Power generation control device, power supply control system, power generation control method, and program

Abstract

To provide a power generation control device that can adjust electrical output according to the unit price and demand of generated power in a power system in which a plurality of power generation companies each supply generated power, while preventing unfair bias in the benefits or disadvantages of some power generation companies.SOLUTION: A power generation control device provided in each of a plurality of power plants includes an optimal value determination unit that determines the optimal value of the power output of the power plant on the basis of the unit price of the generated power supplied to a power grid, and an adjustment unit that adjusts the command value of the electrical output according to the frequency of the power grid, with the optimal value as the upper limit of the electrical output.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure 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 program for a power system in which power generation is liberalized and multiple independent power generation companies each supply generated power. [Background technology]

[0002] Traditionally, the power system has been operated by essentially one electric utility per region. A local electric utility owns a sufficient number of power plants to meet the electricity demand of that region, and has been responsible for adjusting the load dispatch of power plants to meet the local electricity demand at the lowest fuel cost. Each of the many power plants has different fuel cost characteristics, and even if the total amount of electricity generated is the same, the total fuel cost depends on the quality of the load dispatch to the power plants. It is important for electric utilities to adjust the load dispatch to power plants to meet the local electricity demand at the lowest fuel cost.

[0003] If we call the load distribution that minimizes fuel costs optimal load distribution, then the optimal load distribution of a power plant can generally be obtained using the equal incremental fuel cost method. A property widely known in economics as the law of increasing marginal cost, which states that the additional cost required to add one unit of power generation, or utility, increases with utility, also applies to power plants. The equal incremental fuel cost method utilizes this property to determine the optimal load distribution of operating power plants. Therefore, traditionally, electric power utilities have decided on the combination of power plants to operate, and then distribute the load according to the equal incremental fuel cost method to save on fuel costs (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 63-066144 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, power generation in the electricity system has been liberalized, and each region now receives electricity from power plants operated by traditional electric utilities and new independent power producers. Traditional electric utilities are also independent power producers, and they share local demand with multiple independent power producers. The electricity system generates electricity according to demand. For power producers, demand is a given, and at the same time, the total amount of electricity generated by all power producers is also a given. Therefore, assuming demand remains constant, for example, if a power producer increases its power generation to improve profits, another power producer will reduce its power generation to ensure that supply and demand are equal. Although it is not often recognized, producers who reduce their power generation to adjust supply and demand are forced to endure a decline in their profits.

[0006] In the days when local power plants belonged to a single power generation company, the profits of each power plant were not important, so a single power generation company could simply allocate the load to power plants based on the total amount of power generated to meet local demand with minimal fuel costs. However, when multiple power generation companies share local demand, fairness is also required in how that demand is distributed.

[0007] In a liberalized power system, each power plant can be a unit of revenue, and it is inevitable that each power plant will act selfishly to improve its own profits. Therefore, technology is needed to harmonize the selfish actions of each power plant so that the overall demand is met without excess or shortage.

[0008] The object of the present disclosure 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 program that can adjust electrical output according to the unit price and demand of generated power, while preventing unfair bias in the benefits or disadvantages of some power generation companies in a power system in which multiple power generation companies each supply generated power. [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a power generation control device provided in each of a plurality of power plants includes an optimal value determination unit that determines an optimal value for the power plant's electrical output based on the unit price of generated power supplied to the power grid, and an adjustment unit that adjusts a command value for the electrical output according to the frequency of the power grid, with the optimal value as the upper limit for the electrical output.

[0010] According to one aspect of the present disclosure, 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 an optimal value of electrical output corresponding to the unit price of generated power supplied to an electric power system, and an aggregate value of an equilibrium point signal, which is an electrical output value adjusted to bring the deviation between the frequency of the electric power system and a reference frequency closer to zero, and a unit price determination unit that determines the unit price based on the aggregate value of the optimal value and the aggregate value of the equilibrium point signal.

[0011] According to one aspect of the present disclosure, a power supply control system that controls power supplied to a power grid includes the power generation control device according to the above aspect and the unit price determination device according to the above aspect.

[0012] According to one aspect of the present disclosure, a power generation control method includes a step of determining an optimal value of an electrical output of a power plant based on the unit price of generated power supplied to an electric power grid, and a step of adjusting a command value of the electrical output according to the frequency of the electric power grid, with the optimal value set as an upper limit of the electrical output.

[0013] According to one aspect of the present disclosure, the program causes a power generation control device provided in each of a plurality of power plants to execute the steps of determining an optimal value for the power plant's electrical output based on the unit price of generated electrical power supplied to the power grid, and adjusting a command value for the electrical output according to the frequency of the power grid, with the optimal value set as an upper limit for the electrical output. [Effects of the Invention]

[0014] According to the above aspect, in a power system in which multiple power generation companies each supply generated power, it is possible to adjust electrical output according to the unit price and demand of the generated power while preventing unfair bias in the benefits or disadvantages of some power generation companies. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing the overall configuration of a power supply control system according to a first embodiment. [Figure 2] 1 is a first block diagram showing a functional configuration of a power generation control device according to a first embodiment. [Figure 3] FIG. 2 is a second block diagram showing the functional configuration of the power generation control device according to the first embodiment. [Figure 4] 1 is a block diagram showing the functional configuration of a tallying device and a unit price determination device according to a first embodiment. [Figure 5] FIG. 2 is a diagram showing the overall configuration of a power supply control system according to a modified example of the first embodiment. [Figure 6] FIG. 10 is a diagram showing the overall configuration of a power supply control system according to a modified example of the second embodiment. [Figure 7] FIG. 6 is a block diagram showing the functional configuration of a power generation control device according to a second embodiment. [Figure 8] FIG. 10 is a first diagram for explaining the function of a reallocation device according to a second embodiment. [Figure 9] FIG. 10 is a second diagram for explaining the function of the reallocation device according to the second embodiment. [Figure 10] FIG. 2 illustrates an example of a hardware configuration of an allocation device according to at least one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment The first embodiment will be described in detail below with reference to the drawings.

