On-line Monitoring and Data Analysis of Environmental Vibration of High Concrete Dam

As we all know, our country has actually gradually developed into a country with frequent occurrence of global earthquakes. The global earthquakes in the southwest region are the most serious. The most severe earthquake occurred in parts of the southwest. In short, the seismic performance design of a high dam is reflected under the action of the high dam for a given amount of seismic motion and input load. At present, one of the main technical methods for studying high dam seismic engineering is to use model calculations and experiments on its structural dynamics. Moreover, the earliest dam prototype dynamic experiments in my country only occurred in the 1970s and 1980s, and few people in China conducted experiments on these dams. Although there were already a certain degree of practical results at that time, a batch of valuable materials was obtained. However, no matter from the perspective of safety or the actual effect on vibration, as well as the prototype dynamic measurement and test method of the above-mentioned main dam, it has not been well applied to the current expressway. Therefore, it is necessary to consider finding an alternative original kinetic test method. The purpose of this article is to in-depth study the data analysis and application of the online monitoring system of environmental vibration of reinforced concrete high dams in my country. A new online monitoring system for dam environmental vibration is carried out for simulation experiments. Experimental research shows that the noise frequency of the three detection points of environmental noise and vibration monitoring is basically controlled between 1.5~2.0 hz, while the noise frequency of the detection point of the symmetrical location is relatively close.

Acoustic methods in real-time welding process monitoring: Application and future potential advancement

The rapid advancement of the welding technology has simultaneously increased the demand for the online monitoring system in order to control the process. Among the methods that could be possibly used to assess the weld condition, an air-borne acoustic method grasps the attention from scholars due to its ability to provide a simple, non-contact, and low-cost measurement system. However, it is still lack of resources involving this subject in an attempt to deeply understand the emitted sound behaviour during welding especially when dealing with a complete deviation of a process parameter, welding types, workpiece material as well as the noise from the surrounding. This paper reviews the application of the acoustic method in monitoring the welding process. Specifically, this review emphasized the source of both structure-borne and air-borne acoustic during the welding process and the significance of applying the acoustic method in more detail. By focusing on the liquid state welding process, the scope of discussion converged on the arc and laser welding process. In the last part of this review, the potential future advancement of this method is pointed out before the overall conclusion is made.

Characteristics of six layered Al/Si3N4 functionally graded materials prepared through two-step pressureless sintering process

The rapid advancement of the welding technology has simultaneously increased the demand for the online monitoring system in order to control the process. Among the methods that could be possibly used to assess the weld condition, an air-borne acoustic method grasps the attention from scholars due to its ability to provide a simple, non-contact, and low-cost measurement system. However, it is still lack of resources involving this subject in an attempt to deeply understand the emitted sound behaviour during welding especially when dealing with a complete deviation of a process parameter, welding types, workpiece material as well as the noise from the surrounding. This paper reviews the application of the acoustic method in monitoring the welding process. Specifically, this review emphasized the source of both structure-borne and air-borne acoustic during the welding process and the significance of applying the acoustic method in more detail. By focusing on the liquid state welding process, the scope of discussion converged on the arc and laser welding process. In the last part of this review, the potential future advancement of this method is pointed out before the overall conclusion is made.

Online Transformer Monitoring System

Power transformers, are basically used for stepping up& down the voltage levels. They are the primary equipment used in power transmission system. So it is primary to maintain all the transformers located geographically, but due to lack of man power it is impossible to monitor regularly. Due to these reasons, if a failure occurs in transformer may cause the network power shutdown. Though there are lot of protection measures that accompany a transformer, but by providing a online monitoring system will increase the reliability and reporting instantaneous fault confidently. This paper gives out the details in design and construction of an automatic monitoring system for power transformer parameters. A node-mcu module [esp8266] was enabled to monitoring of voltage, oil level and temperature (oil & winding) on a typical power transformer. With the internet of things (IoT), a self-defense system is designed and implemented for the transformer. In this system Transformer parameter are continuously marked and a graph is plotted. If the level of the parameter increases than the actual value, it gives buzzer alarm, if no action taken then the whole system will be tripped safely in power transformers.

Centralized on-line monitoring system for pipeline and cable environment and fresh air of air conditioning

Aiming at the problem of on-line centralized monitoring error of pipeline and cable environment and fresh air of air conditioning, a utility model is designed, a centralized monitoring system of pipeline and cable environment and fresh air of air conditioning is disclosed, the system structure configuration is optimized, and the system performance is improved by combining multiple central air conditioning controllers, data processors, acquisition servers and other equipment, combined with LabVIEW technology, the system software function and operation process are improved. Finally, the experiment proves that the centralized online monitoring system for pipeline and cable environment and air conditioning fresh air can better reduce the monitoring error and ensure the real-time monitoring quality of pipeline and cable environment and air conditioning fresh air.

Research on Early Warning Technology of Lightning Arrester Defects Based on Multi-stage Information and Bayesian Inference

The differences in the probability of occurrence of different equipment and defects lead to the small sample characteristics of the defect of the arrester, which makes it difficult to train an accurate prediction model. It is difficult to identify the abnormal state when the arrester monitoring data does not exceed the limit and increase steadily relying on the arrester monitoring index and threshold to judge the defect. Therefore, a lightning arrester defect early warning method based on multi-stage information and Bayesian inference is proposed. The Bayesian inference algorithm is used to calculate the probability of defect cause categories under different feature quantities. According to the new test evidence, the probability of the defect cause category under different feature quantities is updated to identify the defect cause. The algorithm automatically adjusts the prior probability indicators of equipment defects and causes in the model based on the new detection data and annotation conclusions to ensure the accuracy of defect cause classification. The lightning arrester operation and maintenance data and online monitoring system of a power company is used to analyze and verify the effectiveness and correctness of the method proposed in this paper, which provides effective supportfor the lightning arrester operation and maintenance.

Transient Voltage UWB Online Monitoring System for Insulation Failure Analysis and Fault Location of GIL

Transient voltage generated in ultra-high voltage (UHV) transmission system has a severe impact on the insulation state of gas-insulated transmission lines (GIL). In order to monitor the transient voltage process occurring in UHV GIL during operation, this paper constructs a transient voltage ultra-wideband (UWB) online monitoring system based on capacitive voltage division. This system has been applied in an 1100 kilovolt (kV) GIL utility tunnel project. It can be used to analyze the characteristics of the recorded transient voltage waveforms for distinguishing different types of insulation failure. In this paper, through the case studies in time domain and time–frequency domain, the case of SF6 gap breakdown and that of post insulator flashover have differentiated characteristics in instantaneous frequency. Additionally, a case of secondary discharge is successfully estimated through the time–frequency distribution of the transient voltage. In order to find the malfunctioning chamber of GIL rapidly, a two-terminal TW-based fault location method based on this monitoring system is developed in this paper. The case study validates the locating accuracy which directly support for shortening the maintenance time of GIL.