JP7276039B2 - Insulation deterioration diagnosis device - Google Patents

Insulation deterioration diagnosis device Download PDF

Info

Publication number
JP7276039B2
JP7276039B2 JP2019172027A JP2019172027A JP7276039B2 JP 7276039 B2 JP7276039 B2 JP 7276039B2 JP 2019172027 A JP2019172027 A JP 2019172027A JP 2019172027 A JP2019172027 A JP 2019172027A JP 7276039 B2 JP7276039 B2 JP 7276039B2
Authority
JP
Japan
Prior art keywords
rotating machine
insulation deterioration
partial discharge
concentration
risk
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2019172027A
Other languages
Japanese (ja)
Other versions
JP2021050922A (en
Inventor
和城 大石
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Meidensha Corp
Original Assignee
Meidensha Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Meidensha Corp filed Critical Meidensha Corp
Priority to JP2019172027A priority Critical patent/JP7276039B2/en
Publication of JP2021050922A publication Critical patent/JP2021050922A/en
Application granted granted Critical
Publication of JP7276039B2 publication Critical patent/JP7276039B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Testing Relating To Insulation (AREA)
  • Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
  • Tests Of Circuit Breakers, Generators, And Electric Motors (AREA)

Description

本発明は、高圧回転機の絶縁劣化を診断するための技術に関する。 The present invention relates to a technique for diagnosing insulation deterioration of a high-voltage rotating machine.

近年、例えば高圧回転機の固定子コイルから発生する部分放電と、その部分放電に起因して発生するガスを検出し、固定子コイルの絶縁劣化の兆候を診断するための技術が提案されている（例えば、特許文献１～３）。 In recent years, for example, techniques have been proposed for diagnosing signs of insulation deterioration in the stator coils by detecting partial discharges generated from the stator coils of high-voltage rotating machines and gas generated due to the partial discharges. (For example, Patent Documents 1 to 3).

特開２００２－２６７７１２号公報Japanese Patent Application Laid-Open No. 2002-267712 特開２０１２－００７９２４号公報JP 2012-007924 A 特開２０１９－０３２１８４号公報JP 2019-032184 A

タービン用、水車用などの高圧回転機の絶縁劣化診断はオフライン（停止中）で行ってきたが、容易に停止できないインフラ設備のため、運転中でも回転機の異常を検知できる手段の実現が望まれている。 Insulation deterioration diagnosis for high-voltage rotating machines such as turbines and water turbines has been performed offline (when stopped), but it is infrastructure equipment that cannot be easily stopped. It is rare.

また、高圧回転機は部分放電を許容する絶縁システムのため、部分放電による直接的な地絡や短絡事故以外にも部分放電に起因して発生する腐食性ガスが原因となる回転機内構造物損傷に伴う事故も存在する。したがって、部分放電の発生状況がどのように推移しているかを診断する技術と、部分放電によって発生した腐食性ガスの発生状況がどのように推移していくかを診断する技術が同時に必要となる。 In addition, high-voltage rotating machines have an insulation system that allows partial discharge, so in addition to direct ground faults and short-circuit accidents due to partial discharge, corrosive gas generated due to partial discharge can cause damage to the internal structure of the rotating machine. There are also accidents associated with Therefore, technology for diagnosing how the occurrence of partial discharge changes and technology for diagnosing how the corrosive gas generated by partial discharge changes is required at the same time. .

特許文献１～３に例示される従来の診断技術は、オンラインでも部分放電に因る絶縁劣化の診断が行えるが、部分放電に伴う異常の事象の診断がなされてない。 The conventional diagnostic techniques exemplified in Patent Documents 1 to 3 can diagnose insulation deterioration due to partial discharge even online, but they do not diagnose abnormal events associated with partial discharge.

本発明は、以上の事情を鑑み、高圧回転機の部分放電による絶縁劣化とこれに伴う異常な事象をオンライン診断できることを課題とする。 SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to enable online diagnosis of insulation deterioration due to partial discharge in a high-voltage rotating machine and abnormal events associated therewith.

そこで、本発明の一態様は、高圧回転機の絶縁劣化診断装置であって、前記高圧回転機の冷媒温度を検出する冷媒温度測定部と、前記高圧回転機の内部環境を検出する回転機内環境測定部と、前記高圧回転機の部分放電を検出する部分放電測定部と、前記高圧回転機内の腐食性ガス濃度を検出する回転機内ガス濃度測定部と、前記高圧回転機内の結露により生じた水分の硝酸イオン濃度を検出するイオン濃度測定部と、前記冷媒温度、前記内部環境、前記部分放電の発生パターン、前記腐食性ガス濃度、前記硝酸イオン濃度のいずれかに基づき前記高圧回転機内の絶縁劣化を診断する診断部とを備える。 Accordingly, one aspect of the present invention is an insulation deterioration diagnosis device for a high-pressure rotating machine, comprising: a coolant temperature measuring unit that detects a coolant temperature of the high-pressure rotating machine; a measuring unit, a partial discharge measuring unit that detects partial discharge in the high-pressure rotating machine, a rotating machine gas concentration measuring unit that detects the concentration of corrosive gas in the high-pressure rotating machine, and moisture generated by dew condensation in the high-pressure rotating machine. insulation deterioration in the high-voltage rotating machine based on any one of the coolant temperature, the internal environment, the pattern of occurrence of partial discharge, the corrosive gas concentration, and the nitrate ion concentration. and a diagnostic unit for diagnosing the

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記内部環境に基づき補正した前記部分放電の発生パターンに基づき当該部分放電に伴う異常な事象の特徴量を抽出する。 According to one aspect of the present invention, in the insulation deterioration diagnosis device, the diagnosis unit extracts a feature quantity of an abnormal event associated with the partial discharge based on the occurrence pattern of the partial discharge corrected based on the internal environment.

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記特徴量のパターン形状、位相、大きさに基づき異常放電の発生を判定する。 In one aspect of the present invention, in the insulation deterioration diagnosis device, the diagnosis unit judges the occurrence of abnormal discharge based on the pattern shape, phase, and size of the feature amount.

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記冷媒温度と前記内部環境とに基づき前記高圧回転機内の結露リスクを判定する。 According to one aspect of the present invention, in the insulation deterioration diagnostic device, the diagnostic unit determines the risk of condensation within the high-pressure rotating machine based on the refrigerant temperature and the internal environment.

