Vlf AC Hipot Tester for Power Cable and Generator Insulation Test

VLF AC Hipot Tester for Power Cable and Generator Insulation Test


I. Description of VLF AC Hipot Tester
1) Ultra-low Frequency Insulation Withstand Voltage Test is actually an alternative method of power
Frequency withstand voltage test. As we know, when power frequency withstand voltage test
To large generators and cable, it needs testing transformer or resonant transformers with large
Capacity because their insulation layer are with big capacitance. Such huge equipment, not only
Weight heavy, high cost and application is also inconvenient. In order to solve this problem,
Power Sections adopt reducing the test frequency, thus reducing the capacity of the test power
Supply.
2) With many years of theory and practice at home and abroad, it has been proved that, by 0.1 Hz
AC withstand voltage test alternative power frequency withstand voltage test, not only can have
The same equivalence, but also have much less volume of equipment and greatly reduce the
Weight. Theoretically, capacity is about one over five hundred of the power frequency. Short test
Time, and compared with the power frequency test, this method has more superiority. Many
Developed countries have been using this method.

II. Features of VLF AC Hipot Tester
1. Integrated with advanced technology of modern digital frequency conversion, adopt computer
Controlling, step-up, step-down, measuring, fully automatic protection.
2. All are electronic, small volume, light weight.
3. Large screen LCD display, clear and intuitive, and display the output waveform, test reports print out.
4. Operation is simple and convenient. Design criterions are in full compliance with the electric
Power industry standards "General Technical Conditions of Special Test Instrument in Power Equipment,
Part 4: Ultra-Low Frequency High Voltage Generator General Technical Conditions".
5. The current, voltage, waveform data are directly gained from the high voltage side, sampling, so the
Data is accurate.
6. With over voltage protection function, when the output is over the set value, the instrument will stop
And begin protection, action time is less than 20ms.
7. With over-current protection function: Double protection design for high and low voltage, high side can precisely protect according to set value; When low voltage current is over the set value, the instrument will stop and begin protection, action time is less than 20ms.
8. High voltage output insulation is designed into the step-up device, so no need to connect other external protective resistance. The adoption of high and low voltage closed loop feedback control circuit, so the output without capacitance-up effect.

III. Specifications of VLF AC Hipot Tester
1. Max voltage output: Refer to table 1
2. Output frequency: 0.1Hz, 0.05Hz, 0.02Hz
3. Measurement error < 3%RDG+0.3%FS
4. Positive and negative voltage peak errors < 3%RDG+0.3%FS
5. Power supply: AC220V ± 10%, 50Hz/60Hz
6. Voltage wave form distortion: <5%
7. Environment temperature: 050C
8. Humidity: ≤ 85RH