• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.20-26
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• 2009

In this paper, the switching mode conversion type pulse charger by fly-back converter method for lead battery of the solar cell generator equipment is proposed. And we propose the control circuit and design method of insulated switching mode convert type pulse charger by fly-back convert method in the lead battery. The proposed system can minimize the current consumption by digital pulse. Also the proposed system can generate the constant 10[KHz] frequency, transmit the signal with main control system in the power control system. And it supervises the state of lead battery using one chip micro processor. The proposed the switching mode conversion type pulse charger by the fly-back converter method can charge fast and stabilize lead battery with nominal value 12[V], 20[AH]. Also we propose the design procedure of the power control circuit for turn ratio of fly-back inductor and determining method of values such as the charging current, bulk current, partial current, over current value and fixed charging voltage. The experiment results for the voltage and current wave for partial, bulk, over and fixed charging period show the good charging effect and performance. And the PCB and internal coupling diagram of the switching mode conversion type pulse charger by fly-back converter method is presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.2
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• pp.64-72
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• 2001

In this paper, forward Zero Voltage Switching Multi Resonant Converter(ZVS MRC) for non-contact charging energy transmission is reposed. The forward ZVS MRC is effective in adsorbing parasitic element as well as minimizing the switching loss. That can accommodate very high frequency. So forward ZVC MRC is applied to non-contact charging energy transmission. Used converter has saperatable transformer and synchronous rectifiers. Coupling coefficient(k), leakage inductance, coupling inductance and resonant frequency are observed for the air gap. By using the observed value, this circuit is designed and implemented. This proposed circuit is simulated by the PSPICE and experimented. The voltage stress of a main switch and the output power of the converter are measured. This paper show that is compatible for non-contact charging energy transmission.

• Journal of Power Electronics
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• v.13 no.5
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• pp.779-786
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• 2013

A highly efficient sustaining driver is proposed for plasma display panels (PDPs). When the PDP is charged and discharged, the proposed sustaining driver employs an address voltage source used in an addressing period. A voltage source is used for fully charging the panel to the sustaining voltage, and an initial inductor current helps the panel discharge to 0 V. The resonance between the panel and an inductor is made by shifting the voltage and current bias level when charging and discharging the panel. As a result, the proposed circuit can reduce power consumption, switching loss, heat dissipation, and production cost. Experimental results of a 42-inch PDP are provided to verify the operation and features of the proposed circuit.

• Journal of IKEEE
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• v.15 no.4
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• pp.305-312
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• 2011

A primary interest of this work is to develop an efficient and powerful repetitive pulser system for the application of ultra wide band generation. The important component of the pulser system is a small-sized coaxial type spark gap with planar electrodes filled with SF6 gas. A repetitive switching action by the coaxial spark gap generates two consecutive pulses in less than a microsecond with rise times of a few hundred picoseconds (ps). A set of several parameters for the repetitive switching of the spark gap is required to be optimized in charging and discharging systems of the pulser. The parameters in the charging system include a circuit scheme, circuit elements, the applied voltage and current ratings from power supplies. The parameters in the discharging system include the spark gap geometry, electrode gap distance, gas type, gas pressure and the load. The characteristics of the spark gap discharge, such as breakdown voltage, output current pulse and recovery rate are too dynamic to control by switching continuously at a high pulse repetition rate (PRR). This leads to a low charging efficiency of the spark gap system. The breakthrough of the low charging efficiency is achieved by a parallel operation of two spark gaps system. The operational behavior of the two spark gaps system is presented in this paper. The work has focused on improvement of the charging efficiency by scaling the PRR of each spark gap in the two spark gaps system.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.26-32
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• 2020

In this study, the side reactions that greatly affect the coulombic efficiency of a zinc-air secondary battery are quantitatively analyzed on the basis of the charging-discharging characteristics, open circuit self-discharge characteristics, and a series of calculations. In particular, the charge amounts consumed by water electrolysis and self-discharge during charging process are separately determined so that the charging efficiency (the amount of charge used in actual charging with respect to the applied charge amount) can be estimated, which would enable systematic understanding of the cause of coulombic efficiency degradation. Using two cells with different charging overvoltages, the validity of the proposed method can be assessed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1866-1872
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• 2017

This paper presents the design of in-wheel type Switched Reluctance Motor (SRM) which can be used as both traction motor and power pickup device in a wireless charging system of electric vehicles. The SRM acts as a traction drive in driving mode and a power receiver in charging mode to avoid any additional weights. Double stator axial field SRM is used due to its structure that can be mounted inside the wheel. The charging circuit is integrated with the asymmetric converter and phase windings of SRM, reducing the cost and size of the system. Magnetic resonance is implemented to increase the efficiency. Simulations done in Maxwell and Simplorer verify the effectiveness of the proposed system.

• Journal of the Korean Magnetics Society
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• v.2 no.1
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• pp.69-74
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• 1992

This paper describes the energy and speed characteristics of an induction coil-gun. The coil-gun has some merits that it can be easily installed and repeatedly used many times, it does not damage mechanically in the course of launch and the force exerted on the projectile is distributed uniformly. An equivalent circuit is employed for modeling the coil-gun. The circuit equations and equation of motion are then derived based on the equivalent circuit. These equations are solved numerically by using Runge-Kutta method. Finally the energy transfer ratios are obtained according to the variations of the resonant frequency of driving circuit and charging voltage of capacitors. The muzzle velocities of projectile are also obtained according to the variations of electrical conductivity and initial position of projectile, firing angle of driving circuit, charging voltage of capacitor and resistance of driving coil, respectively.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1869-1871
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• 1998

In this paper, we designed and fabricated a fast switching system for high power pulse. This system consists of a voltage conversion circuit, high voltage charging circuit, trigger circuit, and discharging circuit. Especially discharging line is designed by strip-line for low inductance and resistance. The experimental result is that current slew rate of the system is 6.67kA/86ns and this result is fully qualified for initiating EBW or EFI

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.19-24
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• 2021

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protection problem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-to-turn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slow charging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply (PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. When a quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, the rotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causes the INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristic of HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quench protection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench, which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmed the protection characteristic of INS coils using a rotary HTS flux pump.