Optimal operation planning device, optimal operation planning method and program

Abstract

To create an optimal operation plan that takes into account operational constraints in the time direction. [Solution] An optimal operation planning device according to one aspect of the present disclosure has a first creation unit that creates an optimization problem for calculating an optimal operation plan for a dam and a hydroelectric power generation facility that generates electricity by releasing water from the dam, based on the operating status of the dam and the hydroelectric power generation facility and a predicted value of the amount of water inflow into the dam, and a second creation unit that creates the optimal operation plan by solving the optimization problem, wherein the optimization problem includes a variable constraint that changes depending on the operating status of the dam and the hydroelectric power generation facility.

Description

[Technical Field]

[0001] The present disclosure relates to an optimal operation planning device, an optimal operation planning method, and a program. [Background technology]

[0002] Hydroelectric power generation is carried out using discharges from dams. Generally, discharges from dams are divided into discharges used for hydroelectric power generation and gate discharges, which are discharges not used for hydroelectric power generation. Note that, as prior art related to hydroelectric power generation using discharges from dams, there is known a technology that can create an optimal operation or management plan for a dam or hydroelectric power generation facility (hereinafter, operation or management plans are collectively referred to as "operation plans") using an optimization method (for example, Patent Documents 1 to 4, Non-Patent Documents 1 to 2, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-170807 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-125665 [Patent Document 3] Special Publication No. 2020-517227 [Patent Document 4] Japanese Patent Publication No. 2023-69903 [Non-patent literature]

[0004] [Non-Patent Document 1] Fumio Wakamori, Seiju Funahashi, Shoichi Masui, "Optimal Discharge Planning for Multi-stage Dams During Floods," Transactions of the Institute of Electrical Engineers of Japan. C (1982) [Non-patent document 2] Yamashiro, M., Nakamura, K., Kai, T., and Tatekoji, K., "Optimal Operation Planning of Interconnected Water Systems Considering Flood Forecasting," Transactions of the Institute of Electrical Engineers of Japan, Vol. B (1991) Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional techniques do not take into account operational constraints on changes in the time direction, and it can be difficult to actually apply the operation plan obtained as a result of optimization.

[0006] The present disclosure has been made in consideration of the above points, and aims to provide a technology that can create an optimal operation plan that takes into account operational constraints in the time direction. [Means for solving the problem]

[0007] An optimal operation planning device according to one aspect of the present disclosure includes a first creation unit that creates an optimization problem for calculating an optimal operation plan for a dam and a hydroelectric power generation facility that generates electricity by releasing water from the dam, based on the operating status of the dam and the hydroelectric power generation facility and a predicted value of the amount of water inflow into the dam, and a second creation unit that creates the optimal operation plan by solving the optimization problem, wherein the optimization problem includes a variable constraint that changes depending on the operating status of the dam and the hydroelectric power generation facility. [Effects of the Invention]

[0008] It is possible to create an optimal operation plan that takes into account operational constraints in the time direction. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a hardware configuration of an optimal operation planning apparatus according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a functional configuration of an optimal operation planning device according to an embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of an operation of the optimal operation planning device according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a system including a target dam and a target power generation facility. [Figure 5] FIG. 10 is a diagram illustrating an example of an inflow volume prediction value. [Figure 6]FIG. 10 is a diagram illustrating an example of an optimal operation plan. [Figure 7] FIG. 10 is a diagram showing an example of the amount of change in the amount of water used for generating electricity in a target power generation facility. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] <Background, prior art and its issues> <Background and Prior Art> In hydroelectric power generation using dam discharges, the dam discharges are divided into discharges used for hydroelectric power generation and gate discharges that are not used for hydroelectric power generation. Hereinafter, the amount of discharge used for hydroelectric power generation will be referred to as the "power generation amount," and the amount of gate discharge will be referred to as the "gate discharge amount." The sum of the power generation amount and gate discharge amount (i.e., the amount of water released by the dam) will also be referred to as the "discharge amount." Note that gate discharges are sometimes called, for example, "ineffective discharges."

[0012] As a conventional technology related to hydroelectric power generation using dam discharges, there is known a technology that can create optimal operation plans for dams and hydroelectric power generation facilities using optimization techniques (for example, Patent Documents 1 to 4, Non-Patent Documents 1 to 2, etc.).

