Power Flow Analysis for the Steel Industry

Power System study and analyses are important parts of power system engineering. This innovative concept deals with a 132 kV Grid simulation in Electrical Transient Analyzer Program (ETAP). Existing power distribution system in Pakistan consists of approximately 6000 11 kV feeders, which are mainly analyzed by software FDR-ANA (Feeder Analyses). This software does not have capability to provide comprehensive analyses for integrated power system which is essential. This research paper focused on the detailed analyses and monitoring by using the most modern software ETAP, which performs numerical calculations of large integrated power system with fabulous speed besides, generating output reports. In a developing country like Pakistan it is first time that Off-line monitoring is made which includes current flowing in every branch, power factor, active and reactive power flow, harmonic distortion etc. of large power system. Based upon the recorded data obtained from an actual 132 kV grid which has been implemented in ETAP for Off-line monitoring and analyses.

Distributed Generator (DG) is a small-capacity power plant located within the electrical distribution system and is usually placed on buses directly connected to the load. The placement of distributed generators is a technical effort to reduce voltage drops and power losses in the system. Additionally, Power flow analysis is conducted to plan and determine the power levels within an electrical power system. The results in terms of power losses after adding a DG were achieved in the fifth experiment on bus 149, where the system's total active power loss (P) decreased from 720.822 kW to 682.939 kW, and the total reactive power loss (Q) decreased from 530.02 kVar to 405.835 kVar. These results were obtained from power flow calculations using Electrical Transient Analyzer Program (ETAP) software.Therefore, it can be concluded that the electrical network system is operating efficiently. The results show that the more wind turbine generators are added to the buses, the more the voltage drop is reduced. After simulation, the overall voltage drops still meet the standards according to the text report in ETAP.

Before a new power customer is connected into the power grid, it is an important task to assess the possible impact of this new load on the power quality. This paper proposes a method to analyze the voltage fluctuations and harmonics for the characteristics of many types and quantities of internal frequency conversion equipment and motors in the power consumer. First, the principles and methods for model establishment of voltage fluctuation analysis and harmonic analysis are introduced. Then, according to the actual operation of the loads, the simulation model is established in ETAP (Electrical Transient Analysis Program). The voltage fluctuation and the harmonics injected into the power grid caused by the operation of loads are obtained through simulation. Since the phenomenon that the harmonics exceed the standard in the extreme operating condition, this paper gives reasonable control measures based on the actual condition of the load, the simulation results and the allowable values prescribed by national standards.

Electricity is important in our life. The majority of electricity are generated by using fossil fuel. There are various drawbacks linked with the use of fossil fuel such as emission of greenhouse gases which pollute the environment. Among all renewable energy systems, the solar photovoltaic (PV) system has remarkable results to overcomes these problems due to its availability, cheap and environment friendly. In this paper, 300 MW photovoltaic power system is designed and modeled on Electrical Transient Analysis Program (ETAP). The proposed system consists of 4 strings of photovoltaic arrays and each string of PV array is made up of 27 series connected panels and 9000 parallel connected panels. ETAP is used to perform power flow analysis and harmonic distortion analysis. Also, single-tuned passive filters are designed to reduce the effects of harmonics.

Electric Vehicle (EV) charging infrastructure will be deployed extensively in the near future. This will be as a consequence of the policies approved by the governments of many countries including the UK. The rise in the mass production of EVs and the associated increase in consumer demand significantly exacerbate the problems associated with the operation and management of future electric power networks. The 11/0.433kV local substations that will be used to transform voltage levels and supply the demand from consumers are the most affected, requiring reinforcement where substations are close to their firm capacities. In this paper an 11kV power distribution network is modelled using the power system analysis software Electrical Transient Analyzer Program (ETAP). The peak load values over a year are evaluated under four different Electric Vehicle (EV) penetration levels and three different charging types (slow, fast and rapid) at all twenty substations on site. Transformer loading at twenty substations is carefully observed in all simulations under different scenarios to evaluate the total number of EVs the site can accommodate. Initially ETAP 12.0.0 is employed to conduct power flow analysis and study the existing network conditions and later the voltage variations, real and reactive power changes in the system due to the uptake of EVs. The existing network data as required for the research and as presented in this paper has been obtained in collaboration with distribution network operator (DNO) Scottish and Southern Energy (SSE).

