JP7123711B2 - system - Google Patents

Description

The present invention relates to technology of a system having a water heater capable of producing hot water using electric power.

In recent years, with the decrease in the purchase price of photovoltaic power generation, there are cases where it is desired to consume (self-consumption) at home the power generated by photovoltaic power generation (particularly, surplus power) without selling it. Also, as a means for self-consumption, it is conceivable to operate a water heater, which is generally operated using cheap power at night, using surplus power day and night.

Here, Patent Literature 1 discloses a technique for appropriately operating a water heater day and night. Specifically, in the technology described in Patent Document 1, the hot water supply demand (partial hot water supply demand) from the present to a predetermined time later is calculated, and based on the current heat storage amount of the hot water storage tank and the partial hot water supply demand, the water heater ( heat pump unit). As a result, the water heater can be operated at an appropriate time (timing according to the hot water supply demand) regardless of day or night.

However, with the technique described in Patent Literature 1, it is conceivable that the power consumed by the water heater may exceed the surplus power of the photovoltaic power generation. In particular, in a system having a plurality of water heaters, it is assumed that the plurality of water heaters will operate simultaneously, so there is a possibility that surplus power will be greatly exceeded. In such a case, it is necessary to cover the shortage of power with power other than photovoltaic power generation (for example, power stored in a storage battery, power purchased from a grid power supply, etc.), which is neither efficient nor economical. .

Therefore, in a system having a water heater capable of producing hot water using electric power, a system capable of determining the operation schedule of the water heater in consideration of surplus power is desired.

JP 2018-28411 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the problem to be solved is to provide a system capable of determining the operation schedule of water heaters in consideration of surplus power generated by photovoltaic power generation. is.

The problems to be solved by the present invention are as described above, and the means for solving the problems will now be described.

That is, in claim 1, there is provided a power generation unit capable of generating electric power and capable of supplying power to an electric power load, and a power generating unit capable of producing hot water using electric power, unlike the electric power load, and storing the hot water. , a plurality of water heaters capable of supplying a hot water supply load, the power demand of the power load, and the power generation amount generated by the power generation unit are predicted for each predetermined time period, and the predicted power demand and the power generation Surplus power is calculated for each time period based on the amount of surplus power, the number of water heaters that can be operated with the predicted surplus power is calculated for each time period, and the number of water heaters is calculated based on the calculated number of water heaters. and a control unit that determines an operating schedule.

In claim 2, the control unit determines the order of priority of operation of the water heater, and determines the operation schedule so that the water heater with the higher priority starts operating in an earlier time zone. is.

In claim 3, the control unit predicts the hot water supply demand of the hot water supply load for each of the predetermined time periods, and the integrated amount of the hot water supply demand of the hot water supply load that supplies hot water among the plurality of water heaters is The priority is determined so that the water heater that reaches the predetermined value earlier in the time zone has a higher priority.

In claim 4, the control unit predicts the hot water supply demand of the hot water supply load for each of the predetermined time periods, and determines whether the water heater is required to produce hot water that satisfies the hot water supply demand in a predetermined period. The operation time is calculated, and the priority is determined so that the water heater with the longer required operation time has a higher priority.

In claim 5, the control unit predicts the remaining amount of hot water stored in the water heater for each of the predetermined time periods based on the determined operating schedule, In (1), when the remaining amount is below a predetermined value, the operation schedule is corrected so that the water heater starts operating in an earlier time zone.

As effects of the present invention, the following effects are obtained.

In claim 1, it is possible to determine the operation schedule of the water heater in consideration of the surplus power generated by the photovoltaic power generation.

In claim 2, the higher the priority of the water heater, the faster the hot water can be produced.

In claim 3, the water heater can be operated according to the demand for hot water supply.

In claim 4, the water heater can be operated according to the demand for hot water supply.

In claim 5, it is possible to suppress the occurrence of running out of hot water.

1 is a block diagram showing the overall configuration of a power supply system according to one embodiment of the present invention; FIG. 4 is a flowchart showing processing in operation schedule determination control; The figure which showed an example of the predicted electric power demand and the amount of photovoltaic power generation. The figure which showed an example of the predicted hot-water supply demand of each house. FIG. 4 is a diagram showing an example of surplus power and the number of operable water heaters at each time; The figure which showed the hot-water supply demand of each house, the amount of remaining hot water, the operation time of each water heater, and a priority. A diagram showing the number of water heaters that can be operated at each time and the water heaters that are assigned to operate. FIG. 4 is a diagram showing an example of predicted power demand and solar power generation amount, and power consumption of water heaters to which operation is assigned; The figure which showed an example of the hot-water-supply demand of each house, and the amount of remaining hot water. (a) A diagram showing the number of operable water heaters according to a second specific example. (b) The figure which showed the example which determined the operation start time of a water heater so that operation might be complete|finished by 17:00. (a) A diagram showing the number of operable water heaters according to the third specific example. (b) A diagram showing an example in which the operation start time of the water heater is determined so as to operate the water heater at a time when surplus power can be used more effectively.

