WO2013121899A1

WO2013121899A1 - Electrical apparatus

Info

Publication number: WO2013121899A1
Application number: PCT/JP2013/052368
Authority: WO
Inventors: 晃浩和泉; 佐藤　克彦; 浩一上山
Original assignee: シャープ株式会社
Priority date: 2012-02-13
Filing date: 2013-02-01
Publication date: 2013-08-22
Also published as: JP2013165618A

Abstract

In a power feed system for supplying A/C power to an electrical apparatus (40), a capacitor (10) connects to a power grid (30) via a bidirectional DC/AC converter (20). When the capacitor (10) discharges, the bidirectional DC/AC converter (20) performs a power conversion operation on the basis of the value of an alternating current (Iac) as detected by an alternating current detection unit (50) so that the alternating current (Iac) becomes zero. The electrical apparatus (40) is provided with a load unit that operates by receiving power supplied from the bidirectional DC/AC converter (20), and a power adjusting unit for gradually decreasing the power consumed by the load unit when the output of the load unit is stopped or reduced.

Description

Electrical equipment

The present invention relates to an electric device, and more particularly, to an electric device that can receive power from a distributed power supply device connected to a commercial power system.

In recent years, distributed power supply devices such as solar cells, wind power generators and fuel cells have begun to spread. The DC power generated by the distributed power supply device is converted into AC power by the inverter device and supplied to the electrical equipment. When the power output from the inverter device is lower than the power consumption of the electrical device, the power can be purchased from the power company by supplying insufficient power from the commercial power system.

As described above, in the grid connection in which the distributed power supply device is linked to the commercial power system via the inverter device and power is supplied to the load, the surplus power is reversely flowed to the commercial power system and sold to the power company. You can also

However, the current regulations limit the purchase of surplus power to surplus power in the power generated by solar cells from the viewpoint of securing power quality during grid connection, and power sources other than solar cells have been generated. With respect to electric power, for example, electric power generated by an in-house power generator or discharged electric power from a storage battery, so-called reverse power flow in which surplus electric power flows backward to the power system is regulated. Specifically, when power of about 5% of the rated output power of the inverter device continues to flow backward to the power system for 0.5 seconds, the inverter device is disconnected by operating the reverse power relay. The power system is protected (for example, see Non-Patent Document 1).

As a technique for preventing the occurrence of such reverse power flow, for example, in Japanese Patent Laid-Open No. 2006-149058 (Patent Document 1), in a series voltage compensation uninterruptible power supply, the load suddenly changes to zero. In such a case, a configuration is disclosed in which the occurrence of reverse power flow due to a control delay of the DC / AC converter is prevented by reflecting this sudden change in load on the current command value of the DC / AC converter. In the uninterruptible power supply according to Patent Document 1, the first DC / AC converter absorbs the voltage increase of the commercial power supply, and the second DC / AC converter regenerates the absorbed power to the AC bus. Configured to maintain the voltage of the load. In order to prevent a delay in power control when the load suddenly changes in the above configuration, the control circuit of the second DC / AC converter calculates the product of the fluctuation amount of the commercial power supply voltage and the effective current component of the load current. An AC / DC converter, an adder, a current detector, an active current calculator, and a multiplier for generating a current command value including an effective current component to be passed by the second DC / AC converter A current calculator and an adder, and a current detector, an adder, and a current regulator for controlling the alternating current of the second DC / AC converter according to the current command value are configured.

Japanese Patent Publication “Japanese Patent Laid-Open No. 2006-149058”

However, according to the above-mentioned Patent Document 1, in order to reflect the sudden change of the load current accompanying the sudden change of the load in the current command value of the second DC / AC converter, the control for generating the current command value is performed. The circuit is configured using many circuit elements including an AC / DC converter. For this reason, there is a certain limit in the responsiveness of the alternating current control of the DC / AC converter due to the restriction of the processing speed of the control circuit. As a result, there is a possibility that the reverse power flow due to the control delay of the DC / AC converter cannot be reliably prevented.

Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to reverse a power supply system capable of supplying power from a distributed power supply device connected to a commercial power system at the time of sudden load change. It is to surely suppress the current.

According to one aspect of the present invention, in an electrical device that can receive power from a distributed power supply device linked to a commercial power system, when stopping or reducing the output of a load, the power supplied to the electrical device is reduced stepwise. By doing so, the occurrence of reverse power flow is suppressed. The electrical device includes a load unit that operates by receiving power supply from an external power source, and a power adjustment unit that gradually reduces the power supplied from the external power source when the output of the load unit is stopped or reduced. Is provided.

Preferably, when the output of the load unit is stopped or reduced, the power adjustment unit gradually reduces the power consumption consumed by the load unit.

Preferably, the power adjustment unit is configured to be capable of adjusting the power consumption to be reduced for each step.

Preferably, the external power source includes a power conversion device for converting power between an external power storage unit and a load unit. The electric device further includes a communication unit for communicating with the power conversion device. The power adjustment unit communicates with the power conversion device by the communication unit, so that when the rated output power of the power conversion device is received, the power adjustment unit decreases the power consumption for each step according to the received rated output power of the power conversion device. Adjust the power.

