JP2004077245A - Device for measuring temperature of winding conductor for ac rotary electric machine, and measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring the temperature of a winding conductor for AC rotary electric machine, and a measuring method capable of accurately measuring resistance value to the order of 10<SP>-7</SP>Ω at the minimum when measuring the temperature of a stator winding having a low resistance value to the order of 0.0001 Ω to 0.001 Ω. <P>SOLUTION: The device 30 for measuring the temperature of stator winding conductor is equipped with a measuring basic circuit 36 provided with a variable DC voltage supply means which can supply DC voltage equivalent to or more than AC voltage generated in a three-phase short circuit 33 during three-phase short circuit energizing operation, a limiting resistor 34 limiting the AC voltage generated in the three-phase short circuit 33 and a shunt 35; and a voltage and current measuring means 38 provided with a measuring channel 43 drastically attenuating an AC component superposed on a measurement signal with respect to a DC component, a digital recorder 45 with high resolution and a data processing device 46 processing the measurement signal. Accordingly, since the resistance value of the stator winding 32 can be accurately measured to the order of 10<SP>-7</SP>Ω at the minimum, temperature change of the stator winding 32 can be accurately measured. <P>COPYRIGHT: (C)2004,JPO

Description

【０００８】
固定子巻線４の抵抗値から通電運転中の固定子巻線４の温度を求める方法は、幾つかあるが、例えば、交流回転電機を急速に停止させて停止中の固定子巻線４の抵抗値を無通電状態にして測定した後、測定時刻（無通電状態にしてからの経過時間）および測定した抵抗値から直接通電運転中の温度を推定し評価する方法、または、ある一定間隔で固定子巻線４の抵抗値を連続測定し、測定した固定子巻線４の抵抗値から固定子巻線４の温度を換算して、通電運転中の温度を外挿による推定を行い評価する方法がある。
【０００９】
図１２に、交流回転電機を急速に無通電状態とした後、停止中に固定子巻線４の抵抗値を測定する測定概略を表した説明図を示す。
【００１０】
図１２によれば、固定子巻線４の抵抗値測定は、固定子巻線４の両端、すなわち、中性点側および出力（ライン端子）側に４端子抵抗計１１の抵抗計電流通電線１０と抵抗計電圧通電線１１とを接続して、固定子巻線４の抵抗値を測定する。測定した固定子巻線４の抵抗値から固定子巻線４の温度を算出する場合は数式１を用いる。数式１において、基準巻線抵抗値、基準温度および測定抵抗値を予め測定等により調べておけば、測定巻線抵抗温度が算出できる。
【００１１】
一方、大容量・高電圧回転電機では、急速に回転子を停止することは事実上不可能であり、通電中において固定子巻線４の抵抗値を直接測定するのは困難であるため、通電中の交流回転電機の固定子巻線４の温度を測定する際には、下コイル４ｊと上コイル４ｋとの間にＲＴＤ６を事前に挿入しておき、このＲＴＤ６を使用して固定子巻線４表面の温度、すなわち、導体部８の温度を絶縁部１２を介して測定している。
【００１２】
従来の大容量・高電圧回転電機における通電中の固定子巻線４の温度測定の概略を説明する説明図を図１３に示し、この図１３を参照して、従来の大容量・高電圧回転電機における通電中の固定子巻線４の温度測定方法について説明する。
【００１３】
図１３によれば、従来の通電中の巻線温度測定方法は、絶縁部１２で覆われた下コイル４ｊと上コイル４ｋとの間に事前挿入されるＲＴＤ６に温度測定装置１３を接続して、通電中の固定子巻線４表面の温度の温度を測定する。しかし、大容量・高電圧回転電機では固定子巻線４の絶縁部１２が厚く、導体部８と固定子巻線４表面との温度差が大きくなる。
【００１４】
従って、回転電機運転中において、固定子巻線４の導体部８の温度を測定する場合、できるだけ精度良く測定するために、固定子巻線４の導体部８の温度を直接測定することは重要であり、特に、製造者としては、回転電機運転中における固定子巻線４の導体部８の温度を直接把握するニーズは非常に高い。
【００１５】
そこで、ＩＥＣ規格６０２７９では、幾つかの負荷運転中および三相短絡通電運転中における導体温度測定方法を規定している。ＩＥＣ規格６０２７９で規定されている導体温度測定方法の１つに運転中の交流回転電機の固定子巻線４に外部から直流電圧を印加し、固定子巻線４の直流電圧および電流を測定して固定子巻線４の抵抗値を算出して温度評価する電圧・電流法がある。
【００１６】
図１４にＩＥＣ規格６０２７９で提案されている交流回転電機の三相短絡通電中における固定子巻線４の抵抗値を測定する測定方法のうち、電圧・電流法による固定子巻線抵抗測定回路１４の回路構成図を示す。
【００１７】
図１４に示される固定子巻線抵抗測定回路１４は、直流電圧を供給する直流電圧源１５と、固定子巻線４を三相短絡した三相短絡回路１６と、シャント１７とが電気的に直列接続される。直流電圧源１５は、ＩＥＣ規格６０２７９で推奨している制限抵抗１８を介して直流電源（バッテリー）１９を接続した回路構成としている。
【００１８】
固定子巻線抵抗測定回路１４を構成する三相短絡回路１６の両端、すなわち、中性点２０側および出力側のライン端子２１間にかかる電圧Ｖを測定する電圧測定回路２２が電気的に並列接続される。固定子巻線抵抗測定回路１４を構成するシャント１７の両端には、三相短絡回路１６を流れる電流（三相並列一括）Ｉ_０を測定する電流測定回路２３が電気的に並列接続される。
【００１９】
電圧測定回路２２は、三相平衡したリアクトル２４と第１のフィルタ２５とμＡオーダの電流を計測するμＡ計２６とを電気的に接続して構成し、第１のフィルタ２５を通過する電流をμＡ計２６で測定する。電圧測定回路２２を構成するリアクトル２４および第１のフィルタ２５の抵抗値は事前に測定されており、リアクトル２４の抵抗値はｒａ、第１のフィルタ２５の抵抗値はｒである。
【００２０】
電圧測定回路２２による三相短絡回路１６の両端にかかる電圧Ｖの測定は、第１のフィルタ２５を通過する電流をμＡ計２６で計測することによりなされ、μＡ計２６における電流値の読みをｉとすれば、
【数２】
Ｖ＝（ｒａ／３＋ｒ）ｉ
となる。
【００２１】
電流測定回路２３は、トランス２７と第２のフィルタ２８とｍＶオーダの電圧を測定するｍＶ計２９とを電気的に接続して構成される。電流測定回路２３による三相短絡回路１６を流れる電流（三相並列一括）Ｉ_０の測定は、シャント１７両端にかかる電圧値をｍＶ計２９で測定し、既知のシャント１７の抵抗値からシャント１７を流れる電流値を算出することで、三相短絡回路１６を流れる電流（三相並列一括）Ｉ_０を測定する。
【００２２】
電圧測定回路１９および電流測定回路２０から測定された三相短絡回路１６の両端にかかる電圧Ｖおよび三相短絡回路１６を流れる電流Ｉ_０と、三相短絡回路１６を流れる電流Ｉ_０および各相の固定子巻線４を通電する電流Ｉ_１との関係（Ｉ_１＝Ｉ_０／３）から固定子巻線４の抵抗値Ｒは、
【数３】
Ｒ＝ｉ（３ｒ＋ｒａ）／Ｉ_０
となる。
【００２３】
【発明が解決しようとする課題】
しかしながら、固定子巻線の導体部の温度を直接測定する従来の三相短絡通電中の交流回転電機の固定子巻線導体温度測定装置およびその方法では、固定子巻線導体温度を固定子巻線の抵抗から換算して測定する場合、例えば、タービン発電機や水車発電機のような大容量・高電圧交流回転電機の固定子巻線では、各相の固定子巻線抵抗の大きさが、０．０００１Ω〜０．００１Ωのオーダと非常に小さいため、固定子巻線抵抗を精度良く測定しないと、温度に対する測定精度が低下する問題がある。
【００２４】
具体的に例を挙げて説明すると、例えば、０．０００５Ωの固定子巻線の温度について１℃単位の温度変化を評価するためには、通常の銅製巻線の温度係数は１／２３５（ＪＥＣ２１００等の規格指定値）であるから、０．０００５×１／２３５×１＝２．１３×１０^−６Ωオーダで固定子巻線抵抗を測定することが要求される。
【００２５】
また、交流回転電機を急速に無通電状態とした後、停止中に固定子巻線の抵抗値を測定し、外挿による推定で三相短絡通電運転中の交流回転電機の固定子巻線導体温度を求める従来の交流回転電機の巻線導体温度測定装置および測定方法では、交流回転電機の回転子が停止してからでないと測定が行えないため、例えば、タービン発電機や水車発電機のような大容量・高電圧交流回転電機の場合、停止するまでにかなりの時間を要する。
【００２６】
従って、無通電状態になってから測定を開始する時間までかなりの時間を要し、外挿により固定子巻線導体温度を推定する際に推定した固定子巻線導体温度が精度の良いものであるとは言い難いという問題点がある。
【００２７】
本発明は、上述した事情を考慮してなされたもので、０．０００１Ω〜０．００１Ωのオーダの低抵抗値を有する固定子巻線の温度を測定した抵抗値から算出する際に、固定子巻線導体の抵抗値を精度良く測定可能に構成することで、固定子巻線の温度を精度良く求めることが可能な交流回転電機の巻線導体温度測定装置および測定方法を提供することを目的とする。
【００２８】
また、本発明の他の目的は、交流回転電機の回転子の動作状態に関わらず、無通電状態にあれば、固定子巻線導体温度を測定開始でき、三相短絡通電運転中の固定子巻線導体温度を精度良く推定可能な交流回転電機の巻線導体温度測定装置および測定方法を提供するにある。
【００２９】
【課題を解決するための手段】
本発明に係る交流回転電機の巻線導体温度測定装置は、上述した課題を解決するため、請求項１に記載したように、回転電機の固定子巻線を三相短絡する三相短絡手段と、前記三相短絡手段によって得られた三相短絡回路に直流電圧を可変可能に供給する可変直流電圧供給手段と、前記三相短絡回路と、電流計測用抵抗とを電気的に接続することにより構成される測定基本回路と、前記三相短絡回路に印加された直流電圧値および前記三相短絡回路に通電された電流値を取得する測定チャンネルと、この測定チャンネルからのアナログ出力をデジタル変換し記録するデジタル記録手段と、このデジタル記録手段からの出力をデータ処理して入力結果を出力するデータ処理手段とを備える電圧電流測定手段とを具備したことを特徴とする。
【００３０】
上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定装置は、請求項２に記載したように、前記測定基本回路を前記三相短絡回路に生じる交流電圧に匹敵する直流電圧を印加できるように構成し、前記電圧電流測定手段を測定時に取得されるアナログ測定信号から交流成分を減衰させるフィルタと、このフィルタから出力されるアナログ測定信号を増幅する増幅器とを備える前記測定チャンネルと、１４ｂｉｔ〜１６ｂｉｔの分解能を有する前記デジタル記録手段と、データ処理して処理結果を表示する前記データ処理手段とを電気的に接続して構成し、前記フィルタを商用周波数５０Ｈｚおよび６０Ｈｚでフィルタ利得が−４０〜−８０ｄＢ、入力耐電圧が１００〜６００Ｖで構成し、前記増幅器を増幅率が５０〜１０００倍でドリフトの発生が少なく、前記増幅率で線形性を有する低ドリフトアンプで構成することで、前記固定子巻線の抵抗値を１０^−７Ωオーダまでの精度で測定可能に構成したことを特徴とする。
【００３１】
請求項２記載の交流回転電機の巻線導体温度測定装置において、前記測定基本回路を前記三相短絡回路に生じる交流電圧に匹敵する直流電圧を印加でき、印加可能な直流電圧は５〜２００Ｖである。印加する直流電圧は、測定時に前記三相短絡回路に生じる交流電圧がどのくらいあるのかを見ながら適宜調整して決定する。
【００３２】
本発明に係る交流回転電機の巻線導体温度測定方法は、上述した課題を解決するため、請求項３に記載したように、前記固定子巻線への通電がない無通電状態にて、前記固定子巻線の抵抗値を求め、基準温度における巻線抵抗値に換算する基準抵抗値算出ステップと、スター接続された交流回転電機の固定子巻線を三相短絡し三相短絡回路を形成する三相短絡ステップと、前記交流回転電機が運転され、前記固定子巻線への通電がある状態にて、可変直流電圧供給手段により前記三相短絡回路に印加される直流電圧値および通電される直流電流値を測定することで前記固定子巻線の抵抗値を算出する巻線抵抗値算出ステップと、前記固定子巻線の抵抗値と前記基準抵抗値とを用いて前記交流回転電機の運転中における固定子巻線導体温度を前記電圧電流測定手段で算出する巻線導体温度算出ステップとを含むことを特徴とする。
【００３３】
また、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項４に記載したように、前記回転電機が運転された状態にて測定された前記三相短絡回路の直流電圧値および電流値を平均化処理手段で高速サンプリングして、平均化処理する第１の平均化処理ステップを備え、前記巻線抵抗値算出ステップで巻線抵抗を算出する際に、前記第１の平均化処理ステップで平均化処理された前記三相短絡回路の直流電圧値および電流値を用いて前記交流回転電機の固定子巻線導体温度を測定することを特徴とする。
【００３４】
さらに、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項５に記載したように、前記回転電機が運転された状態にて測定された前記三相短絡回路の直流電圧値および電流値を平均化処理手段で高速サンプリングして、平均化処理して得られた平均値に対して、一定偏差を超える範囲のサンプリングデータを除外する統計的処理を施した後、残りのサンプリングデータを平均化処理する第２の平均化処理ステップを備え、前記巻線抵抗値算出ステップで巻線抵抗を算出する際に、前記第２の平均化処理ステップで平均化処理された前記三相短絡回路の直流電圧値および電流値を用いて前記交流回転電機の固定子巻線導体温度を測定することを特徴とする。
【００３５】
さらにまた、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項６に記載したように、前記交流回転電機を三相短絡通電運転している間、前記巻線短絡導体を冷却し、前記巻線短絡導体の温度変化を抑制する導体冷却ステップを備え、前記巻線抵抗値算出ステップで算出される前記固定子巻線の抵抗値を測定する際の測定誤差の低減を図ったことを特徴とする。
【００３６】
一方、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項７に記載したように、前記交流回転電機を三相短絡通電運転している間、前記巻線短絡導体を冷却し、前記巻線短絡導体の温度変化を抑制する導体冷却ステップと、前記巻線短絡導体の抵抗値を換算式から算出する巻線短絡導体抵抗算出ステップとを備えたことを特徴とする。
【００３７】
また、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項８に記載したように、前記可変直流電圧供給手段に、単相交流可変電圧商用周波電源と、対地から絶縁された変圧器と、単相全波整流装置とを電気的に接続して直流電圧の可変供給を可能に構成した可変直流電圧供給回路を使用して行うことを特徴とする。
【００３８】
さらに、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項９に記載したように、前記交流回転電機を三相短絡通電運転中における前記交流回転電機の固定子巻線の外表面温度を測定する固定子巻線外表面温度測定ステップを備え、前記基準抵抗値算出ステップで基準抵抗値およびデータ処理に必要な数式とともに前記固定子巻線の絶縁部の厚さを入力した後に、前記三相短絡回路の電圧値および電流値を測定することを特徴とする。
【００３９】
さらにまた、上述した課題を解決するため、本発明に係る交流回転電機の巻線導体温度測定方法では、請求項１０に記載したように、前記交流回転電機を三相短絡通電運転中において、前記三相短絡回路の電圧が５０〜６００Ｖと高い場合には、通電を遮断して無通電状態とした後、前記電圧電流測定ステップ、巻線抵抗値算出ステップおよび巻線導体温度算出ステップを例えば、１分間等の任意の一定間隔で前記固定子巻線導体温度を算出し、冷媒温度とほぼ等しくなるまで前記電圧電流測定ステップ、巻線抵抗値算出ステップおよび巻線導体温度算出ステップをくりかえし行って算出した前記固定子巻線導体温度の推移から前記固定子巻線導体温度の推移を関数近似して通電遮断時の固定子巻線導体温度を推定することを特徴とする。
【００４０】
請求項１０記載の交流回転電機の巻線導体温度測定方法において、冷媒温度とほぼ等しくなるまでとは、前記固定子巻線導体温度が冷媒温度との差が０〜５℃の範囲で飽和している状態および冷媒温度との差が０〜２℃の範囲にある状態の少なくとも一方の状態にあることをいう。
【００４１】
【発明の実施の形態】
以下、本発明に係る交流回転電機の巻線導体温度測定装置および測定方法について、図面を参照して説明する。
【００４２】
［第１の実施形態］
図１に本発明の第１の実施形態に係る交流回転電機の巻線導体温度測定装置３０の一例を示す。
【００４３】
