A management and control method and device for a DC power supply battery pack

Abstract

The present invention relates to the field of direct current technology, and in particular to a management and control method and device for a direct current power supply battery pack. It includes: obtaining basic information of the battery pack, constructing a battery equivalent circuit model based on the basic information; identifying the overall series-parallel relationship of the battery network based on the topological structure, generating a series-parallel adjustment plan based on the series-parallel relationship, and then realizing topological reconstruction based on the adjusted series-parallel relationship; reducing the current of battery cells that require trickle charging or low-current discharge by changing the topology to achieve the balance of each battery cell; controlling the charging and discharging of the battery cell according to the series-parallel relationship of the battery cell; using a switch matrix composed of controllable switches to connect a large number of single cells into a reconfigurable battery network; and selecting the optimal battery structure plan system to control the switch array according to the current working conditions. The present invention can realize the management and control of the direct current power supply battery pack, and has the remarkable characteristics of being simple, efficient, and highly accurate.

Description

Technical Field

[0001] The present invention relates to the field of direct current technology, and in particular to a management and control method and device for a direct current power supply battery pack. Background Art

[0002] The state parameters of the DC power battery pack need to be detected and accurately estimated online, including the voltage, current, temperature, SOC, SOH and other data of the single cell. Among them, the monitoring data such as voltage, current, temperature, etc. are relatively easy. The estimation of the key information of charge capacity (SOC: State of Charge) is the biggest technical difficulty in the online precise control of the battery pack. It is even more difficult to accurately estimate the SOC. First of all, in principle, the charging and discharging process of the battery is a very complex electrochemical process. Strictly speaking, each charge and discharge cycle of the battery will affect the performance of the battery and its internal state. Secondly, from the perspective of external characteristics, the battery operating characteristics are highly nonlinear, and the SOC cannot be directly measured. The SOC can only be estimated by detecting the external characteristics of the battery such as terminal voltage, operating current, temperature and other states. Thirdly, from the perspective of SOC calculation, it is generally necessary to establish a corresponding equivalent model, and it is also difficult to establish an accurate battery model. On the one hand, there will be certain errors between most of the abstract ideal models themselves and the actual characteristics of the battery. For example, some common battery models will produce large instantaneous errors when the battery working state switches, which makes it difficult to accurately estimate the SOC. On the other hand, the instability of model parameters is also a major obstacle to SOC estimation. Taking the typical Thevenin and PNGV battery models as examples, during the battery operation process, the model equivalent parameters will change with the changes in the battery's operating current, temperature, and the battery's SOC and SOH states. It is also a relatively complicated task to quantitatively identify the battery parameters under various working conditions. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention provides a management and control method and device for a DC power supply battery pack, the purpose of which is to achieve control over the DC battery.

[0004] Based on the above invention objectives, the present invention is achieved through the following technical solutions:

[0005] A management and control method for a DC power supply battery pack comprises the following steps:

[0006] Acquire basic information of a battery pack, and obtain a battery equivalent circuit of the battery pack according to the basic information;

[0007] Identify the series-parallel relationship of the battery network according to the battery equivalent circuit of the battery group, generate a series-parallel adjustment plan according to the series-parallel relationship, and then reconstruct the topology according to the adjusted series-parallel relationship;

[0008] The current of battery cells that need trickle charging or low current discharge is adjusted by changing the topology to achieve balance of each battery cell;

[0009] Controlling the charging and discharging of battery cells according to the series-parallel relationship of the battery cells;

[0010] A switch matrix composed of controllable switches is used to connect the battery cells in the battery pack into a reconfigurable battery network;

[0011] An optimal battery solution system is determined based on the reconfigurable battery network to control the switch array.

[0012] The step of obtaining a battery equivalent circuit of the battery pack according to the basic information includes:

[0013] Step 201, establishing a model of N batteries in series and M batteries in parallel according to a single battery model in a battery pack, where N and M are the number of batteries in series and in parallel respectively, and the circuits of the N batteries in series and the M batteries in parallel model are respectively equivalent to single battery models;

[0014] Step 202, after the first equivalence, the original battery network is simplified into a new network consisting of equivalent single cells after the series-parallel circuit is equivalent, and the second equivalence is performed again, and the intuitive series-parallel circuit is equivalent to a single cell in the new network after the first equivalence;

[0015] Repeat steps 201 and 202 until the given battery network is finally equivalent to a single battery model, thereby completing the modeling of a battery network with any topology.

