SU359875A1 - CONSTANT VOLTAGE CONVERTER - Google Patents

Description

Iso / std (constant voltage transducers, -containing thyristor | p: ny bl: 01K reverse current load; for example, in the form of a single-phase and ideo-phase inverter with reverse diodes and a switching node, at least The second co-capacitor and two thyristors, the common point of which is connected to one of the capacitor plates, is connected to the DC source through a sequential choke.However, in these 1 | | | HF ports the source voltage in the MOMieHT co-switching unit capacitor is applied to terminals a successive inductance | N | Aus on the BG; Odet, which leads to an increase in the current drawn from the source and circulating IB basic thyristors. This increased current is added to the discharge current of the capacitor. Thus, the amount of current passing through the thyristors of the converter at the moment of locking, more than two hours are two p, aza exceeds the magnitude of the gok circulating up to the uranium command in the thyristors carrying the load. In order for the thyristors to transcend, the capacitor must supply adequate energy that limits yvnuyu power converter.

The choke consists of at least two parts connected in series, and the other capacitor plate is galvanically connected to the common points of connection of the parts.

When performing a switching node in the form of a thyristor bridge, one of the diagonals of which includes a serial LC - chain, the latter is connected to the lining; a COP capacitor connected to the common connection point of the bridge thyristors.

The converter contains two auxiliary inductances, the magnitude of which is less than the inductance of the coaxial half winding. Through one inductance, the choke is connected to the power source, and through the other to the switching node.

When performing three-part throttles, the middle part is shunted by two series-connected elements of one-sided conduction, whose common junction point is connected to the capacitor.

FIG. Figure 1 shows one of the options for the implementation of the proposed converter feeding the measles of a direct current electric motor; in fig. 2 and 3 examples of the implementation of the switching node of the converter; on fig. 4 shows another embodiment of a converter that supplies measles to a direct current electric motor; in fig. 5 is a diagram of a converter supplying an alternating current electric motor; and FIG. 6-8-variants of the execution of the switching node of a PDA | brazo actuator supplying loads requiring large voltage changes.

Inverter / Thyristor COICTOMT converter and switching node 2 for locking these thyristors. The node KO | Mmutation contains two thyristors 3 i 4, sequentially, between two points 5 to 6 so that the anode of the thyristor 3 is connected to point 5, and the cathode of thyristor 4 is connected to point 6, the cathode of thyristor 3 is connected to the anode of the thyristor 4 at point 7. Point 5 is connected to the positive pole of the source 8 of the left side through inductance 9, between terminals 10 and 11 of which the shunt diode 12 can be turned on, and point 6 is directly connected to the negative pole of the source. Inductance 9 is provided with a proM | daily output 13, located approximately in the middle and connected to point 7 via a condensate. 14. The exact output of pin 13 can be determined using the equations for pa, zl, EFFICIENT TRANSIENT PROCESSES in the circuits containing the capacitor .

The inverter /, associated with the switching node in TOi4iKax 5 and 6, feeds the measles 15 DC motor. An anchor is included in the bridge diagonal 16–17, consisting of 18–21 thyristors. The anodes of thyristors 18 and 19 are connected to point 5, and the cathodes of thyristors 20 and 21 with point 6. To the terminals of each of the thyristors 75-21 diodes 22-25 are connected counter-parallel. Such a converter is designed to feed the core 15 with pulses, the amplitude and duration of which controls the magnitude of the average value of the current circulating in the core, and, therefore, the speed of rotation of the motor. The duration of the pulses depends on the duration of the conduction periods and the blocking of the thyristors that feed the measles.

Circuits 18 and 21 control the DC motor in one direction, and thyristors 19 and 20 in a different direction. The closure of these thyristors is performed by the joint action of the capacitor 14 and the inductance 9. For this, the inductance 9 is made on the magnetic core and its two windings are magnetically connected to form an autotransformer. If pin 13 is located approximately in the middle of inductance 9, then the transformation ratio of the primary and secondary windings is equal to one.

