JP6688981B2 - Battery control device - Google Patents

Description

  The present invention relates to a storage battery control device and the like used in a power distribution system that performs a power supply operation for supplying power to a load.

  Conventionally, in a system in which a commercial power source and a storage battery coexist, a configuration has been disclosed in which, when the storage battery is charged with a constant current, the charging rate is set so that the charging is completed at a predetermined time (see, for example, Patent Document 1). . The storage battery of Patent Document 1 has a backup role and a peak shift role.

JP, 2013-176190, A

  However, unless the storage battery is controlled for charging or discharging for an appropriate period, the storage battery does not play a role of peak shift (peak suppression). Then, since the storage battery does not play the role of peak shift (peak suppression), there is a possibility that the stable operation of the power system (commercial power source) may be adversely affected.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a storage battery control device and the like that can control the storage battery such as charging and discharging for an appropriate period.

A storage battery control device according to an aspect of the present invention is a power supply operation for supplying power to a load from each of an electric power system, a distributed power supply, and a power storage device, and charging for charging a storage battery included in the power storage device with generated power of the distributed power supply. A storage battery control device used in a power distribution system that performs a reverse power flow operation of causing power flow that is not charged by the storage battery and is not consumed by the load among the generated power of the distributed power supply to the power system. A demand forecasting unit that predicts a demand transition that is a time transition of demand power consumed by a load and a time transition in a predetermined period, and a power generation transition that is a time transition of generated power of the distributed power source and a time transition in the predetermined period. a power generation prediction unit for predicting a remaining capacity of the current of the battery, the maximum battery capacity of the battery, predicted the demand remained at the demand prediction unit, Oyo , The amount of electric power that can be charged by the storage battery during the charging period in which the charging operation is performed based on the power generation transition predicted by the power generation prediction unit, and depends on the state of charge of the storage battery at the start timing of the charging period. The storage state prediction unit that predicts the chargeable amount that is the amount of electric power, and the rate determination unit that determines the target charging rate for matching or approaching the charging rate of the storage battery to the target charging rate. In the predetermined period, the surplus power obtained by removing the demand power from the generated power is a peak based on the demand transition predicted by the demand prediction unit and the power generation transition predicted by the power generation prediction unit. set the period including the time is as the charging period, and the chargeable amount predicted by said power storage status prediction unit to the charging period, the Based on the time length of the conductive period to determine the charge rate for charging the battery over the charge period as the target charging rate in the charging period, the rate determining unit, the said chargeable amount By dividing by the time length of the charging period, the target charging rate is determined to be a constant value over the charging period .

A storage battery control device according to one embodiment of the present invention is used for a power distribution system that performs a discharging operation for discharging a storage battery included in a power storage device and a power feeding operation for supplying power to a load from each of a power system and the power storage device. A storage battery control device, a demand prediction unit that predicts a demand transition that is a time transition of demand power consumed by the load and is a time transition in a predetermined period, a current remaining capacity of the storage battery, and the demand forecast Based on the demand transition predicted by the unit, it is the amount of power that can be discharged by the storage battery during the discharging period in which the discharging operation is performed, and the amount of power that depends on the state of charge of the storage battery at the start timing of the discharging period. A storage state prediction unit that predicts the dischargeable amount, and the target discharge rate that matches or approaches the discharge rate of the storage battery to the target discharge rate. And a rate determination unit that determines, based on the demand transition predicted by the demand prediction unit, it is assumed that power is not supplied from the power storage device to the load during the predetermined period. When the discharge is performed, the period including the time when the electric power supplied from the electric power system to the load is at a peak is set as the discharge period, and the dischargeable amount predicted by the storage state prediction unit for the discharge period. And, based on the time length of the discharge period, a discharge rate for discharging the storage battery over the discharge period is determined as the target discharge rate in the discharge period , and the rate determination unit is capable of performing the discharge. The target discharge rate is determined to be a constant value over the discharge period by dividing the amount by the time length of the discharge period .

  By the storage battery control device or the like according to one embodiment of the present invention, control such as charging or discharging is performed on the storage battery over an appropriate period.

FIG. 1 is a block diagram showing the configuration of the power distribution system according to the first embodiment. FIG. 2 is a schematic diagram showing prediction results of demand power and generated power according to the first embodiment. FIG. 3A is a schematic diagram showing storage battery control different from that of the first embodiment. FIG. 3B is a schematic diagram showing an equivalent demand different from that of the first embodiment. FIG. 4A is a schematic diagram showing storage battery control according to the first embodiment. FIG. 4B is a schematic diagram showing the equivalent demand of the first embodiment. FIG. 5 is a schematic diagram showing a charging period determination process according to the first embodiment. FIG. 6 is a block diagram showing the configuration of the power distribution system according to the second embodiment. FIG. 7 is a schematic diagram showing charge control according to the second embodiment. FIG. 8 is a schematic diagram showing another charge control according to the second embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, order of operations, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the constituent elements in the following embodiments, the constituent elements that are not described in the independent claims showing the highest concept are described as arbitrary constituent elements.

  Further, the electric power amount usually means an integrated value of electric power in a predetermined period and corresponds to energy. The amount of electric power per unit time corresponds to the electric power (power). Since electric power (power) and electric energy (energy) correspond to each other, electric power may be used here in the sense of electric energy (energy), and electric energy is used in the sense of electric power (power). There are cases. And the amount of electric power may be called the amount of electric power.

  Moreover, current, electric power, and electric energy may mean those values. Further, the charging / discharging corresponds to at least one of charging and discharging. The peak may be the maximum or the maximum in a predetermined period.

(Embodiment 1)
FIG. 1 shows the overall configuration of a power distribution system. The power distribution system includes a storage battery control device 1, a distribution board 2, a solar power generation device 3, a power storage device 4, and power sensors 91 and 92, and supplies power to the load 6. The solar power generation device 3 is a distributed power source including a solar cell 31 and a power conditioner 32. The power storage device 4 includes a storage battery 41 and a power conditioner 42. The distributed power source of the power distribution system is not limited to the solar power generation device 3 and may be, for example, a wind power generation device.

  In addition, in the present embodiment, the power distribution system is applied to a single-family dwelling unit, but the power distribution system may be applied to a building such as an apartment house or an office.

