A Study on the Impacts of High Penetration of Inverter Interfaced Power Sources on the Voltage Fluctuations of a Single-Machine Infinite-Bus System

The paper examines the voltage fluctuations of a single-machine infinite-bus system in case of massive integration of current-control type inverters paying particular attention to the short circuit ratio of the inverters. The increase of inverter-interfaced power sources, such as wind and photovoltaic power generation, arouses concerns on the voltage fluctuations in a power system because the increase causes the decrease of the short circuit capacity of a power system. In a power system with low short circuit capacity, an inverter could face challenges in power quality of the power system and the control stability of the inverter. By normalizing active and reactive power with short circuit capacity, the paper exhibits general relationship between the active and reactive power of an inverter, to keep the terminal voltage of an inverter to a designated value, for various resistance-to-reactance-ratios of looking-back impedance of a power system. It also examines the sensitivity of the active and reactive power of an inverter to its terminal voltage. © 2022 The Institute of Electrical Engineers of Japan.