[0017] (Overall composition) FIG. 1 is a diagram showing the overall configuration of a power supply control system according to the first embodiment. FIG. 1 shows an example of a power system 10 in a certain region. The power system 10 according to this embodiment is a power system in which power generation is liberalized, in which multiple power generation companies each own and operate one or more power plants, and the power generated at each power plant is supplied to the power grid. For example, the multiple power plants 1, 2, ..., n shown in FIG. 1 may each be owned and operated by a different power generation company. Furthermore, the power plants may be, for example, thermal power plants, nuclear power plants, or power generation facilities that use natural energy such as solar power or wind power.

[0018] The power supply control system 1 adjusts the electrical output of each power plant in the power system 10. The power supply control system 1 includes a power generation control device 2, a collection device 3, and a unit price determination device 4.

[0019] A power generation control device 2 is provided in each of a plurality of power plants 1, 2, ..., n. The power generation control device 2 adjusts the electrical output of the power plant in which it is installed according to the unit price γ of generated power and the demand of the region (electric power system).

[0020] The collection device 3 collects various pieces of information from each power generation control device 2 for the unit price determination device 4 to determine the unit price.

[0021] The unit price determination device 4 determines the unit price γ of the generated power in the region based on the information collected by the collection device 3.

[0022] (Functional configuration of power generation control device) FIG. 2 is a first block diagram showing the functional configuration of the power generation control device according to the first embodiment. The functional configuration of the power generation control device 2 will be described with reference to Fig. 2. The power generation control device 2 includes an optimum value determination unit 21 and an adjustment unit 22. The optimum value determination unit 21 determines an optimum value u of the power output of the power plant based on the unit price γ of the power generation in the power system. * The adjustment unit 22 determines the optimum value u of the electrical output. * The command value u of the electrical output is adjusted according to the frequency f of the power grid, with

[0023] The processing of the power generation control device 2 will be explained in detail. The power plant's electrical output (command value) that the power generation control device 2 commands the power plant to output is denoted as u. The power plant's electrical output u [kW] has a lower limit u_ (u with an underline; the same applies below) and an upper limit u￣ (u with an overline; the same applies below). The power generation cost of the power plant is approximately expressed by the following equation (1). The coefficients {β2, β1, β0} represent the relationship between electrical output and cost, and their values ​​are determined for each power plant.

[0024]

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[0025] The additional cost of generating electricity when increasing electrical output by one unit is called the marginal cost m c The marginal cost m c is the cost differentiated by the electrical output, and is expressed by the following equation (2).

[0026]

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[0027] In general, the law of increasing marginal cost, known in economics, applies to the cost of generating electricity relative to electrical output. The law of increasing marginal cost states that the additional cost (cost of generating electricity) required to increase utility (electrical output) by one unit gradually increases. This can also be said to mean that the electrical output per unit of cost gradually decreases from the perspective of electrical output. If the cost of generating electricity is approximately expressed as a quadratic equation, as in equation (1), the law of increasing marginal cost is equivalent to equation (3). Equation (3) can also be expressed as β2>0, 2β2u_ + β1>0.

[0028]

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[0029] In a power system where power generation is liberalized, the operation of power plants is determined by the will of the power generation company that owns the power plant. At least during normal times, power generation companies are free to operate or stop power plants, and for example, other power generation companies do not instruct other power generation companies to operate or stop. Therefore, the number of power plants operating as a whole is given. If the number of power plants in operation is n and the power generation cost of each is expressed by equation (1), the optimal load distribution of the power plants in operation, that is, the optimal electrical output to each power plant, is calculated by multiplying the marginal cost m c It is expressed as equation (4) with parameters.

[0030]

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[0031] The optimal load dispatching maintains the total power generation output while changing only the distribution, so from equation (5A), the marginal cost m c The value of is calculated using equation (5B).

[0032]

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[0033]

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[0034] The marginal cost m calculated using equation (5B) cSubstituting σ into equation (4) immediately reveals the electrical output that each power plant should contribute to minimize the total current electrical output of all n power plants. This is known as the equal incremental fuel cost method for optimal operation of a group of power plants. However, to reiterate, in a deregulated power system 10, power is generated by power plants owned by different power producers. For example, each power plant could be owned by a different power producer. In this case, each power producer's primary concern would be their own profits. From the perspective of overall efficiency, it would be rational for less efficient power plants to reduce their power output and for more efficient power plants to increase their power output. However, in a deregulated power system, such altruistic behavior cannot be expected. Each power producer will behave in a seemingly selfish manner to maximize their own profits. The power system requires technology that can accept the seemingly selfish behavior of power producers and harmoniously meet the demand for electricity as a whole. This technology is described below.

[0035] Consider the revenue of a single power plant. If the unit price of the generated electricity is denoted as γ [￥ / kWh], the profit p of the power plant can be expressed by equation (6).

[0036]

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[0037] Since the graph of equation (6) is upwardly convex, the electrical output u that maximizes profit p * is obtained by solving ∂p / ∂u=0 for u as equation (7).

[0038]

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[0039] The value of the unit price of electricity, γ, is the same for all power plants, but the constants β1 and β2, which represent the power generation costs, differ for each power plant. Therefore, the electric output u that maximizes profit p is *The value of varies from power plant to power plant. In a power system 10 where power generation is deregulated, the power plant outputs the electrical output u given by equation (7). * It should be noted that this does not mean that it is acceptable to operate power plants at a fixed rate. In the past, when there was essentially one large electric utility per region, the large local electric utility adjusted the supply and demand of electricity. Therefore, even if independent power generation companies other than the large electric utility freely increased their power output according to equation (7) to maximize their profits, the resulting disturbances in the power supply and demand balance were offset by the large local electric utility reducing its power output. However, it is not fair to assign the responsibility of adjusting disturbances in the supply and demand balance to a specific electric utility. If each power plant were to increase its output arbitrarily, the power system would not function, so technology is needed to ensure that each power generation company shares the responsibility of adjusting supply and demand fairly.