Preferably, the power adjustment unit communicates with the power conversion device by the communication unit when the electric device is electrically connected to the power conversion device or when the power of the electric device is turned on. Receives the rated output power of the converter.

Preferably, the electrical device further includes an input unit for inputting power consumption, which is reduced by the user of the electrical device for each step, to the power adjustment unit.

Preferably, the power adjustment unit is configured to be able to adjust a time interval for reducing power consumption.
Preferably, the external power supply includes a power conversion device for converting power between an external power storage unit and a load unit. The time interval for reducing the power consumption is adjusted according to the power consumption to be reduced for each step and the settling time in the power converter.

Preferably, the electric device further includes a rechargeable battery unit. The power adjustment unit is configured to stop or reduce the output of the load unit and charge the battery unit with surplus power that is not consumed by the load unit among the power supplied from the external power source. The power adjustment unit decreases the charging power of the battery unit stepwise.

Preferably, the power adjustment unit is configured to be able to adjust the charging power to be reduced for each stage.

Preferably, the power adjustment unit supplies the power stored in the battery unit to the load unit when the load unit is restarted.

Preferably, the external power source includes a power conversion device for converting power between an external power storage unit and a load unit. The electric device further includes a communication unit for communicating with the power conversion device. The power adjustment unit communicates with the power conversion device by the communication unit, so that when the rated output power of the power conversion device is received, the power adjustment unit decreases charging for each step according to the received rated output power of the power conversion device. Adjust the power.

Preferably, the electric device further includes an input unit for inputting charging power, which is reduced by the user of the electric device for each step, to the power adjustment unit.

According to the present invention, in a power supply system capable of supplying power to a load from a distributed power supply device linked to a commercial power system, reverse power flow during a sudden load change can be reliably suppressed.

It is a figure which shows roughly the structure of the whole electric power feeding system with which the electric equipment by Embodiment 1 of this invention is applied. It is a circuit diagram which shows the detailed structure of the bidirectional | two-way DC / AC converter in FIG. It is a figure which shows the detailed structure of the electric equipment in FIG. It is a figure which shows an example of the electric power data showing the power consumption of an electric equipment. It is a figure which shows the time change of the power consumption of an electric equipment, and the output power of a bidirectional | two-way DC / AC converter. It is a figure which shows an example of the adjustment amount setting table. It is a figure which shows the modification of the electric equipment in FIG. It is a flowchart for demonstrating the setting of the adjustment amount of the power consumption in the electric equipment shown in FIG. It is a flowchart for demonstrating the setting of the adjustment amount of the power consumption in the electric equipment shown in FIG. It is a figure which shows the detailed structure of the electric equipment by Embodiment 2 of this invention. It is a figure which shows the time change of the power consumption of an electric equipment, the charging / discharging power of a battery part, and the output power of a bidirectional | two-way DC / AC converter. It is a flowchart for demonstrating the setting of the adjustment amount of the charging power of the battery part in the electric equipment by Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 is a diagram schematically showing an overall configuration of a power feeding system to which an electrical apparatus according to Embodiment 1 of the present invention is applied.

Referring to FIG. 1, the power supply system according to the first embodiment is a power supply system for supplying electric power to electric device 40 that is an AC load, and includes DC bus 1, AC bus 2, and power storage unit 10. A bidirectional DC / AC converter 20, a power system 30, and an alternating current detection unit 50.

The DC bus 1 is disposed between the power storage unit 10 and the bidirectional DC / AC converter 20. The DC bus 1 is composed of a positive bus PL and a negative bus NL (see FIG. 2) which are power line pairs.

The power storage unit 10 includes, for example, a secondary battery configured to be rechargeable, such as a lithium ion secondary battery. The power storage unit 10 is configured by connecting a plurality of battery cells in series. The power storage unit 10 exchanges DC power with the DC bus 1.

The bidirectional DC / AC converter 20 exchanges DC power with the DC bus 1. Specifically, when the electric device 40 is driven using the discharge power from the power storage unit 10, the bidirectional DC / AC converter 20 converts the DC power received from the DC bus 1 into AC power to convert the AC bus 2. To supply. When charging power storage unit 10 using power from power system 30, bidirectional DC / AC converter 20 converts AC power received from AC bus 2 into DC power and supplies it to DC bus 1.

The AC bus 2 supplies AC power to the electrical device 40 that is an AC load. As an example, the electric device 40 is an electric device such as an air conditioner, a refrigerator, a washing machine, a television set, a lighting device, or a personal computer used at home. Alternatively, it may be an electric device such as a computer, a copier or a facsimile used in an office, or an electric device such as a showcase or a lighting device used in a store.

The alternating current detection unit 50 is inserted in the alternating current bus 2, detects the alternating current Iac flowing through the alternating current bus 2, and outputs the detection result to the bidirectional DC / AC converter 20.

The power system 30 is connected to the AC bus 2. The electric power system 30 supplies AC power (for example, AC 200V) received from an electric power company or the like. The power system 30 is, for example, a single-phase three-wire commercial AC power system. The AC bus 2 supplies AC power from the power system 30 to the electrical device 40. The AC bus 2 further supplies the bidirectional DC / AC converter 20 with AC power obtained by subtracting AC power supplied to the electric device 40 from the power system 30 purchased from an electric power company or the like. The AC power supplied to the bidirectional DC / AC converter 20 is converted into DC power by the bidirectional DC / AC converter 20 and becomes charging power of the power storage unit 10.

