Control Strategy for Active Standby Photovoltaic Virtual Synchronous Machine with Improved Power Control

The stability issues stemming from grid-connected PV systems are increasingly severe due to the advancement of photovoltaics (PV). This article proposes a control strategy for the virtual synchronizer of a PV system to address this issue. At the same time, a grid frequency-active compensation link is introduced to respond to the power-side output power change caused by the grid-side frequency perturbation, i.e., to adjust the PV array output power to supply ample backup active power for primary regulation of the system. This strategy effectively utilizes the own characteristics of the PV power source so that the system can have an active backup capability during normal operation, this will ensure the stability of the power grid and solve problems such as deteriorating inertia and lack of frequency adjustment capability associated with large-scale grid-connected PV generation.