[0013] For example, Non-Patent Document 1 and Patent Document 2 disclose techniques for optimizing gate discharge volume and power generation volume, thereby maximizing the power generation volume of hydroelectric power generation facilities. In particular, Non-Patent Document 1 calculates an operation that avoids sudden discharge by performing optimization that also evaluates changes in discharge volume.

[0014] Furthermore, for example, Non-Patent Document 2, Patent Document 1, and Patent Document 4 disclose technologies that predict the amount of water inflow into a dam from weather forecasts such as rainfall, and then calculate an optimal discharge plan based on that prediction.

[0015] On the other hand, Patent Document 3 discloses a technology that, when creating a power generation plan, sets constraints such that once power generation equipment is started or stopped, it remains in the started or stopped state for a certain period of time, thereby enabling creation of a good operation plan.

[0016] <Issues with conventional technology> However, conventional techniques do not take into account operational constraints on changes in the time direction, and it can be difficult to actually apply the operation plan obtained as a result of optimization.

[0017] Here, operational constraints on changes in the time direction include, for example, the constraints shown below.

[0018] - The constraint that the amount of power generated must be reduced just before the power generation facility is shut down - The constraint that the amount of power generated must be reduced immediately after the power generation facility is started Constraints on the amount of change in discharge volume

[0019] Constraints on the amount of change in discharge volume include, for example, the requirement that the amount of change in discharge volume over a short period of time be small when the discharge volume is small, and the requirement that the amount of change in discharge volume be large when emergency discharge is required due to heavy rain, etc.

[0020] In addition, for example, the technology disclosed in Patent Document 3 does not describe the optimization problem in a form that can be calculated using mathematical programming, so a trial-and-error search using metaheuristics or the like is required, which increases the calculation time and does not necessarily result in the calculation of the optimal solution.

[0021] Therefore, the following describes an optimal operation planning device 10 that can quickly create an optimal operation plan while taking into consideration operational constraints in the time direction. The optimal operation planning device 10 may be configured as a single device or may be a system configured as a plurality of devices.

[0022] <Example of hardware configuration of optimal operation planning device 10> Fig. 1 is a diagram illustrating an example of a hardware configuration of an optimal operation planning apparatus 10 according to an embodiment. As illustrated in Fig. 1, the optimal operation planning apparatus 10 according to an embodiment includes an input device 101, a display device 102, an external I / F 103, a communication I / F 104, a RAM (Random Access Memory) 105, a ROM (Read Only Memory) 106, an auxiliary storage device 107, and a processor 108. Each of these pieces of hardware is connected to each other via a bus 109 so as to be able to communicate with each other.

[0023] The input device 101 is, for example, a keyboard, a mouse, a touch panel, a physical button, etc. The display device 102 is, for example, a display, a display panel, etc. Note that the optimal operation planning device 10 does not necessarily have to include at least one of the input device 101 and the display device 102, for example.

[0024] The external I / F 103 is an interface with an external device such as a recording medium 103a. Examples of the recording medium 103a include a CD (Compact Disc), a DVD (Digital Versatile Disk), an SD memory card (Secure Digital memory card), and a USB (Universal Serial Bus) memory card.

[0025] The communication I / F 104 is an interface for connecting to a communication network. The RAM 105 is a volatile semiconductor memory (storage device) that temporarily stores programs and data. The ROM 106 is a nonvolatile semiconductor memory (storage device) that can store programs and data even when the power is turned off. The auxiliary storage device 107 is a nonvolatile storage device (storage device) such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory. The processor 108 is an arithmetic device such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit).

[0026] 1 is an example, and the hardware configuration of the optimal operation planning device 10 is not limited to this. For example, the optimal operation planning device 10 may have a plurality of auxiliary storage devices 107 or a plurality of processors 108, may not have some of the hardware shown in the figure, or may have various hardware other than the hardware shown in the figure.

