Power adjustment system and method for controlling power adjustment system

Abstract

The invention provides a power adjustment system and a method for controlling the power adjustment system, which can plan charging and discharging in which restrictions of electricity purchase cost, chargeable and dischargeable amount, and other use are considered at an optimal ratio. A power adjustment system that controls a load device, a battery device, and a power generation device that are connected to a power system is provided with: a fund calculation unit (9) that calculates a fund when the battery device responds as an adjustment force; a respondable amount calculation unit (10) that calculates a respondable amount, which is the adjustment force after the battery device responds; a charging restriction consideration unit (11) that considers the operation restriction of the battery device and the time at which the operation restriction occurs; and a charge / discharge schedule determination unit (12) that determines the charge / discharge time and the response amount of the storage battery device, the charge / discharge schedule determination unit (12) determining a charge / discharge schedule on the basis of the funds, the responsible amount, and the operation restriction.

Description

Technical Field

[0001] The present invention relates to a power adjustment system and a control method for a power adjustment system. Background Art

[0002] The number of users introducing a solar power generation system (PV) and a battery system is increasing in order to increase the ratio of renewable energy and respond to disasters. In particular, an electric vehicle (EV) can be used not only as a means of transportation but also to reduce electricity costs by taking advantage of the value difference caused by time zones of electricity prices, generate income from the regulation power provided to the system, and supply electricity during disasters. Therefore, its introduction has been promoted.

[0003] Prior Art Documents

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-25676 Summary of the Invention

[0005] Problems to be Solved by the Invention

[0006] Patent Document 1 discloses a control method for determining the charging time and amount based on the unit price of electricity and the unit price of electricity for charging the battery. By utilizing Patent Document 1, electricity costs can be reduced. However, in addition to reducing costs (power purchase costs), if the power for emergency adjustment after executing the charge / discharge plan and the amount of electricity for other uses such as mobile use are not considered, there is a problem that sufficient capacity cannot be ensured when used for other uses such as adjustment use and vehicle use.

[0007] The present invention is an invention for solving the above problems, and an object thereof is to provide a power adjustment system and a control method for a power adjustment system that can plan charge / discharge with an optimal ratio considering the constraints of power purchase costs, charge / discharge capacity, and other use utilization.

[0008] Means for Solving the Problems

[0009] To achieve the above object, a power adjustment system of the present invention is a power adjustment system that controls a load device, a battery device, and a power generation device connected to a power system, and is characterized by including: a cost calculation unit that calculates a cost when the battery device responds as a regulation force; a response amount calculation unit that calculates a response amount as a regulation force after the battery device responds; a charge constraint consideration unit that considers the operation constraints of the battery device and the time when the operation constraints occur; and a charge / discharge plan determination unit that determines the charge / discharge time and response amount of the battery device, and the charge / discharge plan determination unit determines a charge / discharge plan based on the cost, the response amount, and the operation constraints. Other aspects of the present invention will be described in the following embodiments.

[0010] Advantages of the Invention

[0011] According to the present invention, it is possible to plan charge and discharge with an optimal ratio while taking into account the constraints of power purchase cost, charge and discharge capacity, and utilization for other purposes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is a diagram showing the basic structure of the power adjustment system according to the first embodiment.

[0013] Figure 2 FIG. is a control block diagram showing the determination of the charge and discharge plan according to the first embodiment.

[0014] Figure 3 FIG. is a diagram showing an example of the charge and discharge plan of an EV.

[0015] Figure 4 FIG. is a diagram showing the calculation result of the first plan of the charge and discharge plan.

[0016] Figure 5 FIG. is a diagram showing the calculation result of the second plan of the charge and discharge plan.

[0017] Figure 6 FIG. is a diagram showing the transition of each optimization factor over time series.

[0018] Figure 7 FIG. is a diagram showing the control flow of the determination of the charge and discharge plan.

[0019] Figure 8 FIG. is a control block diagram showing the determination of the charge and discharge plan considering the degradation according to the second embodiment.

[0020] Figure 9 FIG. is a diagram showing the judgment image when considering degradation.

[0021] Figure 10 FIG. is a diagram showing the calculation flow of the degradation cost.

[0022] Figure 11 FIG. is a control block diagram showing the determination of the charge and discharge plan considering peak cut-off according to the third embodiment.

[0023] Figure 12 FIG. is a diagram showing the calculation image of the peak cut-off excess.

[0024] Figure 13 FIG. is a diagram showing the basic structure of the power adjustment system using a stationary battery according to the fourth embodiment.

[0025] Figure 14This is a diagram showing a control block diagram for determining a charge-discharge plan that changes optimization conditions according to external factors in the fifth embodiment.

[0026] Figure 15 This is a diagram showing the change of a constant based on weather information.

[0027] Figure 16 This is a diagram showing the change of a constant based on traffic information.

[0028] Figure 17 This is a diagram showing the change of a constant based on power information.

