CN115693839A - Intelligent parallel operation method for energy storage system - Google Patents
Intelligent parallel operation method for energy storage system Download PDFInfo
- Publication number
- CN115693839A CN115693839A CN202211205502.9A CN202211205502A CN115693839A CN 115693839 A CN115693839 A CN 115693839A CN 202211205502 A CN202211205502 A CN 202211205502A CN 115693839 A CN115693839 A CN 115693839A
- Authority
- CN
- China
- Prior art keywords
- slave
- parallel operation
- battery pack
- mos tube
- energy storage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 59
- 238000004146 energy storage Methods 0.000 title claims abstract description 52
- 238000007599 discharging Methods 0.000 claims abstract description 43
- 238000012216 screening Methods 0.000 claims description 16
- 238000011010 flushing procedure Methods 0.000 claims description 13
- 230000002159 abnormal effect Effects 0.000 claims description 12
- 238000012544 monitoring process Methods 0.000 claims description 3
- 238000004891 communication Methods 0.000 description 4
- 102100030393 G-patch domain and KOW motifs-containing protein Human genes 0.000 description 2
- 101150090280 MOS1 gene Proteins 0.000 description 2
- 101100401568 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) MIC10 gene Proteins 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 238000013486 operation strategy Methods 0.000 description 1
Images
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention discloses an intelligent parallel operation method for an energy storage system, which relates to the field of energy storage batteries and comprises the steps of acquiring a slave to be selected with the minimum or maximum total voltage as a slave to be combined, issuing a power-on command to the slave to be combined through a host, conducting a preset charging and discharging circuit by utilizing a preset control time sequence after the slave to be combined receives the power-on command so as to complete initial parallel operation of the energy storage system, acquiring a reference voltage value through the host after the initial parallel operation is completed, acquiring all slave machines in the energy storage system, wherein the slave to be combined is the slave to be screened, the slave machines do not have a protection condition information as a protection non-existence mark and the parallel operation condition is not equal to the parallel operation completion condition, issuing the power-on command to all slave to be screened through the slave to be combined in the slave to be screened, and starting parallel operation after the slave to be combined receives the power-on command so as to avoid the problem that a battery pack with large pressure difference is forcedly merged into the same power loop, and the BMS may be damaged or the battery cell may be damaged due to large current impact caused by the pressure difference.
Description
Technical Field
The invention relates to the field of energy storage batteries, in particular to an intelligent parallel operation method for an energy storage system.
Background
Under the large environment that photovoltaic energy storage is widely developed at present, as the requirement of a household energy storage system on the storage capacity of the energy storage system is gradually increased, a single battery pack is difficult to meet the use requirement, and the demand of parallel connection of multiple battery packs is gradually increased. When the multiple battery packs are connected in parallel, the initial electric quantity of each battery pack is different, or the initial electric quantity of each battery pack is different from the electric quantity of other battery packs after temporary self-protection (namely, the state of charge and discharge is not allowed), the voltage difference caused by the different electric quantities is overlarge, and if the battery packs with large voltage difference are forcedly combined into the same power loop, the BMS (battery management system) can be damaged or the battery cell can be damaged by large current impact caused by the different voltage difference.
For the energy storage system with the intelligent parallel operation strategy at present, when a battery pack in the system is continuously emptied and the voltage is very low, due to the characteristics of a lithium ion battery cell, if an external charging power supply arrives at the time, the voltage of the discharged battery pack may suddenly rise to damage the BMS or the battery cell, and the battery pack with low voltage and in a protection state cannot be charged due to overlarge voltage difference (namely, the voltage difference between the self voltage and the external voltage is overlarge), and the external voltage is the voltage at two ends of a load or at two ends of a charger in the energy storage system, and the BMS has power consumption, the electric quantity of the battery is consumed, so that the battery pack with low voltage and in the protection state is severely discharged.
