Operating Planning Device and Operating Planning Method for Energy System

Abstract

To provide an operation planning device and an operation planning method that reduce the number of times in which a storage battery is charged and discharged to suppress deterioration of the storage battery and reduce operating costs.SOLUTION: An operation planning device 20 includes an operation plan calculation unit 24 that performs optimization calculations to minimize the operation cost of a consumer energy system 1 and creates an operation plan, and setting means that sets penalty information for increasing the operating cost of an energy system due to discharge of a storage battery 4, and the operation plan calculation unit 24 performs calculations to reduce driving costs by adding penalty information.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an operation planning device and an operation planning method for an energy system.

Background Art

[0002] In recent years, due to the tight power supply and demand, the increase in fuel costs, and the increase in the feed-in tariff for promoting renewable energy power generation, the domestic electricity price has been rising. In consumers such as buildings, factories, and blocks, in order to improve energy efficiency and respond to BCP (Business Continuity Planning), the introduction of energy systems composed of generators, photovoltaic power generation (PV), storage batteries, etc. has been progressing. Especially recently, the introduction volume of PV has been increasing for the purpose of reducing CO2 emissions in consumers. However, with the increase in the introduction volume of PV, problems such as the excess of contract power and PV power generation suppression have become apparent due to the fluctuations in PV power generation caused by weather conditions. To solve such problems, an operation planning system that predicts the power and heat demands and PV power generation amount in a consumer and optimally operates the energy system has become widespread.

[0003] Patent Document 1 describes a power management device including operation planning means for estimating the progress of deterioration of a storage device based on capacity maintenance rate information in the storage device information, determining at least one of the maximum charge / discharge current, charge termination voltage, and discharge termination voltage of the storage device as restriction information based on the progress of deterioration and storage device temperature prediction information, and determining charge / discharge power using the restriction information. The power management device described in Patent Document 1 plans the charge / discharge power of the storage battery using an optimization calculation so that the electricity charge generated in the energy system is minimized based on PV power generation prediction information, power demand prediction information, and an electricity price system.

[0004] Generally, in a consumer energy system, a storage battery is used to realize the following three functions. The first is the "peak cut" function. Since there is a limit on the contract power for the power consumption of the customer, when the power demand exceeds the contract power, the power previously charged in the battery is discharged to suppress the received power below the contract power. Since the contract power charge affects the whole year, peak cut becomes the top-priority function. The second is the "charging of surplus PV power generation" function. When the PV power generation amount exceeds the power demand, the surplus of the PV power generation is charged and discharged in other time periods to reduce the electricity charge. Since suppressing PV power generation results in energy waste, it becomes the next-priority function. The third is the "peak shift" function. Since the power consumption charge from the power company differs depending on the time periods of day and night, charging is done with the cheaper night-time power from the power company and discharging is done during the expensive daytime to reduce the electricity charge.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since the power management device described in Patent Document 1 formulates an operation plan through optimization calculation aiming at minimizing the operation cost of the energy system, the charge and discharge cycles of the battery increase, and the deterioration of the battery may progress.

[0007] In view of such circumstances, it is made, and an object is to provide an operation planning device and an operation planning method that reduce the charge and discharge cycles of the battery, suppress the deterioration of the battery, and reduce the operation cost.

Means for Solving the Problems

[0008] In order to solve the above problems, the operation planning device of the present invention is an operation planning device that formulates an operation plan for an energy system including a storage battery based on purchased power tariff information and power demand prediction, and includes operation planning calculation means for formulating the operation plan, and setting means for setting penalty information for increasing the operation cost of the energy system by discharging the storage battery. The penalty information is determined based on power price difference information according to time zones, The operation planning calculation means is characterized in that it performs a calculation for reducing the operation cost by adding the penalty information.

Effect of the Invention

[0009] According to the present invention, it is possible to provide an operation planning device and an operation planning method capable of reducing the deterioration of the storage battery by reducing the charge and discharge cycles of the storage battery and reducing the operation cost.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are essential for the solution means of the invention. (First Embodiment) FIG. 1 is a diagram showing the configuration of a consumer energy system to which the energy management device according to the first embodiment of the present invention is applied. In each figure, those with the same reference numerals indicate the same constituent elements or constituent elements having similar functions.

[0012] [Consumer Energy System] The consumer energy system 1 is a consumer such as a building, a factory, or an apartment house to which the energy management device according to the present embodiment is applied. The consumer energy system 1 includes an energy management device 2, a generator 3, a storage battery 4, a PV 5, a heat source machine 6, an electric power load 7, and a heat load 8. The customer energy system 1 includes at least a storage battery 4, and the operation planning device 20 of the energy management device 2 described later formulates an operation plan for the customer energy system 1 based on the purchased power tariff information and the power demand prediction. For example, for "peak shifting", since the power consumption charge varies depending on the time zone, it charges with the inexpensive night-time power and discharges during the expensive daytime to reduce the electricity charge. Therefore, the purchased power tariff information and the power demand prediction are used.

[0013] The customer energy system 1 is connected to a power grid (not shown), and purchases the power insufficient in the customer energy system 1 as purchased power (power purchase) 9 from an electric power company or the like. In addition, the customer energy system 1 purchases the city gas 10 necessary for the operation of the customer energy system from a gas company or the like.

