SU561138A1 - The method of measuring the speed of rotation of a two-motor electric drive with elastic connections and a device for its implementation - Google Patents

Description

There is also known a method by which, when the voltages of two tachogenerators with phase-opposite oscillations are switched on in series, the sum of the oscillations is zero, and the lol Bin voltage CD- corresponds to the actual value of the speed of rotation, or it is possible to install one speed sensor, but in a node baniye 2.

The disadvantage of this method is that

in it, methods of arranging the speed sensors (one sensor in the oscillation node, or two sensors with oscillations opposite in phase) are practically not applicable. One of the ways to reduce electromechanical resonance geniuses in an electric drive system is a significant reduction in the static coefficient of the gain control system. However, such a measure is often unacceptable due to constraints imposed by technical requirements on the accuracy of the automatic speed control system.

According to the proposed method, to improve reliability, reduce mechanical stresses in the shafting and utilities, the automatic control system measures the DPS of both electric motors, compare it to me, the resulting differential signal is corrected from as a function of the excitation flow and the motors and subtracted from the feedback signal according to the rotational speed measured near the antinode of the torsional oscillations of one of the electric motors from the non-working end of its shaft, and the resulting signal is fed to the automatic About regulation.

The drawing shows a device that implements the proposed method.

The device includes two crustal electric motor 1 (or two electric motors installed according to the Tandem kinematic scheme), measles 2 and 3 electric motors, tachogenerator 4, plus clips 5 core electric motor, minus clips 6 korea of the electric motor -j block 7 comparing Korean 2 stresses and advancing : ojoxejucial section i-gb /, common point 8 of the connection of each core with its windings

additional poles and a compensation unit for comparing 9 currents of Korea 2 and 3 (contains a potential separator), output 10 of the voltage comparison unit, output 11 of the current comparison unit. In addition, the device has a unit for isolating the differential SDS (rotational speed) koreas 2 and 3 (contains a scale converter), a potentiometer 1Y associated with the organ for changing the motor excitation flow, the motor speed regulator 14, an independent control signal 15 em sets the speed of rotation of the motor), feedback 16 speed and the output 17 of the speed controller,

A two-core electric motor 1 contains measles 2 and 3 and a tachogenerator 4 articulated with a non-working condom shaft drive engine. The positive ignitions / 1s S of the koreas 2 and 3 of the electric motor 1 are interconnected by means, and the negative terminals are connected to the unit 7 comparing the voltages of these Koreas. Common points 8 are the connections of each crust with its windings of additional popus and compensating sub-1 – U 1 –– to the 9-korea current comparison unit. The outputs 1O and 11, respectively, of blocks 7 and 9 of cores 2 and 3 are connected to the inputs of the block 12 for isolating the difference in emf (rotation rotation) of these cores. The output of the block 12 through the potentiometer 13 is connected to one of the inputs of the speed regulator 14 of the electric motor.

The other inputs of the speed controller, rotation 14 are connected with a response, an independent control signal 15, determining the speed setpoint of rotation of the motor 1g and the output signal of the tachogenerator 4 feedback speed 16 The output 17 of the speed regulator 14 is connected to the rest of the two radar motor control system 1, for example, to the inputs of current regulators of Korea 2 and 3,

In the absence of torsional vibrations, for example, when the engine is rotated for 1 s. steady speed or during acceleration idle, and with equal voltage and currents of Korea 2 and 3, the input and output signals of blocks 7 and 9 are zero.

When torsional oscillations occur, for example, when the billet is seized, the rotational speeds of cores 2 and 3, located near the antinodes of the oscillations, are misaligned relative to the torsional oscillations node O (dissolved OO approximately, midway between the crust) in opposite directions,

Therefore, in the mode of torsional vibrations, the difference in the velocities of the engagement of both Koreas is approximately twice the difference between the rotational speed of each core and the velocity of the shaft section near the node Torsional vibrations.

Therefore, at the inputs of blocks 7 and 9 and at the outputs 10 and 11 of these blocks, signals are proportional to the proportional to the doubled voltage difference 2 d and to the x 2 and 3 core and to the double difference of the voltage drops of 2 uVT in core flail x both korei,

As a result, when torsion wheels 6a x at the output of block 12, the difference in stresses acts

2D 2D-2DUY22dp

Indeed, the resulting signal between the differences of the stresses of the Koreas and the ohmic drops of the stresses in them is proportional to the difference in the SDS of these Koreas and their rotational speeds,

With the help of a large-scale converter included in block 12, B is reduced by a factor of 2 and the necessary scaling of the difference in the rotational speeds of cores 2 and 3. In this connection, the signal dp at the output of potentiometer 13 is equal to the difference between the rotational speed, e.g. from the side of which, near the antinode of torsional vibrations, the tachogenerito 4 is set, and the speed of rotation saha near the co-axial node O,

The signal Dp at the output of the measuring meter 13 is subtracted from the signal of the feedback connection at a speed of 16 received from the A / A generator 4.

Then the total voltage at the output of the tachogenerator 4, which is located: at the free end of the shaft of the electric motor 1 from the side of the core 2j is proportional to the speed of rotation of this shaft section and has the form represented by the curve

The voltage Vi at the output of potentiometer 13 (curve b) is subtracted from this voltage.

 The resultant curve (the difference between curves a and b) is represented by curve C, which does not contain voltage pulsations associated with torsional oscillations and corresponds to the rotational speed of electric motor 1 near the specified nodal point O of its shaft, where there are no torsional vibrations. In effect, the sum signal at the output of the speed regulator 14 does not contain a variable component associated with the torsional vibrations.

Therefore, the output signal 17 of the speed regulator 14 is not critical to the rotational oscillations, as a result of which the operation of the control system and the drive as a whole is improved.

The measured emf of both electric motors, proportional to the torsional oscillation of the motor shaft, must be corrected by the magnitude of the motor's excitation flow, if its rotational speed changes above

primary due to weakening the floor. For this purpose, a potentiometer 13 is used, which is associated with an organ for weakening the excitation flow of the engine (not shown in the drawing).

Claims (1)

1. Schenert D, Weaknesses of the drive of rolling sd-Vans, Journal of Ferrous Metals, 5to (hE unc / EisettjNo 23, pp. 26-33. 2, Dernenburg E, O „Damage to the windings and collectors of high-power rolling motors, Ferrous Metals journal; ta h P UHcl E-15epr-U74, No. 20, p. 7-43,