CN114899927B

CN114899927B - Battery port identification method, inverter and energy storage system

Info

Publication number: CN114899927B
Application number: CN202210827286.5A
Authority: CN
Inventors: 陈健聪; 何文均; 周银
Original assignee: Guangdong Shouhang Smart New Energy Technology Co ltd
Current assignee: Guangdong Shouhang Smart New Energy Technology Co ltd
Priority date: 2022-07-14
Filing date: 2022-07-14
Publication date: 2022-10-14
Anticipated expiration: 2042-07-14
Also published as: CN114899927A

Abstract

The application discloses a battery port identification method, an inverter and an energy storage system. And sending a voltage output command to the N batteries. Input voltages of the M voltage input ports are obtained to obtain a first voltage set comprising the M input voltages. And outputting a voltage output instruction to the Kth battery in the N batteries, and sending a voltage output stopping instruction to the rest batteries. After the first duration, the input voltages of the M voltage input ports are obtained to obtain a second voltage set comprising the M input voltages. And determining a voltage input port corresponding to the address of the Kth battery based on the first voltage set, the second voltage set and the addresses of the N batteries. Through the mode, the battery port can be automatically identified, the operation is simplified, and the error probability is reduced.

Description

Battery port identification method, inverter and energy storage system

Technical Field

The present application relates to the field of energy storage technologies, and in particular, to a battery port identification method, an inverter, and an energy storage system.

Background

With the continuous development of new energy industry, energy storage technology has also been greatly developed, and at present, in an energy storage system combining an inverter and a battery, the inverter is connected with at least one battery, the inverter can communicate with the battery, and can also output alternating current through DC/AC conversion based on the voltage of the battery.

In practical applications, when the inverter is connected to a plurality of batteries, different batteries are usually connected to the inverter by sharing a communication bus therebetween for economic efficiency, and the inverter can obtain an address of each battery by communicating data with the batteries. This mounting method poses a problem in that although the inverter can obtain the address of each battery by data communication with the battery, the inverter cannot directly obtain the correspondence information of the address due to the shared bus, that is, the port of the inverter to which the battery corresponding to each address is connected cannot be known.

However, it is common practice for an installer to manually configure the inverter according to the actual installation method on site, and the installer is required to confirm how many sets of batteries are available and to determine the ports of the corresponding inverters of each set of batteries. The manual configuration method is cumbersome to operate and prone to errors.

Disclosure of Invention

The application aims to provide a battery port identification method, an inverter and an energy storage system, which can automatically identify the battery port, simplify the operation and reduce the error probability.

In order to achieve the above object, in a first aspect, the present application provides a method for identifying a battery port, which is applied to an inverter, where a communication port of the inverter is connected to N batteries, and M voltage input ports of the inverter are connected to the N batteries, where M and N are integers greater than or equal to 2, and the method includes:

acquiring addresses of the N batteries;

sending a voltage output instruction to the N batteries, wherein the voltage output instruction is used for enabling the N batteries to output voltage to the inverter;

obtaining input voltages of the M voltage input ports to obtain a first voltage set comprising M input voltages;

sending the voltage output instruction to a Kth battery in the N batteries, and sending a voltage output stopping instruction to the rest batteries in the N batteries, wherein K is an integer less than or equal to N, and the voltage output stopping instruction is used for stopping the rest batteries in the N batteries from outputting voltage to the inverter;

after a first duration, obtaining input voltages of the M voltage input ports to obtain a second voltage set comprising M input voltages;

and determining a voltage input port corresponding to the address of the Kth battery based on the first voltage set, the second voltage set and the addresses of the N batteries.

In an optional manner, the method further comprises:

within a first duration, acquiring the highest input voltage of the input voltages of the M voltage input ports;

if the highest input voltage is smaller than a power-down threshold of the inverter, obtaining the input voltages of the M voltage input ports is executed to obtain a second voltage set comprising M input voltages.

In an optional manner, the determining, based on the first voltage set, the second voltage set, and the address, a voltage input port corresponding to the address of the kth battery includes:

determining an address of the Kth battery based on the addresses of the N batteries;

sequentially acquiring first difference values between input voltages in the first voltage set and input voltages in the second voltage set under the same voltage input port to acquire M first difference values;

and if one first sub-difference value in the M first difference values is smaller than a first preset difference value threshold, determining that the voltage input port corresponding to the address of the Kth battery is the voltage input port corresponding to the first sub-difference value.

In an optional manner, the method further comprises:

acquiring a sampling error rate and a sampling range of the voltage sampling of the inverter;

determining an input voltage sampling error value of the inverter based on a product of the sampling error rate and a maximum value in a sampling range;

determining the first preset difference threshold based on the input voltage sampling error value.

In an alternative manner, the determining the first preset difference threshold based on the input voltage sampling error value includes:

the first preset difference threshold is any value in [ Ve,2Ve ], where Ve is the input voltage sampling error value.

