Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front
There are presented the characteristics of two versions of Rogowski coils with single- or multi-layer coil wound
 with a screened wire and with the toroidal core made of metal. Приведено характеристики двох варіантів поясів Роговського c одно- або багатошаровою котушкою,
 намотаною е...
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| Date: | 2004 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2004
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| Cite this: | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front / A.I. Gerasimov // Вопросы атомной науки и техники. — 2004. — № 2. — С.18-20. — Бібліогр.: 10 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860198752277495808 |
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| author | Gerasimov, A.I. |
| author_facet | Gerasimov, A.I. |
| citation_txt | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front / A.I. Gerasimov // Вопросы атомной науки и техники. — 2004. — № 2. — С.18-20. — Бібліогр.: 10 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | There are presented the characteristics of two versions of Rogowski coils with single- or multi-layer coil wound
with a screened wire and with the toroidal core made of metal.
Приведено характеристики двох варіантів поясів Роговського c одно- або багатошаровою котушкою,
намотаною екранованим проводом, і з тороїдальним осердям з металу.
Приведены характеристики двух вариантов поясов Роговского c одно- или многослойной катушкой, намотанной экранированным проводом, и с тороидальным сердечником из металла.
|
| first_indexed | 2025-12-07T18:09:57Z |
| format | Article |
| fulltext |
NOISE-RESISTANT AND MECHANICALLY STRONG ROGOWSKI
COILS USED TO MEASURE PARAMETERS OF HIGH-CURRENT PULS-
ES WITH NANOSECOND FRONT
A.I.Gerasimov
All-Russia Scientific Research Institute of Experimental Physics
Pr. Mira, 37, Nizhni Novgorod region, Sarov, 607188, RUSSIA
E-mail: gerasimov@expd.vniief.ru
There are presented the characteristics of two versions of Rogowski coils with single- or multi-layer coil wound
with a screened wire and with the toroidal core made of metal.
PACS: 29.27.-a
As a rule, in high-power electrophysical facilities it
is required to measure parameters of pulsed currents
(pulse shape, current amplitude, length of a pulse, front
and trailing edge) from several kA up to several MA
and with duration from units of ns to ms. As primary
sensors the induction sensors (IS) are used most fre-
quently. IS are installed in the annular slots of reverse
hollow tube current guides so that they do not overhang
the limits of the inner surface of current guides and do
not decrease here the electric strength between coaxial
conductors. This also protects sensors from electrical
breakdown on them from high-voltage inner conductor,
and, thus, protects the desired signal from interference.
However, when measuring currents I of hundreds of
kA the drop of voltage Ln dI/dt on the slot inductance Ln
approaches the value of ~100 kV and higher [1] what
can initiate a breakdown on IS, form the way for flow-
ing of a part of reverse high current through IS and dis-
tort the signal. Thus, at high currents I slots are made
with minimal Ln, and sensors - with the smallest cross-
section that diminishes their mechanical strength. It
should be noted that in the course of operation together
with common mechanical loads sensors are affected by
pressure from the magnetic field p=H2/8π equaling, for
example, ~1 MPa at I = 1 MA.
As a rule, the IS rigidity is formed by its core,
polysterene or plexiglass, most frequently used as cores,
are fragile materials that leads to a number of problems
(at small cross-section of cores), especially those of
large diameter (>500 mm). A framework made of thin
sheet polyethylene is not firm enough, and, what is im-
portant, it “leaks” under mechanical loading.
Below presented are the data on two variants of in-
terference-resistant and mechanically strong modernized
Rogowski coils (RC) developed for measurement of
currents of 10...2000 kA amplitude and 10...100 ns du-
ration. They possess the small cross-section and, thus,
are placed in narrow and shallow ring slots, operate in a
self-integrating mode as the most interference resistant
and most precisely transmitting the form of the mea-
sured current pulse, possess autonomous shields allow-
ing to calibrate independently RC in the amplitude sen-
sitivity and transient characteristic. Besides, the shield
decreases capacitive couplings of RC with other con-
ductors.
To measure the currents, it is expedient to wind the
Rogowski coils with a pitch between turns [2]. Howev-
er, at the outer diameter of RC >300 mm and small
cross-section of dielectric toroidal core it possesses a
small rigidity and strength. In the course of RC opera-
tion this can lead to a change of the pitch, and therefore
to local changes of coil characteristic resistance ρ with
regard to the shield which is its reverse current guide.
Inhomogeneous ρ can excite parasitic high-frequency
oscillations in the shield cavity; adding to the main sig-
nal, they will distort it [3]. That is why there was devel-
oped an original RC where the change of winding pitch
did not affect the value ρ [4].
