A non-singular terminal sliding mode controller for a communication-based hybrid microgrid

Abstract

The paper proposes a robust and effective networked control for a hybrid based islanded microgrid. Renewable energy sources with energy storage systems are linked in parallel using voltage source inverters to supply the loads in a microgrid. The master-slave control strategy is implemented. CAN and the ZigBee networks are selected to share data, where the master controller transmits the reference signals to the slave controllers in the microgrid via these two networks. As the control loop incorporates a communication network and energy storage systems, the impacts of external disturbances, parametric uncertainties, and time delay executed by the devices introduce challenges in control of voltage and current. Thereby, it is crucial to use a robust and stable control approach. Using the binary iteration algorithm, stability criteria in the form of linear matrix inequalities based on the Lyapunov-Krasovskii function are employed to derive the system's maximum allowable delay boundary. As the reliability of the communication network can be affected, a nonsingular terminal sliding mode controller is employed. The proposed robust control method was implemented in MATLAB/Simulink and the True-time 2.0 simulator and its performance were evaluated under different loads, uncertainties, disturbances, and communication impairments. Simulation results show that the desired performance i.e., maintaining the microgrid's stability with accurate voltage and current control even in unallowable delay limits is met.