JP2000312445A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system, in which the service conditions of a battery are varied and the lifetime of the battery is prolonged and the load at replacing is reduced. SOLUTION: This power storage system with a plurality of battery units 42, which are connected in parallel has a commercial power 1 and supply load equipment 5 with power, the dissipation power of the load equipments 5 is detected by a current detector 23, a changeover switch 41 is operated, and the number of the battery units 42 supplying power in response to the working electric energy is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power storage system provided with a storage battery for storing commercial power provided in a power distribution circuit of a house or the like.

[0002]

2. Description of the Related Art Conventionally, there has been known an electric power storage system using a large-capacity storage battery to store and use commercial electric power. In particular, there is a distributed battery power storage system that stores inexpensive nighttime power and uses it in expensive daytime power hours to reduce power charges and achieve power load leveling (registered utility model No. 3045189). Gazette).

At present, lead-acid batteries are generally used as large-capacity storage batteries, but they have many problems such as low energy conversion efficiency and low energy density, and maintenance is troublesome. Therefore, development of a high-density, high-efficiency, long-life, and high-reliability storage battery for home battery power storage is being promoted, and lithium secondary batteries are particularly attracting attention.

[0004]

Generally, it is not desirable to load a storage battery, especially a lithium secondary battery, into a battery such as a quick charge or a rapid discharge, for reliability and long life. However, many electric appliances used in ordinary households, such as air conditioners and electromagnetic cookers, whose power consumption rises sharply with the start of use, use of power from the storage battery in these devices places a load on the storage battery due to rapid discharge. Therefore, it is better not to use the power of the storage battery for these load devices as much as possible. However, the power consumption ratio of these devices in the home is large, and it is desirable to supply power from the storage batteries to these devices in order to reduce the electricity bill and level the load.

Another problem is that in the conventional system, a plurality of storage batteries are used uniformly, and when one storage battery reaches the end of its life, all storage batteries must be replaced with new ones. There is a problem that it becomes a heavy burden on the elderly. The present invention has been made in view of such a problem, and an object of the present invention is to disperse the use state of a storage battery, extend the life of the storage battery, and reduce the burden of replacement. To provide.

[0006]

An electric power storage system according to the present invention includes a plurality of storage batteries connected in parallel to store commercial electric power and supply the electric power to load equipment. Power consumption detection means for detecting power consumption, and control means for controlling the number of storage batteries to be supplied with power according to the power consumption of the load device detected by the power consumption detection means. Further, the control means can determine the storage batteries to be supplied with power in accordance with a predetermined priority, thereby dispersing the life of each storage battery and dispersing the replacement time.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 1 is a block circuit diagram showing an embodiment of a power storage system of the present invention. The commercial power 1 is connected to the system switching device 2 before entering the house. The system switching device 2 includes a first switch 21, a second switch 22, a current detector 23, and a control unit 24.

[0008] The output of the commercial power 1 is supplied from a commercial power supply system (this system has a home outlet not shown) from the first switch 21 to the load device 5 via the current detector 23, and from the first switch 21. It is divided into a charging system that reaches the storage battery device 4 via the bidirectional inverter 3 via the second switch 22. The control unit 24 controls the bidirectional inverter 3
And monitoring and control of the current and voltage values of the storage battery device 4, switching control of the first switch 21 and the second switch 22, and switching control of the switch 41 (described later) in response to a signal from the current detector 23. It is. This control unit 24
Has a timer function for measuring time and outputting a switching signal in the nighttime power zone and other daytime power zones.

The storage battery device 4 has a configuration in which a plurality of series circuits of a storage battery unit 42, a diode 44, and a changeover switch 41 are connected in parallel. The storage battery unit 42 has a configuration in which a plurality of cells 43 are connected in series. Next, the operation of the above circuit will be described. In the cheap nighttime power zone, the first switch 21 and the second switch 22 are turned on to supply the AC power from the commercial power system 1 to the load device 5, and the AC power is converted to the DC power by the bidirectional inverter 3. Convert and changeover switch 41
Are turned ON to charge the storage battery unit 42, that is, the individual cells 43. When the control unit 24 detects that the storage battery unit 42 is fully charged, the corresponding changeover switch 41 is turned off. When all the storage battery units 42 are fully charged, the power supply to the storage battery device 4 is stopped. The second switch 22 is turned off.

