• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.3
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• pp.171-178
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• 2008

Pressure control of hydraulic pump using SRM with pressure predictor and direct torque control method is presented in this paper. Nowadays, high efficiency and high performance motor drive is much interested in hydraulic pump system. But the hydraulic pump system has an inherent defect that its dynamic behavior causes by interaction between the sensor and hydraulic load. It will make low performance of whole system, even unstable and oscillatory. Proposed system integrates pressure predictor and direct instantaneous torque control (DITC). The pressure predictor includes Smith predictor, which is easy to improve unstable or long oscillation in traditional negative feedback control and popular PID control architectures. And DITC method can reduce inherent torque ripple of SRM, and develop smooth torque to load, which can increase stability and improve the torque response of SR drive. So high dynamic performance and stabilization can achieved proposed hydraulic system. At last, the proposed hydraulic system is verified by simulation and experimental results.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.642-647
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• 2018

Gas compressors are mostly driven by motors. It is important to measure the power of motors to evaluate their power efficiency, because the mechanical loads of gas compressors are always varied. In order to measure the power given to the driving motors, the torque should be measured. Manufacturers of compressors usually use the torque data to calculate the compressors qualities such as power consumption, efficiencies and failures. In general, measurements for the shaft torque of the compressors have been based upon contact types, strain gauges. In the cases of larger compressors, the contact type of strain gauges have several disadvantages such as large size and high cost. In this study, a relatively inexpensive and simple torque sensing technique that is not restricted to shaft diameter is introduced using visualization technique. Particle image velocimetry (PIV) has been adopted to complete non-contact torques measurements for rotating motors. In order to compare the performance of the newly constructed torque measurement technique, torque measurement by a transducer based on MEMS technology has been performed simultaneously during experiments.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.508-511
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• 1997

Recently the development of motor speed control systems with both good dynamic performance and simple implementation has been required. The vector control scheme considering flux harmonics for the permanent-magnet AC servo motor having low inertia, low weight, and high efficiency is proposed. To reduce the torque harmonics, current harmonics is employed. The vector control strategy is verified through digital simulation.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.79-83
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• 1997

The inverter fed BLDC(Brushless DC) motor has been increasingly applied to industry and home appliances due to the advance of power electronics and permanent magnet technology, and its high efficiency and good acoustic noise characteristics. The BLDC motor and drives, however, require the rotor position sensors that may cause some problems such as the high cost and space. In this paper, sensorless algorithm for an interior permanent magnet BLDC motor is proposed. The maximum torque per ampere operation with advance angle considering load torque and speed was simulated and verified through the experiment.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.103-105
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• 2009

This paper presents the maximum-power control simulation for PMA-SynRM. For maximum power, the maximum torque / current control method is conducted in constant-torque range and flux-weakening control method is conducted in constant-power range. For considering the nonlinear characteristics of inductance, machine constant is determined by FEM. Finally, experiment is conducted to calculate the efficiency.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.802-804
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• 2002

An analysis of the skeleton type BLDC motor is presented. The single phase skeleton type BLDC motor consists of the stator, rotor with the permanent magnet, and drive circuit with hall sensors that detect the rotor position. The major factors for the initial starting, efficiency, and torque ripples of the skeleton type BLDC motor are the detent groove of the stator and the lead angle of the phase voltage. The performance characteristics according to the angle and height of the detent groove is analyzed. The optimum lead angles of the phase voltage with the torque ripple and motor efficiency is described using the finite element method.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.440-447
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• 2012

This paper provides essential information on research completed with the aim to develop a 'dc motor test and analysis platform' which can be used to provide dc motor characteristics, calculate losses and efficiency, and also work as a dc motor speed controller. A user can test a given dc motor for these analyses by practicing different conventional methods, but, the concept discussed in this paper, reveals how intelligent integration of all these analyses can be done with a single user friendly automated setup. Integration has been accomplished by a technique that can accommodate all types of dc motors with different ratings at various loading conditions. However, experimentally measured results of a 0.5HP separately excited dc motor using the discussed scheme are presented in the paper. Also, a comparison of the methodology of this system with conventional techniques has also been elaborated on to show the effectiveness of the system.

• 전기의세계
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• v.21 no.3
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• pp.41-47
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• 1972

The requirements of a successful design for single phase induction motors with a high efficiency have, in recent years, led to the use of non-quadrature stator windings motors in which a high starting torque is a prime requisite. The capacitor motor is one of above machines in which various possible forms of asymmetry can be occur. These forms of asymmetry in the stator phase windings, encountered in machine designs, are 1) an asymmetrical disposition in space of their magnetic axes, 2) a difference in their effective number of turns, 3) a difference in the distribution of their coil groups per pole and 4) amounts of capacitance of an auxiary winding. In order to apply the effective performance prediction of these form to motors, mading of lower quality-domestic magnetic materials, the analysis and the experimental investigations of its sample motors are described in this paper. The utility of such a motor is demonstrated and it is shown that the effects- a good efficiency, good power factor and high starting torque-of the motor mechanism with non-quadrature stator phase windings can development disadvantages by using the lower quality-domestis magnetic materials.

• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.139-145
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• 2006

The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.8 to 1.3, and the ignition timing was controlled to be at MBT (minimum spark advance for best torque)

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.543-547
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• 1991

This paper illustrates maximum torque per ampare radio operation and efficiency operation, which are prevalently applied to the control of permanent magnet synchronous motor(PMSM). Maximum torque per ampare ratio operation minimizes the copper loss of PMSM and maximum efficiency operation minimizes the total loss of PMSM. To verify the difference of these method, simulation and experiment results applied to IPMSM(Interior type PMSM) and SPMSM(Surface mounted PMSM) are presented.