EPE Association: EPE 2011 - DS1d: Topic 16: FACTS, D-FACTS, Protections Devices and Reliability Issues

EPE 2011 - DS1d: Topic 16: FACTS, D-FACTS, Protections Devices and Reliability Issues
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 - DS1d: Topic 16: FACTS, D-FACTS, Protections Devices and Reliability Issues

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   An new methodology to optimize the efficiency of a multi-sources and multi-converters system under harmonic constraints. Application to light rail systems
By Rémi VIAL, Delphine RIU, Nicolas RETIERE [View]
[Download]

Abstract: A new HVDC power supply network for light rail systems is presented and compared to classical distribution networks based on AC/DC uncontrolled converters. This original supply network use an intermediate high voltage DC feeder which supplies the vehicle through simple synchronous buck converters. Nethertheless, as the number of substations can be increased to improve the line voltage control, harmonic interactions between substations may increase both. Therefore, an adapted tool of power converter filter design has to be developed for such a dynamic and complex system with power electronics converters, AC and DC electrical networks, moving vehicles and harmonic interactions.After a brief presentation of the HVDC supply network, two levels of modeling are then presented. A dynamic model is first described by using a generalized state-space averaging model of converters, which takes into account global losses in converters for switching and conduction phases. Then, a second model is proposed to optimize the parameters of input and output filters of converters according to maximal current and voltage ripples.Finally, this methodology of sizing is applied on a simplified supply network of light rail.

   Application of a Power Electronic Based Fault Current Limiter (FCL) to Reduce Arc Flash Energy in Electrical Grids with High Short-Circuit Power
By Manuel WEILAND, André SCHÖN, Gerhard HEROLD [View]
[Download]

Abstract: Faults in electrical grids with a high short circuit power are, among other things, problematic because of electric arcs. As these arc flashes can come along with a high incident energy and so are a risk, both for persons and equipment, finding ways to reduce the incident energy of arcs makes sense. Fault current limiters (FCL) generally offer the possibility to reduce this arc energy. Currently in a research project the application of a certain type of FCL on the reduction of arc energy is investigated. In this paper the results of the first step of this research project, the theoretical examinations, are summarized. Thereby, for a given system with a high short circuit power a worst case estimation for the incident energy of arcing faults is aspired to. Furthermore, statements on the possible limitation of this energy via the application of the considered FCL are derived.

   Comparison of Multilevel Converter-Based STATCOMs
By Jose VIVAS, Gilbert BERGNA, Maialen BOYRA [View]
[Download]

Abstract: Multilevel converters have become the real option for high voltage and current applications for power systems, especially for FACTS controllers. The Static Compensator (STATCOM) is a shunt-type device which can be used to control reactive power in a network as of its many advantages such as fast speed, compact footprint and small harmonics. In this work a comparison between two of the most promising multilevel converter-based STATCOM has been performed: Cascaded H-Bridge (CHB) and Modular Multilevel Converter (MMC).

   Design and Control of a Novel Dynamic Hybrid VAR Compensator
By Ali ARZANI, Frans DIJKHUIZEN, Hans-Peter NEE [View]
[Download]

Abstract: No abstract provided.

   Fast Acting Autonomous and Rugged Shunt Protection against Open Circuit Faults in High Power Conversion
By Pierluigi TENCA [View]
[Download]

Abstract: Very high voltage and high power converters inserted in transmission and distribution grids have a strategicrole in the operation of the power system of which they are part. Their complete failure is simply notacceptable and, also for this reason, their realizations are highly modular in nature. The exceptionallylarge number of discrete components characterizing such converters implies that the unpredictable localizedfailures of few composing sub-units, be them single components or sub-converters / sub-systems,is an almost certain probabilistic event during the lifetime. In spite of this reality such converters mustguarantee extremely high availability and continuity of grid operation for decades, with the only exclusionof their planned maintenance periods, which recur yearly at most, biennially at present custom.The endeavour is complicated by the fact that even some locally confined and non-propagating faults,having character of open circuit, could be unacceptable for the entire converter. This occurs when thecircuital graph of the converter bestows on such faults the capability of severely altering, or ideally eveninterrupting, the normal grid line currents or the currents in the important converter branches where theymaterialize. In reality a temporary, yet greatly harmful, electric arc may emerge. In approaching thisscenario, the paper proposes a fully autonomous, fast acting shunt device aimed at protecting againstopen circuit faults. The circuit is devised to be as simple and rugged as possible by employing thyristorstogether with rugged passive components only and by avoiding any controller, as well as any externalsupply. Owing to a proposed unconventional use of fuses, arresters and surge protectors in the thyristorstriggering circuit, the shunt intervenes by relying only on the grid current whose flowing must be guaranteed.With the support of simulations the paper concerns the behaviour and design of a shunt rated at1400 A RMS and capable of protecting converter sub-units employing 6.5 kV high power IGBTs.

