Tag Archives: High Power Transformer

Power industry, from power generation to transmission to the distribution, will be used in a product that is . Transformers throughout the power system, modern society, the various sectors of the high demand for electricity stability, security, in the past ordinary transformer has exposed its drawbacks, in particular, the transformer leakage problems, the transformer of the power industry bottlenecks. Dry-type transformers came into being.

      Dry-type transformers: to rely on air convection cooling, generally used for local lighting, electronic circuits and other small capacity transformers in the power system, turbine change, Boiler ash variable change dust desulfurization change are the dry type transformer ratio the is 6000V/400V, used to load with a rated voltage of 380V. Simply put, the dry-type transformer is the core and the windings are not impregnated with insulating oil in transformers. In engineering design, electrical engineers in the selection of dry-type transformers to note the following:

      The temperature control system for a dry-type transformer

      Safe operation and service life of dry-type transformers, depends largely on the safety and reliability of the transformer winding insulation. Winding temperature exceeds the insulation to withstand temperature, insulation damage, is one of the main reason leading to the transformer can not work properly, so the transformer operating temperature monitoring and alarm control is very important.
      Fan automatic control: (1) embedded in low-voltage winding hottest at the Pt100 thermistor temperature resistance measurements take the temperature signal. Transformer load increases, the increase in operating temperature, when the winding temperature reaches 110 ?, the system automatically starts the cooling fan; when the winding temperature as low as 90 ° C, the system automatically stops the fan.
      (2) over-temperature alarm trip: PTC nonlinear embedded in low-voltage winding temperature thermal resistance acquisition winding or core temperature signal. When the transformer winding temperature continues to rise, to approximately 155 ° C, the system output over-temperature alarm signal; if the temperature continues to rise up to 170 ° C, the transformer can not continue to run required secondary protection circuit transmission overtemperature trip signal, the transformer should be rapid trip.

      Second, the protection of dry-type transformers

      Environmental characteristics and protection requirements, dry-type transformers can choose a different shell. IP20 protective shell is usually used to prevent a dia greater than 12mm of solid foreign bodies and rats, snakes, cats, birds and other small animals into, resulting in short-circuit power outages and other vicious failure to provide a safe barrier for the live parts. Shall transformer installed outdoors can use an IP23 enclosure, in addition to the IP20 protection function, but also prevents water droplets into the vertical line within a 60 ° angle. IP23 enclosure transformer cooling capacity will drop, when used to pay attention to the reduction of its operating capacity.

      Overload capacity of the three dry-type transformers

      Overload and ambient temperature of the dry-type transformers, overload, load (initial load), transformer thermal insulation and heating time constant, if necessary, dry change over the load curve to be obtained from the production plant. After the study, experts found that the dry-type transformers Oil Immersed Transformers absolute advantage in the power plant. Modern coal-fired power plants, steam turbine power generation system the generated power for the first time the transformer, most of the dry-type transformers. The dry-type transformers in more fields to human convenience.