SU1061107A1 - Device for control of motor rate with self-check - Google Patents

Abstract

A DEVICE FOR CONTROLLING THE SPEED OF A SELF-CONTROL MOTOR, containing a series-connected reference frequency generator, a code-frequency converter, a frequency divider connected by output to the first input of the comparator unit connected by the output through a series-connected voltage code converter and a voltage amplifier with an engine input, the shaft of which is mechanically connected with the converter speed - frequency, from which it is due to the fact that, in order to improve the reliability of the device, two impulse counters are inserted into it owls, four D triggers, ftS trigger, two pulse drivers, eight AND elements, the first element is NOT, the OR element and the second element are NOT connected to the output, to the C input of the first D flip-flop, and the input to the first output of the speed converter frequency, to the information input of the first pulse generator, to the .C-input of the second D-flip-flop and to the installation input of the first pulse counter connected by the first output to the first input of the first element And, the second output to the second input of the first element And and to the first input of the second element and the third output is from the second {N: am input of the second element I, and the counting input with the converter output: the frequency code and the counting input of the second pulse counter connected by the input to the input of the second element NOT to the second output of the speed-frequency converter, to the information input The second driver and the C-input of the third D-flip-flop, and the first, second and third outputs, respectively, to the first, second inputs of the third element And to the first input of the fourth element And connected with the second input to the BfojsJM third input (Lg And connected to the S-input of the fourth D-trigger connected to the C-input of the second element NOT, D-inputs "- with the Earth bus, R-input - with the output of the fourth element And, and the inverse output - with D-input of the third D-flip-flop connected by 3-input to the output of the fifth element I, inverse output to the first input of the sixth element I, and direct output to the first input of the seventh element I connected by the second input with the inverse output of the first ) -trigger, and the output - with the S-input of the RS-flip-flop, 4 connected To-input to the output pole And, connected by the second input to the direct output of the first D-trigger, connected to the inverse output of the second D-trigger, and S-input to the output of the eighth AND, connected by the first input to the control input of the second pulse shaper and with the inverse the output of the P5 flip-flop connected by the direct output to the first input of the fifth element Nick to the control input of the first form

Description

the HfoiynbcoB rotator / connected by the output to the first input of the OR element, which is connected to the second input to the output of the second pulse generator / and the output to the second input of the comparison unit, and the second inputs of the fifth and eighth elements And are connected to the synchronization buses, and D is the input of the first D-trigger - to the inverse output of the second D-trigger, connected by 5-input and R-input to the outputs of the first and second elements, respectively, And a1-input - to the bus Earth.

The invention relates to a technique for controlling drives of processing equipment, in particular paper machines.

Known control system,. containing the leading voltage source, a comparison circuit, an analog control unit, a motor, a paper machine section mechanism, a discrete frequency-frequency converter, a frequency converter-voltage in, feedback tl 3 "

 The disadvantage of the control system is the relatively low reliability of the reference channel and the comparison circuit (the presence of the driving potentials and the comparison of analog signals transmitted over long cable connections in the workshop conditions), and the lack of a control circuit for checking the speed converter, associated with the drive motor shaft.

The closest technical solution to the present invention is a device for controlling the speed of a drive of a section of a papermaking machine, comprising a reference frequency generator, a master code-frequency converter, a buffer frequency divider, a digital zero-organ, a code-voltage converter, an analog regulating unit, a pulse converter motor rotation speed 2.

In a device with digital null-organ based on a reversible counter: the unreliability elements associated with the shortcomings of analogue technology are eliminated; however, even with a high-quality version of digital electronic blocks, an element of unreliability remains in the controller structure, due to the possibility of primary converter failure, associated with a shaft with an engine shaft and operating under conditions of vibration, dusting excessive temperatures, corrosive media, etc.

The aim of the invention is to compromise the reliability of the device.

