Transformer is a variety of functions and efficiency, for the transformer is an important electrical equipment, it is in the process of use should pay attention to the design of related parameters, for the transformer common technical parameters what? How does it work?
A, rated capacity (kVA) : rated voltage. Rated current continuous operation, the capacity to transport.
B. Rated voltage (kV) : the working voltage that can be borne by the transformer when it runs for a long time.
C. Rated current (A): the current allowed to pass through the transformer for A long time at the rated capacity.
D. no-load loss (kW): the active power absorbed when the rated voltage at the rated frequency is applied to the terminals of one winding and the other windings are opened. It is related to the properties, manufacturing process and applied voltage of the iron-core silicon steel sheet.
E. No-load current (%): the current passing through the primary windings when the transformer is no load at the secondary side at rated voltage, which is generally expressed as a percentage of the rated current.
F. Load loss (kW): short circuit the secondary windings of the transformer and enter the rated current at the rated tapping position of the primary windings. The power consumed by the transformer at this time.
G. Impedance voltage (%) : short-circuit the secondary windings of the transformer and slowly increase the voltage in the primary windings. When the short-circuit current of the secondary windings is equal to the rated value, the voltage applied on the primary side is generally expressed as a percentage of the rated voltage.
H, phase number and frequency: the three-phase phase is represented by S, while the single-phase phase is represented by D. China's national standard frequency f is 50Hz. There are 60Hz countries abroad (such as the United States).
I. temperature rise and cooling: the difference between the temperature of the transformer windings or the upper oil temperature and the ambient temperature of the transformer is called the temperature rise of the windings or the upper oil surface. The temperature rise limit of the oil-immersed transformer windings is 65K and that of the oil surface is 55K. There are also a variety of cooling methods: oil immersed self-cooling, forced air cooling, water cooling, tube type, chip type, etc.
J. Insulation level: there is insulation grade standard. Examples of the expression of insulation level are as follows: High pressure level of 35 kv rated voltage, low voltage level is rated voltage 10 kv transformer insulation level is expressed as LI200AC85 / LI75AC35, including LI200 said the transformer high-voltage lightning impulse withstand voltage is 200 kv, power frequency withstand voltage is 85 kv, low voltage lightning impulse withstand voltage is 75 kv, power frequency withstand voltage of 35 kv, oakes high-tech co., LTD. The insulation level of the oil-immersed transformer products for LI75AC35, said transformer high-voltage lightning impulse withstand voltage is 75 kv, power frequency withstand voltage of 35 kv, Because the low pressure is 400V, we don't have to worry about it.
Label of connection group: the transformer windings are connected into various combinations according to the phase relationship of the primary and secondary windings of the transformer, which is called the connection group of the windings. To distinguish different link group, often using the clock notation, namely the high voltage side voltage phasor as long needle of the clock, fixed on 12, low voltage side voltage phasor as clock short needle, to see where short needle refers to a number, as the link set of the label. As Dyn11 said is a winding (triangle), secondary winding is with center (star), group number (11).
Transformer parameters are very many, to constantly understand the transformer common technology and parameters, and constantly improve the performance and efficiency of the transformer, so that the transformer will play a great role, there will be greater performance improvement.
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