[0016] The identifying the overall series-parallel relationship of the battery network according to the topological structure, generating a series-parallel adjustment scheme according to the series-parallel relationship, and then implementing topology reconstruction according to the adjusted series-parallel relationship includes the following steps:

[0017] Step 301, taking each monomer cluster that has a direct connection relationship with the bus as a first-level starting point, searching for a monomer cluster that has two direct paths with the cluster in the adjacent monomer clusters of the cluster by a pre-set optimization method based on the topological relationship, and dividing these monomer clusters into the same first-level cluster; dividing the monomer cluster that is adjacent to the monomer cluster that already belongs to the same first-level cluster and has two paths into the cluster; taking the monomer cluster that is adjacent to any monomer cluster in any first-level cluster and has only one path and the positive electrodes are connected to the positive electrodes as a first-level starting point, searching and forming the corresponding first-level cluster according to the above method; the adjacent monomer cluster of the cluster is the monomer cluster that is directly connected with the cluster; the monomer cluster with two direct paths represents a monomer cluster in which the positive electrodes of two monomer batteries are connected to the positive electrodes and the negative electrodes are connected to the negative electrodes;

[0018] Step 302: Based on the above-mentioned primary cluster, a monomer cluster adjacent to any primary cluster and having only one path and a negative electrode connected to a positive electrode is searched as a secondary starting point, and a secondary cluster is constructed according to the above-mentioned primary cluster search method; wherein the monomer batteries in the same cluster are in a parallel relationship, the clusters at the same level are in a parallel relationship, and the two directly connected clusters are in a series relationship;

[0019] Step 303, continuously determine the starting point of the next level, and repeatedly perform the above steps to build each level of clusters until the negative electrode of the monomer in the last level of cluster is directly connected to the negative electrode bus;

[0020] Step 304, based on the generated clusters at all levels and the connection relationship between clusters, a tree structure of battery network series-parallel connection is generated with the bus as the root node;

[0021] Step 305 , optimizing the tree structure to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network.

[0022] The method of adjusting the current of the battery cells that need trickle charging or low current discharge by changing the topology to achieve the balance of each battery cell includes the following steps:

[0023] The cluster with the smallest neighborhood path flow is searched according to the measurement data of each battery cell, the smallest cluster is assumed to be the second secondary cluster, and the batteries that need to reduce current are connected in parallel to the second secondary cluster through topology changes.

[0024] The controlling the charging and discharging of the battery cells according to the series-parallel relationship of the battery cells comprises the following steps:

[0025] Step 501, setting a parallel switch on the single battery;

[0026] Step 502, if the number of batteries in the cluster where the cell to be isolated is located is greater than 1, isolation is performed by disconnection;

[0027] Step 503: If the cluster where the cell to be isolated is located only contains the cell, isolation is achieved by closing the parallel switch.

[0028] The switch matrix composed of controllable switches is used to connect the battery cells in the battery pack into a reconfigurable battery network; the steps include:

[0029] A battery network is abstracted as a function Φ = {E, S, D}, where the array E represents the sensor {E1, E2, ..., E n}, each sensor measures the current and temperature data of the corresponding battery cell, n is the number of battery cells in the battery network, array S represents the switch state, array D represents the battery network {D1,D2,...,D n};

[0030] The connection relationship of the battery network is represented as an n-dimensional vector, D i The status includes S B , S S , S P , corresponding to the three connection modes of bypass, series and parallel respectively.

[0031] The charge and discharge operation cycle of the battery network is d, which is subdivided into N adaptation intervals, and the length of each interval is T = d / N; at the beginning of each interval, the battery network reconstruction process will be triggered, and the system will first select an optimal battery structure solution according to the current working conditions to obtain the maximum available capacity in the subsequent interval, and then the system controls the switch array to reconstruct the battery topology; where K is the number of battery topology structures that can be constructed by a battery network containing n battery cells, which is determined by the number of switches L connected to each battery cell; N is the number of adaptation intervals, which is determined by the expected single-cycle operation time and system dynamics performance, and each state C i (i∈{1,...,K}) corresponds to a battery topology respectively.

[0032] The system for selecting the optimal battery solution according to the current working conditions controls the switch array, including:

[0033] Each state C i (i∈{1,...,K}) corresponds to a battery topology structure, and the battery network topology state C i is an L×N matrix:

[0034] in

[0035] In the above formula: Indicates that in the mth interval, the battery network changes from topology C i Reconstructed into topology C j The expected usage capacity after (i,j∈{1,..,K});

[0036] definition Represents the topological structure combination selected in each of the N intervals, and the topological optimization problem is converted into finding the optimal π to minimize the value function J(π). When the value function is the capacity usage of the battery network system, we have:

[0037]

[0038] The constraints are

[0039] in, is the battery network SOC of the jth interval, γ j To use capacity, is the battery network voltage value, is the battery network current value, h is the battery network SOH, V r ,I r are the system load voltage and current demand values ​​respectively. The answer π obtained by solving the value function J(π) is the most ideal battery network topology configuration solution in the interval d.

