SU624302A1

SU624302A1 - Dc electromagnet with boosted excitation

Info

Publication number: SU624302A1
Application number: SU752194372A
Authority: SU
Inventors: Виталий Анатольевич Алфимов; Леонид Фарнаозович Габуния
Original assignee: Научно-Производственное Объединение "Энергия" Главатомэнерго
Priority date: 1975-11-12
Filing date: 1975-11-12
Publication date: 1978-09-15

Description

Изобретение относитс к области электротехники , а именно к мощным электромагнитам посто нного тока, и может быть использовано, в частности, в магнитогидродинами шском генераторе, предназначенном дпп работы в качестве аварийного источника электроэнергии, который должен выходить на режим за малое врем .The invention relates to the field of electrical engineering, namely to powerful electromagnets of direct current, and can be used, in particular, in a magnetohydrodynamic generator of a Shna generator, designed for operation as an emergency source of electrical energy, which should go into operation in a short time.

Известны электромагниты, в которых дл форсировани возбуждени примен етс пускова , обмотка и пусковые сопротивлени , которые после включени электромагнита шунтируютс .Electromagnets are known in which start-up, winding, and start-up impedances are used for boosting the excitation, which are shunted after switching on the electromagnet.

Известен также электромагнит с подвижным .сердечником, в котором форсировка возбуждени обеспечиваетс выполнением обмотки из двух равных секций, включаемых при помоши укрепленных на сердечнике контактов в момент пуска параллельно , а при работе последовательноAlso known is an electromagnet with a movable core, in which the excitation forcing is provided by performing windings from two equal sections, which are switched on by means of contacts fixed at the core at the time of launch, in parallel, and in operation

2 .2

В этом электромагните при форсировкIn this electromagnet when forcing

используетс вс обмотка, поэтому дл all winding is used, so for

его включени требуетс меньша мощность источника, чем при использовании пусковой обмотки.switching it on requires a smaller source power than when using a start winding.

Недостаток такого устройства состоит в том, что при переключении размыкаютс цепи обеих секций, ЭДС самоиндукции на выводах секций достигает значительной величины и возникает дуга на контактах переключающего устройства. Замена контактов переключающего устройства бесконтактными ключами, например тиристорными , не может устранить возникновение ЭДС самоиндукции, которое приводит к пробою ключей.The disadvantage of such a device is that when switching the chains of both sections open, the emf of self-induction at the terminals of the sections reaches a significant value and an arc occurs at the contacts of the switching device. Replacing the contacts of the switching device with contactless keys, such as thyristor ones, cannot eliminate the occurrence of self-induced EMF, which leads to breakdown of the keys.

Целью изобретени вл етс , устранение перенапр жений при переключении секций и упрощение схемы переключени .The aim of the invention is to eliminate overvoltages when switching sections and simplify the switching circuit.

Claims

This is achieved in that the winding sections of the electromagnet are connected in series through diodes, and the switching device keys, for example, thyristor, are connected between the positive terminal and the cathodes of the diodes and between the diodes anodes and the negative terminal of the power supply. The drawing shows a schematic diagram of the described electromagnet. Its winding consists of three identical sections (in principle, the number of sections can be any) 1,2 and .3 interconnected via diodes 4 and 5. The switching device is made on contactless elements, namely on thyristor switches 6-9. The coil of the electromagnet is connected to the power supply 1. O with a key 11. The electromagnet operates as follows. During the start-up period, the thyristor control electrodes are supplied with a control-dt signal (the control signal source is not shown in the drawing). In this case, all the thyristor keys are unlocked, the diodes are closed, and all winding sections are connected in parallel. After the magnetic field reaches the required value, the thyristor switches are locked (the lock circuit is not shown), the diodes are opened, to all sections of the winding are turned on in series. Since the time of opening of the diodes is shorter than the time of closing the keys, switching from parallel connection of sections to a series one occurs without breaking the circuit, and the current in the sections does not change, and consequently, there is no EMF of self-induction. The present invention allows to increase the speed, simplify the control circuits, and increase the reliability of high-power DC electromagnets with forced excitation. Invention Electromagnet of direct current with forced excitation, containing a winding made of P equal sections, a DC power source and a switching device connecting sections either in parallel or in series, characterized in that, in order to eliminate surges at switching sections and simplifying the device, c. it is introduced (AND -1) semiconductor diodes, and the switching device is made on 2 (P-1) keys, for example, thyristor, and the winding sections are connected in series through (AND -1) semiconductor diodes included in the forward direction, and 2 (hl) switching unit switches are on between the positive terminal of the power supply and the cathodes of the diodes and between the diodes of the diodes and the negative terminal of the power supply. Sources of information taken into account during the examination: 1. USSR author's certificate No. 146829, H 01 H 47/06, 1961.

2. German patent number 1845О7, cl. 21 g- 2/01, 1910.

L.I