In addition, the power supply system according to the first embodiment is configured to be able to supply the electric power stored in the power storage unit 10 to the electric device 40. That is, the power feeding system according to the first embodiment is configured to be capable of grid interconnection in which the power storage unit 10 is linked to the power grid 30.

At the time of grid connection, the bidirectional DC / AC converter 20 converts the DC power received from the power storage unit 10 via the DC bus 1 into AC power and outputs the AC power to the AC bus 2. The AC bus 2 supplies the AC power received from the bidirectional DC / AC converter 20 to the electric device 40.

However, in such a power supply system in which the power storage unit 10 is mounted as such a distributed power supply device, it is legally restricted that the discharged power from the power storage unit 10 flows backward to the power system 30 during grid connection from the viewpoint of ensuring power quality. Has been.

Therefore, in the power feeding system according to the present embodiment, the power conversion operation in the bidirectional DC / AC converter 20 is controlled so that a reverse power flow does not occur when power is supplied from the power storage unit 10 to the electrical device 40.

FIG. 2 is a circuit diagram showing a detailed configuration of the bidirectional DC / AC converter 20 in FIG.
Referring to FIG. 2, bidirectional DC / AC converter 20 includes a bidirectional inverter 22,

interconnection reactors

24 and 26, and a control unit 28.

The bidirectional inverter 22 converts the alternating current power received from the alternating current bus 2 into direct current power according to the switching control signals S1 to S4 from the control unit 28, and outputs it to the direct current bus 1. Further, the bidirectional inverter 22 converts the DC power received from the DC bus 1 into AC power in accordance with the switching control signals S1 'to S4' from the control unit 28, and outputs the AC power to the AC bus 2.

Specifically, the bidirectional inverter 22 includes transistors Q1 to Q4, which are switching elements, and diodes D1 to D4. Transistors Q1 and Q2 are connected in series between positive bus PL and negative bus NL constituting DC bus 1. An intermediate point between transistor Q1 and transistor Q2 is connected to R-phase line RL. Interconnection reactor 24 is connected to R-phase line RL.

Transistors Q3 and Q4 are connected in series between positive bus PL and negative bus NL. An intermediate point between transistors Q3 and Q4 is connected to T-phase line TL. Interconnection reactor 26 is connected to T-phase line TL. Between the collector and emitter of each of the transistors Q1 to Q4, diodes D1 to D4 that flow current from the emitter side to the collector side are respectively connected. Transistors Q1-Q4 and diodes D1-D4 constitute a full bridge circuit.

For example, IGBTs (Insulated Gate Bipolar Transistors) can be used as the transistors Q1 to Q4. Alternatively, a power switching element such as a power MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) may be used.

Control unit 28 controls on / off of transistors Q1-Q4 so that AC power supplied from AC bus 2 is converted to DC power that can charge power storage unit 10 when power storage unit 10 is charged. The switching control signals S1 to S4 are generated to control the bidirectional inverter 22.

On the other hand, at the time of discharging power storage unit 10, control unit 28 generates switching control signals S 1 ′ to S 4 ′ based on AC current Iac received from AC current detection unit 50 and controls bidirectional inverter 22. Specifically, control unit 28 sets current target value Iac * of alternating current Iac to “0A”. Then, control unit 28 generates switching control signals S1 'to S4' based on current deviation ΔIac, which is the difference between AC current Iac and current target value Iac *. That is, control unit 28 performs feedback control for making AC current Iac coincide with current target value Iac * (= 0 A).

Thus, when the power storage unit 10 is discharged, the control unit 28 controls the bidirectional inverter 22 so that the alternating current Iac becomes zero. As a result, all AC power output from the bidirectional DC / AC converter 20 is supplied to the electric device 40 via the AC bus 2 and is not supplied to the power system 30. Therefore, reverse power flow to the power system 30 can be prevented.

However, in the configuration in which the bidirectional DC / AC converter 20 is controlled based on the detected value of the alternating current Iac by the alternating current detection unit 50 as described above, the temporal change of the load in the electrical device 40 is bidirectional DC / When the AC converter 20 has a time shorter than the time required for the AC current Iac to follow the target current value Iac * (hereinafter referred to as “settling time”), the generated current deviation ΔIac cannot be corrected by feedback control. there is a possibility. Such a malfunction may occur when the load rapidly decreases due to, for example, the operation of the electric device 40 being stopped. And when alternating current Iac exceeds zero, there exists a possibility of generating the reverse power flow to the electric power grid | system 30. FIG.

Therefore, in the power supply system according to the first embodiment, when the output of the load is stopped or reduced in the electric device 40, the power consumption consumed by the load is reduced stepwise. That is, by adjusting the temporal change of the load in the electrical device 40 so as to be longer than the settling time of the bidirectional DC / AC converter 20, the occurrence of reverse power flow can be suppressed easily and efficiently.

