• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.39-44
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• 2013

In this paper digital phase-shifter for multi-arm spiral antennas was designed by using Hilbert transform. All frequency components in input signal are phase-shifted for 90 degree by Hilbert transform, and the transform is implemented by FIT and IFIT. Digital phase-shifter generates two signals with phase difference of 90 degree by using Hilbert transform from input signals sampled by analog-digital converter(ADC), and then the input signal is phase-shifted for a given phase by using two signals. Hilbert transform based on digital phase-shifter is designed by Xilinx System generator, and the effects of input noise, FIT point, sampling period, initial phase of input signal, and shifted phase are simulated and its results are compared with Matlab results.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1166-1177
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• 2014

A new type of topology with medium-frequency-transformer (MFT) isolation for medium voltage wind power generation systems is proposed in this paper. This type of converter is a high density power conversion system, with high performance features suitable for next generation wind power systems in either on-shore or off-shore applications. The proposed topology employs single-phase cascaded multi-level AC-AC converters on the grid side and three phase matrix converters on the generator side, which are interfaced by medium frequency transformers. This avoids DC-Link electrolytic capacitors and/or resonant L-C components in the power flow path thereby improving the power density and system reliability. Several configurations are given to fit different applications. The modulation and control strategy has been detailed. As two important part of the whole system, a novel single phase AC-AC converter topology with its reliable six-step switching technique and a novel symmetrical 11-segment modulation strategy for two stage matrix converter (TSMC) is proposed at the special situation of medium frequency chopping. The validity of the proposed concept has been verified by simulation results and experiment waveforms from a scaled down laboratory prototype.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.257-262
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• 2008

This paper studies the operational characteristics of Multi-Phase Interleaved Boost converter operating in Boundary Conduction Mode. The generalized transfer functions of interest are derived from the full-order averaged model approach and then the steady-state and dynamic characteristics are analyzed. The theoretical results are verified through an experimental prototype of the 800W boost PFC converter for 60inch PDP power module.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.123-130
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• 2007

This paper presents the generalized and explicit expressions for evaluating the performance of the multi-phase interleaved buck converter (IBC) operating in discontinuous inductor current mode (DICM). The full-order averaged model is derived. The generalized transfer functions of interest are presented and the dynamic characteristics are analyzed. The generalized analysis of converter performance is verified through the experimental and simulation results.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.785-787
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• 2005

This paper addresses the small-signal analysis of the multi-phase interleaved boost converter with the coupled inductors operated in the continuous inductor current mode. The generalized and analytical expressions for the transfer functions of interest are derived for various inductor couplings. The dynamic characteristics are analyzed according to the inductor couplings and verified experimentally. The proposed frequency models will be very useful to design the dynamic controllers of the multi-phase interleaved boost converters.

• Journal of Power Electronics
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• v.19 no.4
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• pp.934-943
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• 2019

A current balance problem exists in multi-phase LLC converters due to the resonant parameter tolerance. This paper presents a current balancing method for interleaved three-phase half bridge LLC converters. This method regulates the phase shift angle of the driving signals between the three phases based on a converter with a floating Y-connection. The floating midpoint voltage has different influences on each phase current and makes the three-phase current balance performance better than midpoint non-floating systems. Phase shift control between modules can further regulate the midpoint voltage. Then three phase current sharing is realized without adding extra components. The current distributions in a midpoint non-floating system and a midpoint floating system are compared. Then the principle and implementation of the proposed control strategy are analyzed in detail. A 3kW prototype is built to verify the validity and feasibility of the proposed method.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.181-184
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• 2005

Operating conditions of photovoltaic power generator is very sensitive to the PV modules. The PV module's control is an importance issue in the removing DC ripple noise. In this paper, the phase-shifted-carrier technique, which is a new three-step dc-dc power multi-converter schemes, is applied to solar generator system to improve the output current waveform. The novel type of three-step dc-dc converter presented has many features such as the good output waveform, high efficiency, low switching losses, low acoustic noise. The circuit configuration is constructed by the conventional full-bridge type converter circuit using the isolated DC power supply for which the solar cell is very suitable. In the end, a circuit design for understanding three-step dc-dc converter and new solar power system were presented

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.3
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• pp.234-240
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• 2007

In this paper, a novel multi-level inverter for low cost high speed switched reluctance(SR) drive is proposed. The proposed multi-level converter has reduced number of power switches and diodes than that of a conventional asymmetric converter for SRM and smaller voltage rating of the dump capacitor comparing with energy efficient c-dump converter. It can supply five operating modes that is boosted, DC-link, zero, negative bias and negative boosted voltage. The proposed multi-level converter has fast excitation and demagnetization modes of phase current, so dynamic response can be achieved. The proposed multi-level converter is verified by computer simulation and experimental results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.2 s.332
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• pp.1-8
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• 2005

An area-efficient DC-DC voltage up-converter in a poly-Si TFT technology for system-on-glass is described which provides low-ripple output. The voltage up-converter is composed of charge-pumping circuit, comparator with threshold voltage mismatch compensation, oscillator, buffer, and delay circuit for multi-phase clock generation. The low ripple output is obtained by multi-phase clocking without increasing neither clock frequency nor filtering capacitor The measurement results have shown that the ripple on the output voltage with 4-phase clocking is 123mV, while Dickson and conventional cross-coupled charge pump has 590mV and 215mV voltage ripple, respectively, for $Rout=100k\Omega$, Cout-100pF, and fclk=1MHz. The filtering capacitor required for 50mV ripple voltage is 1029pF and 575pF for Dickson and conventional cross-coupled structure, for Iout=100uA, and fclk=1MHz, while the proposed multi-phase clocking DC-DC converter with 4-phase and 6-phase clocking requires only 290pF and 157pF, respectively. The efficiency of conventional and the multi-phase clocking DC-DC converter with 4-phase clocking is $65.7\%\;and\;65.3\%$, respectively, while Dickson charge pump has $59\%$ efficiency.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.867-869
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• 1993

In generally Boost Converter is used for Fuel Cell System. Because the output voltage of fuel cell is too small and greatly depends on the load condition, Boost Converter are required to boost and regulate the Fuel Cell voltage for per conversion efficiency. In this Paper, 6-phase Boost Converter is used to boost the Fuel Cell Voltage and regulate the output voltage. Multi phase converter hag some advantages such as low ripple and filter sine. About the Peak Current Control and compare of the Ripple Current of Boost Converter, we have studied.