Below, the electric power supply system 1 which concerns on one Embodiment of this invention is demonstrated.

The power supply system 1 shown in FIG. 1 supplies power purchased in bulk from a grid power supply K or power generated using sunlight (power generated by a photovoltaic power generation unit 11 or the like described later) to a plurality of houses as appropriate. It is to supply (accommodate). A power supply system 1 according to the present embodiment is provided, for example, in an apartment complex, and supplies power to each house in the apartment complex. In this embodiment, three houses (first house A, second house B, and third house C) will be described as an example. In addition, below, the electric power load of the said three houses is called the electric power load H1, the electric power load H2, and the electric power load H3. Moreover, the said three electric power loads are also collectively called the electric power load H. FIG.

The power supply system 1 mainly includes a first power storage system 10 , a second power storage system 20 , a third power storage system 30 , a water heater 40 , a detector 50 and an EMS 60 .

The first power storage system 10, the second power storage system 20, and the third power storage system 30 are connected to a distribution line L that connects a system power supply K and an electric power load H, respectively. More specifically, the first power storage system 10, the second power storage system 20, and the third power storage system 30 are connected in order from the power load H side to the system power supply K side in the distribution line L. It is placed in series with the load H. The first power storage system 10, the second power storage system 20, and the third power storage system 30 are owned by residents of the first house A, the second house B, and the third house C, respectively.

The first power storage system 10 stores power purchased from the system power supply K or power generated using sunlight, and supplies the power to the power load H of each house. The first power storage system 10 includes a solar power generation section 11 , a storage battery 12 and a hybrid power conditioner 13 .

The solar power generation unit 11 is a device that generates power using sunlight. The solar power generation unit 11 is configured by a solar cell panel or the like. The solar power generation unit 11 is installed, for example, in a sunny place such as on the roof of a house. The photovoltaic power generation unit 11 is connected to the distribution line L at a first connection point P1 provided in the middle of the distribution line L via a hybrid power conditioner 13, which will be described later.

The storage battery 12 is configured to be able to charge and discharge electric power. The storage battery 12 is configured by, for example, a lithium ion battery. The storage battery 12 is connected to the solar power generation section 11 via a hybrid power conditioner 13 which will be described later.

The hybrid power conditioner 13 appropriately converts electric power (hybrid power conditioner). The hybrid power conditioner 13 is configured to be able to charge the storage battery 12 with the power generated by the solar power generation unit 11 and the power from the system power source K. In addition, the hybrid power conditioner 13 discharges the power generated by the solar power generation unit 11 and the power charged in the storage battery 12 to the power load H and the like. In addition, the hybrid power conditioner 13 is configured to be able to acquire information about the operating states of the solar power generation unit 11 and the storage battery 12 . Such a hybrid power conditioner 13 is connected to the middle portion of the distribution line L at the first connection point P1.

The hybrid power conditioner 13 of the first power storage system 10 configured in this manner can switch charging and discharging of the storage battery 12 based on the detection result of the corresponding sensor (the first power sensor 51 described later).

The second power storage system 20 is the same as the first power storage system 10, except that the hybrid power conditioner 23 is connected to the distribution line L at a second connection point P2 provided closer to the system power source K than the first connection point P1. configured similarly. Specifically, the solar power generation unit 21, the storage battery 22, and the hybrid power conditioner 23 of the second power storage system 20 correspond to the solar power generation unit 11, the storage battery 12, and the hybrid power conditioner 13 of the first power storage system 10, respectively.

The third power storage system 30 is the same as the first power storage system 10, except that the hybrid power conditioner 33 is connected to the distribution line L at a third connection point P3 provided closer to the system power source K than the second connection point P2. configured similarly. Specifically, the photovoltaic power generation unit 31, the storage battery 32, and the hybrid power conditioner 33 of the third power storage system 30 correspond to the photovoltaic power generation unit 11, the storage battery 12, and the hybrid power conditioner 13 of the first power storage system 10, respectively.

