As a result of increasing fossil fuel price and state-of-the-art technology, more and more residential and commercial consumers of electricity have been installing wind turbines. The motivation being to cut energy bills and carbon dioxide emissions. Purpose. The main goal of this work is developing a control scheme for a variable speed wind turbine generator in order to produce utmost power from varying wind types, and variable wind speed. Novelty. This research paper presents an IGBT power converter control scheme for active power in relation to wind speed and reactive power by adjusting Q-reference (Qref) value in a gearless variable speed wind turbine with permanent magnet synchronous generator. Methods. An effective modelling and control of the wind turbine with the suggested power converter is executed by utilizing MATLAB/Simulink software. The control scheme consists of both the wind turbine control and the power converter control. Simulation results are utilized in the analysis and deliberation of the ability of the control scheme, which reveals that the wind turbine generator has the capability to actively sustain an electric power grid network, owing to its ability to independently control active and reactive power according to applied reference values at variable wind speed. Practical value. This research can be utilized for assessing the control methodology, the dynamic capabilities and influence of a gearless variable-speed wind energy conversion system on electric power grids. A case study has been presented with a (3·10 MW = 30 MW) wind farm scheme.
The impact of COVID-19 on electricity prices in Italy, the Czech Republic, and China
The electric power sector in countries suffering from crises and wars such as Syria, Iraq, Yemen, Libya, etc., is among the most affected infrastructures. Since this sector plays a vital role in the economic growth and in improving people's quality of life, the post-crisis reconstruction of this sector must take into account the requirements and concepts of sustainable development (SD) in addition to technical and economic considerations. This article discusses the role that renewable energy sources (RES) can play in achieving SD in the post-crisis reconstruction phase of the Syrian Electric Power Sector (SEPS) as a case study. Based on the available data, the study period was chosen from 2005 to 2017 and divided into two periods. In the first period (2005-2010), which is the pre-crisis period, the structure of the SEPS and its main characteristics were described while the adoption of RES solutions and SD concepts were investigated. In the second period (2011-2017), the crisis period, the satiation of the SEPS and impact of the crisis were evaluated. The challenges that faced the adoption of SD concepts and RES solution were also addressed at this stage. Based on analysis and comparison of the available data, several scenarios were discussed to evaluate the role of RES in achieving SD in the post-crisis reconstruction phase of the SEPS. EnergyPLAN software was used for the techno and socio-economic evaluation of these scenarios. Our results emphasize the importance of the adoption of RES solutions in the reconstruction phase, as these can help promote SD concepts (reducing greenhouse gas emissions, protecting the environment, increasing energy efficiency, creating jobs, etc.) and securing the electric supply of the SEPS while enhancing its stability.
A Collective Condition Monitoring Algorithm for On-Load Tap-Changers
Proceedings of 19th IEEE International Conference on Environment and Electrical Engineering (EEEIC) / 3rd IEEE Industrial and Commercial Power Systems Europe Conference (I and CPS Europe). New York: IEEE, 2019. ISBN 978-1-7281-0652-6.
Transformer units are widely utilized to transfer the electric power over transmission and distribution networks efficiently. These units can be equipped with an on-load tap-changer (OLTC) to regulate the voltage level of power grids by tap changing operations between different steps of transformer winding to compensate unpredicted fluctuations of voltage. An OLTC is the solely moving and switching component of power transformers, thus it is highly prone to electrical, mechanical, and dielectric defects. Some international surveys indicate that the majority of the failures and outages with respect to power transformers are originated from malfunctions of OLTCs. This paper contains an analytical review of the existing methods for condition monitoring (CM) of OLTCs and proposes a collective CM algorithm, which considers the mechanical, electrical, and dielectric defects and degradations of OLTCs. The algorithm is designed to provide a comprehensive CM output for OLTCs by collecting different types of measurements from certain sensors used by different CM methods.
Utilizing the synchronous condenser for robust functioning of wind farm implanted electric grid
Present-day electricity grids are equipped with sophisticated devices that allow to meet various grid code requirements. These include reactive and active power controls to ensure robust functioning of the grid. Robust operation of the electricity grid entails favourable voltage and frequency profile adjustments that can be achieved through reactive and active power controls. This study presents the synchronous condenser capability of providing voltage regulation and reactive power output, and the active power possibility path of a type-3 wind machine for dynamic state conditions and voltage stability issues. Simulations carried out in the MATLAB/Simulink environment prove the efficiency of the proposed methodology.
