JPH07128394A - Dielectric deterioration monitoring/diagnosing system for electric equipment - Google Patents

Dielectric deterioration monitoring/diagnosing system for electric equipment

Info

Publication number
JPH07128394A
JPH07128394A JP27373893A JP27373893A JPH07128394A JP H07128394 A JPH07128394 A JP H07128394A JP 27373893 A JP27373893 A JP 27373893A JP 27373893 A JP27373893 A JP 27373893A JP H07128394 A JPH07128394 A JP H07128394A
Authority
JP
Japan
Prior art keywords
temperature
insulating layer
conductor
electric
difference
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP27373893A
Other languages
Japanese (ja)
Inventor
Mitsuru Onoda
満 小野田
Takashi Haruta
孝 春田
Hiroyuki Kamiya
宏之 神谷
Original Assignee
Hitachi Ltd
株式会社日立製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd, 株式会社日立製作所 filed Critical Hitachi Ltd
Priority to JP27373893A priority Critical patent/JPH07128394A/en
Publication of JPH07128394A publication Critical patent/JPH07128394A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To provide a dielectric deterioration monitoring/diagnosing system for electric equipment in which the insulation layer of coil in an electric equip ment can be monitored constantly during operation and the dielectrically deterio rated state can be diagnosed easily. CONSTITUTION:Generation of voids in the insulation layer 3 of an armature coil 1 has correlation with deterioration thereof and the heat transmission resistance of the insulation layer 3 increases as the number and size of voids increase. Variation (increase) in the heat transmission resistance in the insulation layer 3 caused by the voids generated therein is detected based on the difference of temperatures detected by a temperature-sensitive element 12A embedded in the conductor 2 of the armature coil 1 and a temperature-sensitive element 12B embedded in the insulation layer 3 thus deciding dielectric deterioration. Since the heat transmission resistance of the insulation layer 3 can be measured easily and arbitrarily even during operation of an electric equipment, deterioration thereof can be monitored constantly during operation and the armature coil 1 can be renewed or repaired at an appropriate time resulting in the prevention of dielectric breakdown.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、電気機器の巻線部分で
の絶縁劣化を監視し、診断するシステムに係り、特に、
高電圧の発電機など回転電機の電機子コイルの絶縁劣化
診断に好適な電気機器の絶縁劣化監視診断システムに関
する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for monitoring and diagnosing insulation deterioration in a winding part of an electric device, and more particularly,
The present invention relates to an insulation deterioration monitoring / diagnosis system for electric equipment suitable for insulation deterioration diagnosis of an armature coil of a rotating electric machine such as a high-voltage generator.

【0002】[0002]

【従来の技術】高電圧で使用される電気機器では、ひと
たび絶縁破壊が発生すると、重大な結果をもたらす。そ
こで、この絶縁破壊を未然に防止するには、絶縁診断に
より絶縁層の劣化状態を把握して寿命期を推定し、適切
な時期にコイルの更新や補修を行う必要がある。
BACKGROUND OF THE INVENTION Electrical equipment used at high voltages has serious consequences once a breakdown occurs. Therefore, in order to prevent this dielectric breakdown, it is necessary to grasp the deterioration state of the insulating layer by insulation diagnosis, estimate the life period, and renew or repair the coil at an appropriate time.

【0003】ところで、現在、高電圧の電気機器、例え
ば定格電圧3kV以上の交流発電機の電機子コイルでの
絶縁構造は、例えば図10のようになっている。
By the way, at present, an insulating structure of a high-voltage electric device, for example, an armature coil of an AC generator having a rated voltage of 3 kV or more is as shown in FIG.

【0004】この図10の例において、電機子コイル1
は、絶縁層3を施された上で電機子鉄心のスロット5内
に、層間詰物4を介在させて挿入巻装されるようになっ
ているが、このとき、絶縁層3としては、マイカ等の基
材にエポキシ樹脂等の樹脂を含浸させて半硬化状に硬化
したマイカテープが用いられており、これをコイル形状
に形成した導体2に巻回し、加熱加圧成型することによ
り、図9(a)に示すように、絶縁層3のマイカ9が含浸
レジン8により均一化された状態で、導体2と一体化さ
れて作られている。
In the example of FIG. 10, the armature coil 1
Is provided with an insulating layer 3 and then inserted and wound in a slot 5 of an armature core with an intervening padding 4 interposed therebetween. At this time, the insulating layer 3 is made of mica or the like. A mica tape which is obtained by impregnating a base material with a resin such as an epoxy resin and hardened into a semi-hardened state is used. The mica tape is wound around a coil-shaped conductor 2 and heat-pressed to form As shown in (a), the mica 9 of the insulating layer 3 is made uniform with the impregnating resin 8 and integrated with the conductor 2.

【0005】ところで、この絶縁層3は、運転開始時
は、この図9(a)の初期状態に示されているように、均
一に一体化されているが、以後は、運転時間の経過に伴
い、電気的劣化、熱的劣化、ヒートサイクル劣化、機械
的劣化、環境劣化といった種々の劣化を受け、この結
果、運転時間の経過につれて、図9(b)に示すように、
絶縁層3の含浸レジン8内全体に多数の小さなボイド
(空所)が現われ、局部的に大きなボイド10が発生し始
める。さらに、運転時間が長くなり劣化が進行して、図
9(c)に示す寿命末期になると、ボイドの量はさらに増
加し、数多くのボイド同士がつながってしまうようもな
る。
By the way, the insulating layer 3 is uniformly integrated at the start of operation as shown in the initial state of FIG. 9 (a), but thereafter, the operation time elapses. Accordingly, various deteriorations such as electrical deterioration, thermal deterioration, heat cycle deterioration, mechanical deterioration, and environmental deterioration are caused. As a result, as the operation time elapses, as shown in FIG. 9 (b),
A large number of small voids in the impregnating resin 8 of the insulating layer 3
(Vacancy) appears, and a large void 10 locally begins to occur. Further, the operating time becomes longer and the deterioration progresses, and at the end of the life shown in FIG. 9C, the amount of voids further increases, and many voids may be connected to each other.

【0006】こうして、ボイド10が存在する状態で高
電圧が印加されると、このボイド部分は、他の部分より
も誘電率が低いので電界が集中し、放電して導電体化し
てしまう。そして、この結果、絶縁パスが短くなり、絶
縁層3の耐電圧特性が低下してしまう。
In this way, when a high voltage is applied in the presence of the voids 10, the void portion has a lower dielectric constant than the other portions, so that the electric field concentrates, and discharges to become a conductor. As a result, the insulating path is shortened and the withstand voltage characteristic of the insulating layer 3 is deteriorated.

