SU1764032A1 - Electromechanical servo drive - Google Patents

Abstract

The invention relates to automation and is intended for use in electromechanical control systems. The aim of the invention is to improve the energy characteristics of an electromechanical tracking system by reducing losses in the engine core winding in dynamic operating modes. The electromechanical tracking system contains a speed sensor 1, position controllers 2, speed 3, power loss 5, current 8, correction device 4, modulator 6, relay element 7, voltage sensor 9, power amplifier 10, quadr 11, electric motor 12 direct current, mechanical transmission 15, control object 17, position sensor 16, current sensors 13, speeds 14.1-2-3-5-8-10-12-15 17 17-13-8,10- 9-7-6-5,13-11-6,15-14-4- 3, 15-16-2.1 Il. (L C vj ON N About CJ Yu

Description

The invention relates to automation and is intended for use in electromechanical control systems.

The aim of the invention is to improve the energy characteristics of an electromechanical tracking system by reducing losses in the engine core winding.

The drawing is a diagram of an electromechanical tracking system.

The system contains a speed setpoint 1, a positioner 2, a speed controller 3, a Correction device 4, a power loss controller 5, a modulator 6, a relay element 7, a current controller 8, a voltage sensor 9, a power amplifier 10, a quad 11, a direct current electric motor 12, a current sensor 13, a speed sensor 14, a mechanical transmission 15, a position sensor 16, an adjustment object 17.

In the electromechanical tracking system, the rotor of the electric motor of the direct current 12 is connected via mechanical transmission 16 to the control object 17, the sensor 16 and the position sensor 1 are connected respectively to the subtracting and summing inputs of the position regulator 2, the output of which is connected to the speed controller summing input 3. The subtractive input of the latter is connected via the correcting device 4 to the output of the speed sensor 14, and the output is connected to the summing input of the power loss regulator 5, the subtracting input of which is The output is connected to the modulator 6 output, and the output is connected to the summing input of current regulator 8. The subtracting input of current regulator 8 is combined with the inputs of quad 11 and connected to the output of current sensor 13 connected to the DC circuit of the DC electric motor 12, and the output through power amplifier 10 is connected to the engine winding 12, in parallel with which voltage sensor 9 is turned on. The output of the latter through relay element 7 is connected to the control input of the modulator 6, whose information input is connected to the output of the quad 11.

The electromechanical tracing system works as follows. Position (p of object 17 is adjusted by moving its working body with an electric motor of direct current 12 through mechanical transmission 16. Measuring the position of the control object is performed using position sensor 16; Engine speed Q 12 is measured by a speed sensor 14, and i is a current by a current sensor 13. The voltage on the core winding is measured by a voltage sensor 9. The output signal ug of the voltage sensor 9 is fed to d relay element 7, which generates a signal

Ue at

U7

-Ue with u9 0

where Ue - const is the voltage corresponding to the level of the logical unit.

The output signal and the relay element 7 are fed to the control input of the modulator 6, the transmission coefficient of which is determined by the ratio

{+1 at U7 Ue; -1 with U7 -Ue.

The information input of the modulator 6 receives the signal un from the output of the quad 11, the output of which operates the signal U13, proportional to the current of the engine winding 12:

im ki3i

where - the transmission coefficient of the current sensor 13.

Thus, at the output of the modulator 6, the signal

kiiki32i2 with ug About U6 ketch k6knki32i2 j

-knki3i with ug Oh,

where kn is the transfer coefficient of the squadrator 11.

The signal U6 at the output of the modulator is proportional to the quad current of the core and, therefore, proportional to the power loss in the core winding:

P 2g, (1)

where r is the resistance of the root chain.

Thus, at the output of the modulator 6, a signal is generated, the absolute value of which is proportional to the power loss in the winding of the core. A change in the sign of this signal when the polarity of the voltage on the motor winding 12 is changed is necessary in order to retain the sign of the reverse (negative) coupling in terms of power loss when the direction of rotation of the engine changes.

