By: Peter Gerhardinger, Nextronex
Distributed architecture in the case of solar inverter configuration means dedicating multiple inverters to a solar array such that the entire array (up to 2MW) is available to feed every inverter via a DC Bus. In this configuration, all the available energy can feed as few inverters as needed at any instant in time. This configuration allows for several benefits. Here are a few of the most significant advantages:
1. Improved Efficiency (Increased Investment Return) – It takes as little as 650 watts of solar power to start exporting energy to the grid. So, every morning, every evening and during overcast conditions, the system expands the operating window by funneling all the available energy to only one solar inverter, which starts exporting energy at 650 watts.
2. Reliability – Units are allowed to rest when not needed. There is less wear and tear on all the units when they are rotated. As the most active electronic component of a solar field this is also the most necessary to maintain function.
3. 100% Up-Time – Should a failure occur, having multiple solar inverters at a field minimizes the impact to the total array. If an inverter fails, the repair process is quick and the rest of the field does not shut down.
At the end of each day the smart controller reads the operating hours of each solar inverter and establishes a sequence for the next day’s operation. Each inverter has three modes; standby, master, or slave. The unit with the least amount of operating hours begins the day as master, and subsequent slave units are brought on as needed in the order of their operating hours. The next day, the sequence is rotated, insuring equal run times for all units.
Nextronex Ray-Max inverters feature distributed architecture.
When the first inverter reaches 85% of its capacity, the next one is brought on, in slave mode. This is repeated until solar noon when all inverters are on. As the day wanes, inverters are pulled off. At the end of the day, the only one left running is the one that started the day. This describes a fully sunny day. It gets more interesting on a partly cloudy day.
Using a distributed inverter architecture design maximizes the field performance and return on investment of any given solar field between 500kW and 10 MW. The built in reliability of multiple inverters, the lower power threshold needed to start the energy production process and the lower per unit use of each inverter presents the distributed architecture design as a superior solution for solar installations.
By: Peter Gerhardinger, Nextronex