• 제목/요약/키워드: equivalent power

검색결과 1,750건 처리시간 0.025초

펄스파워용 고전압 커패시터 등가직렬 임피던스 측정에 관한 연구 (Study on Measurement Technology for Equivalent Series Impedance of High-voltage Pulsed Power Capacitors)

  • 이병윤;이병하
    • 전기학회논문지
    • /
    • 제62권7호
    • /
    • pp.937-942
    • /
    • 2013
  • Equivalent series impedance of high-voltage pulsed power capacitor is one of the important electrical characteristics both for users and for capacitor manufacturers because it may have serious effects on the performance of pulse forming circuits. In this paper, definition of equivalent series impedance and factors which generate equivalent series impedance are reviewed. Theoretical analysis for the calculation of equivalent series impedance based on differential measurement method is described and calculation program has been developed. In order to acquire data which are necessary to calculate equivalent series impedance from discharging current waveform, charging-dischargig controller has been manufactured. Measurement results of equivalent series impedance for high voltage pulsed power capacitor have been given.

A Boundary Protection for Power Distribution Line Based on Equivalent Boundary Effect

  • Zhang, Xin;Mu, Long-Hua
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권2호
    • /
    • pp.262-270
    • /
    • 2013
  • A boundary protection method for power distribution line based on equivalent boundary effect is presented in this paper. In the proposed scheme, the equivalent resonance component with a certain central frequency is sleeve-mounted at the beginning of protected zone. The 'Line Boundary' is built by using boundary effect, which is created by introducing impedance in the primary-side of line. The 'Line Boundary' is significantly different from line wave impedance. Therefore, the boundary protection principle can be applied to power distribution line without line traps. To analyze the frequency characteristic corresponding to traveling-waves of introducing impedance in the primary-side of line, distributed parameters model of equivalent resonance component is established. The results of PSCAD/EMTDC simulation prove the obvious difference of voltage high frequency component between internal faults and external faults due to equivalent resonance component, and validate the scheme.

Operation Algorithm for a Parallel Hybrid Electric Vehicle with a Relatively Small Electric Motor

  • Kyoungcheol Oh;Kim, Donghyeon;Kim, Talchol;Kim, Chulsoo;Kim, Hyunsoo
    • Journal of Mechanical Science and Technology
    • /
    • 제18권1호
    • /
    • pp.30-36
    • /
    • 2004
  • In this paper, operation algorithms for a parallel HEV equipped with a relatively small motor are investigated. For the HEV, the power assist and the equivalent fuel algorithms are proposed. In the power assist algorithm, an electric motor is used to assist the engine which provides the primary power source. Tn the equivalent fuel algorithm, the electric energy stored in the battery is considered to be an equivalent fuel, and an equivalent brake specific fuel consumption for the electric energy is proposed. From the equivalent fuel algorithm, distribution of the engine power and the motor power is determined to minimize the fuel consumption for a given battery state of charge (SOC) and a required vehicle power. It is found from the simulation results that the fuel economy and the final battery SOC depend on the motor discharge energy and it is the best way to charge the battery only by the regenerative braking, not by the engine to improve the overall fuel efficiency of the HEV with the relatively small motor.

XLPE 절연체의 등가 및 가변온도 가속열화실험을 통한 기계적 특성 비교 분석 (A Comparison Study on Mechanical Properties of XLPE Insulation Thermally Degraded at Equivalent and Variable Temperature Conditions)

  • 김태준;황재상;정성훈;김태영
    • KEPCO Journal on Electric Power and Energy
    • /
    • 제8권2호
    • /
    • pp.73-77
    • /
    • 2022
  • Recently, as the number of years of operation has increased for more than 30 years, interest in evaluating the remaining life of major power facilities such as transformers and ultra-high voltage cables is increasing. In particular, the risk of failure is increasing because the underground transmission XLPE cable has been built since 1980 and has been operating in excess of 30 years of design life or close proximity. Therefore, it is necessary to develop an algorithm to evaluate the residual life of the XLPE cable considering the load to determine the risk of failure. Since load data is large amount of data, it is necessary to make the variable load information equivalent to the time unit first in order to calculate the remaining life of the system quickly. In overseas literature, transformers are reported to be standardized for variable load equivalent conversion formulas, but they have not been reported for ultra-high voltage cables. Therefore, in this paper, whether the equivalent conversion formula of a transformer can be applied to XLPE cables was reviewed through accelerated degradation tests under equivalent and variable temperature conditions, and considerations were studied when evaluating the remaining operating life of XLPE cables based on the experimental results.

