Safety protection method for power distribution automation terminal battery

Abstract

The invention discloses a safety protection method for a power distribution automation terminal battery, a power distribution terminal comprises a battery pack, and the battery pack comprises a plurality of single batteries; the safety protection method comprises the following steps: in a current sampling period, controlling the battery pack to discharge, and obtaining a discharge voltage average value of each single battery in the current sampling period; generating a discharge risk value according to the number of the first preset single batteries and the degree that the discharge voltage average value of each first preset single battery deviates from the normal discharge voltage range; the first preset single battery is a single battery of which the discharge voltage average value is smaller than or equal to the minimum value of a normal discharge voltage range; when it is determined that the discharge risk value is larger than the discharge risk threshold value, a discharge high-risk warning signal is generated. Whether the battery pack is abnormal or not during operation is comprehensively judged according to the number of the single batteries with abnormal discharge and the abnormal degree of the discharge voltage average value, and damage to the power distribution terminal due to the fact that the abnormality of the battery pack during operation is not treated in time is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution terminals, and in particular to a safety protection method for a power distribution automation terminal battery. Background Art

[0002] The power distribution terminal includes a battery pack, which is mainly used to power the power distribution terminal equipment. These terminal equipment need to realize accurate telemetry, telesignaling, remote control, and remote adjustment functions, so they must be kept in a safe working environment at all times. When the main power supply fails, the battery pack of the distribution terminal can maintain the operation of the terminal equipment for a certain period of time and complete the opening and closing operations of the switch. It is an important component to ensure the stable operation of the distribution network. Therefore, the safety of the battery pack of the distribution terminal is particularly important. However, there is currently no effective detection method to detect whether the operating status of the battery pack of the distribution terminal is good. Summary of the invention

[0003] The present invention provides a safety protection method for distribution automation terminal batteries to determine whether the operating state of the battery pack of the distribution terminal is abnormal, so as to prevent the battery pack from causing damage due to abnormalities that are not handled in time during operation.

[0004] According to one aspect of the present invention, a safety protection method for a distribution automation terminal battery is provided, wherein the distribution terminal comprises a battery pack, and the battery pack comprises a plurality of single cells;

[0005] The safety protection method for the distribution automation terminal battery includes:

[0006] In the current sampling period, the battery pack is controlled to discharge, and an average discharge voltage of each of the single cells in the current sampling period is obtained;

[0007] A discharge risk value is generated according to the number of first preset single cells and the degree to which the average discharge voltage of each of the first preset single cells deviates from the normal discharge voltage range; the first preset single cell is a single cell whose average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range;

[0008] When it is determined that the discharge risk value is greater than a discharge risk threshold, a high discharge risk warning signal is generated.

[0009] Optionally, generating the discharge risk value according to the number of first preset single cells and the degree to which the average discharge voltage of each of the first preset single cells deviates from the normal discharge voltage range includes:

[0010] Generate a pressure discharge abnormality existence index according to a ratio of the number of the first preset single cells to the total number of single cells in the battery pack;

[0011] generating a discharge voltage abnormality index according to the extent to which the average discharge voltage of each of the first preset single cells deviates from the middle value of the normal discharge voltage range;

[0012] The discharge risk value is generated according to the discharge voltage abnormality existence index and the discharge voltage abnormality index.

[0013] Optionally, generating the discharge voltage abnormality index according to the degree to which the average discharge voltage of each of the first preset single cells deviates from the middle value of the normal discharge voltage range includes:

[0014] Calculating an average value of voltage deviation values ​​according to the voltage deviation values ​​of the first preset single cells, and using the average value of voltage deviation values ​​as the discharge voltage abnormality index;

[0015] Wherein, for each of the first preset single cells, the calculation process of the voltage deviation value includes:

[0016] generating a discharge voltage difference value according to a difference between an average value of the discharge voltage of the first preset single battery and a middle value of the normal discharge voltage range;

[0017] The voltage deviation value is generated according to a ratio of the discharge voltage difference to a middle value of the normal discharge voltage range.

