Thyristor Controlled Phase Shifter Research Articles

Whale Optimization Controller for Load Frequency Control of a Two-Area Multi-source Deregulated Power System

This article discusses a Whale Optimization (WO) controller for design analysis, stability management, application, and performance analysis of a deregulated two-area multi-source energy system. Within the power grid, the Automatic Generation Control (AGC) maintains the power balance and strengthens the sudden frequency disturbance of the grid. Various researchers are targeted many kinds of fast-acting energy-storing devices to dampen space frequency oscillations and diversion of the tie line because of unexpected load variation. To regulate the power flow between multi-areas, load frequency control (LFC) is used by keeping frequency constant. But, to design a controller for minimizing the issues of LFC remains a challenge within the deregulated atmosphere. The main objective of the proposed methodology is to design a controller for minimizing the issues in LFC within the deregulated atmosphere. A two-area deregulated hydrothermal power system is employed to analyze many LFC problems in the deregulated power grid. During this modeling, the Thyristor-Controlled Phase Shifters (TCPS) and Capacitive Energy Storage unit (CES) are placed in the tie line and its control space. To mitigate the various issues of LFC in a two-area deregulated hydrothermal power system, the CES–TCPS combination is placed between the two control areas and the transient performance of constant is evaluated. The WO controller will increase the system power size to focus on the better performance of low-frequency management tasks. In addition, the effectiveness of the WO algorithm in tuning the proportional integral controller is also compared in a different contract (unilateral, bilateral and contract violation cases) scenarios of the proposed deregulated power system. Finally, the simulation is carried out in MATLAB/Simulink platform and the results obtained for the WO controller is compared with the normal and fuzzy PI controllers.

Automatic Generation Control of a Two Area Thermal-Thermal Deregulated Power System with HES and TCPS units for Unscheduled Interchange Price Signals

Automatic Generation Control (AGC) plot for two area inter-connected thermal to thermal Deregulated Power System (DPS) utilizing Unscheduled Interchange (UI) price signal, which has an effect on the power markets is proposed in the paper. Unscheduled Interchange price is one of the most important parts of Availability Based Tariff (ABT) which goes about as an optional control system for regulating the grid frequency. These UI price signals vacillate according to change in grid frequencies which can be open by the participants (generator or load) associated with the grid. The customary AGC system, however, attempts to carry the error of frequency to 0, yet it will be an ineffectual answer for taking an interest producing penalty deviations with frequency. This plan additionally gives the system operator adaptability to plan the generation in an ideal way. In this examination, the execution of a Proportional Integral (PI) controller is proposed because beneficial AGC of 2 area thermal and thermal deregulated system works under the impacts of bi-lateral contracts over the dynamics. The tuning of PI controller parameters is illuminated by utilizing a Moth-Flame Optimization (MFO) algorithm. Further to improve the AGC performance, the Hydrogen Energy Storage (HES) units is incorporated into its control area which can adequately moist the electromechanical motions in a power system, as they give guarantee from the storage limit notwithstanding the generator rotors dynamic energy which can share abrupt deviations in power requirement. The Thyristor Controlled Phase Shifter is proposed in arrangement with tie line between any inter-connected areas that may be applied to balance out frequency motions of the area by fast control of power in tie line over the interconnections. Execution of HES-TCPS units' blend captures the underlying frequency fall just as the power deviations in tie line for an abrupt load unsettling influence and the outcomes show that the charges of UI are extensively limited while keeping up at normal frequency worth. Furthermore, proposed strategy yields an eminent decrease in the control input deviation yet, in addition, guarantees superior soundness for the unscheduled interchange price signals therefore, the market participants can get benefit accordingly.

