JP2024012048A - charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging device capable of stably charging a secondary battery by using a renewable energy.

SOLUTION: In a charging device 20a, a voltage conversion part 31 converts a DC power input from a DC input terminal 23 into a charging voltage of a battery. An AC/DC conversion part 32 converts an AC power supplied from a commercial power supply to the DC power. A switch part 33 selects at least one of a power storage system power output from a power storage device and a commercial system power output from an AC/DC conversion part 32, and outputs the power to a battery. A control part 38 controls a selection of the power storage system power and the commercial system power by the switch part 33 to control so as to select at least the power storage system after the start of the charging of the battery, and to control so as to select only the commercial system power in the case where a power storage residual amount of the power storage device after the start of the charging is a predetermined value or less. In the case where the power storage residual amount of the power storage device in the charging becomes a predetermined value or less, the commercial system power supplied via the AC/DC conversion part 32 from a commercial power supply is output to the battery.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

Application for application of Article 30, Paragraph 2 of the Patent Act 1. Exhibition name: International Logistics Exhibition 2022 2. Date: September 13th to 16th, 2020 3. Venue: Tokyo International Exhibition Center (3-11-1 Ariake, Koto-ku, Tokyo) 4. Name of person who disclosed the invention: LECIP Co., Ltd.

The present invention relates to a charging device that charges a storage battery with power output from a power storage device that stores power generated using renewable energy.

Patent Document 1 listed below discloses a power storage system that charges a storage battery with DC power generated by sunlight, which is a type of renewable energy. In this power storage system, when the output voltage of the solar cell is higher than a predetermined first voltage value and lower than a predetermined second voltage value, the storage battery is charged via a bypass circuit without passing through a charger. Thereby, in such a case, the output voltage of the solar cell is directly output to the storage battery without going through the charger, making it possible to reduce conversion loss caused by the charger.

Japanese Patent Application Publication No. 2011-211885

In this way, electricity generated using renewable energy that constantly exists in nature (or is replenished repeatedly) such as sunlight, wind, geothermal, and wave power is dependent on natural phenomena. For this reason, it is difficult to provide stable power supply, and power storage devices such as storage batteries do not always store sufficient power. Therefore, if the power storage is insufficient, there is a possibility that the power to be supplied from the power storage device to the load will be insufficient. For example, a charging device that charges a storage battery with power output from a power storage device that stores power generated using renewable energy has a problem that the storage battery may become insufficiently charged.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a charging device that can stably charge a storage battery using renewable energy.

In order to achieve the above object, the charging device according to claim 1 is a power storage system that is a DC power output from a power storage device that stores power generated using renewable energy. A charging device that charges a storage battery with power, the power conversion unit capable of converting AC power supplied from a commercial power source into commercial power that is DC power and outputting the same, and the power storage system that is output from the power storage device. a switching unit that selects at least one of electric power and the commercial power output from the power conversion unit and outputs it to the storage battery; and control that controls selection of the storage system power and the commercial power by the switching unit. The control unit controls the switching unit to select at least the power storage system power before starting charging of the storage battery, and controls the remaining power storage amount of the power storage device after starting charging of the storage battery. is less than a predetermined value, the switching unit is controlled to select only the commercial power.

Note that the predetermined value is, for example, around 5% (4 to 6%) of the amount of electricity stored when the electricity is fully stored, and the amount of electricity remaining in the electricity storage device is very small (the state immediately before the electricity storage system can no longer output power from the electricity storage device). This is a value indicating that the amount of electricity stored is Furthermore, "selecting at least one of the storage system power output from the power storage device and the commercial system power output from the power conversion unit" refers to storage system power, commercial system power, or storage system power. and select commercial power (storage power and/or commercial power). Furthermore, "selecting at least the power storage system power" includes both cases where only power storage system power is selected and cases where both power storage system power and commercial system power are selected.

In the charging device according to the invention, the charging device includes a power conversion section, a switching section, and a control section. The power conversion unit can convert AC power supplied from a commercial power source into DC power and output the DC power. The switching unit selects at least one of the power storage system power output from the power storage device and the commercial system power output from the power conversion unit, and outputs the selected one to the storage battery. The control unit controls selection by the switching unit between power storage system power and commercial power, controls the selection of at least power storage system power before starting charging of the storage battery, and controls selection of power storage system power from the power storage device after starting charging of the storage battery. Control is performed so that only commercial power is selected when the remaining amount of stored power is less than a predetermined value. As a result, even if storage system power (or storage system power and commercial power) is selected before the start of charging the storage battery, if the remaining amount of power stored in the power storage device becomes less than a predetermined value after charging starts, commercial power will be used. only are selected. Therefore, when the remaining amount of power in the power storage device falls below a predetermined value while outputting power from the power storage system to the storage battery, that is, during charging, the control unit automatically outputs the power from the commercial power supply from the commercial power source via the power conversion unit. Electric power is selected and output to the storage battery. Moreover, when both the storage system power and the commercial system power are selected, the charging time of the storage battery is shortened, so that high-speed charging of the storage battery becomes possible.

In addition, in the charging device according to claim 1, the control unit is configured to control the charging device before starting charging of the storage battery, giving priority to the control. If the amount of insufficient charge obtained by subtracting the remaining amount of charge of the storage battery from the rated capacity of the storage battery is greater than the remaining amount of charge of the power storage device, the commercial A technical feature is that the switching unit is controlled to select only the system power.

In the invention of the charging device according to claim 2, the control section takes priority over the control described in claim 1 and determines the amount of charge shortage (from the rated capacity of the storage battery to the remaining charge of the storage battery) before starting charging of the storage battery. If the amount obtained by subtracting the amount of electricity) is larger than the remaining amount of power stored in the power storage device, the switching unit is controlled to select only commercial power until the insufficient charge amount becomes equal to or less than the remaining amount of power stored in the power storage device. As a result, during periods when the amount of insufficient charge in the storage battery is greater than the remaining amount of energy stored in the energy storage device, commercial power is output to the storage battery and the battery is charged, so charging cannot be done with the amount of energy remaining in the energy storage device at that time. It becomes possible to make up for the shortage by charging with commercial power. Therefore, even if only the electricity from the storage system is selected and output to the storage battery, after the amount of insufficient charge in the storage battery becomes less than the remaining amount of storage in the storage device, the storage battery will be charged using only the remaining amount of storage in the storage device at that time. (fully charged state).

Furthermore, in the charging device according to claim 1 or 2, alternative power corresponding to the generated power is supplied from the power conversion unit to the charging device according to claim 3. The technical feature is that the alternative power is configured to be able to be supplied to a power storage device, and when power generation using the renewable energy is not performed, the alternative power is supplied from the power converter to the power storage device. shall be.

In the charging device according to the third aspect of the present invention, the charging device is configured so that alternative power corresponding to the generated power can be supplied from the power converter to the power storage device. Then, when power generation using renewable energy is not performed, alternative power is supplied from the power conversion unit to the power storage device. In power generation using renewable energy, the state of power generation, such as whether sufficient power can be generated, is left to natural phenomena. Therefore, when power generation using renewable energy is not performed, alternative power is supplied from the commercial power source to the power storage device via the power converter, thereby making it possible to store power in the power storage device. In other words, it becomes possible to recover from insufficient power storage in the power storage device when power generation using renewable energy is not possible.

In order to achieve the above object, the charging device according to claim 4 is a power storage system that is a DC power output from a power storage device that stores power generated using renewable energy. A charging device that charges a storage battery with power, the power conversion unit capable of converting AC power supplied from a commercial power source into commercial power that is DC power and outputting the same, and the power storage system that is output from the power storage device. a switching unit that selects at least one of electric power and the commercial power output from the power conversion unit and outputs it to the storage battery; and controlling selection of the storage system power and the commercial power by the switching unit; a control unit that retains or externally acquires schedule information of a predetermined length of use time period in which the power load uses the DC power charged in the storage battery and a predetermined length of rest time period in which the power load does not use the DC power; After controlling the switching unit to select at least the power storage system power and start charging the storage battery, the unit controls the switching unit to select at least the power storage system and start charging the storage battery, and then: (1) the remaining amount of power stored in the power storage device is below a predetermined value and the current time is immediately before the suspension time period; (2) if the remaining power storage capacity of the power storage device is below a predetermined value and the current time is immediately before the downtime period; Technically, if the power is included in a certain use time period or a certain suspension time period, charging of the storage battery is restarted after the power storage device has stored power exceeding the predetermined value without selecting the commercial power. Features.

Note that the "predetermined length" of the usage time period or the down time period may be, for example, the value obtained by dividing 24 hours (one day) by an integer (6 hours, 8 hours, 12 hours, 24 hours, etc.), or 24 hours (1 day). The length is a value obtained by multiplying (1 day) by an integer (24 hours, 48 hours, 72 hours, 96 hours, etc.), but it may be any length set in detail down to hours, minutes, and seconds. Typically, the use time period is longer than the down time period, but the down time period may be longer than the use time period, or both may be the same length. In addition, the "predetermined value" of the remaining power storage amount is, for example, around 5% (4 to 6%) of the power storage amount at full power storage, and the remaining power storage amount of the power storage device is only a little (the power storage system power is not output from the power storage device). This is the value indicating the amount of stored electricity that is immediately before output becomes impossible. Furthermore, "selecting at least the power storage system power" includes both the case where only the power storage system power is selected and the case where both the power storage system power and the commercial power system are selected.

In the charging device according to the fourth aspect of the invention, the charging device includes a power conversion section, a switching section, and a control section. The power conversion unit can convert AC power supplied from a commercial power source into commercial power, which is DC power, and output the converted power. The switching unit selects at least one of the power storage system power output from the power storage device and the commercial system power output from the power conversion unit, and outputs the selected one to the storage battery. The control unit controls selection of storage system power and commercial power by the switching unit, and also controls a predetermined usage time period in which the power load uses the DC power charged in the storage battery and a predetermined length down time period in which the power load does not use the DC power. schedule information or retrieve it from an external source. Then, after controlling the switching unit to select at least the power storage system power and start charging the storage battery, the control unit controls the switching unit to select at least the power storage system power and start charging the storage battery, and then (1) determines whether the power storage device is in use when the remaining amount of storage power is below a predetermined value and the current time is not immediately before the stop period; If included in the time period, the switching unit is controlled to select commercial power, and (2) the usage time period or the downtime period in which the remaining amount of electricity in the power storage device is below a predetermined value and the current time is immediately before the downtime period. If it is included in the range, charging of the storage battery is resumed after waiting for the storage device to store power exceeding a predetermined value without selecting commercial power.

As a result, at least after the power storage system power is selected and charging of the storage battery is started, (1) if the remaining power storage capacity of the power storage device is less than a predetermined value and the current time is included in a usage period that is not immediately before a downtime period; , commercial power is selected. Therefore, if the remaining power of the power storage device falls below a predetermined value while outputting power from the power storage system to the storage battery, that is, while charging, and the current time is within a usage period that is not immediately before a downtime period, the control The unit selects commercial power supplied from the commercial power source via the power conversion unit and outputs it to the storage battery. Moreover, when both the storage system power and the commercial system power are selected, the charging time of the storage battery is shortened, so that high-speed charging of the storage battery becomes possible. In addition, at least after the power storage system power has been selected and charging of the storage battery has started, (2) during a usage period or a suspension period in which the remaining amount of electricity in the storage device is below a predetermined value and the current time is immediately before the suspension period; If it is included, charging of the storage battery is resumed after the power storage device has stored power exceeding a predetermined value. Therefore, it prevents commercial power from being selected even though the current time is within the usage period immediately before the downtime or in the downtime, so renewable energy can be used to generate electricity during the downtime. This makes it possible to prevent wasting stored power from the storage system and from using unnecessary commercial power.