On toroidal frame 1 made of dielectric (Fig.1,a) a
coil is wound by coaxial cable 2; each turn of the outer
conductor 3 (braiding) is implemented with break 4 over
the surface of solid cable dielectric 6. Outer conductor 3
serves as a shield for inner conductor 5.
All adjacent shields are subsequently electrically
connected with each other without closing any break 4.
Such a connector is annular conductor 7, soldered, for
example, only to the beginnings (Fig.1,b) or only to the
ends of all braiding turns (more than two conductors 7
can be used).The beginning of the first turn of conductor
5 is connected directly along the face of dielectric 6 by
conductor 8 with beginning of its shield 3. The end of
conductor 5 of the last turn is connected with load resis-
tor 9 placed in electrode 10 which is coaxial to it and
connected to the end of the shield of the last turn. A sig-
nal from resistor 9 is transmitted by cable 11 to
recorder. Fig.1,c shows a variant of resistor connection.
Here conductor 5 is put through the central hole in the
in the isolating resistor case [5].
Thus, in RC toroidal coil conductor 5 and coaxial to
it outer braiding 3, forming a shield of a number (ac-
cording to the number of coil turns) of sections connect-
ed in parallel, are fixed through solid insulation over the
whole coil length (except breaks 4), adjacent turns of
conductor 5 are almost completely shielded from each
other. Therefore, when producing or operating RC, local
changes of winding pitch and deformation of core 1 do
not affect the value of coil characteristic resistance ρ
that remains constant over its whole length. This togeth-
er with absence of the common hollow shield do not
____________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.18-20. 18
mailto:gerasimov@expd.vniief.ru
Fig.1. Device of RC with a coaxial cable coil (a), sweep
of coil turns and their shields (b) and a variant of load
resistor connection (c). Dashed lines - shields (braid-
ing) of turns
Fig.2. Signals from RC at measurement of current with
510 kA amplitude of the first half-wave.
Marks – 100 MHz
provide conditions for excitation of parasitic electric os-
cillations and raises the accuracy of measurements of
amplitude and time parameters of pulse current. Casual
presence of liquid media with different values of dielec-
tric and magnetic constants in RC, submersion of RC
(partial or complete) in such media also does not change
its electric characteristics.
Coaxial property of conductors 3 and 5 significantly
lowers interference from constituent of magnetic flux of
measured current which is parallel to the central axis of
the coils. Each section of the braiding 3 can have its
own outer insulation (it is not presented in fig.1) as well
as the whole coil can be fully covered by film or other
insulation. The absence of the common bulky RC shield
decreases the dimensions of the coils and the drop of
voltage on the inductance of annular slot in the reverse
current guide, what decreases a probability of break-
down to the coil in this place. The coils can be made as
a multilayer one, for there is no capacitive coupling be-
tween adjacent layers. This allows enlargement of elec-
tric length (delay time) of the coils and its inductance
(time constant), as well as sectionalizing of the coil in
order to determine the current position.
There were produced and employed RC of the type
described with a diameter of pass-through hole from
100 to 1700 mm meant for currents registering up to
1600 kA, with front and duration over the base equal-
ing, correspondingly, ≥3 and 20…80 ns. Shielded con-
ductors with polytetrafluorethylene insulation turned out
to be convenient for coils, for example, a conductor
MГТФЭ - 0.12 TУ16 - 505.185 - 71 with 1.5 mm outer
diameter over the braiding and inner conductor diameter
~0.5 mm. The width of break in each braiding turn was
~1 mm what was sufficient for electric strength between
the end and beginning of turns of adjacent shields. For
the typical turn length ~50 mm the interturn capacitance
of inner conductors is reduced by ~50 times as com-
pared to capacitance of common RC.
Outside the coil was wound by several layers of
polyethylene film. Resistors OMЛT, C2-10-2 or УНУ-
Ш, were employed, moreover, according to fig.1,b the
wire leads were removed and holes were drilled over the
cap faces [5].Several RC were implemented with two-
and three-layer as well as four-section coils; breaks in
the layers braids were located one in front of each other.
Coils of the diameter >300 mm were certified by rise
time τ using coils as distributed energy storages, prelim-
inary charged up to 1 kV and switched on the coils load by
a miniature spark gap with solid insulation [6]; as a rule,
τ was equal to the value <1 ns. RC sensitivity was deter-
mined experimentally and usually was 10-2...10-3 V/A.
Fig.2 shows a form of a signal from one of RC with
a frame outer diameter equaling 1180 mm.
