scholarly journals Comparative study of frequency converters of three-phase electric motors in automatic control of technological parameter

2021 ◽  
Vol 2 (3) ◽  
pp. 48-56
Author(s):  
Margarita M. Blagoveshchenskaya ◽  
Mikhail V. Veselov
Keyword(s):  
Pid Controller ◽  
Technological Parameter ◽  
Test Bench ◽  
Frequency Converter ◽  
Electric Motors ◽  
Technological Parameters ◽  
Frequency Converters ◽  
Ac Motors ◽  
Three Phase

Frequency converters of asynchronous three-phase AC motors are widely used in industry, including food production. A thorough understanding of the technical capabilities of frequency converters contributes to their efficient use. This article discusses a technical comparison of two frequency converters of three-phase electric motors of the Russian company "OWEN" and the Danish company "DANFOSS" according to the criterion of the quality of regulation of the technological parameter. For comparison, a test bench was created, in which the devices were tested in turn, under the same conditions. During the preparation and implementation of testing, it turned out that the hardware capabilities of frequency converters for their use in regulating technological parameters are the same, and the parametric capabilities are different. The frequency converter of the "OWEN" company is equipped with a PI controller, and the frequency converter from "DANFOSS" is equipped with a PID controller. As the results of testing the devices show, despite 

scholarly journals Insulation Life Span of Low-Voltage Electric Motors—A Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1738
Author(s):  
Vanessa Neves Höpner ◽  
Volmir Eugênio Wilhelm
Keyword(s):  
Life Span ◽  
Electric Motor ◽  
Low Voltage ◽  
Frequency Converter ◽  
Rate Of Change ◽  
High Rate ◽  
Switching Frequency ◽  
Electric Motors ◽  
Frequency Converters ◽  
High Switching Frequency

The use of static frequency converters, which have a high switching frequency, generates voltage pulses with a high rate of change over time. In combination with cable and motor impedance, this generates repetitive overvoltage at the motor terminals, influencing the occurrence of partial discharges between conductors, causing degradation of the insulation of electric motors. Understanding the effects resulting from the frequency converter–electric motor interaction is essential for developing and implementing insulation systems with characteristics that support the most diverse applications, have an operating life under economically viable conditions, and promote energy efficiency. With this objective, a search was carried out in three recognized databases. Duplicate articles were eliminated, resulting in 1069 articles, which were systematically categorized and reviewed, resulting in 481 articles discussing the causes of degradation in the insulation of electric motors powered by frequency converters. A bibliographic portfolio was built and evaluated, with 230 articles that present results on the factors that can be used in estimating the life span of electric motor insulation. In this structure, the historical evolution of the collected information, the authors who conducted the most research on the theme, and the relevance of the knowledge presented in the works were considered.

scholarly journals Способы компенсации высших гармоник напряжения в судовых электроэнергетических системах

2020 ◽  
Author(s):  
A.S. Kornev ◽  
V.I. Kuznetsov ◽  
H. Pan ◽  
A.P. Senkov
Keyword(s):  
Electric Power ◽  
Electric Propulsion ◽  
Frequency Converter ◽  
Electric Power System ◽  
Propulsion Systems ◽  
Higher Harmonics ◽  
Frequency Converters ◽  
Three Phase ◽  
Harmonic Components ◽  
Waveform Distortions

В статье выполнен анализ способов компенсации высших гармоник в судовой сети единой электроэнергетической системы (ЕЭЭС), в составе которой, основным потребителей электроэнергии является система электродвижения (СЭД). Рассмотрены три схемы компенсации высших гармоник, создаваемых неуправляемыми выпрямителями, входящими в состав преобразователей частоты (ПЧ). Проведено компьютерное моделирование фрагмента структуры ЕЭЭС, запатентованной фирмой Siemens , схемы 18-пульсного выпрямителя, а также схемы с двумя 12-пульсными выпрямителями. Результаты моделирования показали, что в структуре ЕЭЭС фирмы Siemens , пропульсивный трансформатор обеспечивает компенсацию только части высших гармоник, из-за чего, искажения формы напряжения в судовой сети могут быть значительными. Схема, содержащая два 12-пульсных выпрямителя, а также трехфазный трансформатор с четырьмя трехфазными обмотками, имеющими сдвиг фаз на 15 электрических градусов, показала наилучшие показатели по качеству тока, обеспечивая эффективную компенсацию 5, 7, 11, 13 гармонических составляющих тока. Предложенная схема с двумя 12-пульсными выпрямителями позволяет в составе ПЧ применить трехуровневые автономные инверторы напряжения, характеризующиеся высоким качеством тока в обмотках гребного электродвигателя.The article analyzes the methods for compensating for higher harmonics in the ship network of the unified electric power system (UEPS), in which the main electric power consumers are electric propulsion systems (EPS). Three compensation schemes for higher harmonics created by uncontrolled rectifiers that are part of frequency converters are considered. Computer simulation of a fragment of the UEPS structure patented by Siemens, an 18-pulse rectifier circuit, and also circuits with two 12-pulse rectifiers were carried out. The simulation results showed that in the Siemens UEPS structure, a propulsive transformer provides compensation for only a part of the higher harmonics, due to which, voltage waveform distortions in the ship network can be significant. The circuit, containing two 12-pulse rectifiers, as well as a three-phase transformer with four three-phase windings having a phase shift of 15 electrical degrees, showed the best current quality indicators, providing effective compensation for 5, 7, 11, 13 harmonic components of the current. The proposed circuit with two 12-pulse rectifiers allows the use of three-level autonomous voltage inverters, which are characterized by high quality current in the windings of the propeller motor, as part of the frequency converter.