図１に示される交流回転電機の巻線導体温度測定装置３０は、大地から絶縁され直流電圧を可変して印加できる可変直流電圧源３１と、回転電機内の固定子巻線３２を三相短絡した三相短絡回路３３の交流成分を制限する制限抵抗３４と、温度変化に対して抵抗値の変化の少ない抵抗素子であるシャント３５とを電気的に直列接続して構成される固定子巻線抵抗測定基本回路（以下、測定基本回路とする）３６と、固定子巻線３２の電圧および電流を測定する電圧電流測定手段３８とを具備する。
【００４４】
固定子巻線導体温度測定装置３０が具備する三相短絡回路３３は、三相の固定子巻線３２を三相短絡手段としての巻線短絡導体３９で中性点４０側および出力側、いわゆるライン端子４１側を三相短絡して形成される。
【００４５】
固定子巻線導体温度測定装置３０が具備する電圧電流測定手段３８は、２つの測定チャンネル（以下、測定ｃｈとする）４３と、測定ｃｈ４３からのアナログ測定信号をアナログ／デジタル変換（以下、Ａ／Ｄ変換とする）して、デジタル測定信号をメモリした後に出力するデジタル記録手段としての多チャンネルデジタル記録装置（以下、デジタル記録装置とする）４５と、デジタル記録装置４５からのデジタル測定信号を処理して測定値や測定値を代入して入力式を演算した演算結果を表示するデータ処理手段としてのデータ処理装置４６とを備える。
【００４６】
電圧電流測定手段３８が備える２つの測定ｃｈ４３である第１チャンネル（以下、１ｃｈとする）および第２チャンネル（以下、２ｃｈとする）は、両方とも同じ構成をしている。測定ｃｈ４３の１つのチャンネル構成は、測定により得られた測定信号の交流成分を減衰させるフィルタ４９と、フィルタ４９から出力される測定信号を増幅する増幅器５０とを備える。
【００４７】
図２に固定子巻線導体温度測定装置３０に用いられるフィルタ４９の回路構成を示す。
【００４８】
図２によれば、フィルタ４９は、抵抗素子５２と、コンデンサ５３とで形成されるいわゆるＲＣフィルタを複数段、例えば６段接続等の多段接続にして構成される。
【００４９】
フィルタ４９は、三相短絡回路３３の電圧に対しても有効に機能させるために通常フィルタで使用される電圧よりも使用可能な電圧を高く設定し、入力される電圧の上限値（以下、入力耐電圧とする）を少なくとも１００Ｖ、つまり、１００Ｖの電圧では有効に機能し得るように構成される。
【００５０】
フィルタ４９の入力耐電圧は、できるだけ高い方が好ましい。しかし、入力耐電圧を向上させると、フィルタ４９の製作コストが増加するため、必要以上に入力耐電圧を向上させるのは不要な製作コスト増加につながる。そこで、フィルタ４９の入力耐電圧は、好ましくは５〜６００Ｖ、より好ましくは、４０〜３００Ｖ、さらに好ましくは、８０〜２３０Ｖにする。例えば、図２に示されるフィルタ４９は、２５０Ｖまでの電圧に対して有効に機能し得る。
【００５１】
また、フィルタ４９は、フィルタ４９のゲイン特性として、商用周波数である５０Ｈｚまたは６０Ｈｚで少なくとも−５０ｄＢのゲインを得る高減衰特性を有し、例えば、図２に示されるフィルタ４９は、−６０ｄＢのゲインを得るゲイン特性を有する。
【００５２】
フィルタ４９のゲイン特性は、商用周波数である５０Ｈｚまたは６０Ｈｚにおいて、測定精度の観点から言えばできるだけフィルタ減衰率が高い方が好ましい。しかし、フィルタ製作の容易性およびコストと必要とされる測定精度とを考慮してフィルタ減衰率を設定すれば、好ましくは−４５ｄＢ〜−８０ｄＢであり、より好ましくは−５０ｄＢ〜−７０ｄＢであり、さらに好ましくは−５０ｄＢ〜−６０ｄＢである。
【００５３】
測定ｃｈ４３が備える増幅器５０は、増幅率が少なくとも５０倍以上でリニアリティーを示し、かつ、低ドリフト特性を有する低ドリフトアンプである。図１に示される固定子巻線導体温度測定装置３０に用いられる増幅器５０の増幅率は、好ましくは５０倍〜１０００倍であり、より好ましくは、７０倍〜５００倍であり、さらに好ましくは９０倍〜２５０倍である。
【００５４】
電圧電流測定手段３８が備えるデジタル記録装置４５は、少なくとも１４ｂｉｔ（２^−１４＝１／１６３８４）の分解能を有する。図１に示される固定子巻線導体温度測定装置３０に用いられるデジタル記録装置４５の分解能は、出来るだけ良い方が測定上は望ましいが、装置のコストと必要とされる分解能を考慮すれば、１４〜１６ｂｉｔで十分である。例えば、図１に示される固定子巻線導体温度測定装置３０に用いられるデジタル記録装置４５の分解能は、１４ｂｉｔであり、１０Ｖ入力の場合、１０×１／１６３８４＝０．６１ｍＶの分解能となる。
【００５５】
電圧電流測定手段３８が備えるデータ処理装置４６は、平均化処理を行うアベレージング機能および入力された式に平均化処理を行った平均値を代入して演算処理する演算処理機能を有する。データ処理装置４６には、電圧電流測定手段３８で測定される直流電圧値および電流値から算出される固定子巻線抵抗値Ｒａ’と事前測定した固定子巻線抵抗値を９５℃での抵抗値に換算した基準抵抗値Ｒ_９５および固定子巻線導体温度Ｔとの関係を表す数式４を
【数４】

固定子巻線導体温度の測定開始前に事前に入力しておく。
【００５６】
そして、固定子巻線導体温度測定を行い、測定した直流電圧および電流からデータ処理装置４６が演算して得たから数式４を計算し、固定子巻線導体温度Ｔをデータ処理装置４６が換算し、必要に応じてその出力をディスプレイに表示する。
【００５７】
図１に示される固定子巻線導体温度測定装置３０を用いた三相短絡通電運転中における固定子巻線導体温度測定方法について説明する。
【００５８】
まず、三相短絡通電運転中における固定子巻線導体温度測定を実施する前に事前に各相の固定子巻線３２の抵抗値を測定し、測定した抵抗値と抵抗測定時の温度から所定温度の基準抵抗値を算出する基準抵抗値算出ステップを行う。基準抵抗値算出ステップでは、各相の固定子巻線３２の抵抗値を測定し、測定した固定子巻線３２の抵抗値および抵抗測定時の温度を数式１に代入して、数式４に示される基準抵抗値Ｒ_９５を算出する。そして、算出した基準抵抗値Ｒ_９５をデータ処理装置４６に入力する。
【００５９】
次に、各相の固定子巻線３２を三相短絡導体３９で三相短絡して三相短絡回路３３を形成する三相短絡回路ステップを行う。そして、三相短絡回路ステップで三相短絡回路３３を形成した後、固定子巻線導体温度測定装置３０が具備する測定基本回路３６および電圧電流測定手段３８と三相短絡回路３３とを電気的に接続する測定装置接続ステップを行う。
【００６０】
測定装置接続ステップは、まず、測定対象である固定子巻線３２を三相短絡した三相短絡回路３３を測定基本回路３６を構成する可変直流電圧源３１とシャント３５との間に電気的に直列接続する。そして、電圧電流測定手段３８が備える測定ｃｈ４３の一方のチャンネルを三相短絡回路３３に電気的に並列接続し、測定ｃｈ４３の他方のチャンネルをシャント３５に電気的に並列接続することでなされる。
【００６１】
次に、測定者が交流回転電機を三相短絡通電運転状態にして、三相短絡回路３３の直流電圧値および電流値を電圧電流測定手段３８で測定する電圧電流測定ステップを行う。三相短絡回路３３の両端にかかる電圧Ｖｓの測定は、測定ｃｈ４３の一方、例えば１ｃｈが三相短絡回路３３の両端に接続されているので、直接、三相短絡回路３３の両端にかかる電圧Ｖｓ値を測定することでなされる。一方、三相短絡回路３３に流入する電流Ｉｓの測定は、シャント３５を流れる電流値と三相短絡回路３３に流入する電流値とが等しいことを利用して測定される。
【００６２】
三相短絡回路３３に流入する電流Ｉｓの測定についてもう少し具体的に説明すると、三相短絡回路３３に流入する電流Ｉｓの測定は、まず、測定ｃｈ４３の他方、例えば、２ｃｈがシャント３５の両端に接続されて、シャント３５の両端にかかる電圧値が測定される。次に、測定されたシャント３５の両端にかかる電圧値から既知のシャント３５の抵抗値を利用してシャント３５を流れる電流値を算出する。シャント３５を流れる電流値と三相短絡回路３３に流入する電流値とは等しいので、シャント３５を流れる電流値がわかれば三相短絡回路３３に流入する電流値を求めることができる。
【００６３】
次に、電圧電流測定ステップで測定された直流電圧値および電流値からデータ処理装置４６が固定子巻線３２の抵抗値を算出する巻線抵抗値算出ステップを行う。巻線抵抗値算出ステップは、まず、データ処理装置４６で測定された直流電圧値および電流値から三相短絡回路３３の抵抗値Ｒａを算出する。そして、算出した三相短絡回路３３の抵抗値Ｒａから固定子巻線抵抗値Ｒａ’を算出する。
【００６４】
三相短絡回路３３の抵抗値Ｒａは、巻線短絡導体３９Ａの抵抗値Ｒｅｘを含むため、事前に測定した巻線短絡導体３９Ａの抵抗値Ｒｅｘ分を補正する必要がある。
固定子巻線抵抗値Ｒａ’と、三相短絡回路３３の抵抗値Ｒａと、巻線短絡導体３９Ａの抵抗値Ｒｅｘとの関係は、以下の数式５で表される。
【００６５】
【数５】
Ｒａ’＝３（Ｒａ−Ｒｅｘ）
【００６６】
次に、データ処理装置４６が巻線抵抗値算出ステップで算出された固定子巻線抵抗値Ｒａ’と、事前入力される基準抵抗値Ｒ_９５および数式４とから固定子巻線導体温度Ｔを演算する巻線導体温度算出ステップを行い、演算結果、すなわち、固定子巻線導体温度Ｔをディスプレイに表示する。
【００６７】
本実施形態によれば、固定子巻線導体温度測定装置３０が、三相短絡通電運転中に三相短絡回路３３に生じる交流電圧に対して同等以上の直流電圧を供給可能な可変直流電圧供給手段と三相短絡回路３３に生じる交流電圧を制限する制限抵抗３４とシャント３５とを備えた測定基本回路３６と、測定信号に重畳した交流成分を直流成分に対して大幅に減衰させる測定ｃｈ４３と分解能の高いデジタル記録装置４５と測定信号を処理するデータ処理装置４６とを備えた電圧電流測定手段３８とを具備することにより、固定子巻線３２の抵抗値を最小１０^−７Ωオーダまで精度良く抵抗値を測定することが可能となるので、固定子巻線３２の温度変化を１℃程度の精度で測定することが可能となる。
【００６８】
尚、電圧電流測定手段３８が備える２つの測定ｃｈ４３の１ｃｈと２ｃｈとは、同じ構成のため、逆に接続しても測定上支障はない。また、測定ｃｈ４３のチャンネル数は必ずしも２である必要はなく、少なくとも２以上のチャンネル数を有していれば良い。
【００６９】
また、フィルタ４９は、ＲＣフィルタの多段接続となっているが、有効に機能する入力耐電圧範囲（１００Ｖ〜６００Ｖ）およびフィルタ利得特性が同程度（−５０ｄＢ〜−６０ｄＢ）であれば、例えば、デジタルフィルタ等の他のフィルタで実現しても良い。
【００７０】
［第２の実施形態］
図３に本発明の第２の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ａの一例を示す。
【００７１】
固定子巻線導体温度測定装置３０Ａは、第１の実施形態に係る固定子巻線導体温度測定装置３０に対して、電圧電流測定手段３８に代わり、第１の平均化処理装置５５を付加した電圧電流測定手段３８Ａを具備したものであり、その他の箇所は異ならない。従って、第１の実施形態に係る固定子巻線導体温度測定装置３０と異ならない箇所については同じ符号を付して説明を省略する。
【００７２】
図３に示される固定子巻線導体温度測定装置３０Ａは、図１に示される固定子巻線導体温度測定装置３０と同様に、測定基本回路３６と、電圧電流測定手段３８Ａとを具備する。測定基本回路３６には、三相短絡回路３３の両端に電圧電流測定手段３８Ａが電気的に接続され、測定ｃｈ４３の一方のチャンネルで三相短絡回路３３の両端にかかる電圧Ｖｓが、他方のチャンネルで三相短絡回路３３に流入する電流Ｉｓが測定される。
【００７３】
固定子巻線導体温度測定装置３０が具備する電圧電流測定手段３８Ａは、図１に示される電圧電流測定手段３８に高速サンプリングを行い、サンプリングしたデータを平均化処理して平均値を算出する平均化処理手段としての第１の平均化処理装置５５を付加したものであり、第１の平均化処理装置５５は、デジタル記録装置４５とデータ処理装置４６との間に設けられ電気的に接続される。
【００７４】
電圧電流測定手段３８Ａが備える第１の平均化処理装置５５は、０．１秒間で１０００点程度、すなわち、約１００μ秒のサンプリング周期で高速サンプリングを行うことが可能であり、図３に示される第１の平均化処理装置５５では、０・１秒間に１０００点のサンプリングを行い平均化処理することで、安定した精度の良いデータを得ることを可能にしている。
【００７５】
図３に示される固定子巻線導体温度測定装置３０Ａを用いた三相短絡通電運転中の固定子巻線導体温度測定方法は、第１の実施形態に係る三相短絡通電運転中の固定子巻線導体温度測定方法に対して、第１の平均化処理ステップを備える点のみが異なっている。従って、第１の実施形態に係る三相短絡通電運転中における固定子巻線導体温度測定方法と同一内容の箇所については説明を簡略または省略する。
【００７６】
図３に示される固定子巻線導体温度測定装置３０Ａを用いた固定子巻線導体温度測定方法は、まず、測定者は、基準抵抗値算出ステップで基準抵抗値Ｒ_９５を求め、求めた基準抵抗値Ｒ_９５の値および数式４をデータ処理装置４６に入力する。そして、三相短絡回路３３を形成する三相回路短絡ステップと、測定基本回路３６および電圧電流測定手段３８Ａを三相短絡回路３３に電気的に接続する測定装置接続ステップとを行う。
【００７７】
次に、測定者が交流回転電機を三相短絡通電運転状態にして、電圧電流測定ステップを行う。そして、データ処理装置４６は、電圧電流測定ステップで測定された直流電圧値および電流値を０・１秒間に１０００点サンプリングする高速サンプリングを行い、高速サンプリングした直流電圧値および電流値を平均して平均値を算出する平均化処理ステップを行う。
【００７８】
次に、データ処理装置４６は、平均化処理ステップで平均化処理された直流電圧値および電流値、すなわち、直流電圧平均値および電流平均値から固定子巻線抵抗値Ｒａ’を算出する巻線抵抗値算出ステップを行い、巻線導体温度算出ステップを行う。
【００７９】
本実施形態によれば、固定子巻線導体温度測定装置３０Ａが具備する電圧電流測定手段３８Ａは第１の平均化処理装置５５を備え、高速サンプリングを行い、サンプリングしたデータの平均値を算出し出力するので、第１の実施形態に係る固定子巻線導体温度測定装置３０と比較して、安定した精度の良いデータを収集することが可能となる。
【００８０】
従って、本実施形態に係る交流回転電機の巻線導体温度測定方法の方が、第１の実施形態に係る交流回転電機の巻線導体温度測定方法よりも固定子巻線導体温度を測定する測定精度が向上する。
【００８１】
尚、電圧電流測定手段３８Ａが備える第１の平均化処理装置５５のサンプリング能力は、必ずしも０．１秒間で１０００点でなくても良く、５００点〜２０００点の範囲でサンプリングを行うことが可能であれば良い。
【００８２】
［第３の実施形態］
図４に本発明の第３の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ｂの一例を示す。
【００８３】
固定子巻線導体温度測定装置３０Ｂは、第２の実施形態に係る固定子巻線導体温度測定装置３０Ａに対して、電圧電流測定手段３８Ａに代わり、電圧電流測定手段３８Ｂを具備したものであり、その他の箇所は異ならない。従って、第２の実施形態に係る固定子巻線導体温度測定装置３０Ａと異ならない箇所については同じ符号を付して説明を省略する。
【００８４】
図４に示される固定子巻線導体温度測定装置３０Ｂは、測定基本回路３６および電圧電流測定手段３８Ｂを具備する。測定基本回路３６には、電圧電流測定手段３８Ｂが電気的に接続され、測定ｃｈ４３の一方のチャンネルで三相短絡回路３３の両端にかかる電圧Ｖｓが、他方のチャンネルで三相短絡回路３３に流入する電流Ｉｓが測定される。
【００８５】
固定子巻線導体温度測定装置３０が具備する電圧電流測定手段３８Ｂは、図２に示される電圧電流測定手段３８Ａが備える第１の平均化処理装置５５に代わり、高速サンプリングを行いサンプリングしたデータの平均値を算出後、統計処理を施す平均化処理手段としての第２の平均化処理装置５７を付加したものであり、第２の平均化処理装置５７は、デジタル記録装置４５とデータ処理装置４６との間に設けられ電気的に接続される。
【００８６】
電圧電流測定手段３８Ｂが備える第２の平均化処理装置５７は、０・１秒間に１０００点のサンプリングを行い平均化処理した後、平均化処理して得られた平均値に対して、例えば、平均値から±３σ（σ：標準偏差）の範囲内のデータを残し、その他のデータ、すなわち、平均値から±３σの範囲外のデータを除外する等の統計的な処理を実行し、残りのデータのみを平均化処理してより安定した、精度の良いデータを得ることができる。
【００８７】
図４に示される固定子巻線導体温度測定装置３０Ｂを用いた三相短絡通電運転中の固定子巻線導体温度測定方法は、第２の実施形態に係る三相短絡通電運転中の固定子巻線導体温度測定方法に対して、平均化処理ステップの処理内容のみが異なっている。従って、第２の実施形態に係る三相短絡通電運転中の固定子巻線導体温度測定方法と同一内容の箇所については説明を簡略または省略する。
【００８８】
図４に示される固定子巻線導体温度測定装置３０Ｂを用いた固定子巻線導体温度測定方法は、まず、測定者は、基準抵抗値算出ステップで基準抵抗値Ｒ_９５を求め、求めた基準抵抗値Ｒ_９５の値および数式４をデータ処理装置４６に入力する。そして、三相短絡回路３３を形成する三相回路短絡ステップと、測定基本回路３６および電圧電流測定手段３８Ｂを三相短絡回路３３に電気的に接続する測定装置接続ステップとを行う。
【００８９】
次に、測定者が交流回転電機を三相短絡通電運転状態にして、電圧電流測定ステップを行う。そして、データ処理装置４６は、電圧電流測定ステップで測定された直流電圧値および電流値を０・１秒間に１０００点サンプリングする高速サンプリングを行い、高速サンプリングした直流電圧値および電流値を平均して平均値を算出し、さらに、算出した平均値に対して、例えば、平均値±３σの範囲外のデータを除外する統計的な処理を実行する平均化処理ステップを行う。
【００９０】
次に、データ処理装置４６は、平均化処理ステップで平均化処理された直流電圧値および電流値、すなわち、直流電圧平均値および電流平均値から固定子巻線抵抗値Ｒａ’を算出する巻線抵抗値算出ステップを行い、巻線導体温度算出ステップを行う。
【００９１】
本実施形態によれば、固定子巻線導体温度測定装置３０Ｂが具備する電圧電流測定手段３８Ｂは第２の平均化処理装置５７を備え、高速サンプリングしたデータの平均値を算出した後、算出した平均値を例えば、平均値から±３σの範囲外にある平均値を除外する等の統計的な処理を施して出力するので、第２の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ａと比較して、さらに安定した精度の良いデータを収集することが可能となる。
