SU103573A1 - Regulator of electric arc furnace - Google Patents

Description

The invention relates to regulators of arc steel-smelting electric furnaces with a-synchronous three-phase short-circuited motors for driving electrodes, with measuring: orgam, operating on the principle of comparison of voltage and arc current.

According to the invention v. The aim is to increase the quality of regulation, for engine control, the engines connected to the stator circuit of the motor droseeln saturation, iodomagnetic from the output section of the measuring body through the semiconductor valves and connected to the circuit ensuring the required matching of the rotation of the motor, ensure the required alignment of the motor rotation.

FIG. 1 shows an electrical diagram of an extension regulator (for one phase of an electric arc furnace); in fig. 2 - a variant of the circuit with the use of magnetic amplifiers.

The stator circuit of the asynchronous motor AD with a squirrel-cage rotor (Fig. 1) includes five saturation throttles (1DN) ... (5DN) in such a way that when iodomagnetising throttles (1DN). (ZDN) and (5DN) the engine begins to rotate in one direction, and when the chokes (2DN), (ZDN) and (4DN) are sensed, in the opposite direction (gfy, the motor is not fitted). In accordance with i- this, the bias winding of the chokes (MDR) of the middle phase is connected directly to the signal voltage, and the windings control the chokes of the other two

The phases are included through i.e. -nive libniiixMi TiMu (IB) and (2B).

Lumbering are 1 wavelength element ni; .5 A clever scheme on the principle of comparison of stresses. iorscale current measured by the current transformer (CT). and arc voltage. If in excess of the current of the set value, the source of the 1 point of the point (a) becomes higher than the potential of the point (b), and the current in the centals of the control windings of the chokes flows from the point (a) through the windings (4DN), (2DN), rectifier (1B) and winding (ZDN) to point (b). In this way, chokes (2DN) are magnetised. (ZDN) n (4DN) and motor (BP) wrap (a decay, as long as the mismatch does not disappear at the input.

When the arc current is changed, the polarity of the signal at the input changes and the motor rotates in the opposite direction.

FIG. Figure 2 shows a regulator circuit in which two stages of intermediate magnetic amplifiers are used to increase the sensitivity; 1 and STM: (IMF), (ZMU) for one direction of rotation n (2МУ). (4МУ) - for another direction of the rotator.

All magnetic sleeves are made with series-connected windings, alternating-current with positive feedback and operating in relay (or close to, relay) mode.

To destroy the electrical connection between the individual circuits, the intermediate magnetic amplifiers are threaded from a transformer (PT). Each amplifier has the following windings: (OH) - winding altern: enn G1 current; (00) - obg.u-ikodikatelnogo o6pg.THoii communication: (OU) - obiotka control; (ОS) - О: .gotk; 1 (function centered for right full-time setting of the operating point of the amplifier.

In the first two cascades of the tsmeugs winding (OH) there is a convertible contact by the engine, which is; feed through Eif mnsl (BFB) additional resistances (1G) and (2C) -from nap) / engine.

The input signal is on. control windings of amplifiers (1YY) and (2 MU) through rectifiers (VB) c (NOT). 1 rp of one field p} of the signal (when the arc current is less than the set value) the control current flows from the sonotransmit (3G) through the displacement bias (OC) of the map amplifier (1 ill JO rectifier (IJ) to the resistance (4C). This is the result of the knockout (1MU), then (ZYU) and no.imaglich vyvats with droseeln (2dN). (RL11) ir (4DYu.

The motor lowers the electrode until the coc signal is zero. With a different signal polarity, the other arm works similarly.

The rectifier (EC) was used to power the bias windings of all amplifiers, and the capacitors (IE, 2E, 3E and 4E) - to improve the performance of the amplifiers.

Negative feedback; coupling to the voltage of the motor is introduced for

elimination of overshoot via a biofield rectifier (the value of this connection is controlled by resistances of 1C to 20).

L p i dmete and 3 about b and with and

Claims (3)

1. The controller of the steel arc steel arc furnace with an asynchronous three-phase short-circuited motors for driving electrodes, with a measuring organ, which operates according to the principle of equalizing voltage and current magnitude of the arc, which is business of improving the reliability and quality of regulation, for}} motor control used on the day of the stators of the motors of the saturation throttles, swiveling from the output voltage of the measuring body through the semiconductor vectors or included but according to the circuit, minutes needed; 1moe matching the rotational direction of the engine (and sex of the input signal polarity. 2. Prjmenenne in jio controller and. I d; wired magnetic feedback amplifiers with different feedback and input in relay.:; Or close to relay mode and driving the chokes. 3. Application in the controller according to claim 1 is more negative than rigid feedback on the motor voltage. LI GT 1, I L Very much