A Study on Application of Static Synchronous Compensator (STATCOM) in Power Quality Improvement

Flexible AC Transmission System (FACTS) controllers are advanced power electronic devices employed in electrical power systems to enhance system stability, reliability, and power transfer capabilities. These controllers enable dynamic and flexible control of various transmission parameters such as voltage, current, impedance, and phase angle, thereby improving the overall power system performance. FACTS devices are broadly classified into series, shunt, series- series, and series-shunt configurations, each designed to manage reactive power and regulate voltage either by injecting voltage in series or current in shunt with the transmission line. Well-known FACTS devices include Static Var Compensators (SVC), Static Synchronous Compensators (STATCOM), Thyristor Controlled Series Capacitors (TCSC), Static Synchronous Series Compensators (SSSC), and Unified Power Flow Controllers (UPFC), each serving specific roles in power flow control, voltage regulation, and transient stability enhancement. The integration of these controllers provides significant benefits such as increased transmission line capacity, improved voltage stability, minimized transmission losses, and damping of power system oscillations. They are capable of rapid response during transient disturbances, effectively mitigating voltage collapses and enhancing system resilience against faults and contingencies. FACTS controllers not only improve steady-state operational parameters but also address dynamic stability and transient conditions, enabling power systems to operate closer to their stability limits while maintaining security. Their deployment helps avoid costly infrastructural expansions by optimizing existing transmission assets, which is critical given environmental and economic constraints. Recent advances in semiconductor technologies and control algorithms have made FACTS devices more reliable, efficient, and adaptable to modern grids, including renewable integration and deregulated power markets. In summary, FACTS controllers play a vital role in modern power systems by providing flexible, efficient, and reliable solutions for power flow management, voltage control, and system stability enhancement, thereby supporting the evolving demands of today's complex electrical networks.

The static synchronous compensator (STATCOM) is one of the flexible AC transmission system (FACTS) devices. The STATCOM and wide area measurement system (WAMS) are used in power systems. This paper describes the coordinated design of the wide area controllers and STATCOM controllers using a bacterial foraging algorithm (BFA). BFA is a new type of global optimization algorithm. The parameters of the controllers are optimized simultaneously by using the BFA to minimize the fitness function. The fitness function is the performance of the integral of the time-weighted squared error (ITSE). The fitness function is calculated by solving the differential equations. A 10-machine 39-bus new England system is a complex power system and is used to test the method of the coordinated design. The results show that the coordinated design of these controllers can improve the damping of the interconnected power system.

This paper deals with the design and implementation of cascaded H-bridge multilevel voltage source converter-based static synchronous compensator (STATCOM) for simultaneous active and reactive power compensation, voltage stability and damping of power oscillations. The main objective is to provide active power support and maintain the voltage stability by compensating the reactive power in the power system. In this paper, the multi pulse inverter-based STATCOM has been replaced by multilevel inverter-based STATCOM to overcome the drawbacks of the former. Cascaded H-bridge (CHB) MLI for implementation of STATCOM has been used as CHB MLI is considered the best for STATCOM applications due to its modular structure and requirement of lesser number of components. MLI-based STATCOM is used to provide simultaneous reactive power and active power compensation established by using super-capacitor. The super-capacitors are connected with each DC link capacitor of CHB MLI by using the DC-DC buck boost converter. The STATCOM is also used to provide voltage stability during the power quality problems such as voltage sag and voltage swell, it is established by injecting or absorbing reactive power. The STATCOM is also used for damping the power oscillations by controlled injection of reactive power hence enhancing transient stability. Nine-level cascaded H-bridge MLI-based STATCOM is designed for simultaneous reactive power and active power compensation, voltage stability and damping the power oscillations. Exhaustive simulations have been carried out using MATLAB/Simulink and SimPowerSystems software. The simulation results are presented to prove the effectiveness of MLI-based STATCOM for simultaneous active and reactive power compensation, voltage stability and damping of power oscillation.

