JP2022143316A - Design support device and design support program for power supply system - Google Patents

Abstract

To provide a design support device and a design support program for a power supply system that a user can easily grasp a relation among a power generation facility capacity in power generation facilities about a power supply system, power storage facility capacity in power storage facilities, and an amount of power supplied to a target system.SOLUTION: A design support device 10 for a power supply system having power generation facilities and power storage facilities for supplying power to a target system includes: an end point candidate specifying unit 18 for specifying a plurality of power generation facility capacities having an end point candidate that is a point where a coefficient of a linear relation changes in a relation among a power generation facility capacity of the power generation facilities, a power storage facility capacity of the power storage facilities, and an amount of power supplied to the target system; a relation operation unit 20 for calculating a relation between the power storage facility capacity and the amount of power supply in the plurality of power generation facility capacities; an end point specification unit 22 for specifying a point that partial differential changes as an end point; and a presentation unit 26 for presenting a user with the relation among the power generation facility capacity, the power storage facility capacity, and the amount of power supply.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply system design support device and a power supply system design support program.

Conventionally, in an energy system that supplies energy from an energy supply unit to an energy demand unit, techniques have been proposed for optimizing the energy flow rate supplied from the energy supply unit and the installation capacity of the energy supply unit.

For example, in Patent Document 1, when inputting energy demand and supply data, equipment characteristic data (e.g. equipment unit price, equipment-derived CO ₂ , energy conversion efficiency, etc.), equipment that minimizes total cost or total CO ₂ emissions A device is disclosed that calculates and outputs a capacity and an energy flow rate at each hour at the installed capacity based on a linear programming method.

Japanese Patent No. 6669148

By the way, a power supply system for supplying power to a target system, including power generation equipment and power storage equipment, is conventionally known. In such a power supply system, the power generated by the power generation equipment is stored in the power storage equipment, and the power is supplied from the power storage equipment to the target system. Alternatively, the power generated by the power generation equipment is directly supplied to the target system.

Here, a user (for example, a designer of a power supply system) desires to grasp the relationship between the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the amount of power supplied to the target system. . In addition, there is a demand from users to grasp the relationship between the power generation facility cost and the power storage facility cost and the optimum power generation facility capacity and power storage facility capacity. In addition, there is a demand for the user to grasp the conditions of the power generation equipment cost and the power storage equipment cost required to realize the power cost requested by the user.

For example, the relationships may help a user optimize a power delivery system. The larger the capacity of the power generation facility, the higher the cost of the power generation facility (the cost of the facility itself or the running cost), and the larger the capacity of the power storage facility, the higher the cost of the power storage facility. The user wants to reduce the cost of the power generation equipment and power storage equipment as much as possible while reliably supplying the target system with the amount of power required by the target system (that is, to optimize the power supply system). If the user can grasp the relationship between the power generation capacity, the power storage capacity, and the amount of power supplied to the target system, the optimization of the power supply system can be facilitated.

An object of the present invention is to provide a power supply system for supplying power to a target system, including a power generation facility and a power storage facility. To enable a user to easily grasp the relationship with the power supply amount. Alternatively, an object of the present invention is to enable a user to easily grasp the relationship between the optimum power generation capacity and power storage capacity with respect to the power generation facility cost and power storage facility cost. Alternatively, an object of the present invention is to enable the user to easily grasp the conditions of the power generation equipment cost and the power storage equipment cost required to realize the power cost requested by the user. be.

The present invention is a design support device for a power supply system that includes a power generation facility and a power storage facility and supplies power to a target system, wherein the difference between the amount of power generated by the power generation facility and the amount of power demanded by the target system. Based on the net demand profile representing the time change of the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the relationship between the power supply amount to the target system, the coefficient of the linear relationship changes an end point candidate identification unit that identifies a plurality of installed power generation capacities having end point candidates that are points; and a relationship between the power storage installed capacity and the supplied power amount in the plurality of installed power generation capacities based on the net demand profile. and a partial derivative with respect to the power generation capacity with respect to the power supply amount, based on the relationship between the power storage capacity and the power supply amount in the plurality of power generation capacity, and the power supply amount An end point identifying unit that identifies a point at which the partial differential regarding the storage capacity with respect to changes as an end point, and a relationship between the power generation capacity, the storage capacity, and the supply power amount including the identified end point. and a presentation unit for presenting the power supply system.

Preferably, in the net demand profile, the relationship calculation unit includes a plurality of time series consecutive periods in which the amount of power generation is greater than the amount of demand, or a time series in which the amount of demand is greater than the amount of power generation generating an aggregated net demand profile that aggregates a plurality of consecutive periods, and based on the aggregated net demand profile, the relationship between the power storage capacity and the supply power amount in the plurality of power generation capacity. is calculated.

Desirably, the presenting unit further includes a drawing unit that generates a graph showing the relationship between the power generation capacity, the power storage capacity, and the supplied power amount, including the specified end points, wherein the presentation unit includes the graph is presented to the user.

Desirably, the drawing unit is based on the partial differentiation of the power generation facility capacity with respect to the supply power amount specified by the end point specifying unit and the partial differentiation of the power storage facility capacity with respect to the supply power amount, as the graph A normal vector plot diagram is generated by plotting normal vector values of a plane of a convex polyhedron, and the presenting unit presents the normal vector plot diagram to the user.