Voltage Quality and Power Factor Improvement in Smart Grids Using Controlled DG Units
The increased penetration of renewable energy sources in the electrical grid, due to the rapid increase of power demand and the need of diverse energy sources, has made distributed generation (DG) units an essential part of the modern electrical grid. The integration of many DG units in smart grids requires control and coordination between them, and the grid to maximize the benefits of the DG units. Smart grids and modern electronic devices require high standards of power quality, especially voltage quality. In this paper, a new methodology is presented to improve the voltage quality and power factor in smart grids. This method depends on using voltage variation and admittance values as inputs of a controller that controls the reactive power generation in all DG units. The results show that the controller is efficient in improving the voltage quality and power factor. Real data from an electrical network have been used in the simulation model in MATLAB Simulink to test the new approach.
Design of an Emergency Energy System for a City Assisted by Renewable Energy, Case Study: Latakia, Syria
Electrical energy is one of the most important daily needs. Shortage of energy can be very dangerous for any society. This can affect the standard of living and quality of life of the people and even endanger the lives of those in hospitals, and so forth. Developed countries do not face such risks in general because they have well organized electrical systems and high energy security. The developing countries are faced daily with electric system collapses, especially in the case of wars, where many parts of the electrical grid in the country can be damaged and fuel transmission lines for generators cut off. Urban areas in developing countries should have a strategic plan to deal with any unexpected occurrence of energy shortages using any available renewable energy sources. City of Latakia is located in the region which has been suffering from the consequences of war for more than six years. The fact that a high number of migrants from other cities have come to Latakia along with a lack of fuel makes the energy shortage in the city worse. An emergency system could use the cheapest available renewable energy sources in addition to few big portable generators to provide an acceptable energy supply for the most needed requirements of daily life.
Improvement of Voltage Profile and Mitigation of Power Losses in Case of Faults Using DG Units
Distributed generation (DG) units has become an essential part of the smart grid due to increased penetration of renewable energy sources. These units help to improve power quality according to their position and control. Grids could face unexpected faults which affects power quality most especially voltage profile and power losses. This paper presents the potential application of (DG) units as a solution for improving voltage profile and mitigating power losses in loop distribution systems in case of faults for different positions of DG unit. Load flow analysis of a 66/20 kV distribution line network is performed to calculate the various values of voltage and power flow at each bus for different faults in each position of DG unit. Simulation of this distribution substation network with DG units have been developed in the MATLAB/Simulink Environment. The objective of this study is enhancement of voltage profile at various buses and the improvement in power flows in the distribution network with reduction in branch losses in the presence of fault.
Modeling and simulation of the anticipated effects of the synchronous condenser on an electric-power network with participatingwind plants
In traditional electric-power systems, synchronous generator based center electric-power plants have been the main origin of dynamic reactive power sustenance, but owing to the steady growth in the number of renewable power generating plants across the globe and the concurrent dismantling of these rotating synchronous machines principally driven by the demand to decrease carbon emission and reliance on fossil fuels, the need for grid-stabilizing systems is increasing. Also, traditional electric-power generating units are approaching the end of their useful operational life and utility authorities are faced with a difficult resolution of retiring electric-power plants. One way of resolving these issues is the refurbishment of these machines that is the electric-power plants to synchronous condensers. This paper presents a brief assessment of the synchronous machine and the motivation for this research work. It discusses the importance of the synchronous machine in electrical power systems, and the progressive trend in the use of the synchronous machine in electric-power networks. It stresses the need for the use of the synchronous machine for reactive power compensation purposes, with a vivid description given with MATLAB/Simulink simulation model. When the synchronous condenseris connected to the power system model at the terminating end of the network and switched ON, the medium voltage (MV) electrical power network simulation model effectively allows the control of reactive power, which improves voltage stability and power flow control of the proposed network.
Reputation of the Synchronous Condenser Technology in Modern Power Grid
The synchronous condenser nowadays contributes an essential share of resources for generating reactive power to ensure voltage stability in modern power systems. Such resource has to be taken care of by owners of electricity infrastructures. In any case, real projects, experiments and simulation results have shown need to use the synchronous condenser for enhancing power quality of the grid. Hence, traditional generators are being retrofitted to synchronous condensers in order for them to serve a better purpose of voltage stabilization after they are retired and new synchronous condensers are installed by electricity utility managers to serve same purpose too. This paper presents the synchronous condenser technology. It discusses the experience and lessons learnt from the use of the synchronous condenser in real projects. It also provides an outlook on the development of the use of the technology in modern power grid using two simulation study scenarios. These developments include Scenario One: utilizing only the synchronous condenser for voltage regulation on a power grid. And Scenario Two: Installing the synchronous condensers with Type-3 wind farm for voltage support on an electricity network, such contextualization is towards voltage stability in modern power grids.
