A split energy storage system pairing method, pairing system and storage medium

Abstract

The application provides a split energy storage system pairing method, a pairing system and a storage medium. The pairing method comprises the following steps: assigning a switching frequency to each inverter based on the rated working frequency of each inverter; controlling the inverter to be paired to run in no-load mode at the assigned switching frequency, so that each inverter generates a current ripple on the corresponding direct-current power line; controlling each battery pack to sample the current signal on the direct-current power line and obtain a current signal period; when the current signal period obtained by any battery pack meets a preset condition and lasts for a preset time, sending battery matching frame information carrying a target frequency to a communication bus by the battery pack; controlling each inverter to receive the battery matching frame information; and when it is judged that the switching frequency of any inverter when running and the target frequency in the obtained battery matching frame information match, controlling the inverter to send an inverter matching completion frame information to the communication bus. The present scheme realizes accurate pairing between the battery pack and the inverter.

Description

Technical Field

[0001] This invention relates to the field of power energy storage technology, and in particular to a pairing method, pairing system and storage medium for a split-type energy storage system. Background Technology

[0002] Currently, energy storage systems are commonly used to store excess electrical energy and release it when needed, making them an important component of the power system. Energy storage systems are generally divided into two types: integrated and separate. In an integrated energy storage system, the battery pack and inverter are bundled together. In a separate energy storage system, the battery pack and inverter are set up independently, without a fixed binding relationship between them, and are only electrically connected through DC power lines during system components or operation.

[0003] In common split-type energy storage systems, energy storage units utilize independent battery packs and inverters, with system capacity expanded through parallel connections. Each energy storage unit requires pairing before use to ensure proper matching and communication between the inverter and battery pack. Existing pairing methods typically employ point-to-point communication, where each inverter and its corresponding battery pack are identified and paired via a dedicated communication line. However, this approach not only requires additional communication lines, increasing installation and wiring complexity, but also limits the flexible installation and expansion of battery packs, which is particularly inconvenient in split-type energy storage systems.

[0004] Existing technologies also employ methods such as DIP switches, communication line transmission protocols, and BMS (Battery Management System) adaptation to achieve pairing and switching between inverters and battery packs. These methods typically involve additional hardware and software configurations, are cumbersome, and have poor system scalability. Especially in complex application scenarios involving multiple battery packs and multiple inverters in parallel, they still cannot achieve efficient and reliable automatic pairing. Therefore, existing technologies struggle to provide an automatic pairing solution in split-type energy storage systems that ensures pairing accuracy while simplifying wiring and installation. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides an improved pairing method that achieves accurate pairing between battery packs and inverters. It does not rely on cumbersome manual configuration, dedicated point-to-point communication lines, or complex hardware structures. It enables efficient and accurate pairing in application scenarios with multiple battery packs and multiple inverters connected in parallel, and has good scalability, ease of deployment, and operational reliability. It is suitable for the large-scale application of split-type energy storage systems.

[0006] According to a first aspect of the present invention, a pairing method for a split-type energy storage system is provided, the split-type energy storage system comprising multiple energy storage units communicating via a bus, each energy storage unit comprising a group of battery packs and an inverter connected via a DC power line, the pairing method comprising:

[0007] Based on the rated operating frequency of each inverter, different switching frequencies are assigned to each inverter.

[0008] The inverters to be paired are controlled to operate under no-load conditions at the assigned switching frequency, so that each inverter generates current ripple on the corresponding DC power line.

[0009] Each of the battery packs is controlled to sample the current signal on the connected DC power line to obtain the current signal period;

[0010] When the current signal period acquired by any of the battery packs meets the preset conditions and lasts for a preset time, the battery pack sends battery matching frame information carrying the target frequency to the communication bus, wherein the target frequency matches the current signal period.

[0011] Each inverter is controlled to receive the battery matching frame information on the communication bus;

[0012] When it is determined that the switching frequency of any of the inverters is matched with the target frequency in the acquired battery matching frame information, the inverter is controlled to send an inverter matching completion frame information carrying matching battery pack information and used to verify the battery matching frame information to the communication bus.

[0013] In some possible embodiments, different switching frequencies are assigned to each inverter based on its rated operating frequency, including:

[0014] Obtain the rated operating frequency f of each inverter. n The detection error threshold T of the battery pack for the current ripple period t ;

[0015] At the rated operating frequency f of the inverter n Based on this, a set of period intervals is constructed that are at least equal to the detection error threshold T. t Twice the candidate switching frequency;

[0016] According to the address order of each inverter, different switching frequencies are selected sequentially from the candidate switching frequencies and assigned to each inverter.

[0017] In some possible embodiments, the switching frequency f allocated to each of the inverters swi Satisfy frequency limiting condition: f min ≤f swi ≤f max f min f is the rated operating frequency of the inverter. n α times, f max f is the rated operating frequency of the inverter.n β times, where 0 < α < 1, β ≥ 1.

[0018] In some possible embodiments, when the current signal period acquired by any of the battery packs meets a preset condition and lasts for a preset time, the battery pack sends battery matching frame information carrying the target frequency to the communication bus, including:

[0019] Get Battery Pack k The signal period T of the sampled current signal k ;

[0020] Obtain the Inv value of any inverter operating under no-load conditions. k The switching frequency f swk ;

[0021] During the signal period T k When preset conditions are met and the preset time is maintained, the battery pack Bat... k Send a signal carrying period T to the communication bus k The battery frame information matching the target frequency is specified, and the preset condition is: 1 / f swk -T t <T k <1 / f swk +T t T t This is the detection error threshold.

