• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.14-19
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• 2009

The 50 kWp grid connected photovoltaic system which was installed at KEPRI site in 1999 has been operated more than 10 years. In order to acquire long term operation characteristics of medium size photovoltaic system, the operation test data related on power generation electricity and capacity factor of 50 kWp system, which have been collected since 1999, were analysed. From the analysing results, 57.7 MWh in annual power generation electricity of 50 kWp photovoltaic system in 1999 has been decreased 49.1 MWh in 2005 and reached 41.9 MWh in 2008. In addition to, the capacity factor of 50 kWp photovoltaic system also showed 13.2 % in 1999, 11.2% in 2005 and finally reached 9.6% in 2008. The operation test data showed a trend of decreasing of generation electricity and capacity factor during the 10 years operation time and we guessed that was caused by solar cell performance degradation and decreasing of PCS system efficiency.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.563-569
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• 2002

This paper proposes an inverter for the grid-connected photovoltaic system based on the transformer-less inverter. This system consists of a high frequency DC-DC converter, high frequency transformer, diode bridge rectifiers, a DC filter, a low frequency inverter, and an AC filter. The 20kHz switched high frequency converter is used to generate bipolar PWM pulse, and the high frequency transformer transforms its voltage twice, which is subsequently rectified by diode bridge rectifiers for a full-wave rectified 60 Hz sine wave power output. Even though the high frequency link system needs more power semiconductors, a reduced size, light weight, and saved parts cost make this system more comparative than other power conditioning systems due to elimination of 60Hz transformer.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.21-26
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• 2019

This paper is purposed to develop hardware for controlling abnormal temperature that can occur environment and component itself in PCS. In order to be purpose, the hardware which is four part(sensing, PLC, monitoring and output) keep detecting temperature for critical components of PCS and can control the abnormal temperature. Apply to the hardware, it is selected to PV power generation facilities of 20 kW in Cheong-ju city and measured the data for one year in 2017. Through the temperature data, it is found critical components of four(discharge resistance, DC capacitor, IGBT, DSP board) and entered the setting value for operating the fan. The setting values for operating the fan are up to $130^{\circ}C$ in discharge resistance, $60^{\circ}C$ in DC capacitor, $55^{\circ}C$ in IGBT and DSP board. The hardware is installed at the same PCS(20 kW in Cheong-ju city) in 2018 and the power generation output is analyzed for the five days with the highest atmospheric temperature(Clear day) in July and August in 2017 and 2018 years. Therefore, the power generation output of the PV system with hardware increased up to 4 kWh.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.35-45
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• 2022

In this paper, we modeled the devices used easily in PV system circuits. In addition, for full operation of the photovoltaic system, a complete operation system for the DC-DC buck-boost converter and the MPPT control system was modeled and simulated to confirm good operation. we were constructed an actual system with the same conditions in the simulation and experimented. The purpose is to confirm the stable power supply through the load leveling by presenting the PCS considering ESS of photovoltaic power generation. we will do study to apply hybrid capacitors that have high energy density to the same size compared to the EDLC to DVR. As a result, we proposed a single-phase 3 kW grid-connected solar power converter.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.65.2-65.2
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• 2010

Currently the variety of governmental business support and research for supplying solar energy have been actively progressed. As of now, however, There are no practical testing infrastructures of grid-connected photovoltaic system which test performance of solar power facility in domestic. Therefore, in KEPRI, there is in progress construction of practical testing ground of 500 kW class grid-connected PV System for developing the evaluation of the performance technology including the Module, PCS, and etc, that is the important instrument of the PV System, in Gochang area. It analyzed the site creation work for constructing the practical testing ground and new construction of control room and the unit standards, specifications and capacity of required equipment. For the system detailed design, configuration, instrument-specific parameters established, power generation predictions of Array Type and the components of testing ground are needed to build.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.291-292
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• 2010

The main purpose of this study is to design and develop the grid connected 4kW photovoltatic PCS(Power Conditioning System) targeting for Japanese market. To make this task, the development of DC to DC converter, one phase inverter and EMI filters, and the research on connection between inverter and utility line are made. The developed 4kW PCS has fully carried out performance verifications and evaluation works and acquired the JET(Japan Electrical Safety & Environment Technology Laboratories) certification for safety and performance.

• Journal of the Korean Solar Energy Society
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• v.25 no.1
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• pp.27-34
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• 2005

This study aims to evaluate application of a heat recovery ventilator(HRV) using photovoltaic(PV) system. To this end, we analyzed performance of a PV system, which it was evaluated by monthly power wattage and conversion efficiency according to design capacity of a HRV. The results of this study can be summarized as follows. (1) A conversion efficiency of the PCS was evaluated about 86% in rated power. (2) A maximum, minimum and average output power were respectively analyzed 49.2W, 47.3W, and 48.8W. (3) Total power wattage of 200W PV system was 211kW and it was 316kW in case of 300W PV system. (4) Insufficient electrical power of a duct and window type ventilation system was respectively calculated 133.5kW and 147.7kW.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.193-200
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• 2016

Research and development of energy self-consumption introducing photovoltaic and energy storage system at home is very active. This system can manage the home energy in which it charges the electricity generated during the day and uses it during high electricity bills. However, it not yet made up the residential real-time pricing in Korea but it can reduce electricity usage to a certain target on the progressive. In order to introduce the home photovoltaic, it requires PCS(Power Conditioning System). This converts the direct current into alternating current by the electricity generated and used to perform charging and discharging of the energy storage system. The market for self-consumption smart home system is currently increasing because the interests of the general public about solar power, energy storage systems increased. The result of this study is installed on the room environment and the effect was analyzed on the assumption of real-time pricing.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.640-642
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• 2008

This paper presents the design, development and performance of a 250kW power conditioning system(PCS) for large scale photovoltaic power plant. The PV inverter consists of a three phase IGBT stack, L-C filter, transformer and HMI unit for monitoring. To verify the performance of the PV inverter a testing facility was designed and constructed to simulate the characteristics of the solar cell and grid.

• Journal of Power Electronics
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• v.10 no.3
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• pp.328-333
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• 2010

A photovoltaic power conditioning system (PV PCS) that contains single-phase dc/ac inverters tends to draw an ac ripple current at twice the output frequency. Such a ripple current perturbs the operating points of solar cells continuously and it may reduce the efficiency of the current based maximum power point tracking technique (CMPPT). In this paper, the ripple current generation in a dc link and boost inductor is analyzed using the ac equivalent circuit of a dc/dc boost converter. A new feed-forward ripple current compensation method to incorporate a current control loop into a dc/dc converter for ripple reduction is proposed. The proposed feed-forward compensation method is verified by simulation and experimental results. These results show a 41.8 % reduction in the peak-to peak ac ripple. In addition, the dc/ac inverter control system uses an automatic voltage regulation (AVR) function to mitigate the ac ripple voltage effect in the dc link. A 3kW PV PCS prototype has been built and its experimental results are given to verify the effectiveness of the proposed method.