[0014] The energy management device 2 is a system (Energy Management System) that monitors / controls the energy consumption in each category, and includes a BEMS for commercial buildings (Building), a FEMS for factories (Factory), a HEMS for homes (Home), and a CEMS for the entire region including these (Community). In this embodiment, the BEMS, FEMS, and HEMS are taken as examples of the energy management device 2.

[0015] The energy management device (BEMS, FEM, HEMS) 2 is connected to each facility of the customer energy system 1 via a communication network in the customer's premises. The energy management device 2 formulates and controls the operation plan of each facility.

[0016] The generator 3 is a generator for steam / gas turbines or a generator for gas / diesel engines.

[0017] The energy storage battery 4 includes a battery (main body) and a battery power conditioner (PCS: Power Conditioning System) that manages the charging and discharging of the battery (main body). The energy storage battery 4 is, for example, a lithium-ion battery. Also included is the case where a battery of an electric vehicle or the like is used as the energy storage battery 4.

[0018] The PV 5 includes a solar panel (PV) and a PV power conditioner (PCS: Power Conditioning System, also referred to as a PV inverter) that converts the DC power output from the solar panel into AC power.

[0019] The heat source machine 6 is a heat source facility such as a refrigerator or a boiler.

[0020] The power load 7 is power consumption (or power demand) such as air conditioning and lighting. In a factory, the power consumption (or power demand) of production equipment is also included in the power load 7.

[0021] The heat load 8 is, for example, heat consumption such as air conditioning. In a factory, the heat consumption of production equipment is the heat load 8. Note that the heat load 8 may also be referred to as heat demand.

[0022] [Operation Planning Device] FIG. 2 is a block diagram showing the configuration of an operation planning device 20 which is a function of the energy management device 2. The energy management device 2 includes, in addition to the operation planning device 20, a data collection device (scanner; not shown), a demand prediction device (not shown), and a control device 30 that controls each device while measuring the power demand on the current day based on the output of the operation planning device 20 (the operation plan of the previous day). As shown in FIG. 2, the operation planning device 20 includes a processing unit 21 (setting means), an input unit 22 (setting means), an operation plan display unit 23, an operation plan calculation unit 24 (operation plan calculation means), an operation plan data storage unit 25 (setting means), and an operation plan output unit 26. The operation planning device 20 is configured by a server including a PC in addition to a dedicated device. The processing unit 21, together with the operation plan calculation unit 24, is composed of a CPU (Central Processing Unit) or the like, and performs a series of processes related to the operation plan carried out in the operation planning device 20. Further, when changing the charge / discharge penalty coefficient kcp (initial value) of the penalty information (refer to the discharge penalty PB(t) in the following formula (5)), the processing unit 21 updates the charge / discharge penalty coefficient kcp within a preset range.

[0023] The input unit 22 receives information such as weather forecasts, demand prediction information, electricity prices, and gas prices from the energy management device 2. Further, the input unit 22 has a function as a setting means for setting penalty information (refer to the discharge penalty PB(t) in the following formula (5)) for suppressing the discharge of the storage battery 4.

[0024] The operation plan display unit 23 is composed of an LCD (Liquid Crystal Display) device, a driver, etc., and displays the operation plan result on the screen.

[0025] The operation plan calculation unit 24 performs an optimization calculation for formulating the operation plan of the consumer energy system 1. Specifically, the operation plan calculation unit 24 performs an optimization calculation to minimize the operation cost of the consumer energy system 1, formulates an operation plan, and performs a calculation to reduce the operation cost by adding penalty information that increases the operation cost of the energy system due to the discharge of the storage battery 4. Here, the operation cost is the sum of the cost of the purchased power 9 consumed by the power load and equipment in the consumer energy system 1 and the cost of the fuel (city gas 10 in FIG. 1) consumed by the equipment.

[0026] The operation plan is, for example, an operation schedule of 24 hours at 30 - minute intervals for the start / stop of each facility of the energy system and the operation output. The outline of the optimization calculation of the consumer energy system performed by the operation plan calculation unit 24 will be described later. The operation plan calculation unit 24 performs an optimization calculation by adding penalty information (refer to the discharge penalty PB(t) in the following formula (5)).

[0027] The above penalty information is determined based on the power price difference information according to the time zone. That is, the discharge penalty PB(t) (penalty information) is given by (charge-discharge penalty coefficient kcp > power price difference for which charge-discharge is to be suppressed), as shown in the following formula (6). The power price difference for which charge-discharge is to be suppressed is the threshold of the power price difference for suppressing the peak shift due to charge-discharge. For example, it is the electricity price difference (the difference between the maximum value and the minimum value of the electricity price) shown in FIG. 3. The power price difference for which charge-discharge is to be suppressed can be arbitrarily set by the user. Also, when purchasing power at the electricity price of the wholesale power market from a retail business operator, charge-discharge can be performed when the fluctuating electricity price is greater than the power price difference for which charge-discharge is to be suppressed that is set, and charge-discharge can be suppressed when it is smaller. As yet another example, the power price difference for which charge-discharge is to be suppressed may be set to the difference between the maximum value of the electricity price and the power generation unit price of the generator 3 (the fuel cost (\$ / kWh) consumed to generate a unit amount of electric power by the generator).

