SU731545A2 - Dc motor - Google Patents

Description

Forced quenching of thyristors 1-4 is carried out by a forced quenching unit 10 containing a charged serial oscillating circuit made in the form of a series-connected diode I, charging throttle 12 and a storage capacitor 13, a damping parallel oscillating circuit in the form of a storage capacitor 13, a switching thyristor 14 and separation throttle 15, as well as an auxiliary parallel oscillatory circuit from the co-condenser 13, the thyristor 16 and the throttle 17.

The separation choke 15 is connected in series with a bridge thyristor switch, made on thyristors 1-6. The common point of the chokes 15, 17 and the capacitor 13 is connected to the negative power supply bar 18. The anchor of the motor 19 is included in the diagonal of the bridge thyristor switch.

The direct current drive operates as follows.

The motor armature is connected to the power source if the thyristors 1 and 2 (or 3 and 4) of the bridge thyristor switch are in the conductive state. They are unlocked by the action of positive-polarity voltage pulses applied to the control electrodes, and forced downdraution is due to the discharge of the capacitor 13 of the irradiation suppressor unit 10.

In the event that the motor speed is controlled without changing the direction of motion, then only thyristor 2 or 4 is quenched for the purpose of ensuring continuity of the current in the motor's core, while thyristor 6 or 5 is being pulled during the pause. in the motor core circuit, a current is maintained due to the back-EMF of droplets 7 and the motor core 19 according to the action: choke 7, thyristor 1 or 3, measles of motor 19, thyristor 6 or 5

In the case of motor reversal, at the next pause, thyristor 6 or 5 is not removed and therefore thyristors 1 and 2 or 3 and 4 are simultaneously extinguished. Throttle current 7 thus closes on the circuit of thyristor 8 unlocked for the time of reverse engine 19. Thyristors 1 and 2 or 3 and 4 are extinguished when the thyristor 14 is unlocked due to the energy accumulated on the capacitor 13. At the same time, the positive potential of the charge of the kondeiser 13 is applied to the cathode of the thyristor 2 or 4, and the negative is fed to the bus 9 via the imitation source. 6 or 5, then the negative first charge potential koidensatora iostuiaet 13 to the anode of the thyristor 2 or 4. If the thyristor 5 or 6 is closed, the negative charge ioteitspal kondeisa, 1ora 13 is supplied through the open for a time

reverse thyristor 8 to the anodes of thyristors 1 and 3, and open thyristors 1 and 2 or 3 and 4 shone.

Block 10 forced quenching works as follows.

When the power supply is turned on, the capacitor 13 is charged on the following circuits: bus 9, diode 11, choke 12, co-capacitor 13, bus 18. Throttle 12 and capacitor 13 form a sequential oscillating circuit, in which there is a resonance iair l (ies, sequence, condisator 13 charged to a potential higher than the potential of the tire 9.

Due to the presence of the diode 11 in the coitur circuit, the process is terminated as soon as the charge of the condisor 13 stops. The discharge of the co-capacitor 13 is prevented by the diode P. If the switching thyristor 14 is now converted to a conducting state, then, first; 13 volt capacitor potential; Adds to the cathodes of thyristors 2 and 4, and the negative through the power supply to the bus 9 and then in the motor speed control mode without changing the rotation control through the open thyristor 6 or 5 to the anode of the thyristor 2 NLP 4, and in the reverse mode through the thyristor 8, unlocked at the time of motor reversal, to the thyristors 1 and 3, thus locking those thyristors to which the charge accumulated on the capacitor 13 is re-polarized. Second, closes the circuit and the parallel

LC circuit consisting of a capacitor

13, switching switch 14 and separation choke 15. In this circuit, the oscillating process of recharging the capacitor 13 begins.

In addition, through commutating thyristor 14 and separator choke 15 parasitic current flows through the circuit: tenon 9, diode 11, choke 12, commutating thyristor

14, separator choke 15, bus 18. Drossel inductance 12 is selected during

many times greater inductance of separator drossel 15, and this current increases and is much slower than the current of recharging and the co-detector 13.

After reloading the co-sensor 13 to the switching thyristor 14, the source voltage is applied in the forward direction and the voltage of the co-organizer 13 in the reverse, locking direction. The hook as an output voltage on the capacitor 13 is higher than the voltage of the terminal and the quality factor of the parallel circuit: the capacitor 13, the separation choke 15 is high enough, then the ia air and the co-capacitor 13 after recharging will be higher than the voltage of the source of power, the sequence switch of the thyristor 14 under the influence of this ia

will become non-conducting. it

Claims (1)

Claim 20 DC drive according to copyright certificate 350119, characterized in that, in order to expand the range of motor speed control, an additional circuit is included in parallel with the switching thyristor 25 and the isolation choke, containing a thyristor and a choke connected in series.