Unsa ang mga kasagaran nga pagkamalas sa single-phase distribution transformers?

Ang mga single-phase distribution transformers, isip usa ka kritikal nga gamit sa pagbago sa voltage ug power distribution sa sistema sa kuryente, gigamit pinaagi sa dili paubos sa rural nga grid sa kuryente, sa mga low-voltage residential areas, ug sa mga lugar nga may koncentrasyon sa single-phase loads. Kon ang bahin sa single-phase loads sa distribution network nagpadayon nga mobati, ang failure rate sa mga single-phase transformers usab nimoaas. Ang maong pag-identify ug pag-handle niining mga suloy ngadto sa pagpahigayon sa steady nga supply sa kuryente labi nga importante. Sumala sa pinakabag-ong pananaliksik, ang mga karanihang suloy sa single-phase distribution transformers mahimong masayri sa lima ka kategoriya: winding faults, insulation aging, oil leakage, abnormal temperature, ug low-voltage tap faults. Ang mga suloy kini wala lang mag-interfere sa normal nga operasyon sa transformer apan mahimo usab nga mao ang rason sa equipment damage ug interruptions sa power supply. Ang maong artikulo kini mahimong maghatag og comprehensive nga analisis sa mga dahon, karakteristikas, ug mga paraan sa pag-handle sa tanang klase sa suloy, na naghatag og praktikal nga gabay alang sa mga operation ug maintenance personnel sa sistema sa kuryente.

1. Winding Faults

Ang winding faults ang pinakamao nga klase sa suloy sa single-phase distribution transformers, kasagaran sumala sa inter-turn short circuits, open circuits, ug grounding faults sa windings. Ang mga suloy kini adunay dili paubos nga mga dahon sama sa aging sa insulation material, mechanical damage, o manufacturing defects. Ang inter-turn short circuit sa winding mahimo mogulid sa local overheating sa interior sa transformer, nag-accelerate sa insulation aging, ug mahimo mopadayon sa overall damage sa winding. Sumala sa pananaliksik, kon ang may slight short circuit sa winding sa transformer, ang tradisyonal nga mga device sama sa differential protection ug gas protection dili sigurado mopag-operate sa unang bahin sa suloy, na naghatag og mas taas nga pangutana sa fault identification ability sa operation ug maintenance personnel.

(1) Fault Manifestations

• Abnormal Noise: Ang transformer nag-emit og "gurgling" sound sa boiling oil o "sizzling" discharge sound.

• Abnormal Temperature: Ang oil temperature nag-exceed sa standard. Kon ang gas content sa oil nag-exceed sa attention value, ang status sa transformer kinahanglan i-check immediately (sumala sa IEC standards).

• Resistance Imbalance: Ang unbalance rate sa DC resistance sa winding nag-exceed sa 2% (allowable value), nga nagpakita og posible nga deformation sa winding o poor contact.

• Abnormal Voltage: Ang output voltage dili stable ug nag-drop significantly. Mas daghan pa, ang low-voltage winding mas likely mopadayon sa deformation during a sudden short circuit (ang low-voltage winding mas likely mopadayon sa deformation under pressure).

(2) Handling Measures

• Emergency Shutdown: Immediate cut off sa power supply ug stop sa operasyon sa transformer.

• Precise Detection: Gamiton ang infrared thermometer aron imong check ang temperature distribution sa winding, locate ang fault; measure ang DC resistance ug capacitance aron i-evaluate ang degree sa deformation.

• Repair and Replacement: Kon kinahanglan, lift ang cover para sa maintenance, repair o replace ang damaged winding.

(3) Prevention Strategies

• Regular Testing: Conduct winding insulation tests aron maintindihan ang insulation status.

• Avoid Overload: Strictly prohibit ang long-term overload operation sa transformer aron mapalito ang risk sa winding damage.

• Pre-maintenance Inspection: Conduct preventive inspections before the peak load period aron identify ang hidden dangers.

• Stable Installation: Ensure ang transformer installed firmly aron mapalito ang impact sa vibration sa winding.

2. Insulation Aging Faults

Ang insulation aging ang ikaduha nga pinakakaranihang suloy sa single-phase distribution transformers, kasagaran sumala sa aging sa solid insulation materials ug deterioration sa oil insulation. Ang insulation aging mogulid sa pagbag-o sa insulation performance sa transformer ug nag-accelerate sa overall aging sa equipment. Sumala sa estadistika, makapalito sa designed service life (35-40 years) sa transformer down to about 20 years, na lisod kaayo makita sa mga transformers nga nag-operate sa long-term, sa harsh environments, o uban sa insufficient operation ug maintenance.

(1) Fault Manifestations

• Oil Quality Change: Ang transformer oil gradual nag-change gikan sa light yellow hangtod sa orange o brown, ug adunay carbon deposits.

• Insulation Decline: Ang insulation resistance test value lower sa standard, ug ang partial discharge volume increases.

