Battery charge / discharge system and battery adjustment capability service system

Abstract

This battery charge / discharge system includes: a facility control unit for controlling one or more load facilities connected to a power system and one or more storage batteries; and an adjustment capability management unit for storing or externally acquiring the deterioration speed of the storage battery according to the charge state and charge / discharge condition of the storage battery. The facility control unit inputs a first charge state and a first charge / discharge condition of the storage battery to the adjustment capability management unit to acquire a first deterioration speed, acquires, from the adjustment capability management unit, a second charge state and a second charge / discharge condition from which a second deterioration speed equal to or less than the acquired first deterioration speed is obtained, and controls the storage battery on the basis of the second charge state and the second charge / discharge condition.

Description

Battery charging and discharging system and battery balancing service system

[0001] The present invention relates to a battery charge / discharge system and a battery adjustment power service system.

[0002] To reduce CO2 emissions, various types of mobile vehicles are being electrified. Mobile vehicles are equipped with batteries. For example, electric vehicles (EVs) use chargers to charge their batteries, allowing them to run on the stored energy. As electric vehicles become more widespread, their batteries are frequently charged, increasing the demand for electricity at consumer sites where chargers are installed. If this demand for electricity is concentrated at specific times, the cost of electricity usage for consumers increases. Furthermore, in the case of market-linked electricity plans, there is a concern that electricity prices may vary significantly depending on the time of day. Frequent charging of EVs under high electricity prices also increases the cost of electricity usage. Installing new batteries to level out the concentration of electricity demand or to avoid using electricity during times when electricity prices are high raises concerns about the cost of installing such batteries. On the other hand, utilizing the batteries installed in EVs to solve these problems in order to avoid the need for new battery installation raises concerns about battery degradation during uses other than the EV's intended purpose of transportation.

[0003] To solve this problem, it is necessary to understand the degradation risk associated with the use of batteries and create value by utilizing batteries while taking that risk into consideration.As a related prior art, for example, Patent Document 1 provides a battery diagnostic device that can diagnose the degradation risk of storage batteries even if the degradation characteristics of the storage batteries are unknown.

[0004] Patent Document 1 discloses that by providing a diagnostic information update unit that updates a diagnostic information database that stores the operating status of a storage battery and the deterioration risk of the storage battery in association with each other based on the time-series operating information of the storage battery and the deterioration rate of the storage battery, and a diagnostic unit that diagnoses the deterioration risk of the storage battery by referring to the diagnostic information database based on the operating status of the storage battery, it is possible to diagnose the deterioration risk of a storage battery even for storage batteries whose deterioration characteristics are unknown.

[0005] Japanese Patent Application Laid-Open No. 2023-46058

[0006] We thought that there could be cases where an electric vehicle remains connected to a charger while waiting until it is next driven, and during this time, no value is created from any use and the battery simply deteriorates. If operations that suppress the deterioration of batteries installed in such electric vehicles could be realized, it would be beneficial for electric vehicle owners, and if operations that suppress this deterioration could be expanded to multiple uses of the batteries installed in electric vehicles, it would also be beneficial for the administrators of consumer sites where chargers are installed.

[0007] To achieve this, it is necessary to correctly understand the risk of battery degradation, compare and verify that risk with the benefits that can be obtained by using batteries, and then establish appropriate management technology for batteries installed in electric vehicles. However, the problem with Patent Document 1 is that it does not fully clarify what method of utilizing storage batteries should be used to achieve value generation in response to the diagnosed degradation risk.

[0008] The present invention is an invention for solving the above-mentioned problems, and aims to provide a battery charging / discharging system and a battery adjustment power service system that can suppress deterioration of storage batteries while ultimately reducing electricity usage costs.

[0009] To achieve the above object, the battery charge / discharge system of the present invention includes an equipment control unit that controls one or more load equipment and one or more storage batteries connected to a power grid, and an adjustment capability management unit that stores or externally acquires a deterioration rate of the storage battery according to a state of charge and a charge / discharge condition of the storage battery, wherein the equipment control unit inputs a first state of charge and a first charge / discharge condition of the storage battery to the adjustment capability management unit to acquire a first deterioration rate, acquires from the adjustment capability management unit a second state of charge and a second charge / discharge condition that results in a second deterioration rate that is equal to or less than the acquired first deterioration rate, and controls the storage battery based on the second state of charge and the second charge / discharge condition. Other aspects of the present invention will be described in the embodiments described below.

[0010] According to the present invention, it is possible to suppress deterioration of the storage battery and, as a result, to suppress the cost of using electricity.

[0011] FIG. 1 is a diagram of a basic configuration of a battery charge / discharge system. FIG. 2 is an explanatory diagram relating to electricity prices. FIG. 3 is an explanatory diagram relating to electricity demand. FIG. 4 is an explanatory diagram relating to characteristic information of storage batteries stored in an adjustment capability management unit. FIG. 5 is an explanatory diagram relating to a service management unit. FIG. 6 is a processing flow of an equipment control unit. FIG. 7 is another processing flow of the equipment control unit. FIG. 8 is a conceptual diagram of the charge / discharge voltage of a storage battery mounted on an electric vehicle.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications can be made by those skilled in the art within the scope of the technical ideas disclosed in this specification. Furthermore, in all drawings used to explain the present invention, parts having the same function are designated by the same reference numerals, and repeated description thereof may be omitted.

