JPH0926051A - Motor-driven regulating valve controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-driven regulating valve controller which prevents the damage of the motor-driven regulating valve and can secure the continuous operation of a plant over a long period by reducing the usual turning-over action frequency of the motor-driven regulating valve. SOLUTION: In the case of a motor-driven regulating valve controller which detects 8 control process signal and makes out a necessary control signal by conducting the operation processing of the control process signal by means of a regulation meter and rotates the motor of the motor-driven regulating valve forwardly and reversely on the basis of the control signal, the regulation meter consists of a filter circuit 5-5; a hiss gate circuit 5-6; a reference level setter 5-1; a comparison circuit 5-2; a control operation gain circuit 5-3; and a control operation integration circuit 5-4, and is constituted so that the motor may not respond to small change to be contained in the detected control process signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric control valve used in a power plant or the like, and more particularly to an electric control valve control device in which the number of reversing operations of the electric drive section in the forward and reverse directions is reduced. .

[0002]

2. Description of the Related Art Generally, in a power plant, a large number of control process signals such as water level, flow rate, pressure, temperature, etc. are detected and arithmetically processed to generate a necessary control signal to operate a control valve and other control devices. I am trying to let you.

FIG. 11 shows, as an example thereof, a water level detector as a process amount detector in a power generation plant in which water stored in a tank 1 is supplied to downstream equipment through an electric control valve 3 provided in an outflow pipe 2. 4 shows a system configuration in which the water level in the tank is kept at a standard level (NWL) by using No. 4, the electric control valve 3 includes a valve body 3-1 and a gear mechanism 3-2 and an electric motor 3 for driving the valve body 3-1. -3 and.

The control process signal (water level signal a in this case) detected by the water level detector 4 is sent to the controller 5. This controller has a standard level setter 5-1 and a comparison circuit 5-
2, the control calculation gain circuit 5-3, and the control calculation integration circuit 5-4. The water level signal a from the water level detector 4 corresponds to the water level set value from the standard level setter 5-1 in the comparison circuit 5-2. A comparison calculation is performed, and the deviation is multiplied by a control calculation gain constant K in a control calculation gain circuit 5-3 and a control calculation integration circuit 5-4, and further subjected to integral calculation to obtain a valve opening control signal b, which is a valve position calculation. Input to the container 6.

The valve position calculator 6 compares the valve opening control signal b from the controller 5 with the actual opening signal c from the electric control valve 3 and performs an operation so that both signals coincide with each other to calculate the electric motor. Three
The drive signal d of -3 is output. That is, for example, when the water flowing into the tank 1 from the inflow pipe 7 increases and the water level in the tank rises above the standard level, the electric control valve 3 is operated in the opening direction, and conversely, the water level in the tank is normal. When it falls below the level, the electric control valve 3 is operated in the closing direction.

By the way, the water level and other control process amounts in the power plant are constantly changing, and in the system shown in FIG. 11 as well, the electric control valve 3 changes in accordance with the water level change.
Opening and closing operations are frequently repeated. FIG. 12 exemplifies a water level signal a (a portion signal) and a change in the valve opening degree of the electric control valve 3 accompanying it.

[0007]

As described above, the electric control valve 3 is configured to change its opening by starting and stopping the electric motor 3-3. Since a considerable amount of shock is generated at the time of startup of 3, the limit value is generally set for the number of reversing operations per hour. If the number of reversing operations of the electric motor exceeds this limit value, there is a risk of damage to each component, and there is a risk that the function of the electric control valve will be lost accordingly. In such a case, continuous operation of the plant becomes impossible, and the operating rate of the plant decreases.

Therefore, the object of the present invention is to provide a motor-operated control valve control device capable of preventing the damage of the motor-operated control valve by reducing the number of times of constant operation and ensuring a continuous operation of a plant for a long period of time. It is what

[0009]

According to a first aspect of the present invention, there is provided a motor-operated control valve control device for detecting a control process signal,
In the electric control valve control device that calculates the necessary control signal by processing this with the controller and rotates the electric motor of the electric control valve in the forward and reverse directions based on this control signal,
The controller includes a filter circuit, a his gate circuit, a standard level setter, a comparison circuit, a control operation gain circuit, and a control operation integration circuit, and the electric motor controls the detected control process signal. It is characterized in that it is configured so as not to respond to the included small fluctuations.