Further, in the charging device according to claim 4, the control unit restarts charging of the storage battery in the case (2). When it is determined that charging of the storage battery is not completed by the time the usage time period immediately after the suspension time period starts, or the usage time period immediately after the suspension time period begins. A technical feature is that when it is determined that the power storage of the power storage device is not completed before a predetermined time, the switching unit is controlled to select the commercial power. Note that the "predetermined time" before the predetermined time is, for example, the estimated charging time when the storage battery is charged with the power storage system output from the power storage device that is scheduled to store power during the idle period. .

In the invention of the charging device according to claim 5, after at least the electricity storage system power is selected and charging of the storage battery is started, the control unit (2) determines whether the remaining amount of electricity in the electricity storage device is less than a predetermined value and the current state is inactive. If it is included in the use time period or suspension time period that immediately precedes the time period, charging of the storage battery will be resumed after waiting for the power storage device to store more than a predetermined value, but before or after resuming charging of the storage battery. When it is determined that charging of the storage battery is not completed by the time the use time period starts immediately after the rest time period, the switching unit is controlled to select commercial power. Further, the switching unit is also controlled to select commercial power even when it is determined that the storage of power in the power storage device is not completed by a predetermined time before the start of the use time period that is immediately after the stop time period. That is, if it is estimated and determined that the storage battery will not be charged in time by the time the use time period begins, commercial power is selected to charge the storage battery. This makes it possible to prevent the occurrence of a situation in which the storage battery is not fully charged even when the usage period begins.

Furthermore, in the charging device according to claim 6, in the charging device according to any one of claims 1, 2, 4, or 5, the output side of the switching section is , a selection section capable of selecting a plurality of output sections to which a plurality of storage batteries can be connected is connected, and the control section controls the selection section based on the state of charge of the plurality of storage batteries connected to the output section. The technical feature is that

In the charging device according to the invention, the control section controls the selection section based on the charging state of the plurality of storage batteries connected to the output section. The state of charge of the storage battery is, for example, the amount of remaining charge or the degree of deterioration. Typically, a storage battery with a large amount of remaining charge becomes fully charged in a shorter time than a storage battery with a smaller amount of remaining charge. Further, typically, for example, the charging capacity of a storage battery decreases as the deterioration progresses, so a storage battery with a high degree of deterioration becomes fully charged in a shorter time than a storage battery with a small degree of deterioration. As a result, by prioritizing charging of storage batteries with a large amount of charge remaining over batteries with a low amount of charge remaining, or prioritizing charging of storage batteries with a high degree of deterioration over those with a low degree of deterioration, the overall It becomes possible to shorten charging time.

In the charging device of the present invention, when the remaining power of the power storage device becomes less than a predetermined value while outputting power from the power storage system to the storage battery (charging), the control unit selects commercial power to supply the power to the storage battery. Output. Therefore, it is possible to prevent charging of the storage battery from ending with insufficient charging, and it is possible to stably charge the storage battery using renewable energy.

1 is a configuration diagram showing a configuration example of a charging system including first to third embodiments of a charging device of the present invention. FIG. FIG. 2 is a block diagram showing a configuration example of a charging device according to a first embodiment and a second embodiment. It is a flowchart which shows the flow of control processing (basic control processing) performed in the charging device of a 1st embodiment. It is an explanatory view showing an example of a charging pattern by a charging device of a 1st embodiment. It is a flowchart which shows the flow of control processing (control processing with battery assist) performed in the charging device of a 1st embodiment. It is a block diagram showing another example of composition of a charging device concerning a 1st embodiment. It is a flowchart which shows the flow of control processing (control processing with supplementary charge) performed in the charging device of a 2nd embodiment. It is a block diagram showing an example of composition of a charging device concerning a 3rd embodiment. It is a block diagram showing another example of composition of a charging device concerning a 3rd embodiment. It is a block diagram which shows the structural example of the charging system containing 4th Embodiment of the charging device of this invention. It is a block diagram showing an example of composition of a charging device concerning a 4th embodiment. FIG. 2 is an explanatory diagram illustrating an example of power storage and charging in a charging system, an example of power system switching by a charging device, etc. in response to a forklift driving schedule. It is a flowchart which shows the flow of control processing (basic control processing) performed in the charging device of a 4th embodiment. 14 is a flowchart showing the flow of the power storage waiting process shown in FIG. 13. It is a flowchart which shows the flow of control processing (selection control processing) performed in a charging device of a 4th embodiment.

Hereinafter, embodiments of the charging device of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a charging system 10 including a charging device 20 according to the first to third embodiments includes a battery 51 (storage battery) such as a battery-powered forklift (hereinafter referred to as "forklift") 50, ) is used to charge the battery 51 of a vehicle or working machine driven by electric power supplied from a power source. The forklift 50 is an example of an electric vehicle driven by electric power from a mounted battery 51, and includes, for example, an automated guided vehicle (AGV), an electric cart, an electric wheelchair, an electric two-wheeled vehicle, and the like. Work machines include, for example, power tools, electric construction machines, and the like. Note that the electric motor mounted on these and driven by the power of the battery 51 can correspond to the "power load" described in the claims.

As shown in FIG. 1, the charging system 10 mainly includes a solar panel 11 that uses sunlight to generate electricity, a power storage device 13 that stores the power generated by the solar panel 11, and a power storage device 13 and a commercial The charging device 20 is connected to the power source 15 and receives supply of DC power and AC power. Although not shown in the figure, between the solar battery panel 11 and the power storage device 13, by controlling the charging and discharging of the power storage device 13, the DC power supplied from the solar battery panel 11 can be efficiently transferred to the power storage device 13. There is a charge/discharge control device that can store the battery.

The solar panel 11 is sometimes called a solar cell, a solar panel, or the like, and is an example of a power generation device that generates power using renewable energy. Therefore, in the charging system 10, instead of the solar panel 11, it is also possible to use a power generation device that generates electricity using wind power, wave power, tidal power, flowing water power, geothermal heat, biomass-derived energy, or the like.

Power storage device 13 is a power storage device that stores DC power output from solar panel 11 . Typically, it is composed of a storage battery such as a lead acid battery, an alkaline secondary battery, a lithium secondary battery, or a NAS battery, but it may also be an electric double layer capacitor or the like. In the first to third embodiments, the power storage device 13 is configured to be able to be charged and discharged with a DC voltage of 12V or 24V, for example. In the first to third embodiments, the power storage device 13 is set to have an insufficient (insufficient) power storage capacity to charge the battery 51 of the forklift 50, for example, 230 Ah. Note that the DC power output from the power storage device 13 may correspond to "power storage system power" as described in the claims.

The commercial power source 15 is, for example, a source of single-phase 100V or three-phase 200V AC power, and these AC powers are supplied from an electric power company or the like. The battery 51 mounted on the forklift 50 is, for example, a lithium ion battery (lithium secondary battery), and is configured to output DC power with a nominal voltage of 24V, 48V, etc. and a rated capacity of 280Ah, 450Ah, etc. has been done. Note that the nominal voltage (unit: V) is the output voltage obtained when the battery 51 is used in a normal state. The rated capacity (unit: Ah) is the amount of electricity obtained from the fully charged voltage of the battery 51 to the final discharge voltage.

Note that the power storage device 13 and the charging device 20 are electrically connected via a DC power line 14, and the commercial power source 15 and the charging device 20 are electrically connected via an AC power line 16. The forklift 50 and the charging device 20 are electrically connected via the charging cable 18, so that the battery 51 mounted on the forklift 50 can be charged.

As shown in FIG. 2, the charging device 20 (20a) mainly includes a voltage conversion section 31, an AC/DC conversion section 32, a switch section 33, a control section 38, sensors 41, 42, etc. is housed in a metal housing 21. For example, a DC input terminal 23 to which DC power supplied from the power storage device 13 is input, an AC input terminal 24 to which AC power supplied from the commercial power supply 15 is input, and a charging cable 18 are connected to the housing 21. A charging output terminal 25 and the like are provided. In addition, in FIG. 2, in order to distinguish it from the charging device 20b etc. of the other structural example mentioned later, "a" is added to the end of the code|symbol "20" for convenience, and it is the charging device 20a.

The voltage converter 31 steps down or steps up the voltage of the DC power input to the input side from the DC input terminal 23 to convert it into a voltage suitable for charging the battery 51 of the forklift 50, and then converts the voltage to the voltage that is output from the output side. It is a converter. The voltage converter 31 is configured by, for example, a chopper circuit including a semiconductor switching element (IGBT, etc.) and an inductor, and can control the voltage output from the output end by changing the switching frequency of the semiconductor switching element. It is configured as follows. Note that since the DC power output from the power storage device 13 is power storage system power, it is input to the input side of the voltage converter 31 via the DC input terminal 23 and converted into voltage by the voltage converter 31. The output DC power may also correspond to the "storage system power" described in the claims.

The AC/DC converter 32 is a DC power source that converts the AC power input to the input side from the AC input terminal 24 into DC power, reduces the voltage to a voltage suitable for charging the battery 51 of the forklift 50, and outputs it from the output side. It is a unit. The AC/DC converter 32 is configured with a dropper type or switching type circuit system, for example, and converts a single-phase 100V or three-phase 200V AC voltage into a DC voltage such as 24V or 48V that can charge the battery 51. It is configured so that it can be converted into and output. Note that the DC power output from this AC/DC converter 32 can correspond to "commercial power" as described in the claims.

The switch unit 33 is a switching unit having two circuit type switches 33a and 33b that can control on/off of two inputs and outputs, respectively. In the first to third embodiments, selection is made between the power storage system connected to the control unit 38 and output from the voltage conversion unit 31 and the commercial system power output from the AC/DC conversion unit 32. Therefore, the output side of the voltage converter 31 is connected to the input end of one switch 33a, and the output side of the AC/DC converter 32 is connected to the input end of the other switch 33b. The output terminals of these switches 33a and 33b are both connected to the voltage node 39, and are connected to the DC power (storage system power) output from the voltage converter 31 and the DC voltage (storage system power) output from the AC/DC converter 32. The charging output terminal 25 is configured to output commercial power (commercial power) to the charging output terminal 25.

The voltage node 39 is a connection part that connects the two output ends of the switch section 33 (switches 33a, 33b) and is also electrically connected to the charging output terminal 25. In the first embodiment, which will be described later, exclusive control is performed on the switch unit 33 by turning on only one of the switches 33a and 33b (turning the other one off) or turning it off (turning the other one on). That is, since both switches 33a and 33b are never turned on at the same time, voltage node 39 is configured as a mere electrical connection point. On the other hand, in a modified example described later, the switches 33a and 33b can be controlled to be turned on simultaneously, so that the voltage node 39 is connected to the output voltage of the voltage converter 31 and the output voltage of the AC/DC converter 32. It is configured as a voltage synthesis circuit that can synthesize and output.

The control unit 38 is a controller that controls the output voltage and output current of the voltage conversion unit 31 and the AC/DC conversion unit 32, and turns on and off the switch unit 33, and includes, for example, an MPU, memory (RAM, EEPROM), This is a microcomputer module consisting of an interface, etc. Therefore, the voltage conversion section 31, the AC/DC conversion section 32, the switch section 33, and the sensors 41, 42 are electrically connected to the control section 38, and different control processes are controlled in each embodiment described below. This is carried out by the section 38.

