Electrical Transformer Testing

Key points of electrical transformer testing:

  • Rated Capacity (KVA): The capacity to be transported in continuous operation under rated current and rated voltage.
  • Rated Voltage (KV):A operating voltage which transformers can withstand for a long time. In order to adapt to the needs of the power network voltage change, the high-voltage side of the transformer has tapped coil, through adjusting the high-voltage winding turn number to adjust the low-voltage side output voltage.
  • Rated current (A): The current which transformers allow long-term to pass under rated capacity.
  • No-load loss (KW): When the rated voltage of the rated frequency is applied to the terminal of a winding, the active power is absorbed by the rest of the winding. It is related to the voltage exerted by the performance and manufacturing process of the core silicon steel sheet .
  • No-load current (%): When the transformer making side no-load twice at the rated voltage, the current pass through the winding . Generally, it expressed as a percentage of the rated current.
  • Load loss (KW): Make the two winding of the transformer short circuit. The rated current is connected at the rated position of a winding, and the power consumed by the transformer at this time is load loss.
  • Impedance voltage (%): Make the two winding of the transformer short circuit, in a winding slowly rising voltage. When the short circuit current of the two windings is equal to the nominal value, the voltage applied at the first side is generally expressed as a percentage of the rated voltage.
  • Phase and frequency: The three-phase opening is indicated by S, and the single-phase begins with D. China National standard frequency f is 50 Hz. Foreign countries have 60 Hz (such as the United States).
  • Temperature rising and cooling: The difference between the transformer winding or the temperature of the upper oil and the ambient temperature of the transformer are called the temperature rising of the winding or the surface of the upper oil. The ceiling value temperature of the oil-immersed transformer winding is 65K and temperature rising of the oil surface is 55K. There are many ways of cooling: oil-soaked from cold, forced air cooling, water-cooled, tubular, chip and so on.
  • Insulation level: Has the standard of insulating grade.
  • Coupling group marking: According to the phase relationship of transformer's first winding and second winding, the transformer winding are connected into various combinations, which called winding.
  • Physical indicators: Weight, volume (L, W, H)

  • Performance Characteristics of Oil Immersed Power Transformer a. The low voltage winding of oil immersed type transformer adopts copper conductor when it is of small captivity and it generally adopts the cylinder structure of copper foil winding shaft. High volt...
  • Basic Concept of Mining Transformer In order to adapt to the use under the mine, the firm structure and short shape of the transformer is required. The transformer is not equipped with an oil conservator. There is a proper space above t...
  • Characteristics of the Encapsulated Dry Type Transformer The encapsulated dry type transformer is widely used in local lighting, high-rise buildings, airports, CNC machinery equipment of wharf and other places. Simply speaking, an encapsulated dry type tran...