JP2012246889A - Turbine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbine control device configured to improve flexibility and controllability of an integrated power supply in increase of distributed power supplies, and maintain continuity of regulator valve control and stably maintain the power generation output and the system to be controlled even when a plurality of speed regulation rates are switched during a system parallel operation.SOLUTION: A turbine control device includes: a speed regulation rate function generator that receives a turbine rotational speed deviation to obtain an opening command value; and a load setting device that applies a load command value. The control device uses an addition signal of the opening command value and the load command value as a governor command value, and controls the valve opening of a steam regulator valve at an entrance of a turbine. The turbine control device includes: a plurality of speed regulation rate function generators that apply different speed regulation rates, in which a turbine rotational speed deviation is input to obtain an opening command value; a switching device for selecting one of the speed regulation rate function generators; a correction signal storage circuit storing a difference, as a correction signal, in output of the switching device before and after selecting the output by the switching device; and a load setting device for obtaining a load command value as a sum of the correction signal in the correction signal storage circuit and a load request signal. Variations in the governor command value are suppressed before and after the switching device selects an output.

Description

  The present invention relates to a turbine control device, and more particularly, to a turbine control device that has a plurality of nonlinear speed regulation rates and is used by switching according to the operation status of a power system.

  In a turbine that is operating in parallel with the system, an important factor for controlling the opening of the adjusting valve is a speed regulation rate. In general, when a rotational speed deviation that exceeds the speed regulation rate occurs, the control valve is controlled to fully open or close, and conversely, if the deviation does not exceed the speed regulation rate, the control valve is proportional to the deviation. Control is performed so that the opening degree is reached.

  As a speed regulation rate used for such control, a single speed regulation rate has conventionally been provided, but in situations where responsiveness is required, such as when the load is interrupted, the speed is rapidly accelerated and decelerated. It was difficult to control thermal power plants. In other words, if a single speed regulation rate is set to a suitable speed regulation rate during normal system parallel operation, the speed regulation rate remains the same, for example, when a load response is required. Difficult to fit.

  For this reason, a plurality of speed regulation rates or nonlinear speed regulation rate functions have been used. Thereby, it is possible to provide a speed regulation rate suitable for normal system parallel operation and a speed regulation rate suitable for load interruption. Patent Document 1 provides means for switching the speed regulation rate at the time of load interruption and at the time of system parallel operation in order to stably control the thermal power plant at the time of load interruption.

Japanese Patent Laid-Open No. 9-25805

  By the way, many distributed power sources have been installed in recent power systems. As a role that the thermal power plant should play against the configuration change of the power system, it is one aspect to stably control the thermal power plant at the time of load interruption as in Patent Document 1, but the normal system parallel operation state However, it is necessary to contribute to system fluctuations according to the operating state of the distributed power source.

  In consideration of stably performing normal system parallel operation in an electric power system having a large number of distributed power sources, using a single nonlinear speed regulation rate function as a thermal power plant as in Patent Document 1 It is not desirable in terms of stable power supply because it cannot maintain flexibility such as contribution as a centralized power source.

  In contrast, a thermal power plant does not have a single nonlinear speed regulation rate function, but has a plurality of nonlinear speed regulation rate functions, which can be switched and used in normal system parallel operation. Conceivable.

  For example, when the generated power from a distributed power source is unstable, the thermal power plant uses a nonlinear speed regulation rate function that generates a large speed regulation rate as a thermal power plant. It is conceivable to operate to make up aggressively and quickly.

  On the other hand, when the power generated from the distributed power source is stable, thermal power generation can be achieved by using a relatively small speed setting rate or a nonlinear speed setting rate function with a dead band near the rated speed as a thermal power plant. As a plant, it is conceivable to supply a certain amount of power stably and maintain the system stably.

  However, when operating with multiple speed regulation rates switched during system parallel operation, the governor signal suddenly changes due to the discontinuity of the speed regulation rate at the moment of switching, and the accompanying change in the opening of the regulator valve. A change in the turbine rotation speed and a change in the system frequency due to this change occur, making it difficult to maintain the system.

  The present invention maintains the continuity of the control valve to be controlled even when switching multiple speed regulation rates during system parallel operation for the purpose of improving the flexibility and controllability of the centralized power supply accompanying the increase in distributed power supply in the future. Then, it aims at providing the control apparatus of the turbine which maintains the electric power generation output and system | strain of control object stably.

  In order to achieve the above object, in the present invention, a settling rate function generator that obtains an opening command value by inputting a turbine rotational speed deviation, a load setting device that gives a load command value, an opening command value, and a load command value In a turbine control device that controls the valve opening of the steam control valve at the turbine inlet using the added signal of governor as a governor command value, multiple settling rate functions are generated that give different settling rates to obtain the opening command value using the turbine rotation speed deviation as an input , A switch for selecting one of the outputs of a plurality of settling rate function generators, a correction signal storage circuit for storing a difference between the switch output before and after output selection by the switch as a correction signal, and a correction signal A load setting unit that obtains a load command value as the sum of the correction signal of the memory circuit and the load request signal is provided, and fluctuations in the governor command value are suppressed before and after output selection by the switch.

