• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1447-1453
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• 2014

This paper proposes the new method based on the availability of three points measurement and convexity of photovoltaic (PV) curve characteristic at the maximum power point (MPP). In general, the MPP tracking (MPPT) function is the important part of all PV systems due to their power-voltage (P-V) characteristics related with weather conditions. Then, the analog-to-digital converter (ADC) and low pass filter (LPF) are required to measure the voltage and current for MPPT by the digital controller, which is used to implement the PV power conditioning system (PCS). The measurement and quantization error due to rounding or truncation in ADC and the delay of LPF might degrade the reliability of MPPT. To overcome this limitation, the proposed method is proposed while improving the performances in both steady-state and dynamic responses based on the detailed investigation of its properties for availability and convexity. The performances of proposed method are evaluated with the several case studies by the PSCAD/EMTDC$^{(R)}$ simulation. Then, the experimental results are given to verify its feasibility in real-time.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.16-21
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• 2011

Since the maximum power operating point(MPOP) of PCS alters with changing atmospheric conditions temperature conditions shadow conditions it is important to operate for PCS to keep maximum power point tracking(MPPT) continuously. This paper presents the results of modeling PV system by PSIM simulator and investigates the influence on the PV system from aspect of power quality i.e. voltage drop. This paper investigates four MPPT algorithms; Perturbation & Observation(P&O) Improved P&O Incremental Conductance(Incond) Differential coefficient method simulated with irradiation temperature change and shadow conditions.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.4
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• pp.297-304
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• 2022

This study compares the performance of artificial intelligence (AI)-based maximum power point tracking (MPPT) methods under partial shading conditions in a photovoltaic generation system. Although many studies on AI-based MPPT have been conducted, few studies comparing the tracking performance of various AI-based global MPPT methods seem to exist in the literature. Therefore, this study compares four representative AI-based global MPPT methods including fuzzy logic control (FLC), particle swarm optimization (PSO), grey wolf optimization (GWO), and genetic algorithm (GA). Each method is theoretically analyzed in detail and compared through simulation studies with MATLAB/Simulink under the same conditions. Based on the results of performance comparison, PSO, GWO, and GA successfully tracked the global maximum power point. In particular, the tracking speed of GA was the fastest among the investigated methods under the given conditions.

• 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 IKEEE
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• v.24 no.2
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• pp.392-402
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• 2020

This paper proposes a solar tracking system without photo-sensors. The system can be classified into four modules: Solar Tracking, MPPT, ESS, and Real-Time Monitoring. Nine solar panels, as a basic unit, are adopted with grid structures of different heights to reduce wind influence and to enable solar tracking without photo-sensors. The low-cost MCU implements MPPT method which generates PWM switching signal for boost converter. The unit of ESS consists of three-series and four-parallel lithium-ion batteries in order to enable monitoring for abnormalities in temperature and electrical characteristics of battery. Four MCUs used in the system consists of two AVR Atmega128, and two Raspberry PI, and they exchanges operation informations. Experimental results of the proposed system show the solar tracking performance, the possibility of on-site and remote monitoring and the convenience of maintenance based on IoT technology.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.484-487
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• 2015

This paper describes a dual-input battery charger with MPPT control using photovoltaic and piezoelectric energy. Each energy is harvested from photovoltaic cells and piezoelectric cells and is stored to each capacitor. The battery voltage is boosted by charger block and two energy sources are used as input to charge battery capacitor. A DC-DC boost converter is designed to boost the battery voltage, and inductor sharing technique is employed such that only one inductor is required. The time division ratio for piezoelectric cell and photovoltaic cell is set to 8:1. The proposed circuit is designed in a 0.35um CMOS process technology. The condition of battery capacitor is managed by battery management block and the battery voltage can be boosted up to 3V. The maximum efficiency of the designed entire system is 88.56%, and the chip area including pads is $1230um{\times}1330um$.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.81-89
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• 2012

Commonly used horizontal-axis wind turbines (HAWT) have the following structure: two or three blades, a nacelle which contains power converting equipments, generators, and a tower which supports the nacelle. The generated power is transmitted from the nacelle to the ground. Due to this structure, the power transmission lines are twisted when the nacelle is yawing. Thus, slip ring or additional yaw control mechanism is required. We propose a new structure of HAWT which is free of this transmission line problem. Moreover, the size of inverter can be reduced since two generators are connected in parallel in our mechanism so that power is distributed. A controller for yawing is developed so that it works in harmony with the controller for power generation. A MPPT (Maximum Power Point tracking) algorithm is implemented for the proposed system and efficiency of the system is validated by simulation.

• Journal of Power Electronics
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• v.16 no.1
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• pp.9-17
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• 2016

Maximum power point tracking (MPPT) is necessary for photovoltaic (PV) power system application to extract the maximum possible power under changing irradiation and temperature conditions. The β-parameter-based method has many advantages over conventional MPPT methods; such advantages include fast tracking speed in the transient stage, small oscillations in the steady state, and moderate implementation complexity. However, a problem in the implementation of the conventional beta method is the choice of an appropriate scaling factor N, which greatly affects both the steady-state and transient performance. Therefore, this paper proposes a modified β-parameter-based method, and the determination of the N is discussed in detail. The study shows that the choice of the scaling factor N is determined by the changes of the value of β during changes in irradiation or temperature. The proposed method can respond accurately and quickly during changes in irradiation or temperature. To verify the proposed method, a photovoltaic power system with MPPT function was built in Matlab/Simulink, and an experimental prototype was constructed with a solar array emulator and dSPACE. Simulation and experimental results are illustrated to show the advantages of the improved β-parameter-based method with the optimized scaling factor.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.291-298
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• 2020

This study proposed a model that can track MPP faster than the existing MPPT algorithm using the particle swarm optimization algorithm (PSO). The proposed model highly sets the acceleration constants of gbest and pbest in the PSO algorithm to quickly track the MPP point and eliminates the power instability problem. In addition, this algorithm was re-executed by detecting the change in power of the solar panel according to the rapid change in solar radiation. As a result of the experiment, MPP time was 0.03 seconds and power was 131.65 for 691.5 W/m2, and MPP was tracked at higher power and speed than the existing P&O and INC algorithms. The proposed model can be applied when a change in the amount of power is detected by partial shading in a Photovoltaic power plant with Photovoltaic connected in parallel. In order to improve the MPPT algorithm, this study needs a comparative study on optimization algorithms such as moth flame optimization (MFO) and whale optimization algorithm (WOA).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.577-580
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• 2014

In this paper an auto-switching dual-input energy harvesting circuit is proposed. Since the maximum power points of a thermoelectric generator(TEG) output and a vibration device(PEG) output is 1/2 of their open-circuit voltage, an identical MPPT controller can be used for both energy sources. The proposed circuit monitors the outputs of the TEG and PEG, and chooses the energy source generating a higher output using an auto-switching controller, and then harvests the maximum power from the selected device using a MPPT controller. The harvested energy is boosted through a charge pump and stored in a storage capacitor. The stored energy is provided to a load through a PMU(Power Management Unit). The proposed circuit is designed in a $0.35{\mu}m$ CMOS process and its functionality has been verified through extensive simulations. The designed chip occupies $1.4mm{\times}1.2mm$ including pads.