Simulation of the Volt/Var Control in Distribution Feeders by Means of a Networked Multiagent System

The adoption of networked multiagent systems (MAS) has been recently proposed for the solution of the volt/var control (VVC) problem in distribution feeders. However, constraints and limitations due to the communication network, to the dynamic behavior of power system components and regulators, as well as to the measurement uncertainties of the adopted sensors need to be specifically analyzed for the design of the MAS. For this purpose, a cosimulation platform has been built by the integration of two simulation tools: 1) the electromagnetic transient program EMTP-rv; and 2) the communication network simulator Riverbed-OPNET Modeler. This paper presents the modeling and simulation of an asynchronous leaderless MAS-based approach that coordinates the reactive power outputs of a set of power compensators equipped with phasor measurement units via a shared band-limited packet-switched digital communication network. The effects of communication network latency and packet loss on the VVC performances are analyzed for two unbalanced IEEE Test feeders equipped with on-load tap changer transformers. The paper compares the results obtained by using a transmission control protocol (TCP) and a user datagram protocol (UDP), for different levels of background traffic (BT) and different packet discard ratios (PDRs) in the communication links.