[0029] Figure 18 This is a diagram showing the basic structure of a power adjustment system having a solar power generation system in the sixth embodiment.

[0030] Figure 19 This is a diagram showing a control block diagram for determining a charge-discharge plan considering the self-consumption rate in the sixth embodiment.

[0031] Figure 20 This is a diagram showing the output suppression image of the solar power generation system. Detailed Embodiments

[0032] Hereinafter, embodiments of the present invention will be described using the accompanying drawings and the like. The following description shows specific examples of the content of the present invention. The present invention is not limited to these descriptions, and various changes and modifications can be made by those skilled in the art within the scope of the technical idea disclosed in this specification. In addition, in all the drawings used to illustrate the present invention, the same reference numerals are given to parts having the same function, and the repeated description thereof may be omitted sometimes.

[0033] <First Embodiment>

[0034] Figure 1 This is a diagram showing the basic structure of the power adjustment system 100 in the first embodiment. Figure 1 This shows the system structure of a user including the power adjustment system 100. Figure 1 This is the office space of a user such as a certain factory or building.

[0035] Regarding the office space, power is supplied from the power system 1 to the load in the office space through the switchboard 2. Inside the office space, there are N electric vehicles (EVs) 3 used by public vehicles and the like and N chargers 4 capable of bidirectional charging and discharging, and it has: the load 5 (load equipment) in the office space, a smart meter 6 for measuring the amount of power of the load, an EV operation management system 7 for managing the operation time of the EVs, and a power adjustment system 100 for overall power monitoring and control for power optimization.

[0036] The power adjustment system 100 obtains power consumption values from the distribution board 2 and the smart meter 6, obtains vehicle information and charging information from the charger 4, obtains EV operation information from the EV operation management system 7, and outputs instructions for charging and discharging to the charger 4. The power adjustment system 100 is constituted by including the following parts: a cost calculation unit 9 that calculates costs when the electric vehicle 3 responds as an adjustment force; a responsive amount calculation unit 10 that calculates the responsive amount as the adjustment force after the electric vehicle 3 responds; a charging constraint consideration unit 11 that considers the operation constraints of the electric vehicle 3 and the time when such operation constraints are generated; and a charge-discharge plan determination unit 12 that determines the charge-discharge time and responsive amount of the electric vehicle 3 and determines the charge-discharge plan based on costs, the responsive amount, and the operation constraints.

[0037] Assume that the following power contract is signed for this office. Regarding the metering cost in the power price, the power price varies by time period. The operator charges the EV during the time period when the power price is low and discharges power from the EV during the time period when the power price is low. Thus, it is possible to achieve a reduction in the metering cost. On the other hand, since the main use of the EV is as a vehicle, it is necessary to know at which time period it stays and at which time it leaves, and it is also necessary to maintain a sufficient amount of power for vehicle use. Using a block diagram Figure 2 An explanation will be given of the control for achieving a reduction in the power price based on these constraint conditions.

[0038] Figure 2 It is a diagram showing the control block diagram of the charge-discharge plan determination in the first embodiment. Figure 2 It shows the operation outline within the power adjustment system 100. First, in addition to the cost calculation unit 9, the responsive amount calculation unit 10, the charging constraint consideration unit 11, and the charge-discharge plan determination unit 12, the power adjustment system 100 also has an SOC change calculation unit 20. The SOC change calculation unit 20 takes the SOC of each EV as input and outputs the SOC change. Specifically, the cost calculation unit 9 takes the demand prediction value and the power price that varies by time period as input and outputs the power purchase cost. The charging constraint consideration unit 11 takes the SOC change as input and outputs the total responsive amount. The charging constraint consideration unit 11 takes the SOC change, the necessary charging amount of each EV, and the time when the necessary charging amount is required as input and outputs the charging constraint index. As a block diagram, it is described in a way that the operations flow in one direction. However, as described later, the power adjustment system 100 appropriately changes variables and calculates the optimal solution. Therefore, the optimization planning unit repeatedly performs the operations any number of times. The variables of this power adjustment system 100 are set as the charge-discharge power amounts of the EVs at each time, and the charge-discharge power amounts at each time are reflected in the final charge-discharge plan. Figure 3 It shows an image of the finally output charge-discharge plan.

[0039] Figure 3This is a diagram showing an example of the charge and discharge plan of an EV. Figure 3 The charge and discharge plan 30 records the charge and discharge amounts of each EV at each time. The charger is instructed to charge and discharge in such a way as to achieve this charge and discharge amount. In addition, discharge is set to negative and charge is set to positive.

[0040] The operation content of the SOC change calculation unit will be described. In the SOC change calculation unit 20, the future SOC change of each EV is calculated based on the current SOC. The calculation formula is calculated, for example, using Equation (1).

