DE3216864A1 - Method for short-circuit protection of an electrical three-phase machine and a device for implementing the same - Google Patents

Description

FATENTANW * 5i_ «T« E · ⁵ · May 1982

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2WEIBRÜCKEtviST «i1Ö c ·

8OOO MUNICH 2 ^

BBÖGHÄEIBUMG

The present invention relates to the field in electrical engineering, in particular on the processes of Short-circuit protection of electric rotary dream machines and to facilities for the exercise of these procedures.

The present invention can be used successfully for short circuit use of electrical three-phase machines and primarily to protect against winding soles in the btander winding the machine.

The current development of production requires the continuous increase in the number of electric Machines, in particular for electrical three-phase machines

/ simultaneous increase in their performance. Consequently are becoming ever higher demands on the safety when operating these machines, especially in explosive and flammable media, as well as the reduction Their repair costs and consequently higher demands on the safety of their short-circuit protection. . The known protective procedures and facilities for exercising However, the same allow the timely detection of the short circuits in the stator winding of the electrical Three-phase machine not.

A method for short circuit protection of an electrical three-phase machine is known (see, for example, Gimojan GG: "Heiaisschutz von Bergwerk-Blektroanlagen · ¹ , Moscow, Verl Magnetic flux through the turns of the end parts of the coil groups of each winding phase of the stator, separating the current of the negative component from the phase currents, measuring the same, comparing with the maximum current of the negative component, which was separated from the phase currents in error-free operations, and forming a signal to switch off the electrical three-phase machine if the measured current of the negative component exceeds its specified maximum value.

It is also a short circuit protection device

electric rotary stronimascnine known that this procedure exercises (see e.g. Gimojan G.G .: "Heiaisschutz von Bergwerks-k'lektroanlagen", Moεkau, Verl. Nedra, 197Ö) and three power converters, each of which has its input to the corresponding one Phase of the electrical three-phase machine

one

is closed, and / electrically connected in series) Unit for separating out the counter current component, the i3t, iStrömmeß- - and comparison unit and | ^ rmierungseinricht_ung. of the switch-off signal of the three-phase electrical machine, / contains. However, after this method and the device for its exercise, those separated from the phase currents occur The opposing component also flows in error-free operations, for example when starting the electrical three-phase machine can reach sizes with

the. currents of the Countercomponents are comparable to what the need the reduction in sensitivity of the 'protection and thus - the whole establishment leads.

After this procedure and the facility to exercise it, the soles of the windings call in the state he development of the electrical machine does not yet reveal that it has been switched off, which leads to the development of phase bottoms and, for example, to Damage to the stander winding leads. First step in the bowel a switch-off signal from the electrical machine, which indicates the inadequate rapid action of the device.

The invention is based on the object of a club

drive to the short-circuit protection / electrical three-phase machine to develop, which includes such additional operations, which increase the sensitivity and the Rapid action of the short-circuit protection of the electrical machine enable and create a facility for the practice of such additional units which increases the sensitivity and the Enable the facility to take effect quickly.

This is achieved in that an electrical three-phase machine is carried out in the process for short-circuit protection Forming phase currents in phase windings of the standard

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derg of the electric three-phase riveter / simultaneous Generation of a magnetic flux through / turns of the forehead parts the coil groups of each phase of the stator winding, separation of the negative current component from the phase currents, Measurement of the same, comparison of the measured value with the maximum value of the negative current component from the phase currents was sorted out in error-free operations, and formation of a switch-off signal for the electrical Three-phase machine, if the measured value of the negative current component exceeds the specified maximum value, according to the invention at the same time as the measurement of the counter current component the sum of the electromotive force (EMF) is measured by the magnetic flux of the windings the end parts of the coil groups of all three phase windings of the stator is generated, this is compared with the maximum value of the emf generated by this magnetic flux is generated in operations, which short circuits in exclude the stator winding of the electrical three-phase machine, and an additional signal is formed, welohes the electrical three-phase machine switches off if the measured EMF value exceeds the specified maximum value.

