SU1427604A1 - Master control of power reculator of electric duty of arc furnace - Google Patents

Abstract

The invention relates to electrical engineering. The aim of the invention is to improve the speed by changing the structure of the setter in the nominal and limit modes. Signal,

Description

 one

The invention relates to electrothermal conditions, and more specifically to devices for automatically regulating the electric mode of electric arc furnaces.

The purpose of the invention is to increase the speed of the power setting device when the controller processes the maximum deviations of the electric mode of the furnace from a predetermined value by changing the structure of the setting device in nominal and limit modes.

The drawing shows a diagram of the set point of power in the power controller of an electric arc furnace.

The power regulator consists of a power sensor 1, a reversible thyristor amplifier 2. and an electric motor 3 displaces the electrode 4, the power setting device 1 contains a measuring current transformer 5, the output of which is connected to the primary winding of the first isolation transformer 6 with the primary 7 and an additional 8 secondary windings , the second separation transformer 9 with the main 10 and an additional 11 secondary windings, the first rectifying bridge 12, the diagonal of which is connected to the secondary winding 7 of the separating transformer 6, and the output diagonal. through the first active-capacitance filter 13 and

31А27604

the first controllable key 1A is connected

With the potentiometer 15 setting the arc current, the control input 1b is connected via the block 17 of the voltage control to the secondary winding 8 of the isolation transformer 6, the second rectifying bridge 18, the diagonal of which is connected to the secondary winding 10 of the separation transformer 9, and the output diagonal through the second an active capacitive filter 19 and a second control key 20 are connected to an arc voltage setting potentiometer 21, and the control input 22 is connected via a voltage control unit 23 to the secondary winding. 11 split transformer 9.

The regulator works as follows.

A signal proportional to the arc current from the measuring transformer 5 and a signal proportional to the voltage across the arc are respectively supplied to the primary windings of the separating transformers 6 and 9. The voltages from the secondary windings 7 and 10 of these transformers are supplied through rectifying bridges 12 and 1§ , active-capacitance filters 13, 19 and controlled keys 14, 20 on potentiometers 15, 21 of setting current and arc voltage, ac of secondary windings 8 and 11 through voltage control blocks 17 and 23, control voltage 30 and voltage key 20. Control The key 20 is closed and the arc voltage setting potentiometer 21 is disconnected from the output voltage of the arc voltage measurement channel (from the active-capacitive filter 19), the voltage at the control input of the reversing amplifier 2 increases abruptly to a value equal to the voltage at the output of the potentiometer

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nor to the control inputs 16 and 22 of the control keys 14 and 20, the control key 14 is open in the presence of an electric arc current and is closed by its interruptions. The control key 20 is open in the presence of voltage on the arc and is closed by a 40 5 electric motor 3 forcedly rummaged during short circuits x. accelerates to march speed,

moving the electrode 4 upwards to eliminate short circuits. After the elimination of the short circuit, the voltage at the output of the unit 23 at the output of the setpoint adjuster 1 is absent. Voltage on the control; voltage control and input 22 controls in case of equality of voltages taken from potentiometers 15 and 21, the signal

When an electric arc is broken, the voltage at the output of the voltage control unit 17 disappears and the input 16 of the control key 14, the control key 14 closes and the arc current potentiometer 15 is disconnected from the output of the electric arc current measurement channel, the voltage at the control input peQ The versatile amplifier 2 increases abruptly to a value equal to the voltage at the sweat outlet. {the clock 21, and the electric motor 3 accelerates to the marching speed, moving the electrode 4 downward until the electric arc is ignited. After ignition of the electric arc, a voltage appears at the output of the voltage control unit 17 and the input 16 of the controlled

0 of key 14. The control key 14 opens and potentiometer 15 is connected to the output of the active-capacitive filter 13. The voltage at the control input of the reversing amplifier 2 is sharply

5 is reduced, and the normal process of stabilizing the electric mode of the furnace is restored.

During short circuits, the voltage at the output of the block 23 disappears and the voltage is controlled and the input 22 of the control key 20. The control key 20 closes and the potentiometer 21 for setting the arc voltage is disconnected from the output of the arc voltage measuring channel (from the active-capacitive filter 19), the voltage at the control input of the reversible amplifier 2 increases abruptly to a value equal to the voltage at the output of the potentiometer

five

0 5 the electric motor 3 accelerates to the marching speed,

the input of the reverse thyristor amplifier 2 is zero. The motor 3 displaces the electrode 4 is stationary. When the electric mode of the furnace is small, from the set value at the output of the unit 1, the power will decrease. constant voltage, the magnitude and polarity of which depends on the magnitude and sign of the deviation. In this way, the electric motor 3 accelerates to a reduced speed, moving the electrode 4 in the direction of the error compensation.

key 20 is in operation. Control key 20 is opened and potentiometer 21 is connected to output of capacitive 5Q filter 19, voltage at control input of reversible amplifier 2 decreases sharply, and the normal process of stabilization of the electrical mode is restored.

Thus, the power setting device allows to increase the speed when the regulator develops the maximum deviations of the electric mode of the furnace from the specified value. Increase

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The speed allows to reduce the power consumption per ton of steel produced and to improve the performance of the electric ignition unit.

Claims (1)

Invention Formula The power setting of the electric mode regulator of an electric arc furnace containing the first and second isolation transformers, each of which has one main and one additional windings, and the primary windings of the first isolation transformer are connected to the current transformer, the first primary winding of the second isolation transformer contains a terminal for the second electrode is a terminal for connecting to the bottom, the first and the second rectifying bridges, and The output diagonal of the first rectifying bridge is connected to the inputs of the first active capacitive filter, and the output diagonal of the second rectifying bridge to the inputs of the second active capacitive filter, the first output of the first active capacitive filter is connected to the compiler E. Kosarev. Editor O. Spessivykh Tehred A. Kravchuk Proofreader L. Pilipenko Order 4867/57 Circulation 832 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 the output of the second active capacitive filter and with the common point of the current setting potentiometer and the voltage setting potentiometer connected in series, the outputs of the sliders being the outputs of the setter, characterized in that, in order to increase speed by changing the setpoint structure in the nominal and limit modes, it is additionally equipped with two controllable keys and two voltage control units, two inputs of the first of which are connected to the terminals of the auxiliary winding of the first isolation transformer, and you, the stroke - with the control input of the first control key, whose input connected to the second code of the first active-capacitive filter, and the output to the current setting potentiometer; the output of the auxiliary winding of the second isolation transformer is connected to the two inputs of the second voltage control unit, the output of which is connected to the control input of the second control key, whose input is connected to second exit second active-capacitive filter, and the output is with a voltage setting potentiometer. Subscription