[0041] [Mathematical formula 1]

[0042]

[0043] Here, SOC(n, t) is the SOC of the EV at each time period. n represents an arbitrary number corresponding to the number of EVs, and t represents time. P(n, t) is a variable of the power adjustment system 100 and represents the charge and discharge power at each time. Q max (n) is the full charge capacity of each EV. The SOC at t = 0 (SOC(n, -1)) is the current SOC as an input. Through this Equation (1), the SOC that changes according to the variable P(n, t) at each time can be calculated. This SOC(n, t) is output to the subsequent calculation unit.

[0044] In the cost calculation unit 9, the power purchase cost is calculated based on the demand forecast value and the electricity price. The demand forecast value can be past data of an office or the like, or a demand forecast value calculated using other energy management. Regarding the electricity price, if the price for each time period is determined in advance by contract, it can be preset in the power adjustment system. In the case of being linked to the electricity retail market price, this price can also be used as an input. In this cost calculation unit 9, the power purchase cost (cost) considering the charge and discharge at each time period is calculated by the following Equation (2). That is, the cost is the difference in electricity charges during charging and discharging, and C buy (t) operation is to calculate the cost.

[0045] [Mathematical formula 2]

[0046]

[0047] Here, C buy (t) represents the power purchase cost at each time, and P demand is the demand forecast value, and C electric (t) is the variable electricity price. If it is discharge, P(n, t) is negative. Therefore, through discharge, C buy (t) decreases.

[0048] In the available response amount operation unit 10, the available response amount is calculated based on the SOC change. The calculation formulas are, for example, Formula (3) and Formula (4). Formula (3) represents the available discharge amount, and Formula (4) represents the available charge amount.

[0049] [Mathematical Formula 3]

[0050]

[0051] [Mathematical Formula 4]

[0052]

[0053] Here, SOC min represents the lower limit SOC of the EV, P charger represents the maximum output of the charger, T represents the operation time between t and t + 1, and SOC max represents the upper limit SOC of the EV. Formula (3) is an operation formula that takes the smaller value between the capacity that can be discharged to SOC min and the capacity that can be discharged during the operation time T as the available discharge capacity. Formula (4) is an operation formula that takes the smaller value between the capacity that can be charged to SOC max and the capacity that can be charged during the operation time T as the available charge capacity. P charger is the same in the current charging and discharging, but can also be considered separately in the case where the maximum output is different in discharging and charging. SOC min and SOC max can also be set individually for each EV.

[0054] In the charging constraint consideration unit 11, the charging constraint index is calculated based on the SOC change, the necessary charge amount and necessary time of each EV. The operation formula of the charging constraint index is set as the following Formula (5). That is, the charging constraint consideration unit 11 considers the operation constraints of the EV (battery device) and the time when such operation constraints occur.

[0055] [Mathematical Formula 5]

[0056]

[0057] Here, I SOC (n, t) is the charging constraint index, and SOC target (n) is the charging rate required until a certain time T target (n). If the unit of t is minutes, for T target (n), for example, if the time of vehicle use is 3 hours later, it is a value such as 180. When this I SOC (n, t) is large, it indicates a high requirement for charging at the current time. In this embodiment, SOC target(n)-SOC(n, t) and the difference are set to be linear, but the square of the difference can also be used. By using the square, the greater the difference between SOC(n, t) and SOC target (n), the greater the squared value. Therefore, the greater the difference from SOC target (n), the more optimized in the charging direction.

[0058] In the charge and discharge plan determination unit 12, the following formula (6) is used as the objective function, and P(n, t) is used as a variable to minimize the term, thereby implementing optimization.

[0059] [Mathematical formula 6]

[0060]

[0061] Here, K1 to K4 are constants for weighted optimization. By minimizing the solution of the objective function, the optimal solution corresponding to the weight coefficient can be calculated. When K1 is made larger than other weighting coefficients, charge and discharge are planned to reduce the power purchase cost. When K2 is made larger than other weighting coefficients, charge and discharge are planned to increase the dischargeable amount. When K3 is made larger than other weighting coefficients, charge and discharge are planned to reduce the chargeable amount. When K4 is made larger than other weighting coefficients, charge and discharge are planned to reduce the charge constraint index. In this way, by implementing this objective function and weighted optimization, it is possible to plan charge and discharge that optimally considers the constraints of power purchase cost / chargeable and dischargeable amounts / other usage.

[0062] That is, the charge and discharge plan determination unit 12 can determine the charge and discharge plan that minimizes the objective function with the power purchase cost in the cost calculation unit 9, the dischargeable amount and chargeable amount in the response amount calculation unit 10, and the charge constraint index in the charge constraint consideration unit 11 as variables.

[0063] Use Figure 4 and Figure 5 to illustrate the calculation image of this planning unit.

[0064] Figure 4 is a graph showing the calculation result of the first plan of the charge and discharge plan. Figure 5 is a graph showing the calculation result of the second plan of the charge and discharge plan. Assume the case of planning the charging timing of 1 EV. The calculation results in the SOC change calculation unit 20, cost calculation unit 9, response amount calculation unit 10, and charge constraint consideration unit 11 are shown in Tables 40 and 50. The values of K1 to K4 are shown in Tables 41 and 42. The terms of formula (6) and the calculation results of the objective function are shown in Tables 42 and 52.

