JP7511371B2 - Power Supply System - Google Patents

Description

The present invention relates to technology for a power supply system having a water heater.

Technology for power supply systems with water heaters has been publicly known. For example, see Patent Document 1.

Patent document 1 describes a power supply system that includes a solar power generation unit that can generate power using natural energy, a power storage device that can charge and discharge power, and a water heater that consumes power to generate and store heat.

In the power supply system, when surplus power occurs (power generated in the solar power generation unit minus power charged to the power storage device and power consumed by the power load), the system is configured to operate the water heater to consume the surplus power. This configuration allows for effective use of surplus power.

However, the technology described in Patent Document 1 relates to a method of operating a power supply system when there is no power outage (normal times), and does not propose a method of operation during a power outage.

JP 2011-41380 A

The present invention was made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a power supply system that can operate a water heater appropriately during a power outage.

The problem that the present invention aims to solve is as described above, and the means for solving this problem will be explained next.

That is, in claim 1, a power supply system that supplies power to a power load includes a power generation unit capable of generating power using natural energy, a water heater that operates by receiving a supply of power, and a control unit that can control the operation of the water heater , wherein the power load includes a first power load consisting of a plurality of devices that can be controlled at any time, and a second power load consisting of a plurality of devices that can be controlled collectively, and the first power load includes the water heater and a device other than the water heater, and the control unit is capable of executing a surplus power prediction process that predicts whether or not surplus power will be generated by the power generation unit during a power outage, and an operation process that operates the water heater only when it is predicted that surplus power will be generated by the power generation unit, and during the operation process, it is determined whether surplus power will be generated by the power generation unit during a reduction process that gradually reduces the power supplied to the device other than the water heater among the first power loads within a range in which the device is operable, or after a collective stop process that collectively stops the supply of power to the second power load after the reduction process is completed .

In claim 2, the control unit operates the water heater during the operation process only when the surplus power of the power generation unit is greater than the power consumption of the water heater.

In claim 3, the power generation unit further includes a storage battery capable of charging and discharging power from the power generation unit, and the control unit calculates the surplus power of the power generation unit by subtracting the power consumption of the power load and the charging power of the storage battery from the power generated by the power generation unit.

In claim 4, the control unit is capable of executing a notification process to notify the user that the power load can be used when the remaining charge in the storage battery during a power outage is greater than at least the power consumption of the power load.

In claim 5, the control unit notifies the user that the power load can be used only when the sum of the discharge remaining output indicating the output margin of the storage battery and the surplus power of the power generation unit is greater than the power consumption of the power load during the notification process.

The effects of the present invention are as follows:

In claim 1, the water heater can be operated appropriately during a power outage.

In claim 2, the water heater can be operated using only surplus electricity.

In claim 3, an appropriate surplus power value can be calculated.

In claim 4, convenience during power outages can be improved.

In claim 5, a notification can be issued only when the power load can be used reliably.

1 is a block diagram showing a configuration of a power supply system according to an embodiment of the present invention; FIG. 2 is a diagram showing the connection relationship of an EMS. FIG. 2 is a diagram showing an example of a power supply mode during normal operation (when no power outage occurs). FIG. 1 is a diagram showing an example of a power supply mode during a power outage. A diagram showing a list of loads. FIG. 4 is a flowchart showing control during a power outage. FIG. 7 is a diagram showing a continuation of the flowchart in FIG. 6 . FIG. 8 is a diagram showing a continuation of the flowchart in FIG. 7 . FIG. 13 is a diagram showing a specific example of a stage in which electricity demand, etc. is predicted. 1A is a diagram showing a specific example of a stage where power consumption has been reduced, and FIG. 1B is a diagram showing a specific example of a stage where power consumption has been increased. 13A is a diagram showing a specific example of a stage where power consumption is further increased, and FIG. 13B is a diagram showing a specific example of a stage where it is decided to operate the water heater.

The following describes a power supply system 1 according to one embodiment of the present invention with reference to FIG. 1. In this specification, the terms "upstream side" and "downstream side" refer to the direction of power supply from the power grid K.

The power supply system 1 shown in FIG. 1 supplies power from a power grid K or generated power to a load (power load). The power supply system 1 is installed in a house and supplies power to the load of the house (e.g., appliances in the house, etc.). The power supply system 1 mainly comprises a distribution board 10, a general circuit 20, an important circuit 30, a most important circuit 40, a storage system 50, a specific circuit 60, a relay 70, and an EMS 80.

The distribution board 10 distributes power supplied from a power supply source (a power grid K or a power storage system 50 described later) to loads. The distribution board 10 is connected to the power grid K via a power distribution line L1. The distribution board 10 is connected to various loads provided in the house. Specifically, the distribution board 10 is connected to a load (not shown) of the house via a general circuit 20 described later. The distribution board 10 is also connected to a load of the house (such as a television in this embodiment) via a hybrid power conditioner 53, a specific circuit 60, and an important circuit 30 described later. The distribution board 10 is also connected to a load of the house (such as a refrigerator in this embodiment) via a hybrid power conditioner 53, a specific circuit 60, and an important circuit 40 described later.

The general circuit 20 supplies the supplied power to loads installed in the house. The general circuit 20 is connected to the distribution board 10.

The important circuit 30 supplies the supplied power to the loads installed in the house. The important circuit 30 is connected to the distribution board 10 via the hybrid power conditioner 53 and the specific circuit 60.

The most important circuit 40 supplies the supplied power to the loads installed in the house. The most important circuit 40 is connected to the distribution board 10 via the hybrid power conditioner 53 and the specific circuit 60.