Voltage Regulation and Power Loss Minimization in Radial Distribution Systems via Reactive Power Injection and Distributed Generation Unit Placement
Distributed Generation (DG) has become an essential part of the smart grids due to the widespread integration of renewable energy sources. Reactive power compensation is still one of most important research topics in smart grids. DG units can be used for reactive power compensation purposes, therefore we can improve the voltage profile and minimize power losses in order to improve the power quality. In this paper two methods will be used to accomplish the mentioned tasks; the first technique depends on the reactive power demand change of the proposed network loads, whereas the second technique uses an algorithm to control DG units according to the measured voltage values in the feeders to generate the needed reactive power. Both methods were applied to different scenarios of DG unit positions and different reactive power values of loads. The chosen DG unit is made up of a Type-4 wind farm which could be used as a general unit where it is able to control reactive power generation in a wider range separately from active power. The simulation results show that using these two methods, the voltage profile could be improved, power losses reduced and the power factor increased according to the placement of DG units.
Voltage regulation and power losses reduction in a wind farm integrated MV distribution network
A medium-voltage (MV) wind production system is proposed in this paper. The system applies a medium-voltage permanent magnet synchronous generator (PMSG) as well as MV interconnection and distribution networks. The simulation scheme of an existing commercial electric-power system (Case A) and a proposed wind farm with a gearless PMSG insulated gate bipolar transistor (IGBT) power electronics converter scheme (Case B) is compared. The analyses carried out in MATLAB/Simulink environment shows an enhanced voltage profile and reduced power losses, thus, efficiency in installed IGBT power electronics devices in the wind farm. The resulting wind energy transformation scheme is a simple and controllable medium voltage application since it is not restrained by the IGBT power electronics voltage source converter (VSC) arrangement. Active and reactive power control is made possible with the aid of the gearless PMSG IGBT power converters.
Effect of improved electricity product development on the business performance of a public electricity transmission company
Improved electricity product development is becoming more significant to the business performance of electricity transmission companies. Despite the fact that the term improved/new product development is not new, very few studies have investigated the effect of improved electricity product development on the business performance of a public electricity transmission company, most especially in a developing country such as Nigeria. This paper present means by which improved electricity product development can be used to assist electricity transmission company's business performance in order to improve customers' electricity product adoption and other stakeholder's satisfaction in the industry. It is based on a case study of the Transmission Company of Nigeria (TCN), it provide guidelines to stakeholders in the industry in utilizing improved electricity product development to better support electricity transmission companies: it allows transmission companies to launch improved electricity products to end-users; it helps transmission companies to determine the weaknesses of the electricity product delivered to end-users; it allows improved quality of electricity product that customers are willing to pay a premium for, while eliminating epileptic electric-power supply end-users do not want.
Modeling and simulation of a gearless variable speed wind turbine system with PMSG
Wind turbine designs and production is an advance high-tech technology when considering design features from different manufacturers. The design of a wind turbine gearbox is demanding owing to loading and environmental circumstances in which the gearbox must function, Hence, the need for gearless wind turbine designs. As a replacement for gearbox, gearless wind turbine technology can be used, this actually causes the turbine to be more reliable, by reducing downtime and repair costs, an important special consideration for offshore turbines, a place or terrain some more costly to dispatch skilled workers to carry out maintenance operations. This paper analysis a gearless variable speed wind turbine system with Permanent Magnet Synchronous Generator (PMSG). Modelling and simulation of the gearless variable speed wind turbine scheme with PMSG is implemented by utilizing MATLAB/Simulink software. Results shows that the wind turbine has the capability to sustain an electric-power scheme. This research work is beneficial to Model, simulate and analyze the influence of changes in wind speed and Q-reference of a variable speed wind turbine system with permanent magnet synchronous generator.
A review of electric vehicles emissions and its smart charging techniques influence on power distribution grid
Electric vehicle (EV) technology has lately attained a considerable market share. For sustainability, reliability and efficiency of the electric-power distribution grid, this technology have need of the development and implementation of smart charging techniques. With the fast progress of Electric Vehicles (EVs), large-scale charging demand will tremendously affect existing electric-power distribution grid. Hence, the inevitability for a smart charging regime. This review article briefly talk about the various types of electric vehicles. It discusses the grid, smart grid and their relationship with the electric vehicle. A review case of emissions from EVs have been presented. It outlined some proven smart charging techniques by different authors utilizing diverse tools for the electric vehicle. Thereafter, based on the techniques outlined attempts were made to explain the influence of smart EV battery charging management on the distribution grid. From the foregoing, the authors reached the conclusion that the fair share of coal as electrical energy resource should be minimized in order to reduce carbon dioxide emission from EVs. Furthermore, the various electric vehicle smart charging techniques investigated reveal a promising future for smart charging integrated electric-power distribution grid.