The water heater 40 uses electric power to produce hot water. The water heater 40 according to this embodiment includes a first water heater 41 , a second water heater 42 and a third water heater 43 . The first water heater 41, the second water heater 42, and the third water heater 43 are owned by the residents of the first residence A, the second residence B, and the third residence C, respectively. Although the water heater 40 uses (consumes) electric power, it is different from the electric power load H in the present embodiment, and the electric power load H does not include the water heater 40 .

The first water heater 41 boils water using heat generated using a heat pump. The first water heater 41 can use the power supplied to the first house A through the distribution line L to operate the heat pump. The first water heater 41 can store boiled hot water in a hot water storage tank (not shown). The first water heater 41 is installed in the first residence A, and can supply hot water to a hot water supply load (for example, a bathroom, etc.) of the first residence A.

The second water heater 42 and the third water heater 43 are configured in the same manner as the first water heater 41 except that they are installed in the second residence B and the third residence C, respectively. In particular, in the present embodiment, the heating capacity of the first water heater 41, the second water heater 42, and the third water heater 43 and the electric power required for operation (power consumption) are assumed to be substantially the same.

The detection unit 50 detects various types of information. The detection unit 50 includes a first power sensor 51 , a second power sensor 52 , a third power sensor 53 , a first remaining hot water sensor 54 , a second remaining hot water sensor 55 and a third remaining hot water sensor 56 .

The first power sensor 51 detects power flowing through the distribution line L. As shown in FIG. The first power sensor 51 is provided on the distribution line L between the first connection point P1 and the second connection point P2. Also, the first power sensor 51 is provided so as to be adjacent to the system power source K side of the first connection point P1 (so that the connection point between the distribution line L and another power storage system does not intervene). The first power sensor 51 detects the voltage (supply voltage) and current (supply current) of the power (for example, the power flowing to the power load H side and the power flowing to the system power supply K side) flowing through the provided location. To detect. A detection result of the first power sensor 51 is output to the hybrid power conditioner 13 .

The second power sensor 52 detects power flowing through the distribution line L. As shown in FIG. The second power sensor 52 is provided on the distribution line L between the second connection point P2 and the third connection point P3. Also, the second power sensor 52 is provided so as to be adjacent to the system power supply K side of the second connection point P2. The second power sensor 52 detects the voltage (supply voltage) and current (supply current) of power flowing through the provided location. A detection result of the second power sensor 52 is output to the hybrid power conditioner 23 .

The third power sensor 53 detects power flowing through the distribution line L. The third power sensor 53 is provided in the distribution line L so as to be adjacent to the system power supply K side of the third connection point P3. The third power sensor 53 detects the voltage (supply voltage) and current (supply current) of power flowing through the provided location. A detection result of the third power sensor 53 is output to the hybrid power conditioner 33 .

The first remaining hot water sensor 54 detects the remaining amount of hot water (remaining hot water amount) stored in the hot water storage tank of the first water heater 41 . The first remaining hot water sensor 54 is provided in the first water heater 41 .

The second remaining hot water sensor 55 detects the remaining amount of hot water (remaining hot water amount) stored in the hot water storage tank of the second water heater 42 . A second remaining hot water sensor 55 is provided in the second water heater 42 .

The third remaining hot water sensor 56 detects the remaining amount of hot water (remaining hot water amount) stored in the hot water storage tank of the third water heater 43 . A third remaining hot water sensor 56 is provided in the third water heater 43 .

The EMS 60 is an energy management system that manages the operation of the power supply system 1 . The EMS 60 includes an arithmetic processing unit such as a CPU, a storage unit such as a RAM and a ROM, an input/output unit such as a touch panel, and the like. The storage unit of the EMS 60 stores in advance various information, programs, and the like used when controlling the operation of the power supply system 1 . The arithmetic processing unit of the EMS 60 can operate the power supply system 1 by executing the program and performing predetermined arithmetic processing using the various information.

The EMS 60 is electrically connected to the hybrid power conditioners 13, 23, 33. The EMS 60 can transmit a predetermined signal to the hybrid power conditioners 13, 23, 33 to control the operation of the storage batteries 12, 22, 32 (for example, charge and discharge of the storage batteries 12, 22, 32). Further, the EMS 60 is configured such that a predetermined signal can be input from the hybrid power conditioners 13, 23, and 33, and can acquire various types of information (such as the amount of power remaining in the storage batteries 12, 22, and 32).

Also, the EMS 60 is electrically connected to each water heater 40 and can control the operation of each water heater 40 . The EMS 60 is also electrically connected to the first remaining hot water sensor 54, the second remaining hot water sensor 55, and the third remaining hot water sensor 56, and can acquire the detection values of the first remaining hot water sensor 54 and the like.

