Simulation Of Electrical Systems Research Articles

Laboratory for Analysis of Microgrid with Real Time Simulation

It becomes essential for Brazil the formation of critical mass and technological base in the microgrid subject and, mainly, the creation of an infrastructure that allows the accomplishment of research in this area of knowledge. Faced with this necessity, it was verified the viability of implementing a laboratory to perform analysis of microgrids systems in the actual premises of the Laboratory of Automation and Simulation of Electrical Systems, which is allocated in Itaipu Technological Park Foundation - Brazil dependencies. In the presented context, this work brings the description of the provisioned infrastructure - whose the main feature will be to add flexibility of analysis through the joint application of real, emulated elements and real time simulation platform, being at the same level of international reference laboratories as well as the fundamental aspects that provides the basis for your design and the possibilities of research envisaged from its implementation. The joint action of several researchers and enterprises will be stimulated and characterized as fundamental role for the transformation of this laboratory into a national reference in the study of microgrids serving as support for the electrical sector for the complete understanding of the new development trends of the future electrical power.

Inaccuracies due to the frequency warping in simulation of electrical systems using combined state–space nodal analysis

The simulation of electromagnetic transients may suffer from inaccuracies due to a phenomenon known as frequency warping (FW). This paper presents an analysis of the effects of FW on the accuracy of digital simulations, demonstrating that the use of the trapezoidal integration rule (TR), commonly employed in many electromagnetic transients simulators, is the root cause of such inaccuracies. Although FW is considered a major problem in digital signal processing, it is often overlooked when simulating electrical transients. The analysis is carried out in a fourth-order RLC circuit, from which the analytic solution is derived. The circuit is solved using the combined state–space nodal method, considering the TR or recursive convolutions as solution methods for the state–space representation. It was observed that the FW caused a change in the natural oscillation frequency of the system, causing a pulsating behavior of absolute error. The accumulation of errors over time can result in deteriorated solutions when either the time steps are not sufficiently small or the simulation runs for a long enough duration. This paper emphasizes the significance of accounting for the FW phenomenon in digital simulations that rely on integration methods, such as the TR.

Electrical system simulation of an aircraft through ANSYS Electronics Desktop

More Electric Aircraft is a new technology that allows the aeronautical sector to innovate in the electrical part when it comes to implementing it, that is, it consists of replacing part of the current pneumatic, hydraulic and mechanical systems that make up an aircraft, with electrical systems, for this reason, the main purpose is to design and develop a simulation model in ANSYS Electronics Desktop of the Boeing 777 architecture to analyze all the parameters such as: the voltage, current and power of each subsystem, so for the development, they are simulated one by one and later, they are joined based on the electrical diagram of the aircraft in order to be able to test them in normal and abnormal conditions, and make the comparison of when they are simulated individually, in this way, it creates an impact when rebuilding the electrical system, generating advantages that benefit those companies in this sector for the contribution of their innovations.

Xây dựng và khảo sát sự thay đổi của các thông số lò hồ quang điện dựa trên mô hình bảo toàn năng lượng bằng phần mềm Pscad

Actual analysis showed that the arc furnace current contains many harmonics that adversely affect the power quality. There are many domestic and foreign reports on modeling and assessing the impact of EAF on the grid based on different models. However, EAF's selection of capacity for research and application of power quality improvement devices suitable to the power level has not been mentioned, these models are mainly built on Matlab Simulink software. should be primarily academic. PSCAD is one of the widely used software for electrical system simulation and is used by large companies such as ABB, Korean power corporation Kepco. Building EAF model with PSCAD software will increase the ability to apply simulation results into practice. The objective of the paper is to build an electric arc furnace model based on the energy conservation model with PSCAD software, thereby assessing the change of parameters in the model and the effect of this load on electricity grid during operation.

Real-Time Simulation of Power Conversion in Doubly Fed Induction Machine

Currently used methods of simulation of doubly fed induction machines (DFIM), especially in real-time simulators (where a relatively large calculation step is used and high adequacy is required), do not provide the required adequacy, especially in rotor electrical circuits. In order to increase the adequacy of reproducing of electrical processes occurring in the circuits of the wound DFIM rotor, this paper presents a proposal and a verification of a new method of real-time simulation. The new method of mathematical modeling of electrical circuits uses voltage averaging at the calculation step. This method was supplemented by prediction of the machine’s rotor angle, which significantly increases the degree of adequacy of reproducing physical quantities present in DFIM, especially in the machine’s rotor. This method allows real-time simulation of electrical systems with a relatively large calculation step (of the order of 200 µs), while maintaining an appropriate degree of adequacy.