According to a second aspect of the present invention, there is provided a motorized control valve control device, wherein the controller according to the first aspect is a standard level setter.
A controller having a comparison circuit, a control calculation gain circuit, a control calculation integration circuit, and a his gate circuit is replaced, and the electric motor responds to a fine fluctuation included in the detected control process signal. The feature is that it is configured not to.

According to a third aspect of the present invention, there is provided a motor-operated control valve control device, wherein the controller according to the first aspect includes a dead zone circuit, a standard level setter, a comparison circuit, a control calculation gain circuit, and a control calculation integration circuit. If the fluctuation range of the detected control process signal is within a predetermined dead zone, the electric motor ignores the fluctuation range and a change exceeding the range occurs. In this case, a signal corresponding to that is output.

According to a fourth aspect of the present invention, there is provided a motorized control valve control device, wherein the controller according to the first aspect is a standard level setter.
By replacing the controller with a comparison circuit, a control calculation gain circuit, a control calculation integration circuit, and a gain setting device,
When the fluctuation range of the detected control process signal is within a predetermined range W, the gain setter causes the control calculation gain circuit to set the control calculation gain constant K to a small value and outputs a control output. When the fluctuation width of the control process signal is out of the range W, the control operation gain circuit is controlled by setting the control operation gain constant K to a large value. It is characterized in that the output sensitivity is sharpened.

According to a fifth aspect of the present invention, there is provided a motorized control valve control device, wherein the controller according to the first aspect is a standard level setting device.
It is replaced with a controller including a comparison circuit, a control calculation gain circuit, a control calculation integration circuit, a switching setting device and an addition switching device, and the addition switching device is operated by the switching setting device. The switching setting device is configured by an adder circuit that adds the output of the switching contact and the output of the control calculation gain circuit to the output of the control calculation integration circuit, and the switching setting device has a fluctuation range of the detected control process signal of a standard level setting device. When it is within the predetermined range W of the set value, an OFF signal is output to the switching contact of the addition switch, and when the fluctuation width of the control process signal is out of the range W, the addition switch is opened and closed. It is characterized in that an ON signal is output to the contact.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In these figures, the same parts as those in FIG. 11 are designated by the same reference numerals, and description thereof will be omitted unless necessary.

FIG. 1 exemplifies a specific configuration of the motor-operated control valve controller according to the first aspect of the present invention. A controller 51 includes a filter circuit 5-5, a hisgate circuit 5-6, and a standard level setting. 5-1 and comparison circuit 5-2 and control calculation gain circuit 5
-3 and a control calculation integration circuit 5-4. The water level in the tank 1 is detected by the water level detector 4, and is sent to the filter circuit 5-5 of the controller 51 as a water level signal a as shown by the signal a in FIG. The water level in the tank 1 changes not only due to changes in the inflow amount, but also due to changes on the water surface that occur inside the tank, such as surface flushing and waves at the time of tank inflow. In this case, generally, the water level change due to the change of the inflow amount has a long cycle, but the change on the water surface has a short cycle and becomes a small wave. The filter circuit 5
-5 cuts the change on the water surface with a short cycle as a disturbance, and as shown by the signal e in FIG. 2, transmits only the gradual change to the hisgate circuit 5-6. In the His gate circuit 5-6, the gate characteristics given in FIG.
As shown in the partial signal, a hisgate signal that changes stepwise is output. This hisgate signal is compared with the water level set value from the standard level setter 5-1 in the comparison circuit 5-2,
In the control calculation gain circuit 5-3 and the control calculation integration circuit 5-4, the deviation is multiplied by the control calculation gain constant K and subjected to integral calculation to become the valve opening control signal b, which is sent to the valve position calculator 6. Is entered.

