CN219164243U

CN219164243U - Direct current side energy storage device

Info

Publication number: CN219164243U
Application number: CN202320138989.7U
Authority: CN
Inventors: 刘涛; 王龙; 任彦彦
Original assignee: Shanghai Elecon Intelligent Technology Co ltd
Current assignee: Shanghai Elecon Intelligent Technology Co ltd
Priority date: 2023-01-17
Filing date: 2023-01-17
Publication date: 2023-06-09
Anticipated expiration: 2033-01-17

Abstract

The utility model discloses a direct-current side energy storage device, which relates to the technical field of energy storage and comprises an alternating-current charging converter, an energy storage battery pack and a switching power supply, wherein the alternating-current charging converter is connected with the energy storage battery pack and is used for connecting with a mains supply and charging the energy storage battery pack; the switching power supply is connected with the energy storage battery pack through the direct current converter and is used for connecting with the mains supply and supplying power to the load; and the direct current converter samples the load current through a sampler. The embodiment of the utility model can carry out high-efficiency charge and discharge on the energy storage battery pack, and the stability and reliability of power supply of the whole system are improved.

Description

Direct current side energy storage device

Technical Field

The utility model relates to the technical field of energy storage, in particular to a direct-current side energy storage device.

Background

At present, a direct current side energy storage device facing to a base station and other distributed application scenes aims to realize peak valley arbitrage through a direct current side lithium iron phosphate battery and plays a role in standby electricity to a certain extent, but in the current implementation mode, the biggest problem is that the lithium iron phosphate battery is charged and discharged:

a) For a newly-built project, the requirement that capacity expansion possibly exists in the later stage can be comprehensively considered from the earlier stage planning and design stage, so that most of actual field conditions can be solved, but certain cost increase possibly occurs due to the requirement of capacity redundancy expansion, meanwhile, the matching of a base station switching power supply and a direct-current side lithium iron phosphate battery is required to be ensured, the standard standardization is realized, certain problems possibly exist at present, and the convenience of subsequent maintenance is insufficient;

b) For the transformation project, as the original switching power supply of the base station does not have peak clipping and valley filling logic, the function matching cannot be performed, and the charge and discharge operation is completed; even if the original switching power supply of the base station has logic for peak clipping and valley filling, if the battery charging and the load power consumption exist simultaneously, the rated power which can be provided by the switching power supply of the base station can be exceeded, and even the switching power supply plug frame has no redundant position and is provided with an additional switching power supply module, the problem can not be solved;

c) Since the existing direct-current side lithium iron phosphate battery is directly connected in parallel to the direct-current bus and is used as a voltage source when being discharged, the original lead-acid storage battery needs to be completely removed, so that the improvement cost is greatly increased for many occasions, and the lithium iron phosphate battery which needs to be provided needs to leave enough capacity for power supply besides the peak Gu Tao benefit, and the capacity for power supply of the part cannot participate in peak valley arbitrage.

In summary, how to improve the stability and reliability of power supply of the dc side energy storage device is a technical problem in the prior art.

Disclosure of Invention

In order to solve the technical problem, according to an aspect of the present utility model, there is provided a dc side energy storage device, including an ac charging converter, an energy storage battery pack and a switching power supply, where the ac charging converter is connected to the energy storage battery pack, and the ac charging converter is used to connect with a mains supply and charge the energy storage battery pack; the switching power supply is connected with the energy storage battery pack through the direct current converter and is used for connecting with the mains supply and supplying power to the load; and the direct current converter samples the load current through a sampler.

In one possible embodiment, the AC charging converter includes an AC/DC converter and a DC/DC converter, the AC/DC converter is connected to the DC/DC converter, the DC/DC converter is connected to the energy storage battery, the AC/DC converter is used for converting AC power into DC power, and the DC/DC converter is used for converting DC power.

In one possible embodiment, the direct current converter is a DC/DC unidirectional discharge converter or a DC/DC bidirectional converter.

In one possible embodiment, the switching power supply comprises an AC/DC converter.

In one possible embodiment, the battery management system further comprises a first battery management system, the ac charging converter and the energy storage battery pack are respectively connected with the first battery management system, and the first battery management system is used for controlling the ac charging converter to charge the energy storage battery pack.

In one possible implementation manner, the power supply further comprises a second battery management system, wherein the direct current converter and the energy storage battery pack are respectively connected with the second battery management system, and the second battery management system is used for controlling the direct current converter to carry out direct current-to-direct current conversion on electric energy output by the energy storage battery pack or controlling the direct current converter to carry out direct current-to-direct current conversion on direct current output by the switching power supply.

In one possible embodiment, a backup battery pack is further included for powering the load.

