In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are ...In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are incorporated.Three significant CCF groups (real time servers,gateways,reactor protection system) and three typical time intervals (10 min,1 h,and 24 h) are selected in the analysis.It is concluded that the network contribution of CCF accounts for over 68% of the system failure probability.The result indicates that GFM is suitable for the network reliability analysis.展开更多
Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by...Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by analyzing the existing methods, some optimized methods are adopted. Considering safety, those methods are improved in data processing algorithms, floating threshold with multiple values, association with specific working condition, etc. These measures im- prove the nuclear instrument control system in fault tolerance and fault diagnosis, especially, the shutdown number of nucle- ar power plant decreases.展开更多
An overview of recent advances in digital control of low-to medium-power DC/DC switching converters is presented.Traditionally,analog electronics methods have dominated in controlling such DC/DC converters.However,wit...An overview of recent advances in digital control of low-to medium-power DC/DC switching converters is presented.Traditionally,analog electronics methods have dominated in controlling such DC/DC converters.However,with the steadily decreasing cost of ICs,the feasibility of digitally controlled DC/DC switching converters has increased sig-nificantly.This paper outlines a sample of digital solutions for DC/DC switching converters to enhance the performance of DC/DC switching converters.Furthermore,latest research activities pertaining to applications for steady-state and dy-namic performance improvement,such as efficiency optimization,controller auto tuning,and capacitor charge balance control,is discussed.These applications demonstrate the significant advantages and potentials of digital control.展开更多
人机接口设备是核电厂安全级仪控系统(Digital Instrumentation and Control System,DCS)的重要部件,鉴定试验要求在试验应力下对其进行操作,并测试其功能和性能。核电DCS设备鉴定的部分试验条件十分严酷,很难在试验中对设备进行操作。...人机接口设备是核电厂安全级仪控系统(Digital Instrumentation and Control System,DCS)的重要部件,鉴定试验要求在试验应力下对其进行操作,并测试其功能和性能。核电DCS设备鉴定的部分试验条件十分严酷,很难在试验中对设备进行操作。之前采用的方法是测试人员穿防护设备进入温箱等严酷环境进行测试,既影响了试验效率,又可能对测试人员造成健康上的损害。本文首先分析了鉴定试验的环境特点;然后提出采用步进电机进行精确控制的方法,实现对人机接口设备的自动操作;最后结合鉴定试验特点,给出对机械臂的防护措施。基于该测试方法集成的自动测试装置已投入鉴定试验活动中,并实现了远程全自动操作。展开更多
基金Supported by Nuclear Safety Research Association and Tohoku University for Nuclear Researchers Exchange Program 2010National High Technology and Development Program ("863"Program)of China(No.2007AA041009)
文摘In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are incorporated.Three significant CCF groups (real time servers,gateways,reactor protection system) and three typical time intervals (10 min,1 h,and 24 h) are selected in the analysis.It is concluded that the network contribution of CCF accounts for over 68% of the system failure probability.The result indicates that GFM is suitable for the network reliability analysis.
基金Research Project of Hunan Province Education Department(No.14C0972)
文摘Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by analyzing the existing methods, some optimized methods are adopted. Considering safety, those methods are improved in data processing algorithms, floating threshold with multiple values, association with specific working condition, etc. These measures im- prove the nuclear instrument control system in fault tolerance and fault diagnosis, especially, the shutdown number of nucle- ar power plant decreases.
文摘An overview of recent advances in digital control of low-to medium-power DC/DC switching converters is presented.Traditionally,analog electronics methods have dominated in controlling such DC/DC converters.However,with the steadily decreasing cost of ICs,the feasibility of digitally controlled DC/DC switching converters has increased sig-nificantly.This paper outlines a sample of digital solutions for DC/DC switching converters to enhance the performance of DC/DC switching converters.Furthermore,latest research activities pertaining to applications for steady-state and dy-namic performance improvement,such as efficiency optimization,controller auto tuning,and capacitor charge balance control,is discussed.These applications demonstrate the significant advantages and potentials of digital control.
文摘人机接口设备是核电厂安全级仪控系统(Digital Instrumentation and Control System,DCS)的重要部件,鉴定试验要求在试验应力下对其进行操作,并测试其功能和性能。核电DCS设备鉴定的部分试验条件十分严酷,很难在试验中对设备进行操作。之前采用的方法是测试人员穿防护设备进入温箱等严酷环境进行测试,既影响了试验效率,又可能对测试人员造成健康上的损害。本文首先分析了鉴定试验的环境特点;然后提出采用步进电机进行精确控制的方法,实现对人机接口设备的自动操作;最后结合鉴定试验特点,给出对机械臂的防护措施。基于该测试方法集成的自动测试装置已投入鉴定试验活动中,并实现了远程全自动操作。
