2.5mva Mineral Oil Pad Mounted Power Transformer

Mineral oil serves as the insulation and cooling medium, and is the most traditional and mature insulation fluid choice in the power transformer industry. So 2.5mva mineral oil pad mounted power transformer possesses excellent electrical insulation performance, good thermal conductivity, and cost effectiveness advantages. Compared to alternative insulation fluids such as natural esters, although mineral oil has a lower ignition point, it has better low temperature fluidity and higher reliability in cold regions during operation.

The plug in transformer supports two types of incoming line: The first is the ring network feeder type, which is equipped with two sets of primary bushings (a total of 6, for both incoming and outgoing lines) and an internal four position load switch. It can connect the transformer in series to the ring network circuit, enabling fault isolation and non stop maintenance. The 2.5mva mineral oil pad mounted power transformer is usually recommended for this configuration.The radial feeder type is only equipped with one primary bushing and provides single line power supply, with lower cost but reduced reliability accordingly.

The short circuit impedance is an important parameter of a transformer, directly affecting the level of system short circuit current and voltage regulation rate. The typical impedance value of a pad mounted power transformer is 5.0% to 7.5%, and the design target value is usually set at 5.75%. An impedance of 5.75% means that when a three phase short circuit occurs on the secondary side, the short circuit current is approximately 1/0.0575 of the rated current, which is approximately 17.4 times the rated current. Taking the 400V low voltage side as an example, the rated current is approximately 3608A, and the short circuit current is approximately 62.8kA, which is within the range that medium voltage switchgear can withstand.

During full load, the voltage drop is approximately 5.75%, which is acceptable for general industrial loads. According to the IEC 60076 standard, 2.5mva mineral oil pad mounted power transformer has the short circuit capability to withstand thermal effects and dynamic stability effects.

Technical parameter:

Q: For a 2.5mva mineral oil pad mounted power transformer, why is it still necessary to pay attention to its no load loss when it is operating under light load or no load conditions for a long time?

A: Since the no load loss mainly consists of two parts:First, hysteresis loss: the energy loss generated when the iron core is repeatedly magnetized in an alternating magnetic field. Second, eddy current loss: the heat loss caused by the circulating current induced in the iron core by the alternating magnetic field.

Even if the secondary side of the power transformer is completely open circuited or in an unloaded state, its primary side still consumes a constant amount of no load loss. And the no load loss leads to quantifiable and continuously accumulating electricity bills. For scenarios with a running time of over 3000 hours, when selecting the model, priority should be given to those with lower no load losses (such as using high magnetic conductivity oriented silicon steel sheets or amorphous alloy cores). Even if the initial procurement cost increases by 15 to 20%, the difference can be recovered through electricity cost savings within two years.

Equipment

Product Detial

Ring Type

Terminal Type

Transformer Body

Product in Process

Test Center

Winding Workshop