When the thyristors of inverter 1 are locked and the thyristor 4 is open, capacitor 14 is charged from a DC voltage source to a value limited by the source voltage due to the presence of diodes 12 and 22-25. The thyristor 4 is locked as soon as the charge of the capacitor 14 stops when the voltage at its terminals becomes equal to the voltage of source 5.

When thyristors 18 and are open, current / s passes through measles 15 from source 8 / If thyristors 18 and 21 are to be locked (or 19 and 2 (9), then thyristors 3 are removed).

In this case, the capacitor 14 is discharged to 0: a bouting pin, located between M1 between pin 13 AND CLUTCH 11 of inductance 9, b1c, l, ed | CT, vie che | on, at the terminals, max of inductance, there will be meetings, insulating

measles 15 from source 8. This secondary voltage causes the appearance of a periodic current il, opposite in the direction of the current / o, which closes at source 10, representing a small impedance for alternating current due to the presence of coi C, filter tori connected to the source (not shown in the drawing). In addition, in inductance 9, the magnetizing current / t is of the same direction as tUc / o. Therefore, the current r passing through the thyristors of the inverter 1 is equal to

g 0 +, - H.

where ij is the increasing function of the current ondisator 14, fn is the decreasing function of the current inductance 9. Thus, the capacitance of the capacitor 14 and inductance 9 can be chosen such that the current i becomes zero or negative. Thyristors. 18 and

2.1 is locked if the current i is zero or has a negative value for a period of time, exceeds the limit, then their time is locked, i.e., if the time constant of the circuit consisting of inductance 9 and co-capacitor 14, , wa, that the duration of the first half cycle of the current supplied by this circuit, more than a time lock. When TOK i becomes negative., DI | OD, connected in the opposite direction to the terminals

of the corresponding thyristor of the inverter, set up a new conductor and at the same time cause the appearance of a small reverse voltage to lock up, equal to the fall of the direct voltage on the conducting diode.

If the thyristors 18 and 2.1 are open again, current / o appears again in the core 15. In addition, when the thyristor 4 is also open, the capacitor 14 is recharged through the winding located between clamp 10 and output 13 of inductance 9, so that a clamping voltage of 1 x inductance produces a counter voltage, isolating the load from source 8. This counter voltage This causes the appearance in the winding located between the output terminal | M 13 and clamp 11, of a periodic current il, opposite to the current / o, which is closed by the diodes and 22-25. The current i, through the thyristors, is