In one possible embodiment, the battery backup is a lead acid battery.

In one possible embodiment, the energy storage battery pack is composed of a plurality of single lithium iron phosphate batteries connected in series/parallel.

In one possible embodiment, the sampler is a hall current sensor.

According to the embodiment of the utility model, the direct-current converter is arranged between the energy storage battery pack and the load, the alternating-current charging converter is arranged between the commercial power and the energy storage battery pack, and the sampler is arranged to obtain the load power, so that the energy storage battery pack can be charged and discharged efficiently, and meanwhile, the stability and reliability of the power supply of the whole system are improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the utility model as claimed. Other features and aspects of the present utility model will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

Fig. 1 shows a block diagram of a dc side energy store according to an embodiment of the utility model.

Fig. 2 shows a block diagram of a dc side energy store according to an embodiment of the utility model.

Detailed Description

Various exemplary embodiments, features and aspects of the utility model will be described in detail below with reference to the drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In the description of the present utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better illustration of the utility model. It will be understood by those skilled in the art that the present utility model may be practiced without some of these specific details. In some instances, well known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present utility model.

Referring to fig. 1, fig. 1 is a block diagram of a dc side energy storage device according to an embodiment of the utility model.

As shown in fig. 1, the device comprises an ac charging converter 10, a dc converter 20, an energy storage battery 30, a sampler 40 and a switching power supply 50, wherein the ac charging converter 10 is connected with the energy storage battery 30, and the ac charging converter 10 is used for connecting with the mains supply and charging the energy storage battery 30; the switching power supply 50 is connected with the energy storage battery pack 30 through the direct current converter 20, and the switching power supply 50 is used for connecting with the mains supply and supplying power to the load 70; and the dc converter 20 samples the load current through the sampler 40.

According to the embodiment of the utility model, the direct current converter 20 is arranged between the energy storage battery pack 30 and the load 70, the alternating current charging converter 10 is arranged between the commercial power and the energy storage battery pack 30, and the sampler 40 is arranged to obtain load power, so that the energy storage battery pack 30 can be charged and discharged efficiently, and meanwhile, the stability and reliability of power supply of the whole system are improved.

In the embodiment of the utility model, the energy storage battery pack 30 is coupled to the direct current bus of the load 70 through the direct current converter 20 and works in a current source mode, so that the problem of coexistence of the lithium iron phosphate battery and the lead-acid storage battery in the related art is solved, the capacity design of the lithium iron phosphate battery does not need to consider or partially consider the standby power requirement, and the overall investment is reduced to a certain extent.

The discharging of the dc converter 20 according to the embodiment of the present utility model is performed according to the load power obtained by the sampler 40, so that the power supply capability can be controlled with high efficiency, and the released active power is prevented from being greater than the actual load demand, for example, when the load 70 is supplied with power by the dc converter 20, the power of the dc converter 20 for outputting the dc power can be set to be not greater than the load power obtained by the sampler 40, thereby improving the safety of power supply.

The specific implementation manners of the ac charging converter 10, the dc converter 20, the energy storage battery pack 30, the sampler 40, and the load-side switching power supply 50 are not limited in the embodiments of the present utility model, and those skilled in the art may adopt suitable implementation manners according to actual situations and needs.

The AC charging converter 10 may include an AC/DC converter, a DC/DC converter, or may be implemented using other integrated devices, for example.

For example, the DC converter 20 may include a DC-DC converter DC/DC, the switching power supply 50 may include an AC/DC converter AC/DC and a DC/DC converter, the AC/DC converter is connected to the DC/DC converter, the DC/DC converter is connected to the energy storage battery 30, the AC/DC converter is used for converting AC to DC, and the DC/DC converter is used for converting DC to DC, that is, converting a fixed DC voltage to an adjustable DC voltage, and of course, embodiments of the present utility model are not limited to specific implementation of the DC/DC converter and the AC/DC converter, and those skilled in the art may use the same in the related art.

By way of example, the energy storage battery 30 may include a lithium ion battery, such as a lithium iron phosphate battery, a lithium polymer battery.

Illustratively, the load 70 may be a base station in a distributed application scenario.

For example, the dc converter 20 may be of a unidirectional discharge type, in which case the energy storage battery 30 is charged only by the ac charging converter 10, and the load 70 is supplied by converting dc power of the energy storage battery 30 by the dc converter 20 and/or by using electric power output from the switching power supply 50. By selecting a dc converter 20 of the unidirectional discharge type, embodiments of the present utility model may reduce costs.

In one possible implementation, the dc converter 20 is further connected to the switching power supply 50 at the load end, and is configured to perform dc-dc conversion on the dc power output by the switching power supply 50, so as to output the dc power to charge the energy storage battery 30.