[0040] As a technology for achieving this, in this embodiment, a power generation control device 2 shown in Fig. 2 is used to adjust the electrical output of each power plant. The power generation control device 2 is characterized by increasing or decreasing the output of the power plant according to the demand for electricity. In other words, the power generation control device 2 controls the power plant so that if the demand for electricity increases, the power output of the power plant is increased accordingly, and if the demand for electricity decreases, the power generation control device 2 controls the power plant so that the power output of the power plant is decreased accordingly.

[0041] The optimum 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 constants {β2, β1, β0} that represent the costs of the power plant, and the optimum value determination unit 21 determines the optimum value u of the electrical output that maximizes the profit of the power plant according to equation (7). * Determine.

[0042] Also, the optimal value u * Instead of setting the target value of electrical output as * The present embodiment is characterized in that the upper limit of the electric power output is set to u. I The adjustment unit 22 determines the equilibrium point signal u I The lower limit of the electrical output u_ and the upper limit of the electrical output u *The frequency f of the power grid is changed according to the imbalance between power supply and demand. It is known that the imbalance between power supply and demand appears in the fluctuation of AC frequency. The frequency f of the power grid is changed according to the reference frequency f n For example, the reference frequency f n If the frequency f is 60Hz, when the supply is insufficient compared to the demand for electricity, the AC frequency f will be lower than 60Hz, and when the supply exceeds the demand for electricity, the AC frequency will be higher than 60Hz. By utilizing this property, in the power system, each power plant can set the frequency f and the reference frequency f as shown in equation (8). n The electrical output is adjusted in proportion to the difference between u n is the reference electrical output of the power plant [kW], f n is the reference frequency [Hz], δ is the speed adjustment rate (reference frequency f n Frequency increase rate / reference electrical output u n (the rate of output reduction relative to frequency f), and du is a GF signal (governor-free signal) that adjusts the supply and demand of power. The GF signal du may be calculated using the electrical angular velocity of the generator's rotating shaft instead of frequency f as an approximation of equation (8).

[0043]

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[0044] The power generation control device 2 receives the equilibrium point signal u of the electrical output. I Supply and demand are adjusted according to the GF signal du, with the equilibrium point signal u I corresponds to the state in which the level of the power plant's electrical output changes gradually over, for example, several minutes. In contrast, the GF signal du changes in units of seconds. The command value u of the electrical output that the power generation control device 2 commands the power plant is calculated by the equilibrium point signal u as shown in equation (9). I and the GF signal du.

[0045]

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[0046] In the power generation control device 2 of this embodiment, the adjustment unit 22 receives the equilibrium point signal uI The power system frequency f and the reference frequency f n The frequency f of the power system can be measured at the connection point between the power plant and the power system for each power plant, or it can be measured at a representative point in the region and used as a common value for all power plants in the region. The frequency f of the power system is the reference frequency f n Since the GF signal du is approximately normally distributed around a certain frequency (50 Hz or 60 Hz), the time average value of the GF signal du is generally 0. Therefore, the GF signal du does not affect the amount of power supplied by the power plant.

[0047] Reference frequency f of power system frequency f n The integral of the deviation of frequency f from the reference frequency f n For example, if the supply and demand of electricity is balanced, the frequency f is equal to the reference frequency f n The deviation fluctuates randomly around the center. At this time, the integral value of the deviation does not change.

[0048] Also, for example, if the power supply is insufficient, the frequency f is the reference frequency f n Then, the integral value of the deviation increases over time. In other words, the equilibrium point signal u I increases over time, and the level of the power plant's electrical output increases. As stated in equation (7), the power plant's profit is proportional to the power plant's electrical output u * If the electrical output exceeds this limit, profits will be reduced. To prevent this, the adjustment unit 22 adjusts the equilibrium point signal u I The upper limit of u * Let's say.

[0049] Conversely, if the power supply is in excess, the frequency f will be lower than the reference frequency f n Then, the integral value of the deviation decreases over time. In other words, the equilibrium point signal u I decreases over time, reducing the level of electrical output from the power plant.

[0050] In this way, the power generation control device 2 autonomously adjusts the level of electrical output at each power plant to compensate for the imbalance between power supply and demand, so that supply and demand adjustment for the entire power system can also be achieved autonomously and naturally. Furthermore, by having each power plant operate according to the electrical output commands of the power generation control device 2, supply and demand adjustment does not occur as in conventional power systems, where one power generation company increases its output and other power generation companies reduce their output. In other words, the power generation control device 2 can prevent unfair bias in the benefits or disadvantages of some power generation companies.

[0051] (Functional configuration of power generation control device; modified example) The power generation control device 2 may also autonomously determine whether to operate or stop the power plant. This technique will be described below with reference to FIG.

[0052] FIG. 3 is a second block diagram showing the functional configuration of the power generation control device according to the first embodiment. 3, 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 electrical output at which the profit of the power plant becomes zero based on the unit price γ of the generated power. * The control unit 24 determines the minimum value u of the electrical output at which the profit becomes zero. * and the equilibrium point signal u I The start or stop of operation of the power plant is controlled based on the above.

[0053] The details of the processing of the power generation control device 2 shown in Figure 3 will be explained. When the level of electrical output decreases, the profit of the power plant also decreases, and at some point the profit becomes zero. For simplicity's sake, we will assume that the power plant stops operating when the profit becomes zero or less. The electrical output at which the profit p becomes zero is called u. * Then, by solving p=0, the value is determined as shown in equation (10A).

