• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.71-77
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• 2010

A discontinuity of magnetic circuits according to the end effect is generated in PMLSM. And magnetic state of the 3 phase coils becomes unbalanced. Due to the unbalanced magnetic state, the unbalanced flux linkage, back electro-magnetic force and inductance of the 3 phase coils appear. In result, the circulating current is generated by unbalanced inductance even if the input voltages are in balanced state. Then the thrust and efficiency are decreased because of the circulating current. Therefore, in this paper, the unbalanced inductance and the thrust reduction according to discontinuity of magnetic circuits are analyzed by FEA(2D). To demonstrate the validity of the analysis results, the experiment results are compared with analysis results.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.75-80
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• 2000

Recently, there are a great many research for magnetic levitation system. In case electromagnet is operated as the actuator of control system, first of all, we must analysis about an electromagnet. Important parameters of this system are inductance(L) and resistance(R) which are induced from the coil of electromagnet. And attractive force equation is also important. If the load of this system is large, phase delay is caused by self-inductance effect. Because this delay effect cause stability of whole magnetic evitation system to grow worse, a measures to diminish time constant must have been taken. And the linearized attractive force equation which is used at small range of the operating point is compensated to use at larger range, thus the experiment of magnetic levitation system will get a better result.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.893_894
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• 2009

This paper study on the notch effect for d-q axis inductance of interior type permanent magnet (IPM) motor. The variations of d-q axis inductance are analyzed by finite element method (FEM). Applying the notch for cogging torque minimization and maximization of reluctance torque is confirmed to be improve the torque characteristics. Also, speed characteristics is analyzed according to the load current

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.89-93
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• 2002

In the present paper we suggested a parallel-branch structure of aluminum spiral inductor for the use of RF integrated circuit at 1∼3 GHz. The inductor was implemented on P-type silicon wafer (5∼15 Ω-cm) under the standard CMOS process and it showed a improved quality(Q) factor by more than 10% with no degradation of inductance. The effect of the structure modification on the Q factor and the inductance was scrutinized comparing with those of the conventional spiral inductors.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.285-286
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• 2014

Recently, the unipolar gate power source is preferred in inverter system because of cost reduction reason. In this case, designer uses 0V source for turning-off the switching devices instead of negative voltage at Vee source. If the gate driver circuit has some stray inductance, the gate voltage would happen a surge voltage. This paper analyzes that of stray inductance effect during the switching behavior in the circuit and the proposed solutions were verified by pulse test.

• Journal of the Korean Magnetics Society
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• v.19 no.1
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• pp.5-11
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• 2009

The Explosive Magnetic Generator of Frequency (EMGF) has been studied as a method to generate a strong microwave effectively through converting the explosion powder energy into the electromagnetic energy. However, the generated high frequency electromagnetic wave has not been explained clearly yet, for it is known to be difficult to analyze the high frequency electromagnetic wave oscillation using a simple time-varying equivalent circuit model. In this paper, we analyze the problems of the widely used inductance model with an exponential decreasing pattern and investigate the tendency of a more accurate inductance variation model using the finite element method of EMGF inductance by considering the magnetic compression effect. And we have shown via an EMGF output simulation that the new inductance variation model proposed here has an negative effect on EMGF output.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.329-330
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• 2014

This paper presents an analysis of the interleaved effects for the secondary winding distribution of a toroidal transformer. The equations to calculate the leakage inductance are derived using the MMF diagram for the distributed secondary windings. The simulation and experimental results are provided to show the effect of the leakage inductance reduction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.7-10
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• 2002

We designed the flyback planar transformer, which had 8W capacity, with 70V input voltage and 8.2V output voltage for the establishment of design method and the confirmation of application possibility. The numerical value of inductance measured under the switching frequency of 120 kHz was 1650 ${\mu}H$, which was the inductance efficiency of 85~87% against theoretical value. The A.C. resistance of primary and secondary coil was 4.2 ${\Omega}$ and 0.25 ${\Omega}$ respectively. On the other hand, the quality factor for each wound numbers showed quite a high value of 158 and 75 respectively. And the Coupling Factor was 0.96~0.97 under 120 kHz switching frequency. And the shape of the output wave of the planar transformer at 70V input voltage was a stable square wave.

• Journal of Magnetics
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• v.16 no.4
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• pp.391-397
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• 2011

An inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. In this method, the motor is measured at standstill condition, and only a 3-phase voltage source, an oscilloscope and a DC voltage source are required. Depending on the deductive dq-axis voltage equations in the stationary frame of reference, the dq-axis inductances at different current magnitude and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper introduces the principle equations, experiment setup, data processing, and results comparison on the concentrated-winding and distributed-winding IPMSMs.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.940-943
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• 2004

This Paper analysis variable characteristics of inductance profiles and basic magnetic fields for Switched Reluctance Motors(SRM). The varying Inductance and flux linkage on operating control condition are very important for developing control algorithm and SRM accurate drive system. Therefore, we have analytical model for varying inductance and flux linkage with simulation and experimental method, and to find an analytical expression for the SRM coenergy. There are shown some good results that comparison of simulated and analytical inductance, flux linkage and current waves.