Bus voltage modulation method for dynamically reconfigurable series-connected battery system

Abstract

The present invention belongs to the technical field of energy storage in new energy power systems. Disclosed is a bus voltage modulation method for a dynamically reconfigurable series-connected battery system. The method comprises: numbering all battery modules and denoting same as i, collecting voltage values of the battery modules and performing sorting in descending order of the voltage values; selecting a battery module corresponding to the highest voltage value; determining whether the number i of the selected battery module is less than the total number N of battery modules connected in series, and if the determination result is positive, accumulating a voltage value corresponding to the selected battery module, and determining whether an accumulated voltage value of battery modules is within a preset range; and on the basis of the accumulated voltage value of the battery modules, performing an i++ operation, and repeating the above content until an output bus voltage meets a preset range requirement. In the dynamically reconfigurable battery system based on software-defined technology in the present invention, real-time reconfiguration can be performed on the basis of the voltage of each battery module to output an ideal power bus voltage, thereby meeting the requirement for an output power bus voltage.

Description

Series dynamic reconfiguration battery system bus voltage modulation method TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy power system energy storage, and particularly relates to a series dynamic reconfiguration battery system bus voltage modulation method. BACKGROUND

[0002] In order to meet the integrated output requirements of the current base station battery energy storage system, a DC-DC converter block is generally added. The DC-DC converter is a device that converts power of one voltage value into power of another voltage value in a direct current circuit. The DC-DC module has high cost, high requirements for battery consistency, and requires the battery to be of the same type. The construction and management costs are high, and the efficiency is low. SUMMARY

[0003] The present application provides a series dynamic reconfiguration battery system bus voltage modulation method to solve the problems in the prior art.

[0004] The technical solution of the present application to solve the above technical problems is as follows:

[0005] A series dynamic reconfiguration battery system bus voltage modulation method comprises the following steps:

[0006] S1: Start battery module selection, number all battery modules based on bus requirements, set i, and collect the voltage value of each battery module. Arrange all battery modules in descending order according to the voltage value, and number the battery module corresponding to the highest voltage value as 0, and sequentially number i=0, i=1, i=2…… according to the size of the voltage value;

[0007] S2: Select the battery module corresponding to the highest voltage value, i.e. i=0;

[0008] S3: Determine whether the serial number i of the selected battery module is less than the total number N of series battery modules. If the result is yes, add the voltage value corresponding to the selected battery module, and determine whether the voltage accumulation value ∑vi of the battery module is within the preset range;

[0009] S4: According to the voltage accumulation value ∑vi of the battery module, perform i++ operation, and repeat S2-S3 until the output bus voltage meets the preset range requirement.

[0010] Further, in step S3, the determination of whether the voltage accumulation value ∑vi of the battery module is within the preset range comprises:

[0011] S31: compare the voltage cumulative value of the battery module ∑vi with the bus voltage modulation output lower limit value V1, determine whether the voltage cumulative value of the battery module ∑vi is less than the bus voltage modulation output lower limit value V1, if the result is yes, jump to S32; otherwise, jump to S33;

[0012] S32: based on the result of S31 being yes, put the battery module selected this time into the switch-on group, and accumulate the voltage value corresponding to the battery module into the voltage cumulative value, then perform i++ operation, repeat steps S2-S3;

[0013] S33: compare the voltage cumulative value of the battery module ∑vi with the bus voltage modulation output upper limit value V2, determine whether the voltage cumulative value of the battery module ∑vi is greater than the bus voltage modulation output upper limit value V2, if the result is yes, jump to S34; if the result is no, the switch-on group and the switch-bypass group instruction is issued, the series reconstruction action is executed, and the battery module selection is completed;

[0014] S34: based on the result of S33 being yes, put the battery module accumulated this time into the switch-bypass group, and the voltage value corresponding to the battery module selected this time is not accumulated into the voltage cumulative value, and perform i++ operation, repeat S2-S3.

[0015] Further, in S3, determine whether the serial number i of the selected battery module is less than the total number N of the series battery modules, if the result is no, jump to step S5;

[0016] S5: determine whether all battery module combinations have been tried, if the result is yes, jump to S6; if the result is no, shield one master battery module, and repeat S2-S4;

[0017] S6: keep the last selection result, or disconnect the network card of all battery modules, and start the active generation of inter-battery module pressure difference mechanism.

