JP2012005237A - Power plant load controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power plant load controller where a power plant constituted of power generation units having different efficiencies can perform efficient operation for any load command from a center power feeding command office or the power plant.SOLUTION: The power plant load controller of the power plant constituted of a plurality of power generation units includes: a uniform load distribution arithmetic circuit 47 which uniformly load-distributes a load command value of the power plant to the plurality of power generation units by operation states of the plurality of power generation units; a fuel amount arithmetic circuit 40 operating a use fuel amount of the power plant from operation state signals of the plurality of power generation units and operation characteristic functions of the plurality of power generation units; and a correction load arithmetic circuit 41 operating a correction load command value to the plurality of power generation units with which the use fuel amount of the power plant becomes minimum. The load commands to the plurality of power generation units are set as output signals with the load command signal from the center power feeding command office or the power plant as an input signal.

Description

  The present invention relates to a power plant load control device that performs control to distribute a load command from a central power supply command station or a power plant to a plurality of power generation units.

The plurality of power generation units in the power plant are operated based on a load command from the central power supply command station or the power plant. It is common for multiple power generation units to have a mix of old and new types or generators with different power generation methods. In each power generation unit, the power generation capacity and power generation efficiency (the amount of fuel used relative to the amount of power generation) ) Are often different.
Therefore, in order to perform the most efficient operation as a power plant with respect to the load command of the total power generation amount from the central power supply command station or the power plant, an efficient power generation unit for any load command signal each time It is necessary to change the load sharing of power generation units that are not efficient.
As an example of a solution to this problem, Patent Document 1 focuses on the type of fuel used in a gas turbine for a combined cycle plant, and constructs a nonlinear equation based on the LPG / LNG unit fuel unit price, generator unit price, etc., and automatically A technique for biasing to a load command value is disclosed.

JP-A-62-107210

However, the operation of a power generation unit in a conventional power plant, or the power plant load control device is not necessarily operated in an optimum load sharing manner.
In addition, with respect to the combined cycle plant of Patent Document 1 described above, paying attention to the type of fuel used in the gas turbine, a non-linear equation is constructed based on the LPG / LNG unit fuel unit price, generator unit price, etc., and automatically set to the load command value. The biasing technique is based on the premise that the efficiency is the same when the same unit fuel is used for a plurality of applied units, and there is a problem that it cannot be applied when the efficiency of each unit is different. In addition, it is necessary to solve the nonlinear equation, and there are problems that it takes time to determine the bias value and that a solution is not always obtained.

  Therefore, the present invention solves such problems, and the purpose of the present invention is that a power plant composed of power generation units having different efficiencies can be used as a central power supply command station or a load command from a power station. On the other hand, it is to provide a power plant load control device capable of efficient operation.

In order to solve the above-described problems and achieve the object of the present invention, the present invention is configured as follows.
That is, in a power plant load control apparatus configured with a plurality of power generation units, the load command value of the power plant is evenly distributed to the plurality of power generation units according to the respective operating states of the plurality of power generation units. A load distribution calculation circuit; a fuel amount calculation circuit for calculating a fuel amount used in the power plant from each operation state signal of each of the plurality of power generation units and an operation characteristic function of each of the plurality of power generation units; and a fuel used in the power plant A correction load calculation circuit for calculating a correction load command value for the plurality of power generation units that minimizes the amount, and the load command signal from the central power supply command station or the power plant as an input signal. The load command to the power generation unit is used as the output signal.

  With this configuration, optimal load distribution is provided for a plurality of power generation units having different power generation capacities and efficiency characteristics.

  ADVANTAGE OF THE INVENTION According to this invention, the power plant comprised by the power generation unit with different efficiency can provide the power plant load control apparatus which can operate efficiently with respect to the load command from a central electric power feeding command station or a power plant. .

It is a block diagram which shows the outline of the power generation equipment of the power plant which has several power generation units using the power plant load control apparatus of embodiment of this invention. It is a characteristic view explaining the concept to which the power plant load control device of the embodiment of the present invention is applied when the power generation unit has two axes. It is a functional block diagram to which the power plant load control device of the embodiment of the present invention is applied when the power generation unit has two axes. It is a functional block diagram to which the power plant load control device of the embodiment of the present invention is applied when the power generation unit has three axes. FIG. 4B is a functional block diagram showing a configuration of a fuel amount calculation circuit in FIG. 4A showing the embodiment of the present invention. It is the reference diagram which showed the function structure of the load control apparatus of the comparative example.