   Novel Phase Shifted Carrier Modulation for a Cascaded H-bridge Multi-level StatCom
By Chris TOWNSEND, Terrence SUMMERS, Robert BETZ [View]
[Download]

Abstract: Phase shifted carrier modulation enforces harmonic cancellation through each phase-leg in a multi-levelH-bridge StatCom (H-StatCom). The implementation of this scheme, while achieving excellent harmonicperformance suffers from control interactions between the voltage balancing loops. This paper first analysesthese interactions and then develops a phase shifted carrier modulation scheme which avoids the loop interactionsby exploiting an extra degree of freedom in the available switching states. Simulation and experimentalresults are presented that confirm the correct operation of the modulation strategy.

   Optimizing Broadband Harmonic Filter Design for Adjustable Speed Drive Systems
By Hazem ZUBI, Roderick DUNN, Francis ROBINSON [View]
[Download]

Abstract: A novel design method of the improved broadband harmonic filter for diode rectifier type adjustable speed drives using genetic algorithm is presented. The design yields high input and output power quality while reducing the filter size, cost and avoiding resonance problems. Results are illustrated using computer simulations and laboratory experiments.

   Practical Evaluation of Rectangular-Voltage-Fed Distribution System Loaded by Choke-Input Type Three-Phase Diode Rectifier Through Delta/Star Winding Isolation
By Yasuyuki NISHIDA, Hiromichi OHYAMA, Takaharu TAKESHITA [View]
[Download]

Abstract: This paper shows practical evaluation of the rectangular-voltage-fed three-phase distribution system loaded by a choke-input type three-phase diode rectifier through a delta/star winding isolation transformer. Based on experimental date obtained from a 4 [kW] setup, it is shown that the proposed rectangular-voltage-fed three-phase distribution system offers almost unity Total-Power-Factor under the rectifier load condition.

   Reducing Passive Filter Sizes with Tuned Traps for Distribution Level Power Electronics
By Jeffrey BLOEMINK, Tim GREEN [View]
[Download]

Abstract: This paper proposes a filter topology intended for use with mediumvoltage grid-interfaced power electronics as an alternative to thewidely-utilized LCL filter topology. The proposed topology utilizesmultiple shunt RLC trap filters with parameters optimized to minimizethe overall size of the filter while meeting performance requirementsfor connection to the distribution grid. Results indicate a potentialfor reduction of twenty-five to thirty percent in total filter volume for the scenario studied.In addition, total power losses taking place within the filter areslightly reduced.

   Robust control of UPFC for MV distribution grid interconnection under unbalanced conditions
By Maialen BOYRA, Jean-Luc THOMAS, Benchaib ABDELKRIM [View]
[Download]

Abstract: Modeling and control of a Unified Power Flow Controller (UPFC) used for interconnecting medium-voltage (MV) distribution grids is presented. The control strategy is robust under parametrical strategies and unbalanced conditions. A special feature of the work is the use of a Kalman observer for estimating terminal voltage at the receiving-end.

   STATCOM SIZE OPTIMIZATION THROUGH WIND TURBINE OPERATION WITH FIXED POWER FACTOR
By Tobias THURNHERR, Philippe MAIBACH, Carsten RITTER, Mohamed SALEH [View]
[Download]

Abstract: This work presents the operation principles and the corresponding limits of a STATCOM in a wind park application. Dimensioning requirements are outlined, and the STATCOM size reduction considering the wind turbine reactive power contribution is explained. A control philosophy for the STATCOM, which ensures fast and accurate voltage control, is presented. Finally, the control method is underlined with measurements from a wind farm.