  Further, the switching operation for selecting one of the outputs of the plurality of settling rate function generators is executed in the normal operation state of the turbine.

  Further, a load request command is generated by using a target value of the generator output, a first control circuit that determines a load request command according to the detected difference between the generator outputs, and the target value and load command value of the generator output. A second control circuit that determines the output of the first control circuit as a load request command before the output is selected by the switch, and the output of the second control circuit is the load request command after the output is selected by the switch Stipulated in

  In order to achieve the above object, in the present invention, a settling rate function generator that obtains an opening command value by inputting a turbine rotational speed deviation, a load setting device that gives a load command value, an opening command value, and a load command value In a turbine control device that controls the valve opening of the steam control valve at the turbine inlet using the added signal of governor as a governor command value, multiple settling rate functions are generated that give different settling rates to obtain the opening command value using the turbine rotation speed deviation as an input , A switch for selecting one of the outputs of a plurality of settling rate function generators, a correction signal storage circuit for storing a difference between the switch output before and after output selection by the switch as a correction signal, and a correction signal A load setting unit that obtains a load command value as a sum of a correction signal of the storage circuit and a load request signal, and a first control circuit that determines a load request command according to a difference between the target value of the generator output and the detected generator output And the generator A second control circuit that determines a load request command using the force target value and the load command value, and an output of the first control circuit is determined as a load request command before output selection by the switch, and output by the switch After selection, the output of the second control circuit is determined as a load request command.

  According to the present invention, even when a plurality of speed regulation rates are arbitrarily switched during system parallel operation according to the system side request, it is possible to prevent sudden change of the adjusting valve accompanying the switching of the speed regulation rate function. Stable plant control according to the supply and demand of the system can be realized, and the power system can be stably operated.

The figure which shows the structure of the turbine control apparatus by the Example of this invention. The figure which shows the structure of the function selector. The figure which shows the function of the settling rate function generator 2. FIG. The figure which shows the function of the adjustment rate function generator 3. FIG. The figure which shows the function of the adjustment rate function generator 4. FIG. The figure which shows the function of the adjustment rate function generator 5. FIG. The figure which shows each signal at the time of switching from speed regulation rate function 2 to 3. The figure which shows the change of each signal at the time of switching from speed regulation rate function 3 to 2. The figure which shows the structure of the turbine control apparatus by 2nd Example of this invention. The figure which shows the principal part of the circuit structure of the boiler control apparatus of a 2nd Example. The figure which shows each signal at the time of switching from speed regulation rate function 2 to 3 in 2nd Example. The figure which shows each signal at the time of switching from speed regulation rate function 3 to 2 in 2nd Example.

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

  FIG. 1 shows the configuration of the turbine control device in the present embodiment. The turbine control device 201 controls the opening degree of, for example, four sets of steam control valves 25 to 28 provided in the steam introduction portion of the turbine 30. The amount of driving steam introduced from the boiler 20 to the turbine 30 is adjusted by the steam control valves 25 to 28 whose opening degree is adjusted. The generator 29 is driven by the turbine 30.

  The turbine control device 201 inputs the turbine rotational speed 101 detected by the rotational speed detector 31, and finally gives an opening degree command signal 110-113 to the steam control valves 25-28. For this purpose, the turbine control device 201 includes a rated speed setting device 1, a speed regulation command calculation circuit 202, a load setting circuit 203, a load limiter 10, a low value selection circuit 11, and an adjustment valve opening command device 12-15. Prepare. The detailed circuit configuration and operation of each unit will be described below.

  First, the speed regulation command calculation circuit 202 includes a regulation rate function generators 2 to 5, a switch 6, a function selector 7, and a selection signal generation circuit 8. The speed regulation rate calculation circuit 202 receives a rotational speed deviation 102 which is a difference between the turbine rotational speed 101 and the rated rotational speed setter 1.

  The rotational speed deviation 102 is input to the settling rate function generators 2 to 5 illustrated in FIGS. 3 to 6. Each of the functions of the settling rate function generators 2 to 5 in FIGS. 3 to 6 shows the rotational speed deviation 102 (x [rpm]) on the horizontal axis and the output f (x) on the vertical axis.

  The function of each settling rate function generator will be briefly described. The function of the settling rate function generator 2 in FIG. 3 gives an output f1 (x) proportional to the input x in all regions, and the gain at that time is For example, 0.67.

  The function of the settling rate function generator 3 in FIG. 4 is an output f2 (x) that does not output when the input x is within 10 [rpm], but gives a proportional output when the input x exceeds 10 [rpm]. . In this function, a dead zone is set in a region where the rotational speed deviation 102 is smaller than ± 10 [rpm], and speed control is not executed.

