• 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.

• 한국전기전자재료학회논문지
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• 제35권6호
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• pp.631-638
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• 2022

Microgrid, which enables the production and consumption of electricity to be done independently on a small scale, has been studied on one of the solutions of reinforcement for flexibility of electronic system. This study examined the application effect of new microgrid by applying hybrid battery in electric power storage device. We designed the system to highlight the advantage of each battery and complement the disadvantage by using hybrid system with Lithium-ion battery and interval Redox flow battery. It runs with lithium-ion battery during the initial startup while the Redox flow battery operates for a long time at the end of excessive period, and it enables a discharge of Lithium-ion and Redox flow battery at the same time when the load has a large output. We chose Maldives as a subject of this study for organizing and optimizing independent microgrid. Maldives is the country to accomplish 100% domestic electricity in South Asia, but the whole electric power is supplied through diesel generation imported fossil fuel. We organized and optimized microgrid for energy independence on Malahini island to solve Maldives energy cost problem and global energy environment matters. We analyzed the daily power supply and accumulated the power supply from September 18, 2018~February 11, 2019. The accumulated power supply was about 120.4 MWh and the daily power supply was about 800~1000 kWh. Based on the collected information, we divided the cases into three models which are only diesel generator, solar generator as well as diesel generator, and solar+ESS+diesel generator. We analyzed the amount of oil consumption compared to the cost of construction and power output. The result showed that solar+ESS+diesel generator was most economically feasible. As well, we obtained that our considering hybrid battery system reduced the fuel consumption for diesel power generation about 10~15%.

• 한국철도학회논문집
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• 제18권4호
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• pp.325-334
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• 2015

본 논문에서는 하이브리드 에너지 저장장치의 계통연계 제어에 대하여 기술 하였다. 배터리는 큰 에너지 밀도를 가지지만 순간 전력밀도는 낮아 급격한 전류변동이 일어날 경우 수명이 저하된다. 이러한 단점을 보완하기 위해 수퍼커패시터를 함께 사용하는 하이브리드 에너지 저장장치를 구성하였고 이에 대한 제어방법을 제안하였다. 배터리와 수퍼커패시터의 제어를 위해서는 예측형 전류제어기를 가지는 p-q 제어방법을 적용하였다. 제안된 제어기의 효용성을 검증하기 위해 실제 계통모델에 대한 PSIM과 RTDS를 이용한 시뮬레이션을 수행하였다.

• 조명전기설비학회논문지
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• 제26권3호
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• pp.16-23
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• 2012

This paper relates to a study on the economic of electrical storage device for supplying power in sunless days, in the stand alone PV/Wind hybrid system, which it is applied to separate houses. In a photovoltaic/wind hybrid power system used in a separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. For example, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to supply power stably by only the battery based upon pre-estimated sunless days. Accordingly, in order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2004-2012
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• 2014

Energy storage devices are necessary to obtain stable utilization of renewable energy sources. When black-out occurs, distributed renewable power sources with energy storage devices can operate under standalone mode as uninterruptable power supply. This paper proposes a dynamic response analysis with small-signal modeling for the standalone operation of a photovoltaic power generation system that includes a bidirectional charger/discharger with a battery. Furthermore, it proposes a DC-link voltage controller design of the entire power conditioning system, using the storage current under standalone operation. The purpose of this controller is to guarantee the stable operation of the renewable source and the storage subsystem, with the power conversion of a very efficient bypass-type PCS. This paper presents the operating principle and design guidelines of the proposed scheme, along with performance analysis and simulation. Finally, a hardware prototype of 1-kW power conditioning system with an energy storage device is implemented, for experimental verification of the proposed converter system.

• Current Photovoltaic Research
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• 제11권2호
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• pp.58-65
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• 2023

The expanding significance of energy storage (ES) technology is increasing the acceptability of power systems by augmenting renewable energy supply. To deploy such ES technologies, we must select the optimal technology that meets the requirements of the system and confirm the technical and economic feasibility of the business model based on it. Herein, we propose a method and tool for selecting the optimal ES technology and service suitable for meeting the requirements of the system, based on its performance characteristics. The method described in this study can be used to discover and apply various ES technologies and develop business models with excellent economic feasibility.

