FACTS Devices Research Articles

Series FACTS controllers in industrial low voltage electrical distribution networks for reducing fault current levels

In this paper, series FACTS devices like Thyristor control series capacitor(TCSC)and Static synchronous series compensator (SSSC) with designed control logic used to reduce the fault current located in LV distribution network at the LV busbar. The electrical distribution network in small and medium scale industries such as steel plants, process and power plants is through low voltage switchgear (LVS) fed from motor control centre (MCC) switchgear through step down transformer of 11kV or 33kV /415V. The designed switchgear in the LV side for these utilities usually is at 50kA. However, the process loads are continuously increasing and sustained with additional feeders with the existing switchgear. Consequently, the fault current at the busbar of the switchgear increases which may require the replacement of entire switchgear to the new design fault current. However, upgrading the existing switchgear is not an economical solution to the industries. Alternatively reducing the fault current at the busbar is feasible. Controller design implemented for reducing the short circuit current with series FACTS devices. A study carried on 800 MW Thermal power plant Ash handling LVS in ETAP and Matlab. It is observed that the results are encouraging to use series FACTS devices effectively in the LVS.

Optimal control of electrical vehicle incorporated hybrid power system with second order fractional‐active disturbance rejection controller

AbstractThis article proposes a novel control methodology employing a fractional‐active‐disturbance‐rejection‐controller for the combined operation of load frequency control and automatic voltage regulator of a hybrid power system. A two area hybrid power system with diverse energy sources like solar‐thermal, conventional‐thermal and wind sources equipped with appropriate system nonlinearities is investigated. In order to ascertain the role of modern‐day electric‐vehicle (EV), the hybrid power system is incorporated with EVs in both the areas. To establish an effective frequency, voltage and tie line power control of the hybrid power system, a second order fractional‐active‐disturbance‐rejection‐controller with fractional‐extended state observer is modeled as secondary controller. Magnetotactic‐bacteria‐optimization (MBO) technique is applied to obtain optimal values of the controller gains and the hybrid system parameters. The robustness of the controller gains is tested under different system parameter changes from their nominal values. In addition, the effect of incorporating a power system stabilizer on the hybrid power system is evaluated. Further, the impact of integrating renewable sources and EVs in the hybrid power system is explored. Moreover, the stability of the hybrid power system is monitored with the inclusion of FACTS device. The developed controller operates encouragingly with reference to system stability, rapidity and accuracy in comparison to testified control strategies available in the literature. The robustness test under load‐perturbation, solar‐insolation, wind input variations also proves the efficiency of MBO optimized second order fractional‐active‐disturbance‐rejection‐controller gains.

Use of Super Conductor Magnetic Energy Storage System and FACTS Devices for Two-Area Load Frequency Control Having Synchronous Generators and DFIG Wind Generators

Use of Super Conductor Magnetic Energy Storage System and FACTS Devices for Two-Area Load Frequency Control Having Synchronous Generators and DFIG Wind Generators

Review of enhanced power quality using unified power flow control system in electrical network

Flexible FACTS system of AC transmission. FACTS Devices can regulate electricity flow, develop the transmission capacity for power management. UPFC is a multipurpose fact controller carried on design of the constant voltage source. As an electrical device UPFC for rapid reactive power adjustment on high voltage electricity transport grid. Unified power flow control (UPFC). The latest FACTS gadget is UPFC. This combines series and shunting compensator characteristics and enables Power reactive and response to be controlled. UPFC utilization reduces difficulties in power quality including voltage sink and voltage surge. This article addresses UPFC and also several novel topologies for FACTS controllers.

