A Control Strategy of Grid-connected Photovoltaic-storage Inverter Based on Improved Virtual Synchronous Generator

Abstract

With the increasing demand for energy in today's society, the composition of distributed energy represented by photovoltaic energy in the power system is also increasing gradually, which leads to low inertia and under-damping in the micro-grid. This paper proposes a control strategy of optical storage inverter based on improved virtual synchronous generator (VSG).Firstly, it analyzes VSG grid-connected control technology, which can compensate for the damping and inertial components in the micro-grid. On this basis, transient characteristics of VSG control technology are discussed in detail, and the main controller structure of VSG control is optimized based on the power tracking performance improving of VSG control, and the setting basis of each parameter is proposed. Finally, simulation and experimental results indicate that the improved generalized VSG control strategy can eliminate the output power oscillation of the inverter, accelerate the power tracking speed, avoid the repeated switching of the energy storage device in the charging and discharging state, and reduce the demand for the capacity of the energy storage device, the effectiveness of the strategy is verified.

Keywords

• photovoltaic
• energy storage
• virtual synchronous machine
• inverter control
• micro-grid
• distributed energy