On-orbit management method for power type lithium ion storage battery pack

Abstract

The invention discloses an on-orbit management method for a power type lithium ion storage battery pack. The method comprises the following steps: judging the current charging and discharging state and the current task mode of the power type lithium ion storage battery pack; the method comprises the following steps of: acquiring a whole group voltage Vout and a whole group output current Iout of a power type lithium ion storage battery pack in real time, and voltages V1-Vn of each storage battery monomer; wherein n represents the number of the storage battery monomers connected in series; and according to the determined current charging and discharging state and the current task mode of the power type lithium ion storage battery pack, in combination with Vout, Iout and V1-Vn which are acquired in real time, respectively carrying out overcharge management, overdischarge management, balance management and semi-charge shelving management. According to the method, small current equalization management and large current equalization management can be executed respectively according to the current charging and discharging state of the battery in combination with the current task mode, so that the service life of the power type lithium ion storage battery pack is prolonged and the on-orbit working safety is improved while the load discharging requirement is ensured.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to an on-orbit management method for a power-type lithium-ion battery pack. Background Art

[0002] With the rapid development of spacecraft system technology, new payloads have a discharge demand for battery packs of up to 15C or more, far exceeding the discharge capacity of traditional energy-type lithium-ion battery packs. Power-type lithium-ion battery packs have become an important energy storage device for short-term, high-power payloads. The cycle life of power-type lithium-ion battery packs is a shortcoming that restricts the number of times the load works, and is also an important component that affects the safe and stable operation of spacecraft. For short-term, high-power spacecraft with a discharge demand of more than 1,000 times, optimizing the on-orbit management strategy of power-type lithium-ion battery packs, improving on-orbit discharge safety, and extending the service life of power-type battery packs are key links in their on-orbit management.

[0003] At present, for lithium-ion battery packs of low-orbit spacecraft, on-orbit management methods generally only include overcharging, over-discharging and balancing management; for medium- and high-orbit spacecraft, their balancing management strategies are also relatively simple and do not consider the needs of different discharge mission modes. Summary of the invention

[0004] The technology of the present invention solves the problem: overcomes the shortcomings of the prior art and provides an on-orbit management method for a power-type lithium-ion battery pack. The method can respectively perform small current balancing and large current balancing management according to the current charge and discharge state of the battery and in combination with the current mission mode, which is beneficial to extending the service life of the power-type lithium-ion battery pack while ensuring the load discharge demand and improving the on-orbit working safety.

[0005] In order to solve the above technical problems, the present invention discloses an on-orbit management method for a power-type lithium-ion battery pack, comprising:

[0006] Determine the current charge and discharge status and current mission mode of the power type lithium-ion battery pack;

[0007] Real-time acquisition of the voltage V of the entire power lithium-ion battery pack out And the whole group output current I out , and the voltage of each battery cell V1~V n ; Where n represents the number of battery cells connected in series;

[0008] According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management.

[0009] In the above-mentioned on-orbit management method of the power type lithium-ion battery pack, judging the current charge and discharge state and the current mission mode of the power type lithium-ion battery pack includes: judging the current charge and discharge state and the current mission mode of the power type lithium-ion battery pack according to the working state identifier K of the power type lithium-ion battery pack; wherein, when K=0, determining the current mission mode of the power type lithium-ion battery pack is: half-charged standby mode; when K=1, determining the current charge and discharge state and the current mission mode of the power type lithium-ion battery pack is: charging or discharging and not in the half-charged standby mode; when K=2, determining the current mission mode of the power type lithium-ion battery pack is: high-density mission mode; when K=3, determining the current mission mode of the power type lithium-ion battery pack is: low-density mission mode.

[0010] In the above-mentioned on-orbit management method of the power type lithium-ion battery pack, according to the current charge and discharge state and current mission mode of the determined power type lithium-ion battery pack, combined with the V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including:

[0011] S11, when K=0, according to V1~V n , calculate the average value of the battery cell voltage V aver ;

[0012] S12, V aver With the upper limit of the shelving voltage V high Compare; if V aver ≥V high , then connect the balancing circuit of each battery cell and end this process; if it is determined that V aver <V high , then execute step S13;

[0013] S13, V aver With the lower limit of the voltage V low Compare; if V aver ≥V low , then disconnect the balancing circuit of each battery cell and end this process; if it is determined that V aver <V low , then execute step S14;

[0014] S14, connect the charging unit of the power type lithium ion battery pack and determine V aver Is it higher than V high Or whether the power type lithium ion battery pack starts to discharge; if it is determined that V aver ≥V highor I out >0, disconnect the charging unit of the power lithium-ion battery pack and end this process; otherwise, end this process directly.

