SU1469529A1 - Phase switching unit - Google Patents

Description

(21) 3864740 / 24-07

(22) 03/11/86

(46) 03.30.89.VYL № 12

(71) Production and Energy Association Donbassanergo

(72) V.A. Rabochiy and A.A. Rabochiy

(53) 621.316.925 (088.8)

(56) A predetermined phase switching device for testing protective relays in transient conditions. - Electric stations. M., 1967, No. 10, pp.84-85.

Semiconductor phase switch. - Electric stations. M., 1971, No. 3, p. 65-68.

(54) PHASE KEYBOARD DEVICE

(57) The invention relates to a phase switching control device at a predetermined alternating current period.

(The purpose of the invention is to simplify the device, expand the functionality and increase the switching accuracy at the time of the voltage crossing over zero value. The goal is achieved by making the control unit in the form of a temporary bridge, the shoulders of which include optothyristor control diodes. The output elements of the optothyristor are included capacitor charge and discharge circuit. The signal at the right time is provided due to the discharge of the capacitor, charged and discharged in a predetermined sequence, emoy cases moments of opening and cutoff diode bridge rectifying unit. 2 yl.

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The invention relates to electrical engineering, namely, devices for switching on to a predetermined phase, and can be used. use for physical simulation of transients, for testing high-speed relay protection and current sensors, as well as for phase control of switching on power circuits with the aim of limiting switching currents.

The aim of the invention is to simplify the device, expand its field of application and increase the switching accuracy at the time the voltage goes over zero.

Figure 1 shows the device; in fig. 2 - time №1e signal diagrams.

FIG. 1 the following notation is used: 1-6 - diodes of the rectifying bridge of the control unit connected to the phase-shifter; 7 - optocoupler thyristor containing a control diode (arrow out) and an output element (arrow inside ;, included in the conditionally conducting at the moment three-phase rectifier arm; 8 - additional optocoupler thyristor, the control diode of which is included in the conditionally non-conductor current rectifier shoulder; 9 — ballast resistor; 10 — auxiliary rectifier; 11 — resistor to limit the current in the circuit of control diodes of power optocoupler thyristors 12 and 13; 14 — control switch; 15 — charge

cl

Yu

iodine; 16 - charging resistor; 17 -. storage capacitor; 18 - additional, complementary optocoupler thyristor; 19 - discharge resistor; 20 - phase - with regulator. The elements GO-13 and 18 form the power unit of the device, the elements 1-9, 15-19 the control unit.

Fig 2 accepts; the following designations:, Ujj, Upj ,, are the linear 10 voltages of a phase regulator or network in its absence; 1 ,, i- are the currents in the circuits of the corresponding 1.2 diodes of a three-phase rectifier; Uc is the voltage across the capacitor 17. 15

The device works as follows.

Assuming that key 14 is closed manually at time t, (FIG. 2), At this moment 20 diodes 1.7.6 pass through the action of voltage Jos (potential point a is greater than potential c), opposite in phase The voltage 11, -, shown in FIG. 2, wherein the charging diode 15 and the output element of the optocoupler thyristor 7 are open and the capacitor 17 is charged with the voltage Ugj. through a resistor 16 to a value corresponding to the non-target voltage of the applied voltage and constant charging time, for a period of time ,,,,. When the applied voltage and the voltage across the capacitor are equal, the charge stops and the diode 15 closes. The voltage Ut on the capacitor from the time t retains almost constant value, since the discharge circuit 8, 18, 19 At the moment t5, when the voltage goes up to the NIN through a zero value (FIG. 2), the diodes 3, 2 and the control diode of the optocoupler thyristor 8J, flowing through the current i, open up under the action of the voltage Ujjg 45 pulse to the output element of the thyristor 8, which opens the discharge circuit of the capacitor 17. The capacitor 17 is discharged It is located on the circuit 17-8-18-19-17. In this case, the discharge current flows around the control diode of the optocoupler thyristor 18, including the output element in the circuit of the control diodes of the power optocoupler thyristors 12 and 13, the current of which is limited by the resistor 11, The power circuit is turned on at the moment t, corresponding to the moment of the crossing of the voltage U, when the key 14 is reached at the moment when it does not pass

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0 5 O g about 5 p

five

the diode 1 leads, an automatic delay occurs until time t4, after which the process proceeds as described. The delay is due to the fact that in this case there will be nothing to excite the emitter of the optocoupler thyristor 18, since capacitor 17 is discharged and it is required to wait for its aar - and the subsequent discharge through the circuit of the optocoupler thyristor 8, the charge of the same capacitor 17 will start only after that moment the time when the voltage U will again become the greatest and. diode 1 will begin to conduct current again.

Switching on the output circuit is always ensured at the moment of the transition of the voltage Idd, through a zero value, Dp of creeping a given switching phase, it is necessary to shift the voltage system and,, with the help of a phase regulator. , and up to, relative to the voltage of the power circuit, thereby shifting the point of voltage transition through a zero value and, accordingly, the moment of issuing a pulse to turn on the load, which ensures the required switching on phase. If it is required to include the load only at zero voltage, the use of a phase regulator is not required,.

