JP2515743B2 - Output signal adjusting device for valve control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an output signal adjusting device for automatically adjusting a control signal output from a control device to a plant device, particularly a valve.

[Conventional technology]

For example, as seen in the computer control system in a thermal power plant (“Hitachi Commentary” VOL 64 No.6 (1982-6)), until now, a high degree of comprehensive automation has been realized in terms of operation of computer control of plants. Is coming.

[Problems to be solved by the invention]

In the above-mentioned prior art, no consideration is given to automation in maintenance. Regarding the adjustment and determination of the control characteristic function of each equipment, which is important for automating the operation of the plant, the plant engineer who is familiar with the plant side and the software engineer who is familiar with the computer side cooperate with each other and manually contact each other. It was done by advancing the work at.

For this reason, it takes a lot of time to finish the adjustment, and a human calculates the operation rate and sets it in the control device, which may cause an error.

The present invention has been made in view of the above problems,
An object of the present invention is to provide an output adjusting device for a valve control device, which can automatically and accurately adjust a control signal output from a plant device, particularly a control device for controlling a valve.

[Means for solving problems]

The output signal adjusting device for a valve control device according to the present invention for achieving the above object is: (a) The opening degree of a valve driven by a pulse signal before the pulse is input and after the panel is input. A minimum pulse width determining means for determining a minimum pulse width at which the valve does not substantially operate, based on a deviation from the opening degree of, and (b) larger than the minimum pulse width determined by the minimum pulse width determining means. A pulse with a predetermined pulse width,
Pulse width generating means for outputting a predetermined number of pulses to the valve from the fully closed state to the fully open state, and (c) for each predetermined number of pulses output from the pulse width generating means, corresponding to the pulse. Calculating means for calculating a pulse width required to open and close the valve by a unit opening degree based on the opening amount of the valve and the predetermined pulse width; and (d) the pulse width obtained by the calculating means. And means for setting the opening degree of the device in the device.

[Action]

In the present invention, the operating characteristic of the operating end or the setting device with respect to the output from the control device is measured by a device which automatically generates a pulse width. The measurement result is stored in the storage device as the operating end / setting device characteristic information, and the output pulse rate used by the control device is automatically and accurately created based on the stored information and set in the control device. . As a result, a highly accurate and error-free pulse output rate is efficiently set in the control device.

〔Example〕

FIG. 1 shows the configuration of an actuator characteristic adjusting device for valves and the like according to the present invention. This apparatus 1) specifies the controlled device 7 for which characteristic measurement is to be performed, and displays the characteristic measurement result and presents it to the operator. 5) The specified controlled device 7 and input / output device 8 An interface and a minimum pulse width determination device 13 for determining the minimum pulse width 17 that can drive the control target device 7 by confirming that the control target device 7 is driven, and measuring the actuator characteristics of the designated control target device 7 and performing a control process. It comprises a pulse rate determining device 2 for determining the pulse rate 18 used in the device 3. In FIG. 1, reference numeral 4 is a control simulator. The functions of these subsystems will be described in detail below.

The operator request device 5 is CR as shown in FIG.
It consists of T23 and keyboard 24. The following function keys that specify the required functions are assigned to the keyboard.

a "OUTPUT MENU" key 25 to specify the controlled device number b b Request to activate the interface and minimum pulse width determination device 1 "INT &MIN" key 26 c Request to activate the pulse width determination device 2 "PULSE Rat
e "key 27 d Select the pulse rate determined by the pulse width determination device 2,
"MOD OF CTL requesting that the control processor 3 be set
PROG "key 28""Sinulation" key for requesting a simulation test to verify the pulse rate set by the key 29. Also, since the controlled device number does not fit on one screen of the CRT23 , CR when the "OUTPUT MENU" key 25 is pressed
The T screen has a page structure, and the "PAGE FWD" key 30 and "PAGE BAC" key 31 for updating the page of the screen are also allocated on the keyboard.

When the "OUTPUT MENU" key 25 is pressed, the CRT screen 23 shown in Fig. 3 is displayed.

