Genetic algorithm-based fuzzy multi-objective approach to congestion management using FACTS devices

Comparison of BBO, WIPSO & PSO Techniques for the Optimal Placement of FACTS Devices to Enhance System Security

This paper deals with a new operation strategy of FACTS (flexible AC transmission system) device, especially the series compensating device like TCSC (thyristor controlled series compensator) using the linearized sensitivity derived in this paper. In case of a line overflow under contingency state or line congestion at normal state, the FACTS device must change its operating point to relieve the flow congestion and eventually to increase the system security level. In this paper, line flow sensitivity to FACTS device is derived analytically. The sensitivity derivation is based on the DC flow model under the assumption that the generator dispatch is maintained. The power flow control algorithm based on the sensitivity analysis proposed in this paper has several advantages; it is easy to compute, its computation time is short, and its form is very simple etc. Each FACTS device installed in the power system changes its reactance according to the dynamic algorithm proposed in this paper. Its direction and the amount of reactance change depend on the sensitivity of each device. The proposed algorithm in this paper is tested and verified on the IEEE 39 system.

Comparison of computational intelligence algorithms for loadability enhancement of restructured power system with FACTS devices

In this paper, a fully fledged optimal power flow (OPF) algorithm with flexible AC transmission systems (FACTS) devices has been developed and presented aiming at the advancement of how FACTS equipment impacts on the security and economy of the wider power network. The proposed modelling uses Newton’s method along with Lagrangian multipliers, leading to an ecient algorithm that can handle practical power networks independence of initial settings of FACT controllers parameters. Newton’s method provides a suitable vehicle for incorporating the newly developed nonlinear, linearized FACTS models. In this paper, mainly a firing angle-based thyristor controlled series compensators (TCSC) model, a coordinated two-voltage source unified power flow controller (UPFC) model have been developed and presented in details and can easily be extended to other modern FACTS devices such as interline power flow controller (IPFC) and generalized unified power flow controller (GUPFC). The proposed model has capability of converting multi-objective functions into single objective and also can be extended to multiple multi-type FACTS devices. The performance of the proposed model has been validated for IEEE 30 bus system and the solutions so obtained are presented in detail.

Fuzzy based evolutionary algorithm for reactive power optimization with FACTS devices

Growing number of wind turbines is changing electricity generation profile all over the world. This brings challenges for power system operation, which was designed and developed around conventional power plants with directly coupled synchronous generators. In result, safety and stability of the electrical network with high wind energy penetration might be compromised. For this reason transmission system operators (TSO) impose more stringent connection requirements on the wind power plant (WPP) owners. On the other hand flexible AC transmission systems (FACTS) devices offer enhancement of grid stability and can facilitate grid code compliance for WPP. In this paper state-of-the-art in FACTS for WPPs with AC connection is given. FACTS devices with their properties are described. HVDC, which in literature is also often recognized as FACTS device, is out of this paper scope. Academic and industrial research in FACTS applicability for WPPs is summarized. Examples of few existing FACTS applications for wind farms are given.

Optimal allocation of FACTS devices for static security enhancement in power systems via imperialistic competitive algorithm (ICA)

Chapter 31 - Flexible AC transmission systems

In this paper, multi – type Flexible AC Transmission System (FACTS) devices are optimally located for enhancing the loadability of an existing power network within the security margins. Line Stability Index is used to determine the critical lines of the system in increased loading of transmission lines and is used to determine the optimal location of FACTS devices. Differential Evolution Algorithm (DE) is used to determine the optimal location and control parameter settings of the FACTS devices. Among the various FACTS devices, Unified Power Flow Controller (UPFC) and Thyristor Controlled Series Capacitor (TCSC) are chosen and modeled for steady state studies. IEEE- 30 bus test system is used for simulation studies and the results are compared with Genetic Algorithm (GA) to show the advantage and feasibility of the DE approach. Further the results demonstrate that the system loadability can be increased by optimal location and control parameter settings of the multi – type 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.

Transmission systems are under stress and need to be upgraded. Better utilization of the existing grid provides a fast and cheap alternative to building new transmission. One way to improve the utilization of the transmission network is power flow control via flexible ac transmission system (FACTS) devices. While FACTS devices are used today, the utilization of these devices is limited; traditional dispatch models (e.g., security constrained economic dispatch) assume a fixed, static transmission grid even though it is rather flexible. The primary barrier is the complexity that is added to the power flow problem. The mathematical representation of the DC optimal power flow, with the added modeling of FACTS devices, is a nonlinear program (NLP). This paper presents a method to convert this NLP into a mixed-integer linear program (MILP). The MILP is reformulated as a two-stage linear program, which enforces the same sign for the voltage angle differences for the lines equipped with FACTS. While this approximation does not guarantee optimality, more than 98% of the presented empirical results, based on the IEEE 118-bus and Polish systems, achieved global optimality. In the case of suboptimal solutions, the savings were still significant and the solution time was dramatically reduced.