[0054]

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[0055] As shown in FIG. 3, the control unit 24 determines the electric output u * The equilibrium point signal u of the power plant I For example, when the power plant is stopped, the control unit 24 compares u I ≧1.05u * If so, the control unit 24 determines that operation should be started and outputs an operation command to the power plant. I ≦u * If so, it determines that operation should be stopped and issues a shutdown command to the power plant. Note that "1.05" is just an example, and any value may be set for each power plant depending on the characteristics of the power plant. In formula (10A), β0 represents fixed costs. There are two types of fixed costs: those that do not occur if operation is stopped, such as lighting in the power plant's control room, and those that occur even if operation is stopped, such as interest on the power plant's construction costs. The fixed cost β0 in formula (10A) assumes the former, and assumes that β0 = 0 after operation is stopped. If the latter is dominant over the fixed cost β0, the control unit 24 may control the system to continue operation even if profit falls below zero, thereby recovering the fixed cost. Note that the control to stop operation may be performed when profit reaches a predetermined value. The predetermined value may be zero or a negative value. If profit reaches a predetermined negative value -p * If you continue driving until * is determined by equation (10B). In this embodiment, an example in which shutdown is determined based on profit has been described. However, profit is just an example, and shutdown may also be determined based on sales γ×u, for example.

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[0056] (Functional configuration of the aggregation device and unit price determination device) FIG. 4 is a block diagram showing the functional configuration of the tallying device and the unit price determination device according to the first embodiment. The functional configuration of the tallying device 3 and the unit price determining device 4 will be described with reference to FIG.

[0057] The aggregation device 3 collects the optimal value u of the electrical output according to the unit price γ from the power generation control devices 2 of the plurality of power plants 1, 2, ..., n. * and the equilibrium point signal u I The system includes a counting unit 31 that counts the above.

[0058] The unit price determination device 4 includes a total value acquisition unit 41 and a unit price determination unit 42. The total value acquisition unit 41 receives the optimal value u from the calculation device 3. * The sum of the values ​​and the equilibrium point signal u I The unit price determination unit 42 obtains the aggregated value of the optimal value u * The sum of the values ​​and the equilibrium point signal u I Based on the aggregated value of the above, the unit price γ of the generated power is determined.

[0059] 1 and 4 show an example in which the tallying device 3 and the unit price determination device 4 are separate devices, but this is not limiting. In other embodiments, the tallying device 3 and the unit price determination device 4 may be configured as a single device.

[0060] Each power plant has its own upper limit of electrical output, u * If there are n power plants operating in a certain area, the maximum power generation in the entire area is u * Adding up the above gives Σu * On the other hand, the total amount of power generated in the actual area is calculated by I Adding up the above gives Σu I Σu I For Σu * If is large enough, there is no need to worry about the cost of electricity supply increase for the entire region. However, Σu I ≒Σu * In this case, there is no room for additional power generation. In this case, additional power plants must be operated to secure additional power generation.

[0061] The minimum electrical output that allows a power plant to earn a profit p (profit p becomes positive) is calculated as u * u * is differentiated with respect to γ, * Since the value of / ∂γ is negative, increasing the unit price of generated electricity γ will* This will decrease the profits of power plants that are currently shut down, but will generate positive profits. This will increase the margin for profits. In addition, the upper limit of the power output, u, will be set based on the profits of power plants currently in operation. * is determined by equation (7), but u * is differentiated with respect to γ, * The value of / ∂γ is positive, and additional margins can be obtained from power plants currently in operation. In this way, increasing the unit price of generated electricity, γ, increases the margins for power supply capacity.

[0062] Therefore, the unit price determination device 4 sets the unit price γ of the generated power lower if the increase margin is excessive, and sets it higher if the increase margin is insufficient. The processing of the unit price determination device 4 will be described in detail with reference to FIG.

[0063] For example, the regional power supply Σu I Based on this, the appropriate value of the raising margin m U is determined and calculated using equation (11). γ0 is the standard value of the unit price, K γ is a positive proportionality coefficient. 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.

[0064]

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[0065] Furthermore, when 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, as described above, in the power system 10, each power plant adjusts its electrical output and controls operation / stop, thereby autonomously adjusting supply and demand and ensuring a margin for increase.

[0066] (Action, effect) As described above, the power generation control device 2 according to this embodiment calculates 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 grid. * an optimum value determination unit 21 that determines the optimum value u *and an adjusting unit 22 that adjusts a command value u of the electrical output according to the frequency f of the power grid, with the upper limit of the electrical output being set to .

[0067] In this way, the power generation control device 2 enables each power plant to autonomously adjust supply and demand in the entire power system 10. Furthermore, because each power plant operates according to the electrical output commands of the power generation control device 2, it is not possible for one power generation company to arbitrarily increase its output and then have other power generation companies reduce their output to adjust supply and demand, as in conventional power systems. In other words, the power generation control device 2 can prevent unfair bias in the benefits or disadvantages of some power generation companies.

[0068] The adjustment unit 22 of the power generation control device 2 adjusts the frequency f of the power grid and the reference frequency f n The optimum value of the electrical output u is the value of the electrical output that brings the deviation of * The equilibrium point signal u with an upper limit of I is calculated by integral control, and the equilibrium point signal u I The electrical output command value u is adjusted based on

[0069] In this way, the power generation control device 2 enables each power plant to obtain profits from power generation, and also stabilizes the supply and demand balance in the power system.

[0070] Furthermore, the power generation control device 2 determines the minimum value u of the electrical output at which the profit of the power plant becomes zero based on the unit price γ. * a minimum value determining unit 23 that determines the minimum value u of the electrical output; * and the equilibrium point signal u I and a control unit 24 that controls the start or stop of operation of the power plant based on the above.

[0071] In this way, the power generation control device 2 can operate or stop the power plant so that the power plant can more reliably obtain a profit or so that the profit does not become negative.