In an optional manner, after the obtaining the input voltages of the M voltage input ports to obtain a first voltage set including M input voltages, the method further includes:

sending a voltage output stopping command to the N batteries;

obtaining input voltages of the M voltage input ports to obtain a third voltage set comprising M input voltages;

sequentially acquiring second difference values between the input voltage in the first voltage set and the input voltage in the third voltage set under the same voltage input port to obtain M second difference values;

and if at least two difference values in the M second difference values are smaller than a second preset difference value threshold value, determining that at least one battery is not connected with the communication port of the inverter.

In an optional manner, after the sending the voltage output instruction to the kth battery of the N batteries and sending the stop voltage output instruction to the remaining batteries of the N batteries, the method further includes:

acquiring the highest input voltage of the input voltages of the M voltage input ports;

if the highest input voltage is smaller than the power failure threshold value of the inverter, determining that the Kth battery is not connected to a voltage input port of the inverter;

if the highest input voltage is greater than the power-down threshold of the inverter, the input voltages of the M voltage input ports are acquired after a first time period is executed, so that a second voltage set comprising the M input voltages is acquired.

In a second aspect, the present application provides an inverter comprising:

a communication port connected to the battery;

a voltage input port connected to the battery;

a control processing unit, configured to perform data transmission with the battery through the communication port, and acquire an output voltage of the battery through the voltage input port, where the control processing unit includes:

at least one processor and a memory communicatively coupled to the at least one processor, the memory storing instructions executable by the at least one processor to enable the at least one processor to perform a method as described above.

In a third aspect, the present application provides an energy storage system comprising: a battery and the inverter of claim 8;

the inverter is connected with the battery, and is used for converting the voltage output by the battery to output alternating-current voltage.

In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions that, when executed by a processor, cause the processor to perform the method as described above.

The beneficial effect of this application is: the battery port identification method is applied to an inverter, a communication port of the inverter is connected with N batteries, M voltage input ports of the inverter are connected with the N batteries, and M and N are integers which are not less than 2. The method comprises the following steps: the method comprises the steps of obtaining addresses of N batteries, sending a voltage output instruction to the N batteries, wherein the voltage output instruction is used for enabling the N batteries to output voltages to an inverter, obtaining input voltages of M voltage input ports to obtain a first voltage set comprising M input voltages, sending a voltage output instruction to a Kth battery of the N batteries, and sending a voltage output stopping instruction to the rest of the N batteries, wherein K is an integer not larger than N, and the voltage output stopping instruction is used for enabling the rest of the N batteries to stop outputting voltages to the inverter. After the first duration, the input voltages of the M voltage input ports are obtained to obtain a second voltage set comprising the M input voltages. And determining a voltage input port corresponding to the address of the Kth battery based on the first voltage set, the second voltage set and the addresses of the N batteries. In summary, for the first voltage set and the second voltage set, only the kth battery maintains the output voltage, the voltages of the corresponding ports in the first voltage set and the second voltage set are compared one by one, the voltage input port connected with the kth battery can be obtained according to the comparison result, and the voltage input port corresponding to the address of the kth battery can be determined by combining the obtained address of the kth battery. Therefore, the process of automatically identifying the battery port is realized, and compared with manual configuration, the process is simpler to operate and lower in error probability, namely, the operation is simplified, and the error probability is reduced.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic structural diagram of an energy storage system provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a control processing unit according to an embodiment of the present application;

fig. 3 is a flowchart of a method for identifying a battery port according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating an implementation of step 306 shown in FIG. 3, provided in an embodiment of the present application;

fig. 5 is a flowchart of a method for determining whether a battery is connected to a communication port of an inverter according to an embodiment of the present disclosure;

FIG. 6 is a flowchart of a method for determining a first voltage threshold according to an embodiment of the present disclosure;

fig. 7 is a flowchart of a method for identifying a battery port according to another embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an energy storage system according to an embodiment of the present disclosure. As shown in FIG. 1, the energy storage system 100 includes an inverter 10 and N batteries, where N is an integer greater than or equal to 2.

The N batteries comprise a battery A1, a battery A2 and a battery A3 \ 8230and a battery AN. The N batteries are connected to the inverter 10, and the N batteries are used to supply an input voltage to the inverter 10. In one embodiment, each of the batteries A1, A2, and A3 \ 8230is provided with a Battery Management System (BMS), which is a set of control System for protecting the safety of the Battery, constantly monitors the use state of the corresponding Battery, collects the state information of the corresponding Battery, such as the address of the Battery, and transmits the state information to the inverter 10.