• Abnormal Sound: Ang operation sound sharp ug uneven, ug ang aging rate positively correlated sa temperature (sumala sa Arrhenius theory, ang aging rate doubles for every 6°C increase in temperature).

(2) Handling Methods

• Oil Sample Analysis: Conduct chromatographic analysis aron detect ang content sa characteristic gases ug judge ang degree sa aging.

• Oil and Material Disposal: Sumala sa aging situation, decide kon unsa ang dapat ibag-o sa oil, replace ang solid insulation material, ug conduct a comprehensive overhaul if necessary.

(3) Prevention Strategies

• Regular Detection: Regularize ang oil quality detection ug insulation resistance testing aron control ang insulation status.

• Temperature-controlled Operation: Maintain a reasonable temperature (GB standard: ang average temperature rise sa winding sa oil-immersed transformer ≤ 65°C, ug ang temperature rise sa top oil ≤ 55°C).

• Environment Optimization: Improve ang operating environment, reduce ang erosion sa dust, humidity, ug harmful gases; select high-efficiency transformers sama sa S11 type aron mapalito ang temperature rise ug losses.

3. Oil Leakage Faults

Ang oil leakage usa ka frequent ug harmful suloy sa single-phase distribution transformers. Adunay over 40% sa mga suloy sa power transformers, na mogulid sa pagbag-o sa insulation ug heat dissipation performance, ug mogulid sa equipment fire, pollution, ug economic losses.

(1) Fault Manifestations

• Oil Level Drop: Ang oil level gauge shows a decrease sa oil level, ug ang oil stains visible sa surface sa oil tank.

• Related Abnormalities: Ang operation sound sharp ug uneven, ang oil-paper insulation damp, ug ang leakage aggravated sa rainy days ug high-humidity environments.

(2) Fault Causes

Aging/damage sa seals, weld cracking, improper bushing installation, loose connections caused by vibration, oil tank rust, ug abnormal oil pressure caused by a blocked breather.

(3) Handling Methods

• Graded Treatment: Temporarily repair small leaks, ug immediate shutdown ug comprehensive overhaul for serious leaks.

• Root Repair: Replace seals, repair welds/connections, clean the breather, ug ensure ang normal operation sa oil conservator.

(4) Prevention Strategies

• Seal Inspection: Regularly check ang sealing status, ug strengthen fixation sa vibrating environments.

• Material Upgrade: Use high-quality sealing materials, clean ang oil tank aron prevent corrosion; old transformers can be replaced with products with new sealing structures.

4. Abnormal Temperature Faults

Ang abnormal temperature usa ka key suloy sa single-phase distribution transformers, kasagaran sumala sa winding overheating, local overheating sa iron core, ug oil temperature rise. Ika nga ang "trigger" sa mga suloy sama sa insulation aging, oil leakage, ug winding deformation. Sumala sa IEC standards, kon ang hottest spot temperature reaches 140°C, bubbles will be generated sa oil, na mogulid sa pagbag-o sa insulation or cause flashover, damaging the transformer.

(1) Fault Manifestations

• Temperature Exceeding Standard: Ang oil temperature gauge shows an abnormality, ang local surface overheated ug discolored, ug ang oil level sa oil conservator abnormal.

• Abnormal Sound: Emit a "buzzing" sound, na louder as the load increases; ang oil color darker ug carbon deposits appear.

(2) Fault Causes

Transformer overload, internal faults (winding/iron core short circuit), cooling system faults, high ambient temperature, insufficient oil volume due to poor sealing, ug poor installation ventilation.

(3) Handling Methods

• Load Reduction and Shutdown: Immediate reduce the load or shutdown, ug check the cooling system.

• Precise Diagnosis: Use an infrared thermometer aron locate ang over-heated point, take an oil sample for chromatographic analysis, check for internal faults; repair external causes.

(4) Prevention Strategies

• Monitoring and Analysis: Regularly monitor ang temperature, establish a trend analysis; avoid long-term overload.

• Environment Optimization: Optimize ang installation position aron ensure ventilation; clean ang dirt sa heat sink; increase capacity or operate multiple units in parallel sa high-load areas, ug install sunshades ug ventilation devices sa high-temperature environments.

5. Low-voltage Tap Faults

Ang low-voltage tap faults unique sa single-phase distribution transformers, kasagaran sumala sa poor contact, open circuits, ug wrong connections. Kon ang low-voltage side mostly adopts a tap-off design (such as three/four taps), ang quality sa connection directly affects ang output voltage ug operation stability, na lisod kaayo makita sa transformers nga adunay large load fluctuations ug insufficient operation ug maintenance.

(1) Fault Manifestations

• Voltage Abnormality: Ang output voltage unstable, too high/too low.

• Sound Abnormality: Emit a "clatter" "rustling" mechanical friction sound, obvious when the load changes; ang voltage sa low-voltage side unbalanced, ug ang operation temperature abnormally high.