[0065] Figure 4Table 40 shows the operation results of each value when the operation steps are divided by 30 minutes. The SOC at the initial t = 0 is 80%, and the SOC target (1) is 90% at the moment of t = 3. Therefore, it is necessary to plan to charge to SOC 90% before this time point. For example, as Figure 3 shown, the first plan is to charge 2 kWh each at the timings of t = 2 and 3 to make the SOC 90%.

[0066] The SOC transition at this time is calculated by the SOC transition calculation unit 20. The full charge capacity Q of the EV max is 40 kWh. Therefore, a 2 kWh charge increases it by 5%. Based on the SOC transition calculation result, C is calculated by Equation (2) in the cost calculation unit 9 buy (t). For example, at the time point of t = 2, C buy (2) = (20 + 2) × 10 = 220.

[0067] In addition, in the available response amount calculation unit 10, the available discharge amount and the available charge amount are calculated according to Equations (3) and (4). For example, when P charger is 8 kW, T is 0.5, SOC min is 10%, and SOC max is 90%, at the time point of t = 2,

[0068] P Discharge (1, 2) = Min(40 × (85 - 10) / 100, 8 × 0.5) = 4

[0069] P charge (1, 2) = Min(40 × (90 - 85) / 100), 8 × 0.5) = 2.

[0070] In addition, in the charging constraint consideration unit 11, I target (n, t) is calculated based on the difference between the SOC transition and SOC SOC (n). For example, at the time point of t = 2,

[0071] I soc (1, 2) = Max((90 - 85) / (3 - 2), 0) = 5.

[0072] If the constants are determined as K1 to K4 in Table 41, the operation result of the objective function of Equation (6) is as Figure 4 shown in Table 42.

[0073] Next, similar to Figure 5Compare with the second plan of the charging plan implemented at t = 1 and t = 2. In this case, the electricity price from t = 0 to t = 1 is cheaper than that from t = 2 to t = 3. Therefore, the value of the part of K1×C buy (t) is larger than that of the first plan of the plan. In addition, the SOC also rises earlier and approaches SOC max , so the chargeable amount also becomes smaller, and the calculation result of the part of K3×1 / P charge (n, t) also becomes a value larger than that of the first plan of the plan. On the other hand, it reaches SOC target (n) earlier than the first plan of the plan, so the part of K4×ISOC(n, t) becomes a value smaller than that of the first plan of the plan. As a result, the objective function becomes a result smaller than that of the first plan of the plan. Therefore, it is judged that the second plan of the plan is more suitable than the first plan of the plan, and it is determined as the charge-discharge plan. The charge-discharge plan refers to P(n, t), and the charger implements the charge-discharge of the EV according to this plan.

[0074] Figure 6 is a graph showing the change of each optimization factor in the time series. Figure 6 represents the image of the processing so far. Figure 6 represents the timing 60 when the electricity price rises, the timing 61 when the electricity price decreases, and the timing 62 when the charging is completed.

[0075] Regarding Figure 6 , discharging is implemented in the interval where the electricity price is high and lower than 60 - 61, and charging is implemented in the interval of 61 - 62 where the electricity price is cheap, which is the action required by the cost calculation unit. In addition, maximizing the sum of the dischargeable amount and the chargeable amount equivalent to the area of the dischargeable amount and the chargeable amount in this graph is the action required by the response amount calculation unit 10. In addition, considering SOC target 64 (necessary charge amount) and T target 63 (necessary time) to charge to reach the target SOC as early as possible is the action required by the charge constraint consideration unit 11. In this embodiment, all of these are considered in the weighted optimization to determine the charge-discharge plan.

[0076] Figure 7 is a graph showing the control flow S10 of the charge-discharge plan determination. The power adjustment system 100 calculates the charge-discharge plan that satisfies the constraint conditions in S11. In S12, it calculates the value related to Figure 2The SOC transition corresponding to the block of the SOC transition operation unit 20 in the control block diagram. In S13, operations corresponding to the blocks of the cost calculation unit 9, the available response amount operation unit 10, and the charging restriction consideration unit 11 in the control block diagram are executed to calculate the power purchase cost, the total available response amount, and the charging restriction index (operation restriction). In S14, the operation of the objective function corresponding to the block of the charge-discharge plan determination unit in the control block diagram is executed to determine whether the value of the objective function is below a specified value. When it is determined that it is below the specified value (S14, Yes), it is determined as the charge-discharge plan and output. When the condition is not satisfied (S14, No), the plan is re-formulated. This iterative calculation process corresponds to the process of the power adjustment system 100. The condition in S14 is that the value of the objective function is below the specified value, but multiple plan options can also be formulated and the plan option with the minimum value can be adopted, etc. That is, the charge-discharge plan determination unit 12 determines the charge-discharge plan based on the total cost, the available response amount, and the operation restriction.

