scholarly journals Utilizing Data from a Sensorless AC Variable Speed Drive for Detecting Mechanical Misalignments

2013 ◽  
Vol 569-570 ◽  
pp. 465-472 ◽  
Author(s):  
Samieh Abusaad ◽  
Ahmed Benghozzi ◽  
Yi Min Shao ◽  
Feng Shou Gu ◽  
Andrew Ball
Keyword(s):  
Condition Monitoring ◽  
Feedback Signal ◽  
Variable Speed ◽  
Detection Capability ◽  
Conventional Condition ◽  
Additional Equipment ◽  
And Performance ◽  
Thermal Techniques ◽  
Detection Schemes ◽  
Transient And Steady State

Conventional condition monitoring techniques such as vibration, acoustic, ultrasonic and thermal techniques require additional equipment such as sensors, data acquisition and data processing systems which are expensive and complicated. In the meantime modern sensorless flux vector controlled drives can provide many different data accessible for machine control which has not been explored fully for the purpose of condition monitoring. In this paper polynomial models are employed to describe nonlinear relationships of variables available from such drives and to generate residuals for real time fault detection and performance comparisons. Both transient and steady state system behaviours have been investigated for optimal detection performance. Amongst 27 variables available from the drive, the torque related variables including motor current, Id, Iqcurrents and torque signals show changes due to mechanical misalignments. So only these variables are explored for developing and optimising detection schemes. Preliminary results obtained based on a motor gearbox system show that the torque feedback signal, in both the steady and transient operation, has the highest detection capability whereas the field current signal shows the least sensitivity to such faults.

SIMULATION AND PERFORMANCE COMPARISON OF VARIABLE SPEED MULTI-PHASE PMSM MACHINES

2018 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
MOIN SIDDIQUI KHADIM ◽  
FATMA AMREEN ◽  
KHURSHEED SIDDIQUI MOHD ◽  
◽  
◽  
...  
Keyword(s):  
Performance Comparison ◽  
Variable Speed ◽  
And Performance ◽  
Multi Phase

scholarly journals Two Current-Based Methods for the Detection of Bearing and Impeller Faults in Variable Speed Pumps

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4514
Author(s):  
Vincent Becker ◽  
Thilo Schwamm ◽  
Sven Urschel ◽  
Jose Alfonso Antonino-Daviu
Keyword(s):  
Condition Monitoring ◽  
False Alarms ◽  
Signature Analysis ◽  
Variable Speed ◽  
Monitoring Methods ◽  
Time Frequency ◽  
Motor Current ◽  
Load Point ◽  
Bearing Defects ◽  
Current Signature

The growing number of variable speed drives (VSDs) in industry has an impact on the future development of condition monitoring methods. In research, more and more attention is being paid to condition monitoring based on motor current evaluation. However, there are currently only a few contributions to current-based pump diagnosis. In this paper, two current-based methods for the detection of bearing defects, impeller clogging, and cracked impellers are presented. The first approach, load point-dependent fault indicator analysis (LoPoFIA), is an approach that was derived from motor current signature analysis (MCSA). Compared to MCSA, the novelty of LoPoFIA is that only amplitudes at typical fault frequencies in the current spectrum are considered as a function of the hydraulic load point. The second approach is advanced transient current signature analysis (ATCSA), which represents a time-frequency analysis of a current signal during start-up. According to the literature, ATCSA is mainly used for motor diagnosis. As a test item, a VSD-driven circulation pump was measured in a pump test bench. Compared to MCSA, both LoPoFIA and ATCSA showed improvements in terms of minimizing false alarms. However, LoPoFIA simplifies the separation of bearing defects and impeller defects, as impeller defects especially influence higher flow ranges. Compared to LoPoFIA, ATCSA represents a more efficient method in terms of minimizing measurement effort. In summary, both LoPoFIA and ATCSA provide important insights into the behavior of faulty pumps and can be advantageous compared to MCSA in terms of false alarms and fault separation.