[0013] In the embodiment, an example will be described in which a storage battery is controlled while suppressing deterioration of the storage battery, and a consumer uses the storage battery as an adjustment power to reduce electricity prices.

[0014] Fig. 1 is a diagram of the basic configuration of a battery charge / discharge system 100. Fig. 1 shows an example of the system configuration of a battery charge / discharge system 100 installed on the premises of a customer. In Fig. 1, at a customer such as a building, factory, or commercial facility, power is supplied from a power grid 101 through a distribution board 102 to outdoor load equipment 108 (a charger 109 and an electric vehicle 110 connected thereto) and indoor load equipment 111 (load equipment such as lighting equipment 112 and air conditioning equipment 113 inside the building), and power generated by a solar power generation system 107 is also supplied to the outdoor load equipment 108 and the indoor load equipment 111.

[0015] As the number of electric vehicles 110 in use increases, the demand for electricity from the outdoor load equipment 108 may become greater than the demand for electricity from the indoor load equipment 111. For example, in cases where the end of business hours for commercial vehicles and the like coincide, multiple electric vehicles 110 will be connected to the chargers 109 at the same time and charged simultaneously, which is expected to result in concentrated electricity demand within the consumer's premises.

[0016] The battery charging / discharging system 100 in Figure 1 is equipped with an electricity price management unit 104 that has the function of storing or externally acquiring the electricity price determined in accordance with the contract executed by the consumer, and calculating the electricity cost determined according to the stored or externally acquired electricity price and the electricity usage status at the consumer, and is capable of calculating and understanding the electricity cost including the occurrence of concentrated electricity demand within the consumer's premises as mentioned above.

[0017] The battery charge / discharge system 100 also includes an adjustment power management unit 105 that can store or externally acquire specific information about the storage battery and transmit the stored or externally acquired information to the outside, and a service management unit 106 that asks participants to participate in activities aimed at reducing electricity costs, and if a response is received, obtains the information necessary for participation and notifies participants of fees, etc. The equipment control unit 103 sends and receives information between these units and controls the outdoor load equipment 108 or the indoor load equipment 111.

[0018] (Equipment Control Unit) The equipment control unit 103 controls the charging and discharging of the storage battery, and diagnoses the state of the storage battery by utilizing battery data obtained when the storage battery is charged or discharged. The state diagnosis involves detecting the internal resistance and full charge capacity of the storage battery, or the degree of deterioration of these performances from their initial performance, by using the battery voltage and current obtained when the storage battery is charged or discharged.

[0019] The equipment control unit 103 also has a function of searching and acquiring from the adjustment capability management unit 105 the deterioration rate resulting from charging the storage battery to a fully charged state and then continuing to standby in that state, and similarly acquiring from the adjustment capability management unit 105 storage battery operating conditions, such as the charge state and charge / discharge current, that result in a deterioration rate equal to or lower than the deterioration rate when the storage battery is in standby in the fully charged state. By setting the charge state and charge / discharge current of the storage battery as the storage battery operating conditions, it is possible to utilize the storage battery while maintaining a deterioration rate, in other words, a decrease in the value of the storage battery, that is equal to or lower than when the storage battery is in standby in a fully charged state. Furthermore, it is possible to grasp the reduction in electricity costs obtained by operating the storage battery, search from the adjustment capability management unit 105 for the charge state and charge / discharge current conditions that make the decrease in value of the storage battery due to deterioration caused by using the storage battery less than the reduction in electricity costs obtained, and operate the storage battery under those charge state and charge / discharge current conditions.

[0020] (Power Price Management Unit) The following describes the power price management unit 104. As described above, the power price management unit 104 stores or externally acquires the power price determined in accordance with the contract executed by the consumer, and is capable of calculating the power cost determined according to the stored or externally acquired power price and the power usage status of the consumer.

[0021] That is, the electricity price management unit 104 has the functions of retaining or acquiring electricity price information determined in accordance with the electricity contract, measuring electricity usage status, and calculating electricity costs determined according to the electricity contract and electricity usage status.

[0022] FIG. 2 is an explanatory diagram regarding electricity prices. In this embodiment, a plan is shown in which the electricity price 201 varies with time. In FIG. 2, the electricity price 201 includes low-price time periods 202 (low-price time periods 202A, 202B, and 202C) during which electricity prices are low, and also includes high-price time periods 203 (high-price time periods 203A and 203B) during which electricity prices are high. By controlling the outdoor load equipment 108 or the indoor load equipment 111, electricity can be used during the low-price time periods 202 and avoided during the high-price time periods 203, thereby reducing electricity costs.

[0023] 3 is an explanatory diagram of power demand at a consumer. In this embodiment, power demand 301 is shown as an example in which the value gradually increases, peaks, and then gradually decreases. The consumer has a contract based on maximum power demand 302, and if the consumer uses more power than that, the power bill will increase. If control can be achieved to reduce the concentration of power demand using the outdoor load equipment 108 or the indoor load equipment 111 when power demand increases and peaks, it will be possible to suppress increases in power costs.

