JP2001258158A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system which can be installed without storing a secondary battery in a dedicated battery chamber and has an advantage in capital investment. SOLUTION: This power storage system includes a plurality of power storage units Y... connected in parallel with a power system A composed of a system power source 1 and a load 2, and synchronously cooperates a plurality of power storage units Y... by means of a common power controller 30 to perform power compensating operations of the peak cut and the peak shift of the power system A, wherein the battery capacity of a secondary batteries 16... used for a plurality of power storage system units Y... respectively is set so as to be under specified capacity which needs the dedicated battery chamber as specified in Fire Defense Law and related regulations, thus it is possible to install all of the secondary batteries 16... on a floor or the like without using the dedicated battery chamber.

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 which is installed in a large factory, a building, or the like and performs a power compensation operation called power leveling by suppressing power fluctuations in a power system.

[0002]

2. Description of the Related Art A power storage system installed in a large power demanding facility, such as a large factory or a high-rise building, charges a secondary battery with surplus power at night and discharges the power of the secondary battery during a peak power daytime. To perform a power compensation operation such as suppressing a power peak. A specific example of this power storage system is shown in FIG. 3 and described. The power storage system B shown in FIG. 1 is installed in the power system A of the system power supply 1 and the load 2, and is connected between the system power supply 1 and the load 2 via the AC switch 3 and the interconnection transformer 4. 5
And a secondary battery 6 such as a lead battery is connected to the DC side of the power converter 5.

A power converter 5 is a bidirectional AC / DC converter having an inverter function and a converter function. The converter operates to convert AC power from the system power supply 1 to DC and charge the secondary battery 6; The inverter operation for converting the DC power charged in the DC power supply 6 into AC power and supplying the converted DC power to the load 2 is controlled in a switching manner.

For example, when the load 2 is a variable load in a factory, the power peaks during a heavy load in the daytime and the power drops significantly during a light load in the middle of the night. The converter 5 is operated as an inverter to convert the discharge power of the secondary battery 6 into AC and supply the load 2 to the load 2 so that the power peak of the power system A is reduced (peak cut). Is operated as a converter to charge the secondary battery 6 with the surplus AC power of the system power supply 1.

[0005] By peak shifting the discharge power of the secondary battery 6 in this manner, power fluctuations in the power system A are suppressed, and power compensation operations such as reducing daytime power peaks and peak demands are performed. Will be

[0006]

In the case of the above-mentioned power storage system connected to the power system of a factory or a building, the capacity of the storage system is required to be at least about 100 kW, and the discharge time is required to be at least 30 minutes. It has been. In this power storage system with a storage system capacity of 100 kW and a discharge time of 30 minutes, the DC voltage of the
Assuming 0 V, the battery capacity of the secondary battery is (100 × 10
00) W × 0.5 h ÷ 400 V = 125 Ah, and at least 125 Ah is required. Such a battery capacity 12
For example, when a lead battery having a terminal voltage of 2 V per cell is used as a 5 Ah secondary battery, the number of cells required for a lead battery with a DC voltage of 400 V is 200, and the capacity of the secondary battery is equal to the number of cells. = 25000 Ah cell, a large-capacity large-capacity battery is required.

[0007] In addition, as for secondary batteries of a power storage system installed in factories and the like, fire-related regulations stipulate that large-capacity batteries exceeding 4800 Ah cells be installed in a dedicated storage battery room. Therefore, based on the above formula, 250
The rechargeable battery 6 of the 00Ah cell is 4800 of the fire related laws and regulations.
Since the specified capacity of the Ah cell is greatly exceeded, it was necessary to install the Ah cell in a dedicated storage battery room 7 as shown by a chain line in FIG.

[0008] Such a storage battery room 7 should be installed in a relatively safe place in a factory or a building, and sufficient measures should be taken against leakage of electrolyte and gas from the contained secondary battery and gas leakage. It must have a robust and fireproof structure. Therefore, the construction cost of the storage battery room itself becomes high, which makes the power storage system expensive. In addition, when installing a new power storage system in a building such as an existing factory or building, it may be difficult to secure a place to install the special storage battery room in the existing building. Has slowed the spread of power storage systems.