Disclosure of Invention
In order to solve the problems that if a battery pack with large pressure difference is forcibly merged into the same power loop in the process of parallel use of the battery packs, the BMS can be damaged or the battery cell can be damaged due to large current impact caused by the pressure difference, and the battery pack with low voltage and in a protection state can not be charged and can cause serious over-discharge, the invention provides an intelligent parallel operation method for an energy storage system, wherein the energy storage system comprises a host and a plurality of slave machines, the host and the slave machines are both battery packs, the positive terminal of each battery pack is connected with the positive terminal of electrical equipment, and the negative terminal is connected with the negative terminal of the electrical equipment through a preset charging and discharging circuit corresponding to the battery pack; the slave is used for sending a slave information message to the host through the CAN bus; the intelligent parallel operation method comprises the following steps:
s1: starting an energy storage system, wherein a host receives slave information messages sent by all slaves, and the slave information messages contain the total voltage of a battery pack, protection state information and a parallel operation state; the protection state information is a protection existence flag for controlling the battery pack to enter a protection state and reporting the host when the slave BMS detects that the corresponding battery pack is in an abnormal state, or a protection nonexistence flag for reporting the host when the battery pack is not in the abnormal state, wherein the abnormal state comprises: the total voltage of the battery pack is higher than an upper limit value or lower than a lower limit value; the parallel operation state comprises a parallel operation completion state;
s2: the method comprises the steps that each slave machine with the protection state information as protection non-existence marks is obtained through a host machine and is a slave machine to be selected, and the slave machine to be selected with the minimum or maximum total voltage is obtained from the slave machines to be selected and is a slave machine to be merged;
s3: the method comprises the steps that a host computer issues a power-on instruction to a slave computer to be combined, the slave computer to be combined receives the power-on instruction and then conducts a preset charging and discharging circuit by using a preset control time sequence, the parallel operation state is set to be a parallel operation completion state, and the parallel operation state is reported to the host computer;
s4: the method comprises the steps that a battery pack with a parallel operation state as a parallel operation completion state is obtained through a host machine as a parallel slave machine, the maximum voltage value or the minimum voltage value of the total voltage corresponding to each parallel slave machine is obtained, the maximum voltage value or the minimum voltage value is set as a reference voltage value, each slave machine with the protection state information of the protection non-existence mark and the parallel operation state not equal to the parallel operation completion state in an energy storage system is obtained as a slave machine to be screened, slave machines to be screened in the slave machines to be screened are screened through the reference voltage value, and a power-on command is issued to each slave machine to be screened;
s5: and after the slave computer to be connected receives the power-on command, the preset charging and discharging circuit is conducted by using the preset control time sequence, the parallel operation state is set to be a parallel operation completion state, the parallel operation completion state is reported to the host computer, and the step S4 is returned.
Further, the steps from S3 to S4 further include:
s31: and judging whether a slave information message with the parallel operation state being the parallel operation completion state exists through the host, if so, entering the step S4, and if not, returning to the step S2.
Further, in step S4, a slave to be merged in the slave to be screened is screened out through the reference voltage value, specifically:
setting a screening condition through the reference voltage value, and screening out the slave to be screened meeting the screening condition as a slave to be merged; the screening conditions are as follows:
the reference voltage value-preset floatable amplitude value is less than or equal to the total voltage of the slave to be screened and less than or equal to the reference voltage value + preset floatable amplitude value.
Further, when the battery pack is in a protection state, the corresponding preset charging and discharging circuit is in a disconnected state.
Further, the preset charging and discharging circuit includes:
the switch comprises a first switch Mos tube, a first Mos tube and a first Mos tube diode; the negative end of the battery pack is simultaneously connected with one end of a first switch Mos tube, one end of the first Mos tube and the negative end of a first Mos tube body diode; the first switch Mos tube is connected with one end of a first resistor when closed, and the other end of the first resistor, the positive end of the first Mos tube body diode and the positive end of the first Mos tube are connected with one end of a second switch Mos tube, one end of the second Mos tube and the positive end of the second Mos tube body diode when closed; the second switch Mos tube is connected with one end of the second resistor when being closed; and the other end of the second resistor, the second Mos tube and the cathode end of the diode of the second Mos tube body are connected to the cathode end of the electrical equipment when the second Mos tube is closed.
Further, the electrical equipment is a load or a charger;
when the electrical equipment is a load, the energy storage system discharges and parallel-operates the battery pack by an intelligent parallel-operation method so as to provide electric energy for the load;
when the electrical equipment is a charger, the energy storage system charges and operates the battery pack through an intelligent parallel operation method so as to store energy for the battery pack.
Further, in the process of performing discharging parallel operation on the battery pack through the intelligent parallel operation method, the specific steps of conducting the preset charging and discharging circuit by using the preset control time sequence after the slave to be connected receives the power-on instruction are as follows:
and controlling the second switch Mos tube to be closed, controlling the first Mos tube to be closed to start discharging and pre-flushing, wherein at the moment, the current at the positive terminal of the battery pack sequentially passes through the positive terminal of the load, the negative terminal of the load, the second resistor and the first Mos tube and then flows to the negative terminal of the battery pack, after the discharging and pre-flushing is carried out for a preset time, controlling the second Mos tube to be closed, disconnecting the second switch Mos tube, and at the moment, completing the parallel operation of the slave machines.
Further, in the process of charging and parallel operation of the battery pack through the intelligent parallel operation method, the specific steps of conducting a preset charging and discharging circuit by using a preset control time sequence after the slave to be connected receives a power-on instruction are as follows:
and controlling the first switch Mos tube to be closed, then controlling the second Mos tube to be closed to start charging and pre-flushing, wherein at the moment, the current at the positive terminal of the charger sequentially passes through the positive terminal of the battery pack, the negative terminal of the battery pack, the first resistor and the second Mos tube and then flows to the negative terminal of the charger, after the charging and pre-flushing is carried out for a preset time, the first Mos tube is controlled to be closed, the first switch Mos tube is disconnected, and at the moment, the standby and parallel operation of the machine is completed.
