RU1775815C - Single-ended dc voltage converter - Google Patents

Abstract

Usage: power supplies of various systems. SUMMARY OF THE INVENTION: the device allows to increase the conversion efficiency by using both forward and reverse transformations, transfer of energy of reactive elements of throttle (2), capacitor (7) and additional throttle (9) to the load and additional transfer of energy from the power source 1 during the open state of the transistor (3). 2 ill.

Description

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The invention relates to electrical engineering and can be used in power supplies of various systems.

A key boost converter is known in which the turn-off conditions of the transistor are improved by turning the capacitor through the diode parallel to the transistor. The energy of this capacitor is dissipated in a resistor connected in parallel with the diode when the transistor is open, this reduces the efficiency of the converter.

A key DC-DC boost converter is known, comprising a choke connected to the transistor in an autotransformer circuit, a switching diode connected in series with one winding of the throttle and an output filter, an additional diode connected in parallel with a circuit consisting of a switching diode and a second winding of the throttle . In this case, the diodes are turned on according to. The disadvantage of such a converter is its low reliability due to high voltage and current levels when the transistor is turned off, which further reduces the efficiency,

Closest to the technical nature of the proposed converter is a key DC-DC boost converter, in which, to improve the conditions for switching off the transistor, a DC shunt circuit is connected in parallel with it. To transfer the stored energy of the capacitor of the DC circuit, a resonant circuit is connected parallel to the diode, consisting of additional interconnectors, a cut-off diode and a capacitor, and the connection point of the last two elements through the discharge diode is connected to the positive terminal of the power supply.

A disadvantage of such a converter is the reduction in conversion efficiency and functionality due to the use of only the reverse operation of the converter, the transfer of partially stored energy of the shunt capacitor to the power source, which accordingly reduces the current efficiency of the transistor.

The aim of the invention is to expand the functionality and increase the output power through the use of both reverse and forward conversion and to provide the ability to operate with a constant and ripple voltage.

This goal is achieved by the fact that in the known voltage converter containing a power inductor connected by one terminal to the first input terminal of the converter, and by the other terminal through a power transistor, to the second input terminal of the converter, a series DC circuit shunting the transistor, a filter capacitor which through the first diode and a power inductor connected to the input terminals, an additional inductor connected in series with

0 by the second diode, and the third diode, the power inductor is double-wound, the second winding is connected between the second and third diodes included, the last of which is connected to the second

5 to the input terminal of the converter and is connected in parallel with the capacitor of the DC circuit, an additional inductor is connected to the filter capacitor,

Introduction of the second winding in the power

0 the inductor made it possible to transfer the energy of the capacitor of the shunt circuit to the load and additionally ensure the transfer of power to the load from the power source during the open state

5 transistors. At the same time, the current transistor utilization coefficient is improved and it is possible to convert not only a constant, but also a rectified alternating voltage into a constant.

0 which leads to an increase in the utilization factor of the primary alternating voltage supply network (increase in cos p),

Figure 1 presents a diagram of the Converter; figure 2 - diagrams explaining it

5 job.

The converter contains a power source 1, to which a transistor 3 is connected through a two-winding power inductor 2 through its first winding,

0 parallel to which a DC shunt circuit is connected, consisting of diode 4 and capacitor 5 connected in series. The connection point of the throttle 2 and transistor 3 is connected to the capacitor through diode 6

5 7 output filter. The second winding of drossel 2 is connected by one output through a second diode 8 and an additional inductor 9 connected in series to the filter capacitor 7, and the other output to a DC circuit capacitor 5 shunted by the third diode 10, while the third diode 10 is connected in accordance with the second diode 8 and counter to diode 4 of the DC circuit, the load is connected to the output filter - capacitor 7.

The ratio of the number of turns of the first Wi and the second W2 of the windings of the power jumper 2 is selected from the condition of guaranteed discharge of the shunt capacitor into the load circuit.

The diagrams (Fig. 2) show Uynp - the control signal by transistor 3; And is the current of the first winding of the throttle, Us is the voltage across the capacitor 5; Ig - throttle current; But - the current of the diode 10; 1h - current flowing through the transistor 3; 1e - current through diode 6; I is the charge current of the capacitor 7.