[0022] In some possible embodiments, determining that the switching frequency of any of the inverters during operation matches a target frequency in an acquired battery matching frame information includes:

[0023] Get the inverter Inv to be matched i The switching frequency f swi ;

[0024] Get the battery pack to be matched. j The target period T corresponding to the target frequency in the battery matching frame information j ;

[0025] In the inverter to be matched Inv i and battery pack Bat j When the matching conditions are met, the inverter Inv i and battery pack Bat j Pairing successful, the matching condition is: 1 / f swi -T t <T j <1 / f swi +T t .

[0026] In some possible embodiments, controlling each of the battery packs to sample the current signal on the connected DC power line to obtain the current signal period includes:

[0027] The current in the DC power line where the battery pack is located is continuously sampled to obtain multiple sampling points used to represent the measured current value;

[0028] The instantaneous rise slope of each sampling point is calculated based on adjacent sampling points;

[0029] When the instantaneous rising slopes before and after the current sampling point are all positive, record the instantaneous rising slopes corresponding to the current sampling point, and take the average value of the recorded instantaneous rising slopes to obtain the average rising slope.

[0030] When the average rising slope is within the theoretical rising slope range, the current signal period is calculated based on the zero-crossing point, and the target frequency is calculated based on the current signal period.

[0031] In some possible embodiments, before the step of continuously sampling the current in the DC power line where the battery pack is located to obtain multiple sampling points for representing the measured current value, the method further includes the following step:

[0032] The current in the DC power line where the battery pack is located is initially sampled, and the initial period of the current signal is calculated based on the initially sampled current signal.

[0033] In the step of continuously sampling the current of the DC power line where the battery pack is located to obtain multiple sampling points for representing the measured current value, the sampling interval is a preset proportion of the initial period, and the preset proportion is any value between 1 / 20 and 1 / 5.

[0034] In some possible embodiments, the battery matching frame information includes a matching function code, a matching check code, a set of communication addresses for each inverter, a first communication address for the battery pack, and the acquired target frequency;

[0035] The inverter matching completion frame information includes a matching completion function code, the address of the energy storage unit to which the inverter belongs, the first communication address of the battery pack that matches the inverter, the second communication address of the inverter, and the switching frequency allocated to the inverter.

[0036] Before the inverter that sends the inverter matching completion frame information matches the battery pack, the matching check code is the first value.

[0037] In some possible embodiments, when sending the inverter matching completion frame information to the communication bus, the pairing method further includes a matching verification process using the inverter matching completion frame information:

[0038] Send the inverter matching completion frame information to the battery pack that matches the first communication address in the inverter matching completion frame information;

[0039] When the battery pack receives the inverter matching completion frame information, it adjusts the matching check code information of the battery matching frame information to obtain the battery matching completion frame information. The matching check code in the battery matching completion frame information is changed from the first value to the encoding address to which the battery pack belongs.

[0040] The matching verification is successful when the value of the matching check code in the battery matching completion frame information matches the address of the energy storage unit to which the inverter belongs in the inverter matching completion frame information.

[0041] According to a second aspect of the present invention, a pairing system is provided, comprising a processor and a memory, wherein the memory stores a program that is loaded and executed by the processor to implement the split-type energy storage system pairing method as described above.

[0042] According to a third aspect of the present invention, a computer storage medium is provided, the computer storage medium being capable of storing program instructions, which, when executed by a processor, can implement the aforementioned split-type energy storage system pairing method.

[0043] According to the present invention, different switching frequencies are allocated to each inverter based on the inverter's rated operating frequency, and each inverter is controlled to operate under no-load conditions at the allocated switching frequency. This generates current ripple on the DC power line 1, and the battery pack samples the current signal on the DC power line to obtain the current signal period. After the current signal period of any battery pack meets a preset condition and lasts for a preset time, that battery pack sends a battery matching frame information. When the switching frequency of any inverter during operation matches the target frequency in the obtained battery matching frame information, that inverter sends an inverter matching completion frame information, thereby achieving automatic identification and pairing between the battery pack and the inverter. Through the above technical solution, the present invention eliminates the need for a dedicated communication link or manual configuration for each energy storage unit to establish a pairing relationship between the battery pack and the inverter, significantly reducing system wiring complexity and deployment costs, and improving system installation efficiency and scalability. Simultaneously, by utilizing the naturally occurring current ripple in the DC power line as an identification carrier, pairing information transmission between the battery pack and the inverter is achieved, avoiding dependence on additional hardware modules. Furthermore, since each inverter uses a different switching frequency during the pairing phase, the resulting current ripple has good distinguishability in the frequency domain. Combined with the frequency detection and time characteristic parameter determination mechanism on the battery pack side, it can effectively reduce the probability of mismatch and improve the accuracy and stability of the pairing process. It is especially suitable for the scenario of a split-type energy storage system with multiple battery packs and multiple inverters connected in parallel.

[0044] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Attached Figure Description

[0045] Figure 1 A schematic flowchart of a pairing method for a split-type energy storage system according to an embodiment of the present invention is shown;

[0046] Figure 2 A schematic structural diagram of a split-type energy storage system according to an embodiment of the present invention is shown;

[0047] Figure 3 It shows Figure 1 A schematic flowchart of the method for allocating different switching frequencies to each inverter in step S100.

[0048] Figure 4 A circuit topology diagram of an energy storage unit according to an embodiment of the present invention is shown;

[0049] Figure 5 It shows Figure 1 A schematic flowchart of step S300 is shown;

[0050] Figure 6 It shows Figure 1 A schematic flowchart of step S400 is shown;

[0051] Figure 7 The diagram shows the format of the battery matching frame, inverter matching completion frame, and battery completion frame when a battery pack and an inverter have successfully completed matching and matching verification according to an embodiment of the present invention.

