The 220kV Power Transformer Is Doing Testing Now

GNEE Steel power electronic transformer

What is lightning impulse voltage test：

In order to check whether the impact strength of main and longitudinal insulation of transformer meets the provisions of national standards and study and improve the insulation structure of transformer, impulse voltage test shall be carried out. The so-called lightning impulse test is to apply a shock wave simulating the real lightning waveform on the terminals of the transformer winding. Transformers or other electrical equipment shall be tested under the action of such shock wave to see whether they can pass (or damage). The cut-off wave is equivalent to the waveform generated by the flashover of protection gap or air insulation when the lightning wave enters the substation. It is the waveform in which the full lightning wave is suddenly cut off, and the voltage drops sharply to zero. The truncation time can occur in the wave front or wave tail. The wave cutting test is also a test of transformer equipment.

The test must have a device for generating shock wave. The device is called impulse voltage generator. Some corresponding measuring instruments mainly include measuring ball electrode, voltage divider and high-voltage oscilloscope for observing impulse waveform phenomenon. The standard specifies that the full wave of the test waveform is 1.2 ± 30% / 50 ± 20% μ S (wavefront / half peak time) and intercept time are 2-6 μ S The zero crossing coefficient of the truncated wave (i.e. the ratio of the first oscillation peak after truncation to the amplitude of the truncated wave) is in the range of 0.25-0.35. The impact test device is only available for large transformer plants and trial research units. General units can entrust the transformer to the trial research unit for test.

What is Power frequency withstand voltage test：

Power frequency withstand voltage test device is the basic test equipment for power stations, power supply and distribution systems, scientific research institutions and other users. It is used to test the insulation strength of various electrical products, electrical components and insulating materials under the specified voltage, assess the insulation level of products, find the insulation defects of tested products and measure the ability of overvoltage.

power adapter transformer