[0040] A management and control device for a DC power supply battery pack, comprising:

[0041] A model building module, used to obtain basic information of a battery pack and build a battery equivalent circuit of the battery pack according to the basic information;

[0042] A topology reconstruction module, used to identify the overall series-parallel relationship of the battery network according to the battery equivalent circuit of the battery pack, generate a series-parallel adjustment scheme according to the series-parallel relationship, and then realize topology reconstruction according to the adjusted series-parallel relationship;

[0043] A balancing module is used to adjust the current of battery cells that require trickle charging or low-current discharge by changing the topology to achieve balance of each battery cell;

[0044] A charge and discharge control module, used to control the charge and discharge of the battery cells according to the series-parallel relationship of the battery cells;

[0045] A battery network reconstruction module, used to connect battery cells in a battery pack into a reconfigurable battery network using a switch matrix composed of controllable switches;

[0046] A control module is used to determine an optimal battery solution system control switch array according to the reconfigurable battery network.

[0047] The model building module is also used to achieve: establishing a model of N batteries in series and M batteries in parallel according to a single battery model, where N and M are the number of batteries in series and parallel respectively, and equating the series and parallel circuits to single battery models respectively, and replacing the intuitive series and parallel circuits in the battery network with single batteries;

[0048] After the first equivalence, the original battery network is simplified into a new network composed of equivalent single cells after the series-parallel circuit is equivalent, and the second equivalence is performed again, that is, the intuitive series-parallel circuit is equivalent to a single cell in the new network after the first equivalence by using a similar method to the first equivalence;

[0049] Repeat the above steps until the given battery network is finally equivalent to a single battery model;

[0050] The topology reconstruction module is also used to achieve: taking each monomer cluster that has a direct connection relationship with the bus as a first-level starting point, searching for monomer clusters that have two direct paths with the cluster in the adjacent monomer clusters of the cluster through a path search method, and dividing these monomer clusters into the same first-level cluster; dividing monomer clusters that are adjacent to monomer clusters that already belong to the same first-level cluster and have two paths into the cluster; taking monomer clusters that are adjacent to any monomer cluster in any first-level cluster and have only one path and are connected to the positive electrodes as a first-level starting point, and searching to form a corresponding first-level cluster according to the above method;

[0051] Based on the above primary clusters, a monomer cluster adjacent to any monomer cluster in the primary cluster and having only one pathway and the negative electrode connected to the positive electrode is searched as a secondary starting point, and a secondary cluster is constructed according to the search method of the above primary clusters;

[0052] The starting point of the next level is continuously determined, and the above steps are repeatedly performed to construct each level of cluster until the negative electrode of the monomer in the last level of cluster is directly connected to the negative electrode bus;

[0053] Based on the generated clusters at all levels and the connection relationship between clusters, a tree structure representation diagram of the series-parallel connection of the battery network is generated with the bus as the root node;

[0054] The tree structure is optimized to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network.

[0055] Compared with the prior art, the present invention has the following advantages and beneficial technical effects:

[0056] The present invention provides a management and control method and device for a DC power battery pack, which manages the battery from two aspects: battery status monitoring and energy control, based on energy Internet and dynamic reconfigurable battery management technology. On the one hand, the battery energy exchange system collects battery voltage, temperature, charge and discharge current and other status data, and estimates the battery SOC based on the collected data and logic algorithms. On the other hand, the battery energy exchange system dynamically adjusts the topology of the battery pack network according to the status of the single cell and the system charge and discharge status, so that the optimal battery structure solution can be selected to control the switch array of the system. The method is simple, efficient and highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a flow chart of a management and control method of a DC power supply battery pack of the present invention;

[0058] Figure 2 This is a schematic diagram of the primary cluster of the present invention;

[0059] Figure 3 The present invention is a schematic diagram of the structure of a management and control device for a DC power supply battery pack. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0061] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0062] Reference Figure 1 As shown, Figure 1 The present invention provides a method for managing and controlling a DC power supply battery pack, comprising the following steps:

[0063] Step 101, obtaining basic information of a battery pack, and constructing a battery equivalent circuit of the battery pack according to the basic information.