This paper proposes a reactive power planning model, which incorporates flexible AC transmission system (FACTS) devices. The optimal location of multi-type FACTS devices and their control parameters are optimized by a novel bacterial swarming algorithm (BSA) to minimize the real power losses and also to improve voltage profile. The simulation studies have been undertaken on both IEEE 30-bus and 118-bus test systems. Simulation results show that the performance of the power system is improved with multi-type FACTS placed optimally in the reactive power planning model. The advantage of using BSA to determine the location of FACTS devices is demonstrated, in comparison with two other evolutionary algorithms (EAs), i.e., genetic algorithm (GA) and particle swarm optimizer (PSO).

In this paper, a hybrid tabu search and simulated annealing (TS/SA) approach is proposed to minimize the generator fuel cost in optimal power flow (OPF) control with multi-type of flexible AC transmission systems (FACTS) devices. The problem is decomposed into the optimal setting of FACTS parameters subproblem that is searched by the hybrid TS/SA approach and the OPF with fixed FACTS parameters subproblem that is solved by the quadratic programming (QP). Four types of FACTS devices are used: thyristor-controlled series capacitor (TCSC), thyristor-controlled phase shifter (TCPS), unified power flow controller (UPFC), and static VAr compensator (SVC). Test results on the modified IEEE 30 bus system with multi-type of FACTS devices indicate that the proposed hybrid TS/SA approach can obtain better solutions and require less CPU times than genetic algorithm, SA, or TS alone. Using multi-type of FACTS devices results in less total generator fuel cost than using individual FACTS device.

Flexible AC Transmission Systems (FACTS) are essential devices used for the efficient performance of modern power systems and many developing countries lack these devices. Due to the non-existence of these advanced technologies, the national grid remains weak and vulnerable to power stability issues that can jeopardize system stability. This study proposes novel research to solve issues of an evolving national grid through the installation of FACTS devices. FACTS devices play a crucial role in minimizing active power losses while managing reactive power flows to keep the voltages within their respective limits. Due to the high costs of FACTS, optimization must be done to discover optimal locations as well as ratings of these devices. However, due to the nonlinearity, it is a challenging task to find the optimal locations and appropriate sizes of these devices. Shunt VARs Compensators (SVCs) and Thyristor-Controlled Series Compensators (TCSCs) are the two FACTS devices considered for the study. Optimal locations for SVCs and TCSCs are determined by Voltage Collapse Proximity Index (VCPI) and Line Stability Index (Lmn), respectively. Particle Swarm Optimization (PSO) is employed to find the ideal rating for FACTS devices to minimize the system operating cost (cost due to active power loss and capital cost of FACTS devices). This technique is applied to IEEE (14 and 30) bus systems. Moreover, reliable operation of the electricity grid through the placement of FACTS for developing countries has also been analysed; Pakistan being a developing country has been selected as a case study. The planning problem has been solved for the present as well as for the forecasted power system. Consequently, in the current national network, 6.21% and 6.71% reduction in active and reactive power losses have been observed, respectively. Moreover, voltage profiles have been improved significantly. A detailed financial analysis covering the calculation of Operation Cost (OC) of the national grid before and after the placement of FACTS devices is carried out.

Abstract: This study investigates the use of Flexible AC Transmission System (FACTS) devices for power quality management in grid-connected photovoltaic (PV) solar and wind turbine systems within the GA West Municipal District electricity grid in Accra. With a growing reliance on renewable energy sources for sustainable solutions, understanding their impact on low-voltage (LV) networks and effective management strategies is crucial. The study aims to assess the effects of hybrid PV and wind systems, modeling and simulating the GA West Network and IEEE-Low-Voltage Distribution Network (LVDN) and focusing on power factor, active, and reactive power. A 19-busbar test network was modeled to evaluate PV and wind turbine integration with the grid, and IEEE-LVDN was used for validation. The study employed the MATLAB/Simulink simulations. Results show that FACTS devices substantially improve power factor, achieve near-unity levels, and enhance overall network performance by reducing active and reactive power losses. The analysis confirms that FACTS devices boost system capacity, stability, and dynamic behavior. The findings indicate that integrating FACTS devices in grid-connected renewable systems effectively manages power quality and optimizes network performance.Cite this article as: J. Abban, P. Ayambire, F. Sekyere and A. Awopone, “Power management using FACTS device for grid-connected PV solar and wind turbine systems,” Turk J Electr Power Energy Syst., 2025; 5(1), 54-65.