A list of controlled device numbers is displayed. The operator key-in the control target device number to be adjusted in the data setting field and press the request key 32.

When the control target device No. is specified by pressing the key 32, the individual information 39 of the control target device shown in FIGS. 4 and 5 or
40 is displayed on the CRT. The individual information 39, 40 is composed of the following.

a Output point name 33 b Specific 34; Linear (linear), POLYGONAL (polygonal approximation),
There are three types of POLYNOIAL.

c Output point No.35: There is an increasing direction and a decreasing direction.

d Feed Back Input point No. 36 e Open position equivalent to fully closed position 37 f Open position equivalent to fully open position 38 g Minimum pulse width 17 h Pulse rate 18 For these information, set data is stored in advance in the form of a table.

Of the information from a to h, g and h are parameters that need to be finally adjusted by the actual measurement data of the actual machine and reflected in the control program. Below, the minimum pulse width of these 17
And a method of obtaining the pulse rate 18 using actual measurement data will be described in detail.

The function of the interface and the minimum pulse width determination device 1 will be described with reference to the flow charts of FIGS. 1 and 6. The operator request device 5 selects the measurement target device 7 and requests (9). The operator interface and minimum pulse width determination device 1 collects the opening degree 6 of the controlled object 7 from the input / output device 8 as information 12. In the flow chart of FIG. 6, using this information, the counter is first set to "0" at step S1 and the measuring instrument opening 6 at step S2.
Is determined at the intermediate position (50%) as a boundary, and if the current position is below the intermediate position, the increasing pulse width output is used in step S3. On the contrary, if it is above the intermediate position, the decreasing pulse width output is used in step S4. At the first time, the pulse width output 11 of 1000 msec is performed (steps S5 and S6), and the position deviation before and after the pulse width output is obtained at step S7.

When the position deviation> 0 is confirmed at step S9 when the increasing pulse width is output at the first pulse width output (step S8), the interlock OK message is output to the operator request device 5 at S10. Even if the position deviation <0 is confirmed in S9 when the decrementing pulse width is output, the interlock is normal. Therefore, in S10, the interlock OK message is output. On the other hand, if it does not operate normally, an interlock NG message is output to the operator request device 5 in S11, and the interface and minimum pulse width determination device 1 is output.
Complete the process.

When the interlock between the computer and the controlled object 7 is normal (at the end of the processing of step S10), it is confirmed in S12 whether the absolute value of the position deviation is zero. When it is not zero, the minimum pulse width T _M is stored as T ₀ = 1000 msec in S13, and then the pulse width of 500 msec, which is half the previous pulse output time, is set in S14 and output. Again, the position deviation of the controlled object 7 is calculated (S7), and when its absolute value is not zero, the minimum pulse width is set to 500 msec. The above processing is repeated to determine the minimum pulse width with which the controlled object 7 does not operate. The minimum pulse width is implemented in both the increasing direction and the decreasing direction, and the larger one of the two is used as a representative value. The increasing / decreasing direction minimum pulse widths and their representative values determined as described above are transmitted as information 10 from the interface and minimum pulse width determining device 1 to the operator requesting device 5, and the CRT screen 39,
Displayed at 40. This representative value is reflected in the processing device 3.

Next, the pulse rate determination device 2 will be described in detail with reference to FIGS. 1 and 2.

The pulse rate determination device 2 is composed of the following tables and devices.

Valve characteristics storage table 41 Pulse width generator 42 Valve opening reading device 43 Next output pulse width correction device 44 Pulse rate curve / straight line determination device 45 The minimum pulse width 17 determined by the interface and the minimum pulse width determination device 1 is The pulse width output 15 stored in the valve characteristic storage table 41 and generated from the pulse width generator 42
Used as the minimum limit of. When the request signal 13 is given from the operator request device 5 to the pulse rate curve / straight line determination device 45, the valve characteristic investigation start signal 46 is set in the valve characteristic storage table 41. The pulse width generator 42 outputs a pulse width output 15 that meets the designed pulse width time 47. The valve opening 16 from the operation target is stored in the valve characteristic storage table 41 by the valve opening reading device 43.

