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Title: Effect of Variable Speed Wind Turbine Generator on the Stability of a Weak Grid

Abstract

No abstract prepared.

Authors:
; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
908012
DOE Contract Number:
AC36-99-GO10337
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Energy Conversion; Journal Volume: 22; Journal Issue: 1, March 2007
Country of Publication:
United States
Language:
English
Subject:
17 WIND ENERGY; STABILITY; VELOCITY; WIND TURBINES; Wind Energy

Citation Formats

Muljadi, E., Butterfield, C. P., Parsons, B., and Ellis, A. Effect of Variable Speed Wind Turbine Generator on the Stability of a Weak Grid. United States: N. p., 2007. Web. doi:10.1109/TEC.2006.889602.
Muljadi, E., Butterfield, C. P., Parsons, B., & Ellis, A. Effect of Variable Speed Wind Turbine Generator on the Stability of a Weak Grid. United States. doi:10.1109/TEC.2006.889602.
Muljadi, E., Butterfield, C. P., Parsons, B., and Ellis, A. Thu . "Effect of Variable Speed Wind Turbine Generator on the Stability of a Weak Grid". United States. doi:10.1109/TEC.2006.889602.
@article{osti_908012,
title = {Effect of Variable Speed Wind Turbine Generator on the Stability of a Weak Grid},
author = {Muljadi, E. and Butterfield, C. P. and Parsons, B. and Ellis, A.},
abstractNote = {No abstract prepared.},
doi = {10.1109/TEC.2006.889602},
journal = {IEEE Transactions on Energy Conversion},
number = 1, March 2007,
volume = 22,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • This paper proposes a power-smoothing scheme for a variable-speed wind turbine generator (WTG) that can smooth out the WTG's fluctuating power caused by varying wind speeds, and thereby keep the system frequency within a narrow range. The proposed scheme employs an additional loop based on the system frequency deviation that operates in conjunction with the maximum power point tracking (MPPT) control loop. Unlike the conventional, fixed-gain scheme, its control gain is modified with the rotor speed. In the proposed scheme, the control gain is determined by considering the ratio of the output of the additional loop to that of themore » MPPT loop. To improve the contribution of the scheme toward maintaining the frequency while ensuring the stable operation of WTGs, in the low rotor speed region, the ratio is set to be proportional to the rotor speed; in the high rotor speed region, the ratio remains constant. The performance of the proposed scheme is investigated under varying wind conditions for the IEEE 14-bus system. The simulation results demonstrate that the scheme successfully operates regardless of the output power fluctuation of a WTG by adjusting the gain with the rotor speed, and thereby improves the frequency-regulating capability of a WTG.« less
  • Variable rotor speed control of a fixed-pitch wind turbine is investigated on a system consisting of a wind turbine which can operate in a wide speed range, from 0 to 38 Rpm. It produces any desired output from the rated (20 kW) to no-load, providing there is wind enough. A special technique is used to determine the operating point of the wind turbine by using the measured rotor speed and power. A difficult problem with this type of wind turbine control is to determine the upper speed limit reasonably high to capture as much energy as possible but still lowmore » enough to avoid power peaks.« less
  • The hourly wind speed data collected over a six-year period at four wind power measurement locations are used to estimate the annual energy output of a large wind turbine generator. The interannual energy and wind speed variations are discussed. The estimated interannual energy output at each location is related to the mean annual wind speed variation. The data indicate that at three of the four locations the estimated interannual energy variation varied as the square of the mean annual wind speed variation. That is, a 10 percent increase in the mean annual wind speed resulted in a 20 percent increasemore » in the annual energy output. At the fourth location there was an approximate linear relationship.« less
  • A three level control system for a variable speed wind energy conversion scheme (VSWECS) supplying a weak AC system is presented. The objective of the control strategy is to maximize energy capture and simultaneously to support the voltage of the bus where the VSWECS is connected. Using an insulated gate bipolar transistors (IGBT) inverter both control of active and reactive power supplied to the grid and reduction of harmonic distortion can be achieved. The response of the proposed scheme has been tested and evaluated in a test system using a developed computer program simulating in detail the system operation.