DE1810099B2 - AC VOLTAGE STABILIZER - Google Patents

Description

The invention relates to an AC voltage stabilizer, at the input or output of which the deviation of the actual value of the alternating clamping there from a nominal value is periodically determined with a digital clamping measuring device and the output voltage of which is the sum of the fluctuating input voltage unc ¹ by control or regulation Fluctuations in the input voltage is influenced by the additional voltage. which is generated in transformer windings that can be switched on based on the digitally determined deviation, with different digital steps.

Such an AC voltage stabilizer is off U.S. Patent 3,018,431. Compared to other known stabilizers, it generates the phase control thyristors or triacs as an actuator, have less distortion in the waveform of the stabilized voltage and has opposite Stabilizers with continuously controllable resistances (tube or semiconductor circuits) as actuators a significantly lower power loss. It is also less expensive than other known AC voltage stabilizers, which generate the power supplied by the additional voltage in an amplifier.

The AC voltage stabilizer known from US Pat. No. 3,018,431, however, emits the transformer sounds for the additional voltage regardless of the phase of the alternating current passing through the stabilizer, so that overvoltages occur at the switches at the transformer windings . Although these are not critical when using inert transducers as switches, this results in a long sound and control time. ^p - special - when using fast semiconductor scn; .horn the over-mianni'.ii cause harmful losses, which in certain circumstances can lead to the destruction of the switch, and distort the curve shape of the stabilized voltage.

The invention has the object of such switching overvoltages in connection with semiconductor switches to avoid and an alternating voltage stabilizer with a very short control time and good efficiency to enable that does not generate any additional harmonic distortion.

ίο Based on an AC voltage stabilizer of the type mentioned, this object is achieved according to the invention in that for the setting the switching state of the semiconductors switching the transformer windings an intermediate

Memory is provided on the means of a StromnuUdurehgangsdiskriminators the digital deviation information at the moment of each of a MeC period following current zero crossing is transmittable.

The invention can also be modified in such a way that it also works with a closed-loop control AC voltage stabilizer a disturbance value feed-in he follows. This allows the response time to be shortened.

The transformer windings supplying the additional voltage graze only during zero crossings of the alternating current flowing through the stabilizer, which prevents overvoltages will.

Embodiments of the invention are shown schematically in the drawing. Here shows

E ig. 1 is a block diagram of a first embodiment of a regulated AC voltage stabilizer, in which the additional voltage from binary stepped, each, in a special step transformer generated partial voltages is composed and its voltage measuring device one the System deviation during each half cycle of the voltage frequency converter integrating the alternating current contains, which acts on a counter,

F i g. 2 shows an excerpt from a block diagram of a second exemplary embodiment, in which one of the measuring voltage charged memory of an integrator with pulses of the same charge and constant

4j repetition frequency is discharged that counted will.

F i g. 3 shows a block diagram of a third exemplary embodiment a controlled alternating voltage stabilizer, in which a charged by the measuring voltage Memory of an integrator with constant current is discharged and that of one during the discharge time pulses of constant repetition frequency passed through a gate are counted, and

F i g. 4 shows a section from the block diagram of a fourth exemplary embodiment in which each Step transformer several voltage levels by optionally connecting to one of several taps generated by a common auxiliary transformer.

In the first exemplary embodiment, one of the two has the input terminals 1 and the output terminals 2 lines of the stabilizer connecting the series connection of the primary coil of a power converter track 3 as well as the secondary coils of several Smfentransformatoren 4, 5. The primary coils of the step transformers 4, 5 are each connected to two via a two-way thyristor 6, 7 (so-called triac)

Manifolds 8, 9. These are about a sum which the first gate 30 during a between pole 10, the half-case lying in a manner not shown in more detail, two zero passages of the current works with two-way thyristors and the wave over the Summierwiderstäiide (18, 20 in Fig. 1) with a graduation 11 can be actuated, connects the input to the input of an integrator 32. To terminals 1 of the stabilizer connected. The integrator 32 is responsible for the priority of the integration line The step coils of the stepped transformers 4, 5 are two-way via the second gate 31, each with a co-tante away thyristors 12, 13 connected in parallel. The pulses having ignition charge discharged the one around .'electrodes of the two pulse shaper 34, each controlled to a step transformer, a generator 33 formator 4, 5 belonging two-way TTiyristorsen 6 and opposite the polarity of the integrator output span-12. 7 and 13 are connected to ignition circuits 14, 15, which output the reverse polarity voltage. One with that press them alternately. Output of integrator 32 connected zero-com

