トランス技術の新しい時代の始まりは、生産の技術的近代化のための三層プラットフォームの創造に対応しています。まず、アモルファスコア、エステルオイル、高純度巻線材料の開発などのコンポーネント革新により、損失を削減し、設置オプションを広げることが可能になります。次に、監視、デジタルツイン、予測分析などのシステム革新により、資産がデータの源に変わり、強制的な停電を30から50 %削減します。最後に、パフォーマンス調達やトランスフォーマー・アズ・ア・サービスのようなビジネスモデル革新により、リスクと資本の所有権が変更されます。進行中の三方向の革命は、トランスの調達を単なる購入からデータ駆動型の戦略的意思決定プロセスに変えます。.
IEC 60076-20 クラス 1 への効率のアップグレードにより、30から50%の損失削減が可能になり、4年から9年で投資回収が実現します。.
監視への投資は、重要な資産に対する最も迅速な投資回収を保証し、しばしば最初の事故を防いだ後にすでに回収を提供します。.
サービスモデルは、資本の解放とリスクの移転を可能にし、特にキャッシュフローの目的において重要です。.
信頼性保証、デジタル文書、監視下でのテストを伴うトランスを購入すべきです。.
江蘇省スビアン電力は、現代的なトランスと、手頃な価格で監視ソリューションのアップグレードに対応したトランスの製造業者です。.
トランスのタップチェンジャーとは何ですか？
A タップチェンジャー は、トランスの巻線にさまざまなタッピングポイントで取り付けられた切替装置です。この装置の助けを借りて、巻線のターン数の変化とそれに伴う二次側の電圧の変動をもたらす異なるタップ間の接続を切り替えることが可能です。したがって、タップチェンジャーは、トランスのタンク内に組み込まれているか、巻線の上に取り付けられている電圧調整のメカニズムです。.
様々なネットワークで経験される電圧は、日中の負荷の変動、電力線のたわみ、ネットワークによって提供される電圧の変化により、常に減少と増加を繰り返します。生産中に得られた比率でのトランスの固定電圧出力は、電圧供給の問題を引き起こす可能性があり、タップチェンジャーは信頼できる修正手段を提供します。.
すべてのタイプのタップチェンジャーを特徴付けるために使用される3つの重要な側面があります：その電圧ステップ（定格電圧のパーセンテージで表現）、位置の数、調整された電圧の範囲です。例えば、±2×2.5%の範囲で機能する能力を持つ配電トランスがあり、4つのタップ位置を持っていますが、より大きなトランスにはより高度なタップチェンジャーが提供されています。.
オフ回路対負荷時タップチェンジャー
| 特徴 | オフ回路タップチェンジャー (OCTC) | 負荷時タップチェンジャー (OLTC) |
|---|---|---|
| 操作条件 | トランスが無電圧 | トランスが負荷を持つ |
| 一般的な範囲 | ±2×2.5% (5位置)、±4×2.5% (9) | ±8×1.25%（17ポジション）およびそれ以上 |
| 機構 | マニュアル、シンプルな機械式スイッチ | モータードライブ、スプリング式ダイバータ、真空または抵抗遷移 |
| トランスのコスト影響 | +2から+5% | +10から+30% |
| メンテナンス | 最小 | 定期的; 油フィルトレーションと接触検査 |
| 最適 | 配電、安定負荷、季節調整 | 電力トランス、変動負荷、自動電圧制御 |
The choice between the two options is based on one key aspect: does there need to be any adjustment to the voltage produced by the transformer when it is operating? Distribution transformers serving stable loads can be adjusted seasonally using an OCTC and therefore incur almost no costs. However, power transformers supplying fluctuating loads must be equipped with an OLTC in order to ensure the quality of the voltage supplied, and therefore to bear an additional 10-30% cost for compliance with the requirements concerning the voltage quality.
負荷接続タップチェンジャーの動作
負荷の下でタップを切り替えるのは簡単ではありません。タップポイントで回路を開くことはできません。なぜなら、それは負荷電流を中断し、接点を損傷するアークを引き起こすからです。OLTCは、電流がオンになっていない状態で新しいタップ位置を選択できるセレクターと、現在のタップでの電流負荷を新しい位置に移動させるダイバータスイッチを含む2段階のソリューションを提供します。遷移は遷移インピーダンスによって提供されます。これは抵抗素子または真空遮断器である可能性があります。したがって、電流は連続して流れ、すぐに消えます。.