[0018] Optionally, generating the discharge risk value according to the discharge voltage abnormality existence index and the discharge voltage abnormality index includes:

[0019] The discharge risk value is generated according to the square root of the sum of the first proportional value and the second proportional value; wherein the first proportional value is the square of the product of the discharge voltage abnormality existence index and the first weighting coefficient, the second proportional value is the square of the product of the discharge voltage abnormality index and the second weighting coefficient, and the sum of the first weighting coefficient and the second weighting coefficient is equal to one.

[0020] Optionally, when determining that the discharge risk value is greater than the discharge risk threshold, after generating a high-discharge risk warning signal, the method further includes:

[0021] In the next sampling period, controlling the battery pack to charge, and obtaining an average value of the charging resistance of each of the single cells in the next sampling period;

[0022] Generate a battery pack plate evaluation value according to the number of second preset single cells and the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold; the second preset single cells are single cells whose average value of the charging resistance is greater than the preset charging resistance threshold;

[0023] When it is determined that the battery plate evaluation value is greater than the battery plate evaluation threshold, a high-risk charging warning signal is generated.

[0024] Optionally, generating the battery pack plate evaluation value according to the number of second preset single cells and the degree to which the average value of the charging resistance of each of the second preset single cells deviates from a preset charging resistance threshold value includes:

[0025] Generate a charge resistance abnormality existence index according to a ratio of the number of the second preset single cells to the total number of single cells in the battery pack;

[0026] generating a discharge resistance abnormality index according to the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold;

[0027] The battery pack plate evaluation value is generated according to the charge resistance abnormality existence index and the discharge resistance abnormality index.

[0028] Optionally, generating the discharge resistance abnormality index according to the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold value includes:

[0029] Calculating an average value of resistance deviation values ​​according to the resistance deviation values ​​of each of the second preset single cells, and using the average value of resistance deviation values ​​as the discharge resistance abnormality index;

[0030] Wherein, for each of the second preset single cells, the calculation process of the resistance deviation value includes:

[0031] generating a charging resistance difference according to a difference between the second preset charging resistance average value of the single battery and the preset charging resistance threshold value;

[0032] The resistance deviation value is generated according to the ratio of the charging resistance difference to the preset charging resistance threshold.

[0033] Optionally, generating the battery pack plate evaluation value according to the charge resistance abnormality existence index and the discharge resistance abnormality index includes:

[0034] The battery pack plate evaluation value is generated according to the square root of the sum of the third proportional value and the fourth proportional value; wherein the third proportional value is the square of the product of the charging resistance abnormality existence index and the third weighting coefficient, the fourth proportional value is the square of the product of the discharge resistance abnormality index and the fourth weighting coefficient, and the sum of the third weighting coefficient and the fourth weighting coefficient is equal to one.

[0035] Optionally, when determining that the battery plate evaluation value is greater than the battery plate evaluation threshold, after generating a high-risk charging warning signal, the method further includes:

[0036] When the ratio of the number of single cells that meet the preset conditions to the total number of single cells in the battery pack is greater than the requirement threshold, a battery pack maintenance requirement signal is generated; the preset conditions include that the average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range and the average charging resistance is greater than the preset charging resistance threshold.

[0037] Optionally, when the ratio of the number of single cells that meet the preset condition to the total number of single cells in the battery pack is greater than the demand threshold, before generating the battery pack maintenance demand signal, the method further includes:

[0038] Establishing a two-dimensional coordinate map of the battery pack;

[0039] According to the two-dimensional coordinate diagram of the battery pack, obtaining coordinate data of each of the first preset single cells;

[0040] According to the two-dimensional coordinate diagram of the battery pack, obtaining coordinate data of each of the second preset single cells;

[0041] The number of the single cells that meet the preset condition is determined according to the coordinate data of each of the first preset single cells and the coordinate data of each of the second preset single cells.

[0042] The technical solution of the embodiment of the present invention detects the discharge voltage of each single cell in the battery pack, and comprehensively determines whether the battery pack has any abnormality during operation according to the number of single cells with abnormal discharge and the degree of abnormality of the average discharge voltage, thereby preventing the battery pack from causing damage to the distribution terminal if the abnormality is not handled in time during operation, thereby improving the safety of the battery pack of the distribution terminal.