The valve position calculator 6 compares the valve opening control signal b from the controller 51 with the actual opening signal c from the motor-operated control valve 3 and performs a calculation so that both signals match and the electric motor Three
-3 is output, and when the water level in the tank rises above the standard level, the electric control valve 3 is actuated in the opening direction. Conversely, when the water level in the tank falls below the standard level, The electric control valve 3 is operated in the closing direction. In this case, the valve opening control signal b (this is almost equal to the valve opening)
2 changes stepwise in a relatively long span as shown by the signal b in FIG. 2 and does not respond to the minute fluctuations contained in the signal a, so the number of times the electric motor 3-3 reverses is small. Becomes

FIG. 3 exemplifies a specific configuration of the motor-operated control valve control device according to the second aspect of the present invention. The controller 52 includes a standard level setter 5-1, a comparison circuit 5-2, and a control calculation. It includes a gain circuit 5-3, a control calculation integration circuit 5-4, and a his gate circuit 5-6.

The water level in the tank 1 is detected by the water level detector 4 and is input to the comparison circuit 5-2 of the controller 52 as the water level signal a as shown by the signal a in FIG. This water level signal a is compared with the water level set value from the standard level setter 5-1 and its deviation is multiplied by the control operation gain constant K in the control operation gain circuit 5-3 and the control operation integration circuit 5-4, After further integration calculation, the Hisgate circuit 5
Entered in -6. The input signal of the hisgate circuit 5-6 contains a high frequency component due to a fine change on the water surface generated inside the tank, as shown in the g portion signal of FIG. After passing through, the his-gate characteristic b given in advance causes the his-gate signal b to change stepwise as shown by the signal b in FIG. The his gate signal b is input to the valve position calculator 6 as a valve opening control signal.

The valve position calculator 6 is similar to the case of FIG.
The valve opening control signal b from the controller 52 and the actual opening signal c from the electric control valve 3 are compared, calculation is performed so that both signals match, and the drive signal d of the electric motor 3-3 is output. , When the water level in the tank rises above the standard level, the electric control valve 3 is operated in the opening direction. Conversely, when the water level in the tank drops below the standard level, the electric control valve 3 is operated in the closing direction. Let In these cases, the valve opening control signal b changes stepwise in a relatively long span as shown by the signal b in FIG. 4, and does not respond to the fine fluctuation included in the signal a, so that the electric motor The number of inversion operations in 3-3 is small.

FIG. 5 exemplifies a specific configuration of the electric control valve control apparatus according to the third aspect of the present invention. The controller 53 includes a dead zone circuit 5-7, a standard level setter 5-1 and a comparison circuit. 5-2
And a control calculation gain circuit 5-3 and a control calculation integration circuit 5-4
Consists of The dead band circuit 5-7 ignores the fluctuation range of the input signal when the fluctuation range is within a predetermined dead band W set in advance, and outputs a signal corresponding to the fluctuation when the fluctuation exceeds the range. To do.

In this example, the water level in the tank 1 detected by the water level detector 4 is, as shown by a signal a in FIG. 6, a minute variation component on the water surface generated inside the tank and the tank 1. The signal h after passing through the dead zone circuit 5-7 exceeds the dead zone as shown by the signal h in FIG. It is a signal that produces an output only in a part.
Therefore, this h-part signal is sent to the standard level setter 5-1.
The valve opening control signal b after being calculated by the comparison circuit 5-2, the control calculation gain circuit 5-3, and the control calculation integration circuit 5-4.
As shown in the signal of part b of FIG. 6, it changes only when it exceeds a certain width, and the number of reversing operations of the electric motor 3-3 becomes small.

FIG. 7 exemplifies a specific configuration of the motor-operated control valve controller according to the fourth aspect of the present invention. The controller 54 includes a standard level setter 5-1, a comparison circuit 5-2, and a control calculation. Gain circuit 5-3, control calculation integration circuit 5-4, and gain setter 5
-8 and. When the fluctuation range of the water level in the tank 1 detected by the water level detector 4 is small, that is, as shown in FIG. 8, the gain setter 5-8 indicates that the a part signal is the set value of the standard level setter 5-1. When it is within the predetermined range W with respect to (NWL), the control calculation gain circuit 5-3 is made to set the control calculation gain constant K to a small value to make the control output sensitivity dull, and conversely, When the fluctuation range of the water level in the tank 1 is large, that is, when the a-part signal is out of the range W, the control calculation gain circuit 5-3 is caused to set the control calculation gain constant K to a large value. To sharpen the sensitivity of the control output.

