What are the transformer accessories

The performance of these accessories directly determines the reliability, life and safety of the transformer.

1. The heart of the regulating system: On-Load Tap Changer (OLTC)

• Importance: This is inside the transformer.The only moving, most complex precision part. It is responsible for regulating the voltage when the transformer is running under power to ensure the stability of the grid voltage. Its reliability is the top priority of transformer reliability, and once it fails, it often needs to be overhauled by lifting cover, which causes huge losses.

• The "best" standard: Long switching times life (million times class), stable and reliable switching process, long maintenance intervals, excellent material selection (e.g. vacuum switching tube technology).

2. Insulation and connection system core: Bushing

• Importance: It is responsible for leading the high-voltage leads inside the transformer to the outside, as well as providing insulation and support. The bushing is one of the most important insulation weak points of the transformer, and its insulation breakdown is a common cause of transformer burnout or even explosion.

• The "best" standard: Excellent insulating properties, high dirt flash resistance, reliable sealing and high mechanical strength. Especially in the field of UHV/EHV.Dry capacitor casing (RIP/RIS casing) It is recognized as the most advanced and safest technology available.

3. Protection and monitoring system core

This type of accessory is the "nervous system" and "airbag" of the transformer, and is responsible for issuing an alarm or tripping the circuit breaker when an abnormality occurs to protect the transformer body.

• Gas Relay (Gas Relay / Buchholz Relay).

  • Importance: It is the main protection element for transformer internal faults, and can sensitively react to internal minor and serious faults (such as turn-to-turn short circuit, discharge, etc.). Known as the transformer's "sentinel".

  • The "best" standard: Sensitive and reliable action, no false alarm, good sealing, strong anti-vibration ability.

• pressure relief valve (Pressure Relief Device, PRD).

  • Importance: Transformer "safety valve". When a serious internal short circuit occurs, the tank pressure rises sharply, it can instantly open to release the pressure, to prevent the tank deformation or explosion.

  • The "best" standard: Precise opening pressure, quick action, good sealing of return seat, with signal contact.

• Reservoirs andoil level meter (Conservator & Oil Level Indicator).

  • Importance: The oil reservoir is used to compensate for the oil volume change caused by temperature change and to isolate the oil from air. The oil level meter shows the oil level visually, which is the key to determine whether the transformer is leaking or short of oil.

  • The "best" standard: Capsule Oil Storage CabinetIt can better isolate air and moisture, which is the mainstream and better choice at present. The oil level meter should indicate clearly and accurately, and the magnetic column type with remote signal transmission is more advanced.

4. Cooling system core: cooler (heat sink/strong oil air-cooled/water-cooled unit)

• Importance: It is responsible for radiating the heat generated during the operation of the transformer and controlling the temperature of the windings and oil, which directly affects the load capacity and service life of the transformer.

• The "best" standard: High heat dissipation efficiency, low power consumption of fan/oil pump, low noise, reliable operation and corrosion resistance.