Analysis of Power Grid Voltage Stability With High Penetration of Solar PV Systems

Grid integration of solar photovoltaic (PV) systems has been escalating in recent years, with two main motivations: reducing greenhouse gas (GHG) emission and minimizing energy cost. However, the intermittent nature of solar PV generated power can significantly affect the grid voltage stability. Therefore, intermittent solar PV power generation and uncertainties associated with load demand are required to be accounted for to gain a holistic understanding on power grid voltage stability with the high penetration of PV energy sources. This article presents a framework for power grid voltage stability analysis considering uncertainties associated with PV power generation and load demand using Monte Carlo simulation. Commonly used voltage stability indicators such as critical eigenvalue, line loss, reactive power margin have been considered in the proposed framework. The proposed methodology has been verified by analyzing the voltage stability of the IEEE 14 bus test system, with the high penetration of PV energy sources and considering uncertainties associated with load demand. The results provide a clear insight into the voltage stability of power grid with different penetration levels of PV energy sources into the power grid.

I. Introduction

Diminishing fossil fuel reserve and environmental concerns are playing a major role in the transition of power grid from fossil fuel based energy sources to renewable energy (RE) sources. Throughout the world, almost all the countries are setting green house gas (GHG) emission reduction target by replacing conventional fossil-fuel based energy sources by RE sources. Among various RE sources, the PV energy source is gaining immense popularity, because of abundant availability, easy maintenance, and noise free operation, etc., [1], [2]. Due to rapid improvement of power electronic interfaces and sharp decline in price of components associated with PV energy source, as well as ongoing government support schemes, the overall cost of implementing PV energy sources has decreased significantly, in recent years. The total capacity of worldwide grid integrated PV energy sources is expected to increase significantly in the coming days from 494.3 to 1582.9 GW by 2030 [3].