Интервальные критерии распознавания места короткого замыкания в энергосистеме

The problem of locating (place recognition) of a short-circuit (SC) fault in an electric system is considered. It is shown that each fault location is associated with two versions of a complex SC parameter reflected by a ray in its plane. The ray position is determined by the inner impedance angle of the electric network as the equivalent generator with respect to the SC place. The angle variation interval for a fixed SC place is determined by the variation of normal passive parameters of the electric system simulation model. The algorithmic model of the observed power transmission line is the fault locator’s structural element. The model behaves as a tool that converts the observed quantities into a complex measurement as a function of the supposed SC place. The measurement is reflected as a locus in the same plane as the SC parameter specified by the segment of beams. The interval of SC place coordinate values is determined by intersection of the locus with the segment extreme rays. The segment can be adapted to the impedance of purely emergency operating conditions, which is determined by the ratio of emergency components of voltage and current at the supposed fault places.

Modeling and Real-Time Simulation of Induction Motor Using RT-LAB

<span lang="EN-US">This paper presents the modeling and real-time simulation of an induction motor. The RT- LAB simulation software enables the parallel simulation of power drives and electric circuits on clusters of a PC running QNX or RT- Linux operating systems at sample time below 10 µs. Using standard Simulink models including SimPowerSystems models, RT-LAB build computation and communication tasks are necessary to make parallel simulation of electrical systems. The code generated by the Real-Time Workshop of RT- LAB is linked to the OP5600 digital real-time simulator. A case study example of real-time simulation of an induction motor system is presented.This paper discusses methods to overcome the challenges of real-time simulation of an induction motor system synchronizing with a real-time clock.</span>

Algebraic and Parametric Solvers for the Power Flow Problem: Towards Real-Time and Accuracy-Guaranteed Simulation of Electric Systems

The power flow model performs the analysis of electric distribution and transmission systems. With this statement at hand, in this work we present a summary of those solvers for the power flow equations, in both algebraic and parametric version. The application of the Alternating Search Direction method to the power flow problem is also detailed. This results in a family of iterative solvers that combined with Proper Generalized Decomposition technique allows to solve the parametric version of the equations. Once the solution is computed using this strategy, analyzing the network state or solving optimization problems, with inclusion of generation in real-time, becomes a straightforward procedure since the parametric solution is available. Complementing this approach, an error strategy is implemented at each step of the iterative solver. Thus, error indicators are used as an stopping criteria controlling the accuracy of the approximation during the construction process. The application of these methods to the model IEEE 57-bus network is taken as a numerical illustration.

A Hybrid Simulation Tool for the Study of PV Integration Impacts on Distribution Networks

This paper introduces a hybrid simulation tool that is used to study the impacts of integration of photovoltaic (PV) systems on distribution networks. The tool is composed of an electromagnetic transient (EMT) simulation tool interfaced with an open-source phasor analysis tool, OpenDSS. The purpose of this tool is to provide detailed modeling along with fast and accurate simulation of electric systems with interconnected PV systems. The developed tool models the PV energy system using detailed EMTP-type algorithms, while the rest of the distribution system is modeled in phasor domain using OpenDSS. This paper demonstrates some of the functions, applications, and advantages of the hybrid tool. The tool has been tested with a real Florida-based distribution feeder with multiple PV energy systems. A full EMT model of the feeder has been developed in SimPowerSystems to compare and validate the results. The results suggest that the hybrid tool offers significant benefits and functionality over OpenDSS.

Economic impact of considering El Niño‐Southern Oscillation on the representation of streamflow in an electric system simulator

ABSTRACTThe Electric Power System Simulator (SimSEE) is a model that optimizes and simulates the operation of an electric system and has been widely used to analyze the integrated power system in Uruguay. Among the stochastic processes that SimSEE needs to represent are the streamflow inputs to the hydroelectric dams, which constitute a key factor for both energy dispatches and mid‐term planning. A dominant feature of streamflow time series is that they show very high interannual variability, which represents a major uncertainty for energy operation in Uruguay. Part of this variability is associated with El Niño‐Southern Oscillation (ENSO) phenomena. In this work, a climate index associated with ENSO is incorporated to the stochastic generator of streamflow series used by the SimSEE. Forty six‐month‐long simulations are performed with and without such modifications. We find that the system operator can take advantage of the ENSO‐related information incorporated to SinSEE in 65% of the cases (semesters) considered, reducing the total costs of operation. This result still holds in a scenario with larger firm capacity. The amounts saved, however, are reduced as the firm capacity increases. The enhanced generation options associated with a larger firm capacity diminish the overall costs of generation, especially in times of low streamflow, rendering the savings associated with a more efficient management of the reservoir less significant.