[0043] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1A flow chart of a safety protection method for a distribution automation terminal battery provided by an embodiment of the present invention;

[0046] Figure 2 A flow chart of another method for protecting a battery in a distribution automation terminal provided by an embodiment of the present invention;

[0047] Figure 3 A flowchart of another method for protecting a battery in a distribution automation terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1 The present invention provides a flow chart of a method for protecting the battery of a power distribution automation terminal. The present invention can be applied to detecting the operating status of a battery pack of a power distribution terminal. The method can be executed by a safety protection device for the battery of a power distribution automation terminal. The safety protection device for the battery of a power distribution automation terminal can be implemented in the form of hardware and / or software. The power distribution terminal includes a battery pack, and the battery pack includes a plurality of single cells. Figure 1 As shown, the method includes:

[0051] S110: In the current sampling period, the battery pack is controlled to discharge, and an average value of the discharge voltage of each single battery in the current sampling period is obtained.

[0052] In the monitoring process of the entire power distribution terminal, multiple sampling cycles can be set. The duration of each sampling cycle is the same. The sampling cycle can be 20 minutes or 30 minutes. It can be set according to the needs. The sampling interval is set, such as one minute. Then, the discharge voltage value of each single cell is collected every sampling interval. For each single cell, the average discharge voltage of the single cell is calculated according to the discharge voltage values ​​collected at each sampling moment within the sampling cycle.

[0053] S120: Generate a discharge risk value according to the number of first preset single cells and the degree to which the average discharge voltage of each first preset single cell deviates from the normal discharge voltage range; the first preset single cell is a single cell whose average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range.

[0054] The normal discharge voltage range is set by the relevant personnel according to the performance of the battery pack, and is used to characterize the range of the discharge voltage of the single cell when the single cell discharges normally. For each single cell, if the average discharge voltage of the single cell in the current sampling period is less than or equal to the minimum value of the normal discharge voltage range, a discharge voltage too low signal is generated, and the single cell is marked as a battery with too low discharge voltage, where the battery with too low discharge voltage is the first preset single cell; if the average discharge voltage is within the normal discharge voltage range, a discharge voltage normal signal is generated, and the single cell is marked as a battery with normal discharge voltage; if the average discharge voltage is greater than or equal to the maximum value of the normal discharge voltage range, a discharge voltage too high signal is generated, a discharge voltage warning is issued, and the single cell is marked as a battery with too high discharge voltage.

[0055] For each first preset single cell, the degree to which the average discharge voltage value of the first preset single cell deviates from the normal discharge voltage range can be characterized by the degree to which the average discharge voltage value of the first preset single cell deviates from the middle value of the normal discharge voltage range. The degree of deviation can be characterized by the difference between the average discharge voltage value and the middle value or the standard deviation between the average discharge voltage value and the middle value, or can be characterized by other methods, which are not specifically limited here. The middle value of the normal discharge voltage range is equal to the sum of the minimum value and the maximum value of the normal discharge voltage range divided by 2.

[0056] In an optional implementation, the discharge risk value is generated according to a weighted sum of the proportion of the number of first preset single cells and the average value of the degree to which the average value of the discharge voltage of each first preset single cell deviates from the normal discharge voltage range.

[0057] S130: When it is determined that the discharge risk value is greater than the discharge risk threshold, a discharge high risk warning signal is generated.

[0058] The discharge risk threshold is used to characterize the maximum value of the discharge risk value corresponding to the normal discharge of the battery pack. When it is determined that the discharge risk value is greater than the discharge risk threshold, a high-discharge risk warning signal is generated, wherein the high-discharge risk warning signal is not limited to voice, text, light, etc., to warn the user that the battery pack has abnormal discharge. If it is determined that the discharge risk value is less than or equal to the discharge risk threshold, a low-discharge risk signal is generated, the next sampling cycle is entered, and step S110 is re-executed, that is, the smaller the discharge risk value, the more normal the discharge state of the battery pack is.