[0024] As described above, an example of a method for reducing electricity costs has been described. When there is a difference in the price of electricity depending on the time of day, as shown in Figure 2, using electricity when it is cheap and refraining from using electricity when it is expensive can lead to a reduction in electricity costs. It is also possible to reduce electricity costs by distributing electricity demand during times when electricity usage is at its peak. However, even if electricity usage by the outdoor load equipment 108 or the indoor load equipment 111 is controlled to reduce electricity costs, there are limitations because it is also necessary to maintain business and daily life carried out on the consumer's premises.

[0025] Therefore, for the outdoor building load equipment 108 (charger 109 and electric vehicle 110 connected thereto), a means is required that not only uses charger 109 to charge the drive storage battery built into electric vehicle 110, but also discharges the drive storage battery built into electric vehicle 110 as needed, thereby reducing the amount of power procured from power grid 101 through distribution board 102 and suppressing power costs.

[0026] However, frequently using the drive battery built into the electric vehicle 110 for the above-mentioned purposes leads to deterioration of the battery's performance, which is not the intended use of the drive battery, i.e., for purposes other than charging and discharging for driving. Therefore, a method for reducing electricity costs while suppressing the progression of deterioration of the battery installed in the electric vehicle 110 has been desired.

[0027] In view of the above-mentioned problems, operation control for reducing power costs while suppressing the progression of deterioration of the drive storage battery built into the electric vehicle 110 will be described.

[0028] (Adjustment Capability Management Unit) FIG. 4 is an explanatory diagram of the characteristic information of the storage battery stored in the adjustment capability management unit 105. This characteristic information of the storage battery is storage battery deterioration rate data 401 (storage battery deterioration rate data 401A, 401B, 401C), which is one of the deterioration risks according to each condition, with the horizontal axis representing the storage battery's state of charge (SOC) and the vertical axis representing the charge / discharge current. The deterioration risk includes the deterioration rate and the amount of deterioration progress. This storage battery deterioration risk changes as the deterioration level (SOH: State of Health) progresses, so the deterioration characteristics of the storage battery according to the deterioration level are also expressed. Furthermore, because the deterioration risk of a storage battery changes depending on the temperature, it is preferable to have the deterioration risk according to temperature as characteristic data (not shown).

[0029] When an electric vehicle 110 at a consumer site is connected to the charger 109, the drive battery built into the electric vehicle 110 is charged. As the charge increases, the SOC increases, and after reaching 100%, the drive battery is maintained at a high SOC until the electric vehicle 110 is used. It is known that maintaining a high SOC in a battery leads to relatively rapid deterioration.

[0030] Therefore, the equipment control unit 103 obtains from the adjustment capability management unit 105 a full charge condition 402A, which is the deterioration risk when the electric vehicle 110 is left after charging at a high SOC (the current is zero after full charging). Next, in response to a command from the equipment control unit 103, the adjustment capability management unit 105 searches for deterioration-risk equivalent charge / discharge condition 402B that is equivalent to the full charge condition 402A even when a current flows by lowering the SOC, and notifies the equipment control unit 103 of the result. If charging and discharging are performed within the current value range of the deterioration-risk equivalent charge / discharge condition 402B that is equivalent to the deterioration risk of the full charge condition 402A, it is equivalent to leaving the electric vehicle 110 left after charging. It was thought that if this charge / discharge current could be effectively utilized, it would be possible to reduce electricity costs and create value.

[0031] That is, the equipment control unit 103 inputs the first state of charge and the first charge / discharge conditions of the storage battery to the adjustment capability control unit 105 to obtain a first deterioration rate (the deterioration risk when the storage battery is left unused after charging), obtains from the adjustment capability control unit 105 a second state of charge and second charge / discharge conditions that will result in a second deterioration rate that is equivalent to the obtained first deterioration rate, and controls the storage battery based on the second state of charge and the second charge / discharge conditions. Note that although the above description describes obtaining the second state of charge and second charge / discharge conditions that will result in a second deterioration rate that is equivalent to the first deterioration rate, it is also possible to obtain from the adjustment capability control unit 105 a second state of charge and second charge / discharge conditions that will result in a second deterioration rate that is equal to or lower than the first deterioration rate. Furthermore, the expected reduction in electricity costs by operating the storage battery can be obtained from historical information or calculation results, a second deterioration rate can be determined so that the value decline due to deterioration caused by utilizing the storage battery to achieve this is smaller, a second state of charge and second charge / discharge conditions that achieve this second deterioration rate can be searched for using the adjustment power management unit 105, and the storage battery can be operated under these second state of charge and second charge / discharge conditions.When the expected reduction in electricity costs by operating the storage battery can be obtained from historical information, for example, records of past actual values ​​of the amount of electricity charged and discharged by the storage battery and the reduction in electricity costs can be accumulated, and the reduction in electricity costs can be estimated based on these.When the reduction in electricity costs can be obtained by calculation, for example, operating conditions such as the amount of electricity charged and discharged by the storage battery, the expected reduction in electricity procurement, the details of the electricity rate plan, etc. are used as inputs.

