Adaptive VAR Control for Distribution Circuits With Photovoltaic Generators
We show how an adaptive control algorithm can improve the performance of distributed reactive power control in a radial distribution circuit with a high penetration of photovoltaic (PV) cells. The adaptive algorithm is designed to balance the need for power quality (voltage regulation) with the desire to minimize power loss. The adaptation law determines whether the objective function minimizes power losses or voltage regulation based on whether the voltage at each node remains close enough to the voltage at the substation. The reactive power is controlled through the inverter on the PV cells. The control signals are determined based on local instantaneous measurements of the real and reactive power at each node. We use the example of a single branch radial distribution circuit to demonstrate the ability of the adaptive scheme to effectively reduce voltage variations while simultaneously minimizing the power loss in the studied cases. Simulations verify that the adaptive schemes compares favorably with local and global schemes previously reported in the literature.
© 2012 IEEE. Manuscript received August 29, 2011; revised November 08, 2011; accepted December 23, 2011. Date of publication February 14, 2012; date of current version July 18, 2012. This work was supported in part by NSF through NetSE grant CNS 0911041, Southern California Edison, Cisco, and the Okawa Foundation. Paper no. TPWRS-00816-2011. The authors would like to thank C. Clarke, G. D. Rodriguez, E. Kamiab, R. Yinger, R. Neal, P. Haralson, M. Parsons, and M. Montoya in the Advanced Technology Division of Southern California Edison's Transmission and Distribution Business Unit for fruitful discussions.