This is also achieved in that the device

one
for short-circuit protection / electrical three-phase machine for

Exercise the proposed procedure, consisting of three

respective
Current converters, whose / input is connected to the corresponding phase of the electrical three-phase current generator, and off «(electrically connected in series with one another / detector of the negative current component connected to the current converter

. one
is connected / unit for measuring and comparing the

one /
Currents and / or shaping device for the switch-off signal of the

'which are ^ ->

electrical three-phase machine /, according to the invention, electrical

/ a
connected in series with one another ι means for summing and converting magnetic fluxes in EiVIK, which is electromagnetically connected to the turns of the end parts of the coil groups of each phase winding of the stator, contains an additional unit for measuring and comparing and an additional forming device for the switch-off signal of the three-phase electric machine.

As is advantageous, if in the line of the invention, the means for summing and transforming the magnetic fluxes in BI ¹ AK mechanically interconnected bobbins and electromagnetic sensitive element, which is connected to the additional measuring and comparison unit, contains.

It is desirable that the coil body is formed from a dielectric as a cylindrical coil which is fastened within the three-phase electrical machine so that the end faces of the coil are perpendicular to the axis of rotation of the rotor of the three-phase electrical machine, and the axis of rotation coincides with the axis of the coil , and a winding surrounding the coil is used as an electromagnetic sensitive element. It can sometimes be advantageous to design the coil body as a Hing made of electrically conductive material, the surface of which is perpendicular to the axis of rotation of the rotor of the three-phase electrical machine and whose geometric center is located on this axis, while the sensitive element has a ferrite core which the Hing surrounds, and includes a winding that surrounds the ferrite core.

It is also advantageous that the means of summing and reshaping are connected in parallel with one another

corresponding
Encoder of the magnetic flux / the number of Sp ulengr up pairs, each of which is electromagnetically connected to at least one Sp ulengr up penpaar and connected to the additional measuring and comparison unit.

It is advisable to have every mass flow transmitter electromagnetically

the
to connect each phase with a coil group pair.

It is also recommended that each magnetic flux generator be electromagnetic to be connected to a coil group pair of different phases.

It is most beneficial in the case when everyone Magnetic flux generator with two pairs of coil groups is connected, each magnet flux transmitter electromagnetically with. a pair consisting of coil groups of one phase and with another pair consisting of one of the mentioned

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Consists of coil groups and coil groups of the other phase, connect to.

It is also advisable that every MagnetfluiSgeber contains at least one pair of windings, the respective terminal of the same name combined in a connection point is, with the longitudinal axis of each winding parallel to the Axis of rotation of the rotor of the electrical three-phase machine is arranged.

The present invention enables short turns in the stator winding of an electrical circuit to be detected Three-phase machine at the time of its occurrence, which increases the sensitivity and rapid action of the device increase.

In the following, the present invention is applied to an Ii? Execution example on the basis of drawings

explained in more detail. Show it

• a

Pig.l / block diagram of a device for short-circuit protection an electric three-phase machine that has the

. proposed method exercises according to the invention;

a

Fig. 2j] Puncture maintenance image of the front part of the electrical three-phase machine with the means for summing and converting magnetic fluxes into EMF, which is designed as a coil with winding (longitudinal section) according to the _invention .

-Fig. 3! General view of the coil with winding wire according to

the invention;
one
Pig. 4 J General view of the front part of the electrical

Three-phase machine with the means for summing and converting magnetic flux igen into EMF, which is designed as a Sing with a ferrite core (schaubildliche .Ansicht) according to the invention; _a

51 Structural diagram of the means for summing and reshaping of magnetic fluxes in EMF with magnetic flux sensors that are connected to the coil groups of a phase according to the invention;

exn

Fig. 61 Structural diagram of the means for summing and reshaping of magnetic fluxes sent to the coil groups of different Phases are connected according to the invention;

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a

Pig. 7 j Structure of the means for summing and reshaping of magnetic fluxes in BMK nacii Fig. 5 with magnetic flux sensors, at the same time to the coil groups one and

different phases are connected according to the invention; a

Fig. 8! Schematic diagram of the magnetic flux generator according to

the invention;,
one
Fig. 9! Arrangement of the encoder windings in relation to the

Coil groups and the axis of rotation of the rotor of the electrical three-phase machine according to the invention: one

10j view in the direction of arrow A in FIG. 9,

according to the invention.

