The operating voltage of Electrical power transformer should not be higher than 105% of the operating tap voltage, and should not exceed the maximum operating voltage of the system. For special use, it is allowed to operate under rated voltage of not more than 110%.
The top oil temperature of oil-immersed transformer shall not exceed the operating rules or the requirements of the manufacturer. For forced oil circulation water-cooled transformers, the top oil temperature should not often exceed 700℃.
The Electrical Power Transformer with strong oil circulation cooling should be able to control the cooler according to the temperature and/or load.
Electrical Power Transformers in operation should always monitor the instructions of instruments and keep abreast of the operation of transformers in time. If defects or abnormal phenomena are found, measures should be taken to eliminate them in time. If it could not be eliminated at that time, surveillance must be strengthened. Prevent accidents from expanding. The countermeasures are determined as soon as possible.
1. Water supply mode of Transformer cooling water system
When transformer is loaded, the cooling water is usually taken from the technical water supply pipe of the unit. When no-load is running, the cooling water is usually taken from the common water supply pipe of the power station, and is pressurized to supply water to the transformer through the no-load cooling water pump.
2. Drainage mode of Transformer cooling water system
Normally, the cooling water of transformer under no-load and load is discharged to the draft pipe of the unit through the main drainage pipe of the technical water supply system of the unit. Connecting valves are provided for drainage pipes of transformers. When the connecting valve is normally closed, the draft tube of the unit is required to be emptied while the transformer is still operating under narrow load. The connecting valve between the transformer and the adjacent transformer can be opened, and the no-load cooling water can be discharged to the draft pipe of other units.