  The power distribution system uses a solar power generation device 3, a power storage device 4, and a commercial power supply 8 (electric power system 7) as a power supply that supplies power to the load 6. The power system 7 is a system for supplying the building as shown in FIG. 1, and is operated by a power company or the like. The commercial power source 8 is, for example, a power plant operated by a power company or the like. The power system 7 may include a commercial power supply 8. The power system 7 may also mean a power grid.

  AC power (commercial power) is supplied from the commercial power supply 8 to the distribution board 2 through the power system 7. Further, the distribution board 2 is supplied with AC power (generated power) from the solar power generation device 3. Further, AC power (discharge power) is supplied to the distribution board 2 from the power storage device 4.

  The distribution board 2 has a main breaker, a plurality of branch breakers, a switch, and the like built therein. Further, the plurality of branch breakers of the distribution board 2 are provided for the plurality of branch circuits. The distribution board 2 supplies AC power to a plurality of loads 6 via a plurality of branch circuits.

  It should be noted that the plurality of loads 6 in FIG. 1 are an electric device such as a lighting device, an air conditioner, and an information device connected to the plurality of branch circuits.

  The solar cell 31 receives sunlight to generate power. The power conditioner 32 converts the DC power obtained by the power generation of the solar cell 31 into AC power, and outputs the AC power as generated power of the solar power generation device 3. Further, the power conditioner 32 adjusts the frequency and the output voltage of the AC power (generated power) output by the power conditioner 32 in order to perform system interconnection with the power system 7.

  The storage battery 41 is connected to the distribution board 2 via the power conditioner 42. The power conditioner 42 charges and discharges the storage battery 41. Specifically, the power conditioner 42 converts the AC power supplied from the distribution board 2 into DC power and supplies the DC power to the storage battery 41 to charge the storage battery 41. Further, the power conditioner 42 discharges the storage battery 41, converts the DC power supplied from the storage battery 41 into AC power, and supplies the AC power to the distribution board 2.

  Further, the power conditioner 42 adjusts the frequency and the output voltage of the AC power (discharge power) output by the power conditioner 42 in order to perform system interconnection with the power system 7.

  The power generated by the solar power generation device 3 is used for part or all of the demand power, the charging power, and the reverse flow power. The discharged power of the power storage device 4 (storage battery 41) is used as the demand power. The power demand is the total power consumed by the entire load 6 (the total power consumed by the plurality of loads 6). The charging power is the power charged by the storage battery 41. Reverse power flow is power that flows backward to the power system 7.

  The power distribution system performs a power feeding operation of supplying power to the load 6 from each of the power system 7, the solar power generation device 3, and the power storage device 4. In addition, the power distribution system does not charge the storage battery 41 with the power generated by the photovoltaic power generator 3 (power storage operation) and the power generated by the photovoltaic power generator 3 that is not charged by the storage battery 41 and consumed by the load 6. Reverse power flow operation is performed to cause power to flow backward to the power system 7. In the charging operation, the storage battery 41 may be charged with commercial power.

  Regarding the charging of the storage battery 41, the power distribution system directly converts the DC power generated by the solar cell 31 into the DC power for charging without converting the DC power generated by the solar cell 31 into the AC power. The storage battery 41 may be charged. For example, the power distribution system may convert the voltage of the DC power generated by the solar cell 31 into a voltage for charging and charge the storage battery 41.

  The electric power sensor 91 measures the electric current (generated electric current) supplied from the photovoltaic power generator 3 to the distribution board 2, and generates electric power generated by converting the measured value of the generated electric current according to a predetermined reference to the generated electric power data. It is output to the control device 1 periodically (at the sampling cycle). The generated power data indicates, for example, generated power obtained by multiplying the measured value of the generated current by a predetermined generated voltage. The power sensor 91 may be provided in the power conditioner 32.

  The power sensor 92 measures the total current supplied from the distribution board 2 to the entire load 6 (total current supplied to the plurality of loads 6: load current), and measures the load current according to a predetermined standard. Demand power data indicating the converted demand power is output to the storage battery control device 1 periodically (at a sampling cycle). The power demand data indicates, for example, the power demand obtained by multiplying the measured value of the load current by a predetermined load voltage.

  The storage battery control device 1 includes a demand prediction unit 11, a power generation prediction unit 12, a power storage state prediction unit 13, a rate determination unit 14, a data acquisition unit 15, a storage unit 16, and a communication unit 17. Then, the storage battery control device 1 controls the charging / discharging operation performed on the storage battery 41 by the power conditioner 42 by determining the target charge rate and the target discharge rate of the storage battery 41 charged and discharged by the power conditioner 42. .

  That is, the storage battery control device 1 sets, via the power conditioner 42, the charge rate corresponding to the electric power charged by the storage battery 41 and the discharge rate corresponding to the electric power discharged by the storage battery 41 to the target charge rate and the target discharge rate. Control according to rate. Then, the storage battery control device 1 adjusts the commercial power received from the power grid 7 and the reverse power flow to the power grid 7 by controlling the charge rate and the discharge rate.

  In addition, in the power distribution system of the present embodiment, the storage battery control device 1 supplies only the generated power of the solar power generation device 3 to the power system 7 among the generated power of the solar power generation device 3 and the discharge power of the storage battery 41. You may let the reverse flow.

  Further, the storage battery control device 1 may include only a part of the demand prediction unit 11, the power generation prediction unit 12, the power storage status prediction unit 13, the rate determination unit 14, the data acquisition unit 15, the storage unit 16, and the communication unit 17. Good. Other components may be included in a device other than the storage battery control device 1. For example, the storage battery control device 1 may include only the demand prediction unit 11, the power generation prediction unit 12, and the rate determination unit 14 among these, or only the demand prediction unit 11, the power storage state prediction unit 13, and the rate determination unit 14. May be provided.

  The data acquisition unit 15 is an acquisition unit that acquires the generated power data from the power sensor 91 and the demand power data from the power sensor 92. For example, the data acquisition unit 15 stores the generated power data and the demand power data in the storage unit 16 in association with the date and time data. Weather information at the time of measurement may be associated with the generated power data.