[0027] <Example of functional configuration of optimal operation planning device 10> Fig. 2 is a diagram showing an example of a functional configuration of an optimal operation planning device 10 according to an embodiment. As shown in Fig. 2, the optimal operation planning device 10 according to an embodiment includes an optimization problem creating unit 201 and an optimization unit 202. These units are realized, for example, by a process in which one or more programs installed in the optimal operation planning device 10 are executed by a processor 108 or the like. Here, the optimal operation planning device 10 is provided with a predicted value (hereinafter also referred to as "predicted inflow value") of an inflow to a dam (hereinafter also referred to as "target dam") for which an optimal operation plan is to be created, and initial states of the target dam and a hydroelectric power generation facility (hereinafter also referred to as "target power generation facility") that generates power by discharging water from the dam. The initial state includes the initial value of the target dam's water level, the initial value of the amount of water used by each target power generation facility, the initial value of a start-up flag indicating whether each target power generation facility has been started, the initial value of a continuous start-up flag indicating whether each target power generation facility has been started most recently, the initial value of a stop-down flag indicating whether each target power generation facility has been stopped, the initial value of a continuous stop-down flag indicating whether each target power generation facility will be stopped most recently, and the initial value of the gate discharge amount. The initial state represents, for example, the current operating state of the target dam and each target power generation facility (or the operating state corresponding to the initial value when calculating the optimal operation plan). Note that hereinafter, the amount of water used by the target power generation facility will also be referred to as "power generation water usage amount."

[0028] The optimization problem creation unit 201 creates an optimization problem for calculating an optimal operation plan for a target dam and a target power generation facility using the predicted inflow value, initial state, power generation model, water level change model, and optimization parameters as input. The power generation model is a model that represents the relationship between the amount of water to be generated and the amount of power generated by the target power generation facility. The water level change model is a model that represents the relationship between the inflow and outflow amounts and the water level for the target dam. The optimization parameters are various parameters required to create an optimization problem (e.g., upper and lower limits of the amount of water used for power generation by each target power generation facility, upper and lower limits of the water level of the target dam, etc.).

[0029] The optimization unit 202 calculates an optimal operation plan that includes the future optimum dam water level, the future optimum power generation water volume, and the future optimum gate discharge volume by solving the optimization problem created by the optimization problem creating unit 201. In addition to these, the optimal operation plan may also include the values ​​of each decision variable obtained as the solution to the optimization problem (e.g., the value of a decision variable that indicates whether to start or stop each target power generation facility at each time).

[0030] <Example of operation of the optimal operation planning device 10> 3 is a diagram showing an example of the operation of the optimal operation planning device 10 according to an embodiment. In the following, it is assumed that the optimal operation planning device 10 is given an inflow prediction value and an initial state.

[0031] The optimization problem creating unit 201 receives a given predicted inflow value and an initial state (step S101).

[0032] The optimization problem creation unit 201 creates an optimization problem in a format that can be solved by mathematical programming based on the inflow prediction value and initial state input in step S101 above, the power generation model of the target power generation facility, the water level change model of the target dam, and the optimization parameters (step S102). Here, the optimization problem is composed of an objective function, decision variables, constraints called fixed constraints, and constraints called variable constraints. Fixed constraints are constraint conditions that do not change depending on the operating status of the target dam or the target power generation facility. On the other hand, variable constraints are constraint conditions that change depending on the operating status of the target dam or the target power generation facility. Details of the optimization problem will be described later.

[0033] The optimization unit 202 calculates a solution to the optimization problem created in step S102 (step S103). Note that the optimization unit 202 may calculate the solution using an existing mathematical programming solver (for example, Gurobi Optimizer, etc.).

[0034] The optimization unit 202 outputs the solution calculated in step S103 as an optimal operation plan to a predetermined output destination (step S104). Examples of the output destination include the display device 102 such as a display, a storage area such as the auxiliary storage device 107, and other devices connected in a communicable manner (e.g., a control device that controls the operation of the target dam or the target power generation facility based on the optimal operation plan).

[0035] <Optimization problem> The optimization problem created in step S102 above will be described in detail below. Hereinafter, the number of target power generation facilities will be represented as N, and the nth (1≦n≦N) target power generation facility will be referred to as "target power generation facility n." Time will be represented as t. Furthermore, the length of time to be optimized will be represented as T.

[0036] <Input, power generation model, water level change model, optimization parameters> Input (initial state, predicted inflow value) h init : Initial water level of the target dam x init,n: Initial value of power generation water consumption of target power generation facility n z init,n u : Initial value of the startup flag for the target power generation facility n z init,n d : Initial value of shutdown flag for target power generation facility n z1 init,n u : Initial value of the start-up succession flag of the target power generation facility n z1 init,n d : Initial value of the continuous shutdown flag for the target power generation facility n y init : Initial value of gate discharge amount r(t): Predicted inflow to the target dam at time t (1≦t≦T) Power generation model G: Power generation model Water level change model F: Water level change model Optimization parameters L n : Lower limit of power generation water consumption of target power generation facility n H n : Upper limit of water consumption for power generation of target power generation facility n DAM L : Lower limit of water level of the target dam DAM H : Upper limit of water level of the target dam RH k,n : Threshold for dividing the amount of water used for power generation of the target power generation facility n into sections (where 1≦k≦K) ΔH k,n : Upper limit of change in power generation water consumption when the power generation water consumption of the target power generation equipment n belongs to section k (1≦k≦K) S: The length of time the machine operates at minimum output after starting and the length of time the machine operates at minimum output immediately before stopping N: Number of target power generation facilities T: The length of time to optimize b,c: Optimization weights