[0059] The technical solution of the embodiment of the present invention detects the discharge voltage of each single cell in the battery pack, and comprehensively determines whether the battery pack has any abnormality during operation according to the number of single cells with abnormal discharge and the degree of abnormality of the average discharge voltage, thereby preventing the battery pack from causing damage to the distribution terminal if the abnormality is not handled in time during operation, thereby improving the safety of the battery pack of the distribution terminal.

[0060] Figure 2 A flowchart of another method for protecting a battery in a power distribution automation terminal provided by an embodiment of the present invention is provided. Figure 2 , optionally, the method includes:

[0061] S111: In the current sampling period, the battery pack is controlled to discharge, and an average discharge voltage value of each single battery in the current sampling period is obtained.

[0062] S121: Generate a discharge risk value according to the number of first preset single cells and the degree to which the average discharge voltage of each first preset single cell deviates from the normal discharge voltage range; the first preset single cell is a single cell whose average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range.

[0063] S131: When it is determined that the discharge risk value is greater than the discharge risk threshold, a discharge high risk warning signal is generated.

[0064] S141: In the next sampling period, control the battery pack to charge, and obtain the average value of the charging resistance of each single battery in the next sampling period.

[0065] For each single cell, in the next sampling period, the average value of the charging resistance of the single cell is calculated according to the charging resistance collected at each sampling moment.

[0066] S151: Generate a battery pack plate evaluation value according to the number of second preset single cells and the degree to which the average charging resistance of each second preset single cell deviates from the preset charging resistance threshold; the second preset single cell is a single cell whose average charging resistance is greater than the preset charging resistance threshold.

[0067] The preset charging resistance threshold is the maximum value that characterizes the normal charging resistance of the single cell during the charging process, and is the maximum resistance value on the single cell plate during the normal charging process of the single cell. The preset charging resistance threshold is set by relevant personnel in this field according to the protection requirements of the single cell and the performance of the single cell plate. The obtained average charging resistance of each single cell is compared with the preset charging resistance threshold. If the average charging resistance is less than or equal to the preset charging resistance threshold, a normal charging resistance signal is generated, and the single cell is marked as a normal charging resistance battery. If the average charging resistance is greater than the preset charging resistance threshold, a charging resistance abnormality signal is generated, and the single cell is marked as a charging resistance abnormality battery, wherein the charging resistance abnormality battery is the second preset single cell.

[0068] The degree to which the average charging resistance value of each second preset single cell deviates from the preset charging resistance threshold value can be characterized by the difference between the average charging resistance value and the preset charging resistance threshold value, or the standard deviation between the average charging resistance value and the preset charging resistance threshold value, or can be characterized in other ways, which are not specifically limited here.

[0069] In an optional implementation, the battery pack plate evaluation value is generated according to a weighted sum of the proportion of the number of second preset single cells and the average value of the degree to which the average value of the charging resistance of each second preset single cell deviates from a preset charging resistance threshold.

[0070] S161: When it is determined that the battery pack plate evaluation value is greater than the battery pack plate evaluation threshold, a high-risk charging warning signal is generated.

[0071] The battery pack plate evaluation threshold is the maximum value that indicates that the battery pack is charging normally, and is set by relevant personnel in this field according to the requirements of battery pack safety protection and the performance of the battery pack plate. If the battery pack plate evaluation value is less than or equal to the battery pack plate evaluation threshold, a battery pack plate normal signal is generated, indicating that the smaller the battery pack plate evaluation value, the more normal the state of the battery pack plate; if the battery pack plate evaluation value is greater than the battery pack plate evaluation threshold, a high-risk charging warning signal is generated, indicating that the larger the battery pack plate evaluation value, the more abnormal the state of the battery pack plate, and it is necessary to warn of abnormal battery pack plate conditions.

[0072] S171: When the ratio of the number of single cells that meet the preset conditions to the total number of single cells in the battery pack is greater than the requirement threshold, a battery pack maintenance requirement signal is generated; the preset conditions include that the average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range and the average charging resistance is greater than the preset charging resistance threshold.