Preferably, the drawing unit calculates the power generation capacity based on the relationship between the power generation facility capacity, the power storage facility capacity, and the power supply amount, the value of the normal vector, and the unit price of the power generation facility and the power storage facility. generating a map showing the relationship between the equipment unit price of equipment, the equipment unit price of the power storage equipment, and the system cost, which is the cost of the power supply system, and presenting the map to the user. Characterized by

Further, the present invention operates a computer as a design support device for a power supply system for supplying power to a target system, including a power generation facility and a power storage facility, and the computer controls the power generation amount of the power generation facility and the target power. Based on the net demand profile representing the time change of the difference from the demand of the power of the system, the relationship between the power generation capacity of the power generation facility, the power storage capacity of the power storage facility, and the amount of power supplied to the target system , an end point candidate identifying unit that identifies a plurality of installed power generation capacities having end point candidates that are points at which the coefficients of the linear relationship change; a relationship calculation unit that calculates the relationship between the capacity and the power supply amount; an end point identifying unit that identifies a point at which a partial derivative and a partial derivative relating to the power storage facility capacity with respect to the supplied power amount change as an end point, the power generation facility capacity including the specified end point, and the power storage facility capacity; and a presentation unit that presents the relationship with the power supply amount to the user.

According to the present invention, regarding a power supply system for supplying power to a target system including a power generation facility and a power storage facility, the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the power supply capacity of the power storage facility are supplied to the target system. The user can easily grasp the relationship with the power supply amount. Moreover, according to the present invention, it is possible for the user to easily grasp the relationship between the optimum power generation facility capacity and power storage facility capacity with respect to the power generation facility cost and power storage facility cost. In addition, according to the present invention, the user can easily grasp the conditions of the power generation facility cost and the power storage facility cost required to realize the power cost requested by the user.

1 is a schematic configuration diagram of a power supply system design support device according to an embodiment; FIG. FIG. 4 is a diagram showing an example of a profile of power generation and demand; FIG. 4 is a diagram illustrating an example of a profile of net demand; FIG. 4 is a diagram showing reverse cumulative net demand for each residual demand; FIG. 10 shows the maximum n _k , minimum m _k , parameters h _k and l _k determined from the backward cumulative net demand for the residual demand for one period. FIG. 4 is a diagram showing the relationship between the installed power storage capacity and the amount of power usage with respect to the residual demand amount in one period; FIG. 10 is a diagram showing the relationship between the power storage facility capacity and the amount of power usage with respect to the residual demand for the entire term; FIG. 4 is a diagram showing the relationship between the power storage facility capacity and the power utilization rate with respect to the residual demand for the entire term. It is a figure which shows the three-dimensional convex polyhedron which shows the relationship between the power generation installed capacity, electrical storage installed capacity, and a power utilization factor. It is the figure which looked at the three-dimensional convex polyhedron from the positive direction of the power utilization rate axis. FIG. 4 is a plot of normal vectors of planes that constitute a three-dimensional convex polyhedron; FIG. 4 is a contour map showing the relationship between the unit price of power generation equipment, the unit price of electricity storage equipment, and the power system cost.

<1. Outline of Configuration of Power Supply System Design Support Device 10>
FIG. 1 is a schematic configuration diagram of a power supply system design support device 10 according to the present embodiment. In this embodiment, the power supply system design support device 10 is a server computer, but the power supply system design support device 10 may be any computer as long as it exhibits the functions described below. . The functions exhibited by the power supply system design support device 10 described below may be realized by distributed processing in a plurality of computers. That is, the power supply system design support apparatus 10 may be realized by a plurality of computers (for example, a plurality of servers).

The power supply system design support device 10 analyzes the power supply system. The power supply system is a system that includes power generation equipment that generates power and power storage equipment that stores power, and supplies power to a target system. The power supply system design support device 10 analyzes the power supply system, calculates the relationship between the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the amount of power supplied to the target system, and informs the user. offer. The power generation equipment included in the power supply system that is the target of the present embodiment may be various power generation equipment. For example, renewable energy power generation may be performed using renewable energy such as wind power, sunlight, geothermal heat, tidal power, and wave power. The power storage equipment is equipment including a rechargeable secondary battery. The target system may be any system as long as it operates using electric power.

The input/output interface 12 is an interface used to input/output data to/from the power supply system design support device 10 . The input/output interface 12 includes, for example, a communication interface such as a network adapter, a storage medium interface such as a USB connector and an SD card slot, an input interface such as a mouse, keyboard, touch panel or buttons, and an output interface such as a display or speaker. composed of

The memory 14 includes, for example, a HDD (Hard Disk Drive), SSD (Solid State Drive), eMMC (embedded Multi Media Card), ROM (Read Only Memory), RAM (Random Access Memory), or the like. The memory 14 stores a power supply system design support program for operating each part of the power supply system design support device 10 . In the memory 14, a processor 16, which will be described later, stores various data necessary for calculating the relationship between the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the amount of power supplied to the target system. Information is stored.

The processor 16 includes, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a programmable logic device. The processor 16 functions as an endpoint candidate identification unit 18 , a relation calculation unit 20 , an endpoint identification unit 22 , a drawing unit 24 , and a presentation unit 26 according to the power supply system design support program stored in the memory 14 . Hereinafter, the details of the processing performed by the end point candidate identification unit 18, the relationship calculation unit 20, the end point identification unit 22, the drawing unit 24, and the presentation unit 26 will be described, and and the amount of power supplied to the target system, and the details of the processing for presenting the processing results to the user.

<2. Net Demand Profile>
FIG. 2 is a diagram showing an example of a profile of the amount of power generated by the power generation facility and the amount of power demanded by the target system. The amount of power generation can be expressed as the product of the power generation capacity _xp and the unit power generation amount per unit power generation capacity _pt . Shown in FIG. 2 is the profile when the power plant has a certain power plant capacity x _p . Of course, if the power generation capacity x _p of the power plant changes, the profile can also change. Also, the power demand in the target system is expressed as _dt . As shown in FIG. 2, the power generation x _p p _t and the demand d _t change over time. Note that in the present embodiment, time is divided into 1 hour (h) units, and one time period is called one "period". In FIG. 2 (and FIG. 3), periods are represented by numbers in parenthesis. For example, the period from time 0 to 1(h) is period 1, and the period from time 1 to 2(h) is period 2.

