• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.135-141
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• 2005

A hybrid central-WENO scheme is proposed. The fifth order WENO-LF scheme is coupled with a central flux scheme at cell face. Two sub-schemes, the WENO-LF scheme and the central flux scheme, are switched by a weighting function. The efficiency and accuracy of the proposed hybrid central-WENO scheme is validated through several numerical experiments.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.312-319
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• 2012

The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

• Transactions on Electrical and Electronic Materials
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• v.8 no.5
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• pp.222-225
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• 2007

In this paper, we compared the current limiting characteristics of both the hybrid type and the flux-lock type superconducting fault current limiters(SFCLs), which have a magnetic coupling structure between a primary winding and several secondary windings. The limiting impedances of two SFCLs were derived from each equivalent circuit considering the design parameters of SFCL such as the self-inductance of secondary winding and the resistance of $high-T_C$ superconducting(HTSC) element. Through the comparison for the limiting impedances of two SFCLs considering the dependence of the HTSC element's resistance on the applying voltage into the SFCL, the hybrid type SFCL was confirmed to have larger limiting impedance with smaller resistance of HTSC element than the flux-lock type SFCL. It was expected from the analysis that the hybrid type SFCL was more advantageous than the flux-lock type SFCL from the viewpoint of the fault current limiting level.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1219-1226
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• 2017

This paper presents the hybrid stepping machine for linear oscillating generators. The focus of the work is the suggestion of the improved model through the comparison of proposed models ; new flux concentrating PMs mover of the hybrid stepping generator is proposed based on the symmetrical and non-symmetrical stator cores of the surface mounted PMs mover, and non-slanted PMs and slanted PMs of the flux concentrating PMs mover. It is achieved using equivalent magnetic circuit considering leakage elements. Finally, this study suggests new hybrid stepping structure of linear oscillating generator.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.705-713
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• 2012

In this paper, a novel 12/14 hybrid pole type bearingless switched reluctance motor (BLSRM) with short flux path and no flux-reversal in the stator is proposed. The proposed BLSRM has separated rotating torque and suspending force poles. Because of independent characteristics between torque and suspending force poles, the torque control can be decoupled from the suspending force control. Due to the short flux path without any reversal flux, compared to the 8/10 hybrid stator pole BLSRM, the output torque is significantly improved and the air-gap is easier to control. Meanwhile, basic design principle for the proposed structure is described. To verify the proposed structure, finite element method (FEM) is employed to get characteristics of the proposed structure and 8/10 hybrid stator pole BLSRM. Based on the analysis, a prototype of the proposed BLSRM is designed and manufactured. Finally, validity of the proposed structure is verified by the experimental results.

• Journal of Power Electronics
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• v.19 no.1
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• pp.158-167
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• 2019

This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.243-247
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• 2007

Fuel mass flux was experienced with a function of the oxidizer mass flux using initial port area of solid fuel, in stead of regression rate correlation which shows combustion characteristic in hybrid propulsion. The burning rate could be easily obtained by using the oxidizer mass flux of initial port area without iteration, and fuel configuration could be designed simply. In this experiments PE was used as fuel, COX was used as oxidizer. A variation of mass flux of solid fuel with port area is considered by changing the burning time. In the case of approximate 0.5 for an exponent of oxidizer mass flux, using the fuel mass flux correlation is more suitable than regression rate correlation in hybrid propulsion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.228-231
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• 2006

In general, burning time is not considered with a factor of an empirical relation on the combustion characteristic in hybrid propulsion system. So, The effect of burning time on hybrid combustion characteristics and propulsion characteristics was studied. As results, regression rate is decrease with burning time, but fuel mass flux is maintained nearly constant with burning time at given oxidizer mass flux.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.1
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• pp.29-37
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• 2019

A new permanent magnet biased hybrid maglev actuator is developed. Compared to the classical hybrid maglev actuators, the new maglev has unique flux paths such that bias fluxes are separated with control flux paths. The control flux paths have minimum reluctances only developed by air gaps, so the currents to produce control fluxes can be minimized. The consumed power to operate this maglev system can also be minimized. The gravity load can be compensated with the static magnetic forces developed by the permanent magnet bias fluxes while external disturbances are controlled with the bidirectional AC magnetic forces developed by control fluxes by currents. 1-D circuit model is developed for this model such that the flux densities and magnetic forces are extensively analyzed. 3-D finite element model is also developed to analyze the performances of the maglev actuator.

• Journal of Power Electronics
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• v.11 no.5
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• pp.704-712
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• 2011

This paper describes a hybrid induction motor drive system incorporating DTC-hysteresis and Direct Self Control (DSC) schemes to achieve excellent dynamic performance. The control scheme is switched from a circular to a hexagonal flux locus whenever a dynamic condition is encountered. On the other hand, when the motor operates under steady state conditions, a circular flux locus is used. Without major modifications to the simple structure of a basic DTC, hexagonal flux locus operation is established by modifying the flux error status, before it is fed to the look-up table. The feasibility of the proposed hybrid scheme to achieve excellent control performance is verified by experimental results.