كيف تعمل البطانات المحولات: أنواع, أسباب الفشل ودليل الصيانة

تم تصميم المحول للعمل بشكل موثوق لعقود من الزمن, لكن بعض المكونات تتطلب اهتمامًا أكبر من غيرها. من بين جميع ملحقات المحولات, البطانات المحولات​ are among the most critical components because they provide the connections between the internal windings and the external power network.

Although a bushing looks like a simple insulating component, it actually performs several important functions:

• Carrying high-voltage current safely;
• Preventing electrical breakdown between conductor and transformer tank;
• Maintaining insulation performance under temperature, رطوبة, and pollution conditions;
• Ensuring reliable operation of the transformer throughout its service life.

A damaged transformer bushing can lead to partial discharge, فشل العزل, تسرب الزيت, and even unexpected transformer shutdown.

For power utilities, النباتات الصناعية, ومشاريع الطاقة المتجددة, understanding transformer bushings is essential for proper selection and maintenance.

1. ما هو جلبة المحولات?

A transformer bushing is an insulated device installed on the transformer tank that allows an electrical conductor to pass safely through the grounded enclosure.

Inside an oil immersed transformer, the winding is surrounded by transformer oil for insulation and cooling. لكن, the electrical connection must extend outside the transformer to connect with cables, أشرطة التوصيل, or switchgear.

The transformer bushing creates a safe transition point:

Transformer winding → Internal conductor → Transformer bushing → External power connection

Without a suitable bushing, the high-voltage conductor would create excessive electrical stress and could cause insulation failure.

2. How Does a Transformer Bushing Work?

The main challenge of a transformer bushing is controlling the electric field around the high-voltage conductor.

High voltage creates strong electrical stress. If the stress is concentrated in one area, the insulation material may deteriorate over time.

Modern transformer bushings use multiple insulation layers and grading structures to distribute the electric field evenly.

The main components include:

A high-quality bushing must maintain stable insulation performance during:

• Normal operation;
• Short circuit conditions;
• Temperature changes;
• Environmental exposure.

3. الأنواع الرئيسية لبطانات المحولات

Different transformer applications require different bushing designs.

3.1 Oil Impregnated Paper (مكتب بروتوكول الإنترنت) البطانات

Oil Impregnated Paper (مكتب بروتوكول الإنترنت) bushings are widely used in traditional power transformers.

The insulation system consists of:

• Special insulating paper;
• Conductive grading layers;
• زيت المحولات.

المزايا:

• Proven technology;
• تاريخ التشغيل الطويل;
• Suitable for medium and high voltage transformers.

OIP bushings are commonly used in:

• Distribution transformers;
• Power transformers;
• Substation equipment.

لكن, they require regular inspection because oil aging and moisture can reduce insulation performance.

3.2 Resin Impregnated Paper (قطع) البطانات

RIP bushings use epoxy resin instead of oil as the main insulation material.

المزايا:

• لا يوجد خطر تسرب النفط;
• Lower maintenance requirement;
• أداء بيئي أفضل.

They are increasingly used in:

• Renewable energy substations;
• Modern power networks;
• High-voltage applications.

3.3 البورسلين مقابل البطانات المركبة

The external insulation material is another important consideration.

Composite bushings are becoming popular in coastal areas and regions with heavy pollution because of their excellent resistance to environmental conditions.

4. Common Transformer Bushing Failure Causes

Although transformer bushings are designed for long service life, several factors can cause failure.

4.1 Moisture Ingress

Moisture is one of the biggest threats to transformer insulation.

Common causes:

• Aging seals;
• Damaged gasket;
• Improper storage;
• Poor installation.

Moisture reduces dielectric strength and accelerates insulation aging.

4.2 Insulation Aging

After years of operation, insulation materials naturally deteriorate.

Typical signs include:

• Increased dielectric loss;
• Reduced insulation resistance;
• Partial discharge activity.

Regular testing helps identify problems before failure occurs.

4.3 تسرب الزيت

Oil leakage is one of the easiest problems to identify visually.

Possible reasons:

• Aging sealing gasket;
• Loose flange connection;
• Temperature expansion;
• الضرر الميكانيكي.

Even minor oil leakage should be inspected because it may allow moisture to enter the insulation system.

4.4 ارتفاع درجة الحرارة

Excessive temperature can damage the bushing insulation.

Possible causes:

• التوصيلات الكهربائية فضفاضة;
• High contact resistance;
• Transformer overload.

Long-term overheating significantly reduces bushing lifespan.

5. How to Select the Right Transformer Bushings?

When purchasing or replacing transformer bushings, engineers should consider several parameters.

1. الجهد المقنن

The bushing voltage rating must match the transformer system voltage.

مثال:

• 11kV transformer → 12kV class bushing
• 33kV transformer → 36kV class bushing

2. التصنيف الحالي

The bushing current rating must be higher than the transformer operating current.

Incorrect selection may cause overheating.

3. أبعاد التثبيت

Before ordering replacement bushings, always confirm:

• Mounting hole dimensions;
• Flange size;
• Conductor connection type;
• Overall height;
• مسافة الزحف.

Many replacement problems occur because the electrical parameters are correct but the mechanical dimensions are different.

4. Applicable Standards

Common transformer bushing standards include:

• اللجنة الانتخابية المستقلة 60137: Insulated bushings for AC voltages above 1000V;
• IEEE standards for power equipment applications.

6. Transformer Bushings Maintenance Checklist

Regular inspection can significantly extend transformer service life.

7. Common Questions About Transformer Bushings

How long does a transformer bushing last?

A high-quality transformer bushing can typically operate for 20–30 years or longer under proper maintenance.

What causes transformer bushing failure?

The main causes include moisture, شيخوخة العزل, ارتفاع درجة الحرارة, تسرب الزيت, and mechanical damage.

Can a transformer bushing be replaced?

نعم. Replacement is possible if the new bushing matches:

• Voltage rating;
• Current rating;
• Mechanical dimensions;
• Installation requirements.

Why do transformer bushings crack?

Cracking may result from mechanical stress, temperature changes, aging, or external impact.

انسايت الشركة المصنعة

كشركة مصنعة للمحولات ومورد لملحقات المحولات, PDDN understands that reliable transformer operation depends not only on the transformer body but also on every connected component.

For transformer bushing replacement or OEM requirements, customers should provide:

• Transformer rated voltage;
• Current rating;
• رسم التثبيت;
• Existing bushing model;
• المعيار المطلوب.

This information helps ensure electrical compatibility and reliable installation.

حول PDDN

بدن هي منصة على الانترنت منشركة لويانغ داتانغ لتكنولوجيا الطاقة., المحدودة., شركة تصنيع موثوقة ومورد عالمي لـمحولات الطاقة, ملحقات المحولات, مكونات المفاتيح الكهربائية, أنظمة تخزين طاقة البطارية (بيس), وحلول شحن المركبات الكهربائية. منذ 2015, لقد دعمنا شركات المرافق, مقاولو EPC, والعملاء الصناعيين في جميع أنحاء العالم بمنتجات موثوقة, خدمات تصنيع المعدات الأصلية/تصنيع التصميم الشخصي, والخبرة الفنية.