Embodiments of the present invention will now be described.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. The feature of this embodiment is the functional block configuration of the power plant load control apparatus shown in FIG. However, from the viewpoint of ease of understanding, first, referring to FIG. 1, “a configuration of a power generation facility composed of a plurality of power generation units” and FIG. ”Characteristics of the amount of fuel used” will be described first, and then “the functional block configuration of the power plant load control device” showing the characteristics of the first embodiment of the power plant load control device will be described with reference to FIG. 3. To do.
The above will be described in order.

<Configuration of power generation facilities of a power plant having a plurality of power generation units>
FIG. 1 is a configuration diagram showing an outline of power generation equipment of a thermal power plant having a plurality of power generation units.
In FIG. 1, a power generation unit 5 surrounded by a broken line includes a compressor 1, a combustor 2, a gas turbine 3, and a generator 4. There are a plurality (shafts) of power generation units having substantially the same configuration as that of the power generation unit 5, and FIG.
In the power generation unit 5, the fuel is compressed by the compressor (COM) 1 so that the fuel is optimally burned, burned by the combustor 2, and the gas turbine (GT) 3 generates a predetermined rotational output by the burned gas. In response to this, the generator (G) 4 converts the rotational output into electricity to generate electric power, and the electric power is output to the electric power system.

  Although not shown in FIG. 1, a power generation facility that uses the exhaust heat of the power generation unit 5 (N-axis) to generate power with a steam turbine may be further provided. In this case, it becomes a combined cycle power generation facility. The combined cycle power generation facility is called combined. A facility that uses only steam generated in a boiler and generates power using a steam turbine is referred to as conventional.

  When a load command (total output) is received from the central power supply command station or the power plant, a plurality of (N-axis) power generation units (5) share the load and generate power. The power plant load control device 10 distributes this load and distributes it to the plurality of power generation units (5). The power plant load control device 10 receives a load command (total output) from the central power supply command station or the power plant, determines the status, power generation capacity, efficiency characteristics, etc. of the plurality of power generation units (5), and A load command is output to each of the power generation units (5).

<Characteristics of load and fuel consumption when the power generation unit has two shafts>
FIG. 2 is a graph showing the characteristics of the load and the amount of fuel used when the power generation unit 5 has two axes. In FIG. 2, the horizontal axis represents the load of the power generation unit 5, and the vertical axis represents the amount of fuel used by the power generation unit 5. F ₀ represents the characteristics of the power generation unit 5 with relatively low efficiency, and F _n represents the characteristics of the power generation unit 5 with relatively high efficiency.

Speaking of the thermal power generation unit 5, as shown in FIG. 2, the relationship between the power generation output (load) and the amount of fuel used can be expressed by a substantially linear function F (w).
In general, this relational expression (characteristic) is always in a test operation before the power generation unit 5 is fully operated, and is generally obtained as an actual measurement value from the test data at that time. is there. The actually measured value can be diverted as the relational expression.

For Figure 2, with _F 0 (w) is the old power unit 5 in terms of the characteristic line _{F 0, F} n expressed in _{F n} (w) is a new power unit _{5, F} 0 (w) is _F n ( Compared with w), the efficiency is not good. Therefore, in order to give the plant the optimum efficiency, it is better to use the newest power generation unit 5 as much as possible, and it is necessary to change the load distribution of both power generation units 5.

In the following, a method for giving optimum load distribution will be described. It should be noted that there are upper and lower limits for the outputs of F ₀ (w) and F _n (w) mainly because of the mechanical constraints of both power generation units 5.
When the load command value W _D from the central feed command is output, when the total output W _S of the manual operation unit is 0, since the power generating unit 5 is biaxial, basic load command value to both the power generation unit 5 Becomes W _D / 2. Based on this value, in order to give the optimum plant efficiency as described above, the load distribution of the new power generation unit 5 is increased by + Δw, and the load distribution of the old power generation unit 5 is decreased by −Δw.

As a result, the amount of fuel used by both power generation units 5 is expressed by the following formulas (1) and (2), respectively.

It is assumed that the right side of (Equation 1) and (Equation 2) is the original meaning, and the left side is an expression that expresses the meaning of each right side and defines it.
In FIG. 3 to be referred to later, the left side in (Equation 1) and (Equation 2) is used as a variable name for the purpose of simplifying the expression in the drawing.