The amount obtained by subtracting the demand amount _dt from the power generation amount _{xppt is} called the net demand amount _rt . That is, the net demand _rt is represented by the following Equation 1.
r _t = x _p p _t - d _t (Formula 1)
In this specification, the variable t represents a term.

Since the power generation _xppt and the demand _dt change with time as described above, the net _{demand rt} also changes with time. FIG. 3 shows the profile of net demand r _t when the profile of power generation x _p p _t and demand d _t is as shown in FIG. The profile shown in FIG. 3 is also a profile when the power plant has a certain power plant capacity x _p .

In each period, net demand _rt may be positive or negative. _{Needless to say ,} the _{net demand r t} becomes negative. The positive net demand r _t is called surplus generation r _t ⁺ and the negative net demand r _t is called residual demand r _t ⁻ . In the example of FIG. 3, residual demand r _t ⁻ is generated in the 2nd, 5th, 6th, 8th, 10th, and 11th periods.

During the period when the residual demand r _t ⁻ is generated, the power supply system cannot supply the amount of power required by the target system with only the power from the power generation facility. In that case, the power stored in the power storage equipment before that may be supplied to the target system. Naturally, at that time, the amount of electric power required to supply the target system must be stored in the power storage equipment.

If the power generation capacity x _p of the power generation facility is increased, it is possible to prevent the residual demand r _t ⁻ from occurring _. cost) will also increase. Further, if the power storage facility capacity is increased, it is possible to prevent the residual demand r _t ^- from being generated, but increasing the power storage facility capacity also increases the cost of the power storage facility. Therefore, it is desirable to optimize the power generation capacity and the power storage capacity according to the demand _dt . Note that optimization in this specification does not necessarily mean only obtaining an ideal solution, but includes obtaining a solution close to an ideal solution.

Ideally, in FIG. 3, the residual demand r _t ⁻ in each period should be just covered by the surplus power generation r _t ⁺ generated earlier. Therefore, it can be said that the power storage equipment capacity of the power storage equipment should be set to the minimum amount necessary to cover the residual demand r _t ⁻ with the previously generated surplus power generation r _t ⁺ .

<3. Identification of installed power generation capacity having end point candidates>
The relationship between the power generation capacity of the power generation equipment, the power storage capacity of the power storage equipment, and the amount of power supplied to the target system can be represented by a polyhedron (especially a convex polyhedron) in a three-dimensional space. The vertices of the convex polyhedron are the points at which the coefficients of the linear relationship change in the three-way relationship. We refer to this as an endpoint. In other words, the end point is a point where both the partial derivative of the power generation capacity with respect to the supplied power amount and the partial derivative of the power storage capacity with respect to the supplied power amount change. The endpoints can be the optimal solutions for the installed power generation capacity and the installed storage capacity for a given target system.

The end point candidate specifying unit 18 specifies a plurality of installed power generation capacities having end point candidates (in other words, installed power generation capacities at which end points may occur) based on the profile of net demand _rt described above.

A possible endpoint is when the net demand r _t satisfies Equations 2-4 below.

The reason why the end points may occur under the above conditions will be described later.
Further, from Equation 1 above, the installed power generating capacity x _p ^* in each case of Equations 2 to 4 above is expressed by Equations 5 to 7 below.

<4. Calculation of relationship between power storage facility capacity and power supply amount to target system>
<4-1. Calculation of Reverse Cumulative Net Demand for Each Residual Demand r _t ^- >
Based on the _profile of the net demand _rt as shown in _FIG . Calculate the relationship with electric energy. In particular, the relationship calculation unit 20 calculates the relationship between the power storage capacity and the power supply amount for the plurality of power generation capacity x _p ^* identified by the end point candidate identification unit 18 . In the present embodiment, the relationship calculation unit 20 calculates the relationship between the installed power storage capacity and the amount of power to be supplied in order from the smaller one for a plurality of installed power generation capacities x _p ^* . Details of the processing will be described below.

The relationship calculation unit 20 quantifies the relationship between the power storage capacity required to supply power to each residual demand r _t ⁻ shown in FIG. 3 and the power supply amount. First, the relation calculation unit 20 goes back in time and obtains the cumulative net demand amount _rt . What is obtained in this way is called the backward accumulated net demand quantity q _tj . The reverse cumulative net demand quantity q _tj is represented by Equation 8 below.

In Expression 8, i is a variable representing a period, and variable j takes values from 1 to t. In other words, Equation 8 means to find the accumulation of the net demand rt from period _t to period 1.

FIG. 4 is a diagram showing reverse cumulative net demand quantity q _tj for each residual demand quantity r _t ⁻ . In the profile of net demand r _t shown in FIG. 3, residual demand r _t ⁻ is generated in the 2nd, 5th, 6th, 8th, 10th, and 11th periods, as described above. Therefore, the relation calculation unit 20 obtains the reverse cumulative net demand quantity _qtj for each period. FIG. 4(a) is a diagram showing the backward cumulative net demand _qtj for the second period, FIG. 4(b) is a diagram showing the backward cumulative net demand _qtj for the fifth period, and FIG. ) is a diagram showing the backward cumulative net demand _qtj in the 6th period, FIG. 4(d) is a diagram showing the backward cumulative net demand _qtj in the 8th period, and FIG. 4(e) is a diagram showing the 10th period 4(f) is a _diagram showing the reverse cumulative net demand _qtj for the 11th period.

