• 전기학회논문지
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• 제67권9호
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• pp.1174-1180
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• 2018

In December 2017, the government announced plans to increase the current proportion of renewable energy from 7% to 20% by 2030 through a plan called the Renewable Energy 3020 Implementation Plan. Therefore, the demand for installation of photovoltaic(PV), wind turbine(WT) and battery energy storage system(BESS) is expected to increase. In particular, the system combined with energy storage system(ESS) is expected to take up a large portion since PV and WT can receive high renewable energy certificates(REC) weights when combined with ESS. In this study, we calculate the optimal capacity of the power conditioning system(PCS) and the BESS by comparing the economical efficiency and maximize the efficiency of the PV-BESS system in which the PV and the BESS are connected. By analyzing the system marginal price(SMP) and REC, it maximize profits through application of REC weight 5.0 and optimal charge-discharge scheduling according to the SMP changes.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.11-18
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• 2017

In order to maintain customer voltages within the allowable limit($220{\pm}13V$) as much as possible, tap operation strategy of SVR(Step Voltage Regulator) which is located in primary feeder, is widely used for voltage control in the utilities. However, SVR in nature has operation characteristic of the delay time ranging from 30 to 150 sec, and then the compensation of BESS (Battery Energy Storage System) during the delay time is being required because the customer voltages in distribution system may violate the allowable limit during the delay time of SVR. Furthermore, interconnection of PV(Photovoltaic) system could make a difficultly to keep customer voltage within the allowable limit. Therefore, this paper presents an optimal coordination operation algorithm between BESS and SVR based on a conventional LDC (Line Drop Compensation) method which is decided by stochastic approach. Through the modeling of SVR and BESS using the PSCAD/EMTDC, it is confirmed that customer voltages in distribution system can be maintained within the allowable limit.

• 에너지공학
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• 제26권4호
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• pp.107-117
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• 2017

2012년 Renewable Portfolio Standard(RPS) 제도가 시행된 이래, 태양광 및 풍력 등의 신재생 전원에 대한 대규모 투자가 이루어져 왔고, 최근에 정부는 배터리 에너지 저장시스템(Battery Energy Storage System, BESS)의 신재생설비 연계설치에 대한 정책을 도입하여 신재생설비가 전원으로서의 역할이 가능하게끔 유도하고 있다. 정책입안자 입장에서 변화하는 전력산업 환경을 수급관점에서 고려하기 위해서는 개별 정책효과 분석을 단순화하는 방법론을 필요로 한다. 이에 본 연구에서는 초기단계로 시작한 태양광발전 연계형 배터리시스템 정책 분석을 위해 국내 태양광 발전 실적을 바탕으로 태양광 발전량 분포를 일간이용률 지속곡선 형태로 제안하였고, 이를 바탕으로 최적 BESS 용량을 산출하는 방식을 통해 분석의 용이성을 향상시킬 수 있도록 하였다. 본 논문의 방식을 통해 System Marginal Price(SMP) 및 REC 변화에 따른 BESS의 적정용량 범위를 간단히 파악할 수 있으며, 신재생정책 입안자 입장에서 정책효과를 가늠할 수 있도록 하는 도구로 이용할 수 있다. 현행 연계형 BESS 지원정책은 투자유인 제공이 부분적으로 가능하나, 설치 시점의 SMP 및 REC 가격에 영향을 받게 된다는 한계가 있다. REC 가격 상승과 감소에 따라서 시기별 최적용량이 바뀌어 설치비율이 계속 달라질 수 있어 정책변화에 의해 기술의 적용이 달라지는 결과를 가져온다. 따라서, 향후 제도개선을 모색할 경우에는 연계형 BESS 가치평가시, 신재생전원과의 BESS의 발전량 분할로 인해 발생하는 정책지원에 대한 기술 의존성을 해결할 수 있는 방안을 고려하는 연구개발이 필요하다.

• 전기학회논문지
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• 제62권3호
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• pp.417-423
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• 2013

The load of electric railroad can generate voltage fluctuation in the electric railway system because of high speed of the electric railroad and frequent movement and stop. This voltage fluctuation of electric railway system can cause not only voltage imbalance but also harmonic in the utility grid. Therefore the electric railroad system is in need of the reactive power compensation, such as static synchronous compensator (STATCOM) and static var compensator (SVC). Especially, the battery energy storage system (BESS) can control the real and reactive power at the same time. In this paper, the electric railway system using BESS has been modeled to show its voltage compensation effect using Matlab/Simulink.

