Solar Farm Substation

The SNYB -35 series 35kV photovoltaic step-up prefabricated transformer substation (commonly known in the industry as "PV Huabian") is an integrated outdoor step-up power distribution equipment specifically developed for large-scale photovoltaic power plants. The equipment adopts an integrated modular structure, integrating three core units: a 35kV high-voltage switchgear, a photovoltaic-specific step-up transformer, and a 0.8kV low-voltage distribution cabinet . The entire cabinet is assembled, wired, debugged, and subjected to withstand voltage tests in the factory. On-site, it only requires hoisting into place and connecting the photovoltaic DC combiner cable and high-voltage transmission line for commissioning.

This equipment is mainly used for collecting and boosting low-voltage electricity from photovoltaic power plants, transforming the 0.8kV low-voltage electricity generated by the photovoltaic array into 35kV high-voltage electricity, and then transmitting it to the power grid and substation. The product features strong weather resistance, anti-interference, low loss, fully automatic operation, and no manual supervision, making it perfectly suited for harsh conditions such as wind, sand, high temperatures, rain, snow, and high altitudes in outdoor photovoltaic power plants. It is a core supporting boosting device for centralized photovoltaic power plants.

SN YBW-35 / □

• SN Y - Pre-installed equipment
• B - Substation
• W - Outdoor type
• 35 - Rated voltage level on the high-voltage side: 35kV
• The box indicates the transformer's rated capacity (kVA), with common specifications: 2500, 3150, 3500, 4000, and 5000 kVA.

1. Ambient temperature: -40℃～+45℃, suitable for the extreme high and low temperature environment of photovoltaic power stations;

2. Altitude: ≤2000m; for high-altitude areas, customized solutions with enhanced insulation, anti-condensation, and pressure boosting protection can be provided.

3. Relative humidity: Daily average ≤95%, monthly average ≤90%, no persistent condensation, no icing;

4. Environmental conditions: Suitable for outdoor open-air environments, can withstand wind, sand, rain, sun exposure and frost, and contains no strong corrosive or explosive gases;

5. Installation site: The site should be flat, well-ventilated, and have good drainage, with no water accumulation or low-lying areas, and the foundation should be stable and free from settlement.

This 35kV photovoltaic power plant adopts an integrated, independent three-compartment partition structure , divided into a low-voltage compartment, a transformer compartment, and a high-voltage compartment. Each compartment is completely isolated using thickened galvanized steel plates and is equipped with fireproof and heat-insulating layers, anti-arc partitions, and independent ventilation and heat dissipation systems, effectively preventing the spread of faults across compartments and improving equipment operational safety. Each compartment is equipped with independent door locks, maintenance lighting, and anti-misoperation devices, ensuring that maintenance and operation do not interfere with each other.

Standard layout: front low-voltage cabinet room, middle step-up transformer room, and rear 35kV high-voltage cabinet room . The layout conforms to the wiring habits of photovoltaic power stations, making it convenient for photovoltaic cables to be connected and high voltage to be transmitted.

■ Low-voltage switchgear unit (low-voltage compartment)

The low-voltage switchgear is the core unit for photovoltaic power collection, specifically designed for 0.8kV low-voltage photovoltaic systems. It includes a complete set of photovoltaic-specific incoming line cabinets, combiner cabinets, monitoring and control cabinets, and communication cabinets. The cabinet body is made of thickened cold-rolled steel plate with electrostatic powder coating, making it dustproof, waterproof, and anti-aging, suitable for long-term outdoor operation. The cabinet is equipped with high-capacity molded case circuit breakers, photovoltaic-specific fuses, surge protectors, intelligent monitoring and control instruments, communication modules, and combiner terminals.

Main functions : Centrally receive 0.8kV low-voltage power output from multiple photovoltaic string inverters, complete power collection, distribution, voltage stabilization and protection; provide comprehensive protection against overload, short circuit, lightning surge and leakage; collect operating data such as voltage, current, power and power generation in real time, and upload them to the power station backend through the communication system to realize remote monitoring and unattended operation, meeting the intelligent operation and maintenance needs of photovoltaic power stations.

■ Step-up Transformer Unit (Transformer Room)

The transformer is the core equipment for photovoltaic power generation, employing a 35kV photovoltaic-specific low-loss step-up transformer . Either a fully sealed oil-immersed transformer or a dry-type transformer can be selected, suitable for high-power photovoltaic power station conditions. The equipment uses a low-loss iron core and high-temperature resistant insulation materials, possessing overload resistance, impact resistance, high and low temperature resistance, and condensation prevention characteristics. The transformer room is equipped with an automatic temperature control system, forced air cooling fans, heat dissipation ducts, maintenance lighting, oil leakage prevention, and fireproof isolation devices.

Main functions : It can step up the 0.8kV photovoltaic low-voltage power collected by the low-voltage switchgear to 35kV high-voltage power to meet the grid connection and transmission standards; it can adapt to the intermittent photovoltaic power generation and large load fluctuation conditions, has short-term overload operation capability, low power generation loss and strong operation stability, and is the core equipment for photovoltaic power station power voltage step-up and grid connection.

