JP2000209778A - Household electricity storing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a household electricity storing device which supplies its AC output to loads in the house by superposing the output upon commercial power supply in a time zone other than the midnight power supplying time zone by controlling the output current of the storing device to a value smaller than the total current consumption in the house measured by means of a current consumption measuring means. SOLUTION: When the electric current supplied from commercial power supply 17 is larger than a preset allowable value, an output opening/closing means 14 is closed by means of a signal from an overall control section 10. Then the output current of a household electricity storing device 1 is controlled to a value smaller than the total load current of the house and electric power is supplied from the storing device 1 to all loads used in the house by connecting the device 1 to the system of the commercial power supply 17. Therefore, the output of the device 1 will not flow reversely outside of the house and the stored inexpensive midnight power can be utilized effectively in the house during daytime. In addition, the output rating of the device 1 can be reduced, because the device 1 supplies part of the electric current consumed in the house.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home power storage device provided with a power storage means using a secondary battery, stores late-night power, and outputs an AC output to a commercial power supply in a time period other than the time period for supplying midnight power. The present invention relates to a household power storage device that superimposes and supplies a load in a house and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, there is a photovoltaic power generator as an apparatus for superposing and supplying an AC output to a commercial power supply in each home.
As described in Japanese Patent Application Laid-Open No. 10-51959, there is a device for supplying electric power by connecting a direct current generated by a solar cell to a commercial power supply via a circuit breaker provided at an interconnection point by an inverter. . As a photovoltaic power generator installed in a general house, a grid connection technical requirement guideline (hereinafter, referred to as a guideline) for connection of a distributed power supply (private power generation equipment) to a commercial power grid established in 1993. )
Devices based on the "low-voltage distribution system, with reverse power flow to the system" and on the premise of selling surplus power have been developed and marketed. In general, solar power is generated during the daytime when power consumption is low in ordinary houses, and the amount of power generated fluctuates greatly depending on the intensity of sunlight. This is a rational method from the viewpoint of effective use of.

[0003]

However, since the home power storage device is not a power generating device, no reverse power flow should be provided, and when the output is to be connected to a commercial power supply, a reverse power flow is generated. Must be prevented. However, when multiple power storage devices exist in the same system or distributed power generation devices exist in the same system, it is difficult to detect a power failure of the commercial power supply due to the influence of the output of other power storage devices and power generation devices. May occur. In addition, since the power storage device can supply power even during a power failure of the commercial power supply, there is a problem that it is desired to supply power to the load by an independent operation during the power failure of the commercial power supply.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems. A first aspect of the present invention relates to a household power storage device and a method of controlling the household power storage device. In a household power storage device equipped with a means, a current consumption measuring means for measuring the total current consumption in the house, and charging for converting the late-night power AC into DC and charging the power storage means in the household power storage device Output means for converting the direct current of the power storage means into a commercial frequency alternating current in a time zone other than the midnight power supply time zone, superimposing it on a commercial power supply in the house, and discharging and outputting the power, It is characterized in that the output current of the device is controlled so as to be smaller than the total current consumption in the home measured by the current consumption measuring means, and the output of the home power storage device is higher than the total load current in the home. Always keep it low It is intended to control to.

A second aspect of the present invention relates to a household power storage device and a method of controlling the household power storage device. A charging means for converting the alternating current into direct current and charging the power storage means, and converting the direct current of the power storage means into a commercial frequency alternating current in a time zone other than the midnight power supply time zone to a commercial power supply in the house. Output means for superimposed discharge output is provided, and the output means is connected between the commercial power supply and a predetermined load in the house, and the connection point is connected to each line of the commercial power supply side, the load side, and the household power storage device side. A current measuring means for measuring the current of each line is provided, and the output of the household power storage device is enabled only when the current on the commercial power supply side is equal to or higher than a predetermined value, and the output current of the household power storage device is changed to a load current. Smaller than And controlling the sum of the current on the commercial power supply side and the output current of the home power storage device to be substantially equal to the load current. Control is performed such that the current is always lower than the current by a specified value or more.