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記結露リスクがあると判定された場合、腐食性ガスとして検出されたアンモニア及びオゾンの生成量と結露水への吸収速度から推定した硝酸生成量の経時的な増加量に基づき前記高圧回転機の腐食リスクを警告する。 According to one aspect of the present invention, in the insulation deterioration diagnostic device, when it is determined that there is a risk of dew condensation, the diagnostic unit determines the amount of ammonia and ozone detected as corrosive gases and the rate of absorption into the condensed water. The risk of corrosion of the high-pressure rotating machine is warned based on the amount of increase in the amount of nitric acid produced over time estimated from the above.

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記結露リスクがなしであり且つ前記高圧回転機が密閉型である場合、前記結露リスクがあると判定する。 According to one aspect of the present invention, in the insulation deterioration diagnosis device, the diagnosis unit determines that there is the risk of condensation when the risk of condensation is absent and the high-voltage rotating machine is a closed type.

本発明の一態様は、前記絶縁劣化診断装置において、前記診断部は、前記結露リスクがなしであり且つ前記高圧回転機が開放型である場合、前記腐食性ガス濃度として検出されたオゾンガス濃度が規定値以上であると当該オゾンガス濃度に関するリスクを警告する。 According to one aspect of the present invention, in the insulation deterioration diagnosis device, the diagnosis unit detects that the ozone gas concentration detected as the corrosive gas concentration is If the ozone gas concentration is above the specified value, the risk associated with the ozone gas concentration is warned.

本発明の一態様は、前記絶縁劣化診断装置において、前記冷媒温度、前記内部環境、前記部分放電の発生パターン、前記腐食性ガス濃度、前記硝酸イオン濃度及び前記警告の履歴データを保存するデータ蓄積部を備える。 According to one aspect of the present invention, in the insulation deterioration diagnosis device, data storage for storing history data of the refrigerant temperature, the internal environment, the pattern of occurrence of the partial discharge, the concentration of the corrosive gas, the concentration of the nitrate ion, and the warning. have a department.

本発明の一態様は、高圧回転機の絶縁劣化診断方法であって、前記高圧回転機の冷媒温度、内部環境、部分放電の発生パターン、当該高圧回転機内の腐食性ガス濃度、当該高圧回転機内の硝酸イオン濃度のいずれかに基づき当該高圧回転機内の絶縁劣化を診断する。 One aspect of the present invention is a method for diagnosing insulation deterioration of a high-pressure rotating machine, which comprises a refrigerant temperature of the high-pressure rotating machine, an internal environment, a pattern of occurrence of partial discharge, a concentration of corrosive gas in the high-pressure rotating machine, and an inside of the high-pressure rotating machine. Insulation deterioration in the high-voltage rotating machine is diagnosed based on any of the nitrate ion concentrations.

以上の本発明によれば、高圧回転機の部分放電による絶縁劣化とこれに伴う異常な事象もオンライン診断できる。 According to the present invention described above, insulation deterioration due to partial discharge in a high-voltage rotating machine and abnormal events associated therewith can also be diagnosed online.

本発明の一態様である絶縁劣化診断装置のブロック構成図。1 is a block configuration diagram of an insulation deterioration diagnosis device that is one aspect of the present invention; FIG. 前記絶縁劣化診断装置により検出される部分放電の発生パターンの一例。An example of a pattern of occurrence of partial discharge detected by the insulation deterioration diagnosis device. 部分放電パターンの作成過程の説明図。Explanatory drawing of the creation process of a partial discharge pattern. 前記絶縁劣化診断装置による絶縁劣化診断の過程を説明したフローチャート。4 is a flow chart explaining a process of insulation deterioration diagnosis by the insulation deterioration diagnosis device;

以下に図面を参照しながら本発明の実施形態について説明する。 Embodiments of the present invention will be described below with reference to the drawings.

図１に例示された本発明の一態様としての絶縁劣化診断装置１は、高圧回転機２の絶縁劣化を診断する。絶縁劣化診断装置１は、冷媒温度測定部１１、回転機内環境測定部１２、部分放電測定部１３、回転機内ガス濃度測定部１４、回転機内イオン濃度測定部１５、診断部１６及びデータ蓄積部１７を備える。 An insulation deterioration diagnostic device 1 as one aspect of the present invention illustrated in FIG. 1 diagnoses insulation deterioration of a high-voltage rotating machine 2 . The insulation deterioration diagnosis device 1 includes a refrigerant temperature measuring unit 11, a rotating machine environment measuring unit 12, a partial discharge measuring unit 13, a rotating machine gas concentration measuring unit 14, a rotating machine ion concentration measuring unit 15, a diagnostic unit 16, and a data storage unit 17. Prepare.

冷媒温度測定部１１は、高圧回転機２の冷媒温度を検出する。 A coolant temperature measurement unit 11 detects the coolant temperature of the high-pressure rotary machine 2 .

回転機内環境測定部１２は、高圧回転機２の内部環境（例えば、温度、湿度、気圧）を検出する。 The rotating machine internal environment measuring unit 12 detects the internal environment (for example, temperature, humidity, atmospheric pressure) of the high-pressure rotating machine 2 .

部分放電測定部１３は、高圧回転機２の部分放電を検出する。 The partial discharge measurement unit 13 detects partial discharge of the high voltage rotating machine 2 .

回転機内ガス濃度測定部１４は、高圧回転機２内の腐食性ガス（例えば、オゾン、アンモニア）の濃度を検出する。 The rotating machine gas concentration measuring unit 14 detects the concentration of corrosive gases (for example, ozone and ammonia) inside the high pressure rotating machine 2 .

回転機内イオン濃度測定部１５は、高圧回転機２内の結露により生じた水分（例えば、結露水）の硝酸イオン濃度を検出する。 The rotating machine ion concentration measuring unit 15 detects the nitrate ion concentration of moisture (for example, condensed water) generated by condensation inside the high-pressure rotating machine 2 .

