Impact of Different Penetration Level of Type-IV Renewable Energy Resources on Power System Dynamics

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.

I. Introduction

The incorporation of renewable energy sources into the system is on a rapid increase. India is in the 5^th position considering the overall renewable energy sources installed in the system. Renewable energy installed capacity has increased by more than 225% in the last 5 years. India also has a target to add 175 GW of renewable sources to the grid by the year 2022 and 450GW by 2030 as per the Paris agreement. Currently, the renewable energy share is more than 23% of the country's total installed capacity and the major contributing sources towards it are wind and solar [1]. A high level of renewable integration is a strong move towards reducing greenhouse gas emissions and tackling climate change. But, the planning and operation of renewables are challenging due to their irregularity in generation and low inertia characteristics. Therefore, it is of high interest to study the maximum possible level of penetration to a system and the system characterizes which determine this level.