Types Of Flexible AC Transmission System Devices Research Articles

Optimal location of FACTS devices with EVCS in power system network using PSO

The appeal of Electric Vehicles (EVs) is steadily growing, driven by the numerous advantages they offer to both owners and the environment. However, this surge in EV adoption places an increasing demand on the power system network for electric charging. The consequential strain on the power system may lead to instability and potential contingencies within the network. To mitigate these challenges, this paper recommends the installation of Flexible AC Transmission System (FACTS) devices. Specifically, two types of FACTS devices, Static Var Compensator (SVC) and Thyristor-Controlled Series Capacitor (TCSC), are employed to enhance the stability and loading conditions of the power system network. The study focuses on an IEEE 39 bus system network chosen for the installation of Electric Vehicle Charging Stations (EVCS). The objective is to assess the maximum loading factor of each bus within the network. This paper introduces a methodology for determining the optimal locations for both EVCS and FACTS devices. Notably, a Particle Swarm Optimization (PSO) algorithm is employed to optimize the size of FACTS devices and associated installation costs, ensuring an efficient and cost-effective enhancement to the power system's stability and loading conditions.

Hyper-heuristic strategies for optimal power flow problem with FACTS devices allocation in wind power integrated system

This research provides hyper-heuristic methodologies for solving Optimal Power Flow (OPF) issues in power system networks with Flexible AC Transmission Systems (FACTS) devices. OPF can be treated as one of the demanding challenges in the power system operating networks. To address the problems of loss and cost reduction, three types of FACTS devices will be studied in this paper: Static VAR Compensator (SVC), Thyristor-Controlled Series Compensator (TCSC), and Thyristor-Controlled Phase Shifter (TCPS). Two high level hyper-heuristic (HHH) approaches, called Exponential Monte Carlo with counter (EMCQ) and randomly select-Only Improving (OI), are employed as high-level metaheuristic to select and leverage the effectiveness of four low-level metaheuristics (LLH). These low-level metaheuristics comprise the Moth-Flame Optimizer (MFO), Barnacles Mating Optimizer (BMO), Teaching-Learning Based Optimization (TLBO) and Gradient-Based Optimizer (GBO). The usage of HHH solving the OPF problem is tested on the modified IEEE 30 bus system that integrates the thermal generators with the wind power. Findings of the study demonstrated the promising results by HHH which manages to outperform all the selected LLH algorithms.

Research progress and research prospects for configuration method of flexible AC transmission system device

Flexible AC transmission system (FACTS) has become the main development direction of power system in the future, so scientific configuration method of FACTS device is very important. At present, the configuration method of FACTS device has been explored to some extent, but there is still a lack of comprehensive summary of FACTS device configuration method and scientific configuration methods of FACTS device adapting to various application scenes in power system. To this end, this paper summarizes research progress and research prospects of configuration methods of FACTS device. Firstly, starting from the single device configuration within three types of FACTS devices and the multiple device configuration of several types of FACTS devices, research progress of the configuration methods is summarized. Then, from four perspectives which are multiple targets, multiple types, power-supply planning and power grid planning, realization ideas of configuration methods with multiple targets or with multiple types, and the configuration methods considering power-supply planning or considering power grid planning are all are proposed in this paper, which can meet the development needs of power system in the future. The summary of research progress and the four proposed adaptive configuration methods done in this paper aims to provide a reference for the subsequent research on configuration method of FACTS devices.

Optimal placement and sizing of multi-type FACTS devices in power systems using metaheuristic optimisation techniques: An updated review