An object of the present invention is to provide a power storage system that can be easily installed in a factory or a building without using a dedicated storage battery room.

[0010]

In order to achieve the above object, the present invention provides a secondary battery disposed on the DC side of a power converter connected to a single power system via an interconnection transformer. The power storage units that perform the power compensation operation of the peak cut and peak shift of the power system are divided into a plurality of units each including an interconnection transformer and a secondary battery, and the secondary storage in each of the plurality of power storage units is separated. Set the battery capacity of the battery to less than the specified capacity that requires a dedicated storage room, and execute the power compensation operation of a single power system with the total battery capacity of the secondary batteries of multiple power storage units. Features.

Here, each of the plurality of power storage units has a configuration similar to that of a conventional single power storage system. The secondary battery used for each power storage unit is equivalent to a secondary battery of a single conventional power storage system divided and dispersed. The battery capacities of the secondary batteries of each of the plurality of power storage units are all the same or can be set arbitrarily as needed.However, set the capacities of all the rechargeable batteries so small that they do not touch fire-related regulations. Also, by setting the number of divisions of the power storage unit so that the battery capacity can be set small, each power storage unit can be installed in a factory or a building without using a dedicated storage battery room. Become.

In the present invention, the plurality of power storage units are installed in each of a plurality of sections of the building, and the power control controller installed in any single section of the building and the power storage of each section are provided. The units can be connected by a communication line, and each power storage unit can be synchronously and cooperatively operated by a power controller.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the same or corresponding portions are denoted by the same reference symbols throughout the drawings including FIG. 3 to avoid duplication of description.

The power storage system C of the embodiment shown in FIG.
Are connected in parallel to a single power system A composed of a system power supply 1 and a load 2, and are connected to the respective power storage units Y,... Via a communication line 20 such as a LAN. And a common power control controller 30.

Each of the plurality of power storage units Y,... May have the same configuration, and one power storage unit Y is connected between the system power supply 1 and the load 2 via the AC switch 13 and the interconnection transformer 14. The power converter 15 is connected, and a secondary battery 16 such as a lead battery is connected to the DC side of the power converter 15.

Each of the plurality of power storage units Y,.
Cooperative operation control is performed synchronously by the common power controller 30. That is, the power converters 15,... Of the plurality of power storage units Y,... Are bidirectional AC / DC converters having an inverter function and a converter function. The converter operation for charging the secondary batteries 16,... And the inverter operation for converting the DC power charged in the corresponding secondary batteries 16,. By the cooperative operation control of the plurality of power storage units Y,..., The power compensation operation of peak cut and peak shift in the single power system A is executed.

The power controller 30 includes a power system A
, Each of the plurality of power storage units Y,.
Of the inverter operation and the converter operation are output to the power converters 15 via the communication line 20. The power control controller 30 is not limited to the one designed and manufactured exclusively for the power storage system of the present invention, and is applicable even if the control software is incorporated in a personal computer of an operation manager.

A power compensation operation such as a peak cut in a single power system A is performed with the total capacity of the battery capacities of the plurality of power storage units Y,. Therefore, the secondary batteries 16 of each of the plurality of power storage units Y,.
Are set smaller than the battery capacity of FIG. The battery capacity of each of the plurality of secondary batteries 16,.
It is set to less than the required capacity for a dedicated storage battery room according to fire-related regulations. Also, the number of divisions of the power storage units Y,... Is set such that the plurality of secondary batteries 16,... Can be set to a capacity that does not require a dedicated storage battery room.

For example, when the power system A shown in FIG. 1 is installed in a factory or a building, the storage system capacity of the power storage system C connected to the power system A is 100 kW, and the discharge time is 3 hours.
In the case of 0 minute, the power storage units Y,... Are divided into 10 units, and assuming that the unit capacities of the respective power storage units Y,. 10 divided by the unit
kW, which is multiplied by the discharge time 0.5h, 5 kW
h of discharge capacity is required. Here, suppose that the DC voltage of the secondary batteries 16 of each of the power storage units Y,.
Then, the battery capacity of each of the 10 units of rechargeable batteries Y is (100 × 1000) W × 0.5h０．５200V
÷ 10 units = 25 Ah in the calculation formula of 25 Ah.
For example, when a lead battery having a terminal voltage of 2 V per cell is used as one secondary battery 16 having a battery capacity of 25 Ah, the number of cells required for a lead battery having a DC voltage of 200 V is 10
0, and one secondary battery 16 has a capacity × the number of cells = 25.
Ah x 100 cells = 2500Ah cells lead batteries can be used.