[0073] The number of single cells that meet the preset conditions is obtained, that is, the number of single cells that meet the following two conditions at the same time: the average value of the discharge voltage is less than or equal to the minimum value of the normal discharge voltage range, and the average value of the charging resistance is greater than the preset charging resistance threshold. The ratio of the number of single cells that meet the preset conditions to the total number of single cells in the battery pack is used as the battery pack maintenance demand index.

[0074] The demand threshold is the maximum value of the battery pack maintenance demand index corresponding to the time when the battery pack does not need maintenance. If the battery pack maintenance demand index is less than or equal to the demand threshold, a battery pack maintenance-free signal is generated, indicating that the smaller the battery pack maintenance demand index is, the smaller the demand for battery pack maintenance is. If the battery pack maintenance demand index is greater than the demand threshold, a battery pack maintenance demand signal is generated, indicating that the higher the battery pack maintenance demand index is, the higher the demand for battery pack maintenance is, and the battery pack needs to be maintained in a timely manner.

[0075] Optionally, before S171, the step further includes determining the number of single cells that meet a preset condition, specifically:

[0076] Establish a two-dimensional coordinate diagram of the battery pack; obtain coordinate data of each first preset single battery according to the two-dimensional coordinate diagram of the battery pack; obtain coordinate data of each second preset single battery according to the two-dimensional coordinate diagram of the battery pack; determine the number of single batteries that meet the preset conditions based on the coordinate data of each first preset single battery and the coordinate data of each second preset single battery.

[0077] A two-dimensional coordinate system is established, and each single cell in the battery pack is brought into the two-dimensional coordinate system to generate a two-dimensional coordinate map of the battery pack. Each single cell has a unique coordinate data in the two-dimensional coordinate map, and different single cells have different coordinate data.

[0078] After calculating the average discharge voltage of each single cell according to the aforementioned step S111, it is possible to determine which single cells are the first preset single cells, and then obtain the coordinate data of each first preset single cell from the two-dimensional coordinate map. After calculating the average charging resistance of each single cell according to the aforementioned step S141, it is possible to determine which single cells are the second preset single cells, and then obtain the coordinate data of each second preset single cell from the two-dimensional coordinate map. For each first preset single cell, the coordinate data of the first preset single cell is compared with the coordinate data of each second preset single cell one by one, and the coordinate coincidence value is calculated, and the coordinate coincidence value is compared with 0, and all first preset single cells are traversed, and the number of times the coordinate coincidence value is equal to 0 is counted, and it is used as the number of single cells that meet the preset conditions. Among them, the coordinate coincidence value Zc satisfies the following formula:

[0079] Zc=(X1-X2)+(Y1-Y1); wherein X1 is the coordinate value of the X axis of the first preset single cell, X2 is the coordinate value of the X axis of the second preset single cell, Y1 is the coordinate value of the Y axis of the first preset single cell, and Y2 is the coordinate value of the Y axis of the second preset single cell.

[0080] This embodiment detects the discharge risk of the battery pack and the charging resistance of the battery pack plate respectively, determines whether the operating status of the battery pack of the distribution terminal is abnormal, prevents the battery pack from causing damage to the single battery of the distribution terminal due to abnormalities that are not handled in time during operation, and improves the safety of the battery pack of the distribution terminal; this embodiment can also determine the maintenance needs of the battery pack and perform maintenance on the battery pack in time, thereby improving the timeliness of the maintenance of the battery pack of the distribution terminal and improving the safety of the battery pack of the distribution terminal.

[0081] Based on the above embodiments, a specific embodiment is provided. Figure 3 A flowchart of another method for protecting a battery in a power distribution automation terminal provided by an embodiment of the present invention is provided. Figure 3 , optionally, the method includes:

[0082] S112: In the current sampling period, the battery pack is controlled to discharge, and an average value of the discharge voltage of each single battery in the current sampling period is obtained.

[0083] S122: Generate a pressure discharge abnormality existence index according to a ratio of the number of first preset single cells to the total number of single cells in the battery pack.

