原因, 防止, 配電変圧器の故障と管理

配電変圧器は電力供給ネットワークに不可欠なコンポーネントです, 住宅に適した電圧レベルを確保する, コマーシャル, および産業用負荷. しかし, 変圧器の故障 are common and can lead to significant operational and financial losses. Understanding the root causes, preventive strategies, and effective operational management is crucial for minimizing downtime and extending transformer lifespan.

1. Common Causes of Transformer Failure

1.1 Absence or Improper Use of Fuses

Many distribution transformers operate without proper fuses on the high- and low-voltage sides. Some transformers have drop-out fuses or horn-type fuses, but the fuse elements are often replaced by aluminum or copper wires. When a low-voltage short-circuit or overload occurs, these makeshift elements fail to break the circuit, causing transformer burnout.

Table 1: Fuse Requirements by Transformer Capacity

1.2 Incorrect Fuse Rating

Using oversized fuses is another major cause. Fuses rated above the transformer’s capability cannot prevent overloads, resulting in severe overheating and eventual burnout.

1.3 Phase Imbalance in Rural Networks

Rural distribution networks often operate with single-phase supply. Due to haphazard jumper connections and poor management, transformers may operate with unbalanced loads. Long-term phase imbalance causes insulation degradation in one phase, eventually burning out the transformer.

1.4 Tap Changer Issues

1. Unauthorized adjustment of tap changers can result in improper contacts, leading to short circuits and transformer failure.
2. Poor-quality tap changers may have incomplete star contact connections, causing arcing or ground discharge.

1.5 Oil Leakage and Insulation Degradation

Oil-filled transformers rely on oil for cooling and insulation. 時間とともに, sealing gaskets and bushings may deteriorate, leading to oil leakage. Moisture ingress lowers insulation performance, causing discharges and transformer burnouts.

1.6 Lightning Strikes

Most high- and low-voltage distribution lines are overhead. Without timely installation of 10kV surge arresters, lightning strikes can destroy transformers.

1.7 Multiple Core Grounding

Improper grounding of transformer cores can lead to circulating currents, increasing the risk of internal faults and insulation breakdown.

1.8 Short-Circuit Stresses

When low-voltage side experiences a short circuit, currents up to 20–30 times the rated value flow through the transformer. This induces extreme mechanical stress on windings, potentially dislodging insulation and deforming coils.

1.9 Human-Induced Damage

• Copper-aluminum electrochemical corrosion at connections.
• Bushing flashovers due to poor maintenance.

2. Troubleshooting Transformers Burned in Three Days

When a new dry-type transformer fails shortly after commissioning, follow these steps:

1. Verify if the location has a history of failures.
2. Identify the failure area (例えば, 端子, 高圧側).
3. Check environmental conditions (湿度, 封印).
4. Observe smoke timing for patterns.
5. Measure load current; check for overload.
6. Confirm supply voltage, 頻度, and presence of harmonics.

3. Preventive Measures

3.1 Proper Fuse Installation

• Install high- and low-voltage fuses during construction.
• Replace stolen or blown fuses promptly.

3.2 Correct Fuse Rating

• 100 kVA+ transformers: 1.5–2.0 × rated current.
• <100 kVA transformers: 2.0–3.0 × rated current.

3.3 Load Management

• Measure transformer loads during peak periods.
• Balance three-phase loads to avoid neutral overcurrent.

3.4 Tap Changer Regulations

• Only qualified personnel may adjust tap changers.
• Do not adjust when voltage variation is within -10% に +7%.

3.5 Lightning Protection

• Inspect and install surge arresters before the thunderstorm season.

3.6 Routine Maintenance and Inspections

• Monitor oil levels, 色, と温度.
• Inspect bushing surfaces, check for flashover marks.
• Use a megohmmeter to measure insulation resistance.

4. Daily Operation Management

4.1 Regular Patrols and Maintenance

• Clean dust and oil deposits.
• Ensure proper ventilation to prevent overheating.
• Monitor three-phase load currents and balance.

4.2 Protection Against External Damage

• Install transformers in accessible, safe locations.
• Avoid placing low-voltage metering boxes directly on transformers.
• Use insulating covers on high- and low-voltage terminals in areas with animals or debris.
• Regularly trim trees near overhead lines to prevent short circuits.

Distribution transformer reliability relies heavily on both technical design and operational management. By adhering to proper fuse configurations, balancing loads, ensuring lightning protection, and implementing regular maintenance, transformer burnouts can be significantly reduced. Effective management ensures longer service life, minimizes outages, メンテナンスコストを削減します.

洛陽大唐能源科技有限公司, 株式会社. Rを統合したハイテク企業です&D, 変圧器などの電力機器の製造・供給, 新しいエネルギー成分, 配電盤とインバータ. 技術革新を核に, 私たちは、世界中の顧客にサービスを提供するために、高信頼性と高性能の電源ソリューションの開発に注力しています。. 厳格な品質管理システムと国際規格認証を取得しています。, これからも優れた製品を世に送り出し、お客様の安全・安定した電力システムの構築をお手伝いします.