DE2340883A1 - Constant voltage regulator - employs pulse width modulation using thyristor circuit to avoid short-circuit supply problem - Google Patents

Abstract

A thyristor control circuit is used for voltage regulation using a pulse width modulation mode of operation. When the supply is connected, a control pulse is generated for reset thyristor and a first capacitor is charged, while a second capacitor discharges over the output loads. At the end of this process the reset thyristor is inhibited. The load thyristor and power thyristor are gated with a control pulse and thyristor is inhibited after capacitor operation. The next control pulse is applied to the reset thyristor and an inhibiting signal is applied to the power thyristor.

Description

Patent attorneys Dlpl.-Ing. R. B ΓΞ Ε Τ Ζ ββη * DIpWn π · Κ. LAMP. -VIEW

Dr.-lng. R. O: ϊ E T Z Jr. β Mlaehen 22, Steinederfrtr. W.

530-21.229P August 13, 1973

1. Lev Vasilievich Vasiliev, USSR, Yasnogorsk Tulskoi Oblasti, ulitsa Komsomolskaya, 39 (USSR)

2. Elizbar Georgievich Buyanov, USSR, Yasnogorsk Tulskoi oblasti, ulitsa Mashinostoitelei (USSR)

Voltage regulator

The invention relates to a contactless static voltage regulator, in particular on a thyristor voltage regulator, and can be used in DC circuits to control the electric drive different Means of transport, such as mine electric carts and loaders, are used.

Thyristor voltage regulators are known which have a direct current supply source, a working circuit connected to the terminals of the supply source, consisting of a working thyristor (power thyristor)

530- (P. 50 605/2) -Hd-r (8)

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and a consumer connected in parallel to this (e.g. a DC motor) included.

To block the working thyristor, a commutation circuit consisting of a series connection of a commutation capacitor is installed in parallel with it and an auxiliary thyristor switched.

When operating this controller, the charging of the commutation capacitor only take place when the power thyristor is blocked. This is a deficiency of the regulator circuit, since each time the Commutation of the working thyristor in one working cycle, i.e. when it opens after the commutation capacitor has been charged remains, the commutation capacitor is no longer charged in the next operating cycle, so that the circuit loses its control . Restoring the controllability of the. In this case, switching is only possible by mechanically switching off the supply source.

A voltage regulator is also known (cf. GB-PS No. 1 123 022), in which an auxiliary charging thyristor is provided, which is used by the working group ensures independent charging of the commutation capacitor.

A disadvantage of the voltage regulator circuits described above is their poor reliability in the event of a commutation fault the auxiliary thyristors, for example in the event of a sharp increase in the load current, a fault in the thyristor control circuits, because here the source of supply via the series-connected and

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Auxiliary thyristors which have become conductive at the same time are short-circuited.

Furthermore, voltage regulators (cf. GB-PS No. 1 060 317 and No. 1 234 765) are known in which the possibility of a short circuit the supply source is excluded in the absence of commutation of the auxiliary thyristors, since the charging of the commutation capacitor takes place via the consumer.

However, with the regulators mentioned, the charging current of the commutation capacitor is depends on the consumer current, which reduces the control range, since the charging time is reduced with low consumer currents of the commutation capacitor increases.

The invention is based on the object of a voltage regulator to create, which has a wide control range, the controllability the circuit can restore after any failure of commutation, and in which the risk of short circuits of the supply source in the absence of thyristor commutation, is excluded.

This task is performed in a voltage regulator with a power thyristor connected between a supply source and a consumer and one of the series connection of a reactor and a capacitor existing commutation circuit, the one with one end is connected via a quenching thyristor in the circuit between the power thyristor and the consumer, according to the invention thereby solved that the other end of the commutation circuit is connected to one pole (+) of the supply source via an isolating diode,

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while an additional commutation circuit is parallel to the commutation circuit , consisting of the series connection of a thyristor and a choke, is connected to the connection point of the Commutation circuits and the quenching thyristor a capacitor is placed, the second layer of which with the other pole (-) of the supply source connected is.

For a better understanding of the invention it is through a detailed Description of an exemplary embodiment with reference to the drawing consisting of a single figure, which is a basic circuit diagram of the Voltage regulator reproduces explained.

The thyristor voltage regulator has input terminals 1, 2 and Output terminals 3.4. A direct current supply source with the voltage U is connected to the input terminals. The positive pole + the supply source is connected to terminal 1 and the negative pole - to terminal 2. A consumer is connected to output terminals 3, 4 5 connected.

A power thyristor 6 is connected in the circuit between the input terminal 1 and the output terminal 3. The anode of the Power thyristor 6 is connected to the positive pole of the supply source and the cathode is connected to consumer 5.

An isolating diode 7 is connected to the positive pole of the supply source, with which a commutation circuit, consisting of the series connection of a choke 8 and a capacitor 9, is connected in series.

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The lower layer of the capacitor 9 is connected to the cathode of the power thyristor 6 connected.

