Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables
Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of such processes on the modes applying t...
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Інститут технічних проблем магнетизму НАН України
2018
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| Назва видання: | Електротехніка і електромеханіка |
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| Цитувати: | Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables / V.M. Zolotaryov, M.A. Shcherba, R.V. Belyanin, R.P. Mygushchenko, I.M. Korzhov // Електротехніка і електромеханіка. — 2018. — № 2. — С. 47-53. — Бібліогр.: 12 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1493342025-02-09T14:54:17Z Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables Zolotaryov, V.M. Shcherba, M.A. Belyanin, R.V. Mygushchenko, R.P. Korzhov, I.M. Техніка сильних електричних та магнітних полів. Кабельна техніка Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of such processes on the modes applying three-layer polymer insulation to the current-carrying core. Technique. The study was conducted based on the concepts of electromechanics, electromagnetic field theory, mathematical physics, mathematical modeling. Results. A mathematical model has been developed to analyze transients in an electromechanical system consisting of three frequency-controlled electric drives providing current-carrying core motion of ultra-high voltage cables in an inclined extrusion line. The coordination of the electromechanical parameters of the system drives has been carried out and the permissible changes in the supply voltage at the limiting mass while moving current-carrying core of ultra-high voltage cables with applied polymer insulation have been estimated. Scientific novelty. For the first time it is determined that with the limiting mass of the currentcarrying core, the electromechanical system allows to stabilize the current-carrying core speed with the required accuracy at short-term decreases in the supply voltage by no more than 27 % of its amplitude value. It is also shown that this system is resistant to short-term increases in voltage by 32 % for 0.2 s. Practical significance. Using the developed model, it is possible to calculate the change in the configuration and speed of the slack current-carrying core when applying polymer insulation, depending on the specific mass of the current-carrying core per unit length, its tension at the bottom, the torque of the traction motor and the supply voltage to achieve stable operation of the system and accurate working of the set parameters Цель. Целью статьи является проведение анализа электромеханических переходных процессов в системе из трех частотно регулируемых электроприводов на базе асинхронных двигателей, которые управляют движением токопроводящей жилы, а также исследование влияния таких процессов на режимы нанесения на жилу трехслойной полимерной изоляции. Методика. Для проведения исследований использовались положения электромеханики, теории электромагнитного поля, математической физики, математического моделирования. Результаты. Разработана математическая модель, позволяющая анализировать переходные процессы в электромеханической системе, состоящей из трех частотно регулируемых электроприводов, обеспечивающих движение токопроводящей жилы сверхвысоковольтного кабеля в наклонной экструзионной линии. Проведено согласование электромеханических параметров приводов системы и выполнена оценка допустимых изменений напряжения питающей сети при предельной массе движущейся жилы сверхвысоковольтного кабеля с нанесённой на нее полимерной изоляцией. Научная новизна. Впервые определено, что при предельной массе токопроводящей жилы электромеханическая система позволяет стабилизировать скорость перемещения жилы с необходимой точностью при кратковременных уменьшениях питающего напряжения не более чем на 27 % от его амплитудного значения. Также показано, что данная система является устойчивой к кратковременному увеличению напряжения на 32 % в течение 0,2 с. Практическое значение. Использование разработанной модели позволяет рассчитывать изменение конфигурации и скорости движения провисающей токопроводящей жилы при нанесении на нее полимерной изоляции, в зависимости от удельной массы жилы на единицу длины, ее натяжения в нижней точке, момента тягового электродвигателя и величины питающего напряжения для достижения стабильной работы системы и точной отработки заданных параметров. 2018 Article Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables / V.M. Zolotaryov, M.A. Shcherba, R.V. Belyanin, R.P. Mygushchenko, I.M. Korzhov // Електротехніка і електромеханіка. — 2018. — № 2. — С. 47-53. — Бібліогр.: 12 назв. — англ. 2074-272X DOI: 10.20998/2074-272X.2018.2.08 https://nasplib.isofts.kiev.ua/handle/123456789/149334 621.365.5 en Електротехніка і електромеханіка application/pdf Інститут технічних проблем магнетизму НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Техніка сильних електричних та магнітних полів. Кабельна техніка Техніка сильних електричних та магнітних полів. Кабельна техніка |
| spellingShingle |
Техніка сильних електричних та магнітних полів. Кабельна техніка Техніка сильних електричних та магнітних полів. Кабельна техніка Zolotaryov, V.M. Shcherba, M.A. Belyanin, R.V. Mygushchenko, R.P. Korzhov, I.M. Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables Електротехніка і електромеханіка |
| description |
Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled
electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of
such processes on the modes applying three-layer polymer insulation to the current-carrying core. Technique. The study was conducted based on the concepts of electromechanics, electromagnetic field theory, mathematical physics, mathematical modeling.