• 전기학회논문지
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• 제67권2호
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• pp.194-198
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• 2018

The government established the 8th national energy plan that electricity energy from renewables in 2030 will be 20%. The frequency stability problem is one of the key issues to overcome for accomplishing the energy plan. Frequency quality deteriorates due to short term variations of renewables output. Battery energy storage system(BESS) is considered as a good alternative to improve the frequency quality due to its quick response. In this paper, we examined the effectiveness of BESS against the conventional governor properties.

• 전기학회논문지
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• 제63권5호
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• pp.622-628
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• 2014

This paper presents the SOC-based control strategy of BESS(Battery Energy Storage System) for providing power system frequency regulation in the bulk power systems. As the life cycle of BESS would be shortened by frequent changes of charge and discharge required for frequency regulation in a steady state, the proposed algorithm operates BESS within a range of SOC where its life cycle can be maximized. However, during a transient period of which occurrence frequency is low, BESS would be controlled to use its full capacity in a wider range of SOC. In addition, each output of multiple BESS is proportionally determined by its SOC so that the balance in SOC of multiple BESS can be managed. The effectiveness of the proposed control strategy is verified through various case studies employing a test system. Moreover, the control result of BESS with the measured frequency from a real system shows SOC of BESS can be maintained within a specific range although the frequency deviation is biased.

• 전기학회논문지
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• 제67권9호
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• pp.1119-1124
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• 2018

So far BESS(Battery Energy storage system) has been widely applied to power systems rapidly. Usually it has been used to regulate the renewable energy output and to adjust the power system frequency. In 2013, EPRI has reported a study of utilizing BESS to replace two black start generators of American Electric Power(AEP) that will be demolished. If the BESS can be used as a self-starting generator, it is possible to shorten the long-distance primary transmission line and shorten the restoration time because BESS is capable of the high-speed start and there is no restriction on the installation position. This paper presents a possibility of using BESS as a self-starting generator by using PSCAD/EMTDC in Korean power systems. Herein, the process to estimated the required capacity of BESS is also presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.610-612
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• 1995

This paper presents the economic evaluation of battery energy storage system(BESS). Application target of the BESS was decided to both the distribution substation and single customer. 1MW/4MWh BESS under research and development in KERI was used for example. We analyzed and compared BESS with conventional combind cycle. The result shows that BESS is more economic than conventional combind cycle.

• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.67-74
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• 2014

The fluctuation of the output power of wind farms will be able to cause the impact on the Jeju power system such as power quality and stability. To settle the matter, many researchers have proposed the use of the BESS(Battery Energy Storage System) in the wind farm. In this paper, The BESS is applied to each wind farms for mitigating the fluctuation of wind power output. The BESS is controlled for smoothing the output of wind farms. Two kinds of simulation will be carried out. First, the simulation results by using PSCAD/EMTDC simulation program are compared to the measured data from the real power grid in Jeju Island. The other is to analyze the output of wind farms when the BESS is applied to the simulation works. The simulation results will demonstrate the effectiveness of using BESS to stabilize for power grid in Jeju Island.

• 조명전기설비학회논문지
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• 제30권3호
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• pp.79-85
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• 2016

This paper analyzed the influence of wind power fluctuations in grid frequency of a stand-alone microgrid that is hybrid generation system with diesel generator, wind turbine, and Battery Energy Storage System (BESS). The existing island area power system consists of only diesel generators. So the grid frequency can be controllable from load change. But hybrid generation system with Renewable Energy Sources (RES) such as wind energy that has the intermittent output can bring power quality problems. BESS is one of the ways to improve the intermittent output of the RES. In this paper, we analyzed the role of BESS in a stand-alone microgrid. We designed a modelling of wind power system with squirrel-cage induction generator, diesel power system with synchronous generator, and BESS using transient analysis program PSCAD/EMTDC. And we analyzed the variation of the grid frequency according to the output of BESS.