The DC converter 20 may be a bidirectional charge-discharge type (DC/DC bidirectional converter), in which case the DC converter 20 may perform DC-DC conversion on the DC power output from the switching power supply 50 to charge the energy storage battery 30, or may perform DC-DC conversion on the power of the energy storage battery 30 to supply the load 70.

In one possible embodiment, in the case where the sum of the rated charge power of the energy storage battery pack 30 and the load power of the load 70 is smaller than the converted power of the switching power supply 50, the energy storage battery pack 30 is charged only by the direct current output from the switching power supply 50, and the ac charging converter 10 is configured to be in a standby state in which the ac charging converter 10 does not perform electric power conversion.

For example, in the case where the sum of the rated charge power of the energy storage battery 30 and the load power of the load 70 is smaller than the converted power of the switching power supply 50, the electric energy output by the switching power supply 50 may satisfy both the load power requirement and the charge requirement of the energy storage battery 30, so that the energy storage battery 30 can be charged and the load 70 can be supplied with the electric energy output by the switching power supply 50, and in this case, the ac charging converter 10 is set to be in a standby state to prevent overcharging.

In one possible embodiment, in a case where the rated charge power of the energy storage battery pack 30 and the load power of the load 70 are greater than the conversion power of the switching power supply 50, the energy storage battery pack 30 is charged by the direct current output from the ac charging converter 10 and the direct current output from the dc converter 20.

For example, when the rated charging power of the energy storage battery 30 and the load power of the load 70 are greater than the conversion power of the switching power supply 50, the direct current output by the switching power supply 50 alone cannot simultaneously satisfy the charging of the energy storage battery 30 and the power supply of the load 70, so that the embodiment of the utility model limits the conversion power of the direct current converter 20, preferentially satisfies the power supply of the switching power supply 50 to the load 70, and synchronously charges the energy storage battery 30 by using the ac charging converter 10 and the direct current converter 20, thereby improving the power supply efficiency of the load 70 and the charging efficiency of the energy storage battery 30, ensuring that peak valley arbitrage works reasonably and efficiently according to a formulated control logic and a time curve.

Of course, the specific implementation of the limitation of the conversion power of the dc converter 20 according to the embodiment of the present utility model is not limited, and a person skilled in the art may select a related technology to implement according to the actual situation and needs, for example, in the case that the load power is obtained through the sampler 40, the implementation of the present utility model may determine the maximum conversion power of the dc converter 20 according to the output power of the switching power supply 50 and the load power, so as to limit the conversion power and ensure the power supply of the load 70.

In one possible embodiment, in the case where the conversion power of the switching power supply 50 is less than or equal to the load power, the energy storage battery pack 30 is charged only by the direct current output from the ac charging inverter 10.

For example, in the case that the conversion power of the switching power supply 50 is less than or equal to the load power, the ac power output by the switching power supply 50 can only support the load power requirement, and in this case, the embodiment of the present utility model fully performs two-stage conversion (ac-dc, dc-dc) on the mains power by the ac charging converter 10 to obtain dc power to charge the energy storage battery 30.

It should be noted that, each unit of the embodiment of the present utility model may be implemented by a hardware circuit, and for value comparison (such as power comparison), the embodiment of the present utility model may also be implemented by a corresponding comparison circuit, which is not limited to this embodiment of the present utility model.

Referring to fig. 2, fig. 2 is a block diagram of a dc side energy storage device according to an embodiment of the utility model.

In one possible embodiment, as shown in fig. 2, a backup battery pack 60 is further included, the backup battery pack 60 being used to power the load 70.

In one possible embodiment, the battery pack 60 comprises a lead acid battery.

The utility model can be compatible with the standby battery pack 60 at the load end, reduces the use frequency of the standby battery pack 60, reduces the charge and discharge times of the standby battery pack 60, and prolongs the service life of the standby battery pack 60, thereby reducing the capacity of the standby battery pack 60 and the reconstruction cost.

In one possible embodiment, as shown in fig. 2, the apparatus further includes a first BATTERY management system (BATTERY MANAGEMENT SYSTEM, BMS) 80 and a second BATTERY management system (second BMS) 90, where the first BATTERY management system 80 is connected to the ac charging inverter 10, the energy storage BATTERY pack 30, and is used to control the ac charging inverter 10 to charge the energy storage BATTERY pack 30; the second battery management system (second BMS) 90 is configured to control the dc converter 20 to dc-convert the dc power output from the switching power supply 50, or control the dc converter 20 to dc-convert the electric power output from the energy storage battery pack 30.

