CN1012286B - 检测叠片铁心片间短路的方法和设备 - Google Patents

检测叠片铁心片间短路的方法和设备

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CN1012286B
CN1012286B CN89103797A CN89103797A CN1012286B CN 1012286 B CN1012286 B CN 1012286B CN 89103797 A CN89103797 A CN 89103797A CN 89103797 A CN89103797 A CN 89103797A CN 1012286 B CN1012286 B CN 1012286B
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short
measuring
sheet
circuit
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CN1038169A (zh
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兹勒蒂米尔·波西德尔
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General Electric Switzerland GmbH
ABB AG Germany
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Asea Brown Boveri AG Switzerland
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/34—Testing dynamo-electric machines
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/904—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents with two or more sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/9046—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents by analysing electrical signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/52—Testing for short-circuits, leakage current or ground faults

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  • General Health & Medical Sciences (AREA)
  • Electrochemistry (AREA)
  • Pathology (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Basic Packing Technique (AREA)
  • Laminated Bodies (AREA)

Abstract

为了在叠片铁心上探测片间短路(8)，叠片铁心(1)受到一个辅助线圈的磁化。铁表面(15)由一个带有两个在电方面分开，而在机械上互相连接的线圈(6，7)的测量线圈装置(5)来探测。在一个串接的测量仪(9)中，将线圈的输出信号互相进行比较；当片间短路时，通过短路铁片的故障电流在线圈内指示出不同相位移的电压，这电压容许通过片间短路的位置和大小接地。

