Online discharge capacity system of DC battery pack for station

Abstract

The invention discloses an online discharge capacity core system for a station-used DC battery group, and relates to the technical field of power systems. The invention continuously collects the voltage, temperature and internal resistance parameters of a battery during the continuous discharge process, and respectively analyzes and obtains the voltage evaluation index, temperature evaluation index and internal resistance evaluation index of the battery during the continuous discharge process, further extracts the voltage evaluation index, temperature evaluation index and internal resistance evaluation index, sets respective weight coefficients, multiplies and sums them to obtain a health evaluation index, presets a threshold index of the health evaluation index, compares the health evaluation index of each battery with the threshold index, and judges it as unqualified if it is higher than the threshold index, otherwise it is judged as qualified, thereby comprehensively evaluating the use status of the battery, and solving the problem that it is difficult to comprehensively and accurately evaluate the health status of the battery in the prior art, and lacks multi-parameter comprehensive analysis and quantitative evaluation means.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to an online discharge capacity-nuclear system for a station-use DC battery pack. Background Art

[0002] In the power system, the station DC power supply system is a key part to ensure the stable operation of power equipment, and the battery pack is a backup power source, and its performance stability and reliability are crucial.

[0003] However, the online discharge nuclear capacity system of the DC battery group for the station in the prior art still has the following deficiencies in the monitoring and maintenance of the battery group:

[0004] It is difficult to conduct a comprehensive and accurate assessment of the health status of batteries, and there is a lack of multi-parameter comprehensive analysis and quantitative assessment methods. It is impossible to detect potential battery problems in time and provide early warnings, which may lead to sudden battery failures, affecting the stability of the power system, increasing the risk of power outages and operation and maintenance costs.

[0005] In addition, when a battery abnormality is found, corresponding processing cannot be carried out according to the degree of battery abnormality, and the degree of intelligence is low.

[0006] To this end, an online discharge nuclear capacity system for station-use DC battery packs was launched. Summary of the invention

[0007] In order to solve the problems raised in the background technology, the present application provides an online discharge capacity-nulling system for a station-use DC battery pack.

[0008] The online discharge capacity verification system of the station-use DC battery group provided in the present application adopts the following technical solution: the online discharge capacity verification system of the station-use DC battery group comprises:

[0009] Discharge core capacity module: including test preset unit, load supplement unit and load configuration unit;

[0010] The test preset unit is used to preset the automatic execution time of the discharge core capacity, and after reaching the preset automatic execution time, the battery is first divided into X sections; then the X sections of batteries and the DCDC module are connected, and the discharge operation is performed according to the preset standard;

[0011] The load supplement unit is used to determine that the output power is insufficient and start the charger to supplement the power if the battery output power is lower than the preset power during the capacity verification process;

[0012] The load configuration unit is used to discharge the nuclear capacity in parallel with the real load and the dummy load by using the preset nuclear capacity parameters when the real load in the substation cannot meet the discharge operation according to the preset standard;

[0013] Parameter monitoring module: collects the operating parameters of X batteries during the discharge process and conducts a comprehensive evaluation to obtain the health assessment index jks corresponding to each battery during the current discharge process; the operating parameters include voltage, temperature and internal resistance; based on the health assessment index jks corresponding to each battery during the current discharge process, the use status of each battery is determined; the use status includes qualified and unqualified;

[0014] Alarm processing module: Mark the batteries whose usage status is judged to be unqualified and execute corresponding steps for processing.

[0015] Optionally, a comprehensive evaluation is performed on the voltage parameters of each battery during the continuous discharge process, specifically:

[0016] Pre-constructing a voltage standard curve for each battery during the discharge process; extracting the voltage value of each battery at each sampling moment during the current discharge process, and calculating the difference with the voltage value at the same moment in the corresponding voltage standard curve and taking the absolute value, to obtain the voltage deviation value of each battery at each sampling moment during the current discharge process;

[0017] The actual allowable value corresponding to the preset voltage deviation value; if the voltage deviation value calculated at a certain sampling moment in each battery is higher than the preset actual allowable value, the voltage deviation value higher than the actual allowable value is marked as an abnormal fluctuation value;