Abstract The growth of demand, the need for economic efficiency and optimal utilisation of electric power networks and the high cost of construction of new power networks result in inevitable challenges, such as overloading and excessive power transfer along transmission lines, high losses, voltage instability, low power quality, reliability problems and voltage profile problems. To manage the power transmission system, the recently developed Flexible AC Transmission System (FACTS) can be used for electric transmission networks since it plays an important role in enhancing the static and dynamic performance of power systems. However, location, type and capacity of FACTS devices should be optimised to maximise the resulting benefits. In this paper, different types of FACTS devices are discussed along with their modelling and functions. In addition, the proposed and the compared techniques and approaches in the existing research works, such as analytic approaches, arithmetic programming methods, meta-heuristic optimisation techniques and hybrid methods, are discussed. Analytic approaches have insufficient computation accuracy in determining optimal allocation of FACTS devices and arithmetic programming approaches are often inefficient in managing constrained optimisation problems. However, meta-heuristic approaches are stochastic, population-based optimisation algorithms that are highly efficient in dealing with a multimodal, highly constrained, multi-objective and discrete system. Meta-heuristic techniques are the most commonly used methodologies to determine the optimal allocation of FACTS devices. Furthermore, the utilisation of analytic methods or classical optimisation approaches with meta-heuristic optimisation techniques plays an important role in reducing the search space of the proposed meta-heuristic optimisation technique. In the present paper, an overall review of 50 recent research work studies, including proposed and compared approaches and techniques, objective functions, approaches, the utilised FACTS devices, constraints, contingency conditions and all the analysed and simulated parameters, is provided and discussed in details. In addition, a more weighted discussion of the proposed methods based on meta-heuristic optimisation techniques is provided.

Performance evaluation of impedance-based synchronous generator out-of-step protection in the presence of unified power flow controller

Flexible ac transmission system (FACTS) controllers change the transmission line voltage and current signals measured with protection relays. These devices affect the operation of impedance-based relays and can lead to relays under/over-reaching. This study investigates the effects of a unified power flow controller (UPFC) as one of the most important shunt-series compensators on the synchronous generator out-of-step (OOS) protection. A detailed model of the UPFC is used for the purpose of the study and its performance has been simulated in three operational modes of the shunt-series compensator including static compensator (STATCOM), static synchronous series compensator (SSSC) and UPFC. The results show that all the three modes of the UPFC change the impedance trajectory and disrupt the diagnosis of the OOS protection. Moreover, an analytical approach is developed to eliminate the negative effects of the devices. The approach only requires the UPFC voltage and current synchro-phasor data to calculate the modified impedance. The results show that the presented method properly eliminates the negative effects on the OOS relay and prevents it from under-reaching in all the UPFC operation modes. The most important advantage of the modified algorithm is that it can be generalized to other types of FACTS devices.

Impacts and benefits of UPFC to wind power integration in unit commitment

Unified Power Flow Controller (UPFC) is recognized as the most powerful flexible AC transmission systems (FACTS) device for power system operation. This paper addresses how UPFC explores the transmission flexibility and facilitates the integration of uncertain and volatile wind power generation. To this end, a comprehensive unit commitment (UC) model with UPFC and uncertain wind power generation is proposed. Then, some metrics are introduced to evaluate the impacts of UPFC on the reliability, security and economy of power system operation. Further, different dispatch strategies of UPFC are compared to provide helpful guidances on making full use of UPFC to hedge against uncertainties. In addition, facing the challenging mixed-integer non-linear non-convex problems, approximate models are proposed to provide a starting point to solve the problems efficiently. All these models are easy to adapt to other types of FACTS devices. Illustrative numerical results are provided.

Approach for the solution of transmission congestion with multi‐type FACTS devices

This study presents gravitational search algorithm (GSA)-based optimisation technique for the optimum co-ordination of multi-type flexible AC transmission system (FACTS) devices with the existing reactive power sources present in a connected power network. Three types of FACTS devices: namely, unified power flow controller, static var compensator and thyristor controlled series capacitor are used in the present problem and IEEE-30 and IEEE-57 bus systems are taken as standard test systems. The existing reactive power sources are reactive generations of the generators and transformer tap setting arrangements. The main objective of the present study is to reduce active power loss, system operating cost including the cost of FACTS devices and congestion in transmission network. The result obtained with the proposed GSA-based approach is compared with the results obtained by genetic algorithm, differential evolution and particle swarm optimisation techniques. It is observed that by optimal placement of FACTS devices along with the optimal setting of the transformer tap arrangements and control of reactive generations of the generators line loss, system operating cost and transmission congestion is reduced significantly by the GSA-based method compared with other methods.

