VSG Current Balance Control Strategy Under Unbalanced Grid Voltage

In recent years, countries around the world have been vigorously developing new energy and electrifying new energy sources. As a result an increasing number of power electronic devices appear in the grid which makes the power grid develop toward low inertia and low damping. The Virtual Synchronous Generator (VSG) control strategy can simulate the working state of the synchronous generator and provide the grid with inertia and damping, which has become a research hotspot for scholars. Due to the unbalanced load distribution and the random change of power load, the grid voltage may become unbalanced during the actual operation process. The three-phase output current of the VSG would be unbalanced and a fluctuation of output power appears. To solve this problem, a new current and power quality control strategy based on VSG is proposed in this paper, in which the current balancing or constant power is achieved without changing the basic characteristics of the inverters using VSG control strategy.