In each of FIGS. 4(a) to 4(f), the vertical bar on the right end represents the magnitude of the residual demand r _t ⁻ in the relevant period. For example, the vertical bar in FIG. 4(a) indicates −1.5 (kWh) because the residual demand r _t ⁻ in the second period is −1.5 (kWh). The line graph starting from the bottom of the vertical bar traces the backward cumulative net demand one period back to zero (the backward cumulative net demand q _tj equals the magnitude of the residual demand r _t ⁻ ). It represents the quantity demanded _qtj . Here, for the sake of subsequent calculations, even when the backward cumulative net demand _qtj becomes a positive value, it is assumed to be zero.

For the 2nd, 5th, 8th, and 10th periods shown in FIGS. 4(a), (b), (d), and (e), the surplus power generation amount r _t ⁺ in the immediately preceding period is big. For example, the residual demand r _t ⁻ in the second period is smaller than the surplus power generation r _t ⁺ in the immediately preceding period. Therefore, for these periods, the line graph reaches zero in one period. Regarding the 6th and 11th periods shown in FIGS. 4(c) and ( _f ⁾ , it takes a plurality of periods until the line graph reaches zero. It indicates that it is necessary to accumulate multiple periods of surplus power generation r _t ⁺ in order to cover with the amount r _t ⁺ .

<4-2. Calculation of relationship between power storage facility capacity and supplied power amount for each residual demand r _t ^- >
The following processing is performed for each residual demand r _t ⁻ shown in FIGS. 4(a) to 4(f). explain. The relationship calculation unit 20 obtains the relationship between the installed power storage capacity and the supplied power amount based on the reverse cumulative net demand _qtj .

FIG. 5 is a diagram showing the maximum value n _k , minimum value m _k , parameters h _k and l _k determined from the reverse cumulative net demand quantity q _tj for the residual demand quantity r _t ⁻ in one period. Based on the reverse cumulative net demand quantity _qtj , the relational calculation unit 20 obtains its maximum value _nk and minimum value _mk . However, while gradually narrowing the range of j (the number of retroactive periods) to be considered, the maximum value _nk and the minimum value mk of the reverse cumulative net demand quantity _qtj are obtained within a certain _j range. Note that the variable k indicates the stage of calculation.

The maximum value _nk is represented by Equation 9 below.
n _k =max(q _tj )=q _tj2k (within the range of j _2k−1 ≧j≧0) (Formula 9)
The minimum value _mk is represented by Equation 10 below.
m _k =min(q _tj )=q _tj2k+1 (within the range of j _2k ≧j≧0) (Formula 10)

A more specific calculation procedure is shown below. First, when k=0, the following procedures (a) to (c) are executed.
(a) Find the maximum value max(q _tj ) of the reverse cumulative net demand q _tj and j=j ₀ at that time. The sign of the maximum value max(q _tj ) indicates the following contents.
・When the maximum value max(q _tj )<0, the power for the residual demand r _t ⁻ cannot be supplied to the target system.
When the maximum value max (q _tj ) ≥ 0, find the minimum j that satisfies the reverse cumulative net demand q _tj ≥ 0, and if j = j ₀ , the power for the remaining demand r _t ^- is t−j ₀ ) to period t can be supplied to the target system using the surplus power generation amount r _t ⁺ .
The above can be represented by Equation 11 below.

Notice that point n ₀ is plotted at time 0 in FIG. 5 and that j ₀ =10.

(b) Find the minimum value min(q _tj ) of the reverse cumulative net demand quantity q _tj in the range of j ₀ ≧j≧1 and j=j ₁ at that time. The minimum value _m0 is represented by Equation 12 below.
m ₀ =min(q _tj )=q _tj1 (within the range of j ₀ ≧j≧1) (Formula 12)
Notice that point m ₀ is plotted at time 4 in FIG. 5 and that j ₁ =6.

(c) If j1 is not 0, then increment the variable _k by ₁ and repeat the calculation of the maximum value nk and the minimum value _mk . If j ₁ =0, terminate the operation. In operations where k≧1, if j _2k+1 is not 0, increment variable k by 1, repeat the calculation of maximum n _k and minimum m _k , and if j _2k+1 =0, then n _k+1 =m _k , The calculation is terminated with K=k+1.

By the above calculations, as shown in FIG. 5, the maximum value _nk and minimum value _mk (where _k =1, 2, . was taken.

Next, the parameters h _k and l _k are determined from the maximum n _k and minimum m _k values. The parameters h _k and l _k are represented by Equations 13 and 14 below.
h _k =n _K−k −n _K−k+1 (Equation 13)
l _k =n _K−k −m _K−k (Equation 14)

The parameters h _k and l _k are shown in FIG. The parameter h _k corresponds to the supply (possible) power amount that increases according to the retroactive period. The parameter l _k corresponds to the power storage facility capacity required to supply power of the parameter h _k to the residual demand r _t ^- .

Using the obtained parameters _hk and _lk , the relationship between the power storage facility capacity and the amount of power used can be represented by a graph as shown in FIG. The relationship between the power storage equipment capacity x _bt required to supply power to the residual demand r _t ⁻ in period t and the power usage Q′ _t is formulated as follows. In other words, the power consumption Q' _t with respect to the residual demand r _t ⁻ can be formulated as a function Q' _t (x _bt ) of the power storage facility capacity x _bt as shown in Equation 15 below.

FIG. 6 is a diagram showing the relationship between the power storage facility capacity and the amount of power used (the amount of power supplied to the target system) with respect to the residual demand r _t ^- in one period. FIG. 6 is a graph of Equation 15. In FIG. From this figure, it can be seen that the amount of power usage increases in stages as the capacity of the power storage facility increases.

The relationship calculation unit 20 performs the above-described processing for each residual demand r _t ^- , and calculates the relationship between the storage facility capacity and the power usage (power supply to the target system) for each residual demand r _t ^- . do.

