When baoding dry type transformer is running normally, the core must be reliably grounded. If there is no grounding, the suspension voltage of the iron core to the ground will cause intermittent breakdown and discharge of the iron core to the ground. The possibility of forming the suspension potential of the iron core is eliminated after the iron core is grounded. However, when the iron core is grounded at more than two points, the uneven potential between the iron cores will form a circulation between the grounding points, and cause the multi-point grounding fault of the iron core. The iron core grounding fault of the transformer will cause the partial overheating of the iron core. In serious cases, the partial temperature rise of the iron core will increase, and the operation of light gas will even lead to the tripping accident of heavy gas action. Part of the melted iron core formed a short circuit fault between the iron chips, resulting in a large iron loss, which seriously affected the performance and normal operation of the transformer and necessitated replacement of the iron core silicon steel sheet for repair. Therefore, multi-point grounding is not allowed in transformer, and only one point grounding is allowed. What is the scope of gas protection?
The scope includes:
1) polyphase short circuit inside the transformer.
2) short circuit between turns, short circuit between winding and iron core or shell.
3) iron core failure.
4) there will be oil or oil leakage under the oil surface.
5) poor contact of tap switch or weak wire welding.
What are the differences between differential and gas protection?
1. The main transformer differential protection is designed and manufactured according to the principle of circulating current, while the gas protection is designed and manufactured according to the feature that gas will be generated or decomposed when the transformer is in internal fault.
2. Differential protection is the main protection of transformer, and gas protection is the main protection in case of transformer internal failure.
3. Different protection scopes:
A differential protection:
1) polyphase short circuit occurs in the lead wire of the main transformer and the transformer coil.
2) single phase serious inter-turn short circuit.
3) the grounding fault of the protection coil and the lead wire in the high-current grounding system.
B gas protection:
1) polyphase short circuit inside the transformer.
2) inter-turn short circuit, inter-turn short circuit with iron core or external and.
3) iron core failure (heat loss).
4) there will be oil or oil leakage under the oil surface.
5) poor contact of tap switch or loose welding of wire
Baoding zhongyi electric material manufacturing co., LTD. Is a professional transformer manufacturer in baoding transformer factory. It has professional production equipment, lifting equipment, tooling and testing equipment.
Main products: baoding dry type transformer, baoding box type transformer, baoding oil immersed transformer, baoding high and low voltage complete sets of equipment, etc. I companies to follow "detail decides success or failure, honesty molded the future" of the enterprise purpose, adhere to "quality measuring market, seek development by innovation, to management for efficiency" business philosophy, to make my company's products are widely used in power plant, chemical, construction, mining, metallurgy, rail transportation and other industries, to meet the needs of various users, my company rely on superior product quality, thoughtful service, won the trust of our customers.
