Configuring a dry-type transformer requires systematic matching of its technical parameters, structural design, and accessory functions to the actual application scenario (e.g., industrial plants, data centers, commercial buildings) while ensuring compliance with safety standards, energy efficiency, and long-term reliability. Below is a step-by-step guide to configuration, covering core requirements, key parameters, structural options, and practical considerations.

　　1. Pre-Configuration: Clarify Core Requirements

　　Before selecting parameters, first define the application context to avoid mismatches. Key requirements to confirm include:

　　2. Core Technical Parameter Configuration

　　These parameters directly determine the transformer’s performance and compatibility with the power system.

　　2.1 Rated Capacity (kVA)

　　- Selection principle: Match the total active power of downstream loads, considering power factor (PF) and expansion margin.

　　Formula: `Rated capacity (kVA) = Total active load (kW) / Power factor (PF)`

　　- Example: If downstream equipment totals 800kW with PF=0.8, select a 1000kVA transformer (800/0.8=1000).

　　- Margin: Add 10–20% for future load growth (e.g., 800kW load → 1250kVA transformer for expansion).

　　- Derating factors: Reduce capacity if operating in extreme conditions:

　　- Altitude >1000m: Derate by 1% for every 100m increase.

　　- Ambient temperature >40°C: Derate by 2.5% for every 1°C increase.

　　2.2 Voltage Ratio & Tap Changer

　　- Voltage ratio: Determined by primary (input) and secondary (output) voltages.

　　Example: 10kV (primary) → 0.4kV (secondary) → Voltage ratio = 10/0.4 = 25:1.

　　- Tap changer: Compensates for grid voltage fluctuations (e.g., ±5% of rated voltage).

　　- On-load tap changer (OLTC): Adjusts voltage without power interruption (for critical loads like data centers).

　　- Off-load tap changer (OLTC): Requires power shutdown (for non-critical loads like general factories).

　　2.3 Connection Group (Vector Group)

　　Defines the phase relationship between primary and secondary windings, critical for harmonic suppression and system grounding. Common options:

　　2.4 Impedance Voltage (Uk%)

　　- Definition: Voltage drop percentage at rated current, reflecting short-circuit resistance and load capacity.

　　- Selection:

　　- Low Uk% (4–6%): Smaller voltage drop, better for sensitive loads (e.g., precision instruments).

　　- High Uk% (6–8%): Stronger short-circuit withstand capacity, better for industrial loads with frequent startups (e.g., motors).

　　2.5 Insulation Class & Temperature Rise

　　Dry-type transformers use class F or class H insulation (based on IEC 60076-11), which defines maximum allowable temperatures:

　　3. Structural & Accessory Configuration

　　3.1 Cooling System

　　Dry-type transformers rely on air cooling (no oil, fire-safe). Two main types:

　　3.2 Enclosure Design

　　Enclosures protect the transformer from dust, moisture, and physical damage. Select based on installation environment:

　　3.3 Protection & Monitoring Accessories

　　Critical for safety and predictive maintenance:

　　4. Compliance & Standard Validation

　　Ensure the configured transformer meets local and international standards to avoid safety risks and operational failures:

　　　5. Practical Configuration Example

　　Scenario: 1250kVA Dry-Type Transformer for a Data Center

　　6. Common Pitfalls to Avoid

　　1. Undersizing: Ignoring load expansion margin leads to long-term overload and premature failure.

　　2. Mismatched Connection Group: Using Yyn0 for non-linear loads (e.g., data centers) causes harmonic accumulation.

　　3. Neglecting Environmental Adaptation: Using IP20 enclosures in dusty factories leads to insulation degradation.

　　4. Overlooking Cooling Redundancy: Single-fan AF systems risk overheating if the fan fails.

　　By following this framework, you can configure a dry-type transformer that balances performance, safety, and cost while meeting the specific needs of your application. For complex scenarios (e.g., high-harmonic loads, extreme environments), consult with transformer manufacturers for custom solutions.