As described above, in the conventional controller 5, the valve opening control signal is calculated based on the signal from the water level detector 4 so as to faithfully correspond to the amount of change in the water level in the tank 1 and the valve is controlled. Since it was input to the position calculator 6, the motor-operated control valve 3 was frequently opened and closed with a very small amount, and was opened and closed with a large cycle in accordance with the actual fluctuation of the water level. In 54, since the gain constant K of the control calculation gain circuit 5-3 is adjusted by the change width of the signal of the part a, a small change due to the wave of the water surface in the tank 1 is ignored, and the adjustment is made. The output signal of the total 54, as shown by the signal b in FIG. 8, disappears with a small fluctuation, and the valve opening gradually changes as shown in FIG. 8, so that the reversing operation of the electric motor 3-3 is performed. The number of times will be small.

FIG. 9 exemplifies a specific configuration of the electric control valve control device according to the fifth aspect of the present invention. The controller 55 includes a standard level setter 5-1, a comparison circuit 5-2, and a control calculation. Gain circuit 5-3, control calculation integration circuit 5-4, and switching setter 5-9
And an addition switch 5-10. Also, the addition switch 5
-10 is composed of an opening / closing contact 10a which is opened / closed by a switching setting device 5-9, and an adder circuit 10b for adding the output of the control calculation gain circuit 5-3 and the output of the control calculation integration circuit 5-4. There is.

The switching setting device 5-9 is used when the fluctuation range of the water level in the tank 1 detected by the water level detector 4 is small, that is, as shown in FIG. When it is within the predetermined range W with respect to the set value (NWL) of, the OFF signal is output to the switching contact 10a of the addition switch 5-10. As a result, the output of the control calculation gain circuit 5-3 is cut off, and only the output of the control calculation integration circuit 5-4 is provided, so that the sensitivity of the control output becomes dull. On the other hand, when the fluctuation range of the water level in the tank 1 is large, that is, when the a-part signal is out of the range W, an ON signal is output to the opening / closing contact 10a of the addition switch 5-10. Therefore, the output signal of the controller 55 is the control calculation gain circuit 5-3.
And the output of the control calculation integration circuit 5-4 are added, and the sensitivity of the control output becomes sharp.

Therefore, also in the controller 55 of this example, a small fluctuation due to the ripple of the water surface in the tank 1 is ignored, and the output signal of the controller 55 is as shown in FIG.
As indicated by the b-part signal of 0, the small fluctuation disappears, and the valve opening gradually changes as shown in FIG. Therefore, the number of reversing operations of the electric motor 3-3 is small.

The details of the present invention have been described above by taking an example of a system in which a water level detector is used as a process amount detector in a power plant and the water level in a tank is kept at a standard level. The system is not limited to this, a system that detects various control process signals such as water level, flow rate, pressure, temperature, etc. in various plants, performs arithmetic processing on these to generate the necessary control signals, and operates the electric control valve. Can be widely applied to.

[0028]

According to the present invention, by reducing the number of times of reversing operation of the motor-operated control valve at all times, the motor-operated control valve control device capable of preventing the damage and ensuring the continuous operation of the plant for a long period of time is obtained. be able to.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a specific configuration of an electric control valve control apparatus according to claim 1 of the present invention.

FIG. 2 is a graph illustrating a signal waveform and valve opening of each part in the device of FIG.

FIG. 3 is an explanatory diagram illustrating a specific configuration of the motor-operated control valve control device according to claim 2 of the present invention.

4 is a graph exemplifying a signal waveform and valve opening of each part in the device of FIG.

FIG. 5 is an explanatory diagram illustrating a specific configuration of the motor-operated control valve control device according to claim 3 of the present invention.

6 is a graph exemplifying a signal waveform and valve opening of each part in the device of FIG.

FIG. 7 is an explanatory diagram illustrating a specific configuration of the electric control valve control device according to claim 4 of the present invention.

8 is a graph exemplifying a signal waveform and valve opening of each part in the device of FIG.