【0007】従って、平均的にボイドの数が多くなるに
伴い、また局部的に大きなボイドが存在するに伴い絶縁
層3の耐電圧特性が低下し、絶縁破壊に至る虞れが大に
なるので、絶縁劣化とは、絶縁層3内にボイドが発生し
た状態を意味し、劣化の程度は、発生したボイドの個数
の増加と、各ボイドの大きさにより判定できることにな
る。
Therefore, as the number of voids increases on average, and with the presence of large voids locally, the withstand voltage characteristics of the insulating layer 3 deteriorate, and there is a great risk of dielectric breakdown. The insulation deterioration means a state in which voids are generated in the insulating layer 3, and the degree of deterioration can be determined by the increase in the number of generated voids and the size of each void.

【0008】ところで、この絶縁層の劣化状態を診断す
るための従来技術としては、絶縁層の誘電正接(tanδ)
試験、交流電流試験、部分放電試験などの非破壊試験が
一般に実施されている。
By the way, as a conventional technique for diagnosing the deterioration state of the insulating layer, the dielectric loss tangent (tan δ) of the insulating layer is used.
Non-destructive tests such as tests, alternating current tests, and partial discharge tests are generally performed.

【0009】一方、絶縁層の劣化状態の診断とは直接関
連はないが、運転中の電機子コイル3の温度状態を測定
する方法として、従来から、図10に示すように、電機
子コイル3をスロット5内に挿入するとき、図11に示
すように、コイル間に介在させた層間詰物4内に温度検
出用の測温抵抗体6を設けておき、これからのリード線
7を外部に引出し、運転中でも任意にコイルの温度が測
定できるようにした技術が知られている。
On the other hand, although not directly related to the diagnosis of the deterioration state of the insulating layer, as a method for measuring the temperature state of the armature coil 3 during operation, as shown in FIG. When inserting into the slot 5, as shown in FIG. 11, the temperature sensing resistor 6 for temperature detection is provided in the interlayer filling 4 interposed between the coils, and the lead wire 7 from this is drawn out to the outside. There is known a technique capable of arbitrarily measuring the temperature of a coil even during operation.

【0010】なお、この種の技術として、関連するもの
としては、例えば特開昭61−145123号、特開平
2−294003号の各公報の開示を挙げることができ
る。
As related arts of this type, there are the disclosures of JP-A-61-145123 and JP-A-2-294003, for example.

【0011】[0011]

【発明が解決しようとする課題】上記従来技術は、電気
機器が運転中での絶縁層の劣化診断について配慮がされ
ておらず、誘電正接試験などに際して機器を停止させ、
且つ、コイル間の接続部を外し、試験終了後、再接続す
るなどの労力と時間が掛かり、短い周期で定期的に絶縁
診断を行うことが困難であるという問題がある。
The above-mentioned prior art does not take into consideration the deterioration diagnosis of the insulating layer during the operation of the electric device, and the device is stopped during the dielectric loss tangent test.
In addition, there is a problem that it takes time and labor such as disconnecting the connection part between the coils and reconnecting after the test, and it is difficult to perform insulation diagnosis regularly in a short cycle.

【0012】他方、温度の測定なら、上記した従来技術
でも、運転中に実行できるが、しかし、単に温度を測定
しただけでは、絶縁層の劣化状態を判定するのは不可能
である。
On the other hand, if the temperature is measured, the above-mentioned conventional technique can be executed during operation, but it is impossible to judge the deterioration state of the insulating layer by simply measuring the temperature.

【0013】本発明の目的は、コイルの絶縁層内で発生
するボイドの状態を電気機器が運転中でも常時監視で
き、絶縁劣化状態を容易に診断することができるように
した電気機器の絶縁劣化監視診断システムを提供するこ
とにある。
An object of the present invention is to monitor the state of voids generated in the insulating layer of a coil at all times even when the electric device is in operation, and to easily diagnose the state of deterioration of the electric device. To provide a diagnostic system.

【0014】[0014]

【課題を解決するための手段】上記目的は、絶縁層を備
えたコイルを有する電気機器において、そのコイルを構
成する導体の温度と、この導体を覆う絶縁層の温度とを
独立に検出する第1と第2の感温手段を設け、運転時で
の導体の温度と絶縁層の温度の差、及び温度変化が発生
したときでの導体の温度と絶縁層の温度の反応時間(変
化時間)の差の少なくとも一方を測定し、これらを正常
時でのデータと比較することにより達成される。
The above object is to detect the temperature of a conductor forming the coil and the temperature of the insulating layer covering the conductor independently in an electric device having a coil having an insulating layer. The first and second temperature sensitive means are provided, and the reaction time (change time) between the conductor temperature and the insulating layer temperature when the temperature difference between the conductor and the insulating layer during operation and the temperature change occur. It is achieved by measuring at least one of the differences between the two and comparing these with the normal data.

【0015】[0015]

【作用】電気機器運転時での導体の温度と絶縁層の温度
の差、又は温度変化が発生したときでの導体の温度と絶
縁層の温度の反応時間の差は、絶縁層の熱伝導率により
変化する。ところで、電気機器運転中はコイル導体に電
流が流れるので発熱する。この熱は絶縁層の内側から外
側へと伝達し、主として鉄心へ放熱されるが、このとき
の熱伝導率は絶縁層の材料構成や密度になどにより定ま
る定数である。
[Function] The difference between the temperature of the conductor and the temperature of the insulating layer during the operation of the electric device, or the difference in the reaction time between the temperature of the conductor and the temperature of the insulating layer when a temperature change occurs is the thermal conductivity of the insulating layer. It changes with. By the way, during the operation of the electric equipment, a current flows through the coil conductor, so that heat is generated. This heat is transmitted from the inside to the outside of the insulating layer and is mainly radiated to the iron core. The thermal conductivity at this time is a constant determined by the material constitution and density of the insulating layer.

【0016】しかるに、ボイドは気体からなるので熱伝
達抵抗が大きく、このため、絶縁層の内部にボイドが発
生すると、絶縁層の見かけ上の熱伝導率は、最初の値か
ら低下し、その増加の割合は、ボイドの数や大きさに依
存する。一方、上記したように、このボイドの数や大き
さは、絶縁層の劣化を表わす。
However, since the voids are composed of gas, the heat transfer resistance is large. Therefore, when the voids are generated inside the insulating layer, the apparent thermal conductivity of the insulating layer decreases from the initial value and increases. The ratio depends on the number and size of voids. On the other hand, as described above, the number and size of the voids indicate deterioration of the insulating layer.

