SU1302392A1 - Device for forced commutation of converter thyristors - Google Patents

Abstract

The invention relates to a converter technique. The goal is to expand the field of use by increasing frequency capabilities. The device contains a three-phase bridge switching thyristors (CT) 3-8. The pins of the AC bridge KT 3-8 are connected to LC circuits 9-14, the other ends of which are connected to two separation diodes (RD) 17,18. Series-connected thyristors (TS) 15, 16 with a common point are connected to a common point RD 17.18. When disconnecting ZT 16, a charge of capacitors of LC circuits 9–12 is applied. the recharge time of the capacitor of the third LC circuit 13, 14. 3 Il. (L o oo oo x ISD Uf 33 It 3..S.ff, 7, ff 15.16,29,30 ParaA

Description

. The invention relates to converter technology and can be used to force the switching of thyristors in controlled rectifiers and inverters, as well as in traction drives of AC electric locomotives with asynchronous motors.

The purpose of the invention is expansion windings — to the anode and cathode of return diodes 25 and 26. Common connection points of the windings are connected to the terminals of discharge diodes 23 and 24. Charging thyristors I5 and 16 are connected by their leads to a common connection point of separation diodes 17 and 18 Commuting thyristors 4 and 7 are shunted by counter-switched on the utilization of the field of use by means of alternating frequency diodes 27 and 28.

FIG. 1 shows the principle of thyristors 29 connected by cathodes to the circuit of the device forced to the corresponding terminals of thyristor switching; in fig. 2 - diagrams of the converter 1, anodes to control pulses, explaining the operation of the second separating diode of the device, J5, a. also the pulse curves 8. A cathode group of current and voltage distributions at the switching thyristors 30 is connected to capacitors; in fig. 3 is a functional diagram of one of the possible variants of a control signal generator and a voltage diagram explaining its operation.

A forced switching device is connected to common buses connecting the thyristor converter 25 3-8,15,16,29 and 30. 1 with power supply 2 and contains the proposed device operates a three-phase bridge switching 3-8, three switching circuits 9-14, consisting of capacitors 10, 12 and 14 and chokes 9, 11 and 13, two charge thyristors 15 and 16, two separation diodes 17 and 18 switching transformer with two primary windings 19 and 20, two secondary windings 21 and 22, two bit diodes 35. - Capacitor 10 starts transmission 23 and 24, two return diodes 25. charged along the circuit: elements 10,17, and 26, two reverse diodes 27 and 28, two groups of distribution thyristors 29 and 30, a resistor 31, a driver 32 of control signals. The anodes of the thyristor – 40 and the distributing thyristor of the anode grouper 3,5,7 and 15 and the cathodes of the diodes 23, the thyristors 29 to the locking thyristor 26 and 28 are connected to the positive torus of the converter 1 in the reverse of the power supply 2, the cathodes in the same direction and the load current of the transistors 4, 6, 8, and 16 and the anodes of the diodes from the circuit of the power thyristor are pre-24.25 and 27 - to the negative bus of generator 45 to the switching circuit LC-source 2, power 9 and 10.

One ends of the LC circuits 9-14 are connected to the AC terminals of the bridge.

anodes to the terminals of the thyristor converter 1, cathodes - to the anode 20 of the first separating diode 17. A resistor 31 is connected to the buses of the power supply source 2. The outputs of the 32 control signals are connected to the control electrodes of the thyristors

Suppose that at the initial time, the capacitors of 10, 12, and 14 LC circuits are charged with the polarity of the voltage shown in FIG. 1. According to the control diagram (Fig. 2), at time t, tiris 18, 19,23,3,9 and 10 are turned on. The voltage of the primary winding 19 of the switching transformer is applied through triaxial thyristors 3-8, others

At time t, the switching thyristor 5 is turned on, and the load current is transferred from the LC circuit 9 and 10

the ends are to the anode, the cathode of the common point -50 LC circuit I and 12. The capacitor current ko of the connection according to the sequence 12 closes along the circuit: elements 12, but the switched-on diodes 17 and 18. The two primary windings 19 and 20 of the switching transformer are connected according successively from 55 is transferred to the LC circuit 13 and 14. The current of the two secondary windings 21 and 22. The capacitor 14 is closed in the following circuit: Outputs of the primary windings 19 and 20 are elements 14, 19, 23, 7, 13 and 14. connected to the anode and cathode, the separation of the time of the instantaneous significant diodes 17 and 18, the outputs of the second. capacitor current 14 set to

