Identifying the Mathematical Model of a Katkon-Based Harmonic Filtration and Power Factor Correction Device Taking the Magnetic Core Nonlinearity into Account

2017 ◽  
pp. 55-60 ◽  
Author(s):  
Pavel A. BUTYRIN ◽  
◽  
Gennadii G. GUSEV ◽  
Dmitrii V. MIKHEYEV ◽  
Felix N. SHAKIRZYANOV ◽  
...  
2021 ◽  
Vol 295 (2) ◽  
pp. 165-171
Author(s):  
O. KIMSTACH ◽  
◽  
I. ILLIASHENKO ◽  
A. ZHEZHELO ◽  
◽  
...  

The paper analyses the aspects of modelling the operation of a three-phase core-type transformer. The features of the magnetic system construction of the transformer, which generate asymmetry, are disclosed. The fundamentals and methods for modelling a transformer in dynamic modes are considered. The main purpose of the paper is to research the influence of taking into account the asymmetry of the transformer magnetic core on its dynamic model. The paper proposes the mathematical model of a three-phase planar core-type transformer, which takes into account the asymmetry of the magnetic core. The mathematical model is based on the model of a generalized electric machine in the ABC axes, which is widely recognized and characterized by a high level of adequacy. A refined model, which takes into account the power losses in the magnetic core, has used. As is well known, such a model is characterized by higher accuracy and adequacy in the calculation of transient processes. For the proposed mathematical model, a comparative analysis of the calculated curves of transient processes for a 63 kVA transformer with a voltage of 6 / 0.4 kV is made. To disclose the effect of taking into account the magnetic core asymmetry of the transformer in the mathematical model, the current differences were calculated in pu for the modes of switching on at full power and three-phase short circuit. These modes are the most common and indicative in the analysis of the operability and stability of transformers. It was found that the most significant difference, which is obtained by taking into account the magnetic system asymmetry of the transformer, is 5…6% when it is switched on at full load. Thus, the relatively simple transformations and updating of the mathematical model of the transformer allow significantly increase its adequacy. The proposed mathematical model can be more effectively used when the non-typical design of three-phase transformers or reactors with significant asymmetry of the magnetic core is considered.


2013 ◽  
Vol 8-9 ◽  
pp. 77-84
Author(s):  
Alexandru Baloi ◽  
Adrian Pana

Power factor correction in electrical distribution networks can lead to harmonic risk increase. The paper presents a method to anticipate the amplification of network harmonic conditions based on the equivalent network harmonic impedance which can be monitored using virtual instruments. Based on the values of the harmonic impedance and the required reactive power, a mathematical model is implemented through an algorithm and software classes are developed for the solution regarding the type of the reactive power sources (capacitor banks or filters) and the place where it will be installed.


2020 ◽  
Vol 23 (2) ◽  
pp. 28-37
Author(s):  
V. F. SYVOKOBYLENKO ◽  
◽  
V.A. LYSENKO ◽  

Simulation of transient and steady state modes of synchronous motors for the analysis of switching to backup power using mathematical model. Method. The methods of linear algebra, numerical optimization methods, methods of modeling and analysis of established and transient modes are used. Results. The mathematical model of the salient pole rotor and non-salient or cylindrical pole rotor synchronous motor is presented, which is presented in the form of a alternate scheme, which allows to take into account the effect of displacement of current and saturation of the non-salient pole rotor motor's magnetic core. A method for determining the parameters of the synchronous motor based on passport data is proposed, which allows to improve the accuracy of modeling in steady state and transient modes. The mathematical model is reduced to a three-phase coordinate system a, b, c of the stator winding. The rotor windings are modeled in the coordinates d, q. The results of mathematical modeling allow us to determine the magnitude of the shock currents and mechanical moments of the synchronous motor. It is shown that non-synchronous switching on of the synchronous motor, which occurs in case of automatic transfer switch, can lead to engine damage. Shock currents can also be dangerous to other power supply equipment. Thus, synchronous motors, if transfer switch is used, require synchronization before being connected to the network. Scientific novelty. The mathematical model of the synchronous motor was improved taking into account the displacement of current and saturation of the magnetic conduit, the method of determining the parameters of the mathematical model based on the passport data of the engine was improved, which allowed to increase the accuracy of the simulation and the reliability of the simulation results. The modes of power transfer switch are simulated and the values of shock current and shock mechanical moment of the engine are obtained. Practical meaning. The mathematical model of the synchronous motor allows to analyze the behavior of synchronous motors in interaction in the power supply system and to identify the dangerous states of synchronous motors that may occur during the transfer switching. The proposed model improves the accuracy of determination of the limits of dangerous states and improves the reliability of synchronous motors and power supply systems.


Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.


Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.


Author(s):  
Serhii Kovbasenko ◽  
Andriy Holyk ◽  
Serhii Hutarevych

The features of an advanced mathematical model of motion of a truck with a diesel engine operating on the diesel and diesel gas cycles are presented in the article. As a result of calculations using the mathematical model, a decrease in total mass emissions as a result of carbon monoxide emissions is observed due to a decrease in emissions of nitrogen oxides and emissions of soot in the diesel gas cycle compared to the diesel cycle. The mathematical model of a motion of a truck on a city driving cycle according to GOST 20306-90 allows to study the fuel-economic, environmental and energy indicators of a diesel and diesel gas vehicle. The results of the calculations on the mathematical model will make it possible to conclude on the feasibility of converting diesel vehicles to using compressed natural gas. Object of the study – the fuel-economic, environmental and energy performance diesel engine that runs on dual fuel system using CNG. Purpose of the study – study of changes in fuel, economic, environmental and energy performance of vehicles with diesel engines operating on diesel and diesel gas cycles, according to urban driving cycle modes. Method of the study – calculations on a mathematical model and comparison of results with road tests. Bench and road tests, results of calculations on the mathematical model of motion of a truck with diesel, working on diesel and diesel gas cycles, show the improvement of environmental performance of diesel vehicles during the converting to compressed natural gas in operation. Improvement of environmental performance is obtained mainly through the reduction of soot emissions and nitrogen oxides emissions from diesel gas cycle operations compared to diesel cycle operations. The results of the article can be used to further develop dual fuel system using CNG. Keywords: diesel engine, diesel gas engine, CNG


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