[0077] The optimal K1 to K4 change depending on whether the manager emphasizes cost, available response amount, or charging restriction. Therefore, these constants should be determined based on understanding where the manager places emphasis. For example, it is preferable to determine after obtaining a questionnaire through the interface of the system.

[0078] <Second Embodiment>

[0079] In the second embodiment, an example of correcting the price considering the deterioration rate is described. The battery deteriorates due to charge and discharge. Therefore, if this situation is not considered, unnecessary charge and discharge may be performed and the lifespan assumed for the vehicle may not be satisfied. Therefore, it is necessary to consider deterioration for operation. An example considering this situation is described. Figure 8 An example considering this situation is described.

[0080] Figure 8 It is a diagram showing the control block diagram of the charge-discharge plan determination considering deterioration in the second embodiment. Figure 8 The power adjustment system 100A in Figure 2 adds a deterioration cost operation unit 80, and the cost calculation unit 9 becomes a deterioration consideration cost calculation unit 81. The deterioration cost operation unit 80 takes the deterioration rate as input and outputs the deterioration cost. In Figure 8 the deterioration rate is input from the charger 4, but methods such as obtaining the deterioration rate through communication from the charger 4 and estimating the deterioration rate based on the charge-discharge behavior of the charger 4 are also possible.

[0081] Figure 9 It is a diagram showing the judgment image when considering deterioration. In the deterioration cost operation unit 80, it is judged whether the deterioration rate is above the assumption as Figure 9 shown. Figure 9In this figure, the horizontal axis represents the number of years of use (Time), and the vertical axis represents the deterioration rate of the capacity (State of Health of Q: SOHQ). The vertical dashed line represents the number of years of vehicle life, for example, set as the warranty years of the vehicle. If the battery life is less than this value, it is a dangerous value for safety. The curve in the figure is the assumed deterioration curve, which is the deterioration curve where the number of years of vehicle life is consistent with the battery life calculated by an additionally calculated deterioration formula. For example, if the obtained deterioration rate is above the assumed deterioration curve like in Mode A, there is no deterioration compared to the assumption. Therefore, there is room for use outside of vehicle applications. On the other hand, if it is below the assumed deterioration curve like in Mode B, it deteriorates more than the assumption. Therefore, if used outside of vehicle applications, it may not meet the assumed life of the vehicle, and it is inappropriate to use it outside of vehicle applications. In such a case, for example, by Figure 10 such a flowchart to separately consider the deterioration cost.

[0082] Figure 10 is a diagram showing the operation process S20 of the deterioration cost. The deterioration cost calculation unit 80 obtains the deterioration rate in S21. In S22, it determines whether the deterioration rate is above the assumed deterioration curve. When the deterioration rate is above the assumed deterioration curve (S22, Yes), it proceeds to S23, and the deterioration cost is defined by Equation (7).

[0083] [Mathematical formula 7]

[0084] C deg (n)=A×C product (7)

[0085] Here, C deg (n) is called the deterioration cost, which is the cost per kWh of discharge. A is a constant, a value between 0 and 1. C product is the cost per kWh of the product. For example, in the case of 4 million yen and a lifetime discharge capacity of 120,000 kWh, it is 33.3 yen / kWh. Regarding this lifetime discharge capacity, the catalog value can be referred to, or it can be calculated separately by deterioration estimation. Thus, the value of 33.3 yen is lost per kWh of discharge. When the deterioration rate is above the assumed curve, there is a surplus compared to the assumed life of the vehicle. Therefore, it is considered that the loss is less than this C product less. Therefore, multiply by A. That is, when the loss price of the equipment lost due to charge and discharge is not deteriorated compared to the deterioration rate assumed according to the number of operating years, the deterioration consideration cost calculation unit 81 (cost calculation unit 9) determines that the loss price is small and corrects the loss price.

[0086] On the other hand, when the deterioration rate is less than the assumed deterioration curve (S22, No), it proceeds to S24, and the deterioration cost is defined by Equation (8).

[0087] [Mathematical formula 8]

[0088] C deg (n)=C product (8)

[0089] Next, in the deterioration consideration cost calculation unit 81, the total cost (cost) considering the deterioration cost is calculated by the following formula (9). That is, the deterioration consideration cost calculation unit 81 (cost calculation unit) calculates the loss price of the equipment lost due to discharge as part of the cost.

[0090] [Mathematical formula 9]

[0091]

[0092] Here, the processing of selecting the smaller one of 0 in the part of Min(0, P(n, t)) is to extract only the part of the discharge. By setting this formula, the cost of the deterioration cost corresponding to the amount of the capacity considering the discharge can be output to the subsequent stage. Therefore, in the case where the benefit of assuming a large deterioration ratio is small, the optimization is performed in a non-discharging manner. As a result, it is possible to suppress the case where the vehicle cannot meet the assumed life. The subsequent operations are the same as those in the first embodiment such as formula (6), so they are omitted.

