SU394902A1 - DEVICE OF CHARGING OF THE ACCUMULATING CAPACITOR - Google Patents

Description

one

Of course, the shaving is related to electric power industry and is intended for charging the storage capacitor by pulses of constant amplitude from a three-phase AC source in those systems where the charge period period to the period of the supply voltage is large and where the power supply voltage is less than the maximum voltage of the storage capacitor. condenser.

A device for charging a storage capacitor, containing its power transformer, connected via a current-limiting choke and rectifier to a storage capacitor, as well as a control unit, including series-connected phase-shifting units and control pulse drivers, is known.

The proposed device differs from the known one in that the power transformer is made single-phase, while its primary winding is connected as a load in a three-phase network through semistor, connected according to the three-phase rectifier circuit, the control electrodes of which are connected to the outputs of control pulse shapers, which significantly reduces the size and weight of the charging device.

FIG. 1 shows the scheme of the proposed storage capacitor charge device; in fig. 2 is a timing diagram of the signals, explaining the principle of operation of the device.

The device consists of control units /, 2 and 3, each of them includes, respectively, the phase-shifting blocks 4, 5 and 6, the formers 7, S and 5 control pulses, which are waiting for a blocking generator, and also from the storage capacitor 10 power control unit 1 consisting of seven-strikers 12, 13 and 14, a single-phase rectifier 15 of a single-phase transformer 16 with primary and secondary windings 17 and 18, respectively, and a current-limiting droplet 19. p DC converter, but instead of diodes included semistors.

The device works as follows.

At the input of the phase shifting blocks 4, 5 and 6, control pulses appear as soon as the network voltage (the falling part of the sinusoid) exceeds the voltage on the capacitor by a certain amount. The phase-shifting unit 4 outputs a control signal from the positive half-wave of the phase A voltage to the driver 7 of the control pulses, the pulses of which open the twistor 13. The network voltage (figure 2, phase A) is part of the positive sine wave applied to the primary winding 17 of the transformer 16 Under the action of induced emf. in the secondary winding 18, the storage capacitor 10 is charged with a current (FIG. 2, b through the choke 19 and the extractor 15. The charging current will increase the voltage of the capacitor 10 (FIG. 2, e for some amount). will open, the control signal will be removed from it, but it will remain open until the voltage of the network changes sign.

The next control signal arises at the output of the phase-shifting unit 6 from the negative half-wave of phase B at the moment of a certain excess of the network voltage in terms of the absolute value of the voltage on the capacitor, and this happens with a higher network voltage in absolute value than in the previous case. The charging current (Fig. 2, b) of phase B increases the voltage across the capacitor (fig. 2, e).

Further operation of the device is similar and is illustrated by a voltage diagram (Fig. 2).

The duty cycle of the charging current of each phase is greater if the storage capacitor has a long charge compared to the supply voltage, and the conductive HF closes to the next control signal HPS, so it is advisable to use a single-phase transformer instead of a three-phase one. Moreover, the transformer is not magnetized, so

as a voltage is applied alternately to the primary winding as parts of sinusoids of different polarity.

 the three-phase network is three-wire, the winding of the single-phase transformer is connected to the three-phase network through semistor, connected according to the three-phase rectifying bridge, and the winding is connected as well as the load, i.e. to the three-phase rectifier.

Using a single-phase transformer instead of a three-phase one reduces the weight of the converter element (transformer) of the charging device by 30%.

Subject invention

Charging device accumulative CO | Ndensatora containing a power transformer,

connected via a current-limiting choke and rectifier to a co-capacitor capacitor, as well as a control unit, including series-connected phase-shifting units and control pulse shapers, characterized in that, in order to reduce the size and weight, the power transformer is single-phase, and In this case, its primary winding is connected as a load to a three-phase network through semistor, connected according to the three-phase rectifier circuit, the control electrodes of which are connected to the outputs of the control circuit respectively having pulses.