• 한국수소및신에너지학회논문집
• /
• 제29권2호
• /
• pp.197-204
• /
• 2018

In the present study, unsteady flow analysis has been conducted to investigate the blade forces and wake flow around a hybrid street-lamp having a vertical-axis small wind turbine and a photovoltaic panel. Uniform velocities of 3, 5 and 7 m/s are applied as inlet boundary condition. Relatively large vortex shedding is formed at the wake region of the photovoltaic panel, which affects the increase of blade torque and wake flow downstream of the wind turbine. It is found that blade force has a good relation to the variation of the angle of attack with the rotation of turbine blades. Variations in the torque on the turbine blade over time create a cyclic fluctuation, which can be a source of turbine vibration and noise. Unsteady fluctuation of blade forces is also analyzed to understand the nature of the vibration of a small wind turbine over time. The detailed flow field inside the turbine blades is analyzed and discussed.

• Advances in Energy Research
• /
• 제5권2호
• /
• pp.129-145
• /
• 2017

In this study, the use of a micro gas turbine system using biogas to supply heating, cooling and electricity loads of a rural building located in rural area around Tehran has been studied. Initially, the amount of energy needed by the farmhouse was calculated and then the number of needed microturbines was determined. Accordingly, the amount of substances entering biogas digester as well as tank volume were determined. The results of this study showed that village house loads including electrical, heating and cooling and hot water loads can be supplied by using a microturbine with a nominal power of 30 kW and $33.5m^3/day$ of biogas. Digester tank and reservoir tank volumes are $67m^3$ and $31.2m^3$, respectively. The cost of electricity produced by this system is 0.446 US$/kWh. For rural area in Iran, this system is not compatible with micro gas turbine and IC engine system use urban natural gas due to low price of natural gas in Iran, but it can be compatible by wind turbine, photovoltaic and hybrid system (wind turbine& photovoltaic) systems.

• Journal of Electrical Engineering and Technology
• /
• 제9권3호
• /
• pp.1112-1118
• /
• 2014

In island and backcountry areas, electrical power is usually supplied by diesel generators. It is difficult for small scale diesel generators to have an economy of scale owing to the usage of fossil fuels to produce electricity. Also, there is a problem of carbon dioxide emissions that brings some environmental pollution to the entire region of the area. For solving those, this paper proposes a design method of autonomous micro-grid to minimize the fossil fuels of diesel generator, which is composed of diesel generator, wind turbine, battery energy storage system and photovoltaic generation system. The proposed method was verified through computer simulation and micro-grid operation system.

• 조명전기설비학회논문지
• /
• 제27권11호
• /
• pp.57-68
• /
• 2013

The market for distributed power generation based on renewable energy is increasing, particularly for standalone mini-grid applications in developing countries with limited energy resources. Stand-alone power systems (SAPS) are of special interest combined with renewable energy design in areas not connected to the electric grid. Traditionally, such systems have been powered by diesel engine generator sets (DEGS), but also hybrid systems with photovoltaic and/or wind energy conversion systems (WECS) are becoming quite common nowadays. Hybrid energy systems can now be used to generate energy consumed in remote areas and stand-alone microgrids. This paper describes the design, simulation and feasibility study of a hybrid energy system for a stand-alone power system. A simulated model is developed to investigate the design and performance of stand-alone hydrogen renewable energy systems. The analysis presented here is based on transient system simulation program (TRNSYS) with realistic ventilation load of a large store. Design of a hybrid energy system is site specific and depends on the resources available and the load demand.

• 한국수소및신에너지학회논문집
• /
• 제29권6호
• /
• pp.606-619
• /
• 2018

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.666-668
• /
• 2005

Recently the study on the new and renewable energy is being addressed and the application examples about it are also increasing as greatly as possible. In this paper, the battery charge controller of street lamp power using wind and solar energy is made and tested.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.534-538
• /
• 2001

Energy storage devices with high energy density as well as high power density are expected to be developed from the point of view of compensation of fluctuating load and generated power by distributed generations such as wind turbines, photovoltaic cells and so on. SMES (Superconducting Magnetic Energy Storage) has higher power density than other energy storage methods, and secondary batteries have higher energy density than SMES. The hybrid energy storage device using SMES and secondary batteries is proposed as the energy storage method with higher power and energy density, the sharing method of power reference value for each storage device, simulation and experimental results are presented.