[0064] Step 102 , identifying the overall series-parallel relationship of the battery network according to the battery equivalent circuit of the battery pack, generating a series-parallel adjustment scheme according to the series-parallel relationship, and then reconstructing the topology according to the adjusted series-parallel relationship.

[0065] Step 103 , by adjusting the topology to reduce the current of the battery cells that need trickle charging or low current discharge, the balance of each battery cell is achieved.

[0066] Step 104 : controlling the charging and discharging of the battery cells according to the series-parallel relationship of the battery cells.

[0067] Step 105 , a switch matrix composed of controllable switches is used to connect a large number of single battery cells in the battery pack into a reconfigurable battery network.

[0068] Step 106 , determining the optimal battery solution system control switch array according to the reconfigurable battery network.

[0069] In step 101, constructing a battery equivalent circuit model according to the basic information includes:

[0070] Step 201, establish a model of N batteries in series and M batteries in parallel according to the single battery model in the battery pack, where N and M are the number of batteries in series and parallel respectively, and the series and parallel circuits are equivalent to single battery models respectively, set as f(N) and g(M), and then replace the intuitive series and parallel circuits in the battery network with single batteries represented by f(N0) and g(M0), where N0 and M0 are the number of single batteries in the intuitive series and parallel circuits;

[0071] Step 202, after the first equivalence, the original battery network is simplified into a new network composed of equivalent single cells after the series-parallel circuit is equivalent, and the second equivalence is performed again, that is, the intuitive series-parallel circuit is equivalent to a single cell in the new network after the first equivalence by using the same method as the previous one, and the corresponding models are f(f(N01), ..., f(N0N1)) and g(g(M01), ..., g(M0M1)), where N1 and M1 are the number of cells in the series-parallel circuit during the second equivalence;

[0072] Step 203, repeating steps 201 and 202 until the given battery network is finally equivalent to a single battery model, thus completing the modeling of the battery network of any topology.

[0073] The dynamic reconstruction of the battery network topology first requires identifying the overall series-parallel relationship of the battery network based on the topological structure, then providing a series-parallel adjustment plan based on the series-parallel relationship, and then realizing the topology reconstruction based on the adjusted series-parallel relationship. That is, one reconstruction process includes two mapping processes between the battery network topology and the series-parallel relationship.

[0074] The present invention introduces graph-theoretic routing search and spanning tree theory methods to achieve the mapping between battery network topology and series-parallel relationship. Generally speaking, the intuitive battery network abstraction method is to regard each single cell as a vertex and the switch path between the single cells as an edge, so that the entire battery network can be abstracted into a graph. However, since the series-parallel relationship between batteries is not only related to the connectivity between each single cell, that is, whether there is a direct path between the single cell nodes, but also depends on the connection sequence of the positive and negative poles of the single cell. Therefore, the above-mentioned direct abstraction into a graph method cannot fully reflect the connection characteristics of the battery network.

[0075] To address the above problems, the present invention splits each single cell into two vertices, corresponding to the positive and negative poles of the single cell respectively. The two vertices belonging to the same single cell are directly connected and form a top and bottom cluster, called a single cell cluster, thus forming a graph representation of the battery network connection relationship.

[0076] According to the above-mentioned graph representation of the battery network, in step 102, the steps of identifying the overall series-parallel relationship of the battery network according to the topological structure, generating a series-parallel adjustment scheme according to the series-parallel relationship, and then reconstructing the topology according to the adjusted series-parallel relationship include the following steps:

[0077] Step 301, first take each monomer cluster that has a direct connection relationship with the bus as the first-level starting point, search for monomer clusters that have two direct paths with the cluster in the adjacent monomer clusters of the cluster through a path search method, and divide these monomer clusters into the same first-level cluster, such as Figure 2 As shown in the first-level cluster 2 shown; according to the above method, the monomer cluster adjacent to the monomer cluster that already belongs to the same level cluster and has two pathways is also divided into this cluster, such as Figure 2 As shown in the first-level cluster 1, a monomer cluster adjacent to any monomer cluster in any first-level cluster and having only one path and connected to the positive electrode is also taken as a first-level starting point, and the corresponding first-level cluster is searched according to the above method. The adjacent monomer cluster of the cluster is the monomer cluster directly connected to the cluster.

[0078] The monomer cluster with two direct paths represents a monomer cluster in which positive electrodes of two monomer batteries are connected to each other, and negative electrodes are connected to each other.

