SU1508334A1 - Stabilized electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in an automated electric drive with phase-locked speed in systems for transmitting and reproducing information, for example, in a drive for video recorders. The purpose of the invention is to improve the dynamic characteristics of the electric drive. When the power is turned on, motor 1 accelerates to a rotational frequency at which the frequencies of driver unit 5 and pulse speed sensor 2 are equal. In this case, the discriminator 3 is in saturation, the engine 1 is accelerated until a favorable phase arrangement of the frequency sequences occurs. In order to prevent the correction signal from fading away at times of repeated visits of the discriminator 3 in the saturation region, the output signal of the frequency-measuring unit 6 is delayed by the delay element 12. Therefore, the phase error signal from the output of the discriminator is added in proportional mode in the adder 7 3 and from the output of the differentiating element 9. From the output of the adder 7, the corrected signal through the converter 8 is fed to the engine 1. The improvement of the dynamic characteristics has reached a phase error removing jumps. 2 Il.

Description

FIA /

The invention relates to electrical engineering and can be used in an automated electric drive with phase-locked loop speed in systems. Transmission and reproduction of information, for example, in a drive of video recording devices.

The purpose of the invention is to improve the dynamic characteristics of the electric drive.

FIG. 1 shows a diagram of the proposed electric drive; in fig. 2 shows timing diagrams for the operation of the drive.

The electric drive contains a direct current electric motor 1 with a pulsed speed sensor 2, the output of which is connected to the first inputs of the pulsed frequency-phase jBoro 3 and phase 4 discriminators, respectively. The second inputs of the discriminators 3 and 4 are combined and connected to the output of the frequency-master unit 5. The first output of the pulse frequency-phase discriminator 3 is connected to the frequency-measuring unit 6 and through the series-connected adders 7 and the converter 8 - to the rotor circuit of the electric motor 1. The differential output | riziruyuschego element 9 through a controlled key 10 is connected to the second input of the adder 7. In addition, the drive contains an adder-subtractor 11 and a series-connected delay element 12 and a logic element: Ment OR 13, The output of which is connected to the control input of the key 10. The second input of the logic element 1SH 13 is connected to the output of the frequency-measuring unit 6 and the input of the delay element 12. The first input of the adder-subtractor 11 is connected to the output of the isoBoro discriminator 4. The second and third inputs of the adder-subtractor 11 are connected respectively with the second and third outputs of w pulse frequency-phase discriminator 3. The output of the adder-subtractor 11 is connected to the input of differentiating element 9 .

The drive works as follows.

When the power is turned on, the electric motor 1 accelerates to a rotational frequency at which the frequencies of the frequency reference unit 5 and the pulse velocity sensor 2 are equal. At the same time, the discriminator 3 is in the sense that, due to its hysteresis

0

five

0 0 5 0 5 o

characteristic, leads to further acceleration of the electric motor 1 until the favorable phase position of the pulses of the compared frequency sequences (occurrence of two pulses of one sequence between two pulses of another sequence) occurs. From this point in time, the linear mode of operation of the discriminator 3 begins. At the output of the discriminator 3, a pulse signal 14 appears, according to which the frequency-measuring unit 6, which acts as a synchronization indicator, will generate a signal which, through the OR 13 element, goes to the control the input of the key 10, connecting the output of the differentiating element 9 to the input of the adder 7. In order to eliminate the correction signal 15 (at the moments of repeated visits of the discriminator 3 in the saturation region), the output signal of the frequency variation of the rhythm unit 6 is delayed by a delay element 12 for the TO time which determines the correction action in the saturation mode, and through the OR element 13 it goes to the control input of the key 10. Thus, the correction signal 15 is turned off only when the frequency setting unit 5 changes the reference frequency when the discriminator 3 is in saturation (the saturation time is a time longer than .Т). Consequently, in the synchronization pull-in modes and in the proportional in the adder 7, the phase signal 14 is summed ibki from the output of the discriminator 3 and tiruyuschego-compensation signal 15 from the output of the differentiating member 9, the proportional error of the rotation frequency. Due to the absence of blocking, a phase error signal 16 is always present at the output of the phase discriminator 4, as a result of which a correction signal is generated continuously at the output of differentiating element 9.

In the synchronization retraction mode, the amplitude of oscillations of the phase error can exceed the value of 2W. As a result, in the output signal of phase discriminator 4, there are jumps in phase error at 2f / Z, which degrade the operation of differentiating element 9. To eliminate them, the output signal of phase discriminator 4 is summed with the output signal of Saturation 17 when the discriminator 3 overclocks and the Saturation signal is subtracted from during braking 18 on the adder-subtractor 11, as a result of which, at the output of the adder-subtractor 11, a recovery signal 19 of the phase error appears, in which there are no jumps in the phase error. As a result, the differentiation eliminates the error in the operation of the differential of the circulating element 9, due to the surge voltage at its input.

From the output of the adder 7, the corrected signal 20 is fed to the converter 8, providing regulation of the current in the electric motor 1.

For clarity, the output signals 16 and 14 of discriminator 3 and 4 do not show the high-frequency component, due to the pulsed nature of the output signals of discriminators 3 and 4, but reflect only the slowly varying component that characterizes the signal 21 of the drive phase error (Fig. 2). ).

The output signal 16 of the phase discriminator 4 has a phase error jump of 21 G & no lock Recovery of the phase error signal 19 occurs by algebraically summing the signal 16 with the output signals 17 and 18 of the blocking triggers of the discriminator 3, which determine the termination during acceleration and deceleration. When differentiating the recovered phase error signal 19, the differentiation errors due to phase error jumps are eliminated, and the phase error jumps when the key 10 is turned on due to the constant connection of differentiating element 9 through the adder 11 to the output of the phase discriminator 4. At the same time the signal has a component proportional to the speed deviation (signal 15), even when the discriminator 3 is saturated in transients. Obviously, this contributes to a more rapid damping of the oscillations of the phase error in the w-0 mode for the drive to synchronize.

Claims (1)

Invention Formula A stabilized electric drive containing a direct current electric motor with a pulse speed sensor, the output of which is connected to the first inputs of a pulse frequency-phase and phase discriminator, respectively, the second inputs of which 0 are combined and connected to the output of the frequency master unit, the first output of the pulse frequency-phase discriminator is connected to the frequency-measuring unit and through serially connected adder and converter to the main winding of the electric motor, the output of the differentiating element is connected to the second input of the adder via a control key , which is characterized by the fact that, in order to improve the dynamic characteristics of the electric drive, a totalizer-subtractor and a series-connected delay element and logic the OR element, whose output is connected to the control input of the key, and the second input to the output of the frequency-measuring unit and the input of the delay element, the first input of the adder Q of the subtractor is connected to the output of the phase discriminator, the second and third inputs are connected respectively to the second and third outputs pulse frequency-phase discriminator, vy45 the stroke of the adder-subtractor is connected to the input of the differentiating element.