According to a third aspect of the present invention, there is provided a household power storage device and a method for controlling the household power storage device, wherein the output unit of the household power storage device and a commercial power supply are connected to each other. A power failure detection means and a circuit breaker that cuts off the commercial power line are provided on the commercial power side of the connection point with the line, and while the commercial power is being supplied, the output of the home power storage device is current-controlled, and the power is connected to the commercial power system. Power is supplied to a predetermined load in the house, and the circuit breaker is opened as soon as a power outage of the commercial power supply is detected, and the output control of the household power storage device is changed to voltage control to enable autonomous operation,
The home power storage device is controlled so that a full load current of a predetermined load is supplied by the home power storage device after the self-sustaining operation starts.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a household power storage device and a method of controlling the household power storage device according to the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of a first embodiment of a home power storage device 1 provided with a power storage means using a secondary battery. The household power storage device 1 includes a power storage means 2 composed of a secondary battery, a late-night power switching means 5 for opening and closing the connection with the late-night power 3, a voltage detection means 6a for detecting a power supply state of the late-night power 3, Charging means 9 comprising an AC / DC conversion means 7 comprising an active filter for converting an AC input of midnight power into DC and a charging control means 8 for controlling a charging voltage / current to the power storage means, charge / discharge control / input / output control・ Grid connection control ・
A general control means 10 comprising a microcomputer or the like for performing protection control, a discharge voltage conversion means 11 for performing primary voltage conversion at the time of discharge, an inverter for converting DC into AC of commercial frequency and outputting the same, and a quadrature comprising a low-pass filter. Conversion means 12
, A voltage detecting means 6d for measuring the output voltage of the output means 13, an output switching means 14 for opening and closing the output of the output means 13, and a power supply line 15 provided on the load side of the output switching means 14, Voltage detecting means 6 for measuring voltage
c, a current detecting means 1 for measuring an output current of the output means 13
6a, current detecting means 16b for measuring the current on the commercial power supply side,
The current detection means 16c for measuring the load current, that is, the total current consumption in the house in the case of this embodiment, the commercial power supply opening / closing means 18 for opening and closing the power supply of the commercial power supply 17, and the commercial power supply A voltage detecting means 6b for measuring the voltage of the power supply is provided.

In this embodiment, the output opening / closing means 14 is a system interconnection point with the commercial power supply 17. The operation of the first embodiment of the household power storage device 1 having the following configuration will be described. Book first
The embodiment of the example is a case where the power supply system to the house of midnight power and the metered light power that is a normal commercial power supply is separated into the house,
Main breakers 4 and 19 are provided in each power supply system. In this power supply mode, the midnight power is supplied only during a predetermined time zone.

At the time of charging, when the voltage detection means 6a detects the power supply state of the midnight power 3, the overall control means 10 checks the charge state of the power storage means 2, and when the power storage means 2 is in a chargeable state. Closes the late-night power switching means 5 after opening the output switching means 14 or after confirming the opening of the output switching means 14, and stores the nighttime power 3 by the AC / DC conversion means 7 according to an instruction signal from the overall control unit 10. A charging method (for example, in the case of a lithium ion secondary battery) corresponding to the characteristics of the secondary battery constituting the power storage means 2 by the charge control means 8 configured by a step-down chopper or the like. Is controlled by a constant current / constant voltage charging method) so that charging can be completed within the midnight power supply time zone, and the overall control unit 10 detects completion of charging of the power storage means 2 or ends supply of midnight power. It terminates the charge by supplying the time zone of Luke or midnight power is terminated to open the midnight power switching means 5.

