Finite element analysis modeling of high voltage and frequency 3-phase solid state transformers enabled by metal amorphous nanocomposites

2018 ◽  
Vol 33 (15) ◽  
pp. 2138-2147 ◽  
Author(s):  
Mst Nazmunnahar ◽  
Satoru Simizu ◽  
Paul R. Ohodnicki ◽  
Subhashis Bhattacharya ◽  
Michael E. McHenry
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Solid State ◽  
High Voltage ◽  
Element Analysis ◽  
Solid State Transformers ◽  
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Abstract

scholarly journals Modeling Stray Capacitances of High-Voltage Capacitive Dividers for Conventional Measurement Setups

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1262
Author(s):  
Alessandro Mingotti ◽  
Federica Costa ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli ◽  
Paolo Mazza
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Equivalent Circuit ◽  
High Voltage ◽  
Equivalent Model ◽  
Simulation Environment ◽  
Element Analysis ◽  
Ratio Error ◽  
Complicated Geometries

Stray capacitances (SCs) are a serious issue in high-voltage (HV) applications. Their presence can alter the circuit or the operation of a device, resulting in wrong or even disastrous consequences. To this purpose, in this work, we describe the modeling of SCs in HV capacitive dividers. Such modeling does not rely on finite element analysis or complicated geometries; instead, it starts from an equivalent circuit of a conventional measurement setup described by the standard IEC 61869-11. Once the equivalent model including the SCs is found, closed expressions of the SCs are derived starting from the ratio error definition. Afterwards, they are validated in a simulation environment by implementing various circuit configurations. The results demonstrate the expressions applicability and effectiveness; hence, thanks to their simplicity, they can be implemented by system operators, researchers, and manufacturers avoiding the use of complicated methods and technologies.

Dynamic Interaction of High-Voltage Power Transformer Bushings, Turrets, and Tanks

2018 ◽  
Vol 34 (1) ◽  
pp. 397-421 ◽  
Author(s):  
Guo-Liang Ma ◽  
Qiang Xie ◽  
Andrew Whittaker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Voltage ◽  
Power Transformer ◽  
Bending Moment ◽  
Dynamic Interaction ◽  
Electrical Performance ◽  
Element Analysis ◽  
Ground Shaking ◽  
Input Motion

High-voltage (HV) bushings are attached to a power transformer tank either directly or indirectly via turrets. Turrets are used to achieve electrical performance requirements, but their potential impact on the seismic performance of the supported bushings has not been considered. Earthquake simulator testing and finite-element analysis were used to quantify the amplification of ground shaking through tanks (220- and 500-kV) and turrets to the points of attachment of roof- and sidewall-supported bushings. Substantial amplification of motion was seen in both physical experiments and numerical simulations. Sample bracing schemes external to the transformer tank were investigated to potentially reduce the motions experienced by the bushings. Bushing tip displacements were reduced in all stiffening cases studied, but the outcomes for bending moment at the bushing-turret connection were mixed, with no change in some cases and significant reductions in others. The physical and numerical studies described in this paper make clear the importance of dynamic interaction of bushings, turrets, and the power transformer tank. The methods currently used to address the amplification of input motion from the base of a tank to the points of attachment of its bushing are inadequate. The seismic design of HV power transformer tanks and turrets should be supported by finite-element analysis of validated models to avoid dynamic interaction in the bushing-turret-tank system, to minimize seismic demand on the transformer bushings, and to minimize the risk of substation damage in earthquakes.

scholarly journals Finite Element Analysis of Thermal Effects in Diode End-Pumped Solid-State Lasers

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Moustafa Sayem El-Daher
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Solid State ◽  
Thermal Effects ◽  
Beam Quality ◽  
Focal Length ◽  
Thermal Lensing ◽  
Solid State Lasers ◽  
Element Analysis ◽  
Composite Crystals

Thermal effects are the main obstacle to getting high power and good beam quality in diode end-pumped solid-state lasers. In this work, a theoretical investigation of thermal effects in single and dual end-pumped solid-state lasers is carried out using finite element analysis (FEA) for a selected number of widely used laser producing materials, namely, Nd:YAG, Yb:YAG, and Nd:KGW. Crystals with different dimensions are also investigated both in single and in dual end-pumped configuration. Finally, the effect of using composite crystals on thermal lensing is investigated. An experiment to measure the thermal focal length for two different crystals was carried out and a comparison with FEA computed focal length of the thermal lens is made. In all cases studied in this work, results show clear effects of thermal lensing with some differences depending on crystal type, pump power, and size.

Finite Element Analysis and Evaluation of Stator Insulation in High Voltage Synchronous Motor

2012 ◽  
Vol 48 (2) ◽  
pp. 955-958 ◽  
Author(s):  
Jun Zhang ◽  
Shuhong Wang ◽  
Jie Qiu ◽  
Haibo Li ◽  
Qiuhui Zhang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Voltage ◽  
Synchronous Motor ◽  
Element Analysis ◽  
Analysis And Evaluation
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