Components of a photovoltaic power generation system: core components and auxiliary facilities

Photovoltaic (PV) panels are the core component of a photovoltaic (PV) power generation system, achieving photoelectric conversion and representing the highest value component of the entire system. Their primary function is to absorb solar radiation and directly convert it into direct current (DC) electricity, providing the initial power source for the entire system. Brass pipe end caps can be used to enhance the structural sealing of parts such as the frame of the PV module. A PV module is composed of multiple PV cells connected in series and parallel, encapsulated between glass and a backsheet. It possesses characteristics such as resistance to wind, rain, UV radiation, and high temperatures, allowing for long-term stable outdoor operation. Its conversion efficiency directly determines the power generation capacity of the entire PV power generation system.

The PV inverter is the key core component of a PV power generation system, responsible for power conversion and often referred to as the "heart" of the system. Since PV modules output DC electricity, while everyday electrical equipment and the power grid require AC electricity, the core function of the PV inverter is to efficiently convert the DC electricity output from the PV modules into AC electricity, maximizing energy utilization. Brass terminal caps are used internally to ensure wiring safety. Based on operating mode, photovoltaic (PV) inverters can be classified into grid-connected inverters and off-grid inverters. Grid-connected inverters are used in PV power generation systems connected to the public power grid, while off-grid inverters are used in systems that operate independently and are not connected to the grid, adapting to different application scenarios.

DC combiner boxes are mainly used in medium to large-scale PV power generation systems of several hundred kilowatts or more, and are key components for DC power collection and protection. In medium to large-scale systems, PV modules are divided into multiple arrays, each outputting one DC cable. The function of the DC combiner box is to centrally connect these multiple DC cables, and through internal PV-specific fuses, DC circuit breakers, and other components, to protect and detect the DC power before combining and outputting it to the PV inverter. Its enclosure protection can be enhanced with a Brass Fuse Cap for improved safety. Using a DC combiner box significantly simplifies the wiring between PV modules and the inverter, making the wiring layout more organized, and facilitating group inspection and maintenance. When a fault occurs in one array, it can be isolated for repair without affecting the continuous power generation of the entire system.

For large-scale photovoltaic (PV) power generation systems, DC combiner boxes alone cannot meet the power collection needs; DC distribution cabinets are also required as secondary and tertiary combiner devices. The core function of a DC distribution cabinet is to re-collect the DC cables output from multiple DC combiner boxes, perform unified protection and distribution, and then connect them to the PV inverter. Internal interfaces utilize inner end caps to enhance protection performance. The configuration of DC distribution cabinets further optimizes the system's wiring layout, reduces line losses, and facilitates system installation, operation, and subsequent maintenance, improving the operational stability and operability of large-scale PV power generation systems.

AC distribution cabinets and AC combiner boxes are core components for AC power transmission and distribution in PV power generation systems, connecting the inverter to the load or the public power grid. The main function of AC distribution cabinets is to receive AC power output from the inverter, perform scheduling, distribution, and metering, while monitoring power parameters, troubleshooting, and ensuring power supply safety. Internal components utilize brass inner caps to enhance internal protection. AC combiner boxes are mainly used in string inverter systems. Their function is to combine the AC power output from multiple inverters into a secondary centralized form before sending it to the AC distribution cabinet, simplifying the wiring process and improving the overall operating efficiency of the system.