[0018] Further, the specific steps of starting the active generation of inter-battery module pressure difference mechanism in S6 include:

[0019] S61: the energy control unit collects the voltage values of n master battery modules, and compares all the voltage values to obtain the highest voltage value; wherein the battery modules include n battery modules and m pseudo battery modules;

[0020] S62: difference calculation is performed on the highest voltage value in the main road and the rest of the voltage values, to obtain a voltage difference, if the voltage difference is greater than a preset threshold, then the n-1 main battery modules in the main road are reconstructed in the serial direction; if the voltage difference is not greater than the preset threshold, then the main battery module q corresponding to the highest voltage value is forcibly accessed, and n-q-1 main battery modules are selected from the rest of the main battery modules n-q for discharging.

[0021] Further, the specific steps of connecting or bypassing the battery module include:

[0022] S621: the energy control unit generates a control instruction according to the bus voltage requirement, and sends the control instruction to the energy exchange unit;

[0023] S622: the energy exchange unit is a bridge unit of the power loop of each battery module, used to receive the control instruction sent by the energy control unit, and control the state of the single battery module corresponding thereto according to the received control instruction, the state including off, isolation, connection.

[0024] Further, the control instruction includes 0, 1, 2; wherein:

[0025] 0 represents a battery module disconnect instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is disconnected, at this time the power loop corresponding to the battery module is disconnected;

[0026] 1 represents a battery module connection instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is connected, at this time the power loop corresponding to the battery module is connected;

[0027] 2 represents a battery module isolation instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is bypassed, and the power loop corresponding to the battery module is connected.

[0028] Further, the generation of the control instruction is based on real-time calculation of the reconstruction period.

[0029] Further, the lower limit value V1 of the bus voltage modulation output is 57.4V, and the upper limit value V2 of the bus voltage modulation output is 58.4V.

[0030] Further, the battery module includes at least two different types of battery modules.

[0031] The present application has at least the following beneficial effects:

[0032] According to the requirement of the bus voltage, the voltage value of each battery module is collected during the discharging process, and the battery modules are arranged in descending order according to the voltage value, and the battery module corresponding to the highest voltage value is preferentially selected for judgment, and by comparing the voltage value with the preset range, it can be determined that the battery module corresponding to the voltage value is discharged to the switch-on group or the switch bypass group, according to the judgment result, whether to perform i++ operation is determined, through the accumulation of a plurality of battery modules, the combination of the battery module meeting the bus voltage is found, so as to meet the requirement of the output bus voltage.

[0033] The dynamic reconfiguration battery system based on the software definition technology can output ideal power bus voltage in real time according to the voltage of each battery module, and meet the demand of output power bus voltage.

[0034] The dynamic reconfiguration battery system based on the software definition technology can optimize the battery management in the system, balance the battery, ensure the safety of the battery, improve the utilization rate of the battery, and be compatible with multiple types of mixed batteries. It is widely used in step battery utilization and base station storage integrated system. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 is a flowchart of the present application;

[0036] Fig. 2 is a schematic diagram of bus modulation output during discharging of the present application;

[0037] Fig. 3 is a schematic diagram of the energy exchange unit as a bridge unit of the battery module. DETAILED DESCRIPTION

[0038] The principles and characteristics of the present application are described below in combination with all the drawings, and the examples are only used to explain the present application, and are not used to limit the scope of the present application.

[0039] The embodiment of the present application discloses a series dynamic reconfiguration battery system bus voltage modulation method.

[0040] Referring to FIGS. 1-3, a series dynamic reconfiguration battery system bus voltage modulation method includes the following steps:

[0041] S1: battery module selection starts, based on the bus requirement, all battery modules are numbered as i, and the voltage value of each battery module is collected, all battery modules are arranged in descending order according to the voltage value, and the battery module corresponding to the highest voltage value is numbered as 0, and is numbered as i=0, i=1, i=2…… according to the size of the voltage value;

[0042] S2: select the battery module corresponding to the highest voltage value, i.e. i=0;

[0043] S3: judging whether the serial number i of the selected battery module is less than the total number N of the serial battery modules, if the judging result is yes, the voltage value corresponding to the selected battery module is accumulated, and judging whether the voltage accumulation value ∑vi of the battery module is in the preset range;

[0044] S4: according to the voltage accumulation value ∑vi of the battery module, performing i++ operation, and repeating S2-S3 until the output bus voltage meets the preset range requirement. Wherein, the calculated accumulation value of the battery module is the output bus voltage.

