Power generation control device, unit price determination device, power supply control system, power generation control method, and program

Abstract

A power generation control device provided in each of a plurality of power plants is provided with: an optimal value determination unit that determines an optimal value for the power output of the power plant on the basis of the unit price of the generated power supplied to the power system; and an adjustment unit that adjusts a command value of the power output corresponding to the frequency of the power system, using the optimal value as an upper limit of the power output.

Description

Technical Field

[0001] The present invention particularly relates to a power generation control device, a unit price determination device, a power supply control system, a power generation control method, and a computer-readable recording medium in a power system in which a plurality of power generation operators that are liberalized and independent in power generation each supply power generation electricity.

[0002] This application claims the priority of Japanese Patent Application No. 2022-200958 filed on December 16, 2022, and incorporates its content herein. Background Art

[0003] Conventionally, power systems have been substantially operated by a single power operator in each region. The power operator in the region has a sufficient number of power plants to meet the power demand in the region and plays a role of adjusting the load distribution of the power plants to meet the power demand in the region at the minimum fuel cost. Among multiple power plants, the characteristics of the fuel cost of each power plant are different, and even if the total power generation amount is the same, the total amount of fuel cost required depends on whether the load distribution to the power plants is good. Adjusting the load distribution to the power plants to meet the power demand in the region at the minimum fuel cost is important for the power operator.

[0004] If the load distribution with the minimum fuel cost is called the optimal load distribution, the optimal load distribution of a power plant can generally be obtained by the equal incremental fuel cost method. The property well-known in economics as the law of increasing marginal cost, the property that the cost additionally required to add one unit of power generation amount (i.e., utility) increases together with the utility, also applies to power plants. Regarding the equal incremental fuel cost method, it is used to determine the optimal load distribution of the power plants in operation. Therefore, conventionally, the power operator determines the combination of the power plants to be operated and then performs load distribution according to the equal incremental fuel cost method to save fuel costs (for example, refer to Patent Document 1).

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 63-066144 Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] In recent years, with the liberalization of power generation in the power system, power is supplied in each region from the power plants of the former power operators and the power plants of new independent power generation operators. The former power operators are also among the independent power generation operators and share the regional demand with multiple independent power generation operators. The power system generates electricity according to demand. For power generation operators, the demand is fixed, and at the same time, the total amount of power generation of the entire power generation operators is also fixed. Therefore, assuming that the demand is constant, for example, if a certain power generation operator increases the power generation to improve the profit, then any other power generation operator will reduce the power generation to make the demand match the supply. Although rarely realized, for the operator who reduces the power generation for supply-demand adjustment, it will force the profit to deteriorate.

[0010] In the era when the power plants in a region belong to one power generation operator, the profit of each power plant is not important. Therefore, a power generation operator only needs to allocate the total power generation load that meets the regional demand at the minimum fuel cost to the power plants, for example. However, in the case where multiple power generation operators share the regional demand, fairness is also required in the way of demand allocation.

[0011] In the power system with power generation liberalization, sometimes each power plant becomes a profit unit. Therefore, it is inevitable for each power plant to act in a self-interested manner to improve its own profit. Therefore, a technology is needed that coordinates the self-interested behaviors of each power plant to just meet the demand appropriately.

[0012] An object of the present invention is to provide a power generation control device, a unit price determination device, a power supply control system, a power generation control method, and a computer-readable recording medium that can adjust the power output according to the unit price of the generated power and the demand while suppressing the benefits or disadvantages from unfairly favoring some power generation operators in a power system where multiple power generation operators supply the generated power respectively.

[0013] Means for solving the technical problem

[0014] According to one aspect of the present invention, the power generation control device provided in each of the multiple power plants includes: an optimal value determination unit that determines the optimal value of the power output of the power plant according to the unit price of the generated power supplied to the power system; and an adjustment unit that uses the optimal value as the upper limit of the power output and adjusts the command value of the power output corresponding to the frequency of the power system.

[0015] According to one aspect of the present invention, a unit price determination device includes: a total value acquisition unit that acquires, from each of a plurality of power plants, a total value of optimal values of power outputs corresponding to unit prices of generated power supplied to a power system, and a total value of balance point signals that are values of power outputs adjusted in such a manner that a deviation between the frequency of the power system and a reference frequency approaches zero; and a unit price determination unit that determines the unit price based on the total value of the optimal values and the total value of the balance point signals.

[0016] According to one aspect of the present invention, a power supply control system that controls power supplied to a power system includes the power generation control device according to the above aspect and the unit price determination device according to the above aspect.

[0017] According to one aspect of the present invention, a power generation control method includes the steps of: determining an optimal value of a power output of a power plant based on a unit price of generated power supplied to a power system; and adjusting a command value of the power output corresponding to the frequency of the power system with the optimal value as an upper limit of the power output.

[0018] According to one aspect of the present invention, a computer-readable recording medium records a program that causes power generation control devices provided in respective ones of a plurality of power plants to execute the steps of: determining an optimal value of a power output of a power plant based on a unit price of generated power supplied to a power system; and adjusting a command value of the power output corresponding to the frequency of the power system with the optimal value as an upper limit of the power output.

[0019] Advantages of the Invention

[0020] According to the above aspect, in a power system in which a plurality of power generation operators each supply generated power, it is possible to adjust the power output based on the unit price and demand of the generated power while suppressing the benefit or disadvantage from unfairly favoring some power generation operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. is a diagram showing the overall configuration of the power supply control system according to the first embodiment.

[0022] Figure 2 FIG. is a first block diagram showing the functional configuration of the power generation control device according to the first embodiment.

[0023] Figure 3 FIG. is a second block diagram showing the functional configuration of the power generation control device according to the first embodiment.

[0024] Figure 4 FIG. is a block diagram showing the functional configuration of the aggregation device and the unit price determination device according to the first embodiment.

[0025] Figure 5This is a diagram showing the overall structure of the power supply control system according to a modified example of the first embodiment.

[0026] Figure 6 This is a diagram showing the overall structure of the power supply control system according to a modified example of the second embodiment.

[0027] Figure 7 This is a block diagram showing the functional structure of the power generation control device according to the second embodiment.

[0028] Figure 8 This is the first diagram for explaining the function of the redistribution device according to the second embodiment.

[0029] Figure 9 This is the second diagram for explaining the function of the redistribution device according to the second embodiment.