The battery in the embodiment of the present application may be a lithium ion battery, a lithium metal battery, a lead-acid battery, a nickel cadmium battery, a nickel hydrogen battery, a lithium sulfur battery, a lithium air battery, a sodium ion battery, or the like, which is not limited herein. In terms of scale, the battery in the embodiment of the present application may be a single battery cell, or a battery module formed by connecting a plurality of battery cells in series and/or in parallel, or a battery pack formed by connecting a plurality of battery modules in series and/or in parallel, or a power supply device formed by connecting a plurality of battery packs in parallel, which is not limited herein.

The inverter 10 is connected to the N batteries, and converts voltages output from the N batteries to output an ac voltage.

The inverter 10 includes a communication port S1 and M voltage input ports, where M is an integer equal to or greater than 2. Communication port S1 is used for establishing communication connection with battery A1, battery A2, and battery A3 \8230, and battery AN, so that inverter 10 can perform data transmission with battery A1, battery A2, and battery A3 \8230, and battery AN.

The M voltage input ports comprise a voltage input port J1, a voltage input port J2 \8230anda voltage input port JM. The M voltage input ports are for connection with N batteries, wherein each voltage input port is connected with at least one battery, each battery also being connected with at least one voltage input port.

For example, as shown in fig. 1, the voltage input port J1 is connected to a battery, namely, a battery A1.

As another example, battery input port J2 is connected to two batteries, battery A2 and battery A3, and battery A2 and battery A3 are connected in parallel. In this case, the voltage input port corresponding to the battery A1 is a voltage input port J1, and the voltage input ports corresponding to the batteries A2 and A3 are both voltage input ports J2. By analogy, any battery input port can also be connected with more than two batteries.

As another example, battery AN is coupled to two battery input ports, battery input port JM-1 and battery input port JM. In this case, the voltage input ports corresponding to the battery AN are the battery input port JM-1 and the battery input port JM, and the batteries corresponding to the battery input port JM-1 and the battery input port JM are both the battery AN. By analogy, any battery can also be connected with more than two battery input ports.

The inverter 10 further comprises a control processing unit 11, the control processing unit 11 is used for performing data transmission with the battery A1, the battery A2 and the battery A3 \8230throughthe communication port S1, and the control processing unit 11 is further used for acquiring output voltages of the battery A1, the battery A2 and the battery A3 \8230throughthe M voltage input ports.

The control Processing Unit 11 may be a Micro Controller Unit (MCU) or a Digital Signal Processing (DSP) controller.

Referring to fig. 2, fig. 2 illustrates an example of a structure of the control processing unit 11. As shown in fig. 2, the control processing unit 11 includes at least one processor 111 and a memory 112, where the memory 112 may be built in the control processing unit 11 or may be external to the control processing unit 11, and the memory 112 may be a remotely located memory and is connected to the control processing unit 11 through a network.

The memory 112, which is a non-volatile computer-readable storage medium, may be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The memory 112 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory 112 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, the memory 112 may optionally include memory located remotely from the processor 111, which may be connected to the terminal over a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The processor 111 performs various functions of the terminal and processes data by operating or executing software programs and/or modules stored in the memory 112 and calling data stored in the memory 112, thereby performing overall monitoring of the terminal, for example, implementing a battery port identification method according to any embodiment of the present application.

The number of the processors 111 may be one or more, and one processor 111 is illustrated in fig. 2 as an example. The processor 111 and memory 112 may be connected by a bus or other means. Processor 111 may include a Central Processing Unit (CPU), digital Signal Processor (DSP), application Specific Integrated Circuit (ASIC), controller, field Programmable Gate Array (FPGA) device, and the like. The processor 111 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Referring to fig. 3, fig. 3 is a flowchart of a method for identifying a battery port according to an embodiment of the present disclosure. The identification method of the battery port is applied to an inverter, a communication port of the inverter is connected with N batteries, M voltage input ports of the inverter are connected with N batteries, and N and M are integers which are not less than 2. Here, the connection relationship between the inverter and the battery may refer to the above detailed description with respect to fig. 1, and is not described here in detail. The identification method of the battery port comprises the following steps:

step 301: acquiring addresses of N batteries;

data exchange is carried out between the communication port and the N batteries so as to obtain addresses of the N batteries.

Step 302: and sending a voltage output command to the N batteries, wherein the voltage output command is used for enabling the N batteries to output voltage to the inverter.

Step 303: input voltages of the M voltage input ports are obtained to obtain a first voltage set comprising the M input voltages.

Specifically, after the voltage output command is sent to each of the N batteries through the communication port, each battery outputs a voltage to the corresponding voltage input port. In this case, a total of M input voltages can be obtained at the M voltage input ports, and when the M input voltages are respectively denoted as V11, V12, and V13 \8230andv 1M, the first voltage set V1 is (V11, V12, and V13 \8230; V1M). It can be understood that when two or more batteries are connected in parallel and then connected to the same voltage input port, the output voltages of the batteries connected to the same voltage input port are the same.

