## Abstract

Physical security of power networks under power injection attacks that alter generation and loads is studied. The system operator employs Phasor Measurement Units (PMUs) for detecting such attacks, while attackers devise attacks that are unobservable by such PMU networks. It is shown that, given the PMU locations, the solution to finding the sparsest unobservable attacks has a simple form with probability one, namely, κ (G^{M})+1, where κ (G^{M}) is defined as the vulnerable vertex connectivity of an augmented graph. The constructive proof allows one to find the entire set of the sparsest unobservable attacks in polynomial time. Furthermore, a notion of the potential impact of unobservable attacks is introduced. With optimized PMU deployment, the sparsest unobservable attacks and their potential impact are evaluated numerically for the IEEE 30, 57, 118 and 300-bus systems and the Polish 2383, 2737 and 3012-bus systems. It is observed that, as more PMUs are added, the maximum potential impact among all the sparsest unobservable attacks drops quickly until it reaches the minimum sparsity.

Original language | English (US) |
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Article number | 7792204 |

Pages (from-to) | 3354-3368 |

Number of pages | 15 |

Journal | IEEE Transactions on Automatic Control |

Volume | 62 |

Issue number | 7 |

DOIs | |

State | Published - Jul 2017 |

## All Science Journal Classification (ASJC) codes

- Control and Systems Engineering
- Computer Science Applications
- Electrical and Electronic Engineering

## Keywords

- Cyber physical system
- phasor measurement units (PMUs)
- power networks
- power system security