JPS5983204A - Controller for operation of power plant - Google Patents

Abstract

PURPOSE:To linearize the output load of a power plant consisting of plural power units and to control it at a maximum load change rate by adjusting increase and reduction of the load on a basis of the maximum load change rate. CONSTITUTION:Load change controller 2 consists of an input processing part 21, a maximum load change rate calculating part 22, a parameter storage part 23, and an output processing part 24. This controller 2 outputs power plant target load set data d9, power plant load change rate set data d10, a power unit increased/reduced load command d11, and a power unit increased/reduced load control switching command d12 to a load controller 3. The load controller 3 controls the start and the stop of plural power units 41 constituting a power plant 4 on a basis of the switching command d12. Thus, the output load of the power plant consisting of plural power units is linearized, and the power plant is controlled at a maximum load change rate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an operation control device for a power generation plant composed of a plurality of power generation units.

[Technical background of the invention]

Recently, combined cycle power generation units have been developed with the aim of improving power generation efficiency. This power generation unit combines a gas turbine and a steam turbine, and uses the exhaust gas that has driven the gas turbine to drive the steam turbine.
This is designed to make effective use of thermal energy.

However, since this power generation unit has a small single unit capacity, it is necessary to configure a single generating MJ or plant with multiple units for system operation. -1. Since this power generation plant was recently developed, its operation control system has not been completely established, but it is predicted that it will take a control form that is slightly different from conventional ones. For example, since individual power generation units are easy to start and stop, this power generation plant is used for operational control with a large load FA adjustment.

By the way, in general, when operating a power generation plant in a system, it is essential to improve followability to the central power supply command in order to stabilize the power system.

As mentioned above, the FIL system for controlling the operation of a power generation plant consisting of multiple power generation units is still in the development stage, but in order to improve the ability to follow the central power supply command, it is necessary to control the operation at the maximum load change rate that each power generation unit can take. I can think of something to do.

For example, if the rated load of this power plant is now 100%,
The maximum load change rate of each power generation unit in this power generation plant is 1%/min (converted to rated load), 6 shots (11), and the minimum load at which the unit can continue operating is 14% (converted to rated load).
%, the number of operating power generation units currently operating at rated load is 5.
Assume that the target power generation unit load is 50%, and three power generation units are used to operate this. Under these conditions, as shown by curve A in FIG. 1, the five power generation units are simultaneously lowered from 100% rated load (time t1) to 70% load (time tz) at the maximum rate of change. The minimum load of each power generation unit is 14%, so after the power generation plant drops to 70% load, the three power generation units are operated at 14% load as shown in curve B in the figure, and as shown in curve C in the figure. The remaining two power generation units are reduced in load at the maximum load change rate.

When the two power generation units each reach 4% capacity (time t3), the power generation plant load becomes 50%.

After that, the load of the two power generation units scheduled to be shut down will be reduced to 0%, and the remaining three power generation units will be reduced to 16%.
．． Increase to 7%. In this way, the power plant load can be reduced from 100% of the rated value to 50% at the maximum load factor. In addition, in Figure 1, songs &
! B is the load change state for one power generation unit that does not stop;
Curve C represents the load change state for one power generation unit that is stopped.

[Problems with background technology]

However, according to the above method, the load change rate of the power generation plant around time t2 in FIG. 1 is not constant;
There will be issues that will hinder system operation. In other words, the central power supply system (the power supply office) knows the load change rate of each power generation plant in advance, and issues load increase/decrease instructions to each power generation plant based on this information.
We try to maintain a balance between supply and demand in the grid. Therefore, if the load change rate changes while the power generation plant is increasing or decreasing the load, the balance of supply and demand will be disrupted, causing the problem that stable operation of the system cannot be maintained.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an operation control device for a power generation plant that allows a power generation plant including a plurality of power generation units to increase or decrease the load at the maximum rate of change while keeping the rate of load change constant.

[Summary of the invention]

Therefore, in the present invention, the power generation units to be started and stopped are started and stopped at the maximum load change rate, while the remaining operating power generation units are started and stopped at the maximum load change rate RM (
%/min) satisfies the following formula.