In the power supply system 1 configured as described above, the storage battery 12 or the like can be charged with power purchased from the system power supply K or power generated by the solar power generation unit 11 or the like. Further, in the power supply system 1, the power purchased from the system power supply K, the power generated by the solar power generation unit 11, etc., and the power charged in the storage battery 12, etc. are supplied to the power load H of each house and the water heater 40 and the like. Further, in the power supply system 1, surplus power (surplus power) generated by the photovoltaic power generation unit 11 and the like can be reversely flowed to the system power source K and sold.

For example, by outputting power generated by the solar power generation unit 11 or the like to the distribution line L, power can be supplied to the power load H of each house. Also, the storage battery 12 and the like can be caused to perform load follow-up operation based on the detection result of the first power sensor 51 and the like. As a result, when the power from the photovoltaic power generation unit 11 is insufficient for the power load H, power can be supplied to the power load H by discharging the storage battery 12 or the like. Moreover, when the electric power from the photovoltaic power generation part 11 surpluses with respect to the electric power load H, the said electric power can be made to charge the storage battery 12. FIG.

Here, as described above, in the power supply system 1, surplus power can be reverse-flowed to the system power source K (sold). However, as the purchase price of photovoltaic power has decreased in recent years, there are cases where it is desirable to consume surplus power at home (self-consumption) instead of selling it.

Therefore, in the power supply system 1 according to the present embodiment, by operating the water heater 40 at an appropriate time (timing), it is possible to encourage consumption of surplus power by the water heater 40 . Below, the control for determining the time (operation schedule) for operating the water heater 40 (hereinafter referred to as "operation schedule determination control") will be specifically described.

Note that the operation schedule determination control is performed periodically. In this embodiment, it is assumed that the operation schedule determination control is performed every day at 00:00, and the operation schedule for 24 hours from 00:00 is determined.

In step S101 of FIG. 2, the EMS 60 predicts power demand, hot water supply demand, and photovoltaic power generation amount for each predetermined time period. In this embodiment, it is assumed that power demand and the like are predicted at each time (every hour).

Here, the power demand is the total value (W) of power consumed by the power load H of each house.
The hot water supply demand is the energy (Wh) consumed by the hot water supply load of each house.
Also, the amount of solar power generation is the total value (W) of power generated by the solar power generation units (solar power generation unit 11, etc.) of each house.

Since the power supply system 1 according to the present embodiment allows power to be exchanged between a plurality of houses, the predicted values of the power demand and the amount of photovoltaic power generation in step S101 are obtained by summing the predicted values of each house. calculated as On the other hand, since the hot water supply to the hot water supply load of each house is performed by the water heater 40 of each house, the hot water supply demand in step S101 is calculated (predicted) for each house.

It should be noted that the power demand and the like can be predicted by various methods. For example, a method of learning (machine learning) the past power demand of each house by the EMS 60 and making a prediction based on the learning result, or a method of making a prediction based on statistical information on the power demand of general houses can be considered.

FIG. 3 shows an example of the power demand and solar power generation amount predicted in step S101. FIG. 4 also shows an example of the demand for hot water supply of each house predicted in step S101.

EMS60 transfers to step S102, after performing the process of step S101.

In FIG.2 S102, EMS60 calculates the surplus electric power of each time. The surplus power can be calculated by subtracting the power demand from the solar power generation amount at each time predicted in step S101.

FIG. 5 shows an example of the surplus power at each time (especially from 6:00 to 17:00) calculated in step S102.

EMS60 transfers to step S103, after performing the process of step S102.

In step S103, the EMS 60 calculates the number of water heaters 40 that can be operated using surplus power at each time. Specifically, the EMS 60 calculates the number of operable water heaters 40 by dividing the surplus power at each time calculated in step S102 by the power consumption of the water heaters 40 (1 kW in this embodiment). calculate. In addition, when calculating the number of vehicles, fractions are rounded down.

FIG. 5 shows an example of the number of operable water heaters 40 at each time (especially from 6:00 to 17:00) calculated in step S103.

EMS60 transfers to step S104, after performing the process of step S103.

In step S104 of FIG. 2, the EMS 60 calculates the operation time of each water heater 40 required to generate the amount of heat that satisfies the hot water supply demand of each house. Specifically, the EMS 60 determines the hot water supply demand of each house for 24 hours from the execution of the operation schedule determination control (midnight in this embodiment), the water heater of each house at the time of execution of the operation schedule determination control. Subtract the amount of remaining hot water from 40. Furthermore, the EMS 60 calculates the operation time of each water heater 40 by dividing the result of the subtraction by the heating capacity of the water heater 40 (4.5 kW in this embodiment).

