SU1390740A1 - Single-cycle d.c.-to-d.c. voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary sources of power supply of constant voltage electronic equipment, automation and communications. The purpose of the invention is to reduce the weight and size, increase efficiency, reliability by reducing the level of high-frequency interference, enhanced functionality. A second primary winding 12 of the output transformer is inserted into the device and a chain from diode 13 and throttle 14 is connected to it. The winding 12 provides for the reversal of transformer 3. Energy transfer to the secondary side occurs not only during the time interval corresponding to the open state of the controlled keys 1 and 2 , but also at the moment of pause. The presence of drossel 14 in the current circuit of switches 1 and 2 makes them protected from failures in the control circuit and against the core of the transformer 12. An example of a multichannel converter variant is given, in which part of the channel smoothing filters are made only containing capacitors, and partly containing capacitors and chokes. 2 hp f-ly, 4 ill. i (L

Description

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The invention relates to electrical engineering, in particular to converter equipment, and can be applied in secondary sources of electric power supply of constant voltage electronic equipment, automation and communication equipment.

The purpose of the invention is to reduce the mass and size and increase the efficiency, reliability J decreases the level of the high-frequency interference of a single transducer constant voltage to constant.

Fig „1 shows the scheme of one-step conversion | eL constant voltage to constant stress; FIGS. 2 and 3 are diagrams of a converting gas station as a multichannel DC converter with N outputs j in FIG. 4 are time diagrams of currents and voltages showing the operation of the converter.

The DC / DC converter contains (FIG. 1) controlled 1 and 2, the output transformer 3, the output winding 4 of which through the rectifier .5 and the filter 6 is connected to the output terminals 7 to 8 of the converter and the load RI. However, the primary winding 9 of the output transformer is connected to the first power electrode of the controlled key 15 and their connection point through the recovery diode 10 is connected to the single input terminal of the transducer 11, Second legarvich about the output bridge transformer 12 through auxiliary diode 13 of the chain

Connected to an additional choke,.,

And „w

The chain and the point of connection with the additional-throttle 14 are connected to the opposite: the terminal of the other primary winding 9 of the transformer. The point of connection of the first power electrode of the controlled key 2 with the Additional choke 14 and the auxiliary diode 13 is connected to another input terminal 15 of the converter through a recuperative diode

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control from the corresponding outputs of the control unit 18, the inputs of which are connected to the output pins 7 and 8 of the converter and

FIG. Figure 2-3 shows a DC / DC converter circuit as a DC / DC converter with three output voltage ratings. A special feature of these technical solutions is the presence of two additional secondary windings 19 and 20, which, through additional rectifiers 21 and 22 and additional filters 23 and 24, respectively, are connected to additional output pins 25.26 and 277528.converter corresponding Output pins 25 and 26 are connected to the additional load of the converter R, e. output pins 27 and 28 - to the additional load of the converter

In FIG. 2, the output filter 6 of the main channel and the additional filter 24 of the additional channel contain only smoothing capacitors, and the smoothing filter 23 of the additional channel channel comprises a smoothing condenser and a choke. FIG. 3 the output filter of the main channel contains a capacitive filter; And the chokes of the high filters 23 and 24 of the additional channels are made on the same magnesium conduit.

The DC / DC converter (Fig. 1) operates as follows.

Controlled keys 1 and 2 open with and close synchronously. When the opening HivmynbC from control unit 18 falls on the control inputs of controlled keys 1 and 2, they close (time tp, figure 4), the energy from the secondary winding and the output transformer 3 through the rectifier 5 and the output filter 6 is fed to the output pins 7 and 8 of the transducer and the load of the converter R,. At interval time t о t current

16 o Second control electrodes - in additional throttle 14 chains

control from the corresponding outputs of the control unit 18, the inputs of which are connected to the output pins 7 and 8 of the converter and

FIG. Figure 2-3 shows a DC / DC converter circuit as a DC / DC converter with three output voltage ratings. A special feature of these technical solutions is the presence of two additional secondary windings 19 and 20, which, through additional rectifiers 21 and 22 and additional filters 23 and 24, respectively, are connected to additional output pins 25.26 and 277528.converter corresponding Output pins 25 and 26 are connected to the additional load of the converter R, e. output pins 27 and 28 - to the additional load of the converter

In FIG. 2, the output filter 6 of the main channel and the additional filter 24 of the additional channel contain only smoothing capacitors, and the smoothing filter 23 of the additional channel channel comprises a smoothing capacitor and a choke. FIG. The 3 output filter of the main channel contains only a capacitive filter; And the chokes of the high filters 23 and 24 of the additional channels are made on the same magnetic conductor.

The DC / DC converter (Fig. 1) operates as follows.

Controlled keys 1 and 2 open and close synchronously. When the opening HivmynbC from control unit 18 reaches the control inputs of controllable keys 1 and 2, they close (time tp, figure 4), the energy from the secondary winding and the output transformer 3 through the rectifier 5 and the output filter 6 is fed to the output pins 7 and 8 of the converter and the load of the converter R,. At interval time t о t current

in additional throttle 14 chains

Switches 1 and 2 under: are connected to the input pins 15 and 11 of the converter, respectively: Me: “The control capacitor 1 with the primary winding 9 and the primary winding 12 with the auxiliary diode 13 connect the control capacitor 17. Controlled keys receive a signal: s

and in the primary winding 9 of the transformer 3 increases, energy is accumulated in the additional choke 14, as well as the magnetization of the core of the transformer 3 in the forward direction. In this case, the auxiliary diode 13 of the chain is locked and the current through the second primary winding 12 of the transformer does not flow. At the same time, the charge of the corrective condensate 17 connected to the opposite terminals of the primary windings of the transformer 3 is charged.

