scholarly journals Load frequency control of a hydro dominating interconnected power system

2020 ◽  
Author(s):  
◽  
Milan Joshi

Energy is one of the vital figures that impact the development of civilization in the 21st century. It has been projected that by the year 2050, global energy needs will be satisfied by renewable sources. Among these renewable energy resources hydropower is available worldwide with relatively cheaper accessibility for most of the communities. Nevertheless, hydropower's control architecture raises concern for the system operators in terms of preserving the Load Frequency Control (LFC) services due to the elongated response time of hydro turbines in catering for the varying load demands. The varying load demands are inevitable in the power system due to different clients’ energy consumption patterns at different times. This, therefore, places changing control framework requests as per the requirement of diverse clients. Hence, the research proposes and demonstrates the connection of the hydro-hydro framework through the AC tie- line for LFC. The Linear Quadratic Regulator (LQR) is a plan for hydro overseeing framework in discrete mode. The application derived is displayed through closed- loop feedback gains and closed-loop eigenvalues. In the expansion model, the positive effect of a Unified Power Flow Controller (UPFC) and Redox Flow Battery (RFB) in LFC studies is investigated. This proposition moreover shows the joint endeavors of Fuzzy Logic (FL) as well as Proportional Integral Derivative (PID), with control gains well-calculated, through Particle Swarm Optimization (PSO) result into a robust FL-PSO-PID for LFC of the connected hydro framework. The different errors are defined to assess the yield as well as the execution of the FL-PSO-PID. The yield appears through a decline in blunder values as well as minimization in framework responses from accurate estimation for the LFC under various working conditions such as non- linearity, random load alteration, and parametric move as a result of a precise estimate. In the expansion, the effect of energy storage devices is also investigated to understand the enhancement provided frequency control of the hydro system, and the result obtained shows their effectiveness. Finally, the outcomes and future extent of this investigation work have been presented.

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Ashraf M. Abdelhamid ◽  
Ahmed A. M. El-Gaafary

Many studies have been made in the field of load frequency control (LFC) through the last few decades because of its importance to healthy power system. It is important to maintain frequency deviation at zero level after a load perturbation. In decentralized control, the multi-area power system is decomposed into many single input single output (SISO) subsystems and a local controller is designed for each subsystem. The controlled subsystems may have slow poles; these undesired poles may drive the aggregated overall system into the instability region. Thus, it is required to relocate these poles to much more stable places to avoid their effect upon the overall system stability. This study aims to design a new load frequency controller based on the powerful optimal linear quadratic regulator (LQR) technique. This technique can be applied over subsystem level to shift each subsystem undesired poles one by one into a prespecified stable location which in turn shift the overall system slow poles and reduce the effect of the interaction between the interconnected subsystems among each other. This procedure must be applied many times as the number of undesired poles (pairs) until all the desired poles are achieved. The main objective is considered to get a robust design when the system is affected by a physical disturbance and ±40% model uncertainties. LQR can be applied again over the aggregated system to enhance the stability degree. Simulation results are used to evaluate the effectiveness of the proposed method and compared to other research results.


Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2664 ◽  
Author(s):  
Eleftherios Vlahakis ◽  
Leonidas Dritsas ◽  
George Halikias

Load frequency control (LFC) is one of the most challenging problems in multi-area power systems. In this paper, we consider power system formed of distinct control areas with identical dynamics which are interconnected via weak tie-lines. We then formulate a disturbance rejection problem of power-load step variations for the interconnected network system. We follow a top-down method to approximate a centralized linear quadratic regulator (LQR) optimal controller by a distributed scheme. Overall network stability is guaranteed via a stability test applied to a convex combination of Hurwitz matrices, the validity of which leads to stable network operation for a class of network topologies. The efficiency of the proposed distributed load frequency controller is illustrated via simulation studies involving a six-area power system and three interconnection schemes. In the study, apart from the nominal parameters, significant parametric variations have been considered in each area. The obtained results suggest that the proposed approach can be extended to the non-identical case.


2021 ◽  
Vol 309 ◽  
pp. 01036
Author(s):  
Srikanth Boyini ◽  
Srividya Devi Palakaluri ◽  
Rekha Mudundi

This paper provides a load frequency control (LFC) of a micro grid with renewable energy resources (RES). The operation of micro grid with a low inertia system leds to disturbances in power system. The disturbances in frequency is more in micro grid than conventional power system. So there should be a fast recovery of changes in frequency with existing system and interconnected system (RES). Active power injection is the main scheme to control frequency of a system. The matlab simulink tells us that different active power injection system contribute for the fast control of grid frequency with PID controller. The use of ANN technology to this system the load frequency control can be illustrated in faster rate of its recovery. An ANN controller is investigated which handles the inputs collectively in each sector of the power system. Back-transmission time is normally used in the study for neural network education. The performance of the power system is simulated independently with a typically integrated conventional controller and ANN controller. A complete spectrum of small signals is introduced for RESs in the isolated microgrid and a correct role in frequency control studies is taken into account.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8522
Author(s):  
Anna Sibilska-Mroziewicz ◽  
Andrzej Ordys ◽  
Jakub Możaryn ◽  
Pooyan Alinaghi Hosseinabadi ◽  
Ali Soltani Sharif Abadi ◽  
...  

The three-area power system is widely considered a suitable example to test load frequency control of the distributed generation system. In this article, for such a system, for the power stabilization task, we introduce two controllers: Linear Quadratic Regulator (LQR), which is model-based, and Fuzzy Logic Controller (FLC), which is data-based. The purpose is to compare the two approaches from the point of view of (i) ease of implementation and tuning, and (ii) robustness to changes in the model. The model, together with controls strategies, has been implemented in the MATLAB software. Then, it has been tested for different simulation scenarios, taking into account the disturbances and faulty tie-lines between areas. Various quality measures allow to compare the performance of each control strategy. The comparison in terms of parameter change and load disturbances prompt us to propose suitable metrics and advice notes on the application of each controller.


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