Condition classification has been widely used for assessing equipment status for machine condition monitoring and diagnostics. An engine was fitted with one temperature and two pressure sensors to study the machine co...
详细信息
Due to the complex conditions in rotating machinery, the blades usually encounter fluctuating loads, and failures may occur in the operation. Blade vibration is rarely monitored in the practical rotating machinery in ...
Due to the complex conditions in rotating machinery, the blades usually encounter fluctuating loads, and failures may occur in the operation. Blade vibration is rarely monitored in the practical rotating machinery in power plants as the traditional blade vibration method using strain gauge method is hard to be applied in long-time and online monitoring. The blade tip timing method is a promising approach to monitor the blade vibration and several special sensors are developed to realize the online monitoring. Based on the traditional blade tip timing method, an improved approach is established in this work. The proposed method can modify the expected arriving time when the torsional vibration exists. The accuracy is therefore improved in the torsional vibration case. Then the blade vibration monitoring with the traditional blade tip timing method and the proposed method are carried out in the test rig in laboratory. The results validate that, the torsional vibration influences the expected arriving time, and the proposed method can modify the expected arriving time and improve the accuracy of the blade vibration monitoring.
The Electromagnetic Compatibility (EMC) is a major issue for the truck crane designing, due to the large dimension. The conducted disturbance sources of truck crane was measured under stable conditions, the time domai...
详细信息
ISBN:
(纸本)9781467307185
The Electromagnetic Compatibility (EMC) is a major issue for the truck crane designing, due to the large dimension. The conducted disturbance sources of truck crane was measured under stable conditions, the time domain characteristics of possible conducted disturbance sources was analyzed, and typical waveforms were concluded to solve the EMC (Electromagnetic Compatibility) issue. The electromagnetic disturbance characteristics at different test points under different operation conditions were compared, and the influence of different factors was studied. The amplitude and frequency parameters of the major disturbance sources were compared with the standard immunity test pulses suggested by ISO7637-2. The differences between them indicate that the extant standard might not apply to the test of the truck crane. The presented results could form a basis for the development of a special standard for the EMC test of the truck crane and further relevant EMC research.
Impedance method and single terminal travelling wave method are analyzed in paper, applicable scope of optimized solution is presented. Impedance method is of high robustness but low accuracy. Single terminal travelli...
详细信息
This paper studies the fault current frequency spectrum characteristics of single phase ground fault in ungrounded distribution networks, and the fault location method based on it. Firstly, it analyzes the production ...
详细信息
This paper analyzes the general process of power flow transferring and divides it into four parts: 1) the process of first phase selection after fault occurs;2) the process of selective action at the first time;3) the...
详细信息
Fault locator for power distribution system with neutral non-effectively grounded should locate phase-to-phase fault and single-phase-to-ground fault respectively. For phase-to-phase fault, the point can be located by...
详细信息
Estimating low-frequency oscillation modes and the corresponding mode shapes based on ambient data from WAMS measurements has a promising prospect of application in powersystem analysis and control. The present appro...
详细信息
Under the skin effect caused by the alternating electromagnetic field, the transmission line parameters changes with frequency, and different line resistivity, surge impedance, wave speed are presented in one line und...
详细信息
Traditional operation rules depend on human experience, which are relatively fixed and difficult to fulfill the new demand of the modern power grid. In order to formulate suitable and quickly refreshed operation rules...
详细信息
Traditional operation rules depend on human experience, which are relatively fixed and difficult to fulfill the new demand of the modern power grid. In order to formulate suitable and quickly refreshed operation rules, a method of linear decision tree based on support samples is proposed for rule extraction in this paper. The operation rules extracted by this method have advantages of refinement and intelligence, which helps the dispatching center meet the requirement of smart grid construction.
暂无评论