[0030] Figure 10 This is a diagram showing an example of the hardware structure of the distribution device according to at least one embodiment. Detailed Embodiment

[0031] <First Embodiment>

[0032] Hereinafter, the first embodiment will be described in detail with reference to the accompanying drawings.

[0033] (Overall Structure)

[0034] Figure 1 This is a diagram showing the overall structure of the power supply control system according to the first embodiment.

[0035] In Figure 1 an example of the power system 10 in a certain area is shown. The power system 10 according to the present embodiment is a power system with liberalized power generation. Multiple power generation operators each own and operate one or more power plants, and supply the power generated in each power plant to the power system. For example, Figure 1 the multiple power plants 1, 2, ……, n shown can be respectively owned and operated by different power generation enterprises. And, the power plants can be, for example, power generation facilities using natural energy such as sunlight and wind in addition to thermal power plants and nuclear power plants.

[0036] The power supply control system 1 adjusts the power output of each power plant in the power system 10. The power supply control system 1 includes a power generation control device 2, an aggregation device 3, and a unit price determination device 4.

[0037] The power generation control device 2 is provided in each of the multiple power plants 1, 2, ……, n. The power generation control device 2 adjusts the power output of the power plant where the device is installed according to the unit price γ of the generated power and the demand of the region (power system).

[0038] The aggregation device 3 aggregates various information for determining the unit price by the unit price determination device 4 from each power generation control device 2.

[0039] The unit price determination device 4 determines the unit price γ of the generated power within the region based on the information aggregated by the aggregation device 3.

[0040] (Functional Structure of Power Generation Control Device)

[0041] Figure 2 It is the first block diagram showing the functional structure of the power generation control device according to the first embodiment.

[0042] Reference Figure 2 , the functional structure of the power generation control device 2 will be described. The power generation control device 2 includes an optimal value determination unit 21 and an adjustment unit 22. The optimal value determination unit 21 determines the optimal value u of the power output of the power plant according to the unit price γ of the generated power in the power system. * . The adjustment unit 22 uses the optimal value u of the power output * as the upper limit to adjust the command value u of the power output corresponding to the frequency f of the power system.

[0043] The processing of the power generation control device 2 will be described in detail. Let the power output (command value) of the power plant to which the power generation control device 2 issues a command be u. The power output u [kW] of the power plant has a lower limit value u_ (the underline is marked on u. The same applies hereinafter.) and an upper limit value u¯ (the overline is marked on u. The same applies hereinafter.). The power generation cost of the power plant is approximately expressed by the following formula (1). The coefficients {β 2 , β 1 , β 0} represent the relationship between the power output and the cost, and the values are determined by each power plant.

[0044] [Equation 1]

[0045]

[0046] When the power output is increased by one unit, the additional generated power cost is denoted as the marginal cost m c . Since the marginal cost m c is obtained by differentiating the cost with respect to the power output, it is expressed by the following formula (2).

[0047] [Equation 2]

[0048]

[0049] Generally, regarding the power generation cost relative to the power output, the law of increasing marginal cost well-known in economics holds. The law of increasing marginal cost means that the additional cost (power generation cost) required to increase the utility (power output) by one unit gradually increases. From the perspective of power output, it can also be said that the power output per unit cost gradually decreases. If the power generation cost is approximately represented by a quadratic equation as in Equation (1), the law of increasing marginal cost is equivalent to Equation (3). Equation (3) is also expressed as β 2 > 0, 2β 2 u_ + β 1 > 0.

[0050] [Equation 3]

[0051]

[0052] In a power system with liberalized power generation, the operation of power plants is carried out according to the will of the power generation operators who own the power plants. At least usually, the operation / stop of power plants is the freedom of power generation operators. For example, other power generation operators do not instruct another power generation operator to operate / stop. Therefore, overall, the operating power plants are fixed. If the number of operating power plants is n and their respective power generation costs are represented by Equation (1), the optimal load distribution of the operating power plants, that is, the optimal power output to each power plant, is expressed as in Equation (4) with the marginal cost m c as a parameter.

[0053] [Equation 4]

[0054]

[0055] Regarding the optimal load distribution, while maintaining the total sum of the power generation output, only the distribution is changed. Therefore, according to Equation (5A), the marginal cost m c is obtained using Equation (5B).

[0056] [Equation 5A]

[0057]

[0058] [Equation 5B]

[0059]

[0060] If the marginal cost m obtained using Equation (5B) cSubstituting into Equation (4), it is possible to immediately determine the power output that each power plant should contribute in order to obtain the sum of the current power outputs of the n power plants at the minimum cost. This is known as the equal incremental fuel cost method in the optimal operation of a power plant group. However, although it is repetitive, in the liberalized power system 10, power plants are owned by different power generation operators and generate electricity. For example, it is also possible to consider that each power plant is owned by a different power generation operator. At this time, the first concern of each power generation operator will be its own profit. From the perspective of overall efficiency, it is reasonable for the less efficient power plants to reduce their power output and the other more efficient power plants to increase their power output. However, in a liberalized power system, such altruistic behavior cannot be expected. Each power generation operator will take seemingly self-interested actions to maximize its own profit. In the power system, a technology is needed that accepts the seemingly self-interested actions of power generation operators and coordinates them as a whole to meet the power demand. This technology will be described below.

[0061] Consider the profit of a power plant. If the unit price of the generated electricity is denoted as γ [￥ / kWh], the profit p of the power plant is expressed by Equation (6).

[0062] [Equation 6]

[0063]

[0064] Since the graph of Equation (6) is convex upward, the power output u at which the profit p is maximized * is obtained as in Equation (7) by solving ∂p / ∂u = 0 with respect to u.

[0065] [Equation 7]

[0066]

[0067] The value of the unit price γ of electricity is common among all power plants, but the constants β 1 and β 2 are different for each power plant. Therefore, the value of the power output u at which the profit p is maximized * becomes different for each power plant. In the liberalized power system 10, it must be noted that a power plant cannot operate at the power output u given by Equation (7) *Operation. As in the past, in an era when there was substantially one large power operator in each region, the large power operator in the region adjusted the power supply and demand. Therefore, even if the large power operator and other independent power generation operators freely increased their power generation outputs according to Equation (7) to maximize their profits, the resulting disruption to the power supply and demand balance sheet was offset by the large power operator in the region reducing its power generation output. However, it is unfair to make a specific power operator bear the responsibility for adjusting the disruption to the supply and demand balance sheet. If each power plant increases its output without permission, the power system cannot be established. Therefore, a technology is needed that enables each power generation operator to fairly share the responsibility for supply and demand adjustment.

