• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.11
• /
• pp.1976-1980
• /
• 2008

This paper deals the characteristic analysis of Switched Reluctance Motor(SRM) driven by single-pulse mode considering dc link voltage ripple. Two dimensional time-stepped Finite Element Method(FEM) is used to analyze the characteristic of SRM driven by single-pulse mode with dc link voltage ripple. The analysis results is verified by experimental test.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.8
• /
• pp.517-524
• /
• 2004

In this paper, a novel zero-voltage-switching(ZVS) resonant DC-DC converter is proposed. It is composed of two symmetrical active-clamped circuits, the converter can be achieve ZVS in each switches. Also, active clamp capacitor ratios($\alpha$) of proposed circuit can be reduce a peak stress of switching voltage for each main switch. Simulation results using Pspice 9.2 ver and $C^{++}$ characteristic analysis show a provement for the validity of theoretical analysis. The analysis of the proposed Current-Fed Push Pull type DC-DC converter is generally described by using normalized parameter, and achieved an evaluated characteristic values which is needed to design a circuit. We confirm a rightfulness theoretical analysis by comparing a theoretical values and experimental values obtained from experiment using MOSFET as switching devices.

• Progress in Superconductivity and Cryogenics
• /
• v.5 no.2
• /
• pp.36-40
• /
• 2003

Inductive superconducting fault current limiter(SFCL) with DC reator rated on 6.6k $V_{rms}$/200 $A_{rms}$ has been developed in Yonsei University. The development of the DC reactor is the key technology in this type SFCL. This paper deals with the fabrication and characteristic test of the DC reactor. For the development of this magnet, the winding machine for high-Tc superconducting solenoid was manufactured. Using this machine, a large-scale HTS solenoid using Bi-2223 tape was fabricated successfully. This coil has 5 layers which are connected in series each other. The inductance of the DC reactor coil is 84mB. The cooling system was the sub-cooled nitrogen whose temperature is about 65K. The characteristic test of the coil was performed. The full quench current of this coil is about 490A.90A.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.49 no.1
• /
• pp.40-47
• /
• 2000

This paper presents a circuit of resonant voltage resultant type DC/DC converter consists of two unit half-bridge high frequency resonant inverters, and describes operating modes, principle and analysis of the proposed circuit. Also, the analysis of the proposed circuit has generally described by using normalized parameters. Based on the characteristic values, a method of the circuit design is proposed. According to phase shift, the output voltage of the proposed circuit can be controlled. In addition, the justification of theoretical analysis was certified by comparing to the experimental waveforms. In the future, this proposed converter show that it can be practically used as the system of fixed DC voltage source etc.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.301-303
• /
• 2001

This paper proposes the boost input type active clamp DC-DC converter featuring the high efficiency and improved EMI characteristics. The main characteristic of the converter is to operate with the non-pulsating input and output currents. Besides, it has the zero-voltage switching (ZVS) and low voltage stress characteristics. For the proposed converter, the detailed operation principles and the simulation results are presented.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.1
• /
• pp.57-62
• /
• 2013

Because of high torque and easiness of speed control, Direct Current(DC) motors have been used for a long time. But, its applications are limited in circumstance and performance, since they contained brush and commutator. The commutation characteristic gives effect to life and performance of the DC motor. Naturally, the commutation characteristic analysis is strongly required. In this paper, With the result of finite element analysis, The inductance is calculated each rotor position and applied to the voltage equations coupled with commutation equation. Also, contact resistances of brush/commutator assembly are considered using contact area and brush width converted with commutator segments. The time derivative term in the differential equation is solved in time difference method. This algorithm was applied to 2-pole shunt DC motor. We considered commutation characteristic by changing contact resistance between brush and commutator segment.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.383-386
• /
• 1990

This paper concerns a DC-DC converter using the characteristic of series resonance. Operation principle of the system described by the proposed equation is illustrated. Characteristics of steady state of the system which is essential to system design is evaluated for frequency and pulse width characteristic using dimensionless parameter. The proposed circuit based in constant voltage control uses the Pulse Width Modulation - Time Ratio Control method.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2033-2035
• /
• 1998

This paper describes a DC-DC converter connected two unites inverters, a half-bridge type of high frequency resonance inverter, at the input with parallel. The proposed paper certified that theorem waveforms are equal to experiment waveforms, in addition, it estimated characteristics such as characteristic of average power, characteristic of average output voltage, characterisic of output voltage ripple etc., for designing the device with normalized parameter value.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.4
• /
• pp.179-187
• /
• 2001

In recent years, the switching source devices have the advantage of small, light and high reliability with the high-frequency. But, high-frequency switching has disclosed disadvantage of result from stress and turn-on and turn-off peak losses at the switching instant. Accordingly, in this paper propose ZVS-HB type high-frequency resonant DC/DC converter using soft switching technique (Zero-Voltage-Switching, Zero-Current-Switching) with safety operating of circuit at diving on inductive zone, through the circuit design example using the capacitor $C_3,\;C_4$ with soft switching function and division characteristic of resonant Capacitor C, $C_1,\;C_2$, and, the characteristic analysis of circuit is generally described using normalized parameters. Also, this paper certified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using MOSFET.

• Proceedings of the KIPE Conference
• /
• 2003.07a
• /
• pp.54-57
• /
• 2003

A new non linear, mean value, instantaneous following control technique to design half bridge converter is proposed in witch control principle uses characteristic that reset time of analog integrator is inverse proportion In input voltage. It is Important characteristic that compensation and follow-up control time are same with switching frequency. Is completed in one cycle that base control frequency. Have excellence characteristic that follow in order instruction value exactly stationary state as well as transient state. Half bridge converter that apply this control principle can know that have stabilize and excellence characteristic. This technique is verified through an experiment, and know that experiment result and theory agree well.