In this paper, the quality of service (QoS) of communication infrastructure implemented in multi-area power system for load frequency control (LFC) application is assessed in smart grid environment. In study, network induced effects; time delay, packet loss, bandwidth, quantization and change in communication topology (CT) has been addressed to examine the system performance in closed loop. Uncertainty in time delay is approximated as deterministic and stochastic model. The network is modeled considering different network configurations, i.e. change in CT. The modeled communication network guarantees control relevant properties, i.e. stability.The decentralized controller and linear matrix inequality based linear quadratic regulator (LMI-LQR) is implemented to reduce the dynamic performance (mean square error of states variables) of power system as CT changes. Simulation results suggest that proposed scheme of networked control is superior with respect to other design method available in literature and thus robust to communication imperfections.
Index Terms-Bandwidth, Communication topology, LFC, LMI-LQR, Smart Gridfuture smart grid, it is expected that PMU is installed extensively across the power grid. Smart grid (SG) incorporates a two way digital communication technology which integrates the communication technology and intelligent computer processing technology into a large scale power system for quick monitoring, control, self-healing, selforganizing and robustness for physical system, so that consumer may be benefitted [6][7]. SGs require reliable communication systems. It is well known that due to high speed open communication infrastructure, i.e. wireless networks, are unreliable because of time delay, packet loss and the communication failure. Further a comprehensive review on SG potential application and communication requirement is presented in [8].Communication technologies and their impact on power system operation need a closer study to implement the control strategy. The power systems rely on control algorithms having information exchanged via communication networks. Any network effects jeopardize failure rate of control itself. Recently, researchers have reported coupling of power system and communication networks as discrete-event triggering systems for LFC for multi area power system with communication delays [9].In real-time monitoring of smart grid operation, it is essential to exploit the high speed of throughput. The need of real-time information and strict latency requirements for bulk amounts of data has been proposed in [10]. The strict latency of most of the application of smart grid lies between 100 ms to 5 sec [11]. Further the detail description of latency requirements for power system operation is given in [1]. The time duration of transient stability is less than 100 ms, small signal stability is less than 1 sec, voltage stability between 1-5 sec and grid disturbances in range of few minutes. The communication delay on a network includes the transmission delay, propagation delay, q...