[0079] Step 302, based on the above-mentioned first-level cluster, search for a monomer cluster that is adjacent to any monomer cluster in the first-level cluster and has only one path and the negative electrode is connected to the positive electrode as a second-level starting point, and construct a second-level cluster according to the search method of the above-mentioned first-level cluster; wherein the monomer batteries in the same cluster are in a parallel relationship, the clusters of the same level are in a parallel relationship, and the two directly connected clusters are in a series relationship.

[0080] Step 303, continuously determine the starting point of the next level according to the above method, and repeatedly execute the above steps to build each level of clusters until the negative electrode of the monomer in the last level of cluster is directly connected to the negative electrode bus.

[0081] Step 304, based on the generated clusters at all levels and the connection relationship between clusters, a tree structure of battery network series-parallel connection is generated with the bus as the root node;

[0082] Step 305 , optimizing the tree structure to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network.

[0083] In step 103, the current of the battery cells that need trickle charging or low current discharge is reduced by changing the topology to achieve the balance of each battery cell, including the following steps:

[0084] A cluster with a smaller path flow is searched according to the measurement data of each battery cell, the smallest cluster is assumed to be the second secondary cluster, and the batteries that need to reduce current are connected in parallel to the second secondary cluster through topology changes.

[0085] When a battery cell is close to an overcharge or over-discharge state, the corresponding cell needs to be isolated from the battery network. In existing battery systems, each battery cell is basically in a series connection state with multiple cells, so isolation is achieved simply by closing the switch in parallel with the cell. In the dynamic topology battery network adopted by the present invention, some cells will be in parallel with other cells. At this time, the existing isolation method cannot be used, and it is necessary to disconnect them from other cells to achieve the isolation effect. The single cell charge and discharge control based on dynamic reconstruction of the battery network topology needs to identify the series and parallel states of each cell and use different isolation methods.

[0086] In step 104, the charging and discharging of the battery cells are controlled according to the series-parallel relationship of the battery cells, including the following steps:

[0087] Step 401, setting a parallel switch on the single battery;

[0088] Step 402, if the number of batteries in the cluster where the cell to be isolated is located is greater than 1, isolation is performed by disconnection;

[0089] Step 403: If the cluster where the cell to be isolated is located only contains the cell, isolation is achieved by closing the parallel switch.

[0090] In order to improve the flexibility of the battery module, a switch matrix composed of a series of controllable switches is used to connect a large number of single cells into a reconfigurable battery network. By controlling the state of the switches connected to the batteries, the connection mode of the batteries is changed, the circuit topology of the battery network is adjusted, and the output power of the battery pack is adjusted. The core of the reconfigurable switch network lies in the battery energy scheduling algorithm. By operating the state switches in the switch network, the battery connection mode is adjusted, the battery current size is changed, and the energy output state is changed.

[0091] In step 105, a switch matrix composed of controllable switches is used to connect a large number of single cells in the battery pack into a reconfigurable battery network, including the following steps:

[0092] Step 501, abstract a group of battery networks into a function Φ = {E, S, D}, where the array E represents the sensors {E1, E2, ..., E n}, each sensor measures the current and temperature data of the corresponding battery cell, n is the number of battery cells in the battery network, array S represents the switch state, array D represents the battery network {D1,D2,...,D n};

[0093] Step 502: The connection relationship of the battery network is represented as an n-dimensional vector, D i The status includes S B , S S , S P , corresponding to the three connection modes of bypass, series and parallel respectively.

[0094] Optionally, assuming that the charge and discharge operation cycle of a group of battery networks is d, d can be subdivided into N adaptation intervals, and the length of each interval is T = d / N. At the beginning of each interval, the battery network reconstruction process will be triggered. The system will first select an optimal battery structure solution based on the current operating conditions to obtain the maximum available capacity in the subsequent intervals, and then the system controls the switch array to reconstruct the battery topology. Where K is the number of battery topology structures that can be constructed by a battery network containing n battery cells, which is determined by the number of switches L connected to each battery cell. N is the number of adaptation intervals, which is determined by the expected single-cycle operation time and system dynamics performance. Each state C i (i∈{1,...,K}) corresponds to a battery topology respectively.

