• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.1
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• pp.56-61
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• 2019

In this study, a reduction method of leakage current in a three-level photovoltaic power-conditioning system (PCS) is proposed and verified by simulation and experiment. Leakage current generation is analyzed through an equivalent model of the common mode voltage considering a significant parasitic capacitance existing between the photovoltaic array and ground. A leakage current reduction method using pulse-width modulation (PWM) method is also proposed, and a 10-kW three-level photovoltaic PCS simulation and experiment is performed with a $1{\mu}F$ parasitic capacitor based on 100 nF/kW. The proposed method using the PWM method is verified to reduce the leakage current by 73% compared with the conventional PWM method.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.617-621
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• 2001

This paper presents a maximum power point tracking algorithm for Photovoltaic array using only instantaneous output current information. The conventional Hill climbing method of peak power tracking has a disadvantage of oscillations about the maximum power point. To overcome this problem, we have developed a algorithm, that will estimate the duty ratio corresponding to maximum power operation of solar cell. The estimation of the optimal duty ratio involves, finding the duty ratio at which integral value of output current is maximum. For the estimation, we have used the well know Lagrange's interpolation method. This method can track maximum power point quickly even for changing solar insolations and avoids oscillations after reaching the maximum power point.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.687-691
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• 2001

With today's global environmental and energy problems, high expectations exist for solar power generation to reduce carbon dioxide generated by the consumption of fossil fuels. On the other hand, power consumption in residential homes is increasing every year. Among the many household appliances, the power demand for air conditioners increases dramatically during the summer, particularly in the afternoons. As this pattern closely matches the output pattern of solar cells, it should be possible to combine a photovoltaic array with an air conditioner to decrease the energy consumption within the home. We have developed a residential solar-powered air conditioner that operates through a combination of photovoltaic array and commercial power. In this paper, the configuration and specification of the residential solar-powered system are described to a novel high efficiency inverter using a ZVCS boost converter. And the performance evaluations of the solar-powered air conditioner are examined by the analysis of a new tracking controller with a maximum power $P_{max}$ detection of solar cell.

• Journal of Power Electronics
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• v.2 no.3
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• pp.155-161
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• 2002

This paper presents a maximum power point tracking algorithm for Photovoltaic array using only instantaneous output current information. The conventional Hill climbing method of peak power tracking has a disadvantage of oscillations about the maximum power point. To overcome this problem, we have developed an algorithm that will estimate the duty ratio corresponding to maximum power operation of solar cell. The estimation of the optimal duty ratio involves, finding the duty ratio at which integral value of output current is maximum. For the estimation, we have used the well know Lagrange's interpolation method. This method can track maximum power point quickly even for changing solar isolation and avoids oscillations after reaching the maximum power point.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.304-308
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• 2002

This paper studies stand-alone photovoltaic array for solar lighting lamp. The solar lighting lamp has PV modules, batteries. and charge & discharge system. The charge efficiency is improved for the control of each battery which is divided the charge from the discharge to change the structure of existing solar lighting lamp charge & discharge system. so, the charge and discharge times are reduced of 50%. and the depth of discharge control can be controlled in the discharge cut off voltage. This can be effective of battery use. If a battery is out of order, this system can be executed for a regular period. so we saved the repair cost and developed of system's stabilization. It is possible economical effect to apply for solar lighting lamp used photovoltaic array.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.207-212
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• 2002

As is well-known, the maximum power point(MPP) of PV power generation system depends on array temperature and solar insolation, it is necessary to track MPP of solar array all the time. Among various MPP control algorithms, the constant voltage control method, the perturbation and observation(P&O) method and the incremental conductance method(IncCond) have drawn many attractions due to the usefulness of each system. In this paper, the effectiveness of above mentioned three different control algorithms are thoroughly investigated via simulations and proposed efficiency evaluation method on experiment. Both the steady-state and transient characteristics of each control algorithms along with measured efficiency are analyzed, respectively. Finally, a novel MPPT control algorithm combining the constant voltage control and IncCond method for low insolation condition is proposed to improve efficiency of the 3KW PV power generation system.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1171-1173
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• 2000

This paper was analyzed the high-frequency harmonics, power conversion rate, results of the system's monitor, and measuring data of the system power output of a 3-phase photovoltaic power system for grid-connection. The photovoltaic power system consists of a 3-phase inverter array, and data acquisition system. The result of an analyzing data of the 50 kW class grid-connected photovoltaic system showed the stable behavior in utility-interactive operation.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.961-964
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• 2003

Recently, because of the depletion of fossil fuels and the environmental pollution by using fossil fuels and atomic power generation, the interests concerning of new and renewable energy resources are rising rapidly. In this study, the 3kWP photovoltaic power generation system is realized to verify the performance of the PCS developed. The photovoltaic array used in this system is composed of 60 modules of 50Wp capacity. The developed system is tested and the experimental results show the excellent electrical characteristics.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.255-258
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• 2003

Photovoltaic(PV) array, which is generally installed outside, has the possibility to be damaged by high voltage due to lightning. Because the electrical characteristics of PV array have not been fully identified by lightning yet, there is a very important issue whether PV array should be connected with ground or not. In this paper, a basic model of PV array is provided considering the PV cell's barrier capacitance and ground capacitance for analysis of electrical characteristics by lightning using PSCAD/EMTDC.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.208-211
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• 2004

Photovoltaic(PV) array, which is generally installed outside, has the possibility to be damaged by high voltage due to lightning. Because the electrical characteristics of PV array have not been fully identified by lightning yet, there is a very important issue whether PV array should be connected with ground or not. In this paper, a basic model of PV array is provided considering the PV cell's barrier capacitance and ground capacitance for analysis of electrical characteristics by lightning using PSCAD/EMTDC.