SU537420A1 - Device for supplying load with direct current - Google Patents

Description

one

The invention relates to devices for feeding loads from electrochemical current sources such as batteries or batteries of regenerable cells, such as zinc-based, zinc, which are operating in a buffer mode and which provide continuous power supply with a direct current.

The known device for supplying the load contains a two-section battery, a three-phase source of alternating current, a rectifier connected in a one- or three-phase bridge, and a block for monitoring the voltage on the load (buffer battery) and controlling the charging current 1.

In this device, the load (the resistances of which can be connected both to individual sections of the battery and to the battery as a whole) is powered by a constant current of the buffer battery. This battery is connected to a three-phase bridge rectifier connected to an alternating current source, the windings of which are connected by a star. The three terminals of the source are connected to the input terminals of the bridge, and the zero point of the star is connected to the midpoint of the battery through a charge current limiter. The range of variation of voltage across battery sections does not exceed 17%. It is necessary to have a zero point output of a star and at least six diodes. The circuit can not work when connecting the phases of the source of a triangle.

It is also known a device for a DC load terminal comprising

a three-phase AC source with three output terminals, a two-compartment battery, a charging current limiter connected between the midpoint of the battery and one of the output terminals

source, rectifier valves and load control and charging current control unit. 2

This device does not require a zero output, contains six gates, two of which are thyristors, provides a twofold change in the voltage across the battery sections and prevents it from overcharging. For this, the voltage monitoring unit, controlling the level of charge, regulates the charge current by changing the phase angle of the thyristors. Odiako this device also contains a large number of valves.

The aim of the invention is to simplify

devices.

To this end, the second output terminal of the source is connected to the anode of one valve of the detector, and a third output terminal of the cathode of another valve, while the cathode and

the anode of these valves are connected respectively

with positive and negative battery terminals.

FIG. 1 shows a diagram of the device; in fig. 2-variant of the device.

The load 1 (the connectors of which are connected both to the battery and each section separately) is powered by battery 2. The battery is connected to the three terminals 3, 4, 5 of the three-phase AC source and is charged (recharged) with the rectified current of this source. Terminal 3 is connected via a charge current limiter 6 (adjustable choke, resistor or AC semiconductor controller) to the battery midpoint terminal. Terminal 4 is connected via valve 7 to the positive terminal of the battery, and terminal 5 via valve 8 to the negative terminal. A block 9 is connected to the battery terminals, which controls the voltage across the load and controls the battery charge current. The valves in the device in FIG. 1 are thyristors, and block 9 controls the operation of the thyristors. In the device of FIG. 2, the valves 7, 8 are conventional diodes, and the unit 9 controls the charging current by means of an adjustable charge current limiter 6. In the devices of FIG. 1 and 2 source windings can be connected as a star, and a triangle. When connected by a triangle to the terminals 3, 4 and 5, the phase is supplied, and when connected by a star, the line voltage of the source.

When considering the operation of the device, we assume that the source windings are connected by a triangle. Then, in the device of FIG. 1, if the battery voltage is lower than the set value, block 9 sends signals to the valves 7 and 8. When both thyristors are open, the battery is charged by the phase 4 current. 5. At the same time, the battery section through the valve 7 and the limiter 6 can be charged current phase 4, 3, and the lower-current phase 3, 5 (through the limiter 6 and valve 8). By varying the resistance of the charge limiter 6, the voltage across the battery sections can be changed twice.

If the device is configured as shown in FIG. 2, here the battery is in a state of charge from phase 4, 5, and the charge current from this phase is not regulated, and the battery is charged from a constant voltage source. In order to increase the charging current, it is necessary to reduce the resistance of the charge current limiter 6 by means of block 9. It is possible to change the charge current of the battery by changing the voltage applied to its sections by 2 times. At the end of the charge, block 9 turns off limiter 6 (or puts it into a state with minimal conductivity). This transfer can also be carried out after forced charging (charging) of the battery sections for charging at a constant voltage from phase 4, 5.

Therefore, the device can be reduced according to the proposed scheme.

up to two valves and provide the same possibilities of regulating the charge current (charging) of the battery.

Claims (2)

1. Auth. St. No. 399944, cl. H 02J 7/28, 1971. 2. Auth. St. No. 470022, cl. H 02J 7/34, 1972. IL jr bg B4 II rrzn I-m p L-Kb