DE2612976A1 - DC MACHINE - Google Patents

Description

Priority: March 26, 1975, USSR, IJr. 2 113 207

The present invention relates to the Elektroraa ~ schinenbciu »especially on DC machines !! loit IJilfspolen, the bsi olektrißcben power plants in Met & llurgio, HascMnenbau and other industries where the be ~ The constant flow machines drove through heavy loads identify shocks or a pulsation of the current in the armature circle, by feeding the DC machines from sources rectified voltage is conditional <

DC machines are known which contain auxiliary poles with an excitation winding and a reinforcement winding to compensate for a magnetic flux generated by eddy currents of the magnetic conductor of the auxiliary poles in the effective area of the magnetic turning field (commutation zone) when the load current changes dynamically. The magnetic field of the auxiliary poles is built up in the commutation zone by the excitation winding of the auxiliary poles, which is in series with the load circuit. The magnetic field of the auxiliary poles is induced in the turns of the armature winding, which are switched from one parallel winding branch to the other

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cLeii and eich are in elne-a closed state due to a burst ©, one EiIm, which accelerates the change process in the development of the armature winding. In unfavorable conditions, the mentioned switching {commutation) of the windings can be accompanied by a burst of fire, which can result in damage to the brush contact surfaces and the surface of the direct current machine .

In steady-state operating conditions of the DC machine the optimal or spark-free commutation is achieved by setting the magnetic field strength in the communication system. In the case of long-term changes in the load, the Conditions for the optimal setting not disturbed.

Bsi dynamic change of the load current in the magnetic conductor The auxiliary poles induce eddy currents in the area of action build up its own magnetic field of the magnetic ΐ / end field, when it acts, the conditions for optimal commutation are disrupted y / earth.

When setting the Jöelastungsstrom the conditions for the optimal commutation v / restored, at the moment a rapid transition process can, however a brief, intense brush fire occurs. With the pulsation of the current of the circle of circles, the brush fire can be constant to be observed. The strength of the brush fire can be below the mentioned conditions the production possibilities of a mechanism powered by the DC machines, and it is extreme under any circumstances undesirable, as this leads to the accelerated disruption of the gliding Brush contact leads and strong radio interference when receiving

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caused.

To reduce the magnetic field strength of the eddy currents in the event of dynamic changes in the load current, the area of action of the magnetic turning field largely a complete Cleavage of the magnetic field of the auxiliary poles applied. Here, the specific electrical equivalent resistance grows on, and thereby become both the value of the eddy currents and their harmful influence in the area of action of the magnetic turning field is reduced. For many constructions of the magnetic conductor but the auxiliary pole does not always permit its complete splitting, the level of the eddy currents in this one depending on the conditions a satisfactory commutation allowable value, and in a number of cases it is inexpedient for economic and other reasons.

It is also known a DC machine in which the Compensation of the magnetic field of the eddy currents in the commutation zone by forcing the excitation of the auxiliary poles under Ver-r Turning an additional amplifying excitation winding is achieved, which is in series with the secondary winding of a transformer is switched whose primary winding is in the armature circuit of the machine in such a way that the secondary winding of the transformer the voltage is opposite, which is caused by changing the magnetic commutation flux in the booster winding is induced, and above this (see DT-PS 1 240 170, published 1970). The reinforcement conditions are characterized in that by appropriate choice of ohmic Resistance and inductance of the series circuit of the booster winding and the secondary winding of said transformer the time constant of this circuit of the time constants of the

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Equivalent circuit of the eddy current is equated. Here is in the circuit of the amplification with dynamic change of the load current an additional electromotive Force proportional to the rate of change of the load ^ - * Stromes introduced.

