35kv three-phase oil-immersed

Ⅰ. Production Process

1.The production process of rectifier transformers is a core link to ensure their adaptation to nonlinear rectifier loads, suppression of harmonic interference, and guarantee of long-term stable operation. It covers the entire process of precision control from raw material selection to finished product testing. The following is a detailed description of its main production processes:

①Silicon Steel Sheet Cutting:

CNC transverse shearing lines are used for precise cutting to ensure the sheet size deviation is ≤±0.1mm and the cutting burr is ≤0.02mm (to avoid increased eddy current loss).

②Iron Core Lamination:

The “non-laminated upper yoke” process is adopted (first laminating the iron core column, then inserting the upper yoke) to reduce lamination stress; the lamination factor is controlled between 0.96~0.97 (to improve magnetic conductivity).Insulating screws or binding tapes are used for fastening, with uniform fastening force (axial compression ≤1%) to avoid iron core vibration noise (no-load noise ≤65dB).

③Iron Core Grounding Treatment:

Single-point grounding (a grounding plate is led out from the bottom of the iron core) to prevent  caused by multi-point grounding; the grounding resistance is ≤1Ω.

④Iron Core Manufacturing Process:

The iron core is the core of the magnetic circuit, and the process focuses on reducing iron loss, minimizing noise, and ensuring structural strength.

⑤Winding Manufacturing Process:

The winding is the core of the circuit and needs to meet the requirements of voltage resistance, short-circuit resistance, low loss, and harmonic adaptation:Dry-type transformers: The windings are cast with epoxy resin (vacuum degassing ≤-0.095MPa, curing temperature 130℃×8h) to ensure no bubbles in the insulation layer (bubble diameter ≤0.5mm).Oil-immersed transformers: The windings undergo pre-drying (105℃×48h, vacuum degree ≤10Pa), and after dipping in paint, they are dried (120℃×24h) to improve the integrity of the insulation.

⑥Coil Design and Winding:

According to the phase-shifted rectification requirements (e.g., 12/24 pulses), multi-winding segmented winding is adopted to ensure the phase difference accuracy of each winding is ≤±0.5°.The low-voltage winding (rectifier side) is wound using the foil method (copper foil thickness 0.3~0.5mm) to improve heat dissipation efficiency; the high-voltage winding is wound using the continuous or  method to enhance insulation strength.