(Electrical equipment configuration)
Below, with reference to drawings, the structure of the electric equipment 40 by Embodiment 1 of this invention is demonstrated.

FIG. 3 is a diagram showing a detailed configuration of the electric device 40 in FIG.
With reference to FIG. 3, the electric device 40 includes a power plug 60, a power adjustment unit 62, a load unit 64, a control unit 66, a memory 68, and an input unit 70.

When the power plug 60 is connected to an outlet (not shown) provided in the AC bus 2, the electrical device 40 and the AC bus 2 (not shown) are electrically connected. When AC power from the AC bus 2 is transmitted into the electric device 40 through the power plug 60, it is supplied to the load unit 64 through the power line. Thereby, the load unit 64 operates by receiving supply of AC power from the AC bus 2.

A power adjusting unit 62 is provided on the power line connecting the power plug 60 and the load unit 64. The power adjustment unit 62 is configured to be able to switch the power consumed by the load unit 64 per unit time (hereinafter also referred to as “power consumption”) in a plurality of stages. FIG. 4 shows an example of power data representing the power consumption of the electrical device 40. Referring to FIG. 4, the power consumption can be increased by 200W with 2200W as the upper limit.

Returning to FIG. 3, the memory 68 is implemented by a RAM (Random Access Memory) that is a volatile storage device, a ROM (Read-Only Memory) that is a nonvolatile storage device, and the like, and is executed by the control unit 66. In addition, work data necessary for execution of the program by the control unit 66 is stored. The work data includes the power data shown in FIG.

The input unit 70 is a user interface for giving a command for starting / stopping the electric device 40. The input unit 70 is, for example, a push button type switch, and a start command and a stop command are output to the control unit 66 when the user operates the switch. The input unit 70 functions as a user interface for adjusting the output of the load unit 64 when the load unit 64 is operated. Information regarding the output adjusted in the input unit 70 is transmitted to the control unit 66.

Although not shown, the control unit 66 includes a CPU (Central Processing Unit) and an input / output buffer. The control unit 66 inputs signals from each sensor and outputs control signals to each circuit, and controls the electric device 40. Do. Note that these controls are not limited to processing by software, and can be processed by a dedicated hardware circuit.

When the control unit 66 receives a stop command from the input unit 70, the control unit 66 shifts the load unit 64 from the activated state to the stopped state. At this time, the control unit 66 controls the power adjustment unit 62 to reduce the power consumption of the load unit 64 stepwise toward zero.

Specifically, the control unit 66 sets power consumption (hereinafter also referred to as “power consumption adjustment amount”) ΔP to be decreased for each step. The power adjustment unit 62 controls the load unit 64 so that the power consumption decreases in accordance with the power consumption adjustment amount ΔP set by the control unit 66. In this way, the power consumption of the load unit 64 is decreased step by step by the adjustment amount ΔP.

Here, the adjustment amount ΔP of the power consumption is set based on the rated output power of the bidirectional DC / AC converter 20 so that the power exceeding the allowable power defined by the law does not flow backward to the power system 30. The Specifically, the current law stipulates that power exceeding 5% of the rated output power of the bidirectional DC / AC converter is prohibited from continuously flowing backward for 0.5 seconds or more. In other words, it is legally allowed to reverse flow if the power is 5% or less of the rated output power of the bidirectional DC / AC converter.

Therefore, in the first embodiment, the control unit 66 sets the power consumption adjustment amount ΔP to be 5% or less of the rated output power of the bidirectional DC / AC converter 20. According to this, even if the situation where the surplus power flows to the power system 30 side due to the time change of the load in the electric device 40 being shorter than the settling time of the bidirectional DC / AC converter 20, the surplus power is not generated. Because it is kept below the allowable power, there is no violation of laws and regulations.

As an example, it is assumed that the rated output power of the bidirectional DC / AC converter 20 is 5 kW. In this case, the power that allows reverse power flow to the power system 30 side is 250 W, which is 5% of the rated output power. Therefore, the control unit 66 may set the power consumption adjustment amount ΔP so that the allowable power is 250 W or less. According to the power data shown in FIG. 4, the electrical device 40 is configured to be able to adjust power consumption by 200 W. Therefore, by setting the power consumption adjustment amount ΔP to 200 W, it is possible to suppress the surplus power below the legally allowable power.

With this configuration, if the power consumption when receiving a stop command from the input unit 70 is 1000 W, the power consumption of the electrical device 40 is from 1000 W to 0 W as shown in FIG. It will decrease by 200W. FIG. 5 is a diagram illustrating temporal changes in the power consumption of the electrical device 40 and the output power of the bidirectional DC / AC converter 20.

Referring to FIG. 5, when a stop command is given by the user's operation (time t1), the power consumption of electric device 40 decreases step by step by a predetermined adjustment amount ΔP (for example, 200 W). At this time, in the bidirectional DC / AC converter 20, as described above, the power conversion operation is controlled such that the alternating current Iac detected by the alternating current detection unit 50 becomes zero. Thereby, the electric power output from the bidirectional DC / AC converter 20 decreases so as to follow the decrease in the power consumption of the electric device 40. In FIG. 5, there is a power difference between the power consumption and the output power of the bidirectional DC / AC converter 20 at the timing (time t1, t2, t3, t4, t5) at which the power consumption is reduced. The magnitude of this power difference is less than the allowable power required by law.