[0095] In step 106, the optimal battery structure scheme system is selected according to the current working condition to control the switch array, including:

[0096] A battery network (such as a medium-scale reconfigurable battery module) is abstracted as a function Φ = {E, S, D}. The array E represents the sensors {E1, E2, ..., E n}, each sensor measures the current and temperature data of the corresponding battery cell; n is the number of battery cells in the battery network, array S represents the switch state, and array D represents the battery network {D1, D2, ..., D n}, the connection relationship of the battery network can be expressed as an n-dimensional vector; D i The status may be S B , S S , S P , corresponding to the three connection modes of bypass, series and parallel respectively;

[0097] Assuming that the charge and discharge operation cycle of a battery network is d, d can be subdivided into N adaptation intervals, and the length of each interval is T = d / N. K is the number of battery topologies that can be formed by a battery network containing n battery cells, which is determined by the number of switches connected to each battery cell, L. N is the number of adaptation intervals, which is determined by the expected single-cycle operation time and system dynamics performance. Each state C i (i∈{1,...,K}) corresponds to a battery topology structure, and the battery network topology state C i is an L×N matrix:

[0098] in

[0099] In the above formula: Indicates that in the mth interval, the battery network changes from topology C i Reconstructed into topology C j The expected usage capacity after (i,j∈{1,..,K});

[0100] definition Represents the topological structure combination selected in each of the N intervals, and the topological optimization problem is converted into finding the optimal π to minimize the value function J(π). When the value function is the capacity usage of the battery network system, we have:

[0101]

[0102] The constraints are

[0103] in, is the battery network SOC of the jth interval, γ j To use capacity, is the battery network voltage value, is the battery network current value, h is the battery network SOH, V r ,I rare the system load voltage and current demand values ​​respectively. The answer π obtained by solving the value function J(π) is the most ideal battery network topology configuration scheme in the interval d; the answer π obtained by solving J(π) is the most ideal battery network topology configuration scheme in the interval d.

[0104] The present invention also provides a management and control device for a DC power supply battery pack, referring to Figure 3 As shown, including:

[0105] A model building module 11 is used to obtain basic information of the battery pack and build a battery equivalent circuit model according to the basic information;

[0106] A topology reconstruction module 12 is used to identify the overall series-parallel relationship of the battery network according to the topological structure, generate a series-parallel adjustment scheme according to the series-parallel relationship, and then realize topology reconstruction according to the adjusted series-parallel relationship;

[0107] A balancing module 13, used to achieve balance of each battery cell by reducing the current of the battery cell that needs trickle charging or low current discharge through topology changes;

[0108] A charge and discharge control module 14, used to control the charge and discharge of the battery cells according to the series-parallel relationship of the battery cells;

[0109] A battery network reconfiguration module 15 is used to connect a large number of single cells in a battery pack into a reconfigurable battery network using a switch matrix composed of controllable switches;

[0110] The control module 16 is used to select the optimal battery structure solution system to control the switch array according to the current working conditions.

[0111] Optionally, the model building module 11 is further used to implement: establishing a model of N batteries in series and M batteries in parallel according to a single battery model, where N and M are the number of batteries in series and parallel respectively, and the series and parallel circuits are respectively equivalent to single battery models, and the intuitive series and parallel circuits in the battery network are replaced by single batteries;

[0112] After the first equivalence, the original battery network is simplified into a new network composed of equivalent single cells after the series-parallel circuit is equivalent, and the second equivalence is performed again, that is, the intuitive series-parallel circuit is equivalent to a single cell in the new network after the first equivalence by using a similar method to the first equivalence;

[0113] Repeat the above steps until the given battery network is finally equivalent to a single battery model.

[0114] Optionally, the topology reconstruction module 12 is further used to implement:

[0115] Taking each monomer cluster that has a direct connection relationship with the bus as the first-level starting point, searching for monomer clusters with two direct paths with the cluster in the adjacent monomer clusters of the cluster through the path search method, these monomer clusters are divided into the same first-level cluster; monomer clusters that are adjacent to monomer clusters that already belong to the same-level cluster and have two paths are also divided into the cluster; monomer clusters that are adjacent to any monomer cluster in any first-level cluster and have only one path and are connected to the positive electrode are also taken as the first-level starting point, and the corresponding first-level clusters are searched according to the above method;

[0116] Based on the above primary clusters, a monomer cluster adjacent to any monomer cluster in the primary cluster and having only one pathway and the negative electrode connected to the positive electrode is searched as a secondary starting point, and a secondary cluster is constructed according to the search method of the above primary clusters;

[0117] The starting point of the next level is continuously determined, and the above steps are repeatedly performed to construct each level of cluster until the negative electrode of the monomer in the last level of cluster is directly connected to the negative electrode bus;

[0118] Based on the generated clusters at all levels and the connection relationship between clusters, a tree structure representation diagram of the series-parallel connection of the battery network is generated with the bus as the root node;

[0119] The tree structure is optimized to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network.