The charging current of the correction capacitor does not cause an excessive increase in the instantaneous values of the current of the controlled switches 1 and 2, since an additional choke 14 of the chain is located in the circuit of this current. In this case, the rising edge of the voltage on the windings of the output transformer increases. At time t from the control unit 18, an inclusive pulse arrives at the controlled keys 1 and 2. The current of the controlled keys begins to decrease, but drops to zero only at time t, due to the inertia of the keys (for example, resorption of minority carriers in use as controlled keys of power transistors), At time t, self-induction EMF begins to appear at the additional choke 14 and the auxiliary diode 13 of the string opens.

However, the voltage drop at the additional drossede 14 is slow, since at the same time starting with recharge, the correction capacitor 17. From the self-induced EMF, the additional throttle starts flowing through the second primary winding of the output transformer 12. At the same time, the secondary winding of the output transformer occurs and the energy from the additional drossel 14 through the rectifier 5 and the filter 6 is fed to the output pins 7 and 8 of the converter and the load on the converter RI. At time tj, the sum of the voltages on the primary winding 9 of the transformer and the additional choke 14 of the chain reaches the value. In this case, the magnitude of the total voltage is fixed by means of opening recuperative diodes 10 and 16. During the time interval t - t, the current of the additional choke 14 drops, and the core of the output transformer 3 is re-magnetized in the opposite direction. At time t 4, the core of the output transformer is saturated in the opposite direction. Voltage

on its windings and the correction capacitor drops to zero, ipe- the transfer of energy to the secondary side of the transformer. On time interval

continuity

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five

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five

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load current r | supported by the throttles of the output LC filter 6. At the time t from the control unit 18, an opening pulse enters the inputs of the controlled keys 1 and 2 and these processes are repeated, since the choke is present in the input circuit, i.e. element,. in KofopoM, instantaneous changes in the magnetic flux are impossible and, as a result, an instantaneous change in the winding current is possible. In relation to the load on the secondary side of the output transformer, this device is a current source, which makes it possible for many loads to use only a capacitive filter in the circuit of each of them.

This allows the use of smoothing capacitors in part of the output filters, and smoothing capacitors and chokes in part of the output filters (figure 2 and 3JI, and the amount of these smoothing chokes is much smaller, since their task is to maintain a continuous load current only in the time interval t4 - tj. In this case, since the voltage at the throttles of the output filters is synchronous and in-phase, it is possible to combine these chokes by using one magnetic conductor as the core (FIG. 3). he longer reduce the size and weight by reducing the number of structural elements of smoothing chokes.

Timing diagrams (in FIG. 4) illustrate the operation of the embodiments of FIG. 2 and 3. The proposed invention provides the following advantages:

Reducing the mass and dimensions of the output transformer and reducing losses in the active resistances of its windings by increasing the induction variation range in the transformer core (in the well-known technical solution, the induction variation range in the transformer core cannot be greater than V - - B |, induction of saturation, and B - residual induction of the material of the core with the intensity of an external magnetic field equal to zero). At the same time, the range of change and induction in the core of the transformer is increased and, in the limit, it can comprehend when using: - stitching the material of the core with a symmetric loop

1 hysteresis, Bg value,

 Reliability is compromised by the fact that a choke is present in the input circuit of a single-cycle DC / DC converter, i.e. an element that cannot instantly change the winding current, which prevents j j1a out of controllable keys, even when the core of the transformer is locked. In addition, when constructing on the basis of a single-ended converter of a constant voltage, a constant voltage is stabilized. This power supply simplifies the control circuit of the converter, since there is no need for a hard limitation of the voltage filling factor 25 on the output transformer.

Reducing the level of high-frequency noise by reducing the pulsed-overloading of diodes with straightened-20 converter bodies over a period of time corresponding to the recovery time of the reverse resistance of the diodes of the rectifier. The magnitude of these overloads is limited due to the presence of a .drossel in the primary converter circuit.

Expansion of functionality due to the fact that in the presence of multiple loads, i.e. , „When built on the basis of a multichannel voltage source converter, only a capacitive filter can be used in each load circuit.

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Claims (3)

1. Single-ended DC / DC converter contains two controlled keys, an output transformer with a secondary winding, through a rectifier connected to the output filter j 0 5 0 „ five five 0 the receiver, a chain of series-connected throttles and an auxiliary diode, a correction capacitor, the first power electrodes of controllable switches are connected to opposite input terminals, and the second power electrodes are connected to opposite input terminals of the converter through rectifier diodes, each of which is switched in the direction , the opposite direction of conduction of this key, characterized in that, in order to reduce weight and dimensions, increase efficiency, reliability, reduce the level of high frequencies interference, the output transformer is made with two primary windings, one of which is connected to the input terminals of the converter through successively connected control keys and the choke, and the other to the auxiliary diode of the circuit, the first opposite terminals of the two primary windings of the transformer are connected between A corrective capacitor is connected between the second terminals of the primary windings of the transformer. 2. The converter according to claim 1, T is characterized by the fact that, in order to expand the functionality, the output side of the amplifier is provided with additional secondary windings, which through additional rectifiers and additional filters form additional output terminals of the converter, and the output filters of the converter Condensers and chokes are made containing smoothed. 3. The converter according to claim 1, T is characterized in that, in order to expand the functionality, the output transformer is provided with additional secondary windings, which through additional rectifiers and additional filters form additional output terminals of the converter, with output and additional filters are made containing smoothing capacitors only. 28 9. 12 X AT ffl nineteen FIG. 2 , g F1 / g