In FIG. 5, the time interval Δt for reducing the power consumption can be adjusted according to the power consumption adjustment amount ΔP and the settling time of the bidirectional DC / AC converter 20. For example, the time interval Δt may be given to the control unit 66 when the user operates the input unit 70. Thereby, the output power of the bidirectional DC / AC converter 20 can be made to follow the change in power consumption.

(Setting of the adjustment amount ΔP of the power consumption)
As described above, the power consumption adjustment amount ΔP needs to be adjusted according to the rated output power of the bidirectional DC / AC converter 20. Therefore, the electrical device 40 is configured so that an arbitrary value can be selected from a plurality of adjustment amounts so that the specification of the bidirectional DC / AC converter 20 applied to the power feeding system can be met.

As one aspect thereof, the electric device 40 stores a table (hereinafter also referred to as “adjustment amount setting table”) for setting the power consumption adjustment amount ΔP in the memory 68. FIG. 6 is a diagram illustrating an example of the adjustment amount setting table. Referring to FIG. 6, a plurality of power values P1 to P5 having different sizes are set in the adjustment amount setting table.

When the user sets the adjustment amount ΔP using the input unit 70, the control unit 66 causes the display unit (not shown) to display an adjustment amount setting table. The user can set an appropriate power for the rated output power of the bidirectional DC / AC converter 20 as the adjustment amount ΔP by referring to the adjustment amount setting table displayed on the display unit.

Moreover, as another aspect, the information regarding the rated output power of the bidirectional DC / AC converter 20 is controlled by the communication between the bidirectional DC / AC converter 20 and the electrical device 40. The configuration may be obtained by the unit 66.

FIG. 7 is a diagram showing a modification of the electric device 40 in FIG.
With reference to FIG. 7, the electric device 40 </ b> A according to the present modification further includes a communication unit 72 as compared with the electric device 40 illustrated in FIG. 3.

The control unit 66 communicates with a communication unit (not shown) provided in the bidirectional DC / AC converter 20 via the communication unit 72 in a wireless or wired manner. Then, the control unit 66 stores information related to the rated output power of the bidirectional DC / AC converter 20 transmitted from the communication unit of the bidirectional DC / AC converter 20 in the memory 68. The control unit 66 sets the power consumption adjustment amount ΔP based on the information regarding the rated output power stored in the memory 68.

Note that power line communication (PLC) can be used for communication between the electric device 40 and the bidirectional DC / AC converter 20. In this case, the communication unit 72 includes a PLC unit and transmits information via the power line.

FIG. 8 is a flowchart for explaining the setting of the power consumption adjustment amount ΔP in the electrical apparatus 40A shown in FIG. The flowchart shown in FIG. 8 can be realized by executing a program stored in advance in the control unit 66.

Referring to FIG. 8, first, in step S <b> 10, when electrical device 40 </ b> A and AC bus 2 are electrically connected by connecting power supply plug 60 to an outlet provided in AC bus 2, control is performed. The unit 66 communicates with the communication unit provided in the bidirectional DC / AC converter 20 via the communication unit 72 in step S20. Thereby, the control unit 66 receives information regarding the rated output power of the bidirectional DC / AC converter 20.

In step S30, the control unit 66 sets the power consumption adjustment amount ΔP based on the received rated output power of the bidirectional DC / AC converter 20. Specifically, the control unit 66 sets the power consumption adjustment amount ΔP so as to be 5% or less of the rated output power. Then, the control unit 66 outputs the set adjustment amount ΔP to the power adjustment unit 62.

When the control unit 66 receives a stop command from the input unit 70 in step S40, the control unit 66 shifts the load unit 64 from the activated state to the stopped state. At this time, the power adjustment unit 62 controls the load unit 64 to reduce the power consumption of the load unit 64 according to the power consumption adjustment amount ΔP set by the control unit 66 in step S50. When the power consumption reaches zero, the load unit 64 is stopped in step S60.

With this configuration, every time the bidirectional DC / AC converter 20 that supplies power to the electrical device 40A is switched, the electrical device 40A and the switched bidirectional DC / AC converter 20 are switched. Since the information regarding the rated output power is transmitted, the rated output power of the bidirectional DC / AC converter 20 stored in the memory 68 can be updated to the latest value. Thereby, the electric device 40A can always adjust the power consumption reflecting the settling time of the bidirectional DC / AC converter 20.

In the above description, the power consumption adjustment amount ΔP is set based on the information about the rated output power transmitted from the bidirectional DC / AC converter 20 when the electric device 40A is connected to the AC bus 2. Although the configuration is exemplified, the power consumption adjustment amount ΔP is set based on the information about the rated output power transmitted from the bidirectional DC / AC converter 20 when the electric device 40A is turned on. Also good.

FIG. 9 is a flowchart for explaining the setting of the power consumption adjustment amount ΔP in the electric device 40A shown in FIG. The flowchart shown in FIG. 9 is different from the flowchart shown in FIG. 8 in that a process of step S12 is provided instead of the process of step S10.

