Power Electronics in Smart Grid and Renewable Energy Systems [Scanning the Issue

In the transition towards renewable energy systems, the integration of large-scale renewable energy sources (RES) introduces significant operational challenges due to their intermittent nature and lack of physical inertia. This paper explores the efficacy of two Flexible AC Transmission System (FACTS) devices, the Static Synchronous Compensator (STATCOM) and the Static VAR Compensator (SVC), in mitigating the destabilizing effects associated with high levels of RES integration. Through simulation of various contingencies at a Real Time modeled 400kV Pooling Substation, the performance of STATCOM and SVC, each rated at 150 MVAr, is analyzed in maintaining grid stability. Findings highlight STATCOM’s superior dynamic response in managing voltage fluctuations and enhancing system damping compared to SVC. Specifically, STATCOM demonstrates a quicker and more robust capability to inject reactive power during disturbances, thereby ensuring rapid stabilization of grid operations. This research underscores the critical role of advanced FACTS devices in sustaining grid reliability and offers strategic insights for grid operators and policymakers aiming to optimize renewable energy integration without compromising grid stability.

This paper presents an application of a flexible AC transmission system (FACTS) device as additional control in reactive power (VAR) optimization problem and analyzes the impact on system loss minimization. The adopted FACTS device is a new static VAR compensator (SVC). The general SVC consists of internal devices, and local devices, and the operation mode of the general SVC model is voltage control mode only. The new SVC model controls local, remote, internal and external devices simultaneously. It has two modes of operation: (1) Voltage control mode; and (2) Q control mode. This paper analyzes the functions of the new SVC, and implements them in the practical power systems. The impact of VAR optimization with new SVC model on loss minimization is also discussed by comparing it with VAR optimization with general SVC model as well as VAR optimization without SVC model.

Introduction: To date, a variety of studies have been published on the topic of long term energy system transition. Most studies on future energy systems, however, have a shorter time frame or adopt a supranational focus (e.g. the Energy Roadmap, 2011 or the World Energy Outlook, 2015). It then constitutes a sincere challenge to perform a national energy system transition study with as time horizon 2050 and covering a far-reaching transformation of the energy system. VITO, together with the FPB (Federal Planning Bureau) and ICEDD, performed a study to scrutinise the transition of the Belgian national energy system towards a future mix entirely based on renewable energy sources. The focus on renewable energy sources and on building a national energy system completely running on renewable energy can be traced back to three main concerns: – Climate change: Renewable energy sources (RES) are a major instrument in the fight against climate change as RES do not release (net) greenhouse gas emissions. – Security...

This paper introduces an adaptive terminal voltage regulation of a standalone self excited induction generator using flexible AC transmission systems (FACTS). FACTS in the form of static VAR compensator (SVC) is introduced. SVC is used to regulate the terminal voltage of self excited induction generator-based (SEIG) wind generator working with variable speed and load. Since, the wind generator operates over a wide range of operating conditions; the terminal voltage of the induction generator is not regulated. This terminal voltage is controlled by adapting the value of the excitation capacitance of SVC using artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS). Changing the excitation capacitance is performed by controlling the firing angle of SVC under different operating conditions to control the terminal voltage. A mathematical model of SEIG with variable load and speed along with SVC is developed and simulated in MATLAB to get the excitation capacitance required for voltage control. Simulation results are used to train both ANN and ANFIS for on-line prediction of the suitable firing angles required to control the terminal voltage of the system under these operating conditions. Results signify the supremacy of ANFIS over ANN in terms of performance measures.