【0017】従って、導体の温度と絶縁層の温度を比較
し、又は温度変化が発生したときでの導体の温度と絶縁
層の温度との反応時間を比較することにより、絶縁層の
見かけ上の熱伝導率(熱伝達抵抗の逆数)の変化を検出す
ることができ、これから絶縁層の劣化状況を判定し、絶
縁劣化状態を診断することができる。
Therefore, by comparing the temperature of the conductor and the temperature of the insulating layer, or by comparing the reaction time between the temperature of the conductor and the temperature of the insulating layer when a temperature change occurs, the apparent temperature of the insulating layer is compared. A change in the thermal conductivity (the reciprocal of the heat transfer resistance) can be detected, and the deterioration state of the insulating layer can be determined from this, and the insulation deterioration state can be diagnosed.

【0018】[0018]

【実施例】以下、本発明による電気機器の絶縁劣化監視
診断システムについて、図示の実施例により詳細に説明
する。図1は、回転電機、例えば交流発電機の電機子コ
イル1に本発明を適用した場合の一実施例で、温度検出
部12と、絶縁劣化判定部13と、記憶部14とで構成
されている。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An insulation deterioration monitoring / diagnosis system for electric equipment according to the present invention will be described in detail below with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment in which the present invention is applied to an armature coil 1 of a rotating electric machine, for example, an AC generator, and is composed of a temperature detection unit 12, an insulation deterioration determination unit 13, and a storage unit 14. There is.

【0019】まず温度検出部12は、電機子コイル1の
導体2の温度に反応する感温素子12A(第1の感温手
段)と、電機子コイル1の絶縁層3の温度に反応する感
温素子12B(第2の感温手段)と、これらの感温素子1
2A、12Bの信号から導体2の温度T1 と、絶縁層3
の温度T2 とをそれぞれ独立に検出する温度検出手段1
2Cとで構成されている。なお、回転電機には、電機子
コイル1が複数個設けられているので、この温度検出部
12も、電機子コイル1の個数分全部、或いはその内の
いくつかのものに設けられており、検出結果を切り替え
て取り出すようになっている。
First, the temperature detecting section 12 detects the temperature sensitive element 12A (first temperature sensitive means) which reacts to the temperature of the conductor 2 of the armature coil 1 and the temperature sensitive element 12A which reacts to the temperature of the insulating layer 3 of the armature coil 1. Temperature element 12B (second temperature sensing means) and these temperature sensing elements 1
From the signals of 2A and 12B, the temperature T 1 of the conductor 2 and the insulating layer 3
Temperature detection means 1 for independently detecting the temperature T 2 of the
2C and. Since the rotary electric machine is provided with a plurality of armature coils 1, the temperature detecting units 12 are also provided for all of the armature coils 1 or for some of them. The detection result is switched and taken out.

【0020】次に絶縁劣化判定部13は、温度検出部1
2の温度検出手段12Cから導体2の温度T1 と絶縁層
3の温度T2 とを取り込み、これらの温度差ΔTを分析
する温度差分析手段13Aと、同じく温度T1 と温度T
2 とを取り込み、温度T1 が変化したときでの温度T2
の変化遅れ、すなわち温度T1 の変化に対する温度T2
の反応時間差Δtをそれぞれ分析する反応時間差分析手
段13Bと、これら温度差ΔTと反応時間差Δtの分析
により得られるボイドの発生状態から絶縁層3の絶縁性
能を求める絶縁性能判定手段13Cと、この判定結果か
ら絶縁劣化状態を評価する評価手段13Dとで構成され
ている。
Next, the insulation deterioration determining unit 13 is connected to the temperature detecting unit 1.
The temperature difference analyzing means 13A that takes in the temperature T 1 of the conductor 2 and the temperature T 2 of the insulating layer 3 from the temperature detecting means 12C of No. 2 and analyzes the temperature difference ΔT between them, and the temperature T 1 and the temperature T 1 similarly.
2 and the temperature T 2 when the temperature T 1 changes
Change in delay, i.e. temperature T 2 with respect to a change in temperature T 1 of
Reaction time difference analysis means 13B for analyzing the reaction time difference Δt, and insulation performance determination means 13C for determining the insulation performance of the insulation layer 3 from the void generation state obtained by the analysis of the temperature difference ΔT and the reaction time difference Δt. The evaluation means 13D for evaluating the insulation deterioration state from the result.

【0021】そして記憶部14は、この評価結果を格納
記憶するメモリ14Aと、このメモリに格納された評価
結果を出力する出力手段とで構成されている。図2は、
電機子コイル1内での感温素子12A、12Bの設置状
態を示したもので、感温素子12Aは導体2の中心部に
配置し、これにより導体2の温度T1が重点的に効率よ
く検出できるようにしてあり、感温素子12Bは絶縁層
3の中に埋没させて設置し、これにより絶縁層3の温度
2 が重点的に効率よく検出できるようにしてある。な
お、感温素子の設置位置としては、例えば12B’で示
す位置でもよい。
The storage unit 14 is composed of a memory 14A for storing and storing the evaluation result and an output means for outputting the evaluation result stored in the memory. Figure 2
This shows the installation state of the temperature sensitive elements 12A and 12B in the armature coil 1. The temperature sensitive element 12A is arranged in the central portion of the conductor 2 so that the temperature T 1 of the conductor 2 is efficiently focused on. Yes and can be detected, the temperature sensing element 12B is placed in an alumina crucible in an insulating layer 3, thereby the temperature T 2 of the insulating layer 3 are to be detected better focus efficiently. The temperature sensitive element may be installed at a position indicated by 12B ', for example.