The output pulse width correction device 44 sequentially collects the pulse characteristic data 48 from the valve characteristic storage table 41 to monitor the operation characteristic of the operation target device 7. This monitoring method will be described with reference to the processing flow of FIG. First, the valve opening storage table
From 41, (pulse width P ₀ (msec) and opening x ₀ (%) are collected, and the first pulse rate R ₀ is calculated.

In the computer, the pulse rate is defined as the time (msec) required to move the operation target by 1%. Further, (P _i , x _i ) when the pulse width generator 42 outputs a constant pulse width P ₀ 47 to the operation target 7 is output next time.
Captured at this pulse rate R _i Is calculated. Average pulse rate R _av before this And the current rate R _i are compared, and when the deviation is within 3% | R _av −R _i | <3%, the same processing as above is repeated to collect pulse characteristic data.

When the deviation exceeds 3%, it is determined that the linearity up to now is lost and the curve has another characteristic, and the pulse characteristic near the opening before the output of the pulse width P _i is sufficiently investigated. There is a need to. Therefore, the pulse width output in the opposite direction is output at the same time as the pulse output P _i this time in the valve characteristic storage table.
Request to the pulse width generator 42 via 41. Original position x
_After returning to _i-1 , this time A pulse width output 49 of the positive direction is requested to the pulse width generator 42. The same processing is repeated until the pulse rate at this time falls within 3% of R _av . Then, if it falls within the 3% error, another characteristic curve is moved from the next time, so that the data is recollected from the first-time data. The above pulse width output is performed for a pulse width output larger than the minimum pulse width, and is continued until the maximum opening of the valve is reached to determine the valve characteristic data 50, and the pulse rate curve / straight line determination device 45 Output to.

The processing contents of the pulse rate determination device 2 are shown in FIG. 8 by the flow chart method.

1) Equipment N specified by the operator request device 5
Using o.13 as the index, from the operation end information table,
Read the individual information of the controlled device. This individual information is
It is composed of the following elements.

α _MI ； Equivalent to full closed position 37 α _MX ； Equivalent to fully open position 38 Output point No. 35 Feed back opening Input point No. 36 Characteristic 34 (1 linear, 2 polygon, 3 non-linear) Minimum pulse width 17 Pulse rate 18 (Design value) 2) Feed Back When opening position 16 is not fully closed, the closed pulse width is output to output point No. 35 until fully closed.

3) When it is fully opened, output an open pulse width of T (msec) to output point No.35. T (msec) is not less than the minimum pulse width.

4) After outputting the pulse width, read Feed Back opening 16 and P ₀
= T (msec).

5) When the Feed Back opening 16 is not fully open, T (msec)
The pulse width output of is output to output point No.35.

6) Read the Feed Back opening 16 after outputting the pulse width P _i =
Let P _i-1 + T (msec).

7) The operations of 4) and 5) are repeated until the actuator is fully opened, and the characteristics (P _i , X _i ) of the actuator are obtained.

8) If the characteristics of the actuator are linear, Is the pulse rate.

9) In the case of polynomial approximation, x _i = aP _i ² + bP _i + C is calculated from (x _i , y _i ) by the method of least squares.

10) In case of line approximation, pulse rate corresponding to each pulse width output Ask for.

Next, pulse rate change rate Ask for. The point with the largest C _i is the inflection point, and before the inflection point After the inflection point Pulse rate. However, i = m + n.

These results are displayed on the display 23 of the operator request device 5. Display examples are shown in Figs.

In recent years, the automation of operation of power generation plants has been improved more and more, and plant control by computers is often carried out. Examples of control objects include setting control such as load / load rate / pressure / pressure rate setting device and temperature target value setting of the desuperheater, opening degree setting / control of control valve, electric valve, and the like.