The procedure for the short sole protection of an electrical Three-phase machine consists in that in phase windings the electrical three-phase currents are formed without phase currents

Ii? and at the same time a magnetic flux through the windings the end parts of the coil groups of each phase winding of the stator generated and the opposite current from the Phase currents is singled out. Hereafter equal-.ze This current and the sum of the EMF measured by the magnetic flux of the windings of the forehead parts of the Coil groups of all phase windings of the stator in Operated is induced, which exclude short soles in stator windings. If the measured values of the negative current component and the EMF exceed their maximum values, the electrical three-phase machine will switch off signals formed.

The device for short-circuit protection of the electrical Three-phase machine, which carries out the proposed method, contains current converters 1, 2, 5 (Fig. 1), which are connected to corresponding corresponding phases 4,5,6elner electrical three-phase machines 7 are connected. The phases 4, 5 »6 have corresponding coil groups 8 and 9» 10 and 11, 12 and 13. Each Coil group 8, 9> 10, 11, 12, 13 contains turns 14 (Fig. 2) of the end parts of the winding of the stator 15 of the machine 7 · With the turns 14 of all coil groups 8, 9, 10, 11, 12, 13 there is a means 16 for adding and reshaping of magnetic fluxes in EMF with its corresponding inputs 17, 18, I9, 20,21,22 electromagnetically connected.

3216364

A unit 23 is connected to the outputs of the converters 1, 2, 3 Separation of the opposite component of the weed stream connected. A current measuring and comparison unit is attached to the unit 23 24 and to the latter a forming device 25 of the Switch-off signal of the electrical three-phase machine connected. An additional measuring and comparison unit 28 is connected to the outputs 26, 27 of the means 16 and connected to the latter an "additional shaping device 29 for the switch-off signal connected to the electric turntable machine.

To the forming devices 25 and 29 and to the Phases 4, 5, 6 is a circuit breaker 30 of the electrical Three-phase machine 7 connected.

The means 16 for summing and reshaping magnetic

einenL influences in EMK includes a coil body made as a ausj dielectric, cylindrical coil (Fig. 2, ~ j>) is formed from _r, and representing a wound on the spool 31 winding 32, an electromagnetic-sensitive element '. The ends of the winding 32 serve as outputs of the means 16. The coil 31 is fastened to the bearing plate 33 of the machine 7 by means of a screw connection 34 in such a way that its end faces are perpendicular to the axis of rotation 25 of the rotor 36 of the machine 7.

According to another embodiment variant of the means 16 for summing and converting magnetic fluxes in IiMK is the Spool formed as a ring 37 (Fig. 4) which so attached to the windings 14 by means of a bandage 38 is that the surface of the ring 37 is perpendicular to the axis 35 and its geometric center with this axis

^ O 55 collapses. The electromagnetic sensitive element contains a ferrite core, which acts as a surrounding the fiing 37 Ring is formed. A winding 40 is wound on the core 39, the ends of which the outputs 26, 27 of the Display using 16.

Another variant of the version contains the Means 16 (Fig. 1,5) for summing and converting magnetic fluxes into EMF three magnetic flux generators 41, 42, 43 according to the Number of coil group pairs S and 9, 10 and 11, 12 and 13

32163G4

the corresponding phases 4. 5, 6. Each of the transmitters 41, 42, 43 is electromagnetically connected to ι corresponding coil group pairs ti and 9 (phase 4), 10 and 11 (phase 5), 12 and 13 (phase 6). The outputs of the sensors 41, 42, 43 represent the outputs 26, 27 of the means 16.

According to another variant of the execution of the

Each of its sensors 41, 42, 43 is by means of 16 (Fig. 1, 6) for summing and converting magnetic fluxes into EMF

electrpiuagnetisoh. with the coil ^ rU ₁ J pen pair ti

or or

and 11/9 and 13/10 and 12 of the different phases 4 and 5, 4 and 6, 5 and 6 connected accordingly.

