Stock Photo of Inflatable High-Voltage Test TransformerWorking Principle:
Power is input into the operation box, which has overcurrent automatic trip and zero-position interlock device to prevent sudden pressurization. The voltage is regulated by the auto-transformer and then input to the primary winding of the test transformer. According to the principle of electromagnetic induction, the secondary (high-voltage) winding can obtain a voltage amplitude - power frequency high voltage - that is equal to the multiple of the turns ratio between the secondary and primary windings. This power frequency high voltage can be rectified by a high-voltage silicon stack and filtered by a voltage-stabilizing capacitor to obtain DC high voltage, whose amplitude is twice the effective value of the power frequency high voltage.
Precautions:
1. When conducting high-voltage tests, at least 2 or more personnel must participate, with clear division of labor and mutual communication methods. A dedicated person should supervise the on-site safety and observe the test status of the sample;
2. The transformer and control box should be reliably grounded;
3. During the test, the voltage increase speed should not be too fast, and sudden full-voltage energization or de-energization is strictly prohibited;
4. During voltage increase or withstand voltage tests, if any of the following abnormal conditions are found, the voltage should be immediately reduced, the power should be cut off, the test should be stopped, and the cause should be investigated before resuming the test. ① The voltmeter pointer swings significantly; ② There is a smell of burning insulation or smoke; ③ There are abnormal sounds inside the tested sample.
5. During the test, if the sample is short-circuited or breaks down, the overcurrent relay in the control box will operate. At this time, the voltage regulator should be returned to zero, and the power should be cut off before the sample can be removed.