(2) Fault Causes

Poor tap welding, oxidation sa contact surface, insecure installation, failure sa restore connections during operation ug maintenance, large contact resistance caused by a humid environment, ug contact point wear caused by load fluctuations.

(3) Handling Methods

• Power-off Maintenance: Check ang tap connection, re-weld, ug fasten loose parts, replace aging components.

• Cleaning and Protection: Clean poorly contacted parts aron ensure good contact sa tap-changing switch.

(4) Prevention Strategies

• Regular Inspection: Regularize ang inspection sa tap connections, ug use high-quality welding materials ug processes.

• Environment Adaptation: Strengthen moisture-proof measures sa humid environments; for transformers with frequent tap adjustments, replace with reliable connection methods; replace old equipment with products with new tap designs.

6. Application of Intelligent Monitoring Technology in Fault Diagnosis

Kon ang smart grid nag-develop, ang traditional diagnosis mode dependent sa manual experience ug simple instruments gradually replaced by intelligent monitoring technology. Ang fault diagnosis system based on artificial intelligence can monitor ang operation status real-time, early-warning risks in advance, ug improve ang accuracy ug efficiency sa diagnosis.

(1) Mainstream Technologies

• Infrared Sensing Temperature Measurement: With an accuracy of ±1°C, it can accurately detect abnormal temperatures.

• Acoustic Signature Recognition Diagnosis: Analyze ang frequency ug characteristics sa operation sound aron distinguish between normal ug fault sounds.

• Analysis of Dissolved Gases in Oil: Detect ang content sa characteristic gases aron determine ang type ug degree sa internal faults.

• Machine Learning System: Integrate multiple parameters aron establish a fault prediction model.

(2) Application Effects

After applying infrared temperature measurement, a power company increased ang fault detection rate by 65% ug shortened ang processing time by 40%; acoustic signature recognition can detect winding faults 3-6 months in advance. Ang intelligent system can also locate faults ug evaluate ang severity, providing a basis for operation ug maintenance decisions.

7. Maintenance and Prevention Measures for Single-phase Transformers

Most faults sa single-phase distribution transformers related sa long-term operation, environment, ug insufficient operation ug maintenance. Establishing a scientific maintenance system ug implementing preventive measures are the keys sa reducing faults ug extending service life.

(1) Daily Maintenance

• Oil Condition Inspection: Regularly check ang oil level ug oil color aron ensure ang oil level normal ug ang oil quality good.

• Status Monitoring: Monitor ang operation sound, monitor ang temperature, ug establish a trend analysis.

• Component Inspection: Check ang cleanliness, damage, ug discharge traces sa bushings; verify ang grounding system (the grounding resistance of 100 kVA and above ≤ 4Ω, and below ≤ 10Ω).

• Environmental Management: Ensure stable installation, clean surface dirt, ug prevent pollution discharge.

(2) Classified Prevention

• Winding Faults: Avoid overload ug conduct regular insulation tests.

• Insulation Aging: Operate at a controlled temperature ug conduct regular oil quality detection.

• Oil Leakage: Regularly check ang seal ug strengthen fixation sa vibrating environments.

• Abnormal Temperature: Optimize installation, ensure ventilation, ug install temperature monitoring devices.

• Tap Faults: Regularly check connections, use high-quality welding processes, ug prevent moisture sa humid environments.

(3) Standard Adaptation and Optimization

Select high-efficiency transformers according sa GB20052-2020 aron reduce losses ug temperature rise; operate multiple units in parallel sa high-load areas aron reduce ang load pressure sa single unit; strengthen environmental management aron reduce external erosion.

8. Conclusions and Recommendations

Ang common faults sa single-phase distribution transformers interrelated, ug most caused by a single factor leading sa multiple types sa fault manifestations. Building a complete fault diagnosis system that integrates traditional experience ug intelligent technology can improve ang accuracy ug efficiency sa diagnosis.

Operation and Maintenance Management Recommendations

• Monitoring System: Establish a comprehensive monitoring system sa multiple parameters such as temperature, sound, ug oil quality aron master ang status real-time.

• Environment Optimization: Optimize ang installation position ug method aron reduce ang environmental impact.

• Pre-maintenance Tests: Regularly conduct preventive tests (insulation resistance tests, oil quality detection, etc.) aron identify ang hidden dangers.

• Dynamic Adjustment: Adjust ang operation mode ug transformer capacity according sa load changes.

• Technology Upgrade: Adopt high-efficiency ug intelligent monitoring equipment aron improve efficiency ug diagnosis ability.

Ang development sa smart grid helps ang fault diagnosis ug management sa single-phase distribution transformers move towards intelligence ug refinement. It is recommended nga ang power companies introduce new technologies ug standards, build a big data health management system, realize early fault warning ug precise diagnosis, ug improve ang reliability ug economy sa distribution network.