【００９２】
従って、本実施形態に係る交流回転電機の巻線導体温度測定方法の方が、第２の実施形態に係る交流回転電機の巻線導体温度測定方法よりも固定子巻線導体温度を測定する測定精度が向上する。
【００９３】
尚、電圧電流測定手段３８Ｂが備える第２の平均化処理装置５７のサンプリング能力は、必ずしも０．１秒間で１０００点でなくても良く、５００点〜２０００点の範囲でサンプリングを行うことが可能であれば良い。
【００９４】
［第４の実施形態］
図５に本発明の第４の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ｃの一例を示す。
【００９５】
固定子巻線導体温度測定装置３０Ｃは、第１の実施形態に係る固定子巻線導体温度測定装置３０に対して、三相短絡回路３３が備える三相の固定子巻線３２を三相短絡する巻線短絡導体３９Ａを冷却する冷却手段５９を具備したものであり、その他の箇所は異ならない。従って、第１の実施形態に係る固定子巻線導体温度測定装置３０と異ならない箇所については同じ符号を付して説明を省略する。
【００９６】
図５に示される固定子巻線導体温度測定装置３０Ｃは、図１に示される固定子巻線導体温度測定装置３０と同様に、測定基本回路３６および電圧電流測定手段３８と、三相短絡回路３３が備える巻線短絡導体３９Ａを冷却する冷却手段５９とを具備する。冷却手段５９は、三相短絡回路３３が備える巻線短絡導体３９Ａに冷却水を通水する冷却水通水路６０と冷却水を循環させる循環ポンプ６１とを備える。
【００９７】
固定子巻線導体温度測定装置３０Ｃが具備する測定基本回路３６には、電圧電流測定手段３８Ｂが電気的に接続され、測定ｃｈ４３の一方のチャンネルで三相短絡回路３３の両端にかかる電圧Ｖｓが、他方のチャンネルで三相短絡回路３３に流入する電流Ｉｓが測定される。冷却手段５９は、巻線短絡導体３９Ａに冷却水を循環ポンプ６１で循環させて通水することで、巻線短絡導体３９Ａを冷却し、巻線短絡導体３９Ａの温度上昇を抑えて巻線短絡導体３９Ａの温度をほぼ一定に保っている。
【００９８】
図５に示される固定子巻線導体温度測定装置３０Ｃを用いた三相短絡通電運転中における交流回転電機の固定子巻線導体温度測定について説明する。
【００９９】
図５に示される固定子巻線導体温度測定装置３０Ｃを用いた固定子巻線導体温度測定方法は、第１の実施形態に係る固定子巻線導体温度測定装置３０を用いた固定子巻線導体温度測定方法に対して、巻線短絡導体３９Ａを冷却する巻線短絡導体冷却ステップを備える点のみが異なっている。従って、第１の実施形態に係る固定子巻線導体温度測定装置３０を用いた固定子巻線導体温度測定方法と同一内容の箇所については説明を簡略または省略する。
【０１００】
まず、測定者は、基準抵抗値算出ステップで基準抵抗値Ｒ_９５を求め、求めた基準抵抗値Ｒ_９５の値および数式４をデータ処理装置４６に入力する。そして、三相短絡回路３３を形成する三相回路短絡ステップと、測定基本回路３６および電圧電流測定手段３８Ａを三相短絡回路３３に電気的に接続する測定装置接続ステップとを行う。測定装置接続ステップが完了したら、次に、巻線短絡導体冷却ステップを行う。
【０１０１】
巻線短絡導体冷却ステップは、冷却手段５９が備える循環ポンプ６１の運転を開始して固定子巻線３２を三相短絡する巻線短絡導体３９Ａに冷却水を循環させて冷却して、三相短絡通電運転中の巻線短絡導体３９Ａの温度変動を抑えることで、巻線短絡導体３９Ａの抵抗値Ｒｅｘの温度変動を抑制するために行う。
【０１０２】
巻線短絡導体３９Ａの抵抗値Ｒｅｘは、交流回転電機を固定子巻線３２を三相短絡して定格電流値近傍（定格電流値を含む）の電流（以下、約定格電流とする）を連続して通電することにより生じる巻線短絡導体３９Ａの温度上昇に伴って高くなる。従って、巻線短絡導体３９Ａの抵抗値Ｒｅｘを一定とみなして、三相短絡回路３３から固定子巻線抵抗値Ｒａ’を数式５で算出して評価すると誤差を生じることになる。
【０１０３】
そこで、巻線短絡導体冷却ステップで巻線短絡導体３９Ａの抵抗値Ｒｅｘの温度変動を抑制することで、巻線短絡導体３９Ａの抵抗値Ｒｅｘを三相短絡通電運中を通じて一定とみなすことができ、固定子巻線抵抗値Ｒａ’を数式５で算出して評価する際に生じ得る測定誤差を低減させている。以降の測定ステップは、第１の実施形態と同様に、電圧電流測定ステップ、巻線抵抗値算出ステップおよび巻線導体温度算出ステップを行う。
【０１０４】
本実施形態によれば、固定子巻線導体温度測定装置３０Ｃが冷却手段５９を具備することで、三相短絡し連続して定格電流を通電することにより、固定子巻線３２で発生した熱の伝導による巻線短絡導体３９Ａの温度変動を抑え、固定子巻線３２の抵抗値測定の際に生じる測定誤差を低減することができる。従って、本実施形態に係る固定子巻線導体温度測定装置３０Ｃは、第１の実施形態に係る固定子巻線導体温度測定装置３０と比べて固定子巻線３２の抵抗値測定の際に生じる測定誤差をより低減して精度の良い抵抗値測定を可能とし、より精度の高い固定子巻線導体の温度測定を可能とする。
【０１０５】
［第５の実施形態］
図６に本発明の第５の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ｄの一例を示す。
【０１０６】
固定子巻線導体温度測定装置３０Ｄは、第４の実施形態に係る固定子巻線導体温度測定装置３０Ｃに対して、巻線短絡導体温度測定手段６３をさらに具備したものであり、その他の箇所は異ならない。従って、第４の実施形態に係る固定子巻線導体温度測定装置３０Ｃと異ならない箇所については同じ符号を付して説明を省略する。
【０１０７】
図６に示される固定子巻線導体温度測定装置３０Ｄは、図５に示される固定子巻線導体温度測定装置３０Ｃと同様に、測定基本回路３６、電圧電流測定手段３８および冷却手段５９と、巻線短絡導体３９Ａの温度を測定する巻線短絡導体温度測定手段６３とを具備する。
【０１０８】
巻線短絡導体温度測定手段６３は、巻線短絡導体３９Ａの温度を測定する温度測定器６４と、温度測定器６４から出力されるアナログ信号をデジタル信号に変換して出力するＡ／Ｄ変換器６５とを備える。巻線短絡導体温度測定手段６３は、入力側が三相短絡回路３３と電気的に接続され、出力側がデータ処理装置４６と電気的に接続される。
【０１０９】
図６に示される固定子巻線導体温度測定装置３０Ｄを用いた三相短絡通電運転中における交流回転電機の固定子巻線導体温度測定について説明する。
【０１１０】
図６に示される固定子巻線導体温度測定装置３０Ｄを用いた固定子巻線導体温度測定方法は、第４の実施形態に係る固定子巻線導体温度測定装置３０Ｃを用いた固定子巻線導体温度測定方法に対して、巻線短絡導体３９Ａの抵抗値Ｒｅｘを換算式から算出する巻線短絡導体抵抗算出ステップを備える点のみが異なっている。従って、第４の実施形態に係る固定子巻線導体温度測定装置３０Ｄを用いた固定子巻線導体温度測定方法と同一内容の箇所については説明を簡略または省略する。
【０１１１】
まず、測定者は、基準抵抗値算出ステップを行う。基準抵抗値算出ステップでは、運転中と同じ接続状態、すなわち、三相短絡してから十分に長時間放置して温度が安定した状態になったら、運転前に基準巻線抵抗値Ｒａ’ｂ、基準温度Ｔａｂ、および巻線短絡導体３９Ａの基準抵抗値（以下、基準外部抵抗とする）Ｒｅｘｂ３６、基準温度Ｔｅｘｂを測定し、測定したこれらの値および換算に必要な数式をデータ処理装置４６へ事前に入力しておく。
【０１１２】
次に、三相短絡回路３３を形成する三相回路短絡ステップと、測定対象である固定子巻線３２を三相短絡した三相短絡回路３３、測定基本回路３６および電圧電流測定手段３８を電気的に接続する測定装置接続ステップとを行う。そして、測定装置接続ステップが完了したら、巻線短絡導体冷却ステップで巻線短絡導体３９Ａの冷却を行う。
【０１１３】
次に、測定者は、電圧電流測定ステップを行う。電圧電流測定ステップでは、三相短絡回路３３の電圧および電流を測定するとともに、固定子巻線導体温度測定装置３０Ｄが具備する巻線短絡導体温度測定手段６３で巻線短絡導体３９Ａの温度を測定する。
【０１１４】
次に、巻線短絡導体３９Ａの抵抗値Ｒｅｘを数式１に示される換算式から算出する巻線短絡導体抵抗算出ステップを行う。三相巻線短絡導体３９Ａの抵抗値Ｒｅｘの算出は、測定された巻線短絡導体３９Ａの温度Ｔから数式６で巻線短絡導体３９Ａの抵抗値Ｒｅｘを換算して求める。
【０１１５】
【数６】

【０１１６】
巻線短絡導体抵抗算出ステップが完了したら、第４の実施形態と同様に巻線抵抗値算出ステップを行う。巻線抵抗値算出ステップにおける交流回転電機の固定子巻線抵抗値Ｒａ’は、巻線短絡導体抵抗算出ステップで算出された巻線短絡導体３９Ａの抵抗値Ｒｅｘを数式５に代入して演算することにより求める。次に、巻線導体温度算出ステップを行い、データ処理装置４６が固定子巻線導体温度Ｔをデータ処理装置４６のディスプレイに表示する。
【０１１７】
本実施形態によれば、固定子巻線導体温度測定装置３０Ｄが巻線短絡導体温度測定手段６３を具備することで、交流回転電機の三相短絡通電運転中における巻線短絡導体３９Ａの温度を測定可能にし、測定した温度Ｔにおける巻線短絡導体３９Ａの抵抗値Ｒｅｘを考慮した精度のよい測定をすることが可能となる。従って、本実施形態に係る固定子巻線導体温度測定装置３０Ｄは、第４の実施形態に係る固定子巻線導体温度測定装置３０Ｃと比べて固定子巻線３２の抵抗値測定の際に生じる測定誤差をより低減して精度の良い抵抗値測定を可能とし、より精度の高い固定子巻線導体の温度測定を可能とする。
【０１１８】
［第６の実施形態］
図７に本発明の第６の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ｅの一例を示す。
【０１１９】
固定子巻線導体温度測定装置３０Ｅは、第１の実施形態に係る固定子巻線導体温度測定装置３０に対して、測定基本回路３６に代わり、測定基本回路３６Ａを具備したものであり、その他の箇所は異ならない。従って、第１の実施形態に係る固定子巻線導体温度測定装置３０と異ならない箇所については同じ符号を付して説明を省略する。
【０１２０】
図７に示される固定子巻線導体温度測定装置３０Ｅは、測定基本回路３６Ａと、電圧電流測定手段３８とを具備する。測定基本回路３６Ａは、測定基本回路３６に対して、可変直流電圧供給手段としての可変直流電圧源３１と可変直流電圧供給回路６８とを置換した回路構成である。
【０１２１】
図８に可変直流電圧供給回路６８の回路構成を表す回路構成図を示す。
【０１２２】
図８に示される可変直流電圧供給回路６８は、可変直流電圧供給手段の一形態であり、単相交流可変電圧商用周波電源（被試験交流回転電機と同一周波数：５０Ｈｚまたは６０Ｈｚ）６９、対地絶縁変圧器７０、およびダイオード７１で構成される単相全波整流装置７２を電気的に接続して構成する。可変直流電圧供給回路６８は、測定基本回路３６Ａにおいて可変直流電圧源３１と同様に機能し、１００Ａ程度までの大電流を通電することが可能である。
【０１２３】
図７に示される固定子巻線導体温度測定装置３０Ｅを用いた三相短絡通電運転中における交流回転電機の固定子巻線導体温度測定について説明する。
【０１２４】
図７に示される固定子巻線導体温度測定装置３０Ｅを用いた固定子巻線導体温度測定方法は、第１の実施形態に係る固定子巻線導体温度測定装置３０を用いた固定子巻線導体温度測定方法に対して、直流電圧を供給する可変直流電圧供給手段が異なるのみで、測定ステップは基本的に同一である。
【０１２５】
すなわち、第１の実施形態に係る交流回転電機の巻線導体温度測定方法と同様にして、測定者は、基準抵抗値算出ステップ、三相回路短絡ステップ、測定装置接続ステップ、電圧電流測定ステップ、巻線抵抗値算出ステップおよび巻線導体温度算出ステップを行い、固定子巻線導体温度Ｔをデータ処理装置４６のディスプレイに表示する。
【０１２６】
本実施形態によれば、固定子巻線導体温度測定装置３０Ｅは、直流可変電圧供給手段としての可変直流電圧供給回路６８を備えた測定基本回路３６Ａを具備することにより、直流電源供給の際に交流回転電機を三相短絡して約定格電流を通電して運転することにより発生する３倍高調波に起因したビート振動等の影響を受けることなく、安定した直流電圧を交流回転電機の三相短絡回路３３に供給することが可能となる。
【０１２７】
従って、固定子巻線導体温度測定装置３０Ｅは第１の実施形態に係る固定子巻線導体温度測定装置３０と比較して、より精度の良い固定子巻線導体の抵抗値測定を可能とし、より精度の高い固定子巻線導体の温度測定を可能とする。
【０１２８】
尚、図８に示される可変直流電圧供給回路６８を構成する単相全波整流装置７２は、整流素子にダイオード７１を使用した状態で示されているが、必ずしも単相全波整流装置７２で使用される整流素子をダイオード７１に限定するものではない。例えば、単相全波整流装置７２で使用される整流素子をダイオード７１に代わりサイリスタを用いて単相全波整流装置７２を構成しても良い。
【０１２９】
［第７の実施形態］
図９に本発明の第７の実施形態に係る交流回転電機の巻線導体温度測定装置３０Ｆの一例を示す。
【０１３０】
固定子巻線導体温度測定装置３０Ｆは、ＲＴＤ７４を挿入した交流回転電機の固定子巻線３２の温度を導体部と外表面とで測定するもので、第１の実施形態に係る固定子巻線導体温度測定装置３０に対して、固定子巻線外表面温度測定手段７５をさらに具備することで、固定子巻線３２の導体部および絶縁部７６のそれぞれの温度測定を可能にしている。
【０１３１】
固定子巻線導体温度測定装置３０Ｆは、固定子巻線３２の導体部および絶縁部７６のそれぞれの温度測定を可能とすることで、絶縁部７６の径方向長さに対する温度特性（以下、温度勾配とする）を得ることができ、固定子巻線３２の絶縁部７６の温度特性を評価できる。固定子巻線３２の絶縁部７６の温度特性を評価することは、材料開発の観点等から重要であり、有意義なものである。
【０１３２】
固定子巻線導体温度測定装置３０Ｆは、固定子巻線導体温度測定装置３０に対して、固定子巻線外表面温度測定手段７５をさらに具備する点以外は固定子巻線導体温度測定装置３０と異ならないので、第１の実施形態に係る固定子巻線導体温度測定装置３０と異ならない箇所については同じ符号を付して説明を省略する。
【０１３３】
固定子巻線導体温度測定装置３０Ｆは、図１に示される固定子巻線導体温度測定装置３０と同様に、測定基本回路３６および電圧電流測定手段３８と、固定子巻線３２間に挿入されたＲＴＤ７４から温度測定信号を取得して固定子巻線３２の外表面温度を測定する固定子巻線外表面温度測定手段７５とを具備する。固定子巻線外表面温度測定手段７５は、図６に示される固定子巻線導体温度測定装置３０Ｄが具備する巻線短絡導体温度測定手段６３と基本的に同じ構成であり、温度測定対象が異なるだけである。
【０１３４】
すなわち、固定子巻線外表面温度測定手段７５は、ＲＴＤ７４で固定子巻線３２の外表面温度を測定する温度測定器６４と、温度測定器６４から出力されるアナログ信号をデジタル信号に変換して出力するＡ／Ｄ変換器６５とを備える。また、固定子巻線外表面温度測定手段７５の入力側は、ＲＴＤ７４に電気的に接続され、出力側はデータ処理装置４６に電気的に接続される。
【０１３５】
図９に示される固定子巻線導体温度測定装置３０Ｆを用いた三相短絡通電運転中における交流回転電機の固定子巻線導体温度測定について説明する。
【０１３６】
図９に示される固定子巻線導体温度測定装置３０Ｆを用いた固定子巻線導体温度測定方法は、第１の実施形態に係る固定子巻線導体温度測定装置３０を用いた固定子巻線導体温度測定方法に対して、固定子巻線３２の外表面温度を測定する固定子巻線外表面温度測定ステップをさらに行う点が異なる。従って、第７の実施形態に係る固定子巻線導体温度測定装置３０Ｆを用いた固定子巻線導体温度測定方法と同一内容の箇所については説明を簡略または省略する。
【０１３７】
固定子巻線導体温度測定装置３０Ｆを用いた固定子巻線導体温度測定方法は、まず、基準抵抗値算出ステップで基準抵抗値を算出し、データ処理に必要な数式とともに本実施形態では固定子巻線３２の絶縁部７７の厚さをデータ処理装置４６に入力する。次に、測定者は、三相回路短絡ステップ、測定装置接続ステップおよび電圧電流測定ステップを行い、電圧電流測定ステップで三相短絡回路３３の直流電圧値および電流値を測定する時と同時に固定子巻線外表面温度測定ステップを行う。
【０１３８】
固定子巻線外表面温度測定ステップは、固定子巻線外表面温度測定手段７５でＲＴＤ７４で取得される温度情報をＡ／Ｄ変換してデータ処理装置４６でデータ処理することで固定子巻線３２の外表面温度を測定する。電圧電流測定ステップおよび固定子巻線外表面温度測定ステップ以降の測定ステップは、第１の実施形態に係ると同様に巻線抵抗値算出ステップおよび巻線導体温度算出ステップを行う。
【０１３９】
本実施形態によれば、固定子巻線導体温度測定装置３０Ｆが固定子巻線外表面温度測定手段７５をさらに具備することで、測定された固定子巻線３２の導体部および外表面のそれぞれの温度から、固定子巻線３２の絶縁部７６の温度勾配を得ることができ、絶縁部７６の温度特性を評価することができる。
【０１４０】
［第８の実施形態］
本発明の第８の実施形態に係る交流回転電機の巻線導体温度測定方法を説明する。
【０１４１】
本実施形態に係る交流回転電機の巻線導体温度測定方法は、測定対象の固定子巻線３２を三相短絡した三相短絡回路３３の両端にかかる電圧Ｖｓが三相短絡通電運転中において５０Ｖ以上と高い電圧が発生している場合に行うものである。
【０１４２】
三相短絡回路３３の両端にかかる電圧Ｖｓが三相短絡通電運転中において５０Ｖ以上と高い電圧が発生している場合は、電圧・電流法では、測定する直流電圧および直流電流に対して大きな交流成分が重畳する。従って、要求に合う温度精度を得るために必要とされる固定子巻線３２の抵抗値測定精度を維持することが困難となる。そこで、本実施形態に係る交流回転電機の巻線導体温度測定方法では、固定子の固定子巻線３２間に挿入されたＲＴＤ７４を用いて外挿により三相短絡通電運転中の交流回転電機の固定子巻線導体温度を推定するものである。
【０１４３】
本実施形態に係る交流回転電機の巻線導体温度測定装置は、ＲＴＤ７４で固定子巻線３２の外表面温度を測定可能な固定子巻線導体温度測定装置が用いられ、例えば、図９に示される固定子巻線導体温度測定装置３０Ｆが用いられる。
【０１４４】
図１０に本実施形態に係る交流回転電機の巻線導体温度測定方法を説明する説明図（グラフ）を示す。
【０１４５】
図１０に示される説明図では、グラフの横軸に固定子巻線電流が０となった時刻からの経過時間ｔ（ｍｉｎ）をとり、縦軸に温度（℃）または電流（Ａ）をとって、固定子巻線電流が０となった時刻からの経過時間ｔに対する温度（℃）推移を表している。
【０１４６】
