Battery energy storage system

Abstract

The utility model discloses a battery energy storage system, which comprises a battery cluster, a battery management circuit and a control circuit, the battery cluster comprises a plurality of battery packs connected in parallel, each battery pack is provided with a DCDC boost module, the battery management circuit is electrically connected with the battery cluster, and the control circuit is electrically connected with the battery cluster. The battery management circuit is used for collecting battery parameters of each battery pack in a battery cluster, and the control circuit is used for outputting a control signal when the battery parameters are inconsistent, and controlling the charging and discharging current of the corresponding DCDC boosting module until the battery parameters of each battery pack are consistent. The battery cluster of the battery energy storage system is formed by connecting a plurality of battery packs in parallel, and compared with a traditional series connection mode, the control circuit can output a control signal to control the charging and discharging current of each battery pack according to whether the battery parameters of each battery pack are consistent or not, so that the balance control of each battery pack is achieved, and the service life of the battery energy storage system is prolonged. The phenomenon of over-charging or over-discharging of each battery pack in the battery energy storage system is avoided; in addition, the expansibility of the parallel connection mode is good.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery energy storage technology field especially relates to a battery energy storage system.

BACKGROUND

[0002] In recent years, with the vigorous development of new energy industry, the lithium iron phosphate battery in the energy storage field is widely used, but the voltage and capacity of single battery unit cannot completely meet the actual demand. In order to obtain higher voltage and greater capacity, multiple battery units must be connected in series to form a battery pack (PACK) to be put into use. The battery energy storage system composed of multiple battery packs can realize energy storage and bidirectional power flow, help to improve the comprehensive utilization rate of power grid equipment, system peak regulation and frequency modulation and reactive power support capability, and be beneficial to improving the stability, economy and flexibility of power grid operation.

[0003] The battery packs in the existing battery energy storage system are connected in series, the SOC state of each battery pack is different, so the battery state of each battery pack is also different, but in the series circuit, the battery state of each battery pack cannot be monitored and balanced controlled, thereby leading to the phenomenon of overcharging or overdischarging of a certain battery pack during long time use. In addition, the scalability of the series system is poor, so that the cost of updating and maintaining the battery energy storage system is high.

UTILITARY MODEL CONTENT

[0004] In order to solve the technical problems of the current battery energy storage system that the battery packs are connected in series, the balance control of each battery pack cannot be carried out and the scalability is poor, the utility model provides a battery energy storage system and control method.

[0005] In order to achieve the above purpose, the utility model provides a battery energy storage system, which comprises:

[0006] The battery cluster comprises a plurality of parallelly connected battery packs, the communication signal end of each battery pack is connected in parallel to form the communication signal end of the battery cluster, the power supply end of each battery pack is connected in parallel to form the power supply end of the battery cluster, and each battery pack is provided with a DCDC boost module for outputting direct current voltage as high-voltage direct current voltage and adjusting charging and discharging current.

[0007] The battery management circuit is connected with the power supply end of the battery cluster through the collection signal input end, and is used for collecting the battery parameters of each battery pack in the battery cluster.

[0008] A control circuit, a first signal input end of the control circuit is connected with the collection signal output end of the battery management circuit, a first signal output end of the control circuit is connected with a DCDC voltage boosting module of each battery pack, and the control circuit is used for outputting a control signal when the battery parameters of each battery pack are inconsistent, and controlling the charging and discharging current of the corresponding DCDC voltage boosting module until the battery parameters of each battery pack are consistent.

[0009] The battery energy storage system as described above, wherein the battery parameters are SOC, SOH and the like.

[0010] The battery energy storage system as described above, wherein the DCDC voltage boosting module comprises a voltage booster, a primary side of the voltage booster is connected with the power supply end of the battery pack and the first signal output end of the control circuit respectively, and a secondary side of the voltage booster is connected with the power supply end of the battery cluster, and the voltage booster is used for controlling the charging and discharging current of the corresponding battery pack according to the control signal.

[0011] The battery energy storage system as described above further comprises an inverter circuit, a power supply input end of the inverter circuit is connected with the power supply end of the battery cluster, and a power supply output end of the inverter circuit is used for converting the high-voltage direct-current voltage output by the battery cluster into alternating-current voltage.

[0012] The battery energy storage system as described above, wherein the inverter circuit comprises an inverter and a protection unit, a signal input end of the protection unit is connected with the power supply end of the battery cluster, and a signal output end of the protection unit is connected with the inverter.