Advantageous Positioning of Wind Turbine Generating System in MV Distribution Network
2016 17th International Scientific Conference on Electric Power Engineering (EPE 2016). New York: IEEE, 2016. International Scientific Conference on Electric Power Engineering. ISBN 978-1-5090-0907-7.
This paper presents a new method for achieving voltage stability and reduction of power losses with renewable wind turbine generating system (WTGS) installed at different position on a Medium Voltage (MV) distribution system. The proposed network is a three-phase system consisting of 0.4 kV low voltage (LV) feeder with an active power (P) of 8 MW and a negative VAR (QC) of 0.5 MVAR. And a 20 kV MV feeder with an active power (P) of 22 MW and a negative VAR (QC) of 1.5 MVAR. The 0.4 kV and 20 kV feeders has varying positive VAR values of 2, 2.25, 2.5 and 6, 6.5, 7 MVARs respectively. Three sets of data's were observed; data 1, 2, and 3, the feeders are connected to a 20 kV MV distribution network, which is then linked to a 20 kV substation. Thereafter, a 20 kV MV renewable WTGS energy source with IGBT converters is integrated to the network for effective reactive power compensation. Three different Cases have been analyzed; First is the case with the proposed power system network analyzed without any WTGS attached to the network, in other words when the WTGS is switched off (this is designated as Case 1). Second is the situation with the WTGS positioned at the terminal end of the 20 kV MV distribution network (point 1, which is designated as Case 2) and Third is the situation when the position of the wind energy source is changed and stationed at the beginning of the terminal of the 20 kV MV power line (point 2, which is designated as Case 3). Matlab/Simulink software is used for the simulation of the system model. Simulation results for each of the case studies is analyzed and it is observed that research findings for Case 2 is more efficient in achieving improved voltage stability and power losses reduction in medium voltage electric-power distribution network.
Contribution to control strategies for converter connected to unbalanced grid
The paper deals with developed and experimentally tested effective synchronization and power control techniques for grid-connected converter. A new FLL (Frequency Locked Loop) technique is developed that incorporates advantages of both the cascaded delayed signal cancellation and dual second order generalized integrator schemes. Experimental results are evaluated in terms of quality of the positive voltage sequence, frequency and phase angle identification for the grid voltage disturbed by harmonic, subharmonic, and negative sequence components as well as for amplitude, frequency, and phase angle jumps in the voltage. A novel power control technique for grid-connected converter under unbalanced voltage conditions is referred as well. The current positive and negative sequences during grid voltage sags are controlled to assure a proper exchange of active and reactive powers without substantial power ripples, and especially, without current harmonics.
Cost Implication and Reactive Power Generating Potential of the Synchronous Condenser
The objective of this study is to examine the cost implication and reactive power generating potential of the synchronous condenser. Universally, increase in electricity demand constitutes new issues for power generation, transmission and distribution. Synchronous condenser solutions are being initiated globally to be instrumental in the best usage of power resources and offer grid systems support for todays and future sustainable, stable and reliable electrical grid network. This research x-rays the cost implication of the synchronous condenser in today's challenging environment. A vivid description of the reactive power generating potential of the synchronous condenser is shown with Matlab/Simulink environment simulation of a medium voltage (MV) power system network. It is observed that the synchronous condenser is cost-effective as compared to other reactive power generating equipment's and sources. Furthermore, Matlab/Simulink simulation results of the MV electric-power network shows an effective scheme for reactive power generation.
Optimal Location of the Synchronous Condenser in Electric-Power System Networks
2016 17th International Scientific Conference on Electric Power Engineering (EPE 2016). New York: IEEE, 2016. International Scientific Conference on Electric Power Engineering. ISBN 978-1-5090-0907-7.
