电源变压器设计(2)

电源变压器设计

目 录

摘 要 ············································································································································ I Abstract ·············································································································································· II 第1章 电源变压器 ························································································································ 1

1.1电源变压器的简介 ············································································································ 1

1.1.1电源变压器的概念 ································································································ 1 1.1.2电源变压器的工作原理 ························································································ 2 1.1.3电源变压器的功能 ································································································ 3 1.1.4电源变压器的材料 ································································································ 4 1.2对于电源变压器的运行管理 ··························································································· 4

1.2.1电源变压器投运前的检测 ···················································································· 4 1.2.2电源变压器试投运 ································································································ 5 1.2.3电源变压器的运行维护 ························································································ 5 1.2.4电源变压器的异常运行 ························································································ 6 1.3怎样判别电源变压器参数 ······························································································· 7

1.3.1、识别电源变压器 ································································································· 7 1.3.2、功率的估算 ·········································································································· 7 1.3.3、各绕组电压的测量 ····························································································· 7 1.4电源变压器的空载试验和短路试验··············································································· 8

1.4.1电源变压器的损耗 ································································································ 8 1.4.2空载试验----->铁损 ······························································································· 8 1.4.3短路试验----->铜损 ······························································································· 9 1.4.4变压器空载试验和负载试验的目的 ··································································· 9 1.4.5试验要求和注意事项 ···························································································· 9

第2章 电源变压器的设计 ·········································································································· 11

2.1计算变压器的额定功率 ································································································· 11 2.2计算变压器的铁心规格 ································································································· 11 2.3计算变压器线圈匝数······································································································ 12 2.4计算变压器绕组导线的规格 ························································································· 13 2.5选用合适的变压器绝缘材料 ························································································· 13 2.6核算变压器铁心窗口容纳绕组的情况 ········································································ 13

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白城职业技术学院毕业论文

第3章 电源变压器的事故处理方法 ························································································· 15

3.1电源变压器的事故处理 ································································································· 15

3.1.1.绕组故障 ··············································································································· 15 3.1.2套管故障 ··············································································································· 15 3.1.3铁芯故障 ··············································································································· 15 3.1.4瓦斯保护故障 ······································································································· 16 3.2变压器自动跳闸的处理 ································································································· 16 3.3变压器着火 ······················································································································ 16 结 论 ········································································································································· 18 参考文献 ········································································································································· 19 致 谢 ········································································································································· 20

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白城职业技术学院毕业论文

第1章 电源变压器

1.1电源变压器的简介

1.1.1电源变压器的概念

电源变压器的功能是功率传送、电压变换和绝缘隔离，作为一种主要的软磁电磁元件，在电源技术中和电力电子技术中得到广泛的应用。根据传送功率的大小，电源变压器可以分为几档：10kVA以上为大功率，10kVA～0.5kVA为中功率，0.5kVA～25VA为小功率，25VA以下为微功率。传送功率不同，电源变压器的设计也不一样，应当是不言而喻的。有人根据它的主要功能是功率传送，把英文名称“Power Transformers”译成“功率变压器”，在许多文献资料中仍然在使用。

变压器的最基本型式，包括两组绕有导线之线圈，并且彼此以电感方式称合一起。当一交流电流(具有某一已知频率)流于其中之一组线圈时，于另一组线圈中将感应出具有相同频率之交流电压，而感应的电压大小取决于两线圈耦合及磁交链之程度。

一般指连接交流电源的线圈称之为「一次线圈」(Primary coil);而跨于此线圈的电压称之为「一次电压.」。在二次线圈的感应电压可能大于或小于一次电压，是由一次线圈与二次线圈问的「匝数比」所决定的。因此，变压器区分为升压与降压变压器两种。