However, this compensation method for the magnetic field of the vortex currents in the Korniraitierungsaone requires that an the DC machine an external accessory the transformer,

is connected. The primary winding of the transformer is connected to the AnIc circuit, which is why the magnetic conductor of the transformer must be designed with a non-magnetic air gap to prevent magnetic saturation of the core as low _f and sur Induzierimg an EMF necessary Grosse in the secondary winding, the dimensions and weight of the transformer to DECS vergrössern.Das weight of such a transformer is usually of the order

of the weight of the DC machine »The arrangement of the transformer outside the DC machine leads further to a. excessive

Copper consumption for the connection lines between the secondary winding the transformer and the auxiliary winding of the auxiliary poles. The connection of the transformer in the armature circuit in addition to smoothing pulsations of the rectified current, it also has negative consequences: with the increase in inductivity of the armature circuit, the speeds of the transition processes decrease, and as a result the starting, braking " - and reversing time of the electric drive, what drives from large ßeversier steel rolling mills is particularly undesirable

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The second negative effect of the inductance of the armature circuit is a dynamic increase in the running frequency of the DC motors when the load is suddenly switched off. It also causes the transformer to be switched on in the armature circuit a reduction in the efficiency of the system of the electric drive due to the power losses in the primary winding of the transformer

The invention is based on the object of creating a direct current machine in which the magnetic field is compensated the eddy currents in the effective area of the magnetic turning field with dynamic change of the load current guaranteed is without the use of external devices.

This object is achieved in that, in the DC machine, the auxiliary poles with an excitation winding of the auxiliary poles and a reinforcement winding to compensate for a magnetic flux generated in the commutation zone by eddy currents of the magnetic conductor of the auxiliary poles when the load current changes dynamically, the reinforcement winding according to the invention is parallel and in the same direction connected to the excitation winding of the auxiliary _{poles U n} ^ throw ohmic resistance at least twice greater than the ohmic resistance of the excitation winding of the auxiliary poles, the gain winding closer to the commutation zone than the excitation winding of the auxiliary poles with a number of turns equal to or greater and an inductance smaller than that of the Excitation winding or further from the commutation zone than the excitation winding with a number of turns equal to or smaller and an inductance greater than that of the excitation winding in the direction

to reduce the non-magnetic air gap of the iron

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paths of those leakage fluxes of the auxiliary poles which the from the Kolmatierung sz one winding lying further away to increase the inductance of this winding.

Said device can be in the form of plates of ferromagnetic Material contained in the non-magnetic air gaps between the cores of the main poles and the auxiliary poles in the arrangement zone the furthest from the communication zone Winding are attached, or in the form of a bead of the auxiliary pole in the Anordnuiigszone the same winding.

The DC machine according to the invention communicates reliably in the event of any type of change in the load current and is subject to the lioBunutierungsbedingungen no restrictions whatsoever on the terms of change of the current in transitional states or on the frequency and amplitude of pulsations of the current when the Machine made of rectifier systems. The DC machine according to the invention has the main poles in the case of separate excitation reliable commutation even when the armature branch is pulsed. The execution of the invention Machine does not increase its dimensions and allows, according to the commutation conditions, to one Refrain from splitting the frame.

The invention is explained below with reference to the in the drawing illustrated embodiments explained in more detail. Show it:

1 shows the partial cross section of a direct current machine; FIG. 2 the section II-II of FIG. 1; 3 shows the cross section of an auxiliary pole of the machine with a different arrangement of the windings of the auxiliary pole;

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4 shows the basic electrical circuit of the armature circuit of the same machine;

Fig. 5 shows the cross-section of an auxiliary pole of the direct current, machine with an embodiment of the device for winding the reinforcing Induktivitätserhöhung dec auxiliary pole;

6 shows the same auxiliary pole with a further example of the device for increasing the inductance of the field winding of auxiliary pole; and

7 shows the cross section of an auxiliary pole with a bead. The DC machine shown in Figs. 1 and 2 contains an armature 1, which is composed of a core 2 with an armature winding 3 and · a collector 4, which is mounted on a shaft are attached, main poles 6 with a compensation winding 7 and an excitation winding 8. The machine also contains auxiliary poles 9 with an excitation winding 10 and a booster winding 11, which lie between the main poles 6. Here are on each of the auxiliary poles 9 a coil of the excitation winding and on each of the auxiliary poles 9 or at least on the one with the same name Auxiliary poles 9 », for example, either only on the south or only on the north poles, each with one sink of the reinforcement winding 11 arranged. The main and auxiliary poles 6 and 9 are fastened to a frame or yoke 12. One in anchor 1 under the The part of the armature winding 3 that is located at the auxiliary poles 9 is closed by the brushes 13 and forms a commutation zone 14. The brushes 13 are arranged in brush holders 15 which are fastened to carriers 16. The armature circuit 1 of the DC machine is connected to the external circuit by means of terminals and 18 and the excitation winding 8 of the main poles 6 to a (in Fig.