【0022】次に、この図1の実施例の動作について説
明する。まず、温度検出部12は、回転電機(交流発電
機)の運転が開始されたときから停止されるまで導体2
と絶縁層3の温度T1 と温度T2 とを測定し、その測定
結果を絶縁劣化判定部13に伝える。これにより、絶縁
劣化判定部13の中で、まず温度差分析手段13Aは、
回転電機運転時の温度変化による導体2と絶縁層3の温
度差ΔTを取り出し、他方、反応時間差分析手段13B
は、運転時の温度変化による導体2と絶縁層3の反応時
間差Δtを取り出し、それぞれを絶縁性能判定手段13
Cに伝える。
Next, the operation of the embodiment shown in FIG. 1 will be described. First, the temperature detector 12 includes the conductor 2 from the time when the operation of the rotating electric machine (alternating current generator) is started to the time when the operation is stopped.
And the temperature T 1 and temperature T 2 of the insulating layer 3 are measured, and the measurement result is transmitted to the insulation deterioration determining unit 13. Thereby, in the insulation deterioration determination unit 13, first, the temperature difference analysis unit 13A
The temperature difference ΔT between the conductor 2 and the insulating layer 3 due to the temperature change during operation of the rotating electric machine is taken out, and on the other hand, the reaction time difference analysis means 13B.
Takes out the reaction time difference Δt between the conductor 2 and the insulating layer 3 due to the temperature change during the operation, and determines the reaction time difference Δt between them.
Tell C.

【0023】そこで、絶縁性能判定手段13Cは、これ
らのデータを分析し、ボイド発生による温度変化反応速
度の低下を求め、結果を評価手段13Dに送る。評価手
段13Dは、この絶縁性能判定手段13Cから与えられ
た結果に基づいて絶縁劣化状態を評価し、評価結果を記
憶部14のメモリ14Aに記憶するのである。
Therefore, the insulation performance judging means 13C analyzes these data, obtains a decrease in the reaction rate of temperature change due to the occurrence of voids, and sends the result to the evaluating means 13D. The evaluation unit 13D evaluates the insulation deterioration state based on the result given from the insulation performance determination unit 13C, and stores the evaluation result in the memory 14A of the storage unit 14.

【0024】そこで、メモリ14Aは、運転時間と温度
変化の反応速度、及び評価を、それぞれの電機子コイル
1毎に対応して整理し、必要に応じて、それらを出力手
段14Bにより表示、またはプリントアウトさせるよう
にするのである。
Therefore, the memory 14A organizes the operating time, the reaction speed of temperature change, and the evaluation corresponding to each armature coil 1, and displays them by the output means 14B, if necessary, or Print it out.

【0025】ここで、温度変化による電機子コイル1の
導体2と絶縁層3の温度反応時間差とボイド発生量の関
係について説明する。まず図3は、回転電機の起動時で
の導体2と絶縁層3の温度変化を示したものであり、次
に、図4は、運転中での負荷変動により出力が変化した
ときでの導体2と絶縁層3の温度変化を示したものであ
る。
The relationship between the temperature reaction time difference between the conductor 2 of the armature coil 1 and the insulating layer 3 due to temperature change and the amount of void generation will be described. First, FIG. 3 shows a temperature change of the conductor 2 and the insulating layer 3 at the time of starting the rotating electric machine, and then FIG. 4 shows a conductor when the output changes due to a load change during operation. 2 shows the temperature changes of the insulating layer 3 and the insulating layer 3.

【0026】図3の起動時においては、導体2に通電さ
れ始めた結果、まず、この導体2の温度が上昇し始める
が、このとき導体2と絶縁層3の熱伝導率の違いから、
また導体2の温度上昇に対して絶縁層3の温度上昇が遅
れるので、温度変化に対する反応時間に差Δtが現わ
れ、平衡状態では、導体2と絶縁層3に温度差ΔTが現
われる。また、図4の出力が変化したときでも同様で、
やはり反応時間差Δtと、温度差ΔTが現われる。
At the time of start-up in FIG. 3, as a result of energization of the conductor 2, as a result, the temperature of the conductor 2 first starts to rise, but at this time, due to the difference in thermal conductivity between the conductor 2 and the insulating layer 3,
Further, since the temperature rise of the insulating layer 3 is delayed with respect to the temperature rise of the conductor 2, a difference Δt appears in the reaction time with respect to the temperature change, and in the equilibrium state, a temperature difference ΔT appears between the conductor 2 and the insulating layer 3. The same applies when the output of FIG. 4 changes,
After all, the reaction time difference Δt and the temperature difference ΔT appear.

【0027】ところで、電機機器を設置し、まだ運転を
開始していない時点では、当然のこととして、絶縁層3
は、図9(a)に示すように、均一に一体化された初期状
態にある。そして、このときには、まだ絶縁層3には、
劣化は現われていない筈である。そこで、この初期の時
点で或る所定の値を示している絶縁層3の反応時間差Δ
tと温度差ΔTを測定し、それぞれを反応時間差初期値
Δt0、温度差初期値ΔT0とする。
By the way, when the electric equipment is installed and the operation is not yet started, as a matter of course, the insulating layer 3
Are in a uniformly integrated initial state, as shown in FIG. 9 (a). And at this time, the insulating layer 3 still has
Degradation should not have appeared. Therefore, the reaction time difference Δ of the insulating layer 3 showing a certain predetermined value at this initial time point
t and the temperature difference ΔT are measured and used as the reaction time difference initial value Δt 0 and the temperature difference initial value ΔT 0 , respectively.

【0028】しかして、運転時間が進むにつれ、絶縁層
3全体に、図9(b)に示すように、多数の小さなボイド
10や局部的に大きなボイド10が発生すると、これら
のボイド部により熱伝導率が低下(熱伝達抵抗が増加)し
てゆくので、反応時間差Δtと温度差ΔTは、初期値Δ
0、ΔT0よりも大きな値に変化してゆく。そして、図
9(c)に示すように、ボイド10の発生量が増大し、絶
縁層3が寿命期(寿命末期)に達すると、反応時間差Δt
と、温度差ΔTの値は共に大きく増大し、初期値との差
が顕著に表われるようになる。
However, as the operating time progresses, if a large number of small voids 10 or locally large voids 10 are generated in the entire insulating layer 3 as shown in FIG. 9 (b), these voids generate heat. Since the conductivity decreases (heat transfer resistance increases), the reaction time difference Δt and the temperature difference ΔT are the initial values Δt.
The value gradually changes to a value larger than t 0 and ΔT 0 . Then, as shown in FIG. 9C, when the generation amount of the voids 10 increases and the insulating layer 3 reaches the life period (end of life period), the reaction time difference Δt
Then, the values of the temperature difference ΔT both greatly increase, and the difference from the initial value becomes noticeable.

