A comprehensive control strategy for photovoltaic virtual synchronous generator considering frequency regulation capability

Abstract

The existing photovoltaic frequency regulation strategies do not take into account the differences in the frequency regulation capability. So they cannot fully exploit the support capacity to the grid frequency. For the purpose of improving the control precision and regulation effect of PV, a comprehensive control strategy for photovoltaic virtual synchronous generator (PV-VSG) is proposed, which accurately considers the frequency regulation capability. First, the inertia regulation margin, power regulation speed and power regulation margin are taken as the evaluation index of frequency regulation capability of PV. Then, the frequent deviation-free control strategy with integral link and the multiple control modes switching strategy are proposed, whose control parameters are designed according to the frequency regulation capability. In the simulation verification, the proposed method reduces the frequency deviation by 0.11 Hz compared to existing strategies, and can quickly recover to the normal value. At the same time, the frequency regulation utilizes the capability of the PVs, which also validates the effectiveness of the proposed strategy.

Keywords

• PV-VSG
• Frequency deviation-free control
• Frequency regulation capacity
• Coordinated control