However, Ll: Power plant load at the start of load change (%) L
F: Target power generation plant load (%) 1: Power generation unit load at the start of load change (%) tf: Minimum power generation unit load when the target power generation plant reaches negative direction (%)
) Load change rate (%/
(min) [Embodiment of the invention] (6) 2nd page 1 shows a configuration diagram of an operation control device for a power generation plant according to an embodiment of the present invention, in which 1 is a target load power generation unit target value setter; 2 is a load change rate control device, 3 is a load control device, and 4 is a power generation plant.

The load change rate control device 2 includes an input processing section 21, a maximum load change rate needle 9 section 22, a parameter storage section 23, and an output processing section 24. To the input processing unit 21, input 1, target load power generation unit target value, start from device 1, data d1 representing the target number of operating units, data d2 representing the estimated load of the power generation plant, and power generation unit start/stop designation. Data d3 is also output from the load control device 3 't1.
Land f current load data d4 is inputted, and furthermore, data d5 representing the number of units currently in operation is inputted to the power generation plant 1 from the power generation plant 4 targeted for control. The input processing unit 21 transmits target load data d2 of the power generation plant, target number of power generation units in operation d1, current power generation plant load data d4, generator 1, and current number of units in operation data d5 of the power generation plant to the maximum load change rate calculation unit 22. Then, power generation unit maximum load change rate data d6 and power generation unit maximum and minimum load limit value data d7 are transmitted to the A' parameter storage unit 23. Accordingly, the maximum load change rate calculation section 22 sends the output processing section 24 to the target load data d2 of the power generation plant, the target power generation unit operating number data d1, the power generation plant current load data d4, the power generation unit current operation number data d5, and the power generation Unit maximum load change rate data d6 and power plant maximum load change rate data d8 are transmitted.

The output processing unit 24 is a target load setter 3 of the load control device 3.
1 outputs power plant target load setting data d9 and power plant load change rate setting data dlO,
A power generation unit increase/decrease load control switching command dll and a power generation unit increase/decrease load control switching command d12 are output to the power generation unit increase/decrease load control switch 33. At this time, the power generation unit starts,
The stop designation data d3 is transferred from the input processing unit 21 to the output processing unit 2.
4.

The load control device 3 includes a target load setter 31 and a proportional integrator 32.
, a plurality of power generation units increase/decrease load side 1 switch 33 and two adders 34, 35, and the target load power generation unit target value setting device 1 is provided with power generation unit target load setting data d9 and load. Change rate setting data dl
It is configured to control the current load, which is the output of the power generation plant 4, in accordance with o. That is, the target load setter 3
1 generates a power generation ground load command d13 from the given power generation plant target load setting data d9 and load change rate setting data dlo. Power plant current load data d
4 as the power plant load command d13, a subtraction operation is performed in the adder 34 to generate power plant control deviation data d14. This deviation data d14 is integrated in the proportional integrator 32 to generate a power generation unit control command d15, and this power generation unit control command dl
S controls the outputs d16 of the plurality of power generation units 41, and the power generation plant outputs added by the adder 35 of the power generation unit load data d16, that is, the power generation plant current precious stone data d4, is sent to the target load setter 31. It is made to follow the power generation plant precious stone command d13 which is the output. The power generation unit increase/decrease load control switch 33 outputs a power generation unit increase/decrease load command d.
When switched to the ll side, the corresponding power generation unit 41
The output load d16 is the power generation unit increase/decrease load command dll
controlled by

With the above configuration, the power generation ground target load data d2 of the target value setting device 1 is set automatically or manually by a command from the central power dispatch center. The data d1 for the target number of power generation units in operation is generally determined based on the partial load efficiency curve of the power generation ground, the power generation unit start-up and stop loss, and the load curve of the power generation plant so that the overall efficiency of the power generation unit is maximized.
g tlru.

FIG. 3 shows a partial load efficiency curve of a power generation plant composed of multiple generating units. It is known that when there are multiple identical power generation units, the highest efficiency is achieved when the minimum number of operating power generation units is used and the load is distributed evenly. The figure assumes that the power generation plant is composed of five 1L generating units.