[0084] The ratio of the number of single cells whose average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range to the total number of single cells in the battery pack is used as the voltage discharge abnormality existence index.

[0085] S132: Generate a discharge voltage abnormality index according to the degree to which the average discharge voltage of each first preset single battery cell deviates from the middle value of the normal discharge voltage range.

[0086] In an optional embodiment, the square sum of the difference between the average value of the discharge voltage of each first preset single battery and the middle value of the normal discharge voltage range is calculated, and then the square sum is divided by a first value and then the square root is calculated to obtain the discharge voltage abnormality index. The first value is equal to the number of the first preset single batteries minus one.

[0087] Alternatively, in another optional implementation: the voltage deviation value average is calculated based on the voltage deviation values ​​of each first preset single cell, and the voltage deviation value average is used as the discharge voltage abnormality index. The voltage deviation values ​​of each first preset single cell are summed and divided by the number of the first preset single cells to obtain the voltage deviation value average.

[0088] For each first preset single battery, the calculation process of the voltage deviation value includes:

[0089] A discharge voltage difference is generated according to a difference between a discharge voltage average value of the first preset single cell and a middle value of a normal discharge voltage range; and a voltage deviation value is generated according to a ratio of the discharge voltage difference to the middle value of the normal discharge voltage range.

[0090] The discharge voltage difference is obtained by subtracting the discharge voltage average value of the first preset single cell from the middle value of the normal discharge voltage range. The ratio of the discharge voltage difference to the middle value of the normal discharge voltage range is used to represent the degree to which the discharge voltage average value deviates from the normal discharge voltage range.

[0091] S142: Generate a discharge risk value according to the discharge voltage abnormality existence index and the discharge voltage abnormality index.

[0092] The discharge risk value is generated according to the weighted sum of the discharge voltage anomaly existence index and the discharge voltage anomaly index. Optionally, the discharge risk value is generated according to the square root of the sum of the first proportional value and the second proportional value; wherein the first proportional value is the square of the product of the discharge voltage anomaly existence index and the first weighting coefficient, the second proportional value is the square of the product of the discharge voltage anomaly index and the second weighting coefficient, and the sum of the first weighting coefficient and the second weighting coefficient is equal to one.

[0093] Specifically, the discharge risk value YF is calculated by the following formula:

[0094] YF=[(Vh·α) 2 +(Vm·β) 2 ] 1 / 2 ; Wherein, Vh is the discharge voltage abnormality existence index, Vm is the discharge voltage abnormality index, α is the first weighting coefficient, β is the second weighting coefficient, α+β=1, α and β are set by relevant personnel in this field according to the safety protection requirements of the battery pack or the safety performance of the battery pack.

[0095] S152: When it is determined that the discharge risk value is greater than the discharge risk threshold, a discharge high risk warning signal is generated.

[0096] S162: In the next sampling period, control the battery pack to charge, and obtain the average value of the charging resistance of each single battery in the next sampling period.

[0097] S172: Generate a charge resistance abnormality existence index according to the ratio of the number of the second preset single cells to the total number of the single cells in the battery pack.

[0098] The ratio of the number of the second preset single cells to the total number of the single cells in the battery pack is used as a charge resistance abnormality existence index.

[0099] S182: Generate a discharge resistance abnormality index according to the degree to which the average value of the charging resistance of each second preset single battery cell deviates from the preset charging resistance threshold.

[0100] In an optional implementation, the square sum of the difference between the average charging resistance of each second preset single cell and the preset charging resistance threshold is calculated, and then the square sum is divided by a second value and then the square root is calculated to obtain the discharge resistance abnormality index. The second value is equal to the number of the second preset single cells minus one.

[0101] Alternatively, in another optional implementation: the average value of the resistance deviation degree is calculated according to the resistance deviation degree values ​​of each second preset single cell, and the average value of the resistance deviation degree is used as the discharge resistance abnormality index. The resistance deviation degree values ​​of each second preset single cell are summed and divided by the number of the second preset single cells to obtain the average value of the resistance deviation degree.