The sensors 41 and 42 are detection units that have both the functions of a voltage sensor and a current sensor. In the first to third embodiments, the sensor 41 connects the DC input terminal 23 and the voltage converter so that it can detect the voltage and current of DC power output from the power storage device 13 and input to the DC input terminal 23. 31. The sensor 42 also detects the voltage and current of the DC power outputted from the voltage node 39 via the charging output terminal 25, that is, the output voltage and output current of the charging device 20a, and the voltage and current of the DC power outputted from the voltage node 39 via the charging output terminal 25. It is provided so as to be interposed between the voltage node 39 and the charging output terminal 25 so as to be able to detect the terminal voltage and terminal current of the connected battery 51.

In the charging device 20a configured in this way, output power (output voltage, output current) is output to the battery 51 via the charging cable 18 connected to the charging output terminal 25, that is, charging power (charging voltage, charging current) is supplied to the battery 51. Although not shown, the housing 21 is provided with, for example, a charging start switch having an LED, and when this switch is turned on, the control processing of each embodiment executed by the control unit 38 is started. is started, and the LED continues to light up while the process is being executed. Upon completion of the process, the LED turns off.

[First embodiment]
The flow of basic control processing (basic control processing) executed by the charging device 20a of the first embodiment will be described based on FIGS. 3 and 4. Note that in this basic control process, the flow of the control process regarding the charging method of the battery 51 is not mentioned, but here, the case where the battery 51 is charged by the constant current, constant voltage (CCCV) method will be described. The explanation will be based on the following. The CCCV method is a suitable charging method when the battery 51 is composed of a lithium ion battery, and an example of the charging pattern is illustrated in FIG. 4(A).

This basic control processing is realized by the MPU of the control unit 38 executing a basic control program stored in the memory (EEPROM) of the control unit 38. The basic control program (basic control process) is activated by the control unit 38 and the process is started, for example, when the above-mentioned charging start switch is turned on. Further, the control process (not shown) related to the CCCV method (charging method) is executed by the MPU of the control unit 38 in a separate task (thread, process, etc.), and this control process starts the voltage conversion unit 31. When the process (S107) is executed, it is activated and started by the control unit 38 almost at the same time.

As shown in FIG. 3, in the basic control process, first, a predetermined initialization process is performed in step S101. In this process, for example, the work area and flags for this process in the memory (RAM) of the control unit 38 are cleared, and control commands for initial settings are sent to the voltage conversion unit 31, AC/DC conversion unit 32, and switch unit 33. or send out. In the basic control process, as default settings for the switch unit 33, the switch 33a is set to the on state, and the switch 33b is set to the off state.

Next, sensor information acquisition processing is performed in step S103. In this process, voltage information and current information detected by the sensors 41 and 42 are acquired. As described above, the sensor 41 detects information on the output voltage and output current of the power storage device 13, and the sensor 42 detects information on the output voltage and output current of the charging device 20a connected to the charging output terminal 25. Information about the terminal voltage and terminal current of the battery 51 is detected. Therefore, in this process, these voltage information and current information are acquired. Note that if the voltage drop caused by the electrical resistance of the charging cable 18 or the like is large, the terminal voltage of the battery 51 to which a preset standard voltage drop is added is acquired.

In the subsequent step S105, a determination process is performed to determine whether or not charging of the battery 51 is necessary, in other words, whether or not charging of the battery 51 is completed. That is, based on the terminal voltage information acquired in step S103, it is determined that charging is necessary when the terminal voltage of the battery 51 is less than a predetermined voltage value (S105; Yes), and it is determined that charging is necessary when the terminal voltage of the battery 51 is less than a predetermined voltage value (S105; Yes). When the voltage is higher than a predetermined voltage value), it is determined that charging is not necessary (charging is unnecessary) (S105; No).

If it is determined that charging is not necessary (no charging is required) (S105; No), this means that the battery 51 has already been charged, and therefore the voltage converter etc. stop process in step S106 is performed. After the transition, this basic control processing ends. In this voltage converter etc. stop processing (S106), when the voltage converter 31 and AC/DC converter 32 are activated, a control command to stop these voltage converters 31, etc. is sent, or an on operation is performed. Control is performed such as turning off the LED of the charging start switch that is lit.

On the other hand, if it is determined in step S105 that charging is necessary (S105; Yes), in the next step S107, voltage converter startup processing is performed and a startup command and output current value are sent to the voltage converter 31. A control command containing information etc. is sent. Control processing (not shown) regarding the CCCV method is also started. The information on the output current value, etc. is information on the constant current value necessary when performing constant current charging (CC charging) control on the battery 51 that constitutes the CCCV method, and for example, the information on the output current value, etc. It is generated based on information on the output voltage and output current of the battery 51 and information on the terminal voltage and terminal current of the battery 51. Thereby, the DC power supplied from the power storage device 13 is output as charging power to the battery 51 via the voltage converter 31, and constant current charging (CC charging) is started (see FIG. 4(A)).

In the subsequent step S109, a process is performed to determine whether the remaining amount of power stored in the power storage device 13 is equal to or greater than a predetermined value. The predetermined value of the remaining amount of stored power is set to the amount of stored power immediately before the power storage device 13 can no longer output DC power, for example, around 5% (4 to 6%) of the amount of stored power when the power storage device 13 is fully charged. . Therefore, if it is determined that the remaining power storage amount of the power storage device 13 is equal to or higher than the predetermined value (S109; Yes), the power storage device 13 outputs DC power because the remaining power storage amount is not low. There is a high probability that it will continue. Therefore, in this case, the process returns to step S103 and the sensor information acquisition process is performed again. As a result, information on the latest output voltage and output current of the power storage device 13 is acquired, and information on the latest output voltage and output current (terminal voltage and terminal current of the battery 51) of the charging device 20a is acquired. do.

Note that the determination process in step S109 may be performed based on the amount of discharge of power storage device 13 or the amount of charge of battery 51, for example. The amount of discharge of the power storage device 13 can be calculated from the input voltage and input current input from the power storage device 13 to the DC input terminal 23, and the amount of charge of the battery 51 is output to the battery 51 from the charging output terminal 25. It can be calculated from the output voltage and output current. Therefore, in step S109, for example, a process may be performed in which it is determined whether the amount of discharge of power storage device 13 or the amount of charge of battery 51 is less than a predetermined value. The predetermined value of the amount of discharge of the power storage device 13 and the predetermined value of the amount of charge of the battery 51 are set, for example, to values corresponding to around 95% (94 to 96%) of the amount of stored power when the power storage device 13 is fully charged. .

On the other hand, if it is determined that the remaining power storage amount of the power storage device 13 is not greater than or equal to the predetermined value (less than the predetermined value) (S109; No), the power storage device 13 has only a small amount of power remaining. 13, there is a high probability that it will be difficult to output DC power in a short period of time. Therefore, in such a case, the process moves to step S113 (S111; No), and a process of activating the AC/DC converter 32 is performed. Note that in the determination process of step S111, if the AC/DC conversion unit 32 has already been activated (S111; Yes), the AC/DC conversion unit activation process (S113) and the switch unit switching process (S115) are performed again. It prevents people from doing so.

In step S113, an AC/DC converter activation process is performed, and a control command including an activation command, information on an output current value, etc. is sent to the AC/DC converter 32. This output current value information, etc. is also constant current value information necessary when performing constant current charging (CC charging) on the battery 51, as in the case of the voltage converter startup process (S107) described above. , for example, based on the information on the output voltage and output current of power storage device 13 and the information on the terminal voltage and terminal current of battery 51 acquired in step S103.

In the following step S115, switch section switching processing is performed. That is, until now, the switch 33a has been turned on so that the voltage converter 31 converts the DC power supplied from the power storage device 13 and outputs the power storage system power to the charging output terminal 25 (voltage node 39). For the switch unit 33 which was set to (with the switch 33b in the OFF state), the AC/DC conversion unit 32 converts the AC power supplied from the commercial power supply 15 and outputs the commercial power for charging and outputting. The switch 33b is set to the on state (the switch 33a is set to the off state) so that the signal can be output to the terminal 25.

As a result, the current value of constant current charging (CC charging) supplied to the battery 51 may vary, so that the current changes stepwise within the CC charging period, as shown in FIG. 4(B). In the example of the charging pattern shown in FIG. 4(B), the period Ta of CCa is the time period during which the battery 51 is being charged with a constant current (CC charging) using power from the storage system, and the period Ta of CCa is a period of time (a part of Tb) is the time period during which the battery 51 is being charged with constant current (CC charging) using commercial power. Note that if the current value for constant current charging of the battery 51 using power from the storage system is the same as the current value for constant current charging of the battery 51 using commercial power, such a step-like current No change occurs, and the charging pattern becomes, for example, as shown in FIG. 4(A).

After the switch unit 33 is switched by the switch unit switching process (S115) and commercial power is supplied to the battery 51, the process returns to step S103 and the sensor information acquisition process is performed again. As a result, the latest information on the output voltage and output current (terminal voltage and terminal current of the battery 51) of the charging device 20a is acquired, and control processing regarding the CCCV method is continued by another task based on this information. be exposed. In this control process, when the terminal voltage of the battery 51 reaches a predetermined voltage Vc, it switches to constant voltage charging (CV charging) (see FIG. 4(B)), and as charging progresses further and the terminal voltage is within a predetermined range, the constant voltage After the predetermined time has elapsed, this basic control process ends. Note that the order of the AC/DC converter activation process (S113) and switch unit switching process (S115) may be reversed.

In the example of the charging pattern shown in FIG. 4(A), the period Ta is a time period during which the battery 51 is being charged with constant current (CC charging) using power from the storage system, and the period Tb is when the battery 51 is being charged with constant current (CC charging) using power from the commercial system. This is the time period during constant voltage charging (CV charging). On the other hand, in the example of the charging pattern shown in FIG. 4(B), the period Ta is the time period during which the battery 51 is being charged with a constant current (CCa during CC charging) using the storage system power, and the period Tb is the time period when the battery 51 is being charged with a constant current (CCa during CC charging) using the power from the storage system. This is a time period in which the battery 51 is charged with constant current (CCb during CC charging) or constant voltage charged (CV charging) with electric power. Although not illustrated, if the power storage device 13 has a power storage capacity that can sufficiently cover the period during which constant current charging (CC charging) can be performed, during the period of constant voltage charging (CV charging) There is a possibility that the switch unit 33 switches the power system, that is, switches from the storage system power to the commercial power system.

[Modification example]
Next, as a modified example of the first embodiment, a control process having a battery assist function (control process with battery assist) will be described with reference to FIG. In the battery-assisted control process shown in FIG. 5, an algorithm is configured including each process (S101 to S115) that constitutes the basic control process shown in FIG. Therefore, a description of each of these processes (S101 to S115) will be omitted.

The battery assist function shortens the charging time of the battery 51 by outputting the storage system power output from the voltage converter 31 and the commercial system power output from the AC/DC converter 32 to the charging output terminal 25 at the same time. For example, it can be prepared as an optional function according to user needs. Therefore, when the charging device 20a has a specification with a battery assist function, the housing 21 is provided with an unillustrated assist switch that instructs to enable or disable the function, for example.

As shown in FIG. 5, in the control process with battery assist, after it is determined in step S105 that charging is necessary (S105; Yes), a process to determine whether battery assist is available is performed in the subsequent step S121. . If the assist switch is turned on, it is determined that battery assist is present (S121; Yes), and the process moves to the next step S123. On the other hand, if it is turned off, it is determined that there is no battery assist function (S121; No), and since the configuration does not have a battery assist function, that is, the processing content is the same as the basic control process described above, step S107 After moving to , each process (S107 to S115) is executed in the same manner as described above.