Here, the general circuit 20, the important circuit 30, and the most important circuit 40 are connected to different loads. That is, the general circuit 20, the important circuit 30, and the most important circuit 40 supply power to different loads. Specifically, the important circuit 30 and the most important circuit 40 are connected to relatively important loads (specifically, loads to which it is preferable to supply power even during a power outage). The most important circuit 40 is connected to loads that are even more important than the important circuit 30 (specifically, loads to which it is necessary to supply power even during a power outage). The general circuit 20 is connected to other loads (specifically, loads to which it is less necessary to supply power during a power outage).

In this embodiment, as an example, the important circuit 30 is connected to a television 31, a charger 32, a microwave oven 33, a rice cooker 34, and a washing machine 35. The most important circuit 40 is connected to a refrigerator 41, a light 42, an air conditioner 43, and a water heater 44 (heat pump water heater). The general circuit 20 is connected to other loads.

In this embodiment, for convenience, the loads connected to the general circuit 20, the important circuit 30, and the most important circuit 40 may be referred to as "general loads," "important loads," and "most important loads," respectively.

The power storage system 50 stores power and supplies it to a load. The power storage system 50 includes a solar power generation unit 51, a storage battery 52, and a hybrid power conditioner 53.

The solar power generation unit 51 is a device that generates power using sunlight. The solar power generation unit 51 is composed of a solar cell panel, etc. The solar power generation unit 51 is installed in a sunny location, such as on the roof of a house.

The storage battery 52 is configured to be able to charge power. The storage battery 52 is, for example, a lithium ion battery. The storage battery 52 is connected to the solar power generation unit 51 via the hybrid power conditioner 53 described below.

The hybrid power conditioner 53 is a device that appropriately converts power (hybrid power conditioner). The hybrid power conditioner 53 is configured to be able to output the power generated by the solar power generation unit 51 and the power discharged from the storage battery 52 to the distribution board 10 and a specific circuit 60 described later, and to output the power from the distribution board 10 to the storage battery 52. The hybrid power conditioner 53 is also configured to be able to acquire information regarding the performance and operating state of the solar power generation unit 51 and the storage battery 52. The hybrid power conditioner 53 is connected to the distribution board 10 via the distribution line L2 and the distribution line L3. The hybrid power conditioner 53 of the storage system 50 can perform load following operation that can adjust the power discharged (output) according to the power consumption of the load based on the detection results of a power sensor (not shown) and the like.

The specific circuit 60 supplies the supplied power to the important circuit 30 and the most important circuit 40. The specific circuit 60 is connected to the hybrid power conditioner 53 via the distribution line L4. The specific circuit 60 is also connected to the important circuit 30 via the distribution line L5. The specific circuit 60 is also connected to the most important circuit 40 via the distribution line L6.

The relay 70 switches whether or not power is allowed to flow through the power distribution line L5. The relay 70 is provided in the middle of the power distribution line L5. The relay 70 can switch ON/OFF (open/close) based on a control signal from the outside.

The EMS 80 shown in FIG. 2 is an energy management system that manages the operation of the power supply system 1. The EMS 80 includes an arithmetic processing unit such as a CPU, a storage unit such as a RAM or ROM, and an input/output unit such as a touch panel. The storage unit of the EMS 80 stores in advance various information and programs used to control the operation of the power supply system 1. The arithmetic processing unit of the EMS 80 can operate the power supply system 1 by executing the programs and performing predetermined arithmetic processing using the various information.

The EMS 80 is electrically connected to the hybrid power conditioner 53. The EMS 80 is configured to be able to input a specific signal from the hybrid power conditioner 53, and can acquire various information related to the solar power generation unit 51 and the storage battery 52.

The EMS 80 is also electrically connected to the relay 70 and can control the operation of the relay 70.

The EMS 80 is also electrically connected to the lighting 42, air conditioner 43, and water heater 44 of the most important circuit 40, and can control the operation of the lighting 42, air conditioner 43, and water heater 44.

Next, an overview of the power supply mode of the power supply system 1 will be described with reference to Figures 3 and 4.

As shown in FIG. 3, during normal operation (non-power outage), the hybrid power conditioner 53 supplies power generated by the solar power generation unit 51 to the distribution board 10 via the distribution line L2. The power is supplied to the general circuit 20 in response to requests from general loads. The power is also supplied to the important circuit 30 and the most important circuit 40 via the distribution line L3, the hybrid power conditioner 53, the distribution line L4, the specific circuit 60, etc. in response to requests from important and most important loads. Thus, in this embodiment, during normal operation, the power from the hybrid power conditioner 53 is first supplied to the general circuit 20 and the specific circuit 60 via the distribution board 10 (bypassed).

The storage battery 52 also performs load following operation according to the detection results of the power sensor (not shown). For example, if the power generated by the solar power generation unit 51 is not enough to cover the power consumption of the loads, the power discharged from the storage battery 52 is supplied to each load. If the power from the solar power generation unit 51 and the storage battery 52 is not enough to cover the power consumption of the loads, power is purchased (purchased) from the system power source K.

In addition, in FIG. 3, as an example, the arrows show the flow of power when the power from the solar power generation unit 51 and the storage battery 52 alone cannot cover the power consumption of the load, but for example, when the power from the solar power generation unit 51 is in excess of the power consumption of the load (when surplus power is generated), the surplus power can be charged to the storage battery 52 by the load following operation of the storage battery 52. Also, in addition to the surplus power, the storage battery 52 can also be charged with power (relatively inexpensive power) from the system power source K during late night hours.