[0072] The unit price determination device 4 according to this embodiment determines the optimal value u of the electrical output according to the unit price γ of the generated power supplied to the power grid from each of the multiple power plants. * and the power system frequency f is set to the reference frequency f n The equilibrium point signal u is the output target value to approach I and an aggregate value acquisition unit 41 that acquires the aggregate value of the optimal value u * The sum of the values ​​and the equilibrium point signal u I and a unit price determination unit 42 that determines the unit price γ based on the total value of the above.

[0073] In this way, the unit price determination device 4 can adjust the electrical output and control operation / stop at each power plant by increasing or decreasing the unit price γ, allowing autonomous supply and demand adjustment and securing a margin for increase.

[0074] <Modification of the first embodiment> FIG. 5 is a diagram showing the overall configuration of a power supply control system according to a modified example of the first embodiment. 5, the power supply control system 1 according to this modification may further include a counter-adjustment power totalization device 5. For example, when a power plant generates power in excess of the demand in the power grid, the counter-adjustment power totalization device 5 can totalize the amount of excess power generated (counter-adjustment power).

[0075] The counter-adjustment power totalizing device 5 includes a first acquiring unit 51 and a counter-adjustment power calculating unit 52. The first acquiring unit 51 acquires an equilibrium point signal u from the power generation control device 2 of each of the plurality of power plants. I and the actual measured value y of the power plant's electrical output. The counter-adjustment power calculation unit 52 calculates the actual measured value y of the electrical output and the equilibrium point signal u I The difference between this and the actual measured value y is the power [kW] measured at the connection point between the power plant and the power grid.

[0076] In order for the power system 10 to function, it is important to adjust supply and demand, that is, to match the power supplied by the power plant with the demand. In the technology described in the first embodiment, each power plant outputs an equilibrium point signal uI However, in order for a power plant to increase its profits, it adjusts its output according to the equilibrium signal u I As shown in FIG. 5, the counter-adjustment power calculation unit 52 calculates the actual measured value y of the electric output of each power plant and the equilibrium point signal u I The difference between the power output and the equilibrium point signal u is calculated as the amount of power q. I If the amount of power generated exceeds the amount of power q, this amount of power q represents the deregulation power. Furthermore, the deregulation power calculation unit 52 may impose a penalty by reducing the price (sales) for the power supply, for example, by subtracting the amount of power (deregulation power) generated in excess during a predetermined settlement period (e.g., one day) from the total amount of power supplied by the power plant to the power grid during the same period.

[0077] The counter-regulation power aggregation device 5 thus ensures that the power plant receives the equilibrium point signal u I By counting the amount of electricity generated in excess of the target as counterbalance power, it becomes possible to monitor whether each power plant is properly balancing supply and demand. Monitoring counterbalance power acts as a deterrent to excessive power generation, contributing to stabilizing the supply and demand balance in the power system. Furthermore, by deducting an amount corresponding to the counterbalance power from the price of the power generated by the power plant, it becomes possible to more reliably curb excessive power generation by the power plant.

[0078] <Second embodiment> The power supply control system 1 according to the second embodiment improves the profit p of a power generation company when the power generation company owns a plurality of power plants.

[0079] FIG. 6 is a diagram showing the overall configuration of a power supply control system according to a modified example of the second embodiment. In the example of Figure 6, one power generation company supplies electricity to a certain region with multiple power plants, namely, power plants 1, 2, ..., n. Q Suppose a power producer owns power plants 1, 2, ..., n QThe power supply control system 1 further includes a reallocation device 6. The reallocation device 6 reallocates power plants 1, 2, ..., n belonging to the power plant group. Q Redistribute the electrical output of each.

[0080] The reallocation device 6 includes a second acquisition unit 61 and a reallocation unit 62. The second acquisition unit 61 acquires an equilibrium point signal u I and a coefficient β related to the cost of power generation. The reallocation unit 62 obtains the equilibrium point signal u I Based on the coefficient β, the electrical output of each power plant in the power plant group is reallocated so as to minimize the power generation cost of the entire power plant group.

[0081] 6 shows an example in which the redistribution device 6 is added to the power supply control system 1 (FIG. 1) according to the first embodiment, but the present invention is not limited to this. The redistribution device 6 may also be added to the power supply control system 1 (FIG. 5) according to a modified example of the first embodiment.

[0082] FIG. 7 is a block diagram showing the functional configuration of the power generation control device according to the second embodiment. In the power generation control device 2 according to this embodiment, the adjustment unit 22 further adjusts the command value u of the electrical output based on the electrical output reallocated by the reallocation device 6.

[0083] If a power generation company owns multiple power plants, the company has the freedom to choose which power plants to use, and will generally select a combination of power plants based on economic efficiency. If the combination of power plants currently in operation by a power generation company is denoted as Q, the total electrical output supplied by that power generation company can be calculated using the following equation (12).

[0084]

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[0085] In Figure 6, as a specific example, Q={1,2,...,nQ The actual Q is not necessarily consecutive. The total electrical output of a combination Q of power plants is calculated by the equilibrium point signal u of each power plant included in the combination. I The reason is to avoid fluctuations in the total electrical output due to short-term fluctuations in the GF signal.

[0086] In the power system 10 where power generation is deregulated, the total electrical output supplied by the power generation company is determined by the balance between the supply and demand of electricity and is a given for the power generation company. Q The aim is to generate profits by generating electricity at a lower cost. If a power producer owns multiple power plants, as mentioned above, the producer has the freedom to choose which power plants to use. Furthermore, the producer can reduce the total electrical output u Q Profits can be increased by increasing the allocation to efficient power plants and shutting down or reducing the allocation to inefficient power plants. Changing the output allocation of power plants while maintaining the total electrical output supplied by the power generation company is generally referred to as "switching," and this embodiment follows this convention, and the switchover method will be described using Figures 6 to 9.

[0087] FIG. 8 is a first diagram for explaining the function of the reallocation device according to the second embodiment. Suppose a power producer operates a group of power plants with a combination Q. When the combination of power plants to be operated is given, the optimal switchover can be realized using the equal incremental fuel cost method. When switching within combination Q, the equal incremental fuel cost method can be expressed as an optimization problem as shown in the following equation (13).