Taking the structure shown in fig. 1 as AN example, inverter 10 sends a voltage output command to battery A1, battery A2, and battery A3 \8230throughcommunication port S1, battery AN outputs voltage to voltage input port J1 and voltage input port J2 \8230, voltage input port JM makes voltage input port J1 and voltage input port J2 \8230, and input voltages at voltage input port JM are V11, V12, and V13 \8230, respectively, and V1M. The output voltages of the battery A2 and the battery A3 are both V12.

Step 304: and sending a voltage output instruction to the Kth battery in the N batteries, and sending a voltage output stopping instruction to the rest batteries in the N batteries.

Step 305: after the first duration, the input voltages of the M voltage input ports are obtained to obtain a second voltage set comprising the M input voltages.

And K is an integer less than or equal to N, and the stop voltage output instruction is used for stopping the rest of the N batteries from outputting voltage to the inverter.

Specifically, after the voltage output command is sent to the kth battery through the communication port and the stop voltage output command is sent to the rest of the N batteries, only the kth battery outputs the voltage to the corresponding voltage input port, and the other batteries (i.e., the kth battery is not included) of the N batteries stop outputting the voltage.

At the same time, namely after the inverter 10 outputs the command, the timing is started, and the first time period is timed to wait for the output voltage of each battery to be in a stable state. The first duration may be a preset duration, or may also be a duration set according to different application scenarios, which is not specifically limited in the embodiment of the present application.

Then, at the end of the first time period, M input voltages of the M voltage input ports are acquired again, and if the M input voltages are respectively denoted as V21, V22 and V23 \8230andv 2M, the second voltage set V2 is (V21, V22 and V23 \8230andv 2M).

Taking the structure shown in fig. 1 as an example, assume that the kth cell is cell A1, i.e., K =1. Inverter 10 sends a voltage output command to battery A1 through communication port S1, and sends a voltage stop command to battery A2 and battery A3 \8230throughcommunication port S1, and battery AN outputs voltage to voltage input port J1, and battery A2 and battery A3 \8230, and battery AN stops outputting voltage. Then, delaying the first duration, and obtaining the voltage input port J1 and the voltage input port J2 \8230againat the moment when the first duration is ended, wherein the input voltages on the voltage input port JM are V21, V22 and V23 \8230, and VM are respectively.

It should be noted that, a premise of implementing any embodiment of the present application is that, before the method for identifying a battery port is executed, that is, before step 301 is executed, it needs to be determined that the output voltages of the N batteries need to be greater than the power-down threshold of the inverter, so as to prevent an abnormal situation that the output voltage of the battery is less than the power-down threshold of the inverter when the line connection is normal, which causes the inverter to be powered down and shut down, and to facilitate improving the stability of the inverter. When the input voltage of the inverter is smaller than the minimum value, the input voltage is not enough to ensure the normal work of the inverter and can cause the inverter to be powered off.

Meanwhile, during the discharging process of each battery, the inverter needs to be prevented from powering down and shutting down. Based on this, in other embodiments, the method for identifying a battery port may further include the steps of: in the first time period, the highest input voltage of the input voltages of the M voltage input ports is obtained. If the highest input voltage is smaller than the power-down threshold of the inverter, obtaining the input voltages of the M voltage input ports is performed to obtain a second voltage set comprising the M input voltages.

After step 304 is performed, only the kth cell maintains the output voltage, and the other cells stop outputting the voltage. Then, under the condition that the line connection and the work of the whole energy storage system are both normal, the voltages output by other batteries except the kth battery are all zero, and the voltage output by the kth battery is the highest input voltage of the inverter.

In addition, since the kth battery maintains the output voltage, the output power of the kth battery is gradually lost and the output voltage of the kth battery is gradually reduced regardless of whether the energy storage system is connected to an external electric device. Therefore, if the output voltage of the Kth battery is reduced to be smaller than the power failure threshold value of the inverter within the first time length, the timing is immediately ended to prevent the inverter from being abnormally powered off and keep the inverter stably running. While the timing is finished, the obtaining of the input voltages of the M voltage input ports in step 305 is performed to obtain a second voltage set including the M input voltages.

For example, in an embodiment, the first duration is 5 minutes, but when the time is counted to 3 minutes, it is detected that the highest input voltage is smaller than the power-down threshold of the inverter, the time is stopped, and the obtaining of the input voltages of the M voltage input ports in step 305 is started at the 3 minutes to obtain the second voltage set including the M input voltages.

Of course, in other embodiments, in order to further improve the stability of the inverter, the timing may be stopped when the highest input voltage is greater than the power-down threshold of the inverter, and the difference between the highest input voltage and the power-down threshold of the inverter is smaller than the first preset difference, and the obtaining of the input voltages of the M voltage input ports in step 305 is performed to obtain the second voltage set including the M input voltages, where the first preset difference may be set according to an actual application situation, which is not specifically limited in this embodiment of the application. Alternatively, the condition for stopping the timing may be set in other manners based on the highest input voltage and the power-down threshold of the inverter, which is not limited in this embodiment of the application.