FIG. 4 shows an example of a power plant load curve.

The figure shows time t! From tl the load is 100% to 70
%, and the load is 70% from time t3 to t4.
It was assumed that the value changes from 100% to 100% again. In this case, 1
Let us assume that the number of power generating units in operation with maximum efficiency of 00% operation is five, and the number of power generating units in operation with maximum efficiency of 70% operation is four. Load drop from 100% to 70% (
tl-+ta), (1) Generator 11L unit; 5 → 4 units (one generator unit stops) (2) Power generator unit; 5 → 5 units (one generator unit does not stop) Any of the above cases The choice is based on the efficiency comparison between case (1) and case (2) at 70%, t2 → t
3 due to time and start-up and stop losses of the power generation unit. By stopping one power generation unit, t2 → t
It is better to select case (1) when the gain from the improved operating efficiency in step 3 exceeds the startup and shutdown losses of the 14L plant, and in the opposite case, it is better to select case (2). In this way, the target number of power generation units is calculated as the output load of the power generation plant changes.

The generator 11L unit start/stop designation data d3 is specified when the number of power generating units currently in operation is less (more) than the target number of operating units when the power generating plant is increased (decreased) in load, that is, when it is necessary to start (stop) the power generating units. Specify which power generation unit to start (stop). Which power generation unit is selected to be started (stopped) is determined by the cumulative operating time of the power generation unit, maintenance and inspection work, the number of times the power generation unit is started and stopped, and so on.

Power generation plant target load data d2, power generation unit current operating number data d1, power generation ground current load gutter d4
The data d5 on the number of currently operating power generating units is subjected to F-1 information processing in the input processing section 21 so that it can be easily processed in the maximum load change rate calculation section 22, and then transmitted to the calculation section 22. Further, the power generation unit start/stop designation data d3 is signal-processed in the input processing section 21 so as to be easily omitted in the output processing section 24, and then transmitted to the output processing section 24.

The power generation unit maximum rate of change data d6 in the parameter storage section 23 is determined by the maximum load change rate operation of the power generation unit 4. The power generation unit is operated within this conversion rate.

Further, the maximum and minimum load limit value data d'7 of the power generation unit in the storage unit 23 are included in the power generation unit 10, unit capacity I3i, delivery efficiency, and safe operation. Steady operation of the power generation unit, this load control r8M eclipse data d7
Do it within range! Sign.

The large load change rate meter u section 22 inputs from the input processing section 21 human power j', the target operating number of power units dl, the target load data of the power generation ground d2, the current load data of the generator brand d4, and the current operation of the power generation unit. The maximum load change rate RM is given by the following equation (1) based on the number of units data d5, generator unit maximum load change rate data d6, and power generation unit maximum and minimum load limit value data d7 input from the parameter storage unit 23. Calculate.

However, LI: Generation ground load at the start of load change 0) LF
:Target power generation '%, 7''land load @)t, :Generation unit load at the start of load change C%)tf:Target power generation plant j'
((minimum power generation unit load (%) at i?i''h) rm: Maximum power generation 'f of 1 unit, J unit load change rate (%/min) Here, L1 + LF + tf + tf + r, 14 methods for explain.

(i) L: load change (to I start M), plant fi load (%) Ll is the power generation in Figure 2, current plant staff data d4, and input processing section 21 in the same figure. A is input to the load control device from 3.

(++)L, :Target power plant load 0)L, is RIJ
Specifically, the target angle v data d2 of the power generation plant shown in FIG. 2 is inputted from the target load and power generation unit target value setter l via the input processing section 21 shown in the same figure.

o++) tl: Generation unit load at the start of load change (%)
X N1 However, Ll: Power generation at the start of load change, plant load (%)
N1: The number of power generation units in operation at the start of load change N1 is the current number of power generation units in operation data d5 in FIG.
It is input from the power generation ground 4 via the input processing section 21 shown in the figure.

(IV) Lf: Minimum output 7jj when target output 'IIL 7' runt load is reached, unit load (%) LF (A) - ≧ (≦) N if trntn (tmax).

