The Partial Discharge Test of Transformer Using Frequency Modulation Type Series Resonance Method

2014 ◽  
Vol 543-547 ◽  
pp. 705-708
Author(s):  
Yang Su ◽  
Qing Hao Wang ◽  
Bo Liu ◽  
Hai Nan Su ◽  
Yan Hai Huang ◽  
...  
Keyword(s):  
Resonance Method ◽  
Test Methods ◽  
Test Device ◽  
Type Series ◽  
Series Resonance ◽  
Resonance Test ◽  
Modulation Type ◽  
Technical Principles ◽  
Frequency Power ◽  
Discharge Test

Traditional frequency power and test equipment cannot meet the requirements. This paper discusses in detail the composition of FM type series resonance test device, technical principles, characteristics and advantages. And also introduces wiring method, test methods, test standard. The instance proves that discharge test of large transformer using the FM series resonance device is convenient and accurate.

To the Problems of Determination of Dynamic Elasticity Modules of Calcium Silicate Bricks by Means of Resonance Method

2014 ◽  
Vol 897 ◽  
pp. 139-143 ◽  
Author(s):  
Jiří Brožovský ◽  
Ámos Dufka
Keyword(s):  
Modulus Of Elasticity ◽  
Calcium Silicate ◽  
Building Materials ◽  
Resonance Method ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Test Methods ◽  
Test Method ◽  
Resonance Test ◽  
Accuracy Of Measurement

Modulus of elasticity of building materials can be determined in a static way (loading in a press) or by means of non-destructive test methods (ultrasonic pulse method and resonance method); the parameter is most frequently determined for concrete and both methods of determining elasticity modulus are codified in Standards. Elasticity characteristics of calcium silicate bricks were determined by means of resonance test method. Because the shape of calcium silicate bricks (a block with oblong foot) is different from the shape of test specimens for concrete (usually blocks with square foot), expected frequencies for verification of accuracy of measurement by resonance method were determined. Moisture content of calcium silicate bricks (water absorbing capacity is up to 12-14%) has influence on the value of resonance frequency. Difference between dynamic Young's modulus of elasticity from fundamental longitudinal and transverse resonant frequency is on average 2.8%.

Study on the Maintenance and Management of VRLA Battery

2014 ◽  
Vol 644-650 ◽  
pp. 3902-3905
Author(s):  
Wen Cui Li ◽  
Yi Yang ◽  
Hao Zhang ◽  
Jing Xian Lv ◽  
Xin Jian Shu
Keyword(s):  
Test Methods ◽  
Processing Method ◽  
Control Measures ◽  
Lead Acid Battery ◽  
Operation And Maintenance ◽  
Basic Characteristics ◽  
Maintenance Requirements ◽  
Vrla Battery ◽  
Charge Discharge ◽  
Discharge Test

The paper introduced the basic characteristics, maintenance requirements and backward cell processing method of Valve Regulated Lead Acid Battery (VRLA) based on the practice of substation communication, elaborated the charge-discharge test battery requirements. This paper discussed the test of battery operation and maintenance, charge and discharge risk. Through the test methods of battery communication charging and discharging and the steps of analysis, we find out the possible dangerous points in processing of charging and discharging, and at the same time, we list the typical examples on safety risk and carry on the analysis on accident cause to put forward the pre-control measures.

Developing a More Inclusive System Level ESD Characterization Methodology

2005 ◽  
Author(s):  
Johan Rahardjo ◽  
Socorro Miller ◽  
Leo Lopez ◽  
Steve L. Williams
Keyword(s):  
Current System ◽  
Electronic Devices ◽  
Test Methods ◽  
System Level ◽  
Test Methodology ◽  
Inclusive System ◽  
Novel Method ◽  
Contact Discharge ◽  
Field Failure ◽  
Discharge Test

Abstract ESD (Electrostatic Discharge) has become an increasing problem on electronic devices. The electronics industry is always looking for ways to improve the reliability of electronic devices by enhancing their test methods. The industry has found that the current ESD test methods do not encompass all possible scenarios to which electronic devices are exposed at the customer site. This paper describes a novel method to bridge the gap between current system level ESD specifications and customer real world situations. Field failure investigations led us to discover a new customer situation where ESD is induced on a computer system through a peripheral/cable that is already attached (different than hot-plug event). To simulate this scenario, ESD was injected directly into the signal pins of the bus being tested, creating what we call the DCD (Direct Contact Discharge) test methodology. This paper compares DCD against the current ESD standards and demonstrates that introducing DCD into the current ESD testing methodology will significantly lower the system field failures. DCD is not a replacement for current ESD testing practices in the industry; DCD is a complement that allows a more inclusive ESD test coverage

Distributed Capacitance Calculation Model in GIS Voltage Transformer’s Error Test

2015 ◽  
Vol 738-739 ◽  
pp. 820-825 ◽  
Author(s):  
Xian Shun Chen ◽  
Yong Sen Li ◽  
Yang Jiao ◽  
Guo Ci Lei
Keyword(s):  
Power Systems ◽  
Theoretical Basis ◽  
High Reliability ◽  
Resonance Method ◽  
Physical Structure ◽  
Calculation Model ◽  
Equivalent Model ◽  
Metal Shell ◽  
Long Distance ◽  
Series Resonance

With the advantages of miniaturization and high reliability, Gas Insulated Substations (GIS) have been applied to power systems widely. However, GIS voltage transformers have troubles in boosting voltage in error test because of GIS’s special physical structure. A calculation model was proposed to solve the difficulty of distributed capacitances’ calculation when it adopts series resonance method in error test. By analyzing and getting the corresponding parameters of primary equipment, a GIS voltage transformer’s test connection equivalent model was built. Compared with measured value in a 500 kV GIS hydropower station, the error is below 8%. And the results confirmed that the long-distance bus and metal shell will form a large distributed capacitances which have a great impact on the error test. In this paper, the calculation model provides theoretical basis for error test. Moreover, it can be applied to field test, which will save equipment transportation costs, time and resources.

Simulation and Design of Portable Underwater Acoustic Transducer Test Device

2014 ◽  
Vol 599-601 ◽  
pp. 445-450
Author(s):  
Tao Wei Huang ◽  
Di Xiang Chen ◽  
Cheng Guang Fan
Keyword(s):  
Finite Element ◽  
Piezoelectric Ceramic ◽  
Sound Field ◽  
Test Methods ◽  
Comsol Multiphysics ◽  
Test Device ◽  
Underwater Acoustic ◽  
Device Model ◽  
Single Function ◽  
Acoustic Transducer

In this paper, a portable underwater acoustic transducer sensitivity test device is designed to overcome the disadvantages of traditional test methods, such as the bigger size of anechoic pool, and single function of the vibrating column of liquid method. This new design has the advantage of small size, easy to carry and implement. A model of this device is constructed based on the finite element analyse software COMSOL Multiphysics. By calculating the sound field distribution of the test device model, the optimization size of the piezoelectric ceramic can be determined. Also the effect of some other key parameters, such as the material of vessel and thickness, are considered. All these results can provide the theoretical basement of the design of portable underwater acoustic transducer in practice.

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