In an embodiment, whether the connection between the kth battery and the voltage input port of the inverter is normal or not can be detected through the highest input voltage and a power-down threshold of the inverter.

Specifically, the method for identifying the battery port may further include the following steps: after a voltage output instruction is sent to the Kth battery of the N batteries and a stop voltage output instruction is sent to the rest batteries of the N batteries, the highest input voltage of the input voltages of the M voltage input ports is obtained. And if the highest input voltage is less than the power failure threshold value of the inverter, determining that the Kth battery is not connected to the voltage input port of the inverter. If the highest input voltage is greater than the power-down threshold of the inverter, the input voltages of the M voltage input ports are acquired after the first time period is executed, so that a second voltage set comprising the M input voltages is obtained.

After step 304 is performed, i.e. before the first time period has not yet started, the highest input voltage of the input voltages of the M voltage input ports is obtained. As can be seen from the above description, the highest input voltage at this time is the output voltage of the kth battery, and the output voltage of the kth battery is not reduced yet, then the output voltage should be greater than the power-down threshold of the inverter. Therefore, if the highest input voltage is greater than the power-down threshold of the inverter, the connection between the kth battery and the voltage input port of the inverter is in a normal state, and step 305 may be continued. Conversely, if the highest input voltage is less than the power-down threshold of the inverter, it may be determined that the connection between the kth battery and the voltage input port of the inverter is in an abnormal state, for example, the connection between the kth battery and the voltage input port of the inverter is disconnected.

In the embodiment, whether the connection between the Kth battery and the voltage input port of the inverter is normal or not is detected in real time by combining the highest input voltage and the power-down threshold of the inverter, so that an alarm can be given when the connection between the Kth battery and the voltage input port of the inverter is abnormal, a user is prompted to timely process the connection, and the improvement of the working efficiency is facilitated.

The structure of fig. 1 will be described as an example. Assume that K =2 and the 2 nd battery (i.e., battery A2) is not connected to the voltage input port of the inverter. Then, at the time of the first time length, because the battery A1 and the battery A3 \ 8230, the battery AN stops outputting the voltage, and the battery A2 is not connected with the upper voltage input port, the highest input voltage is inevitably smaller than the power failure threshold of the inverter, so that the inverter is powered down and shut down. In other words, if it is detected that the highest input voltage is less than the power-down threshold of the inverter, it can be determined that the battery A2 is not connected to the upper voltage input port.

Step 306: and determining a voltage input port corresponding to the address of the Kth battery based on the first voltage set, the second voltage set and the addresses of the N batteries.

Specifically, for the first voltage set and the second voltage set, only the kth battery maintains the output voltage, the voltages of the corresponding ports in the first voltage set and the second voltage set are compared one by one, the voltage input port connected with the kth battery can be obtained according to the comparison result, and the voltage input port corresponding to the address of the kth battery can be determined by combining the obtained address of the kth battery. Therefore, the process of automatically identifying the battery port is realized, and compared with the process of adopting manual configuration, the process is simpler in operation, namely the operation is simplified, and the error probability is reduced.

In an embodiment, as shown in fig. 4, the process of determining the voltage input port corresponding to the address of the kth battery based on the first voltage set, the second voltage set and the addresses of the N batteries in step 306 includes the following steps:

step 401: based on the addresses of the N batteries, the address of the Kth battery is determined.

Step 402: under the same voltage input port, first difference values between input voltages in the first voltage set and input voltages in the second voltage set are sequentially acquired to obtain M first difference values.

Step 403: and if one first sub-difference value in the M first difference values is smaller than a first preset difference value threshold, determining that the voltage input port corresponding to the address of the Kth battery is the voltage input port corresponding to the first sub-difference value.

As can be seen from the above embodiments, the first voltage set includes the input voltages of the M voltage input ports, and the second voltage set also includes the input voltages of the M voltage input ports, so that for each voltage input port, there is one input voltage in the first voltage set, and there is one input voltage in the second voltage set. Then, two input voltages corresponding to the same voltage input port are differentiated to obtain a first difference, and M first differences can be obtained corresponding to M voltage input ports.

Then, it is determined whether one difference (denoted as a first sub-difference) among the M first differences is smaller than a first preset difference threshold, and if so, it indicates that the input voltage variation of the voltage input port corresponding to the first sub-difference is smaller. In addition, for the first voltage set and the second voltage set, only the Kth battery keeps the output voltage, and the other batteries firstly output the voltage and then stop outputting the voltage. In other words, only the output voltage of the kth cell can maintain a small variation range, while the other cells decrease from the maximum value of the output voltage to zero. In summary, there is only one first sub-difference, and the first sub-difference is smaller than the first preset difference threshold, the input voltage corresponding to the voltage input port changes less, and similarly, only the output voltage of the kth battery can keep a smaller change range, so that the voltage input port connected to the kth battery is the voltage input port corresponding to the first sub-difference, and thus it can be determined that the voltage input port corresponding to the address of the kth battery is the voltage input port corresponding to the first sub-difference.

