Impact of low voltage ride through capability of IBT on voltage stability of an interconnected power system

Abstract

This research investigates the impact of the Inverter-Based-Technology (IBT) response during Low-Voltage-Ride-Through (LVRT) events on the classical P-V steady-state voltage collapse analysis. The response of the IBT Renewable-Energy-Sources (RES) during LVRT events has the form of a reduction in the IBT RES active-power export which is not considered in classical P-V steady-state voltage collapse analysis. The relationship between the transmission (Tx) voltage depression due to a fault on a Tx busbar and the IBT RES active-power export reduction is examined in this research. The classical P-V steady-state voltage collapse grid active-power transfer limits are compared between a conventional synchronous generator scenario (synchronous scenario) and a scenario where both synchronous generators and IBT RES are present (IBT RES scenario) using the Cigre Nordic voltage collapse test network. A novel prediction model is developed to approximate the IBT RES active-power reduction characteristic response to LVRT. Finally, it is shown that both the IBT RES LVRT active-power export response and the IBT RES LVRT reactive-power response impact the Tx-corridor active-power transfer limits and the Tx-corridor reactive-power export requirements not observed in the classical P-V steady-state voltage collapse analysis.