• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.285-293
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• 2004

In this Paper the electronic ballast using the SEPIC(Single Ended Primary Inductor Converter) converter for the multiple electrodeless fluorescent lamps is proposed, which has the structure of the active PFC and self oscillating function. The SEPIC converter system has the characteristics of the power factor with low input current harmonic distortion. The proposed control method is based on the aveage-current-mode using the dedicated integrated circuit UC3854. The proposed electronic ballast has the reduction effect for the energy and manufacturing cost because it is designed for tripple electrodeless fluorescent lamps. The experimental results shows that the power factor is higher and the THD is lower.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.1
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• pp.44-50
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• 2015

This paper presents a high speed synchronous single inductor dual output boost converter using Type-III compensation for power management in smart devices. Maintaining multiple outputs from a single inductor is becoming very important because of inductor the sizes. The uses of high switching frequency, inductor and capacitor sizes are reduced. Owing to synchronous rectification this kind of converter is suitable for SoC. The phase is controlled in time sharing manner for each output. The controller used here is Type-III, which ensures quick settling time and high stability. The outputs are stable within $58{\mu}s$. The simulation results show that the proposed scheme achieves a better overall performance. The input voltage is 1.8V, switching frequency is 5MHz, and the inductor used is 600nH. The output voltages and powers are 2.6V& 3.3V and 147mW &, 230mW respectively.

• Journal of Power Electronics
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• v.17 no.3
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• pp.821-834
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• 2017

This paper reports on a single-inductor multiple-output step-up converter with digital control. A systematic analog-to-digital-controller design is explained. The number of digital blocks in the feedback path of the proposed converter has been decreased. The simpler digital pulse-width modulation (DPWM) architecture is then utilized to reduce the power consumption. This architecture has several advantages because counters and a complex digital design are not required. An initially designed unit-delay cell is adopted recursively for the construction of coarse, intermediate, and fine delay blocks. A digital limiter is then designed to allow only useful code for the DPWM. The input voltage is 1.8 V, whereas output voltages are 2 V and 2.2 V. A co-simulation was also conducted utilizing PowerSim and Matlab/Simulink, whereby the 55 nm process was employed in the experimental results to evaluate the performance of the architecture.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.561-569
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• 2019

Solar photovoltaic can provide electrical energy with only radiation, and its use is expanding rapidly as a new energy source. This study predicts the short and long-term PV power generation using actual converter output data of photovoltaic system. The prediction algorithm uses multiple linear regression, support vector machine (SVM), and deep learning such as deep neural network (DNN) and long short-term memory (LSTM). In addition, three models are used according to the input and output structure of the weather element. Long-term forecasts are made monthly, seasonally and annually, and short-term forecasts are made for 7 days. As a result, the deep learning network is better in prediction accuracy than multiple linear regression and SVM. In addition, LSTM, which is a better model for time series prediction than DNN, is somewhat superior in terms of prediction accuracy. The experiment results according to the input and output structure appear Model 2 has less error than Model 1, and Model 3 has less error than Model 2.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1483-1493
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• 2016

Multiple parallel inverters have multiple resonant frequencies that are influenced by many factors. This often results in stability and power quality problems. This paper develops a multiple input multiple output model of grid-connected inverter systems using a closed-loop transfer function. The influence factors of the resonant characteristics are analyzed with the developed model. The analysis results show that the resonant frequency is closely related to the number, type and composition ratio of the parallel inverters. To suppress resonance, a scheme based on virtual impedance is presented, where the virtual impedance is emulated in the vicinity of the resonance frequency. The proposed scheme needs one inverter with virtual impedance control, which reduces the design complexity of the other inverter controllers. Simulation and experimental tests are carried out on two single phase converter-based setups. The results validate the correctness of the model, the analytical results and the resonant suppressing scheme.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.189-192
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• 2001

This paper proposed that an AC-DC converter system using multiple buck-chopper operates with four choppers connecting to a number of parallel circuits. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer are included to confirm the validity of the analytical results. The partial resonant circuit makes use of an inductor using step-down and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in a partial resonant circuit makes charging energy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.472-472
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• 2000

An analog signal conditioner using fuzzy logic technique, which has multiple-input and multiple-output terminals, is proposed in this paper. The proposed signal conditioner can be employed to linearly translate the level of signals to a standard voltage signal (1-5V) and convert the form of signals to a standard current signal (4-20mA). The implementation method based on the use of a commercial 8-bit microcontroller, the analog-to-digital (A/D) converters, the digital-to-analog (D/A) converters and the voltage-to-current (V/I) converter. The simulation result and the experimental results are presented, which further confirm the feasibility of this approach.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.263-269
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• 2010

Multiple input multiple output (MIMO) has been considered one of the key enablers of broadband wireless communications. The indoor environment is known to be favorable to ensure both high rank property and high signal-to-interference/noise ratio (SINR) to fully exploit MIMO spatial multiplexing (SM) gain. In this paper, we describe several practical deployment cases where repeater links (or relay links), such as those present with an indoor distributed antenna system (DAS), can act as keyholes to degenerate the rank property of MIMO communications. In this case, we cannot exploit MIMO SM gain in indoor environment. We propose a novel MIMO communication scheme which uses simple converter in the devices in repeater links to resolve the rank degeneration issue and to ensure MIMO SM gain in highly MIMO-favorable indoor environment. MIMO SM is possible over the indoor DAS with single cable line through use of simple converters, which enables practical deployment in real fields.

• Journal of Power Electronics
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• v.16 no.3
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• pp.960-969
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• 2016

High-power three-level voltage-source converters are widely utilized in high-performance AC drive systems. In several ultra-power instances, the harmonics on the grid side should be reduced through multiple rectifications. A combined harmonic elimination method that includes a dual primary-side series-connected winding transformer and selective harmonic elimination pulse-width modulation is proposed to eliminate low-order current harmonics on the primary and secondary sides of transformers. Through an analysis of the harmonic influence caused by dead time and DC magnetic bias, a synthetic compensation control strategy is presented to minimize the grid-side harmonics in the dual primary side series-connected winding transformer application. Both simulation and experimental results demonstrate that the proposed control strategy can significantly reduce the converter input current harmonics and eliminates the DC magnetic bias in the transformer.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.133-134
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• 2016

높은 전압을 입력으로 하는 DC/DC 컨버터는 효율 향상 및 소형화를 위한 방안으로 전압의 레벨을 나누어 여러개의 스테이지로 구성하여 병렬 운전을 실시한다. 하지만 여러 개의 병렬구조로 구성된 DC/DC 파워부는 능동 소자와 수동 소자의 오차값 등이 각 단에 흐르는 전력 불평형 문제를 야기시켜 소자의 스트레스 증가 및 발열로 인해 전원공급장치의 소손으로 이어진다. 따라서 본 논문에서는 이러한 각 레벨의 DC/DC 컨버터의 전력 불평형을 개선하기 위해 자기적 결합을 공유하는 다중 입력 변압기를 사용하여 그 문제를 해결하기 위한 방법에 대해 제안한다.