抵抗型OLTCでは、ダイバータが
タップを切り替える際に電流負荷を抵抗素子または2つを通過させます。真空型設計の場合、アーク消滅を担当するのは真空遮断器であり、これにより油がクリーンに保たれ、メンテナンスの間隔が延びます。両方のタイプはIEC 60214-1の性能要件とIEC 60214-2の適用仕様に基づいており、選択は主にライフサイクルコスト計算によって決定されます。真空OLTCは設置コストが高いですが、サービスが少なくて済みます。.
タップチェンジャーの種類
| タイプ | 動作原理 | 典型的な定格範囲 | 価格範囲 |
|---|---|---|---|
| オフサーキット（手動）タップチェンジャー | 機械式スイッチ、無負荷 | 典型的に最大10 MVA | $200-$1,500 |
| 抵抗型OLTC（タンクまたはヘッドタイプ） | 遷移抵抗器を持つダイバータ | 最大約60 MVA | $3,000-$18,000 |
| 真空型OLTC | ダイバータ内の真空遮断器 | 最大200+ MVA | $5,000-$30,000 |
| リアクタ型OLTC | リアクタ遷移、古い設計 | Large power transformers | Rare; replaced by resistor/vacuum |
| Motor drive unit (accessory) | Remote/auto operation of any OLTC | — | $2,000-$10,000 |
For most applications that we deal with today, the issue comes down to whether one chooses a resistor or a vacuum OLTC, although recently, the latter has become more popular and is usually employed in new power transformers because of the longer periods of maintenance. Off-circuit changers, on the other hand, are a completely different product type, simpler and quite inexpensive ($200-$1500), located inside distribution tanks and regulated few times a year when a transformer is switched off.
Key Ratings and Specifications
| パラメータ | 意味 | 一般的な値 |
|---|---|---|
| 定格通過電流 | Maximum continuous load current the OLTC can carry | 250-1,250 A |
| 定格ステップ電圧 | Voltage across the tap range | Up to 3,300 V per step in large units |
| 定格周波数 | Must match the system (50 or 60 Hz) | 50 Hz / 60 Hz |
| Number of positions | Total selectable taps | 5, 9, 17, 33 |
| Step voltage (%) | Voltage change per step as % of rated | 1.25%, 2.5%, 5% |
| 標準 | Design and test basis | IEC 60214-1/-2、IEEE C57.131 |
There are two numbers that are typically out of order in purchase orders. These are the rated through-current, which must be greater than the maximum continuous current rating of the transformer (including overload ratings), and the step voltage — the high step voltage for a given current places quite different demands on the diverter than carrying the same current at a low step voltage and therefore the OLTC rating combines these two numbers.
To illustrate the subject, let’s bring in some guidelines on the tap changer parameters for the traditional types of transformers — the figures that you are supposed to mention in your RFQ:
| Transformer Class | Tap Changer Type | 一般的な範囲 | Through-Current | Approx. Price Impact on Transformer |
|---|---|---|---|---|
| 100-1,000 kVA distribution | Off-circuit (OCTC) | ±2×2.5% / ±4×2.5% | Up to 1,500 A | +2 to +4% |
| 1-10 MVA industrial | OLTC, resistor type | ±6×2.5% | 300-700 A | +10 to +18% |
| 10-60 MVA substation | OLTC, resistor or vacuum | ±8×1.25% | 400-1,250 A | +12 to +25% |
| Above 60 MVA power | OLTC, vacuum type | ±8×1.25% or wider | 1,250-2,500 A | +15 to +30% |
Tap Range, Steps, and Position Selection
Selecting the tap range is a voltage-regulation determination, as opposed to being an educated guess. The process goes generally as follows:
First step is measuring the voltage variation, by recording the primary-side voltage during a full load cycle. The primary voltage changes by ±5-10% from light loads to heavy loads.