[0120] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure, including the claims, is limited to these examples; within the spirit of the present invention, the technical features in the above embodiments or in different embodiments may be combined, the steps may 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 detail for the sake of simplicity.

[0121] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A management and control method for a DC power supply battery pack, characterized in that: The following steps are involved: Obtain basic information of a battery pack, and obtain a battery equivalent circuit of the battery pack according to the basic information; including: step 201, establishing a model of N batteries in series and M batteries in parallel according to a single battery model in the battery pack, where N and M are the number of batteries in series and parallel respectively, and the circuits of the N batteries in series and the M batteries in parallel models are respectively equivalent to single battery models; step 202, after a first equivalence, the original battery network is simplified into a new network composed of equivalent single batteries after the series-parallel circuit is equivalent, and a second equivalence is performed again, and the intuitive series-parallel circuit is equivalent to a single battery in the new network after the first equivalence; repeating steps 201 and 202 until the given battery network is finally equivalent to a single battery model, thereby completing the modeling of a battery network of any topology; Identify the series-parallel relationship of the battery network according to the battery equivalent circuit of the battery pack, generate a series-parallel adjustment plan according to the series-parallel relationship, and then realize the topology reconstruction according to the adjusted series-parallel relationship; including: step 301, take each monomer cluster that has a direct connection relationship with the bus as the first-level starting point, search for monomer clusters with two direct paths with the cluster in the adjacent monomer clusters of the cluster by a pre-set optimization method according to the topological relationship, and divide these monomer clusters into the same first-level cluster; divide the monomer clusters that are adjacent to the monomer clusters that already belong to the same level cluster and have two paths into the cluster; take the monomer clusters that are adjacent to any monomer cluster in any first-level cluster and have only one path and the positive electrode is connected to the positive electrode as the first-level starting point, and search and form the corresponding first-level cluster according to the above method; the adjacent monomer cluster of the cluster is the monomer cluster directly connected to the cluster; the monomer clusters with two direct paths represent two monomer clusters. A monomer cluster in which the positive electrodes of monomer batteries are connected to each other and the negative electrodes are connected to each other; step 302, based on the above-mentioned first-level cluster, search for a monomer cluster adjacent to a monomer cluster in any first-level cluster and having only one path and the negative electrode connected to the positive electrode as a second-level starting point, and construct a second-level cluster according to the above-mentioned first-level cluster search method; wherein, monomer batteries in the same cluster are in a parallel relationship, clusters at the same level are in a parallel relationship, and two directly connected clusters are in a series relationship; step 303, continuously determine the lower-level starting point, and repeatedly execute the above steps to construct clusters at all levels until the negative electrode of the monomer in the last-level cluster is directly connected to the negative electrode bus; step 304, according to the generated clusters at all levels and the connection relationship between clusters, with the bus as the root node, generate a tree structure of series-parallel connection of the battery network; step 305, optimize the tree structure to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network; The current of battery cells that need trickle charging or low current discharge is adjusted by changing the topology to achieve balance of each battery cell; Controlling the charging and discharging of battery cells according to the series-parallel relationship of the battery cells; A switch matrix composed of controllable switches is used to connect the battery cells in the battery pack into a reconfigurable battery network, including: abstracting a group of battery networks into a function Φ = {E, S, D}, where the array E represents the sensors {E1, E2, ..., E n }, each sensor measures the current and temperature data of the corresponding battery cell, n is the number of battery cells in the battery network, array S represents the switch state, array D represents the battery network {D1,D2,...,D n }; Represent the connection relationship of the battery network as an n-dimensional vector, D i The status includes S B , S S , S P , corresponding to the three connection modes of bypass, series and parallel respectively; Determine the optimal battery solution based on the reconfigurable battery network system control switch array, including: each state C i (i∈{1,...,K}) corresponds to a battery topology structure, and the battery network topology state C i is an L×N matrix: In the above formula: The battery network is from topology C i Reconstructed into topology C j The estimated usage capacity after (i,j∈{1,..,K}); definition (i,j∈{1,..,K}) represents the topological structure combination selected in N intervals. The topological optimization problem is converted into finding the optimal π to minimize the value function J(π). When the value function is the capacity usage of the battery network system, we have: The constraints are in, is the battery network SOC of the jth interval, γ j is the usage capacity, V j B is the battery network voltage value, is the battery network current value, h is the battery network SOH, V r ,I r are the system load voltage and current demand values ​​respectively. The answer π obtained by solving the value function J(π) is the most ideal battery network topology configuration solution in the interval d.