Further analysis has shown that when measuring
currents of duration <100 ns one can decrease the core
cross-section and, thus, the total RC cross-section ac-
companied by a simultaneous rise of mechanical
strength through implementation of the core of metal [7].
The influence of short-circuit loop in the cross-sec-
tion of such a core is insufficient at measurement of cur-
rent of tens nanoseconds duration and shorter. The mag-
netic field formed by measured current is centered near
the core surface due to the effect of extrusion of mag-
netic flux from the area of closed turn circuit.
Fig.3 presents RC device [8]. On toroidal core 1 made
of alloy D16 the coil 2 is wound with MГTФ - 0.12 con-
ductor. Resistor 3 of УHУ - Ш type with resistive layers
on face surfaces and with metallized outer 4 and inner 5
cylindrical surfaces is tightly put into the core hole. The
end 6 of the coil conductor is soldered to lead 5 and its
second lead 7 is connected to the core near the hole. In
order to fix turns there are slots 8 in the core.
The signal from resistor 3 is transmitted along the
cable (it is not shown in fig.3), whose central conductor
enters lead 5 as a socket, and the braiding is connected
to the core of resistor. On the cross-section A-A is also
given a variant of RC with resistor of C2-10-2 type in-
sulated with bush 9; wire lead 10 is connected to core 2.
In fig.3,a the largest side of rectangular cross-section of
core 1 is parallel to the common axis of device with
measured current. At 0.5 mm thickness of insulation be-
tween the conductor and the core a decrease of ampli-
tude of signal on the RC output is ~10% and can be
compensated by increase of load resistor rating. The use
of the core as a reverse Rogowski coils current guide
turns out to be convenient. Together with Rogowski
coils this current guide forms a line with distributed pa-
rameters, i.e. the core serves as an external shield. That
is why the external shield may be not applied in the
event that the total RC cross-section as well as dimen-
sions of annular slot in the conductor are to be reduced
what means to reduce thickness of wall of this conduc-
tor and its outer diameter. Moreover, the shield is not
necessary, provided that the electric breakdown to the
coil from the central conductor with measured current is
absent, there would be no breakdown to the coil from
the walls of the slot as well as charged beam particles
____________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.18-20.19
would not come to the coil. In common cases a shield
for RC is preferable. The shield allows one to calibrate
RC outside the working device and then install RC into
the slot without change of RC characteristics. One may
adjoin the shield to the conductor with a slot at one
point, and more expedient - to the place of load resistor
connection to the core.
Fig.3. RC circuit with metal core. a - variant of washer
resistor location in the hole of rectangular core when
its largest side is parallel to the common axis of the de-
vice with measured current
The rise time τ of transfer characteristic of RC with
diameters > 300 mm was determined experimentally, as
it was described above. The value τ depends greatly on
inductance of resistor and a method of connection of a
signal transmitting cable to it; in RC data inductance is
minimal. That is why, as a rule, τ ~ 1 ns. The constant
of time of integration of RC is > 1 μs. Sensitivity of RC
is 10-2 -10-3 V/A.
The majority of the used RC have external shields
with azimuthal gap, electrically connected to the core
near the load resistor. The shield additionally reduces
the wave resistance ρ of the coil. However, the influ-
ence of ρ on the amplitude of voltage U of signal on re-
sistor R<<ρ is small in the self-integrating mode [9]:
U ≈ IRρ[w(R+ρ)]-1 ,
where I - measured current, w - a number of coil turns.
Several sensors were made with coils cable winding, as
well as with sectionalized coils to control the position of
electron beam current.
Fig.4 presents the oscillograms of signals from RC.
Employment of RC with metal coils facilitates their
production, especially, at diameters >500 mm, increases
mechanical strength of RC, reduces cross-section and
outer dimensions, increases the precision of measure-
ments and stability of RC electrical characteristics.
RC of both types were applied both in the self- inte-
grating mode and in the differentiating mode, at produc-
tion, experimental study and test of units of high-power
linear induction electron accelerator LIA-30 (40 MeV,
100 kA, 25 ns) with water-insulated radial lines in in-
ductors [10].
Fig.4. Calibration current pulse (a) and corresponding
signal from RC (b) possessing a core with 1200 mm
outer diameter and 3⋅16 mm2 cross-section made of alu-
minium alloy as well as a signal from RC when measur-
ing current with the first half-wave amplitude of 590 kA
(c). Marks - 100 MHz
REFERENCES
1. S.A.Ekdahl // RSI. 1980, v.51, №12, p.1649-1651.
2. D.G.Pellinen, M.S.Di Capua, S.E.Sampayan et al.
// RSI.1980, v.51, №11, p.1535-1540.
