The 0.1Hz ultra-low frequency high voltage generator is a new type of ultra-low frequency AC test device that mainly uses cosine square wave as the output source. It is mainly used for non-destructive insulation withstand voltage tests on PE (polyethylene)/XLPE (cross-linked polyethylene) plastic power cables in the power sector. It combines modern digital frequency conversion technology, adopts microcomputer control, and the boosting, bucking, measurement, and protection are fully automated, with manual intervention possible during the automatic boosting process.
When conducting power frequency AC withstand voltage tests on cables and other test objects, due to their relatively large capacitance in the insulation layer, a large test transformer or resonant transformer is required. Such huge equipment is not only bulky and expensive, but also very inconvenient to use. To solve this contradiction, the power sector has adopted a lower test frequency, thereby reducing the current and the capacity of the test power supply. The current, voltage, and waveform data are all directly sampled from the high-voltage side, so the data is authentic and accurate.
Features of the 0.1Hz ultra-low frequency high voltage generator:
1. For rated voltages less than or equal to 50kV, a single-unit structure (one booster) is adopted; for voltages greater than 50kV, a series structure (two boosters in series) is used, greatly reducing the overall weight and enhancing load capacity. Moreover, the two boosters can be used separately as ultra-low frequency devices for lower voltage levels.
2. Digital frequency conversion technology and microcomputer control are adopted, making the test process fully automated.
3. Current, voltage, and waveform data are all directly sampled from the high-voltage side, ensuring accurate data.
4. Small size, light weight, simple wiring, and easy operation.
5. LCD with Chinese character display, automatic storage, and automatic printing.
6. Overvoltage protection: when the output exceeds the set voltage limit, the
instrument will shut down for protection, with an action time of less than 20ms.
7. Overcurrent protection: designed with dual protection for high and low voltage sides. The high-voltage side can perform precise shutdown protection according to the set value; the low-voltage side will shut down for protection when the current exceeds the rated current, with action times both less than 20ms.
8. The high-voltage output protection resistor is designed inside the booster, so no external protection resistor is needed.
9. Due to the adoption of a high-low voltage closed-loop negative feedback control circuit, there is no capacitive rise effect in the output.
10. Four-fold protection with rapid action (action time ≤20ms) for reliable guarantee.
11. Multi-frequency selection of 0.1Hz, 0.05Hz, and 0.02Hz, providing a wide test range.
Functions of the 0.1Hz ultra-low frequency high voltage generator:
★ Current, voltage, and waveform data are all directly sampled from the high-voltage side, so the data is authentic and accurate.
★ Overvoltage protection: when the output exceeds the set voltage limit, the instrument will shut down for protection, with an action time of less than 20 milliseconds.
★ Overcurrent protection: designed with dual protection for high and low voltage sides. The high-voltage side can perform precise shutdown protection according to the set value; the low-voltage side will shut down for protection when the current exceeds the rated current, with action times both less than 20 milliseconds.
★ The high-voltage output protection resistor is designed inside the booster, so no external protection resistor is needed.
★ Due to the adoption of a high-low voltage closed-loop negative feedback control circuit, there is no capacitive rise effect in the output.
