• 반도체디스플레이기술학회지
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• 제13권4호
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• pp.43-48
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• 2014

Two-level inverter has some disadvantages like high harmonics contained in the output current, efficiency limit and stress to switching device as IGBT and FET. Many researches have reported multi-level inverter to complement two-level inverter of problems. In this paper, we suggest MPPT algorithm of multi-string three-level solar inverter that considered nowadays. We added midpoint controller in order to implement the MPPT algorithm because the three-level inverter has to need midpoint controller and procured the stability of direct current link. We verify the superiority of multi-string T-Type inverter and the algorithm we suggested with solar irradiance variation experiment and MPPT efficiency measurement. The MPPT efficiency was confirmed with a high efficiency more than 99.97%.

• 한국태양에너지학회 논문집
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• 제39권2호
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• pp.1-9
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• 2019

In order to increase the power generation efficiency of the photovoltaic system, a new algorithm that can follow the maximum power point of the photovoltaic power generation system having nonlinear output characteristics is proposed. Conventional maximum power point tracking (MPPT) algorithms such as Perturbation and Observation (P&O) and InCond (Increment and Conductance) schemes can not find the global maximum power point at a plurality of pole points in the unmatched state of unbalanced PV modules. However, even if the global maximum power point is found at a plurality of pole points, the global maximum power that can not be the real maximum power by the photovoltaic generation system. In order to solve this problem, a few PV companies propose installing several small PV inverters instead of if big one. However, since this will require additional costs, we herein propose a Multi-MPPT system using individual 3-point MPPT to track true MPPT at a plurality of pole points in the unmatched state of unbalanced PV modules.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.140-141
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• 2011

본 논문은 MPPT가 가능한 세 개의 단상 인버터를 삼상(3상 4선) 인버터로 구성하고, 부하 종단의 역조 방지 검출 장비와 연동 운전하여 전체 시스템의 역조 및 역률 제어가 가능한 태양광 발전 시스템 개발에 대한 것이다.

• 신재생에너지
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• 제3권4호
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• pp.69-76
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• 2007

In this paper, a PV multi-string PCS with a grid-connection is proposed. An improved MPPT algorithm for the PV multi-string PCS is suggested. Each PV string has its own MPP tracker and the proposed MPPT algorithm prevents LMPP tracking due to power ripple. In the PV PCS with single-phase inverter has a large current ripple at twice the grid frequency. The current ripple reduction algorithm without external component is suggested. Also, this paper proposes a simple control method to achieve sharing of the PV string voltage and current among the interleaved parallel boost converters. All algorithms and controllers are implemented on a single-chip microcontroller. Experimental results obtained on a 3kW prototype show high performance of the proposed PV multi-string PCS.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.255-258
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• 2007

In this paper, a PV multi-string PCS with a grid-connection is proposed. An improved MPPT algorithm for the PV multi-string PCS is suggested. Each PV string has its own MPP tracker and the proposed MPPT algorithm prevents LMPP tracking due to power ripple. In the PV PCS with single-phase inverter has a large current ripple at twice the grid frequency. The current ripple reduction algorithm without external component is suggested. Also, this paper proposes a simple control method to achieve sharing of the PV string voltage and current among the interleaved parallel boost converters. All algorithms and controllers are implemented on a single-chip microcontroller. Experimental results obtained on a 3kW prototype show high performance of the proposed PV multi-string PCS.

• 전력전자학회논문지
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• 제18권4호
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• pp.349-358
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• 2013

In this paper, the sensorless MPPT algorithm is proposed where the performance of varied duty ratio change has been improved using multi-layer neuro-fuzzy that aligns with neuro-fuzzy based optimized membership function. Since the change of duty ratio of sensorless MPPT is varied by using the neuro-fuzzy, the MPPT response speed is faster than the convectional method and is able to reduce the steady-state ripple. The neuro fuzzy controller has the response characteristics which is superior to the existing fuzzy controller, because of the usage of the optimal width of the fuzzy membership function. The effectiveness of the proposed method has been verified by simulations and experimental results.

• 전기학회논문지
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• 제60권11호
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• pp.2064-2075
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• 2011

In this paper, robust multi-level perturbation and observation (MLPO) maximum power point tracking (MPPT) control are presented of the environmental change including the solar radiation and temperature. Because the maximum power point of the Photovoltaic (PV) is changing according to the solar radiation and temperature, the technology which traces the maximum power point in order to increase the power efficiency is recognized as the very important part. The general requirement for the MPPT is that system is simple, the cost is inexpensive, the PV tracking function and output change are small. Conventional perturbation and observation (PO) method is a simple system but there is the disadvantage that an efficiency of system becomes low. In addation, the incremental conductance (IC) control is required expensive CPU because of a large of calculations. In order to solve this problem, in this paper, the MLPO MPPT control using the method diversifying the step size according to the environment condition is presented. The validity of the MLPO method presenting from this paper is proved through analyzing the solar power generation output error at the steady state.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.346-349
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• 2013

본 논문에서는 MPPT(Maximum Power Point Tracking) 제어기능을 갖는 빛, 진동 그리고 열 에너지를 이용한 삼중입력 에너지 하베스팅 회로를 설계하였다. 설계된 회로는 MPPT 제어를 통해 솔라셀과 압전소자 그리고 열전소자로부터 최대 가용 전력을 수확하고, 수확된 에너지를 저장 커패시터에 병합하여 저장한다. 병합된 에너지는 PMU(Power Management Unit)를 통해 센서노드로 공급된다. MPPT 제어는 변환소자의 개방회로전압과 MPP(Maximum Power Point) 전압간의 비례관계를 이용하여 구현하였다. 제안된 회로는 $0.18{\mu}m$ CMOS 공정으로 설계하였으며, 모의실험을 통해 동작을 검증하였다. 설계된 에너지 하베스팅 회로의 칩 면적은 $945{\mu}m{\times}995{\mu}m$이다.

• Journal of Power Electronics
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• 제18권4호
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• pp.1201-1210
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• 2018

The applications of thermoelectric generators (TEGs) have received a lot of attention both in terms of harvesting waste thermal energy and the need for multi-levels of power. It is critical to track the optimum electrical operating point using DC to DC converters controlled by a pulse that is generated through a maximum power point tracking algorithm (MPPT). In this paper, the hardware implementation of a short-current pulse algorithm has been demonstrated under steady stated and transient conditions. In addition, the MPPT algorithm has been proposed, which is one of the most effective and applicable algorithms for obtaining the maximum power point of TEGs. During this study, the proposed prototype has been validated both analytically and experimentally. It has also demonstrated successful performance, which highlights the claimed advantages of the proposed MPPT solution.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.105-108
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• 2004

In this paper, the simple analog MPPT (Maximum Power Point Tracking) algorithm is proposed for the solar array of KOMPSAT (Korea Multi-Purpose Satellite). This method doesn't need any calculation of power by multiplication of voltage and current and a measurement of the solar array temperature. It is consist of only two sample and hold circuits, two comparators, a flip-flop, and an integrator. The proposed MPPT algorithm is verified by the simulation for the 100[W] solar array.