[0028] The operation plan data storage unit 25 is composed of an external storage device such as an HDD (hard disk drive), and stores the operation plan results in a database form.

[0029] The operation plan output unit 26 outputs the operation plan results as control target values to the control device 30 of the energy management device 2.

[0030] [Outline of Optimization Calculation of Customer Energy System] The outline of the optimization calculation of the customer energy system performed by the operation plan calculation unit 24 will be described. In the optimization calculation of the customer energy system, (1) the power supply-demand balance, (2) the supply-demand balance of thermal energy (for example, steam), and (3) the energy balance of the storage battery in the time direction are calculated.

[0031] [Power Supply-Demand Balance] The power demand D P (kW) representing the power supply-demand balance is represented by formula (1).

[0032] [Equation]

[0033] As an example of thermal energy, the steam demand D S (kW) representing the supply-demand balance of steam is shown by Equation (2). Steam is an example of a heat load. There are cases where steam is used for sterilization and heating in the manufacturing process, for example. Among heat loads, in addition to steam, there is also hot water. Hot water is used for air conditioning and the like.

[0034]

Number

[0035] S, which is the remaining charge of the storage battery representing the energy balance of the storage battery in the time direction BT (kWh) is shown by Equation (3).

[0036]

Number

[0037] The operating cost of the optimization calculation is shown by Equation (4) using the objective function U.

[0038]

Number

[0039] In the optimization calculation, a combination of optimization variables is searched so as to minimize the objective function U. In the optimization calculation, the optimization calculation method is not limited. For example, a mixed-integer linear programming method is used. The optimization variables are the start / stop variable (1: start, 0: stop) of the generator 3 and its output, the start / stop variable (1: start, 0: stop) of the heat source machine 6 and its output, the charging output of the storage battery 4, and the discharging output.

[0040] As described above, in the operation plan for charging and discharging the storage battery 4, each function of "peak cut", "charging of surplus PV power generation", and "peak shift" is executed. Here, if all of "peak cut", "charging of surplus PV power generation", and "peak shift" can be executed, the operation cost can be minimized. Specifically, in the optimal operation plan, the objective function is set to the operation cost as shown in the above formula (4), and the operation plan for the storage battery 4 is formulated.

[0041] The inventor has found that as the number of charge and discharge cycles of the storage battery increases, the deterioration of the storage battery 4 progresses and the life cycle cost may increase. That is, as shown in the above formula (4), in the optimization calculation, in order to minimize the energy cost, peak shift corresponding to the power price difference (hereinafter referred to as peak shift due to power price difference) is also performed. For this reason, the number of charge and discharge cycles of the storage battery increases, leading to deterioration of the storage battery. Hereinafter, the peak shift due to power price difference will be described.

[0042] <Peak Shift Based on Power Price Difference Due to Charge and Discharge of Storage Battery> Peak shift due to power price difference is an operation that reduces the operation cost by charging the storage battery with the power of a generator or purchased power at the power price (generation unit price, electricity rate) at a certain time, and then discharging the power charged in the storage battery at a lower power price than the power price (generation unit price, electricity rate) of the generator or purchased power at a subsequent time. As an example, the peak shift based on the electricity rate price difference due to the charge and discharge of the storage battery 4 is shown.

[0043] FIG. 3 is a diagram for explaining the peak shift based on the electricity rate price difference due to the charge and discharge of the storage battery. The upper diagram in FIG. 3 shows the electricity rate, and the lower diagram in FIG. 3 shows the charge and discharge output of the storage battery. Generally, the electricity rate is high during the daytime and low during the night and early morning. Therefore, as shown in the lower diagram of FIG. 3, the storage battery is charged during the night and early morning, and discharged during the daytime. By doing so, as shown in the upper diagram of FIG. 3, the operation cost corresponding to the electricity rate price difference × discharge amount can be saved.

[0044] FIG. 4 is a diagram for explaining another example of peak shifting based on the difference in electricity rates due to charging and discharging of a storage battery. The peak shifting based on the above-described difference in electricity rates is the case of Case A in FIG. 4. As other examples, there are peak shifting (Case B) in which charging is performed during a time period when the electricity rate is low and then discharging of the storage battery is performed instead of power generation by a generator with a high power generation unit price in a subsequent time period, peak shifting (Cases C and D) in which power generated by PV power generation with a substantially zero unit price of power generation is charged and then discharging of the storage battery is performed instead of purchasing power with a higher electricity rate than the unit price of power generation by PV power generation in a subsequent time period, and peak shifting (Case E) in which power generated by PV power generation with a substantially zero unit price of power generation is charged and then discharging of the storage battery is performed instead of power generation by a generator with a higher unit price of power generation than the unit price of power generation by PV power generation in a subsequent time period.

[0045] In the present embodiment, peak shifting (Cases A and B) that utilizes charging by purchasing power is suppressed. In addition, peak shifting (Cases C, D, and E) that utilizes charging by PV power generation with a substantially zero unit price of power generation is executed because it has a large effect of reducing the operation cost. The discharge penalty PB(t) at this time is represented by Equation (5).

