This paper focuses on power distribution systems with inverter-interfaced renewable energy sources (RESs), and develops a distributed control framework to steer the RES output powers to solutions of ac optimal power flow (OPF) problems. The design of the distributed control algorithm is based on suitable linear approximation of the ac power-flow equations, and leverages the so-called alternating direction method of multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the approximate ac OPF problem is established under suitable conditions on the mismatches between the commanded setpoints and actual RES output powers. Overall, since the proposed scheme can be cast as an ADMM with inexact primal and dual updates, the convergence results can be applied to more general distributed optimization settings.
Bibliographical noteFunding Information:
Manuscript received August 10, 2016; revised December 16, 2016; accepted January 18, 2017. Date of publication February 20, 2017; date of current version August 21, 2018. This work was supported by the U.S. Department of Energy under Contract DE-AC36-08GO28308 with the National Renewable Energy Laboratory. The work of Y. Zhang, M. Hong, and E. Dall’Anese was supported by the Laboratory Directed Research and Development Program at the National Renewable Energy Laboratory. The work of S. V. Dhople was supported by the National Science Foundation under the CAREER Award under Grant ECCS-1453921. The work of Z. Xu was supported by the National Nature Science Foundation of China under Grant 11571221. Paper no. TSG-01062-2016.
- Distributed algorithms
- Distribution systems
- Optimal power flow
- Renewable energy sources