Loss-of-Equilibrium Power System Instability Induced by Converter Operation

This paper focuses on power system stability issues related to loss of equilibrium of Power Electronic Converters (PECs) connected to a large system. The power stability limits examined are associated with maximum power transfer and refer to both constant voltage and constant current PEC operation. The stability limits are defined considering both generation and consumption by the PEC, as well as STATCOM operation. A simple radial system is simulated considering all modes of PEC operation, in order to illustrate loss of equilibrium conditions. The stability limits examined are most likely to be met, when the PEC is supporting the power system by injecting reactive power during a voltage instability incident.