SU997876A1 - Apparatus for controlling non-reversive thyratron-type electric drive of rolling mill rolls - Google Patents

Description

The invention relates to control and regulating devices for rolling mills operating under shock loads, in particular, to control devices for non-reversible valve electric drives of rolling mills.

The device closest to the proposed technical essence and the achieved effect is a control device with an irreversible valve electric drive for rolls of a rolling mill, containing connected in series: a first adder, a first controlled key, a two-stroke rotary speed regulator, a second controlled key, a second adder, a current regulator -and: a pulse-phase control system, a rotational speed sensor, the output of which is connected to the input of the first adder, a current sensor, the output of which is connected to the input of the second sou Matora and key control unit, the output of which is coupled to SVM control key inputs, and inputs - with metal ejection sensor outputs iporogovogo element input. which is connected to the output of a push-pull speed regulator and a zero-body, whose input is connected

with the output of the first adder. e. At the same time 6.KYUK key management contains-, zhvt R-S trigger, a logical element WI-NOT, and two logical elements I.

In the load shedding mode, the controlled keys are opened and break the speed control loop. During the time that the motor current decreases to zero, the voltage on

10, the output of the current controller is also brought to idle level. At the moment when the rotational frequency of the electric motor of a given value is reached, the keys are closed and the controller of the rotational speed is connected to the control system. Thus, the rotational speed of the electric motor is fixed at a predetermined level without current peaks and overshoot 1.

20

However, this device is characterized by increased complexity and lack of reliability.

The aim of the invention is to simplify and increase the reliability of the control device for the irreversible valve electric drive of the rolls of the rolling mill.

The goal is achieved by the fact that the control device is not a versatile valve electric drive, a rolling mill rolls containing a series-connected first adder, a first control switch, a two-stroke rotary frequency controller, a second controlled switch, a second accumulator, a current controller, and a pulse control system phase control, rotation frequency sensors, the output of which is connected to the input of the first adder, a current sensor, the output of which is connected to the input of the second adder, and a threshold element, additionally contains The element and the single-ended rotation frequency regulator, the input of which is connected to the output of the first sum of the device, and the output through the threshold element is connected to the control inputs of the keys. The combination of the above features makes it possible to exclude from the control devices of the non-reversible valve electric drive of the rolls of the rolling mill a complex key management unit, a sensor for ejecting metal from the rolls and a zero organ, while maintaining the equipment life and without reducing the quality of the rolled products. Thus, the invention provides an opportunity to significantly simplify the device for controlling the irreversible motor driven rolls of the rolling mill without impairing its operation,. The drawing shows a block diagram of a control device for a non-reversible fan motor driven rolls of a rolling mill. The device contains two circuits of the subordinate regulation. The current control loop of the electric motor 1 comprises successively connected current regulator 2, system 3 of pulse-phase control, valve converter 4, current sensor and adder 6. The motor frequency control loop contains a subordinate current control loop, two-stroke frequency regulator 7 rotation, the output of which through controlled key 8 is connected to the adder at the input of current regulator 2, and the input through controlled key 9 is connected to the output of adder 10, the input of which is connected to the output of the sensor 11 hours Rotational speed of the electric motor 1. The output of the single-ended controller 12 parts of rotation is connected to the output of the adder 10, all parameters of which are identical with the parameters of the controller 7 through the threshold element 13 connected to the control inputs of the keys 8 and 9, In drawing e Mechanical gear 14 engine rolls and rolls 15 of the rolling mill are also shown. The device works as follows. In the steady state rolling mode, the voltage at the outputs of the regulators 7 / and 12 is positive and exceeds the response threshold of the element 13, corresponding to the idle mode of the electric motor 1. Therefore, the voltage at the output of the threshold element 13 keeps the keys 8 and 9 in the closed state, t .. e. in rolling mode, the device operates as a conventional dual-circuit slave control system. In the load shedding mode, the rotational frequency of the electric motor 1 and the rollers 15 is increased due to excessive electromagnetic momentum and the released potential energy of the elastically deformed elements of the mechanical transmission 14. The voltage at the output of the rotational speed sensor 11 increases, which leads to a decrease in the voltage on the two-stroke 7 and single-ended 12 controllers; rotational speed. The voltages at the outputs of the regulators 7 and 12 change synchronously, since all their parameters are identical, and the same signals are applied to their inputs. When the voltages at the outputs of the regulators 7 and 12 decrease to the level corresponding to idle, the voltage at the output of the threshold element 13 begins to correspond to the threshold, the response. In this case, the threshold element is changes its state and the voltage appearing at its output acts on the control inputs of the keys 8 and 9. The keys 8 and 9 open and turn off the speed regulator 7 from two-. contour control system. Since the input of the push-pull regulator 7 of the frequency of rotation does not receive a signal when the key 9 is opened, the voltage at its output remains unchanged corresponding to the idle level. The input of the single-cycle speed regulator 12 in this mode continues to receive a negative voltage, and therefore at its output. the voltage drops to zero, since the single-ended regulator 12 is powered by a unipolar positive voltage. As long as the electric motor 1 brakes to a predetermined frequency, rotation under the action of the idling torque, the voltage at the output of the adder 10 remains negative. The voltage at the output of current regulator 2 corresponds to the current frequency of rotation of electric motor 1, as it decelerates, the counter-emf of the electric motor decreases, and the resulting feedback circuit reduces the output voltage of current regulator 2. Therefore, the current regulator 2 during deceleration of the electric motor 1 is constantly ready to ramp

Claims (1)

Claim A control device for a non-reversible valve electric drive of the rolls of a rolling mill, comprising a first adder, a first control key, a push-pull speed controller, a second controlled key, a second adder, a current controller and a pulse-phase control system, a speed sensor whose output is connected to the Input of the first adder, a current sensor, whose output is connected to the input of the second adder and a threshold element, characterized in that, with ^d purpose uprscheniya device and higher ezhnosti, further comprising a speed trimmer, whose input is connected to the output of the first adder and the output from the threshold element is connected to the control inputs klyucheyG