[0013] The battery energy storage system as described above, wherein the battery management circuit comprises:

[0014] A WIFI communication module, a communication signal end of the WIFI communication module is connected with a communication signal end of the battery cluster, and the WIFI module is used for uploading the battery parameters monitored by the battery management circuit to an APP;

[0015] A CAN communication module, a communication signal end of the CAN communication module is connected with a communication signal end of the inverter circuit, and the CAN communication module is used for controlling the output of the inverter circuit according to the battery parameters to prevent overcharging or overdischarging.

[0016] The battery energy storage system as described above further comprises an activation module, the activation module is used for obtaining an activation instruction, a signal end of the activation module is connected with a second signal input end of the control circuit, and a second signal output end of the control circuit is used for controlling the work of the battery energy storage system according to the activation instruction.

[0017] Compared with the prior art, the battery energy storage system has the following beneficial effects:

[0018] 1. The battery cluster of the utility model is formed by multiple battery packs in parallel, compared with the traditional series connection mode, the control circuit can output control signals according to whether the battery parameters of each battery pack are consistent, thereby controlling the charge and discharge current of each battery pack, so that the equalization control of each battery pack is achieved, and it is ensured that each battery pack in the battery energy storage system will not appear overcharge or overdischarge phenomenon; in addition, the parallel connection mode is convenient to expand, and the total energy storage capacity can be increased by adding more battery packs to the existing parallel network without changing the configuration or parameters of the existing system.

[0019] 2. The DCDC boost module of the utility model can raise the original low-voltage direct-current voltage to high-voltage direct-current voltage, thereby meeting the use of high-voltage inverters, compared with low-voltage inverters, under the premise of outputting the same power, the battery pack output voltage is high and the current is small, thereby reducing the loss in the energy transmission process.

[0020] 3. The control circuit of the utility model outputs control signals to control the charge and discharge current of the corresponding battery pack when the battery management circuit detects that the voltage parameters of each battery pack are inconsistent, thereby ensuring that the battery parameters of each battery pack in the battery cluster are consistent and achieving the equalization of the battery capacity of each battery pack in the battery energy storage system. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description.

[0022] Fig. 1 It is a battery energy storage system circuit structure schematic diagram of the utility model;

[0023] Fig. 2 It is a part of the circuit schematic diagram of the utility model;

[0024] Fig. 3 It is a part of the circuit schematic diagram of the battery cluster and the inverter circuit of the utility model.

CONCRETE IMPLEMENTATION

[0025] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clearly, the following will further illustrate the utility model by combining with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0026] Please refer to Figs. 1 to 3As shown, the battery energy storage system includes a battery cluster 100, a battery management circuit 200 and a control circuit 300. The battery cluster 100 includes a plurality of battery packs connected in parallel. The communication signal ends of each battery pack are connected in parallel to form the communication signal end of the battery cluster 100. The power supply ends of each battery pack are connected in parallel to form the power supply end of the battery cluster 100. Each battery pack is provided with a DCDC boost module for outputting a direct current voltage as a high-voltage direct current voltage and adjusting the charge and discharge current. The collection signal input end of the battery management circuit 200 is connected to the power supply end of the battery cluster 100. The battery management circuit 200 is used to collect the battery parameters of each battery pack in the battery cluster 100. The first signal input end of the control circuit 300 is connected to the collection signal output end of the battery management circuit 200. The first signal output end of the control circuit 300 is connected to the DCDC boost module of each battery pack. The control circuit 300 is used to output a control signal when the battery parameters of each battery pack are inconsistent, control the charge and discharge current of the corresponding DCDC boost module, and until the battery parameters of each battery pack are consistent. The battery cluster of the battery energy storage system is formed by a plurality of battery packs connected in parallel. Compared with the traditional series connection mode, the control circuit can output a control signal to control the charge and discharge current of each battery pack according to whether the battery parameters of each battery pack are consistent, thereby achieving balanced control of each battery pack and ensuring that each battery pack in the battery energy storage system will not be overcharged or overdischarged. In addition, the parallel connection mode is convenient to expand. The total energy storage capacity can be increased by adding more battery packs to the existing parallel network without changing the configuration or parameters of the existing system.

[0027] Further, as a preferred embodiment of the present scheme but not limited, the battery pack includes a plurality of battery cells connected in series, and the battery cell is a lithium iron phosphate battery cell.

[0028] In the embodiment, the battery pack includes 16 battery cells connected in series. In actual implementation, the number of battery cells can be replaced according to actual design requirements. In the embodiment, the capacity of the battery cell is 100 Ah, and the maximum output power is 5.12 KW. In actual implementation, the battery cell can be replaced by other capacity and maximum output power.