[0032] Here, the above-mentioned approach can automate the process of reducing power costs to the extent that it does not affect the business of the consumer, when the consumer who wants to reduce power costs is the owner of the electric vehicle 110. Also, when a consumer owns multiple premises, if there is a premises where power demand is more concentrated and power costs are likely to increase, the electric vehicle 110 can be moved to the premises where power costs are likely to increase and treated as a mobile battery, and by implementing the above-mentioned approach, it becomes possible to efficiently share the electric vehicle 110 as a mobile battery, thereby realizing a reduction in power costs.

[0033] In other words, if a consumer owns two or more premises where there is a concern that electricity costs will increase, for example, due to a significant concentration of electricity demand or an increase in electricity demand at a time when electricity prices are rising, it is advisable to dispatch more electric vehicles to the premises where there is a concern that electricity costs will increase, and notify the consumer's information terminal that they will be connected to a charger.

[0034] On the other hand, if the consumer who wants to reduce electricity costs is different from the owner of the electric vehicle 110, it is considered necessary to confirm the owner's intention to participate, such as whether he or she can cooperate with or participate in such electricity cost reduction activities. Therefore, the intention to participate is confirmed through the service management unit 106.

[0035] 5 is an explanatory diagram of the service management unit 106. When the service management unit 106 detects that the electric vehicle 110 has entered the premises of a customer and is connected to the charger 109, it displays a message to confirm the owner's intention to participate in the adjustment power service on a screen installed on the charger 109, on a screen installed separately from the charger 109, or by software installed on an information terminal (for example, a smartphone or tablet) held by the owner of the electric vehicle 110.

[0036] As shown in FIG. 5, a screen for confirming the owner of the electric vehicle 110's intention to participate in the adjustment power service is displayed as a selection screen 501 for participation in the electric vehicle 110's adjustment power service, which is aimed at the aforementioned efforts to reduce electricity costs using the electric vehicle 110.

[0037] If the intention to participate is confirmed on the adjustment power service participation selection screen 501, the screen transitions to an information registration screen 502 for participation in the adjustment power service. For example, the user is asked to select an estimated time for the electric vehicle 110 to depart (until this time, the storage battery can be used as adjustment power on the consumer's premises), a required charge level (utilization below this charge level is prohibited), and a contribution level (the higher the contribution level, the greater the current drawn from the storage battery but the higher the compensation; the lower the contribution level, the smaller the current drawn from the storage battery but the lower the compensation). The user's desire to participate in the adjustment power service is received, and the storage battery of the electric vehicle 110 is utilized in accordance with the desire. Note that in the above description of the equipment control unit 103, it was mentioned that a second charge state and second charge / discharge conditions that result in a second deterioration rate that is equal to or less than the first deterioration rate are obtained from the adjustment power management unit 105, and the storage battery is operated. This means that the higher the contribution level selected by the owner of the electric vehicle 110 on the information registration screen 502 for participation in the adjustment capacity service in order to participate in the adjustment capacity service, the more the storage battery is operated in a second state of charge and under second charge / discharge conditions in which the first deterioration rate and the second deterioration rate are equivalent, at a charge level of the storage battery equal to or higher than the required charge level. When there are multiple conditions in which the first deterioration rate and the second deterioration rate are equivalent, adopting the second state of charge and second charge / discharge conditions in which the charge / discharge current is the largest can increase the contribution of the storage battery to reducing electricity costs. When the contribution level selected by the owner of the electric vehicle 110 on the information registration screen 502 for participation in the adjustment capacity service in order to participate in the adjustment capacity service is set low, the storage battery is operated in a second state of charge and under second charge / discharge conditions in which the second deterioration rate is smaller than the first deterioration rate, at a charge level of the storage battery equal to or higher than the required charge level.In addition to specifying the contribution level, it is also possible to obtain the expected reduction in electricity costs by operating the storage battery from historical information or calculation results, determine a second deterioration rate so that the decrease in value of the storage battery due to deterioration caused by using the storage battery to reduce electricity costs is smaller, search from the adjustment power management unit 105 for a second charge state and second charge / discharge conditions that will result in this second deterioration rate, and operate the storage battery under these second charge states and second charge / discharge conditions.

[0038] The equipment control unit 103 then issues a command to each electric vehicle 110, causing each electric vehicle 110 to calculate the effect of reduced electricity costs, which is then stored in the service management unit 106. When the electric vehicle 110 is removed from the charger 109 or when the intention to suspend or cancel participation in the service is confirmed, a portion of the effect of reduced electricity costs is provided to the owner of the electric vehicle 110. The method for providing a portion of the effect of reduced electricity costs may be a method of reducing parking fees while the electric vehicle 110 is parked, a method of reducing shopping fees on the premises of the consumer who has received the effect of reduced electricity costs, or a method of reducing shopping fees for products sold by the consumer. The method may also be realized in a non-monetary way, such as points that can be used instead of money.

[0039] In other words, when operating as a battery adjustment capacity service, it is advisable to provide compensation to electric vehicle owners for the reduction in electricity costs through parking fees for electric vehicles, purchase fees on the consumer's premises, purchase fees for products sold by consumers, or points in a form other than money.