Automatic generation control of power system in deregulated environment using hybrid TLBO and pattern search technique

Abstract In the present work, a hybrid Teaching Learning Based Optimization and Pattern Search (hTLBO-PS) technique with Tilted Integral Derivative (TID) controller is suggested for Automatic Generation Control (AGC) under deregulated environment. In the beginning, a two-area four units thermal-gas system is assumed and Tilted Integral Derivative (TID) controller is employed. The superiority of hTLBO-PS based TID is illustrated by comparing the published results with Genetic Algorithm (GA) and Differential Evolution (DE) tuned I/PI/PID controllers for the identical test scheme. After that the suggested methodology is extended to 2-area with 6-units power system by considering the non-linearities parameters. Additionally, to improve the performance of the system, a Thyristor Controlled Phase Shifter (TCPS) is connected in the tie-line and Superconducting Magnetic Energy Storage (SMES) devices are considered in each area. Finally, the sensitivity analysis of proposed method with perturbation in plant parameters has been analyzed.

Impact of Flexible AC Transmission System Devices on Automatic Generation Control with a Metaheuristic Based Fuzzy PID Controller

The present work proposes a teaching–learning-based optimization (TLBO)-tuned fuzzy proportional-integral-derivative (PID) controller of two-area hydro-thermal generating units for automatic generation control (AGC). The proposed system takes into account the physical constraints such as transport delay (TD), generation rate constraint (GRC), and governor dead band (GDB) nonlinearities. Firstly, fuzzy PID controllers were designed for both the areas and their gains were optimized using various minimization objective function criteria. Furthermore, applications of flexible alternating current transmission system (FACTS) devices such as static synchronous series compensator (SSSC), thyristor-controlled series capacitor (TCSC), thyristor-controlled phase shifter (TCPS), and unified power flow controller (UPFC) were investigated by integrating FACTS devices in appropriate locations of the system. The simulation results revealed that the minimum objective values were attained when the UPFC was placed in the system. Lastly, robustness analysis was done to observe the capability of the proposed controller with UPFC by changing system parameters and considering random load disturbances.

On design of a robust decentralized controller for an interconnected multi-area power system with FACTS devices

In this article, a robust active disturbance rejection control (ADRC) is proposed for load frequency control (LFC) of an interconnected multi-area power system. Two widely employed test systems, namely, two-areas and four-areas hydro-thermal power utilities are concerned to validate the efficacy of the suggested method. To enhance the performance of the system, series flexible ac transmission system (FACTS) like thyristor controlled series compensator (TCSC) and thyristor controlled phase shifter (TCPS) are considered. The simulation results indicated that the system performance is improved with the inclusion of FACTS devices. The adjustable parameters of the proposed FACTS controllers are optimized using particle swarm optimization (PSO) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The investigations showed that the proposed controller provides better dynamic performance than others from the point of view of settling time, peak over/undershoot. Finally, the sensitivity analysis of the system is inspected by varying the system parameters and operating load conditions from their pre-specified values. It is observed that the suggested controller based optimization algorithm is robust and performs satisfactorily with the variations in operating load conditions, system parameters and load patterns.

Load frequency control of multi‐area hybrid power system integrated with renewable energy sources utilizing FACTS & energy storage system

AbstractThis article proposes the minimization of the frequency deviations in the three‐area hybrid power system. The application of thyristor controlled phase shifter (TCPS) and ultracapacitor (UC) is utilized on load frequency control (LFC). The quality of power supply is affected due to continuous and random changes in load during the operation of the power system. Hence, a power system control is required to maintain a continuous balance between power generation and load demand. LFC plays an important role in maintaining constant frequency and voltage in order to ensure the reliability of electric power. The proportional integral derivative (PID) is adopted for the LFC scheme. The three‐area system considered in this article is integrated with conventional and renewable energy sources such as solar, biomass, and fuel cell. TCPS connected in series with the tie‐line ensures the stabilization of the system and provides additional service like dynamic power flow control in the tie‐line and the power quality is sustained by the subordinate control of supercapacitor energy storage. The system variability is basically due to the frequency fluctuations when it is subject to the load deviations. Thus, the suppression of peak value of frequency deviation through power modulation control is the only way to reduce this problem. By using this method, the efficiency of proposed technique becomes better in deregulated environment which is accepted for the load frequency control scheme. By utilizing these technologies, the better results are obtainable than without the usage of TCPS and a supercapacitor.

