What are the main technical parameters of transformers?

Under the specified operating environment and conditions, the main technical data of transformers are generally marked on the nameplate of the transformer. Mainly including: rated capacity, rated voltage and its tap, rated frequency, rated performance data (impedance voltage, no-load current, no-load loss, and load loss), and total weight.

A、 Rated capacity (kVA): The capacity that can be transported during continuous operation at rated voltage and current.

B、 Rated voltage (kV): The working voltage that a transformer can withstand during long-term operation. In order to adapt to the needs of voltage changes in the power grid, the high-voltage side of the transformer has tap changer, and the output voltage on the low-voltage side is adjusted by adjusting the number of turns of the high-voltage winding

C、 Rated current (A): The current that a transformer is allowed to pass through for a long time at its rated capacity

D、 No load loss (kW): The active power absorbed when the rated voltage at rated frequency is applied to one winding terminal and the other windings are open circuited. It is related to the performance and manufacturing process of iron core silicon steel sheets, as well as the applied voltage

E、 Idle current (%): The current passing through the primary winding of a transformer when the secondary side is unloaded at rated voltage. It is generally expressed as a percentage of the rated current

F、 Load loss (kW): Short circuit the secondary winding of a transformer and apply rated current to the rated tap position of the primary winding, resulting in the power consumed by the transformer

G、 Impedance voltage (%): Short circuit the secondary winding of the transformer, gradually increase the voltage in the primary winding, and when the short-circuit current of the secondary winding is equal to the rated value, at this time

H、 Phase number and frequency: Three phases start with S, and single-phase starts with D. The Chinese national standard frequency f is 50Hz. There are countries with 60Hz frequency abroad (such as the United States).

I、 Temperature rise and cooling: The difference between the temperature of the transformer winding or upper layer oil and the temperature of the surrounding environment is called the temperature rise of the winding or upper layer oil. The temperature rise limit for oil immersed transformer windings is 65K, and the temperature rise of the oil surface is 55K. There are also various cooling methods: oil immersed self cooling, forced air cooling, water cooling, tube type, plate type, etc.

J、 Insulation level: There are insulation level standards. The insulation level of a transformer with a high voltage rated voltage of 35kV and a low voltage rated voltage of 10kV is represented as LI200AC85/LI75AC35, where LI200 represents the high voltage lightning impulse withstand voltage of 200kV, the power frequency withstand voltage of 85kV, the low voltage lightning impulse withstand voltage of 75kV, and the power frequency withstand voltage of 35kV. The insulation level of the current oil immersed transformer products of AUX High Tech Co., Ltd. is LI75AC35, which represents the high voltage lightning impulse withstand voltage of 75kV and the power frequency withstand voltage of 35kV. Since the low voltage is 400V, it can be ignored.