At the time of discharging, the end of power supply of the midnight power 3 is confirmed by the voltage detection means 6a, and the elapsed time from the start of power supply of the midnight power 3 is measured by a time measuring means (not shown) built in the overall control unit 10. After confirming that the time is outside the supply time period of the late-night power 3 by measuring the time and confirming that the late-night power switching means 5 is open, it is confirmed that the power storage means 2 can be discharged. Is converted to a DC voltage of a level suitable for generating an AC output of a voltage specified by the guideline when the system is interconnected with the commercial power supply 17 by the discharge voltage conversion means 11 constituted by a boost chopper or the like. The DC voltage is converted to the commercial power 17 by the orthogonal
And generate an AC output of a quality that can be connected to the system.

At this time, the information on the voltage waveform of the commercial power supply 17 is detected by the voltage detecting means 6b and transmitted to the overall control unit 10, and the information on the current supplied from the commercial power supply 17 to the house is detected by the current detecting means 16b. , To the overall control unit 10. The voltage detecting means 6b and the current detecting means 16b also serve as a power failure detecting means for detecting a power failure of the commercial power supply 17.

Each of the loads 21a to 21i in the house is connected to the in-house power supply line 15 and the branch breakers 20a to 20i, respectively.
c, and these loads 21a to 21
The total current supplied to i is detected by the current detecting means 16c, the voltage in the home power supply line 15 supplied to each load is detected by the voltage detecting means 6c, and information on the total load current and the voltage of the home power supply line 15 is obtained. Is transmitted to the overall control unit 10.

The AC output voltage of the home power storage device 1 is detected by the voltage detecting means 6d, and the output current is detected by the current detecting means 16d.
a, and information on the output voltage and output current of the household power storage device 1 is transmitted to the overall control unit 10. The overall control unit 10 controls the waveform, frequency, phase, and current of the output voltage and controls the opening and closing of the output switching unit 14 based on the information. The power supply state of the commercial power supply 17 is confirmed based on the information from the voltage detection means 6b,
To tolerances i ₀ which feed current i1 is preset from the commercial power source 17 by the information from the current detecting means 16b after confirming the closed state of,

[0015]

When i ₁ > i ₀ ≧ 0 (1), the output opening / closing means 14 is closed by a signal from the overall control unit 10, and the output current i ₂ of the household power storage device 1 is reduced to the full load current i. _{For 3} ,

[0016]

The current is controlled to a value such that i ₃ −i ₂ = i ₁ > i ₀ (2), and the power is supplied from the household power storage device 1 to the commercial power supply 17 in system cooperation. At this time, the output voltage is constantly monitored by the voltage detecting means 6d, and the output voltage is limited so as to fall within a specified range of the guideline. Here, the direction in which each current supplies power to the loads 21a to 21i is positive. At this time, the output current i ₂ is set to a predetermined constant value or an arbitrary value within a predetermined allowable range.

In the first embodiment, when the load current fluctuates, when the load current i ₃ increases, all the currents other than the value of the predetermined output current i ₂ of the household power storage device 1 become the commercial power supply 17. There borne, the load current if i ₃ is reduced household electrical storage device 1 in a range which satisfies the expression (1) continues to output, (1) immediately output switching means when confirming not true 14 And the output of the home power storage device 1 is stopped. Once a home electric power storage apparatus 1 is temporarily output stops, for a predetermined load current i ₃ is set in advance it is increased time has stopped output. This is because the output opening / closing unit 14 frequently opens and closes in a short time, and the commercial power supply 17 and the loads 21a to 21
In order to prevent adverse effects on i, hysteresis may be provided by providing a difference in the value of the power supply current i ₁ when opening and closing the output switching means 14.

When a power failure of the commercial power supply 17 is detected by the voltage detecting means 6b and the current detecting means 16b, the household power storage device 1 is immediately activated by the signal from the general control unit 10 by the commercial power switching means 18 and the output switching means 16a. Immediately after confirming that the commercial power supply opening / closing means 18 is open, the household power storage device 1 immediately releases the current control function at the time of output control by the overall control unit 10 and changes the output control to voltage control. When a predetermined time has elapsed after the opening of the commercial power supply opening / closing means 18 has been confirmed, the power failure state of the commercial power supply 17 is confirmed by the voltage detecting means 6b, and then the output opening / closing means 14 is closed, and the home power storage device 1 operates independently. Thus, power is supplied to the loads 21a to 21i in the house. The household power storage device 1 constantly checks the power recovery of the commercial power supply 17 by the voltage detection means 6b, and when the power recovery of the commercial power supply 17 is detected, opens the output opening / closing means 14 to stop the power supply by the self-sustained operation, and set the power storage apparatus in advance. After the power is interrupted in the house for the predetermined time, the commercial power supply 18 is closed and the power supply by the commercial power supply 17 is restarted.

