Coordinated control strategy for simultaneous frequency and voltage stabilisation of the multi-area interconnected system considering communication time delays
Ch. Naga Sai Kalyan, Sambasiva Rao
Abstract
This paper presents a novel tuning approach of the secondary controller in combined load frequency control and automatic voltage regulator of the interconnected power system considering communication time delays (CTDs). Traditional PID is used as a regulator and optimal gain values are rendered with new combined optimisation of the differential evolution-artificial electric field algorithm. The efficacy of the presented algorithm is tested on the two-area reheat thermal plant, which is widely utilised in the literature, and also on some standard benchmark test functions. Moreover, the secondary regulator is not enough to sustain the stability under large disturbances and due to CTDs. Therefore, to dampen the system oscillations further, an interline power flow controller (IPFC) and redox flow batteries coordinated control strategy is implemented. However, the impact of CTDs on the combined model is also analysed. The combined model is subject to random power demand to validate the robustness of the proposed coordinated control scheme.Abbreviations: LFC: load frequency control; DTUs: distant terminal units; DE: differential evolution; CTDs: communication time delays; AVR: automatic voltage regulation; RFB: sedox flow battery; ESD: energy storage device; ISE: integral square error; AEF: artificial electric field; ACE: area control error.