Frequency deviations stabilizations in restructured power systems using coordinative controllers

Modern restructured power system faces excessive frequency aberrations due to the intermittent renewable generations and persistently changing load demands. An efficient and robust control strategy is obligatory to minimise deviations in the system frequency and tie-line to avoid any possible blackout. Hence, in this research, to achieve this target, automatic generation control (AGC) is utilized as a secondary controller to alleviate the changes in interconnected restructured systems at uncertainties. The objective of AGC is to quickly stabilize the deviations in frequency and tie-line power following load fluctuations. This thesis addresses the performance of AGC in two-area restructured power systems with many sophisticated control strategies in the presence of renewable and traditional power plants. As per literature of research work, there are quite a few research studies on AGC of a restructured system using optimized coordinative controllers. Besides, investigations on advanced optimized-based coordinative controller approaches are also rare to find in the literature. So, various combinations of two degrees of freedom (2DOF) controllers are utilized as supplementary controllers to diminish the frequency deviations. Nevertheless, the interconnected tie-lines are typically congested in areas with huge penetration of renewable sources, which may reduce the tie -line capability. Therefore, distinct FACTS controllers and ultra-capacitor (UC) are integrated into two-area restructured systems for strengthening the tie-line power and frequency. Further, new optimization techniques such as cuckoo search (CS), bat algorithm (BA), moth-flame optimization (MFO) are utilized in this work for investigating the suggested 2DOF controllers and compared their performance in all contracts of restructured systems. As per the simulation outcomes, the amalgamation of DPFC and UC with MFObased 2DOF PID-FOPDN shows low fluctuation rate in frequency and tie-line power. Besides, the settling times (ST) of two areas are 9.5 S for ΔF1, 8.2 S for ΔF2, and 10.15 S for ΔPtie. The robustness of the suggested controller has been verified by ±25% variations in system parameters and loading conditions

A new meta‑heuristic optimization‑based MPPT control technique for green energy harvesting from photovoltaic systems under different atmospheric conditions

At present, a photovoltaic (PV) system takes responsibility to reduce the risk of global warming and generate electricity. However, the PV system faces numerous problems to track global maximum peak power (GMPP) owing to the nonlinear nature of the environment especially due to partial shading conditions (PSC). To solve these difficulties, previous researchers have utilized various conventional methods for investigations. Nevertheless, these methods have oscillations around the GMPP. Hence, a new metaheuristic method such as an opposition-based equilibrium optimizer (OBEO) algorithm is used in this work for mitigating the oscillations around GMPP. To find the effectiveness of the proposed method, it can be evaluated with other methods such as SSA, GWO, and P&O. As per the simulation outcome, the proposed OBEO method provides maximum efficiency against all other methods. The efficiency for the proposed method under dynamic PSC is 95.09% in 0.16 s, similarly, 96.17% for uniform PSC and 86.25% for complex PSC

A state-of-the-art review on modern and future developments of AGC/LFC of conventional and renewable energy-based power systems

This paper presents a comprehensive literature review and an up-to-date bibliography on automatic generation control (AGC)/load frequency control (LFC) of interconnected power systems integrated with conventional, renewable and sustainable energy sources. The objective of AGC is to quickly stabilize the deviations in frequency and tie-line power following load fluctuations. Various state-of-the-art AGC strategies have not been reviewed so far, hence, an appropriate review on recent AGC mechanism is indispensable. Salient points discussed and highlighted in this survey include different power system models with/without renewable sources, and integration of sophisticated concepts such as microgrids (MGs), smart grids (SGs), distributed generations (DGs), high voltage direct current (HVDC) links, and power system after liberalization. Furthermore, various examined control approaches like traditional controllers, intelligent methods, adaptive, robust, optimal, variable, soft computing, centralized and decentralized methods with their advantages and disadvantages have been pondered and compared. Further, AGC challenges with incorporation of flexible AC transmission systems (FACTS), energy storage devices and high penetration of renewable sources for modern and future power systems have been addressed. This review concludes the new control schemes namely, electrical vehicles (EVs), fractional-order (FO) based controllers, fuzzy aided controllers, and cascaded controllers with case studies. Research gaps and directions for future developments AGC of power systems are also discussed

A hybrid PEO based maximum power point tracking controller for pv system under partial shading conditions

Solar photovoltaic (PV) energy plays a potential role in the generation of electricity and is eco-friendly to the environment. However, PV systems face the challenge to extract maximum peak power (MPP) on the account of partial shading conditions (PSC). To encounter this problem previously various conventional and soft computing based maximum power point tracking (MPPT) controllers are used to track the MPP. Nevertheless, inaccuracy occurred in the tracking of MPP, hence in this paper, a new metaheuristic hybrid method is introduced such as premature equilibrium optimizer (PEO). This PEO method acts as an MPPT controller and can track the MPP without any oscillation under PSC and has less convergence time, settling time and high efficiency

Review on automatic generation control strategies for stabilising the frequency deviations in multi-area power system

This paper reviews on the function of Automatic Generation Control (AGC) as an intelligent mechanism in enhancing electrical power systems dynamic performance at various perturbations; by sustaining the frequency and tie-line power within the scheduled limits. The review discloses the investigation on the flexible ac transmission system (FACTS), soft computing-based optimisation techniques, centralised approaches, decentralised methods, adaptive control approaches, and robust control techniques in AGC systems. Furthermore, the discussion focuses on applications of AGC with energy storage systems (ESS), high voltage direct current (HVDC) link, distributed generation, microgrids, and smart grids, in both traditional and liberalised power systems. Eventually, this paper concludes by highlighting the economic load dispatch methods, load forecasting methods, and digital control approach in AGC systems