Results. A mathematical model has been developed to analyze transients in an electromechanical system consisting of three frequency-controlled electric drives providing current-carrying core motion of ultra-high voltage cables in an inclined extrusion
line. The coordination of the electromechanical parameters of the system drives has been carried out and the permissible changes
in the supply voltage at the limiting mass while moving current-carrying core of ultra-high voltage cables with applied polymer
insulation have been estimated. Scientific novelty. For the first time it is determined that with the limiting mass of the currentcarrying core, the electromechanical system allows to stabilize the current-carrying core speed with the required accuracy at
short-term decreases in the supply voltage by no more than 27 % of its amplitude value. It is also shown that this system is resistant to short-term increases in voltage by 32 % for 0.2 s. Practical significance. Using the developed model, it is possible to calculate the change in the configuration and speed of the slack current-carrying core when applying polymer insulation, depending
on the specific mass of the current-carrying core per unit length, its tension at the bottom, the torque of the traction motor and the
supply voltage to achieve stable operation of the system and accurate working of the set parameters |
| format |
Article |
| author |
Zolotaryov, V.M. Shcherba, M.A. Belyanin, R.V. Mygushchenko, R.P. Korzhov, I.M. |
| author_facet |
Zolotaryov, V.M. Shcherba, M.A. Belyanin, R.V. Mygushchenko, R.P. Korzhov, I.M. |
| author_sort |
Zolotaryov, V.M. |
| title |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| title_short |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| title_full |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| title_fullStr |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| title_full_unstemmed |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| title_sort |
electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables |
| publisher |
Інститут технічних проблем магнетизму НАН України |
| publishDate |
2018 |
| topic_facet |
Техніка сильних електричних та магнітних полів. Кабельна техніка |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/149334 |
| citation_txt |
Electromechanical transient processes during supply voltage changing in the system of polymer insulation covering of the current-carrying core of ultra high voltage cables / V.M. Zolotaryov, M.A. Shcherba, R.V. Belyanin, R.P. Mygushchenko, I.M. Korzhov // Електротехніка і електромеханіка. — 2018. — № 2. — С. 47-53. — Бібліогр.: 12 назв. — англ. |
| series |
Електротехніка і електромеханіка |
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| fulltext |
ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2 47
© V.M. Zolotaryov, M.A. Shcherba, R.V. Belyanin, R.P. Mygushchenko, I.M. Korzhov
UDC 621.365.5 doi: 10.20998/2074-272X.2018.2.08
V.M. Zolotaryov, M.A. Shcherba, R.V. Belyanin, R.P. Mygushchenko, I.M. Korzhov
ELECTROMECHANICAL TRANSIENT PROCESSES DURING SUPPLY VOLTAGE
CHANGING IN THE SYSTEM OF POLYMER INSULATION COVERING
OF THE CURRENT-CARRYING CORE OF ULTRA HIGH VOLTAGE CABLES
Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled
electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of
such processes on the modes applying three-layer polymer insulation to the current-carrying core. Technique. The study was con-
ducted based on the concepts of electromechanics, electromagnetic field theory, mathematical physics, mathematical modeling.
Results. A mathematical model has been developed to analyze transients in an electromechanical system consisting of three fre-
quency-controlled electric drives providing current-carrying core motion of ultra-high voltage cables in an inclined extrusion
line. The coordination of the electromechanical parameters of the system drives has been carried out and the permissible changes
in the supply voltage at the limiting mass while moving current-carrying core of ultra-high voltage cables with applied polymer
insulation have been estimated. Scientific novelty. For the first time it is determined that with the limiting mass of the current-
carrying core, the electromechanical system allows to stabilize the current-carrying core speed with the required accuracy at
short-term decreases in the supply voltage by no more than 27 % of its amplitude value. It is also shown that this system is resis-
tant to short-term increases in voltage by 32 % for 0.2 s. Practical significance. Using the developed model, it is possible to calcu-
late the change in the configuration and speed of the slack current-carrying core when applying polymer insulation, depending
on the specific mass of the current-carrying core per unit length, its tension at the bottom, the torque of the traction motor and the
supply voltage to achieve stable operation of the system and accurate working of the set parameters. References 12, figures 7.