Referring to FIG. 9, when electric device 40A is turned on and electric device 40A is activated in accordance with an activation command by a user operation in step S12, control unit 66 causes communication unit 72 to be activated in step S20. Through the communication unit provided in the bidirectional DC / AC converter 20. Thereby, the control unit 66 receives information regarding the rated output power of the bidirectional DC / AC converter 20. Then, the control unit 66 performs the process for setting the power consumption adjustment amount ΔP and stopping the operation of the electric device 40A according to the stop command through steps S30 to S60 similar to FIG.

Thus, when stopping the output of the load, the electric device according to the first embodiment reduces the power consumption stepwise so as not to be shorter than the settling time of the bidirectional DC / AC converter. Thereby, since the electric power supplied to an electric equipment from an electrical storage part can be reduced in steps, generation | occurrence | production of a reverse power flow can be suppressed simply and efficiently. Furthermore, the regulation regarding the reverse power flow can be observed by adopting a configuration in which the adjustment amount of the power consumption for each step is variably set according to the rated output power of the bidirectional DC / AC converter.

In the first embodiment described above, the configuration for reducing the power consumption of the electric device stepwise toward zero when stopping the load of the electric device is illustrated, but the application of the present invention is such It is not limited to the scene. Specifically, the point where the present invention can be applied will be described in a confirming manner as long as the output of the load of the electric device is reduced.

Also, it will be described in a confirming manner that the number of stages can be increased or decreased in accordance with the power consumption adjustment amount ΔP in the configuration in which the power consumption according to the first embodiment is reduced stepwise. Therefore, the power consumption adjustment amount ΔP can be set so that the power consumption decreases more continuously.

[Embodiment 2]
FIG. 10 is a diagram showing a detailed configuration of the electric device 40B according to the second embodiment of the present invention.

Referring to FIG. 10, electric device 40B according to the second embodiment further includes battery unit 80, as compared with electric device 40A shown in FIG.

The battery unit 80 includes, for example, a secondary battery configured to be rechargeable, such as a lithium ion secondary battery. The battery unit 80 exchanges power with the power line connecting the power plug 60 and the load unit 64. That is, the battery unit 80 is charged by receiving power supplied from the AC bus 2 through the power plug 60 and the power line. Moreover, the battery part 80 can supply the stored electric power to the load part 64 by discharging toward the power line. Although not shown in the figure, the battery unit 80 is provided with a power converter for converting the power supplied from the AC bus 2 into power suitable for charging the battery unit 80.

In the electric device 40B according to the second embodiment, the power adjustment unit 62 is configured to be able to adjust the power charged in the battery unit 80 per unit time (hereinafter also referred to as “charging power”). For example, the power adjustment unit 62 can switch the charging power in a plurality of stages.

When the control unit 66 receives a stop command from the input unit 70, the control unit 66 shifts the load unit 64 from the activated state to the stopped state. At this time, the control unit 66 controls the power adjustment unit 62 while setting the power consumption of the load unit 64 to zero, so that surplus power that is not consumed by the load unit 64 among the power supplied from the AC bus 2. Is used to charge the battery unit 80. That is, the control unit 66 switches the power supply destination from the load unit 64 to the battery unit 80 in response to the stop command.

Further, when the power supply destination is switched from the load unit 64 to the battery unit 80, the control unit 66 controls the power adjustment unit 62 to gradually decrease the charging power of the battery unit 80 toward zero. .

Thus, in the electric device 40B according to the second embodiment, the load unit 64 is stopped in response to the stop command, while the battery unit 80 is charged using surplus power that is not consumed by the load unit 64. In this charging operation, the charging power of the battery unit 80 is reduced stepwise. Thereby, the electric power supplied to the electric equipment 40B from the electrical storage part 10 can be reduced in steps, stopping the load part 64 rapidly.

Specifically, the control unit 66 sets the charging power (hereinafter also referred to as “charging power adjustment amount”) ΔPch to be decreased for each step. The power adjustment unit 62 controls the power conversion device inside the battery unit 80 so that the charging power is reduced according to the charging power adjustment amount ΔPch set by the control unit 66. In this way, the charging power of the battery unit 80 is decreased step by step by the adjustment amount ΔPch.

The charging power adjustment amount ΔPch is the same as the power consumption adjustment amount ΔP in the first embodiment, so that the power exceeding the allowable power defined by the law does not flow backward to the power system 30. It is set based on the rated output power of the AC converter 20. Specifically, control unit 66 sets charging power adjustment amount ΔPch to be 5% or less of the rated output power of bidirectional DC / AC converter 20. According to this, the time change of the charging power of the battery unit 80 in the electric device 40B becomes shorter than the settling time of the bidirectional DC / AC converter 20, and a situation occurs in which surplus power flows to the power system 30 side. However, the surplus power is kept below the allowable power, so there is no violation of laws and regulations.

Also, the adjustment amount ΔPch of the charging power can be set by the user using the input unit 70, similarly to the adjustment amount ΔP of the power consumption in the first embodiment. Or it is good also as a structure which acquires the information regarding the rated output electric power of the bidirectional | two-way DC / AC converter 20 by communicating between the bidirectional | two-way DC / AC converter 20 and the electric equipment 40B.