A novel symbiotic organisms search algorithm for optimal power flow of power system with FACTS devices

In this paper, symbiotic organisms search (SOS) algorithm is proposed for the solution of optimal power flow (OPF) problem of power system equipped with flexible ac transmission systems (FACTS) devices. Inspired by interaction between organisms in ecosystem, SOS algorithm is a recent population based algorithm which does not require any algorithm specific control parameters unlike other algorithms. The performance of the proposed SOS algorithm is tested on the modified IEEE-30 bus and IEEE-57 bus test systems incorporating two types of FACTS devices, namely, thyristor controlled series capacitor and thyristor controlled phase shifter at fixed locations. The OPF problem of the present work is formulated with four different objective functions viz. (a) fuel cost minimization, (b) transmission active power loss minimization, (c) emission reduction and (d) minimization of combined economic and environmental cost. The simulation results exhibit the potential of the proposed SOS algorithm and demonstrate its effectiveness for solving the OPF problem of power system incorporating FACTS devices over the other evolutionary optimization techniques that surfaced in the recent state-of-the-art literature.

CONGESTION MANAGEMENT BY OPTIMAL ALLOCATION OF FACTS CONTROLLERS USING HYBRID FISH BEE OPTIMIZATION

The role of Independent System Operator (ISO) in the restructured power industry includes system control, capacity planning, transmission tariff and congestion management; the challenging task being minimizing the congestion. One of the popular techniques used to alleviate congestion is using Flexible AC Transmission Systems (FACTS) devices. The power system generally operates near its rated capacity in deregulated market because of intensive usage of transmission grids. So, the major issues that need to be addressed are improving the voltage profile and reducing the power loss in the electrical network. Motivation: The location of FACTS devices can improve the power flow in the line, maintain the bus profile and reduce the losses. However locating the ideal location is a NP problem. This study presents a novel heuristic method to determine the types of FACTS devices and its optimal location in a power system without violating the thermal and voltage limits. Power flow sensitivity index to find the optimal location of UPFC is suggested in this study. A hybrid fish bee swarm optimization is proposed which is based on Artificial Bee Colony (ABC) and Fish School Search (FSS) methods. This proposed algorithm is tested based on IEEE 30 bus system and line performances are studied.

UPFC with series and shunt FACTS controllers for the economic operation of a power system

This paper presents the application of Genetic Algorithm (GA) and Differential Evolution (DE) technique for the minimization of transmission loss and simultaneous reduction in the operating cost of the system using Flexible AC Transmission System (FACTS) devices. Three types of FACTS devices, Thyristor Controlled Series Compensator (TCSC), Static VAR Compensator (SVC) and Unified Power Flow Controller (UPFC) are considered for this purpose. Optimal placement of FACTS devices in the heavily loaded power system reduces transmission loss, control reactive power flow, improves voltage profile of all nodes and also reduces operating cost. The system is reactively loaded starting from base to 200% of base reactive load and the system performance is observed without and with FACTS devices. The proposed technique is applied on IEEE 30-bus system for the optimal setting of FACTS devices. Finally, how system performance is improved with the use of UPFC along with other series and shunt FACTS controller is illustrated.

Fuzzy based evolutionary algorithm for reactive power optimization with FACTS devices

In this paper, optimization techniques such as Genetic Algorithm (GA) and Differential Evolution (DE) along with Fuzzy Logic (FL) is used for the optimal setting of power system variables, including Flexible AC Transmission Systems (FACTS) devices. Here, two types of FACTS devices, Thyristor Controlled Series Compensator (TCSC) and Static Var Compensator (SVC) are used for the optimal operation of the power system as well as in reducing congestion in transmission lines. Optimal placement of FACTS devices in the heavily loaded power system reduces transmission loss, controls reactive power flow, improves voltage profile of all nodes and also reduces operating cost. In this proposed approach fuzzy membership function is used for the selection of weak nodes in the power system for the placement of SVC’s as one of the FACTS devices while the location of TCSC’s are determined by the reactive power flow in lines. The proposed technique is compared with other optimization methods using different globally accepted evolutionary algorithms where the nodes are detected by eigen value analysis and the amount of FACTS devices are determined by evolutionary techniques like, Genetic Algorithm (GA), Differential Evolution (DE) and Particle Swarm Optimization (PSO). The superiority of the proposed fuzzy based optimization approach is established by the results and the comparative analysis with other methods.