Further, the intelligent parallel operation method further comprises the following steps:
a1: acquiring voltage between a positive terminal and a negative terminal of the electrical equipment as external voltage through a host, and accumulating the total voltage of each battery pack in the energy storage system to obtain a total voltage accumulated value;
a2: judging whether the external voltage is higher than the total voltage accumulated value by a preset amplitude value, if so, acquiring that the total voltage is lower than a reference voltage value through a host, and taking a battery pack with protection state information of which the protection is not marked as a slave to be connected;
a3: issuing a self-charging permission instruction to a slave to be merged through a host;
a4: after the slave computer to be connected receives the self-charging permission instruction, starting charging parallel operation, and executing the following steps in the charging parallel operation process:
a41: monitoring whether the current flowing to the slave of any other battery pack exceeds a set threshold value or not in real time through the slave to be connected, if so, entering the step A42, and if not, entering the step A43;
a42: keeping the preset charging and discharging circuit in a disconnected state, enabling the parallel operation to fail, adding 1 to the parallel operation times, judging whether the parallel operation times are larger than or equal to the preset parallel operation times, if so, finishing the charging parallel operation, and if not, returning to the step A41 after a preset time interval;
a43: and (5) conducting a preset charging and discharging circuit, and completing parallel operation.
Further, in the step A4, after the slave device to be merged receives the self-charging permission instruction, before starting the charging and merging, the method further includes:
and the slave to be connected judges whether the protection state information of the slave is a protection non-existing sign or not, acquires the voltage between the positive terminal and the negative terminal of the electrical equipment, judges whether the external voltage difference is greater than 0 or not by comparing the external voltage difference with the voltage between the positive terminal and the negative terminal of the slave to be connected, and starts to perform charging and parallel operation if the external voltage difference is greater than 0.
Compared with the prior art, the invention at least has the following beneficial effects:
(1) The method comprises the steps that a host machine obtains protection state information as each slave machine which is to be selected and does not have a protection mark, the slave machine to be selected is obtained from the slave machines to be selected, the slave machine to be selected with the minimum or maximum total voltage is obtained as a slave machine to be combined, a power-on command is sent to the slave machine to be combined through the host machine, a preset charging and discharging circuit is conducted by utilizing a preset control time sequence after the slave machine to be combined receives the power-on command, the parallel machine state is set as a parallel machine completion state and reported to the host machine, so that initial parallel machine of an energy storage system is completed, a reference voltage value is obtained through the host machine after the initial parallel machine is completed, each slave machine which is provided with the protection state information which does not have the protection mark and is not equal to the parallel machine completion state in the energy storage system is obtained as the slave machine to be screened, the slave machines to be combined in the slave machines to be screened are screened through the reference voltage value, the power-on command is sent to the slave machines to be combined, parallel machine is started after the power-on command is received, the slave machine, the communication state between the cathode end of a battery pack and the cathode end of the electrical equipment is controlled through the preset charging and discharging circuit, and the cathode end of the electrical core of the slave machine to be screened, so as to be screened, the cathode end of the battery pack, and the BMS, and the problem that the high-to be selected, the high-current core of the battery pack is possibly damaged by the high-voltage difference, and the high-voltage impact is avoided, and the high-voltage of the high-voltage circuit is caused by the high-voltage circuit, and the high-voltage circuit is possibly caused by impact is caused by the high-current impact of the high-current impact is avoided;
(2) According to the parallel operation method, the screening condition set by the reference voltage value is utilized, the slave to be screened meeting the screening condition is screened out as the slave to be parallel, so that the parallel operation safety is improved, the problem of BMS damage or battery core damage caused by the fact that the slave is merged into the slave when the battery pack is in an abnormal state is avoided, and the service life of the battery pack is prolonged;
(3) According to the invention, the steps S4 and S5 are circulated, so that the slave machines without the protection state (the protection state information is assigned as the protection non-existence mark) are continuously connected in parallel through the steps S4 and S5, so that the battery pack is charged or discharged, and the problem of serious over-discharge caused by the fact that the battery pack which is low in voltage and in the protection state cannot be charged is solved;
(4) According to the invention, the parallel operation is carried out through the steps A1 to A43 in the intelligent parallel operation process, the parallel operation speed is accelerated, and the parallel operation process is simplified.
Drawings
Fig. 1 is a flow chart of an intelligent parallel operation method for an energy storage system;
FIG. 2 is a block diagram of an energy storage system;
fig. 3 is a diagram of a preset charging/discharging circuit.
Detailed Description
The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.