【0029】これら反応時間差Δtと温度差ΔTは絶縁
性能判定手段13Cに取り込まれるが、この絶縁性能判
定手段13Cには適当な記憶手段が設けてあり、これに
上記した反応時間差初期値Δt0と温度差初期値ΔT0
が格納してある。そこで、絶縁性能判定手段13Cは、
これらの初期値Δt0、ΔT0と、取り込んだ反応時間差
Δtと温度差ΔTとの比δt、δTを求める。 δt=Δt0/Δt×100〔%〕 δT=ΔT0/ΔT×100〔%〕 そして、これらの比δt、δTに基づいて分析を行な
い、初期状態からの低下率から、図5に示すように、予
め想定してある標準の劣化曲線を用い、これにより推定
運転時間nを算定するのである。
The reaction time difference Δt and the temperature difference ΔT are taken into the insulation performance judging means 13C. The insulation performance judging means 13C is provided with an appropriate storage means, and the above reaction time difference initial value Δt 0 and The temperature difference initial value ΔT 0 is stored. Therefore, the insulation performance determination means 13C
The initial values Δt 0 and ΔT 0 and the ratios δt and δT between the taken reaction time difference Δt and the temperature difference ΔT are calculated. δt = Δt 0 / Δt × 100 [%] δT = ΔT 0 / ΔT × 100 [%] Then, analysis is performed based on these ratios δt and δT, and as shown in FIG. 5, from the rate of decrease from the initial state. In addition, a standard deterioration curve that is assumed in advance is used, and the estimated operating time n is calculated from this.

【0030】次に、こうして求められた推定運転時間n
は評価手段13Dに取り込まれ、ここで、この電機子コ
イル1を備えた交流発電機の実際の運転時間Nとの比R
(=n/N)により、図6(a)に示すようにして、絶縁劣
化状態を、○、□、△、×の各適合度にランク分けし、
これらのランクに基づいて、図6(b)に示すように、そ
れぞれ「○:優」、「□:良」、「△:可」、「×:不
可」の各評価を下すののである。
Next, the estimated operating time n thus obtained
Is taken into the evaluation means 13D, where the ratio R with the actual operating time N of the alternator equipped with this armature coil 1
As shown in FIG. 6 (a), the insulation deterioration state is ranked by (= n / N) into each conformity of ○, □, Δ, and ×,
Based on these ranks, as shown in FIG. 6 (b), each evaluation of “◯: excellent”, “□: good”, “Δ: acceptable”, and “x: not acceptable” is made.

【0031】周知のように、この実施例における交流発
電機など電気機器の運転形態としては、起動停止が比較
的頻繁に行われるDSS(daily-start-stop)運転や、そ
れほど頻繁には起動停止を行なわないWSS(weekly-st
art-stop)運転などがあり、さらに連続運転中でも負荷
変動に対応した出力変化運転などがあるが、いずれにし
ても、かなりの頻度で運転状態が変化する。
As is well known, as an operation mode of an electric device such as an AC generator in this embodiment, a DSS (daily-start-stop) operation in which start and stop are performed relatively frequently, or a start and stop in such a case is frequently performed. WSS (weekly-st
There are art-stop) driving, etc., and output changing driving corresponding to load fluctuation even during continuous driving, but in any case, the driving state changes with considerable frequency.

【0032】そこで、上記した一連の処理は、交流発電
機の起動時や、負荷変動時などに所定の頻度で実行さ
れ、これにより評価手段13Dから評価結果が与えら
れ、その都度、順次、メモリ手段14Aに評価結果が格
納されて行く。
Therefore, the series of processes described above is executed at a predetermined frequency when the AC generator is started or when the load changes, and the evaluation result is given from the evaluation means 13D, and the evaluation result is sequentially stored in the memory. The evaluation result is stored in the means 14A.

【0033】そこで、必要に応じて、このメモリ手段1
4Aに格納してある評価結果を出力手段14Bにより表
示させることにより、常時、容易に、対象としている交
流発電機の絶縁劣化の状態を知ることができる。
Therefore, if necessary, this memory means 1
By displaying the evaluation result stored in 4A by the output means 14B, the insulation deterioration state of the target alternator can always be easily known.

【0034】従って、この実施例によれば、運転中に常
時絶縁劣化状態が監視できるから、従来技術のように、
絶縁劣化状態を診断するために機器を停止し、労力と時
間をかける必要がなく、容易に絶縁劣化の程度を診断す
ることができる。
Therefore, according to this embodiment, since the insulation deterioration state can be constantly monitored during operation, as in the prior art,
The degree of insulation deterioration can be easily diagnosed without the need to stop the equipment to spend time and labor to diagnose the insulation deterioration state.

【0035】なお、絶縁性能判定手段13Cとして、フ
ァジー推論により分析を行なう手段を採用してもよく、
これによれば、運転状態(起動停止、負荷変動等)による
データのばらつきが補正でき、より一層、客観的な評価
を得ることができ、さらに正確に絶縁劣化の程度を診断
することができる。
A means for performing analysis by fuzzy inference may be adopted as the insulation performance judging means 13C,
According to this, it is possible to correct data variations due to operating conditions (starting / stopping, load fluctuations, etc.), obtain a more objective evaluation, and more accurately diagnose the degree of insulation deterioration.

【0036】ところで、感温素子12A、12B(12
B’)については、特に詳しく説明しなかったが、これ
らについては、どのような感温素子を用いても良く、例
えば、図11で説明した温度抵抗体6とリード線7から
なるものを用いてもよいが、電機子コイル1は、かなり
の高電圧になっており、従って、検出信号の取り出しに
は絶縁の問題があるので、光ファイバを用いた感温素子
の適用が望ましい。
By the way, the temperature sensitive elements 12A, 12B (12
Although B ') was not described in detail, any temperature sensitive element may be used for these, for example, the one including the temperature resistor 6 and the lead wire 7 described in FIG. 11 is used. However, the armature coil 1 has a considerably high voltage, and therefore there is a problem of insulation in extracting the detection signal. Therefore, it is desirable to apply a temperature sensitive element using an optical fiber.

【0037】光ファイバは絶縁体で電磁誘導の影響を受
ける虞れもないから、検出精度もよく、且つ、細いワイ
ヤ状なので、導体2内や、絶縁層3内への設置も容易で
あるという利点がある。なお、このような光ファイバを
用いた温度測定装置については、例えば、社団法人 電
気学会 発行 “電気学会雑誌”Vol.112、No.10、199
2’832ページなどにより周知であるので、詳しい説明に
ついては割愛する。
Since the optical fiber is an insulator and is not affected by electromagnetic induction, it has good detection accuracy and is a thin wire, so that it can be easily installed in the conductor 2 or the insulating layer 3. There are advantages. A temperature measuring device using such an optical fiber is described in, for example, "Institute of Electrical Engineers", Vol.112, No.10, 199 published by The Institute of Electrical Engineers of Japan.
It is well known from page 2'832, etc., so I will omit the detailed explanation.