With the output terminals 2 via a chip separator 35, the polarity of the during the integration

Voltage converter 16 connected to a measuring device 17, fixed integration voltage accumulating over time

its output via a summing resistor 18 and reports this to the pulse shaper 34 on the one hand

is at the input of an integrator 19, with which the external 15 and the other hand the mains voltage reverser (10 in

which via a summing resistor 20 a con-F i g. 1) and the zero coincidence gate (25 in Fig. 1)

Mnntspanmingsquelle 21 is connected. The Aussiani: ι ¹ .-. Forward-backward counters (24 in Fig. V). Of the

iLs integrators 19 feeds a bipolar threshold value-zero comparator 35 ei hai ¹ \ on the Toisieuersehal-

"■ challung 22, whose two polarities zii'jeord- Hing 29 a Torzeii angular impulse. and he announces

!: eie pulse outputs via a Zünlkanalumpoler 20 this a gate / eii end pulse. During the gate

23 at the two counting pulse detectors of a binary time appears depending on the polarity of the output

^Λ ■ ir-down counters 24 lie. A polarity and integrator 32 accumulated integration span

Independent reset output of the Sehwellwenschal- ung on one of two lines 36, 37 a gate

tiing 22 is a time signal with the input of the integrator 19, which on the one hand determines the polarity of the

l'iinden. The counting channel umpoler controls the counter 25 pulse shaper 34 pulses delivered to the gate 31

> i \ that it runs through a continuous sequence of numbers and that, on the other hand, one side of a double

(· ■ · 2. 1. 0, -M, -I-2...). The exits of the peeling gate 38 opens, so that selecting the gate line

Liüiärsiufen the up / down counter 24 are the pulses emitted by the generator 33 at a

appear on the one hand with one of the two outputs of the gate 38 controlling the counting channel umpoler 23. the

ernden and the Steiierleitung 11 of the L'mpolers 10 30 both outputs of the gate 38 are with the two

applied zero coincidence gate 25 and other inputs of the counting channel reverser (23 in FIG. 1)

KT on the side connected to the stages of a buffer store 26.

'blind who controls the ignition circuits 14,15. Depending on the speed at which the Inte-Mit is discharged the secondary coil of the current transformer 3 is a grator 32 by the constant pulses of the pulse-for-discriminator 27 to determine the zero current throughput 34, the alternating voltage can be used at the beginning connected, whose pulse output on one neither work fast, whereby the discharge time one Transfer control terminal of the buffer store 26 is a very small fraction of each half cycle of the change. stressed, with enough tendons

The summing resistors 18 and 20 are thus a negligibly small error with a heavy discharge ! Hesse that when the nominal voltage occurs on the 40, or: he can work slowly in this way. Output terminals 2 of the stabilizer no current in that during exactly one half cycle of the alternating silk Entrance of the integrator: 19 means. The tension is integrated and within the next or against the voltage at the output terminals 2 Heuende Span- a whole number of subsequent half-periods of the from its setpoint. in this way an alternating voltage flows in and is discharged.

softening proportional current in the input of the 45. The third embodiment represents one with Integrator 19. The output voltage of the Integra control working alternating voltage generator gate 19 thus reaches this input current in one of the two proportional time the upper or the men 39 with the output terminals 40 de- Stabilisauntere Response threshold of the bipolar Schwellwerk gate connecting the series connection of the lines circuit 22, and this gives depending on the polarity of the 50 primary coil of a current transformer 41 and the integrator output voltage at one of their two secondary spu'-ii of several Stufentruiisfonriatoren 42, 43 pulse outputs a counting pulse that is present. The primary coils of the step transformer! Counter switches backwards by one digit. The 42, 43 are each via a two-way thyristor 44, Number of people who go blind during a flow of stream 45 with two collecting lines 46. 47 \. (Measuring time) generated counting impulses is aco the Inte- 55 This sinü via a pole reversal48, which is in no detail Grail of the voltage, deviation proportional. also shown with Zwciwcg-Thv rotors

At the end of each measurement period, the dis-

criminator 27 the response of those ignition switchable. to the input terminals 39 of the stabilizer

Hanging 14, 15, their associated counting levels to die-connected. The primary coils of the stage form

are set at this point in time. 60 mators 42 43 are two-way thyristors 50. 51 par-

The second embodiment differs allele switched. The ignition electrodes of the two jevom first embodiment essentially only because two through-holes belonging to a step transformer its analog-digital wcg thyristors 44 and 50, 45 and 51 shown in FIG. 2 are present converter, which takes the place of the one in Fig. 1 by an ignition circuit 52, 53, which they are alternately dashed shown rectangle 28 circumscribed.

