EPE Association: EPE 2019 - DS2l: Industry Specific Energy Conversion and Conditioning Technologies

EPE 2019 - DS2l: Industry Specific Energy Conversion and Conditioning Technologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 09: Industry-Specific Energy Conversion and Conditioning Technologies > EPE 2019 - DS2l: Industry Specific Energy Conversion and Conditioning Technologies

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   A Marx-based Power Converter Design for Pulsed Magnets in Particle Accelerators
By Todor TODORCEVIC [View]
[Download]

Abstract: This paper presents the design and initial test results on a full-scale 5 kV - 4 kA prototype of the novel Marx-based power converter intended to supply pulsed magnets in particle accelerators. The main design challenges are determined by the inductive load requirements, and protections against switch failures are only a few of the challenges that have been solved.

   A multi-waveform pulsed current generator for slow kicker magnets
By Gregor GRÄWER [View]
[Download]

Abstract: As part of the LIU project at CERN pulsed magnet current generators for phase space painting of the PSB accelerator were developed that generate pulse to pulse programmable waveforms comprising four linear slopes of variable length. A high current generator with a peak current of 400A and a low current version with 40A were developed. Amplitude tolerance is inf.1\%. The waveforms are generated by connecting pre-charged capacitors to the magnet to make the current rise or fall. The final precision is controlled with a feedback loop and a linear class AB power amplifier. Special capacitor charger modules were developed that allow fast up/down voltage adjustment of the capacitors. The charger outputs are floating and tolerate voltages of ±2.5kV. An overview of the entire system is given and the main building blocks are described in detail. Measurement data is presented and the performance of the building blocks is discussed.

   A study to design the locations of reversible substations for minimising power losses of DC railways
By Zhongbei TIAN [View]
[Download]

Abstract: With the increasing concern about the energy and environmental sustainability, energy reduction for railway systems is becoming more significant. This paper evaluates the typical electrification scheme of DC-fed railway systems and proposes a new scheme with inverters for DC railways. With inverters, the regenerated energy by braking trains can be transferred to the distribution network. The design of the locations of inverting substations for minimising power losses is optimised based on a DC railway line.

   Development of a solid-state Marx Generator for Thyratron modulator replacement
By Luis REDONDO [View]
[Download]

Abstract: The design of a solid-state Marx Generator prototype, based on SiC MOSFETs, for replacing existingThyratron modulator technology, in particle accelerators, is described. As for Thyratrons, long-termavailability is a concern. The final aim of the work is to develop a generator for output pulsespecifications of 16 kV, 2.56 kA, 2 µs flat top, 75 ns rise/fall-times and 1 Hz frequency. The preliminary results shown here are for approximately 2 µs output pulse width, with about 3.2 kV and 2.7 KA amplitude, using a coaxial assembling solid-state Marx generator design, with four 800V stages and 24 SiC MOSFETs in parallel per stage. The scale up potential and constraints are discussed.

   Optimized design of a novel energy extraction system for superconducting magnets in future particle accelerators
By Vasilios KARAVENTZAS [View]
[Download]

Abstract: For future accelerators, a new approach is studied for energy extraction systems which enable energy recovery. A converter system which controls the voltage across the magnet chain during the energy extraction process and which transfers the energy to a storage unit is proposed. Due to a large number of degrees of freedom, an optimization procedure based on an electro-thermal model of the converter is developed aiming to maximize both efficiency and power density. The implemented algorithm takes into account the losses, the thermal constraints and the heat sink volume for the semiconductor switches, the volume occupied by the required capacitors as well as the design of the inductor, calculating its geometry, winding properties, losses and thermal model for identifying the winding and core hot spot temperatures. Finally, an optimal point in the design space is identified and the parameters of this particular point are presented. The results are compared to simulations showing a good match with the values calculated with the modules in the optimization tool.

   Output Filter with Adaptive Damping for Interleaved Converters with Low Ripple and High Dynamics
By Georgios TSOLARIDIS [View]
[Download]

Abstract: Interleaved DC-DC converters are used in a wide range of applications offering a high current rating combined with ripple cancellation. In these systems, the design of the output stage is of crucial importance since it not only influences the output ripple at steady state but also affects the dynamic performance of the system. In particular, by reducing the output filter, a higher dynamic performance can be achieved, making interleaved converters especially interesting for high performance sources, used for example in accelerators. In this paper, an adaptive output filter with variable impedance, suitable for a wide range of inductive loads (e.g. magnets), is proposed for interleaved converters with low ripple and high dynamic specifications. The proposed solution is compared with a conventional filter topology and its superiority is exhibited through analytical calculations and simulations.