[0040] 6 shows the operational flow (process S600) of the above-described adjustment power service. First, assume that the owner of the electric vehicle 110 connects the electric vehicle 110 to the charger 109 (process S601). The equipment control unit 103 checks with the adjustment power management unit 105 whether there are any charge / discharge conditions that are equal to or lower than the battery degradation risk when the electric vehicle 110 is left charging (process S602). If there are any charge / discharge conditions that are equal to or lower than the battery degradation risk when the electric vehicle 110 is left charging (process S602, Yes), the equipment control unit 103 compiles the degradation risk equal to or lower than the battery degradation risk when the electric vehicle 110 is left charging, the corresponding current SOC, and the charge / discharge conditions (process S603). On the other hand, if there are no charge / discharge conditions that are equal to or lower than the battery degradation risk when the electric vehicle 110 is left charging (process S602, No), the equipment control unit 103 terminates process S600.

[0041] The equipment control unit 103 then asks the service management unit 106 to confirm whether the electric vehicle owner will participate in the adjustment capacity using the battery, and if so, also confirms the participation conditions (process S604). The equipment control unit 103 checks whether the electric vehicle owner has responded regarding their participation in adjustment capacity and the participation conditions (process S605), and if they have responded regarding their participation in adjustment capacity and the participation conditions (process S605, Yes), sets the specifications from the electric vehicle owner as the charging and discharging conditions (process S606). If they have not responded regarding their participation in adjustment capacity and the participation conditions (process S605, No), process S600 ends.

[0042] FIG. 7 illustrates the operation flow (process S700) of the equipment control unit 103 based on the electricity price information from the electricity price management unit 104 after the charging and discharging conditions have been set in accordance with the specifications of the electric vehicle owner.

[0043] First, the equipment control unit 103 checks whether the current electricity procurement is occurring during a high price time slot or a high electricity demand time slot from information from the electricity price management unit 104 (process S701), and if the current electricity procurement is occurring during a high price time slot or a high electricity demand time slot (process S701, Yes), the equipment control unit 103 proceeds to process S702. If the current electricity procurement is not occurring during a high price time slot or a high electricity demand time slot (process S701, No), the equipment control unit 103 proceeds to process S704.

[0044] In process S702, the equipment control unit 103 checks whether the current state of charge of the storage battery has decreased to the required charge level specified by the owner of the electric vehicle 110. If the current state of charge of the storage battery has decreased to the required charge level specified by the owner of the electric vehicle 110 (process S702, Yes), the equipment control unit 103 ends process S700, and if the current state of charge is higher than the required charge level (process S702, No), the equipment control unit 103 issues a battery discharge command within the range specified by the owner of the electric vehicle 110 (second charge / discharge condition determined from the contribution level) to discharge the battery installed in the electric vehicle 110. In this way, electricity costs are reduced.

[0045] In process S704, it is confirmed whether the current power procurement is in a low price time slot or a low power demand time slot, and if the current power procurement is in a low price time slot or a low power demand time slot (process S704, Yes), the process proceeds to process S705. If the current power procurement is not in a low price time slot or a low power demand time slot (process S704, No), the process S700 is terminated.

[0046] In process S705, the equipment control unit 103 checks whether the current state of charge of the storage battery is higher than a specified staying SOC (second state of charge) by a predetermined amount. If the state of charge is higher than the specified staying SOC (process S705, Yes), the equipment control unit 103 terminates process S700. If the state of charge is not higher than the specified staying SOC (process S705, No), the equipment control unit 103 issues a battery charging command within a range specified by the owner of the electric vehicle (second charging / discharging conditions determined from the contribution level) (process S706). In this way, control to reduce electricity costs can be achieved while confirming the intention of the owner of the electric vehicle 110.

[0047] That is, the electricity price management unit 104 has the functions of retaining or externally acquiring electricity price information determined in accordance with the electricity contract, measuring the electricity usage status, and calculating the electricity cost determined according to the electricity contract and the electricity usage status, and the equipment control unit 103, when controlling based on the charge state and charge / discharge conditions of the storage battery, discharges the storage battery when the electricity price is high and charges the storage battery when the electricity price is low, based on the electricity price information from the electricity price management unit 104.

[0048] In addition, when controlling based on the charge state and charge / discharge conditions of the storage battery, the equipment control unit 103 discharges the storage battery during time periods when the demand for electricity is relatively high, and charges the storage battery during time periods when the demand for electricity is relatively low, based on the electricity price information from the electricity price management unit 104.

[0049] 8 is a conceptual diagram of the charge and discharge voltages of the storage battery (secondary battery) mounted on the electric vehicle 110. In FIG. 8, V1 to V2 are set based on the operating voltage of the secondary battery with a low risk of degradation of the storage battery discussed in FIG. 4 and the voltage corresponding to the required charge level specified by the owner of the electric vehicle 110. V1 or less is below the required charge level (area below dashed line 801A), and V2 or more (area above dashed line 801B) is the upper limit charge state (charge stop threshold) when utilizing the storage battery, such as a specified staying SOC (second state of charge) or a charge level that is greater than the specified staying SOC by a predetermined margin set in consideration of the risk of degradation.