（３式）について前述したＦ_ｎ（ｗ）とＦ_０（ｗ）の上限と下限の範囲内でΔｗを変化させ、Ｆ_all（Δｗ）の最小値を与えるΔｗを求める。 Here, assuming that i = 1, the following (formula 3) is calculated. The left side is a variable name.

Δw is changed within the upper and lower limits of F _n (w) and F ₀ (w) described above for (Expression 3), and Δw giving the minimum value of F _all (Δw) is obtained.

ここで、Δｗ＝Δｗ’の時にＦ_all（ｗ）が最小であると仮定すれば、最適な負荷配分はΔｗ’となる。 The equation for obtaining this is represented by the following (Equation 4).

Here, assuming that F _all (w) is minimum when Δw = Δw ′, the optimal load distribution is Δw ′.

もしくは、

となる制約がある。 However, for the above-mentioned mechanism reasons,

Or

There are some restrictions.

  In FIG. 2, the upper limit and lower limit of the load of the power generation unit 5 that is not efficient and the power generation unit 5 that is efficient are both set to the same value. May be different.

<Configuration of functional block of power plant load control device>
Based on the above concept, FIG. 3 shows a specific configuration example of the power plant load control device. The power plant load control device 10 (FIG. 1) of the present embodiment includes a manual unit correction circuit 36, an equal load distribution calculation circuit 37, a fuel amount calculation circuit 30, a correction load calculation circuit 31, an equal load distribution correction circuit 32 in FIG. 33, manual setting devices 381 and 382, and switching devices 391 and 392 are provided. However, the manual setting devices 381 and 382, the switching devices 391 and 392, and the manual unit correction circuit 36 are generally provided, but are not essential elements in the present embodiment.

3, the load command value W _D from the central feed command / power plant 35 is output. In FIG. 3, “central power supply command station” is abbreviated as “medium pay”, and “central power supply command station / power station” is expressed as “medium power supply / power station”. Further, “power generation unit” is abbreviated as “unit”, and “the number of power generation units in the central power supply command station / power station mode” is expressed as “the number of units in the middle supply / power station mode”.
However, the central feed command / power plant 35 is a representation of a source that outputs the load command value W _D, not included in the power plant load control device 10 of the present embodiment.

The load command value W _D is input to the manual unit correcting circuit 36, from the manual operation unit correcting circuit 36 by subtracting the total output W _{S (total} output of the generator unit being operated by manual) the manual operation unit (W _D -W _S ) is output and input to the equal load distribution calculation circuit 37.
In the equal load distribution calculation circuit 37, the number of power generation units being operated is N (N = 2 in FIG. 3) according to the load command of the central power supply command station or the power plant (medium supply / power plant) 35. Divide (W _D -W _S ) by subtracting the total output W _S (total output of the power generation unit 5 operated manually). Note that a driving mode based on the load command signal W _D equivalent load allocation calculating circuit 37 in the central feed command or power plant 35 as described above.

It exits each case to bear on the average power generation unit 5 of the central feed command or power plant (central dispatching center / plant) 35 N axis load command value W _D of (in FIG. 3 N = 2) It means competence. However, since the power generation efficiency and the power generation efficiency in view of the fuel amount of each of the plurality of power generation units 5 are not considered in this, the fuel amount calculation circuit 30, the correction load calculation circuit 31, and the equal load distribution correction circuits 32 and 33 are optimal. The correction for the conversion is calculated.

  First, the output of the equal load distribution calculation circuit 37 is input to the fuel amount calculation circuit 30. In the fuel amount calculation circuit 30, the operation state signal indicating whether or not each of the plurality of power generation units 5 is operated and the operation characteristic function of each power generation unit 5 (details will be described later) are described above (Formula 1). ) And (Equation 2) are calculated separately. Thereafter, (Equation 3) is calculated, and Δw of the load distribution giving the minimum value is obtained. Then, the result is output to the correction load calculation circuit 31.

Next, the correction load calculation circuit 31 inputs the output result from the fuel amount calculation circuit 30 described above, and first checks whether or not the output result satisfies (Expression 5) and (Expression 6).
If it satisfies, the values accumulated in (Equation 4) are compared, Δw giving the minimum value is obtained, and the result is output to the equal load distribution correction circuits 32 and 33. Here, this value is set to Δw ′.

