RU1837263C - Canal water level control system - Google Patents

Abstract

The aim of the invention is to increase the speed and accuracy of regulation, the reliability of the system when used to control the water distribution on open channels belonging to the Hydraulic structure - reservoir - pump station - hydraulic structure system. This goal is achieved in that the system contains n channel sections according to the number of hydraulic structures, each channel section containing level sensors at the beginning and at the end of the section, series-connected consumer flow sensors and the first adder, series-connected pulse-width regulator and actuator unit associated with the gate outlet of the hydraulic structure, the channel section after the reservoir contains a first threshold block, a control unit, and a pump station rekachki and serially connected flowmeter, a comparison block and a second threshold unit. 7 ill.

Description

The invention relates to automatic regulation, and in particular, to systems for automatically controlling the levels and flow rates of water in open channels.

The aim of the invention is to increase the speed and accuracy of regulation, the reliability of the system when used to control water distribution on open channels belonging to the hydraulic structure - reservoir - pump station - hydraulic structure system.

In FIG. 1 shows a functional diagram of the proposed system.

The system contains sections of the channel 11,12, ..., 1p, reservoir 2, level 3i sensors at the beginning and level 3 sensors at the end

of each channel section, pumping stations 4, pump, flow sensor 5, first adder 6, pulse-width regulator 7, actuating unit 8, shutter 9, pumping station 10, pumping, first threshold block 11, comparison block 12, second threshold block 13 , control unit 14, flow meter 15.

As a level sensor, level sensors of the RUS type are used. In addition, the level sensor 3 comprises a measuring device 16, a comparison element 17 and a driver 18 (Fig. 2). Thus, at the output of each level sensor 3, there are signals Dn (x), DN (t), proportional to the deviation of the water levels from the set value at the beginning and / or at the end of the channel sections.

b /

Ј

and

about:

h N About SL

The pulse-width regulator 7 associated with the hydraulic structure at the beginning of each section of the channel contains a bridge circuit 19, a second adder 20, a module selection unit 21, a sawtooth voltage generator 22, a comparator 23, a relay element 24, and a pulse shaper 25 (Fig. . 3).

The pulse-width controller 7 associated with the hydraulic structure at the end of the channel section 12 in front of the reservoir contains a third adder 26, a module isolation unit 27, a sawtooth generator 28, a comparator 29, a relay element 30, and a pulse shaper 31 (Fig. 4 )

The pumping station 10 of the transfer contains pumping units 32i, 32232m (Fig.

5). The first threshold block 11 comprises threshold elements 33i, 332 (FIG. 5). The second threshold block 13 comprises threshold elements 34i, 342 (FIG. 5). The control unit 14 comprises an on-line order determiner 35, an off-order order determiner 36, and OR gates 37i, 372 (Fig. 5). The switch-on switch 35 includes a first time relay 38, a first pulse shaper 39, a first pulse distributor 40 and a switch-on unit 41 (Fig. 5). The power-on block 41 contains electronic switches 42i, 42242m, relays 43i, 43243m (Fig. 5).

The shutdown priority determiner 36 comprises a second time relay 44, a second pulse shaper 45, a second pulse distributor 46, and a shutdown unit 47 (Fig. 5).

The shutdown unit 47 contains electronic switches 48i, 48248m, relays 49i,

49249m, (Fig. 5).

In FIG. Figure 6 shows a possible implementation of the first 40 or second 46 pulse distributors for the case (t is the number of pump units of the pumping station 10 transfer).

The pulse distributors 40, 46 contain triggers 50i, 502, 50z, 504 and an OR-NOT element 51. The OR-NOT element 51 prevents the simultaneous activation of two or more triggers, for this the outputs of all the triggers 311, 312, are supplied to the inputs of the OR 51 element. When the serial trigger 504 is switched, the input of the element 51 is OR NOT

from all outputs of triggers 50i, 502,504

zeros will be given, that is, a combination of 0000, which will ensure that the first trigger 50t arrives at the input and the valves 40-46 are prepared for operation. If together with switching the last trigger

504 some other trigger will switch, for example, the second 502, then to the input of the element 50- | OR NOT a combination of 0100 will be given instead of 0000, which will not provide

removing units from its outlet, in this case, valves 40-46 do not work.

In FIG. 7 is a timing diagram of the operation of valves 40-46, which illustrates their

principle of operation.

In the system, the regulation of water levels on the channel is carried out according to the scheme with flowing volumes, according to which the relationship between the deviation of water levels

A HH (t) from the set value at the beginning of each section of the channel and the deviation of the water levels L HK (t) from the set value at the end of these sections is determined by the ratio

AHH (thKAHK (t),

where K is the coefficient taking into account the correspondence of the consumer flow Qn and the flow supplied by the hydraulic structure in the head of the considered section of the QB channel.

