Virtual SM-DFIG based automatic control strategy for enhancing the power quality in microgrids

Conventional rotary electrical machines based power plants achieve good quality in power conversion due to the provision of smooth automatic generation control and voltage regulation. But, in case of renewable energy based microgrids, the inherent involvement of static power electronics based power conversion raises the issues of poor power quality and instability during uncertainties due to lack of effective control facility and sufficient moment of inertia. So, an attractive way of mitigating the above mentioned key concerns is to make the microgrid's operation similar to rotary electrical machines based power plant by retaining the advantages of using power electronic converter. With this idea, this paper proposes “Virtual Synchronous Motor (SM)-Doubly Fed Induction Generator (DFIG) based Automatic Control Strategy (VSMIGC)” for microgrids. This provides controlled modulating signals to control the output of the pulse width modulated power electronic inverter used in microgrids. For the performance analysis of the proposed VSMIGC, various power quality indices are measured during uncertainties and compared with those of conventional “Voltage-Current Control Strategy (VIC)” based inverters with respect to standard limits. From results, it is seen that the use of VSMIGC has improved the power quality characteristics of renewable energy microgrids.