MODELING AND SIMULATION OF CONVERTER SYSTEMS PART II: SIMULATION PACKAGE TCAD

1995 ◽  
Vol 05 (04) ◽  
pp. 669-697 ◽  
Author(s):  
ROMUALD SZCZESNY ◽  
MIECZYSLAW RONKOWSKI
Keyword(s):  
Circuit Simulation ◽  
Critical Evaluation ◽  
General Purpose ◽  
Electrical Circuit ◽  
Simulation Program ◽  
Voltage Source ◽  
Engineering Practice ◽  
Pwm Inverter ◽  
Operation Conditions ◽  
Simulation Package

The methods, models and techniques — presented in the companion paper — have been used as a basis for the evaluation of popular general-purpose electrical circuit simulation programs, in particular, their applicability in the analysis of power electronic circuits. As a result of this critical evaluation, the general requirements for the simulation program adequate for converter systems studies and design have been formulated. On this basis the algorithm of TCAD — a general-purpose converter system simulation program — has been elaborated. In presentation of the TCAD program three parties have been distinguished: the first one emphasizes the applications of modern simulation methods for converter systems, the second describes briefly the features of the main modules of the TCAD package, and the third presents some simulation examples of practical converter systems. Three simulation examples are presented: two resonant converters and an induction motor drive fed by a full-bridge voltage source PWM inverter at normal and fault operation conditions. A good agreement between simulation and experimental results has proved that this simulation package is a power tool for research, teaching and engineering practice.

scholarly journals Electrical equivalent circuit for modelling permanent magnet synchronous motors

2021 ◽  
Vol 72 (3) ◽  
pp. 176-183
Author(s):  
Esra Kandemir Beser
Keyword(s):  
Permanent Magnet ◽  
Equivalent Circuit ◽  
Circuit Simulation ◽  
Electrical Circuit ◽  
Simulation Program ◽  
Mechanical Parameters ◽  
Circuit Element ◽  
Electrical Equivalent Circuit ◽  
Mechanical Part ◽  
Simulation Results

Abstract In permanent magnet synchronous motor (PMSM) models, only the stator part is given as an electrical circuit and mechanical equations are used for modelling the mechanical part of the machine. In this study, electrical equivalents of mechanical equations are also obtained and mechanical parameters of a PMSM are expressed as an electrical circuit element. In this way, an exact electrical equivalent circuit is proposed in which both the stator and the mechanical part can be modelled as an electrical circuit for the PMSMs dynamic model. Although PMSM model includes mechanical parameters and variables, the complete model is expressed only in electrical elements and variables. The proposed PMSM circuit was simulated for different load torques in the circuit simulation program. Simulation results show that the proposed circuit operates like a PMSM. Simulation results were verified by another method in the form of solution of the differential equations that constitute the mathematical model of PMSM. Due to the proposed circuit that enables the conversion of mechanical parameters into electrical parameters, PMSM can be modelled and simulated as an electrical circuit with completely electrical elements in a circuit simulation program.

scholarly journals A GaN-HEMT Compact Model Including Dynamic RDSon Effect for Power Electronics Converters

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2092
Author(s):  
Ke Li ◽  
Paul Leonard Evans ◽  
Christopher Mark Johnson ◽  
Arnaud Videt ◽  
Nadir Idir
Keyword(s):  
Power Electronics ◽  
Physical Model ◽  
Order Reduction ◽  
Power Converter ◽  
Compact Model ◽  
Voltage Source ◽  
Power Losses ◽  
Gan Hemt ◽  
Operation Conditions ◽  
Power Electronics Converters

