SU1541726A1 - Dc-to-dc converter - Google Patents

Abstract

The invention relates to converter technology and can be used in electrical technology, charging converters, power supplies of electrophysical installations. The aim of the invention is to improve the overall performance and reduce the installed power of the keys. The device contains a bridge or half bridge on controlled keys 2-5 with two reactors 1.6 in the diagonal of alternating current. The primary windings of the reactors 1,6 are included anti-sequentially. The secondary windings of 7.8 reactors are also connected counter-sequentially and through diodes 9,10 the rectifier is connected to the load 11. The combination of the functions of smoothing and transforming electromagnetic energy makes it possible to reduce by 1.3–2 times the mass volume of the electromagnetic elements and the device as a whole. 3 hp ff, 6 ill.

Description

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ABOUT)

The invention relates to electrical engineering, in particular, to converter technology, and can be used in electrical technology, charge converters, power supplies of electrophysical installations,

The purpose of the invention is to improve the overall dimensions of magnetic elements, reducing the installed

power keys.

Figures 1-4 show the concepts of a DC / DC converter; Figures 5 and 6 show timing diagrams of currents i and voltages U with seeding numbering.

The DC / DC converter (Figure 1) contains reactor 1, a bridge on controlled keys 2-5, and also reactor 6. The reactors are equipped with secondary windings 7 and 8. The primary windings of the reactors are made consistently. The first identical ends of the secondary windings 7 and 8 are connected via the diodes of the rectifiers 9 and JIO to the first load terminal J1, and the second ends of the same name are combined and connected to the second output of the load circuit.

The parameters of the magnetic systems formed by the reactor 1, equipped with a winding 7, and the reactor 6, equipped with a winding 8, are identical.

The converter works as follows. .i

By the time t0 (Figure 5), the keys 2-5 are open. Reactors 1 and 6 transfer into the load 3 the energy stored in them. The load current 11 is the sum of the currents of the secondary windings 7 and 8, which are closed in two circuits: the secondary, the winding 7 — the diode 9 — the load 11 c, the secondary winding 8 — the diode 10 — the load 11.

At time t0, the keys 2 IH 3 are closed. Reverse voltage is applied to diode 30, and it is locked. The current of the secondary winding 8 of the reactor 6 is transferred to the primary winding and closes - on the circuit containing the source) to the power E, switch 2, the primary winding of reactor 1, primary winding of the reactor 6 and switch 3, At this interval the reactor 1 simultaneously performs the function of a transformer direct energy transfer from the primary winding circuit to the load, and output to the load of the accumulated energy

earlier in the magnetic field of the reactor. The reactor 6 accumulates energy and at the same time smoothes the current transformed into the load by the reactor 1.

At time tf, switches 2 and 3 are opened, the primary windings of the reactor 6 are transferred to the secondary and closed through diode 10 and the load 11. According to the load, like the time t0, the sum of the currents of the secondary windings of the reactors flows.

At time t2, keys 4 and 5 are closed. Reverse voltage is applied to diode 9, and it is locked. The secondary winding current 7 of the reactor 1 is transferred to the primary winding and closes the loop, including the power source E, the switch 5, the primary windings of the reactors and the switch 4. At this interval, the reactor 6 combines the function of a transformer that directly transfers energy from the primary winding to load output to the load accumulated earlier energy. The reactor 1 accumulates energy and smoothes the current transformed into the load of the reactor 6.

At time t3, keys 4 and 5 open and a state similar to the previous time tc is established. At time 14, keys 2 and 3 are closed and the processes s of the circuit are repeated.

Switching sequentially into the primary windings of reactors J and 6 of the metering capacitor 12 (Fig. 2) allows parametric stabilization and regulation of the power transmitted to the load by the DC converter.

By the time С „(Fig.6), the keys 2-5 are open. Reactors 1 and 6 transfer to the load 11 the energy stored in them along the circuits: winding 7 - diode 9 - load 11 and winding 8 - diode JO - load I. The capacitor is charged before the voltage of the power source E.