[0037] <Decision Variable> The decision variables are the following continuous and binary variables:

[0038] Continuous variables x n (t): The amount of water used for power generation by the target power generation facility n at time t (1≦t≦T) y(t): Gate discharge volume at time t (1≦t≦T) h(t): Water level of the target dam at time t (1≦t≦T+1) Binary variables z n (t): Operational status of the target power generation facility n at time t (1≦t≦T) (1 is operational, 0 is operational) z n u (t): Start-up flag of target power generation facility n at time t (1≦t≦T) (1 means start-up, 0 means no start-up) z n d (t): Shutdown flag of target power generation facility n at time t (1≦t≦T) (1: Shutdown (stop), 0: Do not shut down) z1 n u (t): Start-up succession flag of the target power generation facility n at time t (1≦t≦T) (1 indicates that it was started up recently (between time tS and time t), and 0 indicates that it was not started up recently) z1 n d (t): Continuous shutdown flag for target power generation equipment n at time t (1≦t≦T) (if 1, it will be shut down in the immediate future (between time t and time t+S+1); if 0, it will not be shut down in the immediate future) r k,n (t): Flag indicating whether the amount of water used for power generation of the target power generation facility n at time t (1≦t≦T) belongs to category k (if 1, it belongs to category k, if 0, it does not belong to category k)

[0039] <Objective function> The following equation (1) is used as the objective function.

[0040]

number

[0041] where p n (t) is the power generation amount of the target power generation facility n at time t, and p n (t)=G(x n (t)).

[0042] That is, the sum of the power generation amount of each target power generation facility n, the water level of the target dam, and the penalty is set as the objective function, and the value of this objective function is maximized.

[0043] Power generation amount p of target power generation facility n n (t) is, for example, when the power generation model G is linear, a certain parameter a n Using p n (t)=G(x n (t))=a n x n At this time, the water level of the target dam is maintained within the range that avoids gate discharge, and the power generation amount p of the target power generation facility n is calculated. n To maximize (t), the optimization weights b and c must be in the order c>b>a. n It is preferable that the following is satisfied.

[0044] ≪Fixed constraints≫ The following fixed constraints are used: fixed constraint (power generation water consumption), fixed constraint (dam water level), and fixed constraint (initial value).

[0045] Fixed constraints (water consumption for power generation) z n (t)=0 when x n (t)=0 z n (t)·L n ≦x n (t)≦z n (t)·H n Fixed constraints (dam water level) DAM L ≦h(t)≦DAM H d(t)=r(t)-(x1(t)++x N (t))-y(t) h(t)=h(t-1)+F(d(t-1))

[0046] The above fixed constraint (dam water level) means that the water level of the target dam is within the upper and lower limits, and the water level is determined by the inflow and outflow to the target dam (i.e., the input and output to the target dam).The water level change model F can be expressed, for example, as a constant function or a piecewise linear function.

[0047] Fixed constraints (initial values) h(0)=h init y(0)=y init x n (0)=x init,n z n u (0)=z init,n u z n d (0)=z init,n d z1 n u (0)=z1 init,n u z1 n d (0)=z1 init,n d

[0048] <<Change Constraints>> The following change constraints are used: a change constraint (amount of change in the amount of water used for power generation), a time change constraint (start-up), and a time change constraint (shut-down).

[0049] · Change constraints (changes in water consumption for power generation) -H n ·(1-r k,n (t))+x n (t+1)-x n (t)≦ΔH k,n r k,n (t)·RH k-1,n ≦x n (t) x n (t)≦r k,n (t)·RH k,n +(1-rk,n (t))·H n r 1,n (t)+···+r K,n (t)=1 However, RH 0,n =0.

