• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.478-480
• /
• 2008

On this paper, digitally controlled push-pull dc-dc converter and dc-ac inverter for induction motor control are presented, which is used one DSP(digital signal processor). This system has 12V battery input for the push-pull converter, and the push-pull converter generates 300V output for induction motor inverter input. In order to compensate the push-pull converter, the transfer function of push-pull converter is derived and digital PI compensator is adapted. Through bode diagram, stability of digital controlled push-pull converter is analyzed. To verify the proposed system, digital simulation of the induction motor drive using digital push-pull converter are performed.

• Journal of Satellite, Information and Communications
• /
• v.12 no.2
• /
• pp.33-37
• /
• 2017

This paper suggests a new reliable push pull converter. The proposed push-pull converter have additional two diodes comparing with conventional push-pull converter. When one of two MOSFETs of the push-pull converter is on state, the other MOSFET is automatically off state due to adding additional diodes. Therefore, the converter is under electric noise environments, the converter avoids short circuit due to turning on of two MOSFETs. In this paper, the suggested converter has been simulated by PLECS software for 100 kHz switching frequency. In simulation, the current of the converter switches increases about 10 % for $20{\mu}sec$ electric noise environments. However, the converter operates very reliably without any short circuit conditions.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1232-1234
• /
• 2003

The push pull forward converter is a very suitable circuit for low output voltage, high output current applications with a wide input voltage range. This converter can be miniaturized by integrate magnetic components such as the output inductor, the transformer and the input inductor. We considered of the efficiency for the push pull forward converter. Developed the push pull forward converter rating are of $36{\sim}72V$ input and 3.3V/30A output. In this converter. the efficiency was measured by 76.4% at full load and 82.95% at half load. The maximum efficiency is up to 83.% at 200kHz, 11A output.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.11 no.4
• /
• pp.385-394
• /
• 2006

The application areas of traditional push-pull converters are limited because the voltage stress of switches is high (twice of the input voltage). But the push - pull converter topology is suitable for unregulated low-voltage to high-voltage power conversion such as the fuel cell. This paper presents a novel power converter structure that is very suitable for the DC/DC converter in fuel cell systems. Based on this structure, a ZVS- ZCS push-pull converter is proposed. The switches of the proposed push-pull converter can operate under ZVS or ZCS condition with the help of a new passive clamping circuit. The passive clamping techniques solves the voltage overshoot problem. Because the buck converter circuit operates at twice the synchronous switching frequency of the push-pull converter, the peak current in the current-fed inductor and transformer is reduced. The operation principle of the proposed converter is analyzed and verified by simulations and experimental results. A 1 kW DC/DC converter was implemented with DSP TMS320F2812, from which experimental results have shown that efficiency improvement and surge suppression can be achieved effectively.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.3
• /
• pp.247-255
• /
• 2013

In this paper, a soft switching DC-DC converter for AC module type photovoltaic (PV) module integrated converter is proposed. A push-pull converter is suitable for a low voltage PV AC module system because the step-up ratio of a high frequency transformer is high and the number of primary side switches is relatively small. However, the conventional push-pull converters do not have high efficiency because of high switching losses by hard switching and transformer losses (copper and iron losses) by high turns-ratio of the transformer. In the proposed converter, primary side switches are turned on at zero voltage switching (ZCS) condition and turned off at zero current switching (ZVS) condition through parallel resonance between secondary leakage inductance of the transformer and a resonant capacitor. Therefore the proposed push-pull converter decreases the switching loss using soft switching of the primary switches. Also, the turns-ratio of the transformer can be reduced by half using a voltage-doubler of secondary side. The theoretical analysis of the proposed converter is verified by simulation and experimental results.

• Journal of Power Electronics
• /
• v.12 no.3
• /
• pp.418-428
• /
• 2012

It is very important to improve the overall efficiency of systems with a source of power that has low-voltage high-current terminal characteristics such as fuel cells. A resonant converter is required for high efficiency systems. However, the peak value of the switches current is large in a resonant converter. This peak current requires a large number of switches and results in system failures. In this paper, an analysis and experiments of a resonant isolation push-pull converter are performed. A switching loss analysis is performed in order to compare losses between a resonant push pull converter and a hard switching push-pull converter. Specially, the conduction loss is studied based on the ratio between the resonant frequency and the switching frequency. In addition, a method for improving the efficiency is implemented with conventional HF insolation converters.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.2
• /
• pp.134-141
• /
• 2004

This paper presents a method of synchronous rectifier(SR) for improving the efficiency in DC/DC converter. The proposed method is used push-pull topology on primary as a single winding self driven synchronous rectification(SWSDSR). Specially, this method can improve efficiency to turn on SR switch during dead time. Finally, the simulation and experimental results will be given to show comparison and analysis on the efficiency between self driven synchronous rectification(SDSR) and SWSDSR method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.4
• /
• pp.343-349
• /
• 2005

This paper proposes a novel zero-voltage-switching (ZVS) Push-pull DC-DC Converter for high input voltage and high power applications. This topology utilizes two switches in series to replace one switch in conventional push-pull converter, and two clamping diodes are introduced. The voltage stress of the switches is the input voltage, and the switches can realize ZVS with the use of the leakage inductance of the transformer. Furthermore, secondary full-wave rectifier with a clamping capacitor is used to eliminate the voltage oscillation and spike of the rectifier diodes due to the reverse recovery. Therefore, the electromagnetic interference is reduced effectively. The operation principle of the proposed converter is analyzed theoretically. The output characteristic, ZVS condition and design principle of the clamping capacitor are discussed. Experimental results obtained from a 270V input 2kW prototype with $95.8\%$ high efficiency confirms the design.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.6
• /
• pp.592-597
• /
• 2005

The push pull forward converter is suitable in a low output voltage, a high output current applications with wide input voltage ranges. All magnetic components including output inductor, transformer and input filter can be integrated into single EI/EE core. The integrated push pull forward converter is considered through the comparison of efficiency according to the circuit parameters. The Nicera company's 5M FEE18/8/10C and NC-2H FEI32/8/20 cores are used for the transformer. The integrated push pull forward converter ratings are of $36\~72V$ input and 3.3V/30A output. In case that NC-2H FEI32/8/20 core used in the converter, the efficiency is measured up to $83.5\%$ at the switching frequency 200 kHz and the 11A load. The efficiencies of $76.4\%$ at a full load and $82.95\%$ at a half load are measured.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.462-463
• /
• 2012

본 논문에서는 Push-Pull 방식의 DC/DC 컨버터를 기초한 새로운 MIC 토폴로지를 제안한다. Push-Pull 컨버터의 변압기의 중간탭에 스위치를 추가하여 입력전류량을 제어하고 인버터는 Unfolder 형태로 스위칭하여 계통과 연계한다. 제안된 토폴로지는 PSIM 시뮬레이션을 통하여 MIC에 적합한 회로임을 검증하였다.