[0102] For each second preset single cell, the calculation process of the resistance deviation value includes:

[0103] A charging resistance difference is generated according to a difference between the second preset single cell charging resistance average value and a preset charging resistance threshold; and a resistance deviation value is generated according to a ratio of the charging resistance difference to the preset charging resistance threshold.

[0104] Specifically, the charging resistance difference is obtained by subtracting the charging resistance average value of the second preset single battery from the preset charging resistance threshold, and the ratio of the charging resistance difference to the preset charging resistance threshold is used to represent the degree to which the charging resistance average value deviates from the preset charging resistance threshold.

[0105] S192: Generate a battery pack plate evaluation value according to the charge resistance abnormality existence index and the discharge resistance abnormality index.

[0106] The discharge risk value is generated according to the weighted sum of the charge resistance abnormality index and the discharge resistance abnormality index. Optionally, the battery pack plate evaluation value is generated according to the square root of the sum of the third proportional value and the fourth proportional value; wherein the third proportional value is the square of the product of the charge resistance abnormality index and the third weighting coefficient, the fourth proportional value is the square of the product of the discharge resistance abnormality index and the fourth weighting coefficient, and the sum of the third weighting coefficient and the fourth weighting coefficient is equal to one.

[0107] Specifically, the battery pack plate evaluation value YH is calculated by the following formula:

[0108] YH=[(Rh·γ) 2 +(Vm·δ) 2 ] 1 / 2 ; Wherein, Rh is the sufficient abnormality existence index, Vm is the discharge resistance abnormality index, γ is the third weighting coefficient, δ is the fourth weighting coefficient, γ+δ=1, γ and δ are set by relevant personnel in this field according to the safety protection requirements of the battery pack or the safety performance of the battery pack plate.

[0109] S202: When it is determined that the battery pack plate evaluation value is greater than the battery pack plate evaluation threshold, a high-risk charging warning signal is generated.

[0110] S212: When the ratio of the number of single cells that meet the preset condition to the total number of single cells in the battery pack is greater than a demand threshold, a battery pack maintenance demand signal is generated.

[0111] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0112] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A safety protection method for distribution automation terminal batteries, characterized in that: The power distribution terminal includes a battery pack, and the battery pack includes a plurality of single cells; The safety protection method for the distribution automation terminal battery includes: In the current sampling period, the battery pack is controlled to discharge, and an average discharge voltage of each of the single cells in the current sampling period is obtained; A discharge risk value is generated according to the number of first preset single cells and the degree to which the average discharge voltage of each of the first preset single cells deviates from the normal discharge voltage range; the first preset single cell is a single cell whose average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range; When it is determined that the discharge risk value is greater than a discharge risk threshold, a discharge high risk warning signal is generated.

2. The safety protection method for distribution automation terminal battery according to claim 1 is characterized in that: The generating of the discharge risk value according to the number of the first preset single cells and the degree to which the average discharge voltage of each of the first preset single cells deviates from the normal discharge voltage range comprises: Generate a pressure discharge abnormality existence index according to a ratio of the number of the first preset single cells to the total number of single cells in the battery pack; generating a discharge voltage abnormality index according to the extent to which the average discharge voltage of each of the first preset single cells deviates from the middle value of the normal discharge voltage range; The discharge risk value is generated according to the discharge voltage abnormality existence index and the discharge voltage abnormality index.

3. The safety protection method for distribution automation terminal battery according to claim 2 is characterized in that: The generating of the discharge voltage abnormality index according to the degree to which the average discharge voltage of each of the first preset single cells deviates from the middle value of the normal discharge voltage range comprises: Calculating an average value of voltage deviation values ​​according to the voltage deviation values ​​of the first preset single cells, and using the average value of voltage deviation values ​​as the discharge voltage abnormality index; Wherein, for each of the first preset single cells, the calculation process of the voltage deviation value includes: generating a discharge voltage difference value according to a difference between an average value of the discharge voltage of the first preset single battery and a middle value of the normal discharge voltage range; The voltage deviation value is generated according to a ratio of the discharge voltage difference to a middle value of the normal discharge voltage range.

