Comparative Analysis of Direct Quadrature (DQ) and Synchonverter Techniques for the Control of $3-\phi$ VSI in AC Micro-Grid

Abstract

The modern power system is advancing towards an inverter dominant system from an alternator-based system. For effective operation, grid-tied micro-grids can be accomplished by employing an efficient inverter control technique that maintains desired performance at the Point of Common Coupling (PCC). The main focus of this paper is to study the comparative analysis of DQ and synchronverter control technique for inverter control. The mathematical modelling of these control techniques is presented. The Sine Pulse Width Modulation (SPWM) technique is used to control the gate pulse of Voltage Source Inverter (VSI). In this paper, the performance of both the control techniques under dynamic conditions i.e., variations in reference active $(\boldsymbol{P}_{\boldsymbol{ref}})$ and reactive $(\boldsymbol{Q}_{\boldsymbol{ref}})$ powers are examined. To verify the effectiveness of the control technique, simulations are carried out in MATLAB/Simulink environment. In synchronverter technique, the instantaneous grid voltages are used from the required mechanical input and induced emf directly act as modulating signals. The response of the synchronverter during the variation in power is smooth compared to DQ control.