大部份的变压器均有固定的铁芯，其上绕有一次与二次的线圈。基于铁材的高导磁性，大部份磁通量局限在铁芯里，因此，两组线圈藉此可以获得相当高程度之磁耦合。在一些变压器中，线圈与铁芯二者间紧密地结合，其一次与二次电压的比值几乎与二者之线圈匝数比相同。因此，变压器之匝数比，一般可作为变压器升压或降压的参考指标。由于此项升压与降压的功能，使得变压器已成为现代化电力系统之一重要附属物，提升输电电压使得长途输送电力更为经济，至于降压变压器，它使得电力运用方面更加多元化，吾人可以如是说，倘无变压器，则现代工业实无法达到目前发展的现况。

电子变压器除了体积较小外，在电力变压器与电子变压器二者之间，并没有明确的分界线。一般提供60Hz电力网络之电源均非常庞大，它可能是涵盖有半个洲地区那般大的容量。电子装置的电力限制，通常受限于整流、放大，与系统其它组件的能力，其中有些部份属放大电力者，但如与电力系统发电能力相比较，它仍然归属于小电力之范围。

各种电子装备常用到变压器，理由是：提供各种电压阶层确保系统正常操作;提供系统中以不同电位操作部份得以电气隔离;对交流电流提供高阻抗，但对直流则提供低的阻抗;在不同的电位下，维持或修饰波形与频率响应。「阻抗」其中之一项重要概念，亦即

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电源变压器设计

电子学特性之一，其乃预设一种设备，即当电路组件阻抗系从一阶层改变到另外的一个阶层时，其间即使用到一种设备-变压器。

对于电子装置而言，重量和空间通常是一项努力追求之目标，至于效率、安全性与可靠性，更是重要的考虑因素。变压器除了能够在一个系统里占有显著百分比的重量和空间外，另一方面在可靠性方面，它亦是衡量因子中之一要项。在它应用方面的差别，使得电力变压器并不适合应用于电子电路上。 1.1.2电源变压器的工作原理

1 是输出和输入共用一组线圈的特殊变压器，升压和降压用不同的抽头来实现.比共用线圈少的部分抽头电压就降低.比共用线圈多的部分抽头电压就升高。

2其实原理和普通变压器一样的，只不过他的原线圈就是它的副线圈?一般的变压器是左边一个原线圈通过电磁感应，使右边的副线圈产生电压，自耦变压器是自己影响自己。

3自耦变压器是只有一个绕组的变压器，当作为降压变压器使用时，从绕组中抽出一部分线匝作为二次绕组；当作为升压变压器使用时，外施电压只加在绕组的—部分线匝上。通常把同时属于一次和二次的那部分绕组称为公共绕组，自耦变压器的其余部分称为串联绕组，同容量的自藕变压器与普通变压器相比，不但尺寸小，而且效率高，并且变压器容量越大，电压越高．这个优点就越加突出。因此随着电力系统的发展、电压等级的提高和输送容量的增大，自藕变压器由于其容量大、损耗小、造价低而得到广泛应用.

由电磁感应的原理可知，变压器并不要有分开的原绕组和副绕组，只有一个线圈也能达到变换电压的目的。当变压器原绕组W1接入交流电源U1时，变压器原绕组每匝的电压降，电压平均分配在变压器原绕组1，2，变压器副绕组W2的电压等于原绕组每匝电压乘以，,4的匝数。在U1不变的下,变更W1和W2的比例，就得到不同的U2值.这种原，副绕组直接串联，自行偶合的变压器就叫自藕变压器,又叫单圈变压器。

普通变压器的原，副绕组是互相绝缘的，只用磁的联系而没有电的联系，依线圈组数的不同，这种变压器又可分为双圈变压器或多圈变压器。由电磁感应的原理可知，并不要有分开的原绕组和副绕组，只有一个线圈也能达到变换电压的目的。当原绕组W1接入交流电源U1时，原绕组每匝的电压降，电压平均分配在原绕组1、2，副绕组W2的电压等于原绕组每匝电压乘以3、4的匝数。在U1不变的下，变更W1和W2的比例，就得到不同的U2值。这种原副绕组直接串联，自行偶合的变压器称为自耦变压器，又叫单圈变压器。

自耦变压器中的电压，电流和匝数的关系和变压器既：U1/U2=W1/W2=I2/I1=K

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