Simultaneous analysis of frequency and voltage control of the interconnected hybrid power system in presence of FACTS devices and demand response scheme

This work confers the simultaneous analysis of voltage and frequency control of the 3-area interconnected hybrid power system (IHPS) consisting of parabolic-trough solar power system (PSP), wind power system (WPS) and dish-stirling solar power system (DSP) under the paradigm of microgrid. The speculated result of the IHPS is presented and analyzed considering real and reactive power as the function of both voltage and frequency. 9The proposed IHPS under investigation has been mathematically modeled for direct coupling like active power–frequency and reactive power–voltage relationships and cross coupling like active power–voltage and reactive power–frequency​ relationships. The system responses under different operating conditions have been investigated to see the cross-coupling behavior of the proposed IHPS in the presence of voltage compensating devices like dynamic voltage restorer (DVR) and Static Synchronous Compensator (STATCOM). Further, Demand Response Scheme (DRS) as a frequency control strategy has been considered to enhance the system stability. System responses have been critically analyzed under Mine Blast Algorithm (MBA) based proportional–integral–derivative (PID) controllers

Optimal parameters estimation of the PEMFC using a balanced version of Water Strider Algorithm

Recently, much attention was paid to the application of renewable energy in environmental issues. Meanwhile, the fuel cell industry, which is considered an environmentally friendly industry, is one of the important components of this project. They are in fact devices for the direct conversion of chemical energy into electrical energy by an electrochemical reaction without the need for any mechanical parts. In this study, it is attempted to model one of their important types, called proton exchange membrane fuel cells, so that it can be used in predicting the behavior of the fuel cell and examining various parameters affecting the performance of the cell. The main idea is to optimal parameters estimation for the proton exchange membrane fuel cells by minimizing the total Squared Error value between the empirical output voltage and the approximated output voltage. For giving better results in terms of accuracy and reliability, a new design of a metaheuristic called the balanced Water Strider Algorithm is utilized. The results of the suggested method are finally validated by comparison with several latest optimizers applied on a practical test case. After running all of the optimizers 30 times independently, the proposed method with minimum absolute error equals 3.4831e−4 shows the best results toward the others.

Optimal Coordination of PSS and SSSC Controllers in Power System Using Ant Colony Optimization Algorithm

Volatility leads to disruption in synchronism between generators of a continuous system. The frequency of the volatility is usually between a few tenths of Hz to several Hz. This volatility is sometimes divided into two types, local and interregional. Local volatility is the low-frequency volatility of a power plant unit or units of a power plant relative to the grid whereas interregional volatility is the volatility of the units of one area relative to the units of another area. The worst kind of low-frequency volatility occurs when the power system in a region has a short three-phase connection to the earth, creating a complete instability of the grid and operating protective systems. One of the ways to improve the dynamic stability and steady-state of the power system is to use power system stabilizers and FACTS devices in the system. In this paper, the stabilization of the power system stabilizers (PSSs) and SSSC is done using the ant colony algorithm. Studies on a four-machine system with the three-phase error were performed in two scenarios and finally compared with the PSO method. The simulation results show that the proposed method produced more accurate performance.

Multi objective control scheme on DFIG wind turbine integrated with energy storage system and FACTS devices: Steady-state and transient operation improvement

This paper presents a novel control scheme in doubly-fed induction generators (DFIG) wind turbine for operation under time-varying unbalanced loads. The proposed control scheme is implemented on a DFIG connected to the external grid. Additional equipment such as battery, thyristor-controlled reactor (TCR) and thyristor-switched capacitor (TSC) are integrated to the DFIG. These devices are integrated to DC link, grid side and rotor side converters. The developed control scheme aims to achieve several purposes simultaneously including voltage compensation, damping fluctuations, regulating frequency, increasing resilience, and balancing the unbalanced time-varying loads. Each purpose is realized by designing a separated control loop on DFIG, battery and TCR-TSC. All the designated control loops are operated coordinately. The non-linear time-domain modelling and simulations are carried out in MATLAB software and demonstrate that the proposed multi-purpose control plan can optimally utilize set of DFIG/battery/TCR/TSC and achieve all the objectives efficiently.

Novel models of power system components for implicit solution of the adjusted power flow problem

AbstractThe solution of the adjusted power flow problem involves handling power system components whose control characteristics possess operational limits. Examples include generator reactive power limits, tap-changing and phase-shifting transformers, and FACTS devices. While the conventional method involves checking for limit violations in an outer loop drawn around the unadjusted power flow problem being solved by the Newton-Raphson (NR) method, for iterative processes, it is desirable to have smooth, continuously differentiable models implicitly handled within a single loop. A novel formulation for a subset of devices is presented for implicit handling within power flow. The steady state characteristics of tap-changing and phase-shifting transformers, and FACTS devices SVC and STATCOM, can be described using the “cut function”, a piecewise linear function traditionally employed in neural networks. A new approximation of the cut function is used for formulating novel equations describing the steady state characteristics. An augmented set of equations is formed and solved by the NR method, eliminating the need of an outer loop. The efficacy of the proposed method is demonstrated by employing it for plotting bus voltage profiles and determining maximum loadability of test systems. Comparisons with the conventional method show that significant savings in computation can be achieved.

