Developing a Security-Enhanced Internet-of-Things Based Communication System for Smart Microgrids
Time: Mon 2021-10-25 09.00
Subject area: Information and Communication Technology
Doctoral student: Aron Kondoro , Elektronik och inbyggda system
Opponent: Giovanni Spagnuolo, Salerno University
Supervisor: Hannu Tenhunen, Integrerade komponenter och kretsar; Anders Hallén, Integrerade komponenter och kretsar; Nerey Mvungi, University of Dar es Salaam; Masoumeh Ebrahimi, Elektronik och inbyggda system
Access to clean and reliable electric power is still a challenge for many local communities in developing countries. Smart micro-grids are one of the new practical solutions that can take advantage of locally available resources to satisfy the energy demands of these communities. They are local low-voltage autonomous power system that consist of renewable power sources, storage systems, and a set of local loads. One of the main challenges in realizing these micro-grids is a robust, ubiquitous and reliable information and communication infrastructure for the control, coordination and monitoring of the power generation and distribution process. The emergence of Internet of Things (IoT) technologies provide a key set of tools to solve this challenge. They facilitate the integration of computational and communication capabilities within power system components. However, integrating these technologies in micro-grids is still a challenge due to stringent security, reliability, and performance requirements of power systems.
In this thesis, we develop a security enhanced communication system for IoT based micro-grids that provides comprehensive security services of confidentiality, availability, integrity, and privacy that can be implemented in a resource constrained environment while satisfying the reliability and performance requirements of micro-grid functions. We utilize fog-based communication architectures to reduce latency of data exchanges and improve the efficiency of the communication process. We use security extensions of standard IoT communication protocols to implement a lightweight and performance-aware security system.
First, we analyze how the integration of IoT in power systems introduces security vulnerabilities in the power generation and distribution process. We develop a simulation model that is used to evaluate the impact of security attacks on different parts of a power system. Using the model, we demonstrate several attack scenarios that can lead to theft of power, loss of privacy, and power outage. This information is used to determine the security requirements for the new system. Then, we build a lab-scale hardware based micro-grid communication system prototype and demonstrate the performance limitations of existing IoT communication security standards. We show that existing standards do not scale and fail to meet the timing requirements for microgrid protection and control operations. We propose new communication specifications and modifications needed to pass the standard power system requirements. Finally, using the security requirements and communication specifications, we develop a secure IoT based communication system that provides encryption, integrity, privacy, and authentication features with minimal impact to performance. We implement and evaluate the design on the lab-scale hardware prototype. We show how the system can support micro-grid protection, control and monitoring using secure communication channels without exceeding the required performance limitations.