Production of photovoltaic string inverters

Can string inverters be used in large-scale PV systems?

When considering large-scale PV systems, a basic distinction is made between two system concepts: those in which string inverters are used and those that favour a central inverter. The following sections look at the broad operational capability of string inverters and consider their application potential in large-scale commercial systems.

Can a string inverter predict the generated power of a PV plant?

Yet, there are hundreds of string inverters inside a PV plant, it is impossible and unnecessary to predict the generated power of each string inverter. A feasible and reasonable way is to divide the string inverters into several clusters first, then to predict the generated power of each cluster.

How do string inverters work?

String inverters typically rely on two-stage power conversion. First, the DC-DC stage converts variable DC voltage into a suitable or fixed voltage required by the DC-AC inverter stage. At the same time, it ensures maximum power, which has been extracted from the PV string via MPPT (Maximum Power Point Tracking) technique.

Do string inverters in a PV cluster have the same power?

Besides, for string inverters inside a PV cluster, the predicted power of every string inverter is considered to be same.

How does a PV string inverter controller work?

Once receiving the required power reserve demand (∆ Prs,i), the PV string inverter controller will collect the operation information of each DC input channels. Then, based on the collected information, the controller will calculate αij based on (6) and ∆ Prs,ij based on (14).

What is a photovoltaic inverter & how does it work?

The core function of today’s photovoltaic (PV) inverter is to harvest direct current (DC) electric energy from a solar PV array, convert it to useful alternating current (AC), and inject the harvested solar electricity into an AC power grid.