• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.435-437
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• 1997

In order to develop the three phase GTO CSI with double recovery path of commutation energy by passive devices (LCD), we studied the clamping circuit to protect switching device and energy recovery circuit to recover absorbed energy of capacitor and DC link inductor. In this paper, we investigated how DC input power is increased or decreased according to energy recovery path with or not in the three phase GTO current source inverter. We used a induction motor as the load of inverter, and controlled a induction motor with V/F constant control. Experimental results show that dissipated DC power is decreased and capacitor voltage Vc is effectively suppressed by double recovery path.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.36-41
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• 2004

In this paper a large scale STATCOM using double-connected multi-step inverter is proposed and operating principle along with control method is detailed. A simple auxiliary circuit including an interphase transformer is employed to improve output voltage waveform of 12-step into 36-step. The proposed scheme could be a cost effective approach in high power applications such as 10MVar to 30MVar STATCOM. Experimental results from a 2KVA laboratory prototype show validity of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.903-907
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• 2002

A hyper-chaos circuit is created by applying identical n-double scrolls with weak coupled method, to each cell. Hyper-chaos synchronization was achieved using dive response synchronization between the transmitter and receiver about each state variable in the SC-CNN. From result of the recovery signal through the demodulation method in the receiver, We shown that recovery quality of state variable $\chi$$_3$ is superior to that of $\chi$$_2$,$\chi$$_1$in secure communication.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.760-762
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• 2000

Hybrid type LPM can be widely applied in the precise position controlled devic because precise linear motion can be directly obtained by the simple control circuit without backlash in the rotary-type stepping motor. Also, LPM can increase the Position resolution, which was limited by mechanical manufacturing limit and characteristic of magnetic material. using micro-step drive method to decrease the noise and vibration further. Especially, Double-side LPM may be replaced the solenoid as the valve driving device without difficulty and give full play to control the valve accurately. Hence, In this paper, magnetic circuit of double-side LPM was confirmed and static thrust force curve according to the relative displacement between stator and mover, was analyzed by the two dimensional finite element method. From this results, we can suppose the excitation current to be controlled optimally.

• ETRI Journal
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• v.32 no.4
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• pp.530-539
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• 2010

As the conventional silicon metal-oxide-semiconductor field-effect transistor (MOSFET) approaches its scaling limits, quantum mechanical effects are expected to become more and more important. Accurate quantum transport simulators are required to explore the essential device physics as a design aid. However, because of the complexity of the analysis, it has been necessary to simulate the quantum mechanical model with high speed and accuracy. In this paper, the modeling of double gate MOSFET based on an adaptive neuro-fuzzy inference system (ANFIS) is presented. The ANFIS model reduces the computational time while keeping the accuracy of physics-based models, like non-equilibrium Green's function formalism. Finally, we import the ANFIS model into the circuit simulator software as a subcircuit. The results show that the compact model based on ANFIS is an efficient tool for the simulation of nanoscale circuits.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.193-197
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• 2001

This paper presents a novel circuit topology of the double two-switch forward type high frequency transformer linked soft-switching PWM DC-DC power converter with tapped inductor filters that can operate under a condition of the low peak voltage stress across the power semiconductor devices and lowered peak current stress through the transformer for some high power applications. This circuit topology of an interleaved two-switch forward soft-switching power converter is proposed in the order to minimize an idle circulating current due to the tapped inductor filter without of any additional active auxiliary resonant-assisted snubber circuits, such as active resonant DC link snubbers and AC link snubbers, active resonant commutation leg link snubbers. The unique advantages of this power converter are less power circuit components and power semiconductor devices, constant frequency PWM scheme, cost effective configuration and wider soft-switching PWM operation range under PWM power regulations load variations. The practical effectiveness of the proposed soft-switching converter circuit topology is tested by simulations and is proved by experimental results received from the 500W-100kHz breadboard setup.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2166-2172
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• 2007

In this study a low-signal equivalent circuit based on the Double Schottky Barrier model is proposed for ZnO-based varistor. Since pin-lead inductance and stray capacitance are considered in pin-lead type ZnO varistor these inductance and capacitance could be removed from the experimental dielectric data of the varistor. According to the equivalent circuit simulation results the higher the varistor-voltage of varistor sample the capacitance of dielectric layer is larger, and the capacitances of semiconducting layer and depletion layer are smaller, while the parallel resistances of semiconducting layer and depletion layer are more larger values. Spectra of the dielectric loss factor $tan{\delta}$ show 2 peaks in low frequency and high frequency regions respectively. The low-frequency peak is due to the relaxation by deep donors and the high-frequency peak is due to the relaxation by shallow donors. Above results are well consistent with the theoretical mechanism of ZnO varistor.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.958-964
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• 2015

This paper implements a model of a double excited three-degree-of-freedom motor (3-DOF) coupled with a PI current controller for position control. The rotational trends of the rotor according to the applied steps are identified using a motion equation. The simulation model is a complete electrical and mechanical model of a 3-DOF motor, which mainly consists of mechanical torque equations, a nonlinear equivalent magnetic circuit, and a PI current controller. This machine is tested using the manufactured control board using the same conditions as in the simulation, where the experimental results also verify the accuracy of the simulation results.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.255-257
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• 1999

Fault location algorithms based on the current distribution factors under the one-phase to earth fault condition of a double-circuit line are presented. The derivation method for current distribution factors is showed, to calculate fault current, fault resistance and the zero sequence current of other parallel circuit which are unknown. As the proposed algorithms 1,2,3 embodies an accurate location by the voltage and the current of the relaying point.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2069-2071
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• 2001

In this paper, a transmitter and a receiver using two identical Hyper-Chaos that n-double scroll circuits are proposed and a hyper-chaos synchronizations are investigated. we are proposed unidirectional coupling of ide n-double scroll cell for hyper-chaos synchronizat. We've shown that simulation result is synchronization.