[0050] In this embodiment, the battery mounted on the electric vehicle 110 is discharged during a period of high electricity prices or high demand, and the case where discharge is performed by repeatedly interleaving discharge and rest periods is shown as an example. The state of charge (SOC_A) of the storage battery before discharge is calculated from the voltage 802 (e.g., 802A) before discharge, and the state of charge (SOC_B) of the storage battery after discharge is calculated from the voltage 802 (e.g., 802B) when the battery is sufficiently rested after discharge and the voltage has stabilized. The current battery capacity (Q_C) can be detected from the difference between these states of charge and the discharge current amount ∫Idt (the integration result of the current I(t) measured between time T1 when voltage 802A is obtained and time T2 when voltage 802B is obtained) that caused this difference in state of charge (Equation 1). The degree of battery capacity degradation (SOH_Q) can be confirmed by calculating the percentage of the current battery capacity Q_C relative to the initial battery capacity (Q_I) (Equation 2). Note that the method of determining the state of charge from the voltage of the storage battery is generally to store the relationship between the storage battery voltage and the state of charge as a characteristic map in advance, and to obtain the state of charge by inputting the measured voltage of the storage battery into the characteristic map. Also, while the method of determining SOH_Q between voltage 802A (time T1) and voltage 802B (time T2) was described above, it is possible to select various two times required to determine SOH_Q, such as determining SOH_Q between voltage 802A (time T1) and voltage 802E (time T5). Q_C = 100 × ∫Idt / (SOC_B - SOC_A) (Equation 1) SOH_Q = 100 × (Q_C / Q_I) (Equation 2)

[0051] Furthermore, by measuring the voltage before and after the start of discharge to determine the voltage change 803 (ΔV = post-discharge voltage - pre-discharge voltage), and simultaneously measuring the current at this time to determine the current change (ΔI = post-discharge current - pre-discharge current) and dividing by this, the current internal resistance (R_C) of the battery can be detected (Equation 3). The current internal resistance R_C of the battery can then be calculated as a percentage of the initial resistance (R_I) to determine the degree of resistance degradation (SOH_R) (Equation 4). In this way, it is possible to check the degree of degradation of the battery's capacity and resistance while performing a discharge process to reduce power costs. While the internal resistance R_C was determined by determining the changes in voltage and current before and after the start of discharge in the above example, it is also possible to determine the internal resistance R_C by determining the changes in voltage and current after the start and end of discharge. R_C = ΔV / ΔI (Equation 3) SOH_R = 100 × (R_C / R_I) (Equation 4)

[0052] That is, in the battery charging / discharging system 100, status diagnosis is realized by detecting the internal resistance and full charge capacity of the storage battery, as well as the degree of deterioration thereof, using the battery voltage and current when the storage battery is charged and discharged.

[0053] Conversely, in the case of low-price or low-demand hours, the battery is charged efficiently during those price periods, so in this embodiment, charging is performed all at once. However, as with discharging, charging can also be performed with pauses in between, and multiple measurements of the degree of deterioration in capacity and resistance observed during charging can be taken.

[0054] In this way, by deploying the adjustment power service and implementing control to reduce electricity costs, it is possible to detect the degree of deterioration of the battery installed in the electric vehicle 110, and therefore it is possible to provide the owner of the electric vehicle 110 with the results of the battery deterioration check in return for participating in the adjustment power service.

[0055] By controlling the facilities and developing services through a system configuration, it is possible to reduce power costs by using the batteries installed in the electric vehicle 110 while suppressing deterioration of the batteries installed in the electric vehicle 110.

[0056] Furthermore, by having the owner of the electric vehicle 110 confirm his or her intention to participate in the effort to reduce electricity costs and provide conditions for participation, it is possible to avoid compromising the convenience of driving after disconnecting the charger.

[0057] Furthermore, by providing a portion of the reduction in electricity costs to the owner of the electric vehicle 110 as compensation, it is possible to provide benefits to both the consumer and the owner of the electric vehicle 110. When the consumer and the owner of the electric vehicle 110 are the same person, it is possible to reduce electricity costs more proactively. In the case of a consumer with two or more premises, if an increase in electricity costs is predicted due to a rise in electricity prices depending on the time of day or a concentration of electricity demand, for example, more electric vehicles 110 are allocated to the premises and connected to chargers. This makes it possible to realize an adjustment power service that can further reduce electricity costs.

[0058] In the above embodiment, the battery charge / discharge system 100 has the service management unit 106, but this is not limiting. A battery balancing power service system may have the battery charge / discharge system 100 and the service management unit 106 and implement the battery balancing power service.

[0059] In other words, the battery adjustment power service system should have a battery charging / discharging system and a service management unit that proposes to the information terminal of the electric vehicle owner that they wish to use the electric vehicle's storage battery through an audible or visually detectable means (for example, an email notification or a notification on the screen of an electronic device such as a smartphone or tablet), and if permission to use the storage battery is obtained from the electric vehicle owner, uses the electric vehicle's storage battery for purposes other than driving the electric vehicle.

