• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.136-137
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• 2017

Maximum power point tracking (MPPT) under partial shading condition (PSC) is a challenging process in the PV array system. The shaded PV panel makes different peak patterns on the P-V curve and misguides the MPPT algorithm. Various kinds of global MPP (GMPP) detecting algorithms are used to overcome this issue. Generally, too frequent execution of GMPP tracking algorithm reduces the achievable power of PV panel due to time spent on the scanning process. Thus, partial shading detection algorithm is essential for efficient utilization of solar energy source. While conventional method only detects fast shading patterns, the proposed algorithm always shows superb performance regardless of the speed of partial shading patterns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.20-26
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• 2013

This paper proposes the maximum power point tracking(MPPT) control of photovoltaic system using fuzzy based variable step size perturbation & observation(FVSS-PO) method. Conventional PO and incremental conductance(IC)MPPT control algorithm generally uses fixed step size. A small fixed step size will cause the tracking speed to decrease and tracking accuracy of the MPP will decrease due to large fixed step size. Therefore, the fixed step size can't be satisfying both the tracking speed and the tracking accuracy. This paper proposes FVSS-PO MPPT algorithm that adjusts automatically step size of PO by fuzzy control according to operating conditions. The validity of MPPT algorithm proposed in this paper prove through compare with conventional PO MPPT algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.8-13
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• 2007

During the last years, there has been an increased interest in the new energy such as photovoltaic(PV) system from the viewpoint of environmental pollution. In this regard, this paper estimates the power quality of grid-connected PV system. As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling that contains incremental conductance MPPT controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(TDD) and total demand distortion(TDD). For the case study, the measured data of the PV way in Cheongwadae, Seoul, Korea is used.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.5
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• pp.67-73
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• 2013

The conversion of solar radiation into electrical energy by Photo-Voltaic (PV) effect is a very promising technology, being clean, silent and reliable, with very small maintenance costs and small ecological impact. The output power produced by the PV panels depends strongly on the incident light radiation. The continuous modification of the sun-earth relative position determines a continuously changing of incident radiation on a fixed PV panel. The point of maximum received energy is reached when the direction of solar radiation is perpendicular on the panel surface. Thus an increase of the output energy of a given PV panel can be obtained by mounting the panel on a solar tracking device that follows the sun trajectory. Tracking systems that have two axes and follow the sun closely at all times during the day are currently the most popular. This paper presents research conducted into the performance of Solar tracking system with photosensors. The results show that an optimized dual-axis tracking system with photosensor performance and analysis. From the obtained results, it is seen that the sun tracking system improves the energy and energy efficiency of the PV panel.ti-junction CPV module promises to accelerate growth in photovoltaic power generation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2627-2635
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• 2013

In this paper micro-scale solar energy harvesting system with a new MPPT control are proposed. In conventional solar energy harvesting systems, continuous perturbation techniques of the clock frequency or duty cycle of a power converter have been used to implement MPPT(Maximum Power Point Tracking) control. In this paper, we propose a new MPPT technique to control the duty cycle of a power switch powering a power converter. The proposed circuit is designed in $0.35{\mu}m$ CMOS process, and the designed chip area including pads is $770{\mu}m{\times}800{\mu}m$.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1865-1874
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• 2011

This paper proposes a novel maximum power point tracking(MPPT) using a new fuzzy control(NFC) algorithm for robust in insolation variation. Maximum power point(MPP) of solar cell has to achieve for improving output efficiency because it is changed with insolation and temperature. Conventional MPPT controller such as constant voltage(CV), perturbation and observation(PO) and incremental conductance(IC) are researched. But these controller have the problem that is failure to MPP with environment changing. The proposed NFC controller is based the fuzzy control algorithm and able to robust control with environment changing. Also the proposed controller of PV system is modeled by PSIM and the response characteristics according to the parameter variation is compared and analyzed. The validity of this controller is proved through response results.

• Journal of Power Electronics
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• v.17 no.1
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• pp.232-241
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• 2017

Advanced control algorithms must be used to make wind power generation truly cost effective and reliable. In this study, we develop a new and simple control scheme that employs model predictive control (MPC), which is used in permanent magnet synchronous generators and grid-connected inverters. The proposed control law is based on two points, namely, MPC-based torque-current control loop is used for the generator-side converter to reach the maximum power point of the wind turbine, and MPC-based direct power control loop is used for the grid-side converter to satisfy the grid code and help improve system stability. Moreover, a simple prediction scheme is developed for the direct-drive wind energy conversion system (WECS) to reduce the computation burden for real-time applications. A small-scale WECS laboratory prototype is built and evaluated to verify the validity of the developed control methods. Acceptable results are obtained from the real-time implementation of the proposed MPC methods for WECS.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.2
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• pp.143-150
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• 2003

An improved MPPT converter with current compensation method for small-scaled PV-applications is presented in this paper. The proposed method implements maximum power point tracking (MPPT) by variable reference current which is continuously changed during one sampling period. Therefore, the Power transferred to the load is increased above 9% by the proposed MPPT converter with current compensation method. As a result, the utilization efficiency of Photovoltaic (PV)-panel can be increased. In addition, as it doesn't use digital signal processor (DSP), this MPPT method has the merits of both a cost efficiency and a simple control circuit design. Therefore, it is considered that the proposed MPPT method is proper to low power, low cost PV-applications. The concept and control principles of the proposed Un moth()d are explained in detail and its validity of the proposed method is verified through several simulated results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.779-788
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• 2014

The satellite should generate electric power efficiently to perform the mission successfully within limited power. For this reason, the electrical power system of LEO satellites usually regulates the power which is generated from the solar cells using MPPT (Maximum Power Point Tracking) method. This paper proposes advanced MPPT algorithm based on the fuzzy logic applied to small CubeSat satellite. The simulation has been performed to confirm the validity of the proposed method by interlocking between MATLAB/Simulink and STK (Systems Tool Kit). The EBA(Energy Balance Analysis) has also been performed at two different pointing modes of KAUSAT-5 for solar irradiation according to the satellite orbit and attitude, and load capacity varied with operation modes by Simulink and STK. The performance of fuzzy logic-based MPPT algorithm was verified through the EBA. The validity of the proposed MPPT algorithm based on the fuzzy logic was also confirmed by comparing with P&O (Perturbation & Observation) algorithm that is general in the MPPT.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.105-113
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• 2013

In this paper a micro solar energy harvesting system with MPPT(Maximum Power Point Tracking) control using a miniature PV(photovoltaic) cell of which the output is less than 0.5V is proposed. The MPPT control is implemented using linear relationship between the open-circuit voltage of a PV cell and its MPP(Maximum Power Point) voltage such that a pilot PV cell can track the MPP of the main PV cell in real time. The proposed circuit is designed in 0.18um CMOS process. The designed chip area is $900um{\times}1370um$ including a load charge pump and pads. Measured results show that the designed system can track the MPP voltage changes with variations of light intensity. The designed circuit with MPPT control delivers MPP voltages to load even though the load is heavy such that it can supply more power when the MPPT control is applied. The proposed circuit does not require any precharged battery resulting in more suitability for miniaturized self-powered systems compared to the existing works.