FIG. 11 is a diagram showing temporal changes in the power consumption of the electric device 40B, the charge / discharge power of the battery unit 80, and the output power of the bidirectional DC / AC converter 20. In FIG. 11, the case where the rated output power of the bidirectional DC / AC converter 20 is 5 kW is assumed as in the first embodiment. The charge power adjustment amount ΔPch is set to 200 W, which is lower than the allowable power (5% of the rated output power = 250 W).

Referring to FIG. 11, when a stop command is given by the user's operation (time t1), electric device 40B shifts from the start state to the stop state. For example, if the power consumption when receiving a stop command from the input unit 70 is 1000 W, the power consumption of the electric device 40B decreases from 1000 W to 0 W.

In the electric device 40B, in response to the stop command, the power supply unit 62 switches the power supply destination from the AC bus 2 from the load unit 64 to the battery unit 80. That is, in response to the stop command, the load unit 64 is brought into a stopped state, while charging of the battery unit 80 is started. Therefore, after time t1, the power supplied from the AC bus 2 to the electric device 40B becomes the charging power of the battery unit 80.

The charging power of the battery unit 80 decreases step by step by a predetermined adjustment amount ΔPch (for example, 200 W). At this time, in the bidirectional DC / AC converter 20, as described above, the power conversion operation is controlled such that the alternating current Iac detected by the alternating current detection unit 50 becomes zero. Thereby, the electric power output from the bidirectional DC / AC converter 20 decreases so as to follow the decrease in the charging power of the battery unit 80. In FIG. 11, there is a power difference between the charging power and the output power of the bidirectional DC / AC converter 20 at the timing of reducing the charging power (time t1, t2, t3, t4, t5). The magnitude of this power difference is less than the allowable power required by law.

When the charging power is reduced to 0 W (time t5), the charging operation of the battery unit 80 is stopped. Electric power is stored in the battery unit 80 by the charging operation over the period from time t1 to time t5. When a start command is given by a user operation to restart the electric device 40B (time t6), power is preferentially supplied from the battery unit 80 to the load unit 64.

When the charge amount of the battery unit 80 falls below a predetermined allowable value due to the power supply from the battery unit 80 to the load unit 64 (time t7), the discharging operation of the battery unit 80 is stopped and the AC bus 2 is used instead of the battery unit 80. Is supplied to the load unit 64. The load unit 64 continues to operate in response to the supply of AC power from the AC bus 2.

FIG. 12 is a flowchart for explaining the setting of the adjustment amount ΔPch of the charging power in the electric device 40B according to the second embodiment.

Referring to FIG. 12, first, in step S10, when power supply plug 60 is connected to the outlet provided in AC bus 2 so that electrical device 40B and AC bus 2 are electrically connected, control is performed. The unit 66 communicates with the communication unit provided in the bidirectional DC / AC converter 20 via the communication unit 72 in step S20. Thereby, the control unit 66 receives information regarding the rated output power of the bidirectional DC / AC converter 20.

In step S70, the control unit 66 sets the adjustment amount ΔPch of the charging power of the battery unit 80 based on the received rated output power of the bidirectional DC / AC converter 20. Specifically, the control unit 66 sets the adjustment amount ΔPch of the charging power so that it becomes 5% or less of the rated output power. Then, the control unit 66 outputs the set adjustment amount ΔPch to the power adjustment unit 62.

When the control unit 66 receives a stop command from the input unit 70 in step S40, the control unit 66 shifts the load unit 64 from the activated state to the stopped state. Specifically, the control unit 66 sets the power consumption of the load unit 64 to zero. Furthermore, the power adjustment unit 62 switches the supply destination of power from the AC bus 2 from the load unit 64 to the battery unit 80 in step S80.

In step S90, the power adjustment unit 62 controls the battery unit 80 so as to decrease the charging power of the battery unit 80 according to the adjustment amount ΔPch of the charging power set by the control unit 66. When the charging power reaches zero, the control unit 66 stops the charging operation of the battery unit 80 in step S100.

Also in the second embodiment, as in the first embodiment, every time the bidirectional DC / AC converter 20 that supplies power to the electrical device 40B is switched, the electrical device 40B and the bidirectional DC / AC after switching are switched. Information regarding the rated output power is transmitted to and from the converter 20. Therefore, the rated output power of the bidirectional DC / AC converter 20 stored in the memory 68 can be updated to the latest value. As a result, the electric device 40B can always adjust the charging power reflecting the settling time of the bidirectional DC / AC converter 20.

In the above description, the charging power adjustment amount ΔPch is set based on the information about the rated output power transmitted from the bidirectional DC / AC converter 20 when the electric device 40B is connected to the AC bus 2. Although the configuration is exemplified, as described with reference to FIG. 9, the charging power is adjusted based on the information about the rated output power transmitted from the bidirectional DC / AC converter 20 when the electric device 40B is turned on. The amount ΔPch may be set.

