Area Hydrothermal Power System Research Articles

Path Finder Optimization Algorithm Tuned 3DOFPID Controller for Frequency Stabilization in Wind Integrated Realistic Power System with HVDC line

In this paper, a novel controller is suggested for the stabilization of the frequency of wind integrated realistic power system (WIRPS) during load uncertainties. 3-degree-of-freedom PID (3DOFPID) based on the pathfinder optimization algorithm (PFOA) is proposed in this paper. Initially, the performance of PFOA tuned 3DOFPID is tested on a widely implemented model of dual area hydro-thermal power system (DAHTPS) for 10% step load perturbation in area-1. Later, the suggested controller performance is analyzed on WIRPS for 10%SLP on area-1. Investigation of WIRPS is carried out by considering and omitting the non-linearity constraint of communication time delays (CTDs). The efficacy of the presented controller efficacy is showcased with the other control techniques. Moreover, the impact of CTDs on WIRPS is demonstrated and a further high voltage DC (HVDC) line is laid with the WIRPS for performance enhancement. The robustness of the presented strategy is established finally with the robustness test.

Optimal Designing of Fuzzy-PID Controller in the Load-Frequency Control Loop of Hydro-Thermal Power System Connected to Wind Farm by HVDC Lines

In this paper an optimized Fuzzy based controller is proposed for automatic generation control of two area hydro-thermal power system connected to the wind farm. The parameters and membership functions of the proposed controller are optimized by a modified version of Cuckoo search algorithm (CSA). Also, a weighted objective function is proposed to minimize the frequency deviation and transmission power oscillation. The suggested heuristic objective function is a weight function from maximum frequency drift and oscillations fading time. To assessing the performance of suggested controller, studies is accomplished by two different scenarios. In the first scenario, the simulations are performed without wind farm and in the second scenario, the simulation is done in the presence of a wind farm. The simulation results indicate that the wind farm presence has major effect on sustained improvement of power system and the reason is considering the load variations in the area, the demand electrical energy in the same area is provided by the wind farm and hence, the frequency oscillations are decreased in both areas.

Discrete Data AGC of Hydrothermal Systems Under Varying Turbine Time Constants Along With the Power System Loading Conditions

The paper deals with the discrete data automatic generation control (AGC) of two area hydrothermal power system operating at different loading conditions. The power system load varies considerably throughout the day and accordingly, thermal and hydropower systems are scheduled to operate at different loading conditions. It is found that steam as well as hydro turbine time constants vary as the power system loading varies. In earlier AGC studies, these parameters are considered to be constant, irrespective of power system loadings. This paper studies the dynamic performance of hydrothermal power system considering the variation of these turbine time constants along with the nominal loading of power system. The studies have been conducted for linear as well as nonlinear models of speed governor and hydroturbine models recommended by the IEEE committee. It is also discovered that conventional empirical formula-based hydraulic governor settings recommended by the IEEE working group are completely unacceptable for hydrothermal power system. A maiden attempt is made to optimize the hydraulic governor settings simultaneously along with the controller gains using metaheuristic algorithm. The comparison of system dynamic responses reveal that optimization-based hydrogovernor settings give the better dynamic performance in case of linear as well as nonlinear models of hydro system, and therefore are strongly recommended over the conventional settings. The paper also deals with the optimum selection of sampling periods for discrete data AGC operation of hydrothermal systems.

Load frequency control in deregulated power system integrated with SMES–TCPS combination using ANFIS controller

In this paper, the application of Adaptive Neuro Fuzzy System (ANFIS) controller is used for mitigating the various Load Frequency Control (LFC) issues in a two area hydrothermal power system under deregulated environment is highlighted. To improve the LFC performance, combination of Super Conducting Magnetic Energy Source (SMES) and Thyristor Controlled Phase Shifters (TCPS) are included in its control area. The implementation of SMES–TCPS combination arrests the initial fall in frequency as well as the tie line power deviations after a sudden load disturbance. To investigate the effectiveness of the proposed approach, the dynamics of the system is analyzed with unilateral, bilateral and contract violation cases for a small load perturbation and the comparative results are also presented. The simulated results show that the performance of ANFIS controller is better than the conventional PI controller and the Fuzzy logic controller.

A novel hybrid PSO-PS optimized fuzzy PI controller for AGC in multi area interconnected power systems

Abstract In this paper, a novel hybrid Particle Swarm Optimization (PSO) and Pattern Search (PS) optimized fuzzy PI controller is proposed for Automatic Generation Control (AGC) of multi area power systems. Initially a two area non-reheat thermal system is used and the gains of the fuzzy PI controller are optimized employing a hybrid PSO and PS (hPSO-PS) optimization technique. The superiority of the proposed fuzzy PI controller has been shown by comparing the results with Bacteria Foraging Optimization Algorithm (BFOA), Genetic Algorithm (GA), conventional Ziegler Nichols (ZN), Differential Evolution (DE) and hybrid BFOA and PSO based PI controllers for the same interconnected power system. Additionally, the proposed approach is further extended to multi source multi area hydro thermal power system with/without HVDC link. The superiority of the proposed approach is shown by comparing the results with some recently published approaches such as ZN tuned PI, Variable Structure System (VSS) based ZN tuned PI, GA tuned PI, VSS based GA tuned PI, Fuzzy Gain Scheduling (FGS) and VSS based FGS for the identical power systems. Further, sensitivity analysis is carried out which demonstrates the ability of the proposed approach to wide changes in system parameters, size and position of step load perturbation The proposed approach is also extended to a non-linear power system model by considering the effect of governor dead band non-linearity and the superiority of the proposed approach is shown by comparing the results of hybrid BFO-PSO and craziness based PSO approach for the identical interconnected power system. Finally, the study is extended to a three area system considering both thermal and hydro units with different controllers in each area and the results are compared with hybrid BFO-PSO and ANFIS approaches.

Variable structure fuzzy gain scheduling based load frequency controller for multi source multi area hydro thermal system

In this paper, variable structure fuzzy gain scheduling is proposed for solving the load frequency control problem of multi source multi area hydro thermal power system. The two control areas are connected via tie line. Each area comprises of both hydro and thermal power plant. The area frequency and tie line power oscillates during load variations are controlled by primary governor controller and secondary Proportional Integral (PI) controller. The PI controller gains are tuned using Ziegler Nichols’ (ZN) method and Genetic Algorithm (GA). ZN method is for conventional bench marking and GA is based on search in the space. In both the methods, the gain values of PI controllers are fixed for any system changes and it is not acceptable. This problem is overcome by scheduling the gain based on system changes using Fuzzy Logic. Finally, Variable Structure System of switching P to PI controller during transient to steady state is integrated with fuzzy gain scheduling. On evaluating all the controller performance based on performance indices, variable structure fuzzy gain scheduling provides better response for multi source multi area hydro thermal power system.