Design of a Robust Cyber Shield for a Grid-Connected PV System via Digital Watermarking Principle-Slides

Abstract: This IEEE PELS Webinar presents of an active defense mechanism for detecting cyber-attacks on sensors controlling a grid-tied PV system. Several possible cyber vulnerabilities in Grid tied PV Systems are discussed. The defense mechanism introduces a private (secret) watermarking signal into the control inputs of the grid-tied inverter system. This will enable the detection of any malicious manipulation of sensor measurements such as data measured via smart meters used to control the inverter. Based on the measured data, and system identification model two statistical tests are conducted to identify anomalies in the system using the presence of the watermarking signal. It shown that when sensor data is compromised and/or replaced by a pre-recorded healthy signal, both test 1 and 2 exhibit high values indicating a possible malicious activity. As an added benefit, the proposed approach can also identify/alert when sensors malfunction. The robustness of the proposed algorithm is tested and validated with several attack scenarios on a grid tied PV system. Select results from an experimental setup are discussed.