During Routine Inspections Of High-voltage Series Reactors, Which Abnormal Indicators Require Immediate Shutdown And Maintenance?

In the daily inspection of high voltage series reactor, if the following index abnormality are found, the reactor must be immediately shut down for maintenance to prevent equipment damage or safety accidents:
I. Abnormal Temperature.
* **Coil or core temperatures above standard limit: **
Standard Limit:
Coil temperature ≤ 95K (H-class insulation), core temperature elevation ≤ 85K.
* **Abnormal Manifestations:** Temperature rise above limit or significantly above historical data (e.g., summer ambient temperature increases of more than 10%).
* ** Risk:** Overheating can cause insulation materials to age, damage, and even start fires.
* **Case: * * Substation reactor coil temperature rises to 110K. Maintenance during downtime indicates partial short-circuit of winding; timely replacement prevents equipment from burning.
* * *Excessively High Local Hot Spot Temperature: **
* ** Methods of detection:** an infrared thermal imager was used to scan the reactor surface, focusing on winding, connectors, insulators, etc.
* **Abnormal Manifestations:**
Local temperature exceeds ambient temperature +50°C or the difference with other parts is greater than15°C.
Risk: Localized overheating may be caused by poor contact, internal short circuit or insulation damage and requires immediate investigation.
ii. Abnormal Sound and vibrations
Increased business noise
Normal noise: The reactor should generate uniform electromagnetic noise at ≤ 65dB (1m from equipment) during operation.
Abnormal Manifestations: sudden increase in noise (over 80dB, for example) or intense discharge sound or mechanical vibration.
Risk: This may be due to loose cores, winding deformation, insulator breakage or internal discharges that require to be closed and inspected.
Case study: abnormal noise of ``buzzing"during reactor operation. After closing, the air gap gasket in the core was found to have fallen off. It was repaired and returned to normal operation.
Excessive Mechanical Vibration
Methods: vibration sensor is used to monitor the reactor body. Vibration acceleration ≤0.1g (peak value).
Abnormal Manifestations: A sudden increase in the amplitude or frequency of a vibration (such as high frequency vibration).
Risk: This may be due to loose winding, core saturation or unstable foundations. Long-term use can lead to structural damage.
III. Abnormal Electrical Parameters
* Current or Voltage Fluctuations Exceeding Limits
Standard limit values: current fluctuation ≤ 5% rating, voltage fluctuation ≤ 10% rating.
Abnormal Manifestations: Current or voltage is always over the limit or shows periodic fluctuations (e.g. synchronized with harmonic frequencies).
Risk: may be due to system harmonic amplification, mismatch of reactor parameters, or internal malfunction. System is shut down to check the reactance ratio.
Case study: A reactor experienced ± 15% current fluctuation. When the power supply is turned off, changes in capacitor bank capacity resonate. Adjust the reactance ratio return and return to normal operation.
* Decreased Insulation Resistance
* Method: Measure the Windto ground insulation resistance with a meter. Omega ≥ 1000 (2500V range).
Abnormal Manifestations: Insulation resistance is below standard or significantly reduced compared to historical data (e.g. by more than 50%).
Risk: This may be due to humidity, aging or partial discharge of insulation. To dry or replace insulation materials, the system must be shut down immediately.
Example: The insulation resistance of a reactor dropped to 200 omega. Damage to the insulation at the end of the winding was found after the shutdown. After repair, the insulation resistance was restored to 1500 Omega.
IV. INTRODUCTION INTRODUCTION Appearances and Structural Abnormalities
** Damaged Outer Shell or insulation**
**Abnormal Manifestations:** Cracks or deformation of the outer shell and electrical arcs, cracks or creep on the surface of the insulator.
**Risk:** May lead to insulation failure, ground failure or short circuit. Damaged components require to be shut down and replaced immediately.
**Case study:** Discharge marks were found on the surface the reactor insulator. When closed, air bubbles form inside the insulator. Replacement eliminated the danger.
**Oil or Gas Spill**
**Abnormal Manifestations:** Decrease or leak of oil in oil leaching reactors and leakage of sealed gas in dry reactor.
**Risk:** Declining oil levels may lead to reduced insulation performance and gas leakage may affect reactor performance or cause explosions.
** Treatment:** Stop the engine immediately, add oil or seal leaks, and check for internal damage.
Protective device operation.
Differential Protection and Overcurrent Protection Operation
Abnormal Symptoms: Protective device alarms or tripping, indicating a short circuit or overload inside the reactor.
Risk: This may be due to internal short circuit, ground fault or system overvoltages. The reactor needs to be shut down for inspection and troubleshooting.
Case study: Differential protection of reactors. After shutdown, an on-ramp short circuit was detected in the winding. The reactor has been repaired and returned to operation.
Temperature protection operation
Abnormal Symptoms: temperature controller sound an alarm or trip, indicating that the temperature of the reactor is rising beyond its limits.
Treatment: Turn off the reactor immediately and check the cooling system (e.g., fans, vents) for blockages or internal malfunctions.