  The functions of the settling rate function generators 4 and 5 in FIGS. 5 and 6 give outputs f3 (x) and f4 (x) corresponding to the input x in all regions, but the rotational speed deviation 102 is ± 10 [rpm ] In a region smaller than] is kept low.

  These functions are switched and used in accordance with appropriate conditions in the normal system parallel operation state. For example, when governor-free operation is performed in which the engine speed response 102 is positively responded and contributes to the stabilization of the power system, it is preferable to select the function of the regulation rate function generator 2 in FIG. Further, when performing the base load operation, it is preferable not to respond to the fluctuation of the rotational speed deviation 102 as a function of the settling rate function generator 3 of FIG.

  A signal obtained by applying the speed deviation signal 102 to the functions of the regulation rate function generators 2 to 5 of FIGS. 3 to 6 described above is given to the switch 6 of the speed regulation command calculation circuit 202. In the switch 6, one of the outputs of the plurality of settling rate function generators is selected by the output of the function selector 7, and this is set as the opening command value 103.

  The selection signal generation circuit 8 operates to give an output when changing the settling rate function according to an appropriate condition in a normal system parallel operation state. Based on the output of the selection signal generation circuit 8, the function selector 7 operates the switch 6 to newly determine the opening command value 103 and responds to the change in the opening command value 103 during the function switching transition. The correction signal 104 for suppressing the fluctuation is output.

  FIG. 2 shows a detailed configuration of the function selector 7. The function selector 7 includes a function storage circuit 71, a correction signal calculation circuit 72, and a previous selection function storage circuit 73. The function selector 7 receives the rotation speed deviation signal 102 and the selection signal from the selection signal generation circuit 8, gives a switching signal to the switching device 6, and gives a correction signal to the subsequent load setting circuit 203.

  The function storage circuit 71 stores one of the functions of the settling rate function generators 2 to 5, and stores one settling rate function Kn, which means the selection signal obtained from the selection signal generation circuit 8, and corrects the correction signal. The result is output to the arithmetic circuit 72. As a result, the function storage circuit 71 stores a new settling rate function after switching the settling rate function.

  On the other hand, the previous selection function storage circuit 73 stores the settling rate function Ko selected by the output of the switching signal generation circuit 8 one time before. The previous selection function storage circuit 73 outputs the previously selected settling rate function Ko to the correction signal calculation circuit 72 based on the output of the selection signal generation circuit 8 and the settling rate function output from the correction signal calculation circuit 72. Store Kn.

  The correction signal calculation circuit 72 uses the output Kn of the function storage circuit 71, the output Ko of the previous selection function storage circuit 73, and the rotation speed deviation 102 to calculate the rotation speed deviation 102 of the function output to the previous selection function storage circuit 73. A value generated by the difference between the output value and the output value in the rotation speed deviation 102 of the function output from the function storage circuit 71 is output as the correction signal 104. In addition, the correction signal calculation circuit 72 outputs the settling rate function Kn selected this time to the previous selection function storage circuit 73, and stores this to be used as the previous selection function at the next switching.

  Specific operations of the correction signal calculation circuit 72 will be described with specific numerical values. For example, the function Ko previously stored in the selected function storage circuit 73 is FIG. 6, the function Kn newly stored in the function storage circuit 71 is FIG. 3, and the rotational speed deviation 102 is 10 [rpm]. , The output (3.35) as a difference between the output (3.35) obtained from the function Ko in FIG. 6 and the output (6.7) obtained from the function Kn in FIG. 3 is corrected. It means that the correction signal 104 is output from the signal arithmetic circuit 72.

  The opening command value 103 and the correction signal 104 obtained by the speed control command calculation circuit 202 are given to the load setting circuit 203 at the next stage.

  The load setting circuit 203 in FIG. 1 includes a correction signal storage circuit 16, a load setting device 9, and an addition circuit. Among these, the correction signal storage circuit 16 stores and holds the one-shot correction signal 104 generated at the moment of function switching and supplies it to the load setting device 9. The load setter 9 receives the plant power generation output command (load request command) 121 and the stored value of the correction signal 104 and performs an operation of outputting the load command value 105. For example, in the previous example, when the function is switched from FIG. 6 to FIG. 3, the output (3.35) given as the difference is received as the one-shot correction signal 104 and added to the plant power generation output command 121. To give a load command value 105. Thereafter, the load setting circuit 203 outputs a value generated as the sum of the opening command value 103 and the load command value 105 from the load setting device 9 as the governor command value 106.

  The low value selection circuit 204 selects a lower value from the governor command value 106 and the output of the load limiter 10 and outputs it to the control valve opening command devices 12 to 15.

  The regulating valve opening commanders 12 to 15 calculate the regulating valve opening commands 110 to 113 from the output of the low value selection circuit 204 and output them to the steam regulating valves 25 to 28.