[0052] Figure 8 It shows Figure 1 A schematic flowchart of step S600 is shown;

[0053] Figure 9 A schematic flowchart illustrating the process of performing frame information matching verification using inverter matching according to an embodiment of the present invention is shown.

[0054] Figure 10 A schematic structural diagram of a computer device according to an embodiment of the present invention is shown;

[0055] In the diagram: 1-DC power line, 2-communication bus, 3-AC bus. Detailed Implementation

[0056] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0057] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0058] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0059] In split-type energy storage systems, to achieve pairing between the battery pack and the inverter, the art typically employs methods such as DIP switches, communication line transmission protocols, BMS (Battery Management System), host computer configuration, or manual or semi-automatic configuration at the software level. Under this technical approach, improvements by those skilled in the art primarily focus on simplifying communication protocols, reducing manual configuration steps, improving communication reliability, and reducing the risk of mismatches—that is, optimizing the complexity of the communication and control systems, without departing from the traditional approach centered on communication configuration. This long-established technological development path has gradually led to an implicit technical bias in the field, namely, the belief that pairing problems should be solved by adding or optimizing communication mechanisms.

[0060] Meanwhile, in the field of energy storage systems, current ripple on DC power lines is generally considered a negative factor, which can cause additional losses, electromagnetic interference and measurement errors. Therefore, existing technologies are generally committed to suppressing or weakening current ripple through filtering, control algorithm optimization and other methods.

[0061] Therefore, within the aforementioned technical understanding framework, those skilled in the art would typically not consider current ripple as an information carrier, much less use it to achieve pairing identification between the battery pack and the inverter.

[0062] However, the inventors of this application break through the aforementioned technical framework and reversely utilize current ripple as the basis for matching between the battery pack and the inverter. This inventive concept overcomes the technical bias in the field that current ripple must be suppressed, thereby achieving reliable matching between the battery pack and the inverter without the need for additional communication cables or manual configuration.

[0063] Figure 1 A schematic flowchart of a pairing method for a split-type energy storage system according to an embodiment of the present invention is shown. Figure 2 A schematic structural diagram of a split-type energy storage system according to an embodiment of the present invention is shown. This split-type energy storage system can be applied to residential energy storage systems, commercial and industrial energy storage systems, microgrids, and distributed energy systems, enabling automatic pairing between inverters and battery packs in scenarios where multiple battery packs and multiple inverters are connected in parallel. Figure 2 As shown, the split-type energy storage system includes multiple energy storage units that communicate via a bus. Each energy storage unit includes a battery pack and an inverter connected via a DC power line 1. Figure 1 In the embodiment shown, the pairing method for the split-type energy storage system includes the following steps S100 to S600.

[0064] Step S100: Based on the rated operating frequency of each inverter, assign different switching frequencies to each inverter.

[0065] The rated operating frequency refers to the operating frequency at which the system is relatively stable and performs well when the inverter is working. The rated operating frequencies of each inverter are the same or similar under normal operating conditions to meet uniform energy conversion performance and electromagnetic compatibility design requirements. However, during the initial deployment or expansion phase of the system, it is necessary to achieve a one-to-one pairing between multiple battery packs and multiple inverters. Therefore, this embodiment of the invention temporarily configures the switching frequency of each inverter during the pairing phase, allowing different inverters to operate at different switching frequencies. Through this configuration, different inverters generate current ripples with different frequency characteristics on their respective DC power lines 1, thereby providing distinguishable physical identifiers for subsequent identification and pairing based on current ripple characteristics.

[0066] Figure 3 It shows Figure 1 The diagram shows a schematic flowchart of the method for allocating different switching frequencies to each inverter in step S100. Figure 3 In the illustrated embodiment, step S100 may include steps S101 to S103.

[0067] Step S101: Obtain the rated operating frequency f of each inverter nThe detection error threshold T of the battery pack for the current ripple cycle t .

[0068] Among them, the detection error threshold T t The minimum distinguishable time interval for the battery pack to differentiate between two different current ripple cycles is determined by the battery pack's sampling performance, timing accuracy, and signal processing capabilities. Due to the influence of factors such as analog-to-digital conversion accuracy, sampling frequency, timing resolution, current sensing accuracy, noise interference, and digital filtering algorithms, the battery pack inevitably has a certain detection error in measuring the current ripple cycle. To ensure sufficient distinguishability of the current ripples generated by different inverters on DC power line 1 at the battery pack side, thereby avoiding misidentification and mispairing, this embodiment of the invention introduces a detection error threshold T. t .

[0069] Step S102: Using the inverter's rated operating frequency f n Based on this, construct a set of period intervals that are at least the detection error threshold T. t Twice the candidate switching frequency.

[0070] Because the detection error threshold T of the current ripple cycle in the battery pack exists... t To avoid confusion of current ripple generated by different inverters on the battery pack side, this embodiment of the invention uses period difference as the distinguishing criterion to construct candidate switching frequencies.