Example one
In order to avoid the problem that a battery pack with large pressure difference is forcibly incorporated into the same power loop, and a large current impact caused by the pressure difference may damage a BMS or cause damage to a battery cell, as shown in fig. 1, the invention provides an intelligent parallel operation method for an energy storage system, as shown in fig. 2, in the embodiment, the connection of 3 battery packs is taken as an example for display, the energy storage system comprises a host and a plurality of slaves, the host and the slaves are both battery packs, the positive terminal of each battery pack is connected with the positive terminal of electrical equipment, and the negative terminal is connected with the negative terminal of the electrical equipment through a preset charge-discharge circuit corresponding to the battery pack; the slave machine is used for sending slave machine information messages to the host machine through the CAN bus (the same CAN communication network or other communication networks are arranged among the battery packs); the intelligent parallel operation method comprises the following steps:
s1: starting an energy storage system, wherein a host receives slave information messages sent by all slaves, and the slave information messages contain the total voltage of a battery pack, protection state information and a parallel operation state; the protection state information is a protection existence flag for controlling the battery pack to enter a protection state and reporting the host when the slave BMS detects that the corresponding battery pack is in an abnormal state, or a protection nonexistence flag for reporting the host when the battery pack is not in the abnormal state, wherein the abnormal state comprises: the total voltage of the battery pack is higher than an upper limit value or lower than a lower limit value; the parallel operation state comprises a parallel operation completion state; when the battery pack is in a protection state, the corresponding preset charging and discharging circuit is in a disconnected state.
The abnormal state further includes: a state where the temperature of the battery pack exceeds a preset value, and the like; the protection state corresponds to a release condition, for example, if the temperature is over-temperature, the protection can be released when the temperature is reduced to the normal temperature; over-voltage, when the voltage slowly falls back to the set range, the protection can be released, and the like.
S2: the method comprises the steps that each slave machine with the protection state information as protection non-existence marks is obtained through a host machine and is a slave machine to be selected, and the slave machine to be selected with the minimum or maximum total voltage is obtained from the slave machines to be selected and is a slave machine to be merged;
s3: the method comprises the steps that a host computer issues a power-on instruction to a slave computer to be combined, the slave computer to be combined receives the power-on instruction and then conducts a preset charging and discharging circuit by using a preset control time sequence, the parallel operation state is set to be a parallel operation completion state, and the parallel operation state is reported to the host computer;
as shown in fig. 2, the preset charging and discharging circuit includes:
the device comprises a first switch Mos transistor MOS1, a first Mos transistor Q1 and a first Mos tube diode Q1_ D1; the negative end B-of the battery pack is simultaneously connected with one end of a first switch Mos transistor MOS1, one end of a first Mos transistor Q1 and the negative end of a first Mos body diode Q1_ D1; the first switch Mos tube Mos1 is connected with one end of a first resistor R1 when closed, and the other end of the first resistor R1, the positive end of a first Mos tube diode Q1_ D1 and the positive end of the first Mos tube Q1 are connected with one end of a second switch Mos2, one end of a second Mos tube Q2 and the positive end of the second Mos tube diode Q2_ D1 when closed; the MOS2 of the second switch Mos tube is connected with one end of a second resistor R2 when being closed; the other end of the second resistor R2, the second Mos tube Q2 and the cathode end of the second Mos tube diode Q2_ D1 are connected to the cathode end P-of the electrical equipment when the second Mos tube Q2 is closed.
It should be noted that, the first resistor and the second resistor may also be set as one resistor R, and the specific setting position is shown in fig. 3.
The steps from S3 to S4 further include:
s31: and judging whether a slave information message with the parallel operation state being the parallel operation completion state exists through the host, if so, entering the step S4, otherwise, returning to the step S2.
S4: the method comprises the steps that a battery pack with a parallel operation state as a parallel operation completion state is obtained through a host machine as a parallel slave machine, the maximum voltage value or the minimum voltage value of the total voltage corresponding to each parallel slave machine is obtained, the maximum voltage value or the minimum voltage value is set as a reference voltage value, each slave machine with the protection state information of the protection non-existence mark and the parallel operation state not equal to the parallel operation completion state in an energy storage system is obtained as a slave machine to be screened, slave machines to be screened in the slave machines to be screened are screened through the reference voltage value, and a power-on command is issued to each slave machine to be screened;
in the step S4, the slave machines to be merged in the slave machines to be screened are screened out through the reference voltage value, which specifically includes:
setting a screening condition through the reference voltage value, and screening out the slave to be screened meeting the screening condition as a slave to be merged; the screening conditions are as follows:
the reference voltage value-preset floatable amplitude value is less than or equal to the total voltage of the slave to be screened and less than or equal to the reference voltage value + preset floatable amplitude value.
In this embodiment, the preset floatable amplitude is 3V.
According to the invention, the screening condition set by the reference voltage value is utilized to screen the slave machine to be screened meeting the screening condition as the slave machine to be parallel-connected, so that the parallel-connection safety is improved, the problem of BMS damage or battery core damage caused by the fact that the slave machine is connected into the battery pack in an abnormal state is avoided, and the service life of the battery pack is prolonged.
