SU603074A1 - Direct frequency converter with artificial switching of thyristors - Google Patents

Description

single phase output; in fig. 2the same with three-phase output.

For simplification, triacs are used in the construction,.

A directly coupled frequency converter (see Fig. 1) consists of a power circuit built on a bridge circuit on symmetric or anti-parallel thyristors 1-6 (chokes, in series with symmetrical thyristors not shown), a forced switching unit consisting of a three-phase diode bridge 7 connected to cTQpoae of direct current to the diagonal of direct current of a single-phase ti-disk cable {5 bridge formed by thyristors 8., one of the diagonals of the cxeMbi in d is included in the alternating current of this bridge The arms of the arm include thyristors 12 and 13, and the other two arms of the chain, formed by connecting the choke 14 and the switching capacitor 1S in one shoulder and the choke 16 and switching capacitor 17 in the other shoulder, to the second pavement diagonal

the circuit is connected to a distribution thyristor nI1Y bridge, formed by thyristors 1 & 21, the second diagonal of which has a load 22 and the current direction load sensor 23, connected to the control unit, which consists of 2.4 generator, pulse distributor and 25 circuits 26 matches. Through the chokes 27, 28, 29 the converter is connected to the network.

In the proposed converter, a method is used to form an output voltage curve by blowing a cyclic connection for equal periods of load to the linear supply lines. In this case, the algorithm for power thyristors is as follows:

AB (2 and 5) (1-6) (2 and 6) (2 and 4) and 4), (3 and 5) ,.

where AB.BCjAC ' is the line voltage to which the thyristor number load is connected. 1, 3,4,5,6, connecting the load to linear voltage m.

It can be seen from the above algorithm that alternation of thyristors 1-3 occurs in turn, and then in the shoulder with thyristors 4-6.

Suppose control pulses from master oscillator 24 through distributor 2 5 pulses are supplied to power circuits 1 and 5 and with a certain delay to the 9, 10, 13, and 13 switches. At this switching terminal, the capacitors 15 and 17 are charged with the polarity indicated in fig. 1. At the next moment of time, the load switches to another linear voltage, suppose using thyristors 1

6.- Consequently, it is necessary to quench the iristor 5, in order to determine which commuting capacitor needs to be connected in parallel with the power thyristor, the load current direction sensor 3 is connected in series with the load, the signal arrives at the coincidence circuit 26. On the other hand, pulses are received from the control of the generator 24 through the distributor of 25 pulses, and from the output of the coincidence circuit, control pulses are sent to various thyristors 18-21, depending on the direction of the load current. If thickening occurs in the shoulder with thyristors 1-3, then the pulse distributor 25 outputs control pulses. on thyristors / 8-11 single-phase thyristor bridge. If extinguishing occurs; in the shoulder with thyristors 4-6, the control pulses are fed to thyristors 9 and 10 of a single phase thyristor bridge. For example, if the direction of the current corresponds to the direction indicated by an arrowhead, then for controlling the thyristor 5, control pulses are applied to the thyristor 20. With some delay sufficient to restore the blocking properties of the thyristor 5, the thyristor 21 turns on, providing accelerated overcharging of the capacitor (we assume that the capacitors charged with polarity indicated in ck (5bkah), lo circuit:, capacitor 17 - thyristors 20. and 21 choke 14 - capacitor 15 thyristor Yu, source of cytans, thyristor 9, choke 16. + capacitor 17. Next It is necessary to repay the thyristor

After the previous switching cycle, the capacitors are charged with polarity,., Indicated without brackets. Then, to quench the thyristor 1, a control pulse is applied to the thyristors 8, 11, 18, as well as some delay, sufficient to restore the blocking properties of the thyristor 1, a control pulse I is applied to the thyristor 19, providing an accelerated capacitor recharge across the circuit + capacitor 17 - thyristors 18 and 19 - choke 14 - capacitor 15 thyristor 8 - power source - thyristor 11 - choke 16 - - V capacitor 17. To provide the initial charge of the condenser capacitors with the polarity indicated without brackets, at the moment the converter is turned on It gives control impulses to the thyristors 9, 10, 12 and 13, as well as the thyristor ,, comprising conductive thyristors 1-3 entrance shoulder.