[0060] As described above, the battery charge / discharge system of this embodiment has the following features: (1) The battery charge / discharge system 100 includes an equipment control unit 103 that controls one or more load equipment and one or more storage batteries connected to a power grid, and an adjustment capability management unit 105 that stores or externally acquires a deterioration rate of the storage battery according to the state of charge and charge / discharge conditions of the storage battery, wherein the equipment control unit 103 inputs a first state of charge and first charge / discharge conditions of the storage battery to the adjustment capability management unit 105 to acquire a first deterioration rate, acquires from the adjustment capability management unit 105 a second state of charge and second charge / discharge conditions that result in a second deterioration rate that is equal to or less than the acquired first deterioration rate, and controls the storage battery based on the second state of charge and the second charge / discharge conditions. This acquires a state of charge and charge / discharge conditions that do not increase the deterioration rate and controls the storage battery, thereby suppressing deterioration of the storage battery and ultimately reducing electricity usage costs.

[0061] (2) The battery charge / discharge system of (1) further includes an electricity price management unit 104 having functions of retaining or externally acquiring electricity price information determined in accordance with an electricity contract, measuring electricity usage status, and calculating electricity costs determined according to the electricity contract and electricity usage status, and the equipment control unit 103, when performing control based on the charge state and charge / discharge conditions of the storage battery, discharges the storage battery when the electricity price is high and charges the storage battery when the electricity price is low, based on the electricity price information from the electricity price management unit 104. This makes it possible to reduce electricity usage costs.

[0062] (3) The battery charge / discharge system of (1) further includes a power price management unit 104 having functions of retaining or externally acquiring power price information determined in accordance with a power contract, measuring power usage status, and calculating power costs determined according to the power contract and power usage status, and the equipment control unit 103, when performing control based on the charge state and charge / discharge conditions of the storage battery, discharges the storage battery during times when power demand is relatively high as a power usage status, and charges the storage battery during times when power demand is relatively low as a power usage status, based on the power price information from the power price management unit 104. This makes it possible to reduce power usage costs.

[0063] (4) In the battery charge / discharge system of (1), the equipment control unit 103 controls the charge / discharge of the storage battery and diagnoses the state of the storage battery by utilizing battery data when the storage battery is charged or discharged. This may be applied to (2) or (3).

[0064] (5) In the battery charging / discharging system described in (3) above, the status diagnosis can detect the internal resistance and full charge capacity of the storage battery, as well as the degree of deterioration thereof, by using the battery voltage and current when the storage battery is charged and discharged (see Figure 8).

[0065] (6) In the battery charge / discharge system of (2) above, the equipment control unit 103 calculates the effect of reducing electricity costs obtained by operating the storage battery, and searches from the adjustment capability management unit 105 for a state of charge and charge / discharge current conditions that result in a smaller decline in the value of the storage battery due to deterioration than the effect of reducing electricity costs obtained, and operates the storage battery under the above-mentioned state of charge and charge / discharge current conditions. This ultimately makes it possible to reduce electricity usage costs.

[0066] (7) A battery balancing service system includes the battery charging / discharging system described in (1) to (6) above, and a service management unit that proposes to an information terminal of an electric vehicle owner that they wish to use the electric vehicle's storage battery through a means that can be detected audibly or visually, and that, if permission to use the storage battery is obtained from the electric vehicle owner, utilizes the electric vehicle's storage battery for purposes other than driving the electric vehicle. This allows the electric vehicle's storage battery to be used effectively to reduce electricity usage costs.

[0067] (8) In the battery adjustment capacity service system described in (7) above, compensation for the reduction in electricity costs can be provided to the owner of the electric vehicle through the parking fee for the electric vehicle, the cost of purchases on the customer's premises, the cost of purchasing products sold by the customer, or points in a form other than money.

[0068] (9) In the battery adjustment capacity service system of (8) above, if a consumer owns two or more premises where there is a concern that the cost of receiving electricity will increase at a premises where electricity demand is most concentrated or where electricity prices that vary depending on the time of day are high, etc., it is advisable to dispatch more electric vehicles to the premises where there is a concern that the cost of electricity will increase, and notify the consumer's information terminal that they will be connected to a charger.

[0069] When batteries installed in electric vehicles are used as balancing power, there is a concern about battery degradation for purposes other than their intended use. Meanwhile, electric vehicles are sometimes left connected to a charger, during which time the batteries installed in the electric vehicles continue to deteriorate. By applying the battery charging / discharging system and battery balancing power service system of the present invention, it is possible to utilize the batteries installed in electric vehicles as balancing power while suppressing battery degradation that occurs when the vehicles are left unused for long periods of time. This makes it possible to reduce electricity costs for consumers while suppressing battery degradation.