Solution of the Optimal Power Flow Problem Considering FACTS Devices by Using Lightning Search Algorithm

In this study, the optimal power flow (OPF) problem including flexible AC transmission systems (FACTS) devices, ever increasing in the planning and operating of the modern power systems has been addressed. The thyristor-controlled series capacitor and the thyristor-controlled phase shifter are used as FACTS devices. The solution to this problem is proposed by using a new heuristic algorithm known as the lightning search algorithm (LSA) based on the phenomenon of lighting. The LSA method is generalized from the mechanism of step leader propagation. The performance, success and robustness in the solution of this problem of the LSA are evaluated and tested on IEEE test systems, which are the modified IEEE 30-bus and IEEE 57-bus test systems. The multi-objective functions are used in the solution analysis processes of this problem. These objective functions are defined as the minimization of the fuel cost, minimization of the emission and minimization of the active power loss of the test system. The numerical results of the LSA are compared to different methods presented in the recent literature, which are ant lion optimizer, grey wolf optimizer, dragonfly algorithm, moth-flame optimization. The outcomes obtained from simulation study indicate the potential of the LSA method in solving the OPF problem including FACTS devices for operating and planning of the modern power systems.

Robustness Analysis of LFC for Multi Area Power System integrated with SMES–TCPS by Artificial Intelligent Technique

Load frequency control (LFC) plays an essential role in a power system (PS) to sustain the grid frequency for the period of sudden load demand variations. Hence, this manuscript deals with the execution of adaptive neuro fuzzy inference system (ANFIS) approach for LFC of three-area unequal thermal power system. The ANFIS controller proposed in the manuscript combines the advantages of Fuzzy Logic Control (FLC) as well as rapid response and flexible nature of artificial neural network. To improve the LFC performance, offered controller is simulated with superconducting magnetic energy storage (SMES) units and Thyristor controlled phase shifter (TCPS) individually and in combination. The performance of proposed ANFIS controller is superior and robust compared to existing control schemes and improved performance is observed particularly in the presence of SMES–TCPS combination. The realization of SMES & TCPS combination curtail frequency and tie power variation quickly after an unexpected load disturbance. To validate the usefulness of the proposed controller, integral time weighted absolute error (ITAE) and integral square error (ISE) performance error indices are used. Robustness of offered controller is demonstrated against wide variation in the system parameters.

Impact of TCPS, SMES and DFIG on Load Frequency Control of Nonlinear Power System Using Differential Evolution Algorithm

In recent times, wind power is increasingly being integrated in the existing power system network for well-known reasons, but due to unpredictable variations in wind speed, the load frequency control (LFC) of such power systems becomes a difficult task. This paper addresses the problem of LFC of a multi-source hydrothermal nonlinear power system having wind power penetration. Differential evolution (DE) algorithm has been used to optimally tune the proportional, integral and derivative controller used for LFC in the power system subjected to fluctuations of wind power and load. The reheat and generation rate constraints nonlinearities have been considered appropriately for both areas. Besides, the impact of thyristor-controlled phase shifter (TCPS) and superconducting magnetic energy storage (SMES) on the LFC performance has been analyzed with the parameters of TCPS and SMES being tuned using DE algorithm. The system has been investigated for various operating conditions including the weak grid condition to establish the effectiveness of the proposed approach for wide variations in system conditions. The performance is analyzed and discussed in respect of frequency and tie-line power deviations, peak overshoot, settling time, and value of performance index. Further, robustness of the system is investigated by varying the system parameters from − 50 to + 50% in steps of 25% and step load disturbance from 1 to 20% in steps of 5%. Modeling and simulations are carried out using MATLAB/Simulink® to demonstrate the effectiveness of the DE algorithm.