Second step is to calculate the required regulation range. It is essential to add together impedance drop in the transformer, which is typically 4-8% when at full load, and voltage variation on the primary side to get to know regulations range.
Next step is to find out the step size used in establishments. Standard distribution step size varies according to each transformer used, which varies from 2.5% to 1.25% for power transformers needing more precision.
Fourth step is to pick out the midpoint of the range, which should be centered around a nominal ratio of ±8×1.25%, producing range of voltage regulation tapping by 10% for 33/11kV applications.
Final step is to synchronize with the AVR. When working on automatic mode, the relay keeps track of the voltage on the bus and sends the command to the motor drive to change each step in delay mode, which is approximately 30-120 seconds.
Where Each Type Belongs
- Distribution transformers (50-2,500 kVA): Off-circuit tap changers, ±2×2.5% or ±4×2.5%, adjusted at commissioning and seasonally;
Substation power transformers (5-60 MVA): Resistor-type OLTC with ±8×1.25% or ±6×2.5% adjustments with the possibility of automatically regulating voltage;
Large power and generator transformers (>60 MVA): Vacuum-type OLTC operating over wide ranges, sometimes on both HV and LV windings (two OLTCs);
Industrial furnace and arc loads: OLTCs made for fast operations and big switching rates;
Renewable energy tie transformers: OLTC to help with variable generation and hold voltage in the grid.
ブランドと価格比較
| ブランド | 起源 | Strength | Approx. Price Range (OLTC, standalone) |
|---|---|---|---|
| MR (Reinhausen) | ドイツ | The global OLTC benchmark; vacuum and resistor types | $6,000-$35,000 |
| ABB | スイス/スウェーデン | Complete transformer + OLTC packages | $5,000-$30,000 |
| シーメンス | ドイツ | OLTC for large power transformers | $6,000-$32,000 |
| 日立エナジー | Switzerland | Power transformer tap changing | $7,000-$35,000 |
| シュナイダーエレクトリック | フランス | Distribution-class tap changers | $3,000-$15,000 |
| 江蘇省蘇辺電力 | 中国 | OCTC and OLTC-equipped transformers, IEC 60214 coordination | $2,000-$12,000 |
In the field of on-load tap changers, MR Reinhausen is regarded as the benchmark as the majority of large transformers globally are manufactured by MR or its licensed version; ABB, Siemens, and Hitachi Energy providing complete solutions around these machines or their partner’s OLTC technology. The equipment passes all necessary tests according to IEC 60214 and IEEE C57.131, having all required records of its lifetime and maintenance. For those who want the same result but at a more attractive price, Jiangsu スビアン電力 creates equipment with the same OLTC able to make devices as one. Jiangsu Subian Electric Power supplies equipment successfully operating for IEC 60214 and shipping worldwide with all commonplace records of tests at a price 40-60% less than the cost of European transformers. If you opt for MR equipment or find a cost-efficient analogue, ensure that you mention OLTC’s name in your purchase agreeing to purchase the exact unit rather than just referring to it in general.
Step-by-Step Selection Guide
First, choose between an OCTC or an OLTC. If you can take the transformer out of service while changing taps and if the load changes gradually, then an OCTC is the way to go. If, however, you want to keep the voltage constant while the load is in a state of constant change, then you should choose an OLTC.
Next, define the regulating range. Take down the actual voltage variation and find the required range, keeping in mind that +8×1.25% is enough to cover most situations when using electricity.
Next, choose the step size; use 2.5% for economy purposes and 1.25% for more precise regulation.
Then, check the through-current. OLTC must have a capacity greater than the maximum continuous current of the transformer, which also includes any overload commitments.
Furthermore, ensure that the voltages are compatible. Confirm that the OLTC handles your transformer’s step voltage, because the product of the tap current by the step voltage will cause stress on the diverter.
Decide on whether you want to use a resistor or a vacuum. A resistor would be a better option as it is cheaper and has been in use for a long time, whereas a vacuum would have lower maintenance costs.
Finally, do not forget to include automatic controls. A motor drive, AVR relay, and position indicator are not only necessary for your OLTC, but you should also specify the control voltage needed for it to function.