The converter operates as follows. In the initial state, the voltages on the capacitors 5 and 7 are almost equal to the input voltage, the currents of the windings of the throttle 2 are absent, When a control Uynp signal is applied to the transistor 3, the latter opens (1h), the current li increases in the first winding Wi of the throttle 2 (Fig. 2, 0-ti) simultaneous resonant discharge of capacitor 5 (Us) (Fig. 2) along the circuit: capacitor 5 - second (L / 2) winding drossel 2 - diode 8 - inductor 9 - filter capacitor 7. After the capacitor 5 (tf-ta) is completely discharged, and the current in the inductor 9 (Ig) is closed by the circuit: capacitor 7 - discharge diode 10 - second winding W2 throttle 2 - diode 8 - inductor 9.

The transfer of the stored energy of the capacitor 5 is achieved by the voltage of the second winding L / 2 of the jumper 2, which serves as the voltage source for the discharge circuit of the capacitor 5. From the moment of the conductivity of the diode 10 (ti, Fig. 2) depending on the ratio of the turns of the first Wi and the second L / 2 of the windings of the throttle 2, you can get a different operating mode of the throttle 9, during the open state of the transistor 3. When from I I

wearing coils W2 / Wi output current in DrosUox

after 9 the discharge of the capacitor 5 decreases. The current decreasing rate (h is determined by the inductance of the jumper 9 and the difference between the output voltage and the voltage on the second Wa winding of the jumper 2.

If the voltage difference is relatively large, the inductor 9 will operate at full energy during the open state of the transistor 3.

It should be noted that in the case of incomplete transfer of the stored energy by the inductor 9 to the capacitor 7 from the source 1, the power will be transferred to the load much more (t / r-t5, Fig. 2).

After removing the control signal Uynp from transistor 3, the current And of the first Wi winding of the jumper 2 continues to increase and closes along the circuit: diode 4 - capacitor 5 of the power supply 1 - inductor 2. The capacitor 5 resonantly charges the current h of the jumper 2, if the current of the jumper 9 is zero and the diode 10 does not conduct. Upon reaching

voltage across capacitor 5 (gz). equal to the input supply voltage, the current growth And in the first Wi winding of the circuit 2 stops, the voltage on it changes polarity and the process of transferring the stored energy of the circuit 2 to the capacitor 5 begins, the current of the circuit 2 decreases. At time b), the voltage across the capacitor 5 is equal to the output voltage, the diode 6 opens. From this moment, the capacitors 5 and 7 are simultaneously charged by the current of the first winding Wi of the jumper 2. The voltage on the second winding L / 2 of the jumper 2 has a reverse polarity and is equal to the voltage difference between the output and input voltages, this ensures the transfer of the stored energy of the cross-link 9 to the capacitor 7.

The drossel 2 current mode of operation can be either continuous or intermittent. In the event that the current of the cross-link 9-by the time the transistor 3 is turned off has a certain value, the charging of the capacitor 5 will be carried out by the difference of the currents of the first Wi winding of the cross-link 2 and the cross-link 9. The diode 10 stops conducting when the voltage across the capacitor 5 is equal to the drop the voltage on the diode 10. The charge of the capacitor 5 will be the difference between the currents of the chokes 2 and 9. Thus, it is possible to achieve an increase in the charging time to ° C sensor 5 and a decrease in the slew rate of the voltage from the transistor 3, and therefore some x teaching acceptable decrease in the condenser 5.

By transferring the stored energies in the main and additional reactive elements of the converter to the load, by additionally transferring the power of the power source to the load during the forward stroke, conversion efficiency is achieved and the converter's functionality is expanded. In particular, it is possible to convert both a constant and a pulsating voltage to a constant, the output power of the converter increases, the coefficient of utilization of transistors in current increases, and it improves when converting an alternating voltage.

Claims (1)

SUMMARY OF THE INVENTION A single-ended DC / DC converter comprising a power inductor connected by one output to the first input terminal of the converter and the other through a power transistor to the second input terminal of the converter, a series DC circuit, shunting the power transistor, a filter capacitor connected through the first diode and the SILOY inductor to the input terminals, an additional inductor connected in series with the second diode, and a third diode, characterized in that, in order to expand about Areas of application and increase of output power, power reactor made by double-winding, the second winding is turned on according to the included second and third diodes, the last of which is connected to the second input terminal of the converter and connected in parallel to the capacitor of the DC circuit, an additional inductor is connected to the filter capacitor. 0 i ii b b ± $ pb b. 1