In step S123, a process for starting the voltage converter and the like is performed. That is, in this process, the voltage converter 31 and the AC/DC converter 32 are activated almost simultaneously. As a result, the voltage converter 31 outputs storage power, and the AC/DC converter 32 outputs commercial power.

In the following step S125, switch section switching processing is performed. In the initialization process (S101), the switch unit 33 sets the switch 33a to the on state and the switch 33b to the off state, so in this process, control is performed to switch the switch 33b from the off state to the on state. This is done for the switch section 33. As a result, in the switch section 33, both switches 33a and 33b are set to the on state. Note that the order of the voltage converter etc. activation process (S123) and the switch unit switching process (S125) may be reversed.

By switching the switch unit 33 in the switch unit switching process (S125), the battery 51 is supplied with both the power storage system power and the commercial power system, so that the charging time of the battery 51 can be shortened, and the battery 51 enables high-speed charging. Note that if the supply of power storage system power output from the voltage converter 31 is stopped due to a decrease in the amount of power stored in the power storage device 13, only the commercial system power output from the AC/DC converter 32 is supplied to the battery 51. be done. Therefore, the charging pattern based on the battery-assisted control becomes a curve of charging voltage and charging current that has a shape that is a compression of the charging pattern shown in FIG. 4(A) in the time axis direction.

In addition, when performing control processing with battery assist, the configuration of the charging device 20a shown in FIG. 2 may be changed to a charging device 20b having the configuration shown in FIG. 6 (another configuration example), for example. That is, in the charging device 20b, the switch section 33, which was provided on the output side of the voltage conversion section 31 and the AC/DC conversion section 32 and functioned as a selection switch between power storage system power and commercial power system, is eliminated, and the DC input terminal The switch unit 34 to which the DC power (storage system power) of the power storage device 13 input from the power storage device 23 and the DC power (commercial system power) output from the AC/DC converter 32' is inputted is connected to the switch unit 34 of the voltage converter 31'. Provided on the input side. This switch unit 34 is connected to the control unit 38 and selects between the power storage system power of the power storage device 13 inputted from the DC input terminal 23 and the commercial system power outputted from the AC/DC conversion unit 32'. configured to obtain.

The voltage converter 31' and AC/DC converter 32' that constitute such a charging device 20b differ in configuration from the voltage converter 31 and AC/DC converter 32 described above in the following points.

That is, the voltage converter 31' has an input side configured to be able to input two systems of DC power (DC power of the power storage device 13 and DC power of the AC/DC converter 32'), and It has a function of converting the voltage of at least one (or both) of the DC power into a voltage suitable for charging the battery 51 of the forklift 50 by stepping down or stepping up the voltage, and then outputting the voltage from the output side. In other words, the difference is that the input side has two input specifications.

Further, the AC/DC converter 32' converts the AC power input to the input side from the AC input terminal 24 into DC power, lowers the voltage to a voltage corresponding to the output voltage when the power storage device 13 is fully charged, and outputs the voltage. It has a function to output from the side. That is, the difference is that the voltage is converted to the output voltage of the power storage device 13. Note that the DC power output from the AC/DC converter 32' may correspond to "commercial power" as described in the claims. Further, the DC power of the power storage device 13 inputted from the DC input terminal 23 can correspond to "storage system power" as described in the claims.

By configuring the charging device 20b in this way, the voltage node 39 that was necessary in the charging device 20a described above becomes unnecessary, and the voltage synthesis circuit that is necessary for the voltage node 39 in this modified example is also unnecessary. The number of parts can be reduced, and the product cost of the charging device 20b can be reduced. Note that if the configuration of the charging device 20b according to this modified example is viewed as a creation of a technical idea, it can be expressed as follows.

``A charging device that charges a storage battery with power storage system power that is DC power output from a power storage device that stores power generated using renewable energy,
a power conversion unit capable of converting AC power supplied from a commercial power source into commercial power that is DC power and outputting the converted power;
a switching unit that selects and outputs at least one of the power storage system power output from the power storage device and the commercial system power output from the power conversion unit;
a voltage conversion unit that converts the DC power output from the switching unit into a charging voltage for the storage battery;
a control unit that controls selection of the storage system power and the commercial system power by the switching unit;
Equipped with
The control unit controls the switching unit to select at least the power storage system power before the start of charging the storage battery, and the remaining amount of power stored in the power storage device is equal to or less than a predetermined value after the start of charging the storage battery. The charging device is characterized in that the switching unit is controlled so as to select only the commercial power in the case where the switching unit selects only the commercial power. ”

Note that the predetermined value is, for example, around 5% (4 to 6%) of the amount of electricity stored when fully charged, and the amount of electricity remaining in the electricity storage device is very small (the state immediately before the electricity storage system cannot output power from the electricity storage device). This is a value indicating that the amount of electricity stored is Furthermore, "selecting at least one of the storage system power output from the power storage device and the commercial system power output from the power conversion unit" refers to storage system power, commercial system power, or storage system power. and select commercial power (storage power and/or commercial power). Furthermore, "selecting at least the power storage system power" includes both cases where only power storage system power is selected and cases where both power storage system power and commercial system power are selected.

In the configuration in the above “ ”, the charging device includes a power conversion section, a voltage conversion section, a switching section, and a control section. The power conversion unit can convert AC power supplied from a commercial power source into DC power and output the DC power. The switching unit selects and outputs at least one of the power storage system power output from the power storage device and the commercial system power output from the power conversion unit. The voltage conversion section converts the DC power output from the switching section into a charging voltage for the storage battery. The control unit controls selection by the switching unit between power storage system power and commercial power, controls the selection of at least power storage system power before starting charging of the storage battery, and controls selection of power storage system power from the power storage device after starting charging of the storage battery. Control is performed so that only commercial power is selected when the remaining amount of stored power is less than a predetermined value.

As a result, even if storage system power (or storage system power and commercial power) is selected before the start of charging the storage battery, if the remaining amount of power stored in the power storage device becomes less than a predetermined value after charging starts, commercial power will be used. only are selected. Therefore, when the remaining power of the power storage device falls below a predetermined value while power is being output from the power storage system to the voltage conversion unit, that is, during charging, the control unit will cause power to be supplied from the commercial power source via the power conversion unit. Commercial power is selected and output to the voltage converter. Therefore, it is possible to prevent charging of the storage battery from ending with insufficient charging, and it is possible to stably charge the storage battery using renewable energy. Moreover, when both the storage system power and the commercial system power are selected, the charging time of the storage battery is shortened, so that high-speed charging of the storage battery becomes possible.

As described above, the charging devices 20a and 20b according to the first embodiment include the voltage conversion sections 31 and 31', the AC/DC conversion sections 32 and 32', the switch sections 33 and 34, and the control section 38. The voltage conversion section 31 converts the DC power input from the DC input terminal 23, and the voltage conversion section 31' converts the DC power output from the switch section 34 into a charging voltage for the battery 51, respectively. The AC/DC converters 32, 32' convert AC power supplied from the commercial power source 15 into DC power and output the DC power. The switch units 33 and 34 select at least one of the power storage system power outputted from the power storage device 13 and the commercial system power outputted from the AC/DC converter 32 and output it to the battery 51 and the voltage converter 31'. . The control unit 38 controls the selection of the storage system power and the commercial power by the switch units 33 and 34 so that at least the storage system power is selected before starting charging of the battery 51, and After the start, control is performed so that only commercial power is selected when the remaining amount of power stored in the power storage device 13 is less than or equal to a predetermined value.

As a result, even if the power storage system power output from the voltage converters 31, 31' is selected before the start of charging the battery 51, if the remaining amount of power stored in the power storage device 13 falls below a predetermined value after the start of charging, (S109; No), only the commercial power output from the AC/DC converters 32, 32' is selected (S115). Therefore, if the remaining amount of power stored in the power storage device 13 becomes equal to or less than a predetermined value while power storage system power is being output to the battery 51 (charging) (S109; No), the control unit 38 causes the commercial power supply 15 to Commercial power supplied via the DC converters 32 and 32' is selected and output to the battery 51. Therefore, it is possible to prevent charging of the battery 51 from ending with insufficient charging, and it is possible to stably charge the battery 51 using renewable energy. Furthermore, if both the storage power output from the voltage converters 31, 31' and the commercial power output from the AC/DC converters 32, 32' are selected (S121; Yes), the battery Since the charging time of battery 51 is shortened, high-speed charging of battery 51 becomes possible.

[Second embodiment]
Next, as a second embodiment, a control process having a supplementary charging function (control process with supplementary charging) will be described with reference to FIG. Similarly to the modified example of the first embodiment described above, the control process with supplementary charging shown in FIG. . Therefore, a description of each of these processes (S101 to S115) will be omitted. Note that the control process with supplementary charging can be performed by the charging devices 20a and 20b.

In the basic control process of the first embodiment described above, as shown in the charging patterns shown in FIGS. 4(A) and 4(B), the DC power output from the power storage device 13 (the After the battery 51 was charged at a constant current (CC charge) using electric power), the battery 51 was charged at a constant voltage (CV charge) using DC power (commercial power) output from the AC/DC converters 32, 32'. In other words, after the power storage system power that can be supplied by the power storage device 13 is used up based on the remaining power stored at the time (remaining power storage amount at the time of the power storage device 13), the AC/DC converter 32, 32' The insufficient charge of the battery 51 was being charged using electric power.

Therefore, in the second embodiment, contrary to the basic control process of the first embodiment, only the insufficient charge amount of the battery 51 which is insufficient with the remaining amount of electricity stored in the power storage device 13 at that point in time is first stored in the AC/DC converter. After constant current charging (CC charging) with the commercial power of 32, 32', constant current charging (CC charging) or constant voltage charging (CV The algorithm was configured so that the battery can be recharged (recharged). In other words, for the remaining charge which cannot be charged by the battery 51 with the power storage system based on the remaining power stored in the power storage device 13 at the current time, the commercial power of the AC/DC converter 32, 32' is first used to supplement the battery 51. It was to be.

As shown in FIG. 7, in the control process with supplementary charging, after it is determined in step S105 that charging is necessary (S105; Yes), a charging shortage calculation process is performed in the subsequent step S131. In this process, a calculation is performed to determine the amount of insufficient charge of the battery 51 by subtracting the remaining charge from the rated capacity of the battery 51. For example, when the rated capacity of the battery 51 is 450Ah and the remaining charge is 10Ah, the insufficient charge of the battery 51 is determined to be 440Ah (=450Ah-10Ah).

In the next step S133, a determination process is performed to determine whether supplementary charging of the battery 51 is necessary, based on the insufficient charge amount of the battery 51 calculated in step S131. That is, a process is performed to determine whether the amount of insufficient charge of battery 51 is greater than the remaining amount of electricity stored in power storage device 13 at the current time (the remaining amount of electricity stored at the point in time is smaller than the amount of insufficient charge of battery 51). If the amount of insufficient charge of the battery 51 is larger than the remaining amount of electricity stored in the power storage device 13 at the current time (S133; Yes), charging cannot be completed with only the storage system power based on the remaining amount of electricity at the time. , the battery 51 may become insufficiently charged. Therefore, in this case, the process moves to the subsequent step S135.