1' ... (・) 1, = Possible, LF: Target power generation plant load (%) N1: Number of power generation units in operation during kj hours between load changes tmin"maρ: Power generation unit minimum (maximum) load limit value (%) tm (tmax) is the maximum power generation unit in Figure 2,
Minimum load limit value data d7, parameters stored,
L2: Target emission 1; Ground load (%) trrl, n(t
(man) 2 Minimum (maximum) load control device for power generation units) N1; Number of power generation units in operation at the start of load change NF: Target number of power generation units in operation N is the target number of power generation units in operation d1 in Fig. 2
The target load and power generation unit target value setter 1 are inputted via the input processing section 21 shown in the figure.

In addition, at power plant decrease (increase) - load, LF/N
1 <(>) tmin (tman), if the condition is met, one or more power generation units will be stopped (started).
Since it is necessary to do so, it becomes N1-N, lol.

(V) r: Maximum power generation unit load change rate of power generation unit (%/m1n) r is the power generation unit maximum load change rate data d in Figure 1
6, and is stored in the parameter storage section 23 in the figure.

According to (1) to (V) above, F> LX+Lr+Z1 r
'(and r is determined, and the above equation (1) is calculated.

FIG. 5 is a flowchart summarizing the processing at this time.

Next, the output processing unit 24 uses the power generation ground target load data d2 and the power generation unit maximum load change rate data d8 from the maximum load change rate calculation unit 22 to generate the power generation schedule/t target load setting data d9 and output'. i. Output the Zolant load change rate setting data diO to the target load setter 31 of the load control device 3 to operate the output load of the power generation plant at the maximum load change rate. Further, according to the power generation unit start/stop designation data d3 from the input processing unit 21, the power generation unit increase/decrease load control switch 33 corresponding to the power generation unit 41 to be started, started, or stopped is switched to the power generation unit increase/decrease load command data dll side. As such, the power generation unit increase/decrease load control switching command data d12 is output from the output processing 11s24 to the power generation unit increase/decrease load control switch 33. Next, the output processing unit 24 outputs power generation unit increase/decrease load command data dll to the power generation unit) 41 corresponding to the power generation unit start/stop designation data d3, and the power generation unit 4
1 is hoisted and stopped in accordance with the power generation unit maximum load change rate data d6.

For example, to explain the case where the operation of the power generation plant 4 is controlled under the same conditions as explained in FIG. The number of operating units data d1 is 3 units, and the power plant target load data d2 is 50%.
, data to designate the two power generation units 41 to be stopped is given as the power generation unit start/stop command data d3.

At the same time 15. From the plant 4, 5 units are supplied as the current number of Kornit units data d5, and furthermore, the current power generation plant load data d4 is provided from the load control device 3.

The load change rate control device 2 uses these data d1 to d5 and the power generation unit maximum load change rate data d6, which is stored in advance in the parameter storage unit 23, as 1%/min, the power generation unit maximum, and the load limit value data. 14 as d7
From the % minimum load limit value, first, the maximum load change rate RM is obtained based on the above equation (1), and this is output to the target load setter 31 as the power generation plant load change rate setting data dlo. The target load setter 31 outputs the power plant load command data d13 by integrating the power plant load change rate setting data dlO, and calculates the deviation from the power plant current load data d4 fed back from the power plant 4. The power generation unit control command d15 data calculated by the proportional integrator 32 is transferred to the power generation unit which has been switched to the d15 side.
vt! i, 3 via unit increase/decrease load control switch 33
It is added to the transmission unit 41 of the base. At the same time, the power generation unit increase/decrease load switch 33 is issued based on the power generation unit start/stop command d3 and outputs the unit increase/decrease load control switching command d12 to select two power generation units 41 to be stopped among the five power generation units 41 currently in operation. is switched to the dll side, and outputs the power generation unit maximum load change rate data d6, that is, 1%/min, as the generator 1u unit increase/decrease load command dll, and stops the two predetermined power generation units 41.