In order to model GaN-HEMT switching transients and determine power losses, a compact model including dynamic RDSon effect is proposed herein. The model includes mathematical equations to represent device static and capacitance-voltage characteristics, and a behavioural voltage source, which includes multiple RC units to represent different time constants for trapping and detrapping effect from 100 ns to 100 s range. All the required parameters in the model can be obtained by fitting method using a datasheet or experimental characterisation results. The model is then implemented into our developed virtual prototyping software, where the device compact model is co-simulated with a parasitic inductance physical model to obtain the switching waveform. As model order reduction is applied in our software to resolve physical model, the device switching current and voltage waveform can be obtained in the range of minutes. By comparison with experimental measurements, the model is validated to accurately represent device switching transients as well as their spectrum in frequency domain until 100 MHz. In terms of dynamic RDSon value, the mismatch between the model and experimental results is within 10% under different power converter operation conditions in terms of switching frequencies and duty cycles, so designers can use this model to accurately obtain GaN-HEMT power losses due to trapping and detrapping effects for power electronics converters.

Implementing and using finite automata toolkits

1996 ◽  
Vol 2 (4) ◽  
pp. 295-302 ◽  
Author(s):  
BRUCE W. WATSON
Keyword(s):  
Flight Control ◽  
Program Verification ◽  
Finite Automata ◽  
Circuit Simulation ◽  
Implementation Strategies ◽  
Digital Circuit ◽  
General Purpose ◽  
Genetic Sequencing ◽  
Java Program ◽  
Fire Engine

Finite automata and various extensions of them, such as transducers, are used in areas as diverse as compilers, spelling checking, natural language grammar checking, communication protocol design, digital circuit simulation, digital flight control, speech recognition and synthesis, genetic sequencing, and Java program verification. Unfortunately, as the number of applications has grown, so has the variety of implementations and implementation techniques. Typically, programmers will be confused enough to resort to their text books for the most elementary algorithms. Recently, advances have been made in taxonomizing algorithms for constructing and minimizing automata and in evaluating various implementation strategies Watson 1995. Armed with this, a number of general-purpose toolkits have been developed at universities and companies. One of these, FIRE Lite, was developed at the Eindhoven University of Technology, while its commercial successor, FIRE Engine II, has been developed at Ribbit Software Systems Inc. Both of these toolkits provide implementations of all of the known algorithms for constructing automata from regular expressions, and all of the known algorithms for minimizing deterministic finite automata. While the two toolkits have a great deal in common, we will concentrate on the structure and use of the noncommercial FIRE Lite. The prototype version of FIRE Lite was designed with compilers in mind. More recently, computation linguists and communications protocol designers have become interested in using the toolkit. This has led to the development of a much more general interface to FIRE Lite, including the support of both Mealy and Moore regular transducers. While such a toolkit may appear extremely complex, there are only a few choices to be made. We also consider a ‘recipe’ for making good use of the toolkits. Lastly, we consider the future of FIRE Lite. While FIRE Engine II has obvious commercial value, we are committed to maintaining a version which is freely available for academic use.

FORESAIL-1 and ESTCube-2 Cubesat experiments of Coulomb drag propulsion

2021 ◽  
Author(s):  
Pekka Janhunen ◽  
Petri Toivanen ◽  
Jarmo Kivekäs ◽  
Matias Meskanen ◽  
Jouni Polkko
Keyword(s):  
Solar Wind ◽  
Orbital Motion ◽  
General Purpose ◽  
Low Earth Orbit ◽  
Voltage Source ◽  
Status Report ◽  
Plasma Stream ◽  
Low Thrust ◽  
Coulomb Drag ◽  
Positive Mode