[0045] Specifically, all the collected voltage values are arranged in descending order according to the size of the voltage value, and each battery module is numbered i, the battery module corresponding to the highest voltage value is numbered 0, and the like, i=0, i=1, i=2, …; At the beginning of the battery module selection, the battery module numbered 0 is selected, that is, the battery module corresponding to the highest voltage value is preferentially selected, and it is first judged whether the battery module numbered 0 is less than the total number N of the battery modules, if the judging result is yes, the subsequent operation is performed, that is, the judgment of the voltage accumulation value ∑vi is performed, according to the judgment result, the i++ operation is selected, and S2-S3 is repeated in turn, until the output bus voltage meets the preset range requirement, that is, the combination of the battery modules meets the requirement of the output bus voltage.

[0046] It should be emphasized that: in the embodiment, two different types of battery modules can be used, and the voltages of the two types of battery modules are different.

[0047] Further, in S3, judging whether the voltage accumulation value ∑vi of the battery module is in the preset range, the judging steps specifically include:

[0048] S31: comparing the voltage accumulation value ∑vi of the battery module with the lower limit value V1 of the bus voltage modulation output, judging whether the voltage accumulation value ∑vi of the battery module is less than the lower limit value V1 of the bus voltage modulation output, if the judging result is yes, jumping to S32; otherwise, jumping to S33;

[0049] S32: based on the yes result of S31, the selected battery module is put into the switch-on group, and the voltage value corresponding to the battery module is accumulated into the voltage accumulation value, and then the i++ operation is performed, and S2-S3 is repeated;

[0050] S33: comparing the voltage accumulation value ∑vi of the battery module with the upper limit value V2 of the bus voltage modulation output, judging whether the voltage accumulation value ∑vi of the battery module is greater than the upper limit value V2 of the bus voltage modulation output, if the judging result is yes, jumping to step S34; if the judging result is no, the switch-on group and the switch-bypass group instruction are issued, the serial reconstruction action is executed, and the battery module selection is ended.

[0051] S34: based on the result of S33 being yes, the battery module accumulated this time is put into the switch bypass group, and the voltage value corresponding to the battery module selected this time is not accumulated into the accumulated value, and i++ operation is performed, and S2-S3 is repeated.

[0052] Specifically, the lower limit value V1 of the bus voltage modulation output is 57.4V, and the upper limit value V2 of the bus voltage modulation output is 58.4V. The voltage accumulated value of the battery module is compared with V1, if the voltage accumulated value ∑vi < V1, the battery module selected this time is put into the switch on group, and the voltage value corresponding to the battery module is accumulated into the voltage accumulated value, which is equivalent to marking the battery module, and other battery modules are selected for judgment, that is, i++ calculation is performed, and S2-S3 is repeated to select multiple battery modules for combination.

[0053] If the voltage accumulated value ∑vi is not greater than V1, jump to S33, that is, compare the voltage accumulated value Σvi with the upper limit value V2 of the bus voltage modulation output, if Σvi > V2, the battery module accumulated (selected) this time is put into the switch bypass group, and the voltage value corresponding to the battery module selected this time is not accumulated into the voltage accumulated value, that is, the battery module selected this time is invalid (does not meet the requirements), and then i++ operation is performed to select the next battery module, and S2-S3 is repeated to select the combination of battery modules meeting the requirements.

[0054] If ∑vi is not greater than V2, it means that the selected battery module meets the requirements, the instructions of the switch on group and the switch bypass group are issued, the serial reconstruction action is performed, and the selection of the battery module is completed. The output modulation voltage is 57.4V-58.4V, as shown in FIG. 2.

[0055] Further, in S3, it is judged whether the serial number i of the selected battery module is less than the total number N of the series battery modules, if the judgment result is no, jump to step S5;

[0056] S5: judge whether all the selected combinations of battery modules are tried, if the judgment is yes, jump to step S6; if the judgment is no, shield one master battery module, and repeat steps S2-S4;

[0057] S6: keep the last selection result, or disconnect the network card of all battery modules, and start the mechanism of actively generating pressure difference between battery modules.