[0088]

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[0089] In equation (13), Δu I,i is the electrical output that power plant i, an element of Q, will switch. Since the electrical output of the entire combination Q must remain unchanged before and after the switch, ΔuI,i The sum of these is 0. Equation (13) represents the optimization problem of minimizing the sum of the costs c of each power generation cost that makes up combination Q, with this as a constraint.

[0090] The optimization problem of equation (13) can be solved by the Lagrange multiplier method. Let the Lagrange multiplier be λ, and the Lagrange function L(Δu I , λ) as in equation (14), Δu I The optimal value of Δu satisfies the simultaneous equations in Eq. (15). I ∈R nQ and λ∈R 1 is.

[0091]

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[0092]

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[0093] Expanding the two equations, n in equation (16) Q This results in a simultaneous equation of degree +1.

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[0095] Expanding the cost c, we obtain equation (17).

[0096]

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[0097] Equation (17) is the Lagrange multiplier λ and Δu I The optimal solution is obtained as shown in equations (18) and (19).

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[0099]

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[0100] As shown in Figs. 6 and 8, the redistribution device 6 receives the respective equilibrium point signals u from the operating power plants. I and the parameters {β2,β1,β0} that represent the power generation cost, and the switching electrical output Δu I Figure 7 shows the electrical output Δu I This shows how the electrical output u is reflected. I is reflected in the electrical output u in the same way as the GF adjustment signal. I This is independent of the equilibrium point signal u I This is to strictly determine based only on frequency f. For the combination Q of operating power plants, the electrical output Δu I Since the sum of these becomes 0, the electrical output Δu I The equilibrium point signal u I Whether or not the power consumption is reflected in the power consumption is irrelevant to the function of the anti-adjustment power totalizing device 5 according to the modified example of the first embodiment (FIG. 5), so there is no problem with handling it this way.

[0101] Each power plant has a limit to the rate at which its electrical output can be changed. For example, it is impossible to increase electrical output from 0% to 100% in one second. Therefore, the electrical output Δu I To avoid sudden changes in the value of Δu I For example, the time rate of change of the transferred electrical output may be limited so that even the power plant with the slowest rate of change in electrical output can follow. When limiting the rate of change of the electrical output transferred by each power plant, equation (20) may be used as a constraint in determining the rate of change so that the time rate of change limit does not affect equation (12).

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[0103] The reallocation process (using the Equal Incremental Fuel Cost Method) involves constantly repeating the calculations of Equations (18) and (19), resulting in continuous time-based rebalancing. This allows optimal load distribution to be achieved in real time.

[0104] Power generation companies that own multiple power plants have the freedom to select and use the most efficient power plants among their owned plants, so they should be able to select the most economically optimal power plant. Electricity demand changes over time. For example, during the daytime, demand for electricity is high because production activities are active, while at night, demand for electricity is low because most production activities are stopped. As demand fluctuates over time, the optimal combination of power plants must also change accordingly. Power generation companies review the combination Q of power plants they operate through a separate combinatorial optimization process. Reviewing the combination Q of power plants they operate involves either (1) shutting down the power plants included in combination Q, (2) adding a new power plant to combination Q, or (3) maintaining combination Q. Of these, the process for (3) is shown in Figure 8. (2) simply adds a new power plant to Q. The process performed by the electrical output reallocation device after the addition is exactly the same as (3). (1) requires a partial change to the process of the reallocation unit 62 of the reallocation device 6, which is explained below using Figure 9.

[0105] FIG. 9 is a second diagram for explaining the function of the reallocation device according to the second embodiment. Before the revision, suppose a power producer is operating a group of power plants with a combination Q, and then shuts down power plant k from combination Q. The remaining power plants are the combination Q minus power plant k, so we denote this as Q\k. After shutting down power plant k, the total electrical output before shutting down must be substituted by the remaining power plants. This is a constraint, and is expressed by equation (21).

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[0107] The optimization problem for minimizing the cost with the constraints of Equation (21) is expressed by Equation (22).

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[0109] As mentioned earlier, this problem can also be solved by the Lagrange multiplier method. Specifically, equations (23) and (24) are used.

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[0112] For the power plant k to be shut down, the electrical output is set to the current value u I,k Since it must be changed to 0, the electrical output to be transferred is expressed as equation (25).

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[0114] If we do so, then equation (12) also holds true for the case of "(1) shutting down power plants included in combination Q." Therefore, the difference between the case of "(1) shutting down power plants included in combination Q" (Figure 9) explained here and the case of "(3) maintaining combination Q" explained earlier (Figure 8) is determined by whether or not there is a power plant, such as power plant k, whose output is externally specified rather than left to the equal incremental fuel cost method. If everything is left to the equal incremental fuel cost method, then the answer is (3), and if not, the answer is (1).

[0115] Let us use the symbol k to represent a power plant whose output is externally specified. Since there can be multiple k's, we will denote the set of k's by K. That is, K={1,2,...,n K},k∈K, then Δu I,k In this case, as shown in equation (12), the electrical output of the power plants belonging to K can be changed by r without changing the overall output of the power plants Q in operation. I,k The problem of optimizing the output of power plants that do not belong to K (i.e., belong to the set Q\K) using the equal incremental fuel cost method is expressed as equation (26). For example, to shut down power plant k, K={k},r I,k = 0 kW. For example, if power plant k is stopped and power plant k+1 is increased to 100 MW, then K = {k, k+1}, r I,k+1 =100MW.

[0116]

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[0117] In this way, the power supply control system 1 according to this embodiment can increase the profits of a power generation company when the power generation company owns multiple power plants by reallocating the electrical output of each power plant using the reallocation device 6.

[0118] <Hardware configuration> FIG. 10 is a diagram illustrating an example of a hardware configuration of an allocation device according to at least one embodiment. An example of the hardware configuration of each device included in the power supply control system 1 will be described below with reference to FIG.

