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Technical characteristics of photovoltaic grid-connected cabinets

Release time:

2025-07-02

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Abstract

As a core device connecting photovoltaic power plants to the grid in photovoltaic power generation systems, the photovoltaic grid-connected cabinet has the following technical characteristics:

1. Structural Design and Protection Performance

Cabinet Strength and Protection Level ：
- The cabinet is made of cold-rolled steel, stainless steel, or engineering plastics, with a thickness ≥2mm, and features resistance to sun exposure, corrosion, and mechanical impact (such as IP65 protection level).
- The cabinet design meets the needs of natural ventilation, has good heat dissipation performance, and the internal temperature is more than 15℃ lower than the ambient temperature.
- High protection level: IP65 (dustproof and waterproof), IP54 (salt spray corrosion resistance), suitable for complex outdoor environments (such as high temperature, high humidity, salt spray, etc.).
Modular Layout ：
- Zoned design (inlet area, outlet area, metering area independent compartments), convenient for fault location and maintenance.
- Supports quick installation (such as slide rail + hook claw fixing components), and the four corners of the cabinet top are equipped with removable lifting rings.

2. Safety Protection Functions

Four-Dimensional Safety Protection Mechanism ：
1. Islanding Protection ：Disconnects the grid-connected switch within 0.2 seconds when the grid is powered off, avoiding the islanding effect threatening the safety of maintenance personnel.
2. Overvoltage/Undervoltage Protection ：Automatically cuts off abnormal voltage to prevent equipment damage.
3. Leakage Current Monitoring ：Real-time detection of grounding faults to ensure personnel safety.
4. Temperature Warning ：Triggers an alarm or shutdown when overheating to prevent fire hazards.
Short Circuit and Overload Protection ：
- Equipped with circuit breakers, fuses, etc., with a current carrying capacity of 20kA~40kA, and a short-time withstand of 80kA/1s short-circuit current.
- Supports Low Voltage Ride Through (LVRT) and High Voltage Ride Through (HVRT) to maintain grid voltage stability.

3. Intelligence and Remote Monitoring

Data Monitoring and Analysis ：
- Built-in bidirectional smart meter and power quality online monitoring device, real-time monitoring of voltage, current, power, harmonics, and other parameters.
- Supports Modbus, CAN, IEC 61850, and other communication protocols, and works with the SCADA system.
Remote Control and Maintenance ：
- Integrated Internet of Things module (such as 4G/5G), supports cloud platform access, and realizes visualization of power generation data.
- Automatic alarm for abnormal conditions (such as voltage fluctuations, inverter failures), with an average fault response time reduced to 15 minutes.
Intelligent Dispatching Function ：
- Supports seamless switching between self-generation and grid-connection (such as commercial and industrial rooftop projects).
- Integrated MPPT tracking and multi-machine parallel control to improve power generation efficiency to over 98.5%.

4. Adaptability to Multiple Scenarios

Voltage and Capacity Adaptability ：
- Low-voltage grid connection (220V/380V): Suitable for household use (≤50kW) and small commercial and industrial projects.
- High-voltage grid connection (10kV/35kV): For large ground power stations (≥1MW), supporting a maximum of 1.6MW access per cabinet.
Special Scenario Optimization ：
- Commercial and Industrial Rooftops ：Equipped with harmonic suppression function to reduce harmonic interference (such as a 1.2MW power station in a certain automobile factory).
- Agricultural Greenhouses/Photovoltaic-Aquaculture Integration ：IP65 protection + corrosion-resistant design, dual-channel MPPT input compatible with shade shading.
- Remote Areas ：Integrated energy storage BMS, supporting off-grid/grid-connected dual-mode operation (such as the continuous power supply stability of a Tibetan off-grid power station reaching 99.9%).

5. Core Component Selection and Reliability

Electrical Components ：
- Circuit breakers: Schneider, ABB, and other international brands or leading domestic brands such as CHINT and Delixi, with breaking capacity ≥ grid short-circuit current (such as 25kA~31.5kA).
- Relays and sensors: OMRON, Weidmüller, and other long-life products with high accuracy (temperature ±1℃, voltage linearity ≤0.5%).
Cabinet Material ：
- Indoor: Cold-rolled steel powder coating (thickness ≥1.2mm).
- Outdoor: 304 stainless steel (thickness ≥2.0mm), salt spray test ≥1000 hours.
Certification and Standards ：
- Passed CCC, CE certification, and complies with GB/T 35726 (islanding protection), IEC 61850 (communication protocol), and other standards.

6. Energy Storage Integration and Expansion Functions

Photovoltaic and Energy Storage Integration Design ：
- Integrated bidirectional inverter (PCS), supporting energy storage battery charging and discharging management.
- Peak shaving and valley filling: Storing surplus electricity during the day and supplying electricity at night (such as a commercial complex in Zhejiang Province saving 180,000 yuan in electricity costs annually).
Off-grid Switching Technology ：
- Static switch (STS) achieves millisecond-level grid-connected/off-grid switching, ensuring uninterrupted operation of sensitive loads (such as hospitals, data centers).
Future Expandability ：
- Reserved BMS communication interface and bidirectional inverter installation space to support future energy storage upgrades.

7. Easy Maintenance

GGD Cabinet Advantages ：
- Fixed structure, low maintenance cost (30% cost savings compared to GCS/MNS cabinets).
- Depth ≥800mm, 150mm internal operating space reserved, allowing for easy component insertion and removal even while wearing gloves.
Labels and Documentation ：
- All terminal blocks and circuits are labeled according to national standards (L1/L2/L3 correspond to phase wires, PE is the protective ground wire), allowing novice electricians to quickly get started.

Photovoltaic Grid-Connected Cabinet The technical characteristics revolve around safety, reliability, intelligence, and scene adaptability. It meets diverse needs from household use to hundreds of megawatt-level power stations through high protection levels, multiple protection functions, modular design, and intelligent monitoring. Technical selection should consider project scale, environmental conditions, and grid requirements, prioritizing certified products with scalability. If you are planning a photovoltaic project, please feel free to leave a message to inquire and obtain a professional selection scheme!

Key words:

Core functions of a photovoltaic grid-connected cabinet

What are the differences between smart meters and ordinary meters?

Hunan Chengyuan Electrical CO.,LTD