Description
Very Low Frequency High Voltage Test Set For Cable And Generator , Ultra-low Frequency AC High Voltage Testing
Detailed Product Description
I. Product Description
This test set model VLF-90KV/0.1Hz is designed to perform on-site withstand voltage test with very-low frequency technology for power generators or 45KV and below XLPE power cable. Compared with Hipot test set at main power frequency, VLF HV Test Set just needs much small test power capacity(About 1/500 in theory). Its size and weight also is decreased greatly. Specially the appearance of surveillance can discover the generator insulation abnormal phenomena such as surface corona, discharge and so on.
Based on electronic frequency conversion and microprocessor controlled technology, Model VLF-90KV/0.1Hz has excellent performance.
It is prohibited to boost voltage without load, or to connect with resistive load. If the specimen capacitance is less than 0.05uF, the test set output waveform will be bad. For better performance, optional capacitor is necessary to connect.
Until now , the designed test set also forms many different serialized model according to different withstand test applications through HV booster number of configurations in each set, The alike model can see other typical model at following clause.
II. Product Feature
Electronic frequency conversion
Microprocessor Controlled
Two HV boosters, 90KV output in series; or 40KV/50KV for single one
Large LCD display
Sine Wave Output
Overvoltage protection, action time is less than20ms
Over current protection for both input and output side, action time is less than20ms
Output current/Voltagewave form is sampled at high voltage side directly
HV Current Limiting Resistor inside
Micro-printer inside
Output voltage will not be affected by capacitive current during test since closed-loop negative feedback design
III. General Technical Data
Output: 0~ 90KV(peak), continuously adjustable, output by shielded cable
Output frequency: 0.1Hz, 0.05Hz, 0.02Hz
Load range: 0.1Hz, ≤0.5μF ; 0.05HZ,≤0.1μF ;0.02HZ ≤2.5μF;
Measurement accuracy: 3 %
Positive and negative voltage peak errors: ≤ 3%
Voltage wave form distortion: ≤ 5%
Power supply fuse tube:20A
Time range:0-99min
Power Input:220V±5%,50/60Hz, stability of frequency: fluctuation less than 0.5%
Operation condition: Indoor and outdoor;
Temperature: -10C--+40C;
Humidity: ≤ 85%RH 7.
Controller:356mm×280mm×220mm, 4kg,1 Piece
40KV High voltage Booster:320mm×188mm×360mm,25kg, 1 Piece
50KV High voltage Booster:320mm×188mm×360mm,50kg, 1 Piece
IV. Typical Model
V. Test Voltage standard
1 For MV and below class XLPE cable:
Test peak voltage formula: Ｕmax＝3Ｕ0,
Ｕ0＝Single-phase rated voltage of cable
Test time :60mints
2 For generator stator
Ｕtest＝1.414*βKＵ0,
Utest---- 0.1Hz peak test voltage (kV);
β-------0.1Hz and 50Hz voltage equivalent factor, usually taking 1.2;
K------ Usually take 1.3 to 1.5, generally take 1.5;
Uo----- Generator stator windings rated voltage (kV).