本実施形態に係る三相短絡通電運転中の交流回転電機の固定子巻線導体温度測定は、まず、交流回転電機の固定子巻線３２を三相短絡した三相短絡回路３３に約定格電流を連続通電する。そして、ＲＴＤ７４で取得された固定子巻線３２の外表面温度Ｔ_Ｒ、固定子巻線電流Ｉａおよび冷媒温度Ｔｃを連続測定する。
【０１４７】
次に、固定子巻線３２の温度が完全に飽和したことをＲＴＤ７４から取得される固定子巻線３２の外表面温度Ｔ_Ｒの指示値で確認する。そして、固定子巻線３２の温度が完全に飽和したら、交流回転電機を無通電状態にする。交流回転電機を無通電状態にすると、固定子巻線電流Ｉａは減少を開始し、やがて、Ｉａ＝０となる。
【０１４８】
Ｉａ＝０となったら、例えば、無通電状態とした時点（ｔ＝０）から１分後に、固定子巻線導体温度測定装置３０Ｆが具備する電圧電流測定手段３８で固定子巻線抵抗Ｒａ’を測定し、測定した固定子巻線抵抗Ｒａ’から固定子巻線導体温度Ｔを求める。そして、例えば、１分毎等のある一定間隔毎に測定を行い、固定子巻線導体温度Ｔと冷媒温度Ｔｃとがほぼ等しくなるまで測定を続ける。
【０１４９】
測定によって得られた固定子巻線導体温度Ｔを例えば、指数関数等で近似することによって、固定子巻線導体温度Ｔは、経過時間ｔの関数で表され、近似により得られた固定子巻線導体温度Ｔの関数式にｔ＝０を代入すれば、固定子巻線電流Ｉａが減少開始した時点（ｔ＝０）、すなわち、定格電流通電時の固定子巻線導体温度Ｔを推定することができる。
【０１５０】
本実施形態では、測定対象の固定子巻線３２を三相短絡した三相短絡回路３３の両端にかかる電圧Ｖｓが三相短絡通電運転中において５０Ｖ以上と高い電圧が発生している場合においても、無通電状態にして、素早く温度測定を行うことができるので、外挿により三相短絡通電運転中の固定子巻線３２の導体部の温度を推定することができる。
【０１５１】
また、外挿により三相短絡通電運転中の固定子巻線３２の導体部の温度を推定する際に、固定子巻線導体温度測定装置３０Ｆが測定基本回路３６と電圧電流測定手段３８とを具備することで交流成分を大幅除去が可能となることから、固定子巻線電流ＩａがＩａ＝０となれば、回転子が停止する前から固定子巻線導体温度Ｔの温度測定を開始することができるので、より正確に三相短絡通電運転中の固定子巻線３２の導体部の温度を推定することができる。
【０１５２】
尚、本実施形態に係る交流回転電機の巻線導体温度測定装置は、図９に示される固定子巻線導体温度測定装置３０Ｆに限らず、ＲＴＤ７４から固定子巻線の外表面温度を測定する固定子巻線外表面温度測定手段を外付けにより付加すれば、他の実施形態で用いた固定子巻線導体温度測定装置３０〜３０Ｅを適用しても良い。
【０１５３】
また、ＲＴＤ７４から固定子巻線の外表面温度を測定する固定子巻線外表面温度測定手段を外付けしなくても、三相短絡通電運転開始から固定子巻線導体温度が安定するまで十分な時間が経過した後に行う場合には、他の実施形態で用いた固定子巻線導体温度測定装置３０〜３０Ｅを適用しても良い。
【０１５４】
以上に説明したように、本発明に係る交流回転電機の巻線導体温度測定装置および測定方法によれば、固定子巻線導体温度測定装置３０が、三相短絡通電運転中に三相短絡回路３３に生じる交流電圧に対して同等以上の直流電圧を供給可能な可変直流電圧供給手段としての可変直流電圧源３１と三相短絡回路３３に生じる交流電圧を制限する制限抵抗３４とシャント３５とを備えた測定基本回路３６と、測定信号に重畳した交流成分を直流成分に対して大幅に減衰させる測定ｃｈ４３と分解能の高いデジタル記録装置４５と測定信号を処理するデータ処理装置４６とを備えた電圧電流測定手段３８とを具備することにより、固定子巻線３２の抵抗値を最小で１０^−７Ωオーダで抵抗値を精度良く測定することが可能となる。従って、固定子巻線３２の温度変化を１℃程度の精度で精度良く測定することが可能な交流回転電機の巻線導体温度測定装置および測定方法を提供することができる。
【０１５５】
また、高速サンプリングを行い、サンプリングしたデータの平均値を算出し出力する第１の平均化処理装置５５を備えた電圧電流測定手段３８Ａを具備する固定子巻線導体温度測定装置３０Ａまたは高速サンプリングしたデータの平均値を算出した後、算出した平均値を統計的な処理を施して出力する第２の平均化処理装置５７を備えた電圧電流測定手段３８Ｂを巻線導体温度測定に使用することで、より安定した精度の良いデータを収集することができる。
【０１５６】
さらに、測定対象の固定子巻線３２を三相短絡し連続して約定格電流を通電することにより、固定子巻線３２で発生した熱の伝導による巻線短絡導体３９Ａの温度変動を抑える冷却手段５９を具備する固定子巻線導体温度測定装置３０Ｃを交流回転電機の巻線導体温度測定に使用することで、巻線短絡導体３９Ａの抵抗値Ｒｅｘの測定誤差を抑えて固定子巻線３２の抵抗値測定の際に生じる測定誤差を低減することができる。
【０１５７】
さらにまた、冷却手段５９および巻線短絡導体温度測定手段６３を具備する固定子巻線導体温度測定装置３０Ｄを交流回転電機の巻線導体温度測定に使用することで、交流回転電機の三相短絡通電運転中における巻線短絡導体３９Ａの温度を測定可能にし、測定した温度Ｔにおける巻線短絡導体３９Ａの抵抗値Ｒｅｘを考慮した精度のよい測定をすることができる。
【０１５８】
一方、直流可変電圧供給手段としての可変直流電圧供給回路６８を備えた測定基本回路３６Ａを具備する固定子巻線導体温度測定装置３０Ｅを交流回転電機の巻線導体温度測定に使用することにより、直流電源供給の際に交流回転電機を三相短絡して約定格電流を通電して運転することにより発生する３倍高調波に起因したビート振動等の影響を受けることなく、安定した直流電圧を交流回転電機の三相短絡回路３３に供給することができ、より精度の良い固定子巻線導体の抵抗値測定を可能とし、より精度の高い固定子巻線導体の温度測定が可能となる。
【０１５９】
また、固定子巻線外表面温度測定手段７５を具備する固定子巻線導体温度測定装置３０Ｆを交流回転電機の巻線導体温度測定に使用することで、測定された固定子巻線３２の導体部および外表面のそれぞれの温度から、固定子巻線３２の絶縁部７６の温度勾配を得ることができ、絶縁部７６の温度特性を評価することができる。
【０１６０】
さらに、本発明に係る固定子巻線導体温度測定装置３０〜３０Ｆは、測定対象の固定子巻線３２を三相短絡して形成される三相短絡回路３３の両端にかかる電圧Ｖｓが三相短絡通電運転中において５０Ｖ以上と高い電圧が発生している場合においても、無通電状態にして、素早く温度測定を行うことができるので、外挿により三相短絡通電運転中の固定子巻線３２の導体部の温度を推定することができる。
【０１６１】
さらにまた、外挿により三相短絡通電運転中の固定子巻線３２の導体部の温度を推定する際に、本発明に係る固定子巻線導体温度測定装置３０〜３０Ｆが測定基本回路３６と電圧電流測定手段３８〜３８Ｂとを具備することにより交流成分の大幅な除去が可能となることから、固定子巻線電流ＩａがＩａ＝０となれば、回転子が停止する前から固定子巻線導体温度Ｔの温度測定を開始することができるので、より正確に三相短絡通電運転中の固定子巻線３２の導体部の温度を推定することができる。
【０１６２】
尚、本発明に係る交流回転電機の巻線導体温度測定方法では、基準抵抗値測定ステップで、各相の固定子巻線３２の抵抗値を測定し、測定した固定子巻線３２の抵抗値および抵抗測定時の温度を数式１に代入して、数式４に示される基準抵抗値Ｒ_９５を算出した後、算出した基準抵抗値Ｒ_９５をデータ処理装置４６に入力しているが、データ処理装置４６に数式１を入力しておき、測定した固定子巻線３２の抵抗値および抵抗測定時の温度データをデータ処理装置４６に入力できるような固定子巻線導体温度測定装置を構成して基準抵抗値Ｒ_９５を算出をさせても良い。
【０１６３】
【発明の効果】
本発明に係る交流回転電機の巻線導体温度測定装置および測定方法によれば、交流回転電機を約定格速度で三相短絡通電運転中に固定子巻線抵抗を精度良く測定することが可能となるので、被試験交流回転電機の固定子巻線導体温度を精度良く安定して測定可能な交流回転電機の巻線導体温度測定装置および測定方法を提供することができる。
【０１６４】
また、本発明に係る交流回転電機の巻線導体温度測定装置および測定方法によれば、三相短絡通電運転中において固定子巻線を三相短絡した際に生じる固定子巻線間の電圧が高く電圧・電流法が適用できない場合においても、無通電状態にして、回転子が停止する前から固定子巻線導体温度Ｔの温度測定を開始することができるので、外挿によって推定する固定子巻線導体温度をより精度良く測定可能な交流回転電機の巻線導体温度測定装置および測定方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図２】本発明の第１の実施形態に係る交流回転電機の巻線導体温度測定装置に備えられる測定ｃｈが有するフィルタの回路構成を示す回路構成図。
【図３】本発明の第２の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図４】本発明の第３の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図５】本発明の第４の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図６】本発明の第５の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図７】本発明の第６の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図８】本発明の第６の実施形態に係る交流回転電機の巻線導体温度測定装置に可変直流電圧供給手段として用いられる可変直流電圧供給回路の回路構成を示す構成概略図。
【図９】本発明の第７の実施形態に係る交流回転電機の巻線導体温度測定装置の構成を示す構成概略図。
【図１０】本発明に係る交流回転電機の巻線導体温度測定方法であり、通電停止後の経過時間と固定子巻線導体温度との関係を示した説明図。
【図１１】交流回転電機に用いられる固定子の構成を示す構成概略図。
【図１２】従来の通電中の固定子巻線導体温度測定方法であり、交流回転電機を停止して固定子巻線の抵抗測定を行う固定子巻線抵抗測定回路の回路構成を説明する説明図。
【図１３】従来の通電中の固定子巻線導体温度測定方法であり、ＲＴＤを使用して固定子巻線導体温度測定を行う固定子巻線導体温度測定回路の回路構成を説明する説明図。
【図１４】ＩＥＣ規格６０２７９にて規定される三相短絡通電運転中の交流回転電機の固定子巻線導体温度測定する固定子巻線抵抗測定回路の回路構成を説明する説明図。
【符号の説明】
３０，３０Ａ，３０Ｂ，３０Ｃ，３０Ｄ，３０Ｅ，３０Ｆ…固定子巻線導体温度測定装置、３１…可変直流電圧源（可変直流電圧供給手段）、３２…固定子巻線、３３…三相短絡回路、３４…制限抵抗、３５…シャント（電流計測用抵抗）、３６，３６Ａ…測定基本回路、３８，３８Ａ、３８Ｂ…電圧電流測定手段、３９，３９Ａ…巻線短絡導体（三相短絡手段）、４０…中性点、４１…ライン端子、４３…測定ｃｈ、４５…デジタル記録装置、４６…データ処理装置、４９…フィルタ、５０…増幅器、５２…抵抗素子、５３…コンデンサ、５５…第１の平均化処理装置、５７…第２の平均化処理装置、５９…冷却手段、６０…冷却水通水路、６１…循環ポンプ、６３…巻線短絡導体温度測定手段、６４…温度測定器、６５…Ａ／Ｄ変換器、６８…可変直流電圧供給回路（可変直流電圧供給手段）、６９…単相交流可変電圧商用周波電源、７０…対地絶縁変圧器、７１…ダイオード、７２…単相全波整流装置、７４…ＲＴＤ（抵抗温度デバイス）、７５…固定子巻線外表面温度測定手段、７６…絶縁部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for measuring a stator winding conductor temperature of an AC rotating electric machine, and in particular, to short-circuit an output terminal of a stator winding of the AC rotating electric machine to energize at a rated or near-rated rotational speed. The present invention relates to an apparatus and a method for measuring a stator winding conductor temperature during operation.
[0002]
[Prior art]
FIG. 11 is an explanatory view showing an enlarged structure of a part of a stator 1 used in a conventional AC rotating electric machine.
[0003]
In a stator 1 shown in FIG. 11, a stator winding 4 is wound around a slot 3 provided in a stator core 2, and the stator winding 4 is pressed into the slot 3 by a wedge 5. The stator winding 4 includes a stator winding (hereinafter, referred to as a lower coil) 4j wound around the outer periphery of the stator core 2 and a stator winding (hereinafter, referred to as an upper coil) wound around the inner periphery. 4k is wound.
[0004]
Further, in a large-capacity, high-voltage rotating electric machine, a resistance temperature device (hereinafter, referred to as an RTD) 6 as a temperature measuring element is dispersed between a lower coil 4j and an upper coil 4k at a place where a temperature measurement is required. Insert. A spacer 7 that fills the gap is inserted in a place where the RTD 6 is not inserted and a gap is generated between the lower coil 4j and the upper coil 4k.
[0005]
The temperature measurement of the stator winding 4 during operation of the AC rotating electric machine, that is, during energization will be described.
[0006]
In measuring the temperature of the stator winding 4 during energization, it is desirable to measure the temperature of the conductor 8 in the stator winding 4. Therefore, when the AC rotating electric machine is a small-capacity machine, the resistance value of the stator winding 4 is measured, the temperature of the stator winding 4 is calculated from the measured resistance value, and the A method for determining the temperature of the winding 4 is generally used, and is also accepted in JEC, IEEE and IEC standards. Equation 1 below shows a conversion formula for calculating the temperature of the stator winding 4 from the measured resistance value.
[0007]
(Equation 1)

[0008]
There are several methods for obtaining the temperature of the stator winding 4 during the energizing operation from the resistance value of the stator winding 4. For example, the AC rotating electric machine is rapidly stopped to stop the stopped stator winding 4. After measuring the resistance value in the non-energized state, a method of directly estimating and evaluating the temperature during energizing operation from the measurement time (elapsed time since the non-energized state) and the measured resistance value, or at a certain interval. The resistance value of the stator winding 4 is continuously measured, the temperature of the stator winding 4 is converted from the measured resistance value of the stator winding 4, and the temperature during the energization operation is extrapolated and evaluated. There is a way.