Since the lead battery of 2500 Ah cell as described above is about half of the capacity of 4800 Ah cell specified in the fire-related regulations, the secondary battery 16 of this lead battery can be placed on the floor of a factory without using a dedicated storage battery room. It can be installed in an optional place with a minimum space required. Therefore, each of the plurality of power storage units Y,... Can be constructed as inexpensive equipment in a small space that does not require a dedicated storage battery room, and can be distributed to a plurality of divisions of a factory or floors of each floor of a building. Deployment is easier.

If a LAN line is used for the communication line 20 connecting the power storage units Y,..., And the common power controller 30 thus distributed, the number of divisions of the power storage units Y,. Even so, it can be easily connected to the common power controller 30 at low cost.

The embodiment shown in FIG. 2 is an application of the power storage system C of FIG. 1 to a building 40 having a plurality of floors, and comprises a single power supply 1 outside the building and a load 2 on each floor of the building 40. For the power system A, a plurality of power storage units Y,.
Are connected in parallel to the loads 2,... On each floor, and the secondary batteries 16,. Further, the power control controller 30 is provided at an arbitrary floor serving as a central control room of the building 40, and is connected to the power storage units Y,.
N and the like.

In the embodiment shown in FIG. 2, the rechargeable batteries 16,... Installed on each floor of the building 40 are batteries having a capacity less than a specified value that does not require a dedicated storage battery room. Can be installed together with the two-way power converters 15,..., Whereby maintenance of the power storage units Y,.

The battery capacity of the secondary batteries of the plurality of power storage units Y,... Can be reduced as the number of divided units increases, and the secondary batteries among a small number of units, such as a few, can be shared. Even though the battery capacity can be less than the specified capacity that makes the storage battery room unnecessary, such a common use of the secondary battery among the units complicates the entire power storage system due to an increase in the number of units, and It is not preferable because the wiring performed using a thick cable having a relatively large current capacity between the units becomes complicated.

[0025]

According to the present invention, an electric power storage system connected to a single electric power system is constituted by a plurality of divided and distributed electric power storage units, and a plurality of electric power storage units are used in a plurality of electric power storage units. Since the battery capacity is set small enough not to touch fire-related regulations, it is necessary to install secondary batteries without using a dedicated storage room even in a single power system with a large power compensation capacity. This makes it possible to provide an electric power storage system that can be installed in factories, buildings, and the like with a favorable capital investment. In addition, since it becomes easy to install an electric power storage system without building a storage battery room in a new building or an existing building such as a factory or a building, the spread of the electric power storage system to a building such as a factory or a building becomes easy. It will be easier.

[Brief description of the drawings]

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

FIG. 2 is a circuit diagram when the power storage system of FIG. 1 is applied to a building;

FIG. 3 is a circuit diagram showing an example of a conventional power storage system.

[Explanation of symbols]

 A power system 1 system power supply 2 load C power storage system Y power storage unit 15 power exchanger 16 secondary battery 20 communication line 30 power control controller

Claims (2)

[Claims] An electric power storage for executing a power compensation operation of peak cut and peak shift by a secondary battery disposed on the DC side of a power converter connected to a single power system via an interconnection transformer. Divide the unit into multiple units, each with an interconnection transformer and secondary battery, and set the secondary battery capacity of each of the multiple power storage units to less than the specified capacity that requires a dedicated storage battery room A power storage system characterized in that a power compensation operation of a single power system is executed with a total battery capacity of secondary batteries of a plurality of power storage units. 2. A plurality of power storage units are installed in each of a plurality of sections of a building, and a power control controller installed in an arbitrary single section of the building and a power storage unit of each section are provided. The power storage system according to claim 1, wherein the power storage units are connected by a communication line, and each power storage unit is operated by a power control controller in a synchronous and cooperative manner.