基于分布函数优选的风电机组可靠性建模与分析研究

Research on reliability modeling and analysis of wind turbine based on distribution function optimization

可靠性模型是可靠性分析的基础,传统的可靠性建模以整个系统为研究对象,通过利用所有故障数据对系统的分布函数进行拟合、参数估计和模型优选,以确定系统的分布类型及分布函数,进而计算系统的可靠性指标。风电机组是一个典型的复杂机电系统,各子系统的功能、结构以及故障形式各不相同,用一个分布函数来确定整个系统的故障分布显然不合适。对此,基于收集整理的风电机组故障数据,提出基于分布函数优选的风电机组可靠性建模和分析技术,利用常用的指数分布、正态分布、对数正态分布、威布尔分布和伽马分布,对风电机组各子系统的故障间隔时间进行分布函数拟合、参数估计和拟合优度分析,确定了各子系统故障间隔时间的分布函数和子系统可靠度函数。在此基础上,采用Copula连接函数,在考虑子系统故障相关性的基础上,建立了风电机组的整机可靠度函数模型,并以某海上风电机组的故障数据为例进行了实例分析,验证了所提方法的可行性。

The reliability model is the foundation of reliability analysis.Traditional reliability modeling focuses on the entire system as the research object.By using all fault data to determine the distribution type and function of the system,and then calculate the reliability index of the system.Wind turbine is a typical complex electromechanical system,with different functions,structures,and fault forms of each subsystem.It is obviously inappropriate to use one distribution function to determine the fault distribution of the entire system.Based on the collected and sorted fault data of wind turbines,this paper proposes the distribution function optimization-based reliability modeling and analysis technology of wind turbines.By using the commonly used Exponential distribution,Normal distribution,Log-normal distribution,Weibull distribution and gamma distribution,the distribution function fitting,parameter estimation and goodness of fit analysis of the fault interval of each subsystem of wind turbines are carried out,and the distribution function and subsystem reliability function of the fault interval time of each subsystem are determined.Then,a Copula connection function was used to establish the reliability function model for wind turbines,taking into account the fault correlation between subsystems.Finally,an example analysis was conducted on the fault data of a offshore wind turbine to verify the feasibility of the method proposed in this paper.