Development of Highly Accurate Transmission Capacity Calculation Program considering Thermal Resistance Decrease by Convection and Heat Radiation

2013 ◽  
Vol 133 (3) ◽  
pp. 286-294
Author(s):  
Masahiko Nakade ◽  
Kenji Umekawa ◽  
Toshiya Kano ◽  
Tomotada Ishikawa
Keyword(s):  
Thermal Resistance ◽  
Transmission Capacity ◽  
Heat Radiation ◽  
Capacity Calculation ◽  
Resistance Decrease

scholarly journals Model of Complex Heat Transfer in the Package of Rectangular Steel Sections

2020 ◽  
Vol 10 (24) ◽  
pp. 9044
Author(s):  
Rafał Wyczółkowski ◽  
Marek Gała ◽  
Vazgen Bagdasaryan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Resistance ◽  
Heat Radiation ◽  
Low Carbon ◽  
Contact Heat ◽  
Total Thermal Resistance ◽  
Model Calculations ◽  
Complex Heat Transfer ◽  
Steel Sections

During heat treatment of rectangular steel sections, a heated charge in the form of regularly arranged packages is placed in a furnace. The article presents a model of a complex heat transfer in such a package using the thermo-electric analogy. The model considers the following types of heat transfer: conduction in section walls, conduction and natural convection within gas, heat radiation between the walls of a section, as well as contact conduction between the adjacent sections. The results of our own experimental research were used for calculations of heat resistance applying to natural convection and contact conduction. We assumed that the material of sections was low-carbon steel and the gas was air. The result of the calculations of the presented model is total thermal resistance Rto. The calculations were performed for the temperature range 20–700 °C for four geometrical cases. Due to the variability of conditions for contact heat conduction, we assumed that total thermal resistance for a given charge is contained within a value range between Rto-min and Rto-max. We established that the value of Rto depends significantly on the section’s geometry. The larger the section sizes, the greater the changes of Rto. The minimal and maximal values of Rto for all packages were 0.0051 (m2·K)/W and 0.0238 (m2·K)/W, respectively. The correctness of model calculations was verified with the use of experimental data.

scholarly journals Automatic cross-border transmission capacity calculation in electric power interconnections

2009 ◽  
Vol 22 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Dragan Popovic
Keyword(s):  
Steady State ◽  
Computer Program ◽  
Electric Power ◽  
Electricity Markets ◽  
Transmission System ◽  
Transmission Capacity ◽  
Capacity Assessment ◽  
State Security ◽  
Cross Border ◽  
Capacity Calculation

The paper deals with relevant methodological and practical aspects of automatic cross-border transmission capacity assessment in electric power interconnections. It is based on advanced methodology for steady-state security analyses, using all its favourable properties, respecting the latest criterions, standards and practice of European Transmission System Operators (ETSO). The practical presentation of developed computer program is made on example of transmission capacity calculation in condition of ex Second UCTE synchronous zone. This presentation gives an overview of the characteristics and possibilities of this computer program, regarding the real necessities of operational practice in new conditions of liberalized electricity markets. .

scholarly journals Effect of Shell Temperature on Thermal Resistance and Junction Temperature for Power Diode

2021 ◽  
Vol 2101 (1) ◽  
pp. 012029
Author(s):  
Fan Chen ◽  
Long Chen ◽  
Pengfei Lian ◽  
Dapeng Liu ◽  
Shuai Tao ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Order Effect ◽  
Junction Temperature ◽  
Thermal Failure ◽  
Pn Junction ◽  
Shell Temperature ◽  
Aging Test ◽  
Before And After ◽  
Resistance Decrease ◽  
Power Diode