In parallel with the commutation circuit, which consists of the choke 8 and the capacitor 9, there is an additional commutation ^ circuit, consisting of the series connection of a charging thyristor 11 and one Choke 12, switched. Here, the anode of the thyristor 11 is connected in the circuit between the isolating diode 7 and the choke 8, while the cathode of the thyristor 11 is connected to one end of the choke 12, the other end of which is in the circuit between the capacitor 9 and the anode of a quenching thyristor 10 is placed.

At the common point 13 of the commutation circles and the Quenching thyristor 10 is connected to a capacitor 14, the second of which Coating is connected to the negative pole of the power source.

The mode of operation of the controller is based on the principle of pulse width modulation .

When the voltage is applied from the supply source, there is an oscillating Charging of the commutation capacitors 9 and 14 via the isolating diode 7 and the choke 8 takes place (the polarity of the charge is shown without brackets). Then a control pulse is given to the quenching thyristor 10, the capacitor 9 oscillating over the Isolating diode 7, the choke 8, the quenching thyristor 10 and the consumer 5 to a voltage that exceeds U (bis'2 U), further charged will. In this case, the capacitor 14 discharges to zero

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via the consumer 5. After completion of the charging of the condenser, Sators 9 and discharge of the capacitor 14 is the quenching thyristor 10 blocked. Then the power thyristor 6 and the Charging thyristor 11 is given control pulses at the same time, as a result of which the thyristors mentioned are opened. Via the power thyristor 6 and the load 5, a current flows, and the capacitor 9 is charged in an oscillating manner via the charging thyristor 11 and the Chokes 8 and 12 µm (the polarity of the charge is in parentheses shown), while the capacitor 14 oscillates via the isolating diode 7, the thyristor .11 and the choke 12 to a voltage

voltage that exceeds U discharges.

After completion of the charge reversal of the capacitor 9 and charging of the capacitor 14, the thyristor 11 is blocked.

When the next control pulse arrives at the quenching thyristor 10 is to the power thyristor 6, a reverse voltage from the Koinmutierungskondensatoren 9 and 14 for the time, the Restoration of the blocking properties of the power thyristor 6 is required, laid. After blocking the power thyristor 6 the capacitor 9 oscillates via the isolating diode 7, the choke 8, the quenching thyristor 10 and the consumer 5 to a voltage, which exceeds the voltage U, while the capacitor is charged 14 is discharged to zero. After completion of the charging of the capacitor 9 and the discharge of the capacitor 14, the Quenching thyristor 10 blocked. These processes are ended before the next following control pulses arrive at the power thyristor and at the charging thyristor 11.

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When the next following control pulses arrive at the power thyristor 6 and the charging thyristor 11, those described above are implemented Repeated processes «In the event of a sharp rise in the consumer current and a drop in the supply source voltage, the isolating diode prevents 7 the discharge of the commutation capacitors 9 and 14 via the supply source, so that the energy supply for the commutation remains unchanged preserved. If the power thyristor i6 turns off has not blocked for any reason after the discharge of the commutation capacitors 9 and 14 via the quenching thyristor 10, is thanks to the charging thyristor 11, the working capacity of the regulator is restored. When the next control pulse arrives at the charging thyristor 11 and on the power thyristor 6, the commutation capacitors 9 and 14 are again provided with one for blocking the power Sthyristors 6 charge sufficient energy. This makes it possible, the control pulses at any time from the auxiliary thyristors 10 and 11 (the thyristor 6 in the consumer circuit remains open in this case, and the consumer is connected to the full voltage of the Supply source placed) and the mentioned impulses if a voltage regulation is required feed again at consumer 5.

From the description of the circuit according to the invention it can be seen that that the isolation diode 7 maintains the charge of the commutation capacitors in the event of a drop in the voltage of the supply source (for example as a result of a sharp increase in the consumer current) permitted, while the additional commutation circuit, which consists of the series connection of the charging thyristor 11 and the choke 12 , the ability of the circuit to restore control

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■ Barfcelt determined after a commutation fault, since the commutation capacitors are charged independently of the consumer current.

In addition, the capacitor 14 closes the possibility of a short circuit of the supply source via the thyristors in the event of a fault commutation, which also affects operational reliability of the bowler increased.

All of this allows the voltage regulator according to the invention to be used successfully in facilities where extensive Regulation of the voltage at the consumer is required.

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Claims (1)

Claim Voltage regulator with one between a supply source and one Load switched power thyristor and one from the series connection of a. Choke and a capacitor existing commutation circuit, which is connected to one end via a quenching thyristor Circuit is connected between the power thyristor and the consumer, characterized in that the other end of the commutation circuit is connected to one pole (+) of the supply source via an isolating diode (7), while parallel to the commutation circuit an additional commutation circuit consisting of the series connection of a thyristor (11) and a choke (12) is connected, with the connection point of the commutation circuits and the quenching thyristor (10) a capacitor (14) is connected, the second coating is connected to the other «pole (-) of the source of supply. 509809/0491 L β · r s β i t β