[0050] The first equation above is the change in the amount of water used for power generation per unit time (i.e., x n (t+1)-x n The second equation above means that the amount of water used for power generation x belonging to section k n (t) is RH k-1,n On the other hand, the third equation above means that the amount of water used for power generation x belonging to section k is n (t) is RH k,n The fourth equation above means that the amount of water used for power generation x n (t) means that it belongs to only one interval k.

[0051] If the unit time (that is, the time width between t and t+1) is Δt, then, for example, Δt=1 [hour].

[0052] Time-varying constraints (start-up) z n u (t)≦1-z n (t-1) z n u (t)≦z n (t-1)+z n (t) z n u (t)≧-z n (t-1)+z n (t)

[0053] The above three equations represent the relationship between the operation shutdown state of the target power generation facility n at time t and the startup flag.

[0054] z n u (ts)≦z1 nu (t),s=0,1,···,S z1 n u (t)≦z n u (t)+z n u (t-1)+···+z n u (tS) L n z1 n u (t)≦x n (t)≦L n z1 n u (t)+H n (1-z1 n u (t))

[0055] The first and second equations above express the relationship between the startup continuous flag of the target power generation equipment n at time t and the startup flag of the target power generation equipment n from time tS to time t. In addition, the third equation above means that the target power generation equipment n will be operated at the lower limit of the amount of power generation water used for a certain period of time after startup (from time t to time t+S if it is started up at time t).

[0056] Time change constraints (falling) z n d (t)≦1-z n (t) z n d (t)≦z n (t-1)+z n (t) z n d (t)≧z n (t-1)-z n (t) The above three equations represent the relationship between the shutdown status of the target power generation facility n at time t and the shutdown flag.

[0057] z n d (t+s+1)≦z1 n d(t),s=0,1,···,S z1 n d (t)≦z n d (t+1)+z n d (t+2)+···+z n d (t+S+1) L n z1 n d (t)≦x n (t)≦L n z1 n d (t)+H n (1-z1 n d (t))

[0058] The first and second equations above express the relationship between the continuous shutdown flag of the target power generation equipment n at time t and the shutdown flag of the target power generation equipment n from time t+1 to time t+S+1. Furthermore, the third equation above means that the target power generation equipment n will be operated at the lower limit of the amount of water used for power generation for a certain period until shutdown (from time t to time t+S+1 if shutdown is at time t+S+1).

[0059] <Example> An example of the optimal operation planning device 10 according to the above embodiment will be described below. In this example, the system shown in Fig. 4 is the target system. The system shown in Fig. 4 is a system in which water flows into a target dam from an upstream river, and two target power generation facilities n (n = 1, 2) generate electricity by discharging water from the target dam. The target dam is also capable of gate discharge in case of an emergency.

[0060] In this embodiment, the following is used as the initial state:

[0061] h init =300[m] x init,n =0[m3 / s] y init =0[m3 / s] z init,n u =0 z init,n d =0 z1 init,n u =0 z1 init,n d =0

[0062] That is, in the initial state, the target power generation equipment n (n=1, 2) is not generating power, has not discharged at the gate, has not been started up recently, and will not be shut down recently.

[0063] The predicted inflow value r(t) is the one shown in Figure 5. The predicted inflow value shown in Figure 5 is based on the assumption that rain will fall three times, and that the inflow to the target dam will increase three times.

[0064] In addition, for the power generation model G, for n=1,2, p n (t)=G(x n (t))=a n x n (t)=1.0·x n (t) is used. The water level change model F is F(d(t)) = 0.2 d(t).

[0065] Furthermore, the following optimization parameters are used:

[0066] L n =1 [m3 / s] H n =10[m3 / s] DAM L =280[m] DAM H =320[m] RH 1,n =3 [m3 / s] RH 2,n =6 [m3 / s] RH 3,n =10[m3 / s] ΔH 1,n =1 [m3 / s] ΔH 2,n =2[m3 / s] ΔH3,n =3 [m3 / s] N=2[units] T=72 [hours] S=5 [hours] b=1.01 / a n =1.01 c=1.01·b

[0067] Under the above settings, an optimal operation plan was calculated using the optimal operation planning device 10 according to the embodiment. The results are shown in Figure 6. As shown in Figure 6, it can be seen that the optimal operation planning device 10 according to the embodiment can use all of the discharge volume for power generation by setting the gate discharge to 0. It can also be seen that the optimal operation planning device 10 according to the embodiment maintains the water level as high as possible. Furthermore, it can be seen that the optimal operation planning device 10 according to the embodiment can generate power at the lower limit of the amount of water used for power generation for a certain period of time (5 hours) immediately before the target power generation equipment 2 is lowered and immediately after it is started up.