i I. +.,

Since the currents i and / t again are a correspondingly increasing function of the current of the capacitor 14 and a decreasing function of the current of the inductance 9, the inverter's open thyristors / can be closed again. Since TO.KI / m, zl, and Il are visible from the leakage inductance of an autotransformer (inductance; in step 9), installation inductance, and equivalent resistance of various elements, in particular diodes 22-25, the switching time of the prototype 3 | depends on the same elements. To eliminate this, on both sides of the inductor 9 and subsequently; B: there are two identical inductances 26 (see Fig. 2) connected to it, the value of which is less than the inductance 9, the diameter is so small that it has no effect nor on the contour configuration. By increasing the currents ii and il, it is possible to facilitate the locking of the inverter thyristors by means of 1ВЫ | бора1 for an autotransformer 9 transformation ratio greater than one. For this, a | vtatraisf.or, mater 9 (see fig. 3) M | 0, can be equipped with two intermediate pins 27 and 28. Between these pins are pg turns, and between each terminal and the corresponding end of 29 or 30 coil - ui turns (). Conclusions 27 and 28 are interconnected through thyristors 3.1 and 32, connected in series so that. their anodes face the positive pole of the source. The common points of the thyristors 31 and 32 are connected to the capacitor 14. The thyristor 31 is unlocked simultaneously with thyristor 4, and the thyristor 32 - with thyristor m 3. Thus o6.pai3OM, during the charging of the condenser 14 its charge current passes through the circuit: “+ istachnika -inducti.v1n.ost 26 - pin 27 - thyristor 31 - capacitor 14 - thyristor 4 -“ - source. At the same time, the current magnitude / 1 is increased by a coefficient. Similarly, during the discharge of a capacitor, the discharge current passes through the circuit: capacitor 14 - thyristor 32 - output 28 - end 30 of the coil - inductance 26 - thyristor 3 - capacitor 14 and transformation ratio also is equal to a switching node with one condensate, and it dies in such a way that during switching each time, the oscillating circuit consisting of inductance 9 and capacitor 14 performs two functions. The first function is to isolate the powered load from the power source, which eliminates the harmful effects that can occur when the diodes 22-25 are short-circuited, and the second is to underestimate open thyristors. In some cases, these functions can be separated either out of circuit considerations, or to power the load. The converter (see Fig. 4) contains a bridge of tirpstor 53-36 included so that the anodes of thyristors 55 and 34 are connected at point 5, and the cathodes of thyristor O1 55 and 55 - at point 6, with the cathodes of thyristors 55 and 34 connected to the anodes of tirlestors 55 and 36 SO (From; appropriately at points 7 and 57. Diagonal 5-6 of the bridge is connected parallel to source 8 of constant voltage, and point, 5 is connected to through inductance 9, between terminals W and // which includes a reverse diode 12 and point 6 is directly connected to an "- source. Katu. inductance 9 is provided with an intermediate terminal 13, with connected to point 7 through a capacitor 14, and the diagonal 7-57 of the bridge includes a sequential oscillating circuit containing a capacitor 5S and an inductance 39. When you receive a control impulse on the control electrodes of thyristors 55 and 36 for TOG ;, to make these thyristors conductive, capacitor 58 is charged from source 8 so that its lining acquires a positive potential relative to point 7. After capacitor 58 is charged, these thyristors are locked. When the thyristors 18 and 21 are open, a current flows through the winding of the core 15 from point 16 to point 17. If the thyristors 34 and 55 are unlocked to lock these thyristors, then the capacitor 58 is discharged through diodes 24, 22 and 25, 23. The latencies 22-24 and 25-25 form a short circuit between the points. 5 and b. Since the thyristors 34 and 55 continue to be conductive, the current circuit I passing through the measles 15 closes, on the one hand, through the included reverse diodes 23 and 22, and on the other hand, through diodes 24 and 25, the diode current of the capacitor 58 passes through the diodes 22 and 25 in the forward direction, and a voltage U appears at the terminals of the inductance 9. Thus, the instantaneous current supplied from the source is increased by a certain value L /, which can be limited only with a large value of inductance 9. Therefore, source 8 pr. continues to ing into the armature winding 15, the current / -f-AA which is added to the current / already proh1od, .schemu therethrough. Owing to STioro, condensate p 58 should produce a bale greater than 2 / - | -D / in order for: on the back of the jacks 22 and 25 to be sufficient for locking the thyristors 18 and 2. The discontinuous power of the dist. The natural converter is limited, since it is necessary to break, set the current, actually equal to 2 / + D / VM.to current /. In addition, to limit the buildup of D / inductance. There should be a very large 9 (several millienegens). However, the inductance for the supply current is connected in parallel with the winding of the core 15, therefore, it reduces the current flowing through this winding, and the stronger, the shorter the time constant of the inductive load. The proposed converter allows I1 induction, iV, but step 9 and taking into account the capacitance value of capacitor 14, to calculate the frequency of the circuit's own oscillations, corresponding to the charge of the capacitor 14 from the HI network, to discharge it through the thyristor circuit 33. Inductance values. 