• Journal of Power Electronics
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• v.11 no.4
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• pp.408-417
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• 2011

The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.3
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• pp.214-222
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• 2015

The superiority of gallium nitride FET (GaN FET) over silicon MOSFET is examined in this paper. One of the outstanding features of GaN FET is low reverse-recovery charge, which enables continuous conduction mode operation of totem-pole bridgeless boost power factor correction (PFC) circuit. Among many bridgeless topologies, totem-pole bridgeless shows high efficiency and low conducted electromagnetic interference performance, with low cost and simple control scheme. The operation principle, control scheme, and circuit implementation of the proposed topology are provided. The converter is driven in two-module interleaved topology to operate at a power level of 5.5 kW, whereas phase-shedding control is adopted for light load efficiency improvement. Negative bias circuit is used in gate drivers to avoid the shoot-through induced by high speed switching. The superiority of GaN FET is verified by constructing a 5.5 kW prototype of two-module interleaved totem-pole bridgeless boost PFC converter. The experiment results show the highest efficiency of 98.7% at 1.6 kW load and an efficiency of 97.7% at the rated load.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.137-143
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• 2013

This paper presents development of variable speed generation (VSG) system with energy saving function. The rubber tyred gantry crane (RTGC) requires the power from diesel-engine. Significant fuel savings by reducing the engine speed can be achieved, because all of operation modes except hoisting are required lower power than rated value of engine. When low speed operation output voltage of generator is decrease until acceptable range of motor driver inverters and auxiliary load supplier. According to power demand engine speed is varying from 20 to 60Hz, and voltage is varying between 210Vac and 480Vac. When idle mode or low power operation dc/dc converter operates by constant output voltage control and inverters dc site voltage is compensated by it. This paper proposed 3-phase interleaved boost converter which has the same structure as the commercially available 3-phase inverter and current sharing capability. 400kW interleaved converter is designed and a performance of converter is evaluated through several experiments with a RTGC system. Energy saving VSG system can cut down fuel consumption by 36% and 21.3% at idle and unidirectional load operations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.6-13
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• 2014

In this paper, a multiwavelength-switchable first-order fiber flexible filter is newly proposed, which is based on a polarization-diversity loop. The proposed filter consists of a polarization beam splitter, three half-wave plates(HWPs), and two high birefringent fibers(HBFs). The proposed filter has a good flexibility in adjusting relative angular difference between the principal axes of two HBFs by inserting an HWP between two HBFs. The first-order flat-top or narrow band transmission spectra and the zeroth-order transmission spectra, which had a channel spacing of ~0.8nm, could be obtained by controlling the three HWPs, and, in particular, each of them could also be interleaved. In addition, zeroth-order transmission spectra with a channel spacing of ~0.8nm could be flexibly converted into those with a channel spacing of ~0.4nm through the control of three HWPs, and also be interleaved. The transmission characteristics of the proposed filter was theoretically analyzed and experimentally verified.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1629-1638
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• 2016

Differential power processing (DPP) systems are among the most effective architectures for photovoltaic (PV) power systems because they are highly efficient as a result of their distributed local maximum power point tracking ability, which allows the fractional processing of the total generated power. However, DPP systems require a high-efficiency, high step-up/down bidirectional converter with broad operating ranges and galvanic isolation. This study proposes a single, magnetic, high-efficiency, high step-up/down bidirectional DC-DC converter. The proposed converter is composed of a bidirectional flyback and a bidirectional isolated switched-capacitor cell, which are competitively cheap. The output terminals of the flyback converter and switched-capacitor cell are connected in series to obtain the voltage step-up. In the reverse power flow, the converter reciprocally operates with high efficiency across a broad operating range because it uses hard switching instead of soft switching. The proposed topology achieves a genuine on-off interleaved energy transfer at the transformer core and windings, thus providing an excellent utilization ratio. The dynamic characteristics of the converter are analyzed for the controller design. Finally, a 240 W hardware prototype is constructed to demonstrate the operation of the bidirectional converter under a current feedback control loop. To improve the efficiency of a PV system, the maximum power point tracking method is applied to the proposed converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.2
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• pp.96-105
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• 2021

Large-scale power converters consist of series or parallel module combinations. In these modular converter systems, the interleaving technique can be applied to improve capacitor reliability by reducing the ripple of the I/O current in which each module operates as a phase difference. However, when applying the interleaving technique for conventional three-level boost converters, the short-circuit period of the converter can be an obstacle. Such problem is caused by the absence of a low-level inductor of the conventional three-level boost converter. To solve this problem, a three-level boost converter with a low-level inductor is proposed and analyzed to enable interleaved operation. In the proposed circuit, the current ripple of the output capacitor depends on the neutral point connections between the modules. In this study, the ripple current is analyzed by the neutral point connections of the three-level boost converter that has a low-level inductor, and the effectiveness of the proposed circuit is proven by simulation and experiment.

• Journal of Power Electronics
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• v.19 no.3
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• pp.665-675
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• 2019

Renewable energy based on photovoltaic systems is beginning to play an important role to supply power to remote areas all over the world. Owing to the lower output voltage of photovoltaic arrays, high gain DC-DC converters with a high efficiency are required in practice. This paper presents a novel interleaved DC-DC boost converter with a high voltage gain, where the input terminal is interlaced in parallel and the output terminal is staggered in series (IPOSB). The IPOSB configuration can reduce input current ripples because two inductors are interlaced in parallel. The double output capacitors are charged in staggered parallel and discharged in series for the load. Therefore, IPOSB can attain a high step-up conversion and a lower output voltage ripple. In addtion, the output voltage can be automatically divided by two capacitors, without the need for extra sharing control methods. At the same time, the voltage stress of the power devices is lowered. The inrush current problem of capacitors is restrained by the inductor when compared with high gain converters with a switching-capacitor structure. The working principle and steady-state characteristics of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by experimental results.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.31-33
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• 2007

In this paper, a simple digital control scheme for the single/parallel module buck converters is proposed using a digital state feedback control method. The discrete state feedback controller structure for the robust tracking control is derived by using the error state. The proposed control system can precisely achieve the interleaved current sharing and the output regulation, and can achieve the systematical controller design for a given converter specification using the pole placement technique. For a design example, the single module buck converter is simulated using the MATLAB Simulink software and two 100W parallel module buck converters with a TMS320F2812 DSP is implemented.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.5
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• pp.339-346
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• 1991

In this paper the performance of communication system in the electrical power line using error correcting codes is analysed. The BCH codes and interleaved code are to be used for correcting burst and random errors in the power line channels. The data rate of 2400 bps and the carrier frequency of 12KHz are assumed. Actual power line noise is recorded and simulated in the BPSK PLC system model.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.227-228
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• 2017

본 논문에서는 모듈라 ESS에 사용되는 인터리브드 DC-DC 컨버터의 평균 모델을 이용하여 제어 시스템을 설계함으로써 기존 소신호 모델 기반 제어의 동작점이 변동하는 경우 과도 응답 특성이 저하되는 단점을 개선하고자 한다. 또한, PSIM 시뮬레이션과 실험을 통해 제시된 설계방법의 우수성을 실증하고자 한다.