If not, the output result from the fuel amount calculation circuit 30 is first accumulated in (Equation 4), Δw is changed, and (Equation 3) is recalculated in the fuel amount calculation circuit 30. Then, the calculation described above is repeated in the correction load calculation circuit 31.
Correction values −Δw ′ and + Δw ′ determined to be the most efficient by the correction load calculation circuit 31 are output to the equal load distribution correction circuit 32 and the equal load distribution correction circuit 33, respectively.

を演算し、各発電ユニット５に負荷指令値を与える。 The uniform load distribution correction circuit as a whole is composed of the equal load distribution correction circuits 32 and 33 in FIG. The uniform load distribution correction circuit as a whole receives the correction values −Δw ′ and + Δw ′ of the correction load calculation circuit 31,

And a load command value is given to each power generation unit 5.

Even load distribution correction circuit 32 and specifically to the correction value -Derutadaburyu 'compensation load calculation circuit 31, W _{D /} 2 (2 shaft generator unit of output equivalent load allocation calculating circuit 37 is input through a switch 391 (−Δw ′ + W _D / 2), which is the total value of the power output averaged at 5), is given as a load command value to the old power generation unit # 1 having a relatively poor fuel usage efficiency.

Further, even load distribution correction circuit 33 and the correction value + [Delta] w 'of the correction load calculation circuit 31, the output of the equivalent load allocation calculating circuit 37 is averaged by the power generation unit of W _{D /} 2 (2 axes entered via the switch 392 (+ Δw ′ + W _D / 2) is given as a load command value to a new (new) power generation unit # 2 with relatively good use efficiency of the fuel amount.

As described above, depending on the relationship between the output of each power generation unit (# 1, # 2) and the amount of fuel used, the power plant load control device 10 gives the optimum load command value to each power generation unit (# 1, # 2). This improves the power generation efficiency of the power plant as a whole.
Here, the characteristic of the relationship between the output of the power generation unit 5 and the amount of fuel used is used, but the characteristic that controls the operation of the power generation unit 5 in this way is referred to as an operation characteristic function.
However, the operation characteristic function is not necessarily only the characteristic of the relationship between the output of the power generation unit 5 and the amount of fuel used. For example, there may be a relationship between the output of the power generation unit 5 and the power generation efficiency.

  Note that the switches 391 and 392 may be controlled by manual setting devices 381 and 382, respectively. Here, the meaning of “manual” in the manual setting devices 381 and 382 means that it can be set manually, and does not necessarily mean that it is set manually. Rather, it is rarely done manually. In the load command value correction of the power generation unit 5 in FIG. 3 described above, the control as “manual” is not involved.

(Second Embodiment)
A method will be described in which the power generation unit 5 is expanded based on the two-axis method and further expanded when the power generation unit 5 is the N-axis.

<Relationship between load and fuel consumption when power generation unit is N-axis>
Next, the relationship between the load and the amount of fuel used when the power generation unit 5 is an N-axis will be described.
In case the power generating unit 5 is N axis, _w = the load of the power generation unit _{5 {w 1, w 2,} ···, w i, ··· w N} Distant, its load used fuel amount Is expressed as f _i (w _i ) for each power generation unit 5. Note that i indicates the i-th power generation unit 5.
F (w), which is the total amount of fuel used in the power plant, can be expressed by the following (Equation 8). In the following, the function f _i (w _i ) expressed in lower case of f represents the relationship between the load of each power generation unit 5 and the amount of fuel used, and the function F (w) expressed in upper case of F represents the power plant This represents the relationship between the total load and the total amount of fuel used.

発電所が最も良い効率で運転する為に、各軸の負荷ｗを変化させ、最小となるＦ（ｗ）を求める必要がある。 F (w), the total amount of fuel used in the power plant,

In order for the power plant to operate at the best efficiency, it is necessary to change the load w of each axis and obtain the minimum F (w).

で表すと、｛ｗ_１，ｗ_２，・・・，ｗ_ｉ，・・・ｗ_Ｎ｝は下記の（１０式）で表せる。 The load w of each power generation unit 5 is

{W ₁ , w ₂ ,..., W _i ,... W _N } can be expressed by the following (Equation 10).

上式においてＷ_Ｄ／Ｎが既知の値で、（Δｗ）が変数である。

In the above equation, W _D / N is a known value, and (Δw) is a variable.

