Matlab Simulink Software Environment Research Articles

SVM Based Methodology for Classification of Internal Faults from Other Disturbances in Power Transformer

This paper introduces a differential protection scheme for power transformers based on a Support Vector Machine (SVM) approach, designed to effectively classify internal faults while distinguishing them from other disturbances, such as magnetizing inrush currents and overexcitation conditions. The feature vector used for classification is extracted from the differential signal by computing the energy of the detail 2 coefficients obtained through wavelet transform analysis. This feature vector serves as input to the SVM classifier, ensuring accurate discrimination between fault conditions and non-fault disturbances. Comprehensive simulations are performed to evaluate the scheme under various scenarios, including internal transformer faults, diverse magnetizing inrush conditions, overexcitation states, and normal operating conditions with varying load levels. The power transformer is modeled and analysed using the MATLAB Simulink software environment.

Modelling and simulation hybrid electric vehicle with hydrogen fuel cells

The article is devoted to the development of simulation model in the MATLAB Simulink software environment of an electric vehicle hybrid traction drive based on fuel cells and lithium battery. The applied topologies of battery and hybrid traction drives are considered. A traction drive model has been synthesized, in which the main energy source is a fuel cell (FC) with a proton exchange membrane (PEM), and the unevenness of the transport load is smoothed out by a high-power buffer storage unit (BSU) based on a lithium-titanium-oxide (LTO) battery.The dependence of the required BSU capacity on the power of the primary source, reduced to a ton of vehicle weight, was obtained. Based on this, the optimal range of hybrid power plant parameters was determined (FC power from 5 to 11 kW/t, LTO battery capacity from 6 to 10 Ah/t) when driving according to the WLTC load cycle. The calculated fuel consumption in this case was 0.56 kg/(km-t), and the time of included state of FC was 94.53%.

Моделирование силовой части электромобиля на базе ездового цикла

Nowadays, improving the power train of an electric vehicle, particularly an electric vehicle, is one of the major research areas in the field of transportation vehicles. Due to unstable load levels, frequent braking and acceleration, the efficiency of the power train needs to be improved using the latest components and techniques. The aim of the paper is to develop an efficient power train for an electric vehicle based on the world driving cycle. In this study, the existing driving cycles were analyzed and the most optimal one was selected based on its perfor mance under different operating conditions. As a result of the obtained calculations, the optimum power of a traction motor (TEM) was selected. Based on the selected power, the corresponding model of the motor is selected and its traction characteristics are built. In the MatlabSimulink software environment the modeling of traction drive, based on the driving cycle WLTC, is performed, the blocks of the model are presented and described mathematically, the dependencies a(t), E(t) and V(S) are obtained, which confirm the adequacy of mathematical modeling. An appropriate drive is selected in comparison with other models.

Разработка эффективного контроллера отслеживания точки максимальной мощности для фотоэлектрической системы

A method is presented to improve the performance of off-grid photovoltaic systems using a battery charge controller equipped with solar panel maximum power point tracking (MPPT) technology. Today, the MPPT controller is an effective technology that ensures the ideal functioning of solar panels by searching and selecting the optimal power point. The purpose of the study is to develop and evaluate the performance of a battery charge controller for solar panels based on the maximum power point tracking method. The proposed method uses a perturbation and observation algorithm and tracks the maximum power point based on the current and voltage output characteristics. A DC/DC buck converter was used in the study. The model of the proposed method was implemented in the Matlab Simulink software environment, and the efficiency of the operating algorithm was assessed. In addition, based on this model, an MPPT controller was developed, which was tested in real conditions. The reliability of the proposed method was also assessed. As a result of the study, the effectiveness of the developed system was revealed through a comparative analysis with a commercial battery charge controller

Mathematical modeling of dynamic processes of agricultural mobile energy vehicles on an electric drive