[0009]
FIG. 12 is an explanatory diagram showing an outline of measurement for measuring the resistance value of the stator winding 4 during stoppage after the AC rotating electric machine is rapidly turned off.
[0010]
According to FIG. 12, the resistance value of the stator winding 4 is measured at both ends of the stator winding 4, that is, at the neutral point side and the output (line terminal) side, with a resistance meter current conducting wire of a four-terminal resistance meter 11. The resistance value of the stator winding 4 is measured by connecting the resistance winding 10 to the resistance meter voltage conducting wire 11. Formula 1 is used to calculate the temperature of the stator winding 4 from the measured resistance value of the stator winding 4. In Expression 1, if the reference winding resistance, the reference temperature, and the measured resistance are checked in advance by measurement or the like, the measured winding resistance temperature can be calculated.
[0011]
On the other hand, in a large-capacity, high-voltage rotating electric machine, it is practically impossible to stop the rotor quickly, and it is difficult to directly measure the resistance value of the stator winding 4 during energization. When measuring the temperature of the stator winding 4 of the middle AC rotating electric machine, an RTD 6 is inserted between the lower coil 4j and the upper coil 4k in advance, and the stator winding is used by using the RTD 6. The temperature of the four surfaces, that is, the temperature of the conductor portion 8 is measured via the insulating portion 12.
[0012]
FIG. 13 is an explanatory diagram for explaining the outline of the temperature measurement of the stator winding 4 during energization in the conventional large-capacity, high-voltage rotating electric machine. Referring to FIG. A method for measuring the temperature of the stator winding 4 during energization in the electric machine will be described.
[0013]
According to FIG. 13, the conventional method of measuring the temperature of the winding during energization is to connect the temperature measuring device 13 to the RTD 6 that is inserted beforehand between the lower coil 4j and the upper coil 4k covered with the insulating part 12. The temperature of the surface of the stator winding 4 during energization is measured. However, in a large-capacity, high-voltage rotating electric machine, the insulating portion 12 of the stator winding 4 is thick, and the temperature difference between the conductor 8 and the surface of the stator winding 4 becomes large.
[0014]
Therefore, when measuring the temperature of the conductor 8 of the stator winding 4 during operation of the rotating electric machine, it is important to directly measure the temperature of the conductor 8 of the stator winding 4 in order to measure as accurately as possible. In particular, there is a very high need for the manufacturer to directly grasp the temperature of the conductor 8 of the stator winding 4 during operation of the rotating electric machine.
[0015]
Therefore, the IEC standard 60279 defines a method of measuring the conductor temperature during some load operations and during the three-phase short-circuit energizing operation. One of the conductor temperature measuring methods defined in IEC standard 60279 is to apply a DC voltage to the stator winding 4 of an AC rotating electric machine in operation from outside and measure the DC voltage and current of the stator winding 4. Voltage / current method for calculating the resistance value of the stator winding 4 and evaluating the temperature.
[0016]
Among the measurement methods for measuring the resistance value of the stator winding 4 during the three-phase short-circuiting of an AC rotating electric machine proposed in IEC standard 60279 in FIG. FIG.
[0017]
The stator winding resistance measuring circuit 14 shown in FIG. 14 includes a DC voltage source 15 for supplying a DC voltage, a three-phase short circuit 16 in which the stator winding 4 is short-circuited in three phases, and a shunt 17 electrically. They are connected in series. The DC voltage source 15 has a circuit configuration in which a DC power source (battery) 19 is connected via a limiting resistor 18 recommended by IEC standard 60279.
[0018]
A voltage measuring circuit 22 for measuring a voltage V applied to both ends of the three-phase short circuit 16 constituting the stator winding resistance measuring circuit 14, that is, between the neutral point 20 side and the line terminal 21 on the output side is electrically connected in parallel. Connected. The current (three-phase parallel collective) I flowing through the three-phase short circuit 16 is provided at both ends of the shunt 17 constituting the stator winding resistance measuring circuit 14.₀Is electrically connected in parallel.
[0019]
The voltage measurement circuit 22 is configured by electrically connecting a three-phase balanced reactor 24, a first filter 25, and a μA meter 26 for measuring a current on the order of μA, and detects a current passing through the first filter 25. It measures with the μA meter 26. The resistance values of the reactor 24 and the first filter 25 constituting the voltage measurement circuit 22 are measured in advance, and the resistance value of the reactor 24 is ra and the resistance value of the first filter 25 is r.
[0020]
The voltage V applied across the three-phase short circuit 16 by the voltage measurement circuit 22 is measured by measuring the current passing through the first filter 25 with a μA meter 26, and reading the current value in the μA meter 26 with i given that,
(Equation 2)
V = (ra / 3 + r) i
It becomes.
[0021]
The current measurement circuit 23 is configured by electrically connecting a transformer 27, a second filter 28, and an mV meter 29 for measuring a voltage on the order of mV. Current flowing through the three-phase short circuit 16 by the current measuring circuit 23 (three-phase parallel batch) I₀Is measured by measuring the voltage value applied to both ends of the shunt 17 with the mV meter 29 and calculating the current value flowing through the shunt 17 from the known resistance value of the shunt 17 to obtain the current flowing through the three-phase short circuit 16 (three-phase Parallel batch) I₀Is measured.
[0022]
The voltage V across the three-phase short circuit 16 measured from the voltage measurement circuit 19 and the current measurement circuit 20 and the current I flowing through the three-phase short circuit 16₀And the current I flowing through the three-phase short circuit 16₀And the current I flowing through the stator winding 4 of each phase₁(I₁= I₀/ 3), the resistance value R of the stator winding 4 becomes
(Equation 3)
R = i (3r + ra) / I₀
It becomes.
[0023]
[Problems to be solved by the invention]
However, in a conventional stator winding conductor temperature measuring apparatus and method for an AC rotating electrical machine during three-phase short circuit energization in which the temperature of the conductor portion of the stator winding is directly measured, the stator winding conductor temperature is measured by the stator winding. When measuring by converting from the resistance of the wire, for example, in the stator winding of a large-capacity, high-voltage AC rotating electric machine such as a turbine generator or a water turbine generator, the magnitude of the stator winding resistance of each phase is , In the order of 0.0001Ω to 0.001Ω, there is a problem that unless the stator winding resistance is accurately measured, the measurement accuracy with respect to temperature is reduced.
[0024]
Specifically, for example, in order to evaluate the temperature change of the stator winding of 0.0005Ω in the unit of 1 ° C., the temperature coefficient of the normal copper winding is 1/235 (JEC2100 Etc.), 0.0005 × 1/235 × 1 = 2.13 × 10^-6It is required to measure the stator winding resistance on the order of Ω.
[0025]
In addition, after the AC rotating electric machine is rapidly de-energized, the resistance value of the stator winding is measured during the stop, and the stator winding conductor of the AC rotating electric machine during the three-phase short-circuit energizing operation is estimated by extrapolation. In the conventional winding conductor temperature measuring device and measuring method for an AC rotating electric machine that determines the temperature, measurement cannot be performed until the rotor of the AC rotating electric machine is stopped. In the case of a large-capacity, high-voltage AC rotating electric machine, it takes a considerable amount of time to stop.
[0026]
Therefore, it takes a considerable amount of time from the non-energized state to the time to start measurement, and the stator winding conductor temperature estimated when extrapolating the stator winding conductor temperature is accurate. There is a problem that it is hard to say.
[0027]
The present invention has been made in view of the above-described circumstances, and when calculating the temperature of a stator winding having a low resistance value on the order of 0.0001 Ω to 0.001 Ω from the measured resistance value, An object of the present invention is to provide a winding conductor temperature measuring device and a measuring method for an AC rotating electric machine capable of accurately determining the temperature of a stator winding by configuring the resistance value of a winding conductor to be able to measure accurately. And
[0028]
Another object of the present invention is to measure the stator winding conductor temperature in a non-energized state, regardless of the operating state of the rotor of the AC rotating electric machine, and start the stator during the three-phase short-circuit energized operation. It is an object of the present invention to provide a winding conductor temperature measuring device and a measuring method of an AC rotating electric machine which can accurately estimate a winding conductor temperature.
[0029]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a winding conductor temperature measuring device for an AC rotating electric machine according to the present invention includes three-phase short-circuit means for three-phase short-circuiting the stator winding of the rotating electric machine, as described in claim 1. By electrically connecting the variable DC voltage supply means for variably supplying a DC voltage to the three-phase short circuit obtained by the three-phase short circuit, the three-phase short circuit, and a current measuring resistor. A configured measurement basic circuit, a measurement channel for acquiring a DC voltage value applied to the three-phase short circuit and a current value supplied to the three-phase short circuit, and converting an analog output from the measurement channel into a digital signal. It is characterized by comprising a digital current recording means for recording, and a voltage / current measuring means comprising data processing means for performing data processing on an output from the digital recording means and outputting an input result.
[0030]
In order to solve the above-described problem, a winding conductor temperature measuring device for an AC rotating electric machine according to the present invention, as described in claim 2, converts the measurement basic circuit to an AC voltage generated in the three-phase short circuit. A filter configured to be capable of applying a DC voltage, a filter that attenuates an AC component from an analog measurement signal obtained at the time of measuring the voltage / current measurement unit, and an amplifier that amplifies the analog measurement signal output from the filter. A measurement channel, the digital recording means having a resolution of 14 bits to 16 bits, and the data processing means for processing data and displaying a processing result are electrically connected to each other, and the filter is operated at commercial frequencies of 50 Hz and 60 Hz. The filter gain is -40 to -80 dB, the input withstand voltage is 100 to 600 V, and the amplifier has an amplification factor of 50 to Generates less drift 000 times, by configuring it low drift amplifier having linearity in the amplification factor, the resistance value of the stator winding 10^-7It is characterized in that it can be measured with accuracy up to the order of Ω.
[0031]
3. The winding conductor temperature measuring apparatus for an AC rotating electric machine according to claim 2, wherein the measurement basic circuit can apply a DC voltage comparable to an AC voltage generated in the three-phase short circuit, and the applicable DC voltage is 5 to 200 V. is there. The DC voltage to be applied is determined by appropriately adjusting while observing the AC voltage generated in the three-phase short circuit during measurement.
[0032]
The method for measuring the winding conductor temperature of the AC rotating electric machine according to the present invention, in order to solve the above-described problem, as described in claim 3, in a non-energized state where there is no energization to the stator winding. A step of calculating a resistance value of the stator winding and converting it into a winding resistance value at a reference temperature, and forming a three-phase short circuit by three-phase short-circuiting the stator windings of the star-connected AC rotating electric machine. The three-phase short-circuiting step, the AC rotating electric machine is operated, and in a state where the stator winding is energized, the DC voltage value applied to the three-phase short-circuit by the variable DC voltage supply means and energized. A winding resistance value calculating step of calculating a resistance value of the stator winding by measuring a DC current value of the AC rotating electric machine using the resistance value of the stator winding and the reference resistance value. Preset stator winding conductor temperature during operation Characterized in that it comprises a winding conductor temperature calculating step of calculating by the voltage current measuring means.
[0033]
According to a fourth aspect of the present invention, there is provided a method for measuring the temperature of a winding conductor of an AC rotating electric machine according to the present invention. A first averaging process step of high-speed sampling of a DC voltage value and a current value of the phase short-circuit by the averaging processing means and averaging the same, and calculating the winding resistance in the winding resistance value calculating step. And measuring a stator winding conductor temperature of the AC rotating electric machine using the DC voltage value and the current value of the three-phase short circuit averaged in the first averaging process step. .
[0034]
Further, in order to solve the above-mentioned problem, in the method for measuring the winding conductor temperature of an AC rotating electric machine according to the present invention, as described in claim 5, the three-dimensional measurement is performed while the rotating electric machine is operated. Statistical processing for sampling the DC voltage value and current value of the phase short circuit at high speed by the averaging processing means and excluding sampling data in a range exceeding a certain deviation from the average value obtained by the averaging processing. After performing the second averaging process step, the second averaging process step includes averaging the remaining sampling data, and calculating the winding resistance in the winding resistance value calculating step. The stator winding conductor temperature of the AC rotating electric machine is measured by using the DC voltage value and the current value of the three-phase short circuit that has been subjected to the conversion processing.
[0035]
Still further, in order to solve the above-mentioned problem, in the method of measuring the winding conductor temperature of the AC rotating electric machine according to the present invention, as described in claim 6, during the three-phase short-circuit energizing operation of the AC rotating electric machine, A cooling step of cooling the winding short-circuit conductor and suppressing a temperature change of the winding short-circuit conductor, and measuring a resistance value of the stator winding calculated in the winding resistance value calculating step. Is characterized by reducing the measurement error.
[0036]
On the other hand, in order to solve the above-described problem, in the method of measuring the winding conductor temperature of the AC rotating electric machine according to the present invention, as described in claim 7, during the three-phase short-circuit energizing operation of the AC rotating electric machine, A conductor cooling step of cooling the winding short-circuit conductor and suppressing a temperature change of the winding short-circuit conductor; and a winding short-circuit conductor resistance calculating step of calculating a resistance value of the winding short-circuit conductor from a conversion formula. It is characterized by the following.
[0037]
According to another aspect of the present invention, there is provided a method for measuring a winding conductor temperature of an AC rotating electric machine, wherein the variable DC voltage supply means includes a single-phase AC variable voltage commercial frequency. Power supply, a transformer insulated from the ground, and a single-phase full-wave rectifier are electrically connected to each other using a variable DC voltage supply circuit configured to enable variable supply of DC voltage. I do.
[0038]
Further, in order to solve the above-mentioned problem, in the method for measuring the winding conductor temperature of an AC rotating electric machine according to the present invention, as described in claim 9, the AC rotating electric machine is configured to rotate the AC rotating electric machine during a three-phase short-circuit energizing operation. A stator winding outer surface temperature measuring step for measuring an outer surface temperature of the stator winding of the electric machine, wherein the reference resistance value calculating step includes a reference resistance value and an insulation required for the stator winding together with a mathematical expression required for data processing. After inputting the thickness of the part, the voltage value and the current value of the three-phase short circuit are measured.
[0039]
Still further, in order to solve the above-described problem, in the method for measuring the winding conductor temperature of the AC rotating electric machine according to the present invention, as described in claim 10, the AC rotating electric machine performs the three-phase short-circuit energizing operation, When the voltage of the three-phase short circuit is as high as 50 to 600 V, after the current is cut off and the current is turned off, the voltage / current measurement step, the winding resistance value calculation step, and the winding conductor temperature calculation step are performed, for example. Calculate the stator winding conductor temperature at an arbitrary constant interval such as one minute, and repeat the voltage current measurement step, the winding resistance value calculation step, and the winding conductor temperature calculation step until the temperature becomes substantially equal to the refrigerant temperature. The transition of the stator winding conductor temperature is approximated by a function from the calculated transition of the stator winding conductor temperature to estimate the stator winding conductor temperature at the time of energization interruption.
[0040]
In the method for measuring a winding conductor temperature of an AC rotary electric machine according to claim 10, the difference between the stator winding conductor temperature and the refrigerant temperature is saturated in a range of 0 to 5 ° C. until the refrigerant temperature becomes substantially equal to the refrigerant temperature. The temperature is in at least one of a state where the temperature is different from a temperature of the refrigerant and a state where the difference from the refrigerant temperature is in the range of 0 to 2 ° C.
[0041]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a winding conductor temperature measuring device and a measuring method for an AC rotating electric machine according to the present invention will be described with reference to the drawings.
[0042]
[First Embodiment]
FIG. 1 shows an example of a winding conductor temperature measuring device 30 of an AC rotary electric machine according to a first embodiment of the present invention.
[0043]
The winding conductor temperature measuring device 30 of the AC rotating electric machine shown in FIG. 1 includes a three-phase short circuit between a variable DC voltage source 31 insulated from the ground and capable of applying a variable DC voltage and a stator winding 32 in the rotating electric machine. A stator winding configured by electrically connecting in series a limiting resistor 34 for limiting an AC component of the three-phase short circuit 33 and a shunt 35 which is a resistance element having a small resistance value change with temperature. It comprises a resistance measurement basic circuit (hereinafter referred to as a measurement basic circuit) 36 and a voltage / current measuring means 38 for measuring the voltage and current of the stator winding 32.
[0044]
The three-phase short-circuit circuit 33 included in the stator winding conductor temperature measuring device 30 includes a three-phase stator winding 32 and a winding short-circuit conductor 39 serving as a three-phase short-circuit means. It is formed by three-phase shorting the line terminal 41 side.
[0045]
The voltage / current measuring means 38 included in the stator winding conductor temperature measuring device 30 includes two measuring channels (hereinafter referred to as measuring channels) 43 and an analog / digital conversion (hereinafter referred to as A) of an analog measuring signal from the measuring channel 43. / D conversion), and stores a digital measurement signal in a memory. The digital measurement signal is output after the multi-channel digital recording device (hereinafter, referred to as a digital recording device) 45 as a digital recording device. A data processing device 46 is provided as data processing means for displaying a calculation result obtained by processing and substituting the measured value or the measured value to calculate the input expression.
[0046]
The first channel (hereinafter, referred to as 1ch) and the second channel (hereinafter, referred to as 2ch), which are the two measurement channels 43 included in the voltage / current measuring unit 38, have the same configuration. One channel configuration of the measurement channel 43 includes a filter 49 for attenuating the AC component of the measurement signal obtained by the measurement, and an amplifier 50 for amplifying the measurement signal output from the filter 49.
[0047]
FIG. 2 shows a circuit configuration of the filter 49 used in the stator winding conductor temperature measuring device 30.
[0048]
According to FIG. 2, the filter 49 is configured by connecting a so-called RC filter formed by a resistance element 52 and a capacitor 53 in a plurality of stages, for example, in a six-stage connection such as a six-stage connection.
[0049]
The filter 49 sets a usable voltage higher than a voltage used in a normal filter so as to function effectively also with respect to the voltage of the three-phase short circuit 33, and sets an upper limit value of an input voltage (hereinafter referred to as input). Withstand voltage) is at least 100 V, that is, a voltage of 100 V can effectively function.
