Dynamic Virtual Inertia and Damping Control for Zero-Inertia Grids

TL;DR

This paper proposes a dynamic virtual inertia and damping control method for grid-forming inverters in low- and zero-inertia power grids, enhancing stability and robustness during faults and oscillations.

Contribution

It introduces a novel approach with dynamic inertia and damping constants, along with frequency and phase shift functions, supported by theoretical stability proof and detailed real-time case studies.

Findings

Enhanced grid stability during faults and oscillations

Demonstrated improved robustness over traditional synchronous generators

Validated approach through real-time simulations with microsecond timestep

Abstract

In this paper virtual synchronous generation (VSG) approach is investigated in application to low- and zero-inertia grids operated by grid-forming (GFM) inverters. The key idea here is to introduce dynamic inertia and damping constants in order to keep power gird stable during different types of faults, islanding or large power balance oscillations. In order to achieve such robustness, we introduce frequency and phase angle shift functions to VSG along with dynamics virtual generator parameters. The stability of such approach is theoretically proven and theoretical results are supported by detailed case studies in RTDS (Real-Time Digital Simulator) NovaCor 1.0 with GFM inverters dynamics simulated with 1-3 microseconds timestep using two-level universal inverter model. Case studies include all aforementioned types of faults and demonstrate increased power grid robustness and survivability in comparison with traditional synchronous generation of comparable size.