<4-3. Calculation of relationship between power storage facility capacity and power usage (power supply amount)>
The relationship calculation unit 20 aggregates (more specifically, sums) the power usage function Q′ _t (x _bt ) for each residual demand r _t ⁻ , thereby obtaining the given power generation x _p p _t and (Electricity) It is possible to obtain the relationship between the power storage facility capacity _xb and the power consumption Q' with respect to the profile of the demand _dt . The relationship between the power storage facility capacity x _b and the power consumption Q′ is represented by the following Equation 16.

Furthermore, as shown in Equation 17 below, the relationship between the power utilization rate y and the power storage facility capacity _xb can be obtained by dividing the power usage Q' by the total demand _dt .

FIG. 7 shows a graphical representation of Equation 16, and FIG. 8 shows a graphical representation of Equation 17. FIG. It should be noted that the value on the vertical axis at the power storage facility capacity x _b =0 corresponds to the power usage amount Q′ and the power utilization rate y that can be used without the power storage facility. The slope of the graph corresponds to the number of residual demands r _t ⁻ that can be supplied. As the power storage facility capacity x _b increases, the number of individual residual demand amounts r _t ⁻ for which the power usage amount Q′ reaches the maximum decreases, so the slope becomes smaller. The slope is 1 because power is eventually supplied to the remaining residual demand r _t ⁻ .

<4-4. Charge/discharge efficiency>
When charging and discharging power storage equipment, it is necessary to consider charging and discharging efficiency. In this specification, e is the charge/discharge efficiency of the power storage equipment. In particular, the charge/discharge efficiency e is divided into charge efficiency e _c (0<e _c <1) and discharge efficiency e _d (0< _ed <1). Here, e=e _c ·e _d . When the power storage equipment is charged with the surplus power generation amount r _t ⁺ , the electric energy charged in the power storage equipment is e _{cr t} ⁺ . When the stored power is discharged to the residual demand r _t ⁻ to satisfy the demand, the stored power to be supplied is r _t ⁻ /e _d . When the power storage facility capacity x _b necessary for exchanging power of the surplus power generation r _t ⁺ and the residual demand r _t ⁻ is obtained in consideration of the charge/discharge efficiency e, the net demand r _t can be converted as follows: Easy to calculate.

Since the residual demand r _t ⁻ is increased by 1/e _d , the actual power consumption Q is obtained by multiplying the power consumption Q′ via the power storage equipment by the discharge efficiency e _d .
Q=e _d Q'
_Henceforth , the net demand amount rt is treated as one in consideration of the charge/discharge efficiency e.

<4-5. Numerical formula representing the relationship between the power storage facility capacity and the amount of power used (supplied power amount)>
The relationship between the power storage capacity and the power consumption at a certain power generation capacity _xp is a piecewise linear function as shown in FIG. The function is represented by Equation 18 below.

n in Equation 18 corresponds to the number of residual demand r _t ^- . However, the continuous residual demand r _t ^- is aggregated and counted as one. The process of aggregating continuous residual demand r _t ⁻ will be described later. Also, Q0 is the amount of power used when the power storage facility capacity is _zero , and is represented by Equation 19 below.

In Equation 19, J ₊ is a set of periods when surplus power generation r _t ⁺ is occurring (that is, when x _p p _t ≧d _t ), and J ₋ is a set of periods when residual demand r _t ⁻ is occurring ( That is, the set of periods when x _p p _t ≤ d _t . In this case, it is not necessary to consider the charge/discharge efficiency e for the amount of power used.

Next, the value of x _bi (see Equation 18) where the slope of the piecewise linear function representing the relationship between the installed storage capacity and the amount of power consumption changes is the residual demand r _t ⁻ and surplus power generation r _t ⁺ in a certain period. Indicates that it is a sum.

As shown in Equation 8, when the power generation facility capacity x _p is fixed and the relationship between the power storage facility capacity and the power consumption is determined, the reverse cumulative net demand q _tj is the basic information. j can take from 1 to T. Here, the maximum value n _k , minimum value m _k , and parameters h _k and l _k described above are also represented by Equations 20 to 23 below.

However, k'=Kk. The magnitude relation of j is
1≦j _2(K−1) ≦j _2K−3 ≦・・・≦j _2k+1 ≦j _2k ≦・・・≦j ₀ ≦T
becomes.

As shown in Equation 15, in the piecewise linear function of the installed storage capacity and the amount of power usage with respect to the residual demand r _t ⁻ in period t, the boundaries where the slope changes are represented by h _k and l _k . This is the same for the piecewise linear function of the installed storage capacity and the amount of electricity used in the whole period. That is, the value of x _bi , which is the boundary where the slope of Equation 15 changes, is expressed by Equation 24 below as the partial sum of the residual demand r _t ⁻ and the surplus power generation r _t ⁺ in a certain period.

である。 however,

is.

Differentiating Equation 24 with respect to x _p yields Equation 25 below.

When a certain power generation capacity x _p is fixed, the relationship between the power storage capacity x _b and the power consumption Q is established, and the end point between the two is (x _bi , Q(x _bi )). Now, let us consider changing the power generation capacity _xp . If dx _bi /dx _p in Equation 25 is constant, in other words, if the period j=J _s ~J _e of the net demand corresponding to x _bi does not change, it will not be an end point. It corresponds to the ridgeline of a convex polyhedron showing the relationship between the power generation capacity, the power storage capacity, and the power supply amount. The end point is the point of the installed power generation capacity x _p at which the value of Equation 25 changes. The conditions that can satisfy such conditions are the conditions shown in Equations 2 to 7 above.

<4-6. Dharma Drop Algorithm>
A profile of net demand r _t can be aggregated when surplus generation r _t ⁺ (or residual demand r _t ⁻ ) occurs continuously (in consecutive periods). Assume that a set of periods in which surplus power generation r _t ⁺ (or residual demand r _t ⁻ ) occurs is identified, and that the identified period is t _s to t _e . Numbering the period by j, the aggregate net demand r _sumj is given by Equation 26 below.