18,19,23,5,11 and 12. At time t ,. switching thyristor 7 is turned on, and the load current from the LC circuit 11 and 12

thyristors 29 are connected by cathodes to the corresponding terminals of thyristor converter 1, anodes to 5 cathodes of the second separation diode 8. The cathode group of distribution thyristors 30 is connected

5 3-8,15,16,29 and 30. The proposed device works in an emic manner, 35. - Condenser 10 starts recharging along the circuit: elements 10.17, 0, the thyristor anode group 29 of the thyristor 29 to the closing thyristor of converter 1 in the reverse direction, and the load current is transferred from converter I to V LC commuting circuit 9 and 10.

the anodes to the terminals of the thyristor converter 1, the cathodes to the anode 0 of the first separating diode 17. A resistor 31 is connected to the buses of the power supply source 2. The outputs of the 32 control signals are connected to the control electrodes of the thyristors

3-8,15,16,29 and 30. The proposed device works in an emic manner,. - Condenser 10 starts recharging along the circuit: elements 10,17, the limiting thyristor of the anode group of thyristors 29 to the closing thyristor of converter 1 in the opposite direction, and the load current is transferred from the circuit of the power thyristor of converter I to switching LC - Chain 9 and 10.

Suppose that at the initial time, the capacitors of 10, 12, and 14 LC circuits are charged with the polarity of the voltage shown in FIG. 1. According to the control diagram (Fig. 2), at time t, tiris 3-8, 15,16,29 and 30 are included. - Condenser 10 starts recharging along the circuit: elements 10,17, the limiting thyristor of the anode group of thyristors 29 to the closing thyristor of converter 1 in the opposite direction, and the load current is transferred from the circuit of the power thyristor of converter I to switching LC - Chain 9 and 10.

18,19,23,3,9 and 10. The voltage of the primary winding 19 of the switching transformer is applied through races of the AND circuit 12. And the current of the capacitor 12 is closed along the circuit: elements 12, is transferred to the LC circuit 13 and 14. The capacitor current 14 is closed along the circuit: elements 14,19,23,7,13 and 14. On the interval of time, the instantaneous value of the current of the capacitor 14 becomes

18,19,23,5,11 and 12. At time t ,. switching thyristor 7 is turned on, and the load current from the LC circuit 11 and 12

less load current and discharge diode 23 is closed.

The energies of the load current and the throttles 13 are transmitted to the capacitor 14 through the circuit: elements 13, 14, 29, 1, 7, and 13. From the curves for example, the voltage on the switching capacitors shows that due to the energy stored in the switching reactor in the time interval t -t ,. the voltage on the capacitor 14 becomes higher than the voltage of the power source and the other. Thyristor 7 is locked by a voltage difference U Ug - time tj starts the output of the excess energy of the switching capacitor 14 to the power source 2 along the circuit: elements 14,13, 28,32,2,24,20,17, 18 and 14.

At time t, the voltage of the capacitor 14 is equal to the voltage of the power supply and, and the switching process ends. From the voltage curves of the switching capacitors, and, d, and (Fig. 2), it is clear that at the end of the switching process, the voltage on the switching capacitors 10 and 12 is lower than the voltage of the power supply 2. Therefore, dosarbing of switching capacitors 10 and 12 is performed on the time interval t, -tg.

At time t according to FIG. 2 control pulses are applied to thyristors 3.5 and 16, and capacitors 10 and 12 are charged in circuits: elements 2,3,9,10,17,16,2 and 2,5,11,12,16,2 . Thus, the dispensing of the capacitors 10 and 12 is performed during the recharging of the capacitor 14 of the third LC circuit.