Awake to another variant of the agent 16 (Fig. 1,7) for summing and converting magnetic fluxes into EMF, the transmitter 41 is electromagnetic in this with two coil group pairs ü and 9 (phase 4) as well as Ü and 11 (phases 4 or 5)> the encoder 42 with two pairs of coil groups 12 and 13 (phase 6) as well as 9 and 13 (phases 4 and 6) and the encoder 43 with two pairs of coil groups 10 and 11 (Phase 5) as well as 10 and 12 (phases 5 and 6).

Each of the magnetic flux generators 41, 42, 43 contains windings 44 and 45 (Fig.a). One end of the winding with the same name 44 and 45 are united at connection point 46, while the other ends of the same name are used as outputs 26, 27 of the means 16 are used.

The Ldnbsachsen 47 (Pig. Ü, 9, 10) of both windings 44 and 45 are perpendicular to the axis of rotation of the rotor 36,

The device for Kur zscülußschut ζ an electrical Drenstrominascnine to practice the proposed method This is how it works.

The main faults in the stator winding are as follows an electrical three-phase machine knowni

the

- Windingscnluß in j front parts of the stator winding ei ner of the phases;

- Short circuit between the phases in the stator winding;

- Short circuit between the phases at the output of the rotary electric machine;

- Short circuit between the phases in the cable connecting the electrical machine and the circuit breaker;

- Double earth fault of the transformer winding.

In the case of short-circuits between the turns 14 (Jj'ig. 2) and phase short-circuits in the winding of the stator Ib, if the number of short-circuited turns 14 is more than ¹ j 20 to 30% of the total number of turns 14, 23 occurs at the output of the unit (S ¹ Ig. 1) to separate out the opposite component of the current on a signal. Xn of the current measuring and comparison unit 24, the size of this signal is compared with the maximum value of the negative current component that was separated from the phase currents in fault-free operations. The signal then passes into the forming device 25 of the switch-off signal of the electrical three-phase machine, which sends a switch-off signal for the switch 30.

the

In the event of a short circuit between two windings 14 (Pig. 2) of the The stator 15 of the mascnine 7 are the magnetic fluxes generated within the electrical machine 7 by the currents of the Turns 14 of the coil groups 8, 9, 10, 11, 12, 13 of the end parts of the winding of the stator 15 of phases 4, 5> 6 are generated by the means 16 for summing and reshaping of magnetic fluxes summed up in EMF and converted into EMF. The EBjK arrives at the outputs 26 and 27 of the means 16 in the additional measuring and comparison unit 28. In the . Unit 28 will compare it with the maximum value of the SLiIK, which was determined in companies that exclude short circuits in the stator winding 15 of the machine 7. Since the EMF at the outputs 26 and 27 dea means 16 in this type of short circuit is greater than the maximum value mentioned is, occurs at the output of the unit 28, a signal which is in the formation device 29 of the Aussonaltsignals electric three-phase machine arrives, after which the latter gives the output signal for the off switch 30.

When adding up the magnetic fluxes from all coil groups 8, 9, 10, 11, 12, 13 (Fig. 1,2) works simultaneously the means 16 for summing and converting magnetic fluxes in EiViK as follows.

With a Windungεsohluß in any of the The coil groups 8, 9, 10, 11, 12, 13 penetrate the

Current in its windings generates magnetic flux in the winding 32 of the coil j> 1 (Fig. 1 »2, 3) and induces an SMK at its ends. The size of this EMF is higher than the maximum value of the MK that is induced at the ends of the winding 32 in operations which exclude the short-circuits in the winding of the stator 15. by

In larger electrical three-phase machines 7 b

the
the magnetic flux generated by the current in windings 14 in the case of a winding short in any coil group u, 9, 10, 11, 12, 13 of the winding of the stator 15 the ring 3? (Fig. 4) / whereby a current is induced that a

Magnetic field generated around this ring 37. Through the ferrite core 39 a current flows which, at winding 40 (Pig. 4}, generates an EMF that is greater than the maximum value is the emf generated at these ends in plants which exclude short circuits in the winding of the stator 15 '.

When adding up the magnetic fluxes of individual coil groups 8, 9, 10, 11, 12, 13, the means 16 for summing and converting magnetic fluxes functions as follows.