Proposed Equivalent Circuit and Parameter Identification Method for Electro-Magnetic Resonance Based Wireless Power Transfer

  • Kawamura, Atsuo;Kim, Tae-Woong
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권4호
    • /
    • pp.799-807
    • /
    • 2013
  • The proper equivalent circuit is newly presented for electro-magnetic resonance based wireless power transfer. Based on the proposed equivalent circuit of open-ended helical antennas, the parameter identification of helical antennas can be well derived for highly efficient wireless power transfer. The well-established equivalent circuit in high frequency ranges is developed for analyzing a resonance enhanced-electromagnetic coupling helical antennas and the unknown parameters for helical antennas are identified by experiments. The effectiveness based on the proposed equivalent circuit is verified through experiments.

Tie Line Constrained Equivalent Assisting Generator Model (TEAG) Considering Forced Outage Rates of Transmission Systems

  • Park, Jaeseok;Tran, Trung-Tinh;Sungrok Kang;Park, Dongwook;Jaeyoung Yoon;Seungil Moon;Roy Billinton
    • KIEE International Transactions on Power Engineering
    • /
    • 제4A권2호
    • /
    • pp.91-99
    • /
    • 2004
  • This paper illustrates a tie line constrained equivalent assisting generator (TEA G) model considering forced outage rates of transmission systems for reliability evaluation of interconnected power systems. Interconnections between power systems can provide improved levels of reliability. It is expected that the TEAG model developed in this paper will prove useful in the solution to problems related to the effect of transmission system uncertainties in the reliability evaluation of interconnected power systems. The characteristics and concept of this TEAG considering transmission systems are described in detail by sample studies on a simple test system.

A Study on the Dynamic Reduction for Large Power System

  • Kim, Jin-Yi;Won, Dong-Jun;Moon, Seung-Il
    • KIEE International Transactions on Power Engineering
    • /
    • 제12A권1호
    • /
    • pp.1-5
    • /
    • 2002
  • This paper presents the procedure to construct equivalent model of large power system based on nonlinear time simulation responses. It consists of coherency identification, generator aggregation and network reduction. Coherency index that can be directly implemented to this procedure is proposed. Generator aggregation based on detailed model is performed. This procedure can be used to construct equivalent model in PSS/E. It is also possible to reduce the large power system directly from the nonlinear time responses. This procedure is applied to the transient stability analysis of Korea power system that now experiences rapid changes. The equivalent model is compared with the original model in its size, accuracy, speed and performance. This paper shows that the developed equivalent model is a good estimate of the original system.

Korean Power System Security Analysis Using Benchmark Systems

  • Cho Yoon-Sung;Jang Gilsoo
    • KIEE International Transactions on Power Engineering
    • /
    • 제5A권3호
    • /
    • pp.207-213
    • /
    • 2005
  • This paper deals with the development of benchmark systems based on the Korea Electric Power Corporation (KEPCO) system. A novel procedure for constructing a dynamic equivalent system of the KEPCO system is proposed. By using such a system, various scenarios can be simulated and compared with the original system. The results of the simulation show the benefits of the proposed equivalent system and its validity is confirmed by applying it to the KEPCO system.

Static Equivalent Model of Inverter-based Distributed Energy Resource for Fault Analysis of Power Distribution Grid

  • Kim, Dong-Eok;Cho, Namhun;Yang, Seung-Kwon
    • KEPCO Journal on Electric Power and Energy
    • /
    • 제2권4호
    • /
    • pp.569-575
    • /
    • 2016
  • In this paper, we propose a method to develop a static equivalent model of an inverter-based distributed energy resource (DER), where the model is used for a steady-state fault analysis of a power grid. First, we introduce the characteristics of an inverter-based DER as well as its general configuration. Then, we derive the equivalent model of the DER on the basis of the characteristics. Last, the performance of the proposed method is proven by the results of computer simulations.

Development of Tie Line Constrained Equivalent Assisting Generator Model (TEAG) For Reliability Evaluation of NEAREST -Ⅲ

  • Tran TrungTinh;Choi Jae-Seok;Kim Hyung-Chul;Moon Seung-Il;Billinton Roy
    • KIEE International Transactions on Power Engineering
    • /
    • 제5A권1호
    • /
    • pp.31-39
    • /
    • 2005
  • This paper illustrates a tie line constrained equivalent assisting generator (TEAG) model considering forced outage rates of transmission systems for reliability evaluation of interconnected power systems. Interconnections between power systems can provide improved levels of reliability. It is expected that the TEAG model developed in this paper will prove useful in the solution to problems related to the effect of transmission system uncertainties in the reliability evaluation of interconnected power systems. It is important that interconnection between power systems can provide the improved levels of reliability. Therefore, It is expected that the TEAG model developed in this study will provide some solution among many problems for interconnected power systems as an optimal tie line capacity and a connected point between assisting systems and assisted system. The characteristics and validity of this developed TEAG considering transmission systems are introduced by case study of three IEEE MRTS interconnected.