SU1394372A1 - A.c.-to-high d.c. voltage converter - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used in secondary power supplies. The purpose of the invention is to expand the functionality and increase: the power factor when adjusting the output voltage. The device includes smoothing chokes 1, 2, the winding taps of which are connected to the input terminal 3. Valves 10, 11 are connected between the free terminals. Between the cathode of the valve 10 and the anode of the valve 11 a chain of capacitors 4, 5 is connected, the connection point of which is connected to the input terminal 6. Between the other free leads of chokes 1, 2 a three-pole switch is turned on 9. The use of chokes and a switch ensures that the output voltage rises. In this case, the output voltage is determined by the duration of the closed state of the switch outputs and the ratio of the turns of the half windings of the chokes. The first harmonic of the current consumed coincides in phase with the input voltage, regardless of the frequency of adjustment, with the result that the power factor has a higher value. 2 hp f-ly, 4 ill. with $ b (L s

Description

with so

four

W

The invention relates to converter equipment and can be used in secondary power sources of radio electronic and electrical equipment.

The purpose of the invention is to enhance the functionality and increase the power factor when adjusting the output voltage.

Figures 1-3 show schematic diagrams of alternating voltage to high voltage converters in figure 4, which are diagrams of currents and voltages illustrating their operation.

The converter (Fig. 1) contains smoothing chokes 1 and 2, the winding taps of which are connected to the input terminal 3, the series-connected filter capacitors 4 and 5, whose common point is connected to the input terminal 6, and the free terminals to the input terminals 7 and 8, and three

hank W1.1 throttle 1; I W2 ° coils W2.1 droplets 1i 1 current of capacitor 4; U (- input voltage amplitude i U, voltage across the load; IH load current; IL UR level of the smoothing chokes -, Wd / W1 Rdr - ratio of the turns of the half windings of the chokes; t,, t, tj, t, T - time points .

When considering the operation of converters, we assume that the pulsations of the magnetic flux of the smoothing chokes are negligible.

The converter of FIG. 1 operates as follows. In the time interval ttt g corresponding to the positive half-period of the input voltage (Ug, has a polarity indicated in FIG. 1 without brackets), pins 1 and 3 of the switch 9 are closed, and in the interval t (floor the polarity of Ugx is shown in FIG. 1 in brackets) - conclusions 2 and 3. In so doing,

Lucian switch 9, the first and second 25 interval t, t t diode 10 is locked.

the terminals of which are connected to the ends of the windings of Chokes 1 and 2, and the third - to the input terminal 6. The beginning of the winding of the chokes 1 is connected to the anode of the diode 10, the drosel is the 2nd cathode of diode 11, the cathode of the diode 10 is connected to the output terminal 7, the anode of the diode 11 - with output pin 8.

The converter of FIG. 2 differs from the converter of FIG. 1 in that the three-pole switch 9 contains serially connected controllable switches 12 and 13, the free terminals of which are the first and second terminals of the switch, and the common point is the third terminal.

The converter of FIG. 3 differs from the converter of FIG. 1 in that the three-pole switch 9 contains a control switch 12 and diodes 14-17, wherein the series-connected diodes 14 and 15 are connected in parallel to the switch 12, the anode of the diode 14 is connected to the cathode of the diode 16 , the cathode diode -itt processes are repeated with the difference that diode 11 is open, and diode 12 is locked, the current of winding W1.2 of droplets 2 is closed through the switch and the source of supply voltage, and the current of winding W2.1 through filter capacitors and load throttle 1, capacitor 5 is discharged, and capacitor 4 is charged. At other intervals, the diodes 10 and 11 are open, the current chokes 1 and 2 is closed along the circuit: winding

Yes 15 - with the anode of diode 17, the cathode of diode 16 and the anode of diode 17 are respectively W2,1 - diode 10 - parallel connected load and circuit formed by series-connected capacitors 4 and 5 - diode 11 - winding V / 2.2. The capacitors 4 and 5 are charged by the first and second pins of the switch, and the common point of the diodes 14 and 15 is the third pin.