In one case the magnetic flux comes from the coil group

pair 8 and 9, 10 and 11, 12 and I3 (Fig. 1,5) of a phase 4, 5 or 6. The signal from groups 8 and 9 is received via the inputs 17. and 18 to the encoder 41, this from

2 ^l j> the groups 10 and 11 via the inputs 19 and 20 to the transmitter 42 and this from the groups 12 and 13 via the inputs 21, 22 to the transmitter 43. This occurs at the outputs 26 and 27 of the means 16 EMF that is greater than the maximum value of the EMF that is induced at these outputs 26 and 27 in operations that exclude short circuits in the winding of the stator I5. ,

In another case, the magnetic flux originates from pairs of coil groups 8 and 11, 9 and 13, 10 and 12 (Fig. 6) of different phases 4 and 5> 4 and 6 or 5 iuid 6. Das Signal from groups 8 and 11 is sent via inputs 17 and 20 to encoder 41, this from groups 9 and 13 via inputs 18 and 22 to encoder 42 and this from groups 10 and 12 via inputs I9 and 21

the encoder 45. Thereafter, the means 16 works analogously / to case described above.

In another case, the magnetic flux from two pairs of coil groups ti and 9 (phase 4) and β and 11 (phases 4 and 5) reaches the transmitter 41 (pig.7), which is supplied by two pairs of coil groups 12 and 15 (phase 6) and 9 and 15 (phases 4 and 6) to the encoder 42, and that of two lipulengruppenpaaren lü and 11 (phase 5) and IO and 12 (phases 5 and 6) to the encoder 45. Thereafter, the means 16 works analogously to the Pail described above.

The mode of operation of one of the magnetic flux transmitters 41, 42, 45 will be explained using the example of transmitter 41.

The windings 44 and 45 (Fig. Ö, 9, 10) are from Magnetic flux penetrates through, the sink groups 8 resp. 9 is generated. Since the magnetic fluxes of groups a and 9 in the event of malfunctions in the winding of the stator 15, yrsseninäßi ^ are essentially different from each other, so are the EMF induced in the windings 44 and 45 are different great. As a result, an EMF occurs at the ends of the windings 44 (outputs 26, 2? Of the means 16), the larger one than its mentioned maximum value is.

The present invention enables an essential feature Reduction of the repair costs of electrical three-phase machines that have subdivided windings. In addition, the present invention enables

Increasing the risk of safety when operating electrical

Dr ehst r omraas chinen.

Claims (10)

