Photovoltaic inverter reports grid overvoltage

What is the overvoltage mechanism of a grid-interactive PV inverter?

The vast majority of grid-interactive PV inverters and many storage inverters fall into this category. The overvoltage mechanism, which will be explained and analyzed in detail in an upcoming publication , is this: after the fault, the voltage on the faulted phase is nearly zero, so the power on that phase is also near zero.

Does NREL test commercial PV inverters during ground fault conditions?

This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL.

Why is overvoltage a problem in LV grids?

However, overvoltage is the main challenge in many LV grids with PV, and is one of the main limiting factors in increasing PV penetration in LV grids. Overvoltage caused by PV systems happens when the power flow path is reversed from customers to the LV transformers.

Can a PV inverter withstand a ground fault?

As such, the test plan used is designed to isolate the response of the PV inverter to a ground fault, and not to exactly simulate the wide range of ground fault conditions possible on real distribution feeders.

Does a solar PV inverter bus cause overvoltage?

In addition, overvoltage is much more severe at the solar PV inverter bus compared to that at the POM. This issue was singled out as a key finding and further study to develop a better understanding was recommended by NERC.

How can a PV inverter reduce energy consumption?

Coordination of EESSs and active and reactive powers of PV inverters through a combination of localised and distributed control methods can minimise the active power curtailment and prevent the overvoltage while reducing the energy storage need .