Self-Security for Grid-Interactive Smart Inverters

Widespread utilization of smart inverters in the power grid with information exchange capability through cyber-physical networks poses the threat of cyberattack. The stability and reliability of the power grid can be jeopardized, resulting in economic loss to utility and consumers if inverters are hacked to perform malicious actions. Communication protocols have been developed focusing on the safety of the data transfer, where data can be encrypted or requires certificate-based authentication. System-level protections mainly focus on collecting data from nearby cyberphysical devices and controllers to provide security measures. However, only communication protocols and system-level protections are insufficient if an attacker gains access to the utility/aggregator. There can be substantial cases where data from the authorized utility operator can be identified as safe by the existing protection measures, whereas the data is harmful to an inverter. A device-level protection to identify and prevent malicious commands autonomously can add an ultimate layer of protection and make the inverters and the system more secure. This project aims to develop an self-security firmware for the inverter controller to provide device-level protection from harmful setpoints. The self-security firmware will provide three significant advantages in addition to the system-level protection and communication protocols. The device-level protection is achieved: (a) locally in real-time using a novel reference model method, (b) adaptively under any grid condition, and (c) autonomously when the system-level protection is bypassed. Phase I focuses on the design of the self-security firmware and its feasibility and marketing plan. First, the reference models used as the heart of the self-security firmware will be developed and evaluated for different cyberattack scenarios. Then, the compatibility of the self-security firmware will be achieved to operate with any commercial inverters. Furthermore, a control board with self-security firmware will be developed and evaluated. In Phase II, the full functionality of the self-security firmware will be implemented on hardware and tested by the potential users. The self-security firmware will enrich the overall security of energy infrastructure, allowing integration of more inverters and renewable energy resources in the network. The U.S. has witnessed steady growth for string inverters, while central inverters are anticipated to maintain their market share. With its device-level protection features, the self-security firmware is expected to be of interest primarily to the smart grid- interactive inverter manufacturers and vendors.