  The storage unit 16 stores a history of generated power and demand power. Specifically, the storage unit 16 stores the generated power data and the demand power data over a certain past period (for example, the past one week, one month, or three months), and is stored before the past certain period. Old data of is deleted sequentially.

  The demand prediction unit 11 is a predictor that predicts the time transition of the demand power on the day (target day) when the storage battery 41 is controlled, based on the history of the demand power in the storage unit 16 at a fixed time every day. This time transition of the demand power is a time transition of the power consumed by the load 6 in one day. Here, the time transition of the demand power is also referred to as the demand transition.

  The demand prediction unit 11 predicts the time transition of the demand power on the target day by, for example, obtaining the average of the demand power at each time based on the history of the demand power. Further, the demand prediction unit 11 may predict the time transition of the demand power using only the demand power data of the same day as the target day of all the demand power data.

  The power generation prediction unit 12 is a predictor that predicts the time transition of the generated power on the target day based on the history of the generated power in the storage unit 16 at a fixed time every day. Here, the time transition of the generated power is also referred to as the power generation transition. Of all the generated power data, the power generation prediction unit 12 predicts the time transition of the generated power on the target day by using only the generated power data associated with the past weather information similar to the weather forecast of the target day. May be. Further, the power generation prediction unit 12 may predict the time transition of the generated power on the target day by obtaining the average of the generated power at each time.

  Each of the demand prediction unit 11 and the power generation prediction unit 12 may make the prediction on the night before the target day when the storage battery 41 is controlled or on the morning of the target day.

  FIG. 2 shows the demand transition predicted by the demand prediction unit 11 and the power generation transition predicted by the power generation prediction unit 12. In FIG. 2, the time transition of the demand power X1 on a day is the demand transition predicted by the demand prediction unit 11, and the time transition of the power generation power X2 on a day is the power generation transition predicted by the power generation prediction unit 12.

  The demand power X1 increases in the morning when the consumer starts the activity. After that, in the daytime, the demand power X1 changes according to the usage state of the load 6. Then, in the evening, the demand power X1 is increased again by preparing dinner, or by the consumer who returns home using the load 6. After that, the demand power X1 decreases.

  The generated power X2 increases from time t1 (near sunrise time), which is the operation start time of the power conditioner 32, in the weather in which the amount of solar radiation is sufficiently secured. Then, in the daytime, the generated electric power X2 decreases after reaching the maximum value in the vicinity of the time t2 which is the time in the south. Then, the generated power X2 becomes 0 after time t3 (near sunset time), which is the operation stop time of the power conditioner 32.

  FIG. 3A shows storage battery control performed on the demand power X1 and the generated power X2, and shows storage battery control different from the present embodiment. The amount of electric power that can be discharged with the remaining capacity of the storage battery 41 may be referred to as the dischargeable amount. In addition, the amount of electric power that can be charged by the portion obtained by subtracting (subtracting) the remaining capacity from the maximum battery capacity of the storage battery 41 may be referred to as the chargeable amount.

  The maximum battery capacity is the battery capacity of the storage battery 41 considering the deterioration of the storage battery 41. The maximum battery capacity is the rated capacity in the initial state when the use of the storage battery 41 is started. The maximum battery capacity then decreases from the rated capacity according to the degree of deterioration of the storage battery 41. Further, the dischargeable amount may be further limited by other conditions (conditions different from the charge state of the storage battery 41). Similarly, the chargeable amount may be further limited by other conditions (conditions different from the charge state of the storage battery 41).

  Hereinafter, a specific operation example will be described. Here, at midnight, the remaining capacity of the storage battery 41 is small and the dischargeable amount is “0”. After the time t1 in the morning, the generated power X2 is supplied, and the generated power X2 is preferentially used for the demand power X1 (area A102 in FIG. 3A). However, until the time t11 when the generated power X2 reaches the demand power X1, the remaining amount obtained by subtracting the generated power X2 from the demand power X1 is insufficient power, and this insufficient power is covered by commercial power (area A101 in FIG. 3A). .

  Then, from time t11 to time t13 when the generated power X2 is equal to or higher than the demand power X1, the demand power X1 is covered only by the generated power X2. From time t11 to time t13, the remainder obtained by subtracting the demand power X1 from the generated power X2 is surplus power, and the surplus power is preferentially used for the charging power of the storage battery 41 (area A103 in FIG. 3A). Then, at time t12, the storage battery 41 reaches the fully charged state. After time t12, the surplus power is reversely flowed to the power grid 7 and sold to the power company (area A104 in FIG. 3A).

  Then, after the time t13, the generated power X2 becomes lower than the demand power X1. After time t13, the remainder obtained by subtracting the generated power X2 from the demand power X1 is insufficient power, and the insufficient power is covered by the discharged power of the storage battery 41 (area A105 in FIG. 3A). Then, at time t14, the dischargeable amount of the storage battery 41 decreases to “0”, and then the insufficient power is covered by commercial power (area A106 in FIG. 3A).

  FIG. 3B shows the equivalent demand Y100 when the storage battery control of FIG. 3A is performed. The equivalent demand Y100 corresponds to the electric power that flows into the building from the electric power system 7 (purchased electric power) and the electric power that flows out from the building to the electric power system 7 (electric power sales). Further, the equivalent demand Y100 shown in FIG. 3B is an equivalent demand when the storage battery control different from the present embodiment is performed.

  As shown in FIG. 3B, commercial power is purchased from midnight until time t11 when the generated power X2 reaches the demand power X1. Then, since the charging is performed from time t11 to time t12 when the storage battery 41 reaches the fully charged state, the equivalent demand Y100 is “0”. Then, from the time t12 to the time t13 when the generated power X2 decreases to the demand power X1, power is sold with the generated power X2.

  Then, from time t13 to time t14 when the dischargeable amount of the storage battery 41 decreases to "0", the equivalent demand Y100 is "0" because the discharge is performed. Then, after time t14, commercial power is purchased.

  In the equivalent demand Y100 shown in FIG. 3B, the peak of the electric power sold (reverse power flow) is large, and the electric power system 7 may be in an unstable state. When the power system 7 is unstable, the fluctuation range of the system voltage and frequency of the commercial power supplied from the commercial power source 8 via the power system 7 is large, and the supply and demand balance of the commercial power is lost. .