Analysis of Energy Storage Device in Hydro-Thermal Power Systems Using Fuzzy Logic Controller

This work presents the Automatic generation control in an interconnected hydro-thermal power system to stabilize the frequency oscillations due to load changes. Advantage of facts devices are utilized here to improve the stability of the system. Thyristor controlled phase shifter (TCPS) is added in the tie line whose input is the area control error. The output of the phase shifter is the change in phase angle based on the error. The TCPS-RFB (Redox flow battery) and TCPS - SMES (Superconducting magnetic energy storage) combinations are compared against each other in terms of peak overshoot and settling time. The results proves that SMES is most effective than RFB. Then the LFC of hydrothermal plant with TCPS in tie line and SMES in one area is analyzed with different controllers like P, PI, PID and Fuzzy logic controller to find the best controller for these specific applications. The criterion for comparison remains to be the same. And finally fuzzy logic controller is found to best among the ones under consideration.

Capacitive energy storage with optimized controller for frequency regulation in realistic multisource deregulated power system

Energy storage systems have great potential in maintaining the power balance and sustaining the grid frequency during sudden disturbances to support the automatic generation control in a power system. Hence, the role of a capacitive energy storage unit as an energy storage device and a thyristor-controlled phase shifter in the automatic generation control of a two-area interconnected power system having multiple gas-hydro-thermal mixed generating units in a deregulated power environment has been investigated in this paper. The recently developed sine-cosine algorithm is used to search the optimal gains of the proportional-integral controller using the integral of time-multiplied absolute error criteria. In addition, the effectiveness of the sine-cosine algorithm tuned proportional-integral controller is also compared with the popular particle swarm optimization algorithm tuned proportional-integral controller in different contract (unilateral, bilateral and contract violation cases) scenarios of the proposed deregulated power system. The impact of the coordinated action of the capacitive energy storage and thyristor-controlled phase shifter units has been validated on the area frequency, tie-line power, and generated power of different units. The analyses revealed that sine-cosine algorithm optimized proportional-integral controller with a capacitive energy storage unit give better dynamic response in all scenarios of the deregulated electricity market under different operating conditions.

Effect of TCPS, SMES, and DFIG on load frequency control of a multi-area multi-source power system using multi-verse optimized fuzzy-PID controller with derivative filter

In this paper, a novel multi-verse optimized fuzzy-PID (proportional–integral–derivative) controller with derivative filter (fuzzy-PIDF) is proposed for load frequency control of a two-area multi-source power system, with each area consisting of a reheat thermal and a hydro unit. The superiority of the Multi-Verse Optimizer algorithm is demonstrated against some recently published modern heuristic optimization techniques. For comparative analysis of the proposed control scheme, the conventional integral, proportional–integral, and PIDF controllers are also implemented. The effect of the thyristor-controlled phase shifter, superconducting magnetic energy storage, and doubly fed induction generators, considered individually and in various combinations, is investigated. Further, with an integral controller optimized using Multi-Verse Optimizer, the value of the integral of time multiplied absolute error, one of the performance indicators, is reduced by 85.61%, 83.91%, 70.42%, 67.69%, and 73.15% compared with optimization of the integral controller using Ant Lion Optimizer, Grey Wolf Optimizer, Differential Evolution, Bacterial Foraging, and Particle Swarm Optimization, respectively. Also, to quote a representative case, with Multi-Verse Optimizer, the settling times in respect of frequency deviations of area-1, area-2, and tie-line power are improved by 94.36%, 98.28%, and 95.44%, respectively, as compared with the results obtained using Ant Lion Optimizer. Further, robustness of the proposed control scheme is also investigated against variation of system parameters within ±10% besides random step load disturbances. Of all the controllers implemented here, the proposed optimized fuzzy-PIDF controller exhibits the best performance. Modeling and simulations were carried out using MATLAB/Simulink.

