The DC high voltage generator is a very good test instrument
In their daily work, electric power workers often need to conduct DC withstand voltage tests on electrical equipment, which requires the use of a DC high voltage generator (referred to as: DC high voltage generator). Especially when conducting DC withstand voltage and leakage current tests on lightning arresters, the DC high voltage generator is a very good test instrument. So, what other tests require the use of a DC high voltage generator? Below, we will briefly introduce the tests that the DC high voltage generator can be used for.
1. Insulation resistance test: Insulation resistance is the most basic insulation indicator for electrical equipment and circuits. When a DC voltage is applied to a dielectric, after a certain period of polarization process ends, the resistance corresponding to the leakage current flowing through the dielectric is called insulation resistance. When using a DC high voltage generator to apply voltage to the tested material, the current on the tested material does not instantly reach a stable value, but rather has a decay process. At the same time as applying voltage, a large charging current flows through, then the absorption current slowly decreases, and after a long period of absorption current, it finally reaches a relatively stable conduction current. The higher the measured resistance value, the longer the time required to reach equilibrium. Therefore, in order to correctly read the measured resistance value during the measurement process, it should be read after the value stabilizes.
2. DC withstand voltage and leakage test: For good insulation, the leakage current is very small under the action of DC voltage. At the same time, under the same DC voltage, the current passing through the insulation decreases with the extension of the applied voltage time. In the case of good insulation, as the applied DC voltage increases, due to the acceleration of ion movement, the leakage current will also increase. However, within a not too high voltage range, the leakage current increases linearly with the applied voltage, and the increase is very small.
3. Rubber and plastic cable DC withstand voltage test: The test voltage is 3 times the rated voltage of the cable. Under the specified test voltage (the test voltage increases by 0.5 times the rated voltage at each level, and each level stays for 1 minute, recording the leakage current; note: if the leakage current does not increase proportionally with the voltage, it must be analyzed and checked in time. Before the voltage, use a high-voltage megohmmeter to check the withstand voltage of the DC high voltage generator. The usage method is the conventional connection method: one phase is connected to one phase for withstand voltage, one phase is connected to one phase for withstand voltage, one phase is equipped with a withstand voltage device, the other phase is two-phase grounding, and the three-phase resistance is three times.