Over the past few decades, Central American countries have seen a steady increase in their energy needs. Luckily, the region has abundant renewable energy resources and, as a result, has been busy constructing wind and photovoltaic power facilities. However, while these renewable sources are promising, they come with some risks—mainly, their variable power generation can pose a challenge to the interconnected regional system. This paper explores the current state of the Central American power system and the obstacles it faces as it strives to transition to a more environmentally-friendly energy system. To do so, the authors employed power flow analysis and transient stability studies, which were conducted using ETAP (Electrical Transient Analyzer Program) to model and simulate the power system. Their study revealed that the Central American power system is at risk of instability, and they suggest that integrating ancillary services and storage solutions could strengthen its resilience. Additionally, the authors advocate for the development of microgrids, energy management, and sustainable decarbonization plans. Lastly, the authors emphasize the importance of short-, medium-, and long-term power planning to make better decisions.

The chapter covers general issues related to power quality in Electric Arc Furnaces. The use of electric arc furnaces (EAF) for steelmaking has grown dramatically in the last decade. Of the steel made today 36% is produced by the electric arc furnace route and this share will increase to 50 by 2030. The electric arc furnaces are used for melting and refining metals, mainly iron in the steel production. AC and DC arc furnaces represent one of the most intensive disturbing loads in the sub-transmission or transmission electric power systems; they are characterized by rapid changes in absorbed powers that occur especially in the initial stage of melting, during which the critical condition of a broken arc may become a short circuit or an open circuit. In the particular case of the DC arc furnaces, the presence of the AC/DC static converters and the random motion of the electric arc, whose nonlinear and time-varying nature is well known, are responsible for dangerous perturbations such as waveform distortions and voltage fluctuations. Nowadays, arc furnaces are designed for very large power input ratings and due to the nature of both, the electrical arc and the melt down process, these devices can cause large power quality problems on the electrical net, mainly harmonics, inter-harmonics, flicker and voltage imbalances. The Voltage-Current characteristic of the arc is non-linear, what can cause harmonic currents. These currents, when circulating by the electric net can produce harmonic voltages, which can affect to other users. In evaluation and limitation, there are some definitions and standards to quantify the disturbance levels, such as (***IEC, 1999), (***IEEE 1995), and (***IEEE, 1996). and. The total harmonic distortion (THD), short-term voltage flicker severity (Pst), and long-term voltage flicker severity (Plt) are used. However, sometimes it is desired to record voltage and current waveforms in the specified duration to track the disturbance levels.

Physical phenomena fundamental to rotating, baroclinically driven flows are studied with reference to results of numerical simulation of rotating annulus flows, using a modified Galerkin Model. Both local and global effects of sources, sinks, and transports of heat and momentum are discussed. A convenient ‘energy exchange” diagram reveals detailed information that is used to analyze nonlinear equilibration and amplitude vacillation of quasi-geostrophic baroclinic eddies. Transient inertial oscillations, sidewall boundary layers, and internal boundary layers are also discussed. A detailed study of symmetric flows is made, eleven of which are tested numerically for stability with respect to three-dimensional disturbances of a given zonal wave number. Two of the four unstable cases are integrated to a numerical steady state with finite-amplitude, quasi-geostrophic baroclinic waves. With the ‘rigid-lid’ geometry assumed, the average zonal velocity is zero, resulting in zero phase velocity of the waves. The structure of the thermal wave is nearly coherent in the vertical. These numerical results are consistent with laboratory observations. The eddy flow is quasi-geostrophic except in horizontal boundary layers, where the flow is driven toward low pressure. A small cross-isotherm advection is sufficient to maintain the temperature wave against diffusion and vertical advection. The eddy flow adjusts spontaneously toward the form of the fastest growing or slowest decaying disturbance representable by the truncated space resolution. The eddy flow feeds energy into the mean zonal flow in ‘barotropic-type’ interactions reflected mainly by the familiar ‘tilted trough’. During equilibration, the eddy flow alters the mean zonal flow in such a way that eddy energy sources are reduced relative to energy sinks. However, this adjustment is small compared to the change of total flow, which reflects a relatively large change of eddy amplitude. This suggests that small errors in the mean zonal flow representation can lead to relatively large errors in total flow representation. In most flows studied the kinetic energy dissipation is concentrated in thin boundary layers. In spite of this thinness, the basically laminar character of these dissipative boundary layers allows accurate and economical numerical simulation through the use of characteristic functions, which is a natural refinernent of the basic Galerkin method used. (In this prototype study, only “moderately characteristic’ functions are used, thus sacrificing numerical economy while simplifying the programming.) Similarly, the generation of potential energy, which is transformed into the kinetic energy of the flow, is accurately simulated. In most cases studied, this generation is also concentrated in thin boundary layers where thermal energy is extracted from cold fluid and added to warm fluid.

