• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.246-252
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• 2012

Recently, concern over climate change and global politics associated with traditional fossil fuel energy sources has driven significant increase in wind energy utilization over the past decade around world. Generally, life-time of wind turbine system should be guaranteed for twenty years. Therefore, performance deterioration of wind turbine system occurs owing to aging effects for long term operation. In this work, a new type of auto tuning algorithm for overcoming the problem of performance deterioration is proposed. Furthermore, various simulations are carried out to verify the feasibility of the proposed scheme.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.43-52
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• 2015

The performance of a photovoltaic array is affected by temperature, solar insolation, partial shading effect, and array configuration. Maximum power point tracking(MPPT) techniques are employed in photovoltaic systems to make full utilization of the PV array output power which depends on solar irradiation and ambient temperature. As much as MPPT is important in photovoltaic systems, many MPPT techniques have been developed. In this paper, several major existing MPPT methods are comparatively analyzed and novel hybrid MPPT algorithm is proposed. The proposed hybrid MPPT algorithm is developed in combination with traditional MPPT methods to complement each other for improving performance and mitigating partial shading effects. The proposed algorithm is implemented and validated using MATLAB/Simulink simulation tool.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.153-156
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• 2001

Maximum Power Point Tracking(MPPT) Is used in wind power generation systems to maximize wind power turbin output power, irrespective of wind speed conditions and of the load electrical characteristics. In this paper we do the equivalent modeling the mechanical energy of wind power turbine according to wind speed into the synchronous generator. We analyse the equivalent modeling output part of rectifier into DC/DC converter input part theoretically. We design a control algorithm for variable voltage according to wind speed intensity and density so that load voltage of chopper is controlled steadily using the maximum power point tracking(MPPT) control method. We analyse a battery charging characteristics and a charging circuit for power storage enabling the supply of stable power to the load. We design a system and do the modeling of it analytically so that it supplies a stable power to the load by constructing a DC-AC inverter point. Also we design a charging circuit usable in actual wind power generation system of 30kW and confirm its validity.

• New & Renewable Energy
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• v.8 no.3
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• pp.14-22
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• 2012

Performance of photovoltaic (PV) generator systems relies on its operating conditions. Maximum power extracted from PV generators depends strongly on solar irradiation, load impedance, and ambient temperature. A most maximum power point tracking (MPPT) algorithm is based on a perturb and observe method and an incremental conductance method. It is well known the latter is better in terms of dynamics and tracking characteristics under condition of rapidly changing solar irradiation. However, in case of digital implementation, the latter has some error for determining a maximum power point. This paper presents a PID based MPPT algorithm for such PV systems. We use neural network technique for determining PID parameters by online learning approach. And we construct a boost converter to regulate the output voltage from PV generator system. Computer simulation is carried out to evaluate the proposed MPPT method and we accomplish comparative study with a perturb and observe based MPPT method to prove its superiority.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.1
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• pp.23-29
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• 2018

A stand-alone Photovoltaic (PV) system is one of the most important energy system for Mongolian nomadic herders. Basically, a stand-alone PV system uses two DC-DC converters. This makes the system costly, size bigger and difficult to move from one place to another place for the nomadic herders. A combined control algorithm for charging the battery using Stage of Charge (SOC) and Maximum Power Point Tracking (MPPT) is proposed in this paper. The batteries are charged by the three stage method; bulk, absorption and float charge. In the bulk stage used the MPPT function in this study. The performance of the proposed control algorithm is evaluated in both steady and changing weather conditions. The results are obtained using PSIM software. The results obtained in this paper are useful in designing a stand-alone PV system in the rural life like Mongolian nomadic herders.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.123-129
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• 2014

Photovoltaic and fuel cell systems can be used as power source in mobile robots. At this time the photovoltaic system generally generate power in daytime. The starting time of fuel cell is slower than the lithium battery. To compensate for these disadvantages, a battery charge-discharge system is used. Especially the bi-directional converter is used mainly in the charge-discharge method. The controller in a buck converter controls the input voltage of the converter to meet the maximum power point tracking(MPPT) performance. First of all, the simulations of hybrid system for battery charge-discharge system in each step simulated using solar and fuel cell modeling as input source in PSIM. Experiment of the buck and bi-directional converter system is conducted through using photovoltaic/fuel cel simulator(pCube) instead of solar and fuel cell. This hybrid system for battery charge discharge using photovoltaic/fuel cell generates emergency power for the communication system in mobile robot.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.55-61
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• 2011

The small-sized wind turbine generating system with the output power less than 10kW, which can be installed in some areas of hills, parks, and cities due to its flexibility, is one of the progressive research and development fields in renewable energy. It is important for the small wind turbine generators to have low cost, high reliability as well as high efficiency. To meet these requirements, development of various maximum-power-point-tracking (MPPT) control schemes should be required. Generally, the output of the controller can be connected to a 48V battery to supply power to a DC load. In this work, the design and implementation of an FPGA-based MPPT controller for small-sized wind turbine generating system is presented. For the verification of the practical performance of various MPPT algorithms, CRIO controller from NI has been used.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.69-75
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• 2013

To increase the efficiency of the photovoltaic, almost photovoltaic appliances are controlled by Maximum Power Point Tracking(MPPT). Existing most of the PV MPPT techniques have used power which multiplies sensed output current and voltage of the solar cell. However, these algorithms are unnecessarily complicated and too expensive for small and compact system. The other hand, the proposed MPPT technique is only one sensing of the MPPT converter's output current, so there is no need to insert another sensors of battery side. Therefore, this algorithm is simpler compared to the traditional approach and is suitable for low power solar system. Further, the novel proper charge/discharge algorithm for the battery with PV MPPT is developed. In this algorithm, there is CC battery charge mode and load discharge mode of the PV cell & battery dual. Also we design current control to regulate allowable current during the battery charging. The proposed algorithm will be applicable to battery included solar cell applications like solar lantern and solar remote control car. Finally, the proposed method has been verified with computer simulation.