• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
• /
• pp.224-227
• /
• 1997

This study discuss two subjects : maximization of transmission capability and regulation of voltages along line within the permissible bounds. Series and parallel line compensation methods have been applied for those purposes using capacitors and reactors. In this paper, the effect of series and shunt line compensation for symmetrical line is analyzed. The results obtained in this paper can be applied 765kV class EHV transmission system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.569-571
• /
• 2003

As a definition of NERC, Available Transfer Capability(ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate ATC, accurate and defensible TTC, CBM and TRM should be calculated in advance. In this paper, we propose a method to quantify TRM using probabilistic load flow based on the method of moment. Generation output, bus voltages, loads, and line outages are considered as complex random variables (CRV) to take into account for uncertainties related to the transmission network conditions. Probability Density Function (PDF) of line flow at the most limiting line is used to quantify TRM with the desired probabilistic margin. Suggested method is compared with the results from conventional CPF method and verified using 24 bus MRTS, and the suggested method based on PLF shows efficiency and flexibility for the quantification of TRM compared with the conventional method.

• 전기학회논문지
• /
• 제66권1호
• /
• pp.7-15
• /
• 2017

Ambient Adjusted line Rating(AAR) method for overhead transmission lines considering Risk Tolerance(RT) was proposed in this paper. AAR is suitable for system operators to plan their operation strategy and maintenance schedule because this can be designed as a seasonal line rating. Several candidate transmission lines are chosen to apply the proposed method in the paper. As a result, it is shown that system reliability was significantly enhanced through maximizing transfer capability, solving the system constraints.

• 한국산학기술학회논문지
• /
• 제18권12호
• /
• pp.762-767
• /
• 2017

본 논문은 전기자동차의 충전부하 이동성에 의한 전력시스템 선로에서의 전송전력에 대한 해석과 개선에 대한 내용을 제시하였다. 전기자동차는 화석연료의 고갈과 환경보호의 중요성이라는 측면에서 사용범위가 크게 늘어나고 있으며, 가까운 미래에 가솔린 연료를 사용하는 운송수단을 대체할 것으로 예상되고 있다. 기존의 예측된 고정 부하량에 기초한 전력시스템에서 전기자동차의 이동성 충전부하는 특정 지역에서 이동성 충전부하의 증가로 인한 전송선로에서의 전송전력 집중과 과부하의 문제를 발생시킨다. 이러한 현상의 해석을 위해 New England 시험계통을 부하특성을 기반으로 4개의 지역으로 분할하여 전기자동차 충전부하의 이동을 고려한 예상 시나리오를 가정하였다. 예상 시나리오에서는 표준이 되는 전기자동차의 충전용량을 고려하여 지역단위의 부하량을 최대 31%까지 증가하면서 선로에서의 전송전력 집중과 과부하 현상을 해석하였다. 이러한 선로에서의 과부하 문제에 대한 해결책으로 TCSC를 과부하가 발생한 선로에 직렬 연결하여 선로의 전송전력을 선로제한값 보다 작은 부하율 100% 이내의 값으로 직접 제어할 수 있도록 하였다. 시뮬레이션 결과로부터 전력시스템에 몇 개의 TCSC를 적용함으로써 전기자동차의 이동성 부하 충전에 의한 선로에서의 전송전력 문제를 효과적으로 그리고 경제적으로 해결할 수 있음을 보였다.

• Journal of Electrical Engineering and Technology
• /
• 제12권3호
• /
• pp.1046-1052
• /
• 2017

The load on the power grid of South Korea is expected to grow continuously until the late 2020s, and it is necessary to increase the transfer capacity from the Eastern grid to the Seoul-Gyeonggi region by reinforcing the transmission network for the electric power system to remain stable. To this end, the grid reinforcement by two bipole LCC HVDC transmission systems have been considered on account of the public acceptability and high growth of the fault current level, even though an additional 765kV system construction is more economical. Since the probability of the existing 765kV double circuit transmission line trip is extremely low, a dynamic simulation study was carried out to estimate the efficient HVDC capacity able to stabilize the transient stability by utilizing the HVDC overload capability. This paper suggests the application plan to reduce the HVDC construction capacity with ensuring the transient stability during the 765kV line trip.

• 전기학회논문지
• /
• 제59권3호
• /
• pp.485-491
• /
• 2010

Total Transfer Capability (TTC) should be pre-determined in order to estimate Available Transfer Capability (ATC). Typically, TTC is determined by considering three categories; voltage, stability and thermal limits. Among these, thermal limits are treated mainly in this paper on the evaluation of TTC due to the relatively short transmission line length of Korea Electric Power Corporation (KEPCO) system. This paper presents a new approach to evaluate the TTC using the Dynamic Line Rating (DLR) for the thermal limit. Since the approach includes not only traditional electrical constraints but also real-time environmental constraints, this paper obtains more cost-effective and exact results. A case study using KEPCO system confirms that the proposed method is useful for real-time operation and the planning of the electricity market.

• Journal of Power Electronics
• /
• 제15권5호
• /
• pp.1367-1379
• /
• 2015

A hybrid HVDC system that is composed of line commutated converter (LCC) at the rectifier side and voltage source converter (VSC) in series with LCC at the inverter side is studied in this paper. The start-up strategy, DC fault ride-through capability, and fault recovery strategy for the hybrid HVDC system are proposed. The steady state and dynamic performances under start-up, AC fault, and DC fault scenarios are analyzed based on a bipolar hybrid HVDC system. Furthermore, the immunity of the LCC inverter in hybrid HVDC to commutation failure is investigated. The simulation results in PSCAD/EMTDC show that the hybrid HVDC system exhibits favorable steady state and dynamic performances, in particular, low susceptibility to commutation failure, excellent DC fault ride-through, and fast fault recovery capability. Results also indicate that the hybrid HVDC system can be a good alternative for large-capacity power transmission over a long distance byoverhead line.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.186-188
• /
• 2004

This paper describes the feasibility study of HVDC system application to KEPCO power system for increasing power transfer capability or the flexibility of power delivery from one area to the other using the existing transmission line. This paper assumes the 345kV transmission line connecting between Shinokchun and Sedaegu to be converted to the DC line by replacing the AC insulator with that of DC. Then, the HVDC bipole system of 1000MVA with $\pm300kV$ is designed and the contingency studies are carried out.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1986년도 하계학술대회논문집
• /
• pp.257-260
• /
• 1986

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1997년도 전력전자학술대회 논문집
• /
• pp.211-215
• /
• 1997

Localized communication networks for office automation, security monitoring, environmental management of buildings, computer communications, and other applications enjoy every increasing demand. This paper proposes a direct sequence spread spectrum communication system for use in power line data transmission. Advantages of power distribution circuits include reasonably universal coverage and easy access vis a standard wall plug. Disadvantages include limited communication bandwidth, relatively high noise levels, and varying levels of impedance, noise, and attenuation. Spread spectrum signalling provides immunity to narrow-band signal impairments and multiplexing capability. Our prototype power line communication module supports completely physical and data link layers based on the international standard ISO 10368 for reliable high-speed power line communication system. Moreover it provides useful functions to compose a plant monitoring and control system. All the circuits of the communication module are included in one compact circuit. Thus a functional communication system for the power line plant monitoring and control is implemented.