JP5390443B2 - Steam turbine controller - Google Patents

Description

  The present invention relates to a turbine control device, and more particularly to a steam turbine control device capable of easily adjusting a change in control characteristics due to replacement of each device or aging deterioration accompanying maintenance of a power plant.

FIG. 6 is a control system diagram of a conventional turbine control device provided in a power plant such as a nuclear power plant, and a portion enclosed by a one-dot chain line is a turbine control device 8.
In FIG. 6, 1 is a steam generator in a nuclear power plant, and the steam generated here is introduced into a steam turbine 5 through a main steam stop valve 3 and a steam control valve 4 provided in a main steam system pipe 2. . As is well known, the main steam stop valve 3 is fully closed when the turbine is stopped, and fully opened during turbine operation. On the other hand, the steam control valve 4 adjusts the amount of steam flowing into the steam turbine 5 by adjusting the valve opening based on an opening command signal V12 output from a turbine control device 8 described later.

  The steam turbine 5 generates a turbine output corresponding to the amount of steam inflow, and drives the generator 6 directly connected to the turbine rotation shaft to generate power. The steam that has flowed into the steam turbine 5 and finished work is condensed by a condenser, and then returns to the steam generator 1 again through a low-pressure feed water superheater and a high-pressure feed water superheater (not shown). .

  Three steam pressure detectors 7A, 7B and 7C of the same type are installed on the inlet side of the main steam stop valve 3, that is, on the inlet side of the steam turbine 5, and these steam pressure detectors 7A, 7B are installed. And steam pressure signals A1, B1 and C1 detected at 7C and 7C are introduced into the turbine controller 8 indicated by a one-dot chain line frame. The turbine control device 8 individually inputs steam pressure signals A1, B1, and C1 to three pressure control devices 9A, 9B, and 9C having the same configuration.

  The pressure control devices 9A, 9B, and 9C control the steam pressure signals A1, B1, and C1 detected by the steam pressure detectors 7A, 7B, and 7C to have a predetermined pressure. Although not shown, the outline of the pressure control device 9A will be described as a representative. The pressure is determined from the steam pressure signal A1 detected by the steam pressure detector 7A and the pressure set value set by a pressure setter (not shown). The deviation signal is calculated, and the pressure deviation signal is output as the pressure control signal V9A. The pressure control signals V9B and V9C are output in the same manner for the pressure control devices 9B and 9C.

  The pressure control signals V9A, V9B, and V9C output from the pressure control devices 9A, 9B, and 9C are input to the intermediate value selector 10 in the next stage, and the intermediate value among the three input signals. Is output as V10.

  As described above, the steam pressure detectors 7A to 7C of the same type and the three pressure control devices 9A to 9C having the same configuration are installed, respectively, and the intermediate value selector 10 is provided even when a single failure occurs. This is because the remaining detectors detect normally and ensure control reliability (see, for example, Patent Document 1).

The intermediate value signal V <b> 10 output from the intermediate value selector 10 is input to the pressure control adjustment device 11. The pressure control adjusting device 11 performs a calculation process necessary for the pressure on the inlet side of the main steam stop valve 3 to be constant, and any of the pressure control devices 9A to 9C output from the intermediate value selector 10 is used. For example, the pressure control signal is input to a specific frequency gain attenuating filter (notch filter) to attenuate the specific frequency included in the pressure control signal, and advance / lag compensation calculation is performed. Multiplication is performed and the steam valve opening command V11 is output to the steam valve control device 12.
The steam valve control device 12 transmits (outputs) an opening degree command signal V12 for adjusting the opening degree of the steam control valve 4 to the steam control valve 4 by the signal circuit 13.

  Thus, in the conventional turbine control device 8, the pressure control adjustment device 11 adjusts the frequency characteristics included in the detected steam pressure signals A1, B1, and C1. The value set here is the optimum value determined by the actual machine test when constructing the power plant. For each periodic inspection of the power plant, it is not necessary to adjust the optimum value by the same actual machine test as at the time of construction, and it is adjusted by the minimum necessary test.

