SU1461636A1 - Method and apparatus for regulating electric drive of flywheel press - Google Patents

Description

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 The invention relates to optimal systems for controlling the frequency of rotation of electric drives of flywheel presses and is intended for use in forging and pressing machinery.

The purpose of the invention is to simplify the adjustment process while optimizing the electric drive and improving the reliability of the device implementing this method.

Cynj, HOCTb of the method is illustrated in Fig. 1, in which curve (1) shows the motor current, curve (2) shows the variable component of the current, curve (3) shows a correction signal, and curve (4) shows the current of the press motor under optimal operation (the variable is missing and the correction signal is zero in this case). FIG. 2 shows a block diagram of a device for automatically optimizing an adjustable electric drive of a flywheel drive of a press; in fig. 3 is an example of a specific embodiment of the device.

The method involves extracting a variable component of the electric motor current, due to the cyclical nature of the press load, memorizing its values and introducing into the node the current cut-off of the electric drive in antiphase with setting the current limit. Gradually, during two three technological cycles of the press, the motor current is stabilized.

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In this case, the component of the motor current is variable and the correction signal corresponding to it takes a value close to zero.

The device (Fig. 2) for implementing the described method comprises a low-pass filter 1 connected in series, an alternating current component of the motor component 2, an amplifier 3 and a storage element 4. The low-pass filter input 1 is connected to the current sensor 5, and the output to the node 6 current cut-off of the electric drive. FIG. 2 - electric drive elements are designated: speed controller 7, current controller 8, thyristor converter 9, electric motor 10.

The device for controlling the electric drive of the press works as follows.

The signal from the sensor 5 of the electric drive current is fed to the low-pass filter 1, which prevents the penetration of signals of a frequency of 150 Hz and above, due to the operation of the thyristor converter, into the measuring channel. The filtered current signal ("smooth component") from filter 1 is supplied to the variable selection element 2, then to amplifier 3, the value of the variable component is stored in the element 4 connected to the drive cut-off node 6.

In the case of non-optimal operation of the electric drive, the electric motor current has a variable component, due to the cyclic nature of the press load. The correction signal corresponding to this variable component of the current, acting on the node 6 of the drive cut-off, reduces the cut-off current setting, which leads to a decrease in the variable component of the current and, in the final

as a result, to the stabilization of the motor current, i.e. the onset of the optimal mode.

The described device for adjusting the electric drive of the flywheel press is characterized by simplicity, increased reliability, does not require maintenance and adjustment during operation.

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Claims (2)

1. The method of adjusting the electric drive of the flywheel press, which consists in maintaining the motor current at the minimum level for operation by correcting the limited current of the drive, characterized in that, to simplify the control process, the variable component of the motor current is determined due to the cyclic nature of the load press, the value of which is memorized and used as a correction signal. 2. A device for controlling the electric drive of the flywheel drive of the press, which contains series-connected speed controller, current shutdown node, current controller connected to the electric drive, speed sensor, output connected to the speed controller, and current sensor output connected to the second 0 to the input of the current cutoff node, characterized in that, in order to increase the reliability of operation, it contains a low-pass filter connected in series, an element for extracting a variable component of the motor current, an amplifier and a storage element connected by a low-pass filter input to the current sensor, and the output of the storage element to the third input of the node current cut-off drive. R . one FI.2. FI.5