scholarly journals Introducing LQR-fuzzy for a dynamic multi area LFC-DR model

Author(s):  
Palakaluri Srividya Devi ◽  
R.Vijaya Santhi

It is well known that Load Frequency Control (LFC) model plays a vital role in electric power system design and operation. In the literature, much research works has stated on the advantages and realization of DR (Demand Response), which has proved to be an important part of the future smart grid. In an interconnected power system, if a load   demand changes randomly, both frequency and tie line power varies. LFC-DR model is tuned by standard controllers like PI, PD, PID controllers, as they have constant gains. Hence, they are incapable of acquiring desirable dynamic performance for an extensive variety of operating conditions and various load changes. This paper presents the idea of introducing a DR control loop in the traditional Multi area LFC model (called LFC -DR) using LQR- Fuzzy Logic Control. The effect of DR-CDL i.e. (Demand Response Communication Delay Latency) in the design is also considered and is linearized using Padé approximation. Simulation results shows that the addition of DR control loop with proposed controller guarantees stability of the overall closed-loop LFC-DR system which effectively improves the system dynamic performance and is superior over a classical controller at different operating scenarios.

2020 ◽  
pp. 146-157
Author(s):  
Dr. Anand Gondesi ◽  
Dr. Varaha Narasimha Raja. Ch

Today, in power systems the Load Frequency Control (LFC) problem plays a vital role in an interconnected power system, wherein it maintains the system frequency and tie line flow at their scheduled values during normal period. It is due to frequency of power system, which changes over time with respect to continuous load variation. The present chapter proposes a new methodology to study the Load Frequency Control (LFC) problem of a three area inter-connected system using R Fuzzy system (FS) approach. Moreover, this technique is applied to control the systems which include three areas considering a non-linearity Generation Rate constraint (GRC) having two steam turbines and one hydro-turbine tied together. The main advantage of this controller is its high insensitivity to large load changes and plant parameter variations even in the presence of non-linearity. Furthermore, it is tested on a three-area power system to illustrate its robust performance. The results obtained by using Rule Based Fuzzy PID controller explicitly show that the performance of this proposed controller is superior to conventional controller in terms of several parameters like overshoot, settling time and robustness.


Author(s):  
Muhammad Abdillah ◽  

Load frequency control (LFC) problem has been a foremost issue in electrical power system operation and is becoming more important recently with growing size, changing structure, and complexity in interconnected power systems. In general, LFC system utilizes simple proportional integral (PI) controller. However, due to the PI control parameters are commonly adjusted based on classical or trial-error method (TEM), it is incapable of obtaining good dynamic performance for a wide range of operating conditions and various load change scenarios in a multi-area power system. This paper introduces a novel control scheme for load frequency control (LFC) using hybrid fuzzy proportional integral (fuzzy PI) and linear quadratic regulator (LQR) optimal control, where fuzzy logic control (FLC) is used to adjust the gains KP and KI of PI controller which called fuzzy PI in this paper, while the LQR optimal control method is employed to obtain the feedback gain KOP through Algebraic Riccati Equation (ARE). The merit of both control strategies is to tune their control feedback gains, which are KP, KI and KOP, regarding various system operating conditions. Artificial immune system (AIS) via clonal selection is utilized to optimize the membership function (MF) of fuzzy PI and weighting matrices Q and R of LQR optimal control in order to obtain their optimal feedback gains. To examine the efficacy of the proposed method, LFC of two-area power system model is utilized as a test system. The amalgamation of fuzzy PI-LQR is applied to improve the dynamic performance of two-area LFC. Other control schemes such as PI controller, hybrid PI controllerLQR, and hybrid fuzzy PI-LQR are also investigated to the studied a test system. The obtained simulation results show that the proposed method could compress the settling time and decrease the overshoot of LFC which is better than other approaches that are also employed to the tested system in this study.


Author(s):  
Charles Komboigo ◽  
Naomitsu Urasaki ◽  
Tomonobu Senju ◽  
Mohammed Elsayed Lotfy ◽  
Abdul Motin Howlader ◽  
...  

Abstract In this paper, a modern two stage frequency control approach for two area interconnected power system with doubly fed induction generator (DFIG) based wind turbine is proposed. For first stage, a proportional integral derivative (PID) controller is designed for every conventional thermal area to control frequency and tie line power. In the second stage, a PID controller is implemented in DFIG to regulate its speed and accordingly control system frequency particle swarm optimization is used to tune the controllers of conventional thermal units and DFIG. The effectiveness and robustness of the proposed control scheme are investigated under different operating conditions using MATLAB/Simulink.


2020 ◽  
Vol 9 (3) ◽  
pp. 39-50
Author(s):  
Tawfiq H. Elmenfy

The use of proportional integral (PI) load frequency control (LFC) to ensure the stable and reliable operation of electric power system is practical important. Any imbalance between synchronous generators and consumption loads will cause frequency unstable within the complete power system. The purpose of the load frequency control (LFC) is to keep the power system frequency and the inter-area tie power as near equilibrium point. This article introduces a gain schedule PI fuzzy load frequency control (GLFC) applying to two area electric power system. The GLFC consists of two level control systems, where the PI controller in the conventional form and its parameters are tuned in real time by fuzzy system. A fuzzy rule base is constructed in the form set of IF-THEN that describe how to choose the PI parameters under different operating conditions. The simulation has been conducted in MATLAB Simulink package. The effectiveness of the GLFC is measured by comparison with conventional PI load frequency controller.


2016 ◽  
Vol 12 (1) ◽  
pp. 30-42
Author(s):  
Pasala Gopi ◽  
P. Reddy

This paper investigates Load Frequency Control of multi area inter connected power system having different turbines with PID controller. The gain values of controller are optimized using different Metaheuristic Algorithms. The performance and validity of designed controllers were checked on multi area interconnected power system with various Step Load Perturbations. Finally, the performance of proposed controllers was compared with conventional controller and from the result it was proved that the proposed controller exhibits superior performance than conventional controller for various Step Load Perturbations.


2020 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Hady H. Fayek

Remote farms in Africa are cultivated lands planned for 100% sustainable energy and organic agriculture in the future. This paper presents the load frequency control of a two-area power system feeding those farms. The power system is supplied by renewable technologies and storage facilities only which are photovoltaics, biogas, biodiesel, solar thermal, battery storage and flywheel storage systems. Each of those facilities has 150-kW capacity. This paper presents a model for each renewable energy technology and energy storage facility. The frequency is controlled by using a novel non-linear fractional order proportional integral derivative control scheme (NFOPID). The novel scheme is compared to a non-linear PID controller (NPID), fractional order PID controller (FOPID), and conventional PID. The effect of the different degradation factors related to the communication infrastructure, such as the time delay and packet loss, are modeled and simulated to assess the controlled system performance. A new cost function is presented in this research. The four controllers are tuned by novel poor and rich optimization (PRO) algorithm at different operating conditions. PRO controller design is compared to other state of the art techniques in this paper. The results show that the PRO design for a novel NFOPID controller has a promising future in load frequency control considering communication delays and packet loss. The simulation and optimization are applied on MATLAB/SIMULINK 2017a environment.


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