診断部１６は、前記冷媒温度、前記内部環境、前記発生パターン、前記腐食性ガス濃度及び前記硝酸イオン濃度に基づき前記高圧回転機の絶縁劣化とこれに伴う異常な事象を診断し、これに基づく警告を行う。 Diagnosis unit 16 diagnoses insulation deterioration of the high-pressure rotating machine and abnormal events associated therewith based on the refrigerant temperature, the internal environment, the occurrence pattern, the corrosive gas concentration, and the nitrate ion concentration, and based on this, warn.

データ蓄積部１７は、前記冷媒温度、前記内部環境、前記発生パターン、前記腐食性ガス濃度及び前記硝酸イオン濃度並びに前記診断の結果の履歴データを保存する。 The data storage unit 17 stores history data of the refrigerant temperature, the internal environment, the generation pattern, the corrosive gas concentration, the nitrate ion concentration, and the diagnosis result.

以下に具体的な診断例について説明する。 A specific diagnostic example will be described below.

１．高圧回転機２内の結露状況の監視
開放型／密閉型の違いによらず、高圧回転機２内では固定子及び回転子を冷却するために運転中は常に冷媒（水または空気）が高圧回転機２内に供給される。特に、夏場では空気中の水分が非常に多く、過剰に冷却することにより熱交換部位で結露する場合が多い。この現象は密閉型でも起こりえる（完全密閉ではないため呼吸作用により各部品の隙間から高湿度の空気が混入する）。 1. Monitoring of dew condensation inside the high-pressure rotating machine 2 Regardless of whether it is an open type or a closed type, the refrigerant (water or air) is always rotating at high pressure in the high-pressure rotating machine 2 to cool the stator and rotor during operation. It is supplied inside the machine 2 . Especially in summer, there is a lot of moisture in the air, and excessive cooling often causes dew condensation at the heat exchange parts. This phenomenon can occur even in a sealed type (because it is not completely sealed, high-humidity air enters through the gaps between parts due to respiration).

結露した水滴は空気の流れにのり高圧回転機２内を巡り、空気の流れがよどんだ部分や温度の低い部品表面に付着する。そして、水滴中に放電起因のガス（アンモニア、オゾン）が溶解し硝酸が発生することで結露した部位が腐食する。このことから高圧回転機２内で結露が生じているかどうかを判断することは非常に重要である。 Condensed water droplets ride on the flow of air, circulate inside the high-pressure rotating machine 2, and adhere to parts where the flow of air is stagnant and the surfaces of parts with low temperatures. Gases (ammonia, ozone) caused by the discharge are dissolved in the water droplets to generate nitric acid, which corrodes the dew-condensed portions. For this reason, it is very important to determine whether dew condensation has occurred within the high-pressure rotating machine 2 .

絶縁劣化診断装置１は以下の過程により高圧回転機２内の結露状況を診断する。 The insulation deterioration diagnosis device 1 diagnoses the state of dew condensation inside the high-voltage rotating machine 2 through the following process.

Ｓ１０１：回転機内環境測定部１２は、高圧回転機２内の温度、湿度及び気圧の測定値に基づき露点温度を算出する。 S<b>101 : The rotating machine internal environment measuring unit 12 calculates the dew point temperature based on the measured values of the temperature, humidity and air pressure inside the high pressure rotating machine 2 .

Ｓ１０２：冷媒温度測定部１１は、高圧回転機２の冷媒温度を検出する。 S<b>102 : The coolant temperature measurement unit 11 detects the coolant temperature of the high-pressure rotating machine 2 .

Ｓ１０３：診断部１６は、前記冷媒温度が前記露点温度を下回る場合、高圧回転機２内で結露が生じていると判断し、その警告を発する。 S103: When the coolant temperature is lower than the dew point temperature, the diagnosis unit 16 determines that condensation is occurring inside the high-pressure rotating machine 2 and issues a warning.

２．高圧回転機２内の部分放電発生状況の監視
図２は高圧回転機２の固定子コイルの対地絶縁部位で生じる部分放電の発生パターンを示す。Ｕ，Ｖ，Ｗの３相のうち、Ｕ相の部分放電（ＰＤ）の発生パターンを示す。このパターンを得ることにより、以下の（１）～（４）の絶縁状態を判断できる。 2. Monitoring of Occurrence of Partial Discharge in High-Voltage Rotating Machine 2 FIG. Of the three phases of U, V, and W, the pattern of occurrence of partial discharge (PD) in the U phase is shown. By obtaining this pattern, the following insulation states (1) to (4) can be determined.

（１）主絶縁層内のボイド放電
通常、固定子コイルは電線の周囲に主絶縁層を設け、レジン含浸して形成される。レジン含浸時に極小のボイドが形成され、このボイド内で部分放電が発生する。通常、このボイドは非常に小さく（空間ギャップの目安：数μｍ～数十μｍ）、放電量もわずかであることからすぐに絶縁破壊するまでには至らない。しかし、長期間放電が継続すると以下の「層間剥離」に進行する。 (1) Void Discharge in Main Insulating Layer Normally, a stator coil is formed by providing a main insulating layer around an electric wire and impregnating it with resin. Minimal voids are formed during resin impregnation, and partial discharge occurs within these voids. Usually, the voids are very small (approximate of the space gap: several micrometers to several tens of micrometers), and the amount of discharge is very small, so dielectric breakdown does not occur immediately. However, if discharge continues for a long period of time, it progresses to the following "delamination".

（２）層間剥離（電線側）
長期的なボイド放電や絶縁層の機械的/熱的な損傷により絶縁層内部で剥離が生じると、比較的大きな空間ギャップ（空間ギャップの目安：数十μｍ～数百μｍ）が生じ、ボイド放電よりも大きな放電が発生する。 (2) Delamination (wire side)
When peeling occurs inside the insulating layer due to long-term void discharge or mechanical/thermal damage to the insulating layer, a relatively large spatial gap (approximate of the spatial gap: several tens of μm to several hundreds of μm) occurs, causing void discharge. A discharge larger than

（３）スロット放電
絶縁層の外側にある電界緩和層（低抵抗層）の消失やレジンの枯れが進行するとスロット内に隙間が生じ、負極性（０～１８０°）よりも正極性（１８０～３６０°）のタイミングで非常に大きな放電が生じる。特に、１８０～２４０°の範囲に急峻な放電パターンが得られることが多い。 (3) Slot discharge As the electric field relaxation layer (low resistance layer) outside the insulating layer disappears and the resin withers, a gap occurs in the slot, and the positive polarity (180 to 360°), a very large discharge occurs. In particular, a sharp discharge pattern is often obtained in the range of 180 to 240°.