Key words: electromechanical transient processes, ultra-high voltage cable, mathematical modeling, frequency-controlled
electric drives, polymer insulation covering.
Цель. Целью статьи является проведение анализа электромеханических переходных процессов в системе из трех
частотно регулируемых электроприводов на базе асинхронных двигателей, которые управляют движением токопро-
водящей жилы, а также исследование влияния таких процессов на режимы нанесения на жилу трехслойной поли-
мерной изоляции. Методика. Для проведения исследований использовались положения электромеханики, теории
электромагнитного поля, математической физики, математического моделирования. Результаты. Разработана
математическая модель, позволяющая анализировать переходные процессы в электромеханической системе, со-
стоящей из трех частотно регулируемых электроприводов, обеспечивающих движение токопроводящей жилы сверх-
высоковольтного кабеля в наклонной экструзионной линии. Проведено согласование электромеханических параметров
приводов системы и выполнена оценка допустимых изменений напряжения питающей сети при предельной массе
движущейся жилы сверхвысоковольтного кабеля с нанесённой на нее полимерной изоляцией. Научная новизна. Впер-
вые определено, что при предельной массе токопроводящей жилы электромеханическая система позволяет стабили-
зировать скорость перемещения жилы с необходимой точностью при кратковременных уменьшениях питающего
напряжения не более чем на 27 % от его амплитудного значения. Также показано, что данная система является ус-
тойчивой к кратковременному увеличению напряжения на 32 % в течение 0,2 с. Практическое значение. Использова-
ние разработанной модели позволяет рассчитывать изменение конфигурации и скорости движения провисающей
токопроводящей жилы при нанесении на нее полимерной изоляции, в зависимости от удельной массы жилы на еди-
ницу длины, ее натяжения в нижней точке, момента тягового электродвигателя и величины питающего напряже-
ния для достижения стабильной работы системы и точной отработки заданных параметров. Библ. 12, рис. 7.
Ключевые слова: электромеханические переходные процессы, сверхвысоковольтный кабель, математическое моде-
лирование, частотно регулируемые электроприводы, нанесение полимерной изоляции.
Introduction. The modern phase of technological
development for applying polymer insulation to current-
carrying cores of power-driven cables is characterized by
the use of adjustable AC electric drives. These drives are
made on the basis of asynchronous motors with frequency
control, which have high dynamic and energy perform-
ance. At the same time, when two or more adjustable
drives are used in one system, the solution to the problem
of their electrical and mechanical parameters coordination
becomes much more complicated. When choosing the
optimal structure of the control unit of the whole system,
it becomes necessary to model complex electrodynamic
processes, which now is most appropriate to implement
using the Matlab/Simulink/Sim-PowerSystems package.
This approach helps to investigate the laws of fre-
quency regulation and determine the most appropriate
system regimes for its stability, speed and other indicators
[10]. When operating these drives systems, there is also
the task of studying their operation stability when chang-
ing the supply network parameters, which is especially
important in case of maximum mechanical loads of the
drives and their power supply from the power supply sys-
tem with a limited installed capacity of the servicing sub-
station. The use of computer modeling to solve this type
of problems makes it possible to significantly reduce the
material costs and timing of such systems design.
This research provides an estimation of the operation
stability of electromechanical system with vector control
of frequency-controlled electric drives considering short-
term changes in the supply network voltage. It is known
[10] that the vector control advantages are the high accu-
racy of diagram optimization at a set speed, the preserva-
48 ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2
tion of the necessary torque magnitude at low rotational
speeds, the smooth operation of the motor and the rapid
reaction to load jumps due to the high dynamics of regula-
tion. At the same time, the quantitative analysis of the
stability and accuracy of the specified parameters optimi-
zation - motion speed and the torque shaft of the drive, are
currently insufficiently studied.