As described above, FIGS. 3 to 6 show the functions of the respective settling rate function generators in this embodiment. In either case, an output obtained by multiplying the speed regulation rate f _n (x) (n is the number of the regulation rate function) in accordance with the rotational speed deviation 102 indicated by x in the figure.

  Next, in the turbine control device shown in FIGS. 1 and 2, the change of each signal when the function of the settling rate function generator 2 is switched to the function of the settling rate function generator 3 is shown in FIG. This will be described using a chart. However, the rated speed setting device 1 shall give a signal rated at 3000 [rpm] (system frequency reference 50 [Hz]).

  In this figure, signals of respective parts from the upstream to the downstream of the control flow of FIG. 1 are sequentially described from the lower side to the upper side of FIG. As the signal of each part, the turbine speed 101, the regulation rate function output 103, the correction signal 104, the load setting signal 105, the governor command value 106, the control valve opening command 110-113, and the generator output 206 are displayed.

  Also, in this figure, the rated rotational speed operation (3000 [rpm]) by the settling rate function 2 is performed before the time t1 shown on the horizontal axis, and the turbine rotational speed 101 by the settling rate function 2 is 3000 [rpm] between the times t1 and t2. ] From 2990 [rpm] to 1090 [rpm], a transient state before time t3 (2990 [rpm]) operating speed reduction by the settling rate function 2, and a switching transient state by the settling rate function 3 after time t3, The driving | running state by the subsequent settling rate function 3 is shown.

  In the operating state before time t1, the turbine speed 101 is at the rated 3000 [rpm], and the signals of the other parts are stably kept constant. For example, it is assumed that the settling rate function output 103 and the correction signal 104 hold 0%, and the load setting signal 105, the governor command value 106, and the control valve opening command 110-113 maintain 50%.

  Hereinafter, the control and the results will be described in time series. First, when the turbine speed 101 decreases from 3000 [rpm] to 2990 [rpm] from time t1 to time t2 by 10 [rpm], it is proportional to the speed deviation 102 by the settling rate function 2 selected at this time. As a result, the opening command value 103 increases by 6.7%. Further, the governor command value 106 is increased by the increase in the opening command value 103 (the value that was 50.0% at the time t1 is increased by 6.7% to 56.7% at the time t2). Further, the control valve opening commands 110 to 113 and the generator output 206 are increased. At this time, since the switching has not occurred, the correction signal 104 does not increase or decrease.

  Between times t2 and t3, the turbine rotation speed 101 is stable at approximately 2990 [rpm] and does not fluctuate, and thus the stable operation state by the settling rate function 2 is continued. In this state, the opening command value 103 is generally maintained at 6.7% and the governor command value 106 is maintained at 56.7%.

  On the other hand, at time t3, the selection signal in FIG. 2 was changed for some reason, and switching from the settling rate function 2 to the settling rate function 3 was executed. In this case, the circuit of FIG. 2 receives the output (selection signal) of the selection signal generation circuit 8, and the function storage circuit 71 outputs the output of the new settling rate function 3 to the correction signal calculation circuit 72. At the same time, the previous selection function storage circuit 73 outputs the output of the conventional regulation rate function 2 to the correction signal calculation circuit 72. The correction signal calculation circuit 72 performs the calculation as described above from the rotation speed deviation 102 and the settling rate functions 2 and 3 at time t3, and the one-shot generated at the moment of function switching generated by the correction signal calculation circuit 72. The correction signal 104 is output.

  In this case, the opening command value 103 by the settling rate function 2 before switching is 6.7%, but after switching, the opening command value 103 by the settling rate function 3 becomes 0%. Further, from this, a signal corresponding to 6.7% is obtained as the correction signal 104.

  As a result, the opening command value 103 which is one input of the adder of the load setting circuit 203 in FIG. 1 is decreased by 6.7%, while the load setting signal 105 which is the other input of the adder is 6 Will increase by .7%, and as a result, the adder output will not fluctuate.

  In this way, the load setting circuit 203 outputs the value generated by the sum of the correction signal 104 and the load setting signal 105 as the governor command value 106, and then continues operation. That is, the correction signal 104 generated by the switching of the settling rate function changes in a manner reflected in the load setting signal 105 of the load setting device 9, and thereafter, the control is continued without changing as the governor command value 106. The This means that even if a plurality of speed regulation rates are switched during system parallel operation, switching is possible without affecting the generator output.

  Next, in the turbine control device shown in FIGS. 1 and 2, the change of each signal when the function of the settling rate function generator 3 is switched to the function of the settling rate function generator 2 is shown in FIG. This will be described using a chart. However, since the description and explanation premise of the chart of FIG. 8 are the same as those of FIG. 7, main differences will be described.

  In this figure, the rated rotational speed operation (3000 [rpm]) using the settling rate function 3 is performed before time t1 shown on the horizontal axis, and the turbine rotational speed 101 based on the settling rate function 3 is set to 3000 [rpm] between time t1 and t2. 2990 [rpm] is a transient state that is reduced by 10 [rpm], before the time t3, the speed is reduced by the settling rate function 3 (2990 [rpm]), after the time t3, the switching transient state is set by the settling rate function 2, and thereafter The operation state by the settling rate function 2 is shown.