（４）高抵抗層異常（コイルエンド、溝外直線部）
スロットから出たコイルは電界緩和のために、スロット出口からある一定距離まで高抵抗層を形成し、スロット出口付近での異常放電を低減する。この高抵抗層の形成方法が不十分な状況、特にスロット内の低抵抗層と高抵抗層が接触不良になるとこの放電が発生する。この放電は電線／スロットの電位と高抵抗層端部の電位に位相差が生じることによりボイド放電などとは逆極性の放電となる。 (4) High resistance layer abnormality (coil end, groove outside straight part)
The coil extending from the slot forms a high-resistance layer up to a certain distance from the slot exit for electric field relaxation, thereby reducing abnormal discharge near the slot exit. This discharge occurs when the method of forming the high resistance layer is insufficient, especially when the low resistance layer and the high resistance layer in the slot have poor contact. This discharge has a polarity opposite to that of void discharge or the like due to a phase difference between the potential of the wire/slot and the potential of the end of the high resistance layer.

部分放電のパターンは、例えば図３に示された以下の過程により作成されて経時的にデータ蓄積部１７に保存される。 The partial discharge pattern is created, for example, by the following process shown in FIG. 3 and stored in the data storage unit 17 over time.

Ｓ２０１：１サイクル目、２サイクル目、・・・、Ｎサイクル目の電位変化と部分放電の測定値を得る。 S201: Obtain measured values of potential change and partial discharge in the 1st cycle, the 2nd cycle, . . . , the Nth cycle.

Ｓ２０２：１秒ごとまたは任意の秒数毎にＳ２０１のデータを重ね合わせ、位相パターンと頻度のパターンを計算する。 S202: The data of S201 are superimposed every second or every arbitrary number of seconds, and the phase pattern and the frequency pattern are calculated.

Ｓ２０３：さらに、Ｎ秒又はＮ分毎に重ね合わせて代表的な位相パターンと頻度のパターンを作成し保存する。 S203: Further, a representative phase pattern and a frequency pattern are created and stored by being superimposed every N seconds or N minutes.

Ｓ２０４：以上の操作を繰り返し、数年間の部分放電のパターンがデータ蓄積部１７に保存される。 S204: By repeating the above operation, the pattern of partial discharge for several years is stored in the data storage unit 17. FIG.

Ｓ２０５：前記蓄積された部分放電のパターンから、図２に示される特徴量を抽出し、（２）～（４）のいずれかに該当する異常放電を検出して警告を発する。 S205: From the accumulated partial discharge pattern, the feature quantity shown in FIG. 2 is extracted, and an abnormal discharge corresponding to any of (2) to (4) is detected and a warning is issued.

３．高圧回転機２内のガス発生状況の監視
固定子コイルの絶縁が健全である場合、コイル絶縁部（スロット内外）に部分放電が発生するとＮＯX及びアンモニアが発生する。前記絶縁部の劣化が進み、オゾンが発生しだすとオゾンによりＮＯX及びアンモニアが酸化されるが、湿度が高いとアンモニアの発生量が多くなり、常時アンモニアが残存する。表１はこの状態を経日的に示すもので、露点温度が１０℃を超えるとオゾンとアンモニアとが共存することとなる。同表に示された温度、湿度は加温しているコイル周辺の環境における測定値である。 3. Monitoring of Gas Generation Status in High-Voltage Rotating Machine 2 When the insulation of the stator coil is sound, NOx and ammonia are generated when partial discharge occurs in the coil insulation (inside and outside the slots). When the insulation part deteriorates and ozone is generated, NOx and ammonia are oxidized by the ozone. Table 1 shows this state over time. When the dew point temperature exceeds 10°C, ozone and ammonia coexist. The temperature and humidity shown in the table are measured values in the environment around the heated coil.

Figure 0007276039000001
Figure 0007276039000001

また、オゾン、アンモニアは部分放電の電荷量として１万ｐＣ以上であれば常時観測される。オゾンは劣化初期の段階では主絶縁層の表面を覆っている電界緩和層（低抵抗層：スロット内、高抵抗層：スロット外の溝外直線部）が部分放電や熱劣化により剥離及び消失することにより発生し始める。そのオゾン発生量は電界緩和層の剥離面積（または剥離部分の縁部の長さ）に依存して多くなる。 In addition, ozone and ammonia are always observed when the charge amount of partial discharge is 10,000 pC or more. In the early stage of ozone deterioration, the electric field relaxation layer covering the surface of the main insulating layer (low resistance layer: inside the slot, high resistance layer: straight part outside the groove outside the slot) peels off and disappears due to partial discharge and thermal deterioration. It starts to occur. The amount of ozone generated increases depending on the stripped area of the electric field relaxation layer (or the length of the edge of the stripped portion).

さらに、劣化が進むと部分放電や熱劣化により主絶縁層の厚みが減少するので、より局所的に大きな部分放電が発生し始め、これに伴い、オゾンやアンモニアの発生量が増えていく。 Furthermore, as the deterioration progresses, the thickness of the main insulating layer decreases due to partial discharge and thermal deterioration, so that larger partial discharges begin to occur locally, and along with this, the amount of ozone and ammonia generated increases.

したがって、高圧回転機２の絶縁劣化の状況を判断するためには高圧回転機２内のオゾンとアンモニアの発生量を把握すればよい。 Therefore, in order to determine the state of insulation deterioration of the high-voltage rotary machine 2, the amount of ozone and ammonia generated in the high-voltage rotary machine 2 should be grasped.