An Optimal Control of Integrated Hybrid Power System with FACTS Devices Using Student Psychology‐Based Optimization Algorithm

AbstractIn this paper, a student psychology‐based optimization algorithm (SPBOA)‐based proportional‐integral‐derivative (PID) controller is implemented for load frequency control (LFC) of an isolated hybrid power system (IHPS) and a grid‐connected HPS (GHPS) models. In the designed models, a combined‐cycle gas turbine, a diesel engine generator, a wind turbine generator and a solar photovoltaic generating unit are used as the main power generating units. A superconducting magnetic energy storage is used with IHPS model to improve the dynamic stability of the studied system. A single area power system is connected with IHPS model through a tie‐line to form a GHPS. In the GHPS, a thyristor‐controlled series controller and a unified power flow controller are associated with the tie‐line power flow control. In this work, electric vehicle is also connected as a load to both the IHPS and GHPS models. The output profile of the proposed SPBOA‐based PID controller of both models is compared with whale optimization algorithm (WOA) and quasi‐oppositional‐based WOA (QOWOA). The performance of IHPS and GHPS models are studied under the different load perturbations. The robustness analysis and frequency domain analysis in terms of Bode plot are also shown in favor of the SPBOA method.

RETRACTED: FPGA-based adaptive linear-line approximation and implementation for optimum photovoltaic device power control

Photovoltaic technology is one of the greatest attractions among the various renewable energy sources, coupled with the availability of atmospheric temperature in quantity and without emissions of greenhouse gases due to its poor PV power. Therefore, networking opportunities lie in applying electrical power generation and transmission methods to produce voltage level with favorable rates for effective application. The photovoltaic panel’s suitable methodology is important for analyzing, controlling, and monitoring a PV generator’s design. The photovoltaic system is the basic component of a PV device, so the PV array needs to be run at the highest power point to optimize the system’s energy production. In the system, a solar tracking system is needed to function at the maximum power point. The characteristics of a PV cell’s output power and energy are semi, and therefore its output fluctuates in compliance with the difference in solar irradiation and temperature. An amount of studies has been aimed at designing successful MPPT schemes over the last decade. Research projects are still increasing interesting; however, discovering building FACTS devices and resolving their digital quality issues. Besides, the architecture of MPPTs that could cope with irradiance and temperature is difficult. The establishment of innovative strategies and transmitted source inverter control techniques for a PV device with different pulse widths. To build a filter that remove the solar array PV panel’s using current instantaneous reactive power. The voltage regulation filter based mostly on PV array is then configured with adjusted adaptive threshold control with sequence analysis size. The MATLAB simulator and FPGA and legitimate digital numerical simulations are expected to show strong harmonic adjustment for the existing PV-based SAPF.

An Effective Hybridized GWO-BSA for Resolving Optimal Power Flow Problem with the Inclusion of Unified Power Flow Controller

The key intention of this research paper is to find a solution to the optimal power flow problem (OPF) for four different scenarios, such as minimization of fuel cost, minimization of voltage deviation at the buses, minimization of real power loss and enhancing the voltage stability of the system. An effective hybridized Grey Wolf Optimization (GWO) and Backtracking Search optimization Algorithm (BSA) is introduced in this paper to resolve the OPF problem with incorporation of Unified Power Flow Controller (UPFC), a versatile FACTS device. The efficacy of the suggested approach is verified using the IEEE 30-bus test system. Finally, results of this hybrid method are superior to those accessible in the literature.