[0093] <Third Embodiment>

[0094] In the third embodiment, the calculation of the cost in the case of making a power contract with the basic cost corresponding to the maximum value of the spending and demand for the target office is described. For the purpose of reducing this basic cost, reducing the maximum value of the demand is called peak clipping. In the case of this office, achieving peak clipping results in cost reduction.

[0095] Figure 11 is a diagram showing the control block diagram of the charge / discharge plan determination considering peak clipping in the third embodiment. Figure 12 is a diagram showing the calculation image of the peak clipping excess. Figure 11 of the power adjustment system 100B and Figure 2 In comparison, the cost calculation unit 9 is used as the peak clipping consideration unit 110. In the peak clipping consideration unit 110, the peak clipping excess is calculated based on the demand prediction value and the peak clipping target value and reflected in the objective function. The calculation formula is, for example, formula (10).

[0096] [Mathematical formula 10]

[0097]

[0098] Inside the Max term Figure 12 The symbol 120 is the change in the total demand value in the office including the charge / discharge output of the EV. Pthreshold is the peak cut-off target value 121. P excess represents the peak cut-off excess 122 relative to the peak cut-off target value 121. This relationship is described in Figure 12 . Figure 12 represents the predicted time-series change in power demand. The symbol 120 is the trend of the total demand value in the office including the charge / discharge output. By setting this as the P of the peak cut-off target value 121 threshold as follows, the basic cost can be reduced. Therefore, it is necessary to reduce the peak cut-off excess 122 of P excess . To reduce this P excess , the objective function is changed to the following formula (11).

[0099] [Mathematical formula 11]

[0100]

[0101] Here, K5 is a constant for weighted optimization. By minimizing the objective function formula (11), a charge / discharge plan is formulated in the direction of reducing the peak cut-off excess, and control considering the cost based on peak cut-off can be performed.

[0102] That is, when the charge / discharge plan determination unit 12 implements peak cut-off control for the purpose of reducing the contract power, the charge / discharge plan is determined according to the amount of power predicted to exceed the contract power value.

[0103] <Fourth Embodiment>

[0104] Figure 13 is a diagram showing the basic structure of a power adjustment system using a stationary battery in the fourth embodiment. In the fourth embodiment, the content that the same processing as the described embodiments can also be performed on battery equipment instead of an EV is described.

[0105] Figure 13 is the same structure as Figure 1 , but the electric vehicle 3 and the charger 4 are changed to a stationary battery 130 and a converter 131. In addition, the EV operation management system 7 is changed to a battery management system 132. As an example of the stationary battery 130, a battery introduced for the purpose of supplying power to an office during a power outage can be cited. Regarding this stationary battery 130, it is also assumed that it can be used in other applications even if it is not for vehicle use. For example, since the power consumption is huge during the day, there is a constraint to maintain a full charge to prevent a power outage. According to this situation, the calculation process can be performed in the same manner as in the first embodiment. Regarding the calculation process, since it is the same as in the first embodiment, it is omitted. In this way, even in the stationary battery 130 without a clear other use such as an EV, the capacity for use in other applications can be ensured with the same idea.

[0106] <Fifth Embodiment>

[0107] The constant optimized by weighting in the first embodiment is determined by the system administrator, but the change of the constant due to external factors will be described.

[0108] Figure 14 It is a diagram showing a control block diagram for determining a charge / discharge plan that changes optimization conditions according to external factors in the fifth embodiment. Figure 14 The power adjustment system 100C inputs weather information, traffic information, and power information as external factors. These pieces of information are input from the weather information input unit 140, the traffic information input unit 141, and the power information input unit 142, and are used for calculation in the optimization condition determination unit 143. In the optimization condition determination unit 143, an optimization constant is determined based on these pieces of information and output to the charge / discharge plan determination unit 12.

[0109] Figure 15 It is a diagram showing the change of the constant based on weather information. When bad weather occurs and the probability of power outages and the like increases, the amount that can be discharged from the EV should be ensured more. In addition, it is considered to use the EV for moving earlier than expected in bad weather. Therefore, for example, the precipitation probability is input as an index of bad weather, and K2 and K4 increase as Figure 15 shown. Therefore, in the case where the probability of bad weather is high, the dischargeable amount can be ensured and the SOC can be ensured early. target .

[0110] That is, the power adjustment system also has an optimization condition determination unit 143 that determines the weights of cost, response amount, and operation constraints through external factors. When the optimization condition determination unit 143 determines the charge / discharge plan based on the cost, response amount, and operation constraints, it takes the weather information as an input, and when it determines that the weather is bad, it makes the weights of the response amount and the operation constraint judgment greater than the cost.

[0111] Figure 16 It is a diagram showing the change of the constant based on traffic information. In the case of traffic system disorder, it is considered that the possibility of using the EV at a time earlier than T target increases. Therefore, as an index of traffic system disorder, the surrounding congestion loss time and the number of delay information of the public transportation system are input, and K4 increases as Figure 16 shown. In this way, when the traffic system is disordered, the SOC can be ensured in advance target and the use of the vehicle for its intended purpose can be realized in advance.

