Power conditioning and control requirements of coal fired MHD generators

Demirjian, A.M.; Quijano, I. M.

doi:10.2514/6.1981-246

Cited by 4 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8 The current controllers were originally developed to regulate the electrode current distribution by correcting the effects of cathode nonuniformities in the diagonal generators and to provide current consolidation. 9 It was shown in Ref. 8 that by utilizing the current controllers as power shufflers, one can improve the performance of the diagonally connected generator and make it identical to the performance of a particular Faraday generator (uniform electrode current) under all load conditions.…”

Section: Introductionmentioning

confidence: 98%

Loading Schemes for a 50 MWth Diagonally Connected MHD Generator

Plan

Demirjian

1982

Journal of Energy

View full text Add to dashboard Cite

The characteristics of diagonally connected subsonic MHD generators operating with and without current control/power shuffle circuits are investigated. The results of the analysis are presented for the 50 MW th CDIF 1B2 generator. It is shown that an axial current flows in the uncontrolled diagonal generator which decreases the generator's performance. Electrode current control circuits can be used as power shufflers to eliminate the axial current and to improve the efficiency. The improved performance efficiency can be maintained to part-load conditions when the inverter, channel, and combustor controls are integrated. Control requirements for generators with midchannel power taps are also discussed.

show abstract

Section: Introductionmentioning

confidence: 98%

Loading Schemes for a 50 MWth Diagonally Connected MHD Generator

Plan

Demirjian

1982

Journal of Energy

View full text Add to dashboard Cite

show abstract

“…The design and operation of the power takeoff (PTO) for diagonal-type magnetohydrodynamic (MHD) generators have been investigated experimentally in the University of Tennessee Space Institute (UTSI) diagonal conducting wall (DCW) channel, 1 ' 2 the U-25B channel, 3 and the AVCO Mark VI channel, 4 among others. Analytical studies have been published by Levi, 5 Pan and Doss, 6 ' 7 Ishikawa and Wu, 8 Ishikawa et al, 9 and others, that primarily concenPresented as Paper 82-0922 at the AIAA 20th Aerospace Sciences Meeting, Orlando, FL, Jan. 11 -14, 1982; received June 6, 1982; revision received March 6, 1985.…”

Section: Introductionmentioning

confidence: 99%

Fault analysis of midchannel power takeoff in diagonal conducting wall magnetohydrodynamic generators

Ishikawa

Scott

1985

Journal of Propulsion and Power

View full text Add to dashboard Cite

The effects of loading faults on the midchannel power takeoff of a diagonal conducting wall magnetohydrodynamic generator are investigated. The fault analysis considers loading schemes for connecting multiple external loads to the channel. It is shown that applying the concept of diodes in series with power takeoff electrodes as implemented in the end regions is harmful or ineffective for the midchannel power takeoff, since it may trigger premature faults or cause the multiple loading to be ineffective. It is also shown that faults can be treated in the same manner as other off-design conditions in the power takeoff of the end region. Twodimensional calculations show that an open-circuit condition in the upstream load circuit results in a large current density at power takeoff anodes accompanied by a shorting current over the interframe insulators at the cathode. A short-circuit condition in the upstream load circuit causes a large current density at the power takeoff cathodes and drives a shorting current at the anode.

show abstract

“…In addition, the channel performance is investigated using constant current output in various regions of the channel in order to take advantage of possible cost savings for the inverter system under these conditions.3. 4…”

Section: Introductionmentioning

confidence: 99%

End region and current consolidation effects upon the performance ofan MHD channel for the ETF conceptual design

Wang

Smith

1982

20th Aerospace Sciences Meeting

View full text Add to dashboard Cite

Operating conditions which yielded the peak thermodynamic efficiency (41 percent) for an ETFsize MHD/steam plant were previously identified by considering only the active region (the primary portion for power production) of an MHD channel. In this paper, the efforts of the previous study are extended to include the investigation of the effects of the channel end regions on the overall power generation. Considering these effects the peak plant thermodynamic efficiency is found to be slightly lowered (40.7 percent) and the channel operating point for the peak efficiency is shifted to the supersonic mode (Mach No., M c-v 1.1) rather than the previous subsonic operation (M c-\. 0.9). The sensitivity of the channel performance to the B-field, diffuser recovery coefficient, channel load parameter, Mach number, and combustor pressure is also discussed. In addition, methods for operating the channel in a constant-current mode are investigated. This mode of channel operation is highly desirable from the standpoint of simplifying the current and voltage consolidation for the inverter system. This simplification could result in significant savings in the cost of the equipment. The initial results of this study indicate that this simplification is possible, even under a strict Hall field constraint, with reasonable plant thermodynamic efficiency (40.5 percent).

show abstract

Power conditioning and control requirements of coal fired MHD generators

Cited by 4 publications

References 1 publication

Loading Schemes for a 50 MWth Diagonally Connected MHD Generator

Loading Schemes for a 50 MWth Diagonally Connected MHD Generator

Fault analysis of midchannel power takeoff in diagonal conducting wall magnetohydrodynamic generators

End region and current consolidation effects upon the performance ofan MHD channel for the ETF conceptual design

Contact Info

Product

Resources

About