The summing input of the controller 2 of the position from the output of the setpoint adjuster 1 is given a signal u, proportional to the required value of the adjustable coordinate of the system. The second subtraction input of the controller 2 of the position receives the signal U16 from the output of the position sensor proportional to the measured value p of the adjustable coordinate. In controller 2

the position calculates the error of the regulation of E-ui-uie and transforms it in accordance with the chosen law of regulation, for example, P-, PD-, or PI-. The output signal of the position controller 2 is fed to the summing input of the speed controller 3, the subtracting input of which receives a signal u from the output of the correction device 4. The output of its speed sensor 14 acts on the output of the correction device 4. The purpose of the correction device 4 is the formation of predetermined dynamic properties of the speed control loop. In this case, the correction device 4 can be performed, for example, in the form of a proportional, real differentiating, integro-differentiating or other link.

The output signal from the speed controller 3 is fed to the summing input of the power loss controller 5, on the subtracting input of which the signal from the output of the modulator 6 acts, which is proportional to the power loss in the engine core.

The signal us from the output of the power loss regulator 5 is fed to the summing input of the current regulator 8, the second subtractive input of which is connected to the output of the current sensor 13. The output signal of the current regulator 6 is fed to the input of the power amplifier 10, to the output of which the main winding of the motor 12 is connected.

Thus, the electromechanical tracking system contains four control loops: the main one, which is formed by the position controller 2 and the position sensor 16, and three subordinates. The first slave current loop includes a current regulator 8 and a current sensor 13. The second subordinate power loss circuit contains a power loss regulator 5 and a power loss measuring transducer consisting of a current sensor 13, a voltage sensor 9, a relay element 7, a quad 11 and a modulator 6. The third subordinate control loop speed contains a speed controller 3, a speed sensor 14 and a correction device 4.

The effect of the slave power loss control loop is as follows. In any mode of operation of the electromechanical tracking system, the signal ue, proportional to the power losses in the core winding, is fed to the readout input of the power loss controller 5. As a result, in dynamic modes of operation, the power losses in the core of the engine, which is known to constitute the bulk of engine losses, is always minimized.

The speed Q and the position p in the electromechanical tracking system are related to the current by the ratios

Q Ј / idt; (2)

I

m} / idt, about o

(3)

p Km / Qdt SC

about

where I is the moment of inertia of the mechanical masses, reduced to the motor shaft;

c is the engine constant;

Km - the transmission coefficient of the mechanical transfer device.

The power loss in the core winding is proportional to the square of the current and is determined by formula (1). The energy that is lost in the form of heat in the root winding,

E / P d t / g i2 d t. (4) oo

From equations (1), (2), (3) and (4) it follows that the losses are proportional to the square of the current and, therefore, are strongly dependent on its instantaneous values. The motor speed is proportional to the integral of the current and, therefore, does not depend on instantaneous values, but is determined by the area of the figure formed by the current in the transient process. The position of p is proportional to the double integral of the current.

Consequently, different current patterns can correspond to practically identical transients for position. The best process is one in which the energy loss during the transition process is minimal.

Negative feedback on power losses operates in the electromechanical tracking system in such a way that at high currents the voltage on the core winding and, therefore, the motor current decreases, i.e. current is limited to minimize losses in the engine core winding,

Thus, in the proposed electromechanical tracking system, in comparison with the known technical solution, the energy losses in dynamic modes are reduced and, consequently, the energy characteristics are improved. In this case, the positive effect is achieved in a simple way and does not require significant changes in the typical structures for technical implementation.

element base of electromechanical control systems.

Consequently, the use of a power loss regulator in the well-known electromechanical servo system makes it possible to improve its energy characteristics by reducing the losses in the core winding.

Claims (1)

An electromechanical tracking system comprising a position setter, the output of which is connected to a summing input of a position regulator, the subtractive input of which is connected to the output of a position sensor mechanically connected to the rotor of a DC motor, and the output - to a summing input of the speed regulator, and current regulators connected in series, a power amplifier and a direct current electric motor, with a speed sensor input connected to the rotor, and a current sensor connected to the core circuit, the output of which is connected to the subtractive input of the current regulator, as well as a relay element, characterized in that, in order to improve the energy performance by reducing losses in the core winding in dynamic modes of the system, a correction element, voltage sensor, quadrator, the modulator and the power loss controller, the summing input of which is connected to the output of the speed regulator, the output is connected to the summing input of the current regulator, and the subtractive input is connected to the output of the modulator, whose information input through a quad, connected to the output of the current sensor, controlling through a relay element connected to the output of a voltage sensor connected in parallel to the core winding of the dc motor, and the output of the speed sensor through a corrective element connected to the subtracting input of the speed regulator.