Investigation of Inverter Temperature Prediction Model in Wind Farm Based on SCADA Data

The inverter is one of the key components of wind turbine,and it is a complex circuit composed of a series of components such as a variety of electronic components and power devices.Therefore,it is difficult to accurately identify the operation states of inverter and some problems regarding its own circuit,especially in the early stages of failure.However,if the inverter temperature prediction model can be established,the early states can be identified through the judgment of the output temperature.Accordingly,considering whether the inverter heats up normally from the perspective of heat dissipation,a method for the early operation state identification of the inverter is provided in this paper.A variable selection method based on fusion analysis of correlation and physical relationship is adopted to extract variables as input variables,which have high correlation with inverter temperature.Then multi-input and multi-output temperature prediction model of inverter is established based on a nonlinear autoregressive exogenous model(NARX)network,and the prediction temperature residual is used as the real-time standard to evaluate the inverter states.For validating this,the validity and reliability of the established temperature prediction model are verified through case analysis,and the performance comparison with various models demonstrates that the proposed method has higher accuracy.The construction method of the prediction model can be used for reference to other aspects of wind turbine.All these bring huge benefits to wind energy industry.

Open-Circuit Faults Diagnosis in Direct-Drive PMSG Wind Turbine Converter

The condition monitoring and fault diagnosis have been identified as the key to achieving higher availabilities of wind turbines.Numerous studies show that the open-circuit fault is a significant contributor to the failures of wind turbine converter.However,the multiple faults combinations and the influence of wind speed changes abruptly,grid voltage sags and noise interference have brought great challenges to fault diagnosis.Accordingly,concerning the open-circuit fault of converters in direct-driven PMSG wind turbine,a diagnostic method for multiple open-circuit faults is proposed in this paper,which is divided into two tasks:The first one is the fault detection and the second one is the fault localization.The detection method is based on the relative current residuals after exponential transformation and on an adaptive threshold,and the localization method is based on the average values of fault phase currents.The scheduled diagnosis method is available to both the generator-side converter and the grid-side converter,allowing to detect and locate single and double open-circuit faults.For validating this,robustness test and multiple open-circuit faults diagnosis are presented in a 2-MW direct-driven PMSG wind turbine system,the results validate the reliability and effectiveness of the proposed method.