The 0.1Hz ultra-low frequency high-voltage generator is an instrument specifically designed for insulation withstand voltage tests of power equipment, especially suitable for large-capacitance devices such as power cables and large generators.
This device replaces the traditional 50Hz power frequency withstand voltage test by outputting a 0.1Hz ultra-low frequency high-voltage signal, significantly reducing the size of the test equipment and the required power supply capacity, making on-site tests more convenient and efficient.
Main Features
Compact and lightweight: The theoretical power supply capacity required is only 1/500 of that of power frequency test equipment, greatly enhancing portability.
High degree of automation: Controlled by a microcomputer, it can automatically complete voltage rise, voltage drop, measurement, and shutdown protection, making operation simple.
Reliable data: Key data such as current and voltage are directly sampled from the high-voltage side, avoiding errors caused by leads.
Complete protection functions: Equipped with overvoltage and overcurrent dual protection, with an action time of less than 20ms, ensuring the safety of the equipment and the test subject.
Good output waveform: Overcomes the problem of unstandardized waveforms in traditional mechanical generators and eliminates the “capacitance rise effect”.
Conventional technical parameters (reference)
The following are the reference technical parameters for common models, and the specific values may vary for different products:
Output voltage (peak): Multiple specifications such as 30kV, 50kV, 60kV, 80kV, etc., suitable for cables of different voltage levels.
Output frequency: 0.1Hz (common), 0.05Hz, 0.02Hz, multiple adjustable settings.
Load capacity: At 0.1Hz frequency, the maximum load capacitance is typically 0.5μF to 1.1μF, which can meet the testing requirements of cables several kilometers long.
Measurement accuracy: ±(3% full scale + 0.5kV).
Waveform distortion: ≤5%.
Working power supply: AC 220V ±5%, 50Hz.
Applicable environment: Temperature -10℃ to +40℃, humidity ≤85% RH.
Main application scenarios
Cross-linked polyethylene (XLPE) power cables: Used for handover or preventive withstand voltage tests of cables at 10kV, 35kV, etc., voltage levels, effectively detecting defects such as “water trees” in insulation.
Large high-voltage generators: The stator winding has a large capacitance to ground, making it suitable for withstand voltage tests using ultra-low frequency equipment.
Power capacitors: Used for AC withstand voltage tests of capacitors.
Core working principle
The ultra-low frequency high-voltage generator reduces the demand for power supply capacity by lowering the test frequency. The device first converts 220V, 50Hz power frequency electricity into a low-voltage signal with adjustable frequencies such as 0.1Hz through inverter and frequency conversion technology, and then boosts it to the required high-voltage level through a step-up transformer to provide the test voltage for the subject under test.
Selection method
Before purchasing or using, the following key points need to be confirmed:
Confirm the voltage level and capacitance of the subject under test
This parameter is the basis for selecting the higher output voltage and load capacity (larger output capacitance) of the generator. Common cable capacitance values can be estimated as follows:
10kV single-core cable: approximately 0.15 to 0.38μF/km.
35kV single-core cable: approximately 0.11 to 0.19μF/km.
Note the minimum load requirement
If the capacitance of the subject under test is too small (such as less than 0.05μF), it may not be able to output a standard waveform. Usually, a high-voltage capacitor of about 0.1μF needs to be connected in parallel to assist in the output.
Post time: Mar-25-2026