[0068] As a technology for implementing this operation, in the present embodiment, the power generation control device 2 shown in Figure 2 is used to adjust the power output of each power plant. The power generation control device 2 is characterized in that it causes the power plant to increase or decrease its output according to the power demand. That is, the power generation control device 2 performs the following control: if the power demand increases, the power output of the power plant is correspondingly increased, and if the power demand decreases, the power output of the power plant is correspondingly decreased.

[0069] The optimal value determination unit 21 of the power generation control device 2 inputs the unit price γ of the generated power. The power generation control device 2 records the constants {β 2 , β 1 , β 0} representing the cost of the power plant, and the optimal value determination unit 21 determines the optimal value u * of the power output that maximizes the profit of the power plant according to Equation (7).

[0070] Moreover, it is also a feature of the present embodiment that instead of setting the optimal value u * as the target value of the power output, the optimal value u * is set as the upper limit value of the power output. The adjustment unit 22 of the power generation control device 2 determines the balance point signal u I of the power output of the power plant. The adjustment unit 22 causes the balance point signal u I to vary between the lower limit value u_ of the power output and the upper limit value u * according to the imbalance of the power supply and demand. As is well known, the imbalance of the power supply and demand is manifested in the variation of the AC frequency f. The frequency f of the power system is maintained at the reference frequency f n . For example, assuming that the reference frequency f n is 60 Hz, then if the supply is insufficient relative to the power demand, the AC frequency f is lower than 60 Hz, and if the supply exceeds the power demand, the AC frequency f is higher than 60 Hz. Utilizing this property, in the power system, each power plant adjusts its power output in proportion to the difference between the frequency f and the reference frequency f n as shown in Equation (8). Here, un is the reference power output [kW] of the power plant, f n is the reference frequency [Hz], and δ is the speed regulation rate (rate of increase in frequency relative to the reference frequency f n / rate of decrease in output relative to the reference power output u n . du is the GF signal (governor free signal) for adjusting the power supply and demand of the power. Regarding the GF signal du, as an approximation of Equation (8), the electrical angular velocity of the rotating shaft of the generator can be used instead of the frequency f for calculation.

[0071] [Equation 8]

[0072]

[0073] The power generation control device 2 adjusts the supply and demand according to the GF signal du with the power output balance point signal u I as the center. The balance point signal u I corresponds to a state where the level of the power output of the power plant slowly changes over, for example, a few minutes. In contrast, the GF signal du changes in units of seconds. The command value u of the power output commanded by the power generation control device 2 to the power plant is the sum of the balance point signal u I and the GF signal du as shown in Equation (9).

[0074] [Equation 9]

[0075]

[0076] In the power generation control device 2 of the present embodiment, the adjustment unit 22 makes the balance point signal u I depend on the integral value of the deviation between the frequency f of the power system and the reference frequency f n . The frequency f of the power system can use the value measured at the connection point between the power plant and the power system for each power plant, or the value measured at the representative point in the region can be used as a common value for all power plants in the region. The frequency f of the power system is approximately normally distributed with the reference frequency f n (50 Hz or 60 Hz) as the center. Therefore, the time average value of the GF signal du is usually 0. Therefore, the GF signal du does not affect the amount of power supplied by the power plant.

[0077] The integral value of the deviation of the frequency f of the power system from the reference frequency f n represents the long-term trend of the deviation of the frequency f from the reference frequency f n . For example, if the power supply and demand are balanced, the frequency f fluctuates randomly above and below the reference frequency f n as the center. At this time, the integral value of the deviation does not actually change.

[0078] And, for example, if the power supply is insufficient, the frequency f deviates to the negative side with respect to the reference frequency f n and the integral value of the deviation increases with time. That is, the balance point signal u I increases with time, and the power output level of the power plant increases. As described in Equation (7), the profit of the power plant is maximized at the power output u * and if the power output exceeds this value, the profit will be damaged instead. To prevent this, the adjustment unit 22 sets the upper limit of the balance point signal u I to u * .

[0079] Conversely, if the power supply exceeds, the frequency f deviates to the positive side with respect to the reference frequency f n and the integral value of the deviation decreases with time. That is, the balance point signal u I decreases with time, and the power output level of the power plant decreases.

[0080] The power generation control device 2 autonomously adjusts the power output level in this way so that each power plant compensates for the imbalance between power supply and demand, and thus can also autonomously and naturally achieve the adjustment of the overall power supply and demand of the power system. And by each power plant operating according to the power output command of the power generation control device 2, unlike the conventional power system, the part where one power generation operator increases the output does not require other power generation operators to reduce the output for supply and demand adjustment. That is, the power generation control device 2 can suppress the benefits or disadvantages from unfairly favoring a part of the power generation operators.

[0081] (Functional structure of the power generation control device; modified example)

[0082] And the power generation control device 2 can autonomously determine the operation and stop of the power plant. Hereinafter, with reference to Figure 3 , this technology will be described.

[0083] Figure 3 is the second block diagram showing the functional structure of the power generation control device according to the first embodiment.

[0084] As Figure 3 shown, the power generation control device 2 may further include a minimum value determination unit 23 and a control unit 24. The minimum value determination unit 23 determines the minimum value u * of the power output at which the profit of the power plant becomes zero according to the unit price γ of the generated power. The control unit 24 controls the start or stop of the operation of the power plant according to the minimum value u * of the power output at which the profit becomes zero and the balance point signal u I .

[0085] Regarding Figure 3The detailed content of the processing of the power generation control device 2 shown will be described. If the level of power output decreases, the profit of the power plant will decrease accordingly, and in some places, the profit will become zero. For simplicity, the case where the power plant stops operating when the profit is zero or less will be described. If the power output u at which the profit p becomes zero is denoted * , then by solving p = 0, its value is determined as shown in Equation (10A).