[0050]
It is preferable that the input withstand voltage of the filter 49 be as high as possible. However, if the input withstand voltage is improved, the manufacturing cost of the filter 49 is increased. Therefore, if the input withstand voltage is increased more than necessary, unnecessary manufacturing cost increases. Therefore, the input withstand voltage of the filter 49 is preferably set to 5 to 600 V, more preferably 40 to 300 V, and further preferably 80 to 230 V. For example, the filter 49 shown in FIG. 2 may work effectively for voltages up to 250V.
[0051]
Further, the filter 49 has a high attenuation characteristic of obtaining a gain of at least -50 dB at a commercial frequency of 50 Hz or 60 Hz as a gain characteristic of the filter 49. For example, the filter 49 illustrated in FIG. Is obtained.
[0052]
The gain characteristic of the filter 49 is preferably as high as possible at the commercial frequency of 50 Hz or 60 Hz from the viewpoint of measurement accuracy. However, if the filter attenuation rate is set in consideration of the ease and cost of manufacturing the filter and the required measurement accuracy, it is preferably −45 dB to −80 dB, more preferably −50 dB to −70 dB, More preferably, it is -50 dB to -60 dB.
[0053]
The amplifier 50 included in the measurement channel 43 is a low drift amplifier having a linearity at an amplification factor of at least 50 or more and having low drift characteristics. The amplification factor of the amplifier 50 used in the stator winding conductor temperature measuring device 30 shown in FIG. 1 is preferably 50 to 1000 times, more preferably 70 to 500 times, and still more preferably 90 to 500 times. Times to 250 times.
[0054]
The digital recording device 45 provided in the voltage / current measuring means 38 has at least 14 bits (2^-14= 1/16384). The resolution of the digital recording device 45 used in the stator winding conductor temperature measuring device 30 shown in FIG. 1 is preferably as good as possible in terms of measurement. However, considering the cost of the device and the required resolution, 14 to 16 bits is sufficient. For example, the resolution of the digital recording device 45 used in the stator winding conductor temperature measuring device 30 shown in FIG. 1 is 14 bits, and when 10 V is input, the resolution is 10 × 1/16384 = 0.61 mV.
[0055]
The data processing device 46 included in the voltage / current measuring unit 38 has an averaging function for performing averaging processing and a calculation processing function for performing calculation processing by substituting the averaged value obtained by the averaging processing into the input equation. The data processing device 46 includes a stator winding resistance value Ra ′ calculated from the DC voltage value and the current value measured by the voltage / current measurement means 38 and a stator winding resistance value measured in advance at 95 ° C. Reference resistance value R converted to value₉₅And Equation 4 representing the relationship between the stator winding conductor temperature T and
(Equation 4)

Input beforehand the measurement of stator winding conductor temperature.
[0056]
Then, the stator winding conductor temperature is measured, and the data processing device 46 calculates the expression 4 from the measured DC voltage and current. The data processing device 46 converts the stator winding conductor temperature T. And, if necessary, display the output on a display.
[0057]
A method of measuring the temperature of the stator winding conductor during the three-phase short-circuit energizing operation using the stator winding conductor temperature measuring device 30 shown in FIG. 1 will be described.
[0058]
First, before performing the stator winding conductor temperature measurement during the three-phase short-circuit energizing operation, the resistance value of the stator winding 32 of each phase is measured in advance, and a predetermined value is determined from the measured resistance value and the temperature at the time of resistance measurement. A reference resistance value calculating step of calculating a reference resistance value of the temperature is performed. In the reference resistance value calculation step, the resistance value of the stator winding 32 of each phase is measured, and the measured resistance value of the stator winding 32 and the temperature at the time of the resistance measurement are substituted into Expression 1 to be expressed by Expression 4. Reference resistance value R₉₅Is calculated. Then, the calculated reference resistance value R₉₅Is input to the data processing device 46.
[0059]
Next, a three-phase short circuit step of forming the three-phase short circuit 33 by short-circuiting the stator windings 32 of each phase with the three-phase short conductor 39 is performed. Then, after the three-phase short circuit 33 is formed in the three-phase short circuit step, the measurement basic circuit 36 and the voltage / current measurement means 38 of the stator winding conductor temperature measuring device 30 and the three-phase short circuit 33 are electrically connected. Perform a measurement device connection step to connect to the measurement device.
[0060]
In the measuring device connection step, first, a three-phase short circuit 33 in which the stator winding 32 to be measured is three-phase short-circuited is electrically connected between the variable DC voltage source 31 and the shunt 35 constituting the measurement basic circuit 36. Connect in series. Then, one of the channels of the measurement channel 43 provided in the voltage / current measurement unit 38 is electrically connected in parallel to the three-phase short circuit 33, and the other channel of the measurement channel 43 is electrically connected in parallel to the shunt 35.
[0061]
Next, the measurer puts the AC rotating electric machine into the three-phase short-circuit energizing operation state, and performs a voltage / current measurement step of measuring the DC voltage value and the current value of the three-phase short circuit 33 by the voltage / current measurement unit 38. The voltage Vs applied across the three-phase short circuit 33 is measured by measuring the voltage Vs applied directly across the three-phase short circuit 33 because one of the measurement channels 43, for example, one channel is connected to both ends of the three-phase short circuit 33. This is done by measuring the value. On the other hand, the current Is flowing into the three-phase short circuit 33 is measured by using the fact that the current flowing through the shunt 35 is equal to the current flowing into the three-phase short circuit 33.
[0062]
The measurement of the current Is flowing into the three-phase short circuit 33 will be described more specifically. The measurement of the current Is flowing into the three-phase short circuit 33 is performed by first setting the other of the measurement channels 43, for example, 2ch to both ends of the shunt 35. Connected, the voltage value across the shunt 35 is measured. Next, a current value flowing through the shunt 35 is calculated from the measured voltage value applied to both ends of the shunt 35 by using a known resistance value of the shunt 35. Since the current value flowing through the shunt 35 is equal to the current value flowing into the three-phase short circuit 33, the current value flowing into the three-phase short circuit 33 can be determined if the current value flowing through the shunt 35 is known.
[0063]
Next, the data processing device 46 performs a winding resistance value calculation step of calculating the resistance value of the stator winding 32 from the DC voltage value and the current value measured in the voltage / current measurement step. In the winding resistance value calculation step, first, the resistance value Ra of the three-phase short circuit 33 is calculated from the DC voltage value and the current value measured by the data processing device 46. Then, a stator winding resistance value Ra 'is calculated from the calculated resistance value Ra of the three-phase short circuit 33.
[0064]
Since the resistance value Ra of the three-phase short circuit 33 includes the resistance value Rex of the winding short-circuit conductor 39A, it is necessary to correct the resistance value Rex of the winding short-circuit conductor 39A measured in advance.
The relationship among the stator winding resistance Ra ', the resistance Ra of the three-phase short circuit 33, and the resistance Rex of the winding short-circuit conductor 39A is expressed by the following Equation 5.
[0065]
(Equation 5)
Ra '= 3 (Ra-Rex)
[0066]
Next, the data processing device 46 calculates the stator winding resistance value Ra 'calculated in the winding resistance value calculation step and the reference resistance value R which is input in advance.₉₅A winding conductor temperature calculating step of calculating the stator winding conductor temperature T from Equation 4 and Equation 4 is performed, and the calculation result, that is, the stator winding conductor temperature T is displayed on a display.
[0067]
According to the present embodiment, the stator winding conductor temperature measuring device 30 supplies a variable DC voltage capable of supplying a DC voltage equal to or greater than the AC voltage generated in the three-phase short circuit 33 during the three-phase short circuit energizing operation. A measurement basic circuit 36 including a means and a limiting resistor 34 for limiting an AC voltage generated in the three-phase short circuit 33 and a shunt 35; a measurement channel 43 for greatly attenuating an AC component superimposed on a measurement signal with respect to a DC component; By providing a voltage / current measuring means 38 having a digital recording device 45 having a high resolution and a data processing device 46 for processing a measurement signal, the resistance value of the stator winding 32 can be reduced to at least 10^-7Since the resistance value can be accurately measured to the order of Ω, the temperature change of the stator winding 32 can be measured with an accuracy of about 1 ° C.
[0068]
The 1ch and 2ch of the two measurement channels 43 included in the voltage / current measurement unit 38 have the same configuration, so that even if they are connected in reverse, there is no problem in measurement. Also, the number of channels of the measurement channel 43 does not necessarily need to be two, and it is sufficient that the number of channels is at least two or more.
[0069]
The filter 49 is a multi-stage connection of RC filters. If the input withstand voltage range (100 V to 600 V) and the filter gain characteristic that function effectively are approximately the same (−50 dB to −60 dB), for example, It may be realized by another filter such as a digital filter.
[0070]
[Second embodiment]
FIG. 3 shows an example of a winding conductor temperature measuring device 30A of an AC rotary electric machine according to a second embodiment of the present invention.
[0071]
The stator winding conductor temperature measuring device 30A is different from the stator winding conductor temperature measuring device 30 according to the first embodiment in that a first averaging device 55 is added instead of the voltage / current measuring means 38. It is provided with a voltage / current measuring means 38A, and other portions are not different. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0072]
The stator winding conductor temperature measuring device 30A shown in FIG. 3 includes a measurement basic circuit 36 and a voltage / current measuring unit 38A, similarly to the stator winding conductor temperature measuring device 30 shown in FIG. The measurement basic circuit 36 is electrically connected to the voltage / current measuring means 38A at both ends of the three-phase short circuit 33. The voltage Vs applied to both ends of the three-phase short circuit 33 in one channel of the measurement channel 43 is applied to the other channel. , The current Is flowing into the three-phase short circuit 33 is measured.
[0073]
The voltage / current measuring means 38A included in the stator winding conductor temperature measuring device 30 performs high-speed sampling on the voltage / current measuring means 38 shown in FIG. 1 and averages the sampled data to calculate an average value. A first averaging device 55 as an averaging device is added. The first averaging device 55 is provided between the digital recording device 45 and the data processing device 46 and is electrically connected. You.
[0074]
The first averaging device 55 included in the voltage / current measuring unit 38A can perform high-speed sampling at a sampling period of about 1000 points in 0.1 second, that is, about 100 μs, as shown in FIG. The first averaging device 55 can obtain stable and accurate data by sampling and averaging 1000 points in 0.1 second.
[0075]
The stator winding conductor temperature measuring method during the three-phase short-circuit energizing operation using the stator winding conductor temperature measuring device 30A shown in FIG. 3 is based on the stator during the three-phase short-circuit energizing operation according to the first embodiment. The only difference from the method for measuring the winding conductor temperature is that a first averaging step is provided. Therefore, the description of the same contents as those of the method of measuring the stator winding conductor temperature during the three-phase short-circuit energizing operation according to the first embodiment will be simplified or omitted.
[0076]
In the stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30A shown in FIG. 3, first, the measurer first calculates a reference resistance value R in a reference resistance value calculating step.₉₅And the obtained reference resistance value R₉₅Is input to the data processing device 46. Then, a three-phase short circuit step for forming the three-phase short circuit 33 and a measuring device connection step for electrically connecting the measurement basic circuit 36 and the voltage / current measuring means 38A to the three-phase short circuit 33 are performed.
[0077]
Next, the measurer puts the AC rotating electric machine into a three-phase short-circuit energizing operation state and performs a voltage / current measurement step. The data processing device 46 performs high-speed sampling in which the DC voltage value and the current value measured in the voltage / current measurement step are sampled at 1000 points in 0.1 second, and averages the high-speed sampled DC voltage value and the current value. An averaging process step for calculating an average value is performed.
[0078]
Next, the data processing device 46 calculates a winding value for calculating the stator winding resistance value Ra ′ from the DC voltage value and the current value averaged in the averaging process step, that is, the DC voltage average value and the current average value. A resistance value calculating step is performed, and a winding conductor temperature calculating step is performed.
[0079]
According to the present embodiment, the voltage / current measuring unit 38A included in the stator winding conductor temperature measuring device 30A includes the first averaging device 55, performs high-speed sampling, and calculates the average value of the sampled data. Since the output is performed, it is possible to collect stable and accurate data as compared with the stator winding conductor temperature measuring device 30 according to the first embodiment.
[0080]
Therefore, the measurement method of measuring the stator winding conductor temperature of the AC rotating electric machine according to the present embodiment is better than the measuring method of the winding conductor temperature of the AC rotating electric machine according to the first embodiment. The accuracy is improved.
[0081]
The sampling capability of the first averaging device 55 included in the voltage / current measuring unit 38A does not necessarily have to be 1000 points in 0.1 second, and sampling can be performed in a range of 500 points to 2000 points. Is fine.
[0082]
[Third Embodiment]
FIG. 4 shows an example of a winding conductor temperature measuring device 30B of an AC rotary electric machine according to a third embodiment of the present invention.
[0083]
The stator winding conductor temperature measuring device 30B is different from the stator winding conductor temperature measuring device 30A according to the second embodiment in that a voltage / current measuring unit 38B is provided instead of the voltage / current measuring unit 38A. , Other parts are not different. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30A according to the second embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0084]
The stator winding conductor temperature measuring device 30B shown in FIG. 4 includes a measurement basic circuit 36 and a voltage / current measuring unit 38B. Voltage / current measuring means 38B is electrically connected to the measurement basic circuit 36, and the voltage Vs applied to both ends of the three-phase short circuit 33 in one channel of the measurement channel 43 flows into the three-phase short circuit 33 in the other channel. Is measured.
[0085]
The voltage / current measuring unit 38B included in the stator winding conductor temperature measuring device 30 performs high-speed sampling instead of the first averaging device 55 included in the voltage / current measuring unit 38A illustrated in FIG. After calculating the average value, a second averaging processing device 57 as an averaging processing means for performing statistical processing is added. The second averaging processing device 57 includes a digital recording device 45 and a data processing device 46. And are electrically connected.
[0086]
The second averaging device 57 included in the voltage / current measuring unit 38B samples 1000 points in 0.1 seconds, performs averaging processing, and then performs, for example, Statistical processing, such as excluding data within a range of ± 3σ (σ: standard deviation) from the average value and excluding other data, that is, data outside a range of ± 3σ from the average value, is performed. By averaging only data, more stable and accurate data can be obtained.
[0087]
The stator winding conductor temperature measuring method during the three-phase short-circuit energizing operation using the stator winding conductor temperature measuring device 30B shown in FIG. 4 is based on the stator during the three-phase short-circuit energizing operation according to the second embodiment. Only the processing content of the averaging processing step differs from the method of measuring the winding conductor temperature. Therefore, the description of the same contents as those of the method of measuring the stator winding conductor temperature during the three-phase short-circuit energizing operation according to the second embodiment will be simplified or omitted.
[0088]
In the stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30B shown in FIG. 4, the measurer firstly sets a reference resistance value R in a reference resistance value calculating step.₉₅And the obtained reference resistance value R₉₅Is input to the data processing device 46. Then, a three-phase circuit short-circuiting step for forming the three-phase short-circuit 33 and a measuring device connection step for electrically connecting the measurement basic circuit 36 and the voltage / current measuring means 38B to the three-phase short-circuit 33 are performed.
[0089]
Next, the measurer puts the AC rotating electric machine into a three-phase short-circuit energizing operation state and performs a voltage / current measurement step. The data processing device 46 performs high-speed sampling in which the DC voltage value and the current value measured in the voltage / current measurement step are sampled at 1000 points in 0.1 second, and averages the high-speed sampled DC voltage value and the current value. An average value is calculated, and further, an averaging process step is performed on the calculated average value, for example, to perform a statistical process of excluding data outside the range of the average value ± 3σ.
[0090]
Next, the data processing device 46 calculates a winding value for calculating the stator winding resistance value Ra ′ from the DC voltage value and the current value averaged in the averaging process step, that is, the DC voltage average value and the current average value. A resistance value calculating step is performed, and a winding conductor temperature calculating step is performed.
[0091]
According to the present embodiment, the voltage / current measuring means 38B included in the stator winding conductor temperature measuring device 30B includes the second averaging processing device 57, calculates the average value of the high-speed sampled data, and then calculates the average value. Since the average value is output after performing a statistical process such as excluding the average value outside the range of ± 3σ from the average value, for example, the winding conductor temperature measuring device of the AC rotating electric machine according to the second embodiment is provided. Compared with 30A, more stable and accurate data can be collected.
[0092]
Therefore, the measurement method of measuring the stator winding conductor temperature of the winding conductor temperature of the AC rotating electric machine according to the present embodiment is better than the measuring method of the winding conductor temperature of the AC rotating electric machine according to the second embodiment. The accuracy is improved.
[0093]
Note that the sampling capability of the second averaging device 57 included in the voltage / current measuring unit 38B does not necessarily have to be 1000 points in 0.1 seconds, and sampling can be performed in the range of 500 points to 2000 points. Is fine.
[0094]
[Fourth embodiment]
FIG. 5 shows an example of a winding conductor temperature measuring device 30C of an AC rotary electric machine according to a fourth embodiment of the present invention.
[0095]
The stator winding conductor temperature measuring device 30C is different from the stator winding conductor temperature measuring device 30 according to the first embodiment in that the three-phase stator winding 32 included in the three-phase short circuit 33 is three-phase short-circuited. The cooling means 59 for cooling the winding short-circuit conductor 39A is provided, and other portions are not different. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0096]
A stator winding conductor temperature measuring device 30C shown in FIG. 5 includes a measurement basic circuit 36 and a voltage / current measuring unit 38, and a three-phase short circuit, similarly to the stator winding conductor temperature measuring device 30 shown in FIG. And a cooling means 59 for cooling the winding short-circuit conductor 39 </ b> A provided in 33. The cooling means 59 includes a cooling water passage 60 for passing the cooling water through the winding short-circuit conductor 39A provided in the three-phase short circuit 33, and a circulation pump 61 for circulating the cooling water.
