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What factors lead to inaccurate measurement results of DC high voltage generator

:2022-09-01 16:22:01:

DC high-voltage generator is widely used in the power testing department to conduct DC high-voltage test on high-voltage electrical equipment such as zinc oxide arrester, power cable, transformer and generator. It is an important equipment in the high-voltage testing industry. However, some factors may affect the accuracy of the test value. Let's analyze the factors that affect the test value:

1. Temperature effect: if the temperature is too high, the leakage current will be too large. When the temperature of the test product is controlled at 30-80 ℃, the test result is better. The leakage current changes more obviously in this temperature range. It should be reminded that, especially in low-temperature weather, if the test result is out of tolerance, the influence of the ambient temperature should be considered, and the test failure or product damage cannot be judged only.

2. Leakage current effect: if the leakage current is subdivided, it can be divided into volume leakage current and surface leakage current. The magnitude of surface leakage current depends on the influence of moisture on the external insulation surface of the test product. Clean the product surface, wipe it dry if necessary, or connect the shielding ring to effectively avoid excessive leakage current. In addition, the DC leakage test using the DC high voltage generator is to comprehensively analyze the tested object through the magnitude of the leakage current, the change of the leakage current during the continuous boosting process, and the stability of the leakage current during the test.

The high-voltage test is a destructive test, but it can find the defects that cannot be found by the non-destructive test, especially when there are small bubbles and non penetrating defects in the insulator. The disadvantage is that the insulation will be damaged during the test. This requires that the output test voltage be applied to different test objects in strict accordance with the regulations.

DC withstand voltage test is to judge whether the insulation material is qualified under the specified time and voltage, whether the insulation material is broken down and whether there is flashover.


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