  In the operating state before time t1, the turbine speed 101 is at the rated 3000 [rpm], and the signals of the other parts are stably kept constant. For example, it is assumed that the settling rate function output 103 and the correction signal 104 hold 0%, and the load setting signal 105, the governor command value 106, and the control valve opening command 110-113 maintain 50%.

  Hereinafter, the control and the results will be described in time series. First, from time t1 to time t2, the turbine rotational speed 101 decreases by 10 [rpm] from 3000 [rpm] to 2990 [rpm]. The settling rate function 3 selected at this time is ± 10 [rpm]. Therefore, even if a speed deviation occurs, the output remains 0% and does not change. The output of the regulation rate function 2 selected later has a value of about 6.7% in proportion to the rotational speed deviation 102. However, since it is not selected in this state, it is indicated by a dotted line in FIG. It is described. For this reason, the other signals are not changed until time t3, and the previous state is maintained.

  On the other hand, at time t3, the selection signal in FIG. 2 is changed for some reason, and switching from the settling rate function 3 to the settling rate function 2 is executed. In this case, the circuit of FIG. 2 receives the output (selection signal) of the selection signal generation circuit 8, and the function storage circuit 71 outputs the output of the new settling rate function 2 to the correction signal calculation circuit 72. At the same time, the previous selection function storage circuit 73 outputs the output of the conventional regulation rate function 3 to the correction signal calculation circuit 72. The correction signal calculation circuit 72 performs the calculation as described above from the rotational speed deviation 102 at time t3 and the settling rate functions 2 and 3, and the one-shot generated at the moment of function switching generated by the correction signal calculation circuit 72. The correction signal 104 is output.

  In this case, the opening command value 103 based on the settling rate function 3 before switching is 0%, but after switching, the opening command value 103 based on the settling rate function 2 is 6.7%. In addition, from this, a signal corresponding to −6.7% is obtained as the correction signal 104.

  As a result, the opening command value 103 which is one input of the adder of the load setting circuit 203 of FIG. 1 is increased by 6.7%, while the load setting signal 105 which is the other input of the adder is 6 Will be reduced by .7%, resulting in no change in the adder output.

  In this way, the load setting circuit 203 outputs the value generated by the sum of the correction signal 104 and the load setting signal 105 as the governor command value 106, and then continues operation. That is, the correction signal 104 generated by the switching of the settling rate function changes in a manner reflected in the load setting signal 105 of the load setting device 9, and thereafter, the control is continued without changing as the governor command value 106. The This means that even if a plurality of speed regulation rates are switched during system parallel operation, switching is possible without affecting the generator output.

  FIG. 9 shows a modified embodiment of the circuit of FIG. In this example, a turbine control device 201 and a boiler control device 21 are provided, and so-called turbine follow-up control is performed. In the case of the turbine follow-up control, the boiler control device 21 obtains a target signal for the amount of power that should be borne by the power plant in accordance with the system frequency command 124 given from the central power supply command station 22, and the boiler according to the target signal. 20 is controlled.

  Further, the boiler control device 21 determines a load request command 121 to be given to the load setting device 9 of the turbine control device 201. The circuit of FIG. 10 omits the description of the circuit part for controlling the boiler 20 in the circuit configuration of the boiler control device 21 and describes only the circuit part for determining the load request command 121 to be given to the load setting device 9. .

  In the boiler control device 21 of FIG. 10, two sets of control systems for determining a load request command 121 to be given to the load setting device 9 are switched and used. The first control system is the generator output control in the normal control, and the second control system is the generator output control when the settling rate is changed.

  First, generator output control in normal control will be described. Here, the target generator output setting unit 212 gives the target value P0 of the generator output. This value corresponds to a target signal of the amount of power that should be borne by the power plant, which is determined according to the system frequency command 124 given from the central power feeding command station 22. The generator output correction signal ΔP0 is added to the target signal P0. The generator output correction signal ΔP0 is obtained by converting the opening degree command value 103 of FIG. 9 into the system frequency control deviation amount Δf by the conversion circuit 18 and further converting it to the generator output by the frequency fluctuation correction circuit 211 of FIG. It is a thing. Therefore, the output of the addition circuit AD1 can be said to be a signal in which the power generation correction amount ΔP0 determined by the short-cycle speed change signal in the turbine governor control is added to the target power generation amount P0 determined by the long-cycle system frequency command 124. .

  In the generator output control in the normal control, the deviation signal is obtained by the addition circuit AD2 using the output of the addition circuit AD1 as a target signal, the turbine generator output 122 as a feedback signal, and the load request command 121 is determined by the proportional integration control circuit 213. To do.