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1, 2, not indicated) source of energy by means of terminals 19 and connected.

In Fig. 1 and 2, the reinforcement winding 11 is on the Eilfspolen 9 closer to the Kummutierungssone 14 than the excitation winding 10 arranged.

Fig «3 shows an auxiliary pole of the machine in cross section the arrangement of the excitation winding 10 'dös auxiliary pole 9 closer to the commutation zone 14 as the porting winding 11 '. In Pig. 1 and 3 is also a commutation zone 14 · penetrating magnetic communication flux φ, shown.

. Pig. 4 shows the armature circuit of the DC machine. The armature circuit "consists of the compensation winding 7 connected to the armature by means of the brushes 13 and the excitation winding 10 of the auxiliary poles connected in series with it, to which the reinforcement winding 11 is connected in parallel and in the same direction. The number of turns is W _{11 of} the reinforcement winding 11 is equal to or greater than the number of turns w-, _Q of the winding of the auxiliary poles and the inductance of the reinforcement winding is selected to be smaller than the inductance of the winding 10 of the auxiliary poles 9, if the reinforcement winding 11 is closer to the commutation zone 14 is present as the winding 10 of the auxiliary poles 9, as shown in Pig. 1,., or the number of turns w /, of the reinforcement winding 11 'is equal to or less than the number of turns W ₁₀ of the winding 10' of the auxiliary poles 9 and the inductance of the reinforcement winding 11 'greater than the inductance of the winding ld' of the auxiliary poles 9 when the reinforcement winding 11 ' is far more from the commutation zone 14 than the winding 10 * of the auxiliary poles 9, as indicated in FIG. 3.

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The parallel connection of the winding 10 (Pig. 4) of the auxiliary poles 9 and the strengthening winding 11 is achieved by summation their magnetic fluxes in the commutation zone 14 when the current passes through in the winding on 10 and 11 (or 10 'and 11') from the beginning of the windings determined to the end. The beginnings of said windings 10 and 11 are indicated in FIG. 4 with the symbol · $ £ (asterisk) provided.

5, 6 and 7 show different design variants of the device for reducing the non-magnetic section 1 'when those leakage fluxes φ _{α of} the auxiliary poles pass through which the winding 10 or 11' further away from the commutation zone 14 for the purpose of increasing inductance in this Completion include.

In Fig. 6 and 7 the non-magnetic sections 1 'of the passages of the leakage fluxes Φ * are dashed without the use of the device for increasing the inductance of the winding 10 and in solid lines the same sections 1 of the paths of the leakage flux φ ₅ after the application of the device for inductance ε - Increase of the winding 10 of the auxiliary poles 9 indicated.

In Fig. 5, the same designations are used for the booster winding 11 'specified.

In FIGS. 5 and 6, the device for increasing the inductance of the winding 11 'and 10 is in the form of plates 20 and 20', respectively Ferromagnetic material produced in the non-magnetic distances between the main poles 6 and the auxiliary poles 9 are fastened in the arrangement zone of the windings 11 * and 10, which are furthest away from the commutation zone 14 are.

In Fig. 5, the said plates 20 are attached to the frame 12

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ΐ ± £ ΐ; In Fig. 6, the plates 20 "are uniform with the auxiliary pole 9 executed.

In Fig. 6, the reinforcement ^{winding 11 f is} attached to two adjacent main poles 6 in difference to the cases shown in Figs. 1, 2 and 3, where the reinforcement winding 11 (H ') is arranged on the auxiliary poles 9. In FIG. 7, the device for increasing the inductance of the field winding 10 of the auxiliary pole 9 is designed in the form of a bead 21 of the auxiliary pole 9 in the anoronation zone of its field winding 10. When using the device shown in Pig · 7 in the form

a bead 21 takes the auxiliary pole 9 of the non-magnetic portion of the paths of leakage fluxes _φ ο from the value 1 'to the value 1 abjso that the leakage flux φ ^ and the inductance of the winding 10 of the auxiliary poles 9 to rise.