FIG. 9 is an explanatory diagram illustrating a specific configuration of the motor-operated control valve control device according to claim 5 of the present invention.

10 is a graph exemplifying a signal waveform and valve opening of each part in the device of FIG.

FIG. 11 is an explanatory diagram illustrating a specific configuration of a conventional electric control valve control device.

12 is a graph exemplifying a signal waveform and valve opening of each part in the apparatus of FIG.

[Explanation of symbols]

 1 ... Tank 2 ... Outflow piping 3 ... Electric control valve 3-1 ... Valve body 3-2 ... Gear mechanism 3-3 ... Electric motor 4 ... Water level detector 5, 51-55 ... Controller 5- 1 ... Standard level setter 5-2 ... Comparison circuit 5-3 ... Control operation gain circuit 5-4 ... Control operation integration circuit 5-5 ... Filter circuit 5-6 ... His gate circuit 5-7 ... Dead zone circuit 5-8 ... Gain setting device 5-9 ... Switching setting device 5-10 ... Addition switching device 6 ... Valve position calculator 7 ... Inflow piping

Claims (5)

[Claims] 1. An electric control for detecting a control process signal, performing arithmetic processing on the control process signal to generate a necessary control signal, and rotating an electric motor of an electric control valve in forward and reverse directions based on the control signal. In the valve control device, the controller includes a filter circuit, a hisgate circuit, a standard level setter, a comparison circuit, a control calculation gain circuit, and a control calculation integration circuit, and the electric motor is detected. A motor-operated control valve control device characterized in that it is configured so as not to respond to minute fluctuations contained in the control process signal. 2. An electric control for detecting a control process signal, performing arithmetic processing on the control process signal to generate a necessary control signal, and rotating the electric motor of the electric control valve in forward and reverse directions based on the control signal. In the valve control device, the controller includes a standard level setter, a comparison circuit, a control calculation gain circuit, a control calculation integration circuit, and a hisgate circuit, and the electric motor detects the control process signal. An electric control valve control device characterized in that it is configured so as not to respond to minute fluctuations contained in 3. A motorized control for detecting a control process signal, processing it by a controller to generate a necessary control signal, and rotating an electric motor of a motor control valve in forward and reverse directions based on the control signal. In the valve control device, the controller includes a dead zone circuit, a standard level setter, a comparison circuit,
The electric motor includes a control calculation gain circuit and a control calculation integration circuit. When the detected variation width of the control process signal is within a predetermined dead zone range W, the electric motor is ignored and the range W is set. When there is a change that exceeds the above, the electric control valve control device is configured to output a signal corresponding to the change. 4. An electric control for detecting a control process signal, performing arithmetic processing on the control process signal to generate a necessary control signal, and rotating an electric motor of an electric control valve in forward and reverse directions based on the control signal. In the valve control device, the controller includes a standard level setter, a comparison circuit, a control operation gain circuit, a control operation integration circuit, and a gain setter, and the gain setter detects the detected control value. When the fluctuation width of the process signal is within the predetermined range W, the control calculation gain circuit is made to set the control calculation gain constant K to a small value to make the sensitivity of the control output dull, and conversely, the control is performed. When the fluctuation range of the process signal is out of the range W, the control calculation gain circuit is configured to set the control calculation gain constant K to a large value to sharpen the sensitivity of the control output. An electric control valve control device characterized by the above. 5. An electric adjustment in which a control process signal is detected, the controller is operated to perform arithmetic processing to generate a necessary control signal, and the electric motor of the electric control valve is rotated in forward and reverse directions based on the control signal. In the valve control device, the controller comprises a standard level setter, a comparison circuit, a control operation gain circuit, a control operation integration circuit, a switch setter and an addition switcher, and the addition switcher is The switching setter is constituted by an opening / closing contact that is operated to open / close and an adder circuit that adds the output of the control calculation gain circuit and the output of the control calculation integration circuit, and the switching setter detects the detected control process signal. When the fluctuation range is within the predetermined range W of the set value of the standard level setter, an OFF signal is output to the opening / closing contact of the addition switching device, and the fluctuation range of the control process signal deviates from the range W. The electric control valve control device is configured to output an ON signal to the opening / closing contact of the addition switching device during the operation.