[0015] In the above-mentioned on-orbit management method of the power type lithium-ion battery pack, according to the current charge and discharge state and current mission mode of the determined power type lithium-ion battery pack, combined with the V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including:

[0016] S21, when the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, determine whether the power type lithium ion battery pack is being charged or discharged; wherein, if it is determined that the power type lithium ion battery pack is being charged or discharged, that is, K=1, execute step S22;

[0017] S22, V out With the charge alarm threshold V charge Compare; if V out ≥V charge , the charging unit is immediately turned off; if it is determined that V out <V charge , then execute step S23;

[0018] S23, V out and the discharge alarm threshold V discharge Compare; if V out <V discharge , the load devices are shut down one by one in the order of their priority from low to high to reduce the discharge power; otherwise, this process ends.

[0019] In the above-mentioned on-orbit management method of the power type lithium-ion battery pack, according to the current charge and discharge state and current mission mode of the determined power type lithium-ion battery pack, combined with the V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including:

[0020] S31, when the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, determine whether the power type lithium ion battery pack is in the high-density task mode; wherein, if it is determined that the power type lithium ion battery pack is in the high-density task mode, that is, K=2, execute step S32;

[0021] S32, according to the maximum battery cell voltage max{V1~V n} and the minimum battery cell voltage min{V1~V n}, the monomer dispersion ΔV=max{V1~V n}-min{V1~V n};

[0022] S33, comparing ΔV with the discrete threshold V; if it is determined that ΔV≥V, then starting the small current balancing; if it is determined that ΔV<V, then directly ending this process.

[0023] In the above-mentioned on-orbit management method of the power type lithium-ion battery pack, according to the current charge and discharge state and current mission mode of the determined power type lithium-ion battery pack, combined with the V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including:

[0024] S41, when the power type lithium ion battery pack is not in the half-charged standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, and the power type lithium ion battery pack is not in the high-density task mode, that is, K≠2, determine whether the power type lithium ion battery pack is in the low-density task mode; wherein, if it is determined that the power type lithium ion battery pack is in the low-density task mode, that is, K=3, then execute step S42;

[0025] S42, according to the maximum battery cell voltage max{V1~V n} and the minimum battery cell voltage min{V1~V n}, the monomer dispersion ΔV=max{V1~V n}-min{V1~V n};

[0026] S43, comparing ΔV with the discrete threshold V; if it is determined that ΔV≥V, then large current balancing is started; if it is determined that ΔV<V, then the current process is terminated directly.

[0027] The present invention has the following advantages:

[0028] The present invention discloses an on-orbit management method for a power-type lithium-ion battery pack, which obtains the output voltage of each single cell and the output current of the whole group of the power-type lithium-ion battery pack in real time, judges the current charge and discharge state and the current mission mode, and carries out overcharge management, over-discharge management, balancing management and half-charge shelving management; the balancing management can be divided into small current balancing management and large current balancing management according to the current mission mode, which is beneficial to extending the service life of the power-type lithium-ion battery pack while ensuring the load discharge demand, and improving the on-orbit working safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of an on-orbit management method for a power-type lithium-ion battery pack in an embodiment of the present invention;

[0030] Figure 2 The present invention is a flowchart of a half-charged storage management of a power lithium-ion battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] According to the length of the discharge interval, the working mode of the battery pack discharging to a short-term high-power load can generally be divided into a high-density mission mode, a low-density mission mode and a waiting mode. After the on-orbit test is completed, the spacecraft will be in the waiting mode for a long time, and the power-type lithium-ion battery pack has no discharge demand. Therefore, the present invention discloses an on-orbit management method for a power-type lithium-ion battery pack. In the waiting mode, the power-type lithium-ion battery pack is managed by half-charge shelving; when the power-type lithium-ion battery pack is charged and discharged, the difference in the state of charge of each monomer will gradually expand, and overcharging and over-discharging will also cause irreversible damage. Therefore, when the power-type lithium-ion battery pack is charged and discharged, overcharge and over-discharge management are carried out; in the high-density mission mode and the low-density mission mode, if the discreteness of the monomer voltage is large, balanced management is carried out; through overcharge management, over-discharge management, balanced management and half-charge shelving management, the on-orbit management of the power-type battery pack is completed.

[0033] Reference Figure 1 In this embodiment, the on-orbit management method of the power type lithium-ion battery pack includes:

[0034] Step 1: determine the current charge and discharge state and current task mode of the power type lithium-ion battery pack.