• 전기학회논문지
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• 제63권4호
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• pp.476-483
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• 2014

This paper describes the operational analysis results of the bipolar DC distribution system coupled with the distributed generators. The energy management for AC/DC power trade and the operational principle of distributed generators and energy storages were first analyzed by computer simulation with PSCAD/EMTDC software. After then a hardware simulator for the bipolar DC distribution system was built, which is composed of the grid-tied three-level inverter, battery storage, super-capacitor storage, and the voltage balancer. Various experiments with the hardware simulator were carried out to verify the operation of bipolar DC distribution system. The developed simulator has an upper-level controller which operates in connection with the controllers for each distributed generator and the battery energy storage based on CAN communication. The developed hardware simulator are possible to use in designing the bipolar DC distribution system and analyzing its performance experimentally.

• 전기학회논문지
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• 제65권5호
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• pp.724-729
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• 2016

Nowadays high-cost energy storage system using flywheel or secondary battery is applying to hybrid generation system with WT(Wind Turbine) and diesel generator in island areas for stable operation. This paper proposes an operating algorithm and modeling method of the hybrid generation system that can operate for variable wind speed and load, which is composed of energy storage system, variable-speed PMSG(Permanent Magnet Synchronous Generator) WT and diesel generator applied in island areas. Initially, the operating algorithm was proposed for frequency and voltage to be maintained within the proper ranges for load and wind speed changes. Also, the modeling method is proposed for variable speed PMSG WT, diesel generator and BESS(Battery Energy Storage System). The proposed operating algorithm and modeling method were applied to a typical island area. The frequency and voltage was kept within the permissible ranges and the proposed method was proven to be appropriate through simulations.

• Advances in Energy Research
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• 제4권1호
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• pp.47-68
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• 2016

A well designed hybrid power system (HPS) can deliver electrical energy in a cost effective way. In this paper, model for HPS consisting of photo voltaic (PV) module and wind mill as renewable energy sources (RES) and solar lead acid battery as storage device connected to unidirectional grid is developed for peak demand reduction. Life time energy cost of the system is evaluated. One year hourly site condition and load pattern are taken into account for analysing the HPS. The optimal HPS is determined for least life time energy cost subject to the constraints like state of charge of the battery bank, dump load, renewable energy (RE) generation etc. Optimal solutions are also found out individually for PV module and wind mill. These three systems are compared to find out the most feasible combination. The results show that the HPS can deliver energy in an acceptable cost with reduced peak consumption from the grid. The proposed optimization algorithm is suitable for determining optimal HPS for desired location and load with least energy cost.

• 전기학회논문지P
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• 제65권4호
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• pp.235-241
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• 2016

Grid-connected, large-capacity energy storage systems (ESS) can be used for peak load supply, frequency regulation, and renewable energy output smoothing. In order to confirm the capability of battery ESS to provide such services, 4MW/ 8MWh battery ESS demonstration facility was built in the Jocheon substation on Jeju Island. The frequency regulation technology developed for the Jocheon demonstration facility then became the basis for the 28MW and 24MW frequency regulation ESS facilities installed in 2014 at the Seo-Anseong and Shin-Yongin substations, respectively. The operation control systems at these two facilities were continuously improved, and their successful commercialization led to the construction of additional ESS facilities all over Korea in 2015. In seven (7) locations nationwide (e.g., Shin-Gimje and Shin-Gyeryeong), a total of 184 MW of ESS had been commercialized in 2016. The trial run for the new ESS facilities had been completed between April and May in 2016. In this paper, results of the trial run from each of the ESS facilities are presented. The results obtained from the Seo-Anseong and Shin-Yongin substations during a transient event by a nuclear power plant trip are also presented in this paper. The results show that the frequency regulation battery ESS facilities were able to quickly respond to the transient event and trial run of ESS is necessary before it is commercialized.