EPE Association: EPE 2017 - DS2i: Power Electronics in T&D Systems I

EPE 2017 - DS2i: Power Electronics in T&D Systems I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 06: Grids and Smart Grids > EPE 2017 - DS2i: Power Electronics in T&D Systems I

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   Active power filter with current balancing capability for two-phase systems
By Julio VIOLA [View]
[Download]

Abstract: Two-phase residential installations have become very common in Ecuador since different policies promptthe users to replace gas stoves and water heaters by electric appliances. The addition of a second phase tothe originally installed single-phase wiring is required to obtain 220Vrms. This fact carries an intrinsicunbalance since single- and two-phase loads coexist. In this paper a topology for an active power filteris proposed which is able of balancing of the currents leading to a balance in the active power in eachphase. This added feature does not interfere with the capability of the active power filter for reactivepower compensation. The proposed topology is tested by simulations for two-phase systems havingphase voltages with 120° and 180° of difference.

   An Improved Modulation Method of Three-phase Face-to-Face Modular Multilevel Converter
By Shuhuai SHI [View]
[Download]

Abstract: An improved modulation algorithm is proposed for three-phase face-to-face topology. The algorithm could make the face-to-face dc transformer use 1: 1 ac transformer or omit ac transformer in a wide variable ratio range to reducing the volume of the system. The simulation in MATLAB/Simulink validates the proposed algorithm.

   Control of a Multi-terminal DC Transmission System with Reduced Power Oscillation
By Christian ALCOTA [View]
[Download]

Abstract: The control of multiterminal HVDC systems based on local variables has shown a better performance, interms of dynamical response and implementation simplicity, than constant DC voltage and droop control.However, power oscillations can be produced due to the interaction among different HVDC stations. Inthis paper, a modified control logic for this type of control is proposed in order to reduce the poweroscillations generated when the HVDC stations change its operation mode. The new control logic locksthe operating mode of each station for a given time avoiding interactions with other HVDC stations aftersudden changes in the DC voltage or power.

   Coordinated control logic of photovoltaic and regenerative electric power in distribution system and verification of its effect
By Tetsuo FUJITA [View]
[Download]

Abstract: This paper reports simple and effective control logic for connecting abrupt, steep and short-term power sources (for example, regenerative power from electric railway vehicles) to distribution lines with renewable energy units connected. With conventional centralized control systems, power conditioner units were unable to keep voltage of the distribution line within an acceptable range when extremely steep regenerative power flowed backward in the line, due to control delay. This new logic has power conditioner units exchange calculated control amounts between themselves repeatedly in fixed intervals. When voltage of the distribution line rises relatively slowly from renewable energy generators such as PV, the power conditioner unit can suppress the voltage rise immediately with no control delay, if regenerative power flows backward to the lines and voltage departure from an acceptable range is foreseen. This logic needs no central control unit in particular, as its power conditioner units can effectively execute and coordinate control between themselves. We verified the effectiveness of this logic through an experiment at our demonstration facility.

   DESIGN OF A PUBLIC DC GRID OF A BUSINESS PARK
By Will DE JAGER [View]
[Download]

Abstract: This paper describes the design of a DC grid as a utility grid on of a business park. The center of the DC grid is a DC substation. The DC substation is supplied from the MV AC grid. With a transformer and an Active Front End, the AC voltage of 10 kV is transformed into 750 VDC. At customer side, the 750 VDC is converted to the required DC voltage for his application.

   Development of Continuous Series Voltage Compensator for load voltage regulation and negative sequence compensation in a 6.6kV distribution line
By Shunsuke TAMADA [View]
[Download]

Abstract: Continuous voltage compensator was developed to improve power quality issues of distribution lines. It consists of series and shunt transformer connected through static power converters. In this paper, the compensation methods using series and shunt converters were investigated, and manufacturing of actual rating 6.6kV 3MVA prototype was reported.

   Dual-circuit hybrid circuit breaker
By Chuanyue LI [View]
[Download]

Abstract: A DC fault will propagate quickly in a DC grid and results in significant DC voltage drop and largecurrent increase. To protect the DC grid from the DC faults, the concept of hybrid HVDC circuit breaker(DCCB) is widely-accepted due to its low conducting loss and fast operation speed. The unidirectionalDCCB recently is considered to fulfil the protection criteria. However, for a well-built DC grid, amassive number of unidirectional DCCB will be applied. This will lead to the high capital cost. For aterminal applied multiple unidirectional DCCBs, their MOVs could be shared to reduce their capitalcost. The dual-circuit DCCB is proposed to reduce the size of MOVs by 50\% based on the idea ofsharing MOV. And the performance of the DC fault blocking is maintained. The structure and operationprinciple of the dual-circuit DCCB are introduced. Comparing with the unidirectional DCCB, the faultblocking capability and the economy of the dual-circuit DCCB is verified.

