Sensor Attacks and Robust Defence on HVAC Systems for Energy Market Signal Tracking

The power flexibility from smart buildings makes them suitable candidates for providing grid services. The building automation system (BAS) that employs model predictive control (MPC) for grid services relies heavily on sensor data gathered from IoT‐based HVAC systems through communication networks. However, cyberattacks that tamper sensor values can compromise the accuracy and flexibility of HVAC system power adjustment. Existing studies on grid‐interactive buildings mainly focus on the efficiency and flexibility of buildings’ participation in grid operations, whereas the security aspect is lacking. In this paper, we investigate the effects of cyberattacks on HVAC systems in grid‐interactive buildings, specifically their power‐tracking performance. We design a stochastic optimisation‐based stealthy sensor attack and a corresponding defence strategy using a robust control framework. The attack and its defence are tested in a physical model of a test building with a single‐chiller HVAC system. Simulation results demonstrate that minor falsifications caused by a stealthy sensor attack can significantly alter the power profile, leading to large power tracking errors. However, the robust control framework can reduce the power tracking error by over 70% under such attacks without filtering out compromised data.