FIG. 6 shows an example of the demand for hot water supply and the amount of remaining hot water of each house, and the operation time of each water heater 40 calculated in step S104.

In the present embodiment, it is assumed that the water heater 40 is operated continuously for a necessary time (not operated in multiple times) from the viewpoint of improving operating efficiency. For example, as shown in FIG. 6, since the operation time of the water heater 40 (first water heater 41) of the first house A is four hours, in the present embodiment, the first water heater 41 is continuously operated for four hours. put it into operation.

EMS60 transfers to step S105, after performing the process of step S104.

In step S<b>105 of FIG. 2 , the EMS 60 determines the order of priority of operation of the water heater 40 . Here, the order of priority is the order indicating which water heater 40 should preferentially start operating. Prioritization can be based on various criteria. For example, the order of priority is determined so that the water heater 40 in a house with an early demand for hot water is preferentially operated, or the water heater 40 with the longest operating time calculated in step S104 is preferentially operated. A method of determining the order of priority is conceivable.

In this embodiment, it is assumed that the order of priority is determined so that the water heater 40 of a house having an early demand for hot water is preferentially operated. In the example shown in FIG. 4, the hot water supply demand for the second residence B occurs at the earliest time (6:00). Therefore, in the example of FIG. 4, it is also possible to set the priority of the water heater 40 of the second house B to the highest.

However, the demand for hot water supply is relatively small and can be covered by the amount of hot water remaining in water heater 40 . For this reason, it is not preferable from the viewpoint of improving the operating efficiency to determine the priority of operation of the water heater 40 based on a relatively small amount of demand for hot water supply. Therefore, in the present embodiment, the order of priority is determined based on the time when the integrated amount of demand for hot water supply of each house reaches a predetermined value. Specifically, in each house, the demand for hot water is generated based on the time when the integrated amount of demand for hot water reaches a predetermined percentage (for example, 50%) of the demand for hot water for the day (24 hours from midnight). Judgment of early housing.

For example, in the example shown in FIG. 6, since the hot water demand of the first residence A is 17.2 (kWh), the time when 50% of the hot water demand (i.e., 8.6 (kWh)) is reached is used as the reference time. As such, determine the order of priority. Based on such determination, in the present embodiment, the first residence A (first water heater 41) has the first priority, the second residence B (the second water heater 42) has the second priority, and the third It is assumed that house C (third water heater 43) is determined to have the third priority (see FIG. 6).

EMS60 transfers to step S106, after performing the process of step S105.

In step S106 of FIG. 2, the EMS 60 preferentially allocates the operating time from the water heater 40 having the highest priority. At this time, the EMS 60 allocates the operation time of the water heater 40 based on the number of water heaters 40 that can be operated at each time calculated in step S103.

Specifically, the EMS 60 allocates the operation time of the water heater 40 so that the water heater 40 having a higher priority starts operating at an earlier time. In this embodiment, since one water heater 40 can be operated at 8 o'clock (see FIG. 5), the water heater 40 with the highest priority (in this embodiment, the first water heater 41 of the first house A ) will start operating at 8:00. As described above, the water heater 40 is operated continuously, so the first water heater 41 is assigned to operate for four hours from 8:00 to 11:00 (see FIG. 7). Note that in FIG. 7, the time assigned to operate the water heater 40 is blacked out.

Further, in the present embodiment, as shown in FIG. 7, since the two water heaters 40 are operable at 9 o'clock, at that time, in addition to the first water heater 41, the other water heater 40 can be operated. Therefore, the EMS 60 starts operating the water heater 40 having the second priority (the second water heater 42 of the second house B) at 9:00. The second water heater 42 is assigned to operate for three hours from 9:00 to 11:00.

Here, when the operations of the first water heater 41 and the second water heater 42 are assigned as described above, only one water heater 40 is operable at 11 o'clock. are two (the first water heater 41 and the second water heater 42). In this case, at that time (11:00), the power consumption of the first water heater 41 and the second water heater 42 cannot be covered by the surplus power (see 11:00 in FIG. 8), so the power shortage is the storage battery. 12 or the like or power purchased from the system power source K.

As described above, in the present embodiment, even if the surplus power is insufficient after the operation of the water heater 40 (the power consumption of the water heater 40 cannot be covered), the operation efficiency of the water heater 40 can be improved. , the water heater 40 is not stopped.

