• Title/Summary/Keyword: Variable wind turbine

Search Result 177, Processing Time 0.028 seconds

Characteristics Analysis is of Permanent-Magnet Type Wind Generator with Variable Load (부하가변에 따른 영구자석형 풍력발전기의 운전특성 해석)

  • Hwang, Don-Ha;Kang, Do-Hyun;Kim, Yong-Joo;Choi, Kyeong-Ho;Bae, Sung-Woo;Kim, Dong-Hee
    • Proceedings of the KIEE Conference
    • /
    • 2002.11d
    • /
    • pp.121-123
    • /
    • 2002
  • This paper presents the finite-element (FE) analysis results of a permanent-magnet (PM) generator for wind-power applications under different operating conditions. Finite-element method is applied to analyze generator performance at no-load and load with variable resistance and inductance. The results of FE analysis show that proposed PM generator is a useful solution for small-scale wind-turbine systems.

  • PDF

Expected Life Evaluation of Offshore Wind Turbine Support Structure under Variable Ocean Environment (해양환경의 변동성을 고려한 해상풍력터빈 지지구조물의 기대수명 평가)

  • Lee, Gee-Nam;Kim, Dong-Hyawn;Kim, Young-Jin
    • Journal of Ocean Engineering and Technology
    • /
    • v.33 no.5
    • /
    • pp.435-446
    • /
    • 2019
  • Because offshore structures are affected by various environmental loads, the risk of damage is high. As a result of ever-changing ocean environmental loads, damage to offshore structures is expected to differ from year to year. However, in previous studies, it was assumed that a relatively short period of load acts repeatedly during the design life of a structure. In this study, the residual life of an offshore wind turbine support structure was evaluated in consideration of the timing uncertainty of the ocean environmental load. Sampling points for the wind velocity, wave height, and wave period were generated using a central composites design, and a transfer function was constructed from the numerical analysis results. A simulation was performed using the joint probability model of ocean environmental loads. The stress time history was calculated by entering the load samples generated by the simulation into the transfer function. The damage to the structure was calculated using the rain-flow counting method, Goodman equation, Miner's rule, and S-N curve. The results confirmed that the wind speed generated at a specific time could not represent the wind speed that could occur during the design life of the structure.

Analysis of Steady State Characteristics of Doubly-Fed Induction Generator in Wind Turbine system (이중여자 유도발전 풍력시스템의 정상상태 특성 해석)

  • Jang, Bo-Kyoung;Ro, Kyoung-Soo
    • Proceedings of the KIEE Conference
    • /
    • 2009.07a
    • /
    • pp.460_461
    • /
    • 2009
  • This paper analyzes the steady state characteristics for variable speed wind power system with doubly-fed induction generator(DFIG). This paper explains the equivalent circuit and phasor diagram of DFIG for different operating conditions. It also simulates the torque-slip characteristics with respect to changes of different parameters. Simulation results show the torque-slip characteristics, stator power factor-rotor voltage and stator current-rotor voltage.

  • PDF

Probabilistic Reliability Evaluation of Power Systems Including Wind Turbine Generators Considering Wind Speed Correlation

  • Wu, Liang;Park, Jeong-Je;Choi, Jae-Seok;Ei-Keib, A.A.
    • Journal of Electrical Engineering and Technology
    • /
    • v.4 no.4
    • /
    • pp.485-491
    • /
    • 2009
  • The importance of renewable energy sources has been growing at a high rate as a result of being environment friendly. In particular, wind power is one of the most successfully utilized of such sources to produce electrical energy. Because of the randomness of wind speed, the reliability impact on this highly variable energy power is important aspect that needs to be assessed. In this paper, the impact on the reliability indices of wind speed correlation between two farms is considered.

Modified Control Scheme to Regulate the Active Power Output of Doubly Fed Induction Generator (이중여자 권선형 유도발전기의 출력조정을 위한 제어 기법)

  • Park, Young-Ho;Won, Dong-Jun;Park, Jin-Woo;Moon, Seung-Il
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1232-1233
    • /
    • 2007
  • As the number of wind turbines installed increase, the power from wind energy starts to replace conventional generation units and its influence on power system can not be neglected. Because of the intermittent nature of wind resource, the output power of wind turbine fluctuates according to wind speed variation. In this point of view, it is necessary for wind turbines to be equipped with power regulation ability. The doubly fed induction generator (DFIG) is one of the main techniques used in variable speed wind turbines. This thesis focuses on the development of modified control scheme of DFIG to regulate output power. The proposed control scheme achieves active power output regulation so as to stabilize the power system.

  • PDF

Design of a wind turbine generator with low cogging torque by using evolution strategy (진화론적 알고리즘을 이용한 코깅토크가 적은 풍력발전기의 설계)

  • Park, Ju-Gyeong;Cha, Guee-Soo;Lee, Hee-Joon;Kim, Yong-Sub
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.11
    • /
    • pp.755-760
    • /
    • 2016
  • The demand for independent generators using renewable energy has been increasing. Among those independent generators, small wind turbine generators have been actively developed. Permanent magnets are generally used for small wind turbine generators to realize a simple structure and small volume. On the other hand, cogging torque is included due to the structure of the permanent magnet synchronous machine, which can be the source of noise and vibration. The cogging torque can be varied by the shape of the permanent magnet and core, and it can be reduced using the appropriate design techniques. This paper proposes a design technique that can reduce the cogging torque by changing the shape of the permanent magnets for SPMSM (Surface Permanent Magnet Synchronous Motor), which is used widely for small wind turbine generators. Evolution Strategy, which is one of non-deterministic optimization techniques, was adopted to find the optimal shape of the permanent magnets that can reduce the cogging torque. The angle and outer diameter of permanent magnet were set as the design variable. A 300W class wind turbine generator, whose pole/slot combination was 8 poles/18 slots, was designed with the proposed design technique. The properties of the generator, including the cogging torque and output voltage, were calculated. The calculation results showed that the cogging torque of the optimized model was reduced compared to that of the initial model. The design technique proposed by this paper can be an effective measure to reduce the cogging torque.