SYNOPSES In the UK, the Electricity Act of 1989 was amended in 2000 to remove the distinction between private and public electric supply companies. The customers in the UK saved £ 700 million in one year under de-regulation. In the US, Congress passed the Energy Policy Act in 1992 that de-regulated the wholesale electric market and mandated electric utilities to open up the transmission system on an equal basis to all who utilize it. During the past decade, the demand for electricity in the United States has increased by 35 percent, whereas, the generation has increased only by 18 percent. With the bulk power transactions and reservations, the transmission system now operates closer to its stability limits. Voltage instability occurs when the balance between the reactive power producing sources and the VAR losses cannot be maintained. The limited construction of new transmission lines has pushed the power industry toward the development of advanced technologies such as flexible ac transmission system (FACTS), static VAR compensators (SVC), static synchronous compensators (STATCOM), unified power controllers (UPFC), and distributed superrconducting magnetic energy storage (D-SMES). In a nuclear power plant, offsite and onsite electric power systems are required to provide sufficient capacity and capability to assure that the containment integrity be maintained during power operation or in case of a postulated accident. Analyses must verify that the electric grid remains stable in case of loss of the nuclear unit, the largest other unit on the grid or the most critical transmission line and a change it due to deregulation would affect those analyses. Nuclear Regulatory Commission (NRC) staff ensures that the licensees maintain adequate voltages to the Class 1E (safety) buses. If the operator has failed to restore adequate voltages, the Class 1 E buses should be automatically separated from the offsite power system and connected to the emergency diesel generators. Most utilities use on-line contingency analysis and the control centers notify them when the offsite power system in their nuclear plant is degraded. The control centers use load conservation procedures to provide the plant a stable offsite power system. The control centers have assured the NRC staff that the nuclear power plants are their preferred customers and that they will be provided with an adequate offsite power system even under reduced grid generation availability. This paper discusses the voltage stability, power transfer limits, reactive reserves, methods of improving voltage stability (such as superconductivity), load conservation procedures and effects of deregulation on nuclear power generating stations.

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.

Summary form only given. Energy has been the life-blood for continuing progress of human civilization. Since the beginning of industrial revolution around two centuries ago, the global energy consumption has increased by leaps and bounds to accelerate the human living standard on this planet, particularly in the industrialized nations. Per-capita energy consumption, particularly in electrical form, has been a barometer of a nation's economic prosperity. Today, the major amount of electricity is generated by fossil fuel and nuclear power plants. Fossil Juel plants create environmental pollution problem whereas the nuclear plants have safety problem. These pollution and safety problems are now causing major concerns in our society. How can we continuously improve our living standard, and at the same time, live in a cleaner and safer environment? Renewable energy sources, and possibly the fusion energy in future (if at all possible), can to a certain extent mitigate these problems, but conservation of energy with more efficient use of electricity is a definite method of solving this problem. Power electronics and drives technology is recently showing a major impact in energy conservation besides its general role in global industrial automation. The presentation will begin by broad introduction of global energy generation, depletion of fossil and nuclear fuels, environmental pollution, and energy conservation scenarios. The role of power electronics and drives technology, which has gone through rapid advancement during the last four decades will be reviewed in a broader perspective. The recent advances of power semiconductor devices, converter topologies, variable frequency drives, control and estimation techniques will be discussed, and technology trends will be outlined wherever possible. More recently, the emerging AI technology tools, such as expert system, fuzzy logic, neural network and genetic algorithm are expanding the frontier of power electronic and drives.

This paper primarily focuses on an investigative study on allocating Flexible AC transmission system (FACTS) devices on radial distribution systems. The FACTS device that is used in this paper is static var compensator (SVC). In this paper, SVC is placed on each bus except substation bus and study the results to find the best location for allocation. A design of SVC was done by fixed reactance method. The total power loss of network and voltage of nodes have been analyzed for each allocation and the sequences of each implementation have been compared to find the best location of SVC. The proposed algorithm has been executed on IEEE 33-bus and 69-bus standard test systems.

The control of reactive power in any transmission network is important to ensure voltage stability of the entire power grid. Flexible AC Transmission Systems (FACTS) have proven to be efficient in providing controllability to reactive power for voltage stability management. However, the performance of the FACTs devices largely depends on the installation location. A fuzzy logic technique for finding the optimal location for the Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) FACTS devices with specific security indices is proposed in this paper. The proposed indices for SVC placement are the Loss Sensitivity Factor (LSF) and critical voltage, while the considered indices for TCSC placement are the loss sensitivity factor (LSF) and line stability index (LSI). The indices are fuzzified to obtain a suitability index which determines the suitable line(s) and node(s) accordingly. The proposed approach is implemented on the IEEE 30 bus network. The SVC reduced the overall transmission loss by 1.6%, while the TCSC reduced the transmission loss by 4.94 %. The loading margin also improved by 24.87% and 2.92% using SVC and TCSC, respectively. The voltage profile also remained close to 1 p.u under varying load conditions. The results indicate the effectiveness of the proposed technique at reducing transmission loss, improving voltage stability and improving voltage profile simultaneously.

