PECULIARITIES OF MACHINERY CONDITION VIBRATION MONITORING WITH USING THE S-DISCRIMINANTS

2020 ◽  
pp. 4-11
Author(s):  
A. G. Sokolova ◽  
F. Ya. Balitsky ◽  
V. D. Sizarev

The paper presents the results of the specific vibration condition monitoring approach for maintenance of unique critical equipment provided complete access impossibility to its components (due to radiation environment) throughout the entire operation period. The approach bases on the previously proposed S-discriminants of vibrations which are calculated with adaptation to the reference state of the equipment. The method showed its high efficiency in detecting the moment of machine operation process imbalance and in tracking the equipment components degradation, starting from the earliest stage. It is illustrated on the example of the movable neutron reflector PO-3 of the IBR-2 research reactor that it is possible not only to detect in time the moment when a fault occurs, but also to make a preliminary express diagnosis of its condition.

Author(s):  
Fanny Pinto Delgado ◽  
Ziyou Song ◽  
Heath F. Hofmann ◽  
Jing Sun

Abstract Permanent Magnet Synchronous Machines (PMSMs) have been preferred for high-performance applications due to their high torque density, high power density, high control accuracy, and high efficiency over a wide operating range. During operation, monitoring the PMSM’s health condition is crucial for detecting any anomalies so that performance degradation, maintenance/downtime costs, and safety hazards can be avoided. In particular, demagnetization of PMSMs can lead to not only degraded performance but also high maintenance cost as they are the most expensive components in a PMSM. In this paper, an equivalent two-phase model for surface-mount permanent magnet (SMPM) machines under permanent magnet demagnetization is formulated and a parameter estimator is proposed for condition monitoring purposes. The performance of the proposed estimator is investigated through analysis and simulation under different conditions, and compared with a parameter estimator based on the standard SMPM machine model. In terms of information that can be extracted for fault diagnosis and condition monitoring, the proposed estimator exhibits advantages over the standard-model-based estimator as it can differentiate between uniform demagnetization over all poles and asymmetric demagnetization between north and south poles.


Author(s):  
Tao Wang ◽  
Jikun Li ◽  
Yuwen Liu

The control of permanent magnet synchronous motor has become an important research, and many control methods have been developed because of its high efficiency and energy-saving characteristics. This article proposes a new motor control approach based on synergetic approach in control theory (SACT) and sliding-mode control (SMC). Since the load torque of the motor will change, the moment of inertia will increase in the experiment. The load torque is estimated by the sliding-mode observer. The moment of inertia is calculated by the least squares method by adding a forgetting factor. The practical application of synergetic control theory broadens the train of thought to meet the demand of high-performance motor drive further. The simulation and experimental results show that this control scheme in this article can improve the transient response and system robustness of dynamic systems.


2021 ◽  
Vol 263 (5) ◽  
pp. 1794-1803
Author(s):  
Michal Luczynski ◽  
Stefan Brachmanski ◽  
Andrzej Dobrucki

This paper presents a method for identifying tonal signal parameters using zero crossing detection. The signal parameters: frequency, amplitude and phase can change slowly in time. The described method allows to obtain accurate detection using possibly small number of signal samples. The detection algorithm consists of the following steps: frequency filtering, zero crossing detection and parameter reading. Filtering of the input signal is aimed at obtaining a signal consisting of a single tonal component. Zero crossing detection allows the elimination of multiple random zero crossings, which do not occur in a pure sine wave signal. The frequency is based on the frequency of transitions through zero, the amplitude is the largest value of the signal in the analysed time interval, and the initial phase is derived from the moment at which the transition through zero occurs. The obtained parameters were used to synthesise a compensation signal in an active tonal component reduction algorithm. The results of the algorithm confirmed the high efficiency of the method.


1990 ◽  
Vol 37 (5) ◽  
pp. 1564-1570 ◽  
Author(s):  
Bing Zhou ◽  
D. Warner ◽  
J. Rohlf ◽  
D. Osborne ◽  
A. Marin ◽  
...  

2009 ◽  
Vol 2009 (8) ◽  
pp. 473-477 ◽  
Author(s):  
Xinying Zhang ◽  
Yingying Qu ◽  
Xuesen Fan ◽  
Xia Wang ◽  
Jianji Wang

The utilisation of an ionic liquid-[bmim][BF4] as both reaction medium and promoter for the reaction between aldehyde and 4-hydroxy-6-methylpyran-2-one is described. Without any added catalyst, this reaction was realised efficiently to give arylbispyranylmethane derivatives in high yields. Alternatively, when this reaction was carried out in the presence of acetic anhydride, fused pyran derivatives were obtained. These two novel procedures have advantages such as an environmentally benign nature, high efficiency, simple operation process and mild reaction conditions. As an application, these procedures were used in the preparation of novel 5-substituted pyrimidine nucleoside derivatives with potential antiviral activities.


Author(s):  
James C. Adams

Industrial aeroderivative gas turbines are becoming increasingly popular for use in both on-shore and off-shore installations. The characteristics of these machines — high efficiency in simple cycle operation, small size, and light weight — make them ideal for industrial applications. As the aeroderivative gas turbine has become more widely used, the need for more reliable monitoring methods has become increasingly apparent. Traditional velocity transducer based seismic monitoring systems have had several shortcomings when applied to aeroderivative gas turbines. One of these problems was nuisance alarms due to increasing transducer noise output. Another was not detecting increasing casing vibration because of transducer deterioration. Overcoming these problems has required advances in transducer technology as well as changes in signal processing techniques. This paper describes the technology and techniques used in new seismic vibration monitoring systems.


2013 ◽  
Vol 838-841 ◽  
pp. 1018-1023
Author(s):  
Tao Wang ◽  
Le Wang ◽  
Cang Nan Li

With the background of bridge on Riverside Avenue cross over Yangtze River tunnels in Nanjing, studies on the influence of bridge construction and operation on the Yangtze River tunnels are as followed. First, safety control standards of Yangtze River tunnels are presented according to safety situation of the tunnel and the deformation property of super large shield tunnels. Then bridge construction and operation process is simulated to study the engineering influence on adjacent Yangtze River tunnel, to which the excavation of bearing platform foundation pits and piles, and bridge loads are considered. Safety state of Yangtze River tunnel during bridge construction and operation period is estimated based on the safety control standards and numerical simulation results. Construction scheme is optimized, and suggestions are also given to reduce harmful effect on the tunnels brought by construction of the bridge.


2010 ◽  
Vol 450 ◽  
pp. 259-262 ◽  
Author(s):  
Chao Ching Ho ◽  
Tzu Hsin Kuo ◽  
Tsung Ting Tsai

Designing a robust condition monitoring system for a machine tool spindle is an important task because the spindle has a significant effect on the processing quality. In this study, a solar-powered wireless sensor system is installed inside the spindle and is used to monitor the machine tool processing state in real time, thereby improving the processing quality. Accelerometer sensors are employed to estimate tool wear; these sensors monitor the vibration of the spindle. The vibration monitoring data of the high-speed spindle is wirelessly transmitted to an external information device in real time. As an alternative to sensors that employ wired power transmission, a solar energy transmission system has been developed to provide the required electric power to the sensor system. The experimental results show that the proposed system successfully measures the vibration frequency of the rotational machine tool spindle.


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