The structure shown in fig. 1 is still taken as an example. Assume that K =1 and the address of the kth cell, i.e., the 1 st cell, i.e., cell A1, is A1. Meanwhile, the first voltage set V1 is (V11, V12, V13 \8230; V1M), and the second voltage set V2 is (V21, V22, V23 \8230; V2M).

For a first voltage input port J1, a first difference V31= V11-V21 between the input voltages in the first set of voltages and the input voltages in the second set of voltages; for the second voltage input port J2, a first difference V32= V12-V22 between the input voltages in the first set of voltages and the input voltages in the second set of voltages; for the third voltage input port J3, a first difference V33= V13-V23 \8230betweenthe input voltages in the first set of voltages and the input voltages in the second set of voltages, and for the mth voltage input port JM, a first difference V3M = V1M-V2M between the input voltages in the first set of voltages and the input voltages in the second set of voltages. Thus, M first differences may be obtained as: v31, V32, V33 \8230andV 3M.

It is assumed that V31 is smaller than a first preset difference threshold, V32, V33, 8230, and V3M are both larger than the first preset difference threshold, at this time, V31 is a first sub-difference, a voltage input port corresponding to V31 is a first voltage input port J1, that is, the 1 st cell (cell A1) is connected to the first voltage input port J1. When the address of the battery A1 is A1, the voltage input port corresponding to the address A1 of the battery A1 is the first voltage input port J1.

Then, by setting K =2 again and performing the above process again, the voltage input port corresponding to the address A2 of the battery A2 can be determined as the second voltage input port J2. By analogy, the voltage input port corresponding to the address of each battery can be determined one by one. Therefore, the process of automatically identifying the battery ports is realized, namely the inverter can determine the corresponding relation between the address of each battery and the voltage input port, and the inverter is favorable for correctly controlling the charging and discharging process of the batteries and carrying out corresponding battery management tasks through the connection relation. Meanwhile, compared with a scheme adopting manual configuration in the related technology, the scheme provided by the application adopts an automatic identification mode, so that the operation is simpler, the error probability is reduced, and the working stability and reliability of the inverter can be improved.

It should be noted that, in this embodiment, one difference value smaller than the first preset difference value threshold value in the M first difference values is used as a determination criterion, and in other implementations, other determination manners may also be used as the determination criterion, so long as the voltage input port to which the battery is connected can be correspondingly identified. For example, in another embodiment, the absolute values of the differences between the input voltages in the first voltage set and the input voltages in the second voltage set under the same voltage input port may be sequentially obtained to obtain M absolute values, and one of the M absolute values that is smaller than the first preset difference threshold may be used as a judgment basis.

In some embodiments, after step 303 is executed, it may be determined whether the connection between each battery and the communication port S1 of the inverter 10 is abnormal, and step 304 may be executed only when the connection between each battery and the communication port S1 of the inverter 10 is normal.

Referring to fig. 5 in particular, as shown in fig. 5, the method for identifying a battery port further includes the following steps:

step 501: and sending a stop voltage output instruction to the N batteries.

Step 502: input voltages of the M voltage input ports are obtained to obtain a third voltage set comprising the M input voltages.

Step 503: and sequentially acquiring second difference values between the input voltage in the first voltage set and the input voltage in the third voltage set under the same voltage input port to acquire M second difference values.

Step 504: and if at least one difference value in the M second difference values is smaller than a first preset difference value threshold value, determining that at least one battery is not connected with the communication port of the inverter.

In this embodiment, after step 501 is performed, the N cells should each stop outputting voltage. At this time, if there is at least one battery not connected to the communication port of the inverter, there is one or more batteries not connected to the communication port of the inverter, and the battery not connected to the communication port of the inverter cannot receive the output stop voltage command output by the inverter and maintains the output voltage, so that an abnormal condition that at least one difference value is smaller than the first preset difference value threshold value occurs.

Therefore, whether the current N batteries are connected with the communication port of the inverter or not can be determined, if at least one battery is not connected with the communication port of the inverter, an alarm can be given when the battery is not connected with the communication port of the inverter, so that a user is prompted to process in time, and the work efficiency is improved.

Take the structure shown in fig. 1 as an example. Assume that the 2 nd battery (i.e., battery A2) is not connected to the communication port of the inverter. Then, after step 501 is completed, since only the 2 nd battery (i.e., battery A2) maintains the output voltage, one difference value smaller than the second preset difference value threshold is obtained from the M obtained input voltages, which is the input voltage of the 2 nd voltage input port J2.

