A Distributed Hierarchy Based Framework for Validating Edge Devices Performing State Estimation in a Power System

Recent cyber-attacks on power grids highlight the necessity to protect the critical functionalities vital for the safe operation of a grid. One such example is the power grid state estimation (SE), since various attacks can be launched by manipulating the SE results. In this paper, we propose a distributed hierarchy based framework to secure SE on edge devices. The data for SE is acquired from the phasor measurement units (PMUs) installed at various locations within the grid. These PMUs may be reprogrammed by a malicious actor to manipulate the data which may cause SE results to be inaccurate. Moreover, SE is carried out at a fixed central location, which makes it a prime target for cyber-attacks. Our proposed framework ensures that data aggregation and SE are carried out at a random device, and incorporates security features such as attestation and trust management to detect malicious devices. We test our proposed framework on a physical cluster of Parallella boards, monitoring a virtual IEEE 5 bus system. We also do simulations on the IEEE 118 bus system. Our simulations show that the trust for malicious devices nominally reduces with the number of attestations.