SU1764125A1 - Multicell stabilized direct current voltage converter - Google Patents

Abstract

Usage: in the devices of the secondary power supply of electronic equipment. SUMMARY OF THE INVENTION: Using a control device (1) for charging and discharging a capacitor (9), when charging is performed using a switch (10) controlled by pulses from control circuits, and the discharge is controlled by a switch (10), controlled by voltage pulses. from the output of the rectifier. 2 Il.

Description

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with

VJ Och

 Yu

SP

The invention relates to electrical engineering, in particular to converter equipment, and can be used in secondary sources of electrical power for electronic equipment.

A stabilized DC voltage converter is known, which contains a power amplifier, a power transformer, output rectifier diodes, an output filter choke and capacitor, measuring elements on resistors, second rectifier diodes, an additional capacitor, a transistor, comparators, a source of reference voltage. When N converters are connected in parallel, the occurrence of a malfunction in one of the converters leads to a decrease in its output voltage and the protection circuit generates a signal to turn it off. However, when the load current changes, for example, from idling to the nominal value, at least one of the parallel operating transducers will be closed, because the voltage on the additional capacitor is absent, which leads to a complete emergency shutdown of the closed transducer.

Closest to the invention is a voltage converter containing a control circuit, N cells, each of which has a key element and a power transformer, the output windings of the transformers are connected via a rectifier to the output filter, a comparator of fault detection. The disadvantage of this converter is the lack of indication of a malfunctioning cell, which makes it difficult to search for a malfunctioning cell, repair the converter and reduce reliability indicators.

The purpose of the invention is to increase reliability by detecting and indicating a faulty converter cell,. The goal is achieved by the fact that in a multi cell stabilized DC voltage converter containing a control circuit, a logic element OR, N cells connected in parallel along the output, each of which contains a voltage converter with a power transformer at the output, the secondary winding of which is connected through the rectifier to the output filter, additionally each cell contains a diode, the anode of which is connected to the control circuit, and the cathode through the first resistor is connected to the first capacitor lead and the collector of the transistor, the base of which through the second resistor is connected to one of the terminals of the secondary winding of the power

cell transformer, and the emitter - to the second capacitor lead, and the thyristor control electrode is connected to the collector of the transistor through the threshold element, to the anode of which the display element is connected, another lead connected to the positive terminal of the additional DC source, the negative terminal of which

connected to the emitter of the transistor, the cathode of the thyristor and to the common bus; the anodes of the thyristors of each cell are connected to the inputs of the logic element OR; In the proposed device, a method of controlling a row of a capacitor is applied, when its charge is performed using a switch made on a diode, pulses, coming from the control circuit, and the discharge - using a switch made by a transistor, which is controlled by the pulse voltage from the rectifier output. Ways to control the charge and discharge of a capacitor using semiconductor switches in various automation devices

are known. Using the control circuit for charging and discharging a capacitor in a multi-cell stabilized DC-DC converter allows you to get a new positive

The effect is to increase the reliability of the converter by detecting and indicating. faulty cell, which confirms that the proposed solution meets the criterion of significant differences.

FIG. 1 shows the structural scheme of a multi-cell stabilized DC / DC converter; in fig. 2 shows time diagrams of voltages.

The converter has an operating circuit 1, cells 2.1-2.2, 2.N, containing a voltage converter 3, made, for example, by a two-stroke half-bridge circuit, a power transformer

4 at the output of voltage converter 3, whose secondary winding through a rectifier 5, made, for example, according to a two-half-period circuit with a midpoint, is connected to the output filter of the cell

0 2, the diode 7, the anode of which is connected to the control circuit 1, and the cathode through a resistor 8 to the first output of the capacitor 9 and the collector of the transistor 10, the base of which through the second resistor 11 is connected to one

5 from the terminals 12 of the secondary winding of the power transformer 4, and the emitter is connected to the second terminal of the capacitor 9. The collector electrode of the thyristor 14 is connected to the collector of the transistor 10 through the threshold element-Zener diode 13, for example, the control electrode 15 is connected to the anode. series-connected resistor and LED; The other output of the display element 15 is connected to the positive terminal of an additional source of constant voltage 16, the negative terminal of which is connected to the emitter of the transistor 10, the cathode of the thyristor 14 and the common bus 17. The anodes of the thyristors 14 of each cell 2.12.N are connected respectively to 1, ... , N inputs of the logic element OR 18, the output of which is connected to the control circuit 1. The control circuit 1 can be implemented, for example, as the control part of a DC voltage regulator.

Stabilized Converter works as follows.

The control circuit 1 generates wide-modulated pulses at the input of cell 2, from where they arrive at voltage converter 3 and diode 7. A diode 7 through a diode and a resistor 8 periodically recharges capacitor 9. When the cell is in good condition 2, voltage pulses (Fig. 2 Ui) c of the output 12 of the secondary winding of the power transformer 4 opens the transistor 10, which discharges the capacitor 9. Since the voltage on the capacitor 9 (Fig. 2, c) is below the threshold threshold 13, then output b Cell 2 will have a high signal level ( u. 2, b yield). If one of the cells 2 fails, voltage pulses from the output 12 of the secondary winding of the power transformer 4 of this cell will be absent (Fig 2, Ui). The trasistor 10 is closed, so the capacitor 9 will be recharged before the trigger voltage of the threshold element 13 (Fig. 2, Uc), which will lead to the opening of the thyristor 14, and a low voltage level at the output of the faulty cell (Fig. 2, output b ). The signals from the output b are fed to the input of the logic element OR 18, processed, fed to the control circuit 1 and form a trip signal for the stabilized converter. When the thyristor 14 is opened, the LED of the display element 15 is turned on and the malfunctioning cell 2 is indicated. The indication of the malfunctioning cell reduces the time required to search for and replace the malfunctioning cell, which is especially important for high-power converters (up to tens of kilowatts) containing tens of cells.

Thus, the advantage of the proposed solution in comparison with the prototype is to increase the reliability of the device by reducing the time of fault search by detecting and indicating the faulty cell,

Claims (1)

Invention Formula Many cell constant voltage converter, containing a control circuit, an OR logic unit, N cells connected in parallel along the output, each of which contains a voltage converter, with a power transformer at the output, the secondary winding of which is connected via a rectifier to an output filter, characterized in that by detecting and indicating a faulty cell, each cell additionally contains a diode, the anode of which is connected to the control circuit, and the cathode through the first resistor is connected to the first capacitor terminal and the trap collector ican whose base via a second resistor connected to one of the terminals of the secondary winding of the power transformer of the cell, and the emitter - to the second output of the capacitor, and the control is connected to the collector of the transistor through the threshold element a thyristor electrode, to the anode of which under-0 keys is an indication element, another output connected to the positive output of an additional source of constant voltage, the negative output of which connected to the emitter of the transistor, the cathode of the thyristors and to the common bus, the anodes of the thyristors of each cell are connected to the inputs of the logical element OR. cells Fie.2 cells