• 전기학회논문지
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• 제64권1호
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• pp.16-22
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• 2015

As the development of Battery Energy Storage System(BESS) and the increasing of intermittent energy sources like wind power and photovoltaic, the application of BESS in load frequency control is considered as an effective method. To evaluate the effectiveness of BESS application in frequency control, we defined a governor free model of BESS to conduct dynamic simulation. Using the BESS dynamic model, we implemented the power system dynamic model including steam, gas and hydro turbine generators. In this paper we study the control performance of BESS in primary frequency control. The effect of BESS speed regulation rate and response time on governor free operation is investigated. In addition, we compared BESS from steam turbine generator in view point of frequency regulation.

• 대한치과기공학회지
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• 제36권4호
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• pp.267-275
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• 2014

Purpose: The purpose of this study is to analyze denture satisfaction by burdened cost types. Methods: All 588 subjects in Gyeongsangnam-do, Korea was surveyed randomly. The study was conducted for about 24 days from March 28th to April 20th, 2014. The objects who participated in the survey were offered self-report questionnaires for this study. Results: Satisfaction with Half Price of the National Health Insurance Support Denture patients appears the highest point of $2.98{\pm}0.22$, and The Governor Pledge Free Denture appears $2.90{\pm}0.17$ the lowest. Also Pay Denture appears $2.96{\pm}0.21$. Provincial authority regulated medical carelessness inefficiently and at all during the procedure, without having to pay the cost of individual. also provincial authority support low budget. This is the result from the lowest satisfaction of The Governor Pledge Free Denture patient. Conclusion: According to the survey results, The Governor Pledge Free Denture and The Total Pay Denture's satisfaction are higher than The National Health Insurance Support Denture. and The National Health Insurance Support Denture are more uncomfortable than pay denture to use.

• 대한전기학회논문지
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• 제40권1호
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• pp.10-17
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• 1991

An improved control method in turbine control system is proposed. By automatic follow-up design, power system frequency may be maintained within prespecified range. Base or half load control is possible by distributing power plant load allotment. Otherwise, diminutive frequency-load control is dine by governor-free operation in power plant. This paper proposes governor-free operation which is automatically followed by load-limitter setter. The condition which limits governor action may be somewhat improved within boiler condition by this idea. This design has been implemented at Samchunpo thermal power plant. The improved practical results are shown.

• 전기학회논문지
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• 제66권6호
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• pp.905-910
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• 2017

As the development of BESS(Battery Energy Storage System), the application of BESS in load frequency control is considered as effective method. So, KEPCO(Korea Electric Power Corporation) have installed about 236MW ESS for GF(Govner Free) function from 2014. In this paper, we implemented Simulink Model for KEPCO GF ESS and analyzed one year historical operation data generated by Simulink model and actually measured frequency data. The operation results were divided into action for maintaining SOC and frequency. In addition, we also analyzed cycle life of GF ESS using two ESS cycle life model. We concluded the ESS cycle life models are not appropriate, because Most of the SOC swing in operation results are below 10%.

• 전기학회논문지
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• 제67권5호
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• pp.617-625
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• 2018

Since FERC order 755 was published, each frequency regulation market rules of the North American ISO/RTO have been revised in many parts. In 2016, the domestic CBP market has also changed its market rules to allow ESS to participate in the frequency regulation reserve services(Governor Free and Automatic Generation Control). This paper compares and analyzes the changed North American ISP/RTO market and domestic CBP market rules. In particular, we compare PJM and CAISO frequency regulation market pricing mechanism and settlement rules with the settlement rules of the domestic CBP market and compare the factors of each market used to compensate the participating resources in terms of resource dependency and accuracy.

• KEPCO Journal on Electric Power and Energy
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• 제6권2호
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• pp.123-127
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• 2020

KEPCO has installed Frequency Regulation ESS (FR ESS) of 376 MW since 2015. Frequency Regulation is ancillary service to support stabilizing system frequency, which is divided into governor free and automatic generation control. KEPCO operates FR ESS as governor free application and leads FR ESS market with capability of diverse demonstration and operation experiences. To expand FR ESS role during transient states of power system, KEPCO has extended operating time of charging and discharging. KEPCO has also changed speed droop lower than before to improve contribution on frequency compensation, and acquired much experiences of differentiating bad cells from others. Based on these technologies and know-hows, KEPCO Research Institutes received request of feasibility study and technical cooperation for overseas FR ESS business. This paper suggests the simple and practical method for making technological feasibility study of FR ESS.

• 벤처창업연구
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• 제4권3호
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• pp.39-54
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• 2009