9 and the capacitance of the K1Ondeis, torus 14 are selected, kimi, which would have a semi-half-square oscillation circuit inductance 9 - the capacitor 14 had a duration almost equal to the duration of the leriod of the circuit capacitor 38 - inductance 39, which is somewhat longer, and the thyristor locking time . When the thyristor, rya 34 and 35 are conducted, the charge capacitor 14: et1c from source 8 through the thyristor 35 so that its input, connected, with output 13, becomes positive. As a result, electromotive force occurs in inductance 9, which destroys or even makes a negative current flowing through a winding connected between terminal 13 and terminal 11. Thus, an inductive load, consisting, for example, of the motor windings, is derived from: 8, and the current flowing through the thyristors 18 and 21, which is neo go to interrupt, it stores the value /. Krom.e that. When; thyristors 33 and 36 become conductive, capacitor 14 is discharged through a winding connected between outputs 13 and clamp 11, due to which the current in the winding connected between clamp 10 and output 13 instantly disappears and the HIC control is isolated from the load during time | A capacitor 14 is recharged. At the same time, the generator 55 is recharged from the source 8, and the series oscillating circuit consisting of the capacitor 38 and inductance 39 can be locked. Each time the capacitor 38 recharges, the thyristors 33 and 36 remain conductive. FIG. 5 shows a converter in which the load is, for example, four motors 40-43 of the alternating current motor, and the number of windings is not limited. Winding 40-43 included in the ring pattern. The common wheelbarrow of windings 40-43 is connected, on the one hand, to point 5 through thyristor 18, shunted by diode 22, and, on the other hand, to point 6 through thyristor p 44, schun1tirovanny diode 45. In addition, common points of windings 40 -43, respectively, are connected, on the one hand, to point 5 via thyristors 19, 44 and 46, shunted by diodes 23, 45 and 47, and, on the other hand, to point 6 through thyristors 48, 21 and 20, shunted by diodes 49, 26, and 24. The windings should be periodically powered with current, first in one direction, and then on, log, o. Ehmi thyristors 18 and 21 are open, then through-windings 40 and. 4} the same currents are passed, and through oi6MioTki 42 and 43 are opposite positively directed currents. At | 3 € L switching with a capacitor 14 at-. Only in the case when it is supplied with a stable direct current source, and HIC cannot be used, if the DC voltage fluctuates greatly, for example, the inverter load / consists of synchronous windings or an asynchronous electric motor, the rotational speed of which is regulated in wide and narrows by varying the frequency of the test voltage. In this scenario, the voltage of source 8 should decrease, while decreasing the frequency in order to avoid iron saturation of the electric motor. TaiKHiM, the voltage can grind up thousands in the range of 1: 20, and in this case the current remains constant: m, 6SLI the electric motor works with a steady torque. A change in voltage is de-energized by affecting the power source, which may, for example, serve as a control rectifier. The thyristor lock-in current is proportional to, for example, a pit: neither U, so the switching unit thyristor and diode diodes must be designed to pass currents at the maximum supply voltage. For this, the switching node (see Fig. 6-8) contains the same set of circuit elements from inductances 9 and. 26, capacitor 14, thyristors 5 and and dyad-12, fed from source 8, and a bridge with thyristors 33-36, one diagonal of which is powered from voltage source 50, a. the other diagonal contains at least one capacitor 38. The bridge of thyristors 33-36 is connected between thyristors 5 and and clamps 5 and 6. The anode of the thyristor 33 is connected to the aHi of the thyristor 34, and the cathode of the mountain 35 with the cathode of the thyristor 36 The cathodes 33 and 34, respectively, are connected to the anodes of thyristors 35 and 36. General, the point of the cathodes of thyristors 35 and 36 is connected to the common negative pole of the sources 50 VI 8, and the common point of the anodes of the thyristors 33 and 34 is connected, on the one hand, point 5 through the diode 51, open source 8, and, on the