Description

本发明涉及一种检测电机叠片铁心片间短路的方法，在这方法中，利用一个辅助绕组将叠片铁心磁化，而铁心表面则用一个装有串接的测量仪表的测量线圈装置进行探测。
本发明还涉及一种实施这方法的设备。
本发明起源于一种现有技术，如在AT-杂志“ELIN杂志”1984年1/2册，第58页上登载的一段‘定子铁心上的磁分路测位’中所叙述的。
层叠的定子铁心，特别是电机的定子铁心，在制造时和在运行期间的维护采用定子铁心环激励的测量方法，以额定感应来检测片间短路。该方法显示出在局部温度差异下片间短路电流的效应，但要求有大功率的和能调整的高压电源以及大截面的励磁线圈。
对于带有内装绕组杆的定子铁心片来说，用这种检测方法只能辨认在齿冠表面上的缺陷位置（许多铁心之间的短路），而不能辨认在槽底和槽侧的铁片缺陷。用这个方法只能识别具有一定接触电阻并因此而产生局部温度差异的片间短路，而不是所有的片间短路位置。而且仅仅凭借温度升高并不足以对片间短路位置作出定量的判断。
通常的铁片检测方面的缺陷可以用前述“ELIN杂志”公布的在一个弱的磁轭感应下由片间短路电流的磁场的测量方法来避免。
对于叠片铁心的磁化只需要一个低压电源。这样，实际上几乎所有的片间短路都能查明，也包括那些位于槽边或槽底的片间短路。此外，还包括整个极靴的镗制表面（也包括槽表面）叠片绝缘的状态。铁心可以用内装的转子来检测。这一公知的方法能够对片间短路的位置进行合格的分析。可能实现的铁片修理的效率就能立即很容易地进行控制。此外，还能对许多电机的叠片铁心状态作比较。在时间进程中的叠片铁心的变化和老化就能加以确定。
但不利的是：对于一个叠片铁心-缺陷位置来说，其读出的测量值读数与故障电流成正比（“起因”），而不与在运行中出现的过热温度成正比（“后果”）。但是，由于“起因”和“后果”纯属物理的关系而不是简单的从属关系，因此就必须凭借一些经验才能解释测量的结果。在这里，对显示出来的测量值读数的解释并没有问题，因此，这种显示出的测量值读数都是来源于缺陷，困难解释的是扩散的测量值读数，因为，这既关系到“热点”也关系到叠片铁心的非均匀性。
为了能使测量值读数定量地与全然不同的叠片铁心类型相符合，将在每一测量开始时都进行相对的校准。叠片铁心的小分段在接通激励时被表面地短路（校准失误点），并对此登记测量值读数。对于一个实际的定子铁心缺陷读数，根据进行中的相对校准，可以从中推断出实际缺陷的大小。
从现有技术出发，本发明的任务是创制出一种不存在前述缺点的检测叠片铁心片间短路的方法，在这方法中不必进行对完整无缺的或校准缺陷位置的程序性相对校准，就能得出故障点位置和大小的定量结论。
本发明的另一任务就是提供一种实行这方法的设备。
根据本发明，这任务是这样解决的，即，通过利用至少两个在电的方面分开并径向隔开的，但在机械上相互连接的测量线圈，就可以从测量线圈中感应电压的相位差和/或振幅变化查明片间短路电流的磁场的径向分布。
用于实施该方法的相应的设备包括：一个用于对叠片铁心充磁的辅助线圈，一个带有两个在电方面分开，但机构上又相互连接的测量线圈的测量探针，一个连接在测量线圈上用于掌握在测量线圈中感应电压的相位角偏差和/或振幅变化的测量设备和一个串接的记录单元。
下面将根据附图对本发明作较详细的说明。
图1说明定子铁心的环状激励的原理图;
图2说明测量线圈位置的概略;
图3在两个定子齿上的测量设备的截面图，并附有在未受损害的定子铁心上的相应矢量图;
图4与图3相似但带有片间短路时的布置图;
图5用于产生基准信号的布置图并附有相应的矢量图;
图6测量设备的概略图示连同其机组连接图;
图7表示相位差变化的曲线图。
一个电机的定子铁心1利用一个围绕定子铁心的线圈2以通常测量中的环状激励使其微弱地磁化（图1）。在这测量中的磁轭感应只占额定感应的大约5-10%。对感应线圈的供电，低压网路就够用了。环状磁化最好通过一个接到低压网路上的可调节输出电压的自耦变压器（调节变压器）3来实现。通过并联电容器4的无功
电流补偿，可能会发生馈电电流IQ的减少。在这测量中最大的馈电电流大约为20A。
通常用额定磁轭感应的铁片检测把片间短路的加热（“热点”）记录下来（红外线摄影机人工探测）与此不同，在本方法中，叠片铁心的表面备有一个线圈装置5，该装置包括两个相互牢牢地连结，但径向又相互隔离的测量线圈6，7，由其确定片间短路电流的磁场的径向分布（图2和3）。在测量线圈6，7的端头测量得的没有片间短路的铁心的电压Um1、Um2是与线圈端头之间的磁位或者与磁化电流成正比的。测量线圈因此被用作测量线圈端头之间线积分的磁性电压表（“罗高夫斯基线圈”）。两测量线圈感应电压之间的夹角等于零（图3）。当发生片间短路8时，故障电流IF通过短路的铁片，在测量线圈6，7中感应出不同相位移的电压UF。
测量线圈6、7是对故障电流的感应线圈，这线圈在叠片铁心的径向方向上测量出故障电流的不同磁感应BF。借此，当片间存在短路8时，在测量线圈6，7的电压之间就产生了相位移△α（见图4和5的矢量图）。
由故障电流引起的测量电压的相位移是随片间短路电流的大小和磁路长短而定的。加强测量线圈6，7的电压，并用一个相位检测器9来确定测量电压的相位角偏差△α和/或振幅变化△φ（图6）。
最好把测量线圈6，7装入一个可移动的载运器10上，利用
绳索传动和一只驱动马达11可以使之沿着槽口从叠片铁心1的一端移动至另一端。一个与驱动马达11相连接的自动同步发送机或位移传感器12可以使其掌握载运器，并随之测量线圈装置5的轴向位置。
通过铁片电流引起的测量电压的相位偏差△α和/或振幅变化△φ可用一个X-Y记录器13，以一系列线条（每一条线代表一个槽口）予以记录。
将沿着槽口记录下来的信号与相当于铁片电流的信号作比较。一条用细的导体制成的，并具有与片间短路相同宽度16的回线14被固定在齿冠表面15上并馈以与片间短路电流相当的电流（图5）。
片间短路电流是通过接到网路中的自耦变压器3进行馈电的。来自短路铁片的片间短路电流是由铁片之间的已知电压值和单张铁片的阻抗来确定的。测量线圈的信号（△α）然后连同和不连这回线电流分别予以记录（△αE），并与片间短路电流的信号（△αF）进行比较（图7）。
如果不用绳索传动，载运器也可制成扁平形的自行行走的支架，这样，根据图6，其驱动马达与一个位移传感器或者自动同步发送机相连接以掌握其行驶的路程。
上面所述的方法对于带有内装转子的电机也能用于定子铁心的检测。但在这种情况下，转子在电机的一端必须与地面完全绝缘，就象通常大的发电机那样。
一个在电机的两端不绝缘的轴象一个次级短路绕组一样，由于良好的磁力耦合，在弱的激励情况下仍能通过几百安培的电流。在
电机一端的轴是否不带绝缘可以用一个罗高夫斯基线圈测量轴电流和测量在电机非驱动一端的对地轴电压以及通过大大提高到为定子铁心磁化所需要的安培匝而加以确定。
在带有内装转子的电机情况下，特别是大的叶轮机，其定子铁心的充磁最好由一个强电流的馈电电源来实现，这电源在电机的两端之间与绝缘的轴相连。