パワーエレクトロニクスシステムの並列化シミュレーションにおける自動回路分割法

パワーエレクトロニクスシステムの並列化シミュレーションにおける自動回路分割法

The Design of Substation Electrical Simulation

In this paper, the substation electrical simulation system was designed on the MCGS development platform. The designs include simulation system interface design, database establishment, component modeling, and operating process design. The simulation system not only can simulate the substation switching operation and the fault, but also has the functions of real-time data, historical data and alarm records. The designed simulation system is simple, clear, and easy to use. It can be applied to the teaching and training of the substation operator.

Predicting the behavior of a grid-connected photovoltaic system from measurements of solar radiation and ambient temperature

This paper presents a methodology to predict in a statistically reliable way the behavior of a grid-connected photovoltaic system. The methodology developed can be implemented either in common programming software or through an off-the-shelf simulation of electrical systems. Initially, the atmospheric parameters that influence the behavior of PV generators (radiation and temperature) are characterized in a probabilistic manner. In parallel, a model compound by various PV generator components is defined: the modules (and their electrical and physical characteristics), their connection to form the generator, and the inverter type. This model was verified for comparing their behavior with output measured on a real installed system of 3.6kWp. The solar resource characterized and the photovoltaic system model are integrated in a non-deterministic approach using the stochastic Monte Carlo method, developed in the programming language DPL of the electrical-systems simulation software DIGSILENT®. It is done to estimate the steady-state electrical parameters describing the influence of the grid-connected photovoltaic system. Specifically, we estimated the nominal peak power of the PV generator to minimize network losses, subject to constraints on nodes voltages and conductor currents.

Using electrical analogy to describe mass and charge transport in lithium-ion batteries

This article deals with an electrical model of lithium-ion battery, based on a 1D analog representation of mass and charge transport phenomena. By using an electrical analogy to describe migration and diffusion of species and charges in electrodes and electrolyte, the model can be directly implemented in standard simulation software used in electrical engineering (such as Saber, in our case), so that it can be easily employed for the simulation of electrical systems involving lithium-ion batteries. The paper explains how the analog model is obtained from mass and charge transport equations, then it presents a comparison with results obtained by means of a finite element method. At last, some electrical power systems are simulated in order to show advantages of our modeling method.

A Combined State-Space Nodal Method for the Simulation of Power System Transients

This paper presents a new solution method that combines state-space and nodal analysis for the simulation of electrical systems. The presented flexible clustering of state-space-described electrical subsystems into a nodal method offers several advantages for the efficient solution of switched networks, nonlinear functions, and for interfacing with nodal model equations. This paper extends the concept of discrete companion branch equivalent of the nodal approach to state-space described systems and enables natural coupling between them. The presented solution method is simultaneous and enables benefitting from the advantages of two different modeling approaches normally exclusive from one another.

Digital simulation of electrical systems to reinforce laboratory teaching

For the purpose of reinforcing undergraduate laboratory teaching, we have shown some applications of PSpice in the simulation of communication and control systems. Examples discussed include the telephone link, the quadrature PSK system, a feedback control system with transport lag and nonlinearity, and a digital control system. In each example, a schematic diagram of the system, the input circuit file, and representative output graphs are given. With behavioral modeling of some devices in the system, the simulation time for each job is kept to within a few minutes. As a result, students are able to run such programs using the evaluation version of the package on their personal computers.

Analog simulation of a ferroresonant system including analysis of hysteresis loop

In the present paper, we shall develop the analog simulation of electric systems involving saturable core coils. Two cases are analyzed here. In the first one, we consider simulation of the behaviour of a saturable core coil, fed by a sinusoidal voltage generator; we use a mathematical model of the hysteresis loop that enables to select the loop branches without the help of any switching device. In the second case, a more complex one, simulation of a ferroresonant circuit is performed, which contains non-linearities about inductance and losses.