Compensating Voltage Sagin Single Phase and Three Phase Lines Using FCL

Voltage sag compensation is provided on both sides of the Point of Common Coupling (PCC) by using FACTS Devices (STATCOM, APF, DSTATCOM, DVR, UPFC) and FCL. The FACTS dev ices provide compensation on input side and FCL provides compensation on output side. A sensitive load is considered at output side of PCC. This paper presents a component called Fault Current Limiter (FCL) in three phase lines. The main objective of the designed component is to protect the sensitive load from the shunt faults. The compensation is being provided at output side of PCC. Load voltage reduces upon the occurrence of shunt fault. The planned structure prevents voltage sag and counter balance the phase-angle of the PCC once fault prevalence. As a result, different feeders which are interlinked to the sub-station PCC can have attentive power quality. During this paper a high performance 3-phase fault current electrical model is planned. The analysis and design is carried out in MATLAB with SIMULINK.

Steady-state model of VSC based FACTS devices using flexible holomorphic embedding: (SSSC and IPFC)

For proper planning, operation, control and protection of the power system, the development of suitable steady-state mathematical model of FACTS devices is a key issue. The Fast and Flexible Holomorphic Embedding (FFHE) method converges faster and provides the flexibility to use any state as an initial guess. But to investigate the effect and ability of FACTS devices using FFHE technique, it is necessary to develop an embedded system for these devices. Therefore, this paper presents FFHE-based embedded system for VSC-based FACTS controllers, such as, SSSC and IPFC. The embedded system is also proposed for their controlling modes.The introduced embedded system is flexible which allows to take any state as an initial guess instead of fixed state, which leads towards the reduced run-time and decrease the required number of terms, as compared to standard HELM. To demonstrate the effectiveness and practicability, the proposed FFHE-based models of FACTS devices have been tested for several cases. Further, the developed recursive formulas for power balance equations, devices’ physical constraints and their controlling modes are thoroughly investigated and examined. From several tests, it is found that the proposed FFHE-based FACTS models requires less execution time and reduce the error at higher rate.

Fuzzy Distribution Static Compensator based control strategy to enhance low voltage ride through capability of hybrid renewable energy system

ABSTRACT Hybrid renewable energy systems (HRES), which are based on doubly fed induction generators (DFIG), have good fault ride-through (FRT) capacity. However, to increase the fast response of compensation and good transient performance of HRES, FACT devices such as Distribution Static Compensators (DSTATCOM) are employed. Normally PI controllers are optimized to control the operation of DSTATCOM. Due to various disturbances arising owing nonlinearity of WECS, a more robust and fast, a fuzzy logic controller (FLC) is explored for DSTATCOM control and that can make the HRES to match the low-voltage ride-through (LVRT). This paper proposes a strategy through a battery energy storage system (BESS) embedded with fuzzy-based DSTATCOM. The proposed strategy improves the DC-link voltage, voltage at PCC, reactive power, and active power by 15.68%, 64%, 13%, and 33%, respectively, as compare to DSTATCOM alone. The design includes a simple controller-based series dynamic braking resistor (SDBR). The simulations of the control strategies were performed on MATLAB to study the LVRT performance of HRES with BESS embedded fuzzy-based DSTATCOM. Simulation results showed improved performance of the proposed strategy compared to DSTATCOM alone.

Steady-State models of STATCOM and UPFC using flexible holomorphic embedding

To investigate the effect and ability of FACTS devices using Fast and Flexible Holomorphic Embedding technique (FFHE), it is necessary to develop an embedded system for these devices. Therefore, this paper presents FFHE based embedded system for STATCOM and UPFC. The embedded system is also proposed for their controlling modes.The introduced embedded system for STATCOM and UPFC is flexible which allows to take any state as an initial guess instead of fixed state, which leads towards the reduced runtime and decrease the required number of terms, as compared to standard Holomorphic Embedded Load-Flow Method (HELM). To demonstrate the effectiveness and practicability, the proposed models of STATCOM and UPFC have been tested for several cases. Further, the developed recursive formulas for power balance equations, devices’ physical constraints and their controlling modes are thoroughly investigated and examined. From several tests, it is found that the proposed embedded system requires less execution time and reduce the error at higher rate.

