What aspects should be taken into consideration during the design of AIS voltage transformers?

Dyson

07/15/2025

I. Key Elements of Mechanical Structure Design

The mechanical structure design of AIS voltage transformers ensures long - term stable operation. For 66 kV outdoor AIS voltage transformers (pillar - type structure):

Pillar Material: Use epoxy resin casting + metal frame for mechanical strength, pollution/weather resistance. Special design needed for 66 kV (vs 35 kV & below). Dry - type insulation (porcelain/epoxy shell) requires sufficient bending/impact resistance for harsh outdoors.
Heat Dissipation: Rely on natural convection; ensure winding temperature rise ≤ 80 K. For electronic types, add forced air cooling/thermal materials (e.g., heat pipe modules control bus temp rise < 65 K at 40 °C, 14% below industry standards).
Anti - Vibration: Follow GB/T 20840.11 - 2025 (transport: 10 g vibration elements; post - transport checks). Use shock - absorbing brackets/damping materials (e.g., honeycomb cardboard + polyurethane foam; internal displacement < 1 mm under 3 g transport at 5000 m altitude).

II. Insulation Medium & Structure Design

Core to insulation performance, safety, and environmental - friendliness:

Sealing: Single - channel multi - seal groove (22% - 25% compression rate). EPDM “O” - rings, stainless steel welded tanks, double - layer O - rings ensure airtightness (annual leakage ≤ 0.5%). Comply with weld checks (X - ray, dye) and hydrostatic tests.
Insulation Structure: For electromagnetic types, use side - yoke cores or 3 - single - phase combinations. For capacitive types, optimize capacitor dividers/electromagnetic units. Meet electrical clearance/creepage (e.g., PD3: 12 kV system creepage ≥ 240 mm).

III. Environmental Adaptability Design

Ensures reliable outdoor operation:

Temperature: Operate at - 40 °C ~ + 55 °C (GB/T 4798.4). Use stable materials (silicone rubber/epoxy resin; 155 °C epoxy passes IEC 60216 - 1). Optimize heat dissipation (e.g., silver - plated copper bars pass 1000 - hour salt spray, contact resistance change ≤ 15%).
Anti - Pollution: Design per PD3 (high CTI epoxy, RTV coatings). E.g., polyurea coatings (≥ 1 mm) improve UV resistance 3x (QUV test: ΔE < 3 after 5000 h).
Anti - Aging: Verify via IEC tests (CTI, thermal aging, salt spray). Use tinned copper bars (≥ 15 μm; pass 56 - day damp - heat tests). Include protection (anti - aging/rust - resistant explosion - proof membranes; avoid water/frost heave).

IV. Safety Protection Design

Ensures system/equipment safety:

Fuses: Primary: RW10 - 35/0.5 (0.5 A, 1000 MVA breaking). Secondary: 3 - 5 A (protection), 1 - 2 A (metering); fusing time < protection action time.
Grounding: Follow “single - point grounding” (primary neutral, secondary at control room, tertiary open - delta). Comply with resistance standards (varies by type/scenario).
Explosion - Proof: Membrane bursting pressure = 2× rated (e.g., 66 kV: 0.8 MPa for 0.4 MPa rated). Use anti - aging/rust - resistant materials (polycarbonate/stainless steel); avoid water/frost heave.

VIII. Conclusions & Suggestions

AIS voltage transformer design requires comprehensive consideration of structure, insulation, environment, safety, and intelligence.

Design Tips: Pillar structure (epoxy + metal frame); heat dissipation (optimize convection, add cooling if needed); anti - vibration (shock - absorbing materials, test validation).
Safety: Fuses (matching specs), single - point grounding, explosion - proof membranes (2× rated pressure, anti - aging materials).

Future designs will focus on environmental - friendliness, intelligence, and digitization. Follow standards/specs to ensure stable operation.

Topics

AIS VT/PT Design and Simulation

Dyson

Focused on the design of electrical equipment, proficient in electrical principles and relevant specifications, and skilled in using design software. From intelligent substations to various types of electrical equipment, I am adept at optimizing design solutions, integrating new technologies. With practical experience and collaborative management capabilities, I deliver outstanding electrical design achievements.