DE2246592C3 - Total extinguishing device for the inverter valves of a DC link converter feeding a rotating field motor - Google Patents

Description

40 Fig. 1 shows the circuit of a converter

The invention relates to a total extinguisher motors. The three-phase winding of a synchronous for the from a control set with consequent Im- machine 1 is from a three-phase network R, S, T pulse ignitable inverter valves of a DC-AC converter fed by a controlled rectifier 2, an intermediate circuit 3 with smoothing inductance 4 and with the A controlled inverter 5 is fed between the output terminals of the rectifier 45. In the outflow intermediate circuit, the series connection of an exemplary embodiment, the rectifier 2 is constructed from six mutating capacitors and a first controllable controllable converter valves 2a to If in rotary converter valves and parallel to the commutation bridge circuit. To the alternating capacitor, the series connection of a second control converter 5 are controllable converter valves 5a to 5 / baren converter valve and a reversing throttle 50 is also interconnected in a three-phase bridge circuit. collected. The controllable converter valves 2a to If

Such a total extinguishing device for one and 5a to 5 / can be, for example, thyristors. DC link converter with impressed DC voltage With the motor rotor of the three-phase synchronization is known from US-PS 36 21 366. In this motor 1 is a speedometer 6 and an example total extinguishing device it is possible that the im 55 wise permanent magnetic or with Hallgenera commutation capacitor stored energy for gates equipped rotor position encoder 7 mechanically commutation the operating current is not sufficient. couples. The signals of the rotor position sensor 7 are This means that operational malfunctions and operational failures via an amplifier 8 and a logic stage 9 are one possible. Tax rate 10 supplied, from which via line cable

From DT-AS 15 13 518, the converter valves 5a to 5 / of the inverter are used to feed a 60

Rotary field motor a DC link converter known, ters 5 are controlled. The signals of the Taclio

for an impressed direct current in the intermediate dynamos 6 are in an adder 12 with a

circle is designed. In this DC link converter, the speed value is compared to that of the adding stage 12

is to be fed to a bridge string of the inverter via an input 13. The received

An extinguishing device with a separate cone 65 control deviation is on a speed controller 14,

mutation capacitor assigned. its output to compare its signal voltage

There is the task of a device of the one with the signals of a current transformer 15 of a second

to be designed in such a way that the adder stage 16 is supplied when the above-mentioned type is used. The current transformer 15 is

α τ three-phase feed line arranged. The Adt fel6 is followed by a current regulator 17. of "iber lines 18 the converter valves la ^ ⁰ I f Hes rectifier 2 are driven. ^BLS rv / Auseanesklemmen 3a and 3b of the intermediate • 1 are of the series circuit of two steaer ^k" tromrichterventile 19 and 20 and a throttling order ^Barer · bridges 21 the controllable ^SChW1P _r fchterventil 20 and the Umschwingdrossd 21 ^1? 22 Knmmutierungskondensator parallel Ge-Se Serenschaltung are made of the components and 21 and the parallel communication "capacitor 22 of the main Bestandf sum erasing means, in the communi-J Wikl dSnchronmaschine 1

The motor current iu, for example, from the thyristor 5α to the thyristor 5b ties inverter 5 with the aid of the machine voltage of the syncnron machine 1.

For operating speeds, the Kiemer than about are one-tenth of the rated speed, but me machine voltage is not sufficient, so that can be made zero with HiIIe the sum extinguishing device, the motor current in the one act of commutation

got to. . .

The functionality of the total extinguishing device is illustrated using the diagrams in F. g 2 erlame.t. In the diagrams, the ignition pulses Z _ for the il 5 Sb d 5 / of the armpit

In the diagrams, the ignition pulses are _

mmenlöscheinrichtung, in the communication converter valve 5α, Sb and 5 / * echselnchfc of the windings of the synchronous machine 1 _»5 5 ters and the firing pulses for the Z-TA Stromnchter utie are ungsiP-inductances. The control valves 19 and 20 of the total extinguishing function de I ^I Comrichterventile 19 and 20 can Thy motor current / ", the voltage wc at the Kornmutierungsbaren Stromncnierkondensator 22, the voltage H ₁₉ at the converter

of the commutation capacitor 22 valve 19 and the current i _L , which is provided by the Umschw> ngnesqueJle 23, which flows a voltage choke 20 , plotted against the time did. For the ^ emits and the description of the commutation process via a diode 24, it is assumed that the converter valve and 5 / des

Inverter 5 lead current that the motor current ^^ converter valve 5 a is to be commutated to the converter valve Sb and that the commutation capacitor 22 with the in F 1 g. 1 is charged.