4, the following definitions are taken55

chen: Ug, I in voltage and current at the input of the converter; 1 d - the current flowing through pins 3 and 1 of the switch 9; U j / i tighter on ob0

five

the diode 11 is open, the throttle 1 current is closed through the supply voltage source and pins 1 and 3 of switch 9, and the throttle 2 current flows through the circuit: input terminal 6 is a parallel-connected capacitor 5 and a circuit formed by series-connected capacitor 4 and a load diode 11 - winding VJ2. 2 input terminal 3. Condenser 4 is discharged with a current equal to 1 c, and capacitor 5 is charged with current D1 11 - 1 c. From the supply voltage source

is the current I gx

tj -itt processes are repeated with the difference that diode 11 is open, and diode 12 is locked, winding current W1.2 throttle 2 is closed through the switch and supply voltage source, and winding current W2.1 throttle 1 is through filter capacitors and load , capacitor 5 is discharged, and capacitor 4 is charged. At other intervals, the diodes 10 and 11 are open, the current chokes 1 and 2 is closed along the circuit: winding

W2,1 - diode 10 - parallel connected load and circuit, formed by series-connected capacitors 4 and 5 - diode 11 - winding V / 2.2. Capacitors 4 and 5 zar

current is not consumed from the supply voltage source.

The processes occurring in the circuits of figure 2 and 3, are similar to the processes in

: heme of figure 1. In this case, the scheme for

FIG. 2, on the interval t, t t, the key is closed: 12, on the interval t, t is the key 13. In the circuit of FIG. 3, the intervals are closed, closed, the key is

C t

 t

2

t j t

tA KEY 12

on other intervals - wound interval t,; t t 4 and 12 and diodes 15 and 16 winding current W1 .1 flows, in the interval t – j t t through switch 12 and diodes 14 and 17 - winding current W1.2.

The introduction of an additional throttle 2 and three-pole switch 9 into the circuit makes it possible to increase the output voltage level and increase the power factor during regulation. This is due to the fact that in the proposed converter, the current of each of the chokes in the closed state of the respective switch outputs flows through the power supply source, and at other times, through the power source and

load. The voltage on each of the filters is 25 ends of the main and additional windings

The capacitors are determined by the duration of the closed state of the switch outputs t and the ratio of the turns of the half windings of the chokes, and in the ideal case, in the absence of losses, it can reach an infinitely large value. The output voltage is controlled by varying the duration tc. The presence of a switch allows one to form a curve of current consumption in such a way that the angle of its first harmonic shift relative to the supply voltage is zero, regardless of the degree of control. In this case, the power factor, determined only by the distortions of the consumed current, has an increased value (with a double adjustment range of not less than 0.9).

Claims (3)

1. AC-to-DC constant voltage converter containing two input and two output terminals for connecting respectively an AC voltage source ten 15 20 and load, smoothing choke, the winding tap of which is connected to the first input terminal, connected between the output terminals a circuit of two series-connected filter capacitors, the common connection point of which is connected to the second input terminal, and two diodes, the cathode of the first and the anode of the second diode are connected respectively, with the first and second output pins, and the anode of the first - with the beginning of the winding smoothing throttle, characterized in that, in order to expand functionality and increase the coefficient In addition, a choke with a winding tap and a three-pole switch is added, while the start of the winding of the additional choke is connected to the cathode of the second diode, and the tap of the winding is connected to the first input terminal. 0 five 0 five 0 The main chokes are connected to the first and second terminals of the switch, and the third output of the switch is connected to the second input terminal. 2. A converter according to claim 1, characterized in that the three-pole switch comprises two serially connected control keys, the free key inputs being the first and second terminals of the switch, and their common connection point is the third output of the switch. 3. The converter according to claim 2, characterized in that the three-pole switch contains a control key and four diodes, the circuit of the first and second diodes connected in series is connected in parallel with the key, the anode of the third diode is connected to the anode of the first, the fourth cathode - with the cathode of the second, the free terminals of the third and fourth diodes are the first and one terminals of the switch, and the common junction point of the first and second diodes is the third terminal of the switch. f1 / g. IG .41 F1 / g.