2009년 7월 현재 충청남도는 지구 4바퀴의 거리인 16만km를 돌며 민선4기 출범이후 3년 만에 2502개 기업을 유치. 지금까지 3000여개 기업을 방문 상담해 왔는데 이는 하루 3개 기업 이상을 찾아다닌 셈이며 이 같은 노력으로 모두 40조 4659억 원의 투자를 유치하였다. 특히 충남지사의 공약사항인 국내 기업유치목표 1000개의 250%인 2502개 기업을 3년 만에 초과달성한 것이다. 외자유치 액은 5건에 12억2000만 달러로 올해 목표치(12억 달러)보다 2000만 달러를 초과 달성하였는데 현재 진행 중인 3건의 외자유치 협상까지 성사되면 연말까지 외자유치 액이 14억 달러를 초과하게 된다. 이런 성과는 도지사와 함께 호흡을 맞춘 기업유치부서 공무원들의 공격적인 기업유치전략이 주효했기 때문인데 충남도는 수도권 위주의 유치기업 목표를 다른 시도와 신도시 개발지역 등 전국으로 확대한 것은 물론 전략산업인 디스플레이, 자동차부품, 철강, 석유화학 등을 부각시켜 연관 산업 및 협력업체 등을 집중 공략한 덕분이며 또한, 도 본청과 시 군 태스크포스(TF) (35명)를 편성, 치밀하고 정확한 이전정보를 기반으로 정보공유 및 협력 네트워크를 구축하는 등 유기적 조직관리가 잘 된 것이다. 투자유치 관련 공무원뿐 만 아니라 구성원 대다수가 현재 실적이나 미국 발 금융위기, 수도권 규제완화 등에 연연하지 않고 충남의 투자여건 및 다른 지역과 차별화된 인센티브를 집중 홍보 하면서 공격적인 기업유치로 전국 1위 경제도로 도약하겠다는 구체적 달성목표를 정하고 이를 실천하고 있다. 외자유치를 위한 국내외 여건은 나쁘지만 이를 극복하기 위한 충남지역의 투자기반 인프라 마련을 위해 외국인 투자지역을 확대하고 행정 재정적 지원을 위한 다양한 시책을 추가 발굴하고 있다. 지방정부의 성공적 투자유치 핵심역량은 지방정부 수장의 강력한 리더십과 전문성을 확보한 부서조직 및 조직원들의 일치단결, 이를 구현해 낼 수 있는 우월하고 차별화된 투자유치 세부전략 등이 시스템적 사고 하에 융합되는데 있다.

• 전기의세계
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• 제24권5호
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• pp.97-102
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• 1975

This paper describes the result of a Study for the Optimum Operating method with Spinning reserve in case of outage of large generator unit to improve the system stability and prevent the system frequency drop. This is usually done by governor free operation, so we focused our attention to the operating Char acteristics of spinning reserve. Nexy, a study was made to mesure the upper limit of Spinning reserve and when this upper limit cannot match the required power, a relationship between the amount of spinning reserve and that of the load shedding requirement was searched with regard to several system operating conditions to use it in our future system operation. By this study, the optimum system operating method was recommended for reliable operation of power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.52-53
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• 2007

현 CBP(Cost Based Pool)에서 주파수조정은 전기품질유지와 전력계통 안정성 확보에 절대적으로 필요한 계통운영보조서비스의 항목이다. 이는 해외 전력계통에서도 예외없이 채택하여 적용하고 있으며 적극적인 참여를 유도하기 위하여 다양한 비용보상 방안을 시행하고 있다. 순시 주파수조정은 발전기 조속기 특성에 따라 다양한 출력응동특성을 가지고 있으며 이에 따라 계통에 기여하는 바도 달라지게 된다. 따라서 주파수조정에 참여하는 발전기의 계통기여도에 따른 주파수추종운전 능력에 대한 평가를 계량화할 수 있는 방법이 요구된다.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.227-232
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• 2016

To test the effectiveness of using an energy storage system for frequency regulation, the Energy New Business Laboratory at KEPCO Research Institute installed a 4 MW energy storage system (ESS) demonstration facility at the Jocheon Substation on Jeju Island. And after the successful completion of demonstration operations, a total of 52 MW ESS for frequency regulation was installed in Seo-Anseong (28 MW, governor-free control) and in Shin-Yongin (24 MW, automatic generation control). The control system used in these two sites was based on the control system developed for the 4 MW ESS demonstration facility. KEPCO recently finished the construction of 184 MW ESS for frequency regulation in 8 locations, (e.g. Shin-Gimjae substation, Shin-Gaeryong substation, etc.) and they are currently being tested for automatic operation. KEPCO plans to construct additional ESS facilities (up to a total of about 500 MW for frequency regulation by 2017), thus, various operational tests would first have to be conducted. The high-speed characteristic of ESS can negatively impact the power system in case the 500 MW ESS is not properly operated. At this stage we need to verify how effectively the 500 MW ESS can regulate frequency. In this paper, the effect of using ESS for frequency regulation on the power system of Korea was studied. Simulations were conducted to determine the effect of using a 524 MW ESS for frequency regulation. Models of the power grid and the ESS were developed to verify the performance of the operation system and its control system. When a high capacity power plant is tripped, a 24 MW ESS supplies power automatically and 4 units of 125MW ESS supply power manually. This study only focuses on transient state analysis. It was verified that 500 MW ESS can regulate system frequency faster and more effectively than conventional power plants. Also, it was verified that time-delayed high speed operations of multiple ESS facilities do not negatively impact power system operations. It is recommended that further testing be conducted for a fleet of multiple ESSs with different capacities distributed over multiple substations (e.g. 16, 24, 28, and 48 MW ESS distributed across 20 substations) because each ESS measures frequency individually. The operation of one ESS facility will differ from the other ESSs within the fleet, and may negatively impact the performance of the others. The following are also recommended: (a) studies wherein all ESSs should be operated in automatic mode; (b) studies on the improvement of individual ESS control; and (c) studies on the reapportionment of all ESS energies within the fleet.