[0046]

Equation

[0047] For the charge / discharge penalty coefficient kcp in Equation (5), it is set to be smaller than the difference between the unit price of power generation by PV power generation (substantially zero) and the power price of purchasing power or power generation (the difference in power price for performing charge / discharge).

[0048] However, as described above, in the optimization calculation aimed at minimizing the operation cost, even when the difference in electricity rates is small, peak shifting is executed, the number of charge / discharge cycles of the storage battery increases, the deterioration of the storage battery progresses, and as a result, there is a problem that the life cycle cost increases.

[0049] In the present embodiment, in the optimization calculation, a penalty is provided so as to suppress the charge / discharge of the storage battery for peak shifting with a low priority for the user when the assumed difference in power price is not satisfied.

[0050] Specifically, based on the predicted results of power demand and PV power generation, the charge and discharge of the battery for peak shifting with low priority for the user are suppressed. For this purpose, a discharge penalty PB(t) (penalty information) for suppressing the charge and discharge of the battery is added to the objective function U for calculating the operating cost of the optimization calculation. The objective function U to which the discharge penalty PB(t) is added is represented by Equation (6), and the discharge penalty PB(t) in Equation (6) is represented by Equation (5). By providing the discharge penalty PB(t) to the objective function U for calculating the operating cost, the discharge (number of discharges) of the battery 4 can be reduced. Since the discharge can be reduced, the charging for the discharge also disappears, and as a result, the charge and discharge of the battery 4 can be reduced.

[0051]

Number

[0052] When performing charge and discharge using the price difference of the electricity bill calculated using the objective function U shown in Equation (6), a penalty cost exceeding the electricity bill price difference occurs, so the charge and discharge using the electricity bill price difference are suppressed. By preventing peak shifting below the assumed power price difference, the number of charge and discharge cycles of the battery 4 can be suppressed, and the progress of deterioration can be prevented.

[0053] On the other hand, the discharge for peak cutting and the charging of PV surplus power need to satisfy the constraint conditions of the power supply and demand balance (the conditions of Equation (1)) and the constraint conditions of the contract power for power purchase (the conditions of Equation (7)), so they are executed regardless of the penalty.

[0054]

Number

[0055] As described above, in this embodiment, among the three functions executed by the operation planning device 20, namely "peak cutting", "charging of surplus PV power", and "peak shifting", "peak cutting" and "charging of surplus PV power" are executed without executing "peak shifting". For this reason, "peak cutting" and "charging of surplus PV power" are targeted. Also, regarding "peak shifting", it is characterized in that peak shifting due to the power price difference is not executed. In order to execute "peak cutting" and "charging of surplus PV power" without executing "peak shifting", a discharge penalty PB(t) is provided (set) in the objective function U for calculating the operation cost, thereby reducing the discharge (number of discharges) of the storage battery 4.

[0056] <Comparison of operation plans between the case without discharge penalty and a certain case> Hereinafter, the operation plans in the case without discharge penalty and a certain case will be compared and described. The operation plan of this embodiment is an operation plan for each day, and the operation plan for the next day is formulated the day before every day. That is, since the weather information for the next day is input the day before, it is predicted how much PV power will be generated, and how much power demand and heat (steam) demand will occur, and the one-day operation plan of the generator and storage battery for the next day is formulated. In reality, the weather information input is updated every few hours. For example, weather forecasts (temperature, humidity, solar radiation) are input from the contracted weather provider to the input unit 22 (Fig. 2) of the operation planning device 20. Also, the power and heat demands change moment by moment, and information is input every few hours. The operation planning device 20 re-predicts and re-formulates the above one-day operation plan formulated the previous day every 30 minutes, for example, based on these weather information and updated information on power and heat demands.

[0057] First, the operation plan in the case without discharge penalty will be described. FIG. 5 is a diagram for explaining an operation plan in a case without a discharge penalty. The upper diagram in FIG. 5 shows the electricity price, and the lower diagram in FIG. 5 shows the electricity in each facility. The horizontal axis indicates the slots of the operation plan time, representing 24 slots obtained by dividing one day into 24 hours. In addition, when reforecasting and redrawing every 30 minutes, it is set as 48 slots.

[0058] It is assumed that the consumer energy system 1 (see FIG. 1) is equipped with one generator (generation output: 300 kW) and one storage battery (charge / discharge output: 200 kW, charge capacity: 500 kWh). The purchase electricity price from the power company is 14 / kWh (8:00 to 18:00), 6 / kWh (0:00 to 8:00, 18:00 to 24:00), and the generation cost of generator 3 (see FIG. 1) is 10 / kWh.

[0059] As shown by the broken line connecting the upper and lower diagrams in FIG. 5, the generation costs reverse between daytime and nighttime with power purchase and generation by generator 3 (during the daytime, the generation cost by generator 3 is lower than that of power purchase). Here, the generation cost by generator 3 (two-dot chain line) is assumed to be constant. Here, the PV generation is even cheaper than the generation by generator 3 (PV generation cost 0).

[0060] Also, as shown in FIG. 5, the consumer energy system 1 must be able to handle power demands up to a maximum of 600 (kWh) based on a power demand of 100 (kWh).

