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 TesterDetailed 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, segment, and phase-to-phase insulation is an important item to assess whether the winding meets requirements. To increase the winding test voltage without saturating the transformer or instrument transformer core excessively, which would cause excessive excitation current, the test frequency needs to be increased, typically to 100Hz—400Hz.
There are several methods to obtain a 100Hz—400Hz power supply, among which the most applicable 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 core is not saturated, the main magnetic flux it produces must be a flat-topped wave. Since the flat-topped main magnetic flux contains a significant third harmonic component Φ3, and the third harmonic flux frequency f3=3f1, the main flux induces a third harmonic phase electromotive force.
Since the primary side is star-connected and the secondary side is open-delta, the core operates in a saturated state, and the no-load current I is a peaked wave. In addition to the fundamental component, it 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 voltages available), 150Hz,
Waveform distortion ≤1%
Capacity: 3-150kVA
No-load operation time: ≤5 minutes
Load operation time: 40-60 seconds