As shown in FIG. 4, when the hybrid power conditioner 53 detects a power outage, it outputs the power from the solar power generation unit 51 and the storage battery 52 to the specific circuit 60 via the distribution line L4, not to the distribution board 10. Specifically, the hybrid power conditioner 53 supplies the power generated by the solar power generation unit 51 to the specific circuit 60 via the distribution line L4. The power is supplied to the important circuit 30 and the most important circuit 40 (the important load and the most important load) via the distribution line L5 and the distribution line L6, respectively. In addition, when the power from the solar power generation unit 51 is not enough to cover the power consumption of the important load and the most important load, the storage battery 52 discharges, and the power from the storage battery 52 is supplied to the specific circuit 60 (and thus the important load and the most important load) via the distribution line L4. In addition, when the power from the solar power generation unit 51 is surplus to the important load and the most important load, the surplus power can be charged to the storage battery 52.

In this way, during a power outage, the hybrid power conditioner 53 supplies power from the solar power generation unit 51 and the storage battery 52 to the specific circuit 60 (and thus to the important circuit 30 and the most important circuit 40) without bypassing it. This allows the power supply system 1 to make the solar power generation unit 51 and the storage battery 52 function as emergency power sources during a power outage and supply power to some loads (important loads and most important loads) excluding general loads.

As described above, during a power outage, power can be supplied only to some loads (important loads and the most important loads), thereby conserving limited power (specifically, power from the solar power generation unit 51 and the storage battery 52).

As described above, the system is configured to conserve power consumption by limiting the supply of power to certain loads (important and most important loads) during a power outage. However, if unlimited power is consumed by these loads, there is a concern that the limited power will be consumed in a short period of time, and then power will no longer be supplied (power will no longer be usable).

Therefore, in this embodiment, the EMS 80 performs control (hereinafter referred to as "power outage control") to maintain the supply of power to the load during a power outage while improving convenience.

The details of the power outage control are explained in detail below using Figures 5 to 8.

First, using Figure 5, we will explain in detail the loads whose operation (ON/OFF, etc.) is controlled during power outage control.

As shown in FIG. 5, in the power outage control, the most important load and important loads to which power may be supplied during a power outage are the control targets. As described above, the most important loads (refrigerator 41, lighting 42, air conditioner 43, and water heater 44) are connected to the most important circuit 40. The important loads (television 31, charger 32, microwave oven 33, rice cooker 34, and washing machine 35) are connected to the important circuit 30 (see FIG. 1). Here, a relay 70 is provided on the distribution line L5 connecting the specific circuit 60 and the important circuit 30. Therefore, by controlling the operation of the relay 70, the important circuit 30 can be disconnected at any time. In other words, the supply of power to the important loads can be cut off all at once at any time.

In addition, as shown in FIG. 5, the most important loads, lighting 42, air conditioner 43, and water heater 44, can be controlled to be turned on/off at any time.

As shown in FIG. 5, the service levels of the lighting 42 and the air conditioner 43 can be adjusted as desired. Specifically, the illuminance of the lighting 42 can be adjusted as desired. In this embodiment, the illuminance of the lighting 42 can be adjusted to five levels, from 1 to 5. Note that in this embodiment, the lighting 42 is not controlled to 0 (OFF).

The air conditioner 43 can also adjust the set temperature as desired. In this embodiment, the set temperature of the air conditioner 43 can be adjusted to six levels, from 0 (=OFF) to 5. Note that the maximum set temperature of the air conditioner 43 (=5) in this embodiment means that the set temperature is the temperature that has been set in advance by the user of the air conditioner 43 (such as a resident of the house). In other words, in this embodiment, the set temperature of the air conditioner 43 can be adjusted to six levels, from the temperature set by the user, gradually lowering the output until it is finally turned OFF.

As shown in FIG. 5, important loads (television 31, charger 32, microwave oven 33, rice cooker 34, and washing machine 35) are the targets of "notifications." "Notifications" are used to notify users (residents of a home, etc.) of loads (appliances) that are recommended to be operated. The processing related to such "notifications" will be explained together with the processing of step S35 described below.

Next, the flow (flowchart) of power outage control will be described using Figures 6 to 8. Note that power outage control is executed repeatedly (e.g., every few minutes) by EMS 80 when a power outage occurs. By executing power outage control, EMS 80 predicts power demand and power generation, and controls the operation of the load connected to the specific circuit 60 based on the prediction results. A specific description will be given below.

In step S10, EMS 80 determines whether or not it is possible to acquire external information by any method (for example, via various communication means (such as the Internet)). Here, external information refers to various types of information that can be used when predicting the amount of power generation, etc., in step S12, which will be described later. External information includes, for example, information such as the latest weather forecast. If EMS 80 determines that it is possible to acquire external information ("YES" in step S10), it proceeds to step S11. On the other hand, if EMS 80 determines that it is not possible to acquire external information ("NO" in step S10), it proceeds to step S13.

In step S11, the EMS 80 acquires external information. In this process, the EMS 80 acquires information (such as a weather forecast) for making the prediction in step S12, which will be described later, by any method. For example, when acquiring information about a weather forecast, the EMS 80 can acquire a weather forecast from the current time to any time. For example, the EMS 80 acquires a weather forecast from the current time to the end of the period (hereinafter referred to as the "planned period") that is the subject of the operation plan of the power supply system 1 (for example, until the time when the generation of surplus power ends on the next day). The EMS 80 can also acquire a weather forecast for an even longer period (as long as possible). In addition to the weather forecast, the external information can include data on the past power generation by the solar power generation unit 51, data on the past power purchases, etc. After performing the process of step S11, the EMS 80 proceeds to step S12.

In step S12, EMS 80 predicts the power demand and power generation (power generation) from the present to the end of the planned period. In this process, EMS 80 makes the prediction based on information such as the weather forecast acquired in step S11, and various information it has in advance (data on past power generation, data on past power purchases, etc.). EMS 80 also predicts power demand, etc. for each time (every hour).