[0068] Also, a scatter diagram plotting the amount of change in the amount of water used for generating electricity (i.e., the amount of change between the amount of water used for generating electricity at time t and the amount of water used at time t+1) for the target power generation facility 1 is shown in Figure 7. As can be seen from Figure 7, when the amount of water used for generating electricity is less than 3 [m3 / s], the amount of change is 1 [m3 / s] or less, and when the amount of water used for generating electricity is less than 6 [m3 / s], the amount of change is 2 [m3 / s].

[0069] From the above, it can be seen that an optimal operation plan can be created that takes into account operational constraints in the time direction.

[0070] <Modification> Modifications of the above embodiment will be described below. Note that the following modifications can be combined with multiple modifications as appropriate, as long as they do not contradict each other.

[0071] <<Variation 1>> The threshold value RH for dividing the amount of water used for power generation of the target power generation facility n into sections k-1,n For example, RH may be a value that can vary depending on the time t. k-1,n(t). This allows, for example, the RH depending on the time of day (e.g., daytime and nighttime). k-1,n (t) can be a different value.

[0072] Similarly, the upper limit ΔH of the change in the amount of water used for generating electricity when the amount of water used for generating electricity of the target power generation equipment n belongs to the section k (1≦k≦K) k,n may also be a value that can vary depending on the time t, for example.

[0073] <<Variation 2>> In the above embodiment, a change constraint (amount of change in amount of water used for generating electricity) was set for when the amount of water used for generating electricity increases, but a change constraint (amount of change in amount of water used for generating electricity) may also be set for when the amount of water used for generating electricity decreases.

[0074] <<Variation 3>> The power generation model G may be a function of the water level and the amount of water used for power generation. For example, p n (t)=G(x n (t),h(t))=a n x n (t)·h(t), etc.

[0075] <<Variation 4>> The number of startups and shutdowns may be added as a penalty to the objective function shown in the above formula (1). That is, the objective function shown in the following formula (2) may be used instead of the above formula (1).

[0076]

number

[0077] In addition, d u ,d d is the optimization weight.

[0078] <<Variation 5>> The change in the amount of water used for generating electricity of each target power generation facility n (1≦n≦N) may be added as a penalty to the objective function shown in the above formula (1). In other words, the objective function shown in the following formula (3) may be used instead of the above formula (1).

[0079]

number

[0080] Note that d is the optimization weight.

[0081] Variation 6 Let N=2. In this case, the absolute value of the difference in the amount of water used for generating electricity for the two target power generation facilities n (n=1, 2) may be added as a penalty to the objective function shown in the above formula (1). In other words, the objective function shown in the following formula (4) may be used instead of the above formula (1).

[0082]

number

[0083] Note that d is the optimization weight.

[0084] <<Variation 7>> The square of the amount of water used for power generation of each target power generation facility n (1≦n≦N) may be added as a penalty to the objective function shown in the above formula (1). In other words, the objective function shown in the following formula (5) may be used instead of the above formula (1).

[0085]

number

[0086] Note that d is the optimization weight.

[0087] <Variation 8> The objective function may be formulated as a quadratic function, where the product of the water level and the amount of water used for power generation is the power generation amount. In other words, instead of the above formula (1), the objective function shown in the following formula (6) may be used.

[0088]

number

[0089] <Variation 9> Regarding the power generation amount included in the objective function, the coefficient of the water level on the power generation amount may be discretized and the power generation amount may be formulated as a piecewise linear function. That is, instead of the above equation (1), the objective function shown in the following equation (7) may be used.

[0090]

number

[0091] where h p (t) is the water level at time t when h(t) is expressed as a piecewise linear function that divides it into M piecewise linear parts.

[0092] In this case, the following constraints are used:

[0093]

number

[0094] where D m is a constant representing the lower bound of the m-th piecewise linear m (t) is a binary variable that indicates which piecewise linearity the water level belongs to at time t (1 if it belongs to the mth piecewise linearity, 0 otherwise).

[0095] <<Variation 10>> As a constraint, upper and lower limits may be set on the amount of power generated. n L ≦p n (t)≦p nH Here, p n L is the lower limit of the power generation amount of the target power generation facility n, and p n H is the upper limit of the power generation capacity of the target power generation facility n.

