Virtual synchronous generator of PV generation without energy storage for frequency support in autonomous microgrid

TL;DR

This paper introduces a novel virtual synchronous generator control for photovoltaic systems in autonomous microgrids, enabling frequency support without energy storage by emulating traditional generator dynamics.

Contribution

The study proposes a new VSG control method for PV that provides frequency regulation without energy storage, using a power-voltage curve analogy and emulated governor and swing control.

Findings

Effective frequency support demonstrated in simulations.

No energy storage required for primary frequency regulation.

Robust performance under various operating conditions.

Abstract

In autonomous microgrids frequency regulation (FR) is a critical issue, especially with a high level of penetration of the photovoltaic (PV) generation. In this study, a novel virtual synchronous generator (VSG) control for PV generation was introduced to provide frequency support without energy storage. PV generation reserve a part of the active power in accordance with the pre-defined power versus voltage curve. Based on the similarities of the synchronous generator power-angle characteristic curve and the PV array characteristic curve, PV voltage Vpv can be analogized to the power angle {\delta}. An emulated governor (droop control) and the swing equation control is designed and applied to the DC-DC converter. PV voltage deviation is subsequently generated and the pre-defined power versus voltage curve is modified to provide the primary frequency and inertia support. A simulation model of an autonomous microgrid with PV, storage, and diesel generator was built. The feasibility and effectiveness of the proposed VSG strategy are examined under different operating conditions.