The article considers the issues of modeling the processes of agricultural mobile energy vehicles (MEV) with electric drive (ED). A review of modern literature on the problem under study as well as questions on modeling the functional properties of mobile machines and improving the quality indicators of MEV work are presented. A mathematical model of the motion of the MEV with an electric motor is presented, as well as a description of the method used and a sequence of actions for conducting research. Preliminary theoretical studies of motion in different modes of operation have been carried out. The proposed model is convenient for implementation and calculation in any of the applied software products that support the modeling of dynamic systems with an electromechanical drive. The proposed model, the solution of which is based on the methods of numerical integration of systems in the Matlab Simulink software environment, made it possible to simulate the dynamic processes of electromechanical power transmission of MEV during various agricultural operations. With the help of this model, the analysis of electromechanical processes in transient and steady-state operating modes, as well as dynamic processes in the power transmission were carried out. Graphs of changes in the studied parameters of the MEV power transmission are obtained and elastic moments in the joints of the 5-mass design scheme are determined. The use of the model allows you to track the change in statistical characteristics when the conditions of the experiment change. The model has shown its operability when performing simulation of agricultural operations: fertilization, cultivation and sowing, and it can be used at the design stage to study the characteristics of dynamic processes of small-class traction MEV power transmissions with an electromechanical drive. With different parameters of the model, there is a change in the mathematical expectation of the angular velocity of the ED from 147.89 to 156.87 rad/s, a change in the mathematical expectation of the speed of the MES from 4.51 to 4.79 m/s.

Synthesis of an Observer Providing a Finite-Time State Estimation Based on the Output

The paper proposes a new method for synthesizing a full-order state vector observer for a certain class of linear stationary systems with unknown input signal. Two approaches that ensure the convergence of the estimation error (i.e., the error between the state vector estimate and the true state vector) to zero in a finite time are considered. The convergence time is set by the designer in the process of observer construction. The system parameters are assumed to be known and stationary, but the relative degree (from the measured output and the unknown input) is equal to one. The synthesis process using the first approach consists of two stages. In the first stage two auxiliary observers are used to estimate the initial conditions of the object in finite time. In the second stage, a third observer is introduced into the loop to perform online estimation of the system state vector. All the above three observers have the same structure that provides their insensitivity to the input signal, but different parameters. The second approach uses aggregation of auxiliary observers and introduce a delay operator to estimate the state vector. This method provides convergence of the observation error to zero after a delay time. The paper contains a rigorous mathematical proofs of the performance of the obtained solutions. To demonstrate the effectiveness and operability of the proposed approach computer simulation was carried out in the MATLAB Simulink software environment. A two-channel fourth-order mechanical system is considered as an plant. The simulation results illustrate the convergence of the state vector estimation error to zero in a finite time specified by the developer.

Адаптивное скользящее управление бесколлекторным двигателем

Brushless DC motors offer many advantages over brushed DC motors. In this article, based on the constructed kinematic model of a brushless motor, a classical sliding mode of motor control is synthesized. A study of the sliding mode of motor control was carried out in the Matlab Simulink software environment and the shortcomings of the classical sliding controller were established. To eliminate these shortcomings, an adaptive sliding controller has been synthesized, consisting of a classical sliding controller and a PI controller. Simulation in the Matlab Simulink software environment proves the efficiency of a synthesized adaptive sliding controller that controls a brushless motor in an environment of noise and disturbances.

DC/DC converter in the electric vehicle traction system

DC-DC converters are used in various electrical devices including the traction system of electric vehicles. Electric vehicles use synchronous motors with permanent magnets as drives. Their distinctive feature is the nonlinear dependence of the electromagnetic torque of the motor on its input voltage. One of the ways to improve the energy characteristics of an electric vehicle is to include a DC-DC converter in the engine power supply circuit. The study has examined the main types of DC-DC converters, studied their advantages and disadvantages; a method has been determined to increase the energy efficiency of an electric vehicle by using a multi-channel DC-DC converter as part of its power circuit. This structure makes it possible to reduce the requirements for individual power switches and converter elements, and is also optimal from the point of view of weight and size indicators, since converters of this type do not have a transformer. Based on the review, a multichannel DC-DC converter circuit has been selected for integration into the traction electric drive system. The Tesla Model S has been chosen as the base vehicle. Based on the calculated dynamic characteristics of the electric vehicle, main parameters of the DC-DC converter have been determined, computer simulation of the power plant of an electric vehicle with a DC-DC converter has been carried out in the Matlab Simulink software environment. The use of the converter improves the energy efficiency of vehicles, and is also a better solution compared to installing a battery with a higher voltage.