2. The management and control method of a DC power supply battery pack according to claim 1 is characterized in that: The method of adjusting the current of the battery cells that need trickle charging or low current discharge by changing the topology to achieve the balance of each battery cell includes the following steps: The cluster with the smallest neighborhood path flow is searched according to the measurement data of each battery cell, the smallest cluster is assumed to be the second secondary cluster, and the batteries that need to reduce current are connected in parallel to the second secondary cluster through topology changes.

3. The management and control method of a DC power supply battery pack according to claim 1 is characterized in that: The controlling the charging and discharging of the battery cells according to the series-parallel relationship of the battery cells comprises the following steps: Step 501, setting a parallel switch on the single battery; Step 502, if the number of batteries in the cluster where the cell to be isolated is located is greater than 1, isolation is performed by disconnection; Step 503: If the cluster where the cell to be isolated is located only contains the cell, isolation is achieved by closing the parallel switch.

4. The management and control method of a DC power supply battery pack according to claim 1, characterized in that: The charge and discharge operation cycle of the battery network is d, which is subdivided into N adaptation intervals, and the length of each interval is T = d / N; at the beginning of each interval, the battery network reconstruction process will be triggered, and the system will first select an optimal battery structure solution according to the current working conditions to obtain the maximum available capacity in the subsequent interval, and then the system controls the switch array to reconstruct the battery topology; where K is the number of battery topology structures that can be constructed by a battery network containing n battery cells, which is determined by the number of switches L connected to each battery cell; N is the number of adaptation intervals, which is determined by the expected single-cycle operation time and system dynamics performance, and each state C i (i∈{1,...,K}) corresponds to a battery topology respectively.

5. A management and control device for a DC power supply battery pack, characterized in that: include: A model building module, used to obtain basic information of a battery pack and build a battery equivalent circuit of the battery pack according to the basic information; A topology reconstruction module, used to identify the overall series-parallel relationship of the battery network according to the battery equivalent circuit of the battery pack, generate a series-parallel adjustment scheme according to the series-parallel relationship, and then realize topology reconstruction according to the adjusted series-parallel relationship; A balancing module is used to adjust the current of battery cells that require trickle charging or low-current discharge by changing the topology to achieve balance of each battery cell; A charge and discharge control module, used to control the charge and discharge of the battery cells according to the series-parallel relationship of the battery cells; A battery network reconstruction module, used to connect battery cells in a battery pack into a reconfigurable battery network using a switch matrix composed of controllable switches; A control module, configured to determine an optimal battery solution system control switch array according to the reconfigurable battery network; The model building module is also used to achieve: establishing a model of N batteries in series and M batteries in parallel according to a single battery model, where N and M are the number of batteries in series and parallel respectively, and equating the series and parallel circuits to single battery models respectively, and replacing the intuitive series and parallel circuits in the battery network with single batteries; After the first equivalence, the original battery network is simplified into a new network composed of equivalent single cells after the series-parallel circuit is equivalent, and the second equivalence is performed again, that is, the intuitive series-parallel circuit is equivalent to a single cell in the new network after the first equivalence by using a similar method to the first equivalence; Repeat the above steps until the given battery network is finally equivalent to a single battery model; The topology reconstruction module is also used to realize: taking each monomer cluster having a direct connection relationship with the bus as a first-level starting point, searching for monomer clusters having two direct paths with the cluster in the adjacent monomer clusters of the cluster by a path search method, and dividing these monomer clusters into the same first-level cluster; dividing monomer clusters adjacent to monomer clusters that already belong to the same-level cluster and have two paths into the cluster; A monomer cluster adjacent to any monomer cluster in any primary cluster and having only one pathway and connected to the positive electrode is also taken as a primary starting point, and the corresponding primary cluster is searched and formed according to the above method; Based on the above primary clusters, a monomer cluster adjacent to any monomer cluster in the primary cluster and having only one pathway and the negative electrode connected to the positive electrode is searched as a secondary starting point, and a secondary cluster is constructed according to the search method of the above primary clusters; The starting point of the next level is continuously determined, and the above steps are repeatedly performed to construct each level of cluster until the negative electrode of the monomer in the last level of cluster is directly connected to the negative electrode bus; Based on the generated clusters at all levels and the connection relationship between clusters, a tree structure representation diagram of the series-parallel connection of the battery network is generated with the bus as the root node; The tree structure is optimized to obtain a tree structure representation of the series-parallel relationship of any topology of the entire battery network.

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