[0097]
A voltage / current measuring means 38B is electrically connected to the measurement basic circuit 36 provided in the stator winding conductor temperature measurement device 30C, and the voltage Vs applied to both ends of the three-phase short circuit 33 in one channel of the measurement channel 43 is measured. The current Is flowing into the three-phase short circuit 33 on the other channel is measured. The cooling means 59 cools the winding short-circuit conductor 39A by circulating cooling water through the winding short-circuit conductor 39A by the circulation pump 61, suppresses the temperature rise of the winding short-circuit conductor 39A, and short-circuits the winding. The temperature of the conductor 39A is kept almost constant.
[0098]
The measurement of the stator winding conductor temperature of the AC rotating electric machine during the three-phase short-circuit energization operation using the stator winding conductor temperature measurement device 30C shown in FIG. 5 will be described.
[0099]
The stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30C shown in FIG. 5 is performed by using the stator winding conductor temperature measuring device 30 according to the first embodiment. It differs from the conductor temperature measuring method only in that a winding short-circuit conductor cooling step for cooling the winding short-circuit conductor 39A is provided. Therefore, the description of the same contents as those of the stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30 according to the first embodiment will be simplified or omitted.
[0100]
First, the measurer calculates the reference resistance value R in the reference resistance value calculation step.₉₅And the obtained reference resistance value R₉₅Is input to the data processing device 46. Then, a three-phase short circuit step for forming the three-phase short circuit 33 and a measuring device connection step for electrically connecting the measurement basic circuit 36 and the voltage / current measuring means 38A to the three-phase short circuit 33 are performed. After the measurement device connection step is completed, the winding short-circuit conductor cooling step is performed next.
[0101]
In the winding short-circuit conductor cooling step, the operation of the circulation pump 61 provided in the cooling means 59 is started to circulate cooling water through the winding short-circuit conductor 39A that short-circuits the stator winding 32 in three phases, thereby cooling the three-phase conductor. This is performed to suppress the temperature fluctuation of the resistance value Rex of the winding short-circuit conductor 39A by suppressing the temperature fluctuation of the winding short-circuit conductor 39A during the short-circuit energizing operation.
[0102]
The resistance value Rex of the winding short-circuit conductor 39A is such that a current near the rated current value (including the rated current value) (hereinafter referred to as approximately the rated current) is continuously obtained by three-phase short-circuiting the stator winding 32 in the AC rotating electric machine. The temperature rises as the temperature of the winding short-circuit conductor 39 </ b> A rises due to energization. Therefore, if the resistance value Rex of the winding short-circuit conductor 39A is regarded as constant and the stator winding resistance value Ra 'is calculated from the three-phase short-circuit circuit 33 by using Expression 5, an error will occur.
[0103]
Therefore, by suppressing the temperature fluctuation of the resistance value Rex of the winding short-circuit conductor 39A in the winding short-circuit conductor cooling step, the resistance value Rex of the winding short-circuit conductor 39A can be regarded as constant throughout the three-phase short-circuiting operation. In addition, the measurement error that may occur when the stator winding resistance value Ra ′ is calculated and evaluated using Expression 5 is reduced. The subsequent measurement steps include a voltage / current measurement step, a winding resistance value calculation step, and a winding conductor temperature calculation step, as in the first embodiment.
[0104]
According to the present embodiment, since the stator winding conductor temperature measuring device 30C includes the cooling means 59, three-phase short-circuiting is performed, and the rated current is continuously supplied, so that the heat generated in the stator winding 32 is generated. , The temperature fluctuation of the winding short-circuit conductor 39A due to the conduction of the stator winding 32 can be suppressed, and the measurement error generated when measuring the resistance value of the stator winding 32 can be reduced. Therefore, the stator winding conductor temperature measuring device 30C according to the present embodiment is generated at the time of measuring the resistance value of the stator winding 32 as compared with the stator winding conductor temperature measuring device 30 according to the first embodiment. A measurement error can be further reduced to enable accurate resistance value measurement and a more accurate temperature measurement of the stator winding conductor.
[0105]
[Fifth Embodiment]
FIG. 6 shows an example of a winding conductor temperature measuring device 30D of an AC rotary electric machine according to a fifth embodiment of the present invention.
[0106]
The stator winding conductor temperature measuring device 30D is different from the stator winding conductor temperature measuring device 30C according to the fourth embodiment in that a winding short-circuit conductor temperature measuring means 63 is further provided. Are not different. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30C according to the fourth embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0107]
The stator winding conductor temperature measuring device 30D shown in FIG. 6 includes a measurement basic circuit 36, a voltage / current measuring unit 38, and a cooling unit 59, similarly to the stator winding conductor temperature measuring device 30C shown in FIG. And a winding short-circuit conductor temperature measuring means 63 for measuring the temperature of the winding short-circuit conductor 39A.
[0108]
The winding short-circuit conductor temperature measuring means 63 includes a temperature measuring device 64 for measuring the temperature of the winding short-circuit conductor 39A, and an A / D converter for converting an analog signal output from the temperature measuring device 64 into a digital signal and outputting the digital signal. 65. The input side of the winding short-circuit conductor temperature measuring means 63 is electrically connected to the three-phase short circuit 33, and the output side is electrically connected to the data processing device 46.
[0109]
The measurement of the stator winding conductor temperature of the AC rotating electric machine during the three-phase short-circuit energizing operation using the stator winding conductor temperature measuring device 30D shown in FIG. 6 will be described.
[0110]
The stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30D shown in FIG. 6 is based on a stator winding using the stator winding conductor temperature measuring device 30C according to the fourth embodiment. It differs from the conductor temperature measuring method only in that a winding short-circuit conductor resistance calculating step of calculating the resistance value Rex of the winding short-circuit conductor 39A from a conversion formula is provided. Therefore, the description of the same contents as those of the stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30D according to the fourth embodiment will be simplified or omitted.
[0111]
First, the measurer performs a reference resistance value calculating step. In the reference resistance value calculation step, when the connection state is the same as that during operation, that is, when the temperature is stabilized after a three-phase short circuit and a sufficient long period of time, the reference winding resistance value Ra′b, The reference temperature Tab, the reference resistance value (hereinafter referred to as reference external resistance) Rexb 36 of the winding short-circuit conductor 39A, and the reference temperature Texb are measured, and the measured values and the formulas required for the conversion are previously sent to the data processing device 46. Enter in.
[0112]
Next, a three-phase short circuit step for forming a three-phase short circuit 33, a three-phase short circuit 33 in which the stator winding 32 to be measured is short-circuited in three phases, a basic measurement circuit 36, and a voltage / current measurement means 38 are electrically connected. And a measuring device connecting step of performing a dynamic connection. Then, when the measurement device connection step is completed, the winding short-circuit conductor 39A is cooled in the winding short-circuit conductor cooling step.
[0113]
Next, the measurer performs a voltage / current measurement step. In the voltage / current measurement step, the voltage and current of the three-phase short circuit 33 are measured, and the temperature of the winding short conductor 39A is measured by the winding short conductor temperature measuring means 63 provided in the stator winding conductor temperature measuring device 30D. I do.
[0114]
Next, a winding short-circuit conductor resistance calculating step of calculating the resistance value Rex of the winding short-circuit conductor 39A from the conversion formula shown in Expression 1 is performed. The resistance value Rex of the three-phase winding short-circuit conductor 39A is calculated by converting the resistance value Rex of the winding short-circuit conductor 39A from Equation 6 from the measured temperature T of the winding short-circuit conductor 39A.
[0115]
(Equation 6)

[0116]
When the winding short-circuit conductor resistance calculation step is completed, a winding resistance value calculation step is performed as in the fourth embodiment. The stator winding resistance value Ra ′ of the AC rotating electric machine in the winding resistance value calculation step is calculated by substituting the resistance value Rex of the winding short-circuit conductor 39A calculated in the winding short-circuit conductor resistance calculation step into Equation 5. We ask by doing. Next, a winding conductor temperature calculation step is performed, and the data processor 46 displays the stator winding conductor temperature T on the display of the data processor 46.
[0117]
According to this embodiment, since the stator winding conductor temperature measuring device 30D includes the winding short-circuit conductor temperature measuring means 63, the temperature of the winding short-circuit conductor 39A during the three-phase short-circuit energizing operation of the AC rotating electric machine is reduced. It is possible to perform measurement and to perform accurate measurement in consideration of the resistance value Rex of the winding short-circuit conductor 39A at the measured temperature T. Therefore, the stator winding conductor temperature measuring device 30D according to the present embodiment is generated when measuring the resistance value of the stator winding 32 as compared with the stator winding conductor temperature measuring device 30C according to the fourth embodiment. A measurement error can be further reduced to enable accurate resistance value measurement and a more accurate temperature measurement of the stator winding conductor.
[0118]
[Sixth Embodiment]
FIG. 7 shows an example of a winding conductor temperature measuring device 30E of an AC rotary electric machine according to a sixth embodiment of the present invention.
[0119]
The stator winding conductor temperature measurement device 30E is different from the stator winding conductor temperature measurement device 30 according to the first embodiment in that a measurement basic circuit 36A is provided instead of the measurement basic circuit 36. Is not different. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0120]
The stator winding conductor temperature measurement device 30E shown in FIG. 7 includes a measurement basic circuit 36A and a voltage / current measurement unit 38. The measurement basic circuit 36A has a circuit configuration obtained by replacing the measurement basic circuit 36 with a variable DC voltage source 31 and a variable DC voltage supply circuit 68 as variable DC voltage supply means.
[0121]
FIG. 8 is a circuit configuration diagram showing the circuit configuration of the variable DC voltage supply circuit 68.
[0122]
The variable DC voltage supply circuit 68 shown in FIG. 8 is one form of a variable DC voltage supply means, and includes a single-phase AC variable voltage commercial frequency power supply (the same frequency as the AC rotating machine to be tested: 50 Hz or 60 Hz) 69, and a ground insulation. A single-phase full-wave rectifier 72 including a transformer 70 and a diode 71 is electrically connected. The variable DC voltage supply circuit 68 functions in the same manner as the variable DC voltage source 31 in the measurement basic circuit 36A, and can supply a large current up to about 100A.
[0123]
The measurement of the stator winding conductor temperature of the AC rotating electric machine during the three-phase short-circuit energizing operation using the stator winding conductor temperature measurement device 30E shown in FIG. 7 will be described.
[0124]
The stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30E shown in FIG. 7 is based on the stator winding conductor temperature measuring device 30 according to the first embodiment. The measuring steps are basically the same as the conductor temperature measuring method except that the variable DC voltage supplying means for supplying the DC voltage is different.
[0125]
That is, in the same manner as the method of measuring the winding conductor temperature of the AC rotating electric machine according to the first embodiment, the measurer can calculate a reference resistance value, a three-phase circuit short-circuiting step, a measuring device connection step, a voltage / current measurement step, A winding resistance value calculation step and a winding conductor temperature calculation step are performed, and the stator winding conductor temperature T is displayed on the display of the data processing device 46.
[0126]
According to the present embodiment, the stator winding conductor temperature measurement device 30E includes the measurement basic circuit 36A including the variable DC voltage supply circuit 68 as the DC variable voltage supply means, so that the DC power supply can be performed. A stable DC voltage is supplied to the three-phase AC rotating electric machine without being affected by beat vibration and the like caused by the third harmonic generated by operating the AC rotating electric machine by short-circuiting the three-phase AC rotating electric machine and passing a rated current. It can be supplied to the short circuit 33.
[0127]
Therefore, the stator winding conductor temperature measuring device 30E enables more accurate stator winding conductor resistance value measurement as compared to the stator winding conductor temperature measuring device 30 according to the first embodiment, It is possible to measure the temperature of the stator winding conductor with higher accuracy.
[0128]
Although the single-phase full-wave rectifier 72 constituting the variable DC voltage supply circuit 68 shown in FIG. 8 is shown using the diode 71 as a rectifying element, the single-phase full-wave rectifier 72 is not necessarily used. The rectifying element used is not limited to the diode 71. For example, the single-phase full-wave rectifier 72 may be configured by using a thyristor instead of the diode 71 for the rectifier used in the single-phase full-wave rectifier 72.
[0129]
[Seventh embodiment]
FIG. 9 shows an example of a winding conductor temperature measuring device 30F of the AC rotary electric machine according to the seventh embodiment of the present invention.
[0130]
The stator winding conductor temperature measuring device 30F measures the temperature of the stator winding 32 of the AC rotating electric machine in which the RTD 74 is inserted, between the conductor portion and the outer surface, and the stator winding according to the first embodiment. In addition to the conductor temperature measuring device 30, a stator winding outer surface temperature measuring means 75 is further provided to enable the temperature measurement of each of the conductor portion and the insulating portion 76 of the stator winding 32.
[0131]
The stator winding conductor temperature measuring device 30F is capable of measuring the temperature of the conductor of the stator winding 32 and the temperature of the insulating portion 76, and thereby has a temperature characteristic (hereinafter, referred to as temperature) with respect to the radial length of the insulating portion 76. Gradient), and the temperature characteristics of the insulating portion 76 of the stator winding 32 can be evaluated. Evaluating the temperature characteristics of the insulating portion 76 of the stator winding 32 is important and significant from the viewpoint of material development and the like.
[0132]
The stator winding conductor temperature measuring device 30F is different from the stator winding conductor temperature measuring device 30 in that a stator winding outer surface temperature measuring device 75 is further provided. Therefore, portions that are not different from the stator winding conductor temperature measuring device 30 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0133]
The stator winding conductor temperature measuring device 30F is inserted between the measurement basic circuit 36 and the voltage / current measuring means 38 and the stator winding 32, similarly to the stator winding conductor temperature measuring device 30 shown in FIG. A stator winding outer surface temperature measuring means 75 for obtaining a temperature measurement signal from the RTD 74 and measuring the outer surface temperature of the stator winding 32. The stator winding outer surface temperature measuring means 75 has basically the same configuration as the winding short-circuit conductor temperature measuring means 63 provided in the stator winding conductor temperature measuring device 30D shown in FIG. Only different.
[0134]
That is, the stator winding outer surface temperature measuring means 75 converts the analog signal output from the temperature measuring device 64 into a digital signal by measuring the outer surface temperature of the stator winding 32 with the RTD 74. And an A / D converter 65 for outputting the data. The input side of the stator winding outer surface temperature measuring means 75 is electrically connected to the RTD 74, and the output side is electrically connected to the data processing device 46.
[0135]
Measurement of the stator winding conductor temperature of the AC rotating electric machine during the three-phase short-circuit energization operation using the stator winding conductor temperature measurement device 30F shown in FIG. 9 will be described.
[0136]
The stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30F shown in FIG. 9 is performed by using the stator winding conductor temperature measuring device 30 according to the first embodiment. The difference from the conductor temperature measuring method is that a stator winding outer surface temperature measuring step of measuring the outer surface temperature of the stator winding 32 is further performed. Therefore, the description of the same contents as those of the stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30F according to the seventh embodiment will be simplified or omitted.
[0137]
The stator winding conductor temperature measuring method using the stator winding conductor temperature measuring device 30F first calculates a reference resistance value in a reference resistance value calculating step, and in the present embodiment, calculates a reference resistance value together with a mathematical expression necessary for data processing. The thickness of the insulating portion 77 of the winding 32 is input to the data processing device 46. Next, the measurer performs a three-phase circuit short-circuiting step, a measuring device connection step, and a voltage-current measurement step, and simultaneously measures the DC voltage value and the current value of the three-phase short-circuit 33 in the voltage-current measurement step. Perform a winding outer surface temperature measurement step.
[0138]
In the stator winding outer surface temperature measuring step, the temperature information obtained by the RTD 74 by the stator winding outer surface temperature measuring means 75 is A / D converted, and the data processing device 46 performs data processing on the stator information. The outer surface temperature of 32 is measured. In the measurement steps after the voltage / current measurement step and the stator winding outer surface temperature measurement step, a winding resistance value calculation step and a winding conductor temperature calculation step are performed as in the first embodiment.
[0139]
According to the present embodiment, since the stator winding conductor temperature measuring device 30F further includes the stator winding outer surface temperature measuring means 75, each of the measured conductor portion and outer surface of the stator winding 32 is provided. From this temperature, the temperature gradient of the insulating portion 76 of the stator winding 32 can be obtained, and the temperature characteristics of the insulating portion 76 can be evaluated.
[0140]
[Eighth Embodiment]
A method for measuring the winding conductor temperature of an AC rotary electric machine according to an eighth embodiment of the present invention will be described.
[0141]
In the method of measuring the winding conductor temperature of the AC rotating electric machine according to the present embodiment, the voltage Vs applied to both ends of the three-phase short circuit 33 in which the stator winding 32 to be measured is three-phase short-circuited is 50 V during the three-phase short-circuit energizing operation. The above is performed when a high voltage is generated.
[0142]
When the voltage Vs applied to both ends of the three-phase short circuit 33 is as high as 50 V or more during the three-phase short-circuit energizing operation, the voltage / current method uses a large AC with respect to the DC voltage and DC current to be measured. The components overlap. Therefore, it becomes difficult to maintain the resistance measurement accuracy of the stator winding 32 required to obtain the temperature accuracy that meets the demand. Therefore, in the method of measuring the winding conductor temperature of the AC rotating electric machine according to the present embodiment, the three-phase short-circuit energizing operation of the AC rotating electric machine is performed by extrapolation using the RTD 74 inserted between the stator windings 32 of the stator. It estimates the stator winding conductor temperature.
[0143]
As the winding conductor temperature measuring device of the AC rotating electric machine according to the present embodiment, a stator winding conductor temperature measuring device capable of measuring the outer surface temperature of the stator winding 32 with the RTD 74 is used. The stator winding conductor temperature measuring device 30F is used.
[0144]
FIG. 10 is an explanatory diagram (graph) illustrating a method for measuring the winding conductor temperature of the AC rotary electric machine according to the present embodiment.
[0145]
In the explanatory diagram shown in FIG. 10, the horizontal axis of the graph indicates the elapsed time t (min) from the time when the stator winding current becomes 0, and the vertical axis indicates the temperature (° C.) or the current (A). Thus, the temperature (° C.) transition with respect to the elapsed time t from the time when the stator winding current became 0 is shown.
