【作者】 田文革；

【导师】 林莘；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2003， 硕士

【摘要】 阻抗匹配平衡牵引变压器(本文中简称平衡变压器)是一种将一次侧三相对称电压变换为二次侧二相垂直电压的降压变压器，它不同于已有的任何一种变压器，短路电流的分析计算和短路试验必须予以重新研究。 变压器的短路强度只能通过短路试验来验证，国家标准GB1094.5-1985《电力变压器 第5部分 承受短路的能力》只适用于电力变压器，对平衡变压器等特殊变压器并无具体规定，对于平衡变压器，如果可以用单相电源预先短路法模拟三相电源的短路试验，那么其它特种变压器的短路试验也可以参照进行，这对提高我国变压器试验室的试验能力具有重要意义。 本文从平衡变压器的工作原理入手，建立平衡变压器各绕组中电流之间的电流映射关系矩阵和矢量关系，推导平衡变压器短路电流有效值和峰值的计算公式。 平衡变压器在运行中可能发生单臂短路、双臂短路、双臂先后短路、空载短路、负载短路、高压侧短路事故。分析、计算平衡变压器运行中各种可能发生的短路方式下的短路电流，通过对比分析，找出运行中最严酷的短路方式，并进行试验验证。 建立一定的试验条件，在1.5相电源双臂预先短路情况下进行短路试验，使短路试验能够同时满足实际运行中发生短路时的短路电流有效值和短路电流峰值的要求，并进行试验验证。 本文推导峰值系数与品质因数和合闸初相角的函数关系式，依此编制峰值系数曲线程序，利用对品质因数和合闸初相角的控制可使每个绕组都受到规定峰值的作用。利用本文中的峰值系数曲线程序可以使短路试验时施加的电流峰值更加准确，该程序适用于各类变压器的短路试验。 利用推导的短路试验方法对一台SF2—QY—25000—110／27.5GY型阻抗匹配平衡牵引变压器进行短路试验，解决了工程实际问题。更多还原

【Abstract】 Impedance-matching balanced traction transformers (balanced transformers in this paper for short) are step-down transformers , they transfer symmetrical three phase voltage in primary side to perpendicular two phase voltage in secondary side . They are different from any other transformers, so their short-circuit current analysis and short-circuit test method must be taken into special account.GB1094.5-85 Power transformers Part 5 Ability to withstand short circuit only applies to power transformers , not to balanced transformers . If short-circuit test on balanced transformers can be performed by means of single phase supply instead of three phase supply, and other special transformers can also be done in this way ,so it is very significant to improve test capacity of transformer laboratory in our country.The relation among all short-circuit current in each winding is described , and the rms value and peak value equation of short circuit current are concluded in this paper.Single-arm short-circuit fault, both-arm short-circuit fault, both-arm sequent short-circuit fault, short-circuit fault under no load, short-circuit fault under on load, short-circuit fault in primary side may occur in balanced transformers in power system, which short-circuit fault is the most serious is decided according to calculation and test.Under some conditions, short-circuit test on balanced transformers can be performed by means of 1.5 phase supply . It is proved to be equivalent to the short-circuit fault during their operation. The test results comply with GB1094.5-1985.The equation among peak factor, quality factor, switch initial angel is concluded . On the basis of the equation, peak factor curve has been programmed . The rms value, peak value and switch initial angel can be shown in the screen of computer . Switch initial angel can be corrected automatically to make the peak value in each winding comply with requirements. This program has been applied for short-circuit test on all kinds of transformers.The short circuit test method in this paper applies to balanced transformers, such as Y/V impedance-matching balanced transformer and YNA impedance-unmatching balanced transformers . The analysis method of short-circuit current applies to all special transformers, for example, split winding transformers, Z connection winding transformers.Finally, a SF2-QY-25000-110/27.5 GY balanced transformer has been tested, the result is approved by China National Transformer Quality Supervision Testing Center.更多还原