Vlf (Very Low Frequency) 50kv Portable AC Hipot Test System

VLF(Very Low Frequency) 50kV Portable AC Hipot Test System

I. Introduction
1. VLF (Very Low Frequency) Testers are suitable for testing power cables, transformers, switchgear, rotating machinery and other electrical apparatus.
2. VLF (Very Low Frequency) Testers combines modern advanced digital variable frequency technology and micro computer control together, therefore, it can realize the full automatic voltage boost, stepdown, measurement and protection as well as the manual intervention in the process of automatic voltage boost. The full electronic design ensures the small size and light weight. The big LCD screen ensures the clear and visual display, and can display the output sinusoidal wave form. The printer outputs test reports.

II. Features

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
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