Voltage-dependent models of power generation units: A detailed analysis for control center application

Abstract

Presently, the reactive power limits of the power generation models implemented in the TSO's system security assessment tools do not respond to the voltage magnitude. This may lead to overoptimistic results in high load situations with low grid voltages. This paper proposes a voltage-dependent model of power generation units with detailed consideration of internal synchronous machine effects. The model has been implemented in a professional power flow tool and tested thoroughly. It is then compared to a full dynamic simulation with the help of a test grid. It is shown that the power flow with the proposed model yields positive margins and is thus suitable for control center applications.