The DC machine shown in Fig. 1, 2 and 4 ″ operates as follows. If the load current remains the same, its distribution over windings 10 and 11 connected in parallel inversely proportional to the Y values of the ohmic resistances of these windings 10, 11. The setting of the strength of the magnetic commutation flux Φ ^ of the auxiliary poles 9 to the optimum or spark-free commutation in the aforementioned current distribution in the windings 10 and 11 takes place in a known manner Way,. "For example according to the method of determining the area the sparkless work of the DC machine. With temperature fluctuations the ohmic Y / i resistances of the windings, which for each of the resistances of windings 10 and 11 can be different, the commutation of the machine in

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whose steady-state operating conditions are disturbed. To avoid With this phenomenon, the ohmic resistance of the gain winding 11 or 11 * must be at least twice greater than the Olympic resistance of the excitation winding 10 or 10 ' of auxiliary pole 9 can be selected

In the event of a dynamic change in the load current in the magnetic conductor of the auxiliary poles 9, eddy currents are induced which generate a magnetic flux in the commutation zone 14-. The mentioned magnetic flux of the eddy currents slows down the change of the magnetic coinutation flux H ^ » ^{what e} ^ - ^ne disturbance of the kcmmutie- ·. : j tion of the DC machine initiated. The magnetic flux of the Y / ir in currents is directed in the commuti orange one 14 against a magnetic flux generated by the flow through the windings 10 and 11 of the auxiliary poles 9. If the number of turns of the windings 10 and 11 or 10 'and 11 * is unequal, as indicated above, the compensation of the magnetic flux of the eddy currents in the corrosion zone 14 with a dynamic change in the load current is caused by such a change in the flow rates of the windings 10 and 11 or 10 * and 11 'achieved, which causes an amplification of the change in the magnetic flux in the commutation zone 14, which actually leads to the compensation of the magnetic flux of the eddy currents in the commutation zone 14.

In the. Arrangement of the reinforcement winding 11 closer to the commutation zone 14 as the excitation winding 10 of the auxiliary poles 9, as shown in FIGS. 1 and 2, and if this is the booster winding 11 has a larger number of turns and a smaller inductance than the excitation winding 10, the Current in the booster winding 11 with dynamic change

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of the load current change faster than in the excitation winding 10 of the auxiliary poles 9. When the load current rises, a greater I '€ * il of the current is generated in the boosting winding 11 than in steady-state operation with constant load current and when the load current decreases, a smaller part of the current than in steady-state operation or a current flowing in the opposite direction to steady-state operation. The redistribution of the current in the windings 10 and 11 connected in parallel with dynamic change in the load current causes a change in the flow through the windings 10 and 11, which in turn intensifies the change of the magnetic flux in the commutation zone V4- guaranteed.

When applying the embodiment shown in Fig. 3 of the 'auxiliary pole, in which the reinforcement winding 11 ^f further from the commutation zone 14 as the excitation winding 10' is located and a smaller Yß.naungszah.1 and a greater inductance than the excitation coil 10 'which is When the load current changes dynamically, the current in the boosting winding 11 'changes more slowly than in the excitation winding 10 * of the auxiliary poles 9 a larger part of the load current flow than in stationary operation. The described redistribution of the current in the parallel-connected windings 10 * and 11 * ensures, as in the previous case, a change in the flow through the windings 10 'and 11 *, which in turn increases the change in the magnetic flux in the commutation zone 14.

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With the same Y / indungszaiii of the windings 10 and 11 (Fig. 1,2) or 10 'or 11' (Fig. 3) takes place in the parallel-connected Windings 10 and 11 or 10 'and 11 * in the case of a dynamic one Change in the load current a redistribution of the current in relation to its distribution in stationary operation in the manner as indicated above for the case of an unequal number of turns of the windings 10 and 11 or 10 * and 11 '.

However, in this case, due aie said windings change the flux observed j thanks to the Stromneuverteilung in the windings 10 and 11 or 10 'and 11 * but the load current during dynamic change a displacement of the liittelpunktes of the total flux of said windings in the direction to the commutation zone 14 when the load current increases and in the opposite direction when the load current decreases, which likewise ensures an amplification of the change in the magnetic flux in the conanutation zone 14.