[0119] As shown in FIG. 10, a computer 900 includes a processor 901 , a main memory device 902 , an auxiliary memory device 903 , and an interface 904 .

[0120] The power generation control device 2, the aggregation device 3, the unit price determination device 4, the counter-adjustment power aggregation device 5, and the reallocation device 6 described in each of the above-described embodiments are each implemented in a computer 900. The operations of each of the above-described processing units are stored in the auxiliary storage device 903 in the form of a program. The processor 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The processor 901 also allocates storage areas in the main storage device 902 to be used for various processes in accordance with the program. The processor 901 also allocates storage areas in the auxiliary storage device 903 to store data being processed in accordance with the program.

[0121] The program may be for realizing some of the functions to be performed by the computer 900. For example, the program may be combined with other programs already stored in the auxiliary storage device 903 or other programs implemented in other devices to perform the functions. 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, some or all of the functions realized by the processor 901 may be realized by the integrated circuit.

[0122] Examples of the auxiliary storage device 903 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. The auxiliary storage device 903 may be an internal medium directly connected to the bus of the computer 900, or an external storage device 910 connected to the computer 900 via the interface 904 or a communication line. Furthermore, when this program is distributed to the computer 900 via a communication line, the computer 900 that receives the program may load the program into 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.

[0123] As described above, several 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 forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0124] <Additional Notes> The power generation control device, the unit price determination device, the power supply control system, the power generation control method, and the program described in the above-described embodiments can be understood, for example, as follows.

[0125] (1) According to the first aspect of the present disclosure, a power generation control device 2 provided in each of a plurality of power plants controls 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 grid. * an optimum value determination unit 21 that determines the optimum value u *and an adjusting unit 22 that adjusts a command value u of the electrical output according to the frequency f of the power grid, with the upper limit of the electrical output being set to .

[0126] In this way, the power generation control device 2 enables each power plant to autonomously adjust supply and demand in the entire power system 10. Furthermore, by operating each power plant according to the electrical output commands of the power generation control device 2, supply and demand adjustments are not performed by one power generation company increasing its output and other power generation companies reducing their output, as in conventional power systems. In other words, the power generation control device 2 can prevent unfair bias in the benefits or disadvantages of some power generation companies.

[0127] (2) According to the second aspect of the present disclosure, in the power generation control device 2 according to the first aspect, the adjustment unit 22 adjusts the frequency f of the power grid and the reference frequency f n The value of the electrical output adjusted to approach zero the deviation from the optimum value u * The equilibrium point signal u with an upper limit of I is calculated by integral control, and the equilibrium point signal u I The electrical output command value u is adjusted based on

[0128] In this way, the power generation control device 2 enables each power plant to obtain profits from power generation, and also stabilizes the supply and demand balance in the power system.

[0129] (3) According to the third aspect of the present disclosure, the power generation control device 2 according to the second aspect calculates the minimum value u of the electrical output at which the profit p of the power plant becomes a predetermined value based on the unit price γ. * a minimum value determination unit 23 that determines the minimum value u * and the equilibrium point signal u I and a control unit 24 that controls the start or stop of operation of the power plant based on the above.

[0130] In this way, the power generation control device 2 can operate or stop the power plant so that the power plant can more reliably obtain a profit or so that the profit does not become negative.

[0131] (4) According to the fourth aspect of the present disclosure, the unit price determination device 4 determines an optimal value u of the electrical output according to the unit price γ of the generated power supplied to the power grid from each of the plurality of power plants. * The aggregated value of the power system frequency f and the reference frequency f n The equilibrium point signal u is the value of the electrical output adjusted to approach zero. I and an aggregate value acquisition unit 41 that acquires the aggregate value of the optimal value u * The sum of the values ​​and the equilibrium point signal u I and a unit price determination unit 42 that determines the unit price γ based on the total value of the above.

[0132] In this way, the unit price determination device 4 can adjust the electrical output and control operation / stop at each power plant by increasing or decreasing the unit price γ, allowing autonomous supply and demand adjustment and securing a margin for increase.

[0133] (5) According to a fifth aspect of the present disclosure, a power supply control system 1 that controls the power supplied to a power grid includes a power generation control device 2 described in any one of the first to third aspects and a unit price determination device 4 described in the fourth aspect.

[0134] (6) According to a sixth aspect of the present disclosure, the power supply control system 1 according to the fifth aspect further includes a counter-adjustment power aggregating device 5 that aggregates counter-adjustment power from each of the plurality of power plants. The counter-adjustment power aggregating device 5 aggregates the power grid frequency f and the reference frequency f from each of the plurality of power plants. n The equilibrium point signal u is the value of the electrical output adjusted to approach zero. I and a first acquisition unit 51 that acquires an actual measured value y of the electric power output of the power plant, and a first acquisition unit 52 that acquires an actual measured value y of the electric power output and an equilibrium point signal u I and an inverse regulation power calculation unit 52 that integrates the difference between the inverse regulation power and the excess power generated, and calculates the amount of excess power generated as the inverse regulation power q.

[0135] In this way, the power supply control system 1 can monitor whether each power plant is appropriately adjusting supply and demand by aggregating the deregulation power using the deregulation power aggregation device 5. Monitoring the deregulation power acts as a deterrent to excessive power generation, contributing to stabilizing the supply and demand balance in the power system. Furthermore, by deducting an amount corresponding to the deregulation power from the price of the power generated by the power plant, it is possible to more reliably suppress excessive power generation by the power plant.

