SU720835A1 - Power regulator for electric arc furnace - Google Patents

Description

(54) ARC POWER REGULATOR

I

This invention relates to electrothermal conditions.

Known power regulators are arc arc furnaces that contain for each furnace phase a voltage transformer switch of a power transformer, a reversing converter connected by an output to an electrode displacement motor, and an input to an output of a comparator unit, the first input of which is connected via a rectifier to a current sensor the form of an air-driven current transformer, its second input through an additional rectifier is connected to the output of a voltage sensor connected by the input between the bottom and the outlet of the non-working end of ektroda.

The voltage sensor in these devices is designed as a matching transformer, in the primary circuit of which a resistor is connected with the steps that are switched by the switch contacts of the voltage transformer switch of the power transformer, which reduces the control accuracy;

In order to eliminate this drawback, the voltage sensor is made in the form of a contactless selsyn, the terminals of the field winding of which are the input of the sensor, the terminals of the stator winding are its output.

The selsyn rotor is mechanically connected with the voltage step switch of the power transformer, and between the terminals of the air current transformer and the rectifier a second non-contact selsyn is connected, and its excitation windings are connected to the terminals of the current transformer, and

pins of the stator winding - to the rectifier;

FIG. 1 shows the proposed controller; in fig. 2 is a graph of voltage changes at the output of a voltage sensor.

The power regulator of an electric arc furnace contains a reversible thyristor converter 1 connected to the motor 2 of the mechanism for moving the electrode of the furnace 3 and the comparator unit 4 connected to the target 5 power connected to the power transformer 6.

As a reversing transducer 1, for example, a thyristor converter such as STU-022 can be used.

Comparison unit 4 is made on load resistances 7, and rectifier bridges 8-9 are connected to its inputs.

The power setting device 5 comprises an arc current sensor 10 and a voltage sensor 11.

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Sensor 10 for arc arc; it is made in the form of an air transformer 12 of the current and selsyns 13. The exclsin excitation winding 13 is connected to the current air transformer 12, and the selsin's winding GbTGZTbra 13, g1bdklyuyenna To the infrared bridge 8 of unit 4 compare. A non-contact selsyn of type 5D 501 can be used as a selsi for 13. As an airborne current transformer, it can be used with RogbVSKoTSG with an increased JadKGSecheny for the output voltage: a voltage close to the nominal voltage of the selsyn field winding 13 Pc. The poice departed via the single way directly at the installation site with the load connected. The sensor 11 is high and is made in the form of a selsyn 16, the excitation winding 17 of which is through an additional resistance of 18 TGTBDT between the bottom and the electrode terminal. .-.-.---. . The rosin of the selsyn 16 through the reducer 19 MJO hani11es1 (and St. Ezan with the switch 20 switches the voltage of the furnace transformer. The winding 21 of the stator of the selsyn 16 Lodkl1checheShSchr myyethe 8 block 4 compare. -; -., -.,., .. ,,, .. The regulator operates in the following manner. During the period of melting, the furnace operates at the highest voltage. At the winding 17 of the excitation of the selsynn 16, with this additional resistance of 18, the accelerator of the silo voltage ... -, ...- ,, the rotor of the selsine 16 rotated by an angle di, and the voltage Ui is removed from the winding of the rotor (see Fig. 2), the cat The station arrives at the emergency bridge 8, block 4, comparison, and another rectifier, MoqT, 9, unit, comparison, r10, is pushed from the winding 15 of the rosin 13, the excitation of which is connected to the power line of the transformer 12, V. .; ,, ;;; The power unit corresponding to the required mode of the furnace is set by turning the rosin rotor 13. voltage difference between the windings of the ripple is 1HlHxHlqctto 8 A 9 isoMympiCyr by the historical process of reconfiguration. Lem G and TtOcfyfiaeT on the motor 2 Extend the jumble of electrodes. MexaHH3jvi the front panel changes the length for each and the next 1 in n% of the VDGtei SyiM supports the specified arc power. In accordance with the requirements of 1MShon) 1bg1GG1 (1H7th of the metal dissipation, the working voltage on the furnace electrodes is reduced. The voltage is reduced by 1IRZh5 6 across the stage of the HanpS eHujFi furnace transformer 6. If there is a switch on the switch transformer of the HanpS eHujFi furnace transformer 6. If there is a switch on the switch transformer of the HanpS eHujFi furnace transformer 6. If there is a switch on the switch transformer of the HanpS eHujFi furnace transformer 6. If there is a switch, the switch of the transformer of the HanpS eHujFi furnace transformer 6. If there is a switch, the switch of the transformer of the HanpS eHujFi furnace transformer 6. If there was a switch on the switch of the transformer of the HanpS eHujFi 6, then the ETTB switch of the transformer would be able to get the power of the transformer of the HanpS eHijFi furnace |, thus, TfOHanpHsreHWHa. output of selsyn 21 increases. At the same time

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Claims (2)

720835, and in its excitation winding 17, the voltage is W; E, 1 is the result of the voltage pulling from the winding 21 of the selsyn rotor 16 to the alternating bridge 7 varies according to the figure shown in FIG. 2, gdes (1, g,, UK - at the turn of the rotor of the rotor and Dapr Jennie at the output of the selsyn corresponding to the first and last slave stages of the power transformer 6. Thus, the output voltage of the rectifying bridge 8 of the unit 4 is compared to the last working stage more than the first. As a result, during the period of melting, when there is a large number of accidental disturbances, the regulator has a lower sensitivity, this ensures a lower frequency of response of the electrode displacement motor, therefore, In the technological period, when it is important to maintain a given mode with greater accuracy, the sensitivity of the regulator increases, as a result of which the furnace efficiency increases.The power regulator Regul I1or of the electric arc furnace, containing for each phase of the furnace a voltage switch transformer, a reversing converter connected by an OUTPUT to an electrode displacement motor, and an input to an output of a comparison unit, the first input of which is 15oz GW1 p ind Tel is connected to the current sensor; made in the form of the air “ro ro of the joKa transformer, its second input through an additional rectifier is connected to the voltage sensor input, the main input between the bottom and the output of the NerabtDonet ElKoTroDa, which differs from the JTO; In order to improve the control accuracy, the voltage sensor is designed as a contactless selsyn, the excitation winding leads of which are YIE THm ™ stator coupling 6Gc - 0 0VSODOM, the selsin rotor mechicySV using the power transformer switch of the Transformer and the transformer between the transformer and the transformer. A second-contact selsin is switched on, and its excitation windings are connected to the output of the transformer, and the outputs of the stator cover are to the rectifier. Sources of information, npHfljrtbie Considering during the examination 1. Svenchansky AD and others. Automation of electrothermal installations, M., “Energy, 1968, p. 232-237. 2. Authors certificate of the USSR 452080, cl. H 05 B 7/148, 1974. -, - -, f J, -f r; - -, "y; .-,. ,, iwzb (fi) (/ " (/ g Zgrad.) 2 to