Participation of Virtual Inertia Emulating Constant Power Generating PV Power Plants in Microgrid Frequency Support

High penetration of Photovoltaic (PV) generation in standalone microgrids challenges frequency stability due to the absence of inherent inertia and limited frequency regulation capability. This paper proposes a coordinated control framework that enables a PV system to provide both inertial response and primary frequency control without using an energy storage system. Inertial response is implemented through a Virtual Synchronous Generator (VSG) control strategy, while primary frequency support is achieved by reserving a portion of the available PV power using Flexible Power Point Tracking (FPPT) in Constant Power Generation (CPG) mode. The main contribution of this work is the integration of VSG-based inertia emulation with FPPT-based power reservation within a unified PV control structure, allowing simultaneous inertial and primary frequency support. Unlike existing approaches, the proposed method preserves the conventional MPPT structure and does not require modification of the DC/DC converter control loop. An adaptive voltage step size is employed to ensure fast convergence to the flexible operating point and robust performance under irradiance variations. Simulation results obtained from a standalone microgrid model in MATLAB/ Simulink® demonstrate fast stabilization of the DC-link voltage, reduced rate of change of frequency, lower frequency deviation, and faster frequency recovery under different scenarios.

کلیدواژه ها:

Constant Power Generation (CPG) ، Flexible Power Point Tracking (FPPT) ، Frequency Support ، Voltage regulation ، Virtual Inertia ، Virtual Synchronous Generator (VSG)