  In the generator output control which is the second control system, when the one-shot correction signal 104 when the regulation rate fluctuation occurs is given, the output of the adder circuit AD1 is used as a target signal, and the load command value 105 is fed back. A deviation signal as a signal is input to the proportional integration control circuit 213 to determine the load request command 121.

  As can be inferred from the above description of FIGS. 9 and 10, according to this circuit configuration, the load command value 105 normally executes control determined by the first control system, and one-shot at the time of transition of the regulation rate switching. The fluctuation of the opening command value 103 is canceled by the correction signal 104, and thereafter, the process smoothly shifts to the generator output control by the second control system. The fact that the above results are obtained by the control system of FIGS. 9 and 10 will be described with reference to the time charts of FIGS.

FIG. 11 shows changes in respective signals when switching from the function of the settling rate function generator 2 to the function of the settling rate function generator 3 in the turbine control device of FIG. 9.
However, in FIG. 11, the system frequency control deviation amount 123 and the load request command 121 are newly added. However, since the other charts are described and explained in the same manner as in FIG. The point will be described.

  In this figure, the rated rotational speed operation (3000 [rpm]) using the settling rate function 2 is performed before the time t1 shown on the horizontal axis, and the turbine rotational speed 101 based on the settling rate function 2 is set to 3000 [rpm] between the times t1 and t2. 2990 [rpm] is a transient state that is reduced by 10 [rpm], before the time t3, the speed is reduced by the settling rate function 2 (2990 [rpm]), after the time t3, the switching transient state is set by the settling rate function 3, and thereafter The operation state by the settling rate function 3 is shown.

  In the operating state before time t1, the turbine speed 101 is at the rated 3000 [rpm], and the signals of the other parts are stably kept constant. For example, it is assumed that the settling rate function output 103 and the correction signal 104 hold 0%, and the load setting signal 105, the governor command value 106, and the control valve opening command 110-113 maintain 50%. Further, the system frequency control deviation amount 123 is set to 0% because the settling rate function output 103 that is the input holds 0%. Moreover, the load request | requirement instruction | command 121 which the boiler control apparatus 21 gives shall be hold | maintained at 50%.

  Hereinafter, the control and the results will be described in time series. First, when the turbine speed 101 decreases from 3000 [rpm] to 2990 [rpm] from time t1 to time t2 by 10 [rpm], it is proportional to the speed deviation 102 by the settling rate function 2 selected at this time. As a result, the opening command value 103 increases by 6.7%. On the other hand, in the boiler control device 21, the system frequency control deviation amount 123 decreases in response to the fluctuation of the opening command value 103, but this magnitude is about 0.167 Hz with respect to the rated frequency (for example, 50 Hz). Therefore, in response to this, the proportional integration control circuit 213 controls the load request command 121 in a decreasing direction. However, since this magnitude is sufficiently small compared to the fluctuation from the settling rate function 2, the entire control system Increases the governor command value 106 by the increment of the opening command value 103 (which was 50.0% at time t1, but increased by 6.7% to 56.7% at time t2), Increase / decrease valve opening degree commands 110 to 113, and hence the generator output 206 is increased. At this time, since the switching has not occurred, the correction signal 104 does not increase or decrease.

  Between times t2 and t3, the turbine speed 101 slightly fluctuates at about 2990 [rpm], and the operation state by the settling rate function 2 is continued. In this state, the opening command value 103 is generally maintained at 6.7% and the governor command value 106 is maintained at 56.7%. The system frequency control deviation amount 123 fluctuates corresponding to the settling rate function output 103 that is the input.

  On the other hand, at time t3, the selection signal in FIG. 2 was changed for some reason, and switching from the settling rate function 2 to the settling rate function 3 was executed. In this case, the circuit of FIG. 2 receives the output (selection signal) of the selection signal generation circuit 8, and the function storage circuit 71 outputs the output of the new settling rate function 3 to the correction signal calculation circuit 72. At the same time, the previous selection function storage circuit 73 outputs the output of the conventional regulation rate function 2 to the correction signal calculation circuit 72. The correction signal calculation circuit 72 performs the calculation as described above from the rotational speed deviation 102 and the settling rate functions 2 and 3 at time t3, and outputs a one-shot correction signal 104 generated at the moment of function switching.

  In this case, the opening command value 103 by the settling rate function 2 before switching is approximately 6.7%, but after switching, the opening command value 103 by the settling rate function 3 becomes 0%. Further, from this, a signal corresponding to 6.7% is obtained as the correction signal 104.

  Before and after this switching, the control in the boiler control device 21 is controlled by the first control system as described with reference to FIG. 10 (proportional with the output of the adder AD1 as the target value and the generator output 122 as the feedback signal). (Integral control) is switched to control determined by the second control system (proportional integral control using the output of the adder AD1 as a target value and the load command value 105 as a feedback signal), according to the integral time constant of the proportional integral control circuit 213. The time changes in the direction in which the difference between the two control systems converges.