SVC(Static Var Compensator) is a shunt connected FACTS(Flexible AC Transmission System) controller consists of TCR(Thyristor Controlled Reactor), TSC(Thyristor Switched Capacitor) & filter elements for reactive power compensation. In this paper extended version of SVC representation by synchronizing the step down transformer reactance & overall SVC reactance. SVC reactance contains capacitive reactance of shunt capacitor and TCR reactance. Thus this model is termed as Integrated Transformer Firing Angle Model. This model controls the voltage magnitude at electrical bus & thereby enhances the system stability as well. Here, ieee-5 bus system is considered for overall analysis. Load flow for an uncompensated 5-bus system is carried out first & next to this load flow done for SVC compensated 5-bus system by means of Integrated Transformer Firing Angle Model. All the load flow study & system analysis have been conducted by using MATLAB/SIMULINK software.

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.

In this paper, prototypes of two shunt flexible AC transmission system (FACTS) devices, a thyristor switched reactor (TSR)-based static VAr compensator (SVC) and a thyristor controlled reactor (TCR)-based static VAr compensator- have been developed. The design and testing of both a TSR-based SVC and a TCR-based SVC are accomplished in the Power Systems Research Laboratory of Nigde University. The TSR-based SVC and TCR-based SVC devices are studied in three-bus and single machine infinite bus systems for three-phase static load conditions. The effects of TSR-based SVC and TCR-based SVC devices on load voltages are also analyzed. Experimental results show that significant improvement in reactive power compensation and voltage regulation is achieved by using TSR-based SVC and TCR-based SVC.

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.

Flexible AC transmission systems (FACTS) technology is widely adopted and utilized to maintain the performance of power systems. However, the improvements of power system performance achieved by FACTS devices depend on the right sizing and allocation of such devices. For technical and economic considerations, a FACTS device's location and size should be selected very carefully in order to maximize its benefits to the power system. In this paper, the sizing and location of a static VAR compensator (SVC) are optimally determined using a new optimization technique called lightning attachment procedure optimization (LAPO). The optimal allocation of the SVC is determined regarding the improvement of voltage deviation index and the reduction of total active power losses. The system is optimized in two cases: once without SVC installation in order to find out the optimal settings of the system that achieve the objective functions, and another time with SVC installation to determine its optimum sizes and locations by which the required objective functions are achieved. Then the system performance is analyzed after optimization with and without SVC devices to show the impact of the optimum sizing and location of the SVC on the system. The study is validated using the standard IEEE 30-bus system, while the developed LAPO is performed by MATLAB M-Files and the system performance analysis in different cases is performed by NEPLAN software.

It is my honor to present the proceedings of the 2024 3rd International Conference on Smart Grid and Green Energy (ICSGGE 2024). ICSGGE 2024 is an event that brings together the world’s leading experts and scholars in the fields of smart grid and green energy, and is also an excellent platform for sharing the latest research results and discussing the application of cutting-edge technologies in related research domains. With the increasing severity of global climate change and energy crisis, smart grid and green energy, as the key means to solve the energy problem, have received extensive attention from the international community. In order to further promote technological innovation, academic exchanges and cooperation in the fields of smart grid and green energy, ICSGGE 2024 was held from April 19th to 21st, 2024 in Chengdu, China (virtual conference). ICSGGE 2024 brought together top scholars and researchers from all over the world, who shared their latest research results and practical experiences in the fields of smart grid and green energy in this conference. Such topics as The Role of Smart Grids to Drive Cities Towards Carbon Neutrality (by Prof. Steivan Defilla, Tianjin University, China), Role of Energy Conservation & Management in Energy Transition (by Prof. Muhammad Asif, King Fahd University of Petroleum & Minerals, Saudi Arabia), among others were discussed during the keynote speech part. Through exchanges and discussions, we have jointly explored the development trends and future research direction of smart grid and green energy, stimulated innovative thinking, and promoted academic exchanges and cooperation. This proceedings of ICSGGE 2024 contains excellent academic papers from all around the world, which not only cover the basic theories, teaching methods, and evaluation systems of smart grid and green energy, but also discuss in depth the applications and innovations in many fields. Topics include but are not limited to Smart Grid Security, Energy Transfer and Interactive Technology, Communication-Based Control and Protection, Photovoltaic Systems and Solar Energy Engineering, Power Electronics and Drives, Wind Energy Generation, etc. Each paper has been strictly reviewed and screened to ensure its academic value and practical application value. We would like to express my heartfelt thanks to all the experts and scholars, organizers, sponsors and participants who have contributed to and supported this conference. And we believe that all the experts and scholars have harvested fruitful results and inspired new inspirations in this event. Through our joint efforts and wisdom, the ICSGGE 2024 has become a grand event in the fields of smart grid and green energy, and made a new contribution to the promotion of electronic and energy engineering. The Committee of ICSGGE 2024 List of Committee Member is available in this Pdf.