Comparative Study of Current Controllers for Shunt Active Power Compensators used in Smart Grids Applications

This paper presents a comparative study among different current controllers implemented in a Shunt Active Power Compensator (SAPC) to be used in smart grid applications. During the operation of a smart grid, the SAPC should deliver sinusoidal or non-sinusoidal currents to the Point of Common Coupling (PCC), and this current exchange must be precisely controlled. Three current controllers are analysed in this paper. The two first controllers are a hysteresis band controller and a feedforward proportional controller. Both controllers are designed to work in stationary reference frame. The third one is a PI controller implemented in a synchronous reference frame. The results show that the synchronous reference frame PI controller is unable to track currents with a significant harmonic distortion. Conversely, the behavior of the two stationary reference frame controllers remains unaffected by a high harmonic content in the reference currents. Finally, the results also show that among them, the hysteresis bandwidth controller presents the best performance with similar power losses.