[0096] <<Variation 11>> Information for starting or stopping the target power generation facility n may be provided from the outside. For example, information for starting or stopping the target power generation facility n at time t may be z n in (t) may be given from the outside (e.g., a terminal used by an operator, etc.). In this case, the conditions to satisfy the information for starting or stopping the target power generation facility n are used as constraints.

[0097] <<Variation 12>> The constraint may be a power curve constraint.

[0098] In this case, for example, the following expressions included in the time change constraint (start-up) are changed as follows:

[0099] (Before change) z n u (ts)≦z1 n u (t),s=0,1,···,S z1 n u (t)≦z n u (t)+z n u (t-1)+···+z n u (tS) L n z1 n u (t)≦x n (t)≦L n z1 n u (t)+H n (1-z1 n u (t)) (After change) zn u (ts)=z n u,s (t),s=0,1,···,S x n (t)≦z n u,s (t)·UP n s +(1-z n u,s (t))·H n ,s=0,1,···,S z n u,s (t)·UP n s +(1-z n u,s (t))·L n ≦x n (t),s=0,1,···,S where z n u,s (t) is a binary variable that takes the value 1 if the target power generation facility n is started at time ts, and 0 otherwise. UP n s is the upper limit of the power generation usage of the target power generation facility n at time ts. n s ≦UP n s+1 By doing so, it becomes possible to gradually start up the target power generation facility n.

[0100] Similarly, for example, the following expressions included in the time change constraint (falling) are changed as follows:

[0101] (Before change) z n d (t+s+1)≦z1 n d (t),s=0,1,···,S z1 n d (t)≦z n d (t+1)+z n d (t+2)+···+z n d (t+S+1) L n z1 n d (t)≦x n (t)≦L n z1 n d (t)+H n (1-z1 n d (t)) (After change) z1 n d (t)=z n d (t+s+1),s=0,1,···,S x n (t)≦z n d,s (t)·DOWN n s +(1-z n d,s (t))·H n ,s=0,1,···,S z n d,s (t)·DOWN n s +(1-z n d,s (t))·L n ≦x n (t),s=0,1,···,S where z n d,s (t) is a binary variable that takes a value of 1 if the target power generation facility n is to be shut down at time t+s+1, and a value of 0 if not. n s is the lower limit of the power generation usage of the target power generation equipment n at time t when the target power generation equipment n is shut down at time t+s+1. n s ≦DOWN n s+1 By doing so, it becomes possible to gradually shut down the target power generation facility n.

[0102] <<Variation 13>> As the constraints, the following constraints on continuous operation and continuous stoppage may be used.

[0103] (Restrictions on continuous operation) z n (t)-z n (t-1)≦z n (τ),τ=t+1,···,min{t+T n work -1,T} where T n work is the length of time that the target power generation equipment n needs to operate continuously after startup.

[0104] (Consecutive stop restrictions) z n (t-1)-z n (t)≦1-z n (τ),τ=t+1,···,min{t+T n stop -1,T} where T n stop is the length of time that the target power generation equipment n must be continuously shut down after being shut down.

[0105] <<Variation 14>> As the constraints, the following constraints on the number of activations and constraints on the number of shutdowns may be used.

[0106] (Start count constraint) z n u (1)+···+z n u (T)≦ZMAX n u where ZMAX n u is the upper limit of the number of startups for the target power generation facility n.

[0107] (Stop count constraint) z n d (1)+···+z n d (T)≦ZMAX n d where ZMAX n dis the upper limit of the number of shutdowns for the target power generation facility n.

[0108] The present invention is not limited to the above-described specifically disclosed embodiments, and various modifications, changes, combinations with known technologies, etc. are possible without departing from the gist of the claims. [Explanation of symbols]

[0109] 10 Optimal operation planning device 101 Input Device 102 Display device 103 External I / F 103a Recording media 104 Communication I / F 105 RAM 106 ROM 107 Auxiliary storage 108 processors 109 Bus 201 Optimization Problem Creation Department 202 Optimization Department

Claims

1. a first creation unit that creates an optimization problem for calculating an optimal operation plan for a dam and a hydroelectric power generation facility that generates electricity by discharging water from the dam, based on an operating state of the dam and the hydroelectric power generation facility and a predicted value of the amount of water inflow into the dam; a second creation unit that creates the optimal operation plan by solving the optimization problem; and The optimization problem includes: An optimal operation planning device, wherein the change constraints, which are constraints that change depending on the operating state of the dam and the hydroelectric power generation facility, include an upper or lower limit for each time of the change in the amount of water used by the hydroelectric power generation facility for power generation.