S5: and after receiving the power-on instruction, the slave computer to be connected switches on a preset charging and discharging circuit by using a preset control time sequence, sets the parallel operation state as a parallel operation completion state, reports the parallel operation completion state to the host computer, and returns to the step S4.
According to the invention, the steps S4 and S5 are circulated, so that the slave machines without the protection state (the protection state information is assigned as the protection non-existence mark) are continuously connected in parallel through the steps S4 and S5, so that the battery pack is charged or discharged, and the problem of serious over-discharge caused by the fact that the battery pack which is low in voltage and in the protection state cannot be charged is solved.
The electrical equipment is a load or a charger;
when the electrical equipment is a load, the energy storage system discharges and parallel-operates the battery pack by an intelligent parallel-operation method so as to provide electric energy for the load;
when the electrical equipment is a charger, the energy storage system charges and operates the battery pack through an intelligent parallel operation method so as to store energy for the battery pack.
In the process of discharging and parallel-operating the battery pack through an intelligent parallel-operating method, after the slave parallel-operating machine receives a power-on instruction, the specific steps of conducting a preset charging and discharging circuit by using a preset control time sequence are as follows:
and controlling the second switch Mos tube to be closed and then controlling the first Mos tube to be closed to start discharging and pre-flushing, wherein at the moment, the current of the positive terminal B + of the battery pack sequentially passes through the positive terminal P + of the load, the negative terminal P-of the load, the second resistor and the first Mos tube and then flows to the negative terminal B-of the battery pack, after the discharging and pre-flushing is carried out for a preset time, the second Mos tube is controlled to be closed, the second switch Mos tube is disconnected, and at the moment, the standby and the operation are completed from the parallel machine.
In the process of charging and parallel operation of the battery pack through an intelligent parallel operation method, the specific steps of conducting a preset charging and discharging circuit by using a preset control time sequence after the slave to be connected receives a power-on instruction are as follows:
the first switch Mos tube is controlled to be closed, then the second Mos tube is controlled to be closed to start charging and pre-flushing, at the moment, the current of the positive terminal P + of the charger sequentially passes through the positive terminal B + of the battery pack, the negative terminal B-of the battery pack, the first resistor and the second Mos tube and then flows to the negative terminal P-of the charger, after the charging and pre-flushing is performed for a preset time (the charging and pre-flushing function is realized), the first Mos tube is controlled to be closed, the first switch Mos tube is disconnected, and at the moment, the parallel operation of the secondary motor is finished.
It should be explained that the electrical devices in the preset charging and discharging circuit are all controlled by the BMS corresponding to the battery pack, and each BMS realizes intelligent management and control in the energy storage system by the CAN message (such as a power-on command) sent by the main BMS.
The intelligent parallel operation method further comprises the following steps:
a1: acquiring voltage between a positive terminal and a negative terminal of the electrical equipment as external voltage through a host, and accumulating the total voltage of each battery pack in the energy storage system to obtain a total voltage accumulated value;
a2: judging whether the external voltage is higher than the total voltage accumulated value by a preset amplitude value, if so, indicating that the total current of the current energy storage system is the charging current, namely the whole energy storage system is in a charging state, acquiring that the total voltage is lower than a reference voltage value through a host, and protecting the battery pack of which the state information is that no sign exists is protected as a standby slave;
a3: issuing a self-charging permission instruction to a slave to be merged through a host;
a4: after the slave to be connected receives the self-charging permission instruction, starting charging parallel operation, and executing the following steps in the charging parallel operation process:
a41: monitoring whether the current flowing to the slave of any other battery pack exceeds a set threshold value or not in real time through the slave to be connected, if so, entering the step A42, and if not, entering the step A43;
a42: keeping the preset charging and discharging circuit in a disconnected state, enabling the parallel operation to fail, adding 1 to the parallel operation times, judging whether the parallel operation times are larger than or equal to the preset parallel operation times, if so, ending the charging parallel operation (namely, before the charging voltage difference (external voltage difference) of the battery pack disappears, no response is made to a self-charging allowing instruction so as to protect the battery cell and the BMS), and if not, returning to the step A41 after the preset time interval; in this embodiment, the preset parallel operation frequency is equal to 5 times, and the preset time duration is 1 minute;
a43: and (5) conducting a preset charging and discharging circuit, and completing parallel operation.
It should be noted that, if other battery packs stop charging or start to shift to a discharging state, the voltage will be lower, so that the external voltage difference of the battery pack is reduced or eliminated; if the charging is continued, the undervoltage battery pack basically has no chance to complete parallel operation before other battery packs complete one cycle, and the undervoltage battery pack is merged after the next cycle of battery pack discharging.