The embodiment of the utility model does not limit the specific implementation manner of the BMS, and a person skilled in the art can refer to the related technology for implementation, wherein the BMS can also prevent the battery from being overcharged and overdischarged, prolong the service life of the battery and monitor the state of the battery.

The embodiment of the utility model utilizes the battery management unit to realize BMS communication among the AC charging converter 10, the energy storage battery pack 30 and the DC converter 20, can ensure that the real-time state of charging and discharging of the battery meets the technical safety requirement, and ensures the charging and discharging safety and the normative rationality of the lithium iron phosphate battery.

In one possible embodiment, the energy storage battery pack 30 comprises a lithium iron phosphate battery, the backup battery pack 60 comprises a lead acid battery, and the sampler 40 comprises a hall sensor.

The direct current side energy storage device of the embodiment of the utility model can solve the problem that the charging and discharging of the direct current side lithium iron phosphate battery (the energy storage battery pack 30) is matched with the original switching power supply (the switching power supply 50) of the base station in the related technology by arranging the direct current converter 20 between the energy storage battery pack 30 and the load 70, arranging the alternating current charging converter 10 between the commercial power and the energy storage battery pack 30 and arranging the sampler 40 to acquire the load power, the problem that the rated power provided by the switching power supply of the base station is exceeded under the condition that the charging of the direct current side lithium iron phosphate battery and the power supply of the load 70 occur simultaneously, the original lead-acid storage battery (the standby battery pack 60) of the base station is completely forced to be dismantled, and the transformation cost is greatly increased, the DC-DC conversion device (DC converter 20) with the function of unidirectional discharge or bidirectional charge-discharge is additionally arranged between the lithium iron phosphate battery equipped with the energy storage device and the base station DC bus, and the charging ACDC+DCDC (alternating current charge converter 10) two-stage conversion charging device for the lithium iron phosphate battery can be additionally arranged at the alternating current side, meanwhile, the sampling of the load power requirement by combining with the Hall current transformer (sampler 40) is combined, the reasonable and efficient charge-discharge of the lithium iron phosphate battery is carried out, meanwhile, the original lead-acid storage battery of the base station is compatible, the two can exist simultaneously, the use frequency of the original lead-acid storage battery is reduced, the charge-discharge times of the original lead-acid storage battery are reduced, the service life of the original lead-acid storage battery is prolonged, the capacity of the lithium iron phosphate battery is reduced, the reconstruction cost is reduced, and meanwhile, the original lead-acid storage battery and the newly added lithium iron phosphate battery exist simultaneously, thus increasing the stable reliability of the power supply of the entire system.

The foregoing description of embodiments of the utility model has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The direct-current side energy storage device is characterized by comprising an alternating-current charging converter, an energy storage battery pack and a switching power supply, wherein the alternating-current charging converter is connected with the energy storage battery pack and is used for connecting with the mains supply and charging the energy storage battery pack; the switching power supply is connected with the energy storage battery pack through the direct current converter and is used for connecting with the mains supply and supplying power to the load; and the direct current converter samples the load current through a sampler.

2. The direct current side energy storage device of claim 1, wherein the AC charging converter comprises an AC/DC converter and a DC/DC converter, the AC/DC converter being connected to the DC/DC converter, the DC/DC converter being connected to the energy storage battery, the AC/DC converter being configured to convert AC power to DC power, the DC/DC converter being configured to convert DC power.

3. The direct current side energy storage device of claim 1, wherein the direct current converter is a DC/DC unidirectional discharge converter or a DC/DC bi-directional converter.

4. The direct current side energy storage device of claim 1, wherein the switching power supply comprises an AC/DC converter.

5. The direct-current side energy storage device of claim 1, further comprising a first battery management system, wherein the ac charging inverter and the energy storage battery are each coupled to the first battery management system, and wherein the first battery management system is configured to control the ac charging inverter to charge the energy storage battery.

6. The direct current side energy storage device according to claim 1, further comprising a second battery management system, wherein the direct current converter and the energy storage battery pack are respectively connected with the second battery management system, and the second battery management system is used for controlling the direct current converter to perform direct current-to-direct current conversion on electric energy output by the energy storage battery pack or controlling the direct current converter to perform direct current-to-direct current conversion on direct current output by the switching power supply.

7. The direct side energy storage device of claim 1, further comprising a backup battery for powering the load.

8. The direct current side energy storage device of claim 7, wherein said battery backup is a lead acid battery.

9. The direct current side energy storage device of claim 1, wherein the energy storage battery pack is a plurality of single lithium iron phosphate batteries connected in series/parallel.

10. The direct current side energy storage device of claim 1, wherein the sampler is a hall current sensor.