Mechanical Design of a 750 kW Direct-drive Wind Turbine Generator System (750kW급 풍력터빈발전기의 기계설계)

  • Sohn, Y. U.;Son, J. B.;Park, I. S.;Kim, Y. C.;Kim, K. R.;Chung, C. W.;Chun, Ch. H.;Ryu, J. Y.;Park, J, I.;Byun, C. J,;Kim, D. H.
    • 유체기계공업학회:학술대회논문집
    • /
    • 2004.12a
    • /
    • pp.379-384
    • /
    • 2004
  • A prototype of 750 kW direct-drive wind turbine generator system, KBP-750D is under development in Korea. For the gearless, direct-drive prototype a synchronous generator with permanent magnets has been developed. The upwind 3-blade type machine employs variable speed and pitch control. The operating ranges of wind and rotor speed are 3 to 25 m/s and 9 to 25 rpm, respectively. The tip speed ratio of rotor blade is 7.5, designed for power coefficient 0.47, The blade pitch and torque are controlled with the predefined torque-speed curve according to the conditions of wind and public electric grid. This paper describes the outlines of primary components of KBP-750D.

  • PDF

Sensitivity of WindSIM in Complex Terrain

  • Shin, Chongwon;Han, Kyungseop
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2010.11a
    • /
    • pp.180.2-180.2
    • /
    • 2010
  • The purpose of this research is to analyze the sensitivity of WindSIM in complex terrain. As the flat areas for wind turbine installation become scarce globally, it becomes inevitable to install wind turbines in complex terrain. In order to predict annual energy production (AEP) in a more precise manner in complex terrain, it is of great importance to conduct such research. Three parameters: reference velocity, roughness and resolution have been chosen to see to which parameter WindSIM was the most sensitive in terms of annual energy production in complex terrain. By fixing two parameters and setting one parameter as a variable, it could be easily found that how annual energy production was effected by the change in each parameter.

  • PDF

Variable-Speed Prime Mover Driving Three-Phase Self-Excited Induction Generator with Static VAR Compensator Voltage Regulation-Part H : Simulation and Experimental Results-

  • Ahmed, Tarek;Nagai, Schinichro;Soshin, Koji;Hiraki, Eiji;Nakaoka, Mutsuo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
    • /
    • v.3B no.1
    • /
    • pp.10-15
    • /
    • 2003
  • This paper presents the digital computer performance evaluations of the three-phase self-excited induction generator (SEIG) driven by the variable speed prime mover such as the wind turbine using the nodal admittance approach steady-state frequency domain analysis with the experimental results. The three-phase SEIG setup is implemented for small-scale rural renewable energy utilizations. The experimental performance results give a good agreement with those ones obtained from the digital computer simulation. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable speed prime mover employing the static VAR compensator (SVC) circuit composed of the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor(TSC) is designed and considered herein for the wind-turbine driven the power conditioner. To validate the effectiveness of the SVC-based voltage regulator of the terminal voltage of the three-phase SEIG, an inductive load parameter disturbances in stand-alone are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and thyristor triggering angle response of the TCR are plotted graphically. The simulation and the experimental results prove the effectiveness and validity of the proposed SVC which is controlled by the Pl controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed prime mover.

Wind Power Grid Integration of an IPMSG using a Diode Rectifier and a Simple MPPT Control for Grid-Side Inverters

  • Ahmed, Tarek;Nishida, Katsumi;Nakaoka, Mutsuo
    • Journal of Power Electronics
    • /
    • v.10 no.5
    • /
    • pp.548-554
    • /
    • 2010
  • In this paper, a 1.5 kW Interior Permanent Magnet Synchronous Generator (IPMSG) with a power conditioner for the grid integration of a variable-speed wind turbine is developed. The power-conditioning system consists of a series-type 12-pulse diode rectifier powered by a phase shifting transformer and then cascaded to a PWM voltage source inverter. The PWM inverter is utilized to supply sinusoidal currents to the utility line by controlling the active and reactive current components in the q-d rotating reference frame. While the q-axis active current of the PWM inverter is regulated to follow an optimized active current reference so as to track the maximum power of the wind turbine. The d-axis reactive current can be adjusted to control the reactive power and voltage. In order to track the maximum power of the wind turbine, the optimal active current reference is determined by using a simple MPPT algorithm which requires only three sensors. Moreover, the phase angle of the utility voltage is detected using a simple electronic circuit consisting of both a zero-crossing voltage detecting circuit and a counter circuit employed with a crystal oscillator. At the generator terminals, a passive filter is designed not only to decrease the harmonic voltages and currents observed at the terminals of the IPMSG but also to improve the generator efficiency. The laboratory results indicate that the losses in the IPMSG can be effectively reduced by setting a passive filter at the generator terminals.