At time t0, keys 2 and 3 are closed. Reverse voltage is applied to diode 10 and it is locked. The current of the secondary winding 8 of the reactor 6 is transferred to the primary winding and closes the loop containing the power source E, key 2, the primary windings of the reactors, the metering capacitor 12 and key 3. The capacitor 12 is recharged by the same circuit into the load

energy from the primary winding circuit, at the same time bringing previously accumulated energy to the load. The reactor 6 accumulates energy and smoothes the current transformed into the load of the reactor 1.

At time t1, the voltage on the capacitor 12 reaches the value E. The condition appears to unlock the diode 10, as a result of which the current from the primary winding of the reactor 6 is transferred to the secondary winding 8 and shuts off through the diode 10 and the load P, while the keys 2 and 3 de-energize . The reactors transfer the energy stored in them to the load.

At time t2, keys 4 and 5 are closed. Reverse voltage is applied to diode 9, and it is locked. The secondary winding current 7 of the reactor 1 is transferred to the primary winding and closes along a loop that includes a power source E, a switch 5, the primary windings of reactors, a capacitor 12 and a switch 4. The reverse of the capacitor 12 is reversed. load energy from the primary circuit and leads to the load stored energy. The reactor 1 accumulates energy and smoothes the current transformed into the load of the reactor 6.

At time t3, the voltage on the capacitor 12 reaches the value E. The condition appears to unlock the diode 9, as a result of which the current from the primary winding of the reactor 1 is transferred to the secondary winding 7 and is closed through the diode 9 and the load LL. Keys 4 and 5 are de-energized. The reactors transfer the energy stored in them to the load. At time 14, switches 2 and 3 are closed, and the processes in the converter are repeated.

In order to ensure the efficiency of the converter to a rapidly alternating load (Lig.Z), the reactors are equipped with third windings 13 and 14, the beginnings of which are combined and connected to one of the power supply terminals, and the ends are fed through to the opposite output of the power source E .

Diodes 15 and 16 are normally locked and do not affect the operation of the converter. With a sharp decrease in load, the voltage on the reactor windings, including on windings 13 and 14, increases. When the voltage on them reaches the value of E, diodes 15 and 16 open and limit the overvoltage at this level, ensuring the output of excess energy from the reactors to the source nutrition.

Converter (fsh.4) can be performed on thyristors 3 and 5 according to a half bridge circuit, one of the terminals of the alternating current of which is formed by a common point of coupling capacitors 17 and 18. Parameters of magnetic systems formed by reactor 1, equipped with winding 7 and reactor 6, are provided with winding 8, are identical.

By the time tc, the thyristors 3 and 5 are off, the capacitor 17 is charged before the voltage of the power source E, the capacitor 18 is completely discharged. Reactors 1 and 6 transfer to the load 11 the energy stored in them along the circuits: secondary winding 7 - diode 9 - load 11 and secondary winding 8 - diode 10 - load 11.

5 At time t0, the thyristor 5 is turned off by the control pulse. Reverse voltage is applied to diode 9, under the action of which it is locked. Capacitor 17 starts discharging

0 through the thyristor circuit

5 and the primary windings of the reactors, and the capacitor 18 is charged from the power source E along the same circuit. Reactor

6 performs simultaneously both the function of a transformer which directly transfers energy from the primary circuit to the load, and also brings the energy previously accumulated in the magnetic field of the reactor to the load. The reactor J accumulates energy and simultaneously smoothes the current transformed into the load by the reactor 6.

At time t, the voltage across the capacitor 18 becomes equal to E,

with capacitor J7 - equal to zero, respectively. A condition appears to unlock the diode 9, as a result of which the current from the primary winding of the reactor is transferred to the secondary winding 7 and

It is closed through diode 9 and the load JJ, through which, as at the moment to, the sum of the currents of the secondary windings of the reactors flows. Thyristor 5 de-energizes and restores its locking properties.