3. J.M.Anderson // RSI. 1971, v.42, №7, p.915-926.
4. A.I.Gerasimov, E.G.Dubinov // Prib. Tekh. Eksp.
1988, №3, p.93-95 (in Russian).
5. A.I.Gerasimov, E.G.Dubinov // Prib. Tekh. Eksp.
1983. №3. p.110-112(in Russian).
6. A.I.Gerasimov, E.G.Dubinov // Prib. Tekh. Ek-
sp.1983, №2, p.139-141 (in Russian).
7. A.I.Gerasimov Inventor’s Certificate № 1213854 //
Byull. Izobret., 1986, №46, p.284 (in Russian).
8. A.I.Gerasimov // Prib. Tekh. Eksp. 1991, №1,
p.150-152 (in Russian).
9. V.Nassisi, A.Luches // RSI. 1979, v.50, №7, p.900-
902.
10.A.I.Pavlovski, V.S Bossamykin, A.I.Gerasimov et
al. // Prib. Tekh. Eksp.1986, №2, p.13-25.
ПОМЕХОУСТОЙЧИВЫЕ И МЕХАНИЧЕСКИ ПРОЧНЫЕ ПОЯСА РОГОВСКОГО ДЛЯ ИЗМЕРЕ-
НИЯ ПАРАМЕТРОВ СИЛЬНОТОЧНЫХ ИМПУЛЬСОВ С НАНОСЕКУНДНЫМ ФРОНТОМ
А.И. Герасимов
Приведены характеристики двух вариантов поясов Роговского c одно- или многослойной катушкой, на-
мотанной экранированным проводом, и с тороидальным сердечником из металла.
ПЕРЕШКОДОСТІЙКІ І МЕХАНІЧНО МІЦНІ ПОЯСИ РОГОВСЬКОГО ДЛЯ ВИМІРУ
ПАРАМЕТРІВ ПОТУЖНОСТРУМОВИХ ІМПУЛЬСІВ З НАНОСЕКУНДНИМ ФРОНТОМ
А.І. Герасимов
Приведено характеристики двох варіантів поясів Роговського c одно- або багатошаровою котушкою,
намотаною екранованим проводом, і з тороїдальним осердям з металу.
20
A.I.Gerasimov
All-Russia Scientific Research Institute of Experimental Physics
Pr. Mira, 37, Nizhni Novgorod region, Sarov, 607188, RUSSIA
REFERENCES
А.И. Герасимов
А.І. Герасимов
|
| id | nasplib_isofts_kiev_ua-123456789-79317 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T18:09:57Z |
| publishDate | 2004 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Gerasimov, A.I. 2015-03-31T08:40:26Z 2015-03-31T08:40:26Z 2004 Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front / A.I. Gerasimov // Вопросы атомной науки и техники. — 2004. — № 2. — С.18-20. — Бібліогр.: 10 назв. — англ. 1562-6016 PACS: 29.27.-a https://nasplib.isofts.kiev.ua/handle/123456789/79317 There are presented the characteristics of two versions of Rogowski coils with single- or multi-layer coil wound
 with a screened wire and with the toroidal core made of metal. Приведено характеристики двох варіантів поясів Роговського c одно- або багатошаровою котушкою,
 намотаною екранованим проводом, і з тороїдальним осердям з металу. Приведены характеристики двух вариантов поясов Роговского c одно- или многослойной катушкой, намотанной экранированным проводом, и с тороидальным сердечником из металла. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Сильноточные импульсные ускорители Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front Перешкодостійкі і механічно міцні пояси Роговського для виміру параметрів потужнострумових імпульсів з наносекундним фронтом Помехоустойчивые и механически прочные пояса Роговского для измерения параметров сильноточных импульсов с наносекундным фронтом Article published earlier |
| spellingShingle | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front Gerasimov, A.I. Сильноточные импульсные ускорители |
| title | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| title_alt | Перешкодостійкі і механічно міцні пояси Роговського для виміру параметрів потужнострумових імпульсів з наносекундним фронтом Помехоустойчивые и механически прочные пояса Роговского для измерения параметров сильноточных импульсов с наносекундным фронтом |
| title_full | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| title_fullStr | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| title_full_unstemmed | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| title_short | Noise-resistant and mechanically strong Rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| title_sort | noise-resistant and mechanically strong rogowski coils used to measure parameters of high-current pulses with nanosecond front |
| topic | Сильноточные импульсные ускорители |
| topic_facet | Сильноточные импульсные ускорители |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/79317 |
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