Model-Free Cyber-Resilient Coordinated Inverter Control in a Microgrid

The increasing number of inverter-based resources (IBR) in the grid introduces new challenges due to the fast transient response and low inertia of IBRs. Set point automatic adjustment with correction enabled (SPAACE)-based techniques smoothen the transient response of an IBR already installed in a grid by modifying its set point without accessing its internal parameters in a model-free approach. Coordinated SPAACE (CSPAACE) further enhances SPAACE performance by incorporating communication links to exchange tracking error values between IBRs; however, this creates openings for cyberattacks. This work adds a detection and mitigation algorithm for both denial of service (DoS) and false data injection (FDI) attacks on the communication channels. Long short-term memory (LSTM) detects anomalies in the inputs received from other inverters, and bidirectional LSTM (BiLSTM) mitigates the adverse effect of attacks on the voltage and frequency stability of a microgrid. A hybrid co-simulation platform is developed using a computer running PSCAD/EMTDC software, a network switch, and two Raspberry Pi computers, where the cyberattacks are conducted on the network switch using one of the Pis. The testbed is used to study the effectiveness of the proposed detection and mitigation method under DoS and FDI attacks and various grid transients.