Predictive Assessment of Bus Body Life in the Matlab Simulink Software Environment

Predictive Assessment of Bus Body Life in the Matlab Simulink Software Environment

Kinematic Model for Stabilization and Orientation Control of the Suspended Equipment of an Unmanned Aerial Vehicle

The article is devoted to the development and research of a kinematic model of stabilization and orientation control of the suspended equipment of an unmanned aerial vehicle (UAV). The created model is based on the kinematic model of a three-axis gimbal (TAG): the structure of the TAG for the UAV, the mathematical description of the TAG of the UAV and the derivation of kinematic equations for the problems of stabilizing and controlling the orientation of the UAV suspension equipment. In the general case, the derivation of the kinematic equations of the TAG on the UAV is a complex process and is similar to the derivation of a kinematic model of a robotic arm with six degrees of freedom. The TAG is considered as a manipulative mechanism with six degrees of freedom: three degrees of freedom are determined by the UAV rotations around the axes of the coordinate system attached to the UAV, and three degrees of freedom are set by the frames of the TAG along the channels of yaw, roll and pitch during rotational movements of these frames around the corresponding axes of the coordinate systems attached to the frames of the TAG. Such a statement in the general case does not have an unambiguous solution for the tasks of stabilization and orientation control of the suspended equipment of UAV. To eliminate this ambiguity, optimization is used in the process of designing the TAG and installing the TAG in such positions on the UAV that reduce the computational complexity of the tasks being solved. The kinematic model is presented in the article by kinematic equations, the solution of which ensures the stabilization of the suspended equipment of UAV, and kinematic equations, the solution of which allows you to control the equipment (camera) of the UAV when tracking moving objects (moving targets) in space. The simulation of the TAG in the MATLAB Simulink software environment was performed. The simulation results in the MATLAB Simulink software environment prove the adequacy of the developed kinematic model of the TAG and its effectiveness for solving the problems of stabilization and orientation control of the suspended equipment of UAV.

Analysis of the operation of electromagnetic bearings in the difference of the center of the magnetic system relative to the axis of rotation and variations of the supply voltage

The article sets the task of reducing the consumption of electrical energy by electromagnetic bearings. To achieve this goal, it is proposed to shift the center of the magnetic system of bearings that compensate for the weight of the rotor relative to the axis of rotation. The displacement value is assumed to be equal to half the clearance value in the safety bearings of the unit under consideration. A mathematical model of a radial electromagnetic bearing, its design scheme, taking into account the displacement of the center of the magnetic system relative to the axis of rotation, a block diagram of a three-loop control system and formulas for calculating the parameters of regulators are presented. Regulator settings for a specific type of electromagnetic bearings are determined. A calculation model has been developed that makes it possible to study the operation of an electromagnetic bearing when the center of the magnetic system is displaced relative to the axis of rotation and the supply voltage is varied. The results of simulation in the Matlab Simulink software environment of the process of rotor ascent from safety bearings and rotor levitation in a displaced state at different values of the supply voltage are given. It is shown that the voltage reduction by 16.7% ensures stable operation of the electromagnetic suspension of the rotor in all possible modes. Therefore, shifting the center of the magnetic system can reduce the power consumption of electromagnetic bearings by 30%.

Mathematical Modeling the Performance of an Electric Vehicle Considering Various Driving Cycles

Currently, the estimated range of an electric vehicle is a variable value. The assessment of this power reserve is possible by various methods, and the results of the assessment by these methods will be quite different. Thus, building a model based on these cycles is an extremely important task for manufacturers of electric vehicles. In this paper, a simulation model was developed to determine the range of an electric vehicle by cycles of movement. A mathematical model was created to study the power reserve of an electric vehicle, taking into account four driving cycles, in which the lengths of cycles and the forces acting on the electric vehicle are determined; the calculation of the forces of resistance to movement was carried out taking into account the efficiency of the electric motor; thus, the energy consumption of an electric vehicle is determined. The modeling of the study of motion cycles on the presented model was carried out. The mathematical evaluation of battery life was based on simulation results. Simulation modeling of an electric vehicle in the MATLAB Simulink software environment was performed. An assessment of the power reserve of the developed electric vehicle was completed. The power reserve was estimated using the four most common driving cycles—NEDC, WLTC, JC08, US06. Studies have shown that the highest speed of the presented US06 cycle provides the shortest range of an electric vehicle. The JC08 and NEDC cycles have similar developed speeds in urban conditions, while in NEDC there is a phase of out-of-town traffic; therefore, due to the higher speed, the electric vehicle covers a greater distance in equal time compared to JC08. At the same time, the NEDC cycle is the least dynamic and the acceleration values do not exceed 1 m/s2. Low dynamics allow for a longer range of an electric vehicle; however, the actual urban operation of an electric vehicle requires more dynamics. The cycles of movement presented in the article provide a sufficient variety and variability of the load of an electric vehicle and its battery over a wide range, which made it possible to conduct effective studies of the energy consumed, taking into account the recovery of electricity to the battery in a wide range of loads. It was determined that frequent braking, taking into account operation including in urban traffic, provides a significant return of electricity to the battery.