[0070] REFERENCE SIGNS LIST 100 Battery charge / discharge system 101 Power system 102 Distribution board 103 Equipment control unit 104 Electricity price management unit 105 Adjustment power management unit 106 Service management unit 107 Photovoltaic power generation system 108 Building outdoor load equipment (load equipment) 109 Charger 110 Electric vehicle (storage battery) 111 Building indoor load equipment (load equipment) 112 Lighting equipment 113 Air conditioning equipment 201 Electricity price 301 Electricity demand 401 Deterioration rate data 402A Full charge condition 402B Deterioration risk equivalent charge / discharge condition 501 Adjustment power service participation selection screen 502 Information registration screen for adjustment power service participation

Claims

1. A battery charging and discharging system comprising: an equipment control unit that controls one or more load equipment and one or more storage batteries connected to a power grid; and an adjustment capability management unit that stores or externally acquires a deterioration rate of the storage battery according to the state of charge and charge and discharge conditions of the storage battery, wherein the equipment control unit inputs a first state of charge and first charge and discharge conditions of the storage battery to the adjustment capability management unit to acquire a first deterioration rate, acquires from the adjustment capability management unit a second state of charge and second charge and discharge conditions that result in a second deterioration rate that is equal to or less than the acquired first deterioration rate, and controls the storage battery based on the second state of charge and the second charge and discharge conditions.

2. A battery charging / discharging system as claimed in claim 1, further comprising an electricity price management unit having functions of retaining electricity price information determined in accordance with an electricity contract, measuring electricity usage status, and calculating electricity costs determined in accordance with said electricity contract and said electricity usage status, wherein said equipment control unit, when controlling based on the state of charge and charging / discharging conditions of said storage battery, discharges said storage battery when the electricity price is high and charges said storage battery when the electricity price is low, based on the electricity price information from said electricity price management unit.

3. A battery charging / discharging system as claimed in claim 1, further comprising an electricity price management unit having functions of retaining electricity price information determined in accordance with an electricity contract, measuring electricity usage status, and calculating electricity costs determined in accordance with said electricity contract and said electricity usage status, wherein said equipment control unit, when controlling based on the state of charge and charging / discharging conditions of said storage battery, discharges said storage battery during times when electricity demand is relatively high as said electricity usage status, and charges said storage battery during times when electricity demand is relatively low as said electricity usage status, based on said electricity price information from said electricity price management unit.

4. A battery charging / discharging system according to claim 1, characterized in that the equipment control unit controls the charging and discharging of the storage battery and diagnoses the state of the storage battery by utilizing battery data obtained when the storage battery is charged or discharged.

5. A battery charging / discharging system according to claim 2, wherein the equipment control unit controls charging and discharging of the storage battery, and diagnoses the state of the storage battery by utilizing battery data obtained when the storage battery is charged or discharged.

6. A battery charging / discharging system according to claim 3, characterized in that the equipment control unit controls the charging and discharging of the storage battery, and diagnoses the state of the storage battery by utilizing battery data obtained when the storage battery is charged or discharged.

7. A battery charging / discharging system as claimed in claim 4, characterized in that the condition diagnosis detects one or more of the internal resistance, full charge capacity, degree of deterioration of resistance, and degree of deterioration of capacity of the storage battery by using the battery voltage and current when the storage battery is charged and discharged.

8. A battery charging / discharging system as claimed in claim 5, characterized in that the condition diagnosis detects one or more of the internal resistance, full charge capacity, degree of resistance degradation and degree of capacity degradation of the storage battery by using the battery voltage and current when the storage battery is charged and discharged.

9. A battery charging / discharging system as claimed in claim 6, characterized in that the condition diagnosis detects one or more of the internal resistance, full charge capacity, degree of deterioration of resistance, and degree of deterioration of capacity of the storage battery by using the battery voltage and current when the storage battery is charged and discharged.

10. A battery charging / discharging system as described in claim 2, characterized in that the equipment control unit obtains the effect of reducing electricity costs obtained by operating the storage battery from historical information or calculations, searches from the adjustment power management unit for a charging state and charging / discharging current conditions that will result in a smaller decline in the value of the storage battery due to deterioration than the obtained effect of reducing electricity costs, and operates the storage battery under the charging state and charging / discharging current conditions found.

11. A battery charging / discharging system as described in claim 3, characterized in that the equipment control unit obtains the effect of reducing electricity costs obtained by operating the storage battery from historical information or calculations, searches from the adjustment power management unit for a charging state and charging / discharging current conditions that will result in a smaller decline in the value of the storage battery due to deterioration than the obtained effect of reducing electricity costs, and operates the storage battery under the charging state and charging / discharging current conditions found.

12. A battery adjustment capacity service system comprising: a battery charging / discharging system according to any one of claims 1 to 11; and a service management unit that proposes to an information terminal of an electric vehicle owner, via a means that can be detected audibly or visually, that the electric vehicle owner wishes to use the storage battery of the electric vehicle, and that, if permission to use the storage battery is obtained from the electric vehicle owner, utilizes the electric vehicle's storage battery for purposes other than driving the electric vehicle.

13. A battery balancing capacity service system as described in claim 12, characterized in that the owner of the electric vehicle is compensated for the reduction in electricity costs through parking fees for the electric vehicle, purchase fees on the consumer's premises, purchase fees for products sold by the consumer, or points in a form other than money.

14. A battery adjustment capacity service system as described in claim 12, characterized in that, if a consumer owns two or more premises and there is a premises where there is a concern about an increase in the cost of receiving electricity, the electric vehicles are dispatched in large numbers to the premises where there is a concern about an increase in the electricity cost, and the consumer's information terminal is notified that they will be connected to a charger.

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