In order to insert the commutation,

IrSe ^ emits and the over ^OU Ü *, th ^ resistance 25 at the Koramutierungskonden-

^Un η vZ »gate 22 is still placed on this loading device. Aut oiese b

SnfSes is a controllable first converter of the logic stage 9 a differentiating stage Imnulseeber 26 connected downstream, which controls a converter valve 19 via a Ä df. the

, 5

_W e can receive the total extinguishing slip ignition signal Z ₁₉ via the ignition stage 27

22nd

ϋΐ ^ ,, βϋί

31 is due to the potential separation and because of the _{gate voltage Uc is} equal to zero. The time ? = -

Omschwingdrossd 21 and the

20 _Zeilpu "fc,." The span

Stage 33 is connected to a release input 34 of To stage 10. Be released on d.esen input 34Aonnen all firing pulses for the StrpmnchteivenUIe 5y b "Sf of the inverter 5 when di exceeds sensed Spanrunjg on KommutierungskondensatorM a ^ gege requested limit of voltmeter 33, which is given by the kippwtrt the indicator stage 33rd The tension indicator 33 can increase the drive speed analogously to the tension indicator 31. those larger than about ten ft Λ ! ^ ΰ ^ Ά & £ Ά ϊΑί

ft Λ

5b and 5 / das tunuMfuai ^^ ^. "". _

begins to flow. The capacitor voltage; continues to rise until at time "* ₆ the motor current iu is again the size of the intermediate circuit current. Commutation process in .er D im uttmit is completed. Commutation capacitor 22 for the next commutation is charged with the correct polarity when converter valve 19 and the resulting starting ■ ₂ via the second low-voltage converter valve 21, which can be referred to as "via the

5 * 6

Ignition stage 31 conductive controlled. The commutation Regarding the derivation of the ignition command for the

capacitor 22 then swings around and has in the time-reversing thyristor 20, st to mention that the Zc. point ^ the span required for the next commutation ^ ^ ™ «™ £ *«>% £ t ™ J £

The delayed release of the pulses from the changeover valve is dependent on the load current and is therefore different from the time λ. from calculated causes that borrowed can be long. The ignition of the current after the positive end voltage Uc _{1 of} the commutation valve 20 can therefore not be higher by a fixed period of time capacitor 22 than that from the actual example after time A ₂ . Rather, it must be avoided under all circumstances

ίο that when the converter valve iy

^nu " ^g- ·, _ _ the converter valve 20 is already ignited, since

^g ι ["" ~~ "i _M. ^{2 this} results in a completely different current flow in the main

U ₁₁ = | / U _cl + -ς- ■ i _D commutation circle and thus an order

proper commutation would no longer take place.

where Lm are those involved in the commutation process by the described firing sequence for the current-motor leakage inductances. The breakover voltage Uc ₁ richtervcntilc 20 and 21 is this requirement met the voltage indicator stage 33 is selected so that since the ignition command for the converter valve 20 from the one hand, the losses of the subsequent presence of the (negative) blocking voltage oscillating process are covered and that other- is derived at the converter valve 19. On the other hand, an initial voltage U _Co is obtained with which, if necessary, the commutation is already completed in relation to the previous commutation slave 5. rune significantly higher current are commutated. The auxiliary voltage source 23 can be run with low power, since it is only used for the initial charging of the

In order to make the quenching device safe from no-load operation, commutation capacitor 22 must be used. The actual reloading of the commutation condensing intermediate circuit current id , ie to maintain its full functionality even with a ₅ , occurs, as described, through the ignition, the converter valve 19 is acted upon with a permanent delay for the valves 5a to 5 / of the alternating ignition signal Z19 until the voltage indicators «5. The auxiliary voltage source 23 is additional capacitor stage 33 responds. Would z. B. between the borrowed only to cover the leakage losses of the commu time A ₂ and the time A _{5 of} the intermediate circuit 30 tierungskondensators 22 and the own consumption of the current ia as a result of a regulator intervention on the tax rate indicator stage 26 with generator operation of the drive of the rectifier bridge 2, so would that be needed.

