Results of 10-Joule wire-burn test performed on 70 kV rail-gap crowbar protection system for high power klystrons and gyrotron

Srinivas, Y.; Kushwah, M.; Kulkarni, Sanjay; Sathyanarayana, K.; Khilar, P.; Pal, Biswajit; Shah, P.; Makwana, A.R.; Kadia, B.R.; Dani, S.; Singh, Raghuraj; Parmar, K. G.; Bora, D.

doi:10.1109/fusion.2002.1027650

Cited by 11 publications

(7 citation statements)

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“…The overcurrent protection signals output by the protection circuits will be sent to the high-voltage power supplies. Usually, the crowbars are used in the power supplies of the gyrotrons on the other tokamak devices [6,7], different from it, the insulted gate bipolar transistors (IGBTs) are used in the high-voltage power supplies in the EAST ECRH system [8]. If the high-voltage power supplies receive the turn-off signal or protection signal from the gyrotron control system, the IGBTs will be shut down within several microseconds, thus the connection between the power supply and the gyrotron will be cut off.…”

Section: Overcurrent Protection System For Gyrotronsmentioning

confidence: 99%

“…where μ 0 = 4π × 10 −7 T ⋅ m/A (6) Bringing H ≃ 4 and μ 0 into 5, we can got the relationship between the maximum relative permeability μ rmax and the saturation magnetic induction B max μ rmax ≃ 198943.68B max (7) Since this formula is got by assuming the relative permeability μ r is a constant which is equal to the maximum relative permeability μ rmax , the calculated saturation magnetic induction B max is larger than the real saturation magnetic induction B s .…”

Section: Simulationmentioning

confidence: 99%

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Overcurrent protection for gyrotrons on the experimental advanced superconducting tokamak

Feng

et al. 2018

IET Science, Measurement & Technology

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Section: Overcurrent Protection System For Gyrotronsmentioning

confidence: 99%

Section: Simulationmentioning

confidence: 99%

Overcurrent protection for gyrotrons on the experimental advanced superconducting tokamak

Feng

et al. 2018

IET Science, Measurement & Technology

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“…The crowbar is kept ON until the input CB opens, which can take as long as 100 ms. This along with the triggering of the crowbar reduces the dc voltage close to zero [3].…”

Section: Introductionmentioning

confidence: 99%

Thyristor voltage equalising network for crowbar application

Joshi

2018

IET Power Electronics

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Many high-voltage applications are realised with series connected thyristors. Voltage imbalance among series connected thyristors during steady state as well as in transients is one of the major concerns. This voltage imbalance is mitigated by using static and dynamic balancing network. Dynamic balancing networks are typically designed based on reverse recovery charge of the thyristor during turn-off, which suits many applications. But this is not the case for a crowbar application, where turn-off of the thyristor is not a major circuit constraint. This study proposes the design method for dynamic balancing network considering gate turn-on delay time and the balancing network component tolerances. The study derives two models for the dynamic balancing network based on its charge-discharge cycle. The importance of charge-discharge cycle in the design of dynamic balancing network during high di/dt operation is emphasised. Influence of dynamic balancing resistance and crowbar current limiting inductance on voltage imbalance, charging current and discharging current is studied using the analytical model. The proposed design method also offers flexibility to incorporate differences in propagation delays among the thyristor drivers that are used to trigger individual thyristors. Such delays cannot be directly incorporated in the conventional balancing network design method based on reverse recovery. Further, it is also analytically shown that designing the dynamic balancing network based on reverse recovery charge makes the balancing network lossy and bulky for crowbar application. Simulation studies and experimental results on a 12 kV, 1 kA crowbar consisting of six series connected thyristors confirm the theoretical analysis and validate the proposed approach for crowbar applications.

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“…And before S being closed, The transfer function is still equation (10). The characteristic equation of equation (10) is,…”

Section: The Analytic Calculationmentioning

confidence: 99%

“…The klystron loads may happen short-circuit fault occasionally. In order to avoid damage the klystron loads and HVPS itself, the power energy absorbed by one klystron must be no more than 10J [10], [11] from start of short-circuit fault to action of protection switch. However，the transient process of short-circuit fault is few studied during LHCD-HVPS operation.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Short Circuit Fault for 4.6GHz/6MW LHCD High Voltage Power Supply

Yang¹

2017

JEEE

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4.6GHz/6MW Lower Hybrid Current Drive (LHCD) is one of plasma current heating methods for ExperimentalAdvanced Superconducting Tokamak (EAST). High Voltage Power Supply (HVPS) is the power supply subsystem of 4.6GHz/6MW LHCD system, which was designed, built and accepted successfully by Chinese National Development and Reform Commission in 2015. Then the new system has been in use for the 2015 EAST campaign. This paper presents the structure of 4.6GHz/6MW LHCD-HVPS and its transient operation state when its klystron load has short circuit fault. In order to protect the klystron and HVPS itself, the short-circuit fault and its transient process are analyzed and calculated in detail. And a three-electrode gas switch has been built to eliminate the short-circuit fault in microseconds. In addition, the effectiveness of the three-electrode gas switch has been verified by simulation and experiment result. The HVPS has been used in 4.6GHz/6MW LHCD system and it has good performance for the entire 2015 EAST campaign.

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Results of 10-Joule wire-burn test performed on 70 kV rail-gap crowbar protection system for high power klystrons and gyrotron

Cited by 11 publications

References 0 publications

Overcurrent protection for gyrotrons on the experimental advanced superconducting tokamak

Overcurrent protection for gyrotrons on the experimental advanced superconducting tokamak

Thyristor voltage equalising network for crowbar application

Analysis of Short Circuit Fault for 4.6GHz/6MW LHCD High Voltage Power Supply

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