SU1659978A1 - Pneumatic proportionally-integrated regulator - Google Patents

Abstract

The invention relates to technical means of automation, namely to pneumatic proportional-integral controllers. The purpose of the invention is to improve the quality of control. A corrective link is installed in the controller, consisting of constant throttling 1.1 and comparison element 10, the first flow chamber and the nozzle of which are connected to the line of the actuator, the first plus chamber with the reference channel, the second plus and minus chambers are respectively connected with the second minus and the positive chambers of the comparison element 4, the second flow chamber is in communication with the atmosphere, the second nozzle of the comparison element 10 is connected via a throttle 11 to the feed channel and directly to its negative chamber, as well as a rotary chamber and a chamber with a spring of the second switching relay 9. Improving the quality of control will allow the controller to be used as a backup in the NCR systems. 1 il.

Description

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The invention relates to technical means of automation, namely to pneumatic proportional-integral regulators.

The purpose of the invention is to increase the quality of control.

The drawing shows a schematic diagram of the controller.

The regulator contains an integral link, made in the form of element 1 in comparison, variable throttle 2 and capacitance 3; a proportional link consisting of a comparison element 4, a pressure divider 5, a constant throttle 6 and a power amplifier 7, two switching relays 8 and 9, a correction element made on the basis of the comparison element 10 and a constant throttle 11.

The first positive and negative chambers of the integral element comparison element 1 are connected to the channels of the variable variable Rper and the task P3d, the second negative camera is directly, and the second positive camera and capacity 3 are connected to the output of this comparison element via a variable throttle 2. The first flow chamber of element 4 of the proportional link is in communication with the atmosphere, the first plus chamber with capacity 3, the first minus with task channel P3d, the second plus and minus chambers with outputs of pressure divider 5, the inputs of which are connected to the channels Rper and P3d. The second flow chamber is connected via a constant choke 6 to the power supply channel and through the power amplifier 7 to the output of the controller Pout. The output of the regulator Pout through the first switching relay is connected to the line of the Rome actuator connected to the first nozzle and the flow chamber of the corrective element comparison element 10. The first positive chamber of the reference element 10 is connected to the RSD task channel. the second flow chamber is in communication with the atmosphere, the second nozzle is connected via a constant choke 11 to the power supply channel and directly to the first minus chamber of the comparison element and the output of the corrective link Pcr connected through the second switching relay with capacitance 3. The second plus and minus cameras the comparison element 10 is communicated respectively with the second negative and positive cameras of the proportional element comparison element 4.

The regulator works as follows.

In accordance with the switching scheme in the mode of automatic control (RK

 0) changes in the output signal of the Pout controller are described by the expression

Rvyh (Rper - Rzd) + (Ri - RZD).

where Ku Ku - sz 7.5 - coefficient

defined by the design parameters of the reference element;

F, f are the effective areas of the large and small membranes of the reference element;

Cd 1 - the transfer ratio of the pressure divider 5, the first setting parameter;

Re is the pressure at the outlet of the integral element (in the tank 3).

l

Pu j-S (Rper-Rzd) sN,

where Ti is the time constant of the link choke 2 is capacity 3, the second setting parameter.

Thus, the regulator implements the standard PI-law, and due to a decrease in Ku times the differences on the measuring membranes of the comparison element 1 integral part, a reduction (up to 0.25%) of the displacement of the control point of the regulator is achieved.

In the remote control mode (Pk 1), the actuator line is connected via the first switching relay 8 to the remote control channel P y. The output Rcor of the corrective element changes in accordance with the expression

Rkor RZD + tg Rome - Kd (Rper - RZD).

Since capacitance 3 at Pk 1 is communicated via the second switching relay 9 with the output of the correction link (PuRc), the output of the controller is (in this mode)

ROUTE KU KDRP RZD) + (Rkor Rzd) ROME.

Accordingly, the transition from the manual remote control mode to the automatic control mode is unstressed even with a non-zero mismatch at the controller input (Rper f Rd). In the prototype, this transition is inevitably accompanied by a jump in the line of the actuator.

This property allows using the proposed controller as a backup in the NCR systems.

The invention has been implemented on serial elements and prepared for industrial use.

Claims (1)

Invention Formula A pneumatic proportional-integral regulator containing an integral link, made in the form of a comparison element, the first plus and minus chambers of which are connected to the variable and assignment channels, the second the minus chamber is directly, and the second plus chamber and the tank are connected to the output of the reference element via a variable choke, and the proportional link, made as an element of comparison with the choke divider, the first flow chamber of the comparison element communicating with the atmosphere, and the second through a constant choke connected to the power channel and through the power amplifier and the first switching relay to the line of the actuator, the first positive chamber of the reference element is connected to the capacity of the integral link, Connecting to the output of the second relay switching minus first chamber - a reference channel, and the second positive and negative chamber through the throttle channels are connected to the divider and the variable assignment, and the control channel is connected to The respective channels of the first and second relay switching, and a remote control channel associated with the second srpl of the first switching relay, characterized in that, in order to improve the quality of control, it has a correction link consisting of a constant throttle and a reference element, the first flow chamber and the nozzle which are connected to the line of the actuator, the first positive chamber is connected to the task channel, the second positive and negative cameras are connected respectively to the second negative and positive cameras of the proportional link comparison element, The flow chamber is connected to the atmosphere, the second nozzle of the corrective element comparison element is connected via a constant choke to the power supply channel and directly to its first negative chamber, as well as to the flow chamber and the spring chamber of the switching relay.