は各軸の負荷値に変化を与える係数であり、軸数によって一義的に決まる整数である。ここで、ｉ（１・・・Ｎ）はｉ番目の発電ユニット５の軸数である。またαは後記する係数の組み合わせを識別するための添え字であり、累乗を表すものではない。 Also,

Is a coefficient that changes the load value of each axis, and is an integer uniquely determined by the number of axes. Here, i (1... N) is the number of axes of the i-th power generation unit 5. Α is a subscript for identifying a combination of coefficients described later, and does not represent a power.

および、

The coefficient satisfies the following conditional expressions (Expression 12) and (Expression 13). Here, N is the total number of axes of the power generation unit 5.

and,

Further, (Equation 11) can be summarized as shown in Table 1. In Table 1, M is the maximum number when α is assigned in order, which represents each combination of coefficients. That is, Table 1 shows that there are M combinations of meaningful coefficients.
This application example will be described in the case of the number of power generation units = 3 (third embodiment).

Here, paying attention to Δw · p _i ^α of the changing term in (Equation 9), omitting the notation of W _D / N that does not change, and setting Δw to u, (Equation 8) becomes the following (Equation 14 ).

上式の（１５式）を解くことにより（１４式）の最小値を与えるｕが求められる。 Since α = 1, 2,..., M from (Equation 14) in the above equation, the following equation is calculated for an arbitrary α.

By solving (Equation 15) of the above equation, u that gives the minimum value of (Equation 14) is obtained.

したがって、発電所に最も良い効率を与える負荷配分は、（１６式）に列挙されたものの中の最小値であって、（１７式）となる。 Including _{p i} ^alpha in the u and combination numbers in Table 1 alpha, (15 type) solutions that satisfy at anew _{v i} a, α = 1,2, ···, against M, in each case Assuming that the minimum value of all the used fuel amounts F (w) is F _i (v _i ) and enumerates the minimum values in all cases, the following (Equation 16) is obtained.

Therefore, the load distribution that gives the best efficiency to the power plant is the minimum value among those listed in (16), and is (17).

と表せる。一般的に上式の（１７式）で最適な負荷配分値が求められる。
なお、（１７式）の最適値の算出において、都度、演算をいってもよいし、あるいはあらかじめ計算しておいたものを表形式にしておいて、最も良い効率のものをその表から選択する演算でもよい。 Here, if the value that minimizes the total fuel consumption F (w) in v _i described above is v _β ,

It can be expressed. Generally, the optimal load distribution value is obtained by the above equation (17).
In the calculation of the optimum value of (Equation 17), calculation may be performed each time, or what has been calculated in advance is displayed in a table format, and the one with the highest efficiency is selected from the table. Calculation may be used.

(Third embodiment)
As the second embodiment described above, a method in which the power generation unit is generalized as the N-axis will be described more specifically as a third embodiment of the power plant load control device in the case where the power generation unit 5 has three axes.

<Relationship between load and fuel consumption when power generation unit has 3 shafts>
Now load command from the central feed command is set to W _D, even load command value to each axis becomes W _{D /} 3.

In the method shown in the case where the power generation unit 5 is an N-axis, N = 3 is applied to obtain an optimal load distribution.
Here, if N = 3 is applied in (Expression 14), the following (Expression 18) is obtained.

Also, the above (13) is the following (19).

と表せる。 Further, from the above (Equation 12), when N = 3, the following (Equation 20) is obtained.

It can be expressed.

なお、（１９式）と（２０式）の両方を満たしている（ｗ_１，ｗ_２，ｗ_３）の組み合わせとしては、例えば（−２，０，２）もあるが、Δｗが変化する際において、前記組み合わせは（−１，０，１）と実質的に等価となってしまうので除かれている。 From the above, Table 2 shows the combinations of (20 equations). This is a combination pattern of load distribution (w ₁ , w ₂ , w ₃ ) of each axis.

In addition, as a combination of (w ₁ , w ₂ , w ₃ ) that satisfies both (Equation 19) and (Equation 20), for example, there are (−2, 0, 2), but when Δw changes The combination is excluded because it is substantially equivalent to (-1, 0, 1).

At this time, since M = 12 in [Table 2], applying all the patterns in Table 2 to (Equation 18) gives the following.

Therefore, the following calculation is performed for the above [101] to [112].

ここで、［１２５］を（１６式）に代入し、再計算すると、

が求められる。
（２１式）のなかの最小のものを大小比較で選択する。 Here, the solution which gives the minimum value for each of the above [113] to [124] is represented by v, and the enumerated one is [125] below.