In a daytime power period other than the nighttime power period, the first switch 21 is turned off and the second switch 22 is turned off.
Is turned on, the DC power from the storage battery device 4 is converted into AC power by the bidirectional inverter 3 and supplied to the load equipment 5. Here, when the power consumption of the load device 5 in use is small, that is, when the current value detected by the current detector 23 is small, the changeover switches 41 of the storage battery units 42 that can cover this current value are turned ON. , The number of power supplies. When the power consumption increases, the changeover switches 4 connected to the storage battery units 42 that are not used so that necessary and sufficient power can be supplied.
Turn 1 ON.

FIG. 2 is a diagram showing a configuration of the storage battery device 4. The storage battery device 4 has ten storage battery units 42a to 42a to
In this configuration, changeover switches 41a to 41j are connected to 42j via diodes 44a to 44j, respectively, and a discharge current at which one storage battery unit 42 is not overloaded is temporarily assumed to be 1A. If the power consumption of the load device 5 is 100 W, the current value detected by the current detector 23 is 1 A,
When only the changeover switch 41a is turned ON, the storage battery unit 4
Power is supplied only from 2a. Then, when another electric device is turned on and the power consumption of the load device 5 rises to, for example, 500 W, a current of 5 A is required,
1b to 41e are turned ON and five storage battery units 42a
To 42e. As a result, the current value that each storage battery bears is only 1 A, and it is possible to prevent overload. As described above, the number of storage battery units 42 to be used so as not to overload each storage battery unit 42 while corresponding to the magnitude of power consumption of the load device 5, that is, the detected current value of the current detector 23 is changed. It is.

Further, the order of use of the storage battery units is 42a.
By setting the order of → 42b → ‥‥‥ → 42j, the life of the storage battery comes for each use order. Therefore,
The batteries must be replaced one by one starting from the one with the life end. When the capacity of a certain storage battery unit 42 has decreased to the lower limit, the corresponding switch 41 is turned off.
By setting the switch to F, the corresponding switch 41 of another storage battery unit 42 is turned on to switch the storage battery unit 42. Thus, overdischarge can be avoided, and the burden on other storage battery units 42 can be avoided. When the storage battery device 4 cannot supply the power of the load device 5, the first switch 21 is turned on and the second switch 22 is turned off, and the electric power is supplied from the commercial power system 1. Then, when the night power time zone is reached, the second
The switch 22 and the changeover switch 41 are turned on to perform charging.

The present invention is not limited to the above embodiment. For example, in the illustrated embodiment, the storage battery unit 42 has a configuration in which a plurality of unit cells 43 are connected in series to form a unit. But also,
Each storage battery unit 42 may have a different capacity.

The current detector 23 may be provided between the bidirectional inverter 3 and the second switch 22. The power consumption detecting means may be one that detects on / off of a power switch of the load device. The power consumption detecting means may detect the power consumption of the entire load device, or may detect the power consumption of each load device.

[0015]

As described in detail above, according to the present invention, the use of the storage battery is dispersed and the burden on each individual is reduced, so that the reliability and the life of the storage battery can be improved, and
Since the usage status of individual storage batteries is not uniform and the order of use can be set arbitrarily, the replacement time of each storage battery can be changed, and even if the storage battery fails, only the failed battery should be replaced Is possible, and the burden of the replacement work on the user is reduced. In addition, a storage battery having a lower usage order has a smaller discharge amount, so that the burden on the storage battery is reduced, and the life of the storage battery is longer than that of normal use. As a result, the life of the entire storage battery can be extended.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a power storage system of the present invention.

FIG. 2 is a diagram showing a configuration of a storage battery device 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 commercial power 2 system switching device 3 bidirectional inverter 4 storage battery device 5 load equipment 21 first switch 22 second switch 23 current detector (power consumption detection means) 24 control unit (control means) 41 changeover switch 42 storage battery unit (storage battery) ) 43 cell 44 diode

Claims (2)

[Claims] 1. A power storage system comprising a plurality of storage batteries connected in parallel to store commercial power and supply the power to a load device, comprising: a power consumption detecting means for detecting power consumption of the load device; And a control unit that controls the number of the storage batteries that supply power according to the power consumption of the load device detected by the power consumption detection unit. 2. The power storage system according to claim 1, wherein the control unit determines the storage battery to be supplied with power according to a predetermined priority.