  Therefore, in the present embodiment, the storage battery control shown in FIG. 4A is performed.

  Similar to the above-described operation example, here, at midnight, the remaining capacity of the storage battery 41 is small and the dischargeable amount is “0”. After the time t1 in the morning, the generated power X2 is supplied, and the generated power X2 is preferentially used for the demand power X1 (area A2 in FIG. 4A). However, until the time t11 when the generated power X2 reaches the demand power X1, the remainder obtained by subtracting the generated power X2 from the demand power X1 is insufficient power, and this insufficient power is covered by commercial power (area A1 in FIG. 4A). .

  Then, from time t11 to time t13 when the generated power X2 is equal to or higher than the demand power X1, the demand power X1 is covered only by the generated power X2. From time t11 to time t13, surplus power, which is the remainder of subtracting the demand power X1 from the generated power X2, is generated. A period in which surplus power is generated is called a power surplus period T1. Then, the rate determination unit 14 sets the charging period T11 for charging the storage battery 41 so that the reverse flow power is suppressed within the power surplus period T1.

  In the present embodiment, the rate determination unit 14 sets the charging period T11 to the same period as the power surplus period T1 (T1 = T11). The peak of the surplus power is included in the charging period T11. That is, the charging period T11 includes the time when the reverse power flow is at a peak when the entire amount of the surplus power is reversely flowed to the power system 7.

  The rate determining unit 14 is a determiner that determines the target charge rate or the target discharge rate. The target charge rate is a target charge rate that matches or approaches the charge rate of the storage battery 41. The target discharge rate is a target discharge rate that matches or approximates the discharge rate of the storage battery 41. For example, the rate determination unit 14 sets the charging period T11 and determines the target charging rate based on the set charging period T11 and the like. The charging period T11 may be the power surplus period T1 or a part of the power surplus period T1.

  The rate determination unit 14 determines whether or not surplus power is generated for each unit time by comparing the average value of the demand power X1 and the average value of the generated power X2 with each other, for example, The surplus period T1 is determined. When this unit time is set to a short time length, the power surplus period T1 may be set to a plurality of fine periods due to instantaneous fluctuations in the demand power X1 or the generated power X2.

  Therefore, the unit time may be set to about 1 hour, for example. As a result, the power surplus period T1 is suppressed from being unnecessarily finely divided by the instantaneous fluctuation of the demand power X1 or the generated power X2.

  The power storage state prediction unit 13 is a predictor that predicts a chargeable amount and a dischargeable amount. For example, the chargeable amount is the amount of power that can be charged by the storage battery 41 during the charging period T11, and is the amount of power that depends on the state of charge of the storage battery 41 at time t11, which is the start time (start timing) of the charging period T11. Further, for example, the dischargeable amount is the amount of power that can be discharged by the storage battery 41 during the discharging period T21, and is the amount of power that depends on the state of charge of the storage battery 41 at time t15, which is the start time (start timing) of the discharging period T21. is there.

  The state of charge of the storage battery 41 may be the remaining capacity of the storage battery 41 or the ratio of the remaining capacity to the maximum battery capacity of the storage battery 41. The ratio of the remaining capacity to the maximum battery capacity of the storage battery 41 is also called SOC.

  The scheduled charging power amount, which is scheduled as the amount of power charged by the storage battery 41 in the charging period T11, may be the chargeable amount predicted by the storage state prediction unit 13. The planned charging power amount may be a part or the whole of the surplus power amount in the charging period T11.

  The power storage state prediction unit 13 holds in advance data such as the maximum battery capacity of the storage battery 41. In addition, the power storage state prediction unit 13 acquires the current remaining capacity data of the storage battery 41 from the power conditioner 42 via the communication unit 17. Then, the electricity storage state prediction unit 13 starts the charging time T11 (time of day) based on the remaining capacity of the storage battery 41, the maximum battery capacity of the storage battery 41, the prediction result of the demand power X1, the prediction result of the generated power X2, and the like. A chargeable amount depending on the state of charge at t11) is predicted.

  The communication unit 17 is a communication device that performs communication. Specifically, the communication unit 17 communicates with the power conditioner 42 by wire or wirelessly. In addition, the communication unit 17 acquires data such as the current remaining capacity of the storage battery 41 from the power conditioner 42.

  For example, the rate determining unit 14 suppresses the peak of the reverse flow power by determining the target charging rate in the charging period T11 so that the charging power of the storage battery 41 is averaged in the charging period T11.

  Specifically, the rate determination unit 14 divides the chargeable amount based on the state of charge at the start time (time t11) of the charging period T11 by the time length of the charging period T11 to obtain the target charging rate in the charging period T11. Derive. As a result, the rate determination unit 14 derives a target charging rate that is a constant value during the entire charging period T11.

  Then, when the current time reaches the start time (time t11) of the charging period T11, the rate determining unit 14 transmits the derived data of the target charging rate to the power conditioner 42 via the communication unit 17. Specifically, the rate determination unit 14 sends the derived target charging rate data to the power conditioner 42 from the start time (time t11) of the charging period T11 to the end time (time t13) of the charging period T11 to the power conditioner 42. To send regularly via.

  That is, the rate determination unit 14 instructs the power conditioner 42 to have a constant target charging rate from time t11 to time t13. The power conditioner 42 charges the storage battery 41 based on the target charging rate instructed by the rate determining unit 14.

  However, in the first period (time t11 to time t111) of the charging period T11 and the last period (time t131 to time t13) of the charging period T11, since the surplus power is small, the charging rate for charging the storage battery 41 is Substantially lower than the indicated target charge rate. In addition, during the period from time t111 to time t131, the surplus electric power is sufficiently large, so the charging rate for charging the storage battery 41 becomes the instructed constant target charging rate.

  Then, the storage battery 41 is almost fully charged at the end time (time t13) of the charging period T11 by the charging in the charging period T11.

  That is, during almost the entire charging period T11, the surplus power is the charging power charged by the storage battery 41 (area A3 in FIG. 4A) and the reverse flow power sold (area A4 in FIG. 4A). Used for both. Then, charging is performed according to the target charging rate determined by the rate determining unit 14 over the entire power surplus period T1. Therefore, the reverse flow power is suppressed over the entire power surplus period T1.