scholarly journals Cascade frequency converters control features

2020 ◽  
Vol 241 ◽  
pp. 37
Author(s):  
A. Vorontsov ◽  
V. Glushakov ◽  
M. Pronin ◽  
Yu. Sychev
Keyword(s):  
High Voltage ◽  
Single Phase ◽  
Power Converters ◽  
Low Voltage ◽  
Frequency Converter ◽  
Frequency Converters ◽  
Three Phase ◽  
In Series ◽  
Load Characteristics ◽  
Active Rectifiers

The structures of systems with high-voltage cascade frequency converters containing multi-winding transformers and low-voltage low-power converters connected in series at each output phase of the load are considered. Low-voltage blocks contain three-phase diode or active rectifiers, DC capacitor filters, single-phase stand-alone voltage inverters and block disconnecting devices in partial modes (in case of failure when part of the blocks are disconnected). The possibilities of operation of cascade converters are determined, equations for correcting tasks to units in partial modes are given, tables of correction of tasks with estimates of achievable load characteristics are proposed. The results of experiments on the model of a powerful installation with a cascade frequency converter are presented, confirming the possibility of ensuring the symmetry of the load currents when disconnecting part of the blocks and the asymmetry of the circuit.  

Comparison of Energy Indicators of the Electric Lift Drive of the Ekg-5 Excavator with Different Power Converters

2021 ◽  
Vol 64 (3) ◽  
pp. 53-59
Author(s):  
Eduard Grekov ◽  
◽  
Alexei Bezgin ◽  
Viktor Sorokin ◽  
Ildar Yamansarin ◽  
...  
Keyword(s):  
Electric Motor ◽  
Power Converters ◽  
Frequency Converter ◽  
Electric Motors ◽  
Joint Work ◽  
Two Phase ◽  
Electric Drives ◽  
Three Phase ◽  
Energy Indicators ◽  
Asynchronous Electric Motor

The energy indicators of the EKG-5 excavator lifting electric drive with thyristor power circuits have been determined according to the systems thyristor direct frequency converter - two-phase asynchronous electric motor, converter-DC motor and direct frequency converter - three-phase asynchronous electric motor. Losses in electric motors and converters have been determined, taking into account the specifics of their joint work in theefficiency for the excavation cycle were determined based on the results of calculating the simulation model, the initial data for which were the parameters of the excavation cycle of the lift drive of a real excavator. Distortion coefficients of the mains current were determined for two cases: during digging and during accelerated lowering of an empty bucket. For comparison, the energy indicators of the selected electric drives with a filter-compensating device were calculated. The analysis of energy indicators is made.

scholarly journals THE INFLUENCE OF THE INPUT INDUCTANCE ON THE QUALITATIVE INDICATORS OF ACTIVE CONTROLLED RECTIFIER

2021 ◽  
pp. 18-23
Author(s):  
Denis Krylov ◽  
Olga Kholod
Keyword(s):  
Control System ◽  
Electromagnetic Compatibility ◽  
Modulation Frequency ◽  
Frequency Converter ◽  
Voltage Source ◽  
Stable Operation ◽  
Active Rectifier ◽  
Semiconductor Converters ◽  
Three Phase

The main part of electricity is used by industrial plants in a converted form and the use of semiconductor converters is growing rapidly. The requirements for the quality of semiconductor converters are increased. And their impact on the power supply, load and related consumers is increased too. One of the most popular converters in the segment of low and medium power drives is a frequency converter made on the basis of a three-phase stand-alone voltage inverter. A significant disadvantage of such converters is the use of a diode rectifier at the input of the circuit, which has disadvantages as the inability to recover electricity to the mains in the mode of dynamic braking of an induction motor and significant distortions of the mains current. These disadvantages can be eliminated by using an active rectifier instead of a diode rectifier, which provides a sinusoidal shape of the mains current in phase with the mains voltage and the possibility of bidirectional energy exchange with the load. The efficiency of the active rectifier-voltage source is determined by the selected control algorithm of the circuit switches and the correct task of the inductance of the input choke. A mathematical model of a three-phase active rectifier-voltage source, working with a fixed modulation frequency with a vector algorithm for building a control system and analysis of the influence of the input inductance on the quality of its work was created. From the simulation results it became obvious that the proposed structure of the control system provides stable operation of the converter and acceptable standards for electromagnetic compatibility with the mains at a fixed modulation frequency; the proposed algorithm for calculating the value of the input inductances allows you to correctly select their allowable value, and obtained in the simulation of the dependence allows you to most accurately determine the value of the input inductances on the allowable level of distortion of mains current and supply voltage.