Claims (7)

1、检测电极叠片铁心(1)片间短路的方法，在这方法中，叠片铁心(1)利用一个辅助绕组(2)将其磁化，而铁心表面则用一个装有串接的测量仪表(9)的测量线圈装置(MS1，MS2)予以探测，其特征在于：通过利用至少两个在电方面分开并径向隔开的，但在机械上又相互连接的测量线圈(6，7)就可以从测量线圈(6，7)中感应电压(UM1，UM2)的相位差和/或振幅变化查明片间短路电流(IF)的磁场的径向分布，利用固定在铁片表面(15)上的一个相应宽度的回线(14)馈以相当于片间短路电流的电流所产生的信号与测试信号进行比较，所述测量线圈(6，7)安装在一个可移动的载运器(10)上，以便沿铁心槽口移动。
2、根据权利要求1的方法，其特征在于：通过一个相位检测器（9）就可以查明测量线圈（6，7）信号的相位差（△α）。
3、根据权利要求1的方法，其特征在于：用一个记录器（13）来掌握测量线圈（6，7）信号的振幅差（△φ）。
4、根据权利要求1-3中任一项的方法，其特征在于：所述载运器（10）系利用一台驱动马达（11）使之沿铁心（1）从一端移向另一端。
5、根据权利要求1-3中任一项的方法，其特征在于：铁心（1）的充磁是由一个强电流的馈电电源通过转子轴来实现的，这电源在电极的两端之间与绝缘的轴相连。
6、根据权利要求4的方法，其特征在于：铁心（1）的充磁是由一个强电流的馈电电源通过转子轴来实现的，这电源在电极的两端之间与绝缘的轴相连。
7、用于实施根据权利要求1的方法的设备，其特征在于：一个用于对叠片铁心（1）充磁的辅助线圈（2），一个带有两个在电方面分开的，但在机械上相互连接的测量线圈（6，7）的测量线圈装置（5），一个连接在测量线圈上、用于掌握在测量线圈中感应电压（UM1，UM2）的相位角偏差和或振幅变化的测量设备（9），一个连接在测量设备上的记录单元（13），一个固定于铁片（15）表面上具有相应宽度的回线（14），以及一个安装所述测量线圈（6，7）用的可移动的载运器（10）。
CN89103797A 1988-05-30 1989-05-30 检测叠片铁心片间短路的方法和设备 Expired CN1012286B (zh)

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CH676526A5 (zh) 1991-01-31
EP0344558A2 (de) 1989-12-06
JPH0225766A (ja) 1990-01-29
US4996486A (en) 1991-02-26
DE58907060D1 (de) 1994-04-07
EP0344558B1 (de) 1994-03-02
EP0344558A3 (de) 1992-04-15
JP3119854B2 (ja) 2000-12-25
CN1038169A (zh) 1989-12-20

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