  FIG. 4B shows the equivalent demand Y1 when the storage battery control of FIG. 4A is performed. In the equivalent demand Y1, the peak of the sold power (reverse flow power) becomes smaller than the equivalent demand Y100, and the peak of the sold power is suppressed. In particular, in FIG. 4B, the peak of the sold electric power is suppressed to the upper limit target value K1 or less.

  The upper limit target value K1 is an index that is determined so that the power system 7 does not become unstable, and indicates a standard for suppressing the peak of the sold electric power from becoming too large. For example, the upper limit target value K1 is a value that is instructed at any time by a demand response signal (hereinafter referred to as a DR signal) transmitted from a power company, an aggregator, or the like. Alternatively, the upper limit target value K1 may be a constant value determined in advance by a power company, an aggregator, or the like.

  As described above, the storage battery control device 1 according to the present embodiment can suppress the peak of the sold power (reverse power flow power) when the surplus power of the photovoltaic power generation device 3 is reversely flowed, and the power grid 7 of the power system 7 can be suppressed. It can contribute to stabilization.

  Next, at time t13, the generated power X2 decreases until it becomes equal to the demand power X1. After time t13, the remainder obtained by subtracting the generated power X2 from the demand power X1 is insufficient power, and the insufficient power is covered by the discharged power of the storage battery 41 and the commercial power. However, in the equivalent demand Y100 shown in FIG. 3B, the peak of the purchased electric power (commercial electric power supplied to the load 6) is large, and the electric power system 7 may become unstable.

  Therefore, in the present embodiment, the storage battery control shown in FIG. 4A is performed.

  After time t13, the insufficient power is covered by the discharged power of the storage battery 41 and the commercial power. When the commercial power supply covers all of the power shortage, the rate determination unit 14 sets a period including the period in which the commercial power (Y200 in FIG. 4B) supplied to the load 6 exceeds the upper limit target value K2 as the discharge period T21. Set. That is, the discharge period T21 includes a period in which the commercial power supplied to the load 6 when the discharge power of the storage battery 41 is not supplied to the load 6 exceeds the upper limit target value K2.

  That is, the discharge period T21 includes the time when the commercial power supplied to the load 6 is at a peak when the discharge power of the storage battery 41 is not supplied to the load 6. In the discharging period T21, the commercial power supplied to the load 6 is the upper limit target value when the commercial power covers all the insufficient power, that is, when the discharge power of the storage battery 41 is not supplied to the load 6. The period may exceed K2.

  The upper limit target value K2 is an index that is determined so that the power system 7 does not become unstable, and indicates a standard for suppressing the peak of purchased power from becoming too large. For example, the upper limit target value K2 is a value that is instructed at any time by a DR signal transmitted from a power company, an aggregator, or the like. Alternatively, the upper limit target value K2 may be a constant value predetermined by a power company, an aggregator, or the like.

  The power storage state prediction unit 13 predicts the dischargeable amount based on the state of charge at the start time (time t15) of the discharge period T21. Specifically, the power storage state prediction unit 13 starts the discharge period T21 based on the remaining capacity of the storage battery 41, the maximum battery capacity of the storage battery 41, the prediction result of the demand power X1, the prediction result of the generated power X2, and the like. The dischargeable amount depending on the charge state at time (time t15) is predicted. In addition, the scheduled charging power amount in the above-described charging period T11 may be reflected in the dischargeable amount predicted by the power storage state prediction unit 13.

  For example, the rate determination unit 14 determines the target discharge rate in the discharge period T21 so that the discharge power of the storage battery 41 is averaged in the discharge period T21, and thereby the purchased power (commercial power supplied to the load 6 is supplied. ) Peak is suppressed.

  Specifically, the rate determination unit 14 divides the dischargeable amount based on the state of charge at the start time (time t15) of the discharge period T21 by the time length of the discharge period T21 to obtain the target discharge rate in the discharge period T21. Derive.

  Then, when the current time reaches the start time (time t15) of the discharge period T21, the rate determination unit 14 transmits the derived target discharge rate data to the power conditioner 42 via the communication unit 17. Specifically, the rate determining unit 14 transmits the data of the derived target discharge rate to the power conditioner 42 from the start time (time t15) of the discharge period T21 to the end time (time t16) of the discharge period T21 to the power conditioner 42. To send regularly via.

  That is, the rate determination unit 14 instructs the power conditioner 42 about the target discharge rate from time t15 to time t16. The power conditioner 42 discharges the storage battery 41 at the target discharge rate instructed by the rate determining unit 14.

  Then, in the entire period of the discharging period T21, the insufficient power is covered by the discharging power discharged by the storage battery 41 (area A5 in FIG. 4A) and the commercial power (area A6 in FIG. 4A). Then, the discharge is performed according to the target discharge rate determined by the rate determination unit 14 over the entire discharge period T21. Therefore, the purchased electric power is suppressed over the entire period of the discharging period T21.

  Then, as shown in FIG. 4B, in the equivalent demand Y1, the peak of the purchased power (commercial power supplied to the load 6) becomes smaller than the equivalent demand Y100, and the peak of the purchased power is suppressed. In particular, in FIG. 4B, the peak of the purchased electric power is suppressed below the upper limit target value K2.

  As described above, the storage battery control device 1 in the present embodiment can suppress the peak of the purchased power (commercial power supplied to the load 6) when the insufficient power is covered by the commercial power, and the power grid 7 It can contribute to stabilization.

  Moreover, there is a plan in which the basic price fluctuates depending on the peak value of the purchased power in the electric rate plan that the user contracts with the electric power company or the aggregator. In general, the higher the peak value of purchased power, the higher the basic charge. In this case, since the peak of the purchased electric power is suppressed, the user can make a contract with a cheap electric power rate plan, and the electric rate becomes low, which is economically advantageous.

  The storage battery control device 1 described above is used in a power distribution system that performs a power feeding operation to supply power from the power system 7 (commercial power source 8), the distributed power source (such as the solar power generation device 3), and the power storage device 4 to the load 6. To be This power distribution system includes a charging operation of charging the storage battery 41 included in the power storage device 4 with the generated power of the distributed power supply, and a power of the generated power of the distributed power supply that is not charged by the storage battery 41 and consumed by the load 6 to the power system 7. Reverse power flow is performed.