The goal is achieved by having a device for controlling the speed of an engine With self-control; containing a series-connected reference frequency generator, code-frequency converter, frequency divider connected by an output to the first input of the comparator unit connected by an output through a series-connected converter

0 code - voltage and voltage amplifier with the input of the engine, the shaft of which is mechanically connected to the speed-frequency converter, two pulse counters, four

5 S-trigger, two pulse drivers, eight AND elements, the first element is NOT, the OR element and the second element are NOT connected to the C input of the second D flip-flop, and the input to the first output is the speed, frequency, informational the input of the first pulse shaper, to the C input of the second D-flip-flop and to the setup input of the first pulse counter, connected by the first output to the first input of the first element And, the second output to the second input of the first element And, and the first input of the second element and; third exit - with the second entrance

0 of the second element I and the counting input with the output of the converter code - frequency and with the counting input of the second pulse counter connected by a setup input to the input of the second

5 elements NOT, to the second output of the transducer speed - frequency, to the information input of the second pulse shaper and to the C input of the third D-flip-flop, and the first, second and third outputs respectively to the first, second inputs of the third element And to the first input of the fourth The element And, connected by the second input with the second input of the third element And connected by the output

to the S input of the fourth D - trigger connected with the C input with the output of the second element NOT) - input - with

 bus ground, R-input - with the output of the fourth element And, and inverse

50 output - with D-input of the third D-flip-flop, connected by the S-input to the output of the fifth element And / inverse output - to the first input of the sixth element And, and the terminal inlet to the first input of the seventh element And connected by the second input with the inverse output the first D-flip-flop, and the output - with the 5-input of the P5-flip-flop, connected by the R-input to the output of the sixth And element, connected by the second input to the direct output 4 of the first D-flip-flop, connected by the D-input to the inverse output of the second B-trigger , and S is the inputs and - to the output of the eighth element And, connected pervol to a stroke with a control input of the second PF of the pulse generator and an inverted output of the P5 flip-flop connected by a direct output to the first input of the fifth element AND, and to the control input of the first pulse shaper connected by the output to the first input of the OR element connected by the second input to the output of the second pulse driver, and the output to the second input of the comparator unit, the second inputs of the fifth and eighth elements I are connected to the synchronization bus, and the D input of the first D-flip-flop is connected to the inverse output of the second L-flip-flop, 5-th input and the R-input to the outputs respectively of the first and second AND-elements, AD-input - with shinop ground.

FIG. 1 shows a block diagram of the device; in fig. 2 - time diagram of the device.

The device contains the reference frequency generator 1, code converter - frequency 2, frequency divider 3, comparison unit 4, converter code - voltage 5, voltage amplifier 6, motor 7, speed converter - frequency 8, second pulse shaper 9, first pulse shaper 10-, element OR 11, control object 12, unit 13 for monitoring the speed-frequency converter, containing the second 14 and first 15 pulse counters, the third 16 and fourth 17 And elements, the first 18 and second 19 And elements, the fourth 20 and second 21 D-flip-flops, in oproy 22 and first 23 elements are NOT, third 24 and first (25 D-triggers, seventh 26 and sixth 27 elements And, (5-trigger 28, fifth 5 and eighth 30 elements And, sync bus 31, earth bus 32, etc. My exits are 33 and 34 of the third and first) -triggers.

The device works as follows.

The speed reference signal is generated as a frequency reference.

where is the conversion factor of the converter code - frequency 2, which is determined by the speed setpoint code;

the division ratio of the division "B tel frequency 3; fo reference oscillator frequency 1,

The speed feedback signal is generated by converter 8.

10 in the form of sequences of rectangular pulses, with a duty cycle equal to two, at each of its two outputs (see FIG. 2). Using shapers 9 and 10 at the inputs

5 of the element OR 11, unipolar pulses are formed, corresponding to the rectangular pulses of the above-mentioned sequences from both outputs of the converter 8.

0

The feed formers 9 and 10. are equipped with control inputs that allow blocking the passage of pulses from the speed converter - frequency 8 to the corresponding input of the element.

5 OR 11.

The discrete signals with the frequencies {j and f are integrally Compared in the comparison block {null-organ) 4, the error code is converted into a voltage

0 by the converter 5 and is fed to the voltage amplifier 6, which controls the speed of the drive motor 7, and hence the control object (machine section mechanism) 12,

5 which provides a stretch of paper strip with a speed equal to the peripheral speed of the working gas or cylinder of this section of the papermaking machine,

With engine shaft 7 mechanically

0 A rotating element (modulator) of the converter 8 is connected. The accuracy of the speed control of the engine and mechanism in the steady state is determined only by the stability

5 reference frequency generator 1.