At this time, it can be determined that there is a communication port where the battery is not connected to the inverter, in this embodiment, the battery A2 is taken as an example, and after prompting the user, the user can quickly determine the battery that is not connected to the communication port of the inverter by finding the battery to which the 2 nd voltage input port J2 is connected, which also helps the user to quickly troubleshoot and solve the problem. Of course, it is understood that if other batteries are not connected to the communication port of the inverter, the at least one difference value smaller than the second preset difference value threshold value may also be caused to exist. In other words, it can be determined that at least one battery is not connected to the communication port of the inverter as long as it is detected that at least one difference is smaller than the second preset difference threshold.

In the embodiment of the present application, the first preset difference threshold and the second preset difference threshold may be set according to an actual application, which is not specifically limited in the embodiment of the present application. The first preset difference threshold and the second preset difference threshold may be the same or different.

For example, in order to more reasonably set the first preset difference threshold and the second preset difference threshold to improve the accuracy of identifying the battery port, the first preset difference threshold and the second preset difference threshold may be determined based on the relevant characteristic parameters of the inverter for voltage sampling. The following description is given by taking the first preset difference threshold as an example, and the setting method of the second preset difference threshold is similar to that of the first preset difference threshold, which is not repeated here.

Specifically, in an embodiment, as shown in fig. 6, the method for identifying a battery port further includes the following steps:

step 601: and acquiring a sampling error rate and a sampling range of the voltage sampling of the inverter.

Step 602: an input voltage sampling error value for the inverter is determined based on a product of the sampling error rate and a maximum value in the sampling range.

The sampling error rate and the sampling range are determined by the characteristics of the inverter itself, and different inverters have different sampling error rates and different sampling ranges, which are not limited in this embodiment. For example, in one embodiment, the sampling error rate of the inverter is 1%, and the sampling range is [0,1000v ]; in another embodiment, the sampling error rate of the inverter is 2% and the sampling range is [0,500v ].

Then, by multiplying the sampling error rate by the maximum value in the sampling range, the input voltage sampling error value of the inverter can be obtained. For example, if the sampling error rate of the inverter is 1% and the sampling range is [0,1000v ], the sampling error value of the input voltage of the inverter is 1000 × 1% =10V; the sampling error rate of the inverter is 2%, and the sampling range is [0,500v ], so that the sampling error value of the input voltage of the inverter is 500 × 2% =10V.

Step 603: a first preset difference threshold is determined based on the input voltage sampling error value.

Specifically, it can be known from the above steps that the input voltage sampling error value is the maximum error value that may occur when voltage sampling is performed, so the input voltage sampling error value may affect the actual sampling voltage value, that is, each of the acquired input voltages. Therefore, the first preset difference threshold is determined by combining the input voltage sampling error value, the risk of abnormal identification of the battery port caused by the sampling error can be reduced, and the accuracy of identifying the battery port is improved.

In one embodiment, the step 603 of determining the first preset difference threshold based on the input voltage sampling error value includes the following steps: the first preset difference threshold is any one of [ Ve,2Ve ], where Ve is an input voltage sampling error value.

For example, the sampling error rate of the inverter is 1%, and the sampling range is [0,1000v ], then the sampling error value of the input voltage of the inverter is 1000 × 1% =10V. The first predetermined difference threshold is set to [10V,20V ], i.e., 10V or less and the first predetermined difference threshold is set to less than or equal to 20V.

In this embodiment, the first preset difference threshold is set to any one of [ Ve,2Ve ], on one hand, the first preset difference threshold is not less than the input voltage sampling error value, so that the abnormal occurrence of the voltage input port to which the battery is connected, which is not recognized due to the undersized first preset difference threshold, can be prevented. Specifically, if the first preset difference threshold is smaller than the input voltage sampling error value, and the first preset difference threshold is set too small, at this time, it may occur that none of the obtained M difference values satisfies the condition that the M difference values are smaller than the first preset difference threshold, so that the voltage input port to which the battery is connected cannot be identified. Therefore, by setting the first preset difference threshold not less than the input voltage sampling error value, the probability of identifying the voltage input port connected with the battery can be improved, and the accuracy and the stability of identifying the battery port are improved.

On the other hand, the first preset difference threshold is not more than twice of the input voltage sampling error value, so that the abnormal condition that one battery is connected with a plurality of voltage input ports is identified due to the fact that the first preset difference threshold is set to be overlarge can be prevented. Specifically, if the first preset difference threshold is greater than the twice input voltage sampling error value, and the first preset difference threshold is set too large, it may occur that a plurality of differences among the M obtained differences all satisfy that the difference is smaller than the first preset difference threshold, and in this case, the voltage input port to which the battery is actually connected cannot be correctly identified. Therefore, by setting the first preset difference threshold not greater than the twice input voltage sampling error value, the probability of identifying the voltage input port connected with the battery can be improved, and the accuracy and the stability of identifying the battery port are further improved.