As a result, the load curve of the power generation plant 4 decreases linearly from 100% load to 50% load at the maximum load change rate, as shown by α in FIG. That is, the two power generation units 41 each descend at a maximum load change rate of 1%/min from time t1, as shown by γ on the opposite side of the figure. On the other hand, the remaining three generator units 41 descend along the curve β so that the power generation plant 4 output d4 declines at the maximum load change rate RM calculated by the above equation (1).

Next, when the output d4 of the power generation plant 4 reaches 50% load, the load control device 3 controls the power generation The current load data d4 controls the load of the three power generation units 41 so that the power generation plant 4 maintains this 50% load.

As a result, after each of the three power generation units 41 reaches 14% at time t3 as shown by the curve β in FIG. As it falls from 4% (time t3) to 0% (time 1+), it increases to 16.7%.

In this way, the load of the power generation plant 4 can be reduced from 100% to 50% at the maximum load change rate between times t1 and t3, as in the case of FIG. 1, and linearly reduced during that time. Therefore, it becomes possible to smoothly and stably operate the system of a power generation plant consisting of a plurality of power generation units.

Note that by making it possible to change the maximum load change rate data d6 stored in the parameter storage section 23 of the load change rate control device 2 from the outside, the power generation unit 4
Thermal stress management of one gas turbine and a steam turbine can be facilitated.

In general, the lifespan of gas turbines and steam turbines is controlled by the thermal stress generated by load vibrations of power generating units. The thicker the power generation unit load change rate, the greater the thermal stress generated due to the load change. Therefore, by making the maximum load change rate of the power generation unit variable, it is possible to easily manage the thermal stress of the gas turbine and steam turbine.

〔Effect of the invention〕

As described above, according to the present invention, the output load of a power generation plant consisting of a plurality of power generation units can be made linear and controlled at the maximum load change rate.

As a result, i! in response to the load change command from the central dispatch center! ] It becomes possible to obtain a power generation plant with good followability and a high load adjustment capacity that is useful for stabilizing the city's four-power grid.

[Brief explanation of the drawing]

FIG. 1 is a load curve diagram of a power generation plant consisting of multiple power generation units, FIG. 2 is a block diagram of a power generation plant operation control device according to an embodiment of the present invention, and FIG. 3 is a load curve diagram of a power generation plant consisting of multiple power generation units. Partial load efficiency curve diagram, 4th
The figure is a power generation plant precious stone curve diagram, Figure 5 is a flowchart of processing in the load change rate control device in Figure 2, and Figure 6 is a load curve explaining an example of maximum load change rate control in Figure 2. It is a diagram. 1...Target load power generation unit target value setter, 2...
Load change rate control device, 3... Load control device, 4...
Power generation plant, 21... Input processing unit, 22... Maximum load change rate calculation unit, 23... Parameter storage unit, 24
... Output processing unit, 31... Target load setting device, 32.
... Proportional integrator, 33... Power generation unit increase/decrease load control switch, 34.35111111 adder, 41... Power generation unit. Figure 7 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) In an operation control device for a power generation plant consisting of multiple power generation units, a parameter storage unit that stores the maximum and minimum load limit values of the power generation unit and the maximum load change rate of the power generation plant, the target load of the power generation plant, and the power generation unit an input processing unit for inputting the target number of operating units, the current load of the power generation plant, and the number of currently operating power generation units, the maximum and minimum load limit values of the power generation units, the maximum load change rate of the power generation units, the target load of the power generation plant, the target number of operating power generation units; a maximum load change rate calculation unit that calculates a maximum load change rate of the power generation plant based on the current load of the power generation plant and the current number of power generation units; a maximum load change rate of the power generation plant; a power generation plant target load; a maximum load change rate of the power generation unit; A load change rate control device consisting of each part of an output processing unit that outputs a power generation unit increase/decrease load control switching command, and a load change rate control device that switches a power generation unit to be started or stopped based on the power generation unit increase/decrease load control change command to maintain the maximum load change rate of the power generation unit. A power generation grand operation control device comprising: a load control device that starts and stops a power generation unit that is currently in operation according to the power generation plant maximum load change rate and the power generation plant target load at the same time. (2. The power generation ground operation control device as set forth in claim 1, wherein the storage contents of the parameter storage section can be changed from the outside.