The relationship calculation unit 20 calculates the relationship between the power storage capacity and the supply power amount in the plurality of power generation capacity based on the profile of the aggregated net demand _{r_sumj} .

The profile of the aggregated net demand _{r_sumj} has alternating positive and negative components over time. Here, for the sake of simplicity, r _t =0 is regarded as the surplus power generation r _t ⁺ , and the profile of the aggregated net demand r _sumj is positive in the first period (surplus power generation r _t ⁺ ) and negative in the final period. (residual demand r _t ⁻ ). This can be handled by appropriately adjusting the aggregation start period of the original profile. The surplus generation r _t ⁺ and the residual demand r _t ⁻ have the same number of components, and if m is the number of components, the aggregate net demand r _sumj profile has 2m components.

For the profile of aggregate net demand r _sumj , find the period with the smallest absolute value and denote that period as j ^* . This is expressed in Equation 27 below.
|r _sumj* |=min(|r _sumj |) (Formula 27)
The components of each period of the profile of the aggregate net demand r _sumj are subjected to the following operations represented by Equation 28 below to obtain r _sum′j .

This operation finds the profile of the aggregated net demand r _sumj after supplying the maximum surplus generation r _t ⁺ to the residual demand r _t ⁻ when a storage facility of capacity |r _sumj* | is installed. correspond to Due to charging and discharging, the surplus power generation r _t ⁺ approaches zero by the charging amount, and the residual demand r _t ⁻ approaches zero by the discharging amount. Note that although the charge/discharge efficiency e of the power storage equipment is not taken into consideration in Equation 28, the charge/discharge efficiency e described above may be taken into account. Supplying the maximum surplus power generation r _t ⁺ to the residual demand r _t ⁻ is equivalent to maximally charging and discharging, which means that the state of charge (SOC) from ₀ to It is equivalent to performing m charge/discharge of 1.

The aggregated profile r _sum'j is zero at j=j ^* . For other j, the absolute value decreases from the original _{r_sumj} but the sign remains the same. The components before and after j=j ^* that is zero, r _sumj*−1 and r _sumj*+1 , have the same sign.

Aggregate the three periods j=j ^* -1, j ^* , j ^* +1 of r _sum'j to obtain a new aggregated net profile r _newj' represented by Equation 29 below.

In r _newj' , the surplus power generation r _t ⁺ and the residual demand r _t ^- have the same number of components, and the number of components is 2m-2.

As described above, by repeating profile aggregation→charging/discharging, one profile is zeroed→profile aggregation is repeated, the number of profile components can be reduced by two for each operation. Finally, the profile can be aggregated into one with m+1 operations. Let r _sumj ^k be the profile after the k-th aggregation. When k=1, the sum of r _t is r _sumj ¹ , and the number of components at that time is 2m _i . Here, the subscript i corresponds to the id of the power generation capacity _xp . The number of components in r _sumj ^k is 2(m _i −k+1). The increment Δx _bk of the power storage facility capacity at r _sumj ^k and the increment ΔQ _k of the power usage at that time are expressed by the following equations 30 and 31.

The relationship between the installed storage capacity and the amount of electricity used is a piecewise linear function. The slope ∂Q/∂x _b in the range x _bk−1 ≦x _b ≦x _bk is (m _i −k+1), which is equal to the number of full cycle charge/discharge cycles in this region. A boundary point x _bk whose slope changes with a piecewise linear function is expressed by Equation 32 below.

However, Δx _b0 =0. The power usage amount in x _bk is represented by Equation 33 below.

However, ΔQ ₀ =0.

Supplying power from the surplus power generation r _t ⁺ to the residual demand r _t ⁻ through the power storage equipment is the same as when the surplus power generation r _t ⁺ is regarded as a sand dune and the residual demand r _t ⁻ is regarded as a hole. , the sand mound is read as "Dharma drop Daruma", and at each aggregation stage, Daruma dolls equal to the minimum height (or depth) are dropped and buried in the holes, erasing Daruma dolls and holes one by one. You can imagine it in the same way as you go. Therefore, the above algorithm is called the Dharma Dropping Algorithm.

<5. Identification of the end point in the relationship between the power generation capacity, the power storage capacity, and the power supply amount>
<5-1. Mathematical Expression>
The end point identification unit 22 identifies the end point based on the relationship between the power storage capacity and the power supply amount in the plurality of power generation capacity calculated by the relationship calculation unit 20 . Specifically, the end point identifying unit 22 identifies, as an end point, a point at which the partial differentiation of the power generation facility capacity with respect to the supplied power amount and the partial differentiation of the power storage facility capacity with respect to the supplied power amount change. The processing of the end point identification unit 22 will be specifically described below.

The relationship between the power generation facility capacity _{xp, the power storage facility capacity xb ,} and the power supply amount (that is, the power usage amount Q) is expressed by Equation 34 below.

However, x _b is in the range of x _bn-k ≤ x _b ≤ x _bn-k+1 . The reason why the right side can be transformed as in the second line is that x _b0 =0, and the coefficients of x _bi in the first line of the right side are all 1 due to the cancellation of adjacent terms.

Equation 34 is substantially the same as Equation 18. Formula 18 is a formula when the power generation capacity x _p is fixed, but as shown in Formula 19, Q ₀ and x _bi are functions of x _p , so Q = Q (x _p , x _b ) It is expressed as a function of two variables.

The partial derivative of Equation 34 (that is, the amount of electricity used) with respect to the storage installed capacity _xb is represented by Equation 35 below.

The partial derivative of _Eq .

where J ₋ is the set of periods in which residual demand r _t ⁻ occurs (that is, when x _p p _t ≦d _t ). J ₊ is the set of epochs of the period corresponding to x _bi .