４．高圧回転機２内の硝酸の発生状況の監視
高圧回転機２内の結露により結露水が発生し、さらに、オゾン及びアンモニアの発生が長期間継続すると、結露水にオゾン及びアンモニアが溶解し、亜硝酸イオンの生成を経て硝酸イオンが生成される。以下に硝酸が生成されるプロセスについて説明する。
（１）アンモニアの溶解
結露水の水滴付近に滞留するアンモニア（ＮＨ3）のガスが水滴に溶けると、以下の反応により、当該水滴のアンモニウムイオン濃度が増加する。このとき前記水滴はアルカリ性（例えば、ｐＨ８．０）となる。 4. Monitoring the state of nitric acid generation in the high-pressure rotating machine 2 When condensation occurs in the high-pressure rotating machine 2 and ozone and ammonia continue to be generated for a long period of time, ozone and ammonia dissolve in the condensed water. Nitrate ions are generated through the generation of nitrate ions. The process by which nitric acid is produced is described below.
(1) Dissolution of Ammonia When the ammonia (NH 3 ) gas remaining near the condensation water droplets dissolves in the water droplets, the ammonium ion concentration of the water droplets increases due to the following reaction. At this time, the water droplets become alkaline (for example, pH 8.0).

ＮＨ3＋Ｈ2Ｏ→ＮＨ4 +＋ＯＨ-
（２）オゾンの溶解
オゾン（Ｏ3）は、水滴表面付近に溶解しているアンモニアとの以下の反応により、亜硝酸イオン（ＮＯ2 -）を生成させる。亜硝酸は弱酸性であるので、水滴は酸性（ｐＨ６．０～６．５）となる。 NH 3 +H 2 O→NH 4 + +OH −
(2) Dissolution of Ozone Ozone (O 3 ) generates nitrite ions (NO 2 − ) through the following reaction with ammonia dissolved near the surface of water droplets. Since nitrous acid is weakly acidic, water droplets are acidic (pH 6.0 to 6.5).

ＮＨ3＋Ｏ3→ＮＯ2 -＋Ｈ+＋Ｈ2Ｏ
また、水滴表面においてアンモニア分子（ＮＨ3）とアンモニウムイオン（ＮＨ4 +）とが一定比率で存在する場合、以下の平衡反応により、消費したアンモニアを補給するようにアンモニウムイオンからアンモニアに変化する。 NH3 + O3 → NO2- + H ++ H2O
Also, when ammonia molecules (NH 3 ) and ammonium ions (NH 4 + ) exist at a constant ratio on the surface of water droplets, the following equilibrium reaction converts ammonium ions into ammonia so as to replenish the consumed ammonia.

ＮＨ4 +＋ＯＨ-→ＮＨ3＋Ｈ2Ｏ
放電によりオゾン及びアンモニアが連続的に供給されると、上述のオゾン及びアンモニアの溶解が常に起こり、時間の経過と共にｐＨの変化（６～８）や亜硝酸イオンの濃度が高くなっていく現象が生じる。
（３）オゾンの供給量が増加
オゾンの供給量が増加すると、アンモニウムイオンとの反応以外にも、亜硝酸イオンとの以下の反応が起こり、硝酸イオンが生成される。 NH 4 + +OH − →NH 3 +H 2 O
When ozone and ammonia are continuously supplied by electric discharge, the above-mentioned ozone and ammonia dissolution always occurs, and the phenomenon that the pH changes (6 to 8) and the concentration of nitrite ions increases with the passage of time. occur.
(3) Increase in supply of ozone When the supply of ozone increases, the following reaction with nitrite ions occurs in addition to the reaction with ammonium ions to generate nitrate ions.

ＮＨ3＋Ｏ3→ＮＯ2 -＋Ｈ+＋Ｈ2Ｏ
ＮＯ2 -＋Ｏ3→ＮＯ3 -＋Ｏ2
硝酸生成反応とは直接関係ないが、結露水の水質を変化させる以下の現象も生じる。
（４）二酸化炭素（ＣＯ2）の溶解
二酸化炭素は水滴に溶けると当該水滴は弱酸性（ｐＨ６．５）となる。 NH3 + O3 → NO2- + H ++ H2O
NO2- + O3 → NO3- + O2
Although not directly related to the nitric acid production reaction, the following phenomenon that changes the water quality of the condensed water also occurs.
(4) Dissolution of carbon dioxide (CO 2 ) When carbon dioxide dissolves in water droplets, the water droplets become weakly acidic (pH 6.5).

５．絶縁劣化診断
高圧回転機２の運転が開始されると診断部１６は以下の絶縁劣化診断過程を実行する。 5. Insulation Deterioration Diagnosis When the operation of the high-voltage rotating machine 2 is started, the diagnosis section 16 executes the following insulation deterioration diagnosis process.

Ｓ１：部分放電測定部１３から部分放電の発生パターンを取得する。 S1: Acquire the pattern of occurrence of partial discharge from the partial discharge measuring unit 13 .

Ｓ２：回転機内環境測定部１２から環境パラメータを取得する。前記環境パラメータとしては、例えば、高圧回転機２内温度、湿度、気圧、露点温度が取得される。 S2: Acquire environmental parameters from the environment measuring unit 12 inside the rotating machine. As the environmental parameters, for example, the internal temperature of the high-pressure rotating machine 2, humidity, atmospheric pressure, and dew point temperature are acquired.

Ｓ３：前記取得された環境パラメータに基づき前記発生パターンの補正を行う。前記発生パターンは、図３の通りに行えば得られるが、部分放電の発生パターンは、環境パラメータ（温度、湿度、気圧）により変わるので、補正が必要となる。そして、この補正された部分放電の発生パターンに基づき例えば図２に示した４つの特徴量（（１）主絶縁層内のボイド放電、（２）層間剥離、（３）スロット放電、（４）高抵抗層異常）が抽出される。 S3: Correcting the occurrence pattern based on the acquired environmental parameter. The pattern of occurrence can be obtained as shown in FIG. 3, but since the pattern of occurrence of partial discharge varies depending on environmental parameters (temperature, humidity, atmospheric pressure), correction is required. Then, based on this corrected partial discharge occurrence pattern, for example, the four characteristic quantities shown in FIG. 2 ((1) void discharge in the main insulating layer, (2) delamination, (3) slot discharge, (4) high-resistance layer anomaly) is extracted.

Ｓ４：前記特徴量のパターン形状、位相、大きさを計算して異常放電の発生を判定する。 S4: The pattern shape, phase, and magnitude of the characteristic quantities are calculated to determine the occurrence of abnormal discharge.