■ 35kV High Voltage Switchgear Unit (High Voltage Room)

The 35kV high-voltage switchgear is the high-voltage transmission and protection unit for equipment. It is typically equipped with a 35kV vacuum circuit breaker cabinet, disconnecting switch, instrument transformer cabinet, surge arrester, live display device, grounding switch, and a complete set of five-proof interlocking devices. The cabinet has high insulation strength and good sealing performance, making it suitable for 35kV high-voltage operation requirements.

Main functions : Controls the grid connection and transmission of 35kV high-voltage power, and performs opening and closing operations; has comprehensive protection functions against short circuit, overload, overvoltage, undervoltage, and grounding faults, and can quickly trip and cut off the power supply in case of a fault to protect the transformer and front-end photovoltaic equipment; can realize high-voltage metering, line monitoring, and lightning protection and grounding protection, prevent high-voltage side safety accidents, and ensure the safe and stable operation of photovoltaic power stations connected to the grid.

1. Photovoltaic-specific adapter design: Optimized for the intermittent power generation and large load fluctuation characteristics of photovoltaic power plants, it is shock-resistant, overload-resistant, and adaptable to the special operating conditions of photovoltaic power plants;

2. Integrated structure: High and low voltage transformers are prefabricated as a whole, eliminating the need for civil engineering power distribution rooms. They can be put into operation on site by hoisting, which greatly shortens the construction period of photovoltaic power stations;

3. High safety protection: Three independent compartments, five electrical protections, lightning protection grounding, fireproof and heat insulation multiple protections to prevent the spread of electric arc, short circuit and fire faults;

4. Ultra-low loss configuration: Adopting a photovoltaic-specific low-loss step-up transformer effectively reduces photovoltaic power generation losses and increases the overall power generation of the power station;

5. Strong outdoor weather resistance: The whole machine is waterproof, dustproof, corrosion-resistant, UV-resistant, and resistant to high and low temperatures, making it suitable for various photovoltaic scenarios such as mountains, deserts, and lakes;

6. Intelligent Operation and Maintenance Adaptation: Standard configuration includes data acquisition and remote communication modules, supporting unattended operation and remote monitoring, and adapting to intelligent photovoltaic power station management systems;

7. Easy maintenance: Modular structure design, neat layout, simple daily inspection, fault diagnosis and parts replacement, and low operation and maintenance cost.

1. Foundation construction: Pour high-strength concrete foundation according to equipment drawings, and reserve the positions of photovoltaic low-voltage cable trench, high-voltage outlet hole and grounding electrode to ensure that the foundation is flat, drainage is smooth and the foundation is solid;

2. Equipment placement: A large crane is used to lift the container as a whole and stabilize it. After leveling and correction, the equipment is fixed to prevent tilting and stress.

3. Wiring construction: Connect the photovoltaic low-voltage combiner cable and 35kV high-voltage transmission cable in accordance with specifications, and fully connect the grounding system of the entire station, with a grounding resistance ≤4Ω;

4. System debugging: Conduct insulation resistance testing, power frequency withstand voltage testing, protection setting verification, communication point-to-point debugging, and simulated fault transmission testing;

5. Phased trial operation: First, conduct a no-load trial operation, then conduct a phased trial operation with photovoltaic load. After confirming that the temperature rise, parameters, protection, and communication are all normal, the system will be officially connected to the grid and put into operation.

1. During the grid-connected operation of the equipment, it is strictly forbidden for non-professional operation and maintenance personnel to open the high and low pressure chamber doors or touch live parts. High-voltage operations must be carried out by certified personnel.

2. Daily inspection: Monitor the background operation data daily, and conduct on-site inspections of the enclosure, ventilation and heat dissipation, equipment temperature, operating noise, and cable joint status every month to identify potential problems such as condensation, overheating, and leakage.

3. Quarterly maintenance: Tighten high and low voltage terminals, clean dust and debris inside the cabinet, and check the operating status of temperature control, fan, communication, and lightning protection devices;

4. Annual maintenance: Conduct insulation testing of the entire unit, calibration of protection devices, instrument calibration, test transformer oil quality and level, aging status of components, comprehensively investigate potential equipment hazards, and ensure long-term stable power generation of the power station.

1. The equipment must be transported upright throughout the entire process. Tilt, inversion, impact, and heavy pressure are strictly prohibited. During transportation, take precautions against rain, shock, and collision.

2. The equipment should be stored in a dry, ventilated, flat, and non-corrosive place, avoiding long-term exposure to the sun, rain, and sand.

1. This product is manufactured and tested in strict accordance with national and photovoltaic industry standards. Each piece of equipment undergoes full-item withstand voltage, protection, and insulation tests before leaving the factory.

2. Product warranty period: 12 months after official grid connection or 18 months after delivery (whichever comes first). During the warranty period, free repair and replacement of parts will be provided for non-human-caused damage.

3. The manufacturer provides a full range of technical services, including on-site hoisting guidance, wiring and debugging, communication integration, and operation and maintenance training. After-sales service is rapid, ensuring the continuous and stable power generation of the photovoltaic power station.