软件MTBF计算方法研究

对传统的软件可靠性模型进行了分析和研究,指出了传统模型存在的一些问题,提出了将未确知理论应用于软件可靠性的研究中,该方法摆脱了对软件故障过程的各种分布假设,算法简单、稳健性好。最后通过实例对新算法和传统算法进行了比较与分析。     

三峡五级船闸控制系统可靠性分析

 为了分析三峡五级船闸控制系统的可靠性，采用了故障树分析法，建立了控制系统的故障树 模型，并对该两冗余系统进行了定性及定量分析，由此计算出平均无故障时间(MTBF) 。在此基础上，进一步提出了通过增加仿真模型来改进并联冗余结构，从而提高了系统决策 可靠性。     

提高电力调度通信网可靠性的技术实现

描述了3种提高电力调度通信网可靠性和稳定性的技术实现方式,包括中心调度机冗余技术,双U口技术以及路由备份技术。阐述了在工程组网中,如何综合运用这3种技术,组成一个完整的容灾调度系统;同时介绍了这种容灾调度系统的2种衍生运用方式,为电力用户提供新的应用。     

一种基于MATLAB的军用电子板卡可靠性预计计算方法

为解决军用电子板卡可靠性计算速度及准确性等问题,先对其预计计算模型和计算方法进行阐述,介绍利用MATLAB预计可靠性的方法,给出计算步骤,并举例进行说明该方法与传统方法相比提高了效率和准确性。     

试运行期间风电机组平均故障间隔时间的估计

试运行期间平均故障间隔时间(mean time between failures,MTBF)是反映风电机组可靠性的重要指标,但由于此期间的运行故障数据样本少且故障停机随机性较强,现有MTBF分析方法的误差较大。针对此种小样本估计问题和故障的随机性,提出了一种利用多台机组运行信息的MTBF估计方法。其基本思路是:根据风电机组安装及其故障数据的特点,构造具有相同配置的多台故障停机的随机截尾数据,对机组的可靠度进行Kaplan-Meier非参数估计;基于这种初步估计结果,再进行二参数威布尔(Weibull)分布拟合,并根据Weibull分布的性质计算得到机组的MTBF。该文利用北方某风电场的试运行数据,对2012年11月投产的20台风电机组进行了MTBF分析计算,结果表明该方法能够有效提高机组试运行期MTBF估计的精度。     

An analysis of reliability in the early stages of photovoltaic systems in Japan

In order to disseminate Photovoltaic (PV) technologies into the energy network, the cost down is not only important, but also improving the performance of the PV system is significant issues. Long‐term reliability is one of the most important issues in terms of PV system performance. Previous researches were mainly focused on the reliability of PV modules, but the PV system is composed of a power conditioner, wiring, junction box, and so on. To improve the reliability of PV systems, it is important to accumulate trouble cases focused on all components of PV system. In this paper, we aim at evaluation of the reliability for the PV system on the early stages of PV system's lifetime by using large number of Japanese PV systems' data from the field Test in Japan. New Energy and Industrial Technology Development Organization has been running the “Field test project in Japan” from 1992. In this project, PV system users have cooperated with the collection of monitoring data and reported on the information of maintenance and certain failures of PV systems for 4 years after installation of PV system. Using those reports each year of installation, we evaluated reliability of PV systems by means of parameters such as Mean Time Between Failure, Mean Time To Repair, and the suspension time of PV system. As a result, the main trouble of PV systems was related power conditioner, and a few trouble of PV module was caused by typhoon. Moreover, the trend of the failure rate before FY 2000 of installation was demonstrated as the trend of initial failure in “bathtub curve;” however, the trend of its after FY 2001 of installation was indicated as the accidental failure in “bathtub curve.” Further, the operator simply forgot to restart the power conditioner after maintenance or suspensions of PV system in many trouble cases, and the user did not notice that it had been suspended for a while. These trouble cases can be avoidable easily through the effective alarm such as error message of power conditioner systems with monitoring systems. Thereby, monitoring with the evaluation method of PV systems is one of the important technologies due to the long‐term reliability and stable operation. Copyright © 2010 John Wiley & Sons, Ltd.