JP4839279B2 - Turbine control device and turbine control method - Google Patents

Description

  The present invention relates to a turbine control device and a turbine control method, and more particularly, a turbine control suitable for an apparatus for controlling a fluid flow rate flowing into a turbine, having a function for converting a steam flow rate request signal into a control valve opening command signal. The present invention relates to an apparatus and a turbine control method.

  In general, turbine control is performed by controlling a control valve provided in a pipe for steam flowing into the turbine to adjust the flow rate of steam flowing into the turbine. That is, the steam flow request signal from the flow control unit that determines the steam flow to the turbine is converted into a control valve opening command signal by a function obtained from the relationship of the inflow steam amount to the valve opening, and the control valve is controlled. To do. Such a technique is described in, for example, Japanese Patent Application Laid-Open No. 2005-189016.

  Since the function obtained from the relationship between the inflow steam amount and the valve opening degree changes due to the mechanical characteristics of the valve, the valve operation with respect to the valve opening command signal, that is, the valve stroke Must be measured and corrected to a characteristic equivalent to the planned value.

JP 2005-189016 A

  It is converted into a valve opening command signal according to the characteristics of the function, and the control valve operates based on the valve opening command signal.However, conventionally, the valve adjustment switch is turned on manually and the test input signal is input to the function. Then, the stroke of the operated control valve is measured, and the function parameter is manually changed so that the measured value falls within the allowable range of the planned value, and the function parameter is adjusted.

  Therefore, it takes time and labor to input test input signals, manually convert function parameters, and measure the control valve stroke, and human errors will occur for the input, conversion operation, and control valve stroke measurement. The possibility of occurrence is also increased.

  An object of the present invention is to provide a turbine control device and a turbine control method capable of automatic adjustment with a simple configuration.

  In order to achieve the above object, the present invention generates a test steam flow rate request signal, selects one of the control steam flow rate request signal and the test steam flow rate request signal, and selects the selected signal as a predetermined signal. Convert to opening command signal according to conversion rules, input control valve operation signal indicating operation of control valve according to the opening command, and convert the control valve operation signal to a signal corresponding to steam flow request signal The conversion rule is corrected by comparing a signal corresponding to the steam flow request signal output when the test steam flow request signal is selected with the generated test steam flow request signal. Configured.

  Specifically, during adjustment of the function parameters, a signal corresponding to the steam flow request signal is calculated from the valve stroke signal, a correction amount for the shortage of the test signal input to the function is calculated, and input to the function After the correction amount is added to the test signal and input to the function, the valve opening command signal output from the function is stored in the parameter Y of the function to automatically adjust the parameter Y.

  According to the present invention, automatic adjustment is possible with a simple configuration. More specifically, the parameter Y of the function can be adjusted with a simple configuration based on the valve stroke signal, adjustment time and labor can be reduced, and adjustment that leads to suppression of human error is also possible.

  The present invention will be described below with reference to the drawings.

FIG. 1 shows a turbine control circuit provided with a circuit for automatically adjusting a function parameter Y according to the present invention, and is characterized in that a function parameter adjusting circuit 1 is additionally provided. In the figure, a function (f _{1 (X)} ) 16 having parameters X1 to Xn and Y1 to Yn, a control valve 22 for adjusting the flow rate of steam flowing into the turbine, and a stroke of the control valve 22 are measured, and the measured values are used. Although the valve stroke measuring device 23 for outputting a certain valve stroke signal 26 is provided, in this embodiment, the valve stroke of the control valve 22 is measured for the parameters Y1 to Yn of the function 16, and the function is based on the measured value. In order to automatically adjust the sixteen parameters Y1 to Yn, the function parameter adjusting circuit 1 additionally adjusts the parameter Yn of the function 16 automatically.

The steam flow command unit 30 obtains and outputs a steam flow request signal 31 based on the load and the turbine rotational speed. In the function 16, the parameters Xn and Yn are set in a one-to-one relationship. For example, the function 16 has characteristics shown by a graph that smoothly connects the intersections as shown in FIG. When X1 is input from the changeover switch 8 as the steam flow rate request signal 31, in the function 16, the corresponding Y1 is output as Y = f1 _(X) . That is, when X1, X2,..., X6 are input, Y1, Y2,. The intermediate value is interpolated as shown in FIG. Here, X1 to Xn are predetermined constants, and Y1 to Yn are variables that change by adjustment. In normal control, the steam flow rate request signal 31 selected by the changeover switch 8 (contact point b and contact point c connected) is input to the function 16, converted by function characteristics, and then output as the valve opening command signal 17. Operate the valve. The opening degree of the control valve 22 is adjusted via the servo amplifier 20 and the servo valve 21 by the valve opening degree command signal 17 which is the output of the function 16. That is, the opening degree of the control valve 22 is detected as the valve opening degree signal 25 by the differential transformer 24 and feedback-controlled so as to follow the valve opening degree command signal 17.

  The function parameter adjustment circuit 1 includes a valve adjustment switch 2, a valve adjustment mode 1 to an N selection switch 3, a changeover switch 4, a comparator 5, a parameter changeover 6, an integrator 7, a changeover switch 8, a changeover switch 9, and a holding circuit 10- 1 to N, changeover switches 11-1 to N, and function 12.

  The valve adjustment switch 2 is operated when parameter adjustment is performed. During the parameter adjustment, an ON signal is output, and the change-over switch connects the contact a and the contact c. Adjustment of the parameter Yn of the function 16 is performed by sequentially adjusting the parameters Y1 to Yn one by one, but K1 to Kn are also determined in advance as test input signals to be input to the function 16 according to the parameter to be adjusted.

  The valve adjustment mode 1 to N selection switch 3 is a switch for selecting a parameter to be adjusted. When adjusting Yn, the mode N is selected and used.

  The changeover switch 4 switches the input terminal to N when the mode N is selected based on the selection result of the valve adjustment modes 1 to N selection switch 3, and outputs the value of Kn.

  The comparator 5 receives the test input signal Kn and the test input equivalent signal 15 and outputs an ON signal when the deviation between the two signals is equal to or greater than the parameter H or less than L. In other cases, an OFF signal is output.

  The parameter switching 6 switches the parameters H and L of the comparator 5 according to the selection of the valve adjustment modes 1 to N selection switch 3. That is, the adjustment allowable range of the parameter Yn is switched according to the valve adjustment mode.

  When the output of the comparator 5 is ON, the integrator 7 outputs a value obtained by integrating the deviation between the test input signal K and the test input equivalent signal 15 as the correction amount 14. When the output of the comparator 5 is OFF, the output immediately before the output is turned OFF is held and output as the correction amount 14.

  When the output of the valve adjustment switch 2 is OFF, the changeover switch 8 outputs a steam flow request signal 31 that is an input of b from c, and when the output of the valve adjustment switch 2 is ON, a correction amount is added to the test input signal K. The value obtained by adding 14 is output from c.

  The changeover switch 9 switches the output terminal to any one of 1 to N according to the selection result of the valve adjustment modes 1 to N selection switch 3 and outputs a valve opening command signal 17 that is an output of the function 16.

  The holding circuits 10-1 to 10 -N operate according to the selection result of the valve adjustment modes 1 to N selection switch 3.

  When the mode N is selected, the holding circuit 10-N outputs the X input as it is from the Y, and when the selection is canceled, the output is held at the input value of X immediately before the cancellation.

  The changeover switches 11-1 to 11 -N also operate according to the selection result of the valve adjustment modes 1 to N selection switch 3. When the mode N is selected, the changeover switch 11-N outputs the output immediately before being selected from c, which is the input of a, and when the selection is canceled, the holding circuit 10-N which is the input of b. Are output from c.

  The function 12 is a function for inversely converting the valve stroke signal 26 output from the valve stroke measuring device 23 of the control valve 22 into a test input signal, and the output is a test input equivalent signal 15.

  This flow realizes the function of the block diagram shown in FIG. 1, and it is needless to say that the operation of this flow may be realized by microcomputer software (program).

  The operation flow of the parameter adjustment circuit in FIG. 2 will be described.

  In step 1-1, the valve adjustment switch 2 is turned ON so that the test input signal is selected.

  In step 1-2, the valve adjustment mode N selection switch is turned ON.

  In step 2-1, by selecting the valve adjustment mode N, the input terminal of the changeover switch 4 is switched, and Kn that is an input signal corresponding to the parameter Yn of the function 16 is output as a test input signal. Accordingly, the parameter switch 6, the switch 9, the holding circuit 10, and the switch 11 are switched.

  In Steps 2-2 to 2-4, the comparator 5 compares the deviation between the test input signal Kn and the test input equivalent signal (15) Ka, and the deviation is switched by selecting the valve adjustment mode N. In the case of Hn or more or Ln or less, the output of the comparator 5 is turned ON. In this case, the integrator 7 adds ΔK to the previous output Ky and outputs the correction amount 14.

  In step 2-5, when the deviation is less than Hn and greater than Ln, the output of the comparator 5 is OFF, so the integrator 7 outputs the previous output Ky as the correction amount 14 as it is.

  In Step 2-6, the correction amount 14 calculated in Step 2-4 and Step 2-5 is added to the test input signal Kn and input to the function 16.

  In step 2-7, the function 16 outputs an output value corresponding to the input value as the valve opening command signal 17 according to the characteristics. The valve opening command signal 17 is held at step 2-12.

  In Step 2-8, the deviation between the valve opening command signal and the valve opening signal 25 is amplified by the servo amplifier 20, and the servo valve 21 is operated, whereby the control valve 22 is operated.

  In Step 2-9, the valve stroke measuring device 23 measures the stroke operation amount of the control valve 22, and outputs the measured value to the function 12 as the valve stroke signal 26.

  In step 2-10, the valve stroke signal 26 is converted into a test input equivalent signal 15 according to the characteristics of the function 12. And it returns to step 2-2, 2-3, and repeats that step 2-4 or 2-5 is performed.

  On the other hand, if it is determined in step 2-3 that “Kn−Ka ≧ Hn or Kn−Ka ≦ Ln” is “NO”, in step 2-11, the deviation between the test input signal Kn and the test input equivalent signal Ka. Is within the range of Ln to Hn, it is determined that the valve opening command signal 17 at that time is satisfied, and the valve adjustment mode selection switch is turned OFF.

  In steps 2-12 to 2-14, when the selection switch is turned off, the holding circuit 10-N holds and outputs the value immediately before the selection switch is turned off, and the changeover switch 11-N switches the input terminal to b. Therefore, the value immediately before the selection switch, which is the output of the holding circuit 10-N, is turned off is output. Therefore, the value of the parameter Yn of the function 16 is the value of the valve opening command signal 17 immediately before the selection switch is turned off. Fixed.

  Therefore, the adjustment of the parameter Yn is completed, and in step 3, the valve adjustment switch 2 is turned off and the parameter adjustment is completed.

  FIG. 3 shows the function parameters Yn, the valve opening command signal 17, the correction amount 14, the test input equivalent signal 15, and the test input signal Kn when the parameter Yn is adjusted using the parameter adjustment circuit shown in FIG. Shows the transition.

It turns ON the valve adjustment switch 2 at T _a. When the valve adjustment mode N selection switch is turned on at T ₀ , the test input signal Kn is selected, the control valve 22 is operated based on it, and the test input equivalent signal 15 is increased according to the stroke operation amount.

  Due to the deviation between the test input signal Kn and the test input equivalent signal 15, a correction amount is generated and increases until it falls within the allowable range of Hn and Ln of the comparator 5. Along with this, the valve opening command signal 17 that is the output of the function 16 increases.

Since the test input equivalent signal 15, the correction amount 14, and the valve opening command signal 17 are stable, when the valve adjustment mode N selection switch is turned off, the value of the valve opening command signal 17 held in the holding circuit 10-N is changed. to be input to the parameter Yn through the switch 11-N, function parameters Yn by T ₁ rises, is directly fixed. Then, the valve adjustment switch 2 is turned OFF at T _b.

