Integrated Solution: Pad Mounted Transformers Nagpapataas sa Efektiibilidad ug Reliability sa Distributed Solar PV Systems
1. Ang Pook nga Rol sa Pad Mounted Transformer (PMT) sa Distributed PV Systems
Ang Pad Mounted Transformer (PMT) usa ka fully sealed, box-type transformer nga gisulod diretso sa ground-level concrete pad (pad). Kini angay sa voltage step-up ug grid interconnection sa distributed photovoltaic (PV) power plants. Ang iyang primary functions mao kini:
- Voltage Transformation:Steps up ang low-voltage electricity output gikan sa PV inverters (e.g., 0.8kV) ngadto sa 10kV o 35kV aron mapasabot ang grid interconnection requirements.
- System Integration:Integrates high-voltage switches, protection devices, ug metering equipment, naghunam sa footprint ug nagpataas sa system reliability.
- Safety Isolation:Ang fully enclosed design maghatag og dustproof, moisture-proof, ug corrosion-resistant capabilities, makapuyo sa harsh outdoor environments.
2. Key Technical Parameters ug Selection Guidelines sa Pad Mounted Transformer
2.1 Capacity Matching Principle
- Capacity Calculation:Dili bayad mas dako kaysa maximum output power sa PV system (typical na gi-configure sa 1.1~1.2 times the rating).
- Example: Usa ka 19.9MW PV project nga gisulod og 8 units of 2.5MVA PMTs (total capacity of 20MVA).
- Voltage Level:Pili 10kV o 35kV batasan sa grid connection point voltage (e.g., usa ka 8.3MW project sa Shanghai gamit ang 10kV grid connection).
2.2 Core Selection Parameters
|
Parameter |
Requirement |
|
Efficiency |
≥98.5%, reducing transmission losses |
|
Protection Class |
IP54 o higher (dustproof and waterproof) |
|
Insulation Material |
Epoxy resin cast dry-type transformer (fire-resistant, pollution-free) |
|
Cooling Design |
Forced air cooling o natural cooling, with temperature rise ≤85℃ |
2.3 Compatibility Design
- Inverter Matching:Ang input voltage range kinahanglan mopasabot sa inverter's output voltage (e.g., 0.8kV → 10kV).
- Protection Device Integration:Built-in fuses, surge arresters (lightning arresters), ug temperature sensors; interfaces for external anti-islanding protection ug fault isolation devices.
3. Pad Mounted Transformer System Integration Schemes
Intelligent Monitoring Integration
- Sensor Configuration:Real-time monitoring sa temperature, current, ug voltage.
- Communication Interface:Supports Modbus o IEC 61850 protocol para sa integration sa PV monitoring systems (e.g., Acrel-1000DP).
- Safety Protection:
Anti-islanding device:Disconnects within 0.5 seconds after detecting grid power loss.
Arc detection:AI-enabled intelligent arc fault identification (e.g., Huawei solution).
4. Pad Mounted Transformer Typical Application Case Studies
4.1 19.9MW Distributed PV Project
- PMT Configuration:8 units of 2.5MVA pad-mounted transformers, deployed near 4 substations for close connection to 10kV distribution rooms.
- Results:Annual power generation of 14.95 million kWh, system efficiency >80%, reduced cable length by 30%.
4.2 Shanghai 8.3MW Rooftop PV Project
- Solution Features:
- 5 PMTs (2 units of 2.5MVA + 2 units of 1.6MVA + 1 unit of 0.8MVA) matched to groups of inverters with different capacities.
- Fiber optic ring network for data transmission, enabling remote power forecasting and dispatch response.
4.3 Environmental Interference Resistance Design
- High Wind Areas:Strengthened mounting bracket fixtures (e.g., wind load-resistant components).
- High Humidity Environments:Use anti-salt spray coatings (for coastal projects) and inverters with Potential Induced Degradation (PID) recovery function.
5. Economic Benefits and O&M Optimization
5.1 Investment Return (ROI):
- Changchun 500kW Project:Annual generation 584,000 kWh, self-consumption rate of return 12.2%, payback period ≈5.3 years.
5.2 Operations & Maintenance (O&M) Strategy:
- Intelligent Diagnostics:IV curve scanning for real-time fault component localization.
- Preventive Maintenance: Overload risk alerts for transformers based on temperature data.