[0071] In this embodiment of the invention, after the inverters are paired, they need to operate at the rated switching frequency. Therefore, when allocating switching frequencies for pairing to each inverter, it is necessary to avoid the rated switching frequency, f. n With period T n The relationship is: T n =1 / f n Furthermore, to prevent matching errors caused by the switching frequency interval between two different inverters being too close, a preset frequency value is given for the switching frequency interval between different inverters. This preset frequency value can be twice T. t Specifically, the constructed candidate switching frequencies can be, for example, f sw1 =1 / (1 / f n +2T t ), f sw2 =1 / (1 / f n +4T t ), f sw3 =1 / (1 / f n +6T t Alternatively, the constructed multiple candidate switching frequencies can be, for example, f sw1 =1 / (1 / fn -2T t ), f sw2 =1 / (1 / f n +2T t ), f sw3 =1 / (1 / f n +6T t ).

[0072] It is worth noting that, assuming this distributed energy storage system comprises N energy storage units, and each of these N units contains N battery packs, the N inverters are selected according to their addresses, with f0 selected from each. sw1 f sw2 ... f swN As their respective switching frequencies. The switching frequencies allocated to each inverter satisfy the frequency constraint condition: f min ≤f swi ≤f max f min f is the rated operating frequency of the inverter n α times, f max f is the rated operating frequency of the inverter n β times, f swi Let α be the switching frequency of the i-th inverter sorted by address, where 0 < α < 1 and β ≥ 1. This frequency constraint ensures that the amplitude of the current ripple generated by the inverter during the pairing phase is within a reasonable range suitable for detection. This avoids situations where excessively high switching frequencies result in excessively small ripple amplitudes and reduced signal-to-noise ratios, hindering reliable battery pack detection. Conversely, it avoids situations where excessively low switching frequencies lead to excessively large ripple current amplitudes, exceeding the safe operating range of the inverter and related power devices.

[0073] In some embodiments, α can be, for example, 0.2, 0.4, 0.5, 0.6, 0.8, or 0.9. β can be, for example, 1, 1.5, or 2. It is understood that the values ​​of α and β can be adjusted according to the hardware performance of the specific system, the accuracy of current sensing, and the inverter's tolerance.

[0074] Step S103: Select different switching frequencies from the candidate switching frequencies in sequence according to the address order of each inverter and assign them to each inverter.

[0075] The inverter address is a unique identifier assigned to each inverter in the system, such as a communication address or hardware serial number. This identifier determines the allocation order of each inverter, ensuring that each inverter can obtain a unique switching frequency and preventing two inverters from being assigned the same switching frequency.

[0076] During the pairing phase, the switching frequency of each inverter remains unchanged after the allocation process until pairing is complete.

[0077] Step S200: Control the inverters to be paired to operate under no-load conditions at the assigned switching frequency, so that each inverter generates current ripple on the corresponding DC power line.

[0078] Figure 4 A circuit topology diagram of an energy storage unit according to an embodiment of the present invention is shown. Figure 4 As shown, the battery pack in the energy storage unit is connected to the inverter via DC power line 1. The current ripple generated by the inverter during no-load operation is: , among which, U bat T is the battery voltage. on Where L is the on-time of the inverter switching transistor, and L is the inductance of the inverter circuit, such as... Figure 4 L1.

[0079] In this step, controlling the inverter to operate under no-load conditions aims to avoid the superimposed effects of load impedance changes and external disturbances on the DC-side current waveform. This prevents these factors from affecting the amplitude, phase, and periodic characteristics of the current ripple, and avoids masking or distortion of the current ripple characteristics caused by the switching frequency. Therefore, by controlling the inverter to operate under no-load conditions, it can be ensured that the generated current ripple is mainly dominated by the inverter's switching actions, making the periodic characteristics of the current ripple more stable, predictable, and distinguishable, which is beneficial for the battery pack to accurately detect and identify the ripple frequency.

[0080] Step S300: Control each battery pack to sample the current signal on the connected DC power line to obtain the current signal period.

[0081] It should be noted that the current signal period refers to the periodic characteristic time parameter obtained after performing time-domain analysis on the current signal, used to characterize the periodic variation trend that may exist in the current signal. Specifically, the original sampling signal of the battery pack may include non-target components such as electromagnetic interference, sampling noise, and control fluctuations. Therefore, if the period is calculated directly based on the original sampling data, the period identification may be unstable due to the influence of the above-mentioned non-target components, resulting in the inability to obtain an accurate current signal period.

[0082] To address the aforementioned issues, in an optional embodiment, such as Figure 5 As shown, step S300 includes steps S301 to S304.

[0083] Step S301: Continuously sample the current of the DC power line where the battery pack is located to obtain multiple sampling points used to represent the measured current value.

[0084] In an optional embodiment, to ensure accurate capture of the current signal periodic characteristics, step S301 further includes: performing preliminary sampling of the current in the DC power line 1 where the battery pack is located, and calculating the initial period of the current signal based on the preliminary sampled current signal. This preliminary sampling step obtains a rough estimate of the current signal period by rapidly measuring the current in the DC power line 1 within a short period of time, which serves as a reference for subsequent fine sampling.

[0085] In step S301, the sampling interval is a preset proportion of the initial period, and the preset proportion is any value between 1 / 20 and 1 / 5, such as 1 / 20, 1 / 10, or 1 / 5. By setting the sampling interval to a certain proportion of the initial period, a sufficient number of sampling points can be obtained within one current signal cycle to calculate the instantaneous rise slope and periodic characteristics, thereby improving the accuracy and reliability of current signal period identification.

[0086] Step S302: Calculate the instantaneous rise slope of each sampling point based on adjacent sampling points.

[0087] The instantaneous upward slope is calculated based on adjacent sampling points i. L (n) and i L The current difference between (n+1) is calculated by dividing by the sampling interval Δt, i.e., by the following formula:

[0088] ;

[0089] Where k(n) is the instantaneous rising slope of the nth sampling point, i L (n) represents the current value at the nth sampling point, i L (n+1) represents the current value at the (n+1)th sampling point, and Δt represents the sampling interval.