Electric Arc Furnace (EAF) with nonlinear characteristic and often causes various power quality (PQ) problems is the common seen smelting equipment in the industrial power system. Electricity users and utilities continuously seek the useful solutions for the improvements of these PQ problems. In recent years, the applications of using solar photovoltaic (PV) technology for PQ controls are become more and more because of the increasing installations of solar PV power generations. Purpose for this study aims to design a multi-mode PV-STATCOM system for the mitigation of voltage fluctuation that caused by EAF in the steel plant system. Performance of proposed PV-STATCOM design is tested and verified by MATLAB/Simulink simulations under a real 11.4 kV electric feeder with a 45 ton AC EAF load. Results show the proposed system has a well performance than that in general PV-STATCOM that only using unique control mode.

Due to their particular feature, direct current (dc) electric arc furnace (EAF) installations are peculiar loads that cause moderate to severe power quality (PQ) disturbances in the feeding power systems. Among them, voltage fluctuations and waveform distortions are the most impactful ones, and they should be adequately addressed in order to mitigate the detrimental effects. Several types of models have been developed in order to evaluate the effects of EAFs on networks, and chaotic models have been specifically recognized as suitable tools to evaluate the impact of EAFs in terms of PQ disturbances. This article compares the performance of three chaotic models (Chua, Lorenz, and Rössler) aiming at estimating PQ indices values of dc EAFs. The procedure exploits a block diagramming tool of the dc EAF installation and minimizes the deviation of estimated PQ indices from the actual ones through a new Monte Carlo optimization procedure, performed upon the parameters of the three chaotic models. To comply with the time-varying nature of the current and voltage waveforms in a dc EAF installation and with the wide presence of interharmonics, traditional, and advanced PQ indices are considered in this article. Actual data collected at an Italian dc EAF installation are used to conduct a numerical comparative analysis and to validate the effectiveness of the models in estimating the PQ disturbances.

Arc furnaces are used in industries for induction heating and welding. Due to the rapid growth of nonlinear loads, such as power electronic control equipments and Electric arc furnace (EAF) power quality problems such as harmonics and voltage flicker are introduced in the power system. It occurs because of the time-varying and non-linear behaviour of the electric arc furnace operation. Hence an Electric arc furnace model is needed to analyze the power quality. In this paper, a time domain model called hyperbolic model for electric arc furnace is analyzed using MATLAB. The model is used to study its behaviour on the power system using MATLAB. To improve the power quality D-STATCOM is proposed, in which the control strategies used are Direct, Indirect control and Hysteresis controller. Direct control technique uses P-Q theory in which transformation is based on orthogonal reference frame. Indirect control technique uses d-q theory in which transformation is based on synchronous reference frame. Hysteresis controller uses Hysteresis Bandwidth to produce the switching signals.