::::::::. · ΟZ I b ob PATENT LAWYERS CELLWOMAN ZWEIBRÜCKENSTR. 15th 80OO MUNICH 2 Pavlodarsky industrialnyj May 5, 1982 institute _{RZ / Os} Pavlodar / Soviet Union P 89 242 VERi ¹ AHEM ZUM EUKZSCHLTJSSCHUTZ BIlTSR .EL3EERISCHEN • THREE-PHASE MACHINE AND EQUIPMENT TO REALIZE THESE QPATENT TERMS Process for short-circuit protection of an electrical Three-phase machine through - Formation of phase currents in phases (4, 5, 6) the winding of the stator (15) of the electrical three-phase machine (7) with simultaneous generation of a magnetic the flux through j turns (14) of the front parts of the coil groups (8 and 9, 10 and 11, 12 and 13) of each phase (4,5,6) the winding of the stator (15), - Separation of the opposite component of the current from the phase currents; "Measurement of the same, - comparison with the maximum current magnitude of the negative component, which was separated from the phase currents in fault-free operations, and - Formation of a signal, if the measured one Current value of the opposing component exceeds the specified maximum current value, which the electrical three-phase machine (7) switches off, thereby marked, that - Simultaneously with the measurement of the negative component of the current the sum value of the ME is measured by the magnetic flux of the turns 14 of the end parts of the coil groups (S and 9, 10 and 11, 12 and 13) of all three Phase windings (4, 5, 6) of the stator (15) is generated, ij - this is compared with the maximum value of the emf, which is generated by this magnetic flux in factories, which exclude short circuits in the winding of the stator (15) of the three-phase electrical machine (7), and - an additional signal is formed, which the electrical three-phase machine (7) switches off when the measured EMF value exceeds the specified maximum size. 2. Device for short-circuit protection of electrics Three-phase machines for performing the method according to claim 1, consisting of - three current converters (1, 2, 3) »their respective inputs ah the corresponding phases (4, 5i 6) of the electrical Three-phase currents oh ine (7) are connected, and from / ^ <£ which are electrically connected in series with each other) Detector (23) of the counter current component, which is connected to the Stromumf oraier (1,2,3) is connected, one Unit (24) for measuring and comparing the currents and one Forming device (25) for the switch-off signal the electrical three-phase machine (7) / 7d ad u r c h indicated that they electrically connected in series Means (16) for summing and transforming magnetic fluxes in EMF, which is electromagnetic with the windings (14) the end parts of the coil groups (8 and 9, 10 and 11, 12 and 13) of each phase winding (4, 5, 6) of the stator (15) is connected, an additional unit (28) for measuring and comparing the currents and yj has an additional correcting unit (29) of the switch-off signal of the electric drumming machine (7). 3. Device according to claim 2, characterized iohnet that the means (16) for summing and transforming magnetic fluxes in BMK mechanically interconnected bobbins and a electromagnetic sensitive element which connected to the additional measuring and comparison unit (28) is, contains. 4. Device according to claim 5, characterized draws, daü the coil body is formed from a dielectric as a cylindrical coil (51), the inside of the electrical three-phase machine (7) is attached so that the end faces of the coil (31) perpendicular to the rotary shaft (35) of the rotor (36) of the electrical three-phase machine (7) stand, and the axis of rotation (35) with the axis of the Spu-Ie (31) coincides, and as an electromagnetic-sensitive element the ^Spui: e (31) surrounding the winding (32) is utilized. 5. 'device according to claim 3 »d a d u r c h characterized, that the coil body is designed as a ring (37) made of electrically conductive material, the surface of which perpendicular to the axis of rotation (35) of the rotor (36) of the electrical three-phase machine (7) and the geometric center is on this axis (35) while the sensitive element a ferrite core (39) »which surrounds the ring (37), and a winding (40) which surrounds the ferrite core (39), contains. 6, device according to claim 2, characterized in that that the means (16) of lamination and reshaping encoders (41, 42, corresponding
43) of the magnetic flux / the number of coil group pairs (8 and 9, 10 and 11, 12 and 13), ν of which each is electromagnetically connected to at least one coil group pair (8 and 9, 10 and 11, 12 and 13) and to the additional measuring and comparison unit (28) is connected. 7. device naoh claim 6, characterized in that that each magnetic flux transmitter (41, 42, 43) electromagnetic with a coil group pair (8 and 9 »IO and 11, 12 and respective phase (4, 5, 6) is connected. 8. Device according to claim 6, characterized iohnet that each magnetic flux transmitter (41, 42, 4J) electromagnetic connected to a pair of coil groups (8 and 11, 9 and 13, 10 and 12) of different phases (4 and 5 »4 and 6, 5 and 6) is. 9. Device according to claim 6, characterized in that in the i'alle, if everyone Magnetic flux generator (41, 42, 43) electromagnetic with two Coil pit pairs (8 and 9> 8 and 11; 12 and 13, 9 and 13; 10 and 11, 10 and 12) is connected, each magnetic flux transmitter (41, 42, 43) electromagnetic with a pair consisting of coil groups (ü and 9 »10 and 11, . 12 and 13) of a phase (4, 5, 6), and with another pair, which consists of one of the mentioned coil groups (8, 13, 10) and coil groups (11, 9 »12) of the other phase (5, 4, 6) is connected. 10. Device according to one of claims 6, 7, 8 or 9, characterized in that each magnetic flux generator (41, 42, 43) contains at least one pair of windings (44 and 45), each of which has the same name Connections combined in a connection point (46) are, where the longitudinal axis (47) of each winding (44 and 46) parallel to the axis of rotation (35) of the rotor (36) of the electric Three-phase machine (7) is arranged.