Triple Frequency Generator
Product Features
The triple frequency power generator, triple frequency voltage generator, and triple frequency high voltage generator are designed to meet the requirements of <>, <>, and <Regulations for Preventive Tests of Electrical Equipment>>—1995 for triple frequency induced voltage withstand tests and partial discharge tests.
The induced voltage withstand test for transformers and instrument transformers is an important test to verify whether the product meets national standards. The longitudinal insulation induction test of winding layers, turns, sections, and phase-to-phase insulation is an important item to verify whether the winding meets requirements. To increase the test voltage without causing excessive saturation of the transformer or instrument transformer core and excessive excitation current, the test frequency is usually increased to 100Hz—400Hz.
There are multiple methods to obtain a 100Hz—400Hz power supply, among which the most applicable are:
① Three variable frequency generator sets combined (100Hz—400Hz);
② Three single-phase transformers combined (150Hz), and the most convenient is the second method.
Three single-phase transformers combination method: the primary side is star-connected, and the secondary side is open delta. When the core is not saturated, the main flux it produces must be a flat-top wave. Since the flat-top waveform of the main flux contains a significant component of third harmonic magnetic energy 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 wave, it also contains higher harmonics. Among the higher harmonics, the amplitude of I is larger. 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, some 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
