This paper proposes an indirect power control of doubly fed induction generator （DFIG） with the rotor connected to the electric grid through a back-to-back pulse width modulation （PWM） converter for variable speed...This paper proposes an indirect power control of doubly fed induction generator （DFIG） with the rotor connected to the electric grid through a back-to-back pulse width modulation （PWM） converter for variable speed wind power generation. Appropriate state space model of the DFIG is deduced. An original control strategy based on a variable structure control theory, also called sliding mode control, is applied to achieve the control of the active and reactive power exchanged between the stator of the DFIG and the grid. A proportional-integral-（P1） controller is used to keep the DC-link voltage constant for a back-to-back PWM converter. Simulations are conducted for validation of the digital controller operation using Matlab/Simulink software.展开更多
Continuous monitoring of wind turbine(WT)opera-tion can improve the reliability of the wind turbine and lower the operation and maintenance costs.To improve the condition mon-itoring(CM)and fault detection performance...Continuous monitoring of wind turbine(WT)opera-tion can improve the reliability of the wind turbine and lower the operation and maintenance costs.To improve the condition mon-itoring(CM)and fault detection performance on WTs,this paper proposes an artificial intelligence-based probabilistic anomaly detection approach that can not only provide a deterministic estimation of the WT condition but also evaluate the uncertainties associated with the estimation.An abnormal WT condition is detected based on the evaluated uncertainties,to provide a noise-free incipient fault indication.Compared to the conventional deterministic CM approaches with a residual-based anomaly detection criterion,the proposed probabilistic approach tends to accurately detect the faults earlier,which allows more time for maintenance scheduling to prevent WT component failure.The early fault detection ability of the proposed approach was verified on an operational WT in China.展开更多
In this study, an analysis of the wind energy potential in the southwest geo-political region of Nigeria was conducted. A 37-year （1971-2007） wind speed data set measured at 10m height, obtained from eight meteorolo...In this study, an analysis of the wind energy potential in the southwest geo-political region of Nigeria was conducted. A 37-year （1971-2007） wind speed data set measured at 10m height, obtained from eight meteorological stations within the region was analyzed using a 2-parameter Weibull function. Besides, a techno- economic evaluation of large wind energy conversion systems with power ratings ranging from 0.6 to 2 MW at different hub heights based on the levelized unit cost of electricity was made for the different sites considered. The result showed that electricity cost varied from 0.06997 and 0.11195 S/（kW. h） to 2.86611 and 4.585785/（kW-h） at limit values of turbine specific cost band intervals of 1000 and 1600 S/kW. It was further shown that Lagos, having the highest accumulated power outputs of 430.10kW/a from DeWind D7 at 70 m hub height, is the most preferred for economically usable power generation in terms of the levelized unit cost.展开更多
文摘This paper proposes an indirect power control of doubly fed induction generator （DFIG） with the rotor connected to the electric grid through a back-to-back pulse width modulation （PWM） converter for variable speed wind power generation. Appropriate state space model of the DFIG is deduced. An original control strategy based on a variable structure control theory, also called sliding mode control, is applied to achieve the control of the active and reactive power exchanged between the stator of the DFIG and the grid. A proportional-integral-（P1） controller is used to keep the DC-link voltage constant for a back-to-back PWM converter. Simulations are conducted for validation of the digital controller operation using Matlab/Simulink software.
基金The work was supported in part by the Australian Research Council(ARC)Discovery Grant(DP170103427/180103217)in part by the Funda-mental Research Funds for the Central Universities(No.2017BSCXB58)and the Postgraduate Research&Practice Innovation Program of Jiangsu Province.
文摘Continuous monitoring of wind turbine(WT)opera-tion can improve the reliability of the wind turbine and lower the operation and maintenance costs.To improve the condition mon-itoring(CM)and fault detection performance on WTs,this paper proposes an artificial intelligence-based probabilistic anomaly detection approach that can not only provide a deterministic estimation of the WT condition but also evaluate the uncertainties associated with the estimation.An abnormal WT condition is detected based on the evaluated uncertainties,to provide a noise-free incipient fault indication.Compared to the conventional deterministic CM approaches with a residual-based anomaly detection criterion,the proposed probabilistic approach tends to accurately detect the faults earlier,which allows more time for maintenance scheduling to prevent WT component failure.The early fault detection ability of the proposed approach was verified on an operational WT in China.
文摘In this study, an analysis of the wind energy potential in the southwest geo-political region of Nigeria was conducted. A 37-year （1971-2007） wind speed data set measured at 10m height, obtained from eight meteorological stations within the region was analyzed using a 2-parameter Weibull function. Besides, a techno- economic evaluation of large wind energy conversion systems with power ratings ranging from 0.6 to 2 MW at different hub heights based on the levelized unit cost of electricity was made for the different sites considered. The result showed that electricity cost varied from 0.06997 and 0.11195 S/（kW. h） to 2.86611 and 4.585785/（kW-h） at limit values of turbine specific cost band intervals of 1000 and 1600 S/kW. It was further shown that Lagos, having the highest accumulated power outputs of 430.10kW/a from DeWind D7 at 70 m hub height, is the most preferred for economically usable power generation in terms of the levelized unit cost.
