Such huge equipment is not only bulky and expensive, but also very inconvenient to use. To solve this contradiction, the test frequency is reduced, thereby reducing the capacity of the test power supply. Years of theory and practice at home and abroad have proven that the 0.1Hz ultra-low frequency withstand voltage test can replace the power frequency withstand voltage test, not only with equivalent effectiveness, but also with greatly reduced equipment size and weight. The capacity is about one five-hundredth of that at power frequency, and the test procedure is greatly simplified. Compared with power frequency testing, it has more advantages, which is why developed countries commonly adopt this method. China's Ministry of Electric Power has commissioned the Wuhan High Voltage Research Institute to draft the industry standard "Ultra-low Frequency (0.1Hz) Withstand Voltage Test Method for 35KV and Below Cross-linked Polyethylene Insulated Power Cables." China is currently promoting this method, and this instrument has been developed based on this national need. It can be widely used in AC withstand voltage tests for cables, large high-voltage rotating motors, and power capacitors.
It has power supply overcurrent, high-voltage overcurrent, protection functions, and functions such as the inability to start high voltage if the output voltage regulator is not returned to zero. It is a replacement product for traditional power frequency withstand voltage testing equipment. The ultra-low frequency AC withstand voltage device is a new type of ultra-low frequency AC testing device that mainly uses sine wave orcosine square wave as the output source. It is mainly used for non-destructive insulation withstand voltage testing of PE (polyethylene)/XLPE (cross-linked polyethylene) plastic power cables in the power sector. It has reached the international advanced level of the late 20th century and the domestic leading level.
1. Output voltage: (KV) 30, 50, 80
2. Output frequency: 0.1Hz, 0.05Hz, 0.02Hz
3. Load capacity: 0.1 Hz max 1.1uF
0.05 Hz max 2.2uF
0.02 Hz max 5.5uF
4. Measurement accuracy: 2.5%
5. Voltage positive and negative peak error: ≤2.5%
6. Voltage waveform distortion: ≤5%
7. Operating conditions: indoor and outdoor; temperature: -10℃∽+40℃; humidity: ≤85%RH
8. Power supply: AC 50 Hz, 220V ±5%