Converter valve 19 go out. The commutation should also be mentioned that the total extinguishing device used in the execution capacitor 22 could no longer be reloaded, for example as a start-up aid, and thus also the ignition stage 10 no longer be released via the 35 device when the voltage indicator stage 7 for the machine-controlled voltage indicator is reached. The commutation required minimum speed of inverter 5 would then remain de-energized. The mentioned ignition duration signal for the thyristor 19 is switched off by approximately 10% of the nominal speed in a simple manner, by blocking the differential stage 26, which can advantageously be switched off from a sequence of high. A corresponding blocking input can consist of frequency individual pulses, can be via 40 of the differentiating stage 26 of FIG. 1 provided. It should be emphasized, however, that the described total circuit current ία of the commutation capacitor 22 is charged in the extinguishing device not only as a start-up circuit for a functional manner. Is suitable in converter motors. In all this case, the commutation process lasts for converters with an intermediate circuit, regardless of longer than usual; However, this has no disadvantageous 45 to the type of rotary field motor, fully functional an influence on the functioning of the total extinguishable. For example, the rotating field motor can also have a device. be ^{e 'ne} three-phase asynchronous.

For this purpose 2 sheets of drawings

Claims (2)

The motor current can be commutated without interference even at very low operating speeds with little effort. Claims. According to the invention, this object is achieved 1. Sum eraser means for disengaging from a that of the indirect converter for an on-rate ^ ignitable hfolgerichtigen'mpulsen ₅ impressed current .m DC ^ sgeleg "st that _in Wechselrichtervenfile of a polyphase motor commutation circuit, a part of the motor Wick diners indirect converter, intermediate in which lungs is arranged and that the voltage at the output terminals of the DC Conical mutierungsko.idensator a Span.iungs.nd.katorstufe intermediate circuit, the series circuit of a grain fed ISU whose output only a Freigabemutierungskondensators and a first control signal ₁₀ for the Z and. Pulses of the changeover valve.le ble converter valve and emits parallel to the cone to the control rate when the voltage at the mutation capacitor has reached a value, the series connection of a commutation capacitor, a second controllable converter valve and one of the following commutation voltage is switched-reversing choke is et, e dadurchg dingt, which is also the largest possible for commutation indicates that the Zwischenkreisum- sufficient ₁₅ Betnebsstromes. is judge for an impressed current in the intermediate, the inventive Summenloschemrichtung designed circuit (3), that little effort in commutation, and with it is ensured that the circuit part of the motor windings reasonable voltage on the commutating capacitor is always for classified and that the voltage at the commutation one commutation is sufficiently large. A voltage _{indicator 20 is obtained} with a short commu level (33), the output of which is fed to a voltage indicator 20, the output of which is only then controlled and therefore only receives a small momentary release signal for the ignition pulses of the dips. In addition, the total extinguishing device is self-adjusting valves (5a to 5 /) to the control set (10), ie it emits no-load operation even if the direct current is interrupted if the voltage at the commutation is fully functional. capacitor has reached a value (Ua) , which is preferably a subsequent commutation voltage (Uc ₂ ) judge valve ignition pulses can be fed to the second controllable current, which requires a second, which also emit the highest voltage indicator level for commutation, with which is sufficient at the end of the possible operating current. commutation the first controllable current 2. Total extinguishing device according to claim 1, richterverUile as reverse voltage commutation, characterized in that the second control voltage can be detected. This ensures that the converter valve (20) supplies ignition pulses - that the currentbars bridging the intermediate circuit are not switched on at the same time, a second voltage indicator stage of the converter valves are not switched on at the same time, where - (30) emits, with which at the end of the commutation at the load currentab> for the ignition point ängige the controllable on the first converter valves (19) of the commutation capacitor charging time berückals reverse voltage lying Kommutierungsspan- is taken into _35th The operational safety of the voltage (Uc ₂ ) can thus be determined. Total extinguishing facility further increased. In the following the sum according to the invention extinguishing device exemplarily on the basis of FIG. 1 ui.d 2 explained in more detail.