• New & Renewable Energy
• /
• v.4 no.1
• /
• pp.37-43
• /
• 2008

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This paper describes the results for the mechanical and environmental tests of pretreatment system material. Mechanical Characteristics make differences between parent / weldment, Notch existence / non-existence and air/$H_2O$ conditions. As a result, the life of pipe lines needs to maintain and fit for the operating period. Based on actual situations, the tension test of pipe welding-parts is carried out varying the exposure time of hydrogen sulfide and the fatigue resistance test is also performed inserting a notch into the pipe welding part, being exposed to the hydrogen sulfide environment for 720 hours.

• Proceedings of the KIPE Conference
• /
• 2012.11a
• /
• pp.135-136
• /
• 2012

Renewable energy is getting more important due to its alternative usage of fossil fuel. This paper discusses the system using Peak-cut alagorithm of solar power which takes great proportion in renewable energy. It also proves the validity of this system by simulation and experiment.

• New & Renewable Energy
• /
• v.4 no.4
• /
• pp.3-9
• /
• 2008

In design PV (photovoltaic) system, there are many important factors to consider for best site selection. It is essential to understand to know the amount of sunlight available and how to minimize the shadings. This study presents basic concepts for understanding sun's position and insolation. also it gives easy tools for topography analysis. Finally, this study shows some theoretical calculations of power generation losses by topographic obstacle's elevations and disadvantages in economic feasibility, that is about 7million won loss per year for case of 10 degree topography elevation with assuming average Korea's topography elevation as 5 degree.

• Journal of the Korean Society of Industry Convergence
• /
• v.13 no.3
• /
• pp.145-151
• /
• 2010

This study is for getting basic data through grasping the obtained heat by structure of each unit and the effects of environment improvement based on judgement for whether or not a solar heating system of renewable energy installations is possible to set up in village hall public buildings as community center and senior citizen center. Conducting a survey of community center and senior citizen center in Ibam-Myon, Yeongyang-Gun, Gyeongsangbuk-Do and the analysis, obtained solar heat of 414,309,678 kcal every year and from this, effects of 131.48995 $TCO_2$. These figure equate to 26,298 pines effect. These results show that the advantage of reducing building operating costs in the long run besides effects of environment improvement.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.6
• /
• pp.433-439
• /
• 2018

This study considers the design of a submodule test circuit for the modular multi-level converter (MMC)-based HVDC systems. A novel submodule test circuit is proposed to provide not only an AC but also a DC component to the submodule current. However, the current waveforms depend on the capacitor voltages. Therefore, determining the capacitance value of the test circuit is important. Finding a proper capacitance value is easy when the proposed analysis method is used. Simulation and experimental results show the usefulness of the proposed method.

• KEPCO Journal on Electric Power and Energy
• /
• v.8 no.1
• /
• pp.21-29
• /
• 2022

Power generated from renewable energy has continuously increased recently. As the distributed generation begins to interconnect in the distribution system, an accurate generation forecasting has become important in efficient distribution planning. This paper explained method and current state of distributed power generation forecasting models. This paper presented selecting input and output variables for the forecasting model. In addition, this paper analyzed input variables and forecasting models that can use as mid-to long-term distributed power generation forecasting.

• Journal of Power Electronics
• /
• v.11 no.3
• /
• pp.360-368
• /
• 2011

This paper proposes an active frequency with a positive feedback in the d-q frame anti-islanding method suitable for a robust phase-locked loop (PLL) algorithm using the FFT concept. In general, PLL algorithms for grid-connected PV PCS use d-q transformation and controllers to make zero an imaginary part of the transformed voltage vector. In a real grid system, the grid voltage is not ideal. It may be unbalanced, noisy and have many harmonics. For these reasons, the d-q transformed components do not have a pure DC component. The controller tuning of a PLL algorithm is difficult. The proposed PLL algorithm using the FFT concept can use the strong noise cancelation characteristics of a FFT algorithm without a PI controller. Therefore, the proposed PLL algorithm has no gain-tuning of a PI controller, and it is hardly influenced by voltage drops, phase step changes and harmonics. Islanding prediction is a necessary feature of inverter-based photovoltaic (PV) systems in order to meet the stringent standard requirements for interconnection with an electrical grid. Both passive and active anti-islanding methods exist. Typically, active methods modify a given parameter, which also affects the shape and quality of the grid injected current. In this paper, the active anti-islanding algorithm for a grid-connected PV PCS uses positive feedback control in the d-q frame. The proposed PLL and anti-islanding algorithm are implemented for a 250kW PV PCS. This system has four DC/DC converters each with a 25kW power rating. This is only one-third of the total system power. The experimental results show that the proposed PLL, anti-islanding method and topology demonstrate good performance in a 250kW PV PCS.

• New & Renewable Energy
• /
• v.10 no.3
• /
• pp.47-54
• /
• 2014

Recently, BESS is considered as one of essential countermeasure for demand side management. However, an economic evaluation is critical issue for the introduction of power system because the cost of BESS is very high in present stage. Therefor, this paper presents economic evaluation method for customer use case by considering peak shaving function based on the real time price. From the case study on the model power system and educational customer, it is confirmed that the proposed method is a practical tool for the economic analysis of BESS. and analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP (Non-Delivery Power) and NDE (Non-Delivery Energy). The indexes can only consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, this paper presents the new performance indexes for the investment of the distribution facilities considering both the expected interruption cost for the load section and the operation characteristics of Energy Storage System. The results from a case study show that the proposed methods can be a practical tool for the reliability management in distribution systems including Energy Storage System.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.1
• /
• pp.155-160
• /
• 2019

In this paper, we propose an efficient grid-independent ESS control system through the control of renewable energy and agricultural ICT by utilizing the prediction of energy production and consumption. The proposed system is an integrated management system that can perform maintenance and monitoring by visualizing the accurate phase and data of power system. It can automatically cope, collect, process, and control the data. Also, it can analyze the power generation of solar power generation, consumption pattern of installed facilities, and operation trend of facilities. Further, it can predict the consumption of energy production and present the optimal energy management method by using the OpenAPI of the Korea Meteorological Administration, thereby reducing unnecessary energy consumption and operating cost.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.1165-1166
• /
• 2006

This paper presents performance monitoring results of large scale photovoltaic (PV) system supported by general dissemination & regional energy program in korea government polices for new and renewable energy resources. 80kW PV system and monitoring system is constructed and monitored PV system performance to observe the overall effect of environmental conditions on their operation characteristics. The PV system performance has been evaluated and analyzed for component perspective (PV array and power conditioning unit) and global perspective (system efficiency, capacity factor, and electrical power energy and power quality etc.) for six month monitoring periods.