In step A4, after the slave device to be incorporated receives the self-charging permission instruction, before starting the charging and operation, the method further includes:
and the slave to be connected judges whether the protection state information of the slave is a protection non-existence sign or not, acquires the voltage between the positive terminal and the negative terminal of the electrical equipment, judges whether the external voltage difference is greater than 0 or not by comparing the external voltage difference with the voltage between the positive terminal and the negative terminal of the slave, and starts to perform charging parallel operation if the external voltage difference is greater than 0 (indicating that the external voltage difference exists).
It is to be noted that a BMS (battery management system) within the battery pack has a charging voltage difference detection function, and the BMS recognizes that the battery pack is currently in a charged state when the external voltage is higher than the battery voltage by 1V or more.
In addition, the parallel operation means that a first Mos tube and a second Mos tube of a preset charge-discharge circuit are closed finally, and a smooth loop can be formed for running current; for the pre-charging, before a smooth loop is formed, a resistor limits a small current, and the battery or the load can be pre-charged by closing different switch Mos tubes to raise the voltage, so that the voltage difference is reduced after the smooth loop is formed, and the BMS or the battery core is not damaged by a large current.
The parallel operation has two trigger conditions, one is that the host computer sends an instruction of allowing self-charging through a power-on command in a CAN message sent down, and the second is that the host computer sends an instruction of allowing self-charging and the slave computer detects external pressure difference under the condition that the first trigger condition does not exist. The two different parallel operation triggering conditions can enable the battery packs with the symbol conditions to be parallel operated. The first power-on command means that the power-on command is relatively safe, and the host considers that the BMS receiving the power-on command does not have an overcurrent risk after closing the first Mos tube and the second Mos tube; the second type of the self-charging permission instruction indicates that the host considers that each battery pack has an overcurrent risk, but considers that the battery pack can cause overdischarge if not shut down, so that the battery pack is permitted to enter a charging parallel operation process under specific conditions.
The method comprises the steps that a host machine obtains protection state information as each slave machine to be selected without a protection mark, the slave machine to be selected with the minimum or maximum total voltage is obtained as a slave machine to be merged, a power-on command is issued to the slave machine to be merged by the host machine, a preset charging and discharging circuit is conducted by the slave machine to be merged by using a preset control time sequence after the slave machine to be selected receives the power-on command, a parallel operation state is set as a parallel operation completion state and reported to the host machine, so that initial parallel operation of an energy storage system is completed, a reference voltage value is obtained through the host machine after the initial parallel operation is completed, the slave machines with the protection state information as the protection mark and the parallel operation state not equal to the parallel operation completion state in the energy storage system are obtained as slave machines to be screened, the slave machines to be merged in the slave machines to be screened are screened through the reference voltage value, the power-on command is issued to the slave machines to be merged, the slave machines to be merged are started to be merged after the power-on command is received, the slave machines, the communication state between a negative electrode end of a battery pack and an electrical core end and an electrical equipment end is controlled through the preset charging and discharging circuit which is set for each battery pack, and the negative electrode, and the slave machine information message received, and the slave machine, so that the battery pack with a large voltage difference is prevented from being merged into a large voltage loop, and the battery pack is possibly damage to the BMS can be damaged by the battery cell impact on the BMS.
It should be noted that all directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.
Moreover, descriptions of the present invention as relating to "first," "second," "a," etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating a number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of the technical solutions by those skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
Claims (10)
1. An intelligent parallel operation method for an energy storage system is characterized in that the energy storage system comprises a host machine and a plurality of slave machines, the host machine and the slave machines are battery packs, a positive terminal of each battery pack is connected with a positive terminal of electrical equipment, and a negative terminal is connected with a negative terminal of the electrical equipment through a preset charge-discharge circuit corresponding to the battery pack; the slave is used for sending a slave information message to the host through the CAN bus; the intelligent parallel operation method comprises the following steps:
s1: starting an energy storage system, wherein a host receives slave information messages sent by each slave, and the slave information messages contain the total voltage of a battery pack, protection state information and parallel operation state; the protection state information is a protection state which is used for controlling the battery pack to enter a protection state and reporting a protection existence mark of the host when the slave BMS detects that the corresponding battery pack is in an abnormal state, or a protection nonexistence mark which is used for reporting the host when the battery pack is not in the abnormal state, wherein the abnormal state comprises the following steps: the total voltage of the battery pack is higher than an upper limit value or lower than a lower limit value; the parallel operation state comprises a parallel operation completion state;
s2: obtaining all slave machines with protection state information as protection non-existing marks as slave machines to be selected through the host machine, and obtaining the slave machine to be selected with the minimum or maximum total voltage as a slave machine to be combined from the slave machines to be selected;
s3: the method comprises the steps that a host computer issues a power-on instruction to a slave computer to be combined, the slave computer to be combined receives the power-on instruction and then conducts a preset charging and discharging circuit by using a preset control time sequence, the parallel operation state is set to be a parallel operation completion state, and the parallel operation state is reported to the host computer;
s4: the method comprises the steps that a battery pack with a parallel operation state as a parallel operation completion state is obtained through a host machine as a parallel slave machine, the maximum voltage value or the minimum voltage value of the total voltage corresponding to each parallel slave machine is obtained, the maximum voltage value or the minimum voltage value is set as a reference voltage value, each slave machine with the protection state information of the protection non-existence mark and the parallel operation state not equal to the parallel operation completion state in an energy storage system is obtained as a slave machine to be screened, slave machines to be screened in the slave machines to be screened are screened through the reference voltage value, and a power-on command is issued to each slave machine to be screened;
s5: and after receiving the power-on instruction, the slave computer to be connected switches on a preset charging and discharging circuit by using a preset control time sequence, sets the parallel operation state as a parallel operation completion state, reports the parallel operation completion state to the host computer, and returns to the step S4.
