Thyristor Controlled Series Capacitor Research Articles

MATHEMATICAL POWER FLOW MODEL IN AN ELECTRICAL SYSTEM CONTAINING A SERIAL COMPENSATOR THRISTOR CONTROLLED REACTIVE COMPONENT

A unified mathematical model of the power flow in a system containing a reactive component compensator consisting of capacitor banks connected in series to a thyristor control reactor is presented. The application of the FACTS (Flexible Alternative Current Transmission System - Controlled flexible DC power transmission) technology is shown to reduce the gap between the controlled and unmanaged modes of operation of the electric power system (EPS), presenting dispatching personnel with additional degrees of freedom in the management of power flows and voltages in excess and deficit areas of the electric network. The main objectives of the FACTS technology application are studied: increasing the transmission line capacity to the thermal limit; optimizing power flows in a complex heterogeneous network; increasing the static and dynamic stability of the electric power system. To assess the action of the new generation of regulators of the power system, two alternative models of power flow in the electric power system are considered. In the first model, the concept of alternating series reactance is used as a state variable. In the second model, the characteristic of the advance angle is used, given in the form of a nonlinear dependence in the problem of calculating the power flow using the Newton-Raphson method. Conclusions are made on the presented models of power flow allowing to estimate possibilities of the serial capacitor with thyristor control TCSC (Thyristor Controlled Series Capacitor), as FACTS device, on improvement of modes of functioning of electric power system.

Predictive machine learning and data acquisition for power quality improvement in facts devices with optimum power flow control based on cross difference progression and coordination examining algorithm

Flexible AC Transmission Systems (FACTS) present a decision to issue trouble relief for over-extended electric power transmission lines as a result of optimal power flow (OPF) by controlling. To keep away from conventional impacts among a few gadgets placed in a similar grid, an organized control is fundamental. To defeat the issues which happen in optimal power flow to actualize the cross difference progression and coordination inspects strategy, a supervisory controller giving difference progression power flow with numerous destinations is acquired for avoiding congestion, it gives secure transmission and farthest point dynamic power misfortunes. There is no information on gadgets that have been defined in this systematic control of Thyristor controlled series capacitor (TCSC) and Thyristor controlled phase shifting Transformer (TCPST), static VAR compensator (SVC), all of these compensators providing efficient improvements and situations are described. Different optimization techniques are used as a part of the character to deal with the problem of OPF. In some experimental works, the upgrade method is used for finding out all of the fuel costs or the environmental pollution that occurs during the generation of energy. However, in some further research actions, FACTS controlled devices are used to develop the flow of electricity without considering the cost of electricity generation. While a specific end goal of using the FACTS control devices is to help optimize the congestion in the power system, it also aggregates the power loss which enhances the load capacity of the structure. The FACTS and its practical limitations are executed into the IEEE 30-bus test power framework and customized utilizing the Cross Difference Progression and Coordination Examining (CDP&CE) algorithm with MATLAB and the outcomes are given. Here, IoT-based data analytics is defined as the process, which is used to examine varied data from the bus system using Principal Component Analysis (PCA) method, the results of which help to take the necessary decisions. The effect of FACTS gadgets is implemented on standard IEEE-30 transmission framework with supporting numerical outcomes by utilizing MATLAB Software.

Optimal Load Shedding of Power System Including Optimal TCSC Allocation Using Moth Swarm Algorithm

Voltage collapse, blackout and voltage instability are considered main problems faced by the power systems which are due to the lack of reactive power in the system. One of the most important sources for injecting reactive power to the system is the flexible AC transmission systems (FACTS) devices. Thyristor-controlled series capacitor (TCSC) is one of the modern FACTS devices that can be used for reducing the overloading in line flow, allowing power system to operate in secure state and improving power system stability. In this paper, optimal steady-state load shedding and TCSC allocation in power system problems are comprehensively solved using a new robust and effective technique, called moth swarm algorithm. This algorithm is based on the moth’s orientation toward moonlight considering a new adaptive crossover and Levy flight mutation. Optimal load shedding and TCSC allocation are achieved simultaneously to remove or mitigate congestion and emergency situations. To prove the capability of the proposed algorithm for minimizing the amount of load shedding and active power loss, improving voltage profile and voltage stability, standard IEEE 30-bus test system is used under normal and contingency operations at different single- and multiobjective functions. The results obtained by the proposed algorithm are compared with those obtained by other well-known optimization techniques: TLBO, PSO, GWO, WOA, MFO. These results demonstrate the effectiveness and robustness of the proposed algorithm.