Taking into account that many irrigation systems are equipped with telemechanical communication lines in the proposed system to increase the reliability of operation

by reducing the elements of the water level control system, in contrast to the prototype, not a radio link is used, but a cable link of the telemechanics system.

The system operates as follows. In the initial state, the flow rate supplied to the channel and disassembled by the pumping stations 4 of the swap (consumers) is balanced and the system operates stably. Wherein

The water levels at the beginning and end of each section of the canal and at the end of the reservoir are maintained constant.

If the balance between the supplied flow rate and the flow rate taken away at any site, for example, Is, is violated, the signal qs (t) is proportional to the value of the change in the flow rate of the pumping station 4 of the pumping station of this section from the output of the consumer flow sensor 5. Information from this

the sensor enters the first input of the first adder 6 of the considered section, where it is summed with signals about the change in the consumption of consumers in all downstream sections of the channel. Moreover, on

the output of the first adder 6 of the fifth section of the channel has a signal (I (t) proportional to the total consumption of consumers of the considered and all lower sections of the channel. Thus, the signal

ft (t) at the output of the first adder 6 i-ro channel section (, 4, ... n) is determined by the expression

& (t) -qi (t) + Фм- 9 qi (t). (2)

where n is the total number of sections of the channel;

qi (t) is the signal proportional to the consumption of the consumer of the 1st section;

Fm - a signal proportional to the total consumption of consumers of all the lower sections of the channel,, 4 ... p.

The signal fe (t) at the output of the first adder 6 of the fifth channel section is fed to the third input of the pulse-width regulator 7, which is connected with the hydraulic engineering structure at the beginning of the section. The pulse-width regulator 7, on the basis of the signal FB (T.), generates control pulses that act on the actuating unit 8 and move the shutter 4 of the hydraulic structure. The direction of movement of the shutter 4 is determined by the sign of the total signal at the output of the second adder 20 of the pulse-width regulator 7. It should be noted that the summation of the signals in the second adder 20 is made taking into account the coefficient ft of the correspondence between the changes in water levels and the change in water consumption of consumers and a constant weight coefficient K, characterizing the specific features of the channel sections (averaged depth, bottom width, length, etc.).

In order to increase the accuracy of controlling the water distribution in each channel section, the output signals of sensors 3i, 32 of water levels proportional to the deviations of AHH (t), AHK (t) water levels at the beginning and end of the channel section are respectively transmitted to the first and second input latitudinally. pulse regulator 7 associated with the hydraulic structure at the beginning of the section. In this case, if equality (1) is not satisfied, the signal Ux (t) appears in the output (diagonal) of the bridge circuit 19 of the controller 7, which is proportional to the discrepancy between the consumer flow rate and the flow rate supplied at the beginning of the section. Pulse-width regulator 7 of i-ro section (.5 Forms control pulses according to algorithm П

UmMMi (t) (t) + KiUxi (t). (3)

where Ki is the constant weight coefficient of the i-ro channel section:

Uxi (t) is the signal in the diagonal of the bridge circuit 19 of the controller 7 of the i-ro section.

Thus, the magnitude of the opening of the shutter 4 of any section of the channel depends on the total consumption of consumers of this and all downstream sections of the channel and on the magnitude of the discrepancy between the consumer and the flow rate

the site in question. Unlike the prototype in the proposed system, signals about deviations of water levels at the beginning and end of each section of the channel are not transmitted to the upstream sections of the channel.

This is explained by the fact that in order to achieve the required control speed it is enough to generate control signals in each section of the channel taking into account the signal proportional to the total

consumption of consumers of the considered and all downstream sections of the channel. This reduces the number of system elements and increases the reliability of its operation.

At the output of the comparison unit 12, there is a signal Ј (t) defining the difference between the flow rate QHC. pumping station 10 pumping, and the total consumption of consumers of the channel section after the reservoir and all the lower sections of the channel, that is

ОнМ Ons “-“,

(4)

35

If QHc (t)

qi (t).