[0086] [Equation 10A]

[0087]

[0088] As Figure 3 shown, the control unit 24 compares the power output u at which the profit becomes zero * with the equilibrium point signal u I of the power plant. For example, when the power plant is stopped, if u I ≥1.05u * , it is determined that operation starts, and an operation instruction is output to the power plant. Also, when the power plant is operating, if u I ≤u * , it is determined that operation stops, and a stop instruction is output to the power plant. In addition, "1.05" is an example, and an arbitrary value can be set for each power plant according to the characteristics of the power plant, etc. In Equation (10A), β 0 represents the fixed cost. Among the fixed costs, for example, there are two types: costs such as the lighting in the control room of the power plant that do not occur as long as the operation stops, and costs such as the interest in the construction cost of the power plant that occur even if the operation stops. The fixed cost β 0 in Equation (10A) assumes the former, and it is assumed that β 0 = 0 after the operation stops. If the latter dominates in the fixed cost β 0 , the control unit 24 can control in such a way that operation continues even if the profit is less than zero, so as to recover the fixed cost. In addition, regarding the control of stopping operation, it can be controlled in such a way that operation stops when the profit becomes a preset value. The preset value can be zero or a negative value. If operation continues until the profit becomes a preset negative value -p * , then u * is determined by Equation (10B). In this embodiment, an example of judging operation stop based on profit has been described. However, profit is an example, and for example, operation stop can also be judged based on the sales amount γ×u.

[0089] [Equation 10B]

[0090]

[0091] (Functional Structures of Aggregation Device and Unit Price Determination Device)

[0092] Figure 4 This is a block diagram showing the functional structures of the aggregation device and the unit price determination device according to the first embodiment.

[0093] Reference Figure 4 , the functional structures of the aggregation device 3 and the unit price determination device 4 will be described.

[0094] The aggregation device 3 has an aggregation unit 31 that aggregates the optimal value u of the power output corresponding to the unit price γ from the power generation control devices 2 of multiple power plants 1, 2, ……, n * and the balance point signal u I .

[0095] The unit price determination device 4 has an aggregation value acquisition unit 41 and a unit price determination unit 42. The aggregation value acquisition unit 41 acquires the aggregation value of the optimal value u * and the aggregation value of the balance point signal u I from the aggregation device 3. The unit price determination unit 42 determines the unit price γ of the generated electricity based on the aggregation value of the optimal value u * and the aggregation value of the balance point signal u I .

[0096] In addition, in Figure 1 and Figure 4 , an example is shown where the aggregation device 3 and the unit price determination device 4 are separate devices, but it is not limited to this. In other embodiments, the aggregation device 3 and the unit price determination device 4 can be configured as one device.

[0097] Each power plant has an upper limit value u * for the power output. If there are n power plants operating in a certain area, the maximum value of power generation in the entire area is obtained by adding n u * and is represented by Σu * . On the other hand, for the actual total power generation in the area, n u I are added and used as Σu I . If Σu * is sufficiently large relative to Σu I , there is no need to worry about the adjustment margin for the power supply in the entire area. However, if Σu I ≈Σu * , there is no room for adjustment margin. At this time, it is necessary to add operating power plants to ensure the adjustment margin.

[0098] The minimum power output at which the power plant can obtain a profit p (the profit p is positive) is u * calculated by Equation (10). Since ∂u is obtained by differentiating u * with γ* The value of / ∂γ is negative, so if the unit price of generated electricity γ is increased, u * The power plant with positive profit p will decrease even if it is currently stopped. This can increase the adjustment margin. In addition, the upper limit value u of the power output considering the profit of the power plant currently in operation * Determined by formula (7), but using γ to u * The ∂u obtained by differentiation is * The value of / ∂γ is positive, and additional margin of adjustment can be obtained from the power plant currently in operation. In this way, if the unit price γ of the generated electricity is increased, the margin of adjustment of the power supply capacity increases.

[0099] Therefore, if the adjustment margin is excessive, the unit price determination device 4 sets the unit price γ of the generated power to a low level, and if the adjustment margin is insufficient, the unit price determination device 4 sets the unit price γ of the generated power to a high level. Figure 4 , the processing of the unit price determination device 4 is described in detail.

[0100] For example, if the power supply volume Σu in a region is I To determine the appropriate value of the adjustment margin m u , and can be calculated using formula (11). 0 is the base value of the unit price, K γ is a positive proportionality coefficient. In addition, the formula for calculating the unit price γ is not limited to a linear function. It can also be a general polynomial or exponential function.

[0101] [Formula 11]

[0102]

[0103] Furthermore, if the unit price determination device 4 notifies the power generation control device 2 of each power plant of the unit price γ of the generated electricity, then in the power system 10, as described above, the power output is regulated or the operation / stop control is performed in each power plant, thereby autonomously adjusting the supply and demand or ensuring the adjustment margin.

[0104] (Function, effect)

[0105] As described above, the power generation control device 2 according to the present embodiment includes an optimal value determination unit 21 that determines the optimal value u of the power output of the power plant based on the unit price γ of the generated power supplied to the power system. * and the adjustment unit 22, the optimal value u * As the upper limit of the electric power output, the command value u of the electric power output is adjusted according to the frequency f of the electric power system.

[0106] Accordingly, the power generation control device 2 can autonomously perform supply-demand adjustment in the entire power system 10 in each power plant. Moreover, by having each power plant operate according to the command of the power output of the power generation control device 2, situations like those in conventional power systems, where one power generation operator arbitrarily increases its output and other power generation operators are required to reduce their outputs for supply-demand adjustment, will not occur. That is, the power generation control device 2 can prevent benefits or disadvantages from being unfairly skewed towards a part of the power generation operators.

[0107] Moreover, the adjustment unit 22 of the power generation control device 2 calculates, through integral control, the value of the power output that makes the deviation between the frequency f of the power system and the reference frequency f n approach zero, and sets the optimal value u * of the power output as the upper limit of the balance point signal u I , and adjusts the command value u of the power output according to the balance point signal u I .

[0108] Accordingly, the power generation control device 2 can enable each power plant to obtain the profit from power generation and can stabilize the supply-demand balance of the power system.

[0109] Moreover, the power generation control device 2 further includes: a minimum value determination unit 23 that determines the minimum value u * of the power output at which the profit of the power plant becomes zero according to the unit price γ; and a control unit 24 that controls the start or stop of the operation of the power plant according to the minimum value u * of the power output and the balance point signal u I .

[0110] Accordingly, the power generation control device 2 can start or stop the operation of the power plant so that the power plant can more reliably obtain profit or the profit does not become negative.

[0111] Moreover, the unit price determination device 4 according to the present embodiment includes: a total value acquisition unit 41 that acquires, from each of a plurality of power plants, the total value of the optimal value u * of the power output corresponding to the unit price γ of the power generation power supplied to the power system, and the total value of the balance point signal u n that is the output target value for making the frequency f of the power system approach the reference frequency f I ; and a unit price determination unit 42 that determines the unit price γ according to the total value of the optimal value u * and the total value of the balance point signal u I .