Here, the EMS 80 predicts the power demand separately for the important circuits 30 and the most important circuits 40. More specifically, it predicts the power demand of the important loads (such as the television 31) and the most important loads (such as the refrigerator 41) separately. In addition, as will be described in detail later, the power demand of the water heater 44 is not predicted at this time because the water heater 44 is operated only in specific cases (power demand is predicted assuming that the water heater 44 is not operated).

After performing the processing of step S12, EMS80 proceeds to step S13.

In step S13, EMS 80 predicts (calculates) the remaining amount of stored power (remaining amount of storage battery 52) at each time based on the prediction result in step S12. At this time, EMS 80 calculates the remaining amount of stored power, assuming that power will be supplied in the order of generated power from solar power generation unit 51 and discharged power from storage battery 52 in response to power demand. EMS 80 also calculates the remaining amount of stored power, assuming that the surplus of power (surplus power) generated by solar power generation unit 51 is charged to storage battery 52. EMS 80 calculates the SOC (charging rate (%)) as the remaining amount of stored power. After performing the process of step S13, EMS 80 proceeds to step S14.

In step S14, EMS 80 determines whether the minimum value of the predicted remaining amount of stored power is less than a predetermined threshold value α. Specifically, EMS 80 determines whether the minimum value of the predicted remaining amount of stored power at each time is less than threshold value α (e.g., 10%). The threshold value α is a value that is set to ensure a minimum amount of power in storage battery 52, and can be set arbitrarily.

If EMS 80 determines that the predicted minimum remaining charge will be less than threshold value α (YES in step S14), it proceeds to step S15. After the transition, EMS 80 processes steps S15 to S20 to reduce power demand in order to maintain the amount of charge stored in storage battery 52. On the other hand, if EMS 80 determines that the predicted minimum remaining charge will not be less than threshold value α (NO in step S14), it proceeds to step S21 (see FIG. 7). After the transition, EMS 80 processes steps S21 to S27 to improve the convenience and comfort of residents.

In step S15, EMS 80 determines whether the current service level of air conditioner 43 is greater than 0. If EMS 80 determines that the current service level of air conditioner 43 is greater than 0 ("YES" in step S15), it proceeds to step S16. On the other hand, if EMS 80 determines that the current service level of air conditioner 43 is 0 ("NO" in step S15), it proceeds to step S17.

In step S16, the EMS 80 lowers the service level of the air conditioner 43 by one. For example, if the current service level of the air conditioner 43 is "3", the service level is lowered to "2". This reduces the power consumption of the air conditioner 43. After performing the process of step S16, the EMS 80 returns to the process of step S11.

Meanwhile, in step S17 to which the process proceeds from step S15, the EMS 80 determines whether the current service level of the light 42 is greater than 1. If the EMS 80 determines that the current service level of the light 42 is greater than 1 ("YES" in step S17), the process proceeds to step S18. On the other hand, if the EMS 80 determines that the current service level of the light 42 is 1 or less ("NO" in step S17), the process proceeds to step S19.

In step S18, EMS 80 lowers the service level of lighting 42 by one. For example, if the current service level of lighting 42 is "3", the service level is lowered to "2". This reduces the power consumption of lighting 42. Note that since the processing of step S18 is performed via the judgment of step S17, EMS 80 does not lower the service level of lighting 42 to "0". After performing the processing of step S18, EMS 80 returns to the processing of step S11 again.

On the other hand, in step S19, which is transitioned from step S17, the EMS 80 determines whether the important circuit 30 is connected to the specific circuit 60. Specifically, the EMS 80 determines whether the relay 70 is ON (closed) and whether power can be supplied from the specific circuit 60 to the important circuit 30. If the EMS 80 determines that the important circuit 30 is connected to the specific circuit 60 ("YES" in step S19), it transitions to step S20. On the other hand, if the EMS 80 determines that the important circuit 30 is not connected to the specific circuit 60 (disconnected) ("NO" in step S19), it transitions to step S28 (see FIG. 8).

In step S20, the EMS 80 disconnects the important circuit 30. Specifically, the EMS 80 switches the relay 70 to OFF (open) to cut off the supply of power from the specific circuit 60 to the important circuit 30. After performing the process of step S20, the EMS 80 returns to the process of step S11.

Meanwhile, in step S21 (see FIG. 7) to which the process proceeds from step S14, the EMS 80 determines whether the important circuit 30 is disconnected from the specific circuit 60. Specifically, the EMS 80 determines whether the relay 70 is in the OFF (open) state and the supply of power from the specific circuit 60 to the important circuit 30 is cut off. If the EMS 80 determines that the important circuit 30 is disconnected from the specific circuit 60 ("YES" in step S21), the process proceeds to step S22. On the other hand, if the EMS 80 determines that the important circuit 30 is not disconnected from the specific circuit 60 ("NO" in step S21), the process proceeds to step S23.

In step S22, the EMS 80 connects the important circuit 30. Specifically, the EMS 80 switches the relay 70 ON (closed) to enable power to be supplied from the specific circuit 60 to the important circuit 30. After performing the process of step S22, the EMS 80 returns to the process of step S11 (see FIG. 6).

On the other hand, in step S23, which is entered from step S21, EMS 80 determines whether the current service level of lighting 42 is less than 5 (maximum). If EMS 80 determines that the current service level of lighting 42 is less than 5 ("YES" in step S23), it proceeds to step S24. On the other hand, if EMS 80 determines that the current service level of lighting 42 is 5 (maximum) ("NO" in step S23), it proceeds to step S25.

In step S24, EMS 80 raises the service level of lighting 42 by one. For example, if the current service level of lighting 42 is "3," the service level is raised to "4." This improves the convenience and comfort of the occupants. After performing the processing of step S24, EMS 80 returns to the processing of step S11 (see FIG. 6).