Let D be the total power demand _dt of the target system. That is, D is represented by Equation 37 below.

The power usage rate y is obtained by dividing the power usage amount Q by D (y=Q/D).

The component of the normal vector of each surface of the three-dimensional convex polyhedron representing the relationship between the power generation capacity _{xp, the power storage capacity xb ,} and the power consumption Q is expressed by Equation 38 below.

Equations 35 and 36 can be applied to Equation 38. Note that the rate of change in the amount of electricity used and the vector (∂y/∂x _p , ∂y/∂x _b , 1) with the third component set to 1 (=∂y/∂y) are one plane of the convex polyhedron is the normal vector of

<5-2. End Point Generation Condition 1 When x _b = 0>
Consider x _p with x _b −=0 and ∂Q/∂x _p varying.

So ∂Q/∂x _p changes when the elements of J ₋ change. Since J ₋ is a set of periods in which the residual demand r _t ⁻ occurs, when the element changes, the period t that was (r _t < 0) until then becomes (r _t > 0 ), that is, when r _t =0 or x _p p _t =d _t . Therefore, when x _p =d _t /p _t , the end point is x _b =0. That is, (x _p ,x _b ,y)=(d _t / _pt ,0,y ₀ ) is the endpoint.

を構成するＪ_ｈの要素が変化するとき、２つ目は、ｘ_ｂｈ＝ｘ_ｂｈ＋１となるときである。 <5-3. End Point Generation Condition 2 When x _b = x _bh >
Consider x _p such that ∂Q/∂x _p varies with x _b =x _bh . There are two possible cases for this condition. The first is

The second is when x _bh =x _{bh +1} .

<5-3-1. When the elements of J _h change>
Let x _bh be one of the results obtained from the calculation of the residual demand r _t ⁻ for period t. That is, let it be l _k or l _k +h _k obtained by manipulating the reverse cumulative net demand quantity q _tj shown in Equation 8. Note that the h in J _h is a subscript and is unrelated to the h in h _k . When the elements of _jh change, the following three cases are conceivable.

であり、逆向き累積正味需要量ｑ_ｔｊの最大値である。
ｎ_０＜０では、ｌ_Ｋ＝ｎ_１－ｍ_０、ｌ_Ｋ＋ｈ_Ｋ＝ｎ_０－ｍ_０であるが、ｎ_０＝０では、ｌ_Ｋ＋ｈ_Ｋ＝－ｍ_０となる。ｘ_ｂｈ＝ｌ_Ｋ＋ｈ_Ｋのとき、ｎ_０＜０→ｎ_０＝０でＪ_ｈの要素が変化する。 (i) When n ₀ < 0 becomes n ₀ = 0 Note that n ₀ is

, which is the maximum value of the reverse cumulative net demand _qtj .
When n ₀ <0, l _K =n ₁ −m ₀ and l _K +h _K =n ₀ −m ₀ , but when n ₀ =0, l _K +h _K =−m ₀ . When x _bh =l _K +h _K , the elements of J _h change as n ₀ <0→n ₀ =0.

となるとき、端点が発生する。

When , an endpoint occurs.

(ii) When n _k > q _tj (where j _2k < j < j _2k-1 ) becomes n _k = q _tj (n _k = max(q _tj ) = q _tj2k (where j _{2k- 1} ≥ j ≥ 0 range))
At this time as well, the elements of _Jh change.

(iii) When mk < _qtj ( _where j2k+ ₁ <j<j2( _{k +1)} ) becomes mk = _qtj (mk = min( _qtj ) = _{qtj2k +1} (where _j2k ≧ j ≧ 0 range))
At this time as well, the elements of _Jh change.

となることに対応する（ｊ_ｋ’’及びｊ_ｋ’’’は適当なｊ）。 In cases (ii) and (iii) above,

(j _k'' and j _k''' are the appropriate j).

と表されるから、

となるときに端点が発生する（ｊ_ｋ’’及びｊ_ｋ’’’は適当なｊ）。 <5-3-2. When x _bh =x _bh+1 >
Again, x _bh and x _bh+1 are

Since it is expressed as

(j _k'' and j _k''' are appropriate j).

The endpoint specifying unit 22 specifies endpoints by the above-described calculation.

<6. Drawing calculation results>
The drawing unit 24 draws a graph representing the relationship between the installed power generation capacity _{xp, the storage installed capacity xb ,} and the amount of power supplied (that is, the amount of power used Q) or the power usage rate calculated by the relationship calculation unit 20. to draw. In particular, the drawing unit 24 draws the graph including the end points specified by the end point specifying unit 22 (the end points are specified). FIG. 9 shows an example of a convex polyhedron generated by the drawing unit 24 and showing the relationship between the power generation capacity, the power storage capacity, and the power utilization rate. In FIG. 9, some endpoints are numbered P, and some planes of the convex polyhedron are numbered S. In FIG.

10 shows a view of the convex polyhedron shown in FIG. 9 viewed from above (that is, from the positive direction of the power utilization rate axis). The drawing unit 24 visualizes the partial differential values obtained in the calculation process of the end point specifying unit 22, that is, the normal vectors (∂y/∂x _p , ∂y/∂x _b ) of each surface of the convex polyhedron. FIG. 11 shows a normal vector plot diagram in which values of normal vectors of planes forming a three-dimensional convex polyhedron, generated by the rendering unit 24, are plotted. The diagram shown in FIG. 10 and the normal vector plot diagram shown in FIG. 11 have a dual relationship. The normal vector plot diagram shown in FIG. 11 exhaustively represents the correspondence relationship between the cost setting (power generation cost and power storage cost) and the optimum solution.