Mobility simulation modelling of wheeled military vehicles under off-road traffic conditions

Ensuring the mobility of military vehicles (MV) is especially urgent in the conditions of modern hybrid wars and determines the growth of requirements for their designs. The influence of cross-country ability indicators, suspension and tire characteristics on limiting the maximum possible off-road speeds was analyzed. It is shown to limit the maximum speeds depending on the maximum permissible values of the vibrational loads level on the human body, disturbed by irregularities, the off-road micro-profile and the corresponding transmission functions of the suspension and tires.
 An analysis of literary sources, as well as standards regarding the methods of evaluating the movement mobility, determining the limit vibrational loads from the point of view of limiting the maximum speed of movement of the MV sample, was carried out. To study the influence of the suspension on the vibro-oscillatory properties of the MV sample, taking into account that vertical vibrations are the determining factors in the formation of vibro-oscillatory loads (the specific significance of longitudinal and transverse vibrations in total is within 20%), a dynamic equivalent model adequate to the physical process was built for a car with a 4x4 wheel formula. According to the specified model, the structure of simulated computer modeling of the wheeled vehicles movement in the MATLAB Simulink software environment was worked out.
 The possibility and parameters of the deterministic setting of the heights of irregularities of the off-road micro-profile with the possibility of operational change of both the characteristics of the suspension/tires and the type and condition of the off-road were worked out. Adequacy of the model was previously evaluated by evaluating the degree of reproduction of known experimental studies and determines the feasibility of forming a typical section of the off-road micro-profile for evaluating the effectiveness of the suspension.

Analysis of Exchange Power in the Power System of an Unmanned Aerial Vehicle with a BlDC Engine

The purpose of this work is the analysis of the power supply system of unmanned aerial vehicle. One of the most important tasks of this system is to ensure the smallest possible losses in order to achieve greater endurance of the aircraft, which means – the ability to complete the mission. The presence of an inactive component of consumed power obviously reduces the efficiency of the entire unmanned aerial vehicle. Considering also that due to the influence of wind, speed changes and other factors, the power system spends a significant amount of time in the transition mode, the impact of this phenomenon becomes even more significant. Thus, the phenomenon of the occurrence of exchange power in the power supply system of an unmanned aerial vehicle is analyzed. One of the most common solutions for unmanned aerial vehicles is the use of a BLDC motor, which is a further development of DC motors and was created with the aim of improving their basic characteristics. This type of engine has gained its popularity due to numerous advantages: high reliability, efficiency, speed and others. The principles of control of the BLDС engine are given. The unmanned aerial vehicle power supply system, built on the basis of a buck converter and a bridge inverter, was analyzed. An equivalent circuit of the converter is built, taking into account the losses in the electric circuit. On its basis the relations for determining the value of exchange power in the power supply system are derived. With the help of these expressions, it is possible to determine the value of the exchange energy at an arbitrary time interval in the real power supply system of the aircraft. A model of the power supply system of an unmanned aerial vehicle with a BLDC engine was built in the Matlab Simulink software environment. A time diagram is obtained, on the basis of which it is possible to draw a conclusion about the content of exchange power in the converter circuit. To minimize this phenomenon, it is necessary to develop a compensation system or an intelligent control system.