A Static Synchronous Compensator (STATCOM) is one of the Flexible AC Transmission System (FACTS) device which plays an vital role in power system network in alleviation of small and large transient disturbances and better voltage regulation. This paper proposed a self tuning Proportional-Integral (PI) controller for STATCOM which provided a voltage support at point of common coupling (PCC). Self tuning of PI controller was achieved by adapting PI controller gains with system parameters by using Bats Echolocation controller which mimics the Bats Echolocation behavior. In the proposed controller, the system voltage (parameter) at point of common coupling compared with reference voltage and then Bats Echolocation Controller updates the PI controller gains according to the variation obtained between them. This paper also proposed a Cascaded Multilevel Inverter (CMLI) instead of conventional Voltage Source Inverter (VSI) for STATCOM to obtain better voltage regulation at point of common coupling. The voltage imbalance between H-bridge cells in CMLI was rectified by prosing Multicarrier Pulse Width Modulation (PWM) techniques, The proposed controller was validated by comparing the simulation results with fixed gain PI controller and Self tuning PI controller using Neural controller and Particle Swarm Optimization.

Series compensated power system may lead to a very unusual problem known as Subsynchronous Resonance (SSR). Flexible AC Transmission Systems (FACTS) controllers are widely applied to mitigate subsynchronous oscillations. The Static Synchronous Compensator (STATCOM) is a shunt device of the FACTS family using power electronics to control power flow and improve transient stability on power grids. With the advent of Wide Area Measurement (WAM) technology, it is possible to measure the states of a large interconnected power system with synchronized Phasor Measurement Units (PMU). In this paper the concept of using remote signals acquired through PMU has been proposed to damp SSR. An auxiliary subsynchronous damping controller (SSDC) for a STATCOM using the remote accelerating power of generator signal as the stabilizing signal has been designed to damp subsynchronous oscillations. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels) source converter. The voltage source converter described in this paper is a harmonic neutralized, 48-pulse GTO converter. The IEEE Second Benchmark (SBM) model is considered for the analysis and the complete digital simulation of the STATCOM within the power system is performed in the MATLAB/Simulink environment using the Power System Blockset (PSB).

Power consumption has risen dramatically in the last two decades, yet power generation and transmission have been severely hampered due to limited resources and environmental restrictions. Some transmission lines are essentially charged, and system stability becomes a limiting issue in energy transmission. A range of steady-state control problems has been addressed by flexible AC transmission system (FACTS) controllers. A FACTS is a system made up of static equipment used to transmit electrical energy via AC lines. Since the 1970s, FACTS devices have been utilized to create and improve the dynamic performance of modern power systems. This paper examines different techniques and tactics for coordinating control across FACTS controllers in multi-machine power systems in depth. The authors are certain that academics will find this survey study to identify important references in FACTS controller coordination.KeywordsFlexible alternating current transmission systemPower transfer limitingUnified power flow controllerOptimization methods

In recent years, power demand has increased substantially while the expansion of power generation and transmission has been severely limited due to limited resources and environmental restrictions. As a consequence, some transmission lines are heavily loaded and the system stability becomes a power transfer-limiting factor. Flexible AC transmission systems (FACTS) controllers have been mainly used for solving various power system steady state control problems. However, recent studies reveal that the FACTS controllers could be employed to enhance power system stability in addition to their main function of power flow control. The literature shows an increasing interest in this subject for the last two decades, where the enhancement of system stability using FACTS controllers has been extensively investigated. This paper presents transient stability enhancement of power system using Thyristor Switched Series Capacitor (TSSC) device. The performance of IEEE 9 Bus system is evaluated with and without TSSC device. This approach has been simulated using MATLAB /SIMULINK.

Voltage stability assessment of isolated hybrid dish-stirling solar thermal-diesel microgrid with STATCOM using mine blast algorithm

This paper presents a novel nonlinear control scheme for designing static synchronous compensators (STATCOM). A passivity-based approach is proposed for designing robust nonlinear STATCOM controller. The mathematical model of STATCOM will be represented by a Euler-Lagrange (EL) system corresponding to a set of EL parameters. By employing the Park's transformation, the differential geometry approach is used to investigate the power system dynamics with considering STATCOM under the synchronous d-q frame. The STATCOM controller based on passivity is obtained with a feedback control law from linear system models. Digital computer simulation for a large operation point variations have been studied the STATCOM controller design. Simulation results show that the proposed STATCOM controller can effectively enhance transient stability of the power system even in the presence of large operation point variations

The increasing demand for reliable and high-quality electrical power has led to the development of advanced techniques for controlling power flow in transmission networks. Flexible AC Transmission Systems (FACTS) are key technologies designed to enhance the controllability and stability of AC power systems. Among FACTS devices, the Static VAR Compensator (SVC) is widely used to regulate voltage, improve power factor, and maintain system stability under varying load conditions. This project focuses on the design and implementation of a Static VAR Compensator for improving voltage stability and reactive power management in an AC transmission system. The SVC achieves rapid reactive power compensation using thyristor-controlled reactors (TCRs) and thyristor-switched capacitors (TSCs), allowing dynamic adjustment to changing system conditions. By maintaining voltage within desired limits, the SVC enhances the reliability, efficiency, and operational flexibility of the transmission network. The project includes simulation and analysis of the SVC in different loading scenarios to demonstrate its effectiveness in reducing voltage fluctuations, improving power quality, and minimizing transmission losses. The implementation of SVC in a transmission system represents a cost-effective solution for modern power systems, enabling better control of power flow and contributing to the stability of the electrical grid.

