scholarly journals Checkability of the circuits in FPGA designs according to power dissipation

Author(s):  
V. V. Antoniuk ◽  
A. V. Drozd ◽  
J. V. Drozd ◽  
H. S. Stepova

The authors consider the checkability issues of FPGA designs and analyze the logical (structural and structurally functional) checkability. The paper describes the features of safety-related systems that can operate in normal and emergency mode. In these modes different input data are fed to the inputs of the digital circuits of the components, which leads to an expansion of the structurally functional checkability to dual-mode. The paper shows the problem of hidden faults, which can accumulate in the normal mode and manifest themselves in the emergency mode. The features of checkability of circuits in FPGA projects and its advantages important for critical applications are noted. The limitations of the logical checkability of the circuits are analyzed, as well as the possibility and expediency of expanding the traditionally used logical form to power usage checkability. The study defines the checkability of circuits in FPGA projects by power usage and determines its subtypes — lower and upper checkability. Lower checkability is important in identifying faults that lead to lower power usage, for example, in chains of common signals, such as reset or synchronization. The upper one is important for identifying faults that increase the level of power usage, for example, short-circuits. The authors identify the possibility of assessing the power usage checkability of FPGA projects in terms of the power dissipation or power consumption and indicate the possibility of developing upper checkability by the dissipated power. The features of power dissipation monitoring for FPGA projects are noted. An analytical assessment for the checkability of circuits for short-circuit faults, which increase the dissipated power, and the organization of monitoring its excess are proposed. Experiments in Quartus Prime Lite CAD to assess upper checkability by power dissipation of scalable shift register circuits, that are implemented in FPGA projects, based on default IP-Core and a custom VHDL description, are carried out. The paper presents experimental results, that estimate the dependence of the checkability level on the area, occupied by the circuit on the FPGA chip.

2020 ◽  
Vol 178 ◽  
pp. 01057
Author(s):  
Olga Ahmedova ◽  
Anatoliy Soshinov ◽  
Natalia Shevchenko

Devices of fault location are widespread in electrical grids. In overhead power lines of voltages of 10 kV and higher, such devices are based on measurements of parameters in emergency mode. These devices can be divided into two main groups: designed to determine fault location of short circuits and of ground short circuit. In both cases, when detecting fault location, analyzed are not only the current and voltage parameters at the accident time, but also the parameters of overhead power line. When analyzing equivalent circuits of power lines, approximate tabular values of direct and quadrature parameters are used. It was revealed, that the line parameters are significantly affected by external atmospheric factors: ambient temperature, soil moisture, wind strength and direction, ice formation, etc. To accurately determine the fault location, it is necessary to evaluate the influence of these factors on the linear parameters of the overhead line. The paper presents analysis of the influence of changes in atmospheric factors on parameters of overhead power line. A methodology for calculating the operation setpoints of the device for fault location in power line is given.


2019 ◽  
pp. 118-126
Author(s):  
Oleksandr Drozd ◽  
Viktor Antoniuk ◽  
Miroslav Drozd ◽  
Volodymyr Karpinskyi ◽  
Pavlo Bykovyy

This paper is dedicated to the problem of the circuit checkability of components in the safety-related systems, which operate objects of the increased risk and are aimed at ensuring safety of both a system and a control object for accident prevention and a decrease in their consequences. Importance of the checkability of the circuits for ensuring safety in critical applications is emphasized as safety is based on the use of fault tolerant circuitry decisions and their efficiency is defined by the circuit checkability. Development of a logical checkability from testability to structurally functional and dual-mode model which formalizes a problem of the hidden faults and defines ways of its solution is shown. The limitation of a logical checkability in detection of faults in chains of the common signals and the need for development of checkability out of the limits of a logical form, including suitability to checking the circuits on the basis of their power consumption is considered. Power-consumption-oriented checkability (Power-checkability) allowing detection of faults in chains of the common signals is defined. Its analytical assessment for the circuits implemented in FPGA is offered. Experiments providing estimation of power-checkability for FPGA-implementation of iterative array multipliers with various activities of input signals are carried out.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2160
Author(s):  
Arthur K. Barnes ◽  
Jose E. Tabarez ◽  
Adam Mate ◽  
Russell W. Bent

Protecting inverter-interfaced microgrids is challenging as conventional time-overcurrent protection becomes unusable due to the lack of fault current. There is a great need for novel protective relaying methods that enable the application of protection coordination on microgrids, thereby allowing for microgrids with larger areas and numbers of loads while not compromising reliable power delivery. Tools for modeling and analyzing such microgrids under fault conditions are necessary in order to help design such protective relaying and operate microgrids in a configuration that can be protected, though there is currently a lack of tools applicable to inverter-interfaced microgrids. This paper introduces the concept of applying an optimization problem formulation to the topic of inverter-interfaced microgrid fault modeling, and discusses how it can be employed both for simulating short-circuits and as a set of constraints for optimal microgrid operation to ensure protective device coordination.


2014 ◽  
Vol 513-517 ◽  
pp. 281-285
Author(s):  
Cheng Sun ◽  
Min Ju Ding ◽  
Yong Feng Zhang ◽  
Xun Tan ◽  
Peng Wang ◽  
...  

