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.

2. Test and research high-voltage transmission lines gas insulation, corona loss, electrostatic induction, long string insulation flashover voltage, internal insulation partial discharge and live work and other items must be spares, and also test and research the gas insulation of high-voltage transmission lines, corona discharge loss, Necessary spare parts for static induction, high voltage between long string insulation, partial discharge and live working.

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

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

High-voltage test transformers and power transformers have different operating conditions, the same principles, large changes, and 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 the operating overvoltage, and the transformer is tested, but the sample is discharged and a gradient overvoltage is generated on the winding during operation.

⑤ Short working hours, 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 transformation requires heat dissipation and cooling.

The operating conditions are favorable and the design safety factor is small. The test voltage of the test transformer itself is only 105%-11% of the rated voltage. The test voltage of the power transformer is high, and the design temperature rise of the test transformer is also low, so it only runs for a short time such as 5 minutes.

Corona-free test transformer: In order to meet the needs of measuring the partial discharge of the insulation of power equipment, some test transformers have very small partial discharges, and the influence of the test voltage frequency and waveform. AC withstand voltage test-the effective value of the instrument measured power frequency discharge or breakdown -Take the peak voltage.

The waveform is similar to a sine wave with the same two half waves. For this reason, attention must be paid to whether the voltage waveform output by the test transformer meets the requirements.