Abstract Accurate measurement of junction temperature can avoid thermal failure of diode. During aging test, junction temperature should be indirectly calculated by testing its thermal resistance. In this paper, junction-to-case thermal resistance (Rthjc) of XX diode is tested by T3ster based on transient dual interface method. Its Rthjc is about 1.23K/W at 25°C and contains PN junction thermal resistance, metal shell thermal resistance and Sn-based solder thermal resistance, respectively. These three types of thermal resistance decrease in order. Effect of shell temperature on junction temperature and Rthjc is then discussed. As shell temperature increases, temperature variation of PN junction before and after heating and corresponding thermal resistance Rthjc both increase.

scholarly journals THERMAL RESISTANCE DECREASE BETWEEN CASE OF POWER SEMICONDUCTOR DEVICE AND ITS RADIATOR

2017 ◽  
Vol 2017 (2) ◽  
pp. 104-113
Author(s):  
Виктор Тихомиров ◽  
Viktor Tikhomirov ◽  
Владимир Воробьев ◽  
Vladimir Vorobev ◽  
Михаил Измеров ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Semiconductor Device ◽  
Power Semiconductor Device ◽  
Power Semiconductor ◽  
Resistance Decrease

scholarly journals A Topology Analysis-Based MMC-HVDC Grid Transmission Capacity Calculation Method

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 822
Author(s):  
Xiao Yu ◽  
Bing Zhao ◽  
Shanshan Wang ◽  
Tiezhu Wang ◽  
Lu Zhang
Keyword(s):  
Calculation Method ◽  
Transmission Capacity ◽  
Affecting Factors ◽  
Multilevel Converter ◽  
Topology Analysis ◽  
High Voltage Direct Current ◽  
Operation Modes ◽  
Capacity Calculation ◽  
Power Limits ◽  
Power Dispatching

Modular multilevel converter-based high voltage direct current (MMC-HVDC) has a broad application prospect in renewable energy transmission. With the development of converter capacity, the transmission capacity calculation for MMC-HVDC grids becomes important for power dispatching. The existing method depends on manual work and is suitable for a simple grid. However, as the grid structure and operation modes become more and more complex, it becomes difficult to calculate the transmission capacity of different operation modes for an MMC-HVDC grid. This paper analyzed and simplified affecting factors and basic topologies. On this basis, a topology-based MMC-HVDC grid transmission capacity calculation method is proposed. First, an MMC-HVDC grid is divided into sending end grid, transmission section lines, and receiving end grid. Then the power limits of these three parts are calculated. Finally, the transmission capacity is determined by analyzing the connection mode of these three parts. This method can be adapted to any kind of MMC-HVDC grid and can be easily programmed.

scholarly journals A Study on the Effect of Bond Wires Lift-Off on IGBT Thermal Resistance Measurement

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 194
Author(s):  
Dan Luo ◽  
Minyou Chen ◽  
Wei Lai ◽  
Hongjian Xia ◽  
Xueni Ding ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Power Dissipation ◽  
Resistance Measurement ◽  
Insulated Gate Bipolar Transistor ◽  
Igbt Modules ◽  
Igbt Module ◽  
Bond Wires ◽  
Solder Fatigue ◽  
Lift Off ◽  
Resistance Decrease

Bond wire lift-off will cause an increase of remaining wires’ power dissipation, which usually is ignored for healthy modules. However, only partial wires’ power dissipation transfers through thermal path from junction to case, which will lead to overestimate the whole power dissipation from collector to emitter pole and underestimate the calculated thermal resistance using the proportion of temperature difference to power dissipation. A FEM model is established to show the change of heat flow after bond wires were removed, the temperature of bond wires increases, and the measured thermal resistance decrease after bond wires lift-off. It is validated by experimental results using open package Insulated Gate Bipolar Transistor (IGBT) modules under different current conditions. This conclusion might be helpful to indicate the bond wires lift-off and solder fatigue by comparing the change of measured thermal resistance. Using the Kelvin setup to measure thermal resistance will cause misjudgment of failure mode due to the ignoring of wires’ power dissipation. This paper proposed that the lift-off of bond wires will lead to underestimating the thermal resistance measurement, which will overestimate the lifetime of IGBT module and misjudge its state of health.

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