The target value setting control of the main steam bypass valve (MSBV), which is an embodiment of the present invention, will be described below. MSBV has the following information.

The pulse rate 18 is determined by the operating end characteristic measuring device. First, after confirming that the interface between the computer and the valve setting device is normal by the interface and the minimum pulse width determination device 1, the minimum pulse width 15 is also determined by the same device. The minimum pulse width 17 is 100 msec in both increasing and decreasing directions. This minimum pulse width 17 is automatically displayed in MIN PULSE TIME in FIG. Next, the pulse rate determining device 2 determines the pulse rate.

Fig. 9 shows a plot of the measured data in a graph for easy viewing. When these collected data are calculated by the pulse rate determining device 2 to obtain the pulse rate 18, 449 (mse
c /%). This pulse rate is the PULSE RATE shown in Fig. 4.
It is automatically displayed in column 18.

The above information is automatically reflected in the control processing table 3 by pressing the function key 28 of MOD OF CTL PROG in FIG.

To confirm whether or not this pulse rate is actually set correctly, press the SIMULATION function key 29 shown in FIG. 3 to carry out an actual machine test. Figure 10 shows the process of simulating this valve. As shown in Fig. 10, the MSBV is a function of boiler outlet temperature and turbine inlet steam temperature for main steam pipe warming. After completing the main steam pipe warming, the main steam valve (MSV) is fully opened, and the pulse operation is completed by squeezing it to the 70% opening where the life consumption of the MSBV is the smallest. The control simulator 4 forcibly establishes the operation timing 19 of each operation from the operator requesting device 5 to operate the valve with the operation output 22 with each target value set as a target, so that the valve operates normally up to the target value. Check at opening 21. FIG. 10 is automatically displayed on the CRT 23 of the operator request device 5.

〔The invention's effect〕

1. The computer control parameters that could not be adjusted by the conventional operator can now be implemented with a simple operation using a CRT and keyboard. In addition, the adjustments that have been performed manually until now have been automated by a computer, which has improved work efficiency and reliability.

2. By determining and outputting the output pulse width for characteristic measurement based on the relationship between the pulse width and the opening up to the previous time, it is possible to obtain highly accurate operating end characteristics and improve controllability.

3. The characteristics of the actuator are patterned and stored, so that changes in the characteristics of the actuator due to aging can be known.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the device of the present invention, FIG. 2 is a pulse rate determination device, FIG. 3 is an operator request device, and FIG.
The figure shows the pulse rate characteristic display screen (linear), Fig. 5 shows the pulse rate characteristic display screen (non-linear), Fig. 6 shows the minimum pulse width determination processing flow, Fig. 7 shows the non-linear characteristic detection flow, and Fig. 8 shows Pulse rate determination processing flow, Fig. 9 is an example of actual measurement of operating end characteristics, and Fig. 10 is an example of MSBV simulation result display. 1 ... Interface and minimum pulse width determination device, 2
...... Pulse rate determination device, 3 ... Control processing table, 4 ...
Control simulator, 5 ... operator request device, 6 ... opening, 7 ... controlled object, 8 ... input / output device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-168218 (JP, A) JP-A-60-3719 (JP, A) JP-A-61-75408 (JP, A) JP-B 57- 58523 (JP, B2)

Claims (1)

(57) [Claims] (A) Based on a deviation between an opening of a valve driven by a pulse signal before the pulse is input and an opening after the pulse is input, the valve is substantially A minimum pulse width determining means for determining a minimum pulse width that does not operate, and (b) a pulse having a predetermined pulse width larger than the minimum pulse width determined by the minimum pulse width determining means,
Pulse width generating means for outputting a predetermined number of pulses to the valve from the fully closed state to the fully open state, and (c) for each predetermined number of pulses output from the pulse width generating means, corresponding to the pulse. Calculating means for calculating a pulse width required to open and close the valve by a unit opening degree based on the opening amount of the valve and the predetermined pulse width; and (d) the pulse width obtained by the calculating means. And a means for setting the control device for controlling the opening degree of the valve.