Problem description:
According to onsite feedback, the output reactive power of the inverter at night cannot reach the required value. As shown in the following figure, the output reactive power is 14000 kvar, but the actual value is 10800 kvar.
Problem analysis:
Onsite networking mode: STS6000K+SUN2000-185KTL-H1+ smartlogger2000+ third-party background
A total of 7 guidelines were provided, each with 36 185 inverters. The total reactive power of 14000 kVar is evenly distributed to all inverters, and the reactive power of each inverter is about 56 kVar. Check the inverter log. If the reactive power reaches -28, it is limited.
As the reactive power is set to a negative value, the inductive reactive power is output, which decreases the power grid voltage. The log records that the voltage is close to 720 V and is about to reach the lower limit of the voltage range. If the reactive power is increased, the voltage will continue to decrease, and the inverter will shut down. After the reactive power is shut down, the reactive power cannot be output at night.
Troubleshooting:
Reduce the power grid voltage protection lower limit to 700 V. The reactive power of the inverter recovers to the required value at night.