Reactive Power Optimization with SVC & TCSC using Genetic Algorithm

In this paper Genetic Algorithm (GA) is used as an evolutionary tecthniques for the optimal placement of flexible AC transmission systems (FACTS) devices in an interconnected power system. Here two types of FACTS devices has been discussed nemely, Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) for the economic operation and to reduce the transmission loss. Reactively loading of the system is taken from base to 200% of base loading and the system performance is observed without and with FACTS devices. Optimal placement of FACTS devices in the system is determined by calculating active and reactive power flow in lines. FACTS devices along with reactive generation of generators and transformer tap setting are used for the power transfer capacity using GA. The proposed approach is applied on IEEE 14 and IEEE 30-bus test systems. Finally the effectiveness of the proposed GA based method of placement of FACTS devices is established by comparing the results with another standard method of optimization like Particle Swarm Optimization (PSO) technique.

Maximization of Transmission System Loadability with Optimal FACTS Installation Strategy

Instead of building new substations or transmission lines, proper installation of flexible AC transmission systems (FACTS) devices can make the transmission networks accommodate more power transfers with less expansion cost. In this paper, the problem to maximize power system loadability by optimally installing two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). To reduce the complexity of the problem, the locations suitable for SVC and TCSC installations are first investigated with tangent vector technique and real power flow performance index (PI) sensitivity factor and, with the specified locations for SVC and TCSC installations, a set of schemes is formed. For each scheme with the specific locations for SVC and TCSC installations, the MDCP is reduced to a continuous nonlinear optimization problem and the computing efficiency can be largely improved. Finally, to cope with the technical and economic concerns simultaneously, the scheme with the biggest utilization index value is recommended. The IEEE-14 bus system and a practical power system are used to validate the proposed method.

Fitness Sharing Particle Swarm Optimization Approach to FACTS Installation for Transmission System Loadability Enhancement

Proper installation of Flexible AC Transmission Systems (FACTS) devices in existing transmission networks can enable power systems to accommodate more power transfer with less network expansion cost. The problem to maximize transmission system loadability by determining optimal locations and settings for installations of two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). For solving the MDCP, in the paper, the proposed method with fitness sharing technique involved in the updating process of the particle swarm optimization (PSO) algorithm, can diversify the particles over the search regions as much as possible, making it possible to achieve the optimal solution with a big probability. The modified IEEE-14 bus network and a practical power system are used to validate the proposed method.

Minimization of voltage sag induced financial losses in distribution systems using FACTS devices

Voltage sag can have significant economic consequences for different types of industries. Flexible AC Transmission System (FACTS) is originally developed for transmission networks but similar ideas are now starting to be applied in distribution systems. FACTS devices have become popular as a cost effective solution for the protection of sensitive loads from voltage sag. This paper presents the modeling of FACTS devices to minimize the voltage sag induced financial losses. The overall system financial losses due to voltage sag could be significantly reduced depending on the type of FACTS devices used. The short circuit analysis approach is used to incorporate the effect of these devices on financial losses. Voltage sag produced by balanced and unbalanced short circuits is analyzed by means of an analytical approach using system impedance matrix ( Z Bus) which incorporates FACTS devices. Two types of FACTS devices, which are most often used in practical applications, are considered in this study: Distribution Static Compensator (D-STATCOM) and Static VAR Compensator (SVC). Case studies based on a real Indian distribution system are used to illustrate the modeling method and the effectiveness of these devices in minimization of financial losses.

Modeling of FACTS Devices for Voltage Sag Mitigation Studies in Large Power Systems

Flexible ac transmission system (FACTS) devices or their subderivative custom power devices are efficient and often used and recommended power-electronics-based devices for mitigation of voltage sags in electrical power system. With FACTS devices installed, the overall system (and individual bus) sag performance could significantly change depending on the type of the device used. In order to assess this change in sag performance in realistic large power systems, the classical (essentially static) fault calculation procedure should be amended to incorporate the effects of these devices on bus voltages. This paper presents a new approach of quasistatic sag analysis using a system impedance ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm Z} _{\rm bus} $</tex></formula> ) matrix that incorporates FACTS devices. Three types of FACTS devices which are most often used in practical applications are considered in this study: static compensator, static var compensator, and the dynamic voltage restorer. The case studies based on the 295-bus generic distribution system are used to illustrate the modeling method and the effectiveness of these devices in sag mitigation.