A Study on the New Grid Integration Solutions of Offshore Wind Farms

2011 ◽  
Vol 383-390 ◽  
pp. 3610-3616 ◽  
Author(s):  
Xin Yin Zhang ◽  
Zai Jun Wu ◽  
Si Peng Hao ◽  
Ke Xu
Keyword(s):  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Grid Integration ◽  
Variable Speed ◽  
Reliable Operation ◽  
Offshore Wind Farms ◽  
Electrical Interconnection ◽  
Investment Cost ◽  
And Performance

Offshore wind farm is developed in the ascendant currently. The reliable operation, power loss, investment cost and performance of wind farms were effect by the integration solutions of electrical interconnection system directly. Several new integration configurations based on VSC-HVDC were comparative analyzed. For the new HVDC topology applied the wind farm internal DC bus, the Variable Speed DC (VSDC) system that is suitable for those topologies was proposed. The structure of VSDC was discussed and maximum wind power tracking was simulated on the minimal system. It is clear that new integration configurations based on VSC-HVDC has good prospects.

Multi-Zone Proportional Hazard Model for a Multi-Stage Degradation Process

2013 ◽  
Author(s):  
Lin Li ◽  
Zeyi Sun ◽  
Xinwei Xu ◽  
Kaifu Zhang
Keyword(s):  
Decision Making ◽  
Condition Monitoring ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Degradation Process ◽  
Remaining Useful Life ◽  
Monitoring Data ◽  
Status Change ◽  
Multi Stage ◽  
And Performance

Conditional-based maintenance (CBM) decision-making is of high interests in recent years due to its better performance on cost efficiency compared to other traditional policies. One of the most respected methods based on condition-monitoring data for maintenance decision-making is Proportional Hazards Model (PHM). It utilizes condition-monitoring data as covariates and identifies their effects on the lifetime of a component. Conventional modeling process of PHM only treats the degradation process as a whole lifecycle. In this paper, the PHM is advanced to describe a multi-zone degradation system considering the fact that the lifecycle of a machine can be divided into several different degradation stages. The methods to estimate reliability and performance prognostics are developed based on the proposed multi-zone PHM to predict the remaining time that the machine stays at the current stage before transferring into the next stage and the remaining useful life (RUL). The results illustrate that the multi-zone PHM effectively monitors the equipment status change and leads to a more accurate RUL prediction compared with traditional PHM.

Prognostics and Health Management of Choke Valves Subject to Erosion

2013 ◽  
pp. 313-331
Author(s):  
Giulio Gola ◽  
Bent H. Nystad
Keyword(s):  
Condition Monitoring ◽  
Performance Monitoring ◽  
Oil And Gas ◽  
Health Management ◽  
Cost Savings ◽  
Remaining Useful Life ◽  
Work Processes ◽  
Offshore Oil And Gas ◽  
And Performance ◽  
Monitoring Technologies

Oil and gas industries are constantly aiming at improving the efficiency of their operations. In this respect, focus is on the development of technology, methods, and work processes related to equipment condition and performance monitoring in order to achieve the highest standards in terms of safety and productivity. To this aim, a key issue is represented by maintenance optimization of critical structures, systems, and components. A way towards this goal is offered by Condition-Based Maintenance (CBM) strategies. CBM aims at regulating maintenance scheduling based on data analyses and system condition monitoring and bears the potential advantage of obtaining relevant cost savings and improved operational safety and availability. A critical aspect of CBM is its integration with condition monitoring technologies for handling a wide range of information sources and eventually making optimal decisions on when and what to repair. In this chapter, a CBM case study concerning choke valves utilized in Norwegian offshore oil and gas platforms is proposed and investigated. The objective is to define a procedure for optimizing maintenance of choke valves by on-line monitoring their condition and determining their Remaining Useful Life (RUL). Choke valves undergo erosion caused by sand grains transported by the oil-water-gas mixture extracted from the well. Erosion is a critical problem which can affect the correct valve functioning, resulting in revenue losses and cause environmental hazards.

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