Further, in this embodiment, as shown in FIG. 7, after the operation of the first water heater 41 and the second water heater 42 is finished at 11:00, the single water heater 40 becomes operable again at 13:00. Therefore, the EMS 60 starts operating the water heater 40 having the third priority (the third water heater 43 of the third house C) at 13:00. The third water heater 43 is assigned to operate for three hours from 13:00 to 15:00.

Here, when the operation of the third water heater 43 is assigned as described above, the number of water heaters 40 that can be operated at 15:00 is zero, whereas in reality there is one water heater 40 (the third water heater 43) will be operated (see 15:00 in FIG. 8). In this case as well, the power shortage is supplemented by the storage battery 12 or the like.

In this manner, the EMS 60 allocates the operating time so that the water heater 40 with the highest priority starts operating preferentially (early time). The EMS 60 can create an operating schedule by allocating operating times for all of the water heaters 40 included in the power supply system 1 .

EMS60 transfers to step S107, after performing the process of step S106.

In step S107 of FIG. 2, the EMS 60 calculates the amount of remaining hot water in each water heater 40 at each time. Specifically, based on the operation schedule created in step S106, the EMS 60 adds a value obtained by subtracting the demand for hot water supply from the heating amount of the water heater 40 at a predetermined time to the amount of remaining hot water at the immediately preceding time. , the amount of remaining hot water at the predetermined time is calculated. For example, when calculating the remaining hot water amount of the first water heater 41 at 8:00, the EMS 60 calculates the value obtained by subtracting the hot water demand at 8:00 from the heating amount of the first water heater 41 at 8:00. It is added to the amount of remaining hot water in the water heater 41 .

The EMS 60 calculates the remaining hot water amount of each water heater 40 at each time by sequentially performing such calculations for each time. If the calculated remaining hot water amount is a negative value, it means that there is a shortage of hot water at that time.

FIG. 9 shows an example of the demand for hot water supply of each house and the amount of remaining hot water in the water heater 40 of each house at each time calculated in step S107.

EMS60 transfers to step S108, after performing the process of step S107.

In step S108, the EMS 60 determines whether or not there is a time when the remaining oil amount is less than 0 (negative value) for the water heater 40 of each residence. That is, the EMS 60 determines whether or not there is a shortage of hot water in each residence.

When the EMS 60 determines that there is a time when the remaining hot water amount is less than 0 (Yes in step S108), the process proceeds to step S109.
On the other hand, when the EMS 60 determines that there is no time when the remaining hot water amount is less than 0 (No in step S108), the control (operation schedule determination control) ends.

In the example shown in FIG. 9, there is no time when the remaining hot water amount is less than zero.

In step S109, the EMS 60 advances the operation start time of the residential water heater 40 whose remaining hot water amount is less than 0 (hot water is insufficient) by one hour. In this way, the EMS 60 corrects the operation schedule created in step S106 and boils the water one hour earlier, thereby resolving the shortage of remaining hot water.

EMS60 transfers to step S107 again, after performing the process of step S109.

In this way, EMS 60 repeats the processes from step S107 to step S109 until the amount of hot water remaining in water heater 40 at each time becomes 0 or more (that is, until there is no shortage of hot water at each time).

The EMS 60 ends this control (operation schedule determination control) when the amount of remaining hot water in the water heater 40 at each time becomes 0 or more (No in step S108), and determines the operating time of the water heater 40 assigned at that time. Confirm the (operation schedule).

The EMS 60 can encourage self-consumption of surplus power by operating the water heater 40 according to the operating schedule thus determined. Further, at this time, it becomes possible to operate the water heater 40 according to the surplus power. Further, in the present embodiment, even if the power consumption of the water heater 40 exceeds the surplus power, priority is given to the continuous operation of the water heater 40 (the water heater 40 is not stopped), so that the water heater 40 is It can be operated efficiently, and the efficiency of the power supply system 1 as a whole can be improved.

As described above, the power supply system 1 (system) according to the present embodiment is
a photovoltaic power generation unit 11 or the like (power generation unit) capable of generating power and supplying power to the power load H;
a plurality of water heaters 40 capable of producing hot water using electric power unlike the electric power load, storing the hot water, and supplying the hot water to the hot water supply load;
predicting the power demand of the power load H and the amount of power generated by the photovoltaic power generation unit 11 or the like for each predetermined time period (one hour) (step S101);
calculating the surplus power in each time period based on the predicted power demand and the power generation amount (step S102);
calculating the number of water heaters 40 that can be operated with the predicted surplus power for each time period (step S103);
Based on the calculated number of units, the EMS 60 (control unit) determines the operation schedule of the water heater 40 (step S106);
is provided.
By configuring in this way, it is possible to determine the operation schedule of the water heater 40 in consideration of the surplus power generated by the photovoltaic power generation. That is, since the operation schedule can be determined based on the number of operable water heaters 40 calculated based on the surplus power, it is possible to suppress the operation of an excessive number of water heaters 40 for the surplus power. can do.