Computer model of a signal filtering device for a monitoring earth station

Satellite communication systems have an advantage over other communication systems, as they have a large coverage of the territory. The Earth station can be located anywhere in this territory and can be either a legitimate user or a satellite pirate (an illegitimate user). The developers are faced with the task of determining the coordinates of an illegitimate user illegally occupying a frequency resource. The article proposes a block diagram of a signal filtering device, which is part of a device for determining the coordinates of an illegitimate user, a monitoring Earth station. The purpose, requirements and main task of each composite block of the filtration device are defined. The search and analysis of analog filters and signal filtering methods was carried out. In the MatLab Simulink software environment, a computer model of a signal filtering device has been developed according to a block diagram with the possibility of determining the phase run, as well as the settings of the filtering device blocks are disclosed, which can be adjusted during the study of the model. For the bandpass filters included in the filtering device, the phase frequency characteristics of the phase change of the received signal on the frequency of this signal are constructed. A phase lock loop system has been formed with the possibility of changing its parameters. Calculations of the phase incursion through the elements of the filtration device are made.

ВПЛИВ ШВИДКОСТІ ВІТРУ НА РОБОТУ ВІТРЯНИХ ТУРБІН З DFIG ГЕНЕРАТОРОМ НА ВІТРЯНИХ ЕЛЕКТРОСТАНЦІЯХ

The purpose of the work: Determination of the mechanical and electrical parameters of the turbine with a DFIG generator at different values of the wind speed at start-up by means of simulation in the Matlab Simulink software environment. Methodology: a comprehensive approach that includes theoretical research and solving the following tasks: to establish characteristic moments of time in the process of starting a plant with a DFIG generator as a source of electricity; determine the angular speed and braking torque of the turbine during its start-up at different wind speeds; determine the active and reactive power of the DFIG generator during its start-up at different wind speeds. Results: Simulation of the operation of the wind generator was carried out in the Matlab Simulink software environment, in which a system for obtaining electrical energy from wind energy (DFIG) was built. The reactive power of electric motors, the efficiency of which depends on the power factor, is presented Scientific novelty: when the wind speed changes, a change in reactive power and a redistribution of the electric moment of the generator and the torque of the wind are observed. Full power, which is the vector sum of active and reactive power, and is supplied to the network by electric generators. Analysis of graphical dependencies allows you to see changes in time of active and reactive power, which cause changes in torque and speed of rotation in the wind generator. Practical significance: Studying the processes in the wind generator with the help of the proposed model allows you to compare the parameters of their operation under different modes and given wind speeds, determine the maximum values of the mode parameters, and obtain the necessary information for the implementation of reactive power compensation measures. The proposed model also makes it possible to find ways to improve the wind generator and the system for obtaining electrical energy for the operation of enterprises during the intensive reconstruction of Donbas. Key words: energy, active power, reactive power, wind generator, wind speed, transformer, generator, torque, blade rotation speed

Исследование способов оценки качества передаваемого сигнала в канале связи

There are many different measurement methods and methods, thanks to which digital models of the system are analyzed for noise immunity, distortion, security, versatility, cost-effectiveness and accuracy. The concept of “universality” is general in nature and applied to any digital signal, the concept of “cost-effectiveness” is the efficient use of bandwidth, equipment and network resources. “Accuracy” is the key requirement in the construction and transmission of information over a communication network. Various characteristics of the transmission channel - bandwidth, transmission levels, dynamic range, level diagram, amplitude-frequency response, phase-frequency response, the error rate for a certain time interval give an idea of the state of the channel, path, and equipment. According to their analysis, it is easy to eliminate or improve that component of the communication channel. The article presents and investigates popular tools for assessing the quality of transmitted information over a digital communication channel. The MATLAB Simulink software environment was used, a digital communication channel was modeled using QPSK modulation. The MATLAB Simulink software environment was used, a digital communication channel was modeled using QPSK modulation. This modulation is actively used in satellite broadcasting, when streaming satellite channels SD and some HD channels, works at high transmission speeds, thereby being one of their most popular at the moment. An experiment of signal transmission over a communication channel was carried out; the received signal was evaluated in various ways for noise immunity and distortion.

