder]

	Design and Evaluation of a Test Rig for Full-Size Grid Frequency Stabilizer Modules with Ultracapacitors By Malte JOHN	[View] [Download]
Abstract: In order to stabilize the grid frequency in case of sudden loss of power generation, an injection of real power is needed. For this, a Static Var Compensator (SVC) can be combined with ultracapacitors, forming a grid frequency stabilizer. To prove the feasibility of this novel combination, the paper shows the realization of a 1MW class test rig for full-size modules. Single modules are tested using a second module and connecting them at their AC front-end. The control of the AC/DC and DC/DC converters is described and the performance of the test field is shown in measurement results.

	Input-Series and Output-Series High Voltage Converter with Active Balancing Circuit for N-1 Operation By Tiago NABAIS LIMA	[View] [Download]
Abstract: An input-series/output-series converter dedicated to high power applications is presented. Theconverter is composed of plural MF transformers based on DC-DC sub-converters. The seriesconnection allows reaching input-voltage levels in the range of several tens or hundreds of kV. Thepower level can be increased by modularity, even if the size of one MF transformer is generallylimited by the size of the available magnetic cores. Each sub-converter has at its primary side a 3-Level Half-Bridge inverter that generates the MF intermediary voltage. The output circuit of each subconverteris a simple diode rectifier. The series input circuit is completed by an active balancing circuitwhich allows the N-1 operation of the installed channels with unmodified input voltage conditions.The paper presents the new topology together with the adopted control structure. The performance ofthe proposed architecture and its possible mode of operation with one or more disabled sub-convertersis verified with a small-scale demonstrator.

	Optimized design of a Hybrid-MMC and evaluation of different MMC topologies By Viktor HOFMANN	[View] [Download]
Abstract: This paper investigates the combined use of basic cell types (half and full bridges) in a Modular Multilevel Converter in order to achieve an improved MMC performance. Based on an MMC without any additional features (only considering the power transmission capability), an optimal design is presented for additional capabilities such as DC fault ride-through capability or safe operation during reduced DC voltage. These different MMC configurations are compared to a Half and a Full Bridge MMC with regard to the total cost per transmitted power, which includes semiconductor losses and basic power electronic costs.

	Protection of Hybrid Transformers in the Distribution Grid By Johannes BURKARD	[View] [Download]
Abstract: Due to the increasing integration of renewable energy sources and power electronic loads into the distribution grid, a deterioration of the grid power quality is expected. Consisting of a low frequency transformer and a fractionally rated power electronic converter, the hybrid transformer can be applied to ensure a high power quality by controlling voltage, current, active and reactive power dynamically. For the application ingrids with conventional grid protection infrastructure, hybrid transformers have to withstand considerable overvoltage and -current stresses during voltage surges or grid short circuits. Since the semiconductors are less robust than low frequency transformers with respect to these stresses, the effects of possiblefault scenarios and a protection concept are studied in this paper.