After the power supply by the commercial power supply 17 is restarted, power is supplied only from the commercial power supply 17 for a predetermined period of time. After that, if the power storage means 2 in the household power storage device 1 can be discharged, the voltage detection means 6b, 6c, the current detection means 16b,
Based on the information of 16a and 16c, the home power storage device 1 restores the current control function, closes the output opening / closing means 14, and resumes sending the output to the home power supply line 15.

Next, a second embodiment of the present invention will be described. FIG. 2 is a configuration diagram of a second embodiment of the household power storage device 1 including the power storage means 2 using a secondary battery. In this figure, the same parts as those in FIG. 1 are given the same symbols. The present embodiment is an application example in the case of an hourly electricity rate contract. The late-night electric power is intended for electric power in an inexpensive time zone at night, and the home electric power storage device 1 of the second embodiment has such a time. It has a function of charging the power storage means 2 in a band, measuring the time by a time measuring means (not shown) in the overall control unit 10, and discharging and outputting the electricity during an expensive time period of the daytime electricity bill.

Further, in the present embodiment, the power supply target at the time of power failure is limited to the emergency power supply system 15b, and the load 21j which is not desired to be powered down in the event of an emergency such as an emergency light connected to the emergency power supply system 15b via the branch breaker 20d. , 21k, and a self-sustained operation protection cut-off means 22 is provided between the home power supply line 15a and the emergency power supply system 15b to detect the supply current of the commercial power supply 17. Means 1
6b is an in-house power supply line 15a capable of measuring the entire load current in the house
And on the upstream side of the self-sustained operation protection cut-off means 22.

In-home power supply line 15a other than emergency power supply system 15b
Is connected to the downstream side of the commercial power supply opening / closing means 18, and the load current detecting means 16c is a position where the load current i _3a of the in-home power supply line 15a other than the emergency power supply system 15b can be measured, that is, the self-sustained operation protection interrupting means 22 and the commercial power supply The power supply 17 is provided closer to the loads 21a to 21i than the connection point of the power supply line. The configuration of the household power storage device 1 other than the above is the same as the configuration of the first embodiment.

The operation of the household power storage device 1 having the following configuration will be described. When the household power storage device 1 is charged, if it is determined that the power supply time period is the nighttime power supply time period by the clocking means (not shown) inside the overall control unit 10, the output opening / closing means 14 is opened or confirmed, and the voltage detecting means 6b is opened. And current detecting means 16
b, the power supply status of the commercial power supply 17 is checked, and the charging state of the power storage means 2 is checked. If the charging state is possible, the midnight power switching means 5 is closed, and
The power storage means 2 is charged in the same procedure as described above.

The overall control unit 10 terminates charging when the completion of charging of the power storage means 2 is detected or when the midnight power supply time period ends, and the midnight power switching means 5 is opened. It should be noted that the management of the midnight power supply time zone is performed by the overall control unit 1.
This is performed by a timing means (not shown) inside 0. At the time of discharging, the overall control unit 10 confirms that the midnight power supply time period has ended and that the midnight power switching means 5 is open, and then the power storage means 2 can be discharged as in the first embodiment. It is confirmed that the DC voltage of the power storage means 2 is at a level suitable for generating an AC output of a voltage specified in the guideline when the discharge voltage conversion means 11 is connected to the commercial power supply 17 by the system. Then, the DC voltage is converted by the orthogonal conversion means 12 into an AC output of a quality that can be interconnected with the commercial power supply 17. Monitors the supply current i ₁ from the commercial power supply 17 by the current detecting means 16b, (1) When a situation where expression is satisfied, and closed the output switching means 14, very feeding system 15b
The load current i _3a of the in-home power supply line 15a and the output current i ₂ of the home power storage device 1

