• 전기전자학회논문지
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• 제23권1호
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• pp.261-265
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• 2019

기존 양방향 컨버터와 출력 커패시터를 추진용 배터리 쪽으로 이동시킨 양방향 컨버터의 고장률 변화를 분석한다. 두 컨버터의 회로 구조적 동일성과 차이점을 분석하여 커패시터 위치 변경으로 동작전압이 저감됨을 확인한다. 전압스트레스 인자와 동작온도에 따른 커패시터 부품 고장률을 구하고 양방향 컨버터의 고장나무에 적용하여 컨버터 전체 고장률을 구한다. 동작온도와 커패시턴스 값에 따른 고장률과 평균고장시간을 비교 분석하여 설계 변경으로 인한 장 단점을 분석한다.

• Journal of Power Electronics
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• 제11권4호
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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.

• 한국산업융합학회 논문집
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• 제25권1호
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• pp.111-119
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• 2022

This paper is about power transfer between heterogeneous systems in zero-energy buildings. Currently, electricity used in buildings, from renewable energy generation power in buildings, consists of alternating current networks. In order to use electricity, alternating current must be converted to direct current, which typically results in a loss of 10%. In order to solve this problem, research is needed to reduce power loss as much as possible by implementing both a DC network and an AC network in a zero-energy building. Therefore, in this paper, an inter-link converter capable of bidirectional power transfer between DC and AC networks applied to zero-energy buildings is developed. The structure of the inter-link converter to be developed was proposed and its feasibility was verified through simulations and experiments.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제2B권3호
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• pp.133-139
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• 2002

In this paper, a prototype of an active auxiliary quasi-resonant DC link (QRDCL) snubber assisted voltage source bidirectional power converter (AC to DC and DC to AC) operating at zero voltage soft-switching (BVS) PWM nlode is presented for a Battery Energy Storage System (BESS). The operating principle of this QRDCL circuit and multifunctional control-based converter system, including PWM inverter mode in which energy flows from the battery bank to the three-phase utility-grid in addition to an active PWM converter mode in which energy flows from the utility-grid to the battery banks are described respectively by the control implementation on the basis of d-q coordinate plane transformation. The multifunctional operation characteristics of this three-phase ZVS PWM bi-directional converter with QRDCL is demonstrated fer a BESS under the power conditioning and processing schemes of energy supply mode and energy storage mode, and compared with a conventional three-phase hard switching PWM bi-directional converter for a BESS. The effectiveness of the three-phase ZVS PWM hi-directional converter with QRDCL is proven via the simulation analysis.

• 전력전자학회논문지
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• 제19권3호
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• pp.240-248
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• 2014

It is DC power that Output of renewable energy being recently developed and researched. Also, demand of DC power will expect to proliferate due to increase of digital load. Thus, DC distribution system providing high quality of power and reliability has emerged as a new distribution system. If the conventional distribution systems are substituted by proposed DC distribution system, the output of renewable energy can be connected with distribution systems under minimum power conversion. Therefore, in the event of connection with DC load, it can construct an efficient distribution system. In this paper, the integrated parallel operation of power conversion module for DC distribution system is proposed. Also, this paper proposed modularization of power conversion devices for DC distribution system and power control for parallel operation of large capacity system. DC distribution system consists of three power conversion modules such as AC/DC power conversion module 2 set, ESS module 1 set. DC distribution system controls suitable operation depending on the status of the DC power distribution system and load. Integrated operation of these systems is verified by simulation and experiment results.

• 전기전자학회논문지
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• 제23권3호
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• pp.994-1002
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• 2019

본 논문은 농업용 전기차량의 전기식 동력인출장치용 전력변환시스템에 대해 제안한다. 대부분의 전기식 동력인출장치(Electric Power Take-Off : e-PTO)는 상용전원 $220V_{AC}$를 사용한다. 농업용 전기차량의 낮은 배터리 전압을 사용하여 높은 출력 전압을 공급하기 위한 DC-DC 컨버터와 DC-AC 인버터로 구성된 2단 구조를 갖는 양방향 전력변환시스템이 적합하다. 제안하는 전력변환시스템은 1단의 Dual Active Bridge(DAB)컨버터와 2단의 양방향 풀 브릿지 인버터로 구성된다. 또한, 초기 구동시 DC 버스단 커패시터 충전에 의해 발생되는 돌입 전류 저감을 위해 소프트 스타트 알고리즘을 제안한다. 3kW급 전력변환시스템 시제품 및 알고리즘을 구현하고 실험을 통해서 실용성을 입증하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.328-335
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• 1999

Three phase full bridge rectifier has been used to obtain dc voltage from three phase ac voltage source. The rectifier system has drawbacks that power factor is low and power flow is unidirectional. Therefore, when dc voltage increases due to regeneration of power the dynamic resister for dissipation of regeneration power must be installed. But three phase PWM converter can be controlled to operate with unity power factor and bidirectional power flow. Therefore when the PWM converter is used as do supply system, the dissipating resistor is not necessary. On this thesis, in order to design a controller having good performance, the hee phase PWM converter is completely modeled by using circuit DQ-transformation and thus a general and simple instructive equivalent circuit is obtained; the inductor set becomes a second order gyrator-coupled system and three phase inverter becomes a transformer as well. Under given phase angle(${\alpha}$) and modulation index(MI) of the three phase inverter, the dc and ac characteristics are obtained by analysis of the transformed equivalent circuit The validity of the equivalent circuit is confirmed through PSPICE simulation. And based on the dc and ac characteristics a controller with unity power factor is proposed.

• 전력전자학회논문지
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• 제14권3호
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• pp.235-242
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• 2009

본 논문에서는 새로운 비대칭 PWM 제어 방식의 양방향 하프브리지 컨버터를 제안한다. 제안한 컨버터는 구조가 간단하고 넓은 듀티 범위를 가지므로 연료전지와 같은 넓은 전압변동을 가지는 응용에 적합하다. 제안한 비대칭 PWM 방식은 기존의 위상각제어 방식에 비해 스위치 및 변압기의 동작전류를 큰 폭으로 낮추었고 ZVZCS와 동기 정류 방식을 적용하여 높은 효율과 전력밀도를 가질 수 있다. 기존 컨버터와의 비교 분석을 수행하였으며 실험을 통해 본 방식의 타당성을 검증하였다.

• Journal of Power Electronics
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• 제10권3호
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• pp.235-244
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• 2010

This paper presents a new isolated soft-switching bidirectional buck-boost inverter for fuel cell applications. The buck-boost inverter combines an isolated DC-DC converter with a conventional inverter to implement buck-boost DC-DC and DC-AC conversion. The main switches achieve zero voltage switching and zero current switching by using a novel synchronous switching SVPWM and the volume of the transformer in the forward and fly-back mode is also minimized. This inverter is suitable for wide input voltage applications due to its high efficiency under all conditions. An active clamping circuit reduces the switch's spike voltage and regenerates the energy stored in the leakage inductance of the transformer; therefore, the overall efficiency is improved. This paper presents the operating principle, a theoretical analysis and design guidelines. Simulation and experimental results have validated the characteristics of the buck-boost inverter.

• 전력전자학회논문지
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• 제18권5호
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• pp.413-421
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• 2013

This paper proposes residential hybrid distribution system that can supply AC power and DC power to AC load and DC load at the same time. This hybrid distribution system consists of three parts: bidirectional inverter, step-up converter and step-down converter. Also that is used to supply voltage to home application is classified of AC load and DC load as load characteristics. The performance of proposed hybrid distribution system is validated through the hardware implementation and the experimental results.