1. Transformer manufacturers share the main technical parameters of transformers:
Under the specified use environment and operating conditions of the transformer, the main technical data are generally marked on the nameplate of the transformer. It mainly includes rated capacity, rated voltage and its separation, rated frequency, winding connection group, rated performance data (impedance voltage, no-load current, no-load loss and load loss) and total weight.
a. Rated capacity (kVA): rated voltage. The capacity that can be delivered during continuous operation of the rated current.
b. Rated voltage (kV): The working voltage that the transformer can withstand when working for a long time. In order to meet the needs of grid voltage changes, the high-voltage side of the transformer has a tap, and the low-voltage side output voltage is adjusted by adjusting the number of turns of the high-voltage winding.
c. Rated current (A): The current that the transformer allows to pass for a long time under the rated capacity.
d. No-load loss (kW): rated voltage at rated frequency, applied to the terminals of one winding, and the effective power absorbed when the other windings are open. It is related to the performance of the iron core silicon steel sheet, manufacturing process, and applied voltage.
e. No-load current (%): When the transformer is at rated voltage and the side is no-load, the current passing through the winding is usually expressed as a percentage of the rated current.
f. Load loss (kW): When the secondary winding of the transformer is short-circuited, the transformer manufacturer believes that the rated current passes through the rated tapping position of the primary winding. At this time, the power consumed by the transformer.
g. Impedance voltage (%): When the secondary winding of the transformer is short-circuited, the voltage is slowly increased from the primary winding, and the short-circuit current of the secondary winding is equal to the rated voltage applied to the primary side. Usually expressed as a percentage of rated voltage.
h. Phase and frequency: The three-phase starting point is represented by s, and the single-phase starting point 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 temperature difference between the temperature of the transformer winding or upper oil and the surrounding environment of the transformer is called the temperature rise of the winding or upper oil surface. The temperature rise limit of the oil-immersed transformer winding is 65K, and the oil surface temperature rises to 55K. There are also various cooling methods: oil self-cooling, forced air cooling, water cooling, tubes, chips, etc.
j. Insulation level: There are insulation grade standards. The insulation level is displayed as follows: the insulation level of a transformer with a high voltage rated voltage of 35kV and a low voltage rated voltage of 10kV is LI200AC85/LI75AC35. Among them, LI200 is a transformer with high voltage lightning impulse withstand voltage of 200kV, power frequency withstand voltage of 85kV, and low voltage lightning impulse withstand voltage of 75kV. The power frequency withstand voltage is 35kV. The current insulation level of Oaks High-Tech Co., Ltd.'s oil-immersed transformer products is LI75AC35. The high-voltage lightning impulse withstand voltage of the transformer is 75kV, the power-frequency withstand voltage is 35kV, and the low voltage is 400V, which can be ignored. k, connection group label: transformer 1. According to the phase relationship of the secondary windings, the transformer windings are connected to various combinations, which are called connected groups of windings. To distinguish between different connectomes, clock notation is often used. That is to say, the amount of the high-voltage side line voltage is fixed on the long needle of the clock, which is fixed on 12, and the amount of the low-voltage side line voltage is used as the short needle of the clock. If you look at which number the short needle is, it is used as the corresponding connection group. Tag of.
transformer