On the other hand, if the amount of insufficient charge in the battery 51 is not greater than the remaining amount of power stored in the power storage device 13 at the relevant point in time (if it is less than the remaining amount of stored power in the point in time), in other words, it is determined that supplementary charging of the battery 51 is not necessary. In this case (S133; No), charging of the battery 51 can be completed using only the power storage system based on the remaining amount of power stored in the power storage device 13 at that point in time without replenishing the battery 51. Charging function becomes unnecessary. In this case (S133; No), the process content is the same as the basic control process described above, so after moving to step S107, each process (S107 to S115) is executed in the same manner as described above.

In step S135, AC/DC converter activation processing is performed. In this process, a control command including a startup command, information on an output current value, etc. is sent to the AC/DC converters 32, 32'. This output current value information is information on a constant current value necessary when performing constant current charging (CC charging) on the battery 51, and includes, for example, the output voltage and output of the power storage device 13 acquired in step S103. It is generated based on current information and information on the terminal voltage and terminal current of the battery 51.

In the following step S137, switch section switching processing is performed. In the initialization process (S101), the switch units 33 and 34 set the switches 33a and 34a to the on state and the switches 33b and 34b to the off state, so in this process, the switches 33a and 34a are set to the off state. In this state, the switch units 33 and 34 are controlled to turn the switches 33b and 33b on. This makes it possible to output the commercial power of the AC/DC converters 32, 32' to the charging output terminal 25 (charging device 20a) or to the voltage converting section 31' (charging device 20b). become.

Since commercial power is supplied to the battery 51 by switching the switch units 33 and 34 in the switch unit switching process (S137), information on the terminal voltage and terminal current of the battery 51 is obtained by the sensor information acquisition process in step S139. etc. are obtained. This makes it possible to obtain the remaining charge level of the battery 51, so that it is possible to determine whether supplementary charging is necessary when the process returns to step S133 again. Note that the order of the AC/DC converter activation process (S135) and switch unit switching process (S137) may be reversed.

In the previous example, when the remaining amount of stored power in the power storage device 13 is 200 Ah, the remaining amount of stored power is smaller than the insufficient charge amount of the battery 51, 440 Ah, so in the process of determining the necessity of supplementary charging in step S133, It is determined that supplementary charging is necessary (S133; Yes). Therefore, commercial power is supplied to the battery 51 by the AC/DC converters 32 and 32' activated by the AC/DC converter activation process in step S135, and the battery 51 is charged.

As a result, the remaining charge of the battery 51 increases with the passage of time, and the amount of insufficient charge decreases. Then, as the amount of insufficient charge in the battery 51 and the remaining amount of electricity stored in the power storage device 13 approach or reverse in magnitude, the amount of insufficient charge becomes approximately equal to or smaller than the insufficient amount of charge 200Ah (charging Insufficient amount ≦ remaining amount of stored electricity). Therefore, in such a case, it is determined that supplementary charging of the battery 51 is unnecessary (not necessary) by the supplementary charging necessity determination process in step S133 (S133; No), so in this case, the process proceeds to step S107. Then, each process (S107 to S115) is performed in the same manner as described above.

In this way, in the control processing with supplementary charging of the second embodiment, it is possible to compensate for the insufficient charge of the battery 51 by charging with the commercial power output from the AC/DC converter 32. Therefore, after the insufficient charge of the battery 51 becomes equal to or less than the remaining amount of power stored in the power storage device 13, even if only power from the power storage system is selected and output to the battery 51, only the remaining amount of power stored in the power storage device 13 at that point in time is used. It becomes possible to complete charging of the battery 51 (bring it into a fully charged state). Therefore, after the battery 51 is charged with the storage system power, the battery 51 is not charged again with the commercial system power.

In addition, in the second embodiment, the basic control process of the first embodiment (after charging with the storage system power, the battery 51 is charged with the storage system power after replenishing the battery 51 with the commercial system power), Charging is performed in the reverse order compared to charging with electricity. Therefore, the charging pattern under the supplementary charging control has charging voltage and charging current curves that are almost the same as those shown in FIG. 4(A) and FIG. This differs from the charging pattern according to the basic control process of the first embodiment in that the period Tb is the time period during which supplementary charging is being performed and the battery 51 is being charged by the storage system power.

As described above, in the charging devices 20a and 20b according to the second embodiment, during a period when the insufficient charge of the battery 51 is larger than the remaining amount of power stored in the power storage device 13, the AC/DC converters 32 and 32' Since the commercial power output from the battery 51 is outputted to the battery 51 and charged, it becomes possible to compensate for the shortage that cannot be charged with the remaining amount of power stored in the power storage device 13 at the time by charging with the commercial power. . Therefore, after the insufficient charge of the battery 51 becomes equal to or less than the remaining amount of power stored in the power storage device 13, even if only the power storage system power output from the voltage converters 31, 31' is selected and output to the battery 51, It becomes possible to complete charging of the battery 51 (bring it into a fully charged state) using only the remaining amount of power stored in the power storage device 13 at that time.

[Third embodiment]
Next, as a third embodiment, the configuration of charging devices 20c and 20d having an alternative charging function will be described with reference to FIGS. 8 and 9. The alternative charging function is supplied from the solar panel 11 when the solar panel 11 is not generating power due to sunlight conditions, or when DC power cannot be supplied from the solar panel 11 due to a failure or the like. Instead of direct current power, charging devices 20c and 20d can supply direct current power to power storage device 13 as alternative power.

As shown in FIG. 8, the charging device 20c has a configuration in which a switch section 35 is added to the charging device 20a (FIG. 2) of the first embodiment described above. Therefore, in FIG. 8, components that are substantially the same as those of the charging device 20a of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the charging device 20c, the output side of the AC/DC conversion section 32 is connected not only to the switch section 33 but also to the DC input terminal 23 via a switch 35b of the switch section 35.

This switch unit 35 is a switching unit having switches 35a and 35b that can exclusively control on/off of two inputs and outputs. One switch 35a is interposed between the DC input terminal 23 and the input side of the voltage converter 31 to control on/off conduction between them, and the other switch 35b is interposed between the DC input terminal 23 and the input side of the voltage converter 31. It is interposed between the converter 32 and the output side of the converter 32 to control conduction between them. This switch section 35 is connected to a control section 38 and controlled as follows.

For example, when the switch 35a is controlled to be on, the switch 35b is controlled to be off, so that the DC power (storage system power) of the power storage device 13 input from the DC input terminal 23 is converted into voltage via the switch 35a. At the same time, conduction between the output side of the AC/DC converter 32 and the DC input terminal 23 is interrupted. Further, when the switch 35b is controlled to be in the on state, the switch 35a is controlled to be in the off state, so that the DC power (commercial power) output from the AC/DC converter 32 is supplied to the DC input terminal 23 via the switch 35b. At the same time, the conduction between the DC input terminal 23 and the input side of the voltage converter 31 is interrupted.

By configuring the charging device 20c in this way, the commercial power output from the AC/DC conversion section 32 is supplied to the power storage device 13 connected to the DC input terminal 23 via the switch section 35 of the switch section 35. It becomes possible to do so. That is, the commercial power output from the AC/DC converter 32 is output from the DC input terminal 23 in the opposite direction to the energy storage system power output from the power storage device 13 and input to the DC input terminal 23. The power is input to the power storage device 13. Thereby, the power storage device 13 is supplied with alternative power from the charging device 20c in place of the DC power that should be supplied from the solar panel 11, so that the power storage device 13 can store the DC power.

Further, as shown in FIG. 9, the charging device 20d has a configuration in which a switch section 36 is added to the charging device 20b (FIG. 6) of the modified example of the first embodiment described above. Therefore, in FIG. 9, components that are substantially the same as those of the charging device 20b of the modified example are given the same reference numerals, and description thereof will be omitted. In the charging device 20d, the output side of the AC/DC conversion section 32' is connected not only to the switch section 34 but also to the DC input terminal 23 via the switch section 36.

This switch section 36 is a switching section that is connected to the control section 38 and can control one circuit of switches on and off. For example, when the switch of the switch section 36 is controlled to be in the on state, both the switches 34a and 34b of the switch section 34 are controlled to be in the off state. Therefore, the DC power (commercial power) output from the AC/DC conversion section 32' is output to the DC input terminal 23 via the switch section 36, and one of the DC input terminal 23 and the voltage conversion section 31' is output. Continuity between the input side and the output side of the AC/DC converter 32' and the other input side of the voltage converter 31' is disconnected.

By configuring the charging device 20d in this way, the commercial power output from the AC/DC conversion section 32' can be supplied to the power storage device 13 connected to the DC input terminal 23 via the switch section 36. It becomes possible. That is, the commercial power output from the AC/DC converter 32' is output from the DC input terminal 23 in the opposite direction to the energy storage system power output from the power storage device 13 and input to the DC input terminal 23. and is input to the power storage device 13. Thereby, the power storage device 13 is supplied with alternative power from the charging device 20d in place of the DC power that should be supplied from the solar panel 11, so that the power storage device 13 can store the DC power.

As explained above, in the charging devices 20c and 20d according to the third embodiment, alternative power equivalent to the power generated by the solar panel 11 is supplied from the AC/DC converters 32 and 32' to the power storage device 13. It is configured so that it can be done. When the solar panel 11 does not generate power, alternative power is supplied to the power storage device 13 from the AC/DC converters 32 and 32'. In power generation using renewable energy such as the solar cell panel 11, the state of power generation, such as whether sufficient power can be generated, is left to natural phenomena. Therefore, when the solar battery panel 11 or the like does not generate power, alternative power is supplied from the commercial power source 15 to the power storage device 13 via the AC/DC converters 32 and 32', thereby supplying power to the power storage device 13. It becomes possible to store. This makes it possible to recover from insufficient power storage in the power storage device 13 when power generation using renewable energy is not possible.

[Fourth embodiment]
Next, a charging system 60 including a charging device 70 according to a fourth embodiment will be described with reference to FIGS. 10 to 15. As shown in FIG. 10, a charging system 60 including a charging device 70 of the fourth embodiment has the following features: the charging device 70 is configured to be able to charge a plurality of forklifts 50a to 50c, and the charging system 60 includes the charging device 70 of the fourth embodiment. The main difference from the charging system 10 of the first embodiment is that the driving schedule information is acquired from the management computer 80. Therefore, components that are substantially the same as those of the charging system 10 and the charging device 20 of the first embodiment are given the same reference numerals, and description thereof will be omitted. Note that the forklifts 50a to 50c are configured similarly to the forklift 50 described in the charging system 10 of the first embodiment, and the batteries 51a to 51c are also configured similarly to the battery 51 of the forklift 50. Therefore, descriptions of these will also be omitted.

As shown in FIG. 11, the charging device 70 mainly includes a voltage conversion section 31, an AC/DC conversion section 32, switch sections 33, 76, a control section 78, a voltage node 39, sensors 41, 42, etc. These are housed in a metal housing 71. For example, a DC input terminal 73 to which DC power supplied from the power storage device 13 is input, an AC input terminal 74 to which AC power supplied from the commercial power supply 15 is input, and a management computer 80 are connected to the housing 71. An information input/output terminal 75, a charging output terminal group 77 to which a plurality of charging cables 18 can be connected, and the like are provided. In contrast to the charging device 20 of the first embodiment, the charging device 70 is provided with an information input/output terminal 75, a switch section 76, a charging output terminal group 77, and a control section 78 that performs control specific to the fourth embodiment. The difference is that they are Voltage converter 31, AC/DC converter 32, etc., which are denoted by the same reference numerals as those of charging device 20, are substantially the same. Further, the DC input terminal 73 and the AC input terminal 74 are also substantially the same as the DC input terminal 23 and the AC input terminal 24 of the charging device 20, respectively.