The operation of the converter in the three-phase-three-phase variant is as follows (see FIG. 2), where the SO-35 symmetric thyristors, 3639 thyristors, 4O-load, 41 current sensors, 42-47 symmetrical thyristors, 4851 thyristors, 52- load, 53-current sensor, 54-59-diode bridge. Let included thyristors 1,5,30 ,. 34 ,, 42,26, then the current in the load flows as shown by the arrow (see Fig. 2). In accordance with the VII with the control algorithm, the next moment it is necessary to turn off the thyristors 5 34, 46 and turn on the thyristors 6, 35, 47. With the polarity of the switching capacitors indicated in brackets, they dissipate suppression in the right arms of the power bridges (thyristors 4-6 and others), and with the reverse in the left shoulders of power bridges (thyristors 1-3, etc.). To turn off the thyristor 34, a control pulse is applied to the thyristors 9 and 38. In this case, the capacitor 17 is discharged along the circuit: + choke 16 - thyristor 9 - one 54 - thyristor 34 - thyristor 38 -. - and after turning off the thyristor 34 continues to discharge through the load on the circuit:, choke 16 -. thyristor 9 diode. 56 - thyristor 30 load 4O - sensor 41 - thyristor 38 -. At the same time, for turning off the thyristors 5 and 46 sub-drives, control pulses to Thyristors 10, 21 and 51. Two discharge circuits of capacitor 15 are formed. The first circuit: + - choke 14 - thyristor 21 thyristor 5 - diode 59 - thyristor, 1О and after switching off the thyristor 5, the discharge circuit is changed + choke 14 drive 21 - load 22 - sensor 23 thyristor 1 - Diode 58 - thyristor 10 Secondary circuit: + choke 14 - thyristor 5 thyristor 46 - diode 58 thyristor 1O - and after turning off the thyristor 46, the capacitor discharges along the circuit: throttle 14 thyristor 51 - sensor 53 - load 52 thyristor 42 - diode 57 - thyristor 10 After supplying, after a time equal to the recovery time of the locking properties of the thyristors 5, 34, 46, control pulses to the thyristors 12. and 13, an accelerated recharge of the switching capacitors with the polarity indicated without brackets occurs (Fig. 2), and thyristors 21, 38, 51, under the action of reverse voltage, restore their locking ability. Simultaneously with the supply of pulses to the thyristors 12 and 13, the impulses are applied to the inclusive regular power thyristors 6, 35, 47. The next switching cycle should ensure the suppression of thyristors 1, 30.42. The direction of the currents remains the same. In this case, control pulses are applied to the thyristors 8 and 11 of the single-phase bridge and to the thyristors 19, 36, 4E of the distribution bridge. Capacitor 17, discharging on the circuit + - thyristor 35 - tyrnstor ZO - diode 59 - thyristor 11 - choke 16 - -, turns on the thyristor AOR and continues to discharge on the circuit:, + - thyristor 35 - load 40 - sensor 41 - thyristor 34 - 57 diode diode 11 - choke 16 - -. The capacitor 15 forms two switching circuits: the first choke 14-thyristor G9-thyristor 1 - diode 55 - thyristor 8 - + and after turning off the t-thyristor 1 continues to discharge in the circuit: choke 14 - thyristor 19 - sensor 23 - load 22 - ; thyristor 5, - diode 56 - thyristor 8- +. Second circuit - choke: 14 - thyristor 49 - thyristor 42 - diode 54 - thyristor 8 - + and after the thyristor is turned off - 12 continues to discharge in the circuit: .- choke 14 - thyristor 49 n-pgruek 52 - sensor 53 - thyristor 46 diode 55 tnrnstor 8 +. After a time equal to the recovery time51 of the fill properties thyristor 1.30, 42, pulses are applied to turn on the thyristors 18, 37 and 48. At the same time, the switched on thyristors 8 and 11 are formed. A circuit is formed to recharge the capacitors along the circuit: + three phase bridge rectifier, 11tel (common point of cathodes) - thyristor 11 - choke 16 capacitor 17 - thyristor 18 - shooting gallery, pstor 19 - (parallel 36, 37, -18, 49) - choke 14 - capacitor 15 - thyristor 8 - - three-phase bridge rectifier. In this case, the capacitor is recharged with the polarity indicated in the brackets, and the clamping switches 18, 19, 36, 37, 48, 49 are turned off. This ends the full cycle of the switching node. FORM OF THE INVENTION 1. Immediately, a clock frequency converter with natural switching of thyristors, containing counter-parallel including SSh18 thyristor bridges, a unit of forced switching, including an impulse switching unit, including a diode bridge, a single key input, including a key, and a single key, which contains a single key, which contains a single key, and a single key. A converter and output gzz zanny with a diagonal of the spinal current of, tsyufaztsogo t rstornogo osta, a bridge of distribution thyristors, bottom bottom connected to the output pins, Bpol1O) teli nye tristor, omnitrefied throttles and coilshchens They are also a unit, control, a switchboard, a generator, an impulse distributor, phase current sensors and logical part, which, for the sake of simplicity, the forced switching unit a bridge circuit, two shoulders and which are subsequently formed by nominal capacitors and throttles, and the other two shoulders are formed by thyristors, and the diagonal of this bridge circuit is connected to the AC diagonal of the single-phase thyristor bridge, and the other to the other diagonal of the bridge tors.

2. The direct frequency converter according to p. 1, 6 t. L. And h and y with the fact that, in order to improve energy performance, the bridge of distribution thyristors is made in the form of a contour of thyristors connected in series in the conductive direction

Sources of information taken into account in the examination:

1. USSR author's certificate No. 180689, cl. aid 14/02, 1965

2. USSR author's certificate number 213958, cl. 21 b 14/02, 1965.

3. USSR author's certificate No. 309435, cl. 21d l4 / 02; 1968.

4. Koroban N., Mast “a% N. 3. iMytsykG. C. Construction and classification of direct frequency converters with artificial switching., Current tasks of converter equipment, Part 2, Kiev, 1975, p. 132-14.

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