Stability Studies for Photovoltaic Integration using Power Hardware-in-the-Loop Experiments

TL;DR

This paper investigates the impact of photovoltaic inverter integration on frequency stability in a low-inertia, islanded distribution grid using hardware-in-the-loop experiments to provide practical insights for grid operators.

Contribution

It presents a novel hardware-in-the-loop experimental setup to study frequency stability issues caused by PV integration in islanded grids, offering real-world applicable results.

Findings

PV inverter integration affects frequency stability in low-inertia grids

Hardware-in-the-loop experiments reveal stability thresholds and dynamics

Results assist grid operators in managing renewable integration challenges

Abstract

The electrical power network is gradually migrating from a centralized generation approach to a decentralized generation with high shares of renewable energy sources (RES). However, power systems with low shares of synchronous generation and consequently low total system inertia, are vulnerable to power imbalances. Such systems can experience frequency stability problems, such as high frequency excursions and higher rates of change of frequency even under small disturbances. This phenomenon is intensified when the grid under investigation has low or no interconnections (islanded) and thus the challenge for stable operation becomes more significant for the operators. This work focuses on how the frequency stability is affected when a photovoltaic (PV) inverter is integrated into a real non-interconnected distribution grid in Cyprus. In order to capture the realistic interactions of this integration, stability experiments in a hardware-in-the-loop (HIL) environment are performed with the aim to provide insightful results for the grid operator.