Impact Assessment of Heterogeneous Grid Support Functions in Smart Inverter Deployments

TL;DR

This paper evaluates how different heterogeneous smart inverter control modes affect grid stability and efficiency in high PV penetration scenarios, using real-time simulation of a low-voltage distribution network.

Contribution

It provides a comprehensive analysis of the dynamic interactions among diverse inverter control strategies in realistic grid conditions, addressing a gap in existing research.

Findings

Heterogeneous inverter controls can cause adverse interactions affecting stability.

Different control modes impact voltage regulation and system efficiency.

Real-time simulation validates the complex interactions in practical settings.

Abstract

The decarbonization of the energy sector has led to a significant high penetration of distributed energy resources (DERs), particularly photovoltaic (PV) systems, in low-voltage (LV) distribution networks. To maintain grid stability, recent standards (e.g., IEEE 1547-2018) mandate DERs to provide grid-support functionalities through smart inverters (SIs), which typically operate autonomously based on local measurements. However, as DER penetration increases, uncoordinated control modes of SIs can lead to adverse interactions, compromising system efficiency, voltage regulation, and overall stability. While previous studies have demonstrated the benefits of coordinated inverter control and optimal dispatch strategies, the system-wide impacts of heterogeneous SI groups operating under different control modes remain largely unexamined. This paper addresses this gap by assessing the dynamic interactions among multiple SI groups with varying control strategies, namely: Constant Power Factor (CPF), Volt-VAR, and Volt-Watt modes. Furthermore, the analysis covers both resistive and inductive feeder types. The validation is performed using a real-time setup. The CIRGE low-voltage (LV) distribution network is simulated in the Opal-RT platform as the test network, enabling realistic and high-fidelity evaluation of SI control interactions under practical grid conditions.