[0112] Accordingly, by increasing or decreasing the unit price γ, the unit price determination device 4 can adjust the power output or control the start / stop of operation in each power plant, thereby autonomously performing supply-demand adjustment or ensuring the adjustment margin.

[0113] <Variation of the First Embodiment>

[0114] Figure 5 This is a diagram showing the overall structure of the power supply control system according to the variation of the first embodiment.

[0115] As Figure 5 shown, the power supply control system 1 according to this variation may further include a reverse regulation power aggregation device 5. The reverse regulation power aggregation device 5 can aggregate the amount of power (reverse regulation power) generated in excess, for example, when a power plant generates power in excess of the demand of the power system.

[0116] The reverse regulation power aggregation device 5 includes a first acquisition unit 51 and a reverse regulation power calculation unit 52. The first acquisition unit 51 acquires the balance point signal u I and the measured value y of the power output of the power plant from the power generation control devices 2 of multiple power plants. The reverse regulation power calculation unit 52 accumulates the difference between the measured value y of the power output and the balance point signal u I to calculate the amount of power q (reverse regulation power) generated in excess. The measured value y of the power output is the power [kW] measured at the connection point between the power plant and the power system.

[0117] For the power system 10 to be established, it is important to adjust the supply and demand so that the power supplied by the power plant is consistent with the demand. In the technology described in the first embodiment, this is achieved by adjusting the output of each power plant according to the balance point signal u I However, a certain power plant may generate more power than the balance point signal u I in order to increase its profit. As Figure 5 shown, the reverse regulation power calculation unit 52 accumulates the difference between the measured value y of the power output of each power plant and the balance point signal u I as the amount of power q. When the power plant generates power exceeding the balance point signal u I this amount of power q represents the reverse regulation power. And the reverse regulation power calculation unit 52 can, for example, impose a penalty of reducing the equivalent reward (sales amount) for power supply by subtracting the amount of power (reverse regulation power) of the excess generation part during the same period from the total amount of power supplied by the power plant to the power system during a specified settlement target period (for example, one day).

[0118] By thus aggregating the power generated by the power plant exceeding the balance point signal u IThe amount of generated electric power is aggregated as regulating power, and it is possible to monitor whether each power plant has appropriately adjusted supply and demand. Monitoring the regulating power functions as a suppressing force for excessive power generation, and thus it is possible to contribute to the stabilization of the supply-demand balance of the power system. Further, if the amount corresponding to the regulating power is deducted from the equivalent compensation for the power generation amount of the power plant, it is possible to more reliably suppress the excessive power generation of the power plant.

[0119] <Second Embodiment>

[0120] The power supply control system 1 according to the second embodiment increases the profit p of the power generation operator when the power generation operator has a plurality of power plants.

[0121] Figure 6 It is a diagram showing the overall configuration of the power supply control system according to the modified example of the second embodiment.

[0122] In Figure 6 this example, it is assumed that a power generation operator has power plants 1, 2,..., n among a plurality of power plants that supply power to a certain area Q . The power plants 1, 2,..., n Q owned by one power generation operator are also collectively referred to as a power plant group. Further, the power supply control system 1 further includes a redistribution device 6. The redistribution device 6 redistributes the power outputs of the power plants 1, 2,..., n Q belonging to the power plant group, respectively.

[0123] The redistribution device 6 includes a second acquisition unit 61 and a redistribution unit 62. The second acquisition unit 61 acquires, from each of the power plants belonging to the power plant group, a balance point signal u I that is an output target value for bringing the frequency of the power system close to the reference frequency, and a coefficient β related to the cost required for power generation. The redistribution unit 62 redistributes the power outputs of the power plants belonging to the power plant group so as to minimize the overall power generation cost of the power plant group based on the balance point signal u I and the coefficient β.

[0124] In addition, Figure 6 an example in which the redistribution device 6 is added to the power supply control system 1 ( Figure 1 ) according to the first embodiment is shown, but it is not limited thereto. The redistribution device 6 may also be added to the power supply control system 1 ( Figure 5 ) according to the modified example of the first embodiment.

[0125] Figure 7 It is a block diagram showing the functional configuration of the power generation control device according to the second embodiment.

[0126] In the power generation control device 2 according to the present embodiment, the adjustment unit 22 further adjusts the command value u of the power output according to the power output redistributed by the redistribution device 6.

[0127] If a power generation operator has multiple power plants, the power generation operator has the freedom to select the power plants to be used, and usually selects a combination of power plants in consideration of economy. If the combination of power plants operated by a certain power generation operator is denoted as Q, the total power output supplied by the power generation operator is obtained by the following formula (12).

[0128] [Equation 12]

[0129]

[0130] In Figure 6 as a specific example, it is simply shown as Q = {1, 2,..., n Q}. The actual Q is not limited to consecutive numbers. Regarding the combination Q of power plants, the total power output is calculated according to the balance point signals u I of the respective power plants included in the combination. The reason is to avoid fluctuations in the total power output caused by the GF signal that changes within a short period of time.

[0131] In the power system 10 with power generation liberalization, the total power output supplied by the power generation operator is determined by the balance of power demand and supply, and is fixed for the power generation operator. Therefore, the power generation operator pursues profit by generating electricity at a lower cost for the total power output u Q . If a power generation operator has multiple power plants, as described above, the power generation operator has the freedom to select the power plants to be used. Moreover, the power generation operator can increase profit by increasing the allocation to power plants with high efficiency and stopping or reducing the allocation to power plants with low efficiency for the total power output u Q . The situation of changing the output allocation of power plants while maintaining the total power output supplied by the power generation operator is usually referred to as "replacement". Therefore, this embodiment also follows this expression and uses Figures 6 - 9 to describe the replacement method.

[0132] Figure 8 is the first diagram for explaining the function of the redistribution device according to the second embodiment.

[0133] Assume that a power generation operator operates a group of power plants with the combination Q. When the combination of operating power plants is fixed, the optimal replacement can be achieved by the equal incremental fuel cost method. When performing replacement within the combination Q, the equal incremental fuel cost method is expressed as an optimization problem as shown in the following formula (13).

