An active power synchronization control loop for grid-connected converters

The increasing penetration of renewable energy sources in power systems requires new control systems that provide services similar to those of conventional generators. This paper proposes an active power controller that is able to automatically achieve synchronization with the grid and to control the DC link voltage. Through this controller, the converter can be identified with a virtual synchronous generator whose kinetic energy is stored in the DC link. Moreover, the active power loop becomes a second order system whose damping can be programmed freely.