4. The safety protection method for distribution automation terminal battery according to claim 2 is characterized in that: The generating the discharge risk value according to the discharge voltage abnormality existence index and the discharge voltage abnormality index comprises: The discharge risk value is generated according to the square root of the sum of the first proportional value and the second proportional value; wherein the first proportional value is the square of the product of the discharge voltage abnormality existence index and the first weighting coefficient, the second proportional value is the square of the product of the discharge voltage abnormality index and the second weighting coefficient, and the sum of the first weighting coefficient and the second weighting coefficient is equal to one.

5. The safety protection method for distribution automation terminal battery according to claim 1 is characterized in that: After generating a high-risk discharge warning signal when it is determined that the discharge risk value is greater than the discharge risk threshold, the method further includes: In the next sampling period, controlling the battery pack to charge, and obtaining an average value of the charging resistance of each of the single cells in the next sampling period; Generate a battery pack plate evaluation value according to the number of second preset single cells and the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold; the second preset single cells are single cells whose average value of the charging resistance is greater than the preset charging resistance threshold; When it is determined that the battery plate evaluation value is greater than the battery plate evaluation threshold, a high-risk charging warning signal is generated.

6. The safety protection method for distribution automation terminal battery according to claim 5 is characterized in that: The generating of the battery pack plate evaluation value according to the number of the second preset single cells and the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold value comprises: Generate a charge resistance abnormality existence index according to a ratio of the number of the second preset single cells to the total number of single cells in the battery pack; generating a discharge resistance abnormality index according to the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold; The battery pack plate evaluation value is generated according to the charge resistance abnormality existence index and the discharge resistance abnormality index.

7. The safety protection method for distribution automation terminal battery according to claim 6 is characterized in that: The generating of the discharge resistance abnormality index according to the degree to which the average value of the charging resistance of each of the second preset single cells deviates from the preset charging resistance threshold comprises: Calculating an average value of resistance deviation values ​​according to the resistance deviation values ​​of each of the second preset single cells, and using the average value of resistance deviation values ​​as the discharge resistance abnormality index; Wherein, for each of the second preset single cells, the calculation process of the resistance deviation value includes: generating a charging resistance difference according to a difference between the second preset charging resistance average value of the single battery and the preset charging resistance threshold value; The resistance deviation value is generated according to the ratio of the charging resistance difference to the preset charging resistance threshold.

8. The safety protection method for distribution automation terminal battery according to claim 6 is characterized in that: The generating the battery pack plate evaluation value according to the charge resistance abnormality existence index and the discharge resistance abnormality index comprises: The battery pack plate evaluation value is generated according to the square root of the sum of the third proportional value and the fourth proportional value; wherein the third proportional value is the square of the product of the charging resistance abnormality existence index and the third weighting coefficient, the fourth proportional value is the square of the product of the discharge resistance abnormality index and the fourth weighting coefficient, and the sum of the third weighting coefficient and the fourth weighting coefficient is equal to one.

9. The safety protection method for distribution automation terminal battery according to claim 5, characterized in that: When it is determined that the battery plate evaluation value is greater than the battery plate evaluation threshold, after generating a high-risk charging warning signal, the method further includes: When the ratio of the number of single cells that meet the preset conditions to the total number of single cells in the battery pack is greater than the requirement threshold, a battery pack maintenance requirement signal is generated; the preset conditions include that the average discharge voltage is less than or equal to the minimum value of the normal discharge voltage range and the average charging resistance is greater than the preset charging resistance threshold.

10. The safety protection method for distribution automation terminal battery according to claim 9, characterized in that: When the ratio of the number of single cells that meet the preset condition to the total number of single cells in the battery pack is greater than the demand threshold, before generating the battery pack maintenance demand signal, the method further includes: Establishing a two-dimensional coordinate map of the battery pack; According to the two-dimensional coordinate diagram of the battery pack, obtaining coordinate data of each of the first preset single cells; According to the two-dimensional coordinate diagram of the battery pack, obtaining coordinate data of each of the second preset single cells; The number of the single cells that meet the preset condition is determined according to the coordinate data of each of the first preset single cells and the coordinate data of each of the second preset single cells.

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