Here, substituting [125] into (Equation 16) and recalculating,

Is required.
The smallest one of (Expression 21) is selected by size comparison.

２軸目への負荷指令値：

３軸目への負荷指令値：

となる。 Here, for example, in the combination (−1, +2, −1) of (w ₁ , w ₂ , w ₃ ) when α = 8 of the coefficient subscript in Table 2, (18) is minimized. ,
What is optimal load distribution?
Load command value for the 1st axis:

Load command value for the second axis:

Load command value for the 3rd axis:

It becomes.

Here, when the combination of the coefficients (w ₁ , w ₂ , w ₃ ) in Table 2 is the smallest among the combinations other than (−1, +2, −1) described above, In (Expression 22), (Expression 23), and (Expression 24), a load command corresponding to that is instructed to each axis.

  For example, here, assuming that the combination pattern of load distribution of each axis is (0, +1, −1) in the combination of the column of α = 1 in Table 2, this means the following.

２軸目の発電ユニットの使用燃料量：

３軸目の発電ユニットの使用燃料量：

The amount of fuel used by the power generation unit on the first axis:

Amount of fuel used for the second axis power generation unit:

The amount of fuel used by the power generation unit on the third axis:

<Structure of functional block of power plant load control device when the number of power generation units is 3 axes>
FIG. 4A and FIG. 4B illustrate the basic concept in the case where the number of power generation units is three.
The power plant load control device 10 (FIG. 1) of the present embodiment includes a manual unit correction circuit 46, an equal load distribution calculation circuit 47, a fuel amount calculation circuit 40, a correction load calculation circuit 41, an equal load distribution correction circuit 42 in FIG. 43, 44, manual setting devices 481, 482, 483, and switching devices 491, 492, 493. However, the manual setting devices 481, 482, 483, the switching devices 491, 492, 493, and the manual unit correction circuit 46 are generally provided, but are not essential elements in the present embodiment.

In Figure 4A, the load command value W _D is output from the central feed command / power plant 45. In FIG. 4A, as described above, “central power supply command station” is abbreviated as “medium pay”, and “central power supply command station / power station” is described as “medium power supply / power station”. Further, as described above, “power generation unit” is abbreviated as “unit”, and “the number of power generation units in the central power supply command station / power station mode” is described as “the number of units in the middle supply / power station mode”.
However, the central power supply command station / power plant 45 is not included in the power plant load control device 10 of the present embodiment. It illustrates a source that outputs the load command value W _D.

The load command value W _D is input to the manual unit correcting circuit 46, from the manual operation unit correcting circuit 46 by subtracting the total output W _{S (total} output of the generator unit being operated by manual) the manual operation unit (W _D -W _S ) is output and input to the equal load distribution calculation circuit 47.

The load command W _D of the equivalent load allocation calculating circuit 47 central feed command or power plant (central dispatching center / plant) 45, the number of power generating units being operated N (N = 3 in FIG 4A), the (W _D −W _S ) obtained by subtracting the total output W _S of the manual unit (total output of the power generation unit operated manually) is subtracted.
This means the output amount when borne on average by the power generation unit of the central feed command or power plant N axis load instruction W _D of (central dispatching center / plant) (in FIG. 4A N = 3) To do. In FIG. 4A, W _S = 0.

However, this does not take into consideration the power generation efficiency of each of the plurality of power generation units 5 and the power generation efficiency in view of the amount of fuel used, so the fuel amount calculation circuit 40, the correction load calculation circuit 41, the equal load distribution correction circuits 42, 43, 44, the correction for optimization is calculated.
The names of the fuel amount calculation circuit 40, the correction load calculation circuit 41, and the equal load distribution correction circuits 42, 43, and 44, which are the basic configurations described above, are the same as the corresponding circuits in FIG. The logic in the operation is different.

4A, the specific configuration of the fuel amount calculation circuit 40 is shown in FIG. 4B. In the fuel amount calculation circuit 40 shown in FIG. 4B, [101] to [125] are calculated in order as described above, and finally v _α is output to the correction load calculation circuit 41. Since the load distribution combination table for each axis corresponding to Table 2 included in the fuel amount calculation circuit 40 is uniquely determined by the number of axes of the power generation unit 5, it can be created in advance.