   Proposal of the new concept of 'interception of regenerative power' and evaluation of valuable and valueless interception
By Hitoshi HAYASHIYA [View]
[Download]

Abstract: Regenerative energy utilization is one of the most actively discussed topics to improve the efficiencyof power supply system for DC electric railway. We, East Japan Railway Company, have alreadyinstalled four energy storage systems and two regenerative inverters for regenerative energyutilization. In the regenerative energy utilization, the utilization of regenerative energy which isoriginally utilized by other powering train dose not contribute to energy saving and the appropriateevaluation of the effect of such devices is required. In this paper, a novel concept of 'valuableinterception' of regenerative energy is proposed and evaluated supposing one of the existingcommuting DC railway line in Tokyo. As a result, it is shown that the interception of regenerativepower can contribute to the reduction of loss under some conditions.

   Quantification of the Recoverable Braking Energy in a Reversible Railway DC Traction Power Substation
By Alain BOUSCAYROL [View]
[Download]

Abstract: In conventional electric railway transportation systems supplied in DC, regenerative braking energycannot be generally sent back to the electric power grid due to the non-reversible diode rectifiers usedin traction power substations. However, a DC substation could be made reversible by connecting aninverter in parallel with the existing rectifier, hence allowing the energy recovery. This paper presentsthe development of a simulation program to quantify the braking energy that could be recovered withthe addition of this power electronics device.

   Simulative Analysis and Design Considerations for a Novel Thyristor-based Pulsed Current Converter
By Stefan WETTENGEL [View]
[Download]

Abstract: In a previous paper a novel pulsed current converter for a medical application has been proposed. Thyristors are used as semiconductor switches; a simple behavioral turn-off model has been presented. In this paper, it is used for snubber parametrization and simulative investigations regarding the pulsed current converter's expected behavior. Conclusions are drawn as a basis for a future practical design.

   Testing of a 120kV-Pulse Generator with Droop Compensation
By Martin SACK [View]
[Download]

Abstract: A 149-stage Marx-type pulse generator is currently being tested. The generator delivers substantiallyrectangular pulses with a voltage amplitude of up to 120 kV at a rise time of approximately 100 ns intoa resistive load. The generator has been designed for a peak current of 600 A. In order to generaterectangular pulses up to a pulse length of 100 µs with a moderate stage capacitance the droop of theoutput voltage can be compensated by subsequently activating additional stages.

EPE 2019 - DS2l: Industry Specific Energy Conversion and Conditioning Technologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 09: Industry-Specific Energy Conversion and Conditioning Technologies > EPE 2019 - DS2l: Industry Specific Energy Conversion and Conditioning Technologies
	[return to parent folder]

	A Marx-based Power Converter Design for Pulsed Magnets in Particle Accelerators By Todor TODORCEVIC	[View] [Download]
Abstract: This paper presents the design and initial test results on a full-scale 5 kV - 4 kA prototype of the novel Marx-based power converter intended to supply pulsed magnets in particle accelerators. The main design challenges are determined by the inductive load requirements, and protections against switch failures are only a few of the challenges that have been solved.

	A multi-waveform pulsed current generator for slow kicker magnets By Gregor GRÄWER	[View] [Download]
Abstract: As part of the LIU project at CERN pulsed magnet current generators for phase space painting of the PSB accelerator were developed that generate pulse to pulse programmable waveforms comprising four linear slopes of variable length. A high current generator with a peak current of 400A and a low current version with 40A were developed. Amplitude tolerance is inf.1\%. The waveforms are generated by connecting pre-charged capacitors to the magnet to make the current rise or fall. The final precision is controlled with a feedback loop and a linear class AB power amplifier. Special capacitor charger modules were developed that allow fast up/down voltage adjustment of the capacitors. The charger outputs are floating and tolerate voltages of ±2.5kV. An overview of the entire system is given and the main building blocks are described in detail. Measurement data is presented and the performance of the building blocks is discussed.

	A study to design the locations of reversible substations for minimising power losses of DC railways By Zhongbei TIAN	[View] [Download]
Abstract: With the increasing concern about the energy and environmental sustainability, energy reduction for railway systems is becoming more significant. This paper evaluates the typical electrification scheme of DC-fed railway systems and proposes a new scheme with inverters for DC railways. With inverters, the regenerated energy by braking trains can be transferred to the distribution network. The design of the locations of inverting substations for minimising power losses is optimised based on a DC railway line.