As described above, in the electrical device according to the second embodiment, when stopping the output of the load, the battery unit is set so as not to be shorter than the settling time of the bidirectional DC / AC converter while the load unit is stopped. Reduce the charging power of the step by step. Thereby, since the electric power supplied to an electric equipment from an electrical storage part can be reduced in steps, generation | occurrence | production of a reverse power flow can be suppressed simply and efficiently. Furthermore, the regulation regarding the reverse power flow can be observed by adopting a configuration in which the adjustment amount of the power consumption for each step is variably set according to the rated output power of the bidirectional DC / AC converter.

Moreover, in this Embodiment 2, since it was set as the structure which stores the surplus electric power which is not consumed by a load part in a battery part by having made the load part into a halt condition, when restarting a load part, it stores in a battery part. Can be used. Therefore, compared to the first embodiment, it is possible to prevent the load unit from consuming electric power wastefully in order to suppress the occurrence of reverse power flow.

Furthermore, according to the second embodiment, even when the electric device does not have a function of switching the power consumption step by step, the charging unit in the battery unit is gradually reduced while the load unit is stopped. Thus, the power supplied from the power storage unit to the electrical device can be reduced stepwise. As a result, the occurrence of reverse power flow can be suppressed.

In the first and second embodiments described above, the configuration for stopping the output of the load of the electric device when the stop command is given from the input unit 70 in accordance with the user's operation is illustrated. The application of is not limited to such a situation. Specifically, the present invention can be applied to a scene in which the output of the load is automatically stopped or lowered during the operation of the electric device. For example, when the electrical device is an air conditioner such as an air conditioner, control is performed to automatically stop the output of the load when the current room temperature reaches the target temperature. Or, in an electric device equipped with a function such as an automatic operation mode or a fully automatic operation mode such as a washing machine, the output of the load may be drastically reduced due to the switching of the processing process during the operation. is there. Thus, by applying the present invention also to an electrical device in which the output of the load automatically stops or decreases, the occurrence of reverse power flow can be suppressed easily and efficiently.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 DC bus, 2 AC bus, 10 power storage unit, 20 bidirectional DC / AC converter, 22 bidirectional inverter, 24, 26 interconnected reactor, 28 control unit, 30 power system, 40, 40A, 40B electrical equipment, 50 AC current detection unit, 60 power plug, 62 power adjustment unit, 64 load unit, 66 control unit, 68 memory, 70 input unit, 72 communication unit.

Claims

A load unit that operates by receiving power from an external power source;
An electric device comprising: a power adjustment unit configured to reduce the power supplied from the external power source in a stepwise manner when stopping or reducing the output of the load unit.
The electric device according to claim 1, wherein the power adjustment unit gradually reduces the power consumption consumed by the load unit when stopping or reducing the output of the load unit.
The electric device according to claim 2, wherein the power adjustment unit is configured to be capable of adjusting power consumption to be reduced for each stage.
The external power source includes a power conversion device for converting power between an external power storage unit and the load unit,
A communication unit for communicating with the power converter;
The power adjustment unit communicates with the power conversion device by the communication unit, so that when the rated output power of the power conversion device is received, the power adjustment unit is configured according to the received rated output power of the power conversion device. The electric device according to claim 3, wherein power consumption to be reduced is adjusted for each stage.
The power adjustment unit communicates with the power conversion device by the communication unit when the electric device is electrically connected to the power conversion device or when the electric device is powered on. The electrical apparatus according to claim 4, wherein the rated output power of the power conversion device is received.
The electric device according to claim 3, further comprising an input unit for inputting power consumption, which is reduced by the user of the electric device for each step, to the power adjustment unit.
The electric device according to any one of claims 2 to 6, wherein the power adjustment unit is configured to be able to adjust a time interval for reducing power consumption.
The external power source includes a power conversion device for converting power between an external power storage unit and the load unit,
The electric device according to claim 7, wherein the time interval for reducing the power consumption is adjusted according to the power consumption to be reduced for each step and the settling time in the power converter.
Further comprising a rechargeable battery unit,
The power adjustment unit is configured to stop or reduce the output of the load unit and to charge the battery unit with surplus power that is not consumed by the load unit among the power supplied from the external power source,
The electric device according to claim 1, wherein the power adjustment unit reduces charging power of the battery unit in a stepwise manner.
10. The electric device according to claim 9, wherein the power adjustment unit is configured to be capable of adjusting charging power to be reduced for each stage.
The electric device according to claim 9 or 10, wherein the power adjustment unit supplies the power stored in the battery unit to the load unit when the load unit is restarted.
The external power source includes a power conversion device for converting power between an external power storage unit and the load unit,
A communication unit for communicating with the power converter;
The power adjustment unit communicates with the power conversion device by the communication unit, so that when the rated output power of the power conversion device is received, the power adjustment unit is configured according to the received rated output power of the power conversion device. The electric device according to claim 10 or 11, wherein the charging power to be reduced is adjusted for each stage.
The power adjustment unit communicates with the power conversion device by the communication unit when the electric device is electrically connected to the power conversion device or when the electric device is powered on. The electrical apparatus according to claim 12, wherein the rated output power of the power converter is received.
The electric device according to claim 11, further comprising an input unit for inputting charging power to be reduced by the user of the electric device for each step into the power adjusting unit.