Performance Optimization Of Load Frequency Control For Power System Based On Linear Active Disturbance Rejection Control Approach

Automatic generation control(AGC)is a vital means to realize the secondary frequency regulation in modern secondary power grid dispatching center.This type of controlling and regulation is commonly referred to as load frequency control(LFC).Load frequency control automatically track the load perturbation in power systems in real time,and maintain the balance between power generation and load demand to maintain the frequency of the system at the nominal value,which is an important aspect to ensure the power quality.The widespread application of the conventional controllers are not satisfactory to get the better results against the uncertainty and nonlinearity of the system.Therefore,an advanced control methodologies should be used to obtain the satisfactory results.In this study,the linear active disturbance rejection control algorithm have been studied for the LFC mechanism along with the good optimization techniques to tune the parameters of the controller to optimal value.Firstly,the issue of the LFC is more challenging in the complex power systems comprise of high wind power penetration,because of the unpredictable nature of wind.Therefore,a single area power system with high wind penetration have been considered in this dissertation to regulate the frequency by rejecting the internal and external disturbances simultaneously.The framework of LADRC is based on the extended state observer(ESO)to estimate the un-modelled dynamics and external disturbances in real time and compensate for it by a simple linear proportional derivative(PD)control law.Furthermore,the parameters tuning process for LADRC is optimized in to two bandwidths:observer bandwidth and controller bandwidth.To overcome the problem of optimizing the parameters,a modified bat inspired algorithm have been employed to tune the parameters of the controllers for the LFC issue of single area power system with high wind penetration.In the end,to approve the effectiveness of the proposed method,the results have been compared with the conventional PI and Fuzzy logic PI controller.Secondly,in this dissertation the LADRC based LFC scheme have been used for the four area interconnected thermal power system including the boiler dynamics and physical constraints.The purpose of the controller in this system is to regulate the nominal frequency,area control error(ACE),and tie-line power deviation caused by the load perturbation,parameters uncertainty,and could be the nonlinearities in the system.The distinguished feature of LADRC is employed to deal with the internal and external disturbances in real time by estimating and compensating for it by PD control law.However,the parameters of the controller have been optimized by hybrid chaotic firefly bat optimization algorithm in terms of integral time absolute error(ITAE)performance index.Finally,the results of the proposed controller have been compared with the FLPI and FLiPID controller.The simulation results shows the superiority and effectiveness of the LADRC controller as compared PI,FLPI and FLiPID controller.The simulations have been performed with respect to different aspects,such as varying the wind penetration,load perturbation in runtime,parameters uncertainties,and Monte-Carlo based robustness analysis.The results shows that the proposed controller is more robust and stable with the respect to the other controllers.