	Development of a solid-state Marx Generator for Thyratron modulator replacement By Luis REDONDO	[View] [Download]
Abstract: The design of a solid-state Marx Generator prototype, based on SiC MOSFETs, for replacing existingThyratron modulator technology, in particle accelerators, is described. As for Thyratrons, long-termavailability is a concern. The final aim of the work is to develop a generator for output pulsespecifications of 16 kV, 2.56 kA, 2 µs flat top, 75 ns rise/fall-times and 1 Hz frequency. The preliminary results shown here are for approximately 2 µs output pulse width, with about 3.2 kV and 2.7 KA amplitude, using a coaxial assembling solid-state Marx generator design, with four 800V stages and 24 SiC MOSFETs in parallel per stage. The scale up potential and constraints are discussed.

	Optimized design of a novel energy extraction system for superconducting magnets in future particle accelerators By Vasilios KARAVENTZAS	[View] [Download]
Abstract: For future accelerators, a new approach is studied for energy extraction systems which enable energy recovery. A converter system which controls the voltage across the magnet chain during the energy extraction process and which transfers the energy to a storage unit is proposed. Due to a large number of degrees of freedom, an optimization procedure based on an electro-thermal model of the converter is developed aiming to maximize both efficiency and power density. The implemented algorithm takes into account the losses, the thermal constraints and the heat sink volume for the semiconductor switches, the volume occupied by the required capacitors as well as the design of the inductor, calculating its geometry, winding properties, losses and thermal model for identifying the winding and core hot spot temperatures. Finally, an optimal point in the design space is identified and the parameters of this particular point are presented. The results are compared to simulations showing a good match with the values calculated with the modules in the optimization tool.

	Output Filter with Adaptive Damping for Interleaved Converters with Low Ripple and High Dynamics By Georgios TSOLARIDIS	[View] [Download]
Abstract: Interleaved DC-DC converters are used in a wide range of applications offering a high current rating combined with ripple cancellation. In these systems, the design of the output stage is of crucial importance since it not only influences the output ripple at steady state but also affects the dynamic performance of the system. In particular, by reducing the output filter, a higher dynamic performance can be achieved, making interleaved converters especially interesting for high performance sources, used for example in accelerators. In this paper, an adaptive output filter with variable impedance, suitable for a wide range of inductive loads (e.g. magnets), is proposed for interleaved converters with low ripple and high dynamic specifications. The proposed solution is compared with a conventional filter topology and its superiority is exhibited through analytical calculations and simulations.

	Proposal of the new concept of 'interception of regenerative power' and evaluation of valuable and valueless interception By Hitoshi HAYASHIYA	[View] [Download]
Abstract: Regenerative energy utilization is one of the most actively discussed topics to improve the efficiencyof power supply system for DC electric railway. We, East Japan Railway Company, have alreadyinstalled four energy storage systems and two regenerative inverters for regenerative energyutilization. In the regenerative energy utilization, the utilization of regenerative energy which isoriginally utilized by other powering train dose not contribute to energy saving and the appropriateevaluation of the effect of such devices is required. In this paper, a novel concept of 'valuableinterception' of regenerative energy is proposed and evaluated supposing one of the existingcommuting DC railway line in Tokyo. As a result, it is shown that the interception of regenerativepower can contribute to the reduction of loss under some conditions.

	Quantification of the Recoverable Braking Energy in a Reversible Railway DC Traction Power Substation By Alain BOUSCAYROL	[View] [Download]
Abstract: In conventional electric railway transportation systems supplied in DC, regenerative braking energycannot be generally sent back to the electric power grid due to the non-reversible diode rectifiers usedin traction power substations. However, a DC substation could be made reversible by connecting aninverter in parallel with the existing rectifier, hence allowing the energy recovery. This paper presentsthe development of a simulation program to quantify the braking energy that could be recovered withthe addition of this power electronics device.

	Simulative Analysis and Design Considerations for a Novel Thyristor-based Pulsed Current Converter By Stefan WETTENGEL	[View] [Download]
Abstract: In a previous paper a novel pulsed current converter for a medical application has been proposed. Thyristors are used as semiconductor switches; a simple behavioral turn-off model has been presented. In this paper, it is used for snubber parametrization and simulative investigations regarding the pulsed current converter's expected behavior. Conclusions are drawn as a basis for a future practical design.

	Testing of a 120kV-Pulse Generator with Droop Compensation By Martin SACK	[View] [Download]
Abstract: A 149-stage Marx-type pulse generator is currently being tested. The generator delivers substantiallyrectangular pulses with a voltage amplitude of up to 120 kV at a rise time of approximately 100 ns intoa resistive load. The generator has been designed for a peak current of 600 A. In order to generaterectangular pulses up to a pulse length of 100 µs with a moderate stage capacitance the droop of theoutput voltage can be compensated by subsequently activating additional stages.