Analysis of Thyristor Controlled Series Capacitor Performance in Power Flow Control for High Voltage Transmission Lines

Analysis of Thyristor Controlled Series Capacitor Performance in Power Flow Control for High Voltage Transmission Lines

Optimal Series Capacitor Compensation for Transmission Lines

Nowadays, voltage stability issues are the main problems around the world and therefore it is important that to maintain stable voltage stability. Series capacitor compensation plays an important role in the transmission line because it can improve the voltage stability as compared to shunt compensation. The Thyristor-Controlled Series Capacitor (TCSC) is selected in this project for providing capacitor compensation because its ability to control the amount of compensation in the transmission line, and operating in three different mode of region, which are resonance, capacitive, and inductive regions. The Fast Voltage Stability Index (FVSI) is used to determine the system’s stability and determine the weakest line in the system for TCSC placement. The TCSC sizing is optimized by using Differential Evolution (DE) optimization technique. All these processes are simulated on Institute of Electrical and Electronics Engineer (IEEE) 14-bus test system by using MATLAB. The proposed methodology was carried out in few tests, which are system contingency test, line outage test, power loss test, voltage profile improvement test and variable TCSC location. Based on the results, the overall voltage stability of the system was improved. The voltage magnitude for each bus had improved and the total power losses also reduced. Therefore, the optimization is successful and the study’s aim is achieved.

Analysis and Mitigation of Subsynchronous Resonance in a Korean Power Network with the First TCSC Installation

This paper presents a detailed analysis results of the effect of a thyristor-controlled series capacitor (TCSC) on subsynchronous resonance (SSR), which was first applied to a Korean power system. First, the TCSC parameters were calculated, the structure of TCSC with synchronous voltage reversal (SVR) controller was presented, and the torsional characteristics of Hanul nuclear power generator rotor were studied to investigate the natural frequency and mode shape. The test signal method was used to determine the electrical damping in the frequency range of SSR operation through an electromagnetic transient analysis program in various system configurations. The SSR phenomenon was analyzed by comparing the electrical and mechanical damping of a conventional fixed series capacitor (FSC), and the case of a TCSC installed, and the effectiveness of the TCSC without any risk of SSR was demonstrated. As a result, when installing FSC, SSR occurred under sensitive operating conditions, but SSR was prevented in the case of TCSC compensation with SVR. The results obtained in this study can be effectively applied to the installation of TCSC in real power systems.

Suggestion of a New Protection Scheme for a Transmission System Equipped with a Thyristor-Controlled Series Capacitor

A thyristor-controlled series capacitor (TCSC) is employed to a transmission line in order to enhance the usable capacity of the present as well as upgraded lines, improve system stability, reduce losses, and improve power flow control capability. However, in an abnormal situation, the TCSC may transit from the existing operation mode to the other mode according to its control system and protection strategy. There is much difference in the impedance of the TCSC between each mode. This threatens the reliability of the conventional protection system, especially the distance relay, that works based on the measurement of line impedance. In this paper, we suggest a new protection scheme for a distance relay of a transmission line equipped with a TCSC. In the suggested method, in order to mitigate the effect of the TCSC in the fault loop, the TCSC injected voltage is subtracted from the measured phase voltage before supplying the voltage signal to the distance relay. The suggested scheme was verified by a real time digital simulator (RTDS)-based closed-loop test bed of a protective relay. The effect of the TCSC in the fault loop was completely mitigated. The distance relay works properly with the suggested scheme.

Optimal TCSC placement for congestion management in deregulated power systems using antlion optimization algorithm

Congestion management is one of the important issues in the deregulated power systems. There are several methods to eliminate congestion. Utilizing FACTS devices is an appropriate option for large-scale and quick control of flows of transmission lines. FACTS devices such as Thyristor Controlled Series Capacitor (TCSC) can help to mitigate the transmitting flow of power in the congested lines, which leads to an increase in the network loading ability as well as reduction of both losses and production costs. Due to the considerably high price of FACTS devices, it is important to determine their optimum location on the network. Accordingly, in this paper, the Antlion optimization algorithm (ALO) has been employed to conduct a congestion management analysis to determine the optimal location for the installation of TCSC, which is simulated on an IEEE 14-bus test system subject to satisfy the constraints of the market environment.

ABC Algorithm for Estimation of Dynamic Parameters in Radial Power System Transfer path

In this paper, the artificial bee colony algorithm (ABC) is used to predict the stability of the power system and is evaluated the aggregated machine reactance and inertias in the transfer path. The proposed method is used for estimating the dynamic parameters of the aggregated machines for each area utilising the amplitudes of voltage oscillations measured at any three intermediate points on the transfer path. Two types of voltage control equipment are considered, namely, a static var compensator (SVC) and a thyristor controlled series capacitor (TCSC) including the purpose of voltage support and reducing the disturbance in the system. The proposed methods employ bus voltage phasor data at several buses including the voltage control bus and the line currents on the power transfer path. Here, the three phase fault is applied in the power system. Based on the estimation, the dynamics of the power system is improved and the proposed strategy is utilised for improving the overall dynamic security. The proposed technique is implemented in MATLAB/simulink working platform and the output performance is evaluated and compared with the existing methods such as without facts devices, SVC based controller and genetic algorithm (GA) based TCSC controller respectively.