[0134] [Equation 13]

[0135]

[0136] In Equation (13), Δu I，i is the power output replaced for power plant i which is an element of Q. Since the total power output of the entire combination Q must remain unchanged before and after the replacement, the sum of Δu I，i is 0. Equation (13) represents an optimization problem that minimizes the sum of the costs c of each power generation cost that forms the combination Q under this constraint condition.

[0137] The optimization problem of Equation (13) can be solved by the Lagrange undetermined multiplier method. If the Lagrange multiplier is set to λ and the Lagrange function L(Δu I , λ) is set as in Equation (14), then the optimal values of Δu I and λ are the Δu I ∈R nQ and λ ∈ R 1 that satisfy the simultaneous equations of Equation (15).

[0138] [Equation 14]

[0139]

[0140] [Equation 15]

[0141]

[0142] If the two equations are expanded, they become a system of simultaneous equations of degree n Q +1 of Equation (16).

[0143] [Equation 16]

[0144]

[0145] If the cost c is expanded, Equation (17) is obtained.

[0146] [Equation 17]

[0147]

[0148] Equation (17) is a system of linear simultaneous equations of the first degree with respect to the Lagrange multiplier λ and Δu I , and the optimal solutions are obtained as in Equations (18) and (19).

[0149] [Equation 18]

[0150]

[0151] [Equation 19]

[0152]

[0153] As Figure 6 and Figure 8 shown, the redistribution device 6 inputs the respective balance point signals u I and the parameters {β 2 , β 1 , β 0} representing the power generation cost from the power plants in operation, and outputs the replaced power output Δu I . Figure 7 Indicates the manner in which the replaced power output Δu I is reflected in the power output u. The replaced power output Δu I is reflected in the power output u in the same manner as the GF adjustment signal. It is independent of the balance point signal u I . This is to strictly ensure that the balance point signal u I is determined only based on the frequency f. Regarding the combination Q of the power plants in operation, if the replaced power outputs Δu I are added, it becomes 0. Therefore, whether or not to reflect the replaced power output Δu I in the balance point signal u I is independent of the function of the anti-regulation power aggregation device 5 related to the modification example of the first embodiment ( Figure 5 ), and thus there is no inconvenience even if processed in this way.

[0154] In each power plant, there is a limit on the rate of change of the power output. For example, it is impossible to increase the power output from 0% output to 100% output within 1 second. Therefore, the rate of change of Δu I can be restricted so that the value of the replaced power output Δu I does not change abruptly. For example, the time rate of change of the replaced power output can be restricted so that even the power plant with the slowest rate of change of the power output can follow. When restricting the rate of change of the replaced power output in each power plant, Equation (20) can be used as a constraint condition in the determination of the rate of change so that the restriction on the time rate of change does not affect Equation (12).

[0155] [Equation 20]

[0156]

[0157] The redistribution process (based on the equal-increment fuel cost method) continuously replaces in time because the calculations of Equations (18) and (19) are frequently repeated. Thus, the optimal load distribution is achieved in real time.

[0158] Power generation operators with multiple power plants have the freedom to select highly efficient power plants from the owned power plants for use, so the optimal power plants should be selected considering economy. Power demand changes over time. For example, production activities are active during the day, so power demand is high, and most production activities stop at night, so power demand is low. Thus, if the demand changes over time, the corresponding combination of optimal power plants must also change. The power generation operator adjusts the combination Q of operating power plants through separately implemented combination optimization processing. The adjustment of the combination Q of operating power plants means (1) stopping the power plants included in the combination Q, (2) newly adding power plants to the combination Q, and (3) maintaining any one of the combination Q. Among them, the processing of (3) is as Figure 8 shown. (2) just adds new power plants to Q. After adding, the processing by the power output redistribution device is exactly the same as (3). (1) Since part of the processing of the redistribution unit 62 of the redistribution device 6 must be changed, Figure 9 it will be described below.

[0159] Figure 9 Fig. 2 is a second diagram for explaining the function of the redistribution device according to the second embodiment.

[0160] Suppose that before adjustment, the power generation operator operates a power plant group composed of Q, and stops power plant k from the combination Q. The remaining power plants are the power plants after removing power plant k from the combination Q, so it is denoted as Q\k. The total power output before stopping power plant k must be replaced by the remaining power plants after stopping power plant k. This is a constraint condition, and is represented by Equation (21).

[0161] [Equation 21]

[0162]

[0163] The optimization problem of minimizing the cost with Equation (21) as the constraint condition is represented by Equation (22).

[0164] [Equation 22]

[0165]

[0166] This problem can also be solved by the Lagrange undetermined multiplier method as described previously. Specifically, they are Equation (23) and Equation (24).

[0167] [Equation 23]

[0168]

[0169] [Equation 24]

[0170]

[0171] Regarding the stopped power plant k, the power output must be made to become 0 from the current value u I，k Therefore, the replaced power output is expressed by Equation (25).

[0172] [Equation 25]

[0173]

[0174] In this way, for the case of "(1) stopping the power plants included in the combination Q", Equation (12) also holds. Therefore, for the case of "(1) stopping the power plants included in the combination Q" described here ( Figure 9 ), the difference from the previously described case of "(3) maintaining the combination Q" ( Figure 8 ) is that, like the stopped power plant k, the output of the power plant is not left to the incremental fuel cost method but is determined by the presence or absence of the output specified from the outside. If all are left to the incremental fuel cost method, it is (3), otherwise it is (1).

[0175] Let the symbol k represent the power plant whose output is specified from the outside. Since k can also be multiple, the set of k is represented by K. That is, if K = {1, 2,..., n K} and k ∈ K, then Δu I，k is the value specified from the outside. At this time, instead of changing the output of the entire power plant Q in operation as in Equation (12), the problem of specifying the power output of the power plants belonging to K from the outside by r I，k and optimizing the output of the power plants not belonging to K (that is, belonging to the set Q\K) by the incremental fuel cost method is expressed as in Equation (26). For example, in the case of stopping the power plant k, it is only necessary to set K = {k} and r I，k = 0 kW. And, for example, in the case of stopping the power plant k and making the power plant k + 1 100 MW, it is only necessary to set K = {k, k + 1} and r I，k+1 = 100 MW.

[0176] [Equation 26]

[0177]

[0178] In this way, in the case where the power supply control system 1 according to the present embodiment is owned by a power generation operator with multiple power plants, the redistribution device 6 redistributes the power output of each power plant, thereby enabling the power generation operator to increase profits.