The information input/output terminal 75 is an input/output connector configured to be connectable to the main body 81 of the management computer 80, and is compliant with serial bus standards such as USB and RS-232C, for example. In the fourth embodiment, it is connected to the input/output port of the control section 78.

The switch section 76 is a selection section that has a plurality of selectable output terminals for one input terminal, and has a selection section between the side of the voltage node 39 connected to the sensor 42, that is, the output side, and the charging output terminal group 77. It is provided so as to be interposed in between. In the fourth embodiment, corresponding to the charging output terminal group 77 having three charging output terminals 77a to 77c, the switch section 76 has three output terminals, and these terminals are connected to charging output terminals 77a to 77c. It is connected to the. The switch section 76 is connected to a control section 78 so as to be able to control the selection of the output end.

The charging output terminal group 77 includes a plurality of charging output terminals 77a and the like. In the fourth embodiment, the charging output terminal group 77 includes three charging output terminals 77a to 77c so that three charging cables 18 respectively connected to three forklifts 50a to 50c can be connected simultaneously. There is. The number of charging output terminals may be four or more or two. Note that when there is no need to connect a plurality of forklifts 50a etc. to the charging device 70, that is, when the charging device 70 is configured so that only one forklift 50 can be connected, the charging device 20 of the first embodiment is used. As shown, the switch section 76 and the charge output terminal group 77 may be omitted and the charge output terminal 25 may be directly connected to the voltage node 39 instead. In this case, the difference in the configuration of the charging device 70 from the charging device 20 of the first embodiment is that the charging device 70 has an information input/output terminal 75, and that the control unit 78 performs control specific to the fourth embodiment.

The control unit 78 has almost the same hardware configuration as the control unit 38 of the charging device 20 described above, but is configured to be able to communicate information with the main body 81 of the management computer 80 via the information input/output terminal 75. It is equipped with a clock module that can obtain information on the current year, month, day, hour, minute, and second from calendar information and time information, and information on the operation schedules of the forklifts 50a to 50c can be obtained from the main body 81 of the management computer 80. It differs from the control unit 38 of the charging device 20 described above in that it acquires and performs control processing to be described later. Such control processing is stored in a memory (EEPROM or the like) of the control unit 78 and is executed by the MPU. Note that the control unit 78 also performs control processing for the voltage conversion unit 31 and the AC/DC conversion unit 32, similarly to the control unit 38 of the charging device 20.

The management computer 80 is typically a personal computer (hereinafter referred to as a "personal computer") consisting of a main body 81, a display 82, a keyboard 83, a mouse 85, etc. Memorizes, records, stores, or retains schedule information (hereinafter referred to as "memory, etc."). In the fourth embodiment, the management computer 80 is connected to the Internet 100 via a data communication device 87 and an unillustrated ISP (Internet Service Provider). Therefore, the management computer 80 includes, for example, weather information of the area where the charging system 60 is located, and historical information regarding the batteries 51a to 51c mounted on the forklifts 50a to 50c (the number of times the battery 51a etc. have been charged, the past charging current, etc.). It is also possible to obtain (output) the acquired weather information of the area to the charging device 70. It is.

The charging device 70 configured as described above executes control processing (basic control processing) different from the charging device 20 of the first embodiment by acquiring information on the driving schedules of the forklifts 50a to 50c from the management computer 80. do. Here, in order to clarify the difference between the basic control process executed by the charging device 70 of the fourth embodiment and the basic control process executed by the charging device 20 of the first embodiment, refer to FIG. I will explain while doing so. FIG. 12(A) shows an example of power storage and charging in the charging system 10 and an example of power system switching by the charging device 20 in response to the driving schedule of the forklift 50, and FIGS. 12(B) to 12(D) show An example of power storage and charging by the charging system 60 and an example of power system switching by the charging device 70 in response to the driving schedule of the forklift 50a, etc. are illustrated, respectively.

In addition, in FIGS. 12(A) to 12(D), "time of use (*)" (* indicates a, b, ho, f) indicates the operating period or operating days (for example, Monday to Friday) of the forklift 50, etc. , and "downtime period (*)" (* indicates C and D) represents the period of suspension or suspension days (for example, Saturday and Sunday) of the forklift 50, etc. Note that the operating period and operating days are also referred to as operating periods and working days, and the suspension periods and suspension days are also referred to as non-operating periods and non-operating days. "Charging" represents the charging period of the batteries 51, 51a, etc. by the charging devices 20, 70, and "power storage ○○%" represents the power storage period of the power storage device 13 by the solar battery panel 11 etc. and the amount of stored power ○○%. "Regeneration" and an arrow represent a charging period using storage system power, and "commercial" and an arrow represent a charging period using commercial power. Further, an x mark in a rectangular frame indicates that the charging devices 20, 70 do not perform charging. Further, "ts" represents the start time of the forklift 50, etc., and "te" represents the end time of the operation of the forklift 50, etc.

In the basic control process by the charging device 20 of the first embodiment, as described with reference to FIG. Even if the unit 38 makes a selection, if the remaining amount of power stored in the power storage device 13 becomes less than a predetermined value after the start of charging (S109; No), the control unit 38 controls only the commercial power output from the AC/DC converter 32. (S115). As a result, as in the period (c) and period (e) shown in FIG. 12(A), the remaining amount of power stored in the power storage device 13 becomes equal to or less than the predetermined value while the power storage system power is being output to the battery 51 (during charging). In such a case, by selecting commercial power and outputting it to the battery 51, charging of the battery 51 is prevented from being completed with insufficient charge, and the battery 51 can be stably charged using renewable energy. I made it.

However, as in the usage time period (b), when the current time when the remaining amount of electricity in the power storage device 13 falls below a predetermined value during charging is the usage time immediately before the rest time period (c), for example. , in the case of Friday, the day before Saturday (rest day)), or if the current time is in the rest period (c) (for example, in the case of Saturday (rest day)), the period shown in Figure 12 (A) As shown in (f), there is a possibility that a power generation device using renewable energy such as the solar battery panel 11 generates electricity and the power storage device 13 stores electricity during the downtime period (c). In other words, there is a possibility that the charging of the battery 51 performed by selecting commercial power during the use time period (b) was replaced with charging using the power storage system power stored in the power storage device 13 during the rest time period (c). is high. In this example, there is a possibility that unnecessary commercial power was used during the use time period (b), or that stored power from the storage system was wasted during the down time period (c).

Therefore, as shown in FIGS. 12(B) and 12(C), in the basic control processing by the charging device 70 of the fourth embodiment, information on the driving schedules of the forklifts 50a to 50c is transmitted from the management computer 80. By acquiring the information from the charging device 70, the current time when the remaining amount of electricity stored in the power storage device 13 becomes less than a predetermined value during charging is immediately before the stop time period (c), as in the use time period (b). In the case of the time zone or the idle time zone (c) or (d), the remaining power storage capacity of the power storage device 13 becomes 100% or 50% without the control unit 78 selecting commercial power. The configuration is such that charging of the battery 51a, etc. is resumed after waiting for this period. This makes it possible to prevent wasting power storage system power stored in power storage device 13 and suppressing use of unnecessary commercial power system.

The flow of the basic control processing by the charging device 70 is illustrated in FIGS. 13 and 14, and will be described from here on with reference to these figures as well. FIG. 13 shows a flowchart showing the flow of basic control processing executed in the charging device 70 of the fourth embodiment. Further, FIG. 14 shows a flowchart showing the flow of the power storage waiting process shown in FIG. 13. Note that some steps having substantially the same processing content as the basic control processing (FIG. 3) executed in the charging device 20 of the first embodiment are given the same reference numerals, and the description thereof will be omitted.

Although not shown, the housing 71 of the charging device 70 is provided with a charging start switch having, for example, an LED, similarly to the housing 21 of the charging device 20, and this switch can be turned on. As a result, basic control processing by the control unit 78 is started, and the LED continues to be lit while the processing is being executed. Upon completion of the process, the LED turns off. Also, here, the battery 51a of the forklift 50a is selected as a specific one from among the three forklifts 50a to 50c connected to the charging device 70 via the three charging cables 18 by a selection control process to be described later. A case where the charging device 70 charges the battery will be described as an example.

As shown in FIG. 13, in the basic control process of the fourth embodiment, the control unit 78 of the charging device 70 first performs a predetermined initialization process in step S101, and then performs sensor information acquisition process in step S103. Then, based on the obtained voltage information and current information, it is determined in step S105 whether or not it is necessary to charge the battery 51a. If it is determined that charging is not necessary (no charging is required) (S105; No), this means that the battery 51a has been completely charged, so the voltage conversion unit etc. stop processing in step S106 is performed. After transitioning to , this basic control processing ends.

On the other hand, if it is determined in step S105 that charging is necessary (S105; Yes), the voltage converter startup process is performed in the next step S107, and the voltage converter 31 is given a startup command and an output current value. A control command including information such as , etc. is sent, and control processing (not shown) regarding the CCCV method is also started. Thereby, the DC power supplied from the power storage device 13 is output as charging power to the battery 51a via the voltage converter 31, and constant current charging (CC charging) is started.

In the case where it is determined by the subsequent determination process in step S109 that the remaining amount of power stored in the power storage device 13 is equal to or higher than a predetermined value (for example, around 5% (4 to 6%) of the amount of stored power when the power storage device 13 is fully charged) (S109; Yes), since the remaining amount of power storage is not low, the process returns to step S103 and the sensor information acquisition process is performed again. On the other hand, if it is determined that the remaining power storage amount of the power storage device 13 is not greater than or equal to the predetermined value (less than the predetermined value) (S109; No), the power storage device 13 has only a small amount of power remaining. 13, there is a high probability that it will be difficult to output DC power in a short period of time.

Therefore, in such a case, the process moves to step S110, and it is determined whether the current time is immediately before a downtime period or the like. In other words, if the current time is the usage time immediately before the downtime (for example, Friday, the day before Saturday (downday)), or if the current time is in the downtime (for example, Saturday (downday) ), commercial power is not selected immediately, and the power storage device 13 waits for the power storage device 13 to store power up to a predetermined amount of power. Therefore, if the current time is just before the suspension time period (S110; Yes), the process moves to step S200.

On the other hand, if the current time is not immediately before a downtime period, that is, if the current time is a usage time period that is not immediately before a downtime period (for example, if the usage day is Monday, Tuesday, Wednesday, or Thursday), Immediately after the use time period is also a use time period and is not a rest time period. Therefore, as in the case of the first embodiment, the process moves to step S113 (S111; No), and the process of activating the AC/DC converter 32 is performed. Note that in the determination process of step S111, if the AC/DC conversion unit 32 has already been activated (S111; Yes), the AC/DC conversion unit activation process (S113) and the switch unit switching process (S115) are performed again. It prevents people from doing so. Further, the contents of the AC/DC converter activation process (S113) and the switch unit switching process (S115) are the same as those in the first embodiment, so a description thereof will be omitted.

In step S200, power storage waiting processing is performed. Regarding this, the flow of processing is illustrated in FIG. 14, so the explanation will be made with reference to that figure as well. As shown in FIG. 14, in the power storage waiting process, sensor information etc. acquisition process is first performed in step S201. In this process, information on the output voltage and output current of the power storage device 13 detected by the sensor 41, information on the terminal voltage and terminal current of the battery 51a connected to the charging output terminal 77a and detected by the sensor 42, and management Weather information for the area (information on sunshine hours, wind speed, wind direction, etc.) provided by the computer 80, historical information regarding the battery 51a, etc. are acquired.