Voltage Stability Enhancement by Coordination of SVC and TCSC Using Particle Swarm Optimization

The Flexible AC Transmission System (FATCS) plays a vital role in power system performance enhancement. They attributes to accomplish faster and having answers for many issues in power system study. With regards to this, a particles warm optimization (PSO) algorithm is implemented so that to design the coordinated parameters of static VAR compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC). Transient stability of a power system is based on the generator relative rotor angles obtained from time domain simulations outputs. A self-sufficient model of IEEE fourteen bus systems has been given with full detail and voltage stability analysis is done by considering load changing at a bus. PSO applied here is built on searching the values of L and C of SVC, then one can achieve desired and fine coordination. PSO is available with few modification, as change in PSO range & number, difference in selection criteria technique, control technique etc, with due respect to normalize PSO. The results are compared and found that coordination of FACTS devices with each other promises the efficiency of the suggested method for revamping Power flows. When function of TCSC is impelled by some curb, adjustable SVC can supply additional support to upgrade the gross performance.

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.

Comparative study of the effects of SVC and TCSC on the small signal stability of a power system with renewables

This study analyzed the effects of applications of flexible alternating current transmission system (FACTS) devices, such as a thyristor controlled series capacitor (TCSC) and static var compensator (SVC) to handle the oscillations due to wind penetration in an existing network, and to exploit the AC lines to their thermal limits. A small signal stability analysis of an interconnected power system with wind penetration in the presence of FACTS and a power system stabilizer (PSS) was studied under a diverse range of operating conditions. The coordinated tuning of SVC and PSS parameters as well as a TCSC in the presence of a wind energy conversion system was analyzed. The salp swarm algorithm, a recently developed meta-heuristic approach, was used for tuning TCSC, SVC, and PSS parameters. The supremacy of TCSC over SVC for improving system stability was demonstrated under a diverse range of operating conditions.

Modal Control Design of Damping Controllers for Thyristor-Controlled Series Capacitor to Stabilize Common-Mode Torsional Oscillations of a Series-Capacitor Compensated Power System

This paper proposes a unified approach based on modal control theory to design damping controllers of a thyristor-controlled series capacitor (TCSC) for stabilizing the inherent common-mode torsional interactions occurred in a series-capacitor compensated power system. The studied power system includes two nonidentical turbine-generator sets connected to an infinite bus through a common series-capacitor compensated transmission line. The employed TCSC is properly connected in parallel with a part of the series-capacitor bank of the compensated transmission line. The damping controllers of the TCSC employ the speed deviations of both turbine-generator sets as input signals to stabilize unstable torsional modes of the studied system by increasing the damping of these modes. Both frequency-domain approach based on eigenvalue analysis and time-domain scheme based on nonlinear-model simulations under different disturbance conditions are systematically performed. It can be concluded from the simulated results that the employed TCSC joined with the damping controllers designed by using modal control theory can effectively stabilize the common-mode torsional oscillations of the studied series-capacitor compensated system.

An Optimal FACTS Device Allocation for Improving the Power Loss Factors in IEEE 9 Bus System

This paper deals with power quality improvement by using Unified Power Flow Controller (UPFC), Static Synchronous Series Compensator (SSSC) and Second Generation of FACTS Static Compensator (STATCOM) according to change of the reactive and real power of the load, a suitable high response compensator is needed. UPFC, (Thyristor controlled tap changer) TCTC, (Thyristor Controlled Series Capacitor) TCSC, SSSC, STATCOM and SVC are the compensators belonging to FACTS devices. this paper used UPFC (Unified Power Flow Controller), STATCOM (Static Compensator) and static synchronous Series compensator (SSSC). there are three such compensators belonging to FACTS devices. Models for the UPFC, SSSC, and STATCOM are analysis using MATLAB Simulink. The simulation results of nine bus system with UPFC, SSSC, and STATCOM are presented. MATLAB codes are utilized for the implementation of the three FACTS devices in the Newton – Raphson algorithm. Power flow control was evaluated for nine bus system.

