First, let’s understand what they have in common: the role of the ultra-low frequency high voltage generator and the DC high voltage generator is to detect hidden defects in the insulation of electrical equipment, so as to understand and grasp the insulation status of the equipment to ensure the safe and reliable operation of high voltage electrical equipment. . Assess the equipment's ability to withstand overvoltages, artificially simulate various overvoltages, and test the insulation of the equipment to verify its ability to withstand.
The difference between the ultra-low frequency high voltage generator and the DC high voltage generator:
Measure the difference of the test product
The ultra-low frequency high voltage generator is suitable for withstand voltage test items of electrical equipment with large insulation equivalent capacitance, such as measuring power cables, power capacitors, medium-sized generators and motors, etc.) withstand voltage test. The ultra-low frequency insulation withstand voltage test is actually an alternative method of the power frequency withstand voltage test. Because when using the power frequency withstand voltage method to measure large-capacity equipment, a large-capacity test transformer or resonant transformer is required. This leads to very inconvenient use. In order to solve this contradiction, the electric power department adopted to reduce the test frequency and the capacity of the test power supply. According to the theory and practice for many years at home and abroad, the 0.1Hz ultra-low frequency withstand voltage test was used to replace the power frequency withstand voltage test. The pressure test not only has the same equivalence, but also the size of the equipment is greatly reduced, and the weight is greatly reduced. Theoretically, the capacity is about one-fifth of the power frequency, which is more superior than the power frequency test.
The DC high voltage generator is a relatively common DC withstand voltage device in the power preventive test equipment. The early DC high voltage generator can be used for the DC withstand voltage test of the power cable to check the insulation performance of the cable. However, with the power preventive test The research found that the insulation performance of the cable under the DC state is not perfect, and the hidden damage to the cable is greater. The use range of the slow DC high-voltage generator is limited to a certain extent. At this stage, the DC high-voltage generator is mainly used for Measure the leakage current of the zinc oxide arrester or act as a DC power supply.
The design principles of the ultra-low frequency high voltage generator and the DC high voltage generator are similar, including the control part, the high voltage generation part, and the voltage divider measurement part. From the point of view of technical parameters, the big difference between the two is that one is to generate a DC high voltage; the other generates a high voltage with a frequency of 0.1HZ, which is approximately DC.