Design of adaptive wide-area damping controller based on delay scheduling for improving small-signal oscillations

The main aim of this paper is to compensate the delays resulted from communication links transmitting wide-area measurement signals in a new large-scale power system. The proposed controller is based on adaptive delay compensation which is able to handle the uncertainty arising from the phase delay by means of scheduling the delay’s value. In this design, further to compensation of WAMS’s delays, the delay due to internal structure of closed-loop system is also modeled, and by using synthesis H∞/H2 technique, its robustness has been evaluated by defining an objective function. Then, by means of small-signal stability analysis, a wide-area damping controller has been employed for coordination of FACTS devices including STATCOM and HVDC with the controller of rotor-side-convertor (RSC) in DFIG. The simulations have been implemented on 8-area power system including wind farms and FACTS devices through different scenarios.

Multi-objective resilient-constrained generation and transmission expansion planning against natural disasters

In this paper, the resilient-constrained generation and transmission expansion planning (RCGTEP) considering natural disasters such as earthquake and flood is presented. The proposed model contains a two objective problem that the first objective function minimizes the construction and operation costs of resiliency sources (RSs) and, in the second objective function, the minimization of the expected energy not supplied (EENS) due to the outage of the system against the mentioned natural disasters is formulated. Also, the proposed model is constrained to linearized AC optimal power flow (AC-OPF) equations, the planning and operating of RSs constraints such as generation units, hardening transmission lines, parallel and series FACTS devices, resiliency constraints and power system angular stability against earthquakes and floods in the presence of critical and non-critical loads. In order to achieve the best compromise response, the RCGTEP single-objective problem is formulated based on the ε constraint-based Pareto optimization. In addition, this model has the uncertainty of RSs availability against natural disasters, so stochastic programming is used for RCGTEP. Then, the Benders decomposition (BD) method is used to solve the proposed problem and achieve the optimal solution in the shortest possible time. Finally, by implementing the proposed model on an IEEE standard transmission network, the numerical results confirm the capability of this method in improving the economic, operation, angular stability and resiliency indices of the power system simultaneously.

Design of Cost-Effective Compensators to Enhance Voltage Stability and Harmonics Contamination of High-Power More Electric Marine Vessels

In recent years, due to the large spread of power electronics converters onboard shipboard power systems (SPSs), harmonic contamination became an inherent problem. Moreover, as the SPSs are mostly operating in an islanded mode with a limited rating of the generators that feed heavy variable loads, voltage stability issues became a challenge as well. To address these issues, implementing PWM-based FACTS devices using IGBTs such as the active power filters may not be very practical for high-power SPSs due to their limited rated powers, high implementation cost, and high losses. The passive power filters (PPFs) and fixed capacitor-thyristor controlled reactors (FC-TCR) can be effective alternatives due to their capability to operate in high-power applications, smaller losses and, lower cost. The aim of this article is to provide more in-depth analytical investigations to evaluate and compare the behavior of the PPFs and the FC-TCR compensator in reducing the harmonics and enhancing the voltage stability concurrently of high-power SPSs. In addition, details of the voltage stability concept are addressed to visualize the potential risk of the voltage collapse. Besides, the modeling of the FC-TCR and design of the closed-loop control algorithm to ensure voltage stability is conducted. Via intensive simulation studies of a practical ship, which are carried out in MATLAB/Simulink environment, it has been demonstrated that the FC-TCR based on the proposed design can enhance the power quality and voltage stability of SPSs better than traditional PPFs filters.

Satin Bowerbird optimization algorithm for the Application of Optimal power flow of power system with FACTS devices

The following research paper, addresses the issue of the optimal power flow ( OPF) of power system dealt by the proposal of adapting flexible ac transmission FACTS devices with Satin Bowerbird optimization (SBBOA) algorithm. The SBBOA is bio-inspired algorithm; it is carried out based totally on the principle of ‘female-attracted-by-male’ for breeding. The algorithm that is proposed is tested by usingIEEE-30 bus and IEEE-57 bus test systems with FACT devices of two different types. The following are the two types of FACT devices that are kept at fixed locations:
 FACT devices that are kept at fixed locations:
 Thyristor controlled series capacitor and
 Thyristor controlled phase shifter
 The objective of the present study aims at four different functions. They are:
 (a) Minimizing the cost of fuel
 (b) Minimizing active power loss during transmission
 (c) Reduction of emission and
 (d) Minimizing the combination of economic and environmental cost.
 The SBBOA give the finest simulation outcomes than lately proposed optimization algorithms given in the literature.