In the following step S203, processing such as calculation of the required power storage time, etc. is performed. For example, based on information such as the output voltage of the power storage device 13 acquired in step S201 and weather information of the region, the time required for the power storage device 13 to store a predetermined amount of power (power storage A process of calculating or estimating the required time is performed. Further, based on the information on the terminal voltage and terminal current of the battery 51a acquired in step S201, information on the state of charge of the battery 51a (for example, the amount of remaining charge, the degree of deterioration, etc.) is calculated. Processing such as estimation is performed.

The predetermined amount of stored power may be any amount that exceeds the predetermined value of the remaining amount of stored power in the power storage device 13 described above (for example, around 5% (4 to 6%) of the amount of stored power when the power storage device 13 is fully charged). , for example, is set to around 95% (94-96%) or more of the amount of power stored in the power storage device 13 when the power is fully charged, or around 70% (68-72%) or more of the amount of power stored when the power storage device 13 is fully charged.

Calculation and estimation of the required time for power storage can be done based on, for example, the electrical characteristics of the power generation device that uses renewable energy, such as the solar panel 11, accumulated data on past power generation results, and the weather in the area. This is done based on information (information on sunshine hours, wind speed and direction, etc.). In addition, calculation and estimation of the state of charge of the battery 51a can be performed using, for example, the number of times the battery 51a has been charged, accumulated data on past charging currents and discharging currents, information on typical charging and discharging characteristics of batteries of the same type, etc. This is done based on history information provided from the management computer 80.

In the next step S205, based on the required power storage time of the power storage device 13 calculated in step S203, it is determined whether the power storage of the power storage device 13 is completed by a predetermined time before the usage start time when the usage time period starts. Processing is performed to determine whether or not. That is, based on the time required for the battery 51a to be completely charged by the storage system power after the power storage device 13 stores a predetermined amount of power, and the time information of the current year, month, day, hour, minute, and second, If it is estimated that the battery 51a will be charged more than a predetermined time before the start time, charging of the battery 51a will not be completed in time for the use start time when the use time period begins. Therefore, when it is determined in this way (S205; No), it is difficult to charge the battery 51a with the power storage system power supplied from the current power storage device 13, so the main power storage wait process is terminated ( RET2), the process returns to step S111 of the basic control process described above. Then, the process moves to step S113 (S111; No), and the AC/DC converter 32 is activated.

On the other hand, if it is determined that the power storage of the power storage device 13 is completed by the predetermined time before the start time of the use time zone (S205; Yes), the process moves to the following step S207, and then the process proceeds to step S203. Based on the calculated information on the state of charge of the battery 51a, a process is performed to determine whether or not charging of the battery 51a is completed before the usage start time when the usage period starts.

That is, based on the time required to complete charging of the battery 51a with the power storage system power supplied from the stored power storage device 13 and the current time information of the year, month, day, hour, minute, and second, '', the charging of the battery 51a will not be completed in time for the usage start time when the usage period begins. Therefore, even if it is determined in this way (S207; No), it is difficult to charge the battery 51a with the power storage system power supplied from the current power storage device 13, so the main power storage wait process is terminated ( RET2), the process returns to step S111 of the basic control process described above. Then, the process moves to step S113 (S111; No), and the AC/DC converter 32 is activated.

On the other hand, if it is determined that the charging of the battery 51a is completed before the usage start time when the usage period starts (S207; Yes), the power storage device 13 is charged to a predetermined amount of stored power in the subsequent step S209. A process is performed to determine whether or not the power has been stored up to the point where the power has been stored. This determination is performed based on the amount of power stored in the power storage device 13 calculated from the information on the output voltage and output current of the power storage device 13 already acquired in step S201. If it is not determined that the power storage device 13 has stored power up to a predetermined amount of power (it is determined that it is not storing power) (S209; No), the process returns to step S201 and the sensor information etc. acquisition process is performed again.

If it is determined in step S209 that the power storage device 13 has stored power up to the predetermined amount of power (S209; Yes), the main power storage waiting process is ended (RET1) and the process returns to step S103 of the basic control process described above. . As a result, the battery 51a can be charged by the power storage device 13 that has been stored up to a predetermined amount of power, so that, for example, the period (j) shown in FIG. 12(B) and the period ( The battery 51a can be charged during periods (g) and (j) shown in h) and FIG. 12(D). The example shown in FIG. 12(B) is a case where the predetermined amount of stored power described above is set to a value close to full charge (around 95% (94 to 96%) of the amount of stored power), and the example shown in FIG. ) and the example shown in FIG. 12(D) are cases where the predetermined amount of stored power is set to approximately half the value of full charge (around 50% (48 to 52%) of the amount of stored power).

Note that the use time period (E) in FIGS. 12(A) to 12(D) is a use time period (e.g., Monday) that is not immediately before the idle time period, so the power storage system power from the power storage device 13 is used by the battery 51a. If the battery cannot be charged to completion, the process moves to step S113 (S111; No) and the process of activating the AC/DC converter 32 is performed, as in the first embodiment. As a result, the battery 51a is charged with commercial power until charging is completed, as in the period (n) shown in FIG. 12(D).

In the charging device 70 that performs such basic control processing, by performing the selection control processing shown in FIG. Charging power (charging voltage, charging current) is supplied to a battery 51a or the like of the forklift 50a or the like selected from among 50a to 50c by a predetermined charging order determination process.

As shown in FIG. 15, in the selection control process of the fourth embodiment, the control unit 78 of the charging device 70 first performs a predetermined initialization process in step S501. In this process, for example, the work area for this process in the memory (RAM) of the control unit 78 is cleared, all charging flags are turned off, and a control command for initial setting is sent to the switch unit 76. For example, as a default setting of the switch section 76, a predetermined output end is selected and the input end and the predetermined output end are connected. The charging flag is associated with each of the plurality of batteries 51a, etc., and OFF indicates that the battery 51a, etc. is uncharged, and ON indicates that the battery 51a, etc. has been charged.

In the next step S503, battery information acquisition processing is performed. In this process, for example, information on the terminal voltage and terminal current of the battery 51a and the like detected by the sensor 42 is acquired from the sensor 42 while sequentially switching the switch section 76. As a result, battery information of the batteries 51a to 51c connected to the charging output terminals 77a to 77c, respectively, is acquired. Further, historical information regarding the batteries 51a to 51c provided by the management computer 80 (data accumulating the number of times the battery 51a etc. has been charged, past charging currents, discharging currents, etc.) is acquired from the management computer 80.

Therefore, in step S503, the state of charge of the battery 51a, etc. (for example, the amount of remaining charge, the degree of deterioration, It also calculates and estimates information such as the size of The information on the charging states of the batteries 51a to 51c thus obtained is used in the charging order determination process in the next step S505.

In the charging order determination process of step S505, for example, the batteries 51a to 51c are charged in an order that can shorten the overall charging time of the batteries 51a to 51c. For example, a battery 51a or the like with a large remaining charge becomes fully charged in a shorter time than a battery 51a or the like with a small remaining charge. Further, for example, the charging capacity of the battery 51a and the like decreases as the deterioration progresses, so the battery 51a and the like with a large degree of deterioration can be fully charged in a shorter time than the battery 51a and the like with a small degree of deterioration.

For this reason, for example, when the remaining charge is greater in the order of battery 51c→battery 51a→battery 51b, weighting is performed in this order. Furthermore, when the degree of deterioration is greater in the order of battery 51a→battery 51c→battery 51b, weighting is performed in this order. Then, the charging order of the batteries 51a and the like is determined so that charging is started in descending order of the sum of both weights.

In the subsequent step S507, the switch unit 76 is switched to select a corresponding battery 51a or the like to be charged in accordance with the order determined by the charging order determination process in step S505. In the charging order determination process (S505), for example, when charging in the order of battery 51c → battery 51b → battery 51a, the switch unit 76 is controlled to first select the charging output terminal 77c to which the battery 51c is connected. do.

After starting the basic control process shown in FIG. 13 described above, sensor information acquisition process is performed in step S509. In this process, information on the terminal voltage and terminal current of the battery 51c, which can currently be charged by the basic control process, is acquired from the sensor 42. Then, based on the acquired information such as the terminal voltage, it is determined in step S511 whether or not charging of the battery 51c has been completed, and if it is determined that charging has not been completed yet (S511; No), the process returns to step S509 and the sensor information acquisition process is performed again.

On the other hand, if it is determined that the charging of the battery 51c is completed (S511; Yes), the charging flag associated with the battery 51c is set to ON in step S513, and the battery 51c is fully charged. record that it is. Thereafter, the determination process of step S515 is moved on, and each process of steps S503 to S513 is repeated until charging of all the batteries 51a etc. connected to the charging output terminal group 77 is completed (S515; No). This determination is made based on the charging flag. If it is determined that charging of all the batteries 51a etc. connected to the charging output terminal group 77 is completed (S515; Yes), the basic control process shown in FIG. 13 is finished, and then the main selection control process is finished. do. Note that the basic control process ends when charging is completed (FIG. 15; S105; No).

As described above, the charging device 70 according to the fourth embodiment includes the voltage conversion section 31, the AC/DC conversion section 32, the switch section 33, and the control section 78. The voltage converter 31 converts DC power input from the DC input terminal 73 into a charging voltage for the battery 51. The AC/DC converter 32 converts AC power supplied from the commercial power supply 15 into DC power and outputs the DC power. The switch unit 33 selects at least one of the power storage system power output from the power storage device 13 and the commercial power system output from the AC/DC conversion unit 32, and outputs the selected power to the batteries 51a to 51c. The control unit 78 controls the selection of the storage system power and the commercial power by the switch unit 33, and also controls the electric motors (power loads) of the forklifts 50a to 50c to operate for a predetermined length using the DC power charged in the batteries 51a to 51c. Information on the operation schedules of the forklifts 50a to 50c during operating hours and during a predetermined length of downtime when they are not in use is obtained from the management computer 80 (external). Then, after controlling the switch unit 33 to select at least the power storage system power and start charging the battery 51a, etc., the control unit 78 controls the switch unit 33 to select at least the power storage system and start charging the battery 51a, etc., and then (1) the remaining amount of power stored in the power storage device 13 is equal to or less than a predetermined value and the current time is the rest period. If it is included in a usage time period that is not immediately before the stop time, the switch unit 33 is controlled to select commercial power; If it is included in a certain usage time zone or idle time zone, charging of the battery 51a etc. is resumed after the power storage device 13 has accumulated power exceeding a predetermined value without selecting commercial power.

As a result, at least after the power storage system power is selected and charging of the battery 51a etc. is started, (1) the remaining amount of power stored in the power storage device 13 is below a predetermined value and the current time is within a usage time period that is not immediately before a stop time period; If so, commercial power is selected. Therefore, when the remaining power of the power storage device 13 falls below a predetermined value while outputting power from the power storage system to the battery 51a etc., that is, while charging, and the current time is included in a usage time period that is not immediately before a rest time period, The control unit 78 selects the commercial power supplied from the commercial power source via the AC/DC conversion unit 32 and outputs it to the battery 51a and the like. Further, when both the storage power and the commercial power are selected, the charging time of the battery 51a and the like is shortened, so that the battery 51a and the like can be charged at high speed. In addition, at least after the power storage system power is selected and charging of the battery 51a etc. is started, (2) the remaining power storage capacity of the power storage device 13 is below a predetermined value and the current time is immediately before the stop time period or during the stop period. If it is included in the time period, charging of the battery 51a and the like is resumed after the power storage device 13 has accumulated power exceeding a predetermined value. Therefore, it prevents commercial power from being selected even though the current time is within the usage period immediately before the downtime or in the downtime, so renewable energy can be used to generate electricity during the downtime. This makes it possible to prevent wasting stored power from the storage system and from using unnecessary commercial power.