On the other hand, in step S25, which is entered from step S23, EMS 80 determines whether the minimum value of the predicted remaining charge is greater than a predetermined threshold value β. Specifically, EMS 80 determines whether the minimum value of the predicted remaining charge at each time is greater than threshold value β (e.g., 30%). The threshold value β is a value that is set to determine whether the remaining charge of storage battery 52 has some margin, and can be set arbitrarily to a value greater than threshold value α (see step S14, etc.).

If EMS80 determines that the minimum value of the predicted remaining battery charge is greater than threshold value β ("YES" in step S25), it proceeds to step S26. On the other hand, if EMS80 determines that the minimum value of the predicted remaining battery charge is equal to or less than threshold value β ("NO" in step S25), it proceeds to step S28 (see FIG. 8).

In step S26, the EMS 80 determines whether the current service level of the air conditioner 43 is less than 5 (maximum). If the EMS 80 determines that the current service level of the air conditioner 43 is less than 5 ("YES" in step S26), it proceeds to step S27. On the other hand, if the EMS 80 determines that the current service level of the air conditioner 43 is 5 (maximum) ("NO" in step S26), it proceeds to step S28 (see FIG. 8).

In step S27, the EMS 80 increases the service level of the air conditioner 43 by one. For example, if the current service level of the air conditioner 43 is "3," the service level is increased to "4." This can improve the convenience and comfort of the occupants. After performing the processing of step S27, the EMS 80 proceeds to step S28 (see FIG. 8).

Meanwhile, in step S28 (see FIG. 8) to which the process proceeds from step S19, etc., the EMS 80 determines whether or not surplus power will be generated over the entire planning period. Specifically, the EMS 80 determines whether or not a surplus will be generated even after the power from the solar power generation unit 51 is supplied to the load and the storage battery 52 is charged over the entire planning period. If the EMS 80 determines that surplus power will be generated over the entire planning period ("YES" in step S28), it proceeds to step S29. On the other hand, if the EMS 80 determines that surplus power will not be generated over the entire planning period ("NO" in step S28), it proceeds to step S32.

In step S29, the EMS 80 determines whether the water heater 44 is OFF (stopped). If the EMS 80 determines that the water heater 44 is OFF (YES in step S29), the process proceeds to step S30. On the other hand, if the EMS 80 determines that the water heater 44 is ON (NO in step S29), the process proceeds to step S33.

In step S30, EMS 80 determines whether the instantaneous surplus power is greater than the hot water power consumption. Here, "instantaneous surplus power" is the current surplus power value. Also, "hot water power consumption" is the power consumption required to operate the water heater 44. That is, in step S30, EMS 80 determines whether it is possible to operate the water heater 44 with the current surplus power.

Generally, when surplus power occurs, the output (output of surplus power) is suppressed by the hybrid power conditioner 53, so even if the power output from the hybrid power conditioner 53 is detected, it is difficult to grasp the actual surplus power. Therefore, it is necessary to grasp the surplus power (instantaneous surplus power) by other methods. In this embodiment, it is assumed that instantaneous surplus power is occurring when the charge amount of the storage battery 52 matches the charging capacity (maximum value), and the instantaneous surplus power is calculated using the formula "instantaneous surplus power = predicted power generation amount - power consumption - charging power".

If EMS80 determines that the instantaneous surplus power is greater than the hot water power consumption ("YES" in step S30), it proceeds to step S31. On the other hand, if EMS80 determines that the instantaneous surplus power is less than or equal to the hot water power consumption ("NO" in step S30), it proceeds to step S32.

In step S31, the EMS 80 turns on (operates) the water heater 44. After performing the process of step S31, the EMS 80 proceeds to step S33.

Meanwhile, in step S32, which is entered from step S28 etc., the EMS 80 turns off (stops) the water heater 44. After performing the process of step S32, the EMS 80 proceeds to step S33.

In step S33, the EMS 80 determines whether the minimum value of the predicted remaining power storage is greater than "the power consumption of each device + the threshold value α." Here, "the power consumption of each device" refers to the power consumption per operation or per hour of the devices that correspond to important loads (i.e., in this embodiment, the television 31, the charger 32, the microwave oven 33, the rice cooker 34, and the washing machine 35). For example, for devices that are expected to operate continuously for a period of time selected by the resident (in this embodiment, the television 31 or the charger 32), it means the power consumption per hour. Also, for devices that are expected to have a limited operation time (in this embodiment, the microwave oven 33, the rice cooker 34, and the washing machine 35), it means the power consumption per operation.

Here, the fact that the predicted minimum remaining amount of power is greater than "power consumption of each device + threshold value α" means that even if an important load (such as the television 31) is operated, it is expected that the minimum remaining amount of power in the storage battery 52 will not become extremely small (will be greater than or equal to threshold value α). Note that the determination in step S33 can also be made without using threshold value α (for example, threshold value α = 0). In other words, in step S33, it can also be determined whether the minimum remaining amount of power is greater than at least the power consumption of each device. However, from the perspective of ensuring the remaining amount of power, it is desirable to set threshold value α > 0.

EMS80 performs a judgment for each device (i.e., for each of the televisions 31, etc.) in this step S33 and in step S34 described later. If EMS80 judges that the predicted minimum remaining amount of power is greater than "the power consumption of each device + threshold value α" ("YES" in step S33), it proceeds to step S34. On the other hand, if EMS80 judges that the predicted minimum remaining amount of power is equal to or less than "the power consumption of each device + threshold value α" ("NO" in step S33), it ends this control (control during a power outage).

In step S34, EMS 80 determines whether "remaining discharge power + surplus power" is greater than the power consumption of each device at the current time. Here, "remaining discharge power" means how much the output of storage battery 52 can be increased ("maximum output - current output", i.e., the output margin of storage battery 52). Here, the fact that "remaining discharge power + surplus power" is greater than the power consumption of each device at the current time means that there is enough power available to operate important loads (such as television 31).