[0058] Specifically, in S5, it is judged whether all the selected combinations of battery modules are tried, which can be understood as two cases:

[0059] The first case is that no battery module is placed in the switch bypass group, and all battery modules are subjected to voltage accumulation value judgment, and no combination of battery modules meeting the requirements is found. In this case, all battery modules are subjected to combination attempt in step S5, that is, the case of YES in step S5. If the result is YES, the last selection result is kept, or the network cards of all battery modules are disconnected, that is, all battery modules are not connected, and then the mechanism of actively generating pressure difference between battery modules is started to reselect a combination of battery modules meeting the requirements, that is, jump to step S6.

[0060] The second case is that a battery module is placed in the switch bypass group. In this case, the combination selected in step S5 is not all attempted, that is, the case of NO in step S5. If the result is NO, one main battery module is shielded, and a new round of selection is started, that is, i = 1 is started to reselect. It should be noted that when one main battery module is shielded, each main battery module can be shielded once, and the combination is attempted until a satisfactory combination meeting the requirements is found.

[0061] Further, the specific steps of starting the mechanism of actively generating pressure difference between battery modules in S6 include:

[0062] S61: The energy control unit collects the voltage values of the n main battery modules, and compares all the voltage values to obtain the highest voltage value;

[0063] S62: The highest voltage value in the main circuit is subjected to difference calculation with the remaining voltage values to obtain a voltage difference. If the voltage difference is greater than a threshold value, n-1 battery modules in the main circuit are reconstructed in the serial direction. If the voltage difference is not greater than the threshold value, the main battery module corresponding to the highest voltage value is forcibly connected, and n-q-1 main battery modules are selected from the remaining n-q main battery modules for discharging.

[0064] Specifically, in the embodiment, the battery modules include n main battery modules and m pseudo battery modules. It is assumed that the n main battery modules are provided with 5, and the voltage of each main battery module is 12V. The m pseudo battery modules are provided with 5, and the voltage of each pseudo battery module is 2V. After the highest voltage value in the main circuit is subjected to difference calculation with the remaining voltage values, a voltage difference is obtained. If the voltage difference is greater than a threshold value, 4 main battery modules are selected from the 5 main battery modules for reconstruction in the serial direction. If the voltage difference is not greater than the threshold value, the main battery module corresponding to the highest voltage value is forcibly connected, and 3 main battery modules are selected from the remaining 4 main battery modules for discharging. In the discharging process, the 4 main battery modules corresponding to the highest voltage value + 5 pseudo battery modules are connected to the system, so that most of the battery modules can be reconstructed in series and discharged evenly.

[0065] Further, the specific steps of turning on or bypassing the battery module include:

[0066] S621: The energy control unit generates a control instruction according to the bus voltage requirement, and sends the control instruction to the energy exchange unit;

[0067] S622: The energy exchange unit, as a bridge unit of the power loop of each battery module, receives the control instruction sent by the energy control unit, and controls the state of the corresponding single battery module according to the received control instruction, the state including turning off, isolating, and turning on. As shown in FIG. 3, it is a schematic diagram of the energy exchange unit as a bridge unit of the power loop of each battery module.

[0068] The generation of the control instruction is based on real-time calculation of the reconstruction period, which can be up to hundreds of milliseconds. The control instruction includes 0, 1, and 2; wherein:

[0069] 0 represents the battery module disconnect instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is controlled to be disconnected, at this time the power loop corresponding to the battery module is disconnected;

[0070] 1 represents the battery module turn-on instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is controlled to be turned on, at this time the power loop corresponding to the battery module is turned on;

[0071] 2 represents the battery module isolation instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is controlled to be bypassed, and the power loop corresponding to the battery module is turned on.