JP 2009-180188 A

  The frequency characteristics of the above-described steam pressure detectors 7A, 7B, and 7C change due to the replacement of the detector and aging. In addition, when the turbine control device 8 itself is replaced, the analog input characteristics may change before and after the replacement.

  Since the frequency characteristic set in the turbine control device 8 is determined by the behavior of the entire power plant, conventionally, it has not been possible to make a setting that can reflect the change in the frequency characteristic of the individual steam pressure detectors.

  Therefore, an object of the present invention is to provide a steam turbine control device that can easily adjust changes in control characteristics due to replacement of each device or aging deterioration associated with maintenance of a power plant.

  In order to achieve the above object, the invention according to claim 1 is to generate steam by supplying steam generated by a steam generator to a steam turbine via a main steam stop valve and a steam control valve provided in a main steam system pipe. A pressure control signal that is provided in a power plant that drives the machine, and that is a steam pressure detector installed in the main steam system pipe, and a pressure deviation signal between the steam pressure signal detected by the steam pressure detector and the pressure set value. A pressure control device that outputs as a pressure control adjustment device that attenuates a specific frequency in the pressure control signal, performs a lead / lag compensation calculation, and further multiplies the gain and outputs it as a steam valve opening command, A steam control device that outputs an opening command signal for adjusting the opening of the steam control valve based on the steam valve opening command output from the pressure control adjustment device. The turbine control device is provided with a frequency characteristic adjusting device having a first-order lag element, and the time constant of the first-order lag element is adjusted to cancel the frequency characteristic change of the steam pressure signal. .

  ADVANTAGE OF THE INVENTION According to this invention, the change of the control characteristic by replacement | exchange of each apparatus accompanying a power plant maintenance, aged deterioration, etc. can be adjusted easily.

1 is a system diagram of a turbine control device according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a frequency characteristic adjusting device according to the first embodiment. The systematic diagram of the turbine control apparatus which concerns on Embodiment 2 of this invention. The systematic diagram of the turbine control apparatus which concerns on Embodiment 3 of this invention. The systematic diagram of the turbine control apparatus which concerns on Embodiment 4 of this invention. The conventional turbine control system diagram.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the drawings, the same apparatus and the same parts are denoted by the same reference numerals, and repeated description is omitted as appropriate.

[Embodiment 1]
Hereinafter, the turbine control apparatus according to the first embodiment will be described with reference to FIGS. 1 and 2.
The first embodiment is characterized in that a frequency characteristic adjusting device 20 surrounded by a two-dot chain line frame is added to the conventional system shown in FIG. 6, and other devices are the same as the conventional configuration. It is.

  In FIG. 1, the frequency characteristic adjusting device 20 includes an A-system frequency characteristic adjusting device 20A, a B-system frequency characteristic adjusting device 20B, and a C-system frequency characteristic adjusting device 20C corresponding to the steam pressure detectors 7A, 7B, and 7C. The steam pressure signals A1, B1 and C1 are input, respectively.

  These frequency characteristic adjusting devices 20A, 20B, and 20C have a round-trip frequency transfer function (G) for canceling the frequency characteristic that has changed due to replacement of the steam pressure detector or deterioration over time, or replacement of the turbine control device itself. A signal obtained by multiplying the input steam pressure signals A1, B1, and C1 by the one-round frequency transfer function (G) is output as steam pressure signals A2, B2, and C2.

  Therefore, the steam pressure signals A2, B2, and C2 output from the frequency characteristic adjusting devices 20A, 20B, and 20C affect the frequency characteristics that have changed due to replacement of the steam pressure detector or aging, or replacement of the turbine control device itself. The signal is not received.

  Steam pressure signals A2, B2 and C2 output from the frequency characteristic adjusting devices 20A, 20B and 20C, respectively, are input to the next-stage pressure control devices 9A, 9B and 9C, respectively.

  The pressure control signals V9A, V9B, and V9C output from the pressure control devices 9A, 9B, and 9C are input to the intermediate value selector 10, and an intermediate value signal among the three signals is output as V10. Input to the adjustment device 11.

  FIG. 2 is a configuration diagram illustrating an example of the frequency characteristic adjusting device 20, and illustrates the A-system frequency characteristic adjusting device 20A as a representative.

The one-round frequency transfer function G of the frequency characteristic adjusting device 20A is composed of a first-order lag element represented by K / (1 + Ts), and the one-round frequency characteristic can be adjusted by adjusting the time constant T. It has become. K is a gain constant, and s is a Laplace operator.

  As described above, according to the first embodiment, only the characteristics relating to the detection of the steam pressure signals A1, B1, and C1 detected by the steam pressure detectors 7A, 7B, and 7C are investigated and compared, and the change is detected. Even if there is a replacement of the steam pressure detector or aged deterioration or replacement of the turbine control device itself by setting the canceling characteristics in the frequency characteristic adjusting devices 20A, 20B and 20C newly provided in the turbine control device 8. As a result, it is possible to ensure controllability equivalent to that at the time of power plant construction.

[Embodiment 2]
Next, the turbine control apparatus according to the second embodiment will be described with reference to FIG.
In the second embodiment, a test signal output means 30 surrounded by a two-dot chain line frame is added to the signal circuit 13 that connects the steam valve control device 12 and the steam control valve 4 of the conventional system shown in FIG. The other devices are the same as the conventional configuration shown in FIG.

  The test signal output means 30 added in the second embodiment is a test signal generator that generates a high-frequency signal as a test signal (known signal) compared to the fluctuation during normal operation of the steam flow rate introduced into the steam turbine 5. 31 and a signal switching device 32 for inputting two signals of the test signal and the opening command signal V12 output from the steam valve control device 12, and selecting and outputting one of the signals based on the switching command. .

  In the second embodiment, when investigating changes in characteristics of the steam pressure signals A1, B1, and C1, the steam control is performed by operating the signal switch 32 and replacing the known high-frequency test signal V31 with the opening command signal V12. The valve 4 is output. As a result, the steam control valve 4 repeatedly opens and closes the valve opening at a high speed while the test signal V31 is supplied from the signal switcher 32. As a result, the steam pressure supplied to the steam turbine 5 can be vibrated. it can.

  Thus, according to the second embodiment, by adding the test signal output means 30 to the signal circuit 13 that connects the steam valve control device 12 and the steam control valve 4, the valve opening degree of the steam control valve 4 is reduced. It is possible to investigate the frequency characteristics of the main steam system by repeatedly opening and closing at high speeds and vibrating the steam pressure of the main steam system. Thereby, it is possible to easily investigate the frequency characteristic change of the main steam system of the existing power plant.

[Embodiment 3]
Hereinafter, the turbine control device according to the third embodiment will be described with reference to FIG.
The third embodiment is an embodiment for achieving the same object as that of the second embodiment of FIG. 3, and the difference from the second embodiment of FIG. 3 is illustrated in the preceding stage of the pressure control devices 9A, 9B and 9C. The frequency characteristic adjusting device 20 added in 1 is provided.

  That is, in the third embodiment, in the system of the first embodiment shown in FIG. 1, the test signal output means surrounded by a two-dot chain line frame is connected to the signal circuit 13 that connects the steam valve control device 12 and the steam control valve 4. 30 is added, and the other apparatus is the same as that shown in FIG.

  In the case of the third embodiment, similarly to the second embodiment described above, when investigating the change in characteristics of the steam pressure signals A1, B1, and C1, the signal switch 32 is operated to open the known high-frequency test signal V31. Instead of the degree command signal V12, the steam control valve 4 is output. As a result, the steam control valve 4 repeatedly opens and closes the valve opening at a high speed while the test signal V31 is supplied from the signal switcher 32. As a result, the steam pressure supplied to the steam turbine 5 can be vibrated. it can.

  Thus, according to the third embodiment, by adding the test signal output means 30 to the signal circuit 13 that connects the steam valve control device 12 and the steam control valve 4, the valve opening degree of the steam control valve 4 is reduced. It is possible to investigate the frequency characteristics of the main steam system by repeatedly opening and closing at high speeds and vibrating the steam pressure of the main steam system. Thereby, it is possible to easily investigate the frequency characteristic change of the main steam system of the existing power plant.