If EMS80 determines that the "discharge remaining power + surplus power" at the current time is greater than the power consumption of each device ("YES" in step S34), it proceeds to step S35. On the other hand, if EMS80 determines that the "discharge remaining power + surplus power" at the current time is less than or equal to the power consumption of each device ("NO" in step S34), it ends this control (control during a power outage).

In step S35, EMS 80 issues a notification recommending operation of the relevant equipment (important load that can be operated). Specifically, for important loads for which the answer is YES in steps S33 and S34, EMS 80 issues a notification to the resident recommending operation of the important load (equipment) because there is enough power to operate the important load. The resident who receives the notification can operate the relevant equipment and use it.

As a method of notification by EMS80, it is possible to display a specified image or text on the EMS80 itself (touch panel), or to notify using a separate device for notification (liquid crystal panel, speaker, etc.).

After performing the processing of step S35, EMS80 ends this control (control during a power outage).

As described above, the EMS 80 predicts the remaining power storage capacity (steps S10 to S13 in FIG. 6), and if it determines that there is no room for power storage capacity (YES in step S14), it reduces the service level of the air conditioner 43 and the lights 42 to reduce power consumption (steps S15 to S18). If power consumption reduction is still insufficient, it disconnects the entire important circuit 30 to reduce power consumption (steps S19 and S20).

If the EMS 80 determines that there is a certain amount of remaining power storage (NO in step S14), it connects the important circuits 30 and improves the service levels of the lighting 42 and air conditioner 43 as much as possible (steps S21 to S27 in Figure 7).

In addition, if the EMS 80 can operate the water heater 44 using surplus power, it operates the water heater 44 (steps S28 to S32 in FIG. 8). Furthermore, if the EMS 80 can operate an important load, it notifies the resident of this fact (steps S33 to S35 in FIG. 8).

Below, a specific example of a case where control during a power outage is actually performed is shown. Note that Figs. 9 to 11 show the power consumption of each load, the power generated (PV) of the solar power generation unit 51, and the remaining charge (SOC) of the storage battery 52 at each time during a specified planning period. Also, in Figs. 9 to 11, the current time (the time when the process for control during a power outage is being executed) is indicated by a triangular symbol.

First, as shown in FIG. 9, the power demand, power generation amount, remaining battery charge, etc. are predicted (steps S10 to S13). In the illustrated example, the minimum remaining battery charge is 0, so it is determined that the remaining battery charge will be less than a predetermined threshold value α (YES in step S14), and power consumption is reduced (steps S15 to S20).

Figure 10(a) shows a state in which power consumption has been reduced. Specifically, the example shows a state in which the service level of the air conditioner 43 has been lowered to "0" (steps S15, S16), the service level of the lighting 42 has been lowered to "1" (steps S17, S18), and the important circuit 30 has been disconnected (steps S19, S20). By reducing power consumption in this way, the minimum remaining amount of power storage increases. In the example, it is assumed that the minimum remaining amount of power storage has increased to or above threshold value α ("NO" in step S14).

Figure 10(b) shows a state in which power consumption has been increased as a result of the minimum remaining charge increasing above threshold value α. Specifically, it shows a state in which important circuit 30 is connected (steps S21 and S22) and the service level of lighting 42 is increased (steps S23 and S24). Figure 11(a) shows a state in which the service level of air conditioner 43 is further increased (steps S26 and S27).

Figure 11 (b) shows the state in which the water heater 44 is operated in response to the generation of surplus power (steps S28 to S31). In the example shown, after 8:00, sufficient power is stored, so a notification is issued recommending the use of each appliance (steps S33 to S35).

As described above, in the power supply system 1 according to this embodiment, when a power outage occurs, the above-mentioned power outage control is performed, and power can be supplied to the load as much as possible while suppressing power consumption based on predictions of the remaining power storage amount, etc. This makes it possible to maintain the supply of power to the load during a power outage (ensuring the remaining power storage amount) while improving convenience.

As described above, the power supply system 1 according to this embodiment has the following features:
A storage battery 52 capable of charging and discharging electric power;
An EMS 80 (control unit) capable of controlling the operation of a plurality of power loads that operate by receiving power from the storage battery 52;
Equipped with
The EMS 80 is
A process for predicting the remaining charge of the storage battery 52 during a power outage (steps S10 to S13);
When it is predicted that the remaining charge of the storage battery 52 will be less than a first threshold (threshold α), a suppression process (steps S14 to S18) is performed to suppress the power consumption of a first power load (the most important load of the most important circuit 40) belonging to a first group among the multiple power loads;
It is possible to do so.

This configuration makes it possible to maintain the supply of power to the power loads while improving convenience. In other words, by suppressing the power consumption of the most important load only when it is predicted that the remaining charge in the storage battery 52 will fall below the threshold value α, it is possible to maintain the supply of power to the power loads while improving convenience as much as possible.

In particular, in this embodiment, a load (air conditioner 43) that can reduce the service level to 0 (OFF) and a load (lighting 42) that does not reduce the service level to 0 (OFF) are set. In this way, by setting a load that does not reduce the service level to 0 (OFF) even if power consumption is suppressed, it is possible to further improve convenience.

In addition, the EMS 80 is
The power consumption of the first power loads (particularly, the lighting 42 and the air conditioner 43) belonging to the first group is individually predicted (step S12);
In the suppression process, the power consumption of the first power loads is individually suppressed (steps S14 to S18).

This configuration makes it possible to more appropriately maintain the supply of power to the power loads while improving convenience. In other words, by individually suppressing the most important loads, it is possible to maintain the supply of power to the power loads while continuing to use the most important loads as much as possible.