[0061] As shown in FIG. 5, the consumer energy system 1 performs peak shifting due to the electricity price difference (see reference symbol a in FIG. 4). For peak shifting, the storage battery 4 is charged with inexpensive nighttime electricity, and the storage battery 4 is discharged during the expensive daytime to reduce the electricity bill. Here, charging is performed with inexpensive power purchase at 1 to 3 o'clock (see reference symbol b in FIG. 4), and during 8 to 10 o'clock when the power purchase unit price is high, power generation by generator 3 with a low generation cost (see reference symbol c in FIG. 4) and discharge of the storage battery 4 based on the power charged with inexpensive power purchase (see reference symbol d in FIG. 4) are performed. And, in preparation for absorbing the excess PV power generation, the remaining charge amount is set to 0 (see reference symbol e in Fig. 4). In Fig. 4, the remaining charge amount is indicated to show the movement or number of charge and discharge cycles of the storage battery with the remaining charge amount set to 0 in preparation for absorbing the excess PV power generation.

[0062] As shown in Fig. 5, during the daytime from 8 to 18 o'clock, PV5 performs PV power generation with a power generation cost of 0. In particular, from 12 to 14 o'clock, the PV power generation exceeds the power demand (see reference symbol f in Fig. 5).

[0063] For this reason, the consumer energy system 1 charges the storage battery 4 from 12 to 14 o'clock to absorb the excess PV power generation (see reference symbol g in Fig. 5). Note that the charging of the storage battery 4 from 1 to 3 o'clock (see reference symbol a in Fig. 5) is charging using purchased electricity with a low unit price, while the charging from 12 to 14 o'clock (see reference symbol g in Fig. 5) is charging to absorb the excess PV power generation. Although the charge and discharge functions are the same, the purposes are different.

[0064] After 15 o'clock, the PV power generation alone cannot cover the power demand. To cover the power demand, in addition to the PV power generation, power generation by the generator 3 with a lower power generation unit price than the electricity rate (see reference symbol h in Fig. 4) and discharge of the storage battery 4 based on the charging power of the excess PV power generation (see reference symbol i in Fig. 4) are performed.

[0065] In this way, the consumer energy system 1 discharges the excess PV power generation with a power generation cost of 0 from 16 to 18 o'clock. Also, the consumer energy system 1 covers the power demand with low-cost purchased electricity from 19 to 24 o'clock when the purchased electricity unit price is low. In the case without the discharge penalty shown in Fig. 5, in order to make the most of the storage battery 4, a plan is generated to perform charge and discharge exceeding 50% of the remaining charge amount twice a day.

[0066] Next, the operation plan in the case with a discharge penalty will be described. Fig. 6 is a diagram for explaining the operation plan in the case with a discharge penalty. The upper diagram in Fig. 6 shows the electricity price, and the lower diagram in Fig. 6 shows the electricity in each facility. The consumer energy system 1 is assumed to operate under the same conditions as in the case of FIG. 5. Also, the purchase electricity unit price from the power company and the power generation unit price of the generator 3 are the same as in the case of FIG. 5.

[0067] In order to suppress the peak shift that occurred during the 1 to 11 o'clock period in FIG. 5, the consumer energy system 1 executes an analysis in which a penalty for charge and discharge using the electricity price difference shown in the above formula (6) is set. As shown in FIG. 6, the consumer energy system 1 suppresses the peak shift due to the electricity price difference (see reference sign j in FIG. 6). Since the peak shift due to the electricity price difference (see reference sign j in FIG. 6) is suppressed, both the charging during power purchase from 1 to 3 o'clock shown by reference sign b in FIG. 5 and the discharging of the storage battery 4 shown by reference sign d in FIG. 5 are stopped. Also, since the peak shift due to the electricity price difference is suppressed, the remaining charge amount is 0.

[0068] In this case with the discharge penalty (the case where the peak shift due to the electricity price difference is suppressed), during the 1 to 7 o'clock period, the power demand is mainly covered by power purchase, and during the 8 to 11 o'clock period, the power demand is covered by PV power generation and the generator 3 with a low power generation unit price (purchase electricity unit price).

[0069] During the 12 to 14 o'clock period, charging is performed to absorb the surplus PV power generation, and during the 16 to 18 o'clock period, the surplus PV power generation with a power generation cost of 0 is discharged. During the 19 to 24 o'clock period, the power demand is covered by power purchase at a low unit price. In this case with the discharge penalty, since the peak shift using the electricity price difference is suppressed, the number of charge and discharge times in a day is 1 for the charge and discharge of the surplus PV power generation.

[0070] By setting the charge-discharge penalty coefficient \(k_{cp}\) [¥ / kWh] of the penalty term \(P_B\) in Equation (6) to be greater than the electricity price difference, it is possible to suppress the charge and discharge of the storage battery for peak shifting (peak shifting due to the electricity price difference) that utilizes the electricity price difference. Here, what is suppressed is the peak shifting due to the electricity price difference that is desired to be suppressed. The discharge of the storage battery 4 that discharges the excess PV power generation is not suppressed by setting the charge-discharge penalty coefficient \(k_{cp}\) to be smaller than the electricity price difference at which the charge and discharge are performed.

