General Introduction
GB/T 35729 is a national standard that specifies the requirements for photovoltaic grid - connected cabinets, covering aspects such as environmental conditions, technical requirements, test methods, inspection rules, safety requirements, transportation, and storage5. This standard is applicable to the design, production, testing, and use of photovoltaic grid - connected cabinets, providing a unified technical basis and specification for the photovoltaic power generation industry5.
Key Contents Interpretation
Environmental Requirements: The standard stipulates the environmental conditions that photovoltaic grid - connected cabinets should adapt to, including temperature, humidity, altitude, and electromagnetic environment. This ensures the normal operation of the cabinets in different natural environments, preventing malfunctions or damage caused by harsh environmental conditions. For example, in high - temperature environments, the components of the cabinet should have good heat - resistance to avoid overheating and affecting performance.
Technical Requirements
Electrical Performance: Requirements are set for parameters such as rated voltage, rated current, and short - circuit withstand current. The rated voltage and current should match the photovoltaic power generation system and the grid to ensure efficient power transmission. The short - circuit withstand current capability is crucial for withstanding short - circuit faults and protecting the safety of the equipment and the grid.
Protection Functions: Photovoltaic grid - connected cabinets are equipped with a variety of protection functions, such as undervoltage release, overvoltage protection, overcurrent protection, islanding protection, and reverse - current protection1. These protection functions are essential for ensuring the safe operation of the photovoltaic power generation system and preventing damage to the grid and equipment due to abnormal conditions. For example, islanding protection can quickly disconnect the grid - connected switch when the grid fails to prevent the photovoltaic system from operating in an island - mode and endangering the safety of maintenance personnel.
Measurement and Monitoring: The cabinet should have the function of accurately measuring the electrical energy generated by the photovoltaic system and monitoring the operating parameters and status of the system, such as voltage, current, power, and power factor1. This provides data support for the operation and management of the photovoltaic power station, helping operators to understand the operation of the system in a timely manner and take corresponding measures when problems occur.
Test Methods: The standard details the test methods for verifying whether the photovoltaic grid - connected cabinet meets the technical requirements, including electrical performance tests, protection function tests, and electromagnetic compatibility tests. These tests are necessary to ensure the quality and reliability of the product. For example, through short - circuit current tests, the short - circuit withstand capacity of the cabinet can be verified to ensure its safety and stability under fault conditions.
Inspection Rules: The inspection rules include requirements for factory inspections and type inspections. Factory inspections are carried out on each product before leaving the factory to ensure that each product meets the basic quality requirements. Type inspections are carried out on representative products to verify whether the product design and manufacturing process meet the standard requirements. This helps to ensure the overall quality of the product and the consistency of performance.
Safety Requirements: Safety is a top priority. The standard specifies safety requirements such as grounding, insulation, and protection against electric shock to protect the safety of personnel and equipment. For example, reliable grounding measures can ensure that in the event of a leakage fault, the fault current can be safely introduced into the ground to avoid electric shock accidents.
Significance and Impact
Ensuring Grid Connection Quality: By specifying detailed technical requirements and test methods, the standard ensures that photovoltaic grid - connected cabinets have good electrical performance and reliable protection functions, which can effectively improve the quality of grid connection of photovoltaic power generation systems and reduce the impact on the grid.
Enhancing System Safety: The safety requirements and protection functions specified in the standard help to improve the safety and reliability of photovoltaic power generation systems, protect equipment and personnel safety, and reduce the risk of accidents.
Promoting Industry Development: The implementation of the standard provides a unified technical basis and specification for the design, production, and use of photovoltaic grid - connected cabinets, which is conducive to standardizing the market, promoting technological innovation and development in the industry, and improving the overall level of the photovoltaic power generation industry.