Model development according to increase in the active resistance of the conductor to ac current at the surface effect

Purpose. When alternating current with higher harmonics passes through the cable, heating is carried out by the root mean square value of all harmonics. Taking into account the different resistance of the cable depending on the frequency due to the effect of the surface effect, it is advisable to calculate the coefficient of increase in the total current resistance, assuming the action of each harmonic as independent. However, there are prerequisites to consider existing calculation models difficult for algorithmic implementation in software packages. Therefore, the purpose of the work is to develop a calculation model to take into account the increase in the active resistance of the conductor to alternating current due to the surface effect for further use in simulation modeling packages such as, for example, MATLAB.
 Methodology. Methods of linear algebra, linear regression, defining the coefficient of determination.
 Findings. Dependencies for determining the resistance value of high-voltage cable lines to high-frequency currents, which take into account the cross-section and harmonic composition of the current, have been obtained. According to the existing and substantiated graphs (dependencies) obtained on the basis of classical expressions from the literature, new simplified calculation dependencies were obtained (for the cross-section of copper cable lines 240 - 1000 mm2) when current harmonics above the fifth at a base frequency of 50 Hz. Such calculated ratios will allow taking into account several harmonic components of the current during line heating in the MATLAB Simulink software environment.
 The obtained values of the coefficient of determination in defining the calculated dependencies are close to 1, which indicates the correctly selected type of equation and the correctly selected coefficient k for different cross-sections of the cable line.
 Originality. The scientific novelty lies in the development of a new dependence, justified by the high value of the multiple correlation coefficient, the correction factor for the increase in the resistance of the cable core from the harmonic number and the empirical coefficient of the regression model, taking into account the cross section of the cable line.
 Practical value. The practical value of the work consists in obtaining dependencies that can be used in analytical and simulation models when determining the amount of heating of cable lines taking into account the current of harmonics above the fifth at a base frequency of 50 Hz. Such an application will allow in many cases to replace the physical experiment with a simulation in the MATLAB Simulink software environment, which will reduce the necessary human and material costs.

Mathematical Model of Arc Quenching in the Adjacent Chambers of an RMKE-10 Multichamber Lightning Arrester

Multichamber arresters are widely used to protect overhead power lines from lightning surges. To work out recommendations on the multichamber arrester design taking into account the operating conditions, it is necessary to develop a mathematical model of the arc quenching processes in the multichamber arrester discharge chambers. In addition to the processes inside the discharge chambers, such a model should predict the range of multichamber arrester operating conditions in which overlapping of adjacent plasma jets outside the arrester shell does not occur. For this purpose, a mathematical model of the operation of an RMKE-10 multichamber arrester’s two adjacent discharge chambers was developed in the COMSOL Multiphysics software environment. In so doing, the time dependence of the current through the multichamber arrester was used, which was obtained during calculations on the developed model of the multichamber arrester test bench electrical circuit in the Matlab Simulink software environment. Calculations based on the model of two adjacent discharge chambers were carried out for two cases of the distance between the chambers. The conditions excluding the overlapping of the generated arc discharge jets are established. The theoretical and experimental data were compared, and the comparison results have confirmed the adequacy of the developed method for calculating the arc discharges sequentially produced in a multichamber arrester. The lines for further modernization of the multichamber arrester mathematical model have been determined.

Implementation of a Novel Tabu Search Optimization Algorithm to Extract Parasitic Parameters of Solar Panel

The aging of PV cells reduces their electrical performance i.e., the parasitic parameters are introduced in the solar panel. The shunt resistance (RSh), series resistance (RS), photo current (IPh), diode current (Id), and diffusion constant (a1) are known as parasitic or extraction parameters. Cracks and hotspots reduce the performance of PV cells and result in poor V–I characteristics. Certain tests are carried out over a long period of time to determine the quality of solar cells; for example, 1000 h of testing is comparable to 20 years of operation. The extraction of solar parameters is important for PV modules. The Tabu Search Optimization (TSO) algorithm is a robust meta-heuristic algorithm that was employed in this study for the extraction of parasitic parameters. Particle Swarm Optimization (PSO) and a Genetic lgorithm (GA), as well as other well-known optimization methods, were used to test the proposed method’s correctness. The other approaches included the lightning search algorithm (LSA), gravitational search algorithm (GSA), and pattern search (PS). It can be concluded that the TSO approach extracts all six parameters in a reasonably short period of time. The work presented in this paper was developed and analyzed using a MATLAB-Simulink software environment.