[0071] Incidentally, when the charge-discharge penalty coefficient \(k_{cp}\) [¥ / kWh] (penalty information) is made equal to the electricity price difference, the reduction in electricity cost due to peak shifting and the penalty for charge and discharge of the storage battery for peak shifting become equal. This case will be explained. Generally, losses occur during the charge and discharge of the storage battery. Therefore, the operating cost slightly increases when performing charge and discharge of the storage battery for peak shifting. Thus, it becomes an operation plan in the case where there is a discharge penalty shown in FIG. 6.

[0072] The operation of the customer energy system configured as described above will be described below. <Operation Planning Process 1> FIG. 7 is a flowchart showing the operation planning process 1 of the operation planning device 20 of the customer energy system 1. In step S1, the input unit 20 (see FIG. 2) of the operation planning device 20 inputs the power and heat demand prediction results, electricity price, gas price, energy consumption characteristics of the equipment, and the charge-discharge penalty coefficient \(k_{cp}\) as input data for the optimal operation plan. The charge-discharge penalty coefficient \(k_{cp}\) is a coefficient set by the user in advance. For example, it is set by the input unit 20 by the user.

[0073] In step S2, the operation planning calculation unit 24 (see FIG. 2) of the operation planning device 20 performs an optimization calculation for formulating the operation plan of the customer energy system. Specifically, the operation planning calculation unit 24 performs an optimization calculation to minimize the objective function \(U\) in Equation (5) based on the above input data.

[0074] In step S3, the operation plan display unit 23 (see FIG. 2) of the operation plan device 20 outputs the operation plan results of the planned devices (generators, storage batteries, others) to, for example, the control device 30 (see FIG. 1), and ends the processing of this flow. Here, the output of the operation plan results includes display on the operation plan display unit 23, recording on a recording medium (not shown), printing by a printer or the like via an I / F, data transmission via a communication I / F, and the like.

[0075] As a result, it is possible to formulate a plan that suppresses the charge and discharge of the storage battery for peak shifting due to the power price difference.

[0076] [Effect] As described above, the operation plan device 20 according to the present embodiment includes an operation plan calculation unit 24 that performs optimization calculation to minimize the operation cost of the consumer energy system 1 and formulates an operation plan, and a setting means that sets penalty information that increases the operation cost of the energy system due to the discharge of the storage battery 4. The operation plan calculation unit 24 performs a calculation to reduce the operation cost by adding the penalty information.

[0077] With this configuration, it is possible to reduce the charge and discharge cycles of the storage battery, suppress the deterioration of the storage battery, and reduce the operation cost.

[0078] In the operation plan device 20, the penalty information is determined based on the power price difference information according to the time zone. As a result, by preventing peak shifting below the assumed power price difference, it is possible to suppress the charge and discharge cycles of the storage battery 4 and prevent the progress of deterioration. As a result, it is possible to prevent excess contract power and PV power generation surplus while preventing the deterioration of the storage battery 4.

[0079] In the operation plan device 20, in the optimization calculation of the operation plan, an optimization calculation is performed in which the operation cost is used as the objective function, and a discharge penalty term as a virtual operation cost proportional to the discharge amount of the storage battery is added to the objective function to minimize the objective function. As a result, it is possible to prevent peak shifting below the assumed power price difference, suppress the charge and discharge cycles of the storage battery, and prevent the progress of deterioration.

[0080] (Second Embodiment) The configuration of the operation planning device 20 of the consumer energy system according to the second embodiment of the present invention is the same as that in FIG. 2. The operation planning device 20 of the present embodiment is applied to the operation planning device 20 of the energy management device 2 in FIG. 1. The operation planning device 20 of the present embodiment inputs a discharge penalty coefficient kcp, and the operation planning calculation unit 24 performs an optimization calculation based on the discharge penalty coefficient kcp.

[0081] In addition, the operation planning data storage unit 25 stores penalty information for suppressing the discharge of the storage battery 4 based on the number of discharges of the storage battery 4, and has a function as setting means for setting the penalty information by reading out this penalty information. Specifically, the penalty information is the charge / discharge penalty coefficient kcp [ / kWh] in the following formula (5), and stores the input charge / discharge penalty coefficient kcp (initial value) as in step S11 of FIG. 8 below. Also, as in step S12 of FIG. 8 below, the changed (updated) charge / discharge penalty coefficient kcp is stored.

[0082] <Operation Planning Process 2> <Operation Planning Process 2> assumes a case where the price of the electricity charge changes in multiple steps, for example, when purchasing electricity at the spot price in the wholesale electricity market. In such a case, since it is difficult for the user to set an appropriate charge / discharge penalty coefficient kcp, the operation plan is formulated according to the following flow.

[0083] FIG. 8 is a flowchart showing the operation planning process 2 of the operation planning device 20 of the consumer energy system 1 according to the second embodiment. In step S11, the input unit 20 (see FIG. 2) of the operation planning device 20 inputs, as input data for the optimal operation plan, the power / heat demand prediction result, the electricity charge, the gas charge, the energy consumption characteristics of the equipment, the charge / discharge penalty coefficient kcp (initial value), and the battery degradation cost evaluated by the user (the battery degradation cost per charge / discharge).