  Accordingly, the change in the load command value 105 at the instant of switching is only a signal corresponding to −6.7% of the one-shot correction signal. As a result, the governor command value 106 is opened by the one-shot correction signal 104. The change of the degree command value 103 is canceled and does not change before and after switching.

  As the output of the load command value 105 after switching, the output of the addition circuit AD1 in FIG. 10, that is, the power generation amount target signal is given. For this reason, the power generation output does not change before and after time t3, and as a result, the governor command value 106 does not change.

  In this way, the load setting circuit 203 outputs the value generated by the sum of the correction signal 104 and the load setting signal 105 as the governor command value 106, and then continues operation. That is, the correction signal 104 generated by the switching of the settling rate function changes in a manner reflected in the load setting signal 105 of the load setting device 9, and thereafter, the control is continued without changing as the governor command value 106. The This means that even if a plurality of speed regulation rates are switched during system parallel operation, switching is possible without affecting the generator output.

FIG. 12 shows changes in signals of the respective parts when switching from the function of the settling rate function generator 3 to the function of the settling rate function generator 2 in the turbine control device of FIG. 9.
However, in FIG. 12, the system frequency control deviation amount 123 and the load request command 121 are newly added. However, the other charts are described in the same manner as in FIG. The point will be described.

  In this figure, the rated rotational speed operation (3000 [rpm]) using the settling rate function 3 is performed before time t1 shown on the horizontal axis, and the turbine rotational speed 101 based on the settling rate function 3 is set to 3000 [rpm] between time t1 and t2. 2990 [rpm] is a transient state that is reduced by 10 [rpm], before the time t3, the speed is reduced by the settling rate function 3 (2990 [rpm]), after the time t3, the switching transient state is set by the settling rate function 2, and thereafter The operation state by the settling rate function 3 is shown.

  In the operating state before time t1, the turbine speed 101 is at the rated 3000 [rpm], and the signals of the other parts are stably kept constant. For example, it is assumed that the settling rate function output 103 and the correction signal 104 hold 0%, and the load setting signal 105, the governor command value 106, and the control valve opening command 110-113 maintain 50%. Further, the system frequency control deviation amount 123 is set to 0% because the settling rate function output 103 that is the input holds 0%. Moreover, the load request | requirement instruction | command 121 which the boiler control apparatus 21 gives shall be hold | maintained at 50%.

  Hereinafter, the control and the results will be described in time series. First, when the turbine rotational speed 101 decreases from 3000 [rpm] to 2990 [rpm] from time t1 to time t2 by 10 [rpm], the rotational speed deviation 102 is set to 10 [ rpm], but the opening command value 103 is maintained at 0%. On the other hand, in the boiler control device 21, the system frequency control deviation amount 123 decreases due to a decrease in the rotational speed, but this magnitude is about 0.167 Hz with respect to the rated frequency (for example, 50 Hz). In response to this, the proportional integration control circuit 213 controls the load request command 121 in the decreasing direction. In response to this, the load setting signal 105 also decreases.

  Between times t2 and t3, the turbine rotation speed 101 slightly fluctuates at about 2990 [rpm], but the opening degree command value 103 is maintained at 0% by the regulation rate function 3. However, in the boiler control device 21, the system frequency control deviation 123 fluctuates in response to a decrease in the rotational speed, and the load request command 121 and the load setting signal 105 are adjusted to correct this.

  On the other hand, at time t3, the selection signal in FIG. 2 is changed for some reason, and switching from the settling rate function 3 to the settling rate function 2 is executed. In this case, the circuit of FIG. 2 receives the output (selection signal) of the selection signal generation circuit 8, and the function storage circuit 71 outputs the output of the new settling rate function 3 to the correction signal calculation circuit 72. At the same time, the previous selection function storage circuit 73 outputs the output of the conventional regulation rate function 2 to the correction signal calculation circuit 72. The correction signal calculation circuit 72 performs the calculation as described above from the rotational speed deviation 102 and the settling rate functions 2 and 3 at time t3, and outputs a one-shot correction signal 104 generated at the moment of function switching.

  In this case, the opening command value 103 based on the settling rate function 3 before switching is approximately 0%, but after switching, the opening command value 103 based on the settling rate function 2 is 6.7%. In addition, from this, a signal corresponding to −6.7% is obtained as the correction signal 104.

  Before and after this switching, the control in the boiler control device 21 is controlled by the first control system as described with reference to FIG. 10 (proportional with the output of the adder AD1 as the target value and the generator output 122 as the feedback signal). (Integral control) is switched to control determined by the second control system (proportional integral control with the output of the adder AD1 as a target value and the load command value 105 as a feedback signal). The time changes in the direction in which the difference between the two control systems converges.

  Accordingly, the change in the load command value 105 at the instant of switching is only a signal corresponding to −6.7% of the one-shot correction signal. As a result, the governor command value 106 is opened by the one-shot correction signal 104. The change of the degree command value 103 is canceled and does not change before and after switching.