[0035] In this embodiment, the current charge and discharge state and the current task mode of the power type lithium ion battery pack can be determined according to the working state identifier K of the power type lithium ion battery pack. When K=0, the current task mode of the power type lithium ion battery pack is determined to be: half-charged standby mode; when K=1, the current charge and discharge state and the current task mode of the power type lithium ion battery pack are determined to be: charging or discharging and not in the half-charged standby mode; when K=2, the current task mode of the power type lithium ion battery pack is determined to be: high-density task mode; when K=3, the current task mode of the power type lithium ion battery pack is determined to be: low-density task mode.

[0036] Step 2: Obtain the voltage V of the power lithium-ion battery pack in real time out And the whole group output current I out , and the voltage of each battery cell V1~V n Among them, n represents the number of battery cells connected in series.

[0037] Step 3: According to the current charge and discharge state of the power-type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management.

[0038] In this embodiment, it is first determined whether the power type lithium ion battery pack is in the half-charged storage mode, that is, whether K is equal to 0. If it is determined that K=0, the half-charged storage management is carried out, such as Figure 2 As shown in the figure, the half-charge shelving management process is as follows:

[0039] S11, according to V1~V n , calculate the average value of the battery cell voltage V aver .

[0040] S12, V aver With the upper limit of the shelving voltage V high Compare. If V aver ≥V high , then connect the balancing circuit of each battery cell and end this process; if it is determined that V aver <V high , then execute step S13.

[0041] S13, V aver With the lower limit of the voltage V low Compare. If V aver ≥V low , then disconnect the balancing circuit of each battery cell and end this process; if it is determined that Vaver <V low , then execute step S14.

[0042] S14, connect the charging unit of the power type lithium ion battery pack and determine V aver Is it higher than V high Or whether the power type lithium ion battery pack starts to discharge. aver ≥V high or I out >0, disconnect the charging unit of the power lithium-ion battery pack and end this process; otherwise, end this process directly.

[0043] Further, if it is determined that the power type lithium-ion battery pack is not in the half-charged storage mode, that is, K≠0, the following steps S21 to S23 are performed:

[0044] S21, judging whether the power type lithium ion battery pack is being charged or discharged. If it is determined that the power type lithium ion battery pack is being charged or discharged, that is, K=1, then executing step S22, carrying out overcharge / overdischarge management.

[0045] S22, V out With the charge alarm threshold V charge Compare. If V out ≥V charge , the charging unit is immediately turned off; if it is determined that V out <V charge , then execute step S23.

[0046] S23, V out and the discharge alarm threshold V discharge Compare. If V out <V discharge , the load devices are shut down one by one in the order of their priority from low to high to reduce the discharge power; otherwise, this process ends.

[0047] Further, if it is determined that the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, the following steps S31 to S33 are performed:

[0048] S31, judging whether the power type lithium ion battery pack is in a high density task mode. If it is determined that the power type lithium ion battery pack is in a high density task mode, that is, K=2, then executing step S32, carrying out balancing management.

[0049] S32, according to the maximum battery cell voltage max{V1~V n} and the minimum battery cell voltage min{V1~Vn}, the monomer dispersion ΔV=max{V1~V n}-min{V1~V n}.

[0050] S33, compare ΔV with the discrete threshold V. If it is determined that ΔV≥V, the small current balancing management is turned on, that is, the small current balancing switch of the high voltage battery cell is turned on to discharge the high voltage battery cell with a small balancing current; if it is determined that ΔV<V, the current process is terminated directly.

[0051] Further, if it is determined that the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, and the power type lithium ion battery pack is not in the high-density task mode, that is, K≠2, then the following steps S41 to S43 are performed:

[0052] S41, judging whether the power type lithium ion battery pack is in a low density task mode. If it is determined that the power type lithium ion battery pack is in a low density task mode, that is, K=3, then executing step S42, carrying out balancing management.

[0053] S42, according to the maximum battery cell voltage max{V1~V n} and the minimum battery cell voltage min{V1~V n}, and the monomer discreteness ΔV is calculated.

[0054] S43, compare ΔV with the discrete threshold V. If it is determined that ΔV≥V, the high current balancing management is turned on, that is, the high current balancing switch of the high voltage battery cell is turned on to discharge the high voltage battery cell with a large balancing current; if it is determined that ΔV<V, the current process is terminated directly.

[0055] It should be noted that balancing management can be divided into small current balancing management and large current balancing management according to the current mission mode, which is beneficial to extend the service life of power lithium-ion battery packs and improve on-orbit work safety while ensuring the load discharge requirements. Among them, large current balancing management is relative to small current balancing management.