[0084] In step S12, when the processing unit 21 of the operation planning device 20 (see FIG. 2) changes the charge / discharge penalty coefficient kcp (initial value), it corrects (updates) the charge / discharge penalty coefficient kcp within a preset range.

[0085] In step S13, the operation planning calculation unit 24 of the operation planning device 20 (see FIG. 2) performs an optimization calculation for formulating an operation plan for the consumer energy system. Specifically, the operation planning calculation unit 24 performs an optimization calculation to minimize the objective function U of Equation (5) based on the above input data.

[0086] In step S14, the processing unit 21 of the operation planning device 20 calculates the charge / discharge cycle count of the storage battery 4 based on the time-series change of the remaining charge of the storage battery in the operation plan result stored in the operation plan data storage unit 25 (see FIG. 2).

[0087] In step S15, the operation planning calculation unit 24 of the operation planning device 20 determines whether the reduction in operation cost exceeds the storage battery degradation cost (whether the cost reduction > the storage battery degradation cost). If the cost reduction > the storage battery degradation cost, it proceeds to step S16. If the cost reduction ≤ the storage battery degradation cost, it proceeds to step S12.

[0088] In step S16, the operation planning display unit 23 of the operation planning device 20 (see FIG. 2) outputs the operation plan results of the planned devices (generator, storage battery, others) to, for example, the control device 30 (see FIG. 2), and ends the processing of this flow.

[0089] Thereby, when the price of the electricity charge changes in multiple steps, it is possible to formulate a plan that suppresses the charge / discharge of the storage battery, for which the effect of reducing the operation cost of peak shifting due to the electricity price difference becomes small.

[0090] As described above, the operation planning device 20 according to the second embodiment includes an operation planning calculation unit 24 that performs optimization calculations to minimize the operation cost of the customer energy system 1 and formulates an operation plan, and setting means for setting penalty information for suppressing the discharge of the storage battery 4 based on the number of discharge times of the storage battery 4. The operation planning calculation unit 24 performs optimization calculations by adding penalty information.

[0091] With this configuration, it is possible to prevent the contract power from exceeding and the PV power generation from being excessive while reducing the charge and discharge cycles of the storage battery and suppressing the deterioration of the storage battery.

[0092] (Third Embodiment) The third embodiment of the present invention is an example in which the storage battery deterioration cost (per time) is evaluated with high accuracy by monitoring the state of the storage battery, rather than the discharge penalty coefficient kcp.

[0093] FIG. 9 is a block diagram showing the configuration of an operation planning device 20A of a customer energy system according to the third embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals, and the description of overlapping parts is omitted. The operation planning device 20A is applied in place of the operation planning device 20 of the energy management device 2 in FIG. 1. As shown in FIG. 9, the operation planning device 20A further includes a storage battery state monitoring unit 27 and a storage battery deterioration cost database 28 in addition to the operation planning device 20 in FIG. 2.

[0094] The degree to which charge and discharge deteriorates the storage battery varies depending on the remaining charge amount and charging current. In the second embodiment, this factor is corrected when calculating the storage battery deterioration cost (per time). For example, in a situation where the storage battery is likely to be damaged (such as a high temperature or near full charge of the remaining charge amount), the storage battery deterioration cost (per time) is set high, and an objective function U for calculating the operation cost is calculated based on the set high charge and discharge penalty coefficient kcp.

[0095] The deterioration of the storage battery 4 changes depending on the remaining charge amount, the storage battery temperature, the usage period, etc. The storage battery state monitoring unit 27 monitors the storage battery state based on the input storage battery state monitoring information of the remaining charge amount, the storage battery temperature, and the usage period. The database 28 of the battery degradation cost creates and accumulates the battery degradation cost (per time) in the database based on the battery state monitoring information (remaining charge, battery temperature, usage period).

[0096] FIG. 10 is a flowchart showing the operation planning process of the operation planning device 20A of the consumer energy system 1. In step S21, the input unit 22 (FIG. 9) of the operation planning device 20A inputs, as input data for the optimal operation plan, the power / heat demand prediction result, electricity rate, gas rate, energy consumption characteristics of the equipment, and the charge / discharge penalty coefficient kcp (initial value).

[0097] In step S22, the battery state monitoring unit 27 (FIG. 9) of the operation planning device 20A monitors the battery state based on the input battery state monitoring information (remaining charge, battery temperature, usage period).

[0098] In step S23, the processing unit 21 (FIG. 9) of the operation planning device 20A reads out the appropriate battery degradation cost (per time) during operation planning from the database 28 of the battery degradation cost based on the battery state monitoring information (remaining charge, battery temperature, usage period) monitored by the battery state monitoring unit 27.

[0099] In step S24, the processing unit 21 of the operation planning device 20A changes the charge / discharge penalty coefficient kcp based on the battery state monitoring information (remaining charge, battery temperature, usage period). When changing the charge / discharge penalty coefficient kcp (initial value), the charge / discharge penalty coefficient kcp is corrected (updated) within a preset range.

[0100] In step S25, the operation planning calculation unit 24 (FIG. 9) performs an optimization calculation to minimize the objective function U of Equation (6) based on the above input data and the battery degradation cost (per time) read from the database 28 of the battery degradation cost.