In order to increase the operating reliability of the control device under industrial conditions, reheating of the most unreliable link 0 of the feedback pulse sensor was applied by using a converter 8 with two sensitive elements and two outputs and, respectively, two drivers.

5 pulses 9 and 10, of which one (standby) is normally blocked by the control signal generated in block 13.

When the operation mode of the main channel deviates beyond the allowable limits, the circuit automatically switches the main channel to the backup channel by switching the blocking of the drivers 9 and 10 to the reverse. The mentioned switching of the feedback channels occurs only if the monitoring of the state of the backup channel confirms its operability.

The specified functions are modified in a sweet way.

The R-inputs of the installation .nul counters 14 and 15 are supplied by the signals from the outputs of the converter 8. The counters are blocked in those half-periods of the converter's signal following when their installation inputs receive the signal level of logical signals 1, and are: in the pulse counting mode opposite half periods. The output frequency of transducer 2 is fed to the counting inputs of both counters. The capacity of each Id counter is equal to a capacitive frequency divider 3, i.e. N Kg.

In the steady state, the frequency of setting f is equal to the frequency of feedback fgy. In this case, as can be seen from the diagram of FIG. 2, with a duty cycle of following rectangular pulses equal to two (the filling factor is 0.5), the number N N172 is recorded in the corresponding number of meters during the counting half-period. With a duty ratio of 4/3 (fill factor of 0.75), N "0.75No.

The deviation of the borehole pulses of the pre-exploiter 8 from the nominal value equal to two in one direction or another is a characteristic violation of the operating mode of the sensing element of the transducer. It is caused both by changes in the characteristics of radio components and in structural violations (for example, by changing the working gap for inductive or capacitive transducers) by the relative displacement of the emitter-receiver pair in optical transducers and other disturbances of the switch, and by weakening the attachment of the structure due to vibrations and so on. P.). At the same time, as a rule, it is possible to judge about the change in the squiggle. according to the trend of the tendency to disrupt the work long before the emergency state (the disappearance of the signal modulation). Thus, the correctness of the pulse converter of speed for each of its outputs can be judged by whether the number is in the zone of permissible values

(one)

 N N

max

for each control cycle. As the maximum permissible values of the number N, for example, the values 5 and 11 can be taken, which corresponds to 4 n N, 12, i.e. normal l takes a change in the value of the fill factor within 0,, 75.

The operation of the inverter speed control unit 13, the frequency, consists in checking the fulfillment of inequality (1) in each cycle of control, in case of its violation, in developing commands for switching the operating output of the converter 8 to the reserve one. Achieving a number N of 5 is a sign of normal operation, and the achievement of N a value of 12 is a sign of a malfunction. Elements 16 and 17 (and 18 and 19) are connected to the information outputs of the counter 14 (15) so that they produce a single output signal upon arrival in the corresponding. Vukvdie pulse counters with a frequency of CjKy.

The mode of operation of the counter 14 (15) is the alternation of the half period of the counting and the half period of zeroing during each period of the pulse detector signal received at the setting counter input. If during the half period of the count At the output of the element And 16 (18) there is a single snapshot (), then the D-flip-flop 20 (21) is set-. is cast to the state of the unit at the installation S-input and, if the value of N does not reach 12 (the pulse at the output of the element AND 17 (19) is absent), then until the end of the specified half-step at the inverse output of the D flip-flop 20 A log zero signal prohibiting by) input the writing of a unit to trigger 24 (25) at the counting input by the leading edge of the sensor signal at the beginning of the zero-period of zero counter 14 (15). In the case of the absence of a unit signal at the output of the AND 16 (18) element, when either the signal passes through the AND 17 (19) element, when the D-flip-flop 20 (21) by the end of the half-count period is B; the zero state at its inverse output is a unit signal. Allowing the D input to set the D-flip-flop 24 (25) to the single state by means of an "OMV input at the beginning of the zero half period, which is evidence of a malfunction of the pulse sensor from one of the springs kangshov and through the element And 26 (27) leads to the switching of the trigger 28 in the opposite state. Switching (5-flip-flop 28 is performed by switching the locking of the controlled drivers 9 and 10, so that the working feedback pulse is replaced by the backup. This switching occurs only if

The p-trigger 25 (24) of the second kangsha is in the zero state, i.e. The second channel is OK.