EPE 2011 - DS1d: Topic 16: FACTS, D-FACTS, Protections Devices and Reliability Issues
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 - DS1d: Topic 16: FACTS, D-FACTS, Protections Devices and Reliability Issues
	[return to parent folder]

	An new methodology to optimize the efficiency of a multi-sources and multi-converters system under harmonic constraints. Application to light rail systems By Rémi VIAL, Delphine RIU, Nicolas RETIERE	[View] [Download]
Abstract: A new HVDC power supply network for light rail systems is presented and compared to classical distribution networks based on AC/DC uncontrolled converters. This original supply network use an intermediate high voltage DC feeder which supplies the vehicle through simple synchronous buck converters. Nethertheless, as the number of substations can be increased to improve the line voltage control, harmonic interactions between substations may increase both. Therefore, an adapted tool of power converter filter design has to be developed for such a dynamic and complex system with power electronics converters, AC and DC electrical networks, moving vehicles and harmonic interactions.After a brief presentation of the HVDC supply network, two levels of modeling are then presented. A dynamic model is first described by using a generalized state-space averaging model of converters, which takes into account global losses in converters for switching and conduction phases. Then, a second model is proposed to optimize the parameters of input and output filters of converters according to maximal current and voltage ripples.Finally, this methodology of sizing is applied on a simplified supply network of light rail.

	Application of a Power Electronic Based Fault Current Limiter (FCL) to Reduce Arc Flash Energy in Electrical Grids with High Short-Circuit Power By Manuel WEILAND, André SCHÖN, Gerhard HEROLD	[View] [Download]
Abstract: Faults in electrical grids with a high short circuit power are, among other things, problematic because of electric arcs. As these arc flashes can come along with a high incident energy and so are a risk, both for persons and equipment, finding ways to reduce the incident energy of arcs makes sense. Fault current limiters (FCL) generally offer the possibility to reduce this arc energy. Currently in a research project the application of a certain type of FCL on the reduction of arc energy is investigated. In this paper the results of the first step of this research project, the theoretical examinations, are summarized. Thereby, for a given system with a high short circuit power a worst case estimation for the incident energy of arcing faults is aspired to. Furthermore, statements on the possible limitation of this energy via the application of the considered FCL are derived.

	Comparison of Multilevel Converter-Based STATCOMs By Jose VIVAS, Gilbert BERGNA, Maialen BOYRA	[View] [Download]
Abstract: Multilevel converters have become the real option for high voltage and current applications for power systems, especially for FACTS controllers. The Static Compensator (STATCOM) is a shunt-type device which can be used to control reactive power in a network as of its many advantages such as fast speed, compact footprint and small harmonics. In this work a comparison between two of the most promising multilevel converter-based STATCOM has been performed: Cascaded H-Bridge (CHB) and Modular Multilevel Converter (MMC).

	Design and Control of a Novel Dynamic Hybrid VAR Compensator By Ali ARZANI, Frans DIJKHUIZEN, Hans-Peter NEE	[View] [Download]
Abstract: No abstract provided.

	Fast Acting Autonomous and Rugged Shunt Protection against Open Circuit Faults in High Power Conversion By Pierluigi TENCA	[View] [Download]
Abstract: Very high voltage and high power converters inserted in transmission and distribution grids have a strategicrole in the operation of the power system of which they are part. Their complete failure is simply notacceptable and, also for this reason, their realizations are highly modular in nature. The exceptionallylarge number of discrete components characterizing such converters implies that the unpredictable localizedfailures of few composing sub-units, be them single components or sub-converters / sub-systems,is an almost certain probabilistic event during the lifetime. In spite of this reality such converters mustguarantee extremely high availability and continuity of grid operation for decades, with the only exclusionof their planned maintenance periods, which recur yearly at most, biennially at present custom.The endeavour is complicated by the fact that even some locally confined and non-propagating faults,having character of open circuit, could be unacceptable for the entire converter. This occurs when thecircuital graph of the converter bestows on such faults the capability of severely altering, or ideally eveninterrupting, the normal grid line currents or the currents in the important converter branches where theymaterialize. In reality a temporary, yet greatly harmful, electric arc may emerge. In approaching thisscenario, the paper proposes a fully autonomous, fast acting shunt device aimed at protecting againstopen circuit faults. The circuit is devised to be as simple and rugged as possible by employing thyristorstogether with rugged passive components only and by avoiding any controller, as well as any externalsupply. Owing to a proposed unconventional use of fuses, arresters and surge protectors in the thyristorstriggering circuit, the shunt intervenes by relying only on the grid current whose flowing must be guaranteed.With the support of simulations the paper concerns the behaviour and design of a shunt rated at1400 A RMS and capable of protecting converter sub-units employing 6.5 kV high power IGBTs.