[0090] Step S303: When multiple instantaneous rising slopes before and after the current sampling point are all positive, record the instantaneous rising slope corresponding to the current sampling point, and take the average value of the recorded instantaneous rising slopes to obtain the average rising slope.

[0091] In this step, to accurately identify the effective rising edge of the current signal caused by the inverter switching action from the sampled current signal, rather than a spurious rising edge caused by noise, transient disturbances, or occasional fluctuations, the continuity and sign consistency of the instantaneous rising slope are judged. For example, taking the nth sampling point as the current sampling point, if the following conditions are met: k(n-1)>0, k(n)>0 and k(n+1)>0, then only the instantaneous rising slope k(n) corresponding to the current sampling point is recorded, and it is taken as an effective current signal rising edge slope sample, denoted as: K u (x)=k(n), where x represents the xth valid rising edge detected.

[0092] In a complete current signal detection process, the slopes of multiple consecutively detected effective rising edges are statistically analyzed. Assuming a total of N effective rising edge slope samples are recorded, the average rising slope is calculated using the following formula. :

[0093] .

[0094] By ensuring that the instantaneous rise slopes before and after the current sampling point are all positive, isolated slope abrupt changes caused by noise disturbances, sampling jitter, or transient interference can be effectively eliminated, avoiding misjudging non-current signal characteristics as true current rising edges, thereby improving the reliability of rising edge detection. Furthermore, by recording only the instantaneous rise slopes corresponding to sampling points that satisfy the above continuous rise condition and averaging the slopes of multiple detected rising edges, random errors, sampling jitter, and local noise interference in a single measurement can be effectively suppressed, resulting in more representative current signal rising characteristics.

[0095] Step S304: When the average rising slope is within the theoretical rising slope range, calculate the current signal period based on the zero crossing point, and calculate the target frequency based on the current signal period.

[0096] The theoretical rising slope range is predetermined based on the inverter's operating parameters and DC-side circuit characteristics. It corresponds to the theoretical rate of change range of the current signal normally generated on DC power line 1 by the inverter's switching actions. When the average rising slope falls within this theoretical rising slope range, it indicates that the current sampled signal is mainly caused by the inverter's switching behavior, rather than by noise, transient interference, or non-periodic disturbances. Therefore, the periodically changing current signal can be considered to have high reliability.

[0097] By obtaining the time interval between two adjacent zero-crossing points in the same direction, this time interval is determined as one period T of the current signal. The target frequency f of the current signal is calculated according to the following formula: f = 1 / T.

[0098] Step S400: When the current signal period acquired by any battery pack meets the preset conditions and lasts for a preset time, the battery pack sends battery matching frame information carrying the target frequency to the communication bus. The target frequency matches the current signal period.

[0099] Figure 6 It shows Figure 1 The schematic flowchart for step S400 is shown. Figure 6 As shown, step S400 includes steps S401 to S403.

[0100] Step S401: Obtain the battery pack (Bat) kThe signal period T of the sampled current signal k ;

[0101] Step S402: Obtain the Inv value of any inverter operating under no-load conditions. k The switching frequency f swk ;

[0102] Step S403: During signal period T k When preset conditions are met and the preset time is maintained, the battery pack (Bat) will activate. k Send a signal carrying period T to the communication bus k Battery matching frame information matching the target frequency, with the preset condition being: 1 / f swk -T t <T k <1 / f swk +T t T t This is the detection error threshold.

[0103] In this embodiment, by using the battery pack Bat k The period T of the detected current signal k The switching cycle 1 / fsw of any inverter operating under no-load conditions k When the above preset conditions are met, it indicates that the battery pack (Bat) is functioning correctly. k The current information collected on the DC power line conforms to the characteristics of a ripple signal, indicating that the battery pack... k There should be a valid pairing relationship with a certain inverter, but the battery pack... k Which inverter to match requires further determination. Furthermore, to avoid false triggering due to transient interference, electromagnetic noise, or sampling jitter, this embodiment sets the matching state to persist for a preset time before triggering the broadcast behavior, i.e., sending battery matching frame information, thereby improving the stability and reliability of the matching judgment. In some optional embodiments, this preset time can be, for example, 0.5s, 1s, or 1.5s, or any other value between 0.5s and 1.5s.

[0104] exist Figure 7 In the embodiment shown, the battery matching frame information includes the matching function code, the matching check code, the communication address set of each inverter, the first communication address of the battery pack, the obtained target frequency, and the factory code of the battery pack.

[0105] Before the inverter sending the inverter matching completion frame information matches the battery pack, the matching check code is the first value, i.e., the initial value of the matching check code. The matching function code indicates that a battery pack that sent a battery matching frame information received a current signal on DC power line 1 that is similar to ripple information. Further matching operation is needed to determine which inverter's ripple information this current signal matches. When the match is successful, it indicates that the battery pack has matched the inverter.

[0106] The matching check code is used to identify the status of the battery pack and inverter pairing process. Initially, the matching check code is the first value, indicating that the battery pack and inverter have not yet completed pairing. After successful pairing, the check code is updated to the unit address of the energy storage unit to which the battery pack belongs, used to confirm the pairing is complete; the first value can be 0. The value of the matching check code effectively determines whether the pairing between the battery pack and inverter has been successful, and the change of the matching check code is an important indicator of the pairing process. The communication address set of each inverter refers to the unique set of communication addresses for all inverters in the system. Each inverter has a unique communication address in the system, used to identify its identity in the communication network.

