EPE Association: EPE 2015 - LS4d: Wind Energy Systems

EPE 2015 - LS4d: Wind Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 05: Renewable Energy Power Systems > EPE 2015 - LS4d: Wind Energy Systems

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   A Review of Failure Mechanisms in Wind Turbine Generator Systems
By Udai SHIPURKAR [View]
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Abstract: Reliability is a critical consideration for wind turbine generator systems as failures contribute directly to operation and maintenance costs and hence the cost of energy. Improving reliability hinges on an understanding of the mechanisms of failures that occur. This paper discusses the major failure mechanisms in the WT generator system, particularly the converter and the generator, from the point of view of their use in wind turbines. It also looks at the opportunities for improving reliability.

   Analysis on Controller of Grid-Connected Inverter by Using Virtual Circuit
By Zheng ZENG [View]
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Abstract: Controller of grid-connected inverter (GCI) directly affects the performance of inverter-dominated distributed generator. A circuit-based modeling method is proposed to combine the control scheme in software and topology configuration in hardware of a GCI. On basis of the same mathematical model, control blocks are equally changed into circuit models in a GCI. By using the proposed circuit model, mathematical principle and physical nature of proportional-integral (PI) and proportional-resonant (PR) controllers for GCI application are discussed in depth. It concludes that the PI controller cannot tracking sinusoidal reference without error, because of the equivalent capacitor and ac leakage current in circuit model of a GCI. In contrast, due to the extra equivalent inductor and resonance circuit in series compared with PI, the equivalent capacitor in PI is opened, so that the PR control can confirm accurate current-following performance. Selected experimental results are also presented to validate the effectiveness of the proposed modeling method.

   Impedance Modeling of Doubly-Fed Induction Generators
By Ignacio VIETO [View]
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Abstract: This work presents sequence impedance models of Type-III wind turbines based on doubly-fed induction generators (DFIG). The models take into account the effects of both stator- and rotor-side converters as well as their control, including the phase-locked loop (PLL) and current control. The models are developed using the harmonic linearization method which has previously been applied to Type-IV turbines and HVDC converters. The developed models are validated by point-by-point simulation of the detailed switching model and also used to analyze subsynchronous oscillation of Type-III turbines with series-compensated grid.

   Linear Interpolation Model Predictive Control of Large Wind Turbines for Blade Asymmetric Fatigue Loads Mitigation
By Wentao YANG [View]
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Abstract: To reduce the blades asymmetric loads of large wind turbines operated in the above-rated wind speed region, this work proposes a model predictive individual pitch controller with the linear interpolation model. Results show a significant reduction of 1P (once-per-revolution), 2P, 4P blade asymmetric loads within the limits of pitch rate. The proposed model of wind turbine can describe the characteristic of blade bending moment up to 4P (once-per-revolution) frequency. The MPC method with this model can reduce 1P, 2P, 4P blade asymmetric loads significantly within the limits of pitch rate.

EPE 2015 - LS4d: Wind Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 05: Renewable Energy Power Systems > EPE 2015 - LS4d: Wind Energy Systems
	[return to parent folder]

	A Review of Failure Mechanisms in Wind Turbine Generator Systems By Udai SHIPURKAR	[View] [Download]
Abstract: Reliability is a critical consideration for wind turbine generator systems as failures contribute directly to operation and maintenance costs and hence the cost of energy. Improving reliability hinges on an understanding of the mechanisms of failures that occur. This paper discusses the major failure mechanisms in the WT generator system, particularly the converter and the generator, from the point of view of their use in wind turbines. It also looks at the opportunities for improving reliability.

	Analysis on Controller of Grid-Connected Inverter by Using Virtual Circuit By Zheng ZENG	[View] [Download]
Abstract: Controller of grid-connected inverter (GCI) directly affects the performance of inverter-dominated distributed generator. A circuit-based modeling method is proposed to combine the control scheme in software and topology configuration in hardware of a GCI. On basis of the same mathematical model, control blocks are equally changed into circuit models in a GCI. By using the proposed circuit model, mathematical principle and physical nature of proportional-integral (PI) and proportional-resonant (PR) controllers for GCI application are discussed in depth. It concludes that the PI controller cannot tracking sinusoidal reference without error, because of the equivalent capacitor and ac leakage current in circuit model of a GCI. In contrast, due to the extra equivalent inductor and resonance circuit in series compared with PI, the equivalent capacitor in PI is opened, so that the PR control can confirm accurate current-following performance. Selected experimental results are also presented to validate the effectiveness of the proposed modeling method.

	Impedance Modeling of Doubly-Fed Induction Generators By Ignacio VIETO	[View] [Download]
Abstract: This work presents sequence impedance models of Type-III wind turbines based on doubly-fed induction generators (DFIG). The models take into account the effects of both stator- and rotor-side converters as well as their control, including the phase-locked loop (PLL) and current control. The models are developed using the harmonic linearization method which has previously been applied to Type-IV turbines and HVDC converters. The developed models are validated by point-by-point simulation of the detailed switching model and also used to analyze subsynchronous oscillation of Type-III turbines with series-compensated grid.

	Linear Interpolation Model Predictive Control of Large Wind Turbines for Blade Asymmetric Fatigue Loads Mitigation By Wentao YANG	[View] [Download]
Abstract: To reduce the blades asymmetric loads of large wind turbines operated in the above-rated wind speed region, this work proposes a model predictive individual pitch controller with the linear interpolation model. Results show a significant reduction of 1P (once-per-revolution), 2P, 4P blade asymmetric loads within the limits of pitch rate. The proposed model of wind turbine can describe the characteristic of blade bending moment up to 4P (once-per-revolution) frequency. The MPC method with this model can reduce 1P, 2P, 4P blade asymmetric loads significantly within the limits of pitch rate.