SU1697238A1 - D c electric drive - Google Patents

Abstract

The invention relates to electrical engineering, in particular to speed-controlled electric drives. The purpose of the invention is to increase accuracy and speed. In an electric drive, every half-period (more precisely, every positive and negative half-wave speed sensor) compares the required speed with the desired one and produces a control signal by reducing the output signal. The output time of the motor is reduced by reducing the quantization interval by the time of the control signal is doubled. 1 з п. Ф-л, 2 silt

Description

The invention relates to electrical engineering, in particular to speed-controlled electric drives.

The purpose of the invention is to increase accuracy and speed.

FIG. 1 shows the scheme of the proposed electric drive; in fig. 2 - diagrams of his work.

The electric drive comprises an electric motor 1 with a pulse sensor 2 of speed, serially connected differentiating node 3, waiting multivibrator 4 and block 5 for comparing frequencies. The second input of the frequency comparison unit 5 is connected to the output of the pulse speed sensor 2 and the input of the differentiating node 3. The output pulse generator 6 is connected to the second input of the standby multivibrator 4. The speed pulse sensor 2 is equipped with an inverting output connected to

the input of the second differentiating node 7, the output of which is connected to the first input of the second standby multivibrator 8. The second input of the multivibrator 8 is connected to the output of the pulse generator 6, and the output is connected to the first input of the second frequency comparison unit 9, the second input of which is connected to the input of the second differentiating node 7 The first outputs of blocks 5, 9 of the frequency comparison are connected respectively to the first inputs of elements 2 OR 10, 11, the second inputs of which are connected respectively to the second outputs of blocks 5, 9 of the frequency comparison Output of the first el of the terminal 2 OR 10 is connected to the first input of element 2 OR-NOT 12 and the installation input to the trigger unit 13 The output of the second element 2 OR 11 is connected to the second input of the element 2 OR-NOT 12 and the installation input to the nultrigger 13 Output of the element 2 OR NOT

ABOUT

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12 is connected to the counting input of the reversible counter 14, the counting mode setting input of which is connected to the trigger output 13, and the synchronization input is connected to the output of element 2 and 15, the first input of element 2 and 15 is connected to the output of the generator 16 reference pulses, and the second input is connected to output transfer reversible counter 14, information output connected to the input of the inverter 17 code - PWM, the output of which through the power amplifier 18 is connected to the main winding of the electric motor 1. The waiting multivibrator 4 (8) is designed as a counter 19 and trigger 20, the installation input to the unit of which is the first input of the multivibrator and connected to the reset input of the counter 19, the counting input of which is connected to the output of the trigger 20 and is the output of the multivibrator. The output of the counter 19 is connected to the input to the zero setting of the trigger 20. The synchronization input of the counter 19 is the second input of the multivibrator.

Pulse speed sensor 2 can be made, for example, in the form of a sine-cosine rotating transformer (CCWT) 21 with a driver 22 at the output.

The drive works as follows.

The drive is turned on by applying a supply voltage to it. The speed sensor 2 (SCART) outputs the voltage corresponding to the position of the motor shaft 1, the pulse shaper 22 is implemented at the comparator and has a signal Log.1 at the first output, if the input voltage is positive, and a signal Log. O, if the input voltage is negative, the second output of the pulse generator 22 is inverted with respect to the first. Depending on the position of the ACS 21, the signal Log.1 is set at one of the outputs of the pulse generator 22, and the Log is set at the other. A. Suppose that at the first output of the driver, 22 pulses are the signal of Log 1, and at the second - the Log. O. Signal Log. 1, from the first output of the pulse driver 22, is fed to the second input of the frequency comparison unit 5, to the first input of which the signal Log arrives. About from the output of the trigger 20, which is set to the zero position by turning on the power. In this case, a signal Log appears at the first output of the first frequency comparison unit 5. 1, which, through the first element 2IL 10, sets element 2IL-NOT 12 to the zero position, trigger 13 is set to one state

When this reversible counter 14 begins to work on the addition. The code from its output goes to the converter 17, the code - PWM, the signal from which through the power amplifier 18 goes to the engine 1, which begins to rotate.

In the dynamics of the electric drive works as follows.

The signal SURF 21 1) 21 (Fig. 2a) receives 0 to the pulse shaper 22, at the first and second outputs of which a pulse signal of speed is formed (Fig. 26,

In U221, U222)

At the outputs of the first 3 and second 7

5 differentiating nodes, short pulses Uz, U (Fig. 2d, d) are generated from the corresponding input signals U22i, U222- According to the impulse from the first differentiating node 3, the first multivibrator

0 4 forms the impulse of the reference duration W (Fig. 2e) as follows.