An efficient particle swarm optimization algorithm to solve optimal power flow problem integrated with FACTS devices

Optimal power flow (OPF) is one of the most important tools in power system operation and control, which determines the minimum operating cost and retains the control variables in their secure boundaries. This paper takes into account several unbridled practical constraints in the OPF problem, three of which – that is – valve-point effect, multi-fuel option, and, above all, prohibited operating zone are the most conspicuous ones. Further, the flexible alternating current transmission systems (FACTS) devices are considered, as well, which have several merits such as decreasing the active power transmission loss, controlling the power flow, and improving the voltage stability/profile, to name but a few. Accordingly, thyristor controlled series capacitor (TCSC) – the most popular and common component of the FACTS equipment’s category – is utilized in this study. As a result, the OPF problem integrated with such practical constraints referred to above as well as FACTS devices becomes a highly nonlinear-nonconvex optimization problem and to solve it, a reliable and efficient evolutionary algorithm such as fuzzy-based improved comprehensive-learning particle swarm optimization (FBICLPSO) algorithm is introduced. The proposed approach is scrutinized on IEEE 30-bus test system, which is a commonly used test system for solving the non-smooth and non-convex versions of the OPF problem. Comparing the obtained results by the proposed algorithm with the available alternatives in the literature corroborate the potential and effectiveness of the proposed approach.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

A novel optimized fractional-order hybrid fuzzy intelligent PID controller for interconnected realistic power systems

This article presents a novel hybrid fractional-order intelligent proportional-integral-derivative (PID) controller integrated with a fractional-order fuzzy PID controller for load frequency control of a realistic interconnected two-area power system, where each area is powered from a different source. The strategy presented here involves incorporating a damping controller based on a thyristor-controlled series capacitor in the system. In doing so, the parameters of the current controller are optimized via craziness-based particle swarm optimization. The effectiveness of the strategy presented here in load frequency control is validated by extensive simulation examples. The results are compared with a recently published technique based on a fractional-order PID controller. Finally, the sensitivity analysis of the plant is studied by varying the plant parameters and operating load conditions from their prescribed values. It is observed that the current controller is a robust controller and performs satisfactorily with variations in system parameters and load patterns.

Coordination of SVC and TCSC for Management of Power Flow by Particle Swarm Optimization

The Flexible AC Transmission System (FACTS) plays a vital role in power system performance enhancement. They attributes to accomplish faster and having an answer for many issues in power system study. With regards to this, a particle swarm optimization (PSO) algorithm is implemented so that to design the coordinated parameters of static VAR compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC). With behavioral nonlinearities of the power system, linear methods cannot be used to design coordinated parameters of controllers. Simulation is carried out on IEEE-14 bus system with help of MATLAB. PSO applied here is built on searching the values of L and C of SVC, then one can achieve desired and fine coordination. PSO is available with few modification, as change in PSO range & number, difference in selection criteria technique, control technique etc., with due respect to normalize PSO. The results are compared and found that coordination of FACTS devices with each other promises the efficiency of the suggested method for revamping Power flows. When function of TCSC is impelled by some curb, adjustable SVC can apply additional support to upgrade the gross performance.

Type-2 Fuzzy Logic based on PID controller for AGC of Two-Area with Three Source Power System including Advanced TCSC

In This paper, we propose the Interval type-2 fuzzy logic based on the Proportional Integral Derivative (IT2FL-PID) controller for Automatic Generation Control (AGC) of two-area interconnected power system composed by the three source having thermal, hydro and gas units, in coordination with Advanced Thyristor Controlled Series Capacitor (ATCSC) to improve sufficiently the dynamic stability. The IT2FL is able to model uncertainty and imprecision, is applied in order to adjust the parameters of PID controller. The ATCSC associated with two lead-lag blocks is modeled by the Taylor series expansion method. However, sensitivity analysis of the system is studied which demonstrates the capacity of the proposed controllers to wide changes in system parameters and loading condition. In order to verify the effectiveness of the proposed controllers, all the simulation results show that the IT2FL-PID controller coordinate with ATCSC provides better response and robust stability for two-area with three source power systems.

Improving power system damping using a combination of optimal control theory and differential evolution algorithm

This paper presents a novel control strategy to improve the damping capability of sub-synchronous oscillations by tuning of Linear Quadratic Regulator (LQR) optimally in order to reduce the fluctuations in the power system. The proposed model includes the coordination of Power System Stabilizer (PSS) and Thyristor-Controlled Series Capacitors (TCSC) in combination with LQR controllers which is formulated as an optimal control problem. The problem is formulated as a linear regulator problem and then the Differential Evolution (DE) algorithm is utilized to optimize the proposed controlling parameters. Several cases have been studied to show the efficiency of the proposed strategy. Obtained results from a case study on a typical generator demonstrated that the proposed method has the best response and quickest function among conventional controller systems. Moreover, the coordination of the LQR with the other control systems, as an optimal linear regulator problem in order to damp system oscillations provides robust stability for optimizing system performance index. Besides, the flexibility and usability of the LQR controller guarantee the stability of the system to cope with the oscillations.