	Novel Phase Shifted Carrier Modulation for a Cascaded H-bridge Multi-level StatCom By Chris TOWNSEND, Terrence SUMMERS, Robert BETZ	[View] [Download]
Abstract: Phase shifted carrier modulation enforces harmonic cancellation through each phase-leg in a multi-levelH-bridge StatCom (H-StatCom). The implementation of this scheme, while achieving excellent harmonicperformance suffers from control interactions between the voltage balancing loops. This paper first analysesthese interactions and then develops a phase shifted carrier modulation scheme which avoids the loop interactionsby exploiting an extra degree of freedom in the available switching states. Simulation and experimentalresults are presented that confirm the correct operation of the modulation strategy.

	Optimizing Broadband Harmonic Filter Design for Adjustable Speed Drive Systems By Hazem ZUBI, Roderick DUNN, Francis ROBINSON	[View] [Download]
Abstract: A novel design method of the improved broadband harmonic filter for diode rectifier type adjustable speed drives using genetic algorithm is presented. The design yields high input and output power quality while reducing the filter size, cost and avoiding resonance problems. Results are illustrated using computer simulations and laboratory experiments.

	Practical Evaluation of Rectangular-Voltage-Fed Distribution System Loaded by Choke-Input Type Three-Phase Diode Rectifier Through Delta/Star Winding Isolation By Yasuyuki NISHIDA, Hiromichi OHYAMA, Takaharu TAKESHITA	[View] [Download]
Abstract: This paper shows practical evaluation of the rectangular-voltage-fed three-phase distribution system loaded by a choke-input type three-phase diode rectifier through a delta/star winding isolation transformer. Based on experimental date obtained from a 4 [kW] setup, it is shown that the proposed rectangular-voltage-fed three-phase distribution system offers almost unity Total-Power-Factor under the rectifier load condition.

	Reducing Passive Filter Sizes with Tuned Traps for Distribution Level Power Electronics By Jeffrey BLOEMINK, Tim GREEN	[View] [Download]
Abstract: This paper proposes a filter topology intended for use with mediumvoltage grid-interfaced power electronics as an alternative to thewidely-utilized LCL filter topology. The proposed topology utilizesmultiple shunt RLC trap filters with parameters optimized to minimizethe overall size of the filter while meeting performance requirementsfor connection to the distribution grid. Results indicate a potentialfor reduction of twenty-five to thirty percent in total filter volume for the scenario studied.In addition, total power losses taking place within the filter areslightly reduced.

	Robust control of UPFC for MV distribution grid interconnection under unbalanced conditions By Maialen BOYRA, Jean-Luc THOMAS, Benchaib ABDELKRIM	[View] [Download]
Abstract: Modeling and control of a Unified Power Flow Controller (UPFC) used for interconnecting medium-voltage (MV) distribution grids is presented. The control strategy is robust under parametrical strategies and unbalanced conditions. A special feature of the work is the use of a Kalman observer for estimating terminal voltage at the receiving-end.

	STATCOM SIZE OPTIMIZATION THROUGH WIND TURBINE OPERATION WITH FIXED POWER FACTOR By Tobias THURNHERR, Philippe MAIBACH, Carsten RITTER, Mohamed SALEH	[View] [Download]
Abstract: This work presents the operation principles and the corresponding limits of a STATCOM in a wind park application. Dimensioning requirements are outlined, and the STATCOM size reduction considering the wind turbine reactive power contribution is explained. A control philosophy for the STATCOM, which ensures fast and accurate voltage control, is presented. Finally, the control method is underlined with measurements from a wind farm.