Circuit part occurs. One of the current zero passage ⁵ between the input terminal π 39 and the

Discriminator (27 in Fig. 1) controlled gate control output terminals 40 directly connecting line

circuit 29 alternately controls two gates 30, 31, and a connection point of the primary coil of the

1 810 093

Current transformer 41 with the secondary coils of the first at the moment of the Torumschallung at its off-step transformer 42 are the input terminals gang has, discharged. To measure the time required for the polarity reversal 48 and a voltage converter 54 to discharge, which is connected to the integrated chip, which feeds a measuring rectifier 55. At the beginning of this second, the output of the latter is also opened via a summing resistor 56 5 time span, so that the gate is at the input of a gate 57, with which the counter 66 from the normal frct Constant beat is used. At the end of the second period of time, the voltage source 59 and the zero voltage comparator 63, via a summing resistor, the line point 60, a disruptive discharge of the integrator 62 of the gate circuit 61 is connected to the current transformer 41. An at output io 70, which separates the gate 68 again, and it ends the gate 57 lying integrator 62 feeds the gate time of the gate 64, which controls the normal frequency zero voltage comparator 63. This controls a gate generator 65 again separates from the counter.
64, which connects a normal frequency generator 65 with a counter 66 corresponding to the during the discharge time. The counter stages control over the counter position that is reached, the stages of an intermediate store 67 then become the ignition 15 current zero passage through that of the intermediate storage circuits 52, 53 at the next. rather 67 for transferring the setting information to the

With the input of the integrator 62, which initiates a ka ignition circuit 52, 53 and also maintains the beginning of the next integration time through a positive negative feedback operational amplifier, a polarity reversible constant is established via a gate 68, the two-way thyristors 44 , 45, 50, power source 69 connected. Control outputs of a gate ao 51 are set, which are set to control information until the next control circuit 70 is transferred to gates 57 and 68,
the counter 66 and to the zero voltage comparator. In the one shown in FIG and 55 off thyristors 74, 75, 76, 77 or 78, 79, 80, 81 are connected to zero voltage comparator 63. in various ways with collecting lines 82, 83,

In the case of the FIG. 3 controlled exchangers 84, 85 are connected to the taps of a

Selspannungsstabilizer will lie on one intermediate transformer 86 during two. The control line

other subsequent current zero crossings, those of the currents of the two-way thyristors 74 to 81 are present

zero-crossing discriminator 71 of the gate control switch 30 ignition circuits 87 to 94, their control inputs

device 70 reports, the gate 57 is switched through, so that a coding device 95 with not shown

the initially unloaded integrator 62 is an output set output of a buffer (e.g.

voltage assumes, which are connected by the sum of the currents 67 in Fig. 3). With ignition each time

is determined that the measuring rectifier 55, the con one of the associated with a step transformer

Constant voltage source 59 and the Störwertaufschal- 35 two-way thyristor result in four different ones

device 61 at its input. possible output voltages of the step transformer

In a second period of time, which is very short and mators, e.g. B. 0, 1, 2 or 3 volts, 0, 4, 8, 12 volts and

is close to each current zero crossing, becomes 0.16, 32, 48 volts, which can be positive or negative.

the gate 57 is separated and the gate 68 is switched through, depending on how the intermediate transformer

tet. As a result, the integrator 62 is connected upstream with a current 40 tor 68, shown in dashed lines

from the constant current source 69 from the reverse 96 (which corresponds, for example, to the polarity reversal 48 in FIG. 3

Polarity, as it can the zero voltage comparator 63) is set.

1 sheet of drawings

Claims (1)

Claim: AC voltage stabilizer, at the input or output of which the deviation of the local one AC voltage actual value from a nominal value periodically by means of a digital voltage measuring device is determined and its output voltage the sum of the fluctuating input voltage and one counter to the fluctuations through open-loop or closed-loop control The additional voltage influenced by the input voltage is that determined on the basis of the digitally Deviation switchable, different digitally stepped transformer windings generated is characterized in that for .lic Setting · ... g of the switching state of the semiconductors switching the transformer windings a buffer (26 or 67) is provided. on the means of a Sirom zero crossing discriminator (27 b / w. 71) the digital deviation information at the moment each a measuring period following St omnulldurchüanus can be transmitted.