The aim of the paper is to analyze the electrome-
chanical transients in a system consisting of three fre-
quency-controlled electric drives based on asynchronous
motors that control the current-carrying core motion, as
well as the effect of such processes on the modes of ap-
plying three-layer polymer insulation to the current-
carrying core.
The paper studies such freelance regimes as the ap-
pearance of short-term voltage failures in the supplying
three-phase network and short-term increases in this volt-
age. The study is carried out to coordinate the electrome-
chanical parameters of the system two drives and to eval-
uate the permissible level of the voltage failure in the
supply network at the limiting mass of the moving cable.
The material is based on the computer modeling re-
sults of electrical system that includes two induction mo-
tors with vector control, using the scientific statements
presented in [7, 11]. Synthesis of the virtual model uses
the tools of the Matlab / Simulink computer modeling
software package [8], which contains special blocks and
demonstration samples dealing directly with the elements
and systems of the automated electric drive. The princi-
ples of constructing and exploring individual blocks of
virtual models are presented in [6, 7], and the control sys-
tems of electric drives in the monograph [5].
Description of the inclined line. The inclined ex-
trusion line (Fig. 1,a) is in the form of a metal vulcaniza-
tion pipe, inside of which extrusion and vulcanization
(cross-linking) of a polyethylene insulation layer as well
as two polymeric semiconductive layers are applied on
the current-carrying core of high-voltage and ultrahigh
voltage cables. In such a line, the insulation of aluminum
and copper current-carrying cores of power cables is
made with a cross section of 35-2000 mm2 for a voltage
of 10-330 kV. The current-carrying core consists of many
twisted and compacted current-carrying cores, which can
be divided into 5-7 separately sealed and isolated sectors.
A polymeric semiconductive layer 0.4-3 mm thick is ap-
plied to the current-carrying core, on which an insulating
layer of high-quality polyethylene with a thickness of up
to 28 mm and another layer of semiconductive polyethyl-
ene with a thickness of 0.4-3.5 mm are applied. All three
layers are simultaneously applied by extrusion using a
triple extrusion head and vulcanized in a vulcanization
pipe of continuous vulcanization at 450 °C in a medium
compressed to 16 atm. nitrogen in the gaseous state. This is
necessary to ensure the insulation quality, namely to exclude
the presence of conductive microcircuits larger than 50 μm
and groups of closely located microinclusions [4, 12].
The cable current-carrying core with polyethylene
insulation and semi-conductive shielding layers applied
must move at a speed of 0.3-50 m/min inside the vulcani-
zation pipe 172 m long. The motion is carried out as a
result of the effort up to 4.5·104 N electric drive No. 1
(Fig. 1,b).
The principle of line operation, its scheme is shown
in Fig. 1 as follows. The current-carrying core wounded
on the feeding device cylinder, is passed through the elec-
tric drive No. 1 through a triple extrusion head, into which
polyethylene insulation melts and a semiconductive pol-
ymer are simultaneously fed. The head has three extruders
of different capacities: the first (with the highest capacity)
for applying a polyethylene insulation layer, and the sec-
ond for forming semiconductive polymer layers.
In order for the liquid layer of molten polyethylene
to be less displaced relative to the current-carrying core
axis, a twisting mechanism is additionally applied. It
twists the current-carrying core in the direction of its
wires approximately at a pitch equal to one current-
carrying core turn around its axis for 30 linear meters of
its length. This makes it possible to obtain a cylindrical
item with a crust of solidified polyethylene on its surface
and avoid the displacement of the polymeric semiconduct-
ing and insulating layers relative to the current-carrying
core axis, i.e. avoid the polymer layers eccentricity.
The possibility of such technology implementation
is provided by a special configuration of the inclined vul-
canization pipe. The initial part of the pipe, where the
current-carrying core polymer layers are still sufficiently
liquid, is practically vertical. Then the pipe bends and in
its final part, where the current-carrying core polymer
layers are sufficiently hardened, becomes almost horizon-
tal. The bending and cross-section of the pipe are selected
from the conditions of inadmissibility of touching its in-
ternal surface by polymeric layers of the current-carrying
core with all changes in its cross-section, mass, polymeric
layers thickness and linear displacement speed.