Installation and Maintenance
The most maintenance-intensive aspect of a modern transformer is its use of on-load tap changers, as they are the only transformer components to perform mechanical work under load conditions. The switching oil used in typical resistor-type OLTC devices needs to be filtered or replaced according to the manufacturer’s schedule, usually after a period of 100,000 operations or 5-7 years, whichever comes first, while vacuum-operated OLTCs prolong the operating time considerably.
Maintenance procedures
1. Measure and draw up a monthly chart of the operating counter readings.
2. Take OLTC oil samples separately from the main tank oil. The diverter oil carbonizes under switching and gets deteriorated much quicker.
3. Inspect contacts for erosion during general overhauls, and take transition resistor readings according to the requirements of the manual.
4. Test torque characteristics of the motor drive and AVR-relay settings once a year.
5. Make sure that tap position indicator corresponds to the current winding position before any manual operation.
よくある質問
How much does a tap changer add to transformer cost?
An off-circuit tap changer adds roughly 2-5% to the transformer price. An on-load tap changer adds 10-30%, because the OLTC itself costs $3,000-$30,000 (by rating) plus the motor drive and control system. For a 10 MVA transformer, budget $10,000-$25,000 for the OLTC increment.
What is the difference between an off-circuit and an on-load tap changer?
An off-circuit tap changer (OCTC) can only be operated when the transformer is de-energized; it is a simple, cheap switch used to match the transformer to its feeder’s average voltage profile. An on-load tap changer (OLTC) switches taps while the transformer carries load, using a diverter and transition impedance to avoid interrupting current, which makes it suitable for automatic voltage regulation under varying load.
What tap range do I need for my transformer?
For distribution transformers, ±2×2.5% (5 positions) or ±4×2.5% (9 positions) covers most cases. For power transformers feeding fluctuating loads, ±8×1.25% (17 positions) is the common choice, giving ±10% total range. The correct value comes from measuring your voltage variation and transformer impedance drop — do not pick a range from a catalog.
How often should an on-load tap changer be maintained?
Resistor-type OLTCs typically need oil filtration or replacement every 100,000 operations or 5-7 years, whichever comes first. Vacuum-type designs extend that to roughly 300,000 operations. Monitor the operation counter, sample the OLTC oil separately from the main oil, and inspect contacts at each major overhaul.
Can I retrofit an OLTC onto a transformer designed for off-circuit operation?
Infrequently, and typically not cheap. The winding should have the proper tap configuration, the tank should have a mounting turret, and the cooling and clearances must work for the diverter. It is nearly always cheaper to specify the OLTC at the design stage or buy a new transformer. If the need for voltage regulation exists for an already installed fixed-tap unit, one should think about a separate voltage-regulating transformer instead.
参考文献
- IEC 60214-1 — Tap-Changers, Performance Requirements and Test Methods — The core standard for tap changer design and testing.
- IEC 60214-2 — Tap-Changers, Application Guide — Guidance on selecting ranges, steps, and ratings.
- IEEE C57.131 — Requirements for Load Tap Changers — North American OLTC standard.
- MR Reinhausen — Tap Changer Portal — The leading OLTC manufacturer’s product and application documentation.
- IEC 60076-1 — 電力変圧器、一般要件 — Transformer-level standards that the tap changer must satisfy as part of the unit.
- ABB Transformers — Reference for transformer and tap changer integration.
結論
この タップチェンジャー selection can be considered a voltage-regulation solution masquerading as a selection of components. It is necessary to evaluate the test results relative to voltage variation and transformer impedance decrease beforehand. The next step is to select the tap changer according to the proper voltage range and tap size, then select a corresponding model to meet its requirements and specifications, including selection of an off-load tap changer if applicable.
An OCTC adds to the cost of the transformer only roughly 2% to 5%, whereas an OLTC increases the cost in the amount of approximately 10% to 30%. The current and voltage should be matched according to the operating conditions, instead of naming the brand of the equipment.
For off-circuit and on-load tap changer equipped transformers built to IEC 60214 and IEC 60076, contact 江蘇省蘇辺電力 at www.subian-electric.com with your voltage profile and load data for a specification and quote.