Solution of Optimal Reactive Power Dispatch by Symbiotic Organism Search Algorithm Incorporating FACTS Devices

ABSTRACTIn the present work, symbiotic organism search (SOS) algorithm is applied for the solution of optimal reactive power dispatch (ORPD) problem of power system considering flexible AC transmission system (FACTS) devices. The proposed method is tested and examined on modified IEEE 30 bus test system with two types of FACTS devices namely thyristor-controlled series capacitor (TCSC) and thyristor-controlled phase shifter (TCPS), placed at some strategic locations. In this study, ORPD problem has been formulated as single objective, constrained optimization problem that aims to reduce active power loss or total absolute voltage deviation individually. The formulation for conventional OPRD problem is evaluated by considering the settings of control parameters and maintaining the constraints of the FACTS devices as an additional entity. The effectiveness of the proposed method is analysed and compared to the results offered by some other optimization methods. The outcomes of the present work prove the potential of the SOS algorithm in solving ORPD problems of the power system incorporating FACTS devices.

Performance of FACTS and energy storage devices in a multi area wind-hydro-thermal system employed with SFS optimized I-PDF controller

This paper presents automatic generation control of an unequal three area interconnected wind-hydro-thermal system incorporating flexible AC transmission system (FACTS) and energy storage devices. Non-linearities such as boiler dynamics and generation rate constraints are considered to get an insight into realistic power systems. A novel secondary controller named as the integral minus proportional derivative controller with first order filter effect (I-PDF) is proposed for the system. A new heuristic optimization technique called stochastic Fractal Search (SFS) is used for the optimization of the controller gains and other parameters. The comparison of system dynamics using some controllers such as integral (I), proportional–integral (PI), and proportional-integral-derivative (PID), and I-PDF reveals the superiority of the latter. The performance comparison of some FACTS devices such as static synchronous series capacitors, thyristor controlled phase shifter (TCPS), and unified power flow capacitors in the presence of I, PI, PID, and I-PDF controllers is done for damping out frequency oscillations. The results explore promising performance using TCPSs and I-PDF controllers. Also, investigation on integration of some energy storage devices such as capacitive energy storage and Redox Flow Batteries (RFBs) results in further damping and better system performance in terms of peak deviation and settling time. The response profile seems more convincing with RFBs. Sensitivity analysis reveals that the SFS optimized I-PDF controller obtained at nominal conditions in the presence of TCPS and RFB are good enough to widely change the system conditions and parameters.

Evaluation of CES and DFIG unit in AGC of realistic multisource deregulated power system

Summary This article discusses evaluation of dynamic contribution of wind turbine unit of doubly fed induction generators (DFIGs) type and capacitive energy storage (CES) in frequency regulation services in 2-area interconnected power system, having diverse thermal-hydro-gas (T-H-G) generating units in deregulated power environment. To obtain optimal dynamic responses of area's frequency oscillations following a small load perturbation, CES/DFIG units have been included in both control areas in coordination with thyristor controlled phase shifter (TCPS).The behavior of DFIGs to enhance dynamic performances of the proposed power system has been investigated by providing inertial support through modified inertial control scheme. The control scheme responds proportionally to frequency variations due to sudden load changes in the power system and uses wind turbine's kinetic energy to provide the inertial control support under several operational conditions. The gain parameters of the integral controller is obtained by using integral square error technique. The performance of the proposed system has been examined in different contract scenarios. Results show that the coordinated action of CES/DFIG units with TCPS unit provide optimal transient performance by arresting the initial dip in area frequencies as well as the power flow deviation in tie-line between the 2 areas. Further, analysis reveals that CES unit response is better and quicker than DFIG unit to damp the system oscillations.

