Research On Fault Location Method For Variable Pitch System Of Wind Turbine

The world petrochemical energy crisis is becoming more and more obvious,and it is a new trend of the development of renewable energy.And wi nd energy,as an important kind of renewable energy,is developing rapidly.By the end of 2015,China's cumulative installed capacity of 145.4GW is located in the world's first,accounting for 33.6% of the total installed capacity of the world.These figur es mean that there are more than 90 thousand sets of wind turbines need least 20 years of follow-up maintenance.In this process,the fault diagnosis of wind power equipment will be essential and very important.Among all the wind turbine equipments,the variable pitch system which used as the power regulation and safety brake system of the wind turbine is often move with the change of wind speed,and it's working environment is bad,so the failure rate of the variable pitch system is very high.But there are few researches on the fault diagnosis of the pitch system.And the detection and diagnosis of the variable pitch system of wind turbine in the wind farm depend on the SCADA(supervisory control and data acquisition)alarm system.However because of the SCADA system does not consider the strong coupling between the subsystems of the wind turbine and the operating parameters of the wind turbine,the true fault location cannot be confirmed by the ambiguous alarm information appeared in the SCADA system of a wind farm when abnormal data are detected,and this has brought more difficulties to fault repair.Therefore,the Fisher Discriminant Analysis(FDA)method is introduced to the fault diagnosis of pitch-controlled systems in this paper,and a fault source separation method based on the FDA contribution diagram is proposed to identify the alarm information of SCADA.In this approach,the deviation direction of fault data is calculated as well as the deviation contribution rate of each variable to the directio n;then the FDA contribution diagram is generated for recognizing the primary parameter that caused alarm,separating the fault source,and locating the faulty component in the electric pitch system.The effectiveness of this method is verified through the analysis of the simulation data and industrial instances and it can be used in the fault diagnosis and maintenance decision of wind turbines.In addition,this paper,from the structure of the variable pitch system and its logical connection,draw the structure of the variable pitch system diagram and the structure of the logic relation diagram.Then,the fault characteristics of the variable pitch system are analyzed on the basis of the above,including its distribution characteristics,transmission characteristics and performance characteristics.Then with the main power supply,control signals and communication signals as the transmission path,the transmission diagram of each subsystem and structure of the variable pitch system is drawn.Finally,the FMEA analysis method is used to analyze the failure mode of the variable pitch system.Based on the failure modes of the variable pitch system,through the structural topology and transmission path analysis of the variable pitch system,the path analysis is carried out to find out the possible causes of the fault,so as to realize the fault location,and the 9 FMEA analysis tables,including the pitch control system and the actuator,are formed as well.