SU410526A1 - - Google Patents

Description

one

The invention relates to the field of electric traction and is intended primarily for mine locomotives.

A device for controlling a thyristor-pulse converter in the speed controller of mine DC electric locomotives is known. For speed controllers of electric locomotives, in particular, for control devices of a thyristor-pulse converter, alternating current is required along with direct current of different voltages. Therefore, in the control devices of the thyristor-pulse converter, power supply units are used, in which the conversion of a DC voltage of one value into another and into an AC voltage is performed. A separate DC / DC converter is used to convert the DC to AC voltage. This is already the second converter, since the thyristor-pulse converter itself, which the whole device is intended to control, also converts the constant voltage. Therefore, the use of one more converter complicates the circuit and reduces its reliability. In a number of cases, for example, when using a converted voltage to obtain a constant voltage of another magnitude, the form of the converted voltage is less stringent than the reliability of the device. In this case, it is rational to use the output voltage of the thyristor-pulse converter.

The purpose of the invention is to simplify and improve the reliability of the device. This is achieved by connecting the primary winding of the transformer of the power supply unit at one end through a capacitor to the cathode of the power thyristor, and the second to the minus of the power supply. Such a connection makes it possible to refuse to use a special DC / DC converter in the circuit.

The drawing shows a device for controlling a thyristor-pulse converter of a constant voltage supply network.

Thyristor-pulse converter 1

contains power 2 and 3 extinguishing thyristors, as well as switching capacitor 4, choke 5 and diodes b and 7. A load 8 is connected to the output of the thyristor-pulse converter. The control circuit 9 includes

a fixed pulse generator 10 and a moving pulse generator 11. The generator 10 has an output transformer 12 with secondary windings 13 and 14. The winding 13 is connected to the control electrode of the power thyristor 2. The winding 14 is connected via an adjustable choke 15 to the input of the moving pulse generator 11. The generator 11 contains an input transistor 16, a capacitor 17, a resistor 18, a thyristor 19, a storage capacitor 20, a resistor 21 and an output transformer 22 with a secondary winding 23 connected to the control electrode of the quenching thyristor 3 tyri Thorn pulse transformer 1. Power converter / generator 10 and fixed pulse storage capacitor 20 is performed by constant current source. In the case of using the described device for controlling the speed of mine electric locomotives, the power comes from a troll with a voltage of 260 V. The power supply unit 24 comprises a capacitor 25, a transformer 26 and a rectifying bridge 27, the output of which is connected to the capacitor 17 of the generator 11.

The device works as follows.

When power is applied, the charge / switching capacitor 4 and the thyristor-pulse converter 1 along the circuit occur: the positive pole of the power source, the capacitor 4, diode 6, the load 8, the negative pole of the power source. To charge the capacitor 4 in this thyristor-pulse converter, it is not necessary to open the extinguishing thyristor 3, and, therefore, before starting the converter and at the time of its start, the operation of the generator of moving pulses is not necessary. At the same time, when the voltage is applied, the generator 10 starts up and the storage capacitor 20 of the moving pulse generator, 11, is charged. From the winding 13 of the output transformer 12 of the generator 10, a pulse is applied to turn on the power thyristor 2 and the thyristor-pulse converter 1 is put into operation, although the voltage at the output of the power supply unit is absent at this time and, therefore, the generator // does not work. After the thyristor 2 is opened, the supply voltage is applied to the load 8, and a current flows through the capacitor 25 and the primary winding 26 of the power supply 24. A voltage appears on the secondary side of the transformer 26, which charges the capacitor 17 of the generator 11.

When a generator produces stationary pulses 10 for switching on the power thyristor 2 from the secondary winding 14 of this generator, a pulse is output to the input of the transistor 16 of generator 11. The leading edges of these pulses coincide in time. The falling edge of the pulse coming from the winding 14 and entering the input of the transistor 16 can be "stretched" using an adjustable throttle 15. Therefore, if there is power to the capacitor 17 of the generator 11, the transistor 16 will be open for

THAT time, while at its input there is a voltage, i.e. during the action of the input pulse. In other words, the front, front of the input pulse opens the transistor 16, 5 and the rear edge closes. When a voltage appears on the capacitor 17, the transistor 16 opens and the control transition / thyristor 19 of the generator 11 is shunted. After the transistor 16 is closed, i.e., at the posterior y front of the pulse arriving at its input, capacitor 17, discharging through the IS resistor and controlling the thyristor junction 19, opens the thyristor. In this case, capacitor 20 is discharged through the thyristor 19 and the primary winding of the output transformer 22. On its secondary winding 23 an output pulse appears, which is applied to the opening of the extinguishing thyristor 3. The thyristor 3 opens, a circuit appears to recharge the switching capacitor 4, which, after recharging and closing the power thyristor. In this case, the capacitor 25 of the power supply unit 24 is discharged through the load 5 and the winding of the transformer 26. In the following, the operation cycles of the circuit are repeated.

The output voltage of the thyristor-pulse converter is regulated within wide limits (approximately 1:25). The voltage across the capacitor / 7 varies significantly less. This is ensured, firstly, by selecting the parameters of the capacitor 25 and the primary winding of the transformer 26. iBo secondly, with a larger pulse width, i.e., with a higher voltage at the output of the thyristor-pulse converter, the generator transistor 16 also opens for a longer time and the capacitor 17 is charged to lower values of nanotube. This leads to the fact that the range of variation of the voltage on the capacitor 17 is approximately 1: 3. Since the difference between the control current necessary to open the thyristor 19 and the maximum permissible value of the control current in this proportion is acceptable, then additional stabilization of the output voltage power supply 24 is not required.

Subject invention

A device for controlling a thyristor-impulse converter of a low-voltage traction network containing a unit

supplying a mobile pulse generator with a transformer, characterized in that, in order to simplify and increase reliability, it is equipped with a capacitor, one plate of which is connected to the cathode of the power thyristor, and the other through the primary winding of the specified transformer with a negative pole of the traction network.

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