Simple common power transformer fault repair methods
Sort：Industry news Date：2017-09-29 view count:1065 【back】
Power transformer fault phenomenon some common transformer s phenomenon, some can only appear in the large capacity of power transformer, as for the repair method, also is only for small fault repair, if it is a failure, can only in professional manufacturers have professional tools equipment maintenance repair. Please according to the actual situation for identification.
First, pressure and causes of common malfunctions
1. The abnormal noise
(1) when great and noisy sound, may is a problem of transformer core. For example, clip or compression screw loose core. (2) audio clip has the sound of water boiling, issued a "loud gurgling bubbles escape, may be a serious fault, winding makes its nearby parts serious fever makes oil and gas. Tap-changer of poor contact and local point has serious overheating or transformer turn-to-turn short circuit, send out the sound. At this point, should immediately stop the transformer operation, maintenance and repair. (3) audio clip has a continuous and regular impact or friction, some parts may be transformer caused by core vibration mechanical contact, or abnormal noise caused by electrostatic discharge, although this kind of noise anomaly, but without harm to run, don t have to immediately stop operation, should be ruled out in maintenance planning.
2 temperature anomaly
Transformer in a constant load and cooling conditions, environment temperature, under the condition of the original with the condition of high temperature, and a rising trend. The causes of abnormal temperature rise are as follows:
(1) short circuit between transformer interturn, interlayer, shares; (2) local short circuit transformer iron core; (3) caused by magnetic flux leakage vortices or tank and lid fever; (4) long-term overload operation, accident load; (5) the cooling conditions deteriorated, etc.
3. Line 泿 surge current
Line flow (or line interference) in all the factors resulting in failure of transformer is listed as the first. In this category include switching overvoltage, such as peak voltage, line fault anomalies.
4. The manufacturing process
Loose loose terminal or without support, block, poor welding, core insulation fault, short-circuit strength is insufficient.
5. Insulation aging
A long period of more than nameplate power transformer the working status of the transformer. Resulting in transformer overload operation, high temperature led to the premature aging of the insulation. After the aging of transformer insulation board, the decrease of strength of paper. Therefore, the impact of the external failure can lead to insulation damage, and failure.
Three simple method, maintenance treatment
1. The lead part failure
Detection: unbalanced three-phase dc resistance or resistance of infinity, a phase conduction.
Processing method: determine the fault location, to burnish of poor contact pressure. The poor welding welding again. Lack of the welding surface should be increased. Lead cross section should be replaced by the lack of (increase) to meet the demand.
2. The coil failure
Fault detection: usually coil would smell of anxious burnt flavour. Measuring insulation resistance and dc resistance, insulation resistance "zero", dc resistance increase is not stable.
Processing method: to determine the fault condition. If damage slightly, can be used to repair. If failure is serious, should consider to replace the coil.
3. The insulation falling
Detection: transformer for insulation resistance test on a regular basis, such as the measured value change big or below the regulation requirements can be identified as transformer oil be affected with damp be affected with damp or insulation resistance decline.
Methods: transformer insulation resistance drop should be thoroughly dry, oil insulation falling oil change or filtering, fault of transformer and untight seal moisture absorption should be repaired.
4. The iron core fault
Detection methods: wear core screw insulation resistance measurement, such as less than 10 ohms should overhaul. Processing method: hanging out damaged after wear core screw, replace the insulation.
5. For low voltage winding layers in pairs, injured elbow insulation, appear crack.
Processing methods: is the elbow has breakdown of the old insulation removed, or replace the low voltage coils.
6. Iron core fault cause breakdown.
Core insulation fault has iron chip damage, core partial melting, ground fracture and is loose, etc. Such as the damaged parts is not large, the damage a varnish coat can be. Core damage of partial melting is usually due to the insulation of the core bolt which can seriously damage the iron chip, short circuit, pieces of insulation or core grounding is not correct. Processing method is will burning-out some scrape, then coated with varnish.
(1) when great and noisy sound, may is a problem of transformer core. For example, clip or compression screw loose core. (2) audio clip has the sound of water boiling, issued a "loud gurgling bubbles escape, may be a serious fault, winding makes its nearby parts serious fever makes oil and gas. Tap-changer of poor contact and local point has serious overheating or transformer turn-to-turn short circuit, send out the sound. At this point, should immediately stop the transformer operation, maintenance and repair. (3) audio clip has a continuous and regular impact or friction, some parts may be transformer caused by core vibration mechanical contact, or abnormal noise caused by electrostatic discharge, although this kind of noise anomaly, but without harm to run, don t have to immediately stop operation, should be ruled out in maintenance planning.
2 temperature anomaly
Transformer in a constant load and cooling conditions, environment temperature, under the condition of the original with the condition of high temperature, and a rising trend. The causes of abnormal temperature rise are as follows:
(1) short circuit between transformer interturn, interlayer, shares; (2) local short circuit transformer iron core; (3) caused by magnetic flux leakage vortices or tank and lid fever; (4) long-term overload operation, accident load; (5) the cooling conditions deteriorated, etc.
3. Line 泿 surge current
Line flow (or line interference) in all the factors resulting in failure of transformer is listed as the first. In this category include switching overvoltage, such as peak voltage, line fault anomalies.
4. The manufacturing process
Loose loose terminal or without support, block, poor welding, core insulation fault, short-circuit strength is insufficient.
5. Insulation aging
Three simple method, maintenance treatment
1. The lead part failure
Detection: unbalanced three-phase dc resistance or resistance of infinity, a phase conduction.
Processing method: determine the fault location, to burnish of poor contact pressure. The poor welding welding again. Lack of the welding surface should be increased. Lead cross section should be replaced by the lack of (increase) to meet the demand.
2. The coil failure
Fault detection: usually coil would smell of anxious burnt flavour. Measuring insulation resistance and dc resistance, insulation resistance "zero", dc resistance increase is not stable.
Processing method: to determine the fault condition. If damage slightly, can be used to repair. If failure is serious, should consider to replace the coil.
3. The insulation falling
Detection: transformer for insulation resistance test on a regular basis, such as the measured value change big or below the regulation requirements can be identified as transformer oil be affected with damp be affected with damp or insulation resistance decline.
Methods: transformer insulation resistance drop should be thoroughly dry, oil insulation falling oil change or filtering, fault of transformer and untight seal moisture absorption should be repaired.
4. The iron core fault
Detection methods: wear core screw insulation resistance measurement, such as less than 10 ohms should overhaul. Processing method: hanging out damaged after wear core screw, replace the insulation.
5. For low voltage winding layers in pairs, injured elbow insulation, appear crack.
Processing methods: is the elbow has breakdown of the old insulation removed, or replace the low voltage coils.
6. Iron core fault cause breakdown.
Core insulation fault has iron chip damage, core partial melting, ground fracture and is loose, etc. Such as the damaged parts is not large, the damage a varnish coat can be. Core damage of partial melting is usually due to the insulation of the core bolt which can seriously damage the iron chip, short circuit, pieces of insulation or core grounding is not correct. Processing method is will burning-out some scrape, then coated with varnish.
