How much do you know about photovoltaic combiner boxes？

   Photovoltaic combiner box (PV combiner box) generally refers to a combiner box. The combiner box is a wiring device in the photovoltaic power generation system that ensures the orderly connection and confluence function of photovoltaic modules. This device can ensure that the photovoltaic system is easy to cut off the circuit during maintenance and inspection, and reduce the range of power outage in case of photovoltaic system failure. The combiner box is an important component of the power system, and its main function is to introduce high-voltage direct current into the low-voltage distribution system. There are generally two or more combiner boxes installed in the substation for different levels of loads. Users can connect a certain number of photovoltaic cells with the same specification in series to form photovoltaic tandem arrays, and then connect several photovoltaic tandem arrays in parallel to the photovoltaic combiner box. After converging in the photovoltaic combiner box, through the controller, DC distribution cabinet, Solar inverter, and AC distribution cabinet, they can form a complete photovoltaic power generation system to achieve grid connection with the city power.
   Classification and composition of photovoltaic combiner boxes:The photovoltaic combiner box is one of the important components of the photovoltaic power generation system, as well as an important component of the villa solar power generation system. It connects several photovoltaic groups in series and parallel, and through internal combiner units, monitoring modules, and protection devices, achieves functions such as current consolidation, electrical parameter monitoring, overcurrent protection, and lightning protection between photovoltaic groups. Real time data is transmitted to the monitoring and management center of the photovoltaic power station, At the same time, it aims to reduce the use of cables in the photovoltaic power generation system. The electrical principle of the photovoltaic combiner box is shown in the figure.
   The combiner box can be divided into three types in terms of function. The first type is the basic type, without anti backflow and monitoring functions; The second type is equipped with anti reverse function and does not have monitoring function; The third type, which has both anti anti anti anti backflow and monitoring functions, is the most versatile, cost-effective and cost-effective combiner box.
Name of combiner box components and their main impacts:
   1. Circuit breaker and isolation switch: used for isolation; Easy to cut off power for maintenance on the load side
   2. Photovoltaic fuse: prevents the line from withstanding excessive current or short-circuit current, and protects photovoltaic modules
   3. DC Surge protector: to prevent inductive lightning stroke
   4. Anti reverse current diode: To prevent reverse power transmission from high voltage string to low voltage string, but it will cause power loss and require additional heat dissipation devices
   5. Monitoring unit (intelligent controller): monitoring current, Surge protector status, etc. to realize data communication
   6. Voltage transmitter and self powered power supply: providing working power to the intelligent controller