A current-carrying core with polymeric layers must
move in the central part of the vulcanization pipe and can
be considered as a heavy material thread. The angle
between the abscissa axis and the line connecting the be-
ginning and the point with coordinates (x, y), as is known
from mechanics, can be determined from the expression:
H
gx
tg , (1)
where g is the weight of heavy material thread per unit
length and Н is the tension at the lowest point.
Since the manufacture of insulated cable standards
of different cross-sections and at different voltages the
value of g varies, the profile of the sag thread also varies:
21
x
c
у , (2)
where c = H/g is sag constant.
From the equations given, it is clear that the sag con-
stant c should be unchanged to keep the thread profile.
Such profile invariance can be made by adjusting the ten-
sion force H and correspondingly adjusting the motor
shaft of the drive No. 2 (Fig. 1,b), driving the track-type
traction device at a constant technological speed V of the
current-carrying core motion in the vulcanization pipe.
The invariance of the current-carrying core speed is en-
sured by adjusting the torque of the traction motor. These
relationships are the basis for the motion control system
of the current-carrying core inside the vulcanization pipe,
which bend is determined from the sagging equations of
the current-carrying core as a material heavy thread.
ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2 49
Electric drive No. 2
of track-type device
380 V, 50 Hz
380 V, 50 Hz
v = 0.3-50 m/min
Feeding device
Power
supply cable
Receiving device
Track-type
device
R=1,5 m
380 V, 50 Hz
R=1,5 m
Gear unit 1
speed ratio
i=233.7
Electric drive No. 1
of feeding device Gear unit 2
speed ratio i=233.7
Electric drive No. 3
of receiving device
а
b
Fig. 1. Inclined extrusion line of applying and vulcanizing a polyethylene insulation layer and two semiconductive layers
on current-carrying core of high and ultrahigh voltage cables, a – photo of PJSC «Yuzhcable Works» and b – its block diagram
Problem statement and the development of math-
ematical model of electromechanical system. The elec-
tromechanical system is studied. It is schematically shown
in Fig. 1,b and contains three electric drives, based on
asynchronous motors with vector control.
Drives No. 1 and No. 3 set in motion the cylinder of
the deeding and receiving devices and ensure the cable
motion at a constant speed V set by the technological con-
ditions. Drive No. 2 sets in motion the track-type traction
device and provides the required cable tension H when it
moves inside the vulcanization pipe. All drives are built
based on direct control of the torque and flow of an asyn-
chronous motor (DTC method), described in [1, 3, 9].
In this paper, as in [7], a mathematical model was de-
veloped using the Matlab / Simulink software package [8]
to study the electromagnetic processes in electromechanical
system shown in Fig. 1. This system model with two elec-
tric drives with vector control is shown in Fig. 2.
Set torque
Set speed
Electric drive No. 2 of track-type device
Electric drive No. 3
of receiving device
Short-term
switched load
Fig. 2. Mathematical model of a system with two electric drives with vector control
50 ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2
In this model, the effect of two drives No. 1 and
No. 3, providing a set speed of the cable motion, is re-
placed by the equivalent action of one drive, so a system
consisting of two drives is considered in the modeling.
The model has a drive’s receiving device, providing a set
speed of shaft rotation of the asynchronous motor, and,
consequently, a set speed of cable pulling. Also, there is a
drive of the track-type device No. 2, which creates a set
torque on the motor shaft, and, consequently, a set tension
of the cable. Both drives are connected to a three-phase
power supply. To model a short-term voltage failure
mode, an additional active three-phase load is connected
to this source with a key. To visualize the calculation re-
sults, the blocks of virtual oscilloscopes Display of the
Simulink package are used, the inputs of which are con-
nected to the corresponding communication lines.
Each of the two drive units, as in [7], model the elec-
tric drive operation based on an induction motor with vec-
tor control. This model contains an uncontrolled three-
phase rectifier, a three-phase inverter with pulse-width
modulated current (PWM), an asynchronous motor, a
speed controller and an inverter control unit. In order to
avoid overvoltage at the rectifier output when the motor is
switched on in the electric power generation mode, a spe-
cial chopper block is located between the rectifier and the
inverter, which provides the connection of a resistor
shunting the storage capacitance when the voltage across
the set value exceeds it. The block diagram of the drive
realized by the DTC method is given in [2, 3, 8].