  Then, the storage battery control device 1 includes a demand prediction unit 11, a power generation prediction unit 12, and a rate determination unit 14. The demand prediction unit 11 predicts a time transition of the demand power consumed by the load 6, which is a time transition in a predetermined period (for example, one day). The power generation prediction unit 12 predicts a power generation transition which is a time transition of the generated power of the distributed power source and a time transition in a predetermined period. The rate determination unit 14 determines a target charge rate for matching (or matching or approaching) the charge rate of the storage battery 41 with the target charge rate.

  In addition, the rate determination unit 14 is based on the demand transition predicted by the demand prediction unit 11 and the power generation transition predicted by the power generation prediction unit 12, and the surplus power obtained by removing the demand power from the generated power during a predetermined period. Is set as a charging period T11 in which the charging operation is performed.

  Then, the rate determining unit 14 determines the target charging rate based on the scheduled charging power amount scheduled as the amount of power charged by the storage battery 41 in the charging period T11 and the time length of the charging period T11. Specifically, the rate determination unit 14 determines the charging rate for charging the storage battery 41 over the charging period T11 as the target charging rate during the charging period T11.

  As a result, the storage battery control device 1 can control the charging of the storage battery 41 over an appropriate period. Specifically, the storage battery control device 1 can suppress the peak of the reverse flow power by charging the storage battery 41 during the charging period T11 including the time when the surplus power is at the peak. That is, the storage battery control device 1 can suppress the peak of the sold power (reverse flow power) when selling the surplus power of the distributed power sources, and can contribute to the stabilization of the power system 7.

  Further, the storage battery control device 1 further predicts a chargeable amount that is the amount of electric power that can be charged by the storage battery 41 during the charging period T11 and that is the amount of electric power that depends on the state of charge of the storage battery 41 at the start timing of the charging period T11. The situation prediction unit 13 may be provided. Then, the rate determining unit 14 may set the chargeable amount as the scheduled charging power amount.

  As a result, the target charging rate is determined based on the chargeable amount. Therefore, the storage battery control device 1 can appropriately continue charging until the end timing of the charging period T11 based on the chargeable amount.

  The rate determination unit 14 may also determine the target charging rate to be a constant value over the charging period T11.

  As a result, the target charging rate is set to a constant value over the charging period T11. Therefore, charging control becomes simple.

  Further, the rate determination unit 14 may determine the target charging rate by dividing the planned charging power amount by the time length of the charging period T11.

  Thereby, the storage battery control device 1 can average the electric power charged by the storage battery 41 in the charging period T11 including the time when the surplus power is at the peak.

  Further, the rate determination unit 14 may set the power surplus period T1 in which the generated power exceeds the demand power as the charging period T11.

  As a result, charging is performed according to the target charging rate determined by the rate determination unit 14 over the entire power surplus period T1, so that the reverse flow power is suppressed over the entire power surplus period T1.

  The storage battery control device 1 described above performs a discharging operation for discharging the storage battery 41 included in the power storage device 4 and a power supply operation for supplying power to the load 6 from each of the power system 7 (commercial power supply 8) and the power storage device 4. Used in power distribution system. Then, the storage battery control device 1 includes a demand prediction unit 11, a power storage state prediction unit 13, and a rate determination unit 14.

  The demand prediction unit 11 predicts a time transition of the demand power consumed by the load 6, which is a time transition in a predetermined period (for example, one day). The power storage state prediction unit 13 predicts a dischargeable amount that is an amount of electric power that can be discharged by the storage battery 41 during the discharging period T21 in which the discharging operation is performed and that is an amount of electric power that depends on the state of charge of the storage battery 41 at the start timing of the discharging period T21. To do. The rate determination unit 14 determines a target discharge rate for making the discharge rate of the storage battery 41 match or approach (match, or approach) the target discharge rate.

  The rate determination unit 14 also sets the discharge period T21 based on the demand transition predicted by the demand prediction unit 11. Specifically, the rate determination unit 14 determines the time when the power supplied from the power grid 7 to the load 6 is the peak during the predetermined period when it is assumed that the power is not supplied from the power storage device 4 to the load 6. The period including is set as the discharge period T21.

  Then, the rate determination unit 14 determines the target discharge rate based on the dischargeable amount predicted by the power storage state prediction unit 13 for the discharge period T21 and the time length of the discharge period T21. Specifically, the rate determination unit 14 determines the discharge rate for discharging the storage battery 41 over the discharge period T21 as the target discharge rate during the discharge period T21.

  As a result, the storage battery control device 1 can control the discharge of the storage battery 41 over an appropriate period. Specifically, the storage battery control device 1 can discharge the storage battery 41 over a discharge period T21 including the time when the commercial power supplied to the load 6 has a peak when the discharge is not performed. That is, the storage battery control device 1 can suppress the peak of purchased power and can contribute to stabilization of the power system 7.

  The rate determining unit 14 may determine the target discharge rate to be a constant value over the discharge period T21.

  As a result, the target discharge rate is set to a constant value over the discharge period T21. Therefore, discharge control becomes simple.

  The rate determining unit 14 may determine the target discharge rate by dividing the dischargeable amount by the time length of the discharge period T21.

  Thereby, the storage battery control device 1 can average the electric power discharged by the storage battery 41 in the discharging period T21 including the time when the commercial power supplied to the load 6 has a peak when the discharging is not performed.

  Further, in the power feeding operation, power may be further supplied to the load 6 from a dispersed power source (solar power generation device 3 or the like). Further, the storage battery control device 1 may further include a power generation prediction unit 12 that predicts a power generation transition that is a time transition of the generated power of the distributed power source and a time transition in a predetermined period. The rate determination unit 14 sets the discharge period T21 within the power shortage period in which the generated power is less than the demand power, based on the demand transition predicted by the demand prediction unit 11 and the power generation transition predicted by the power generation prediction unit 12. You may.

  As a result, in the power shortage period in which the generated power is short, the discharge period T21 including the time when the commercial power supplied to the load 6 is at the peak when the discharge is not performed is set. Therefore, the storage battery control device 1 can appropriately suppress the peak of commercial power by the discharge power.