A pulse arriving at the installation input into the unit of trigger 20 from the first differentiating node 3 transfers the trigger to

5 position Log. 1 and zeroed the first counter 19. Signal Log. 1 from the output of the trigger 20 is fed to the input of the resolution of the account of the first counter 19, which begins to count the pulses arriving at its clock C0 input from the output of the generator 6 pulses. Upon receipt of a specified number of pulses at the output of counter 19, a pulse Log is formed. 1, which sets the trigger 20 to the zero state. As a result, the output of the trigger 20 produces a signal (Fig. 2e), which is a sequence of pulses of the reference duration, the frequency and duty cycle of which is proportional to the speed of rotation

0 of the motor shaft 1, In block 5 of the frequency comparison, half of the period following the speed sensor signals 2 is compared with the reference time interval and outputting one of the two outputs (Fig. 2h, and) depending on the error sign (A B, A B) of the sequence pulses, the duration of which is proportional to the difference between the periods of the frequencies of the measured and reference signals. The signal LU from the outputs of the frequency comparison unit 5 is passed through the first and second element 2IL to element 2ILYE 12 and trigger 13, which determine the operating mode of the reversal-counter 14, In the presence of a signal

5 Log, 1 on one of the outputs of the frequency comparison block 5, at the output of element 2IL- NOT 12, a signal Log, О, is set, which enables the counter to be reversed by counter 14. Signal Log. 1 from the first vy5

the stroke of the frequency comparison unit 5 sets the trigger 13 to one state, setting the addition mode to a reversible counter. Signal Log. 1, from the second output of the frequency comparison unit 5, sets the subtraction mode of the reversible counter 14.

Thus, if the actual motor speed is less than the required one, then half the period of the speed sensor 2 is greater than the reference interval, the Log signal is set at the first output (A B) of the frequency comparison unit 5. 1, which determines the addition mode of the reversible counter, the code from which is increased, and through the converter 17, the PWM code and the power amplifier 18 increases the speed of the engine 1. If the actual speed of the engine 1 is greater than the required one, then the signal Log. 1, from the second output (A B) of the block 5, decreases the stroke of the reversible counter, and through the converter 17, the code is PWM and the power amplifier 18 decreases the speed of the engine.

Thus, over the positive half-wave of the signal period from the speed sensor, it is compared with the reference period and a signal is generated to control the engine. For the negative half-wave of the period of the signal from the speed sensor, a similar comparison occurs at the second block 9 of the frequency comparison. In this case, the operation of the second differentiating node 7 and the operation of the second standby multivibrator 8 are similar to the operation of the first differentiating node 3 and the first standby multivibrator 4, respectively.

The signals from the outputs of the second frequency comparison unit 9 set the control signals for the second half of the period of the speed sensor 2 signal. Element 2 and 15 prevents the counter from transitioning from the state of all zeros to the position of all ones when working on subtraction, since the signal Log. About from the transfer output WITH the reversible counter 14 in the presence of zeros on the outputs and the input ± 1 it blocks the passage of clock pulses to the clock input of the reversible counter.

A similar blocking is carried out in the state of all units at the output of the reversible counter 14 and the signal Log. 1 at the output of ± 1 to prevent it from entering the state of all zeros.

Thus, the electric drive provides a reduction in the engine's output time at the nominal rotational speed, an increase in the accuracy of stabilization of the engine speed, and the prevention of malfunctions due to the superposition of two impulses of the speed sensor on one impulse.

Claims (1)

Claim 1. A DC motor comprising a motor with a pulse speed sensor 10 connected in series to a differentiating node, a waiting multivibrator and a frequency comparison unit, the second input of which is connected to the output of a pulse speed sensor and 5 to the input of the differentiating node; a pulse generator, the output of which is connected to the second input of the waiting multivibrator, characterized in that, in order to increase accuracy and speed, 0, the first and second elements 2ILI, element 2IL-NOT, trigger, generator of reference pulses, element 2I, reversible counter, second frequency comparison unit, second differential 5 node, the second waiting multivibrator, converter code - PWM, amplifier, and the pulse speed sensor is equipped with an inverting output connected to the input of the second differentiating node, 0 whose output is connected to the first input of the second standby multivibrator, the second input of which is connected to the output of the pulse generator, and the output connected to the first input of the second frequency comparison unit, 5 by the second input of the second differentiating unit connected to the input, the first outputs of the frequency comparison blocks are connected respectively to the first inputs of elements 2IL, the second inputs of which are connected 0 respectively to the second outputs of the frequency comparison blocks, the output of the first element 2IL is connected to the first input of the element 2ILI-NOT and the installation input to the trigger unit, the output of the second element 2IL, or 5 is connected to the second input of element 2IL- NOT and to the input of setting the trigger to zero, the output of element 2OR is NOT connected to the input of the enable resolution of the reversible counter, the input of which account mode is connected 0 with the trigger output, and the synchronization input is connected to the output of element 2I, the first input of which is connected to the output of the generator of reference pulses, and the second input is connected to the output of the reverse transfer 5 counter, information output connected to the input of the converter code - PWM, the output of which through the power amplifier is connected to the main winding of the electric motor. 2 Power pop. 1, that is, with the fact that the waiting multivibrator is designed as a counter and a trigger, the installation input to the unit of which is the first input of the multivibrator and connected to the reset input of the counter, the counting resolution of which is connected to the trigger output and is the output of the multivibrator, the output is connected to the input of setting the trigger to zero, and the synchronization input is the second input of the multivibrator, 2% F t % P J /