In Figure 4A, the correction load calculation circuit 41, v computes a (27 type) with _alpha, determining the smallest F _alpha (v _alpha). Here, as described above, it is assumed that F _α (v _α ) is minimum when α = 8. At this time, the load distributions of 1, 2, and 3 axes are Δw · (−1), Δw · (+2), and Δw · (−1), and are thus output to the equal load distribution correction circuits 42, 43, and 44, respectively. The

The equal load distribution correction circuit 42 receives the correction value Δw · (−1) of the correction load calculation circuit 41 and the output of the equal load distribution calculation circuit 47 through the switch 491 (W _D / 3 (three-axis power generation unit 5). (W _D / 3 + Δw · (−1)) is given as a load command value to the power generation unit 5 on the first axis, which has a relatively poor fuel usage efficiency.

The equal load distribution correction circuit 43 has a correction value Δw · (+2) of the correction load calculation circuit 41 and W _D / 3 (triaxial power generation unit 5 in which the output of the equal load distribution calculation circuit 47 is input via the switch 492. (W _D / 3 + Δw · (+2)) is given as a load command value to the second-axis power generation unit 5 having a relatively good fuel usage efficiency.

The equal load distribution correction circuit 44 has a correction value Δw · (−1) of the correction load calculation circuit 41 and an output of the equal load distribution calculation circuit 47 inputted through the switch 493 (W _D / 3 (triaxial power generation unit 5). (W _D / 3 + Δw · (−1)) is given as a load command value to the power generating unit 5 on the third axis, which has a relatively poor fuel usage efficiency.

The uniform load distribution correction circuit as a whole composed of the uniform load distribution correction circuits 42, 43, and 44 outputs the following load commands to the respective axes.
The load command value for the first axis is (22)
The load command value for the second axis is (Equation 23)
The load command value for the third axis is (24 formulas)
It can also be expressed.

In the above, the power plant load control device distributes the load so that the amount of fuel used in the triaxial power generation unit is the most efficient. Less fuel is required.
In Table 2, when the combination of coefficients (w ₁ , w ₂ , w ₃ ) that minimizes (Equation 18) is another combination, the load on the first, second, and third axes The command value outputs differently accordingly.

  Note that the switches 491, 492, and 493 are also controlled by manual setting devices 481, 482, and 483, respectively. Here, the meaning of “manual” in the manual setting devices 481, 482, 483 means that it can be set manually, and does not necessarily mean that it is set manually. In the load command value correction of the power generation unit in FIG. 4A described above, the control as “manual” is not involved.

<Reference drawing>
FIG. 5 shows a power plant load control device of a comparative example. In order to show that the embodiment of the present invention is superior to the prior art, it will be described as a reference.
In FIG. 5, the power plant load control device includes a manual unit correction circuit 56, a uniform load distribution circuit 57, a plurality of switches 591, and a plurality of manual setting devices 581. Each power generation unit (not shown) has a central power supply command station operation mode and an in-house operation mode. The central dispatching center operation mode is a mode for operating at load command W _D from the central dispatching center 55. House operation mode is a mode for operating the load command value W _D of the power plant 55 side. In FIG. 5, “central power supply command station” is abbreviated as “medium supply”, and “central power supply command station / power station” is described as “medium supply / power station”. Further, “power generation unit” is abbreviated as “unit”, and “the number of power generation units in the central power supply command station / power station mode” is expressed as “the number of units in the middle supply / power station mode”.

Load command value W _D from the central feed command 55 is outputted, when the total output W _S of the power generation unit of the manual operation mode, the to evenly load allocation calculating circuit 57 is a load command value (W D _{-W S)} Output Is done.
When the number of power generation units in the central power supply command station operation mode is N, the load command value for each axis is (W _D −W _S ) / N. The load command value is output to each axis via the switch 591. When the switch 591 is in the manual mode, the load command value of the manual setting device 581 is operated as the load command value of the power generation unit.
In the above, since only are simply allocated from a central dispatching center 55 a load command W _D with the number of power generating units, power plants in the state not be said quantity of fuel efficiency is the best to be used to drive. Therefore, in the operation of the power generation unit by the load control device of the comparative example, the efficiency of the amount of fuel used is generally not good.