[0107] The communication address set stores the communication addresses of all inverters, ensuring that all online inverters can receive battery matching frame information sent by the battery pack. When an inverter receives a battery matching frame information from a battery pack, it compares its own switching frequency with the target frequency stored in the battery matching frame information to determine if a match is possible.

[0108] The battery pack's first communication address is the unique communication address assigned to it within the system. This address allows the inverter to communicate precisely with the battery pack, sending and receiving matching information. The factory code is a unique identifier or identification code for each battery pack and inverter, typically assigned by the manufacturer at the time of product shipment. This factory code identifies the battery pack or inverter's model, production batch, and other information, ensuring the device can be uniquely identified within the system.

[0109] Figure 7 This illustrates a battery matching frame message sent by battery pack A. For example... Figure 7As shown, for the battery matching frame information sent by battery pack A, the matching function code field is filled with 0xxx, indicating that it detected a current signal similar to ripple information on the DC power line. Further matching is needed to determine which inverter's ripple information this current signal matches. The matching check code for the battery matching frame information is the first value, which can be 0. The communication address set field for battery pack A's battery matching frame information contains the communication address set of all inverters, with a value of 0xff, indicating that the battery pack broadcasts the battery matching frame information to all inverters. The first communication address field for battery pack A's battery matching frame information stores battery pack A's own communication address, 0x01. Battery pack A detects current information on the DC power line and obtains the target frequency value for this current information. The target frequency value is 0x14, indicating that the corresponding frequency of the detected periodically changing current signal is 20kHz. The battery pack's factory code is 0x202511211044.

[0110] Step S500: Control each inverter to receive battery matching frame information on the communication bus.

[0111] It should be explained that communication bus 2 is a shared communication channel for all energy storage units in the system. All inverters are connected to communication bus 2 and are in listening mode. When any battery pack sends a battery matching frame information, all inverters can receive the frame information through communication bus 2. By adopting a bus broadcast method, it is possible to achieve synchronous perception of battery packs to be matched by all inverters without having to establish a one-to-one communication relationship between the battery pack and the inverter in advance.

[0112] S600: When it is determined that the switching frequency of any inverter during operation matches the target frequency in the acquired battery matching frame information, the inverter is controlled to send an inverter matching completion frame information carrying matching battery pack information and used to verify the battery matching frame information to the communication bus.

[0113] Figure 8 It shows Figure 1 The schematic flowchart of step S600 is shown. Figure 8 As shown, the process of determining whether the switching frequency of any inverter during operation matches the ripple frequency in the acquired battery matching frame information includes steps S601 to S603.

[0114] Step S601: Obtain the inverter Inv to be matched i The switching frequency f swi ;

[0115] Step S602: Obtain the battery pack to be matched. j The target period T corresponding to the target frequency in the battery matching frame informationj ;

[0116] Step S603: In the inverter to be matched Inv i and battery pack Bat j When the matching conditions are met, the inverter Inv i and battery pack Bat j Pairing successful, matching condition: 1 / f swi -T t <T j <1 / f swi +T t .

[0117] Understandably, the battery pack to be matched (Bat) j After the sampled current information meets the above preset conditions, its battery matching frame information is broadcast. When an inverter Inv... i and battery pack Bat j Meeting the aforementioned matching conditions indicates that the inverter Inv i and battery pack Bat j Initial pairing is complete; at this point, the inverter Inv... i It will broadcast its inverter matching completion frame information.

[0118] Figure 7 The diagram also illustrates an inverter matching completion frame sent by inverter B. This frame includes a matching completion function code, the address of the energy storage unit to which the inverter belongs, the first communication address of the battery pack matched with the inverter, the second communication address of the inverter, the switching frequency assigned to the inverter, and the inverter's factory code. The matching completion function code indicates that a battery pack sending a battery matching frame has successfully paired with an inverter operating under no-load conditions. The second communication address of the matching completion frame is the inverter's communication address, used to identify the inverter that sent the matching completion frame, enabling the battery pack to distinguish between different inverters and perform corresponding pairings.

[0119] When inverter B has not completed pairing, the information in each column of the inverter pairing completion frame can be empty or have initial values. For example... Figure 7 As shown, the matching completion function code of the inverter matching completion frame information is 0x33, indicating that when the target frequency of the battery matching frame information sent by the aforementioned battery pack A is compared with the switching frequency allocated to the inverter B, and the aforementioned matching conditions are met, that is, the battery pack A and the inverter B complete the initial pairing process.

[0120] When battery pack A and inverter B are matched, the value of the energy storage unit address field in the inverter matching completion frame information of inverter B is 1, and the first communication address of the inverter matching completion frame information of inverter B is the communication address of the matched battery pack A, such as 0x01. Subsequently, inverter B can send the inverter matching completion frame to battery pack A through the first communication address 0x01. For the inverter matching completion frame information of inverter B, the second communication address field stores the communication address of inverter B itself, 0x03. The switching frequency field stores the switching frequency 0x14 allocated to inverter B during no-load operation. 0x14 can be represented as a switching frequency of 20kHz. The factory code of inverter B is 0x202511211122.

[0121] Figure 9 A schematic flowchart illustrating the process of performing frame information matching and verification using inverter matching according to an embodiment of the present invention is shown. Figure 9 As shown, the pairing method may further include steps S700 to S900.

[0122] Step 700: Send the inverter matching completion frame information to the battery pack that matches the first communication address in the inverter matching completion frame information.

[0123] The first communication address is the address used by the inverter to identify the target battery pack during the pairing process, such as a COM address or a unique identifier in the bus system.