Power generation facility capacity x _p , power storage facility capacity x _b , power utilization rate y (x _p , x _b , y) and normal vector values, that is, unit prices of power generation and storage facilities (∂y/∂x _p , ∂ y/∂x _b ) ₌ (p ₁ , p ₂ ), and using the operation cost pf and the unit unit price of the backup power supply _If , the power supply system of the power supply system consisting of the power generation equipment, the storage equipment, and the backup power supply The cost L _sys (yen/kWh) is represented by Equation 39 below.
L _sys = p ₁ x _p + p ₂ x _b + p _f (1-y) + I _f (equation 39)
However, (x _p , x _b , y) are the optimum introduction amount and the optimum power utilization rate when (p ₁ , p ₂ ) are given.

From Equation 39, it is possible to obtain the relationship between the unit price of the power generation equipment and the unit price of the electricity storage equipment, and the system cost, which is the cost of the power supply system based on the optimum introduction amount and the optimum power utilization rate at the unit price. The drawing unit 24 draws a map showing the relationship. An example of such a map is shown in FIG. The map shown in FIG. 12 is a contour map, and the lines shown in FIG. 12 indicate sets of power storage equipment unit prices and power generation equipment unit prices that can obtain the same power system cost.

<7. Presentation of information to the user>
The presentation unit 26 provides the graph (convex polyhedron) or map generated by the drawing unit 24 to the user. For example, the display included in the input/output interface 12 is caused to display the above graphs and maps. Alternatively, the data representing the graph or map is transmitted to the user terminal and displayed on the display of the user terminal. Note that the presentation unit 26 does not necessarily need to present the graph or map generated by the drawing unit 24 to the user. Information indicating the relationship between the installed capacity and the amount of power supplied (or power utilization rate) can be presented to the user.

From the information presented by the presentation unit 26, the user can easily grasp the relationship between the power generation capacity of the power generation facility, the power storage capacity of the power storage facility, and the amount of power supplied to the target system.

Although the embodiments according to the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention.

10 power supply system design support device, 12 input/output interface, 14 memory, 16 processor, 18 end point candidate identification unit, 20 relation calculation unit, 22 end point identification unit, 24 drawing unit, 26 presentation unit.

Claims (6)

A power supply system design support device for supplying power to a target system, including power generation equipment and power storage equipment,
Based on a net demand profile that represents a temporal change in the difference between the power generation amount of the power generation facility and the power demand of the target system, the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the an end point candidate identification unit that identifies a plurality of power generation installed capacities having end point candidates that are points at which the coefficient of the linear relationship changes in relation to the amount of power supplied to the target system;
a relationship calculation unit that calculates the relationship between the power storage facility capacity and the supply power amount in the plurality of power generation facility capacities based on the net demand profile;
Based on the relationship between the power storage facility capacity and the supply power amount in the plurality of power generation facility capacities, a partial derivative of the power generation facility capacity with respect to the supply power amount and a partial differentiation of the power storage facility capacity with respect to the supply power amount an end point identification unit that identifies a point where changes in as an end point;
a presentation unit that presents to a user the relationship between the installed power generation capacity, the installed power storage capacity, and the supplied power amount, including the specified end point;
A power supply system design support device comprising: In the net demand profile, the relationship calculation unit is configured to perform a plurality of time-series continuous periods in which the power generation amount is greater than the demand amount, or a time-series continuous period in which the demand amount is greater than the power generation amount. generate an aggregated net demand profile that aggregates a plurality of periods to be generated, and based on the aggregated net demand profile, calculate the relationship between the power storage facility capacity and the supply power amount in the plurality of power generation facility capacities. ,
2. The power supply system design support device according to claim 1, wherein: a drawing unit that generates a graph including the specified end point and showing the relationship between the power generation capacity, the power storage capacity, and the power supply amount;
further comprising
The presentation unit presents the graph to the user,
2. The power supply system design support device according to claim 1, wherein: The drawing unit is a convex polyhedron as the graph based on the partial differentiation regarding the power generation facility capacity with respect to the supply power amount specified by the end point identification unit and the partial differentiation regarding the power storage facility capacity with respect to the power supply amount Generate a normal vector plot figure that plots the values of the normal vector of the plane,
The presentation unit presents the normal vector plot diagram to the user,
4. The power supply system design support device according to claim 3, wherein: Based on the relationship between the power generation facility capacity, the power storage facility capacity, and the power supply amount, the value of the normal vector, and the unit price of the power generation facility and the power storage facility, the drawing unit generating a map showing the relationship between the unit price, the equipment unit price of the power storage equipment, and the system cost, which is the cost of the power supply system;
the presentation unit presents the map to the user;
5. The power supply system design support device according to claim 4, characterized in that: Operate the computer as a design support device for a power supply system for supplying power to the target system, including power generation equipment and power storage equipment;
said computer,
Based on a net demand profile that represents a temporal change in the difference between the power generation amount of the power generation facility and the power demand of the target system, the power generation facility capacity of the power generation facility, the power storage facility capacity of the power storage facility, and the an end point candidate identification unit that identifies a plurality of power generation installed capacities having end point candidates that are points at which the coefficient of the linear relationship changes in relation to the amount of power supplied to the target system;
a relationship calculation unit that calculates the relationship between the power storage facility capacity and the supply power amount in the plurality of power generation facility capacities based on the net demand profile;
Based on the relationship between the power storage facility capacity and the supply power amount in the plurality of power generation facility capacities, a partial derivative of the power generation facility capacity with respect to the supply power amount and a partial differentiation of the power storage facility capacity with respect to the supply power amount an end point identification unit that identifies a point where changes in as an end point;
a presentation unit that presents to a user the relationship between the power generation facility capacity, the power storage facility capacity, and the power supply amount, including the specified end point;
A power supply system design support program characterized by functioning as a

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