[0179] <Hardware Structure>

[0180] Figure 10This is a diagram showing an example of the hardware configuration of the distribution device related to at least one embodiment.

[0181] Hereinafter, with reference to Figure 10 , an example of the hardware configuration of each device included in the power supply control system 1 will be described.

[0182] As Figure 10 shown, the computer 900 includes a processor 901, a main storage device 902, an auxiliary storage device 903, and an interface 904.

[0183] The power generation control device 2, the aggregation device 3, the unit price determination device 4, the reverse regulation power aggregation device 5, and the redistribution device 6 described in each of the above embodiments are respectively installed in the computer 900. Further, the operations of the above-described respective processing units are stored in the auxiliary storage device 903 in the form of programs. The processor 901 reads the programs from the auxiliary storage device 903 and expands them in the main storage device 902, and executes the above processing in accordance with the programs. Further, the processor 901 ensures a storage area used in various processes in the main storage device 902 in accordance with the programs. Further, the processor 901 ensures a storage area for storing data in the storage process in the auxiliary storage device 903 in accordance with the programs.

[0184] The programs can be used to implement a part of the functions that the computer 900 exhibits. For example, the programs can exhibit functions by being combined with other programs already stored in the auxiliary storage device 903 or by being combined with other programs installed in other devices. Further, in other embodiments, the computer 900 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, a part or all of the functions implemented by the processor 901 can be implemented by this integrated circuit.

[0185] As an example of the auxiliary storage device 903, an HDD (Hard Disk Drive), an SSD (Solid State Drive), a magnetic disk, an optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), a semiconductor memory, etc. can be cited. The auxiliary storage device 903 can be an internal medium directly connected to the bus of the computer 900, or can be an external storage device 910 connected to the computer 900 via the interface 904 or a communication line. Further, when the program is transmitted to the computer 900 via the communication line, the computer 900 that has received the transmission can expand the program in the main storage device 902 and execute the above-described processing. In at least one embodiment, the auxiliary storage device 903 and the external storage device 910 are non-transitory tangible storage media.

[0186] As described above, some embodiments of the present invention have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. Similarly to being included in the scope or gist of the invention, these embodiments and their modifications are also included in the scope of the invention and its equivalents described in the claims.

[0187] <Supplementary Note>

[0188] The power generation control device, unit price determination device, power supply control system, power generation control method, and computer-readable recording medium described in the above embodiments are understood as follows, for example.

[0189] (1) According to the first aspect of the present invention, the power generation control device 2 provided in each of the plurality of power plants includes: an optimal value determination unit 21 that determines an optimal value u of the power output of the power plant based on the unit price γ of the generated power supplied to the power system * ; and an adjustment unit 22 that uses the optimal value u * as the upper limit of the power output and adjusts the command value u of the power output corresponding to the frequency f of the power system.

[0190] Accordingly, the power generation control device 2 can autonomously perform supply-demand adjustment in the entire power system 10 in each power plant. Moreover, by having each power plant operate according to the command of the power output of the power generation control device 2, unlike in the conventional power system, it is not necessary for one power generation operator to increase the output while other power generation operators reduce the output for supply-demand adjustment. That is, the power generation control device 2 can suppress the benefits or disadvantages from unfairly favoring a part of the power generation operators.

[0191] (2) According to the second aspect of the present invention, in the power generation control device 2 according to the first aspect, the adjustment unit 22 calculates, by integral control, a value of the power output adjusted in such a way that the deviation between the frequency f of the power system and the reference frequency f n approaches zero, and sets the optimal value u * as the upper limit of the balance point signal u I , and adjusts the command value u of the power output according to the balance point signal u I .

[0192] Accordingly, the power generation control device 2 can enable each power plant to obtain the profit from power generation, and can stabilize the supply-demand balance of the power system.

[0193] (3) According to the third aspect of the present invention, the power generation control device 2 according to the second aspect further includes: a minimum value determination unit 23 that determines the minimum value u of the power output at which the profit p of the power plant becomes a preset value according to the unit price γ * ; and a control unit 24 that controls the start or stop of the operation of the power plant according to the minimum value u * and the balance point signal u I .

[0194] Accordingly, the power generation control device 2 can operate or stop the power plant so that the power plant can more reliably obtain profit or the profit does not become negative.

[0195] (4) According to the fourth aspect of the present invention, the unit price determination device 4 includes: a total value acquisition unit 41 that acquires, from each of a plurality of power plants, a total value of the optimal value u of the power output corresponding to the unit price γ of the generated power supplied to the power system, and a total value of the balance point signal u that is a value of the power output adjusted in such a way that the deviation between the frequency f of the power system and the reference frequency f * approaches zero; and a unit price determination unit 42 that determines the unit price γ according to the total value of the optimal value u n and the total value of the balance point signal u I . * and the total value of the balance point signal u I .

[0196] Accordingly, the unit price determination device 4 can adjust the power output or control the operation / stop in each power plant by increasing or decreasing the unit price γ, thereby autonomously performing supply-demand adjustment or ensuring the adjustment margin.

[0197] (5) According to the fifth aspect of the present invention, the power supply control system 1 for controlling the power supplied to the power system includes the power generation control device 2 according to any one of the first to third aspects and the unit price determination device 4 according to the fourth aspect.

[0198] (6) According to the sixth aspect of the present invention, the power supply control system 1 according to the fifth aspect further includes a counter-regulation power aggregation device 5 that aggregates the counter-regulation power of each of the plurality of power plants. The counter-regulation power aggregation device 5 has: a first acquisition unit 51 that acquires, from each of the plurality of power plants, a balance point signal u that is a value of the power output adjusted in such a way that the deviation between the frequency f of the power system and the reference frequency f n approaches zero, and a measured value y of the power output of the power plant; and a counter-regulation power calculation unit 52 that accumulates the difference between the measured value y of the power output and the balance point signal u I to calculate the amount of over-generated power as the counter-regulation power q. I

[0199] Accordingly, the power supply control system 1 can monitor whether each power plant has appropriately performed supply-demand adjustment by aggregating the counter-regulation power by the counter-regulation power aggregation device 5. Monitoring the counter-regulation power acts as a suppression force for over-generation, so it can contribute to the stabilization of the supply-demand balance of the power system. And if the amount corresponding to the counter-regulation power is deducted from the equivalent remuneration for the power generation of the power plant, the over-generation of the power plant can be more reliably suppressed.

