Design of Networked Discrete Predictive Sliding Mode Stabilizer for Damping Low Frequency Oscillations in Geographically Distributed Power Systems
The rapid growth of technological advances and communication technologies, and also the development and geographical dispersion of industrial processes have made the use of networked control systems in controlling geographically distributed systems inevitable. In these systems, communication between controlling components is established through a telecommunications network, due to non-ideal communication network conditions, some problems such as packet dropouts and time delays are raised as inherent problems of these systems, which can lead to inappropriate performance and even the entire system becomes unstable. In this paper, a new networked discrete predictive sliding mode control structure is proposed in order to stabilize low frequency oscillations in smart grid with geographically distributed network. The proposed method consists of two steps. First a new sliding mode switching function is proposed to design a sliding mode stabilizer and then, a predictive control algorithm is proposed to compensate the nonideal behavior of the communication network, including network latency and packet loss. In order to demonstrate the capability of the proposed method, some numerical studies have been carried out on a 5-area -16-machine system in the presence of three-phase and single-phase faults. Also, in order to make a comparison, a conventional networked stabilizer with lead-lag structure is designed. Simulation results show the capability and superiority of the proposed method.