scholarly journals Planning and Building Electric of an Flower Carnival Car at University of Debrecen

2019 ◽  
Vol 11 (1) ◽  
pp. 19-22
Author(s):  
Antal Apagyi ◽  
Tamás Szmolka ◽  
Géza Husi
Keyword(s):  
Electric Power ◽  
Carrying Capacity ◽  
Planning Process ◽  
Battery Pack ◽  
Variable Frequency ◽  
Electric Motors ◽  
Three Phase ◽  
Variable Frequency Drives ◽  
The Creation

Abstract In this research we will discuss the creation of the flower cart. It will be examined from an economical and environmental perspective. Additionally, the planning process regarding the carrying capacity and battery runtime will be explained. The cart is moved by three-phase electric motors which are controlled by Variable Frequency Drives (VFD). Electric power is supplied by the large battery pack. Overall, the purpose of this vehicle is to be able to participate in the carnival march while increasing the quality of the event.

scholarly journals Development and Rationale of Two-Disk Operating Body of Agricultural Machine for Tillage

2021 ◽  
Vol 20 (5) ◽  
pp. 383-389
Author(s):  
A. S. Ivanov ◽  
M. S. Puzyrev ◽  
E. M. Chikishev
Keyword(s):  
Energy Consumption ◽  
Energy Intensity ◽  
Operating Mode ◽  
Angular Speed ◽  
Technological Parameters ◽  
Agricultural Machine ◽  
Ac Motors ◽  
Translational Speed ◽  
Agricultural Machines

One of the main problems in the design of agricultural machines, including tillage machines, is to ensure the optimal energy intensity of various technological operations. The design, kinematic and technological parameters of rotary tillage machines have a significant impact on the indicators of the energy intensity of the process and the quality of tillage. These parameters include the diameter of the operating body of the agricultural machine, the angular speed and rotational speed of the disks, the number of cutting elements, the translational speed of the operating body, the height of the ridge formed during soil cultivation, the thickness of the cut chips. An important agrotechnical parameter of a rotary tillage machine is the ridging of the furrow bottom. The height of the ridges formed should not be less than 20 % of the depth of the cultivated soil. Currently, in order to ensure the required height of the ridges in the designs of rotary machines, there are a number of restrictions that determine the operating mode and parameters of the units. The degree of influence of the parameters of the developed operating body and the energy consumption on the quality of tillage has been assessed in the process of the research. The experiments have been carried out on an installation that included an operating body, a power unit, control and instrumentation equipment. As the power section, AC motors with a phase rotor were used, the power of which was 0.75 and 1.50 kW, and the speed of rotation was 920, 1500 and 3000 rpm. The parameters have been set that allow to reduce the energy consumption for tillage by 11–17 %, compared to existing machines, and ensure the alignment of the furrow bottom by up to 80 %.

Steady-state modelling method for matrix-reactance frequency converter with boost topology

2011 ◽  
Vol 60 (2) ◽  
pp. 137-148
Author(s):  
Igor Korotyeyev ◽  
Beata Zięba
Keyword(s):  
Fourier Series ◽  
Steady State ◽  
Differential Equations ◽  
Numerical Method ◽  
Frequency Converter ◽  
Double Fourier Series ◽  
Galerkin’S Method ◽  
Galerkin's Method ◽  
Modelling Method ◽  
Three Phase

Steady-state modelling method for matrix-reactance frequency converter with boost topologyThis paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.

scholarly journals Results of Laboratory Studies of the Automated Sorting System for Root and Onion Crops

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1257
Author(s):  
Alexey Dorokhov ◽  
Alexander Aksenov ◽  
Alexey Sibirev ◽  
Nikolay Sazonov ◽  
Maxim Mosyakov ◽  
...  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
Technological Parameters ◽  
Post Harvest ◽  
Manual Sorting ◽  
Sorting System ◽  
Working Bodies ◽  
Automatic Removal

The roller and sieve machines most commonly used in Russia for the post-harvest processing of root and tuber crops and onions have a number of disadvantages, the main one being a decrease in the quality of sorting due to the contamination of working bodies, which increases the quantity of losses during sorting and storage. To obtain high-quality competitive production, it is necessary to combine a number of technological operations during the sorting process, such as dividing the material into classes and fractions by quality and size, as well as identifying and removing damaged products. In order to improve the quality of sorting of root tubers and onions by size, it is necessary to ensure the development of an automatic control system for operating and technological parameters, the use of which will eliminate manual sorting on bulkhead tables in post-harvest processing. To fulfill these conditions, the developed automatic control system must have the ability to identify the material on the sorting surface, taking into account external damage and ensuring the automatic removal of impurities. In this study, the highest sorting accuracy of tubers (of more than 91%) was achieved with a forward speed of 1.2 m/s for the conveyor of the sorting table, with damage to 2.2% of the tubers, which meets the agrotechnical requirements for post-harvest processing. This feature distinguishes the developed device from similar ones.

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