SU584388A1 - Device for charging storage battery - Google Patents

Description

one

The invention relates to the region of the power converter of a technique and can find a hint in devices for accelerating the charge of batteries.

There are various types of forced charge batteries for battery charging, consisting of an initial charge of high current and high density; a stage and charge - discharge PI, followed by a long period of low dose charging with a low current grid. However, the implementation of such methods of charging in the complex meets a number of technical difficulties. The charge-and-discharge mode can be provided with the help of a reverse current detector, and high and low density currents can be provided by means of step-wise switching of the faults of the matching transformer. In three-phase devices, the stepwise switching of the transformer windings leads to a significant complication of the circuit and an increase in the number of additional switching elements.

Three-phase reversible rectifiers based on anti-parallel-connected thyristors or triacs are known, containing a power transformer with two secondary windings connected in a star, each phase of which is connected to the combined anodes (cathodes) of two valves - triacs through which it is connected to opposite the phases of the second second; o1H11oi ooMOTKi ;, irpche.i bullet points oo.viuiOK form the output terminals of the device.

YcTpOHciBa for charging a battery is known on the basis of these rectifiers, which provide a stepwise decrease in charge current using additional thyristor valves included in the 1p direction between the ends of each of the secondary cores and the zero point of the opposite secondary cores. The disadvantages of these devices are the low power factor, the significant installed power of the equipment and the long duration of the process.

In order to increase the power factor, reduce the installed power of the equipment and reduce the duration of the charging process, two additional elements are included in the proposed device, which are connected between the zero points of the secondary windings of the transformer and the output devices connected to the combined anodes and thyristor cathodes.

FIG. 1 is a schematic diagram of the device described; in fig. 2, a-d — operating structures of the device circuits; in fig. 3 is a charge current diagram.

The three-phase transformer 1 contains two equivalent secondary windings connected in direct stars. Ends of each of the secondary

The windings are connected to the two phase ends of the opposite half of the secondary winding through the emistors 2-7, and through the thyristors 8-13 to their zero points and through the key elements 14 and 15 to the output terminals of the device, in parallel with which the battery 16 is connected.

In the forced charge mode of the batteries, the control pulses are applied to all of the emisters 2–7 and thyristors 8–13 in the order of priority n with the key elements 14 and 15 open. As a result, the power circuit turns into a double rectifier bridge circuit. the impaired line voltages of the two secondary windings of the transformer 1 (see fng. 2, a).

Under the difference of the rectified doubled line voltage and battery voltage, a forcing current of large magnitude flows.

Upon reaching the onset of gassing, the control system lowers the control over the thyristors 8–13 and closes the key elements 14 and 15, forming a pattern for rectifying only one line voltage. Depending on the phase of the switching on angle of the 2–7 symStor, the latter work either as direct switching thyristors (see Fig. 2.6) or as reverse turning thyristors {see FIG. 2.8), providing the possibility of reversing the charge current under the action of the difference or rectified linear voltage and battery voltage, or vice versa.

After the battery reaches approximately 90-95% of the charge level, the control pulses are removed from the triacs 2-7 and fed to thyristors 8-13 with the key elements 14 and 15 closed. This forms a new straightening circuit. similar to the six-phase star

and providing the rectification of the phase voltage of the secondary windings of the transformer 1 (see Fig. 2, d). This voltage slightly exceeds the battery voltage of the battery 16, ensuring the flow of a small magnitude of the charge current for a long time.

Pa figs. Figure 3 shows one of the possible charts for controlling the charging current.

0 The proposed scheme has more potential possibilities for implementing other methods of charging batteries.

Due to the four-step diaiazop of regulation of the voltage, the device has a high power factor in all charging modes with a minimum number of key elements.

Instead of a triac 2-7, their aialogues can be used - counter-parallel

0 connected thyristor pairs. Both key and contactless switching devices can be used as key elements of elements 14 and 15.

5F o rm t of the invention

A device for charging a battery containing a three-phase transformer with two secondary windings connected in stars, the ends of each of which

0 are connected via emulator to two adjacent phase ends of the opposing secondary winding and via tyrnstors to their zero points and output terminals, characterized in that, in order to increase the power factor, reduce the installed power of the equipment and reduce the duration of the charging process, it has been added two key elements connected between the zero points of the transformer windings and the output terminals of the device associated with the combined anodes and thyristor cathodes.

-fГ +

FIG. 2