Real problems in utility high voltage network due to grid connected photovoltaic power generation. The experience of endesa.

Abstract

Photovoltaic (PV) systems require connection to a utility power grid to work effectively as energy sources. Numerous problems and unusual configurations have been detected in those connections: Some problems are due to a dysfunction of the faulted-phase relay protection on Substations (Sub.) not originated in all cases by phase imbalance of the PV inverters, other problems are related to an abnormal stationary (resonant) state of generation just after islanding of the plant, where frequency and amplitude of the power signal are in a corrupted stable state caused by the inverters. The final problem to be discussed is related to switch-on sequencing and associated starting inverter’s problems.