High voltage test transformer function:

① Generate power frequency high voltage to act on the insulation of the equipment under test to check whether the equipment under test works reliably under long-term working voltage and instantaneous overvoltage.

②Experimental research on high-voltage transmission line gas insulation, corona loss, electrostatic induction, long-string insulation flashover voltage, internal insulation partial discharge and live work, etc.

In addition, the gas insulation of high-voltage transmission lines is tested and studied. Corona discharge loss, static induction, high voltage between long strings of insulation. Required spare parts for items such as partial discharge and live working.

DC high voltage: the current that impacts high voltage, produces operating shock waves.

Indicators: The power frequency output greatly exceeds the transformer power frequency voltage rating, reaching several hundred kv, several thousand kv 2250kv-3000kv

The operating conditions of high-voltage test transformers and power transformers are different

Same principle, big change, different operating conditions

① Most work under capacitive load, and power transformers generally work under inductive load.

② The required test power is not large, so the transformer capacity is not large, and the power transformation capacity is large.

③ When working, it is often discharged, and the power transformation is provided by an electric protection device.

④ The power transformation operation is aggravated by the atmosphere and operating over-voltage, and the transformer is tested, but the sample is discharged, and a gradient over-voltage is generated on the winding during operation.

⑤ Short working time, shorter full-load operation, 1min withstand voltage test, full-load operation of the power transformer all year round.

⑥ The temperature is low, and the power transformer needs to be cooled by heat dissipation.

The operating conditions are favorable, the design safety factor is small, the test voltage of the test transformer itself is only 105%-11% of the rated voltage, and the test voltage of the power transformer is high.

The design temperature rise of the experimental transformer is also low, so it only runs for a short time, such as 5min.

Non-corona test transformer: to meet the needs of measuring the partial discharge of the insulation of power equipment. Some test transformers have very small partial discharge, and dpc is called a

Test the influence of voltage frequency and waveform. AC withstand voltage test-measuring the effective value of the instrument, power frequency discharge or breakdown-take the peak value of the voltage. National regulations-the test voltage should be 45-65hz AC voltage. Special test, low and or high and this range.

The waveform is an approximate sine wave with the same two half waves.

For this reason, we must pay attention to whether the voltage waveform output by the test transformer meets the requirements.