[0112] That is, the power adjustment system further includes an optimization condition determination unit 143 that determines the weights of costs, response amounts, and operation constraints based on external factors. When determining the charge / discharge plan according to costs, response amounts, and operation constraints, the optimization condition determination unit 143 takes traffic information as an input. When it is determined that congestion occurs, the weight of the operation constraint judgment is made greater than that of costs and response amounts.

[0113] Figure 17 This is a graph showing the change in a constant based on power information. When the probability of a power outage is high, it is necessary to ensure a larger amount of power that can be discharged from the EV. In addition, consider using the EV for movement earlier than expected during a power outage. Therefore, for example, the input power tension rate is used as an index of the probability of a power outage, and K2 and K4 are increased as Figure 17 shown. Thus, when the probability of a power outage is high, the dischargeable amount can be ensured, and the SOC can be ensured in advance. target After that, the processing in the charge / discharge plan determination unit 12 is the same as that in the first embodiment, and thus is omitted.

[0114] That is, the power adjustment system further includes an optimization condition determination unit 143 that determines the weights of costs, response amounts, and operation constraints based on external factors. When determining the charge / discharge plan according to costs, response amounts, and operation constraints, the optimization condition determination unit 143 takes power information as an input. When it is determined that a power outage occurs due to power tension, the weights of the response amount and operation constraint judgments are made greater than that of costs.

[0115] <Sixth Embodiment>

[0116] Figure 18 This is a diagram showing the basic configuration of the power adjustment system 100D having a solar power generation system according to the sixth embodiment. In the present embodiment, a power adjustment system considering the self-consumption rate will be described. To the system shown in the first embodiment Figure 1 a power generation device 180 (solar power generation panel 181, converter 182) is added. An office has introduced a solar power generation panel (PV) to increase the self-consumption rate. In addition, it is assumed that the office cannot reverse current to the system through the distribution board. Therefore, when the power generation amount of the PV is large and the load is small, it is necessary to suppress the power generation of the PV, and the power generation of the PV cannot be effectively utilized. As a countermeasure, as Figure 19 shown, a self-consumption rate consideration unit 190 is added to the optimization calculation.

[0117] Figure 19 This is a diagram showing a control block diagram of charge / discharge plan determination considering the self-consumption rate according to the sixth embodiment. Figure 19 The power adjustment system 100D of Figure 2Regarding the changed points of the block diagram, a self-consumption rate consideration unit 190 is added. In the self-consumption rate consideration unit 190, the power generation suppression amount is calculated based on the PV power generation prediction value and the demand prediction value, and output to the subsequent charge-discharge plan determination unit. The power generation suppression amount is calculated by the following formula (12).

[0118] [Mathematical formula 12]

[0119]

[0120] Here, P suppression (t) represents the PV suppression amount, and P PV represents the PV power generation prediction value. The relationship between this P Figure 20 and the demand is explained in suppression .

[0121] Figure 20 is a diagram showing the output suppression image of the solar power generation system. The solid black line in the figure represents the total demand value in the office including the charge-discharge output, and the dashed black line in the figure represents the PV power generation prediction value 200. The double-arrowed PV suppression amount 201 in the figure, P suppression is the amount by which the power generation is more than the demand. Therefore, the power generation of PV in this part is suppressed. Minimizing this amount can effectively utilize PV power generation. Therefore, the PV suppression amount is added to the objective function as in formula (13).

[0122] [Mathematical formula 13]

[0123]

[0124] Here, K6 is a constant for weighted optimization. By minimizing the objective function formula (13), the charge-discharge plan is formulated in the direction of reducing the PV suppression amount as well.

[0125] That is, the charge-discharge plan determination unit 12 determines the charge-discharge plan based on the suppression amount predicted to suppress the operation of the power generation device 180.

[0126] The above describes the power adjustment system of the present embodiment. However, the power adjustment method has the following characteristics. A control method for a power adjustment system that controls a load device, a battery device, and a power generation device connected to a power system, characterized by having: a cost calculation step of calculating the cost when the battery device responds as an adjustment force; a responsive amount calculation step of calculating the responsive amount as the adjustment force after the battery device responds; a charging constraint consideration step of considering the operation constraint of the battery device and the time when the operation constraint occurs; and a charge-discharge plan determination step of determining the charge-discharge time and the responsive amount of the battery device. The charge-discharge plan determination step determines the charge-discharge plan based on the cost, the responsive amount, and the operation constraint.