[0136] (7) According to a seventh aspect of the present disclosure, the power supply control system 1 according to the fifth or sixth aspect further includes a reallocation device 6 that reallocates the electrical output of each of the power plants belonging to a power plant group consisting of two or more power plants among the plurality of power plants. The reallocation device 6 reallocates the electrical output of each of the power plants belonging to the power plant group based on the frequency f of the power grid and the reference frequency f n The equilibrium point signal u is the value of the electrical output adjusted to approach zero. I and a coefficient β relating to the cost required for power generation; I and a reallocation unit 62 that reallocates the electrical output of each of the power plants belonging to the power plant group based on the coefficient β so as to minimize the power generation cost of the entire power plant group.

[0137] In this way, the power supply control system 1 can reallocate the electrical output of each power plant belonging to the power plant group, thereby increasing the profit of the entire power plant group. A power plant group may consist of multiple power plants owned by a single power generation company, for example. The power generation company can generate the electricity that its own power plant group should supply at the minimum cost, thereby increasing the profit of the power generation company.

[0138] (8) According to an eighth aspect of the present disclosure, in the power supply control system 1 relating to the seventh aspect, the adjustment unit 22 of the power generation control device 2 further adjusts the command value u of the electrical output based on the electrical output reallocated by the reallocation device 6.

[0139] In this way, the power supply control system 1 can autonomously operate the power plants belonging to the power plant group efficiently at the lowest power generation cost.

[0140] (9) According to a ninth aspect of the present disclosure, a power generation control method includes: determining an optimal value u of an electrical output of a power plant based on a unit price γ of generated power supplied to a power grid; * and determining the optimal value u * and adjusting a command value u of the electrical output according to the frequency f of the power grid, with the upper limit of the electrical output being set to u.

[0141] (10) According to a tenth aspect of the present disclosure, a program controls a power generation control device 2 provided in each of a plurality of power plants to calculate an optimal value u of the power output of the power plant based on a unit price γ of the generated power supplied to the power grid. * and determining the optimal value u * and a step of adjusting a command value u of the electrical output according to the frequency f of the power grid, with the upper limit of the electrical output being set to u. [Explanation of symbols]

[0142] 1. Power supply control system 10 Power Systems 2 Power generation control device 21 Optimum value determination section 22 Adjustment part 23 Minimum value determination unit 24 Control Unit 3. Counting device 31 Counting Department 4. Unit price determination device 41 Aggregate value acquisition unit 42 Unit Price Determination Department 5. Anti-adjustment power aggregation device 51 First acquisition part 52 Anti-adjustment power calculation section 6 Redistribution Device 61 Second acquisition part 62 Redistribution Department 900 Computers 901 processor 902 Main storage 903 Auxiliary storage device 904 Interface 910 External storage device

Claims

1. A power generation control device provided in each of a plurality of power plants, an optimal value determination unit that determines an optimal value of the power plant's electrical output based on the unit price of generated power supplied to the power grid; an adjusting unit that adjusts a command value of the electrical output according to the frequency of the power grid, with the optimum value as an upper limit of the electrical output; A power generation control device comprising:

2. the adjusting unit calculates an equilibrium point signal by integral control, which is an electric output value adjusted so as to bring the deviation between the frequency of the power grid and a reference frequency closer to zero and has the optimum value as an upper limit, and adjusts the electric output command value based on the equilibrium point signal. The power generation control device according to claim 1 .

3. a minimum value determination unit that determines a minimum value of the electrical output at which the profit of the power plant becomes a predetermined value based on the unit price; a control unit that controls the start or stop of operation of the power plant based on the minimum value and the equilibrium point signal; The power generation control device of claim 2 further comprising:

4. A power supply control system that controls power supplied to a power grid, The power generation control device according to any one of claims 1 to 3; a unit price determination device; Equipped with The unit price determination device an aggregate value acquisition unit that acquires, from each of a plurality of power plants, an aggregate value of an optimal value of an electric output corresponding to the unit price of generated electric power supplied to the electric power grid, and an aggregate value of an equilibrium point signal that is an electric output value adjusted so that the deviation between the frequency of the electric power grid and a reference frequency approaches zero; a unit price determination unit that determines the unit price based on the aggregated value of the optimal values ​​and the aggregated value of the equilibrium point signals; Equipped with Power supply control system.

5. The power generation system further includes a counter-regulation power aggregation device that aggregates counter-regulation power of each of the plurality of power plants, The counter-regulation power aggregation device a first acquisition unit that acquires, from each of a plurality of power plants, an equilibrium point signal that is an electrical output value adjusted so as to bring the deviation between the frequency of the power grid and a reference frequency closer to zero, and an actual measured value of the electrical output of the power plant; a counter-regulation power calculation unit that calculates the amount of excess power generated as counter-regulation power by integrating the difference between the actual measured value of the electrical output and the equilibrium point signal; The power supply control system according to claim 4, further comprising:

6. In a power plant group consisting of two or more power plants among the plurality of power plants, a reallocation device is further provided that reallocates the electrical output of each of the power plants belonging to the power plant group, The reallocation device a second acquisition unit that acquires, from each of the power plants belonging to the group of power plants, an equilibrium point signal that is an electrical output value adjusted so as to bring the deviation between the frequency of the power grid and a reference frequency closer to zero, and a coefficient related to the cost required for power generation; a reallocation unit that reallocates the electrical output of each of the power plants belonging to the power plant group based on the equilibrium point signal and the coefficient so as to minimize the power generation cost of the entire power plant group; The power supply control system according to claim 4, further comprising:

7. an adjustment unit of the power generation control device further adjusts a command value of the electrical output based on the electrical output reallocated by the reallocation device; The power supply control system according to claim 6.

8. determining an optimal value of the electrical output of the power plant based on the unit price of the generated power supplied to the power grid; adjusting a command value of the electrical output according to the frequency of the power grid, with the optimum value set as an upper limit of the electrical output; A power generation control method comprising:

9. A power generation control device provided in each of a plurality of power plants, determining an optimal value of the electrical output of the power plant based on the unit price of the generated power supplied to the power grid; adjusting a command value of the electrical output according to the frequency of the power grid, with the optimum value set as an upper limit of the electrical output; A program that executes the following.

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