China’s photovoltaic industry has grown rapidly, with installed capacity exceeding 43 GW in 2018. The inverter is an intelligent core component of a photovoltaic power generation system. Inverter technology is advancing rapidly, with increasing power and smarter controls. String inverters rated at 70/80 kW and above are becoming mainstream in domestic projects. String inverters are also increasingly replacing centralized inverters in medium- and high-voltage grid-connected PV plants. Using Jingfuyuan’s SUNTREE 70/80K series as an example, this article introduces their advantages over centralized inverters.

More MPPT channels: SUNTREE 70/80K uses a 4-channel MPPT design to accommodate complex module-installation layouts. The source states that partial shading or individual module failures during operation will not affect the efficiency of the entire system.

Reduced DC combiner-box cost: SUNTREE 70/80K uses a 12-channel input design with fuse protection and integrated DC combiner functions, including combining, lightning protection, switching, and reverse-polarity protection. Each string can connect directly to the inverter’s DC input without a separate combiner box. This simplifies the system, lowers cost, and reduces potential failure points. A waterproof cooling fan is isolated from the internal circuit board, and the enclosure has a protection rating of IP65 for outdoor installation. It can be wall-mounted directly without a separate inverter room and its associated fire protection, air conditioning, and lighting.

Higher output voltage, lower cost: outputs of 480 VAC and 540 VAC can reduce AC cabling costs compared with a conventional central inverter output of 315 VAC. At the same power, higher voltage means lower current and lower losses, allowing smaller AC cables. The source also states that the higher voltage can reduce winding requirements in the step-up transformer, further lowering costs.

Fault location accurate * * . If a local component fails in a power station, it will first respond to the corresponding inverter. Through the monitoring platform, we can directly see the abnormal current and voltage on each MPPT circuit, to quickly locate the fault location. Convenient maintenance, completely eliminate the large-scale downtime caused by economic losses.