• Journal of Power System Engineering
• /
• v.17 no.3
• /
• pp.82-88
• /
• 2013

For commercialized servo drives of the motion stage to include embedded controller, external terminal is provided for tracking command and encoder output, but internal terminal is not for control input. Thus, it is difficult to combine out signal of embedded controller with that of external compensator such as disturbance observer. In this study, for precise tracking control of motion stage without hardware change of the servo drive, tacking control system is composed of an inner loop of servo drive and an outer loop of disturbance observer. Then, the control system is designed so that the output response of actual plant corresponds with nominal model's in transient state as well as in steady state. Finally, the experiment results show that the designed control system is effective to reconcile actual plant behavior with nominal model under nonlinear friction and parameter perturbation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.40 no.1
• /
• pp.45-54
• /
• 2003

Turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently, the study of turbo compressor applied super high speed motor and drive, removing gearbox made its sire small and mechanical friction loss minimum. This paper describes the implementation of the vector control schemes for a variable-speed 131㎾ PMSM(Permanent Magnet Synchronous Motor) drive in super-high speed application.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.219-222
• /
• 2002

There are screw, reciprocating type turbo compressor by structure in an air compressor which is essential equipment on the industrial spot. Recently, the application range of a turbo compressor tend to be wide gradually. And this type of compressor needs high speed rotation of impeller in structure so high ratio gearbox and conventional induction motor driving required. This mechanical system have results of increased moment of inertia and mechanical friction loss. Recent studies of modern turbo compressor have been applied to developing super high speed BLDC motor and driver which remove gearbox that make its size small and mechanical friction loss minimum. To accomodate this tendency, we tried to develope a super high speed motor drive system for 150Hp, 70,000rpm direct drive Turbo compressor using DSP(Digital Signal Processor) and SVPWM(Space Vector Modulation PWM) technique. The results of this specific application show that super high speed driver and controller could be implemented well with digital electronics.

• Tribology and Lubricants
• /
• v.19 no.5
• /
• pp.292-297
• /
• 2003

The fundamental fluid mechanics associated with the rotation of a smooth plane disk enclosed within a cylindrical chamber have been studied experimentally. In order to acquire systematic information pertinent to this problem torque and friction loss data were obtained over a wide range of disk Reynolds numbers for axial clearance-disk radius ratio H/R from 0.025 to 0.2 and radial tip gap-disk radius ratio s/R from 0.021 to 0.105. Loss analysis of hard disk drive (HDD) is presented to describe the contribution of windage loss of a rotating disk. The minimum loss form factor of HDD can be obtained from this analysis at each operation conditions.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.11a
• /
• pp.159-165
• /
• 2001

The fundamental fluid mechanics associated with the rotation of a smooth plane disk enclosed within a cylindrical chamber have been studied experimentally. In order to acquire systematic information pertinent to this problem torque and friction loss data were obtained over a wide range of disk Reynolds numbers for axial clearance-disk radius ratio H/R from 0.025 to 0.2 and radial tip gap-disk radius ratio s/R from 0.021 to 0.105. Loss analysis of hard disk drive(HDD) is presented to describe the contribution of windage loss of a rotating disk. The minimum loss from factor of HDD can be obtained from this analysis at each operation conditions.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2655-2657
• /
• 2005

When a fault relating to the urgent alarm occurs, we must prevent control rods from dropping and make one of two grippers in Control Rod Drive Mechanism (CRDM) grip the drive rod taking a control rod assembly. To enhance the reliability of holding control rods, we order two grippers to hold the drive rod. This action is called the double holding. In the middle of the movement of the drive rod, the latching of the drive rod can cause friction between a gripper and the drive rod. This state may give damage to both the gripper and the drive rod. In this paper, we have devised the method which can have two grippers hold the drive rod more stably, without damaging the equipment.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1998.10a
• /
• pp.330-336
• /
• 1998

The friction and wear characteristics of automotive friction materials reinforced with carbon fibers were studied using a direct drive brake dynamometer. Two types of model friction materials, a low-metallic and an NAO type, were prepared and each of the materials was modified by substituting 5 vol% of carbon fibers with other reinforcing fiber used in the model formulations. Drag tests were carried out to investigate the friction properties of these materials at various braking conditions. Results showed that the modified friction materials were improved in the friction stability and the wear resistance.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.17-18
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.123-124
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.135-136
• /
• 2010