Improving frequency stability for renewable energy power plants with disturbances

Abstract

This study examines the frequency behaviour of renewable energy power plants after a disturbance (frequency stability) by investigating how renewable energy power plants respond to disturbances in the power system and develop ways to improve frequency stability. The frequency parameters that are investigated include the (Rate of Change of Frequency) ROCOF, nadir frequency, frequency deviation and settling time. Since renewable energy power plants can be fairly discriminated from other plants using their inertia constants, the study of frequency stability can be anchored on the inertia constants. Specifically, the inertia constants of steam, hydro, wind and solar. The study finds that after a disturbance, the power plants get out of sync and causes the same-frequency condition of paralleling generators not to be achieved. It is observed that (Renewable Energy Solution) RES plants with low inertia such as hydro-electric power plants have a higher frequency deviation, high ROCOF, but a lower settling time.