2. The intelligent parallel operation method for the energy storage system according to claim 1, wherein the steps S3 to S4 further include the steps of:
s31: and judging whether a slave information message with the parallel operation state being the parallel operation completion state exists through the host, if so, entering the step S4, and if not, returning to the step S2.
3. The intelligent parallel operation method for the energy storage system according to claim 2, wherein in the step S4, the slave to be screened out of the slave to be screened is screened out through the reference voltage value, and specifically:
setting a screening condition through the reference voltage value, and screening out the slave to be screened meeting the screening condition as a slave to be merged; the screening conditions are as follows:
the reference voltage value-preset floatable amplitude value is less than or equal to the total voltage of the slave to be screened and less than or equal to the reference voltage value + preset floatable amplitude value.
4. The intelligent parallel operation method for the energy storage system according to claim 3, wherein when the battery pack is in a protection state, the corresponding preset charging and discharging circuit is in an off state.
5. The intelligent parallel operation method for the energy storage system according to claim 4, wherein the preset charging and discharging circuit comprises:
the first switch Mos tube, the first Mos tube and the first Mos body diode; the negative end of the battery pack is simultaneously connected with one end of a first switch Mos tube, one end of the first Mos tube and the negative end of a first Mos tube body diode; the first switch Mos tube is connected with one end of a first resistor when closed, and the other end of the first resistor, the positive end of the first Mos tube body diode and the positive end of the first Mos tube are connected with one end of a second switch Mos tube, one end of the second Mos tube and the positive end of the second Mos tube body diode when closed; the second switch Mos tube is connected with one end of the second resistor when closed; and the other end of the second resistor, the second Mos tube and the cathode end of the diode of the second Mos tube body are connected to the cathode end of the electrical equipment when the second Mos tube is closed.
6. The intelligent parallel operation method for the energy storage system according to claim 5, wherein the electrical device is a load or a charger;
when the electrical equipment is a load, the energy storage system discharges and parallel-operates the battery pack through an intelligent parallel-operation method so as to provide electric energy for the load;
when the electrical equipment is a charger, the energy storage system charges and operates the battery pack through an intelligent parallel operation method so as to store energy for the battery pack.
7. The intelligent parallel operation method for the energy storage system according to claim 6, wherein during the discharging parallel operation of the battery pack by the intelligent parallel operation method, the specific step of conducting the preset charging and discharging circuit by using the preset control time sequence after the slave and the slave receive the power-on command is as follows:
and controlling the second switch Mos tube to be closed, controlling the first Mos tube to be closed to start discharging and pre-flushing, wherein at the moment, the current at the positive terminal of the battery pack sequentially passes through the positive terminal of the load, the negative terminal of the load, the second resistor and the first Mos tube and then flows to the negative terminal of the battery pack, after the discharging and pre-flushing is carried out for a preset time, controlling the second Mos tube to be closed, disconnecting the second switch Mos tube, and at the moment, completing the parallel operation of the slave machines.
8. The intelligent parallel operation method for the energy storage system according to claim 7, wherein in the process of charging and parallel operation of the battery pack through the intelligent parallel operation method, the specific step of conducting the preset charging and discharging circuit by using the preset control time sequence after the slave machine receives the power-on instruction is as follows:
the first switch Mos tube is controlled to be closed, then the second Mos tube is controlled to be closed to start charging and pre-flushing, at the moment, the current at the positive end of the charger sequentially passes through the positive end of the battery pack, the negative end of the battery pack, the first resistor and the second Mos tube and then flows to the negative end of the charger, after the charging and pre-flushing is preset for a long time, the first Mos tube is controlled to be closed, the first switch Mos tube is disconnected, and at the moment, the parallel operation of the slave machines is finished.