Furthermore, the first power load to be suppressed can be selected according to the individually predicted power consumption of the first power load. For example, the power consumption of the first power loads can be individually predicted, and the power consumption of the first power load with the highest power consumption can be suppressed preferentially. This makes it possible to effectively suppress power consumption. It is also possible to suppress the power consumption of the first power load with the lowest power consumption preferentially. This makes it possible to suppress the power consumption of first power loads (first power loads with low power consumption) that are not likely to be used, while maintaining the power consumption of first power loads (first power loads with high power consumption) that are likely to be used frequently, thereby improving convenience.

In addition, the EMS 80 is
When it is predicted that the remaining charge of the storage battery 52 will be less than the first threshold, a shutdown process (steps S19, S20) can be executed to stop operation of a second power load (an important load of the important circuit 30) among the multiple power loads, which belongs to a second group different from the first group.

This configuration makes it possible to maintain the supply of power to the power loads while improving convenience. In other words, by stopping only the important loads connected to the important circuit 30, it is possible to maintain the supply of power to the power loads while continuing to use the most important loads and improving convenience.

In addition, the EMS 80 is
In the shutdown process, the operation of the second power load is stopped by disconnecting the second power load using a relay 70 provided in the middle of the power distribution line L5 that supplies power to the second power load.

By configuring it in this way, there is no need to control the second power load (important load) individually, which simplifies processing.

In addition, the EMS 80 is
The suppression process is executed with priority over the stop process.

This configuration can improve convenience. In other words, by controlling important loads so as not to stop them as much as possible, residents can use the important loads, improving convenience.

In addition, the EMS 80 is
The remaining charge prediction process, the suppression process, and the stop process are repeatedly executed a plurality of times.

By configuring it in this way, it is possible to perform appropriate processing. In other words, by performing prediction again while controlling the operation of the power load, it is possible to perform processing that is appropriate to the current situation.

In addition, the EMS 80 is
When it is predicted that the remaining charge of the storage battery 52 will be equal to or greater than a second threshold (threshold α) which is set to a value equal to or greater than the first threshold, an operation process (steps S21, S22) can be executed to operate the second power load which has been stopped.

This configuration makes it possible to maintain the supply of power to the power loads while improving convenience. In other words, when it is determined that the supply of power to the power loads can be maintained, convenience can also be improved by operating the important loads.

In addition, the EMS 80 is
When it is predicted that the remaining amount of stored power in the storage battery 52 will be equal to or greater than the second threshold, an increase process (steps S23 to S27) for increasing the power consumption of the first power load can be executed.

This configuration makes it possible to maintain the supply of power to the power loads while improving convenience. In other words, when it is determined that the supply of power to the power loads can be maintained, the power consumption of the most important load is increased, thereby improving the convenience (comfort) of, for example, the lighting 42 and the air conditioner 43.

In addition, the EMS 80 is
The operation process is executed with priority over the increase process.

By configuring in this way, it is possible to improve convenience. In other words, by controlling the restart of stopped important loads to be prioritized, residents can use the important loads, thereby improving convenience.

In addition, the power supply system 1 includes:
The vehicle further includes a solar power generation unit 51 (power generation unit) capable of generating power using natural energy,
The EMS 80 is
A surplus power prediction process (steps S28 to S30) for predicting whether or not surplus power is generated by the solar power generation unit 51;
A specific operation process (step S31) for operating a specific power load (water heater 44) among the first power loads only when it is predicted that surplus power will be generated;
It is possible to do so.

This configuration makes it possible to more effectively maintain the supply of power to the power loads. In other words, by operating a specific power load only when surplus power is generated, it becomes easier to ensure the remaining charge in the storage battery 52.

As described above, the power supply system 1 according to this embodiment has the following features:
A solar power generation unit 51 (power generation unit) capable of generating power by utilizing natural energy;
A water heater 44 that operates by receiving power supply;
An EMS 80 (controller) capable of controlling the operation of the water heater 44;
Equipped with
The EMS 80 is
A surplus power prediction process (steps S28 to S30) for predicting whether or not surplus power will be generated by the solar power generation unit 51 during a power outage;
An operation process (step S31) for operating the water heater 44 only when it is predicted that the solar power generation unit 51 will generate surplus power;
It is possible to do so.

This configuration allows the water heater to operate optimally during a power outage. In other words, the water heater 44 can be operated by utilizing surplus power generated during a power outage.

In addition, the EMS 80 is
In the operation process,
Only when the surplus power of the solar power generation unit 51 is greater than the power consumption of the water heater 44, the water heater 44 is operated.

By configuring it in this way, the water heater 44 can be operated using only surplus power. This allows other power (e.g., power charged in the storage battery 52) to be used by other power loads, improving convenience during power outages.

In addition, the power supply system 1 includes:
Further, a storage battery 52 capable of charging and discharging the power from the solar power generation unit 51 is provided.
The EMS 80 is
The surplus power of the solar power generation unit 51 is calculated by subtracting the power consumed by the power load and the charging power of the storage battery 52 from the power generated by the solar power generation unit 51 .

By configuring in this way, it is possible to calculate an appropriate surplus power value. In other words, since the output of surplus power during a power outage is generally suppressed by the hybrid power conditioner 53, it is difficult to detect the value of surplus power using a power sensor. Therefore, by using the above calculation method, it is possible to calculate a reasonable surplus power value.

In addition, the EMS 80 is
When the remaining charge in the storage battery 52 during a power outage is greater than at least the power consumption of the power load, a notification process (steps S33 to S35) can be executed to notify that the power load can be used.

This configuration can improve convenience during power outages. In other words, when surplus power occurs during a power outage, users (residents, etc.) can be encouraged to use power loads. This can improve convenience for users during power outages.