other hand, with a positive n The source-50 source voltage through inductance 52 and diode 53, which is open to source 50. Common thyristors 33 V 35 and thyristors 34 and 36 are connected via an n-series oscillating circuit containing capacitor 38 and inductance 39. Diodes 5 / and 53 prevent the possibility of / n-bit discharge sources 8 and 50 of one to another. If, for example, the thyristors 33 and 36 are unlocked to switch the current in the load 15 with a sequential oscillating 38-39, then the thyristor 4 is also rubbed off. Thus, charging the M-capacitor to the voltage that interrupts the current through the winding, switch on between the terminal / and terminal //, which isolates the load from the terminal 8. Similarly, the next time you switch thyristors 33 and 36 (or 34 and 35) become and the discharge of the capacitor 14 onovolvoyuvaet the load from the source 8. Mo: copes from 1piran, and thyristors 33 and 36 (or 34 and 35) and thyristor 3 or 4, and the time constants of the molagagnel contours 5 and 38–39 should be chosen in the same way. so that the natruac 15 is reliably infused with each switch. Moreover, it is necessary to ensure that such a continuous time of a consecutive oscillatory 10 circuit 55-39, so that the first stolumn period given by this circuit has a duration exceeding the time of the thyristor overgrowing 18-2.1. Therefore, a circuit consisting of Inductances 26 E 9 and a condenser 15 pai 14 is chosen so that the half-emitter-natural frequency is equal to the period c-hp 38-39. In the Commutation node (see Fig. 6), inductance 53 limits current buildup, noi- 20 stepping from source 50, when oscillating circuit 38-39 switches the thyristors of inverter 1 and, therefore, has zero voltage on its terminals. If the load 15 consumes a large current 25 and the switching frequency is high, the inductance 52 can greatly retard the (circuit path 38-39. To avoid this (see Fig. 7) the inductance 52 and the diode 53 can be replaced by an inductance of 30 54 (in the particular case equal to zero) and a thyristor 55, and the capacitor 55 is connected parallel to the bridge of the thyristors. The thyristor 55 is started only after the switching of the oscillating circuit 35-38-39, and the capacitor 38 is leresar before the voltage of the source 50, have arisen The oscillating circuit 54-56 does not reduce the change in voltage by 40 (Yarn applied to the terminals of the thyristor 55 during the switching time, since this change could cause untimely unlocking of this thyristor. In the switching node (see Fig. 8) the inductance 39 is not in the bridge channel, from the thyristors, but connected between the cathode of diode 51 and the anodes of the thyristors 33 and 34. The capacitor 56 is connected parallel to the inductance 39 and the bridge. Such a switching node circuit reduces the voltage fluctuations at the terminals of the bridge thyristors. In this way, with the help of the following: a convertible converter, it is possible to power any electrical device containing one or several Winding, in particular, and selectors for electric motors of various types. In addition, the transformer will reduce the energy required for switching and interrupting the current intermittently, while allowing the switching frequency and switching frequency to increase. Under these conditions, it is possible to regulate the average value of the current passing through each winding, the fault voltage across the thread. The subject of the invention is 1. A constant-voltage converter comprising a thyristor unit of reverse current to a load, for example, in the form of a single-phase or multiphase inverter with reverse diodes and a switching node consisting of at least one capacitor and. two thyristors, the common point of which is connected to one of the capacitor plates, connected to a direct current source through a series choke, characterized in that, in order to increase reliability, the choke consists of at least two parts connected together consequently, and the other, the capacitor plate is galvanically connected to common points of connection of parts, 2. | Conversion | Ovator according to claim I, characterized in that the execution of the coMmutation node in the form of a thyristor bridge, one of the diagrams of which includes a follower On the LC- / chain, the latter is connected to the O1condenser of the capacitor connected to the common point of the connection of Eu of the two thyristors of the bridge, 3. The transducer of the B. according to claim 1, characterized in that it contains two wobble inductances, the value of which In the middle of the winding of the droosel, and through one of them the choke is connected to the power source, and through the other to the node of the mutation. 4. The converter according to claim I, characterized in that, when making three-part throttles, the middle part is shunted by two series-connected elements of one-sided-conduction, the common connection point of which is connected to the capacitor.

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