[0025]

The output current i ₂ of the home power storage device 1 is controlled so that the following holds: i _3a −i ₂ > 0 (3), and power is supplied from the home power storage device 1. As soon as the load current i _3a decreases and the expression (3) or the expression (1) does not hold, the output opening / closing means 14 is opened immediately, and the power supply from the household power storage device 1 is stopped. Once the power storage device 1 stops outputting, it does not output again for a predetermined time even if the load current _i3a increases.

When the power failure of the commercial power supply 17 is detected by the voltage detection means 6b and the current detection means 16b, the commercial power supply opening / closing means 18, the output opening / closing means 14 and the self-sustained operation protection interrupting means 22 are opened, and the total load in the house is reduced. To the commercial power supply opening / closing means 18 and the self-sustained operation protection cutoff means 2
When a predetermined time has elapsed after confirming the opening of the output circuit 2, the output opening / closing means 14
Is closed, and power supply is started only to the emergency power supply system 15b by the self-sustaining operation of the household power storage device 1.

The output control during the self-sustaining operation of the household power storage device 1 is performed by voltage control. When the emergency power supply system 15b is desired to be uninterrupted, a method of managing the emergency power supply system 15b attached to the household power storage device 1 using the self-sustained operation protection interrupting means 22 as a system cooperation point can be considered.

[0028]

As described above, according to the home power storage device and the control method of the home power storage device according to the first invention, the output current of the home power storage device is made smaller than the total current consumption in the house. , So that the output of the home power storage device does not flow backwards outside the home, the inexpensive midnight power storage can be effectively used only in the home during the daytime, and a part of the current consumption in the home is shared and supplied. Therefore, the output rating of the household power storage device can be reduced.

Further, the output of the home power storage device is always smaller than the power supply current of the commercial power supply, and this is a use method for supplementing the power supply of the commercial power supply. Does not interfere with distributed power systems.

According to the second aspect of the present invention, in addition to the effects of the first aspect, in addition to the effects of the first aspect, the current supplied from the household power storage apparatus is supplied from the commercial power supply. Since the power supply current is lower than the supply current by more than a predetermined value, it is easy to prevent reverse power flow to the outside of the house even when the current consumption in the house decreases, and the fluctuations in voltage and current during a power outage of the commercial power supply become large, so the commercial power supply Power outage detection becomes easier.

Further, according to the home power storage device and the control method of the home power storage device according to the third aspect of the present invention, a predetermined load in the house can be supplied from the home power storage device during a power failure of the commercial power supply. It is possible to provide a household power storage device that is effective in preventing disasters.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a configuration of a household power storage device that is Embodiment 1 of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of a home power storage device that is Embodiment 2 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Home electric storage apparatus, 2 ... Electric storage means, 3 ... Midnight electric power, 4
… Medium power switch.

Continued on the front page F term (reference) 5G015 FA05 FA08 GA11 HA12 JA24 JA32 JA35 JA52 5G066 JA02 JA04 JA20 JB03 5H007 BB00 CC03 CC12 DA05 DB01 DC02 DC05 FA03 FA12 FA14 FA19 GA09

Claims (1)

[Claims] 1. A home power storage device provided with a storage device using a secondary battery, wherein a current consumption measuring means for measuring the total current consumption in the house, and a midnight power AC is converted into a DC in the home power storage device. A charging means for converting the power and charging the power storage means, and converting the direct current of the power storage means into an alternating current of commercial frequency in a time zone other than the midnight power supply time zone and superimposing the direct current on a commercial power supply in the house to discharge output. And a control unit that controls an output current of the home power storage device to be smaller than a total current consumption in the home measured by the current consumption measurement unit.