Online volt/var control in a smart grid with multiple distributed generation systems

Abstract

The higher shares of distributed generation (DG) sources lead to unpredictable rise in voltage level due to intermittent and stochastic characteristics of DGs. This paper intends to report the online Volt/Var control in a smart grid with multiple DG systems. The objective of Volt/Var control is to recover the network voltages within the admissible limits by coordinating the operation of the DG and the OLTC transformer. Firstly, voltage profile of the system is estimated by remote terminal units (RTUs) placed only at DG node. Next, a direct voltage sensitivity based method is developed to choose best DG for reactive power injection in multiple DG environments. Finally, OLTC transformer is employed in voltage regulation process when DGs reactive power is insufficient for maintaining the voltages within predefined limits. The reported method tested on 12-bus radial distribution network to validate the theory. The reported simulation results show that the presented method effectively maintains network voltages within admissible limits.