(5)

then the signal Ј (t) is equal to zero and the block

14 of the control does not change the number of operating pumping units 32i of the pumping station 10. If equality (5) is violated, the output of the comparison unit 12 receives a signal Ј (t), which simultaneously arrives at

the input of the second threshold unit 13, to the second input of the first adder of the channel section located in front of the reservoir and to the second input of the controller 7, connected with the hydraulic structure at the end

section of the channel in front of the reservoir. If the signal Ј (t) has a positive sign, then the flow rate supplied by the pumping station 10 is greater than the total flow rate selected by consumers. Conversely, if the signal

Ј (t) has a negative sign, then the flow rate taken by consumers is greater than the flow rate supplied by the pump station 10. The signal Ј (t) is simultaneously input to the threshold elements 34i, 342 of the second threshold unit 13. If the signal e (t) has a negative sign and its value exceeds the threshold value, equal to 70% of the flow of additional pumping units 32 | of the pumping station 10, the threshold element 34i is triggered, and the ON sequence determiner 35 is activated via the OR logic 37i of the control unit 14, which switches on the first time relay 38 with a delay necessary to confirm the unbalance value that has occurred. In this case, the first pulse shaper 39 generates one rectangular pulse, which is fed to the input of the first pulse distributor 40.

A pulse distributor 40 distributes the pulses supplied to its input across all its outputs. In this case, alternating pulses are generated at its outputs.

Since the first pumping unit 321 of the pumping station 10 is turned on, the output pulse of the pulse generator 39 is fed to the input of the second trigger 502 of the pulse distributor 40. At the same time, at the second output 02 of the distributor 40, a pulse arrives at the input of the key 422 of the switching unit 41, which ensures the relay 432 is activated, its contact is closed and the pump unit 322 is turned on. This provides a step change in the flow rate of the unit 32a, the flow rate supplied to a section of the canal located after the reservoir. If after turning on the additional pumping unit 322, the output signal c (t) of the comparison unit still exceeds the threshold value of the threshold element 34i, the process is repeated and the additional pumping unit 32z and so on is turned on. Additional units of the pumping station 10 will be turned on until the reserve volumes of the section after the reservoir and all the lower sections of the channel are filled up.

If the signal Ј (t) has a positive sign and its value exceeds a threshold value equal to 70% of the flow rate of the additional pumping unit 32k, that is, if the flow rate supplied by the pumping station 10 is greater than the flow rate taken by consumers, then the second threshold element 342 of the second threshold unit 11 is triggered and at the same time, through the OR logic 372 of the control unit 14, the shutdown priority determiner 36 is turned on. The second time relay 44 is delayed to confirm the imbalance that has occurred.

issues a command to the second shaper

45 pulses. In this case, the driver 45 generates one rectangular pulse, which is fed to the input of the second pulse distributor 46. The rectangular pulse of the driver 45 is input to the first trigger 50i of the distributor 46. In this case, at the first output of the distributor

46, a pulse is generated which is fed to the 0 input of the key 48i of the shutdown unit 47 and enables the relay 49i to operate, open its contact and turn off the pump unit 32i. This provides a step change in the amount of flow of the unit

5 32i flow rate supplied to the channel section after the reservoir. If after switching off the additional pump unit 32i, the output total signal of the comparison unit 12 does not change sign and exceeds

0 threshold value of the threshold element 34a, the process is repeated and the next unit 322 is turned off, etc.

The adjustment of the threshold elements 34i, 342 of the second threshold block 13 is provided, proceeding from the requirement to reduce the number of trips of the pump units 32j of the pump station 10 due to the maximum use of the reserve volumes in the channel. This increases the reliability of the operation of the pumping station 10 and significantly reduces energy consumption.

If as a result of turning on or off the pumping units 32i pumping

5 stations 10, the water level at the beginning and / or end of the channel section after the reservoir reaches the maximum or minimum acceptable values, the first threshold block 11 is triggered. Threshold element 33i

0 of the first threshold block 11 is triggered if the water level at the beginning and / or at the end of the channel section after the reservoir reaches the minimum acceptable value. At the same time, a signal is output at its output,

5 which, through the OR logic 37i of the control unit 14, turns on the switching sequence determiner 35 and, accordingly, additional pump units 32i at the pump station 10 are activated, which prevents the channel section from being emptied and increases the reliability of the pump station 10. The threshold element 332 of the threshold block 11 triggers if level

5, the water at the beginning and / or at the end of the channel section reaches its maximum value. At the same time, a signal is generated at its output, which, through the OR logic of the control unit 9, turns on the shutdown priority determiner 36 and, accordingly, additional pump units 32 | pumping station 10, which does not allow unproductive discharges of irrigation water and excessive energy consumption.

In order to ensure the safe operation of the pumping station 10, it is necessary to maintain a predetermined water level in the reservoir. To this end, a signal about deviations of the water level in the selected site of the reservoir (in this case, it is advisable to install the target at the end of the reservoir) is transmitted to the first input of the pulse-width regulator 7, connected to the hydraulic structure at the end of the channel section in front of the reservoir.