[0029] In addition, the battery cluster 100 includes four battery packs connected in parallel. In actual implementation, the number of battery packs can be increased or decreased according to actual requirements.

[0030] Further, as a preferred embodiment of the present scheme but not limited, the DCDC boost module comprises a booster, the primary side of the booster is connected with the power supply end of the battery pack and the first signal output end of the control circuit 300 respectively, the secondary side of the booster is connected with the power supply end of the battery cluster 100, and the booster is used to control the charging and discharging current of the corresponding battery pack according to the control signal.

[0031] In the embodiment, the battery pack composed of 16 battery cells connected in series is connected with the primary side of the booster, and outputs high-voltage direct-current voltage after being boosted by the booster. When boosting, the boost ratio of the booster is 1:8, that is, the direct-current voltage of the original battery pack (51.2V in the embodiment) is boosted to high-voltage direct-current voltage (400V in the embodiment). After being boosted by the DCDC boost module, the battery pack can increase the original low-voltage direct-current voltage to high-voltage direct-current voltage, so as to meet the use of high-voltage inverters. Compared with low-voltage inverters, the battery pack outputs high voltage and small current under the premise of outputting the same power, so as to reduce the loss in the process of energy transmission.

[0032] In addition, when the battery management circuit 200 monitors that the battery parameters of the battery cluster 100 are inconsistent, that is, the battery parameters of each battery pack in the battery cluster 100 are inconsistent, the battery parameters are parameters such as SOC and SOH, and in the embodiment, the SOC parameters of each battery pack are matched to determine whether the battery parameters of each battery pack are consistent. In other embodiments, other parameters can also be selected as the judgment standard.

[0033] Specifically, when the battery parameters of each battery pack in the battery cluster 100 are inconsistent, that is, the SOC parameter of at least one battery pack in the battery cluster 100 is inconsistent with the SOC parameters of other battery packs, at this time, the control circuit 300 outputs a control signal (which can be a PWM signal) to control the corresponding DCDC boost module, that is, the corresponding booster receives the control signal to control the output voltage of the corresponding battery pack, and further control the charging and discharging current of the corresponding battery pack, so as to ensure that the battery parameters of each battery pack in the battery cluster 100 are consistent, and realize the balance of the battery capacity of each battery pack in the battery energy storage system.

[0034] Further, as a preferred embodiment of the present scheme but not limited, the DCDC boost module comprises a booster, the primary side of the booster is connected with the power supply end of the battery pack and the first signal output end of the control circuit 300 respectively, the secondary side of the booster is connected with the power supply end of the battery cluster 100, and the booster is used to control the charging and discharging current of the corresponding battery pack according to the control signal.

[0035] Specifically, the inverter circuit 400 comprises an inverter and a protection unit, a signal input end of the protection unit is connected with a power supply end of the battery cluster 100, and a signal output end of the protection unit is connected with the inverter.

[0036] The protection unit comprises a disconnector and a fuse, one end of the fuse is connected with the power supply end of the battery cluster 100, the other end of the fuse is connected with one end of the disconnector, and the other end of the disconnector is connected with the inverter.

[0037] In this embodiment, the disconnector and the fuse in the protection unit can automatically cut off the circuit in abnormal conditions such as overcurrent, overvoltage, short circuit or leakage current, thereby protecting the safety of the human body and the battery energy storage system; the disconnector can also cut off the direct current circuit, thereby protecting the inverter from electrical faults such as current overload and short circuit, helping to prolong the service life of the inverter and ensure the stable operation of the battery energy storage system.

[0038] Further, as a preferred embodiment of the present scheme but not limited, the battery management circuit 200 comprises a WIFI communication module and a CAN communication module, a communication signal end of the WIFI communication module is connected with a communication signal end of the battery cluster 100, the WIFI module is used to upload the battery parameters monitored by the battery management circuit 200 to an APP, and a communication signal end of the CAN communication module is connected with a communication signal end of the inverter circuit 400, the CAN communication module is used to control the output of the inverter circuit 400 according to the battery parameters, so as to prevent overcharging or overdischarging.

[0039] The WIFI communication module communicates through the RS485 communication mode.