Ｓ５：前記異常放電の発生が判断されると、絶縁異常を警告する信号を出力する。例えば、前記形状及び位相のずれ、放電量の増加（例えば、推定放電電荷量１万ｐＣ以上）が生じると、異常放電と判定される。 S5: When it is determined that the abnormal discharge has occurred, a signal warning of insulation abnormality is output. For example, when the shape and phase shift and the amount of discharge increase (for example, the estimated amount of discharge charge is 10,000 pC or more), abnormal discharge is determined.

Ｓ６：回転機内ガス濃度測定部１４からアンモニアガス及びオゾンガスの濃度の測定値を取得する。 S6: Measured values of the concentrations of the ammonia gas and the ozone gas are obtained from the rotating machine internal gas concentration measuring unit 14 .

Ｓ７：冷媒温度測定部１１から取得された冷媒温度から結露リスクを判定する。結露リスクは上述のＳ１０３により判定される。 S7: Dew condensation risk is determined from the coolant temperature acquired from the coolant temperature measurement unit 11 . The dew condensation risk is determined by S103 described above.

Ｓ８：前記結露リスクがないと判定された場合、高圧回転機２の構造が開放型であれば、アンモニア及びオゾンは外部へ排気されるので、硝酸生成のリスクは非常に小さく、硝酸発生に関する項目を除外できる。一方、結露リスクなしであっても、前記構造が密閉型であれば、高圧回転機２内にアンモニアが充満し、結露が発生した瞬間に大量のアンモニアが結露水に吸収されて硝酸に変わるので、結露リスクありと判定する。 S8: If it is determined that there is no risk of condensation, if the structure of the high-pressure rotating machine 2 is an open type, ammonia and ozone are exhausted to the outside, so the risk of nitric acid generation is very small. can be excluded. On the other hand, even if there is no risk of condensation, if the structure is a closed type, the inside of the high-pressure rotating machine 2 will be filled with ammonia, and the moment condensation occurs, a large amount of ammonia will be absorbed by the condensed water and converted to nitric acid. , determine that there is a risk of condensation.

Ｓ９：前記結露リスクがあると判定された場合、結露水に溶け込むアンモニア量を推定するために、アンモニア生成量を積算する。 S9: When it is determined that there is a risk of dew condensation, the ammonia production amount is integrated in order to estimate the amount of ammonia dissolved in the dew condensation water.

Ｓ１０：前記取得されたオゾン濃度の測定値が規定値以上（０．１ｐｐｍ）以上であれば高濃度の硝酸が生成されるリスクが非常に大きいと判断する。 S10: If the obtained measured value of the ozone concentration is equal to or higher than the specified value (0.1 ppm), it is determined that the risk of generating high-concentration nitric acid is extremely high.

Ｓ１１：回転機内イオン濃度測定部１５から高圧回転機２内の結露水の硝酸イオン濃度を取得して硝酸生成量を推定する。前記結露水は高圧回転機２内で結露しやすい個所に予め設置されたパイプや吸引手段から回転機内イオン濃度測定部１５に供される。尚、結露水を直接採取できない場合、下記のＳ１２と同様にアンモニア及びオゾンの発生量と結露水への吸収速度から硝酸生成量が推定される。 S11: The nitrate ion concentration of the condensed water in the high-pressure rotating machine 2 is acquired from the ion concentration measuring unit 15 in the rotating machine, and the nitric acid production amount is estimated. The condensed water is supplied to the in-rotating machine ion concentration measuring unit 15 from pipes or suction means previously installed at locations where dew condensation is likely to occur within the high-pressure rotating machine 2 . If the condensed water cannot be collected directly, the amount of nitric acid produced is estimated from the amount of ammonia and ozone generated and the rate of absorption into the condensed water, as in S12 below.

Ｓ１２：前記オゾン濃度の測定値が規定値未満である場合、アンモニア及びオゾンの発生量と結露水への吸収速度から硝酸生成量を推定する。 S12: If the measured value of the ozone concentration is less than the specified value, the amount of nitric acid produced is estimated from the amount of ammonia and ozone produced and the rate of absorption into the condensed water.

Ｓ１３：前記推定された硝酸生成量の時間的増大（増加量）に応じて腐食リスクの警告を出力する。 S13: Output a corrosion risk warning in accordance with the estimated temporal increase (increase) in the amount of nitric acid produced.

Ｓ１４：高圧回転機２が結露リスクなし及び開放型の構造であっても、オゾン濃度が管理基準を超えると人体的に大きな影響を与える。そこで、高圧回転機２内のオゾンガス濃度が回転機内ガス濃度測定部１４により監視される。 S14: Even if the high-pressure rotating machine 2 has no risk of dew condensation and has an open structure, if the ozone concentration exceeds the control standard, it will have a great impact on the human body. Therefore, the ozone gas concentration in the high-pressure rotating machine 2 is monitored by the rotating machine gas concentration measuring unit 14 .

Ｓ１５：前記監視されたオゾン濃度の測定値が管理基準以上であると判定されると、オゾン濃度に関する警告を出力する。 S15: If it is determined that the measured value of the monitored ozone concentration is equal to or higher than the control standard, output a warning regarding the ozone concentration.

Ｓ１６：前記監視されたオゾン濃度の測定値が管理基準未満であると判定されると、高圧回転機２は正常であるとみなされる。 S16: If it is determined that the monitored ozone concentration measurement value is below the control standard, the high pressure rotating machine 2 is considered to be normal.

Ｓ１７：以上のＳ１～Ｓ１６により得られた結果及び警告の履歴はデータ蓄積部１７に保存される。その後、Ｓ１に戻る。尚、測定及び推定されたデータは長期間（数年～数十年）保存され、過去データの比較用として適宜に利用される。 S17: The results obtained in S1 to S16 and the history of warnings are stored in the data storage unit 17. FIG. After that, the process returns to S1. Note that the measured and estimated data are stored for a long period of time (several years to several decades) and used appropriately for comparison with past data.