  As the output of the load command value 105 after switching, the output of the addition circuit AD1 in FIG. 10, that is, the power generation amount target signal is given. For this reason, the power generation output does not change before and after time t3, and as a result, the governor command value 106 does not change.

  In this way, the load setting circuit 203 outputs the value generated by the sum of the correction signal 104 and the load setting signal 105 as the governor command value 106, and then continues operation. That is, the correction signal 104 generated by the switching of the settling rate function changes in a manner reflected in the load setting signal 105 of the load setting device 9, and thereafter, the control is continued without changing as the governor command value 106. The This means that even if a plurality of speed regulation rates are switched during system parallel operation, switching is possible without affecting the generator output.

  As described above, according to the present invention, the governor command 106 is not changed in accordance with the switching of the setting rate function, and a plurality of nonlinear setting rates can be switched stably.

  In particular, as shown in FIG. 9, in the plant output control in conjunction with the boiler control device 21, the frequency is set for the system frequency tracking command 124 from the central power feeding command 22 and the governor operation according to the speed regulation rate functions 2 to 5. There is also a function for maintaining the specified value (50/60 [Hz]). By combining the system frequency deviation (Δf) control amount 123 of the turbine controller with the boiler control system, the system frequency correction between the turbine and the boiler is performed. Consistent plant output control is possible.

  In each of the embodiments, the example of performing switching between the settling rate functions 2 and 3 has been described. However, the switching pattern is not limited to this, and the above-described series of switching patterns are not limited to this. Stable switching is possible by operation.

  The present invention is useful when switching a plurality of speed regulation rates during system parallel operation for the purpose of improving the flexibility and controllability of a centralized power source accompanying an increase in distributed power sources.

1: Rated speed setting device 2-5: Settling rate function generator 6: Switcher 7: Function selector 8: Selection signal generation circuit 9: Load setting device 10: Load limiter 11: Low value selection circuits 12-15 : Control valve opening command device 18: Conversion circuit 20: Boiler 21: Boiler control device 22: Central power supply command 25 to 28: Steam control valve 29: Generator 30: Turbine 31: Speed detector 71: Function storage circuit 72 : Correction signal calculation circuit 73: Previous selection function storage circuit 101: Turbine speed 102: Speed deviation 103: Opening command value 104: Correction signal 105: Load command value 106: Governor command value 110 to 113: Adjusting valve opening Command 121: Load request command 122: Turbine generator output 123: System frequency control deviation (Δf)
124: System frequency command 201: Turbine controller 202: Speed control command calculation circuit 203: Load setting circuit 204: Low value selection circuit

Claims (4)

A settling rate function generator for obtaining an opening command value by inputting a turbine rotation speed deviation, a load setting device for giving a load command value, and an addition signal of the opening command value and the load command value as a governor command value. In the turbine control device that controls the valve opening degree of the steam control valve,
A plurality of settling rate function generators for providing different settling rates for obtaining an opening command value by inputting a turbine rotation speed deviation; a switch for selecting one of the outputs of the plurality of settling rate function generators; and the switching A correction signal storage circuit for storing a difference between switch outputs before and after the output selection by the detector as a correction signal, and the load for obtaining the load command value as a sum of the correction signal and the load request signal of the correction signal storage circuit A turbine control device comprising: a setting device, wherein fluctuations in the governor command value are suppressed before and after output selection by the switch. The turbine control device according to claim 1,
A turbine control device, wherein a switching operation for selecting one of outputs of a plurality of settling rate function generators is executed in a normal operation state of the turbine. In the turbine control device according to claim 1 or 2,
The load request command using a target value of the generator output, a first control circuit that determines the load request command according to the difference between the detected generator output, and the target value of the generator output and the load command value. The output of the first control circuit is set to the load request command before the output selection by the switch, and the output of the second control circuit after the output selection by the switch Is defined in the load request command. A settling rate function generator for obtaining an opening command value by inputting a turbine rotation speed deviation, a load setting device for giving a load command value, and an addition signal of the opening command value and the load command value as a governor command value. In the turbine control device that controls the valve opening degree of the steam control valve,
A plurality of the settling rate function generators for obtaining different settling rates, obtaining an opening command value by inputting a turbine rotation speed deviation, a switch for selecting one of the outputs of the plurality of settling rate function generators, A correction signal storage circuit for storing a difference between switch outputs before and after output selection by the switch as a correction signal, and obtaining the load command value as a sum of the correction signal and the load request signal of the correction signal storage circuit Using a load setting device, a target value of the generator output, a first control circuit that determines the load request command according to a difference between the detected generator output, a target value of the generator output, and the load command value A second control circuit that determines the load request command, and an output of the first control circuit is determined in the load request command before output selection by the switch, and a second after the output selection by the switch. The output of the control circuit is used as the load request command. Turbine controller, wherein the mel.

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