Optimal Power Flow with TCSC and TCPS Modeling using Craziness and Turbulent Crazy Particle Swarm Optimization

This paper presents two new Particle swarm optimization methods to solve optimal power flow (OPF) in power system incorporating flexible AC transmission systems (FACTS). Two types of FACTS devices, thyristor-controlled series capacitor (TCSC) and thyristor controlled phase shifting (TCPS), are considered. In this paper, the problems of OPF with FACTS are solved by using particle swarm optimization with the inertia weight approach (PSOIWA), real coded genetic algorithm (RGA), craziness based particle swarm optimization (CRPSO), and turbulent crazy particle swarm optimization (TRPSO). The proposed methods are implemented on modified IEEE 30-bus system for four different cases. The simulation results show better solution quality and computation efficiency of TRPSO and CRPSO algorithms over PSOIWA and RGA. The study also shows that FACTS devices are capable of providing an economically attractive solution to OPF problems.

Assessment of techno-economic contribution of FACTS devices to power system operation

In contemporary power system studies, the optimal allocation and utilization of Flexible AC Transmission System (FACTS) devices are important issues primarily due to their cost. In this study four types of FACTS devices (Static VAr compensator (SVC), Thyristor-Controlled Series Capacitor (TCSC), Thyristor-Controlled Voltage Regulator (TCVR), and Thyristor-Controlled Phase Shifting Transformer (TCPST)) are optimally placed in a multi-machine power system to reduce the overall costs of power generation. The placement methodology considers simultaneously the cost of generated active and reactive powers and cost of selected FACTS devices for a range of operating conditions. The optimal power flow (OPF) and genetic algorithm (GA) based optimization procedure are employed to solve the allocation task. The net present value (NPV) method is used to assess the economic value of the proposed methodology. In addition to net reduction in generation cost allocated FACTS devices increased power transfer across the network and improved damping of electromechanical oscillations.

Voltage control of distribution network with a large penetration of photovoltaic generation using FACTS devices

AbstractIn recent years, there has been a great deal of interest in distributed generation from viewpoints of environmental problems and energy saving measures. Thus, a lot of distributed generators will be connected to the distribution network in the future. However, increase of distributed generators, which convert natural energy into electric energy, raises concerns as to their adverse effects on the distribution network. Therefore, control of distribution networks using Flexible AC Transmission System (FACTS) devices is considered in order to adjust the voltage profile, and as a result more distributed generations can be installed into the networks.In this paper, four types of FACTS devices— Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC), Unified Power Flow Controller (UPFC) and self‐commutated Back‐To‐Back converter (BTB)— are analyzed by comparison of required minimum capacity of the inverters in a residential distribution network with a large penetration of photovoltaic generations. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(3): 16– 28, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20499

Application of particle swarm optimization technique for optimal location of FACTS devices considering cost of installation and system loadability

This paper presents the application of particle swarm optimization (PSO) technique to find the optimal location of flexible AC transmission system (FACTS) devices with minimum cost of installation of FACTS devices and to improve system loadability (SL). While finding the optimal location, thermal limit for the lines and voltage limit for the buses are taken as constraints. Three types of FACTS devices, thyristor controlled series compensator (TCSC), static VAR compensator (SVC) and unified power flow controller (UPFC) are considered. The optimizations are performed on the parameters namely the location of FACTS devices, their setting, their type, and installation cost of FACTS devices. Two cases namely, single-type devices (same type of FACTS devices) and multi-type devices (combination of TCSC, SVC and UPFC) are considered. Simulations are performed on IEEE 6, 30 and 118 bus systems and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India for optimal location of FACTS devices. The results obtained are quite encouraging and will be useful in electrical restructuring.