In addition, the EMS 80 is
In the notification process,
This notifies the user that the power load can be used only when the sum of the remaining discharge output, which indicates the output reserve of the storage battery 52, and the surplus power of the solar power generation unit 51 is greater than the power consumption of the power load.

By configuring it in this way, a notification can be sent only when the power load can be used reliably. This makes it possible to prevent power shortages when using the power load.

The solar power generation unit 51 according to this embodiment is one embodiment of a power generation unit according to the present invention.
Moreover, the EMS 80 according to this embodiment is one embodiment of a control unit according to the present invention.
The threshold value α according to this embodiment is an embodiment of the first threshold value and the second threshold value according to the present invention.
Moreover, the most important load of the most important circuit 40 according to this embodiment is an embodiment of a first power load belonging to the first group according to the present invention.
Moreover, the important load of the important circuit 30 according to this embodiment is an embodiment of a second power load belonging to the second group according to the present invention.
Moreover, the water heater 44 according to this embodiment is one embodiment of a specific electric power load according to the present invention.

Although an 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.

The thresholds (threshold α, threshold β) used in this embodiment are merely examples, and can be set to any value. For example, in this embodiment, in step S14, it is determined whether the minimum remaining amount of power is less than the threshold α, and the process branches to suppress power consumption (step S15 and thereafter) or increase power consumption (step S21). However, if the minimum remaining amount of power is equal to or greater than the threshold α, it is also possible to further determine whether the minimum remaining amount of power is equal to or greater than a separately set threshold (a threshold set to a value equal to or greater than the threshold α) and increase power consumption (step S21). In this way, by setting a difference between the thresholds for suppressing power consumption (step S15 and thereafter) and increasing power consumption (step S21), it is possible to prevent the control of the power load from becoming complicated.

The important loads and most important loads illustrated in this embodiment are merely examples, and the power loads (appliances) to be set as important loads and most important loads can be selected arbitrarily. For example, by setting an appliance that should be able to receive power preferentially even during a power outage as the most important load according to the resident's wishes, it is possible to receive a continuous supply of power as much as possible during a power outage.

The flowchart of the control during a power outage illustrated in this embodiment is an example, and the process contents and order can be changed as desired. For example, in this embodiment, when suppressing power consumption, the EMS 80 processes in the order of lowering the service level of the air conditioner 43, lowering the service level of the lighting 42, and disconnecting the important circuit 30, but the order of the processes can be changed as appropriate. For example, if it is desired to prioritize the comfort of the most important load (air conditioner 43, etc.) over the use of the important circuit 30 (important load), it is also possible to prioritize disconnecting the important circuit 30. Also, in this embodiment, an example is shown in which, if NO in step S19, the process proceeds to step S28, but it is also possible to return to step S11 in order to redo the prediction, for example.

In addition, in this embodiment, the power demand of the important load (TV 31, etc.) and the most important load (refrigerator 41, etc.) is predicted separately in step S12, but the present invention is not limited to this. For example, it is also possible to predict the power demand of the important load and the most important load together. In particular, in this embodiment, for the important load, the operation of each device (TV 31, etc.) is not controlled individually (only control is performed to disconnect them collectively), so it is possible to predict the power demand of the important loads together.

In addition, in this embodiment, the power generation unit is a solar power generation unit 51 that generates electricity using sunlight, but it may also generate electricity using other natural energy sources (e.g., hydropower or wind power).

The configuration of the power supply system 1 illustrated in this embodiment (the presence or absence of each device and the connection relationship) is merely an example and can be changed as desired. For example, the power supply system 1 does not necessarily have to include a power generation unit (solar power generation unit 51).

In addition, in this embodiment, the power supply system 1 is installed in a house, but this is not limited to this and may be installed in, for example, an office, etc.

1 Power supply system 30 Important circuit 40 Most important circuit 44 Water heater 51 Solar power generation unit 52 Storage battery 80 EMS

Claims (5)

A power supply system for supplying power to a power load, comprising:
A power generation unit capable of generating electricity using natural energy;
A water heater that operates by receiving electricity;
A control unit capable of controlling the operation of the water heater;
Equipped with
The power load includes a first power load including a plurality of devices that can be controlled at any timing, and a second power load including a plurality of devices that can be controlled collectively;
The first electric load includes the water heater and an appliance other than the water heater,
The control unit is
a surplus power prediction process for predicting whether or not surplus power will be generated by the power generation unit during a power outage;
an operation process for operating the water heater only when it is predicted that surplus power will be generated by the power generation unit;
It is possible to execute
In the operation process,
During a reduction process in which the power supplied to the device other than the water heater among the first power loads is gradually reduced within a range in which the device can operate, or after a collective stop process in which the supply of power to the second power loads is stopped all at once after the reduction process is completed, it is determined whether surplus power is generated by the power generation unit.
Power supply system. The control unit is
In the operation process,
The water heater is operated only when the surplus power of the power generation unit is greater than the power consumption of the water heater.
The power supply system according to claim 1 . Further, a storage battery capable of charging and discharging the power from the power generation unit is provided.
The control unit is
Calculating surplus power of the power generation unit by subtracting power consumption in the power load and charging power of the storage battery from power generation power of the power generation unit.
The power supply system according to claim 1 or 2. The control unit is
When the remaining amount of power stored in the storage battery during a power outage is greater than at least the amount of power consumed by the power load, a notification process can be executed to notify that the power load can be used.
The power supply system according to claim 3 . The control unit is
In the notification process,
notifying the user that the power load can be used only when a sum of a discharge remaining output indicating a margin of output of the storage battery and surplus power of the power generation unit is greater than a power consumption of the power load;
The power supply system according to claim 4.

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