Synchronization of Coupled Phase Oscillators with Stochastic Disturbances and the Cycle Space of the Graph

TL;DR

This paper analyzes how stochastic disturbances affect the synchronization stability of coupled phase oscillators, revealing the role of graph cycle space in fluctuation severity and how network modifications influence stability.

Contribution

It introduces a novel analysis linking the cycle space of the network graph to phase difference fluctuations under stochastic disturbances.

Findings

Cycle space influences fluctuation severity in the network.

Adding lines or increasing coupling reduces fluctuations if phase differences remain unchanged.

Small cycles significantly impact the stability and fluctuations of the system.

Abstract

The synchronization stability of a complex network system of coupled phase oscillators is discussed. In case the network is affected by disturbances, a stochastic linearized system of the coupled phase oscillators may be used to determine the fluctuations of phase differences in the lines between the nodes and to identify the vulnerable lines that may lead to desynchronization. The main result is the derivation of the asymptotic variance matrix of the phase differences which characterizes the severity of the fluctuations. It is found that the cycle space of the graph of the system plays a role in this characterization. With theory of the cycle space, the effect of forming small cycles on the fluctuations are evaluated. It is proven that adding a new line or increasing the coupling strength of a line affect the fluctuations in the lines in any cycle including this line while it does not affect the fluctuations in the other lines. In particular, if the phase differences at the synchronous state are not changed by these actions, then the affected fluctuations reduce.