Effectiveness of Fuzzy Logic-based FACTS Controller and Classical Controller in Enhancement of Power System Dynamic Stability – A Comparative Study

Performances of Fuzzy Logic based impedance types FACTS controllers and classical controllers in damping power system oscillations have been studied and their effectiveness have been compared. Different FACTS devices are considered, namely (i) Thyristor Controlled Series Compensator (TCSC), (ii) Thyristor Controlled Phase Shifter (TCPS) (iii) Static VAR Compensators (SVC), and their combinations. Mamdani type fuzzy inference system is used. PSS, Lead-Lag and proportional type classical controllers have been considered. Performances of the controller have been demonstrated through time domain simulation studies. Simulation results have been compared and conclusions have been drawn. Results show that the Fuzzy Logic controllers have excellent and comparatively better potential in damping power system oscillations.

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.

Chaotic krill herd algorithm for optimal reactive power dispatch considering FACTS devices

Conventionally, optimal reactive power dispatch (ORPD) is described as the minimization of active power transmission losses and/or total voltage deviation by controlling a number of control variables while satisfying certain equality and inequality constraints. This article presents a newly developed meta-heuristic approach, chaotic krill herd algorithm (CKHA), for the solution of the ORPD problem of power system incorporating flexible AC transmission systems (FACTS) devices. The proposed CKHA is implemented and its performance is tested, successfully, on standard IEEE 30-bus test power system. The considered power system models are equipped with two types of FACTS controllers (namely, thyristor controlled series capacitor and thyristor controlled phase shifter). Simulation results indicate that the proposed approach yields superior solution over other popular methods surfaced in the recent state-of-the-art literature including chaos embedded few newly developed optimization techniques. The obtained results indicate the effectiveness for the solution of ORPD problem of power system considering FACTS devices. Finally, simulation is extended to some large-scale power system models like IEEE 57-bus and IEEE 118-bus test power systems for the same objectives to emphasis on the scalability of the proposed CKHA technique. The scalability, the robustness and the superiority of the proposed CKHA are established in this paper.

Grey Wolf Optimizer Algorithm Based Fuzzy PID Controller for AGC of Multi-area Power System with TCPS

In this paper, a meta-heuristic optimization algorithm has been applied to interconnected Hydro-thermal power system for automatic generation control (AGC). The optimal gains of the fuzzy based proportional, integral and derivative (PID) controllers are obtained by employing the proposed Grey Wolf Optimizer (GWO) algorithm. The generation rate constraint of 3% per minute for thermal power plant and 270% up and 360% down per minute for hydro plant have been considered. The dynamic performance of a two-area interconnected Hydro-thermal power system is investigated and compared with particle swarm optimization (PSO) and differential evolution (DE) techniques by incorporating a Thyristor Controlled Phase Shifter (TCPS) in series with the tie-line. The overall performance of the considered system has been significantly improved by controlling the phase angle of TCPS with the help of proposed Fuzzy PID controller. It is revealed that the frequencies of both area and tie-line power oscillations are quickly damped out by the proposed scheme under step load perturbations. Furthermore, the robustness of the proposed system is analysed when subjected to different loadings without recalculating the gains of the controller.

Solution of optimal power flow with FACTS devices using a novel oppositional krill herd algorithm

Abstract Krill herd algorithm (KHA) is a novel meta-heuristic approach that is influenced from the herding behaviour of the krill swarms searching for food or communication with each other. The proposed opposition based KHA (OKHA) is intended here, for solving the optimal power flow (OPF) problem of power system, incorporating flexible AC transmission systems (FACTS) devices, namely, thyristor controlled series capacitor and thyristor controlled phase shifter. In the proposed OKHA, the concept of opposition based population initialization and opposition based generation jumping are employed in the basic KHA to enhance its computational speed and convergence profile. The potential of the proposed OKHA is assessed, successfully, on modified IEEE-30 bus and IEEE-57 bus test power systems. The four different objective functions are formulated here that reflects the minimization of fuel cost, active power transmission loss, emission and combined economic and environmental cost, separately. Simulation results, presented in this paper, indicate that the proposed approach yields superior solution over the other popular methods surfaced in the recent state-of-the-art literature including basic KHA and also show its effectiveness for the solution of OPF problem of power system equipped with FACTS devices.