  Further, the rate determination unit 14 sets, as the discharge period T21, a period in which the power supplied from the power grid 7 to the load 6 exceeds the upper limit target value K2 when it is assumed that the power is not supplied from the power storage device 4 to the load 6. You may.

  Thereby, the storage battery control device 1 reduces the commercial power supplied to the load 6 to bring the peak of the commercial power supplied to the load 6 closer to the upper limit target value K2, or the commercial power supplied to the load 6. Can be suppressed to the upper limit target value K2 or less.

  Further, the distributed power source in the above-described power distribution system may be the solar power generation device 3 that generates power by sunlight.

  In this case, the storage battery control device 1 charges the storage battery 41 by using the surplus power of the solar power generation device 3, and discharges the storage battery 41 at night when the solar power generation device 3 does not generate power, so that the peak of reverse flow power, Moreover, the peak of the commercial power supplied to the load 6 can be suppressed.

  Further, the rate determination unit 14 may determine the charging period T12 within the power surplus period T1 as shown in FIG. Specifically, the rate determination unit 14 sets, as the charging period T12, a period in which the reversely flowing power Y300 (sold power) when the entire amount of the surplus power is reversely flown to the power system 7 exceeds the upper limit target value K1. To do. Also in this case, the charging period T12 includes the time at which the reverse power flow Y300 is the peak when the entire amount of the surplus power is reverse flow to the power system 7.

  The rate determination unit 14 derives the target charging rate in the charging period T12 by dividing the chargeable amount based on the charging state at the start time of the charging period T12 by the time length of the charging period T12. The target charging rate derived by the rate determining unit 14 is constant during the entire charging period T12.

  Then, the charging is performed in accordance with the target charging rate similarly determined by the rate determining unit 14 over the entire charging period T12 in which the sold electric power exceeds the upper limit target value K1. Therefore, the reverse flow power is suppressed over the entire charging period T12. In this case, since the surplus power is sufficiently large in the charging period T12, it is possible to perform charging at the instructed constant target charging rate over the entire period of the charging period T12.

  Therefore, the storage battery control device 1 can reduce the peak of the sold power (reverse power flow power) toward the upper limit target value K1 when selling the surplus power of the distributed power sources. That is, the storage battery control device 1 can bring the peak of the sold power close to the upper limit target value K1, or can suppress the peak of the sold power below the upper limit target value K1.

  That is, the rate determination unit 14 may set the period in which the reverse flow power exceeds the upper limit target value K1 when the excess power is reversely flowed to the power system 7 as the charging period T12.

(Embodiment 2)
FIG. 6 shows the overall configuration of the power distribution system of this embodiment. Storage battery 41 of the present embodiment is assumed to be in a state where a sufficient chargeable amount is secured. The state in which the rechargeable amount is sufficiently secured is a state in which the rechargeable power amount is large because the remaining capacity of the storage battery 41 is small or the rated capacity of the storage battery 41 is large.

  Compared to the storage battery control device 1 of the first embodiment, the storage battery control device 1A of the present embodiment does not include the power storage state prediction unit 13. The rate determining unit 14 of the storage battery control device 1A is different from the first embodiment in that the surplus power amount accumulated over the charging period is used as the planned charging power amount. That is, in the present embodiment, the planned charging power amount is the surplus power amount obtained by integrating the surplus power over the charging period. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

  As shown in FIG. 7, the rate determination unit 14 sets the power surplus period T1 in which the surplus power Y400 is generated as the charging period T13. Then, the rate determination unit 14 uses the surplus power amount (area A11 in FIG. 7) that is the integrated value of the surplus power Y400 in the entire charging period T13 as the scheduled charging power amount. That is, the rate determination unit 14 derives the target charging rate in the charging period T13 by dividing the surplus power amount by the time length of the charging period T13. The target charging rate derived by the rate determining unit 14 is constant during the entire charging period T13.

  Then, the rate determination unit 14 instructs the power conditioner 42 about the target charging rate for the charging period T13. The power conditioner 42 charges the storage battery 41 based on the target charging rate instructed by the rate determining unit 14. However, since the surplus power Y400 is small during the predetermined period after the charging period T13 starts and before the charging period T13 ends, the charging rate for charging the storage battery 41 is lower than the instructed target charging rate. Will also be substantially lower.

  Further, during a period in which the surplus power Y400 is sufficiently large, charging can be performed at the instructed constant target charging rate. Further, especially near the peak of the surplus power Y400, the surplus power Y400 is larger than the target charging rate. Therefore, a part of the surplus power Y400 is used as the reverse flow power without being charged.

  That is, the rate determination unit 14 may set the surplus power amount obtained by integrating the surplus power over the charging period T13 as the scheduled charging power amount.

  Thereby, the charging rate is set based on the surplus power amount. Therefore, the storage battery control device 1A can appropriately continue charging until the end timing of the charging period T13 based on the surplus power amount.

  The rate determination unit 14 may also determine the target charging rate to be a constant value over the charging period T13.

  As a result, the target charging rate is set to a constant value over the charging period T13. Therefore, charging control becomes simple.

  Further, the rate determination unit 14 may determine the target charging rate by dividing the planned charging power amount by the time length of the charging period T13.

  Thereby, the storage battery control device 1A can average the electric power charged by the storage battery 41 in the charging period T13 including the time when the surplus power is at the peak.

  Further, the rate determination unit 14 may set the power surplus period T1 in which the generated power exceeds the demand power as the charging period T13.

  As a result, charging is performed according to the target charging rate determined by the rate determination unit 14 over the entire power surplus period T1, so that the reverse flow power is suppressed over the entire power surplus period T1.

  Further, the rate determination unit 14 may determine the charging period T14 within the power surplus period T1, as shown in FIG. Specifically, the rate determination unit 14 sets a period in which the surplus power Y400 exceeds the threshold value K11 as the charging period T14. In this case as well, the charging period T14 includes the time at which the reverse flow power reaches a peak when the entire amount of the surplus power Y400 is reverse flowed to the power system 7.