【0038】また、この感温素子12A、12B(12
B’)については、電機子鉄心のスロットに組み込む電
機子コイル1の全てに設けるのが最良の実施例であると
いえるが、費用削減の見地からすれば、比較による評価
が可能なように、最小限2組設けるようにしても良い。
そして、このときでも、図7に示すように、巻線のライ
ン側(高電圧端)とニュートラル側(接地端)にそれぞれ設
けるようにするのが望ましい。
The temperature sensitive elements 12A, 12B (12
Regarding B ′), it can be said that the best example is to provide it in all of the armature coils 1 to be installed in the slots of the armature core, but from the viewpoint of cost reduction, it is possible to evaluate by comparison. At least two sets may be provided.
And, even at this time, as shown in FIG. 7, it is desirable to provide them on the line side (high voltage end) and the neutral side (ground end) of the winding, respectively.

【0039】ところで、既に説明したように、電気機器
運転中、導体2に発生した熱は絶縁層3の内部から外部
へと伝達し、主として鉄心へ放熱される。従って、鉄心
のスロット内でのコイルの密着状態によっても、上記し
た反応時間差Δtと温度差ΔTは変化する。
By the way, as already described, during the operation of the electric device, the heat generated in the conductor 2 is transferred from the inside of the insulating layer 3 to the outside and is mainly radiated to the iron core. Therefore, the reaction time difference Δt and the temperature difference ΔT also change depending on the close contact state of the coil in the slot of the iron core.

【0040】これを図8により説明すると、スロット5
内での電機子コイル1は、この電気機器が運転開始する
前には、図8(a)に示すように、スロット5内に充分に
密着した状態で電機子コイル1が挿入されている。な
お、この図において、11は導電材料からなるライナ
(かいざい物)で、電機子コイル1とスロット5内に隙間
が残らないようにする働きをするものである。
This will be described with reference to FIG.
As shown in FIG. 8 (a), the armature coil 1 in the inside of the armature coil 1 is inserted into the slot 5 in a sufficiently closely contacted state before the electric device starts to operate. In this figure, 11 is a liner made of a conductive material.
This is a (carriage) that serves to prevent a gap from remaining in the armature coil 1 and the slot 5.

【0041】しかして、電気機器が運転を開始した後
は、時間の経過と運転による振動や層間詰物4の枯れな
どから、電機子コイル1とスロット5の間に隙間がで
き、図8(b)に示すように、密着が悪い状態になってゆ
く。このため、絶縁層3の表面からの放熱が悪くなり、
導体2の温度T1 と絶縁層3の温度T2 との差、すなわ
ち、温度差ΔTが低下する。
After the electric equipment has started to operate, however, a gap is formed between the armature coil 1 and the slot 5 due to the passage of time, the vibration due to the operation, the deadness of the interlayer filling 4, and the like. As shown in), the adhesion becomes poor. Therefore, the heat radiation from the surface of the insulating layer 3 becomes worse,
The difference between the temperature T 2 of the temperature T 1 of the insulating layer 3 of the conductor 2, i.e., the temperature difference ΔT is reduced.

【0042】これを、図8(c)に示すように、導体2か
ら絶縁層3までの温度T1 と温度T2の勾配θとして表
わすと、この勾配θが異なり、図8(a)の場合を勾配θ1
とすると、図8(b)の場合は勾配θ2 となる。
If this is expressed as a gradient θ between the temperature T 1 and the temperature T 2 from the conductor 2 to the insulating layer 3 as shown in FIG. 8C, this gradient θ is different, and as shown in FIG. The gradient θ 1
Then, the gradient becomes θ 2 in the case of FIG.

【0043】すなわち、図8(a)の場合は、密着が良い
ことから絶縁層3の熱放散が良く、温度T1 と温度T2
の差が多くあり、勾配θ1 も大きい。他方、図8(b)の
場合は、密着が悪いことから絶縁層3の熱放散が悪く、
温度T1 と温度T2 の差が少なく、勾配θ2 は小さい。
That is, in the case of FIG. 8 (a), since the adhesion is good, the heat dissipation of the insulating layer 3 is good, and the temperatures T 1 and T 2 are high.
There are many differences and the gradient θ 1 is also large. On the other hand, in the case of FIG. 8B, the heat dissipation of the insulating layer 3 is poor due to poor adhesion,
The difference between the temperatures T 1 and T 2 is small and the gradient θ 2 is small.

【0044】従って、これらの間には、勾配θ1 >勾配
θ2 の関係があり、この関係は、運転時間が長くなるに
つれて顕著になる。
Therefore, there is a relation of gradient θ 1 > gradient θ 2 between them, and this relation becomes remarkable as the operating time becomes longer.

【0045】そこで、これを温度差分析手段13Aで解
析し、この解析結果により、反応時間差分析手段13B
による解析結果を補正してやることにより、さらに絶縁
劣化診断値の信頼性を向上させることができる。
Therefore, this is analyzed by the temperature difference analysis means 13A, and the reaction time difference analysis means 13B is analyzed by the analysis result.
The reliability of the insulation deterioration diagnosis value can be further improved by correcting the analysis result according to.

【0046】[0046]

【発明の効果】本発明によれば、運転中の電気機器のコ
イル導体と絶縁層の温度差及び温度変化による導体と絶
縁層の温度変化反応時間差を常時測定し、前記絶縁層内
でボイドが発生した時の前記温度差及び、反応時間差の
変化を検出し、ボイド発生による温度変化反応速度の低
下から絶縁劣化状態を判定するようにしたので、従来の
方法では不可能であった、コイルの絶縁層の劣化状態を
電気機器運転中に常時監視することができ、絶縁劣化状
態を容易に診断し、適切な時期にコイルの更新又は補修
を行うことができるようになり、この結果、絶縁破壊が
未然に防止できるので、信頼性を充分に向上させること
ができる。
According to the present invention, the temperature difference between the coil conductor and the insulating layer of an electric device in operation and the reaction time difference between the temperature change of the conductor and the insulating layer due to the temperature change are constantly measured, and voids are formed in the insulating layer. The temperature difference and the change in reaction time at the time of occurrence were detected, and the deterioration condition of the insulation was judged from the decrease in the reaction rate due to the temperature change due to the occurrence of voids. The deterioration state of the insulation layer can be constantly monitored during operation of electrical equipment, the insulation deterioration state can be easily diagnosed, and the coil can be updated or repaired at an appropriate time, resulting in insulation breakdown. Since it can be prevented, reliability can be sufficiently improved.