以上の絶縁劣化診断装置１によれば、高圧回転機２の部分放電の発生パターンにより固定子コイルの様々な絶縁劣化（例えば、図２で示す異常な部分放電に基づく劣化）を高圧回転機２が稼動中のオンラインで把握できる。さらには、部分放電に起因する高圧回転機２内におけるオゾン発生状況（電界緩和層の異常、主絶縁層の劣化）や硝酸生成による回転機の構成部材の腐食や脱落等へのリスク（結露状況やアンモニア発生量からの硝酸生成量）等のその他の異常な事象を推定できる。また、高圧回転機２の仕様（例えば、密閉型，開放型）に応じた異常な事象の診断も行える。 According to the insulation deterioration diagnosis apparatus 1 described above, various insulation deterioration of the stator coil (for example, deterioration based on abnormal partial discharge shown in FIG. is in operation and can be grasped online. Furthermore, there is a risk of ozone generation in the high-voltage rotating machine 2 due to partial discharge (abnormality of the electric field relaxation layer, deterioration of the main insulating layer) and corrosion and falling off of the components of the rotating machine due to nitric acid generation (condensation status). other abnormal events such as the amount of nitric acid produced from the amount of ammonia produced) can be estimated. In addition, it is possible to diagnose an abnormal event according to the specifications of the high-pressure rotating machine 2 (for example, closed type, open type).

１…絶縁劣化診断装置、１１…冷媒温度測定部、１２…回転機内環境測定部、１３…部分放電測定部、１４…回転機内ガス濃度測定部、１５…回転機内イオン濃度測定部、１６…診断部、１７…データ蓄積部
２…高圧回転機 DESCRIPTION OF SYMBOLS 1... Insulation deterioration diagnostic apparatus 11... Refrigerant temperature measuring part 12... Environment measuring part in rotating machine 13... Partial discharge measuring part 14... Gas concentration measuring part in rotating machine 15... Ion concentration measuring part in rotating machine 16... Diagnosis Part 17... Data accumulation part 2... High pressure rotating machine

Claims (7)

高圧回転機の絶縁劣化診断装置であって、
前記高圧回転機の冷媒温度を検出する冷媒温度測定部と、
前記高圧回転機の内部環境を検出する回転機内環境測定部と、
前記高圧回転機の部分放電を検出する部分放電測定部と、
前記高圧回転機内の腐食性ガス濃度を検出する回転機内ガス濃度測定部と、
前記高圧回転機内の結露により生じた水分の硝酸イオン濃度を検出するイオン濃度測定部と、
前記冷媒温度、前記内部環境、前記部分放電の発生パターン、前記腐食性ガス濃度、前記硝酸イオン濃度のいずれかに基づき前記高圧回転機内の絶縁劣化を診断する診断部と
を備え、
前記診断部は、前記冷媒温度と前記内部環境とに基づき前記高圧回転機内の結露リスクを判定することを特徴とする絶縁劣化診断装置。 An insulation deterioration diagnosis device for a high-voltage rotating machine,
a coolant temperature measuring unit that detects the coolant temperature of the high-pressure rotating machine;
a rotating machine internal environment measuring unit that detects the internal environment of the high-pressure rotating machine;
a partial discharge measuring unit for detecting partial discharge of the high-voltage rotating machine;
a rotating machine gas concentration measuring unit for detecting the corrosive gas concentration in the high pressure rotating machine;
an ion concentration measuring unit that detects the concentration of nitrate ions in moisture generated by condensation in the high-pressure rotating machine;
a diagnosis unit for diagnosing insulation deterioration in the high-voltage rotating machine based on any one of the refrigerant temperature, the internal environment, the pattern of occurrence of the partial discharge, the concentration of the corrosive gas, and the concentration of the nitrate ion;
with
The insulation deterioration diagnosis device, wherein the diagnosis unit judges the risk of condensation within the high-pressure rotating machine based on the refrigerant temperature and the internal environment. 前記診断部は、前記内部環境に基づき補正した前記部分放電の発生パターンに基づき当該部分放電に伴う異常な事象の特徴量を抽出することを特徴とする請求項１に記載の絶縁劣化診断装置。 2. The insulation deterioration diagnosis apparatus according to claim 1, wherein the diagnosis unit extracts a characteristic amount of an abnormal event associated with the partial discharge based on the occurrence pattern of the partial discharge corrected based on the internal environment. 前記診断部は、前記特徴量のパターン形状、位相、大きさに基づき異常放電の発生を判定することを特徴とする請求項２に記載の絶縁劣化診断装置。 3. The insulation deterioration diagnosis device according to claim 2, wherein the diagnosis unit judges the occurrence of abnormal discharge based on the pattern shape, phase, and magnitude of the feature quantity. 前記診断部は、前記結露リスクがあると判定された場合、腐食性ガスとして検出されたアンモニア及びオゾンの生成量と結露水への吸収速度から推定した硝酸生成量の経時的な増加量に基づき前記高圧回転機の腐食リスクを警告することを特徴とする請求項１に記載の絶縁劣化診断装置。 When it is determined that there is a risk of condensation, the diagnosis unit determines the amount of ammonia and ozone detected as corrosive gases and the amount of nitric acid produced based on the increase over time in the amount of nitric acid produced, which is estimated from the rate of absorption into the condensed water. 2. The insulation deterioration diagnosis device according to claim 1 , wherein a warning is given of a corrosion risk of said high-voltage rotating machine. 前記診断部は、前記高圧回転機が密閉型であれば、当該高圧回転機内にアンモニアが充満すると判断し、前記結露リスクがあると判定することを特徴とする請求項１に記載の絶縁劣化診断装置。 2. The insulation deterioration diagnosis according to claim 1 , wherein, if the high-voltage rotating machine is a closed type, the diagnosis unit determines that the inside of the high-voltage rotating machine is filled with ammonia, and determines that there is the risk of condensation. Device. 前記診断部は、前記結露リスクがなしであり且つ前記高圧回転機が開放型である場合、前記腐食性ガス濃度として検出されたオゾンガス濃度が規定値以上であると当該オゾンガス濃度に関するリスクを警告することを特徴とする請求項１に記載の絶縁劣化診断装置。 When the risk of condensation is absent and the high-pressure rotating machine is an open type, the diagnostic unit warns of the risk related to the ozone gas concentration when the ozone gas concentration detected as the corrosive gas concentration is equal to or higher than a specified value. The insulation deterioration diagnosis device according to claim 1 , characterized in that: 前記冷媒温度、前記内部環境、前記部分放電の発生パターン、前記腐食性ガス濃度、前記硝酸イオン濃度及び前記警告の履歴データを保存するデータ蓄積部を備えたことを特徴とする請求項４または６に記載の絶縁劣化診断装置。 7. A data storage unit for storing history data of said refrigerant temperature, said internal environment, said partial discharge generation pattern, said corrosive gas concentration, said nitrate ion concentration, and said warning. The insulation deterioration diagnosis device according to .
JP2019172027A 2019-09-20 2019-09-20 Insulation deterioration diagnosis device Active JP7276039B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019172027A JP7276039B2 (en) 2019-09-20 2019-09-20 Insulation deterioration diagnosis device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2019172027A JP7276039B2 (en) 2019-09-20 2019-09-20 Insulation deterioration diagnosis device