The asynchronous machine model is used and con-
sisted of an electrical part represented by a fourth-order
state space model and a mechanical part model in the
form of a second-order system. All electric variables and
machine parameters were driven to the stator.
The initial equations of the electrical part of the ma-
chine are recorded for a two-phase coordinate system (the
d-q axis) and have the form:
dsqsqssqs dt
d
iRV , (3)
qsdsdssds dt
d
iRV , (4)
drrqrqrrqr dt
d
iRV , (5)
qrrdrdrrdr dt
d
iRV , (6)
dsqsdsdse iiT 5,1 , (7)
where: qrmqssqs iLiL , drmqssds iLiL , (8, 9)
qsmqrrqr iLiL , dsmdrrdr iLiL , (10, 11)
mlss LLL , mlrr LLL . (12, 13)
The mechanical part of the machine was described
by two equations:
me TFT
Jdt
d
1
,
dt
d
. (14, 15)
The following symbols are used in the equations: Rs,
Lls and R'r, Llr are the resistance and inductance of stator
and rotor scattering; Lm is the inductance of the magnetiz-
ing circuit; Ls, L'r are the total inductances of the stator
and rotor; Vqs, iqs and V 'qr, i'qr are the projections of the
stator and rotor stresses and currents on the q axis; Vds, ids
and V 'dr, i'dr are the projections of the stator and rotor
voltages and currents on the d axis; φds, φqs and φ'dr, φ'qr,
are the projections of the stator and rotor flux linkages on
the d and q axes; is the angular velocity of the rotor;
θ is the angular velocity of the rotor; J is the rotor inertia
torque; Te is the motor electromagnetic torque; Tm is the
static load moment; F is the friction coefficient.
This mathematical model has become the basis for the
one developed in the Simulink and for the virtual model of
the asynchronous machine used in this paper. A number of
parameters were calculated from the machine's passport data
on the basis of the method described in [6]. At that, the asyn-
chronous motor RA160MA4 (11 kW, 1460 rpm) was used in
the drive’s receiving device, and RA132S2 (5.5 kW,
1455 rpm) was used in the drive of the tracked chassis.
The analysis of modeling results. Fig. 3 shows the
timing diagrams of the main characteristics of the drive’s
receiving device for the studied time period – 2 s, corre-
sponding to the start-up mode. The diagrams are in good
agreement with the results given in [7]. The Fig. 3 shows
the time-dependent current of the stator motor winding,
the rotor speed, the electromagnetic torque on the motor
shaft, and the reference voltage at the inverter input con-
sidering stable parameters of the supply network or net-
work with infinitely large power.
Based on the modeling results, it can be noted that
the current in the stator of the receiving device's motor
changes in amplitude and frequency during start-up, and
at the initial area the frequency is low and gradually in-
creases as the motor accelerates. It is this trigger mode
that is characterized by low energy consumption. The
motor is monotonously accelerated to a set speed of
1200 rpm for a time equal to 1.35 s and then accurately
reproduces this predetermined rotation frequency in the
subsequent time interval.
At the next stage of the research, dynamic processes in
the drives were modeled with a short-time increase during
0.4 s of the supply voltage from an amplitude value of 380
V to various values up to 500 V. Such a mode was modeled
by connecting the drive to an additional voltage source of
increased amplitude in a time point of 1.4 s (after reaching
the steady state). The results of calculating these processes
for the drive’s receiving device are shown in Fig. 4.
Based on calculation results it follows that, although
the inverter input voltage increases from 580 V to 800 V,
rotor speed does not change. That is, the studied system of
the two drives is stable to short-time increases in the input
voltage in the wide range.
At the next stage, dynamic processes in the drives
were modeled for a short-time (0.4 s) network voltage
failure from the amplitude value u0 to the value u0 – Δu,
with Δu/u0 = 0.54. This mode was modeled by connecting
to a power supply with a limited power of an additional
three-phase load.
The calculating results of these processes for the
drive’s receiving device are shown in Fig. 5 for the phase
voltage and in Fig. 6 for the stator current, the rotor speed,
the electromagnetic torque and the inverter input voltage.
ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2 51
Time, s
Electromagnetic torque, Nm
Rotor speed, rpm
Stator current, А
Inverter input voltage, V
Fig. 3. Timing diagrams of the main characteristics of the drive’s receiving device for a period of time corresponding to the start-up
mode
Stator current, А
Rotor speed, rpm
Electromagnetic torque, Nm
Inverter input voltage, V
Time, s
Fig. 4. Dynamic processes in the drive’s receiving device at a short-term increase in the supply voltage
Time, s
Phase voltage, V
Fig. 5. Dependence of the phase voltage network on time
Fig. 6 shows that the voltage failure (time interval
1.4 – 1.8 s) at the inverter input decreases, current level
in the stator motor winding decreases, but vector con-
trol system increases the electromagnetic torque in or-
der to work at the set speed. It can be seen that with
this voltage failure, the electromechanical system, de-
spite the torque increase, cannot work at the set rotor
speed, which decreases at the end of this time interval
by an amount Δn ≈ 430 rpm.
In order to obtain a quantitative dependence of the
relative decrease in the rotor speed Δn/n0 on the rela-
tive decrease in the network voltage Δu/u0, calculations
were carried out for different values of the load addi-
tionally connected to the network. These dependences
are shown in Fig. 7.
52 ISSN 2074-272X. Електротехніка і Електромеханіка. 2018. №2
Rotor speed, rpm
Electromagnetic torque, Nm
Inverter input voltage, V
Δn/n0 = 0.27
Stator current, А
Time, s
Fig. 6. Dynamic processes in the drive’s receiving device at a short-term failure of the supply voltage
0 20 40 60 80 100
0
10
20
30
40
50
%00/ 0nn
n = const
at
Δu /u0 < 27% n = var
at
Δu /u0 > 27%
Δu/u0 · 100%
Δn/n0 · 100%
Fig. 7. Dependence of the relative decrease in the rotor speed
Δn/n0 of the electromechancal system on the relative decrease in
the network voltage Δu/u0
As can be seen from this figure, there is a threshold
value for the voltage failure Δu/u0100 % = 27 %, below
which the drive ensures stabilization of the set speed with
high accuracy. When this value is exceeded, the relative
rotor speed Δn/n0 increases, that is, the drive does not
provide stabilization of the set speed. The obtained data
on the threshold value of the voltage failure allow us to
formulate the requirements for the parameters of power
supply systems, taking into account their possible connec-
tion to additional power loads.
Conclusions.
1. A mathematical model has been developed to study
the dynamic processes in the electromechanical system
used in the production line for the extrusion coating of
polyethylene insulation and semiconductive polymer lay-
ers on the current-carrying core of ultrahigh-voltage ca-
bles. The investigated system includes electric drives on
the basis of frequency-controlled asynchronous motors
and their load - moving current-carrying core with neces-
sary speed and tension.
2. The coordination of electrical and mechanical pa-
rameters of the system is carried out and the analysis of
its dynamic processes is made. It is determined that with a
critical mass of the current-carrying core, the electrome-
chanical system allows stabilizing the current-carrying
core speed with the necessary accuracy at short-time fail-
ures in the supply voltage of no more than 27 % of its
amplitude value. This is one of the basic requirements for
the parameters of power supply systems, taking into ac-
count their possible connection to additional power loads.
3. It is also shown that this system is stable to a short-
term voltage increase for 0.2 s from a value of 380 V to
500 V.
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Received 15.11.2017
V.M. Zolotaryov1, Doctor of Technical Science,
M.A. Shcherba2, Candidate of Technical Science,
R.V. Belyanin1,
R.P. Mygushchenko3, Doctor of Technical Science,
I.M. Korzhov3,
1 Private Joint-stock company Yuzhcable works,
7, Avtogennaya Str., Kharkiv, 61099, Ukraine,
phone +380 57 7545228, e-mail: zavod@yuzhcable.com.ua
2 The Institute of Electrodynamics of the NAS of Ukraine,
56, prospekt Peremogy, Kiev-57, 03680, Ukraine,
phone +380 44 3662460, e-mail: m.shcherba@gmail.com
3 National Technical University «Kharkiv Polytechnic Institute»,
2, Kyrpychova Str., Kharkiv, 61002, Ukraine,
phone +380 57 7076116, e-mail: mrp1@ukr.net
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