H‐infinity based non‐linear sliding mode controller for frequency regulation in interconnected power systems with constant and time‐varying delays. Issue 11 (1st August 2016)

• Record Type: Journal Article
• Authors: Prasad, Sheetla; Purwar, Shubhi; Kishor, Nand
• Is Part Of: IET generation, transmission & distribution. Volume 10:Issue 11(2016)
• Page Start: 2771
• Page End: 2784
• Publication Date: 2016-08-01
• Subjects: power system interconnection -- variable structure systems -- nonlinear control systems -- H∞ control -- linear matrix inequalities -- control system synthesis -- frequency control -- time‐varying systems -- delays -- Lyapunov methods -- stability -- load regulation -- power system control; frequency regulation -- interconnected power systems -- time‐varying delays -- constant delays -- load frequency control -- LFC scheme -- interconnected system -- communications delays -- time delay‐dependent H∞‐based nonlinear sliding mode controller -- Lyapunov‐Krasovskii functional -- time delay‐dependent stability criteria -- linear matrix inequalities optimisation -- random step load disturbance -- generation rate constraints -- two‐term controller design -- frequency stability; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2015.1475
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : Load frequency control (LFC) scheme communicates from remote terminal units to control centre, followed by control centre action on the corresponding plant units. The conventional dedicated communication channels have constant time delay, while open communication channel, i.e. shared one has time‐varying delay. These delays degrade the dynamic performance or even lead to system instability. In an interconnected system, communications delays cannot be ignored and therefore the time delay is introduced in the area control error signal. In this study, a time delay‐dependent H ∞ ‐based non‐linear sliding mode controller for LFC scheme has been proposed for N area power system. The approach uses Lyapunov–Krasovskii functional based on time delay‐dependent stability criteria and linear matrix inequalities optimisation. Simulation studies are presented for two‐area LFC scheme against step and random step load disturbance and generation rate constraints. Comparison is also made with recently reported; two‐term controller design. The simulation results establish the superiority and applicability of the proposed design for LFC application. The results illustrate that the proposed scheme can effectively enhance the frequency stability via improving the damping of the system.