[0146]
The measurement of the stator winding conductor temperature of the AC rotating electric machine during the three-phase short-circuit energizing operation according to the present embodiment is performed by first applying the rated current to the three-phase short-circuit 33 in which the stator winding 32 of the AC rotating electric machine is short-circuited in three phases. Is continuously energized. Then, the outer surface temperature T of the stator winding 32 obtained by the RTD 74_R, The stator winding current Ia and the refrigerant temperature Tc are continuously measured.
[0147]
Next, the fact that the temperature of the stator winding 32 is completely saturated is obtained from the RTD 74 by the outer surface temperature T of the stator winding 32._RCheck with the indicated value. When the temperature of the stator winding 32 is completely saturated, the AC rotating electric machine is turned off. When the AC rotating electric machine is set in the non-energized state, the stator winding current Ia starts to decrease, and eventually, Ia = 0.
[0148]
When Ia = 0, for example, one minute after the non-energized state (t = 0), the stator winding resistance Ra ′ is obtained by the voltage / current measuring means 38 provided in the stator winding conductor temperature measuring device 30F. Is measured, and the stator winding conductor temperature T is obtained from the measured stator winding resistance Ra ′. Then, for example, the measurement is performed at certain intervals such as every minute, and the measurement is continued until the stator winding conductor temperature T and the coolant temperature Tc become substantially equal.
[0149]
The stator winding conductor temperature T obtained by the measurement is approximated by, for example, an exponential function, so that the stator winding conductor temperature T is represented by a function of the elapsed time t. By substituting t = 0 into the function formula of the wire conductor temperature T, the time when the stator winding current Ia starts to decrease (t = 0), that is, the stator winding conductor temperature T when the rated current is applied is estimated. be able to.
[0150]
In the present embodiment, even when the voltage Vs applied to both ends of the three-phase short circuit 33 in which the stator winding 32 to be measured is three-phase short-circuited is as high as 50 V or more during the three-phase short-circuit energizing operation, Since the temperature can be quickly measured in the non-energized state, the temperature of the conductor of the stator winding 32 during the three-phase short-circuit energized operation can be estimated by extrapolation.
[0151]
When estimating the temperature of the conductor of the stator winding 32 during the three-phase short-circuit energizing operation by extrapolation, the stator winding conductor temperature measuring device 30F connects the measurement basic circuit 36 and the voltage / current measuring means 38 with each other. Since the AC component can be largely removed by the provision, if the stator winding current Ia becomes Ia = 0, the temperature measurement of the stator winding conductor temperature T is started before the rotor stops. Therefore, it is possible to more accurately estimate the temperature of the conductor of the stator winding 32 during the three-phase short-circuit energizing operation.
[0152]
It should be noted that the winding conductor temperature measuring device of the AC rotating electric machine according to the present embodiment is not limited to the stator winding conductor temperature measuring device 30F shown in FIG. 9, but measures the outer surface temperature of the stator winding from the RTD 74. If the stator winding outer surface temperature measuring means is added externally, the stator winding conductor temperature measuring devices 30 to 30E used in other embodiments may be applied.
[0153]
Further, even if the stator winding outer surface temperature measuring means for measuring the outer surface temperature of the stator winding from the RTD 74 is not externally provided, it is sufficient until the stator winding conductor temperature becomes stable from the start of the three-phase short-circuit energizing operation. If the measurement is performed after a lapse of a long time, the stator winding conductor temperature measuring devices 30 to 30E used in other embodiments may be applied.
[0154]
As described above, according to the winding conductor temperature measuring device and the measuring method of the AC rotating electric machine according to the present invention, the stator winding conductor temperature measuring device 30 is capable of controlling the three-phase short circuit during the three-phase short-circuit energizing operation. A variable DC voltage source 31 as a variable DC voltage supply means capable of supplying a DC voltage equal to or greater than the AC voltage generated at 33, a limiting resistor 34 for limiting the AC voltage generated in the three-phase short circuit 33, and a shunt 35. A measurement basic circuit 36, a measurement channel 43 for greatly attenuating an AC component superimposed on a measurement signal with respect to a DC component, a digital recording device 45 with high resolution, and a data processing device 46 for processing the measurement signal. With the provision of the current measuring means 38, the resistance of the stator winding 32 can be reduced to a minimum of 10^-7It is possible to accurately measure the resistance value on the order of Ω. Therefore, it is possible to provide a winding conductor temperature measuring device and a measuring method of an AC rotating electric machine capable of accurately measuring a temperature change of the stator winding 32 with an accuracy of about 1 ° C.
[0155]
Also, the stator winding conductor temperature measuring device 30A including the voltage / current measuring means 38A including the first averaging device 55 for performing high-speed sampling and calculating and outputting the average value of the sampled data or the high-speed sampling is performed. After calculating the average value of the data, the voltage / current measuring means 38B having the second averaging device 57 for performing statistical processing on the calculated average value and outputting the result is used for the measurement of the winding conductor temperature. Thus, more stable and accurate data can be collected.
[0156]
Further, the stator winding 32 to be measured is short-circuited in three phases, and a rated current is continuously applied to the stator winding 32, so that the temperature fluctuation of the winding short-circuit conductor 39A due to conduction of heat generated in the stator winding 32 is suppressed. By using the stator winding conductor temperature measuring device 30C including the means 59 for measuring the winding conductor temperature of an AC rotating electric machine, the measurement error of the resistance value Rex of the winding short-circuit conductor 39A can be suppressed and the stator winding 32 Can be reduced when a resistance value is measured.
[0157]
Furthermore, by using the stator winding conductor temperature measuring device 30D including the cooling means 59 and the winding short-circuit conductor temperature measuring means 63 for measuring the winding conductor temperature of the AC rotating electric machine, a three-phase short circuit of the AC rotating electric machine is achieved. The temperature of the winding short-circuit conductor 39A during the energization operation can be measured, and accurate measurement can be performed in consideration of the resistance value Rex of the winding short-circuit conductor 39A at the measured temperature T.
[0158]
On the other hand, by using the stator winding conductor temperature measurement device 30E including the measurement basic circuit 36A including the variable DC voltage supply circuit 68 as the DC variable voltage supply means for measuring the winding conductor temperature of the AC rotating electric machine, A stable DC voltage can be obtained without being affected by beat vibration and the like caused by the third harmonic generated by running the AC rotating electric machine by three-phase short-circuiting and supplying approximately the rated current when supplying DC power. The current can be supplied to the three-phase short circuit 33 of the AC rotating electric machine, and the resistance value of the stator winding conductor can be measured more accurately, and the temperature of the stator winding conductor can be measured more accurately.
[0159]
Further, by using the stator winding conductor temperature measuring device 30F including the stator winding outer surface temperature measuring means 75 for measuring the winding conductor temperature of the AC rotating electric machine, the measured conductor of the stator winding 32 can be measured. The temperature gradient of the insulating portion 76 of the stator winding 32 can be obtained from the respective temperatures of the portion and the outer surface, and the temperature characteristics of the insulating portion 76 can be evaluated.
[0160]
Furthermore, the stator winding conductor temperature measuring devices 30 to 30F according to the present invention provide a three-phase short circuit 33 formed by three-phase short-circuiting the stator winding 32 to be measured. Even when a voltage as high as 50 V or more is generated during the short-circuit energizing operation, the temperature can be quickly measured without energizing. Therefore, the stator winding 32 during the three-phase short-circuit energizing operation can be extrapolated. Can be estimated.
[0161]
Furthermore, when estimating the temperature of the conductor portion of the stator winding 32 during the three-phase short-circuit energizing operation by extrapolation, the stator winding conductor temperature measuring devices 30 to 30F according to the present invention use the measurement basic circuit 36 and The provision of the voltage / current measuring means 38 to 38B makes it possible to largely remove the AC component. Therefore, if the stator winding current Ia becomes Ia = 0, the stator winding is stopped before the rotor stops. Since the temperature measurement of the wire conductor temperature T can be started, it is possible to more accurately estimate the temperature of the conductor portion of the stator winding 32 during the three-phase short-circuit energizing operation.
[0162]
In the method of measuring the winding conductor temperature of the AC rotating electric machine according to the present invention, in the reference resistance value measuring step, the resistance value of the stator winding 32 of each phase is measured, and the measured resistance value of the stator winding 32 is measured. And the temperature at the time of resistance measurement are substituted into Equation 1 to obtain a reference resistance value R shown in Equation 4.₉₅, And the calculated reference resistance value R₉₅Is input to the data processing device 46, but the equation 1 is input to the data processing device 46, and the measured resistance value of the stator winding 32 and temperature data at the time of the resistance measurement can be input to the data processing device 46. And a reference resistance value R.₉₅May be calculated.
[0163]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the winding conductor temperature measuring device and the measuring method of the AC rotating electric machine according to the present invention, it is possible to accurately measure the stator winding resistance during the three-phase short-circuit energizing operation of the AC rotating electric machine at the rated speed. Therefore, it is possible to provide a winding conductor temperature measuring apparatus and a measuring method for an AC rotating electric machine capable of accurately and stably measuring the stator winding conductor temperature of the AC rotating machine to be tested.
[0164]
According to the winding conductor temperature measuring device and the measuring method of the AC rotating electric machine according to the present invention, the voltage between the stator windings generated when the stator windings are short-circuited in three phases during the three-phase short circuit energizing operation is reduced. Even when the voltage / current method cannot be applied, the temperature measurement of the stator winding conductor temperature T can be started before the rotor stops, even when the rotor is stopped. It is possible to provide a winding conductor temperature measuring device and a measuring method of an AC rotating electric machine capable of measuring the winding conductor temperature with higher accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a first embodiment of the present invention.
FIG. 2 is a circuit configuration diagram showing a circuit configuration of a filter included in a measurement channel provided in the winding conductor temperature measurement device of the AC rotary electric machine according to the first embodiment of the present invention.
FIG. 3 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a second embodiment of the present invention.
FIG. 4 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a third embodiment of the present invention.
FIG. 5 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a fourth embodiment of the present invention.
FIG. 6 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a fifth embodiment of the present invention.
FIG. 7 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a sixth embodiment of the present invention.
FIG. 8 is a schematic configuration diagram showing a circuit configuration of a variable DC voltage supply circuit used as variable DC voltage supply means in a winding conductor temperature measuring device of an AC rotating electric machine according to a sixth embodiment of the present invention.
FIG. 9 is a schematic configuration diagram showing a configuration of a winding conductor temperature measuring device of an AC rotary electric machine according to a seventh embodiment of the present invention.
FIG. 10 is an explanatory diagram showing a method of measuring a winding conductor temperature of an AC rotating electric machine according to the present invention, and showing a relationship between an elapsed time after stopping power supply and a stator winding conductor temperature.
FIG. 11 is a schematic configuration diagram illustrating a configuration of a stator used in the AC rotating electric machine.
FIG. 12 is a conventional method for measuring a stator winding conductor temperature during energization, which explains a circuit configuration of a stator winding resistance measurement circuit that measures the resistance of the stator winding while stopping the AC rotating electric machine. FIG.
FIG. 13 is a conventional method for measuring a stator winding conductor temperature during energization, and is an explanatory diagram illustrating a circuit configuration of a stator winding conductor temperature measurement circuit that measures the stator winding conductor temperature using an RTD. .
FIG. 14 is an explanatory diagram illustrating a circuit configuration of a stator winding resistance measuring circuit that measures a stator winding conductor temperature of an AC rotating electric machine during a three-phase short-circuit energizing operation defined by IEC standard 60279.
[Explanation of symbols]
30, 30A, 30B, 30C, 30D, 30E, 30F: stator winding conductor temperature measuring device, 31: variable DC voltage source (variable DC voltage supply means), 32: stator winding, 33: three-phase short circuit , 34: limiting resistance, 35: shunt (resistance for current measurement), 36, 36A: measurement basic circuit, 38, 38A, 38B: voltage / current measurement means, 39, 39A: winding short-circuit conductor (three-phase short-circuit means), Reference numeral 40: neutral point, 41: line terminal, 43: measurement channel, 45: digital recording device, 46: data processing device, 49: filter, 50: amplifier, 52: resistor element, 53: capacitor, 55: first Averaging device, 57 second averaging device, 59 cooling means, 60 cooling water passage, 61 circulating pump, 63 winding short-circuit conductor temperature measuring means, 64 temperature measuring instrument, 65 A / D converter, 8: Variable DC voltage supply circuit (variable DC voltage supply means), 69: Single-phase AC variable voltage commercial frequency power supply, 70: Ground insulating transformer, 71: Diode, 72: Single-phase full-wave rectifier, 74: RTD ( Resistance temperature device), 75: stator winding outer surface temperature measuring means, 76: insulating unit.

Claims (10)

Three-phase short-circuit means for three-phase short-circuiting the stator winding of the rotating electric machine;
A variable DC voltage supply means for variably supplying a DC voltage to the three-phase short circuit obtained by the three-phase short circuit means, the three-phase short circuit, and a current measuring resistor electrically connected. Measurement basic circuit,
A measurement channel for obtaining a DC voltage value applied to the three-phase short circuit and a current value supplied to the three-phase short circuit; digital recording means for digitally converting and recording an analog output from the measurement channel; A winding conductor temperature measuring device for an AC rotating electric machine, comprising: a voltage / current measuring means including data processing means for processing an output from a digital recording means and outputting an input result. The measurement basic circuit is configured to be able to apply a DC voltage comparable to an AC voltage generated in the three-phase short circuit,
The voltage / current measuring means includes a filter for attenuating an AC component from an analog measurement signal obtained at the time of measurement, an amplifier for amplifying the analog measurement signal output from the filter, and a measurement channel having a resolution of 14 bits to 16 bits. The digital recording means having, the data processing means for displaying the processing result by performing data processing is configured to be electrically connected,
The filter has a commercial frequency of 50 Hz and 60 Hz, a filter gain of -40 to -80 dB, and an input withstand voltage of 100 to 600 V.
By configuring the amplifier with a low drift amplifier having an amplification factor of 50 to 1000 times and less occurrence of drift and having linearity at the amplification factor, the resistance value of the stator winding is reduced to the order of 10 ⁻⁷ Ω. The winding conductor temperature measuring device for an AC rotary electric machine according to claim 1, wherein the measuring device is configured to be able to measure with accuracy. In a non-energized state where no current is applied to the stator winding, a resistance value of the stator winding is determined, and a reference resistance value calculating step of converting the resistance value into a winding resistance value at a reference temperature,
A three-phase short-circuit step of three-phase short-circuiting the stator windings of the star-connected AC rotating electric machine to form a three-phase short circuit;
When the AC rotating electric machine is operated and the stator winding is energized, the DC voltage value applied to the three-phase short circuit and the DC current value applied are measured by the variable DC voltage supply means. A winding resistance value calculating step of calculating a resistance value of the stator winding by doing
A winding conductor temperature calculating step of calculating a stator winding conductor temperature during operation of the AC rotating electric machine by the voltage / current measuring means using the resistance value of the stator winding and the reference resistance value. A method for measuring a winding conductor temperature of an AC rotating electric machine, characterized by comprising: A first averaging process step of high-speed sampling of a DC voltage value and a current value of the three-phase short circuit measured in a state where the rotating electric machine is operated by an averaging device, and performing an averaging process;
When calculating the winding resistance in the winding resistance value calculating step, the AC rotating electric machine uses the DC voltage value and the current value of the three-phase short circuit, which have been averaged in the first averaging processing step. 4. The method for measuring a winding conductor temperature of an AC rotary electric machine according to claim 3, wherein the stator winding conductor temperature is measured. The DC voltage value and the current value of the three-phase short circuit measured in a state where the rotating electric machine is operated are sampled at high speed by the averaging processing means, and the average value obtained by the averaging process is A second averaging process step of averaging the remaining sampled data after performing a statistical process for excluding the sampled data in a range exceeding a certain deviation,
When calculating the winding resistance in the winding resistance value calculation step, the AC rotating electric machine uses the DC voltage value and the current value of the three-phase short circuit averaged in the second averaging processing step. 4. The method for measuring a winding conductor temperature of an AC rotary electric machine according to claim 3, wherein the stator winding conductor temperature is measured. A conductor cooling step of cooling the winding short-circuit conductor and suppressing a temperature change of the winding short-circuit conductor during the three-phase short-circuit energizing operation of the AC rotating electric machine; 4. The method according to claim 3, wherein a measurement error in measuring the resistance value of the stator winding is reduced. A conductor cooling step of cooling the winding short-circuit conductor and suppressing a temperature change of the winding short-circuit conductor during the three-phase short-circuit energizing operation of the AC rotating electric machine,
4. The method according to claim 3, further comprising calculating a resistance value of the winding short-circuit conductor from a conversion formula. The variable DC voltage supply means is configured to electrically connect a single-phase AC variable voltage commercial frequency power supply, a transformer insulated from the ground, and a single-phase full-wave rectifier to enable variable supply of a DC voltage. The method according to claim 3, wherein the measurement is performed using a variable DC voltage supply circuit. The AC rotating electric machine includes a stator winding outer surface temperature measuring step of measuring an outer surface temperature of a stator winding of the AC rotating electric machine during a three-phase short-circuit energizing operation,
After inputting the thickness of the insulating portion of the stator winding together with the reference resistance value and a mathematical expression required for data processing in the reference resistance value calculation step,
The method according to claim 3, wherein a voltage value and a current value of the three-phase short circuit are measured. During the three-phase short-circuit energizing operation of the AC rotating electric machine, if the voltage of the three-phase short-circuit is as high as 50 to 600 V, the energization is cut off to make the non-energized state,
In the winding resistance value calculating step and the winding conductor temperature calculating step, for example, the stator winding conductor temperature is calculated at an arbitrary constant interval such as one minute, and the winding resistance value calculation is performed until the temperature becomes substantially equal to the refrigerant temperature. From the transition of the stator winding conductor temperature calculated by repeating the step and the winding conductor temperature calculation step, the transition of the stator winding conductor temperature is approximated by a function to estimate the stator winding conductor temperature at the time of energization interruption. The method for measuring the temperature of a winding conductor of an AC rotating electric machine according to claim 3, wherein:

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