Publications (2)

Publication Number Publication Date
JP2021050922A JP2021050922A (en) 2021-04-01
JP7276039B2 true JP7276039B2 (en) 2023-05-18

Family

ID=75157547

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2019172027A Active JP7276039B2 (en) 2019-09-20 2019-09-20 Insulation deterioration diagnosis device

Country Status (1)

Country Link
JP (1) JP7276039B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021143926A (en) * 2020-03-12 2021-09-24 株式会社明電舎 Insulation deterioration diagnostic device
JP7192031B2 (en) * 2021-05-19 2022-12-19 東京二十三区清掃一部事務組合 Insulation Deterioration Diagnosis Method for Rotating Machines Using Ozone Concentration Measurement

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006138687A (en) 2004-11-11 2006-06-01 Mitsubishi Electric Corp Device for remotely monitoring partial discharge of rotating machine
JP2006180685A (en) 2004-11-24 2006-07-06 Hokuriku Electric Power Co Inc:The Partial discharge detection method and partial discharge detecting apparatus
JP2009011054A (en) 2007-06-27 2009-01-15 Toshiba Corp Apparatus for measuring physical value information of motor
JP2011130544A (en) 2009-12-16 2011-06-30 Hitachi Ltd Rotary electrical device for electric vehicle, drive control device and insulation diagnosis method
US20130030742A1 (en) 2011-07-28 2013-01-31 Arijit Banerjee Method and system for monitoring a synchronous machine
US20170356945A1 (en) 2016-06-14 2017-12-14 Lsis Co., Ltd. Diagnostic system for electric power equipment
JP2018200179A (en) 2017-05-25 2018-12-20 富士電機株式会社 Partial discharge monitoring apparatus and partial discharge monitoring method for rotary electric machine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6275361A (en) * 1985-09-30 1987-04-07 Toshiba Corp Monitor for armature winding

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006138687A (en) 2004-11-11 2006-06-01 Mitsubishi Electric Corp Device for remotely monitoring partial discharge of rotating machine
JP2006180685A (en) 2004-11-24 2006-07-06 Hokuriku Electric Power Co Inc:The Partial discharge detection method and partial discharge detecting apparatus
JP2009011054A (en) 2007-06-27 2009-01-15 Toshiba Corp Apparatus for measuring physical value information of motor
JP2011130544A (en) 2009-12-16 2011-06-30 Hitachi Ltd Rotary electrical device for electric vehicle, drive control device and insulation diagnosis method
US20130030742A1 (en) 2011-07-28 2013-01-31 Arijit Banerjee Method and system for monitoring a synchronous machine
US20170356945A1 (en) 2016-06-14 2017-12-14 Lsis Co., Ltd. Diagnostic system for electric power equipment
JP2018200179A (en) 2017-05-25 2018-12-20 富士電機株式会社 Partial discharge monitoring apparatus and partial discharge monitoring method for rotary electric machine

Also Published As

Publication number Publication date
JP2021050922A (en) 2021-04-01

Similar Documents

Publication Publication Date Title
JP7276039B2 (en) Insulation deterioration diagnosis device
US8766645B2 (en) Method and device for tracking the degradation of insulators in a rotary machine
US7042229B2 (en) System and method for on line monitoring of insulation condition for DC machines
JP6878256B2 (en) Water quality diagnostic system, power plant, and water quality diagnostic method
JP5143251B2 (en) Monitoring of decrease in refrigerant flow of stator coil
US8552757B2 (en) Method for detecting a fault in an induction machine
WO2011021351A1 (en) Corrosive environment monitoring system and corrosive environment monitoring method
US7411404B2 (en) Apparatus, system, and method for detecting an electrical short condition in a dynamoelectric machine
US20050218906A1 (en) System and method for monitoring of insulation condition
JP2014517320A (en) Method for using PRPD envelope values to classify single and multiple partial discharge (PD) defects in high voltage equipment
JP2021144034A (en) Insulation deterioration diagnostic method
US20170184656A1 (en) Monitoring of insulation conditions during electrical system events using differential current sensor
JP6053606B2 (en) Measurement method for insulation deterioration of electrical equipment
JP3272933B2 (en) Remaining life evaluation method for rotating electrical machine windings
Stone et al. Detection of stator winding stress relief coating deterioration in conventional and inverter fed motors and generators
Cestaro et al. Fault detection in components of synchronous motors through online partial discharge measurements
JP2008002893A (en) Remaining life expectancy evaluation method for turbogenerator stator coil
JP7192031B2 (en) Insulation Deterioration Diagnosis Method for Rotating Machines Using Ozone Concentration Measurement
JP7127629B2 (en) Insulator Deterioration Diagnosis Device and Insulator Deterioration Diagnosis Method for Electric Rotating Machine
JP7380482B2 (en) Insulation deterioration diagnosis device
TW202144798A (en) Gas detection device and method for rotating machine and system for monitoring aging of stator coil wherein the gas detection device includes a suction device and a nitrogen oxide concentration detection unit
Sheikh et al. Invasive methods to diagnose stator winding and bearing defects of an induction motors
US11300602B1 (en) Method for determining the condition of one or more rotating machine assets and profiling their maintenance needs using partial discharge measurements
JP6200198B2 (en) Rotation electricity insulation diagnosis method
CN111323700B (en) Method and device for early warning of magnetic steel faults of generator set

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20220225

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20221228

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20230110

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20230306

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20230404

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20230417

R150 Certificate of patent or registration of utility model

Ref document number: 7276039

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150