A variety of electrical apparatus used in daily life can cause fires because of internal or external factors. During cause identification of an electrical fire, the first short circuit melted marks of copper wire have been considered highly important because they are direct proofs. Additionally, overloaded short circuit caused by the overload of current due to excessive electrical usage can give rise to an electrical fire. Despite extensive research on the first short circuit in fire scenes, the overloaded short circuit remains difficult to be distinguished because of the limitation of commonly used testing methods. Conventional metallographic method is intuitionistic and simple, but may not provide detailed data of crystals such as misorientation of grains. Here a new method (electron backscattered diffraction, EBSD) is applied for identification of the first and overloaded short-circuited melted marks of copper wires in electrical fire scenes. Results show obvious morphological distinctions in melted marks of copper wires between the first and overloaded short circuits. Qualitative and Quantitative differences obtained from the contrast of the above two short circuit situations may assist for cause identification of electrical fires in the future.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Wei He ◽  
Fengshou Liu ◽  
Jie Ji ◽  
Shengyao Zhang ◽  
Hongbing Chen

Hot spot often occurs in a module when the qualities of solar cells mismatch and bypass diodes are proved to be an efficient alternative to reduce the effect of hot spot. However, these principles choosing a diode are based on the parameters of bypass diodes and PV cells without consideration of the maximum heating power of the shaded cell, which may cause serious consequences. On this basis, this paper presents a new approach to investigate partially shaded cells in different numbers of PV cells and different shading scenarios, including inhomogeneous illumination among solar cells and incomplete shading in one cell, which innovatively combines the same cells or divides one affected cell into many small single cells and then combines the same ones, and analyzes the shaded cell. The results indicate that the maximum power dissipation of the shaded cell occurs at short-circuit conditions. With the number of solar cells increasing, the shaded cell transfers from generating power to dissipating power and there is a maximum point of power dissipation in different shading situations that may lead to severe hot spot. Adding up the heat converted from solar energy, the heating power can be higher. In this case, some improvements about bypass diodes are proposed to reduce hot spot.


Sutet ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 24-31
Author(s):  
Redaksi Tim Jurnal

Push-On switches or toggle switches and mechanical relays are mechanical contacts made of metal which, when supplied with electric current, will result in a spike of electrical sparks, called Bouncing Effects. Bounce effects are often a problem in digital circuits, especially in digital electronics circuits, because these Bounce Effects will cause the value of data or signals coming into the circuit inaccurate or indeterminate, when the mechanical switch is pressed as input data. This will undoubtedly lead to undesirable conditions and must be overcome with an electronic circuit called De-Bounce for the data or input signal to be more certain.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6834
Author(s):  
Ruizhu Wu ◽  
Simon Mendy ◽  
Nereus Agbo ◽  
Jose Ortiz Gonzalez ◽  
Saeed Jahdi ◽  
...  

This paper investigates the impact of parameter variation between parallel connected SiC MOSFETs on short circuit (SC) performance. SC tests are performed on parallel connected devices with different switching rates, junction temperatures and threshold voltages (VTH). The results show that VTH variation is the most critical factor affecting reduced robustness of parallel devices under SC. The SC current conducted per device is shown to increase under parallel connection compared to single device measurements. VTH shift from bias–temperature–instability (BTI) is known to occur in SiC MOSFETs, hence this paper combines BTI and SC tests. The results show that a positive VGS stress on the gate before the SC measurement reduces the peak SC current by a magnitude that is proportional to VGS stress time. Repeating the measurements at elevated temperatures reduces the time dependency of the VTH shift, thereby indicating thermal acceleration of negative charge trapping. VTH recovery is also observed using SC measurements. Similar measurements are performed on Si IGBTs with no observable impact of VGS stress on SC measurements. In conclusion, a test methodology for investigating the impact of BTI on SC characteristics is presented along with key results showing the electrothermal dynamics of parallel devices under SC conditions.


2019 ◽  
Vol 2019 (1) ◽  
pp. 209-217
Author(s):  
F Isakov

The article considers the results of the analysis of autotransformers operation mode monitoring. The time diagram of active load current and oil temperature of autotransformer TashTES AT-3 is established and during one year changes of these variables and basic parameters of autotransformer were observed. Technical faults of the power transformer and high power autotransformer are established and methods of their elimination are determined. Damage of transformers and autotransformers with voltage of 110-500 kV of about 30% of the total number of outages which were accompanied by internal short-circuits and two main causes of damage were determined. The main causes of technological failures, which were not accompanied by internal short-circuits, are as follows: 20% of failures in operation of the onload tap-changer, 16% of oil leaks from the bushings, 13% of oil leaks and lowering of oil from the transformer due to violation of welded joints and rubber seals, 4% of engine damage to oil pumps of the cooling system, 3% of pressure increase in high-voltage hermetic bushings, 2% of film protection shell damage. The main reasons of technological violations accompanied by internal short-circuit in the transformer are as follows: breakdown of internal insulation of highvoltage bushings, insufficient short-circuit resistance, wear and tear of winding insulation, breakdown of insulation.


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