By coordinating the parameters of the resistors in the control diode circuits in the proposed device, a transformer is not required, and the inclusion of these diodes in the shoulders of the coupling bridge eliminates the need for smoothing capacitances or a separate DC source. This simplifies the device and improves its weight and size indicators, ..

The proposed circuit allows switching on the control diodes to different arms of the switching bridge and connecting the storage capacitor to the corresponding voltage — to switch on any voltage of the three-phase system at the moment of going through the zero value. For example, if the control diode of the optotristor 7 is inserted into the shoulder of the bridge in which diode 3 is installed, the control diode of the optothyristor 8 will turn on the shoulder of the bridge in which the diode 4 is turned on, and the voltage UL, then the load is turned on at the moment of passing through the zero value of the voltage -U j. The device circuit allows, by adding optocouplers to two other branches of the bridge, two accumulators and two output circuits, to alternately turn on the load in different phases of the three-phase circuit. The multiplication of the output signal is achieved by simply adding control diodes of the power optothyristors. 10 The sensor is connected to another input.

The ability of the phase regulator to refuse when the load is switched to zero voltage and the ability of the circuit to automatically generate an output signal at the exact moment when the voltage crosses the zero value allows the use of the device dp phase control of switching on the power circuits in order to limit the turn-on currents of the power load, for example, lighting, or starting currents of asynchronous motors. All of the above expands the functionality of the device.

Increasing the voltage zero-voltage accuracy is provided by using the control bridge of the control bridge of the three-phase rectifier arising with the active load, according to the principle of operation, as signals for controlling the currents of the arms, precisely at the moment of passing through the zero value of the corresponding voltage.

control unit, and a discharge capacitor circuit, connected in parallel with the storage capacitor, is

15 in order to expand the scope of application, simplify and improve the switching accuracy at the time of voltage crossing over zero value, the control unit is designed as

A 20 phase full-wavelength heat bridge loaded with a newly introduced ballast resistor, the newly introduced controls

25 | optical diode thyristor diodes,

the input elements of which are included respectively in the charge and discharge circuits of the storage capacitor, respectively, accumulate in the discharge circuit

On the 30th capacitor, a control diode of a newly introduced additional optical thyristor is connected, the output element of which is connected to a circuit consisting of in series with

Formula

gaining

A phase-switching device containing a control unit whose inputs have terminals for connecting to

1469529

, 6

corresponding phasoregulator outputs connected to the inputs of the auxiliary end of the power unit, the control key, the charging capacitor charge circuit, the first output of which is connected to the corresponding input of the control unit, the second output through the accumulative control unit, and the accumulating code capacitor discharge circuit connected in parallel to the accumulator capacitor -different

By the fact that, in order to expand the scope of application, simplify and improve the switching accuracy at the time of the voltage passing through zero, the control unit is designed as a three-phase full-wave switching bridge loaded with a newly introduced ballast resistor, the newly entered controls are included in the corresponding shoulders diodes of optocoupler thyristors, the input elements of which are connected in series, respectively, to the charge and discharge circuits of the storage capacitor, to the accumulator discharge circuit Nogo capacitor included control of the newly introduced additional diode optroynogo thyristor, the output element of which is included in the chain consisting of a series-connected control key and the newly introduced control kytsih power optocoupler diode thyristor power unit, and wherein said chain is connected to the output of the auxiliary DC converter vtr

power unit.

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t1 Pi

Editor T. Lazorenko

Compiled by K.PYlan Tehred L. Serdyukov a

Order 1362/55

Circulation 605

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. D. 4/5

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61 (1.2

Proofreader M.Vasilyeva

Subscription

Claims (1)

Claim Phase switching device containing a control unit, the inputs of which have terminals for connecting to I to the corresponding outputs of the phase regulator connected to the inputs of the auxiliary rectifier of the power unit, a control key, a storage capacitor charge circuit, the first output of which is connected to the corresponding input of the control unit, the second output through the storage capacitor is connected to the other input of the control unit, and the discharge circuit of the storage capacitor connected in parallel to the storage capacitor, characterized by 15 in that, in order to expand the scope, simplify and improve the accuracy of inclusion in the moment the voltage passes through the zero value, the control unit is made in the form of a three20 phase half-wave rectifier bridge loaded with a newly introduced ballast resistor; The output diodes of the optocoupler thyristors, the output elements of which are connected in series in the charge and discharge circuits of the storage capacitor, respectively, the control diode of the newly introduced 'additional optocoupler thyristor is included in the discharge circuit of the storage capacitor, the output element of which is connected to a circuit consisting of 25 control keys connected in series and newly introduced control diodes of power optocoupler thyristors of the power unit, and this circuit is connected to the output of the auxiliary rectifier 40 power block.