Used for AC induced withstand voltage tests on 35-220kV class transformers and voltage transformers, assessing the graded insulation level of 35-220kV class transformers and voltage transformers.
SSF Triple Frequency Withstand Voltage Tester Detailed Introduction
Product Features
Triple frequency power generator, triple frequency voltage generator, triple frequency high voltage generator. This product is designed to meet the requirements of <>, <> and
The induced withstand voltage test for transformers and instrument transformers is an important test to verify that the product meets national standards. The longitudinal insulation induction test of winding interlayer, inter-turn, section and phase-to-phase insulation is an important item to verify whether the winding meets requirements. In order to increase the winding test voltage without causing the transformer or instrument transformer core to saturate excessively and lead to excessive excitation current, the test frequency needs to be increased, generally to 100Hz—400Hz.
There are various methods to obtain a 100Hz—400Hz power supply, among which the more applicable ones are:
① Combination of three variable frequency generators (100Hz—400Hz);
② Combination of three single-phase transformers (150Hz), and the most convenient is the second method
Combination method of three single-phase transformers: the primary side is star-connected, and the secondary side is open-delta. When the iron core is not saturated, the main magnetic flux it produces must be a flat-topped wave. Since the main magnetic flux of the flat-topped waveform contains a large component of third harmonic magnetic energy Φ3, and the third harmonic magnetic flux frequency f3=3f1, the main magnetic flux induces a third harmonic phase electromotive force.
Since the primary side is star-connected and the secondary side is open-delta connected, the iron core operates in a saturated state, and the no-load current I presents a peaked wave. In addition to the fundamental wave, it also contains higher harmonics. Among the higher harmonics, the amplitude of I is relatively large. Due to the open secondary, the three-phase fundamental components cancel each other out, leaving only the third harmonic output.
The entire machine's voltage output is achieved by tuning to resonance under a 150Hz power supply. When the voltage rises, a certain squealing sound during resonance is normal.
Technical Parameters
Rated capacity: 5-100kVA
Input: three-phase 380V, 50Hz sine wave
Output: 0-300V, 0-500V, 0-1000V (custom voltage available), 150Hz,
Waveform distortion ≤1%
Capacity: 3-150kVA
No-load operation time: ≤5 minutes
Load operation time: 40-60 seconds