[0124] Step S800: When the battery pack receives the inverter matching completion frame information, the matching check code information of the battery matching frame information is adjusted to obtain the battery matching completion frame information. The matching check code in the battery matching completion frame information is changed from the first value to the encoding address to which the battery pack belongs.

[0125] The battery pairing completion frame information includes a pairing completion function code, a pairing verification code, a target address, a first communication address, a target frequency, and a factory code. The pairing completion function code is derived from changes to the function code to be paired. The target address in the battery pairing completion frame information is the second communication address of the inverter that has confirmed pairing with the battery pack, used to indicate the recipient of the battery pairing completion frame information, thus completing the final confirmation of the pairing process.

[0126] Battery pack 1 sends a battery pack matching completion frame to its unit address 1. After receiving the battery pack matching completion frame, inverter 2 switches the switching frequency to the rated operating power.

[0127] Step S900: When the value of the matching check code in the battery matching completion frame information is consistent with the address of the energy storage unit to which the inverter belongs in the inverter matching completion frame information, the matching check is successful.

[0128] Figure 7 The diagram also illustrates the battery matching completion frame sent by battery pack A after successful matching verification between battery pack A and inverter B. When inverter B receives the battery matching completion frame information from battery pack A, it compares its own switching frequency value with the target frequency of the battery matching completion frame information from battery pack A. If the aforementioned matching conditions are met, inverter B sends an inverter matching completion frame information to battery pack A via bus communication. After successful matching verification between battery pack A and inverter B, the battery matching frame information from battery pack A is transformed into a battery matching completion frame information. The specific transformation process is as follows:

[0129] The battery matching frame information of battery pack A changes from the matching completion function code 0xxx to the matching completion function code 0x33, which is consistent with the matching completion function code in the inverter matching completion frame. This indicates that battery pack A and inverter B have formed a preliminary pairing relationship and require further matching verification. The matching verification code of the battery matching frame information of battery pack A changes from the initial value 0 to the coded address 1 of the energy storage unit to which battery pack A belongs. When this coded address 1 is the same as the value of the energy storage unit address in the inverter matching completion frame information of inverter B, it indicates that the matching verification is successful. Subsequently, the battery matching frame information of battery pack A changes from the original communication address set 0xff representing all inverters to the communication address of inverter B that is matched with battery pack A. Figure 7 It can also be seen that the second communication address of the inverter matching completion frame of inverter B and the target address of the battery matching completion frame information of battery pack A are the same; at the same time, the target frequency value of the battery matching completion frame 0x14 remains unchanged; the factory code of battery pack A is 0x202511211044.

[0130] In this step, the battery pack establishes a preliminary pairing relationship with the inverter that sent the inverter matching completion frame by updating the matching completion function code in the battery matching completion frame to match the matching completion function code in the inverter matching completion frame. Furthermore, the matching verification code in the battery matching completion frame information is updated from its initial value to the coded address of the energy storage unit to which the battery pack belongs. This coded address is then compared with the energy storage unit address in the inverter matching completion frame information to confirm the validity of the pairing result. After successful matching verification, the set of communication addresses representing all inverters in the battery matching completion frame information is updated to the specific communication address of the inverter that matches the battery pack, confirming the pairing relationship between the battery pack and the inverter. After completing this step, the battery pack exits the matching detection mode and enters the normal operation mode, ready to communicate and exchange data with the paired inverter.

[0131] The solution of this invention allocates different switching frequencies to each inverter based on the inverter's rated operating frequency, and controls each inverter to operate under no-load conditions at the allocated switching frequency. This generates current ripple on the DC power line 1, and the battery pack samples the current signal on the DC power line to obtain the current signal period. After the current signal period of any battery pack meets a preset condition and lasts for a preset time, that battery pack sends a battery matching frame information. When the switching frequency of any inverter during operation matches the target frequency in the obtained battery matching frame information, that inverter sends an inverter matching completion frame information. Subsequent consistency matching verification between the battery pack and the inverter is then performed, thereby achieving automatic identification and pairing between the battery pack and the inverter. Through the above technical solution, this invention eliminates the need to set up a dedicated communication link for each energy storage unit or perform manual configuration to establish the pairing relationship between the battery pack and the inverter, significantly reducing system wiring complexity and deployment costs, and improving system installation efficiency and scalability. Meanwhile, by utilizing the inherent current ripple in the DC power line 1 as an identification carrier, pairing information transmission between the battery pack and the inverter is achieved, avoiding dependence on additional hardware modules. Furthermore, since each inverter uses a different switching frequency during the pairing phase, the resulting current ripple has good distinguishability in the frequency domain. Combined with the frequency detection and time characteristic parameter determination mechanism on the battery pack side, this effectively reduces the probability of mismatch and improves the accuracy and stability of the pairing process, making it particularly suitable for split-type energy storage systems with multiple battery packs and inverters connected in parallel.

[0132] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 10 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores relevant data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network. When the computer program is executed by the processor, it implements a pairing method for a split-type energy storage system.

[0133] Those skilled in the art will understand that Figure 10The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0134] In one embodiment, a pairing system is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0135] In one embodiment, a computer-readable storage medium is provided having program instructions stored thereon that, when executed by a processor, can implement the steps in the above method embodiments.