[0200] (7) According to the seventh aspect of the present invention, the power supply control system 1 according to the fifth or sixth aspect further includes a redistribution device 6 that redistributes the power output of each of the power plants belonging to a power plant group composed of two or more of the plurality of power plants. The redistribution device 6 has: a second acquisition unit 61 that acquires, from each of the power plants belonging to the power plant group, a balance point signal u that is a value of the power output adjusted in such a way that the deviation between the frequency f of the power system and the reference frequency f n approaches zero, and a coefficient β related to the cost required for power generation; and a redistribution unit 62 that redistributes the power output of each of the power plants belonging to the power plant group in such a way as to minimize the overall power generation cost of the power plant group according to the balance point signal u I and the coefficient β. I

[0201] Accordingly, the power supply control system 1 can redistribute the power output of each power plant belonging to the power plant group to increase the overall profit of the power plant group. The power plant group is composed of, for example, multiple power plants owned by a single power generation operator. The power generation operator can generate the power to be supplied by the power plant group it owns at the lowest cost, and accordingly can increase the profit of the power generation operator.

[0202] (8) According to the eighth aspect of the present invention, in the power supply control system 1 according to the seventh aspect, the adjustment unit 22 of the power generation control device 2 further adjusts the command value u of the power output according to the power output redistributed by the redistribution device 6.

[0203] Accordingly, the power supply control system 1 can enable the power plants belonging to the power plant group to operate autonomously and effectively at the lowest power generation cost.

[0204] (9) According to the ninth aspect of the present invention, the power generation control method includes the following steps: determining the optimal value u of the power output of the power plant according to the unit price γ of the power generation power supplied to the power system * ; and using the optimal value u * as the upper limit of the power output, and adjusting the command value u of the power output corresponding to the frequency f of the power system.

[0205] (10) According to the tenth aspect of the present invention, a computer-readable recording medium records a program that causes the power generation control devices 2 provided in multiple power plants to perform the following steps: determining the optimal value u of the power output of the power plant according to the unit price γ of the power generation power supplied to the power system * ; and using the optimal value u * as the upper limit of the power output, and adjusting the command value u of the power output corresponding to the frequency f of the power system.

[0206] Industrial Applicability

[0207] According to the above aspects, in a power system in which multiple power generation operators each supply power generation power, it is possible to adjust the power output according to the unit price and demand of the power generation power while suppressing the benefit or disadvantage from unfairly favoring a part of the power generation operators.

[0208] Symbol Explanation

[0209] 1 - Power supply control system, 10 - Power system, 2 - Power generation control device, 21 - Optimal value determination unit, 22 - Adjustment unit, 23 - Minimum value determination unit, 24 - Control unit, 3 - Aggregation device, 31 - Aggregation department, 4 - Unit price determination device, 41 - Aggregate value acquisition unit, 42 - Unit price determination unit, 5 - Reverse adjustment power aggregation device, 51 - First acquisition unit, 52 - Reverse adjustment power calculation unit, 6 - Redistribution device, 61 - Second acquisition unit, 62 - Redistribution department, 900 - Computer, 901 - Processor, 902 - Main storage device, 903 - Auxiliary storage device, 904 - Interface, 910 - External storage device.

Claims

1. A power generation control device is provided for each of a plurality of power plants, and the power generation control device includes: An optimal value determination unit that determines an optimal value of the power output of a power plant according to the unit price of the generated power supplied to the power system; and An adjustment unit that uses the optimal value as the upper limit of the power output and adjusts the command value of the power output corresponding to the frequency of the power system.

2. The power generation control device according to claim 1, wherein, The adjustment unit calculates a balance point signal whose value of the power output adjusted to make the deviation between the frequency of the power system and the reference frequency approach zero by integral control and uses the optimal value as the upper limit, and adjusts the command value of the power output according to the balance point signal.

3. The power generation control device according to claim 2, further including: A minimum value determination unit that determines a minimum value of the power output at which the profit of the power plant becomes a preset value according to the unit price; and A control unit that controls the start or stop of the operation of the power plant according to the minimum value and the balance point signal.

4. A unit price determination device includes: An aggregate value acquisition unit that acquires, from each of a plurality of power plants, an aggregate value of the optimal values of the power output corresponding to the unit price of the generated power supplied to the power system, and an aggregate value of the balance point signals that are values of the power output adjusted to make the deviation between the frequency of the power system and the reference frequency approach zero; and A unit price determination unit that determines the unit price according to the aggregate value of the optimal values and the aggregate value of the balance point signals.

5. A power supply control system controls the power supplied to the power system, and the power supply control system includes: The power generation control device according to any one of claims 1 to 3; and The unit price determination device according to claim 4.

6. The power supply control system according to claim 5, further including an anti-regulation power aggregation device that aggregates the anti-regulation power of each of the plurality of power plants, The anti-regulation power aggregation device has: A first acquisition unit that acquires, from each of a plurality of power plants, a balance point signal that is a value of the power output adjusted to make the deviation between the frequency of the power system and the reference frequency approach zero, and a measured value of the power output of the power plant; and An anti-regulation power calculation unit that accumulates the difference between the measured value of the power output and the balance point signal to calculate the amount of over-generated power as the anti-regulation power.

7. The power supply control system according to claim 5, further including a redistribution device that redistributes the power output of each of the power plants belonging to a power plant group composed of two or more of the plurality of power plants, The redistribution device has: A second acquisition unit that acquires, from each of the power plants belonging to the power plant group, a balance point signal that is a value of the power output adjusted to make the deviation between the frequency of the power system and the reference frequency approach zero, and a coefficient related to the cost required for power generation; A redistribution unit redistributes the power outputs of the power plants belonging to the power plant group in a manner that minimizes the overall power generation cost of the power plant group, based on the balance point signal and the coefficient.

8. The power supply control system according to claim 7, wherein, an adjustment unit of the power generation control device further adjusts a command value of the power output according to the power output redistributed by the redistribution device.

9. A power generation control method, comprising the following steps: determining an optimal value of the power output of a power plant according to the unit price of the power generated and supplied to the power system; and using the optimal value as an upper limit of the power output and adjusting the command value of the power output corresponding to the frequency of the power system.

10. A program that causes power generation control devices provided in respective ones of a plurality of power plants to execute the following steps: determining an optimal value of the power output of a power plant according to the unit price of the power generated and supplied to the power system; and using the optimal value as an upper limit of the power output and adjusting the command value of the power output corresponding to the frequency of the power system.

Images