SU591987A1

SU591987A1 - Method and apparatus for measuring instantaneous current values in a switchable section of commutator-type electric machine

Info

Publication number: SU591987A1
Application number: SU762313462A
Authority: SU
Inventors: Евгений Иванович Буханцов
Original assignee: Предприятие П/Я Г-4847
Priority date: 1976-01-07
Filing date: 1976-01-07
Publication date: 1978-02-05

Description

(54) СПОСОБ ИЗМЕРЕНИЯ МГНОВЕННЫХ ЗНАЧЕНИЙ ТОКОВ(54) METHOD OF MEASURING INSTANT VALUES OF CURRENTS

В КОММУТИРУЕМОЙ СЕКЦИИ КОЛЛЕКТОРНОЙ ЭЛЕКТРИЧЕСКОЙ МАШИНЫ И СТРОЙСТВО ДЛЯ ЕГО ОСУМРСТВЛЕНИЯIN THE COMMUNICATED SECTION OF THE COLLECTOR ELECTRIC MACHINE AND STRUCTURE FOR ITS IMPOSITION

рование может быть осуществлено лишь на машине, специально предназначенной дл испытани . Как правило, така машина не может быть передана в эксплуатацию без восстановительного ремонта.This can only be done on a machine specifically designed for testing. As a rule, such a machine cannot be put into operation without refurbishment.

Целью изобретени вл етс упрощенне способа, заключающеес в упразднении препарировани кор и, как следствие, уменьшении затрат труда и материально-технических средств при испытани х, а также возможность получени осциллограмм коммутации в эксплуатации на любой действующей машине .The aim of the invention is to simplify the method, which consists in eliminating the preparation of the core and, as a result, reducing the labor and material and technical costs of testing, as well as the possibility of obtaining switching waveforms on any operating machine.

Поставленна цель достигаетс тем что между коллекторными пластинами испытуемой электрической машины и резисторами включают разрезную щетку , а полученные на резисторах падени напр жени подают на сумматор.This goal is achieved by the fact that between the collector plates of the tested electric machine and the resistors include a split brush, and the voltage drops obtained with the resistors are applied to the adder.

Устройство дл осуществлени этого способа дл реализации той же цели снабжено разрезной щеткой, предназначенной дл установки в щеткодержатель испытуемой электрической машины, сумматором и зажимом дл соединени с сетью, причем разрезна щетка выполнена в виде пакета механически св занных, но электрически изолированных между собой пластин, ширина которых выбрана меньше межламёльного промежутка коллектора, кажда из этих пластин соединена с заЖимом сети через резисторы, а сумматор включен между резисторами и измерителем тока.An apparatus for carrying out this method for realizing the same purpose is provided with a split brush for insertion into the brush holder of the electric machine under test, an adder and a clip for connecting to the network, the brush being designed as a package of mechanically connected but electrically isolated plates between them, width which selected a smaller collector gap, each of these plates is connected to a clamping network through resistors, and an adder is connected between the resistors and the current meter.

Нр фиг. 1 изображено устройство дл измерений мгновенных значений токов коммутируемой секции; на фиг.2 график палени напр жений на шунтах и их сумма во времени.Hp FIG. 1 shows a device for measuring instantaneous currents of a switched section; Fig. 2 is a graph of the voltage across shunts and their sum over time.

Устройство дл замера мгновенных значений токов.в коммутируемой секции включает разрезную щетку, содержащую пакет механически св занных, но электрически изолированных пластин 1-4, установленных в условно не показанный на фиг. 1 щеткодержатель испытуемой коллекторной машины до соприкосновени с коллектором, пластины 5-7 которого соединены с секци ми 8 и 9 обмотки кор . Ширина казкдой пластины меньше ширины любого межламельного промежутка 10 коллектора. Пластины 1-4 пакета электрически соединены с зажимом 11 внешней цепи через индивидуальные резисторы. 12-15, измерительные выводы 16.которых подключены ко входам 17 сумматора 18, а выход 19 сул 1атора 18 св зан со входными клеммами 20 измерител тока 21 (осциллографом ) .A device for measuring instantaneous currents in a switched section includes a split brush containing a package of mechanically connected but electrically insulated plates 1-4 installed in a conventionally not shown in FIG. 1 is the brush holder of the test collector before contact with the collector, the plates 5-7 of which are connected to sections 8 and 9 of the winding box. The width of the plateau plate is less than the width of any interlaminary gap 10 of the collector. Plate 1-4 package electrically connected to the clip 11 of the external circuit through individual resistors. 12-15, the measuring leads 16. which are connected to the inputs 17 of the adder 18, and the output 19 of the controller 1 is connected to the input terminals 20 of the current meter 21 (with an oscilloscope).

Предложенный способ осуществл етс в следующем пор дке. Если при равномерном вращении кор испытуемой машинц в направлении стрелки 22 прин ть, что плотность тока в пластинах щетки пропорциональна площади их контактировани с коллекторными пластинами 5-7, а также что коммутаци секции 9 начнетс в момент времени,, когда набегающа кромка пластины 1 щетки совпадет с набегающей кромкой коллекторной пластины 5, то по мере увеличени площади контакта между The proposed method is carried out in the following order. If, with a uniform rotation of the test machine's crust in the direction of arrow 22, it is assumed that the current density in the brush plates is proportional to the area of their contact with the collector plates 5-7, and that the switching of section 9 starts at the time point when the incident edge of the brush plate 1 coincides with the incident edge of the collector plate 5, as the contact area between