[0101] In step S26, the processing unit 21 of the operation planning device 20A calculates the number of battery charge / discharge cycles based on the input battery state monitoring information (remaining charge, battery temperature, usage period).

[0102] In step S27, the processing unit 21 of the operation planning device 20A determines whether the cost reduction is greater than the battery degradation cost (per time) based on the calculation result of the number of charge and discharge cycles of the battery and the battery degradation cost (per time) read from the database 28 of battery degradation costs. If the cost reduction is less than or equal to the battery degradation cost (per time), the process returns to step S24 above.

[0103] If the cost reduction is greater than the battery degradation cost (per time), in step S28, the operation plan display unit 23 (FIG. 9) of the operation planning device 20A outputs the operation plan result of the planned equipment (generator, battery, others) to, for example, the control device 30 (FIG. 1), and ends the processing of this flow.

[0104] As described above, the operation planning device 20A according to the third embodiment includes a battery state monitoring unit 27 that monitors the battery state, and a database 28 of battery degradation costs that creates and accumulates the battery degradation cost (per time) based on the battery state monitoring information (remaining charge, battery temperature, usage period). The processing unit 21 of the operation planning device 20A outputs the operation plan result of the planned equipment (generator, battery, others) when the cost reduction is greater than the battery degradation cost (per time) based on the calculation result of the number of charge and discharge cycles of the battery and the battery degradation cost (per time) read from the database 28 of battery degradation costs.

[0105] Thereby, while suppressing the charge and discharge of the battery for peak shifting due to the power price difference, it is possible to accurately evaluate the battery degradation cost (per time) and formulate an operation plan that minimizes the operation cost.

[0106] In particular, in a situation where the battery 4 is likely to be damaged (such as high temperature, near full charge of the remaining charge, etc.), by switching the "discharge suppression power price difference kcp" to a high value, it is possible to suppress the charge and discharge of the battery while taking into account the degradation state of the battery 4, and more appropriately suppress the degradation of the battery while preventing the excess contract power and PV power generation surplus.

[0107] The present invention is not limited to the above-described embodiments, and includes other modifications and application examples as long as they do not depart from the gist of the present invention described in the claims.

[0108] The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, or replace other configurations for a part of the configuration of each embodiment.

Description of Reference Numerals

[0109] 1 Customer Energy System 2 Energy Management Device 3 Generator 4 Storage Battery 5 PV 6 Heat Source Machine 7 Electric Power Load 8 Heat Load 20, 20A Operation Planning Device 21 Processing Unit (Setting Means) 22 Input Unit (Setting Means) 23 Operation Plan Display Unit 24 Operation Plan Calculation Unit (Operation Plan Calculation Means) 25 Operation Plan Data Storage Unit (Setting Means) 26 Operation Plan Output Unit 27 Storage Battery State Monitoring Unit 28 Database of Storage Battery Deterioration Cost PB(t) Discharge Penalty (Penalty Information) Kcp Charge / Discharge Penalty Coefficient (Penalty Information) Steps S1, S11, S12 Setting Steps (Setting PB(t) in Equations (5) and (6)) Steps S2, S13, S25 Operation Plan Calculation Steps (Performing Optimization Calculation Using the Objective Function U in Equation (6))

Claims

1. An operation planning device for formulating an operation plan for an energy system equipped with a storage battery based on purchased power charge information and power demand prediction, operation planning calculation means for formulating the operation plan, and setting means for setting penalty information for increasing the operation cost of the energy system by discharging the storage battery, wherein the penalty information is determined based on power price difference information according to time zones, and the operation planning calculation means performs a calculation for reducing the operation cost by adding the penalty information. An operation planning device characterized by the above.

2. The calculation for reducing the operation cost is an optimization calculation for minimizing the operation cost, and is provided with an input unit for inputting the degradation cost per charge and discharge of the storage battery, and the operation planning calculation means performs the optimization calculation based on the power price difference information and the degradation cost. The operation planning device according to claim 1, characterized by the above.

3. The objective function U for calculating the operation cost of the optimization calculation has a discharge penalty PB(t) for suppressing the charge and discharge of the storage battery, which is the penalty information, the objective function U is represented by formula (6), and the discharge penalty PB(t) is represented by formula (5). 【Equation 6】 【Equation 5】 The operation planning device according to claim 2, characterized by the above.

4. It is provided with a storage unit for storing the degradation costs of a plurality of storage batteries set in advance based on the state of the storage battery, and the operation planning calculation means reads out the degradation cost of the storage battery from the storage unit according to the state of the storage battery during operation, and outputs the operation plan result formulated by the optimization calculation when the reduction of the operation cost exceeds the degradation cost of the storage battery. The operation planning device according to claim 2, characterized in that.

5. An operation planning method for formulating an operation plan for an energy system equipped with a storage battery based on purchased power tariff information and power demand prediction, An operation planning calculation step of performing a calculation to reduce the operation cost of the energy system and formulating the operation plan, A setting step of setting penalty information for suppressing the discharge of the storage battery, which is determined based on power price difference information according to time zones, and having, In the operation planning calculation step, a calculation of an operation plan for reducing the operation cost by adding penalty information is performed An operation planning method, characterized in that.

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