Further, the EMS 60 is
The operation priority of the water heater 40 is determined (step S105), and the operation schedule is determined so that the water heater 40 having the higher priority starts operating in an earlier time zone (step S106). be.
By configuring in this way, it is possible to operate the water heater 40 based on the order of priority. That is, the water heater 40 having a higher priority can produce hot water faster.

Further, the EMS 60 is
predicting the hot water supply demand of the hot water supply load for each of the predetermined time periods (step S101);
Among the plurality of water heaters 40, the priority is set such that the earlier the water heater 40 in which the integrated amount of hot water supply demand of the hot water supply load reaches a predetermined value, the higher the priority. It is decided (step S105).
By configuring in this way, the water heater 40 can be operated according to the demand for hot water supply. That is, it is possible to preferentially operate the hot water heater 40 whose hot water demand is generated (the integrated amount reaches a predetermined value) earlier. As a result, it is possible to suppress the occurrence of running out of hot water.

Further, the EMS 60 is
predicting the hot water supply demand of the hot water supply load for each of the predetermined time periods (step S101);
calculating the required operation time of the water heater 40 required to produce hot water that satisfies the hot water supply demand in a predetermined period (step S104);
The priority may be determined such that the water heater 40 having the longer required operating time has a higher priority (step S105).
By configuring in this way, the water heater 40 can be operated according to the demand for hot water supply. That is, it is possible to preferentially operate the water heater 40 whose operating time is longer to meet the demand for hot water supply. As a result, it is possible to suppress the occurrence of running out of hot water.

Further, the EMS 60 is
Based on the determined operating schedule, the remaining amount of hot water stored in the water heater 40 is predicted for each predetermined time period (step S107),
If the remaining amount falls below a predetermined value in any of the predetermined time periods, the operation schedule is corrected so that the water heater 40 starts operating in an earlier time period (steps S108 and S109). It is.
By configuring in this way, it is possible to suppress the occurrence of running out of hot water. That is, by accelerating the start of operation of the water heater 40, hot water can be produced early.

The power supply system 1 according to this embodiment is an embodiment of the system according to the present invention.
Moreover, the photovoltaic power generation unit 11 and the like according to the present embodiment are an embodiment of the power generation unit according to the present invention.
Also, the EMS 60 and the like according to this embodiment are an embodiment of the control unit according to the present invention.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

For example, although the power supply system 1 is installed in an apartment complex, it is not limited to this, and may be installed in an office, a detached house, or the like.

Further, in the present embodiment, the photovoltaic power generation unit 11 is exemplified as the power generation unit, but the present invention is not limited to this, and it is possible to use various devices capable of generating power (for example, wind power generators, etc.).

In the present embodiment, the power demand and the like are predicted hourly, and the operation schedule of the water heater 40 is determined. , every 30 minutes, every two hours, etc.).

In the present embodiment, the priority of the water heater 40 is determined based on the time period when the integrated amount of hot water supply demand reaches a predetermined value (50%) (see step S105). It is not limited to this. For example, it is also possible to determine the order of priority so that the water heater 40 in a house where the demand for hot water is generated earlier is preferentially operated.

Further, in the present embodiment, the priority of the water heater 40 is taken into consideration when determining the operation schedule, but the present invention is not limited to this. For example, regardless of the priority, it is possible to determine the operation schedule based on the number of water heaters 40 that can operate with surplus power in each time slot.

In the operation schedule determination control of the present embodiment, depending on the number of operable water heaters 40 calculated in step S103, there may be water heaters 40 to which the operating time cannot be assigned.

For example, in step S103, when the number of water heaters 40 that can be operated using surplus power at each time is calculated as in the example (second specific example) shown in FIG. assume. In this case, since the number of water heaters 40 that can operate with surplus power is only one during the time period from 8:00 to 11:00, the water heaters 40 with the second priority or lower (example in FIG. 10A) Then, the operation time of the second water heater 42 and the third water heater 43) cannot be assigned.

However, if the operation time of the water heater 40 is not allocated, the remaining hot water amount of the water heater 40 will eventually run short of the demand for hot water supply, which is not preferable. Therefore, if there is a water heater 40 whose operating time cannot be assigned in step S106, it is preferable to operate the water heater 40 regardless of the number of operable water heaters 40 at each time.