At time t, the next switch begins. The thyristor 8 is turned on and the capacitor 14 is recharged along the circuit: elements 14,13,8,24,20 17,18 and 14. The voltage of the winding 20 of the switching transformer through one of the distribution thyristors 30 of the cathode group is applied to the thyristor of the converter 1 in the opposite direction . The load current from the switching thyristor of the converter 1 is transferred to the LC circuit 13 and 14. At time t, the switching thyristor 6 is turned on and the load current from the LC circuit 13 and 14 is transferred to the LC circuit 11 and 12. The capacitor 12 is recharged along the circuit : elements 12,11,6,24,20,17 and 12. At time t, Q, the thyristor 4 is turned on, and the load current is transferred

ten

J5

 jC chains 1 1

4 12 in

20

25

,,

thirty

35

40

45

50

55

and I / in LC circuit 9 and 10. Capacitor 10 is recharged across the circuit; elements 10,9,4,24,20 and 10. The energy stored by the load current in the choke 9 is transferred to the capacitor 10 along the circuit: elements 9,4,1,30, 10 and 9. The output energy of the switching capacitor 10 is carried out on the time interval t ,, j -t along the chain: elements 10,17-19,23,2,27,31,9 and 10.

At time t ..., the discharge of capacitors 12 and 14 along the following circuits is carried out: elements 2,15,12,11,6,2 and 2,15,18,14,13,8,2. Thus, the dispensing of capacitors 12 and 14 is carried out over the time interval of the recharging of the switching capacitor 10. The implementation of the dispensing of switching LC circuits over the time interval t -t reduces the inter-Baj time between commutations by an amount equal to the duration pulse, and thus expand the functionality of the forced switching node.

The control signal generator 33 (FIG. 3) consists of the distribution of control pulses, implemented in the form of two control channels on the logic elements. Each channel of the pulse distributor consists of amplifiers 34-39, one-shot 40-42, logic elements OR 43 and 44. Shaper 33 also includes a frequency adjuster 45. The outputs of the regulator 45 are connected to the inputs of the shaping amplifiers 34 , the outputs of the amplifier-shaper 34 - with the inputs of one-vibrators 40-42 and with the input of the logic element OR 43. The outputs of the single-oscillators 40-42 are connected to the inputs. amplifier shapers 37-39. The output of amplifier 37 is connected to the input of the OR 44 logical comparison element. From the outputs of the amplifier-form. The telephones 35 and 36 and the logic elements OR 43 and 44 control signals are provided to thyristors 3,5,7 and 16 in the first control channel and to thyristors 4,6,8 and 15 in the second control channel.

The control signal shaping device according to the voltage diagram (Fig. 3) operates as follows.

To the input of frequency controller 45, a signal Uf is applied to the output signal

frequency From the output of frequency regulator 45, two signals are formed: + ID, ID, etc. According to the voltage diagram (Fig. 3), on the trailing edge of the signalob + id, the pulse shaper 34 forms a pulse arriving at the inputs of one-shot 40-42. One-vibration on the leading edge of the pulse U ForU h

pulse pulses of equal duration

time t.-t ,.

 3

t, -t. On the leading edges of these pulses, the formers 37-39 form pulses arriving at the formers 35 and 36 and the logic element 44. On the leading edges of these pulses, the formers 35 and 36 generate control pulses at the inputs of the UPC thyristors.

Claims (1)

Invention Formula A thyristor forced switching device for a converter containing a power source, to the output buses of which the corresponding DC inputs of a three-phase commutating thyristor bridge are connected, the two corresponding thyristors of which are bridged by reverse-connected diodes, the corresponding outputs of two charging thyristors, the corresponding outputs of two return diodes, corresponding - 5 W 15 the following pins of two bit diodes, two split-diode series connected in series, three switching LC circuits connected by one pin to the alternating current outputs of the three-phase bridge of the switching thyristors, other corresponding pin to the first anode, to the cathode of the second and to the common junction point of the separation diodes , a switching transformer connected by the respective outputs of the primary windings to the anode of the first and to the cathode of the second isolation diode, the corresponding conclusions of the secondary voltages The flow to the anodes and cathodes of the discharge and return diodes and to other outputs of the primary windings, the anode and cathode groups of the distribution thyristors connected by anodes to the cathode of the second separating diode, to the anode of the first separating diode and other anodes and cathodes to the corresponding -. thyristor rgo transducer, control signal generator connected to the control electrodes of switching and charging thyristors, characterized in that, in order to expand the range of use by increasing frequency capabilities, other charging thyristor outputs are connected to a common connection point once - 35 separating diodes. 20 25 thirty 4J 1 Oj 3 { iOJ one