To increase the speed of water distribution control over the entire channel, the output signal e (t) of the comparator 12, which carries information about the mismatch between the flow rate supplied by the pump station 10 and the flow rate of consumers of all the lower sections of the channel, starting from the section located after the reservoir, is fed to the second input a pulse controller 7 associated with a hydraulic structure at the end of the section in front of the reservoir and to the second input of the first adder 6 of the channel section in front of the reservoir.

The pulse-width regulator 7, associated with the hydraulic structure at the end of the channel section in front of the reservoir, generates control pulses according to the algorithm

ISMVM / k (t) + KB DNKVM. (6)

where-UshimvSt) is the output signal of the pulse-width regulator 7 associated with the hydraulic structure at the end of the channel section in front of the reservoir;

KB constant weight coefficient characterizing the specific features of the reservoir (depth, geometric parameters, etc.); And НквМ is the deviation of water levels from I setpoint in the selected section of the reservoir j.

| It should be noted that the third | adder 26 pulse-width regulator | 7, associated with hydraulic engineering j at the end of the channel in front of the reservoir. performs the summation of the signals Ј (t) n Д HK (t) taking into account the coefficients of flu Kv.

| Thus, the regulation of water levels in the reservoir is carried out taking into account changes in the consumption of consumers

0

all lower sections of the canal, starting from the section after the reservoir.

The output signal of the first adder 6 of the section in front of the reservoir and the first section of the channel is determined by the expression

FM Jqi (t) + e (t) .. 2. (7)

that is, the output of the comparison unit 12 in the first adder 6 of the section in front of the reservoir and the first section of the channel is summed with a signal proportional to the consumption of consumers of these sections of the channel. It also leads to an increase

with fast water management throughout the canal.

Pulse-width regulator 7, associated with the hydraulic structure at the beginning of the first or section of the channel before

p reservoir, generates control pulses according to the expression

ishim (t) Ј P W + «W + KiUXi (t), (8)

5 where .2.

Thus, the pulse-width regulator 7, associated with the main hydraulic structure, generates a water distribution control signal with

0 taking into account the total consumption of consumers of all sections of the channel, which significantly increases the speed of control throughout the channel. Dynamic control accuracy increases as a result of accounting

5 in the algorithm for controlling the pulse-width regulator of each channel section, the deviations of the water levels from the set values at the beginning and / or at the end of the channel section under consideration separately, i.e.

0 without taking into account deviations of water levels from the set values at the beginning and / or end of all lower sections of the channel. The reliability of the system is improved by reducing the number of

5 elements of a control system, transmitting signals about changes in water levels or flow rates in each section of the channel via a cable communication line and the use of contactless electronic elements (devices).

The introduced set of distinguishing features makes it possible to control the water distribution on open channels belonging to the hydraulic engineering structure - reservoir - pump station - hydraulic engineering system and also significantly reduce unproductive irrigation water discharges.

Claims (1)

The claims A system for regulating the water level on the channel, comprising n sections of the channel according to the number of hydraulic structures, each channel section containing level sensors at the beginning and end of the section, series-connected consumer flow sensors and a first adder, series-connected pulse-width regulator and executive unit, associated with the gate outlet of the hydraulic structure, the channel section after the reservoir contains a first threshold block, a control unit, and a pump station pumping, as well as series-connected flowmeter, a comparison unit and a second threshold unit, the output of the level sensor at the beginning of this section being connected to the first input of the first threshold unit, the second output of which is connected to the second input of the control unit, the third and fourth inputs of which are connected respectively the first and second outputs of the second threshold block, characterized in that, in order to increase the speed and accuracy of regulation, the reliability of the system when used to regulate additional distribution on open channels belonging to the system hydraulic structure - reservoir - pump station - hydraulic structure it additionally contains a level sensor located at the end of the reservoir, at each section of the channel a pumping station, the output of which is connected to the input of the consumer flow sensor, the outputs of the sensors level located at the beginning and end of each section of the channel located after the reservoir are connected respectively to the first and second inputs of the pulse-width the controller associated with the hydraulic structure at the beginning of each channel section, the third input of which is simultaneously connected to the output of the first adder of each channel section and the input of the first adder of the upper section, the output of the first channel section adder after the reservoir is connected to the second input of the comparison unit, the output of the level sensor located at the end of the reservoir is connected to the first input of the pulse-width regulator located on the hydraulic structure at the end of the channel section located th front reservoir, the second input of which is connected to the output of comparison unit and the second input of the first adder of the channel portion, the sensor output level at the end of a channel portion after the reservoir is connected to the second input of the first threshold unit. , Figure 1 Cabbage soup b 77x € (t) 1 PPtNTtN 29 H J / l Il 0/7 3.0W.J2 MM FIG. I. fig.Z WAf / lfJ 0Z / .4 Fa 5 From 39,45 Phage 7 FIG. 6