【0047】また、本発明によれば、電気機器の運転を
停止させることなく絶縁劣化の診断が可能になるので、
診断の頻度を容易に高めることができ、常に精度の良い
診断を行なうことができる。
Further, according to the present invention, it is possible to diagnose insulation deterioration without stopping the operation of electric equipment.
The frequency of diagnosis can be easily increased, and accurate diagnosis can always be performed.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明による電気機器の絶縁劣化監視診断シス
テムの一実施例を示すブロック構成図である。
FIG. 1 is a block diagram showing an embodiment of an insulation deterioration monitoring / diagnosis system for an electric device according to the present invention.

【図2】本発明における感温素子の埋設方法の一例を示
す説明図である。
FIG. 2 is an explanatory view showing an example of a method for embedding a temperature sensitive element in the present invention.

【図3】本発明による検出動作の一実施例を示す特性図
である。
FIG. 3 is a characteristic diagram showing an example of a detection operation according to the present invention.

【図4】本発明による検出動作の他の一実施例を示す特
性図である。
FIG. 4 is a characteristic diagram showing another embodiment of the detecting operation according to the present invention.

【図5】本発明の一実施例において絶縁劣化の評価に採
用されている推定運転時間を説明するための特性図であ
る。
FIG. 5 is a characteristic diagram for explaining an estimated operating time used for evaluation of insulation deterioration in one embodiment of the present invention.

【図6】本発明の一実施例における絶縁劣化の評価方法
を説明するための特性図である。
FIG. 6 is a characteristic diagram for explaining an insulation deterioration evaluation method according to an embodiment of the present invention.

【図7】本発明における電機子コイルに対する感温素子
の設置位置の一例を示す説明図である。
FIG. 7 is an explanatory view showing an example of the installation position of the temperature sensitive element with respect to the armature coil in the present invention.

【図8】鉄心のスロット内でのコイルの密着状態による
反応時間差と温度差の変化を示す説明図である。
FIG. 8 is an explanatory diagram showing changes in a reaction time difference and a temperature difference depending on a contact state of a coil in a slot of an iron core.

【図9】絶縁層内でのボイド発生メカニズムの説明図で
ある。
FIG. 9 is an explanatory diagram of a void generation mechanism in an insulating layer.

【図10】回転電機のスロット内での一般的なコイル構
造の一例を示す説明図である。
FIG. 10 is an explanatory diagram showing an example of a general coil structure in a slot of a rotating electric machine.

【図11】回転電機のスロット内測温方法の従来例を示
す説明図である。
FIG. 11 is an explanatory diagram showing a conventional example of a temperature measuring method in a slot of a rotating electric machine.

【符号の説明】[Explanation of symbols]

1 電機子コイル 2 導体 3 絶縁層 4 層間詰物 5 スロット 6 測温抵抗体 7 リード線 8 含浸レジン 9 マイカ 10 ボイド 12 温度検出部 12A 感温素子(導体内用) 12B 感温素子(絶縁層内用) 12C 温度検出手段 13 絶縁劣化判定部 13A 導体と絶縁層の温度差分析手段 13B 導体と絶縁層の温度変化による反応時間差の分
析手段 13C 絶縁性能判定手段 13D 評価手段 14 記憶部 14A メモリ 14B 出力手段
1 Armature Coil 2 Conductor 3 Insulating Layer 4 Interlayer Filler 5 Slot 6 Resistance Temperature Detector 7 Lead Wire 8 Impregnated Resin 9 Mica 10 Void 12 Temperature Detector 12A Temperature Sensing Element (for Conductor) 12B Temperature Sensing Element (Insulating Layer) 12C Temperature detection means 13 Insulation deterioration determination section 13A Temperature difference analysis means between conductor and insulation layer 13B Reaction time difference analysis means due to temperature change between conductor and insulation layer 13C Insulation performance determination means 13D Evaluation means 14 Storage section 14A Memory 14B Output means

Claims (6)