In this case, the operation start time of the water heater 40 can be determined based on the demand for hot water supply, for example. For example, the operation start time of the water heater 40 is determined so that the operation of the water heater 40 ends until the demand for hot water is generated or the demand for hot water reaches a predetermined ratio (for example, 50%). be able to.

Also, the operation start time of the water heater 40 can be determined so that the operation of the water heater 40 is finished by a predetermined time (for example, the time at which a large demand for hot water is expected to occur (17:00, etc.)). . FIG. 10(b) shows an example in which the operation start times of the second water heater 42 and the like are determined such that the operation of the second water heater 42 and the third water heater 43 will end by 17:00.

In this way, even when the surplus power is insufficient, by giving priority to the operation of the water heater 40, it is possible to prevent the shortage of hot water (running out of hot water).

In addition, in the operation schedule determination control of the present embodiment, the operation time of the water heater 40 is allocated so that the water heater 40 with higher priority starts operating at an earlier time (step S106). Therefore, in some cases, it is assumed that part of the surplus power cannot be effectively utilized.

For example, in step S103, if the number of water heaters 40 that can be operated using surplus power at each time is calculated as in the example (third specific example) shown in FIG. assume. In this case, the process of step S106 of the present embodiment causes the first water heater 41 to operate from 8:00, the second water heater 42 to operate from 9:00, and the third water heater 43 to operate from 13:00.

At 11:00, the number of water heaters 40 that can be operated using the surplus power is one, whereas two water heaters 40 (the first water heater 41 and the second water heater 42) are operated. Surplus power is insufficient at the time of day. Therefore, at this time, the power stored in the storage battery 12 or the like or the power from the system power source K will compensate for the shortage of power.

Here, in the example of FIG. 11A, from 13:00 to 15:00, two water heaters 40 can be operated using the surplus power, whereas one water heater 40 (second Only three water heaters 43) are to be operated. Therefore, if the operation of the second water heater 42 is started at 13:00 instead of 9:00, it can be understood that the second water heater 42 can be operated with only the surplus electric power.

Therefore, as shown in FIG. 11(b), the operation time of the second water heater 42 may be allocated so that the operation of the second water heater 42 starts at 13:00 instead of 9:00. In this way, the water heater 40 having a high hot water bath ranking does not necessarily have to start operating at an early time, and can be operated at a time when surplus power can be used more effectively. However, in this case as well, it is desirable that the water heaters 40 do not run out of hot water.

It should be noted that such processing (processing for effectively utilizing surplus power) can be performed together with the above-described processing of step S106, for example. In addition, both an operation schedule determined from the viewpoint of starting operation of the water heater 40 having a high priority at an early time and an operation schedule determined from the viewpoint of effective use of surplus power are created, and one of them is arbitrarily selected. (For example, a resident of each house or the like can select).

1 power supply system 11.21.31 solar power generation unit 40 water heater 60 EMS

Claims (5)

a power generation unit capable of generating power and supplying power to a power load;
a plurality of water heaters capable of producing hot water using electric power unlike the electric power load, storing the hot water, and supplying the hot water to the hot water supply load;
Predicting the power demand of the power load and the amount of power generated by the power generation unit for each predetermined time period,
calculating the surplus power in each time period based on the predicted power demand and the power generation amount;
calculating the number of water heaters that can be operated by the predicted surplus power for each time period;
a control unit that determines an operation schedule of the water heater based on the calculated number of units;
A system comprising The control unit
Determining the priority of operation of the water heater, and determining the operation schedule so that the water heater with the higher priority starts operating in an earlier time zone;
The system of claim 1. The control unit
predicting the hot water supply demand of the hot water supply load for each of the predetermined time periods;
Among the plurality of water heaters, the priority is determined so that the water heater for which the integrated amount of hot water supply demand of the hot water supply load for supplying hot water reaches a predetermined value earlier has the higher priority. ,
3. The system of claim 2. The control unit
predicting the hot water supply demand of the hot water supply load for each of the predetermined time periods;
calculating the required operating time of the water heater necessary to produce hot water that satisfies the hot water supply demand in a predetermined period;
determining the priority so that the water heater with the longer required operating time has the higher priority;
3. The system of claim 2. The control unit
predicting the remaining amount of hot water stored in the water heater for each predetermined time period based on the determined operating schedule;
If the remaining amount falls below a predetermined value in any of the predetermined time periods, the operation schedule is corrected so that the water heater starts operating in an earlier time period.
System according to any one of claims 1 to 4.

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