  Then, the rate determination unit 14 uses the surplus power amount (area A12 in FIG. 8) that is the integrated value of the surplus power Y400 in the charging period T14 as the scheduled charging power amount, and uses the surplus power amount as the time length of the charging period T14. By dividing by, the target charging rate in the charging period T14 is derived. The target charging rate derived by the rate determining unit 14 is constant during the entire charging period T14.

  Then, charging is performed according to the target charging rate determined by the rate determining unit 14 over the entire charging period T14 in which the surplus power Y400 exceeds the threshold value K11. Therefore, the reverse flow power is suppressed over the entire charging period T14. In this case, since the surplus power Y400 is sufficiently large in the charging period T14, charging can be performed at the instructed constant target charging rate over the entire charging period T14.

  That is, the rate determination unit 14 may set, as the charging period T14, a period in which the surplus power exceeds the threshold value K11 in the power surplus period T1 in which the generated power exceeds the demand power.

  In general, the maximum charge rate at which the storage battery 41 can be charged and the maximum discharge rate at which the storage battery 41 can be discharged are determined by the specifications and performances of the storage battery 41 and the power conditioner 42.

  Therefore, in the first and second embodiments described above, when the target charging rate derived by the rate determining unit 14 exceeds the maximum charging rate, the rate determining unit 14 finally instructs the power conditioner 42 to set the maximum charging rate. It may be determined as a target charging rate. In addition, in the first and second embodiments described above, when the target discharge rate derived by the rate determining unit 14 exceeds the maximum discharge rate, the rate determining unit 14 finally indicates the maximum discharge rate to the power conditioner 42. It may be determined as a target discharge rate.

  Further, the minimum charge rate at which the storage battery 41 can be charged and the minimum discharge rate at which the storage battery 41 can be discharged may be determined depending on the specifications and performances of the storage battery 41 and the power conditioner 42.

  In this case, in Embodiments 1 and 2 described above, when the target charging rate derived by the rate determining unit 14 is lower than the minimum charging rate, the rate determining unit 14 instructs the power conditioner 42 to set the minimum charging rate. It may be determined as a target charging rate. Further, in the above-described first and second embodiments, when the target discharge rate derived by the rate determining unit 14 is lower than the minimum discharge rate, the rate determining unit 14 finally indicates the minimum discharge rate to the power conditioner 42. It may be determined as a target discharge rate.

  The storage battery control devices 1 and 1A may be equipped with a computer. Then, the computer executes the program to realize the functions of the respective units of the storage battery control device 1, 1A described above (in particular, the demand prediction unit 11, the power generation prediction unit 12, the storage state prediction unit 13, and the rate determination unit 14). May be. For example, this computer mainly includes a device including a processor that executes a program, an interface device for exchanging data with another device, and a storage device for storing data. Provide as a component.

  The device including the processor may be a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) that is separate from the semiconductor memory, or may be a microcomputer that includes the semiconductor memory integrally. As the storage device, a storage device having a short access time such as a semiconductor memory and a storage device having a large capacity such as a hard disk device may be used together.

  As a form of providing the program, a form that is stored in advance in a computer-readable ROM (Read Only Memory), a recording medium such as an optical disk, or a form that is supplied to the recording medium via a wide area communication network such as the Internet Etc.

  For example, the program causes a computer to function as the storage battery control device 1 or 1A.

  A program that causes a computer to function as the storage battery control device 1 or 1A can also achieve the same effect as described above. That is, this program can control the storage battery 41 such as charging or discharging for an appropriate period.

  The above embodiment is an example of the present invention. Therefore, the present invention is not limited to the above-described embodiment, and other than this embodiment, as long as it does not deviate from the technical idea of the present invention, depending on the design etc. Of course, various changes can be made.

1, 1A Storage battery control device 3 Photovoltaic power generation device (distributed power source)
4 Storage Device 6 Load 7 Power System 11 Demand Prediction Unit 12 Power Generation Prediction Unit 13 Storage State Prediction Unit 14 Rate Determination Unit 41 Storage Battery

Claims (5)

Of the power supply operation of supplying power to the load from each of the power system, the distributed power source, and the power storage device, the charging operation of charging the storage battery included in the power storage device with the power generated by the distributed power source, and the power generated by the distributed power source A storage battery control device for use in a power distribution system that performs a reverse power flow operation of causing a reverse power flow to the power system, the power not being charged by the storage battery and not being consumed by the load,
A demand prediction unit that predicts a demand transition that is a time transition of demand power consumed by the load and is a time transition in a predetermined period,
A power generation prediction unit that predicts a power generation transition that is a time transition of the generated power of the distributed power source and that is a time transition in the predetermined period,
The charging operation is performed based on the current remaining capacity of the storage battery, the maximum battery capacity of the storage battery, the demand transition predicted by the demand prediction unit, and the power generation transition predicted by the power generation prediction unit. A storage state prediction unit that predicts a chargeable amount that is an amount of power that can be charged by the storage battery during a charging period and that is an amount of power that depends on the state of charge of the storage battery at the start timing of the charging period,
A rate determining unit for determining the target charging rate for matching or approaching the charging rate of the storage battery to the target charging rate,
The rate determination unit,
Based on the demand transition predicted by the demand prediction unit and the power generation transition predicted by the power generation prediction unit, the surplus power obtained by removing the demand power from the generated power is a peak during the predetermined period. Set a period including a certain time as the charging period,
The charging rate for charging the storage battery over the charging period is based on the chargeable amount predicted by the storage state prediction unit for the charging period and the time length of the charging period. Determined as the target charging rate in the period,
The storage battery control device, wherein the rate determination unit determines the target charging rate to be a constant value over the charging period by dividing the chargeable amount by the length of the charging period. The storage battery control device according to claim 1, wherein the rate determination unit sets a power surplus period in which the generated power exceeds the demand power as the charging period. The storage battery control device according to claim 1, wherein the rate determination unit sets, as the charging period, a period in which the surplus power exceeds a threshold value in a power surplus period in which the generated power exceeds the demand power. The storage battery control device according to claim 3, wherein the rate determination unit sets, as the charging period, a period during which the reverse power flow exceeds the upper limit target value when the surplus power flows backward in the power system. The computer program to function as a storage battery control device according to any one of claims 1-4.

Images