[0127] Symbol Explanation

[0128] 1 Power system

[0129] 2 Switchboard

[0130] 3 Electric vehicle (battery equipment)

[0131] 4 Charger

[0132] 5 Load (load equipment)

[0133] 6 Smart meter

[0134] 7 EV operation management system

[0135] 9 Expense calculation department

[0136] 10 Responsive quantity calculation department

[0137] 11 Charging restriction consideration department

[0138] 12 Charge and discharge plan determination department

[0139] 20 SOC change calculation department

[0140] 30 Charge and discharge plan

[0141] 60 Timing of electricity price increase

[0142] 61 Timing of electricity price decrease

[0143] 62 Timing of charging completion

[0144] 63T target (Required time)

[0145] 64SOC target (Required charging amount)

[0146] 80 Degradation cost calculation department

[0147] 81 Degradation consideration expense calculation department

[0148] 100 Power adjustment system

[0149] 110 Peak cut-off consideration department

[0150] 120 Trend of total demand value in the office including EV charge and discharge output

[0151] 121 Peak cut-off target value

[0152] 122 Peak cut-off excess

[0153] 130 Fixed-type battery (battery equipment)

[0154] 131 Converter

[0155] 132 Battery management system

[0156] 140 Weather information input unit

[0157] 141 Traffic information input unit

[0158] 142 Power information input unit

[0159] 143 Optimization condition determination unit

[0160] 180 Power generation equipment

[0161] 181 Solar power generation panel

[0162] 182 Converter

[0163] 190 Self-consumption rate consideration unit

[0164] 200 PV power generation predicted value

[0165] 201 PV suppression amount.

Claims

1. A power regulation system for controlling load equipment, battery equipment and power generation equipment connected to a power system, characterized in that: have: a cost calculation unit that calculates a cost when the battery device responds as an adjustment force; a responsive amount calculation unit that calculates a responsive amount as an adjustment force after the battery device responds; a charging constraint consideration unit that considers the operation constraint of the storage battery equipment and the time when the operation constraint occurs; and A charge and discharge plan determination unit is configured to determine a charge and discharge time and a response amount of the storage battery device. The charge and discharge plan determination unit determines a charge and discharge plan based on the expense, the available response amount, and the operation constraint.

2. The power adjustment system according to claim 1, characterized in that: The expense is the difference between the electricity charges during charging and discharging.

3. The power adjustment system according to claim 2, characterized in that: The cost calculation unit also includes the loss price of the equipment damaged by the discharge as the cost.

4. The power adjustment system according to claim 3, characterized in that: When the loss price of the equipment damaged by charging and discharging has not deteriorated compared with the degradation rate assumed based on the number of years of operation, the cost calculation unit determines that the loss price is small and corrects the loss price.

5. The power adjustment system according to claim 1, characterized in that: The charge and discharge plan determination unit determines a charge and discharge plan based on an amount of electric power predicted to exceed a contracted electric power value when peak cutoff control for the purpose of reducing contracted electric power is performed.

6. The power adjustment system according to claim 1, characterized in that: The power regulation system further includes an optimization condition determination unit that determines weights of the cost, the responsiveness, and the operation constraint based on external factors. The optimization condition determination unit takes weather information as input when determining a charge and discharge plan based on the cost, the responsive amount, and the operation constraint, and when it is determined that the weather is bad, makes the responsive amount and the operation constraint weigh more than the cost.

7. The power adjustment system according to claim 1, characterized in that: The power regulation system further includes an optimization condition determination unit that determines weights of the cost, the responsiveness, and the operation constraint based on external factors. The optimization condition determination unit takes traffic information as input when determining a charge and discharge plan based on the cost, the responsive amount, and the operational constraint, and when it is determined that congestion occurs, gives greater weight to the operational constraint than the cost and the responsive amount.

8. The power adjustment system according to claim 1, characterized in that: The power regulation system further includes an optimization condition determination unit that determines weights of the cost, the responsiveness, and the operation constraint based on external factors. The optimization condition determination unit uses power information as input when determining a charge and discharge plan based on the cost, the responsive amount, and the operation constraint, and when it is determined that power outage occurs due to power shortage, makes the responsive amount and the operation constraint weigh more heavily than the cost.

9. The power adjustment system according to claim 1, characterized in that: The charge and discharge plan determination unit determines a charge and discharge plan based on a suppression amount by which the operation of the power generation facility is predicted to be suppressed.

10. The power adjustment system according to claim 1, characterized in that: The charge and discharge plan determination unit determines a charge and discharge plan that minimizes an objective function having as variables the power purchase cost in the cost calculation unit, the dischargeable amount and the chargeable amount in the responsive amount calculation unit, and the charge restriction index in the charge restriction consideration unit.

11. A control method for a power regulation system, for controlling a load device, a battery device and a power generation device connected to a power system, characterized in that: have: a cost calculation step of calculating the cost when the battery device responds as the regulating force; a responsive amount calculation step of calculating a responsive amount as an adjustment force after the battery device responds; a charging constraint consideration step of considering the operation constraint of the storage battery device and the time when the operation constraint occurs; as well as a charge and discharge plan determination step, determining the charge and discharge time and response amount of the battery device, The charge and discharge plan determination step determines a charge and discharge plan based on the expense, the responsive amount, and the operation constraint.

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