## Abstract

Synchronization is essential for the proper functioning of power grids, we investigate the synchronous states

and their stability for cyclic power grids. We calculate the number of stable equilibria and investigate both the linear and nonlinear stability of the synchronous state. The linear stability analysis shows that the stability of the state, determined by the smallest nonzero eigenvalue, is inversely proportional to the size of the network. We use the energy barrier to measure the nonlinear stability and calculate it by comparing the potential energy of the type-1 saddles with that of the stable synchronous

state. We find that the energy barrier depends on the network size ($N$) in a more complicated fashion compared to the linear stability. In particular, when the generators and consumers are evenly distributed in an alternating way, the energy barrier decreases to a constant when $N$ approaches infinity.

For a heterogeneous distribution of generators and consumers, the energy barrier decreases with $N$. The more heterogeneous the distribution is, the stronger the energy barrier depends on $N$. Finally, we find that by comparing situations with equal line loads in

cyclic and tree networks, tree networks exhibit reduced stability. This difference disappears in the limit of $N\to\infty$. This finding corroborates previous results reported in the literature and suggests that cyclic (sub)networks may be applied to enhance power

transfer while maintaining stable synchronous operation.

and their stability for cyclic power grids. We calculate the number of stable equilibria and investigate both the linear and nonlinear stability of the synchronous state. The linear stability analysis shows that the stability of the state, determined by the smallest nonzero eigenvalue, is inversely proportional to the size of the network. We use the energy barrier to measure the nonlinear stability and calculate it by comparing the potential energy of the type-1 saddles with that of the stable synchronous

state. We find that the energy barrier depends on the network size ($N$) in a more complicated fashion compared to the linear stability. In particular, when the generators and consumers are evenly distributed in an alternating way, the energy barrier decreases to a constant when $N$ approaches infinity.

For a heterogeneous distribution of generators and consumers, the energy barrier decreases with $N$. The more heterogeneous the distribution is, the stronger the energy barrier depends on $N$. Finally, we find that by comparing situations with equal line loads in

cyclic and tree networks, tree networks exhibit reduced stability. This difference disappears in the limit of $N\to\infty$. This finding corroborates previous results reported in the literature and suggests that cyclic (sub)networks may be applied to enhance power

transfer while maintaining stable synchronous operation.

Original language | English |
---|---|

Article number | 013109 |

Pages (from-to) | 1-11 |

Number of pages | 11 |

Journal | Chaos: an interdisciplinary journal of nonlinear science |

Volume | 27 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2017 |

## Keywords

- Eigenvalues
- Ring networks
- Synchronization
- Power systems
- Differential equations