The Application and Technical Analysis of Transformers in Photovoltaic Power Generation Systems

1. Why Do PV Plants Need Transformers?

PV arrays typically output 800V~1500V DC, while grid connection requires 10kV/35kV AC. Transformers perform:

• Voltage Boosting: Steps up inverter output to grid voltage

• Electrical Isolation: Ensures safe separation between plant and grid

• Harmonic Suppression: Filters high-frequency harmonics (THD <3%)

2. Technical Features of PV-Specific Transformers

• Dual-Split Winding Design: Balances dual-inverter input, reducing circulating losses

• ±5% On-Load Tap Changer: Accommodates daily voltage fluctuations (PV output varies up to 30%)

• C5 Anti-Corrosion Rating: Withstands harsh environments (desert/coastal)

• Efficiency ≥99% (Compliant with IEC 60076-57-1202)

3. Key Selection Criteria

4. Common Issues & Solutions

• Issue 1: Nighttime Backfeed
  ▶ Solution: Install reverse-power protection (response time <0.5s)

• Issue 2: Inadequate Cooling
  ▶ Solution: Amorphous core (reduces no-load loss by 70%)

5. Industry Trends

• Smart Monitoring: Integrated temperature/vibration sensors (IoT-enabled)

• Modularization: Prefabricated substations (50% faster deployment)