1, winding fault
There are mainly inter-turn short circuit, winding grounding, phase-to-phase short circuit, disconnection and joint welding.
(1) Short circuit between turns: Short circuit failure due to insulation damage of the winding wire itself. The phenomenon of short circuit fault between turns is that when the turn-to-turn short circuit occurs, the temperature of the transformer overheating oil increases, and the current on the power supply side increases slightly; sometimes there is a "beep" sound and a "beep" sound in the oil, and when it is serious, Oil pillow injection; the cause of the short circuit fault between the turns is that the long-term overload of the transformer causes the insulation between the turns.
(2) Winding grounding: Winding grounding is a partial short circuit of the winding to ground. When the Baoding oil-immersed transformer winding is grounded, the transformer oil quality deteriorates. If the grounding for a long time will cause the grounding phase winding insulation to age and damage, the cause of the winding grounding, the lightning atmospheric overvoltage and the operating overvoltage cause the winding to be affected by the short-circuit current. Deformation, the main insulation is damaged and broken; the insulation strength of the transformer oil is reduced after damp.
(3) Phase-to-phase short-circuit: Inter-phase short-circuit means that when the insulation between the winding phases is broken, the short-circuit between the phases is short-circuited, the oil temperature of the transformer increases sharply, and the three-side switch of the oil-pumped fuel injection main transformer is turned off. The phase-to-phase short circuit of the transformer is due to the transformer. The main insulation aging insulation is lowered, the transformer oil breakdown voltage is low, or the inter-turn short circuit and ground fault of the winding are caused by the expansion of other faults. The arc and the molten copper (aluminum) particles are scattered and scattered, causing the accident to spread and expand. Developed as a phase-to-phase short circuit. When the phase-to-phase short circuit occurs, the dispatch dispatcher and the superior leader should be reported immediately, and the maintenance department should promptly check the cause of the fault and deal with it so that the transformer can resume operation as soon as possible.
(4) Winding and lead wire breakage: When the winding and the lead wire are broken, the arc often causes the transformer oil to decompose and vaporize, sometimes causing phase-to-phase short circuit. The reason is mostly due to poor welding inside the wire, overheating and melting or short circuit between turns. The winding is broken due to the breaking and short-circuit stress.
2, casing failure
The transformer casing is fouled, causing pollution flashes in heavy fog or light rain. The Baoding oil-immersed transformer makes the high-voltage side of the transformer single-phase or phase-to-phase short-circuit.
3, serious leakage
When the transformer runs leaking oil seriously or continuously overflows from the damage, the oil level gauge can no longer see the oil level. At this time, the transformer should be stopped immediately for trapping and refueling, causing the transformer to leak oil due to weld cracking or sealing. The piece fails, and the external force is shocked by the shock and the oil tank is seriously damaged and damaged.
4, tap changer failure
Common faults are poor contact or misalignment of the tap changer, melting and burn of the contact surface and discharge of the contacts or discharge of the taps.
(1) No-load tap-changer failure: The spring pressure of the unloaded tap-changer is insufficient, the roller pressure is uneven, the contact is poor, the effective contact area is reduced, and in addition, there is oil stain at the contact of the switch, and the contact resistance is increased, which will cause during operation. The contact surface of the tap is burnt. If the lead wire is connected or the soldering is poor, it will cause the tap changer to malfunction when it is impacted by the short-circuit current. The Baoding oil-immersed transformer fails to meet the predetermined requirements due to the incorrect voltage of the tap-changer. The three-phase voltage is unbalanced, generating a circulating current, increasing losses, causing transformer failure. The phase-to-phase insulation distance of the tap-changer tapping plate is not enough. The oil on the insulating material is piled up to be damp. When an overvoltage occurs, the tap-changer will also short-circuit the phase-to-phase.
(2) Faults with tap-changer: When the seal of the on-load tap-changer is not tight, the tap-changer will be short-circuited due to the intrusion of rainwater. The current-limiting impedance of the tap-changer may be broken down and burned during the switching process. Broken, the arc between the contacts may be longer and longer, causing the fault to expand, causing the transformer to malfunction. Because the tap changer sometimes gets stuck in the roller, the split switch is stopped at the transition position, causing a phase-to-phase short circuit. Because the additional fuel tank of the tap-changer is not tightly sealed, the oil in the fuel tank communicates with the oil in the transformer, so that the oil level of the tap-changer indicates a false oil level, which does not meet the standard requirements. When the tap-changer is energized, it will endanger the points. The safe operation of the switch.
Baoding Zhongyi Electric Material Manufacturing Co., Ltd. is a professional manufacturer of Baoding Transformer Factory producing transformers. It has professional production equipment, lifting, tooling and testing equipment, and has established a perfect quality management system. The performance indicators of the products have reached the standard. .
The company's main products: Baoding dry type transformer, Baoding box type transformer, Baoding oil immersed transformer, Baoding high and low voltage complete sets of equipment. Our company adheres to the enterprise tenet of "decision determines success or failure, integrity creates future", and abides by the business philosophy of "taking quality by market, innovation by development, management by benefit", which makes our products widely used in power plants, chemical industry, In the construction, mining, metallurgy, rail transit and other industries, to meet the needs of various users, our company relies on high-quality products, thoughtful and meticulous service, has won the trust of our customers.