Dielectric Loss Test DiagramWorking Principle:
Input the power supply into the operation box equipped with overcurrent automatic tripping and zero-position interlock device to prevent sudden voltage application. Adjust the voltage through the auto-transformer and input it to the primary winding of the test transformer. According to the principle of electromagnetic induction, a voltage amplitude equal to the turns ratio between the secondary (high-voltage) winding and the primary winding can be obtained - power frequency high voltage. This power frequency high voltage can be rectified by the high-voltage silicon stack and filtered by the 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. There should be a dedicated person to supervise the site safety and observe the test status of the test object;
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 absolutely not allowed;
4. During the voltage increase or withstand voltage test, if any of the following abnormal conditions are found, the voltage should be immediately reduced, and the power should be cut off to stop the test. After identifying the cause, the test can be resumed. ① The voltmeter pointer swings significantly; ② An odor of insulation burning or smoke is detected; ③ Abnormal sounds are heard inside the test object.
5. During the test, if the test object is short-circuited or breaks down, the overcurrent relay in the control box will operate. At this time, return the voltage regulator to zero, cut off the power, and only then can the test object be removed.
