• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.4
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.916-923
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• 2014

This paper proposes a low-cost switched-mode rectifier (SMR) for a small-scale wind turbine with a permanent magnet synchronous generator (PMSG) system. Also, a sensorless Fuzzy MPPT control is realized by the proposed system. In the PMSG system with the SMR, the synchronous impedance can be replaced as the input inductor of a boost converter. Moreover, the sensorless MPPT control using the Fuzzy technique is carried out by the duty-ratio regulation of the SMR. The relation between the generating power and the duty-ratio is ruled by the chain rule. The wind turbine model is implemented by the squirrel cage induction motor and generated the variable torque when the generator speed is varied. To verify the performance of the proposed system, simulation and experimental results are executed.

• Journal of Power Electronics
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• v.15 no.1
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• pp.54-64
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• 2015

This paper presents a current sensorless maximum power point tracking (MPPT) control method for dual-mode photovoltaic (PV) module-type interleaved flyback inverters (ILFIs). This system, called the MIC (Module Integrated Converter), has been recently studied in small PV power generation systems. Because the MIC is an inverter connected to one or two PV arrays, the power system is not affected by problems with other inverters. However, since the each PV array requires an inverter, there is a disadvantage that the initial installation cost is increased. To overcome this disadvantage, this paper uses a flyback inverter topology. A flyback inverter topology has an advantage in terms of cost because it uses fewer parts than the other transformer inverter topologies. The MPPT control method is essential in PV power generation systems. For the MPPT control method, expensive dc voltage and current sensors are used in the MIC system. In this paper, a MPPT control method without current sensor where the input current is calculated by a simple equation is proposed. This paper also deals with dual-mode control. Simulations and experiments are carried out to verify the performance and effectiveness of the proposed current sensorless MPPT control method on a 110 [W] prototype.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.107-108
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• 2014

본 논문에서는 디커플링 회로가 포함된 PV-AC 모듈형 플라이백 인버터의 전류 센서리스(Sensorless) MPPT(Maximum power point tracking) 제어기법을 제안한다. 기존의 MPPT제어는 각 모듈의 입력단에 존재하는 전압과 전류 센서를 이용하여 최대 전력점을 추종하였다. 본 논문에서는 전력 변환장치의 저 가격화를 위해 MPPT 제어에 요구되는 전류 센서를 사용하지 않는 센서리스 MPPT 기법을 제안한다. 제안한 기법은 시뮬레이션과 실험을 통해 검증하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.484-493
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• 2011

The MPPT algorithm using neuro-fuzzy controller is proposed to improve the performance of fuzzy controller in this paper. The width of membership function and fuzzy rule have an effect on the performance of fuzzy controller. The neuro-fuzzy controller has the response characteristic which is superior to the existing fuzzy controller, because of using the optimal width of the fuzzy membership function through the neural learning. The superior control characteristic of a proposed algorithm is confirmed through simulation and experiment results.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.49-50
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• 2012

Maximum power point tracking(MPPT) algorithm is needed in PV AC module power conditioning system because of the nonlinear current-voltage characteristics. Conventional MPPT algorithm is required to know PV-module output current and voltage. Thus, PV-AC module must have voltage and current sensor. In this paper, a current-sensorless MPPT algorithm, which uses only the voltage sensor, is presented for Flyback inverter.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1293-1302
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• 2014

A flyback inverter using voltage sensorless maximum power point tracking (MPPT) for photovoltaic (PV) AC modules is presented. PV AC modules for a power rating from 150 W to 300 W are generally required for their small size and low price because of the installation on the back side of PV modules. In the conventional MPPT technique for PV AC modules, sensors for detecting PV voltage and PV current are required to calculate the PV output power. However, system size and cost increase when the voltage sensor and current sensor are used because of the addition of the auxiliary circuit for the sensors. The proposed method uses only the current sensor to track the MPP point. Therefore, the proposed control method overcomes drawbacks of the conventional control method. Theoretical analysis, simulation, and experiment are performed to verify the proposed control method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1688-1693
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• 2013

A small-scale wind power generation system with a switched-mode rectifier(SMR) is proposed. To simplify the converter circuit of the wind power generation system, the synchronous inductors of the permanent magnet synchronous generator(PMSG) replace the inductor for the boost converter. The sensorless maximum power point tracking(MPPT) control is carried out for the wind power generation system with the SMR. The proposed system is verified through the simulations and the experiments.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1081-1082
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• 2008

Photovoltaic (PV) power generation system has been widely studied as a clean and renewable power source. The purpose of this study is to keep the output power of photovoltaic cells maximum under any weather conditions. There are so many MPPT (Maximum Power Point Tracking) methods. P&O method has been used as a key MPPT method, both voltage and current coming out from PV array have to be feedback in the method. Thus, the system has a complex structure, and may fail to track MPP of PV array when unexpected weather conditions happen. In order to reduce the feedback components, POS MPPT control method was proposed by the authors. In this paper, the authors apply the POS MPPT control method to three phase PCS system. And the effectiveness of the proposed control scheme is demonstrated through PSCAD/EMTDC simulation.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.259-260
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• 2011

본 논문은 벅-부스트 컨버터의 듀티비 제어를 통해 풍력발전시스템이 최대 효율을 갖도록 MPPT (Maximum power point tracking) 알고리즘을 구현하고, 발전된 전력을 계통으로 전달하기 위한 인버터 제어방법 및 시스템 구성을 제안한다. 특히 풍속정보와 발전기 속도를 제거하여 센서로 인한 단점들을 배제하였고, 제안한 풍력발전시스템과 알고리즘의 유용성을 시뮬레이션을 통해 검증한다.