[0072] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of bus voltage modulation for a series dynamic reconfiguration battery system, the method comprising: The method comprises the following steps: S1: battery module selection starts, based on bus bus requirements, all battery modules are numbered, set as i, and the voltage value of each battery module is collected, all battery modules are arranged in descending order according to the size of the voltage value, and the highest voltage value corresponding to the battery module is numbered as 0, and the voltage value is numbered as i=0, i=1, i=2…… according to the size of the voltage value; S2: select the battery module corresponding to the highest voltage value, that is, i=0; S3: judging whether the serial number i of the selected battery module is less than the total number N of the serial battery modules, if the judging result is yes, then the voltage value corresponding to the selected battery module is accumulated, and the voltage accumulation value Σ of the battery module is judged vi whether in the preset range; S4: According to the voltage cumulative value of the battery module ∑ vi , i++ operation is performed, and S2-S3 are repeated until the output bus voltage meets the preset range requirement; In S3, determine the accumulated voltage value ∑ of the battery module. vi The specific steps for determining whether something is within a preset range include: S31: The voltage cumulative value ∑ of the battery module is compared with the bus voltage modulation output lower limit value V1 vi S31: The voltage cumulative value ∑ of the battery module is compared with the bus voltage modulation output lower limit value V1 vi S31: The voltage cumulative value ∑ of the battery module is compared with the bus voltage modulation output lower limit value V1 S32: based on the result of yes of S31, the selected battery module is put into the switch on group, and the voltage value corresponding to the battery module is accumulated into the voltage accumulation value, and then i++ operation is performed, and steps S2-S3 are repeated; S33: Accumulate the voltage value of the battery module ∑ vi The voltage accumulation value ∑ of the battery module is determined by comparing it with the upper limit value V2 of the bus voltage modulation output. vi If the value is greater than the upper limit of the bus voltage modulation output V2, and the result is yes, then jump to S34; if the result is no, then the switch on group and switch bypass group instructions are issued, the serial reconfiguration action is completed, and the battery module selection ends. S34: based on the result of yes of S33, the battery module accumulated this time is put into the switch bypass group, and the voltage value corresponding to the selected battery module is not accumulated into the voltage accumulation value, and i++ operation is performed, and S2-S3 is repeated; In S3, it is judged whether the serial number i of the selected battery module is less than the total number N of the battery module, if the judgment result is no, jump to S5; S5: judge whether all battery module selection combinations are all tried, if yes, jump to step S6; if no, shield one master battery module, and repeat S2-S4, wherein the battery module includes a master battery module and a pseudo battery module; S6: keep the last selection result, or disconnect the network card of all battery modules, and start the active generation of battery module pressure difference mechanism.

2. The method of claim 1, wherein: The specific steps of starting the active generation of battery module pressure difference mechanism in S6 include: S61: the energy control unit collects the voltage values of n master battery modules, and compares all the voltage values to obtain the highest voltage value; S62: difference calculation is performed between the highest voltage value in the master circuit and the remaining voltage values to obtain the voltage difference, if the voltage difference is greater than the preset threshold, the n-1 battery modules in the master circuit are reconstructed in the serial direction; if the voltage difference is not greater than the preset threshold, the master battery module q corresponding to the highest voltage value is forced to access, and n-q-1 master battery modules are selected from the remaining master battery modules n-q for discharging.

3. The method of claim 1, wherein: The specific steps of connecting or bypassing the battery module include: S621: the energy control unit generates a control instruction according to the bus bus voltage requirement, and sends the control instruction to the energy exchange unit; S622: the energy exchange unit serves as a bridge unit of the power loop of each battery module, used for receiving the control instruction sent by the energy control unit, and controlling the state of the single battery module corresponding thereto according to the received control instruction, the state including turning off, isolating, and turning on.

4. The method of claim 3, wherein: The control instruction includes 0, 1, and 2; wherein: 0 represents the battery module disconnect instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is disconnected, at this time the power loop corresponding to the battery module is disconnected; 1 represents the battery module on instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is connected, at this time the power loop corresponding to the battery module is connected; 2 represents a battery module isolation instruction, when the energy exchange unit receives the instruction, the battery module corresponding to the energy control unit is bypassed, and the power loop corresponding to the battery module is connected.

5. The method of claim 4, wherein: The generation of the control instruction is based on real-time calculation of the reconstruction period.

6. The method of claim 1, wherein: The lower limit value V1 of the bus voltage modulation output is 57.4V, and the upper limit value V2 of the bus voltage modulation output is 58.4V.

7. The method of claim 1, wherein: The battery module includes at least two different types of battery modules.

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