In case the backup Channel is faulty, the circuit is limited to issuing a warning light control command from Exit 33 (34). However, the operation of the inverter 8 with the limit of the 4th duty cycle, sufficient to operate the described control, & does not lead to a failure in the controller.

The connection of the counting input of the G-trigger 20 (21) through the element NOT 22 (23) with the output of the converter 8 is necessary for zeroing the specified trigger at the beginning of each half-period of the counting by the leading edge of the inverted sensor signal, 6-the trigger 20 (21) is always set to the zero state, since the B-input is constantly supplied with a zero potential.

The described part of the sheksh responds only to a signal following with an unacceptable well. If the output of the faulty converter 8 does not change at all (a constant signal of one or zero), then the spacing of the device does not provide a fault signal (there is no switch of the output signal on the counting input of the O-flip-flop 24 (25).

This disadvantage is eliminated by the H & L element AND 29 (30), for one

from the inputs of which a low-frequency (10-20 Hz) signal is supplied from the sinephone bus 31, which periodically records the state of the unit in the trigger 24 (25),

which (when the sensor is in good condition) is reversed by a 4th signal at its counting input.

 the operation of the control circuit for three values is shown in

FIG. 2

Thus, the predicted device allows unambiguously checking the serviceability of the speed-frequency converter.

feedback pulses of the speed control system and provide automatic redundancy in case of a sensor failure in the working channel or, in a state close to the wrong one, i.e. increases the reliability.,

Two independent transducer speeds - the frequency in this system is realized by installing two parts of the transducer in Koimyce with auto-oscillating sensors that react to the rotation of the steel gear.

 The inertial effect of the introduction of the 1 in 4 sentences of inventions is determined by the reduction in the number of control system failures associated with disruptions in the operation of the pulse converters and, consequently, by the reduction of equipment idle.

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Claims (1)

SELF-CONTROLLED ENGINE SPEED CONTROL DEVICE, comprising a reference frequency generator, a code-frequency converter, a frequency divider connected by an output to the first input of the comparison unit, connected by an output through a series-connected converter. Voltage and a voltage amplifier with a motor input, the shaft of which is mechanically It is connected with the speed-frequency converter, which is related to the fact that, in order to increase the reliability of the device, two pulse counters are introduced into it, h three D-flip-flops, Y5-flip-flop, two pulse shapers, eight AND elements, the first element NOT, the OR element and the second element NOT connected by the output to the C-input of the first D-trigger, and the input to the first output of the speed-frequency converter, to the information input of the first pulse shaper, to the C-input of the second B-trigger and to the installation input of the first pulse counter connected by the first output to the first input of the first element And, the second output to the second input of the first element And and the first input of the second element And, third exit house - with the second entrance! ” the second element And, and the counting input with the output of the converter: the frequency code and with the counting input of the second pulse counter connected to the input of the second element NOT, to the second output of the converter, the speed is the frequency, to the information input of the second pulse shaper and to the C-input of the third D -trigger, and the first, second and third outputs, respectively, to the first, second inputs of the third AND element and to the first input of the fourth AND element, connected by the second input to the second input of the third AND element, connected by the output to the S-input to the fourth D-flip-flop connected to the C-input with the output of the second element NOT, the D-input to the Earth bus, the R-input to the output of the fourth AND element, and the inverse output to the D-input of the third D-trigger connected by S- the input to the output of the fifth element And, the inverse output to the first input of the sixth element And, and the direct output to the first input of the seventh element And, connected to the second input with the inverse output of the first D trigger, and the output to the S-input of the RS trigger, connected I ? -the input to the output of the sixth element And connected by the second input to the direct output of the first D-trigger, connected by the D-input to the inverse output of the second D-trigger, and the 5-input to the output of the eighth element And, connected by the first input to the control input of the second shaper pulses and with inverse output! ” An RS-trigger connected by a direct output to the first input of the fifth AND element and to the control input of the first 1061107., Pulse generator ^ connected by the output to the first input of the OR element, connected by the second input to the output of the second pulse shaper, and by the output to the second input of the comparison unit, and the second inputs of the fifth and eighth elements And are connected to the synchronization bus, a D - the input of the first B-trigger — to the inverse output of the second D-trigger connected to the s-input and the R-input with the outputs of the first and second AND elements, respectively, and the a2> input — with the Earth bus.