   Power quality improvement strategies for battery storage systems with low-voltage grid support
By Johannes STÖCKL [View]
[Download]

Abstract: This paper describes implications of 3-phase 4-leg inverter control for grid storage systems with morethan one control target. The presented use case focusses on the concurrent services of power-flowbalancing and market driven operations. Two different priority settings depending on storage operatorbusiness models are shown.

   Research on the Current Commutation in a Novel Hybrid HVDC Circuit Breaker
By Lei FENG [View]
[Download]

Abstract: Recent development renewable energy increases the requirement in constructing multi-terminal HVDC systems or HVDC grids. To increase the system reliability, an HVDC circuit breaker will be required. However the existing HVDC breakers developed in recent years use large amount of IGBTs. Considering the cost reduction in real HVDC grids, this paper presents a novel hybrid HVDC circuit breaker. The proposed topology is based on anti-parallel thyristors and full bridge sub module technique with bidirectional interruption. In normal operation, the fast mechanical switch and small amount of IGBTs handle the low conduction loss. In case of interruption, the faulted current is forced to the snubber capacitor of transfer branch in order to turn off thyristors. The proposed breaker has significant technical advantage compared with other solutions especially in terms of current breaking ability and semiconductor cost. The modular unit design could improve the voltage application easily. Moreover, the voltage stress over the load commutation switch is analyzed based on a simplified model. It is observed that the parameters of snubber circuit and time delay of commutation time have great influence on the voltage stress. A principle prototype has been built and tested with an adaptive triggering board. A current commutation test procedure is developed to verify the voltage stress.

   Transformerless multicellular dc-dc converter for highly efficient next generation dc distribution system
By Yusuke HAYASHI [View]
[Download]

Abstract: A transformerless multicellular dc-dc converter has been newly proposed. The capacitively isolated dc-dc cell converters have been applied to develop the multicellular converter without using high frequency transformers. The high voltage transformation ratio is achieved by the ISOP (Input Series Output Parallel) connection topology of the cell converters and the realization of the highly efficient cell converter is expected because of no transformers. A 144 V-24 V, 200 W prototype of the multicellular dc-dc converter using 3 cell converters based on the capacitive isolation has been developed, and the feasibility of the transformerless multicellular converter has been confirmed.

EPE 2017 - DS2i: Power Electronics in T&D Systems I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 06: Grids and Smart Grids > EPE 2017 - DS2i: Power Electronics in T&D Systems I
	[return to parent folder]

	Active power filter with current balancing capability for two-phase systems By Julio VIOLA	[View] [Download]
Abstract: Two-phase residential installations have become very common in Ecuador since different policies promptthe users to replace gas stoves and water heaters by electric appliances. The addition of a second phase tothe originally installed single-phase wiring is required to obtain 220Vrms. This fact carries an intrinsicunbalance since single- and two-phase loads coexist. In this paper a topology for an active power filteris proposed which is able of balancing of the currents leading to a balance in the active power in eachphase. This added feature does not interfere with the capability of the active power filter for reactivepower compensation. The proposed topology is tested by simulations for two-phase systems havingphase voltages with 120° and 180° of difference.

	An Improved Modulation Method of Three-phase Face-to-Face Modular Multilevel Converter By Shuhuai SHI	[View] [Download]
Abstract: An improved modulation algorithm is proposed for three-phase face-to-face topology. The algorithm could make the face-to-face dc transformer use 1: 1 ac transformer or omit ac transformer in a wide variable ratio range to reducing the volume of the system. The simulation in MATLAB/Simulink validates the proposed algorithm.

	Control of a Multi-terminal DC Transmission System with Reduced Power Oscillation By Christian ALCOTA	[View] [Download]
Abstract: The control of multiterminal HVDC systems based on local variables has shown a better performance, interms of dynamical response and implementation simplicity, than constant DC voltage and droop control.However, power oscillations can be produced due to the interaction among different HVDC stations. Inthis paper, a modified control logic for this type of control is proposed in order to reduce the poweroscillations generated when the HVDC stations change its operation mode. The new control logic locksthe operating mode of each station for a given time avoiding interactions with other HVDC stations aftersudden changes in the DC voltage or power.

