Selection and Technical Trends of Transformers for Photovoltaic Systems: An In-depth Analysis from Engineering Application and Market Perspectives

1.Why must photovoltaic projects pay attention to transformer selection?

In photovoltaic project investment, the cost of transformers does not constitute the highest proportion, but they have a significant impact on system safety, grid compliance, and long-term returns. Incorrect selection may lead to:

• Grid connection failure
• The operation and maintenance costs have increased
• System efficiency decreases

Therefore, the requirements for transformers in photovoltaic projects have shifted from “being able to use” to “being able to use for a long time, stably, and efficiently”.

2.Core technical parameters for selecting photovoltaic transformers

2.1 Rated capacity and efficiency curve

Photovoltaic systems do not operate at full capacity throughout the day. Reasonable capacity allocation should focus on:

• Low load efficiency
• Long-term operational wear and tear
• Short-term overload capacity

High-quality photovoltaic transformers typically maintain high efficiency within the 30%–70% load range.

2.2 Voltage level and wiring method

Common grid-connected voltages include:

• 10kV
• 20kV
• 35kV

Common wiring methods such as Dyn11, Ynd11, etc., a reasonable wiring design can:

• Improve power quality
• Reduce zero-sequence current
• Enhance grid-connected stability

3.Application comparison between dry-type transformers and oil-immersed transformers

3.1 Advantages of dry-type transformers in photovoltaics

Dry-type transformers are suitable for:

• rooftop photovoltaic
• Indoor power distribution
• Places with high fire prevention requirements

Its characteristics include:

• Oil-free and environmentally friendly
• Easy to maintain
• High security

3.2 Performance advantages of oil-immersed transformers

In large-scale ground-mounted photovoltaic power stations, oil-immersed transformers remain the mainstream choice, with their advantages being:

• Lower loss
• Strong heat dissipation capacity
• The cost advantage is evident

With the application of environmentally friendly insulating oil, its environmental adaptability continues to improve.

4.The challenge posed by photovoltaic grid integration to transformer reliability

Photovoltaic grid connection demands extremely high stability from equipment, and transformers must possess:

• High insulation level
• Good temperature rise control
• Lightning protection, moisture resistance, and salt spray resistance

Especially in environments such as deserts, plateaus, and coastal areas, design margin is particularly important.

5.The intelligent development trend of photovoltaic transformers

With the rise of digital power stations, transformers are gradually becoming intelligent nodes:

• Online temperature monitoring
• Partial Discharge Monitoring
• remote operation and maintenance
• Status warning

Intelligentization not only enhances safety but also significantly reduces total lifecycle costs.

6.Future opportunities of photovoltaic transformers from a market perspective

The continuous expansion of global photovoltaics brings not a short-term opportunity, but long-term structural demand. In the future, competitive transformer enterprises often possess:

• Photovoltaic dedicated product line
• International certification capability
• Customized solution capability

The increasing complexity of photovoltaic systems will continuously enhance the market value of high-quality transformers.

Luoyang Datang Energy Technology Co., Ltd. is a high-tech enterprise integrating R&D, manufacturing and supply of power equipment such as transformers, new energy components, distribution cabinets and inverters. With technological innovation as the core, we focus on creating high-reliability and high-performance power solutions to serve global customers. With a strict quality control system and international standard certification, we continue to output excellent products and enable customers to build safe and stable power systems.