Distributed volt/var control in unbalanced distribution systems with distributed generation

Future power distribution systems are expected to have large number of scale smart measuring devices and distributed generation (DG) units which would require real-time network management. Integration of single-phase DG and advanced metering infrastructure (AMI) technologies will add further complexity to the power distribution system which is inherently unbalanced. In order to alleviate the negative impacts associated with the integration of DG, transformation from passive to active control methods is imperative. If properly regulated, DGs could provide voltage and reactive power support and mitigate the volt/VAr problem. This paper presents a distributed algorithm to provide voltage and reactive power support and minimize power losses in unbalanced power distribution systems. Three-phase volt/VAr control problem is formulated and active/reactive powers of DGs are determined in a distributed fashion by decomposing the overall power distribution system into zonal sub-systems. The performance is validated by applying the proposed method to the modified IEEE 37 node test feeder.