• Title/Summary/Keyword: Electric Energy

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KEPCO's Movement on Distribution Sector Regarding Renewable Energy Transition of Distribution Network in Korea (국내 배전망 정책 및 환경변화를 고려한 배전부분 발전방향 연구)

  • Hyun, Seung-Yoon;Kim, Chang-Hwan;Lee, Byung-Sung
    • KEPCO Journal on Electric Power and Energy
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    • v.7 no.1
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    • pp.93-99
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    • 2021

  • The government has proposed a mission to enhance intelligent power networks, decrease coal-fired generation, expand distributed energy resources, and promote energy prosumer into the distribution network in Korea. Installation cost of facility expansion to guaranteed interconnection with small distributed energy resources increases dramatically on KEPCO's distribution sector. And it is hard to withdraw in time. In addition, there are explicit research is required to meet the reliability on grid corresponding to the increase of distributed power. Infrastructure support for accommodating energy prosumer is also needed. Therefore, KEPCO is pushing transition to DSO by expanding distribution management scope and changing its roles. In addition, KEPCO is proactively preparing for integrated operation between distribution network and existing distributed power which is accommodated passively. KEPCO is also trying to accept multiple network users, e.g. building platforms, to manage a data and promote new markets. In the long term, transition to DSO will achieve saving investment costs for accommodating distributed sources and maintaining stable electrical quality. And it will be possible to create new business model using the platform to secure revenue.

  • https://doi.org/10.18770/KEPCO.2021.07.01.093 인용 PDF KSCI

Design of a Cooperative Voltage Control System Between EMS (VMS) and DMS

  • Shin, Jeonghoon;Lee, Jaegul;Nam, Suchul;Song, Jiyoung;Oh, Seungchan
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.3
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    • pp.279-284
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    • 2020

  • This paper presents the conceptual design of a cooperative control with Energy Management System (EMS) and Distribution Management System (DMS). This control enables insufficient reactive power reserve in a power transmission system to be supplemented by surplus reactive power in a power distribution system on the basis of the amount of the needed reactive power reserve calculated by the EMS. This can be achieved, because increased numbers of microgrids with distributed energy resources will be installed in the distribution system. Furthermore, the DMS with smart control strategy by using surplus reactive power in the distribution system of the area has been gradually installed in the system as well. Therefore, a kind of hierarchical voltage control and cooperative control scheme could be considered for the effective use of energy resources. A quantitative index to evaluate the current reactive power reserve of the transmission system is also required. In the paper, the algorithm for the whole cooperative control system, including Area-Q Indicator (AQI) as the index for the current reactive power reserve of a voltage control area, is devised and presented. Finally, the performance of the proposed system is proven by several simulation studies.

  • https://doi.org/10.18770/KEPCO.2020.06.03.279 인용 PDF KSCI

Analysis on Solid Insulator Flashover Characteristics on Moisture Contamination for Electrical Insulation Improvement of ESS (ESS 안전성 개선을 위한 결로 운전 조건 고려 고체절연물 연면 절연파괴특성 분석)

  • Kim, Jin-Tae;Lee, Seung-Yong;Kim, Ji-young;Seok, Bok Yeol
    • KEPCO Journal on Electric Power and Energy
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    • v.7 no.2
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    • pp.317-321
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    • 2021

  • As the large-scale renewable energy power plant increases, the high-capacity and compact Energy Storage System (ESS) is required. However, this trend could reduce the insulation reliability of ESS. In this study, the surface flashover characteristics for four types of solid insulators are investigated in the uniform electric field with AC and Lightning Impulse (LI) voltage waveforms under various contamination levels. In addtion, insulator surfaces are compared based on the contact angle before and after surface flashover. The experimental results show that AC flashover voltage is dependent on the materials and the contamination level, but LI flashover voltage is only associated with the contamination level. Especially, AC flashover voltage of PC (PolyCarbonate) is higher than that of other insulators, which is associated with the unique and sequential creepage discharge propagation pattern of PC. The localized discharges on the surface of PC form corresponding tracking points. Then, the interconnected trackings result in the complete flashover. This flashover patterns degrade the surface of PC much more than that of epoxy and Bulk Molding Compoud (BMC). Thus, the contact angle of PC is significantly reduced compared to that of other insulators. The increased hydrophilicity in the surface of PC enhances the insulator surface conductivity.

  • https://doi.org/10.18770/KEPCO.2021.07.02.317 인용 PDF KSCI