Referring to fig. 7, fig. 7 is a flowchart of a battery port identification method according to another embodiment of the present disclosure. As shown in fig. 7, first, addresses of the respective batteries are acquired, that is, addresses of N batteries are acquired. And then sending a voltage output instruction to all the batteries so that the N batteries output voltage to a voltage input port of the inverter. At this time, input voltages of the M voltage input ports are acquired, and a first voltage set including the M input voltages may be acquired.

Then, the stop voltage output instruction is sent to all the batteries so that all the batteries stop outputting the voltage, and the input voltages of the M voltage input ports are obtained again to obtain a third voltage set. Then, M differences (i.e., the second differences in the above-described embodiment) between the input voltages in the first voltage set and the input voltages in the third voltage set are calculated. If at least one difference value of the M difference values is smaller than a second preset difference value threshold value, determining that at least one battery is not connected with the communication port of the inverter, and performing alarm prompt and ending the process; and if the difference value smaller than the second preset difference value threshold does not exist in the M difference values, determining that each battery is connected with the communication port of the inverter.

Then, a voltage output command is sent to the battery at the address ax, and a stop voltage output command is sent to the batteries other than the address ax so that the battery at the address ax outputs a voltage to the voltage input port of the inverter and the other batteries stop outputting the voltage. Then, acquiring the highest input voltage in the input voltages of the M voltage input ports, if the highest input voltage is smaller than the power failure threshold value of the inverter, determining that the battery with the address ax is not connected with the voltage input port, and performing alarm prompt and ending the process; and if the highest input voltage is greater than the power-down threshold value of the inverter, timing is started. And then, in the timing process, judging whether the timing is finished or not and judging whether the highest input voltage is smaller than a power-down threshold of the inverter or not, and acquiring the input voltages of the M voltage input ports as long as the timing is finished (corresponding to the end of the first time length) or the highest input voltage is smaller than the power-down threshold of the inverter to acquire a second voltage set comprising the M input voltages. Then, M difference values between the input voltages in the first voltage set and the input voltages in the second voltage set are calculated. If one of the M differences (corresponding to the first sub-difference in the above embodiment) is smaller than the first preset difference threshold, the voltage input port corresponding to the first sub-difference corresponds to the battery with the address ax.

Embodiments of the present application also provide a non-transitory computer-readable storage medium storing computer-executable instructions for execution by one or more processors, e.g., to perform the method steps of fig. 3 described above.

Embodiments of the present application further provide a computer program product comprising a computer program stored on a non-volatile computer-readable storage medium, the computer program comprising program instructions which, when executed by a computer, cause the computer to perform the method for identifying a battery port in any of the above-described method embodiments, for example, to perform the method steps of fig. 3 described above.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; within the context of the present application, where technical features in the above embodiments or in different embodiments can also be combined, the steps can be implemented in any order and there are many other variations of the different aspects of the present application as described above, which are not provided in detail for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery port identification method is applied to an inverter, a communication port of the inverter is connected with N batteries, M voltage input ports of the inverter are connected with the N batteries, M and N are integers which are not less than 2, and the method comprises the following steps:

acquiring addresses of the N batteries;

2. The method of claim 1, further comprising:

3. The method of claim 1, further comprising:

acquiring a sampling error rate and a sampling range of the inverter for voltage sampling;

4. The method of claim 3, wherein determining the first preset difference threshold based on the input voltage sampling error value comprises:

the first preset difference threshold is any one of [ Ve,2Ve ], wherein Ve is the input voltage sampling error value.

5. The method of claim 1, wherein after said obtaining the input voltages for the M voltage input ports to obtain a first set of voltages comprising M input voltages, the method further comprises:

sending a voltage output stopping command to the N batteries;

and if at least one difference value in the M second difference values is smaller than a second preset difference value threshold value, determining that at least one battery is not connected with the communication port of the inverter.

6. The method of claim 1, wherein after said sending said voltage output command to a kth cell of said N cells and sending a stop voltage output command to remaining cells of said N cells, said method further comprises:

if the highest input voltage is smaller than the power-down threshold value of the inverter, determining that the Kth battery is not connected to the voltage input port of the inverter;

7. An inverter, characterized by comprising:

a communication port connected to the battery;

a voltage input port connected to the battery;

at least one processor and a memory communicatively coupled to the at least one processor, the memory storing instructions executable by the at least one processor to enable the at least one processor to perform the method of any of claims 1-6.

8. An energy storage system, comprising: a battery and the inverter of claim 7;

9. A non-transitory computer-readable storage medium storing computer-executable instructions that, when executed by a processor, cause the processor to perform the method of any one of claims 1-6.