[0136] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or 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 invention as described above, which are not provided in the details; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for pairing split-type energy storage systems, characterized in that, The split-type energy storage system includes multiple energy storage units that communicate via a bus. Each energy storage unit includes a set of battery packs and an inverter connected via a DC power line. The pairing method includes: Based on the rated operating frequency of each inverter, different switching frequencies are assigned to each inverter. The inverters to be paired are controlled to operate under no-load conditions at the assigned switching frequency, so that each inverter generates current ripple on the corresponding DC power line. Each of the battery packs is controlled to sample the current signal on the connected DC power line to obtain the current signal period; When the current signal period acquired by any of the battery packs meets the preset conditions and lasts for a preset time, the battery pack sends battery matching frame information carrying the target frequency to the communication bus, wherein the target frequency matches the current signal period. Specifically, when the current signal period acquired by any of the battery packs meets a preset condition and lasts for a preset time, the battery pack sends battery matching frame information carrying the target frequency to the communication bus, including: acquiring battery pack information. k The sampling current signal period T k ; Obtain the Inv value of any inverter operating under no-load conditions i The switching frequency f swi During the signal period T k When preset conditions are met and the preset time is maintained, the battery pack Bat... k Send a signal carrying period T to the communication bus k The battery frame information matching the target frequency is specified, and the preset condition is: 1 / f swi -T t <T k <1 / f swi +T t T t This is the detection error threshold; Each inverter is controlled to receive the battery matching frame information on the communication bus; When it is determined that the switching frequency of any of the inverters is matched with the target frequency in the battery matching frame information, the inverter is controlled to send an inverter matching completion frame information carrying matching battery pack information and used to verify the battery matching frame information to the communication bus. The determination that the switching frequency of any of the inverters during operation matches the target frequency in the acquired battery matching frame information includes: obtaining the inverter Inv to be matched. i The switching frequency f swi ; Get the battery pack to be matched. j The target period T corresponding to the target frequency in the battery matching frame information k In the inverter to be matched Inv i and battery pack Bat j When the matching conditions are met, the inverter Inv i and battery pack Bat j Pairing successful, the matching condition is: 1 / f swi -T t <T j <1 / f swi +T t .

2. The pairing method according to claim 1, characterized in that, Based on the rated operating frequency of each inverter, different switching frequencies are assigned to each inverter, including: Obtain the rated operating frequency f of each inverter. n and the detection error threshold T of the battery pack for the current signal period t ; At the rated operating frequency f of the inverter n Based on this, a set of period intervals is constructed that are at least equal to the detection error threshold T. t Twice the candidate switching frequency; According to the address order of each inverter, different switching frequencies are selected sequentially from the candidate switching frequencies and assigned to each inverter.

3. The pairing method according to claim 2, characterized in that, The switching frequency f allocated to each of the inverters swi Satisfy frequency limiting condition: f min ≤f swi ≤f max f min f is the rated operating frequency of the inverter. n α times, f max f is the rated operating frequency of the inverter. n β times, where 0 < α < 1, β ≥ 1.

4. The pairing method according to any one of claims 1-3, characterized in that, Controlling each of the battery packs to sample the current signal on the connected DC power line to obtain the current signal period includes: The current in the DC power line where the battery pack is located is continuously sampled to obtain multiple sampling points used to represent the measured current value; The instantaneous rise slope of each sampling point is calculated based on adjacent sampling points; When the instantaneous rising slopes before and after the current sampling point are all positive, record the instantaneous rising slopes corresponding to the current sampling point, and take the average value of the recorded instantaneous rising slopes to obtain the average rising slope. When the average rising slope is within the theoretical rising slope range, the current signal period is calculated based on the zero-crossing point, and the target frequency is calculated based on the current signal period.

5. The pairing method according to claim 4, characterized in that, Before the step of continuously sampling the current of the DC power line where the battery pack is located to obtain multiple sampling points for representing the measured current value, the following step is also included: The current in the DC power line where the battery pack is located is initially sampled, and the initial period of the current signal is calculated based on the initially sampled current signal. In the step of continuously sampling the current of the DC power line where the battery pack is located to obtain multiple sampling points for representing the measured current value, the sampling interval is a preset proportion of the initial period, and the preset proportion is any value between 1 / 20 and 1 / 5.

6. The pairing method according to any one of claims 1-3 and 5, characterized in that, The battery matching frame information includes the matching function code, the matching verification code, the communication address set of each inverter, the first communication address of the battery pack, and the obtained target frequency; The inverter matching completion frame information includes a matching completion function code, the address of the energy storage unit to which the inverter belongs, the first communication address of the battery pack that matches the inverter, the second communication address of the inverter, and the switching frequency allocated to the inverter. Before the inverter that sends the inverter matching completion frame information matches the battery pack, the matching check code is the first value.

7. The pairing method according to claim 6, characterized in that, When sending the inverter matching completion frame information to the communication bus, the pairing method further includes a matching verification process using the inverter matching completion frame information: Send the inverter matching completion frame information to the battery pack that matches the first communication address in the inverter matching completion frame information; When the battery pack receives the inverter matching completion frame information, it adjusts the matching check code information of the battery matching frame information to obtain the battery matching completion frame information. The matching check code in the battery matching completion frame information is changed from the first value to the encoding address to which the battery pack belongs. The matching verification is successful when the value of the matching check code in the battery matching completion frame information matches the address of the energy storage unit to which the inverter belongs in the inverter matching completion frame information.

8. A pairing system, characterized in that, It includes a processor and a memory, wherein the memory stores a program that is loaded and executed by the processor to implement the split-type energy storage system pairing method as described in any one of claims 1-7.

9. A computer storage medium, characterized in that, The computer storage medium can store program instructions, which, when executed by a processor, can implement the split-type energy storage system pairing method as described in any one of claims 1-7.

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