9. The intelligent parallel operation method for the energy storage system according to claim 8, further comprising:
a1: acquiring voltage between a positive terminal and a negative terminal of the electrical equipment as external voltage through a host, and accumulating the total voltage of each battery pack in the energy storage system to obtain a total voltage accumulated value;
a2: judging whether the external voltage is higher than the total voltage accumulated value preset amplitude value, if so, acquiring that the total voltage is lower than a reference voltage value through the host, and taking the battery pack with the protection state information of which the protection does not have the sign as a slave to be incorporated;
a3: issuing a self-charging permission instruction to the slave to be merged through the host;
a4: after the slave computer to be connected receives the self-charging permission instruction, starting charging parallel operation, and executing the following steps in the charging parallel operation process:
a41: monitoring whether the current flowing to the slave of any other battery pack exceeds a set threshold value or not in real time through the slave to be connected, if so, entering the step A42, and if not, entering the step A43;
a42: keeping the preset charging and discharging circuit in a disconnected state, enabling the parallel operation to fail, adding 1 to the parallel operation times, judging whether the parallel operation times are larger than or equal to the preset parallel operation times, if so, finishing the charging parallel operation, and if not, returning to the step A41 after a preset time interval;
a43: and (5) conducting a preset charging and discharging circuit, and completing parallel operation.
10. The intelligent parallel operation method for the energy storage system according to claim 9, wherein in the step A4, before the parallel operation of charging is started after the slave computer receives the self-charging permission instruction, the method further comprises:
and the slave to be connected judges whether the protection state information of the slave to be connected is a protection non-existence mark or not, acquires the voltage between the positive terminal and the negative terminal of the electrical equipment, judges whether the external voltage difference is greater than 0 or not compared with the voltage difference between the positive terminal and the negative terminal of the slave to be connected as the external voltage difference, and starts to perform charging parallel operation if the external voltage difference is greater than 0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211205502.9A CN115693839A (en) | 2022-09-30 | 2022-09-30 | Intelligent parallel operation method for energy storage system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211205502.9A CN115693839A (en) | 2022-09-30 | 2022-09-30 | Intelligent parallel operation method for energy storage system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115693839A true CN115693839A (en) | 2023-02-03 |
Family
ID=85064309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211205502.9A Pending CN115693839A (en) | 2022-09-30 | 2022-09-30 | Intelligent parallel operation method for energy storage system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115693839A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117293964A (en) * | 2023-09-27 | 2023-12-26 | 广州奥鹏能源科技有限公司 | Data processing method and device for battery parallel operation and terminal equipment |
| CN117293964B (en) * | 2023-09-27 | 2024-07-09 | 广州奥鹏能源科技有限公司 | Data processing method and device for battery parallel operation and terminal equipment |
-
2022
- 2022-09-30 CN CN202211205502.9A patent/CN115693839A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117293964A (en) * | 2023-09-27 | 2023-12-26 | 广州奥鹏能源科技有限公司 | Data processing method and device for battery parallel operation and terminal equipment |
| CN117293964B (en) * | 2023-09-27 | 2024-07-09 | 广州奥鹏能源科技有限公司 | Data processing method and device for battery parallel operation and terminal equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102082307B (en) | Method and system for parallel use of lithium battery modules | |
| US10063070B2 (en) | Battery active balancing system | |
| CN112165156B (en) | Charging/discharging device, battery system, charging/discharging control method, and storage medium | |
| CN110768330B (en) | Charging and discharging control method and device and UPS system | |
| CN103326079B (en) | Set of cells and control method thereof | |
| US20140266049A1 (en) | Detection and prevention of short formation in battery cells | |
| WO2008137764A1 (en) | Fine-controlled battery-charging system | |
| EP4220818A1 (en) | Battery formation apparatus, and control method and system for same | |
| CN114825528A (en) | Parallel battery charging and discharging control system and control method thereof | |
| EP4068561A1 (en) | Charging method and power conversion device | |
| CN115693839A (en) | Intelligent parallel operation method for energy storage system | |
| CN212195110U (en) | Power battery system and electric excavator power system | |
| CN110015126B (en) | Electric automobile and protection control method and system of power battery pack in electric automobile | |
| CN214874327U (en) | High-voltage electrical system and vehicle | |
| CN215419692U (en) | Battery management unit and distributed battery management system | |
| CN217590289U (en) | Accumulator battery | |
| CN109524946A (en) | A kind of BMS battery protection system | |
| CN216959376U (en) | Energy storage BMS high pressure device | |
| CN113595201B (en) | Power battery pack charging device and charging control method | |
| CN220628926U (en) | Battery management circuit, single-cluster battery energy storage circuit and multi-cluster battery energy storage circuit | |
| CN116937723B (en) | Battery control circuit, electronic device and charging control method | |
| CN217182977U (en) | Battery management system with reduced voltage discharge mechanism | |
| CN215418298U (en) | Modularization lithium iron phosphate battery pack with partial charging protection circuit | |
| JP5626756B2 (en) | Lithium ion battery management method and management apparatus | |
| CN216774351U (en) | Lithium battery protection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |