Grid Strength Assessment and Maximum Loadability of a Wind-Dominated Power System Through QV Modal Analysis

With the menace of climate change, a quite vast number of Renewable Energy Sources (RES) is being integrated into the traditional transmission grid. The current trends shows that wind energy is the fastest growing RES. The operation and planning of the existing traditional transmission grid with these large scaled wind farms pose several challenges to the Transmission System Operators (TSO), and planners. A systematic approach is needed to integrate them into the grid. This paper aims to present an iterative QV modal analysis to find the strength of each region of the power system and, thus, the maximum loadability of each region. The P-Q method is used to determine the stability boundary of the test system. These methodologies were applied to the well-known IEEE 14 bus system with a large scale wind farm connected to it.

I. Introduction

The climate change phenomenon is menacing the existence of the world. Policymakers worldwide are busy trying to cope with this phenomenon by integrating a huge amount of renewable energy into their transmission grids. Current trends show that wind energy will play a crucial role in reducing the dependence on fossil fuels. According to [1], 23.7% of the total electricity worldwide comes from hydropower. In some countries like Germany, Denmark, and Spain, wind power market penetration is extremely high. Among the renewable energy resources, wind energy is one of the fastest-growing and the most widely used sources. With this increasing amount of wind energy being integrated into the traditional power system, Transmission System Operators (TSO) and Planners are facing several issues. These wind farms are, generally, located far away from the load centers and long transmission lines are needed to connect them to the existing transmission grid. Hence, the reactive power limitations issues arise [2].