In this paper, authors focus on the use of the synchronous condenser device for voltage stability and power flow control on a three-phase 33 kV Medium Voltage (MV) electric-power system network. Matlab/Simulink is used for the simulation of the proposed system model. To test the validity of the system, measured and calculated power factor values were obtained. Two scenarios were studied; Firstly, is the scenario with the synchronous condenser located at the terminal end of the 33 kV MV network (position 1). And secondly, is the scenario with the synchronous condenser placed at the beginning of the 33 kV MV power Line (position 2). Simulation results obtained from the study are compared in order to determine the most appropriate location for situating the synchronous condenser device. It is observed that the locations of the synchronous condenser equipment have different impacts on the electric-power system network. However, the proposed study of the simulation model base on the location of the synchronous condenser at the terminal end of the 33 kV MV electric-power system network (position 1) demonstrate a more effective and suitable scheme of the electric-power network concerning issues of voltage stability and power flow control.
Analysis of the Synchronous Machine in its Operational Modes: Motor, Generator and Compensator
This paper gives a brief evaluation of the Synchronous Machine. It describes the construction, operating principles and its applications in different operational modes: Motor, Generator and Compensator. It emphasizes the need for the use of synchronous machines for compensation purposes due to its numerous advantages in this regard in power system networks.
Comparative review of reactive power compensation technologies
The quality of electrical power in a network is a major concern which has to be examined with caution in order to achieve a reliable electrical power system network. Reactive power compensation is a means for realising the goal of a qualitative and reliable electrical power system. This paper made a comparative review of reactive power compensation technologies; the devices reviewed include Synchronous Condenser, Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM). These technologies were defined, critically examined and compared, the most promising technology is recommended for the realisation of an effective, efficient, sustainable, qualitative and reliable electrical power network.
Comparison of the Operational Theory and Features of SVC and STATCOM
This paper presents a comparison of the operational theory and features of Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM) in power system networks. It compares the Voltage Regulation, System Stability, Economical and Harmonics of these devices. The comparison shows that both devices are promising in enhancing voltage stability and increases transmission capacity in power system. And it also shows that STATCOM has the ability to provide more capacitive power during fault situation over SVC. Hence, STATCOM exhibits faster response than SVC.
Using renewable MV wind energy resource to supply reactive power in MV distribution network
This paper deals with the use of Medium Voltage (MV) renewable wind energy source to optimize reactive power in a distribution network, it describes the increase of power factor when the reactive power is controlled at a wind farm increase in power factor allows improvement in the stability of distribution networks, and the increase in power factor is used as new methodology to reduce power losses, Matlab/Simulink program is used to show the results of the analysis.
Comparison of Simulation and Standard Method for Computation of Inductance
Recent research in electrical power systems is aim at getting the exact inductance in an electrical network. And this is to achieve a more economical grid system and It is important to minimize loses in electrical power grids, specifically in its impedance for the same reasons. This paper deals with comparison between simulated model in software Agros2D and standard computation of inductance. It is important to know the value of inductance in order to calculation the impedance and to have an economical generation, transmission and distribution grid systems.
Distance Protection Based on Artificial Neural Networks
In this paper we present a new approach to determine the presence of fault in near-real time conditions and to determine the fault existence in the given line length based on the implementation of Artificial Neural Networks (ANN's) in the transmission lines, of an electrical power system.
FACTS Devices Influence on Power Losses in Transmission Systems
Since there are still higher efforts for transmission systems equipment utilization, more control mechanisms and devices are integrated to the systems and their dispatch centers and these will be also in future. FACTS devices purpose is preferably to maintain voltage levels and to control active and reactive power flows. Their implementation in the grid can result from the necessity to improve the system capabilities in a longterm period or to solve some extraordinary states. The paper deals with the implementation of shunt and series FACTS devices into electrical transmission systems and their influence on active power losses. There are provided comparison analyses of how different FACTS types have a potential to changes power losses in the system either in a negative or in a positive way. There are explained basic principles and the results are presented on the IEEE/CIGRE transmission system model.
STUDY OF MV RENEWABLE WIND ENERGY SOURCES IN INTEGRATED MV DISTRIBUTION NETWORKS
This paper deals with Mv integrated reactive power optimization in distribution networks using renewable wind energy sources , here we describe the increase of power factor when the reactive power is controled, which produced in wind farm , the increase of power factor allows improvement in the stability of distribution networks, here we used Matlab- Simulink program to show the results of the model.
The Converter Choice and its Control Circuit Design for Synchronous Generators
Wind power plants equipped with synchronous generator without a gearbox and with a static converter will increase in quantity in future. To decrease the investment costs and plant maintenance it is important to choose the suitable converter for this plant and to improve the plant control strategy which depends on this chosen converter. The whole system was simulated using Matlab/Simulink program so that to get results for making sure this system is functional.