With an appropriate choice of number of turns, inductances and effective resistances of the field winding 10 or 10 * of the auxiliary poles 9 and the reinforcement winding 11 or 11 'can with dynamic Change of the load current a complete compensation of the magnetic flux of the eddy current © in the commutation zone 14 * The commutation conditions for the DC machine correspond to the conditions of a optimal commutation for stationary states. For a choice of this option of amplification of excitement the auxiliary pole 9 is the value of the difference between the inductances of the windings 10 and 11 or 11 * and 10 * to vary.

A greater amplification of the change in magnetic flux

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In the Koiffinutierurigszonc- 14 "with a greater difference in the inductances of the windings 10 isnd 11 (11 ^S1 ) for the variant shown in Fig. 1, 2, 6, 7 or that of the windings 11 'and 10 ^l for the in Fig. 3 and 5. The increase in the difference between the inductances is achieved by lowering the inductance, the ¥ ¥ ¥ ¥ hig located in the vicinity of the commutation zone 14, or by increasing the inductance of the winding located farther away from the coordination zone 14. The possibilities for lowering the inductance of the winding located in the vicinity of the commutation zone 14 are "limited in their selected number of turns.

To increase the inductance of the more distant from the commutation zone 14 winding, a device 20 ^(used from ferromagnetic ^. Material in the form of plates 20 or the like. In Fig. 5 is used to Induktivitätserhöhung the Verstärkungswieklung 11 * means of the Commutation zone 14 is further away than the excitation winding 10 'of the auxiliary pole 9. According to Fig. 5, the device is designed in the form of the plates 20 which are attached to the frame 12 in the vicinity of the arrangement of the reinforcement winding 11' of the auxiliary pole The device shown in FIG. 5 leads to a reduction in the non-magnetic section from the value 1 * to the value 1, which leads to an increase in the leakage flux and consequently the inductance of the gain winding ^11r .

In Fig. 6, the device for increasing the inductance of the field winding 10 of the auxiliary poles is used in the same way. In the variant shown in FIG. 7, the increase in inductivity of the excitation winding 10 is achieved in the same way,

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the section 1 'decreases thanks to the bead 21 to the value 1. By Use of the device for increasing the inductance of the windings 11 'and 10 can reduce the inductance of the windings mentioned according to Pig. 5 or 6 can be increased significantly. However, one is excessive inductance increase undesirable because this see difficulties with their placement as well a disturbance of the linear dependencies between the inductance and the current due to magnetic saturation of ferromagnetic Can cause sections over which the magnetic fluxes of the windings 10 and 11 or 10 * and 11 * close.

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Claims (4)

■■ 'l. ^V: GlcichstroiBiüacchiiie, the auxiliary poles with an excitation winding of the auxiliary poles and a reinforcement winding for the coi & penoä "■ tion of a in the KojnnutierimgßKone by eddy current of the magnet loiter of the auxiliary poles magnetic flux generated with dynamic? Rather change the load atmosphere, characterized by the fact that the winding has a change (11) connected in parallel and in the same direction to the field winding (10) of the auxiliary poles (9) and whose ohmic resistance is at least two-dimensional greater than the ohmic resistance of the field winding (10) of the auxiliary poles (9), v; whether the reinforcement coating (11, 110) closer to the commutation zone (14-) than the excitation winding (10) of the auxiliary poles (9) with a number of turns equal to or greater and an inductance less than that of the excitation winding (10) or further away from the excitation winding (14) than the excitation winding (10 ¹ ) with an inductance number equal to or smaller and an inductance greater than with the excitation voltage cklung (10 '). 2. DC machine according to claim 1, characterized in that it has a device for reducing the uninagne ti see air gap of the iron paths of those leakage fluxes (φ _Β ) of the auxiliary poles (9), which from the commutation zone (14) most distant winding ( 10 or 11 ') to increase the inductance of this winding (10 or 11'). 3. DC machine according to claim 2, characterized in that that the device is designed in the form of plates (20, 20 ') made of ferromagnetic ^) material, R098 ^ 1/0365 the szone in the immagnetic gaps between the cores of the main poles (6) and the auxiliary poles (9) in the arrangement the furthest away from the commutation zone (i4) Winding (10 or 11 ') "are attached. 4. DC machine according to claim 2, characterized g ekenn indicates that the device in the form of a bead (21) of the auxiliary pole (9) in the arrangement zone of the the winding furthest away from the commutation zone (14) (10 or 11 ') is executed. 609841/0365