【特許請求の範囲】[Claims] 【請求項1】 絶縁層を備えたコイルを有する電気機器
において、そのコイルを構成する導体の温度と、この導
体を覆う絶縁層の温度とを独立に検出する第1と第2の
感温手段を設け、上記電気機器運転時での導体の温度と
絶縁層の温度の差、及び温度変化が発生したときでの導
体の温度と絶縁層の温度の反応時間の差の少なくとも一
方の評価により絶縁劣化状態を判定するように構成した
ことを特徴とする電気機器の絶縁劣化監視診断システ
ム。
1. In an electric device having a coil provided with an insulating layer, first and second temperature sensitive means for independently detecting the temperature of a conductor forming the coil and the temperature of an insulating layer covering the conductor. Insulation is performed by evaluating at least one of the difference between the temperature of the conductor and the temperature of the insulating layer during the operation of the electric device, and the difference in the reaction time between the temperature of the conductor and the temperature of the insulating layer when a temperature change occurs. An insulation deterioration monitoring diagnosis system for an electric device, characterized in that the deterioration state is determined.
【請求項2】 請求項1の発明において、上記評価が、
電気機器設置時での運転開始時での導体の温度と絶縁層
の温度の差、及び温度変化が発生したときでの導体の温
度と絶縁層の温度の反応時間の差の少なくとも一方との
比較により与えられるように構成されていることを特徴
とする電気機器の絶縁劣化監視診断システム。
2. The invention according to claim 1, wherein the evaluation is
Comparison with the difference between the temperature of the conductor and the temperature of the insulating layer at the start of operation when installing electrical equipment, and / or the difference in the reaction time between the temperature of the conductor and the temperature of the insulating layer when a temperature change occurs. An insulation deterioration monitoring and diagnosis system for an electric device, wherein the insulation deterioration monitoring and diagnosis system is provided.
【請求項3】 請求項1又は2の発明において、上記評
価が、上記電気機器運転時での温度変化が発生したとき
での導体の温度と絶縁層の温度の反応時間の差による判
定結果を、上記電気機器運転時での導体の温度と絶縁層
の温度の差による判定結果によって補正することにより
与えられるように構成されていることを特徴とする電気
機器の絶縁劣化監視診断システム。
3. The invention according to claim 1 or 2, wherein the evaluation is a judgment result based on a difference in reaction time between the temperature of the conductor and the temperature of the insulating layer when a temperature change occurs during the operation of the electric device. An insulation deterioration monitoring / diagnosis system for an electric device, wherein the insulation deterioration monitoring / diagnosis system is configured to be corrected by a determination result based on a difference between a temperature of a conductor and a temperature of an insulating layer during operation of the electric device.
【請求項4】 請求項1の発明において、上記第1と第
2の感温素子が、光ファイバを用いた感温素子で構成さ
れていることを特徴とする電気機器の絶縁劣化監視診断
システム。
4. The insulation deterioration monitoring and diagnosing system for an electric device according to claim 1, wherein the first and second temperature sensitive elements are composed of a temperature sensitive element using an optical fiber. .
【請求項5】 請求項1の発明において、上記第1と第
2の感温素子は、上記電気機器のコイルの異なった場所
に少なくとも2組設置されていることを特徴とする電気
機器の絶縁劣化監視診断システム。
5. The insulation of an electric device according to claim 1, wherein at least two sets of the first and second temperature sensitive elements are installed at different positions of a coil of the electric device. Degradation monitoring diagnostic system.
【請求項6】 請求項5の発明において、上記2組の感
温素子は、上記電気機器のコイルのライン側とニュート
ラル側に1組以上設置されていることを特徴とする電気
機器の絶縁劣化監視診断システム。
6. The insulation deterioration of an electric device according to claim 5, wherein one or more sets of the two temperature-sensing elements are installed on a line side and a neutral side of a coil of the electric device. Surveillance diagnostic system.
JP27373893A 1993-11-01 1993-11-01 Dielectric deterioration monitoring/diagnosing system for electric equipment Pending JPH07128394A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP27373893A JPH07128394A (en) 1993-11-01 1993-11-01 Dielectric deterioration monitoring/diagnosing system for electric equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27373893A JPH07128394A (en) 1993-11-01 1993-11-01 Dielectric deterioration monitoring/diagnosing system for electric equipment

Publications (1)

Publication Number Publication Date
JPH07128394A true JPH07128394A (en) 1995-05-19

Family

ID=17531883

Family Applications (1)

Application Number Title Priority Date Filing Date
JP27373893A Pending JPH07128394A (en) 1993-11-01 1993-11-01 Dielectric deterioration monitoring/diagnosing system for electric equipment

Country Status (1)

Country Link
JP (1) JPH07128394A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007333631A (en) * 2006-06-16 2007-12-27 Fuji Electric Holdings Co Ltd Method and apparatus for inspecting and manufacturing inorganic insulator
JP4553421B2 (en) * 1999-07-14 2010-09-29 東洋電機製造株式会社 Estimation method of residual breakdown voltage value of rotating electrical machine
JPWO2009130772A1 (en) * 2008-04-24 2011-08-11 東芝三菱電機産業システム株式会社 Deterioration diagnosis device for induction heating device
JP2012154879A (en) * 2011-01-28 2012-08-16 Meidensha Corp Partial discharge measuring apparatus
JP2014215189A (en) * 2013-04-26 2014-11-17 三菱日立パワーシステムズ株式会社 Insulation diagnostic method of electric rotary machine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4553421B2 (en) * 1999-07-14 2010-09-29 東洋電機製造株式会社 Estimation method of residual breakdown voltage value of rotating electrical machine
JP2007333631A (en) * 2006-06-16 2007-12-27 Fuji Electric Holdings Co Ltd Method and apparatus for inspecting and manufacturing inorganic insulator
JPWO2009130772A1 (en) * 2008-04-24 2011-08-11 東芝三菱電機産業システム株式会社 Deterioration diagnosis device for induction heating device
JP5012997B2 (en) * 2008-04-24 2012-08-29 東芝三菱電機産業システム株式会社 Deterioration diagnosis device for induction heating device
JP2012154879A (en) * 2011-01-28 2012-08-16 Meidensha Corp Partial discharge measuring apparatus
JP2014215189A (en) * 2013-04-26 2014-11-17 三菱日立パワーシステムズ株式会社 Insulation diagnostic method of electric rotary machine

Similar Documents

Publication Publication Date Title
US5420513A (en) Dielectric breakdown prediction and dielectric breakdown life-time prediction using iterative voltage step stressing
JP4733989B2 (en) Kenting monitoring control system and operation method thereof
US7432679B2 (en) Non-intrusive method for extrapolating an internal stator temperature
Babel et al. Condition-based monitoring and prognostic health management of electric machine stator winding insulation
EP1760857B1 (en) Quench detection method and apparatus of superconductive conductor
Stone et al. A thermal cycling type test for generator stator winding insulation
US6392419B1 (en) Apparatus for and method of monitoring the status of the insulation on the wire in a winding
WO2006073016A1 (en) Superconductive cable withstand voltage test method
Madonna et al. Evaluation of strand‐to‐strand capacitance and dissipation factor in thermally aged enamelled coils for low‐voltage electrical machines
JPH07128394A (en) Dielectric deterioration monitoring/diagnosing system for electric equipment
Mohammed et al. FBG thermal sensing ring scheme for stator winding condition monitoring in PMSMs
JP2007281275A (en) Method for diagnosing deterioration of molded transformer
US11309773B2 (en) System and method for monitoring temperature of rotating electric machine
EP1703293B1 (en) Method and device for estimating remaining service life of coil
Ward et al. A quality control test for high voltage stator insulation
Toudji et al. Predictive diagnostic based on HF modeling of electrical machines windings
JP6164022B2 (en) Interlayer insulation diagnosis method for winding equipment
TWI765252B (en) Diagnostic method and diagnostic apparatus for electrical machinery, and rotating electrical machine
US7121718B2 (en) Method and device for detecting defects in sheet metal segments of electric generators and motors
JPH07192911A (en) Layer short detector for superconducting coil
SU1163427A1 (en) Method of thermal diagnostic checking of electric machine
JPH063390A (en) Diagnostic method for deterioration of cable
JP4286952B2 (en) Method for measuring partial discharge of rotating machine windings
RU2028639C1 (en) Electric motor insulation tester
JP3853134B2 (en) Estimating remaining life of power cables