Energy Storage Minimization Control in Grid-Connected Photovoltaic Virtual Synchronous Generator

A novel control strategy for minimizing the energy storage of a photovoltaic virtual synchronous generator (PV-VSG) is proposed in this paper. Firstly, a proportional-integral-resonant (PIR) dc-link voltage control is adopted for the supercapacitor (SC)-side dc-dc converter. With the proposed PIR control, the SC can provide frequency regulation support for the grid while taking over the potential double line-frequency power from the dc-link, Secondly, a virtual rotor kinetic energy feedforward control is proposed to directly deliver the grid-side disturbance to the SC. Thirdly, a PV power feedforward control is proposed to transfer the transient energy from the PV side to the grid side. With the above three approaches, the energy storage both in the dc-link and in the SC of a PV-VSG can be minimized. Its effectiveness is verified by PSCAD simulation.