<p>Coulomb drag propulsion taps momentum from a natural plasma stream to generate propellantless low-thrust propulsion for a spacecraft. The plasma is attached to by means of a long, thin, charged metallic tether. The tether's electrostatic field deflects the motion of streaming plasma ions and transfers momentum from them. The technique can be applied in the solar wind (i.e., outside Earth's magnetosphere) to produce general-purpose interplanetar propulsion. This application is called the electric solar wind sail (E-sail). It can also be applied in low Earth orbit (LEO) to brake the satellite's orbital motion. Here the relevant plasma stream is the ram flow of the ionosphere due to the satellite's orbital motion. This application is called the plasma brake and it is useful for satellite deorbiting for mitigating the growing problem of orbital debris.</p> <p>Here we report on progress of two CubeSat missions (FORESAIL-1 and ESTCube-2) that are under construction for measuring the Coulomb drag effect in LEO.  Both are scheduled to fly in 2022. Both satellites deploy up to 300 m long tether, charge it up by a high-voltage source and measure the resulting Coulomb drag. The satellites are slowly spinning and the tether is tightened by the centrifugal force. The tether is deployed from a reel which is rotated slowly by an electric motor.  Both satellites use negative tether polarity, which is the case relevant for the plasma brake. ESTCube-2 contains, in addition, a positive mode experiment which is relevant for the E-sail. The plasma environment in LEO differs from the solar wind, so the measured positive mode Coulomb drag must be scaled to yield a prediction of the strength of the E-sail effect in the solar wind.</p> <p>The Coulomb drag is measured by two independent methods. In the first method we set the tether voltage on and off in sync with the satellite's rotation and thereby accumulate a change of the system's angular momentum. The Coulomb drag is inferred from the measured change of the spin rate per time unit. In the second method we estimate Coulomb drag from the speeded-up lowering of the satelllite's orbital altitude.</p> <p>The presentation is a status report of the technical progress of these two Coulomb drag CubeSat missions; FORESAIL-1 and ESTCube-2.</p>

scholarly journals Simulations of Muon Flux in Slanic Salt Mine

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Mehmet Bektasoglu ◽  
Halil Arslan ◽  
Denis Stanca
Keyword(s):  
Zenith Angle ◽  
Ground Level ◽  
Muon Flux ◽  
Simulation Program ◽  
Grand Unification ◽  
Geant4 Simulation ◽  
Salt Mine ◽  
Neutrino Astrophysics ◽  
Simulation Package

Geant4 simulation package was used to simulate muon fluxes at different locations, the floor of UNIREA mine and two levels of CANTACUZINO mine, of Slanic Prahova site in Romania. This site is specially important since it is one of the seven sites in Europe that are under consideration of housing large detector components of Large Apparatus studying Grand Unification and Neutrino Astrophysics (LAGUNA) project. Simulations were performed for vertical muons and for muons with a zenith angleθ≤60°. Primary muon flux and energies at ground level were obtained from previous measurements. Results of the simulations are in general agreement with previous simulations made using MUSIC simulation program and with the measurements made using a mobile detector.

scholarly journals GENETIC ALGORITHM BASED SOLUTION IN PWM CONVERTER SWITCHING FOR VOLTAGE SOURCE INVERTER FEEDING AN INDUCTION MOTOR DRIVE

2017 ◽  
Vol 27 (2) ◽  
pp. 45-60
Author(s):  
V. Jegathesan
Keyword(s):  
Genetic Algorithm ◽  
Lower Order ◽  
Pulse Width Modulation ◽  
Experimental Results ◽  
Voltage Source ◽  
Pwm Inverter ◽  
Harmonic Elimination ◽  
Transcendental Equations ◽  
Voltage Harmonics

This paper presents an efficient and reliable Genetic Algorithm based solution for Selective Harmonic Elimination (SHE) switching pattern. This method eliminates considerable amount of lower order line voltage harmonics in Pulse Width Modulation (PWM) inverter. Determination of pulse pattern for the elimination of some lower order harmonics of a PWM inverter necessitates solving a system of nonlinear transcendental equations. Genetic Algorithm is used to solve nonlinear transcendental equations for PWM-SHE. Many methods are available to eliminate the higher order harmonics and it can be easily removed. But the greatest challenge is to eliminate the lower order harmonics and this is successfully achieved using Genetic Algorithm without using Dual transformer. Simulations using MATLABTM and Powersim with experimental results are carried out to validate the solution. The experimental results show that the harmonics up to 13th were totally eliminated. 

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