• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.889-896
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• 2020

In general, there are various types of boost converters such as Boost converters, Buck-Boost converters, Flyback converters, Push-Pull converters, etc. Among them, Boost converters are the most widely used and step up converters in a very simple form. However, Boost converter has DCM mode operation, big ripple problem and RHPZ problem. In order to solve these problems, a converter to which the new topology was applied was presented, but among them, the KY converter improved the Boost converter's DCM mode operation, the big ripple problem and the RHPZ problem. However, the conventional KY converter has a drawback that the voltage gain is relatively lower than that of the Boost converter. Therefore, in this paper, we proposed a new KY converter that solves the problem of low voltage gain while having the advantages of the conventional KY converter.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.225-230
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• 2000

This paper describes a double-ended current fed push-pull type high frequency resonant inverter used as the power supply for wax-sealing. The proposed inverter can realize ZVS operation by using resonant capacitor to ZVS capacitor and has some merits not only reduction of switch current distribution but also extension of load range compare to the conventional single-ended current fed push-pull type high frequency resonant inverter. This analysis of proposed circuit uses normalized parameter ad characteristic estimation which is needed in each step before design is generally described according to normalized frequency($\mu$), normalized resistance(λ) and parameters. It is also presented as an example of method of the circuit design based on estimation analysis values from theoretical analysis. The theoretical analysis is proved through experiment and this circuit shows that it can be used practically as the power supply system for wax-sealing and DC-DC converter.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.227-231
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• 2003

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 achieve each switchs ZVS. proposed circuit is active clamp capacitor Ratios can be reduce switching voltage stress of each main switch. Simulation results using Pspice ver 9.2 show that the prove the validity of theoretical analysis.

• Journal of Power Electronics
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• v.14 no.3
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• pp.444-457
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• 2014

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with $k_i$ and $R_L$ as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of $R_L$ and the operating point of the PV simulator to match the controller parameters with $R_L$. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.149-151
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• 2009

본 연구는 다른 에너지원에 비해 출력전류가 커짐에 전압의 드랍이 심한 에너지원을 대상으로하며, 기존의 고효율특성을 갖는 공진형 컨버터가 듀티의 변화에 자유롭지못한 단점을 보안하기위해 캐패시터를 이용하여 기존의 공진형 Push-Pull 컨버터와 부분전압제어가 가능한 Boost컨버터 2대를 결합하여 입력전압의 변화에도 일정한 DClink전압이 형성되도록 하고 있다. 각각 컨버터의 출력전압은 입력전압에 따라 변동하지만 고효율을 위하여 공진형 컨버터부에서 전압할당이 크도록 구성 되었으며, 본 논문은 공진형 Push-Pull컨버터, Boost 컨버터의 동작원리 및 2대의 컨버터를 결합구성 할 경우의 전력의 분담 및 전체적인 제어원리를 다루며, 시뮬레이션을 통하여 이를 입증하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.86-90
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• 2007

An efficient sensing scheme applicable to DC-DC converters is proposed. The output voltage of the DC-DC converter is fed back and converted to a current signal at the input terminal of the sensor to decide if it is in the tolerable range. The comparison is accomplished by a current push-pull action. With the embedded reference current in the sensor realized from the reference voltage. The advantages of the scheme lie in the fairly accurate and efficient implementation in terms of power consumption and chip size overhead compared with conventional voltage-mode schemes as the major parameter in converting voltage to current is determined by (W/L) aspect ratio of the core transistors. In this paper, a DC-DC converter of 5V output from battery range of 2.2V${\sim}$3.6V adopting the proposed sensing scheme is implemented in a 0.35um CMOS process to prove the validity of the scheme.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.4
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• pp.364-375
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• 2014

Parametric array transducers are used for long-range and highly directional communication in an underwater environments. The power amplifiers for parametric array transducers should have sufficient linear output characteristic and high efficiency to avoid communication errors, system heating, and fuel problems. But the conventional power amplifier with fixed source voltage is very low efficient due to large power loss by the big difference between the fixed source voltage and the amplifier output voltage. Thus to solve the problems this paper proposes the high efficiency power amplifier for parametric array transducers. The proposed power amplifier ensures high linearity of output characteristic by utilizing the push-pull class B type amplifier and furthermore gets high efficiency by applying the envelope tracking technique that variable source voltage tracks the envelope of the amplified signal. Also the paper suggests the detailed circuit topology and design guideline of class B push-pull type amplifier and variable output voltage AC/DC converter. Its characteristics are verified by the detailed simulation and experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.4
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• pp.65-72
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• 2000

This paper proposes a Push type High Frequency DC-DC Converter using Zero Voltage Switching to reduce turn on and off loss at the switching instants. This paper has a advantage which is able to operating safely in load short, because DC reactor is connected with resonance reactor in order to supply a fixed safely in load short, because DC reactor is connected with resonance reactor in order to supply a fixed current with low ripple from DC power supply. The capacitor $(C_1, C_2)$ connected in switch are a common using as resonance capacitor and ZVS capacitor. The analysis of the proposed high frequency resonance DC-DC converter is generally described by using normallized parameter, and we has evaluated characteristic values which is needed to design a circuit. We conform a rightfulness of theoritical analysis by comparing a theoretical values and experimental values obtained from experiment using MOSFET as switching devices.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.227-230
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• 2001

This paper deals with a bidirectional ac-dc converter used in ups system application. We propose a Voltage-Source-Charge-Pump-Power-Factor-Correction(VS-CPPFC) ac-dc converters. First of all, we propose a charge pump power-factor-correction converter. Secondly, we derive and analyse a unity power factor condition. The proposed topology is based on a half-bridge for the primary and a current-fed push pull for the secondary side of a high frequency isolation transformer. The advantage of bidirectional flow of power achieved by using the same power components is that the circuit is simple and efficient. And the galvanically isolated topology is specially attractive in battery charge/discharge circuits in ups system. We design equivalent model for the steady-state circuit and analyse operation waveforms for each mode. We show that the proposed model can be applied to ups system by simulation processes.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.197-200
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• 1998

Three switched-capacitor(SC) networks are presented including series-parallel capacitor set, reversed-switched-capacitor network and push-pull switched-capacitor network, the performances of which are discussed. Combining the SC networks with traditional DC-DC converters, we form several new topologies. Experiment and analyzed results show that the behavior of a DC-DC converter with large voltage ratio can be improved. A wider voltage conversion range is also obtained.