At the moment ta, the thyristor 3 is released by the control pulse. Reverse voltage is applied to diode 10, under the action of which it is locked.

five

five

The capacitor 17 begins to discharge, and the capacitor 18 is charged along the resulting circuit from the switched tigris tor 3 and the primary windings of the reactor. In this stage, reactor 1 combines the function of a transformer that transfers energy from the primary circuit to the load with the output of the energy stored in it by the café. Reactor 6 accumulates energy and at the same time smoothes the current transformed into a load per actor J.

At time t3, the voltage on the condenser SATOR 17 becomes equal to E, and on the Condenser 18 it is equal to zero. The condition for unlocking the diode 10 is entered, as a result of which the current from the primary winding of the reactor 6 is transferred to the secondary and is closed through the diode 10 and the load 11 through which, like to the moment t0, the sum of the currents of the secondary windings flows.

At time t, unlocking the thyristor 5, the processes in the converter are repeated.

Improving the mass and size characteristics of the magnetic elements in the developer is achieved by combining the functions of smoothing and transmuting electromagnetic energy. Magnetic elements at higher conversion frequencies work, as a rule, in the natural mode. In this case, as the calculation shows, the mass and dimensions of the reactor in the known converter are approximately equivalent to the mass and weight of the entire magnetic system of the proposed converter with equal pulsations of the load current and the transmitted power. In a known converter, in addition to a reactor, it is necessary to match the levels of supply voltage and voltage on the load, as well as galvanic isolation.

transformer, designed to transfer the rated power load. Thus, a gain is obtained in the mass of the magnetic elements by J, times depending on the required level of pulsations of the load current.

A comparison of the schemes according to the operation modes of the keys 2-5 shows that & known inverter with the same ones and current values of currents

the keys are applied to them in two for large voltages (Lriembo 2E), and, accordingly, the installed power of these keys is doubled.

When the metering capacitor 12 is switched on (the function of which capacitors 17 and 18 can execute) in the primary winding circuit, the power transferred by the converter to the load with an accuracy of losses is determined by the ratio

P 2CE2f,

where f is the key switching frequency;

C is the capacitance of the capacitor 12, and therefore, it is entirely determined by the parameters of the converter, and not the load.

An abrupt decrease in load, characteristic of a number of electrical consumers, causes corresponding voltage jumps on the load and circuit elements. The introduction of windings 13 and 14 with reverse diodes 15 and 16 makes the circuit workable for a rapidly alternating load, limiting the level of overvoltages on the circuit elements and the load.

Claims (3)

1. A DC / DC converter that contains an inverter connected to the input terminals on controlled keys, made according to a bridge or half bridge circuit, to the AC terminals of which a load circuit is connected, through which is in order to improve mass and size parameters and reduce the installed power of the keys, the matching electromagnetic unit is made in the form of two reactors, the primary windings of which are inserted counter-consistently, the first corresponding ends of the secondary windings are coupled and connected to the first terminal of the load circuit, and the second terminals of the windings of the same name via the rectifier diodes connected to the second terminal of the load circuit. 2. A converter according to claim 1, characterized in that, in order to provide parametric stabilization and control of the power transmitted to the load, a metering capacitor is introduced into the primary windings of the reactors in series. 3. The converter is on. t - l and due to the fact that the inverter is made on the thyristors according to the half bridge circuit, one of the terminals of the reactor is supplied with the third windings, The current of which formed a common point of separation capacitors. D. The converter according to claims 1-3, which is characterized by the fact that, in order to provide the possibility of its operation under fast alternating load, both p ".g beginnings of which are combined and connected to one of the input pins, and the ends through additional reverse diodes are connected to another input pin. Put.3 W MI Hi in rr: tit fft Lz PCU Editor N. Yatsola Compiled by I. Zherebina Tech red ed L. Serdyukova Order 287 . Circulation 498 GNSI State Committee on | inventions and discoveries at the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. ftj five Zj i, M , i / r rf vv ii t p7 FIG. 6 Proofreader M.Samborsk Subscription