[0056] In this embodiment, the charging unit is mainly used for charging control of the power type lithium ion battery pack and providing charging power for the power type lithium ion battery pack. The balancing circuit of each battery cell is mainly used for balancing management and providing a discharge channel of balancing current for each battery cell.

[0057] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0058] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A method for managing a power lithium-ion battery pack on track, characterized in that: include: Determine the current charge and discharge status and current mission mode of the power type lithium-ion battery pack; Real-time acquisition of the voltage V of the entire power lithium-ion battery pack out And the whole group output current I out , and the voltage of each battery cell V1~V n ; Where n represents the number of battery cells connected in series; According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management.

2. The on-track management method of a power lithium-ion battery pack according to claim 1, characterized in that: Determining the current charge and discharge state and the current task mode of the power type lithium ion battery pack includes: determining the current charge and discharge state and the current task mode of the power type lithium ion battery pack according to the working state identifier K of the power type lithium ion battery pack; wherein, when K=0, determining the current task mode of the power type lithium ion battery pack is: half-charged standby mode; when K=1, determining the current charge and discharge state and the current task mode of the power type lithium ion battery pack is: charging or discharging and not in the half-charged standby mode; when K=2, determining the current task mode of the power type lithium ion battery pack is: high-density task mode; when K=3, determining the current task mode of the power type lithium ion battery pack is: low-density task mode.

3. The on-track management method of a power lithium-ion battery pack according to claim 2, characterized in that: According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including: S11, when K=0, according to V1~V n , calculate the average value of the battery cell voltage V aver ; S12, V aver With the upper limit of the shelving voltage V high Compare; if V aver ≥V high , then connect the balancing circuit of each battery cell and end this process; if it is determined that V aver <V high , then execute step S13; S13, V aver With the lower limit of the voltage V low Compare; if V aver ≥V low , then disconnect the balancing circuit of each battery cell and end this process; if it is determined that V aver <V low , then execute step S14; S14, connect the charging unit of the power type lithium ion battery pack and determine V aver Is it higher than V high Or whether the power type lithium ion battery pack starts to discharge; if it is determined that V aver ≥V high or I out >0, disconnect the charging unit of the power lithium-ion battery pack and end this process; otherwise, end this process directly.

4. The on-track management method of a power lithium-ion battery pack according to claim 2, characterized in that: According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including: S21, when the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, determine whether the power type lithium ion battery pack is being charged or discharged; wherein, if it is determined that the power type lithium ion battery pack is being charged or discharged, that is, K=1, execute step S22; S22, V out With the charge alarm threshold V charge Compare; if V out ≥V charge , the charging unit is immediately turned off; if it is determined that V out <V charge , then execute step S23; S23, V out and the discharge alarm threshold V discharge Compare; if V out <V discharge , the load devices are shut down one by one in the order of their priority from low to high to reduce the discharge power; otherwise, this process ends.

5. The on-track management method of a power lithium-ion battery pack according to claim 2, characterized in that: According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including: S31, when the power type lithium ion battery pack is not in the half-charge standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, determine whether the power type lithium ion battery pack is in the high-density task mode; wherein, if it is determined that the power type lithium ion battery pack is in the high-density task mode, that is, K=2, execute step S32; S32, according to the maximum battery cell voltage max{V1~V n } and the minimum battery cell voltage min{V1~V n }, the monomer dispersion ΔV=max{V1~V n }-min{V1~V n }; S33, comparing ΔV with the discrete threshold V; if it is determined that ΔV≥V, then starting the small current balancing; if it is determined that ΔV<V, then directly ending this process.

6. The on-track management method of a power lithium-ion battery pack according to claim 2, characterized in that: According to the current charge and discharge state of the power type lithium-ion battery pack and the current task mode, combined with the real-time acquired V out ,I out 、V1~V n , respectively carry out overcharge management, over-discharge management, balance management and half-charge shelving management, including: S41, when the power type lithium ion battery pack is not in the half-charged standby mode, that is, K≠0, and the power type lithium ion battery pack is not charging or discharging, that is, K≠1, and the power type lithium ion battery pack is not in the high-density task mode, that is, K≠2, determine whether the power type lithium ion battery pack is in the low-density task mode; wherein, if it is determined that the power type lithium ion battery pack is in the low-density task mode, that is, K=3, then execute step S42; S42, according to the maximum battery cell voltage max{V1~V n } and the minimum battery cell voltage min{V1~V n }, the monomer dispersion ΔV=max{V1~V n }-min{V1~V n }; S43, comparing ΔV with the discrete threshold V; if it is determined that ΔV≥V, then starting the large current balancing; if it is determined that ΔV<V, then directly ending this process.

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