Relevance. A lot of Russian as well as foreign metallurgical feature electrical steel-mashing complexes based on electric arc furnaces (EAF) and ladle furnaces (LF). These steel-making units generate high-power electrical load, have non-linear volt-ampere characteristics and leaping unbalanced load variation. For this reason, an operating EAF aggravates power quality and causes an increase in the reactive power factor on the incoming feeders of the main electrical substations. To provide for the appropriate power quality and voltage stabilization on the primary side of the furnace transformer, the additional reactive power compensation devices are used. More than 85% of reactive power compensators for EAF and LF are currently released as static var compensators consisting of a thyristor- controlled reactor (TCR) and filter circuits (FC). The analysis of the rated parameters of SVC produced by different companies shows that there is no universal selection method for the harmonic filters configuration. In that regard, a pressing task is to develop a complex approach to determine an optimum configuration of harmonic filters, provided that its their rated power is known. Research objective: developing the improved method used to select the parameters of filter circuits of SVC for electric arc furnace, accounting for different relevance criteria such as: the cost of FCs, active power losses in harmonic filters, filtration coefficient, and the total harmonic distortion of voltage. Methods: experimental arrays of electrical parameters saved on existing electrotechnical complexes “EAF-SVC” and the methods of mathematical modeling of SVC and EAF. Novelty: the suggested developed method of SVC’s filter circuits parameters selection is original as it features the distribution of the total reactive power using the group optimal criteria, which provides for the best technical and economical indexes of FC, as well as accounting for the peculiar features of a certain steel-making unit and its power supply system. This method is also more accurate in terms of analysis of the electrical regimes of FC as it uses real instantaneous current of EAFs of different classes and power. Research outcomes: 1) the executed analysis of parameters of existing SVC produced by different companies; 2) the existing methods of distribution of total reactive power between harmonic filters have been analyzed; 3) the improved mathematical model of complex “EAF-SVC” allowing for the detailed studies of FC operation modes taking into account the real EAF’s current been mode; 4) the patterns of variation of filtration coefficient for different variants of distribution of total reactive power between harmonic filters have been determined on the basis of mathematical model; 5) the improved method of calculation of SVC’s FC providing for the optimum distribution of reactive power between the harmonics filters taking into account a group of different optimal criteria has been developed. Practical significance: the results have significant theoretical importance for electrical engineering of arc furnaces and may be employed in the calculation of static var compensators in power supply systems of steel-making complexes.

Performance analysis of hybrid metaheuristic assisted collateral FO controller for HRES system integrated UPQC

Modern utility systems are being heavily strained by rising energy consumption and dynamic load variations, which have an impact on the quality and reliability of the supply. Harmonic injection and reactive power imbalance are caused by the widespread divergence. Power quality (PQ) issues are mostly caused by renewable energy powered by power electronic converters that are integrated into the utility grid, despite the fact that a range of industries require high-quality power to function properly at all times. Several solutions have been created, but continuing efforts and newly improved solutions are needed to solve these problems by operating according to various international standards. Distributed Static Compensator (DSTATCOM) was created in the proposed model to enhance PQ in a standard bus system. A standard bus system using the DSTATCOM model was initially developed. A real-time dataset was gathered while applying various PQ disturbance conditions. A deep learning controller was created using this generated dataset, which examined the bus voltages to generate the DSTATCOM pulse signal. Two case studies, the IEEE 13 bus and the IEEE 33 bus system, were used to analyze the proposed work. Performance of the proposed deep learning controller was verified in various situations, including interruption, swell, harmonics, and sag. The outcome of THD in the IEEE 13 bus is 0.09% at the sag period, 0.08% at the swell period, 0.01% at the interruption period, and in the IEEE 33 bus was 1.99% at the sag period, 0.44% at the swell period, and 0.01% at the interruption period. Also, the effectiveness of the proposed deep learning controller was examined and contrasted with current methods like K-Nearest Neighbor (KNN) and Feed Forward Neural Network (FFNN). The validated results show that the suggested method provides an efficient mitigation mechanism, making it suitable for all cases involving PQ issues.

Voltage flicker and harmonics are the power quality problems which are introduced to the power system as a result of nonlinear and stochastic behavior of the arc furnace operation. To analyze harmonic and flicker generated by an arc furnace, accur ate arc furnace models are needed. In this paper, different arc furnace models with different level of complexity are reviewed. In the first part of this paper a new developed time domain static model based on a piece-wise linear approximation of the V-I characteristics of the arc furnace is presented. While static arc models are useful for harmonic studies, dynamic models are useful for power quality studies specially the study of voltage flicker. In the second part of the paper, dynamic model for an arc furnace us ing MATLAB (Simulink) is presented. In addition to this, the novelty of this simulation technique lies in the fact that the variation of power transmitted to the load by the arc furnace during the cycle of operation is considered, thus making the proposed model more accurate and dependent on the operating conditions of the load. Finally recommendations are made for the application of some of these models and the accuracy of the presented model to other models from the practical point of view by using MATLAB is shown.