2. The change constraints include:

2. The optimal operation planning device according to claim 1, wherein a constraint is included regarding the amount of change in the amount of water used for power generation, the constraint varying depending on the operating state of the hydroelectric power generation facility.

3. The change constraints include: The optimal operation planning device according to claim 1 , further comprising a constraint indicating that the hydroelectric power generation facility is in a predetermined operating state immediately after startup or immediately before shutdown.

4. 4. The optimal operation planning device according to claim 3, wherein the predetermined operating state is to generate the power using a predetermined lower limit of the amount of water.

5. The optimization problem includes: The optimal operation planning device according to claim 1 , wherein the objective function represents maximizing the total amount of power generated by the plurality of hydroelectric power generation facilities in a predetermined period.

6. The optimal operation planning device according to claim 5 , wherein the objective function represents further maximizing the water level of the dam.

7. 7. The optimal operation planning device according to claim 5, wherein the objective function includes a penalty representing an invalid discharge.

8. 6. The optimal operation planning device according to claim 5, wherein the amount of power generation is calculated as a function of the water level of the dam and the amount of water used for power generation.

9. The optimal operation planning device according to claim 8 , wherein the function is a piecewise linear function.

10. The optimal operation planning device according to claim 7 , wherein the objective function includes penalties representing the number of times the hydroelectric power generation facility is started and the number of times the hydroelectric power generation facility is stopped.

11. 8. The optimal operation planning device according to claim 7, wherein the objective function includes a penalty that represents a change in the amount of water used by the hydroelectric power generation facility for power generation.

12. 8. The optimal operation planning device according to claim 7, wherein the objective function includes a penalty representing the square of the amount of water used by the hydroelectric power generation facility for power generation.

13. 7. The optimal operation planning device according to claim 6, wherein the water level of the dam is calculated as a function of a predicted value of the amount of water inflow into the dam and an amount of water discharged from the dam.

14. The optimal operation planning device according to claim 13, wherein the function is a piecewise linear function.

15. The change constraints include: The optimal operation planning device according to claim 1 , further comprising a constraint indicating activation or deactivation of the hydroelectric power generation facility at a specific time.

16. The change constraints include: The optimal operation planning device of claim 1, further comprising a constraint indicating that the hydroelectric power generation equipment needs to continue operating for a predetermined period after startup, and a constraint indicating that the hydroelectric power generation equipment needs to remain stopped for a predetermined period after shutdown.

17. The change constraints include:

2. The optimal operation planning device according to claim 1, further comprising a constraint that specifies that a change in the operating state of the hydroelectric power generation facility must be a predetermined value immediately after startup or immediately before shutdown of the hydroelectric power generation facility.

18. The change constraints include: The optimal operation planning device according to claim 1 , further comprising a constraint on the number of times the hydroelectric power generation facility is started or stopped.

19. The first creation unit The optimal operation planning device according to claim 1 , wherein the optimization problem is created in a format that can be solved by mathematical programming.

20. a first creation step of creating an optimization problem for calculating an optimal operation plan for a dam and a hydroelectric power generation facility that generates electricity by discharging water from the dam, based on the operating status of the dam and the hydroelectric power generation facility and a predicted value of the amount of water inflow into the dam; a second generation procedure of generating the optimal operation plan by solving the optimization problem; The computer executes The optimization problem includes: An optimal operation planning method in which the change constraints, which are constraints that change depending on the operating state of the dam and the hydroelectric power generation facility, include an upper or lower limit for each hour of the change in the amount of water used by the hydroelectric power generation facility for power generation.

21. a first creation step of creating an optimization problem for calculating an optimal operation plan for a dam and a hydroelectric power generation facility that generates electricity by discharging water from the dam, based on the operating status of the dam and the hydroelectric power generation facility and a predicted value of the amount of water inflow into the dam; a second generation procedure of generating the optimal operation plan by solving the optimization problem; The computer executes The optimization problem includes: The program includes a change constraint, which is a constraint that changes depending on the operating state of the dam and the hydroelectric power generation facility, and includes an upper or lower limit for each time of the change in the amount of water used by the hydroelectric power generation facility for power generation.

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