变压器铁心计算

式中: K D—铁心直径经验系数, 对冷轧硅钢片的铁心及铜绕组的变压器, 一般取K D = 52～57 , 对特大型变压器, 由于运输高度的限制, 此经验系数

有时取得还要大些;

q j — 接缝磁化容量(VA/cm 2),根据斜接缝处磁密(

),从表1.3或表1.4中选取; P r — 额定容量( kVA );

K I 0 — 空载电流附加系数, 铁心为全斜接缝时, 从表1.2 中选取。

表1.2 附加系数 ( 铁心为全斜接缝时 )

注: ①三相五柱式等轭是指主轭和旁轭截面相等, 不等轭是指主轭和旁轭截面不相等。

6 冷轧硅钢片性能数据

冷轧硅钢片性能数据,可按表 1.3公式计算, 或直接从表 1.4 中选取。

2/B B m mj

角重是指边柱中心线外侧铁轭四个角的重量及心柱与铁轭各级填补的重量（如图1.2中阴影部分所示）。标准铁心的角重, 具体数据可从表1.5至表1.7查得, 下面仅以三相变压器为例, 计算其角重。

图1.2 铁心角重计算示意图

p tx—铁心硅钢片单位损耗(W /kg ),

ρ tx —铁心硅钢片密度( g / cm3 ) , 冷轧硅钢片取ρ tx = 7.65 g / cm3 ;

f d —铁心叠片系数, 从表1.1中选取, 采用冷轧硅钢片35Z155时, f d = 0.97 ; S jk—铁心级块毛截面积( cm2 );

b m—铁心级块中的最大片宽( cm ) ;

δm—铁心级块(铁心中两个油道之间或油道至最外级间)的总厚度( cm ) ; m—修正系数。

最外部级块(油道至最外级间的级块) : m = 1 ;

中间级块: 当δm≤7.5 cm 时: m = 1 ;

当δm≥20 c m 时: m = 0.5 ;

当7.5 <δm< 20 cm 时: m = 1.3 －0.04 δm( 1.15 )

摘要

本设计是以亚东亚变压器公司SFSZ-4000/110型变压器铁心为设计题目，主要任务是使得变压器在运行过程中的减少能耗和减小噪声。

本文在现有亚东亚变压器铁心设计的基础上，对变压器铁心的结构进行设计。对一些可以改进的关键问题进行计算，引用那些本来就设计得很好的部件。重点是对铁心片的更合理的选择以及合理的工艺和更好的叠装方法。

本设计采用30QG120型硅钢片叠装后作为铁心的主体，以高低上夹件，高低下夹件为主要夹紧件，再借用原有的其他紧固件和绝缘件构成整个框架对铁心进行设计。

本设计通过对铁心片的合理选择，降低了变压器在运行过程中的能耗并且还有利于噪声的减小。然后再进一步对铁心内部最热点对表面的温差(θo)计算，铁心表面对油的温差(θb)计算，铁心级块的单位高度(1cm)的热负荷(q jk)计算，铁心表面对油的温差(θb)计算，铁心温升计算，铁心内部最热点温升(θm)计算，及其各种耗损计算。

然后重点对硅钢片的叠装方式以及工艺进行概述，最后达到预期设计目得。- 补充说明关于铁心安全接地的问题。

关键字：铁心；能耗；噪声；安全

Abstract

This design is to take second transformer company SFSZ-4000| in East Asia 110 transformer iron heart as to design a topic, the main task is to make the transformer is in the process of circulating in of the decrease can consume and let up voice.

This text carries on a design to the structure of the transformer iron heart on the foundation of existing second transformer iron in East Asia heart design.Carry on a calculation to some keys problems that can improve, quoted from those to originally design good parts.The point is the craft to more reasonable choice of iron heart slice and the reasonable with better fold to pack a method.

This design adopts a 30 QG120 type Huo steel slice fold to pack is iron heart behind of corpus, clip a piece by height, the height bottom clips piece in order to mainly clip a tight piece, again use other tight original firmwares and insulate a composing's the whole frame to carry on a design to iron heart.

This design passes the reasonable choice to iron heart slice and lowered transformer in the process of circulating in of can consume and still be advantageous to a letting up of voice.Then then further to iron heart inner part most hot order to surface of difference in temperature(θ o) calculation, iron heart surface to oil of difference i n temperature(θ b) calculation, the hot burden(qjk) calculation of the unit height(1 cm) of iron heart class piece, iron heart surface to

oil of difference in temperature(θ b) calculation, iron heart Wen Sheng's calculation, iron heart inner part most hot point Wen Sheng(θ m) calculation, and it is various loss calculation.

Then the point pack way and craft to carry on an outline to the Huo steel slice's folding and finally attain an expectation design eyes get.

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Add to explain concerning iron and feel at ease all a problem of connecting the ground.

Key word:Iron heart;Can consume;Zao voice;Safety