[0040] In this embodiment, the battery parameters of each battery pack in the battery cluster 100 monitored by the battery management circuit 200 are uploaded to the APP through the WIFI communication module, the APP is an APP installed on a mobile phone, a tablet computer or a computer for managing the battery energy storage system, and a user can check the battery parameters of each battery pack in the battery energy storage system through the APP, thereby judging the battery state of each battery pack, improving the convenience and user experience of the system; through the WIFI communication module, the battery management circuit 200 can be connected with intelligent devices, realizing intelligent control and data analysis, helping to early warn possible problems of the battery and improving the safety and reliability of the battery use.

[0041] In addition, the battery management circuit 200 can control the output of the inverter circuit 400 through the CAN communication module, so as to prevent overcharging or overdischarging, thereby enhancing the control accuracy and response speed of the battery management system and helping to prolong the service life of the battery.

[0042] Further, as a preferred embodiment of the present scheme but not limited, further comprising an activation module for obtaining an activation instruction, a signal end of the activation module is connected with a second signal input end of the control circuit, and a second signal output end of the control circuit is used for controlling the operation of the battery energy storage system according to the activation instruction.

[0043] In the embodiment, the activation module is a start-stop button for starting the battery energy storage system, when the user presses the start-stop button, that is, the activation module obtains the activation instruction, and the control circuit controls the battery energy storage system to start working (that is, to perform a series of charging / discharging and the like) according to the activation instruction, and if the user wants to turn off the battery energy storage system, the user only needs to press the start-stop button again. By using the start-stop button as the activation module, the user can easily start and stop the battery energy storage system, simplifying the operation process and improving the user experience.

[0044] The utility model embodiment further provides a control method of battery energy storage system, be used for realizing for like above described battery energy storage system in each battery parameter of battery package, the battery parameter is SOC, SOH and the like parameter. The structure and principle of the battery energy storage system can refer to the above embodiment, and here will not be repeated.

[0045] The control method comprises steps S1-S3, wherein:

[0046] S1, obtaining the battery parameter of each battery package.

[0047] Specifically, the obtaining action can be real-time or periodic, that is, the control method can be executed multiple times. The battery parameter can be SOC proportional to voltage, and can also be SOH or average temperature, etc., which can meet the balancing requirements in the specific application environment, and is within the protection scope of the present application.

[0048] S2, matching the SOC parameter in the battery parameter.

[0049] S3, if the matching is inconsistent, controlling the charging and discharging current of the corresponding DCDC boost module until the SOC parameters of each battery package are consistent.

[0050] Specifically, the battery management circuit matches the SOC parameters of each battery pack in the battery cluster collected, judges whether the power of each battery pack is balanced during charging or discharging, and if not, outputs a control signal through the control circuit to control the charging and discharging current of the corresponding DCDC boost module until the battery parameters of each battery pack are consistent, control the output voltage of the corresponding battery pack, and then control the charging and discharging current of the corresponding battery pack, thereby ensuring that the battery parameters of each battery pack in the battery cluster are consistent and balancing the battery power of each battery pack in the battery energy storage system.

[0051] Further, as a preferred embodiment of the present scheme but not limited, the step S3 further comprises steps S31-S32, wherein:

[0052] S31, during charging, if the SOC parameter of a certain battery pack is less than that of other battery packs, control the DCDC boost module of the battery pack to increase its charging current;

[0053] S32, during discharging, if the SOC parameter of a certain battery pack is greater than that of other battery packs, control the DCDC boost module of the battery pack to increase its discharging current.

[0054] Specifically, when the battery energy storage system is charging, if the battery management circuit in the battery energy storage system monitors that the SOC parameter of a certain battery pack is less than that of other battery packs, it will output a control signal through the control circuit to control the DCDC boost module of the battery pack to increase its charging current, so as to ensure that each battery pack in the battery energy storage system can be fully charged at the same time. It should be noted that when any battery pack in the battery energy storage system is fully charged, i.e. the SOC parameter reaches 100%, the battery pack enters the full charging state (i.e. it is prohibited to continue charging), and other battery packs that are not fully charged will continue to charge, so that all battery packs in the battery energy storage system are in the state of being fully charged at the same time.

[0055] When the battery energy storage system is discharging, if the battery management circuit in the battery energy storage system monitors that the SOC parameter of a certain battery pack is greater than that of other battery packs, it will output a control signal through the control circuit to control the DCDC boost module of the battery pack to increase its discharging current, so as to ensure that each battery pack in the battery energy storage system can be fully discharged at the same time. It should be noted that when any battery pack in the battery energy storage system is fully discharged, i.e. the SOC parameter reaches 0%, the battery pack enters the fully discharged state (i.e. it stops discharging), and other battery packs that are not fully discharged will continue to discharge, so that all battery packs in the battery energy storage system are in the state of being fully discharged at the same time.