In addition, in the charging device 70 according to the fourth embodiment, the control unit 78 determines that (2) after at least the power storage system power is selected and charging of the battery 51a etc. is started, the remaining amount of power stored in the power storage device 13 is a predetermined level If the current time is below the value and the current time is included in the use time period or the rest time period immediately before the rest time period, charging of the battery 51a etc. is restarted after waiting for the power storage device 13 to store electricity exceeding the predetermined value, but the battery 51a etc. Before or after resuming charging of the battery 51a, etc., if it is determined that the charging of the battery 51a, etc. will not be completed by the time the use time period starts immediately after the rest time period, the switch unit 33 selects commercial power. control. Further, when it is determined that the storage of power in the power storage device 13 is not completed by a predetermined time before the start of the use time period immediately after the stop time period, the switch unit 33 is controlled to select commercial power. That is, if it is estimated and determined that the battery 51a etc. will not be charged in time by the time the use time period starts, commercial power will be selected to charge the battery 51a etc. This makes it possible to prevent the occurrence of a situation in which the battery 51a and the like cannot be charged even after the usage period has started.

Further, in the charging device 70 according to the fourth embodiment, the control section 78 controls the switch section 76 based on the charging state of the plurality of batteries 51a to 51c connected to the charging output terminals 77a to 77c. The state of charge of the batteries 51a to 51c is, for example, the amount of remaining charge or the degree of deterioration. Typically, a battery 51a or the like with a large remaining charge becomes fully charged in a shorter time than a battery 51a or the like with a small remaining charge. Further, typically, for example, the charging capacity of the battery 51a etc. decreases as the deterioration progresses, so the battery 51a etc. with a large degree of deterioration will be fully charged in a shorter time compared to the battery 51a etc. with a small degree of deterioration. . As a result, a battery 51a etc. with a large remaining charge level is charged with priority over a battery 51a etc. with a small remaining charge level, or a battery 51a etc. with a high degree of deterioration is charged with priority over a battery 51a etc. with a low degree of deterioration. By doing so, the overall charging time can be shortened.

In addition, in the fourth embodiment described above, for example, one day (24 hour unit) of working days is set as five days from Monday to Friday as a usage time period of a predetermined length, and one working day is set as a predetermined length of a down time period. The explanation has been given by exemplifying the case where two non-working days, Saturday and Sunday, are set as schedule information. The length of the downtime period is not limited to this. For example, contrary to the example of the fourth embodiment, one working day is set as two days, Saturday and Sunday, as a usage time period of a predetermined length, and one non-working day is set as a non-working day of a predetermined length. may be set as schedule information for each of the five days from Monday to Friday. In addition, regardless of the day of the week in the calendar, for example, one working day can be set as a working time period of a predetermined length for four consecutive days, and then one non-working day can be set as a non-working day of a predetermined length as a resting time period. The schedule information may be set so that a total of five consecutive days are made into one set and this set is repeated. Furthermore, for example, schedule information may be set to alternately repeat operating time in 12-hour units as a usage time period of a predetermined length, followed by non-operating time in 12-hour units as a rest time period of a predetermined length. You can.

In addition, in the fourth embodiment described above, the control unit 78 of the charging device 70 uses external management as information on the operation schedules (schedule information of operating hours and idle periods) of the forklifts 50a to 50c used in the basic control process. Although the configuration has been described by illustrating the configuration obtained from the computer 80, the present invention is not limited to such a configuration. Such schedule information may be stored in an information storage device such as a solid state drive and housed in the charging device 70 or attached to the outside of the charging device 70. Such schedule information may be stored in an EEPROM or the like.

Furthermore, in the fourth embodiment described above, a case is exemplified in which the charging device 20a of the first embodiment adds a determination process (S110) as to whether or not it is immediately before a rest period, etc., and a power storage waiting process (S200). However, the present invention is not limited to such an algorithm. For example, in the control process with battery assist by the charging device 20b of the first embodiment (FIG. 5) and the control process with supplementary charging by the charging devices 20a and 20b of the second embodiment (FIG. 7), If the determination process (S110) and the power storage waiting process (S200) are added, the current time is included in the usage time zone or the idle time zone immediately before the idle time zone, as described above. However, it prevents commercial power from being selected, so you can avoid wasting the storage system power generated and stored using renewable energy during downtime, or use unnecessary commercial power. It becomes possible to suppress this.

Further, in the fourth embodiment described above, the case where the charging device 70 that performs the basic control processing (FIGS. 13 and 14) executes the selection control processing shown in FIG. For example, the basic control process of the first embodiment (Fig. 3), the control process with battery assist of the first embodiment (Fig. 5), and the control process with supplementary charging of the second embodiment (Fig. The charging device 20 (20a, 20b) that performs 7) may execute the selection control process shown in FIG. 15. In these cases, for example, after starting each control process (FIGS. 3, 5, and 7), the sensor information acquisition process in step S509 is performed. Note that these control processes (FIGS. 3, 5, and 7) end when charging is completed (S105; No in each figure).

In each of the embodiments described above, since the batteries 51, 51a, 51b, 51c (storage batteries) are composed of lithium ion batteries, the batteries 51, 51a, etc. are CCCVed by the charging devices 20 (20a to 20d), 70. Although the case where charging is performed using this method has been described as an example, the application of the present invention is not limited to this. For example, if the batteries 51, 51a, etc. are configured with lead-acid batteries, another charger may be used so that the batteries 51, 51a, etc. are charged by the charging devices 20, 70 using a quasi-constant voltage charging method suitable for lead-acid batteries. It may be configured such that a task (thread, process, etc.) executes control processing related to the quasi-constant voltage charging method. Further, the present invention can be applied to cases where a battery (storage battery) is charged using other charging methods.

Further, in each of the above-described embodiments, the power storage device 13 and the charging devices 20 (20a to 20d), 70 are configured separately, but they may be configured integrally. good. For example, both the power storage device 13 and the charging devices 20, 70 are housed in separate housings, the power storage device 13 is housed in the housing 21 of the charging devices 20, 70, or the power storage device 13 is not charged. The devices 20, 70 may be housed therein.

Further, in each of the embodiments described above, as a storage battery, batteries 51, 51a, etc. of forklift trucks 50, 50a, etc. are electrically connected to charging output terminals 25 of charging devices 20 (20a to 20d), 70 via charging cables 18. For example, if the batteries 51, 51a, etc. are configured to be detachable from the forklifts 50, 50a, etc., without intervening the charging cable 18, the batteries 51, 51a, etc. , 51a, etc. may be configured such that the charging devices 20, 70 can be directly connected to the charging output terminals 25 of the charging devices 20, 70. In addition, the charging device 20 (20a to 20d) is configured so that the batteries 51, 51a, etc. (storage batteries) can be charged using a non-contact power supply method using an electromagnetic induction coil or the like without using the charging cable 18 or the like. , 70 may be configured.

Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The techniques described in the claims include various modifications or changes to the specific examples described above. Further, the technical elements described in this specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims as filed. Furthermore, the techniques illustrated in this specification or the drawings simultaneously achieve a plurality of objectives, and achieving one of the objectives has technical utility in itself. Note that the descriptions in parentheses in the [Explanation of symbols] column can clarify the correspondence between the terms used in each of the embodiments described above and the terms described in the claims.

10, 60... Charging system 11... Solar panel 13... Power storage device 15... Commercial power supply 20, 20a, 20b, 20c, 20d, 70... Charging device 21, 71... Housing 23, 73... DC input terminal 24, 74... AC input terminals 25, 77a, 77b, 77c...Charging output terminals 31, 31'...Voltage conversion section 32, 32'...AC/DC conversion section (power conversion section)
33, 34...Switch section (switching section)
35, 36... Switch section 38, 78... Control section 39... Voltage node (switching section)
41, 42... Sensor 50, 50a, 50b, 50c... Forklift 51, 51a, 51b, 51c... Battery (storage battery)
76...Switch section (selection section)
77... Charging output terminal group 80... Management computer (external)
100...Internet 120...Information providing server

Claims (6)

A charging device that charges a storage battery with power storage system power that is DC power output from a power storage device that stores power generated using renewable energy,
a power conversion unit capable of converting AC power supplied from a commercial power source into commercial power that is DC power and outputting the same;
a switching unit that selects at least one of the storage system power output from the power storage device and the commercial power output from the power conversion unit and outputs it to the storage battery;
a control unit that controls selection of the storage system power and the commercial system power by the switching unit;
Equipped with
The control unit controls the switching unit to select at least the electricity storage system power before starting charging of the storage battery, and the remaining amount of electricity stored in the electricity storage device is equal to or less than a predetermined value after starting charging of the storage battery. The charging device is characterized in that the switching unit is controlled so as to select only the commercial power in the case where the switching unit selects only the commercial power. The control unit, prior to the start of charging the storage battery, gives priority to the control, and
If the undercharge amount obtained by subtracting the remaining charge amount of the storage battery from the rated capacity of the storage battery is greater than the remaining amount of charge in the power storage device, the commercial system The charging device according to claim 1, wherein the switching unit is controlled to select only electric power. It is configured such that alternative power equivalent to the generated power can be supplied from the power conversion unit to the power storage device, and when power generation using the renewable energy is not performed, the power conversion unit supplies the power to the power storage device. The charging device according to claim 1 or 2, wherein the alternative power is supplied to a power storage device. A charging device that charges a storage battery with power storage system power that is DC power output from a power storage device that stores power generated using renewable energy,
a power conversion unit capable of converting AC power supplied from a commercial power source into commercial power that is DC power and outputting the same;
a switching unit that selects at least one of the storage system power output from the power storage device and the commercial power output from the power conversion unit and outputs the selected one to the storage battery;
The selection of the storage system power and the commercial system power by the switching unit is controlled, and a usage time period of a predetermined length during which the power load uses the DC power charged in the storage battery and a rest time period of a predetermined length during which the power load does not use the DC power charged in the storage battery. a control unit that retains or acquires schedule information from the outside;
Equipped with
The control unit controls the switching unit to select at least the storage system power and start charging the storage battery, and then
(1) controlling the switching unit to select the commercial power when the remaining amount of power stored in the power storage device is below a predetermined value and the current time is included in the use time period that is not immediately before the downtime time period;
(2) If the remaining amount of power stored in the power storage device is less than a predetermined value and the current time is included in the usage time period or the downtime period immediately before the downtime time period, the power storage device does not select the commercial power A charging device characterized in that charging of the storage battery is resumed after waiting for storage of electricity in the storage device exceeding a predetermined value. In the case of (2) above, the control unit:
Before or after resuming charging of the storage battery, when it is determined that charging of the storage battery is not completed by the time the use time period immediately after the rest time period starts, or immediately after the rest time period. 5. The switching unit is controlled to select the commercial power when it is determined that the storage of power in the power storage device is not completed by a predetermined time before the start of the usage time period. charging device. A selection unit capable of selecting a plurality of output units to which a plurality of storage batteries can be connected is connected to the output side of the switching unit,
The control unit controls the selection unit based on the charging state of a plurality of storage batteries connected to the output unit, according to any one of claims 1, 2, 4, and 5. Charging device.

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