The development of new smart grid technologies and the rising environmental concerns lead to increased penetration of green energy sources into the existing power grid. This increased penetration of renewable energy sources (RES) into the power system will affect system dynamics. This paper discusses the influence of integrating full converter-based renewable energy sources on different system stability indicators (SSIs) such as rate of change of frequency (ROCOF), frequency nadir, etc. Different test systems such as Kundur's two area model and IEEE-9 bus system are considered to evaluate the impact of different penetration levels of RES on power system stability indicators. The response of the system to common contingencies such as generator outage, load shedding, faults, etc. are studied using Dynamic Security Assessment Tools (DSA Tools) from Powertech Labs. It is observed that the post-disturbance dynamic behavior of a conventional synchronous generator-dominated system is significantly different from that of an inverter-dominated system and it is heavily dependent on penetration level, type of disturbance, type of RES, etc. © 2021 IEEE.