Flexible AC Transmission Systems (FACTS) play a vital role in enhancing the stability, efficiency, and reliability of modern power systems. With the increasing complexity of power grids due to the integration of renewable energy sources, effective control of power flow, voltage regulation, and stability improvement are critical challenges. FACTS devices, such as Static Synchronous Compensator (STATCOM), Unified Power Flow Controller (UPFC), and Thyristor- Controlled Series Capacitor (TCSC), offer advanced solutions to mitigate these challenges by providing dynamic voltage control, reactive power compensation, and congestion management. This paper presents a comprehensive analysis of various FACTS devices, focusing on their control strategies, applications, and impact on improving power system performance. Simulation results demonstrate the effectiveness of FACTS devices in maintaining voltage stability, optimizing power flow, and minimizing transmission losses, ultimately contributing to a more efficient and resilient power grid.

Today, there is a large increase in the demand for electricity. The transmission and distribution networks, however, cannot fulfill unbound demands due to the scarcity of resources. Power lines have losses which make the situation more unfavorable for maximum power transfer. Implementing a flexible AC transmission system (FACTS) is one of the best ways to reduce line losses. This paper proposes a FACTS-based method for minimizing the fault current in the system. Switchgear and protection equipment also perform better when this is done. Moreover, due to the reduced fault current of the switched system, a larger amount of power can be transmitted. Static synchronous series compensator (SSSC), static synchronous compensator (STATCOM), and unified power flow controller (UPFC) are evaluated in this case. With STATCOM and UPFC, fault currents are significantly reduced. Furthermore, STATCOM and UPFC can also reduce the fault currents in the power system in addition to voltage regulation and power flow control. A MATLAB/Simulink model is used to evaluate the model’s feasibility.

This paper investigates the applicability of an integrated approach for the enhancement of voltage stability margin and there by the wind penetration of large wind integrated power systems. The proposed approach involves in two objectives; the identification of weak buses in the given power systems, enhancement of voltage stability margin of the weak buses and there by the wind penetration by optimal placement and tuning of Flexible AC Transmission System (FACTS) controllers. Multiple of one type of FACTS controller namely SVC is used in the current analysis for placement in suitable weak buses. Weak bus identification is carried out byconducting the tangentvectoranalysis. Voltage stability enhancement at high wind penetration is assessedby using the dynamic voltage security index, the index for accessing the proximity of voltage collapse under dynamic loadingconditions. Theoptimization of grid control parameters are carried out by using Particle Swarm Optimization (PSO) by incorporating FACTS Controllers. The developed algorithm have beentested on Wind integrated Kerala grid 25-bus practical system.

FACTS (flexible AC transmission systems) controllers are now widely available and they demonstrate many years of service experience. Their contribution to the control of a transmission system will become more valuable as the demands and varying applications of the system increase. Of the FACTS controllers in service today, the majority are static VAr compensators (SVCs), of which over 1000 give satisfactory service worldwide. Reviewing the available control packages and the experience of refurbishing an SVC, this paper offers some guidelines on the principles of design for replaceable control components that can deliver a renewable, and therefore ongoing, performance for a FACTS controller.

Flexible AC Transmission Systems (FACTS) devices have been used in power systems since the 1970s for the improvement of its dynamic performance. Among these devices, Static Synchronous Compensator (STATCOM) is a shunt connected FACTS device, which is capable of providing reactive power compensation to the power system. STATCOM is a multiple input and multiple output system. In this paper, the CSC based STATCOM is controlled by the pole placement. But the best constant values for pole placement controller's parameters are laboriously obtained through trial and error, although time consuming. So the genetic algorithm (GA) is employed to find the best values for pole placement controller's parameters in a very short time. These methods are tested in MATLAB, and their results are obtained. The simulation results show an improvement in input-output response of CSC-STATCOM.