[Embodiment 4]
Hereinafter, the turbine control device according to the fourth embodiment will be described with reference to FIG.
In the fourth embodiment, the setting value of the frequency characteristic adjusting device 20 added in the first embodiment of FIG. 1 is automatically set based on the result of investigation by the known test signal V31 added in the third embodiment of FIG. The other devices are the same as those shown in FIG. Although there are three systems of steam pressure signals A1, B1 and C1, since all three systems are the same, FIG. 5 shows the steam pressure signal of system A as a representative.

  In the fourth embodiment, when the signal switch 32 is switched and the test signal V31 output from the test signal generator 31 is selected as the opening command signal to the steam control valve 4, the pressure signal A2 and The test signal V31 is input to the set value calculation means 40.

  Since the steam pressure signal A1 detected by the steam pressure detector 7A varies when the test signal V31 is given to the steam control valve 4, the pressure signal A2 output from the frequency characteristic adjusting device 20A is the steam pressure. It vibrates corresponding to the signal A1.

  The set value calculation means 40 compares both the pressure signal A2 and the test signal V31, calculates a set value A5 that is optimal for the frequency characteristic adjustment device 20A, and inputs this to the frequency characteristic adjustment device 20A, thereby inputting the frequency characteristic. The setting of the adjusting device 20 is automatically changed.

  As described above, according to the fourth embodiment, it is possible to reduce the test time, reduce the characteristic change, and improve the control quality by automatically detecting and automatically setting the characteristic change of the power plant. it can.

  In the above-described first to fourth embodiments, the example in which the steam pressure detector to the pressure control device are tripled has been described. However, since multiplexing is not the gist of the present invention, the steam pressure detector to the pressure control device. A single system may be used.

DESCRIPTION OF SYMBOLS 1 ... Steam generator, 2 ... Main steam system piping, 3 ... Main steam stop valve, 4 ... Steam control valve, 5 ... Turbine, 6 ... Generator, 7A, 7B, 7C ... Steam pressure detector, 8 ... Turbine control 9A, 9B, 9C ... pressure control device, 10 ... intermediate value selector, 11 ... pressure control adjustment device, 12 ... steam valve control device, 13 ... signal circuit, 20A, 20B, 20C ... frequency characteristic adjustment device, 30 ... test signal output means, 31 ... test signal generator, 32 ... signal switcher, 40 ... set value calculation means.

Claims (4)

The steam generated by the steam generator is supplied to the steam turbine through the main steam stop valve and the steam control valve provided in the main steam system piping, and is provided in the power plant that drives the generator,
A steam pressure detector installed in the main steam system pipe;
A pressure control device that outputs a pressure deviation signal between the steam pressure signal detected by the steam pressure detector and the pressure set value as a pressure control signal;
A pressure control adjustment device that performs advance / lag compensation calculation after attenuating a specific frequency in the pressure control signal, and further outputs a steam valve opening command by multiplying the gain,
A steam valve control device that outputs an opening command signal for adjusting the opening of the steam control valve based on the steam valve opening command output from the pressure control adjustment device;
In a turbine control device comprising:
The turbine control device is provided with a frequency characteristic adjusting device having a first-order lag element, and by adjusting the time constant of the first-order lag element, a signal for canceling the frequency characteristic change of the steam pressure signal is output. A turbine control device characterized by that.   The turbine control device according to claim 1, wherein the frequency characteristic adjusting device is provided between the steam pressure detector and the pressure control device.   A test signal output for investigating the frequency characteristics of the steam pressure signal by switching the opening command signal to a test signal to a signal circuit for transmitting the opening command signal from the steam valve control device to the steam control valve 3. The turbine control device according to claim 1, further comprising means.   Setting value calculating means for comparing the pressure signal output from the frequency characteristic adjusting device and the test signal output from the test signal output means to calculate the optimum setting value of the frequency characteristic adjusting device is provided. 4. The turbine control device according to claim 3, wherein the setting of the frequency characteristic adjusting device is automatically changed according to a setting value output from the calculating means.

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