(Other inventions)
In the above, the method of calculating and controlling the characteristics (operation characteristic function) related to the load of the power generation unit and the amount of fuel to be used has been described, but using the characteristic data from the viewpoint of the output and power generation efficiency of the power generation unit Also good. In these, it is a difference whether it pays attention to the viewpoint of "power generation efficiency", or the viewpoint of "power generation efficiency", and there is essentially no difference.
In addition, during the test operation before full-scale operation, the above-mentioned “power generation unit output and power generation efficiency” may be obtained as test data. It may be suitable to use. And almost the same effective results are obtained.
In addition, there are other similar concepts related to the amount of fuel with respect to output and power generation efficiency. You may use the characteristic (operation characteristic function) by the concept of those similar.

  In the above, a case where a plurality of power generation units have different “related characteristics of load and fuel amount to be used” has been described. However, in a multi-axis power generation unit, the same type and age are almost the same. There may be multiple power generation units with the following characteristics. In this case, a plurality of power generation units having similar characteristics can be grouped and controlled collectively. At this time, there is an effect that the number of devices (number of parts) and the amount of calculation processing of the equal load distribution correction circuit (42, 43, 44) are reduced.

  In addition, circuits such as a fuel amount calculation circuit, a correction load calculation circuit, and a uniform load distribution correction circuit may have a hardware configuration or a software configuration.

  Moreover, this invention is not limited to a thermal power plant form (combined or conventional).

  As described above, according to the present invention, optimal load distribution is quickly and reliably given to a power plant including a plurality of power generation units having different efficiency characteristics. Therefore, more efficient operation can be performed with respect to the amount of fuel used as compared with the prior art.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Combustor 3 Gas turbine 4 Generator 5 Power generation unit 10 Power station load control device 30, 40 Fuel amount calculation circuit 31, 41 Correction load calculation circuit 32, 33, 42, 43, 44 Equal load distribution correction circuit 35, 45, 55 Medium power supply / power plant, central power supply command station, power plant 36, 46, 56 Manual unit correction circuit 37, 47, 57 Equal load distribution calculation circuit 381, 382, 481, 482, 483, 581 Manual setting device 391 , load command from 392,491,492,493,591 switch W _D central feed command / power plant (load command value, the load command signal)
Total output of _WS manual unit N Number of power generation units

Claims (7)

In a power plant load control device of a power plant composed of a plurality of power generation units,
An equal load distribution calculation circuit that evenly distributes load command values of power plants to the plurality of power generation units according to the respective operating states of the plurality of power generation units;
A fuel amount calculation circuit for calculating the amount of fuel used in the power plant from each operation state signal of each of the plurality of power generation units and each operation characteristic function of the plurality of power generation units;
A correction load calculation circuit for calculating a correction load command value to the plurality of power generation units so that the amount of fuel used in the power plant is minimized;
With
A power plant load control device characterized in that a load command signal from a central power supply command station or the power plant is used as an input signal, and load commands to the plurality of power generation units are used as output signals. The power plant load control device according to claim 1,
A power plant load characterized in that a load command to the plurality of power generation units includes an operation mode based on a load command signal from the central power supply command station and an operation mode based on a load command signal from the power plant. Control device. The power plant load control device according to claim 1,
When the power plant load control device is operated in an operation mode based on a load command signal from the central power supply command station or the power plant,
The power plant load control device, wherein the equal load distribution calculation circuit divides a load command signal from the central power feeding command station or the power plant by the plurality of power generation units. The power plant load control device according to claim 1,
The power plant load control device characterized in that an operation characteristic function of each of the plurality of power generation units is represented by a function of the load of the power generation unit and the amount of fuel used or a function of the output of the power generation unit and the power generation efficiency. The power plant load control device according to claim 1,
Fuel used in a load in which the fuel amount calculation circuit increases or decreases a predetermined amount in the output of the equal load distribution calculation circuit for each of the plurality of power generation units or for the power generation units grouped by the operation characteristic function A power plant load control device characterized in that a total amount of fuel used in a power plant is obtained by obtaining the amounts and adding them. The power plant load control device according to claim 1,
The correction load calculating circuit continuously changes a predetermined amount of load to the output of the equal load distribution calculating circuit for each of the plurality of power generating units or the power generating units grouped by the operation characteristic function. A load control device for a power plant, wherein a load amount value that minimizes the amount of fuel used is determined. The power plant load control device according to claim 1,
In addition, equipped with a uniform load distribution correction circuit,
The power plant load control device, wherein the equal load distribution correction circuit adds an output signal from the correction load calculation circuit to an output signal from the equal load distribution calculation circuit.

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