  FIG. 5 shows an example of another parameter adjustment circuit. Only parts different from FIG. 1 will be described, and description of similar parts will be omitted. 1 differs from the valve stroke signal 26 in that the valve opening signal 25 output from the differential transformer 24 is converted into a test input equivalent signal 15 by the function 13 and used. Even in this method, the same parameter adjustment is possible.

An example of a function parameter adjustment circuit. The function parameter adjustment circuit operation | movement flowchart. Function parameter adjustment circuit operating status. Function characteristics. 4 is another embodiment of the function parameter adjustment circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Function parameter adjustment circuit 2 Valve adjustment switch 3 Valve adjustment mode 1-N selection switch 4, 8, 9 change-over switch 5 Comparator 6 Parameter change-over 7 Integrator 10 Holding circuit -1 to N
11 changeover switch-1 to N
12 functions (f _{2 (X)} )
13 Function (f _{3 (X)} )
14 Correction amount 15 Test input equivalent signal 16 Function (f _{1 (X)} )
17 Valve opening command signal 20 Servo amplifier 21 Servo valve 22 Control valve 23 Valve stroke measuring device 24 Differential transformer 25 Valve opening signal 26 Valve stroke signal 30 Steam flow command section 31 Steam flow request signal

Claims (9)

A test steam flow rate request signal generating unit that generates a test steam flow rate request signal; a selection unit that selects one of the control steam flow rate request signal and the test steam flow rate request signal; and the selected signal as a predetermined signal. a first conversion unit and the control valve to output the control valve operation signal indicating the operation of the control valve in accordance with the opening command operation signal output unit for converting the opening command signal along the conversion rule, wherein A second conversion unit that converts a control valve operation signal into a signal corresponding to a steam flow rate request signal, and a steam flow rate request signal that is output by the second conversion unit when the test steam flow rate request signal is selected. A turbine control apparatus comprising: a correction unit that corrects a conversion rule of the first conversion unit by comparing a corresponding signal with the generated test steam flow rate request signal. The rule of the first conversion unit according to claim 1, wherein the rule is a function including a parameter, and the correction unit is a signal corresponding to the steam flow request signal when the test steam flow request signal is selected. The turbine control apparatus according to claim 1, wherein the parameter is corrected based on a valve opening command signal converted by the first converter. The parameter is defined as an output value with respect to an input value, and the correction unit replaces the output value corrected at the time of previous parameter adjustment with an output value when the test steam flow rate request signal is selected. A turbine control device characterized by that. 3. The correction unit according to claim 2, wherein the correction unit adds a correction amount based on a deviation between the test steam flow rate request signal and a signal corresponding to the steam flow rate request signal to the test steam flow rate request signal. A turbine control device characterized by adding a correction amount calculated last time and a correction amount calculated this time to the steam flow request flow rate signal as a correction amount. According to claim 3, replacement of the output value of the function, turbine control, characterized in that it is made by switching an output value corrected to the output value and the current parameter adjustment end immediately before the corrected during parameter adjustment of the previous apparatus. 3. The correction unit according to claim 2, wherein the correction unit calculates a correction amount for a shortage of the test steam flow rate request signal input to the function based on a signal corresponding to the steam flow rate request signal, and the steam flow rate A turbine control apparatus characterized in that a difference between a signal corresponding to a request signal and a test steam flow rate request signal input to the function is used as a correction amount. In Claim 2, if the difference between the signal corresponding to the steam flow request signal and the test steam flow request signal input to the function is within a predetermined tolerance, the correction unit performs correction. A turbine control device that is not performed . According to claim 1, wherein the control valve operation signal, valve stroke signal, Or, turbine controller, which is a No. valve opening Doshin obtained from the differential transformer valve. A test steam flow request signal is generated, one of the control steam flow request signal and the test steam flow request signal is selected, and the selected signal is converted into an opening command signal in accordance with a predetermined conversion rule. converts the control valve operation signal indicating the operation of the control valve in accordance with the opening command to the signal corresponding to the steam flow demand signal, the flow rate of steam testing steam flow demand signal is output when selected A turbine control method for correcting the conversion rule by comparing a signal corresponding to a request signal and the generated test steam flow rate request signal.

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