• Korean Chemical Engineering Research
• /
• 제58권3호
• /
• pp.381-389
• /
• 2020

본 연구에서는 다양한 신재생 에너지원 기반 전력 공급 시스템 구축하고, 각 시스템의 최적 전력 공급 비용을 비교 분석 하였다. 특히, 풍력 및 태양광 등 대표적인 신재생에너지 생산 기술과 더불어 대형 에너지 저장 시스템 및 바이오매스 기반 전력 생산 기술을 포함함으로써, 신재생에너지 자원의 간헐성 및 에너지 공급과 수요의 불균형의 한계를 극복하였다. 본 연구에서 제안한 6가지의 신재생 에너지원 기반 전력 공급 시스템을 실제 제주도 전력 공급 문제에 적용함으로써, 제주도 지역의 최적 에너지 시스템을 규명하였으며, 다양한 에너지 생산 기술의 조합의 효과를 분석하였다. 분석 결과, 태양광 및 풍력 기반 전력 공급 단가는 각각 0.18, 0.28 $/kWh로 개별 자원 기반의 에너지 생산 시스템의 기존 전력망을 통한 공급 단가에 비해 경쟁력이 낮았다. 또한 자원의 간헐성 및 공급과 수요의 불균형 등 단일자원 기반의 단점을 효과적으로 개선하기 위하여 3가지 신재생 자원 및 대형 에너지 저장 시스템을 포함한 하이브리드 공급 시스템의 경제적 효과를 분석하였다. 그 결과 기존 전통적 전력망 공급과 가격 경쟁력을 갖는 0.08 $/kWh 수준의 100% 신재생에너지 기반 전력 공급 시스템 구축이 가능함을 규명하였다.

• Journal of Electrical Engineering and Technology
• /
• 제12권1호
• /
• pp.161-172
• /
• 2017

In the paper, a hybrid technique is proposed for detecting the location and capacity of distributed generation (DG) sources like wind and photovoltaic (PV) in power system. The novelty of the proposed method is the combined performance of both the Biography Based Optimization (BBO) and Particle Swarm Optimization (PSO) techniques. The mentioned techniques are the optimization techniques, which are used for optimizing the optimum location and capacity of the DG sources for radial distribution network. Initially, the Artificial Neural Network (ANN) is applied to obtain the available capacity of DG sources like wind and PV for 24 hours. The BBO algorithm requires radial distribution network voltage, real and power loss for determining the optimum location and capacity of the DG. Here, the BBO input parameters are classified into sub parameters and allowed as the PSO algorithm optimization process. The PSO synthesis the problem and develops the sub solution with the help of sub parameters. The BBO migration and mutation process is applied for the sub solution of PSO for identifying the optimum location and capacity of DG. For the analysis of the proposed method, the test case is considered. The IEEE standard bench mark 33 bus system is utilized for analyzing the effectiveness of the proposed method. Then the proposed technique is implemented in the MATLAB/simulink platform and the effectiveness is analyzed by comparing it with the BBO and PSO techniques. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.

• 한국산학기술학회논문지
• /
• 제16권5호
• /
• pp.3391-3398
• /
• 2015

현재 대부분의 도서지역에서는 태양광발전을 효율적으로 운용하기 위하여 대용량 연축전지가 많이 사용되고 있지만, 풍력발전의 도입, 축전지 교체로 인하여 리튬이온전지의 도입이 증가하고 있다. 따라서 본 논문에서는 기존에 많이 보급되어 사용되고 있는 연축전지와 리튬이온전지의 장점을 최대한 활용하기 위하여, 연축전지와 리튬이온전지용 하이브리드 BMS 알고리즘을 제시하였다. 즉, 각 전지의 충전상태(state of charge, SOC)를 평가하는 알고리즘과 각 전지의 도입비용과 운용비용에 따른 최적 구성비를 산출하는 하이브리드 운용 알고리즘을 제안하였다. 상기의 알고리즘을 이용하여 다양한 시뮬레이션을 수행한 결과, 기존의 충전상태 평가 방법보다 오차율이 개선되어 정확한 충전상태에 대한 결과가 산출되었고, 각 전지의 도입비용과 운용비용이 최소화되는 조건에서 최적구성비를 구하여, 본 논문에서 제안한 하이브리드 BMS 알고리즘의 유용성을 확인하였다.