SU501459A1 - Device for controlling reversible DC motor - Google Patents

Description

one

The invention relates to the field of converter technology and can be used in electric drive systems and follow DC systems.

A device for controlling a DC reversible electric drive is known, comprising a thyristor bridge with reverse diodes, the diagonal of which includes the core winding, switching devices with pulse transformers connected between the common points of the thyristors and the diodes of the indicated bridge.

The disadvantages of the converter with linear MM co-optors and elements are the increased installed powers and overall dimensions due to the low magnetic permeability of the magnetic circuits of chokes and transformers. In addition, the presence of a linear throttle, connected in series with the power source, leads to a decrease in efficiency. and the output voltage of the converter.

The purpose of the invention is to reduce the weight and size of the device and increase its efficiency. This goal is achieved by installing in each switching device, instead of one linear transformer, two saturable transformers with a rectangular hysteresis loop, the Commutating windings of both transformers are connected in series and opposite, and the demagnetizing windings are connected according to each other and in series with the core motor winding.

The scheme of the proposed device for controlling a reversible direct current drive is shown in FIG. one; in fig. 2 - the same, a simplified version.

To the terminals of the direct current source 1 are mutually connected mutually winding 2-5 saturable transformers with a rectangular hysteresis loop and a thyristor bridge 6-9. To source terminals

1, a reverse diode bridge 10–13 is also connected, the AC terminals of which are connected to the corresponding terminals of the thyristor bridge 6–9. The demagnetizing windings 14 and 15, 16 and 17 are connected in series-consistently with each other and in series with the winding of the electric motor core 18. The switching thyristors 19, 20, to the common point of which the output of the switching capacitor 21 is connected, are connected in series with the working windings 22, 23 and the switching windings 4, 5. Another output of the switching capacitor 21 is connected to the source terminal 1. The terminals of the windings 5 and 22 are connected to additional source 24.

The device operates in the quasi-established mode as follows.

If the TOC flows into the beginning of the demagnetization winding, obziachaei dot, then the core of the transformer is shifted to the saturation state - {- Bs and vice versa. Then, in the time interval YT, when the thyristors 7 and 9 are switched on, under the action of the current of the core 18 in the demagnetizing windings all the cores of the transformers are shifted to the saturation state -Bg.

When the switching thyristor 20 is opened, the switching capacitor 21 is recharged along the circuit: 21, 20, 4, 5, 21. At the same time, the transformer core with windings 4, 16 is re-magnetized from the -BS state to some state b along the dynamic hysteresis loop and back . At this time, the transformer with windings 5, 17 is saturated. During the reloading of the capacitor on the winding 4, there will be a voltage that, through the diode 10, the power source 1, the winding 5 is applied in the opposite direction to the thyristor 9 and quenches it. After that, in the time interval (1-y) T, the current of the core 18 closes along the circuit: 18. 16, 17, 10, 2, 3, 7, 14, 15, 18 remagnetes the core of the transformer with windings 4, 16 into the state saturation-in.,. Next, the thyristors 7 and 9 are unlocked. After a time interval, the ТТ turns on the switching thyristor 19 and the source 1 is recharged along the circuit: 21, 24, 22, 23, 19, 21. At this time, the core of the transformer with windings is 3, 15, 23 and saturated , and the core of the transaurmator with the windings 2, 14, 22 is non-magnetic from saturation state -BS and with the help of winding 2 it quenches the thyristor 7. Then, in the time interval (1-Y), the current cor 18, closes with the chesh-k 18, 16, 17, 9, 4, 5, 12, 15, 14, 18, -remagnetizes the core of the transformer with winding 2, 14, 22 in the saturation state -BS and prepares it for the next percent Essa Gosheni. Further, the processes are repeated.

When the motor is reversed, the pulses that unlock the thyristors 7 and 9 of one diagonal ground are removed for a time from two to three commutation switches, and then fed to the thyristors 6, 8 of another diagonal group of the bridge thyristors. The thyristors 6, 8 are unlocked, and in the time interval y7 to the winding of the core 18 and demagnetizing windings 14-17 of all transformers will be applied

power supply voltage and emf rotation of the electric motor, which remagnetizes all the cores into the + B + state. Then, when the thyristor is unlocked, 20 transformer cores with windings 4, 16 saturate, and transformer cores with windings 5, 17 magnetise and quench thyristor 8. When the thyristor unlocks 19, the transformer core with windings 2, 14, 22 is saturated, and the transformer with windings 3, 17 , 23 reversal and quenches thyristor 6.

Reduced weight, overall dimensions and increased efficiency. The converter is obtained due to the fact that in the switching device the transformers most of the switching period are in a saturated state, and a smaller part in the Unsaturated state. At the same time, the mag- netic permeability of the transformer in the saturated state is much smaller, and in the unsaturated state it is much more than the magnetic permeability of the linear transformer. The equivalent resistance of the switching and demagnetizing windings of saturable transformers is less than the resistance of the switching windings of linear transformers. Equivalent inductance of a core circuit with a saturable transformer is less than the equivalent inductance of a core circuit with a linear transformer.

The operation of the device in a simplified version (Fig. 2) proceeds similarly.

Claims (1)

Invention Formula A device for regulating a direct current reverse current drive containing a thyristor bridge with reverse diodes, the diagonal of which includes a core winding, switching devices with pulse transformers connected between the common points of the thyristors and the diodes of the said bridge, so as to reduce the weight and the dimensions of the device and the increase in its efficiency, each of the mentioned pulse transformers is made in the form of two saturable transformers with a rectangular hysteresis loop, and the workers are 1mut The windings of which are interconnected and successively opposite, and the unwinding windings interconnected according to each other, are connected in series with the winding of the core.