	Coordinated control logic of photovoltaic and regenerative electric power in distribution system and verification of its effect By Tetsuo FUJITA	[View] [Download]
Abstract: This paper reports simple and effective control logic for connecting abrupt, steep and short-term power sources (for example, regenerative power from electric railway vehicles) to distribution lines with renewable energy units connected. With conventional centralized control systems, power conditioner units were unable to keep voltage of the distribution line within an acceptable range when extremely steep regenerative power flowed backward in the line, due to control delay. This new logic has power conditioner units exchange calculated control amounts between themselves repeatedly in fixed intervals. When voltage of the distribution line rises relatively slowly from renewable energy generators such as PV, the power conditioner unit can suppress the voltage rise immediately with no control delay, if regenerative power flows backward to the lines and voltage departure from an acceptable range is foreseen. This logic needs no central control unit in particular, as its power conditioner units can effectively execute and coordinate control between themselves. We verified the effectiveness of this logic through an experiment at our demonstration facility.

	DESIGN OF A PUBLIC DC GRID OF A BUSINESS PARK By Will DE JAGER	[View] [Download]
Abstract: This paper describes the design of a DC grid as a utility grid on of a business park. The center of the DC grid is a DC substation. The DC substation is supplied from the MV AC grid. With a transformer and an Active Front End, the AC voltage of 10 kV is transformed into 750 VDC. At customer side, the 750 VDC is converted to the required DC voltage for his application.

	Development of Continuous Series Voltage Compensator for load voltage regulation and negative sequence compensation in a 6.6kV distribution line By Shunsuke TAMADA	[View] [Download]
Abstract: Continuous voltage compensator was developed to improve power quality issues of distribution lines. It consists of series and shunt transformer connected through static power converters. In this paper, the compensation methods using series and shunt converters were investigated, and manufacturing of actual rating 6.6kV 3MVA prototype was reported.

	Dual-circuit hybrid circuit breaker By Chuanyue LI	[View] [Download]
Abstract: A DC fault will propagate quickly in a DC grid and results in significant DC voltage drop and largecurrent increase. To protect the DC grid from the DC faults, the concept of hybrid HVDC circuit breaker(DCCB) is widely-accepted due to its low conducting loss and fast operation speed. The unidirectionalDCCB recently is considered to fulfil the protection criteria. However, for a well-built DC grid, amassive number of unidirectional DCCB will be applied. This will lead to the high capital cost. For aterminal applied multiple unidirectional DCCBs, their MOVs could be shared to reduce their capitalcost. The dual-circuit DCCB is proposed to reduce the size of MOVs by 50\% based on the idea ofsharing MOV. And the performance of the DC fault blocking is maintained. The structure and operationprinciple of the dual-circuit DCCB are introduced. Comparing with the unidirectional DCCB, the faultblocking capability and the economy of the dual-circuit DCCB is verified.

	Power quality improvement strategies for battery storage systems with low-voltage grid support By Johannes STÖCKL	[View] [Download]
Abstract: This paper describes implications of 3-phase 4-leg inverter control for grid storage systems with morethan one control target. The presented use case focusses on the concurrent services of power-flowbalancing and market driven operations. Two different priority settings depending on storage operatorbusiness models are shown.

	Research on the Current Commutation in a Novel Hybrid HVDC Circuit Breaker By Lei FENG	[View] [Download]
Abstract: Recent development renewable energy increases the requirement in constructing multi-terminal HVDC systems or HVDC grids. To increase the system reliability, an HVDC circuit breaker will be required. However the existing HVDC breakers developed in recent years use large amount of IGBTs. Considering the cost reduction in real HVDC grids, this paper presents a novel hybrid HVDC circuit breaker. The proposed topology is based on anti-parallel thyristors and full bridge sub module technique with bidirectional interruption. In normal operation, the fast mechanical switch and small amount of IGBTs handle the low conduction loss. In case of interruption, the faulted current is forced to the snubber capacitor of transfer branch in order to turn off thyristors. The proposed breaker has significant technical advantage compared with other solutions especially in terms of current breaking ability and semiconductor cost. The modular unit design could improve the voltage application easily. Moreover, the voltage stress over the load commutation switch is analyzed based on a simplified model. It is observed that the parameters of snubber circuit and time delay of commutation time have great influence on the voltage stress. A principle prototype has been built and tested with an adaptive triggering board. A current commutation test procedure is developed to verify the voltage stress.

	Transformerless multicellular dc-dc converter for highly efficient next generation dc distribution system By Yusuke HAYASHI	[View] [Download]
Abstract: A transformerless multicellular dc-dc converter has been newly proposed. The capacitively isolated dc-dc cell converters have been applied to develop the multicellular converter without using high frequency transformers. The high voltage transformation ratio is achieved by the ISOP (Input Series Output Parallel) connection topology of the cell converters and the realization of the highly efficient cell converter is expected because of no transformers. A 144 V-24 V, 200 W prototype of the multicellular dc-dc converter using 3 cell converters based on the capacitive isolation has been developed, and the feasibility of the transformerless multicellular converter has been confirmed.