Impact of hybrid FACTS devices on the stability of the Kenyan power system

<p>Flexible alternating current transmission system (FACTS) devices are deployed for improving power system’s stability either singly or as a combination. This research investigates hybrid FACTS devices and studies their impact on voltage, small-signal and transient stability simultaneously under various system disturbances. The simulations were done using five FACTS devices-static var compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensators (SSSC), thyristor controlled series compensator (TCSC) and unified power flow controller (UPFC) in MATLAB’s power system analysis toolbox (PSAT). These five devices were grouped into ten pairs and tested on Kenya’s transmission network under specific contingencies: the loss of a major generating machine and/or transmission line. The UPFC-STATCOM pair performed the best in all the three aspects under study. The settling times were 3 seconds and 3.05 seconds respectively for voltage and rotor angle improvement on the loss of a major generator at normal operation. The same pair gave settling times of 2.11 seconds and 3.12 seconds for voltage and rotor angle stability improvement respectively on the loss of a major transmission line at 140% system loading. From the study, two novel techniques were developed: A performance-based ranking system and classification for FACTS devices.</p>

Intrinsic time decomposition based differential protection with adaptive threshold for UPFC compensated transmission line

In the presence of nonlinear response created by power electronics-based compensators, reliable fault detection and classification by distance protection relays is a major concern. The unified power flow controller (UPFC) has a dynamic characteristics that causes stability and protection issues. A intrinsic time decomposition (ITD) based strategy is proposed for addressing this issue. A differential energy based detection index computed using ITD and adaptive thresholding technique is employed such that unerring fault detection is achieved wherein faulty phases of a UPFC compensated transmission line are well pointed out. Various fault and non-fault cases considering critical power system conditions are analysed for power systems with varying configurations modelled using EMTDC/PSCAD. A comparison of the current detection method to recently proposed techniques reveals the benefits and feasibility of the presented detection strategy, which has been proved to be accurate and efficient.

Voltage and Reactive Power Control in DFIG Wind Farm Load bus by FACT Device – UPFC

This paper deals with the analysis and simulation of the Unified Power Flow Controller (UPFC) for Grid connected DFIG wind farm system mitigation. The purpose of the paper is to derive and analyze a reactive power control strategy of UPFC dedicated for DFIG mitigation. The FACT device Unified Power Flow Controller (UPFC) is connected with load bus. Paper has demonstrated the improvement in voltages, power transferred to grid, active and reactive power control. Matlab/simulink is used for the work. Paper demonstrated the simulation results for with and without UPFC for Grid connected Doubly Fed Induction Generator wind farm system.

Artificial-neural-network based unified power flow controller for mitigation of power oscillations

The series and shunt control scheme of unified power flow controller (UPFC) impacts the performance and stability of the power system during power swing. UPFC is the most versatile and voltage source converter device as it can control the real and reactive power of the transmission system simultaneously or selectively. When any system is subjected to any disturbance or fault, there are many challenges in damping power oscillation using conventional methods. This paper presents the neural network-based controller that replaces the proportional-integral (PI) controller to minimize the power oscillations. The performance of the artificial neural network (ANN) controller is evaluated on IEEE 9 bus system and compared with a conventional PI controller.

An optimal allocation of UPFC and transient stability improvement of an electrical power system: IEEE-30 buses

<span lang="EN-US">Recently, the expansion process of electrical networks has become crucial with the development of electrical systems. One of the active solutions to progress the performance of an electrical system is the usage of flexible AC transmission system (FACTS). As a new generation of telecommunications and power electronics technology, FACTS has provided a new viewpoint to increase the bearing capacity, better control the grid, and reduce costs. The unified power flow controller had a multi-purpose unit that could command the scenario of providing or consuming the power components and maintaining the bus voltage. The study's novelty resided in presenting a modified particle swarm optimization algorithm-based software system and applied a Newton-Raphson load flow solution to get the best solutions for optimal allocation of unified power flow controllers (UPFC). This study has focused on the functions of the UPFC electrical system with corresponding effects on transient stability. MATLAB software (Simulink/code) and excel sheet were performed on IEEE 30 buses as a case study. It has been shown the effectiveness of UPFC with fast response and autonomous command on the flow of power components. The dynamic response for stability improvement for some network buses had been verified to ensure the robustness of UPFC during a sudden disturbance in electrical load. The case study results illustrate that the number of UPFC increased with load increased by (14% and 21%).</span>

Detailed Analysis of Unified Power Flow Controller- A Review

Renewable techniques have become more appealing for producing energy in village and moderately village regions because they reduce degradation of environment and provide a plentiful supply of free and environmental energy. Several research works have been carried out all over the planet to assess and investigate the feasibility of hybrid renewable resources (combination of two or more) with the electricity generation for usage in diverse implementation and livelihoods. An explanation of photovoltaic renewable energy systems is demonstrated in this paper.

Enhanced power quality using unified power flow controller systems

Electrical system frequently finds and issue due to unstable nature and power quality because of, in relation to great number of nonlinear charges. So, there is need to limit inside of these difficulties and produce fine voltage quality concerns. The Flexible Alternate Flow Transmission Systems (FACTS) are the framework made out of static gear works for the AC transmission of electrical energy. Unified_Power_Flow Controls (UPFC) are the excellent FACTS tools to attach series and shunt together and it could use for framing Power transmission sensitive and active power. Here in the paper, Unified Power Flow Control (UPFC) used to clear the voltage sink and Surge. Unified Control was developed and engineered using amplifiers and rectifiers. The real and reactive modifications in congruous control orientations at the receiver side. Use of Simulink of MATLAB checks quality of energy in the use of Unified Control.

Effect of unified power flow controller installation in dual feed induction generator (DFIG) wind turbines

In recent years, the use of wind energy to generate electricity in the world has been accelerating and growing. Wind farms are unstable when dynamic voltage fluctuations occur, especially sudden and sudden changes in load, and show oscillating performance at their output. In this paper, the Unified Power Flow Controller (UPFC) has been simulated and studied by Matlab software to improve the dynamic stability and transient behavior of the wind power plant in the event of sudden load changes. The simulation results show that by controlling the UPFC series inverter, voltage fluctuations in the PCC bus are prevented and the UPFC parallel inverter injects power after changing the load for faster recovery and stability of the PCC bus voltage and thus the stability of the wind farm. The UPFC can control the active and reactive power at the transmission line, and in fact, controls the output of the wind turbine with the generator from both sides to the fluctuations caused by sudden load changes that play a role such as sudden disturbances and oscillating errors. Also, the presence of UPFC in the system reduces power fluctuations.

The influence of Unified Power Flow Controller to increase the value of Available Transfer Capability on transmission system Java – Bali, Indonesia

Industrial growth and population in Indonesia led to an increase in demand for electricity. It needs a device that can perform a voltage correction profile online so that power will flow through transmission line. TJBTB (Transmisi Jawa Bagian Timur dan Bali) conditions before the installation of UPFC (Unified Power Flow Controller), the power supply received by the load is not 100% obtained from plants in the region, for example the Paiton power plant. In this research, the method used is with the help of MATLAB R2014a simulation by designing a 500 kV transmission system configuration and the placement of the UPFC found in regional IV namely East Java - Bali. From the simulation results, showing that there was a change in power flow when placing the UPFC. The right location is the West Surabaya - Gresik channel. On the Ngimbang bus there is a change in active power which before using UPFC by 1612 MW to 2208 MW after using UPFC, an increase in active power was 36.97%. The UPFC can fulfill all these functions and thereby meet multiple control objectives by adding the injected voltage with appropriate amplitude and phase angle, to the terminal voltage v.