[0056] Further, as a preferred embodiment of the present scheme but not limited, the matching of the SOC parameter in the battery parameter further comprises steps S4-S5 before the matching of the SOC parameter in the battery parameter:

[0057] S4, matching the SOH parameter in the battery parameter with a preset SOH parameter;

[0058] S5, if the SOH parameter of a certain battery pack is lower than the preset SOH parameter, determining that the battery energy storage system is abnormal, and controlling the DCDC boost module of each battery pack to stop charging and discharging.

[0059] Specifically, before the battery energy storage system charges and discharges, whether each battery pack is abnormal is determined by the SOH parameter of each battery pack, so as to ensure that each battery pack is in a normal state before the battery energy storage system charges and discharges, avoid safety accidents caused by battery health problems, and prevent bad battery packs from damaging the entire battery energy storage system, thereby prolonging the service life of the entire battery energy storage system.

[0060] The preset SOH parameter is set to 80%, and in specific implementation, the preset SOH parameter can be adjusted according to actual needs.

[0061] In addition, when the SOH parameter of a certain battery pack in the battery energy storage system is lower than the preset SOH parameter, the battery management circuit outputs a control signal to control the DCDC boost module of each battery pack to stop charging and discharging, and uploads battery fault information to the APP through the WIFI communication module, so that the user can view which battery pack has an abnormal SOH parameter, and then quickly determine the fault cause and troubleshoot.

[0062] Those skilled in the art should understand that the above description is an embodiment provided in combination with specific content, and the specific implementation of the utility model is not limited to these descriptions. Since the industry naming is not the same, it is not limited to the above naming, and it is not limited to the English naming. Any approximation, similarity, or replacement of the method and structure of the utility model, or the technical deduction or replacement under the concept of the utility model, should be considered as the protection range of the utility model.

Claims

1. A battery energy storage system, characterized by, The application relates to a battery cluster and a battery management circuit. The battery cluster comprises a plurality of battery packs connected in parallel, the communication signal end of each battery pack is connected in parallel to form the communication signal end of the battery cluster, the power supply end of each battery pack is connected in parallel to form the power supply end of the battery cluster, and each battery pack is provided with a DCDC voltage boosting module for outputting direct-current voltage as high-voltage direct-current voltage and adjusting the charging and discharging current. The battery management circuit is connected with the power supply end of the battery cluster, and is used for collecting the battery parameters of each battery pack in the battery cluster. The control circuit is connected with the collection signal output end of the battery management circuit, is connected with the DCDC voltage boosting module of each battery pack, and is used for outputting a control signal when the battery parameters of each battery pack are inconsistent, so as to control the charging and discharging current of the corresponding DCDC voltage boosting module until the battery parameters of each battery pack are consistent.

2. A battery energy storage system according to claim 1, wherein, The battery parameters are SOC, SOH and the like.

3. A battery energy storage system according to claim 1, wherein, The DCDC voltage boosting module comprises a voltage booster, the primary side of the voltage booster is connected with the power supply end of the battery pack and the first signal output end of the control circuit respectively, the secondary side of the voltage booster is connected with the power supply end of the battery cluster, and the voltage booster is used for controlling the charging and discharging current of the corresponding battery pack according to the control signal.

4. The battery energy storage system of claim 1, wherein, The inverter circuit is connected with the power supply end of the battery cluster, and the power output end of the inverter circuit is used for converting the high-voltage direct-current voltage output by the battery cluster into alternating-current voltage.

5. A battery energy storage system according to claim 4, wherein, The inverter circuit comprises an inverter and a protection unit, the signal input end of the protection unit is connected with the power supply end of the battery cluster, and the signal output end of the protection unit is connected with the inverter.

6. A battery energy storage system according to claim 4, wherein, The battery management circuit comprises: The WIFI communication module is connected with the communication signal end of the battery cluster, and is used for uploading the battery parameters monitored by the battery management circuit into an APP; The CAN communication module is connected with the communication signal end of the inverter circuit, and is used for controlling the output of the inverter circuit according to the battery parameters, so as to prevent overcharging or overdischarging.

7. The battery energy storage system of claim 1, wherein, The activation module is used for acquiring an activation instruction, the signal end of the activation module is connected with the second signal input end of the control circuit, and the second signal output end of the control circuit is used for controlling the working of the battery energy storage system according to the activation instruction.

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