10 пластиной 1 и коллекторной пластиной 5, падение напр жени на резисторе 12 (пропорциональное току через резистор 12) будет линейно нарастать, как это показано на фиг. 2 кривой 23 до 10 by plate 1 and collector plate 5, the voltage drop across resistor 12 (proportional to the current through resistor 12) will linearly increase, as shown in FIG. 2 curve 23 to

5 момента времени t , когда с набегающей кромкой коллекторной пластины 5 совпадет сбегающа кромка пластины 1 щетки. С момента времени 1 ток пластины 1 и падение напр жени на резис0 торе 12 остаютс посто нными, так как несмотр на перемещение пластины 5, площадь контакта между ней и пластиной 1 остаетс посто нной до момента времени t когда набегающа кромка 5 of the time t, when the incident edge of the brush plate 1 coincides with the incident edge of the collector plate 5. From the moment of time 1, the current of plate 1 and the voltage drop across the resistor 12 remain constant, since despite the movement of the plate 5, the contact area between it and plate 1 remains constant until time t when the ramp

5 пластины 1 совпадет со сбегающей кромкой коллекторной пластины 5. С момента времени t падение напр жени на резисторе 12 линейно уменьшаетс и становитс равным нулю в момент времени tg , так как пластина в Этот мо0 мент перекрывает межламельный промежуток , следующий за коллекторной пластиной 5, и ток в резисторе 12, как и в момент времени tj , равен нулю..5 plate 1 coincides with the running edge of the collector plate 5. From time t, the voltage drop across resistor 12 decreases linearly and becomes equal to zero at time tg, since the plate at This moment covers the interlaminar gap following the collector plate 5, and the current in the resistor 12, as in the moment of time tj, is zero ..

Падени напр жени на резисторах 13 и 14 с моментов времени, соответствующих началу контактировани пластин 2 и 3 щетки с коллекторной пластиной 5, представлены кривыми 24 и 25, сдвинутыми от кривой 23, соответственно на врем tj-t,,tj-tj .. Кривые 24-26 можно рассматривать также как кривые токов в резисторах 12-14 или пластинах 1-3.The voltage drops across resistors 13 and 14 with time points corresponding to the beginning of the contact of the plates 2 and 3 brushes with the collector plate 5 are represented by curves 24 and 25 shifted from curve 23, respectively, for the time tj-t ,, tj-tj .. Curves 24-26 can also be viewed as current curves in resistors 12-14 or plates 1-3.

Claims

By the time t, the plate pack 1-4 contacts only with the collector plate 6, in connection with which the currents of sections 8 and 9 are equal to the current of the parallel branch tq, but have different directions (sections B and 9 belong to different parallel branches of the machine). From the time td, the plate pack 1-4 contacts only with the collector plate 5, in connection with which the currents of sections 8 and 9 are also equal to the current of the parallel branch tq, but have the same direction (sections 8 and 9 belong to the same parallel branch of the machine). Thus, during the time, the current of section 9 was changed to a value of 2 id. on the other hand, at any point in time from tj to t, the instantaneous value of the current of section 9 is equal to the difference between the current of the parallel branch to which section 9 belonged to the point in time t. , and the current of the collector plate 5, which in time from tj to C is equal to the instantaneous value of current in plate 1, at times from 1c to Ij is the instantaneous value of currents in plates 1 and 2, at times from tj to .i. - the sum of the instantaneous values of the currents in the plates 1,2 and 3, i.e. the sum of the instantaneous values of the currents of the brush plates that at the time in question are in contact with the collector titanium. . Thus, by summing the instantaneous values of the currents (see curves 23, 24, 25) using an integrator type 18 or digital computer and an oscillograph sum, it is possible to measure the instantaneous values of currents in the switched section 9, which is shown by curve 26 (FIG. 2). As can be seen from this particular example, with the brush package width equal to the collector division, to obtain an oscillogram of current 1 of the commutated section 9, it is enough to sum up over time t. tj currents are only plates 1-3, since even before the beginning of the contact of plate 4 with the collector plate 5 by the time t. the current in section 9 was reversed by itself. It is easy to show that with other, large brush overlap, to obtain an oscillogram of the current in the section, it may be necessary to sum up the currents of all the brush plates. . : - If necessary, brush holders can be equipped with brushes of a different polarity of the tested machine. ;.: .., The use of the proposed method of measuring the instantaneous values of the currents of the switched section of the collector of electrical equipment and the device for its implementation provides in comparison with the existing following advantages; the elimination of core preparation and the rejection of the time and material and technical resources associated with it; the possibility of a deputy "r-V instantaneous values of the currents of the switched section in the operation of virtually any of the collector electric machines; the possibility of measuring the instantaneous values of the currents of any of the switched sections, and if necessary, successively all sections of the core. Claim 1. The method of measuring the instantaneous values of currents in the switched section of the collector electric machine by measuring the voltage drop across the resistor, included in the circuit of the measured current, different in that. That, in order to simplify the method, between the collector plates of the electric machine under test and the resistors include a split brush, and the resulting voltage drop across the resistors is fed to an adder2, a device for carrying out the method of claim 1, comprising resistors and a current meter connected to the resistors, about tl and h and y s it. in that it is equipped with a split brush designed to be installed in the brush coder of the electric machine under test with an adder and a clip for connecting to the network, moreover, the brush is made in the form of a package of mechanically connected but electrically insulated plates with a width smaller than of the interlaminary gap of the collector, X1 of these plates is connected to the terminal of the network through resistors, and the adder is connected between the resistors and the current meter. Sources of information taken into account in the examination: 1. Author's certificate of the USSR 63869, cl. 21 d «- 32, 1941.

2.K.Shenfe K.I. Dynamo tires and DC motors, ONTI, 1937, p. 145-146.

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