[0018] The number of abnormal fluctuation values ​​of each battery during the continuous discharge process is counted, which is recorded as the number of abnormal pressure hg1; at the same time, the average of each group of abnormal fluctuation values ​​of each battery during the continuous discharge process is calculated, and the calculated average is recorded as the average value of abnormal pressure hg2;

[0019] The voltage change rate is calculated for the voltage values ​​of each battery at adjacent sampling moments during the current discharge process; each group of voltage change rates calculated for each battery during the current discharge process are compared with a set reference change rate, which is obtained by extracting the voltage change rate corresponding to two groups of adjacent time points in the voltage standard curve as the reference change rate corresponding to the voltage change rate of each battery at each adjacent sampling moment;

[0020] If a certain group of voltage change rates of each battery in the current discharge process is higher than the corresponding reference change rate, the voltage change rate higher than the corresponding reference change rate is marked as an abnormal change rate; the number of abnormal change rates of each battery in the discharge process is counted as the number of abnormal changes, the number of abnormal changes is multiplied by the duration between adjacent sampling moments, and the multiplication result is used as the abnormal voltage duration hg3 of each battery;

[0021] According to the formula The number of abnormal pressure hg1, the average value of abnormal pressure hg2 and the duration of abnormal pressure hg3 of each battery are weighted and calculated to obtain the voltage evaluation index hya corresponding to each battery; , as well as They respectively represent the allowed number of abnormal pressures, the preset actual allowed value corresponding to the voltage deviation value, and the allowed duration of abnormal pressures; t1, t2, and t3 are the influence weight factors corresponding to the number of abnormal pressures hg1, the average abnormal pressure hg2, and the duration of abnormal pressure hg3.

[0022] Optionally, a comprehensive evaluation is performed on the temperature parameters of each battery during the discharge process, specifically:

[0023] Preset the maximum allowable temperature value of each battery during the discharge process; extract the temperature value of each battery during the current discharge process, and construct a temperature change curve for each battery, map the preset maximum allowable temperature value as a threshold line in the temperature change curve, mark the part of the temperature change curve that is higher than the threshold line, count the duration corresponding to the marked part and accumulate it to obtain the high temperature duration; at the same time, identify the highest point in the temperature change curve, and use the temperature value corresponding to the highest point as the peak temperature value;

[0024] Extract the temperature values ​​of each battery at each time point during the current discharge process, calculate the average value, and use the calculated average value as the average temperature value; mark the high temperature duration, peak temperature value and average temperature value corresponding to each battery as hp1, hp2 and hp3 respectively;

[0025] According to the formula The high temperature duration hp1, peak temperature value hp2 and average temperature value hp3 of each battery are weighted and calculated to obtain the temperature evaluation index hyb corresponding to each battery; and They represent the allowable high temperature duration and the maximum allowable temperature value respectively; g1, g2 and g3 are the influence weight factors of high temperature duration hp1, peak temperature value hp2 and average temperature value hp3 respectively.

[0026] Optionally, a comprehensive evaluation is performed on the internal resistance parameters of each battery during the continuous discharge process, specifically:

[0027] Extract the internal resistance value of each battery at each time point during the current discharge process, and calculate the internal resistance change rate at adjacent time points, that is, through the formula Calculate and get, where r is the internal resistance change rate, is the internal resistance value at the right time point among adjacent time points, is the internal resistance value at the left time point among adjacent time points;

[0028] The average value of the internal resistance change rate of each group of batteries calculated during the current discharge process is calculated to obtain the average internal resistance change rate of each battery during the current discharge process;

[0029] Arrange the internal resistance change rates of each group calculated for each battery in chronological order, and then calculate the difference between two adjacent groups of internal resistance change rates for each group of internal resistance change rates corresponding to each battery, that is, subtract the internal resistance change rate on the left from the internal resistance change rate on the right of the two adjacent groups of internal resistance change rates. If the difference calculation result of a group is negative, take the absolute value as the descending difference; if the difference calculation result of a group is positive, take it as the ascending difference;

[0030] Sum up all the rising differences and falling differences respectively to get the total rising value and the total falling value, and calculate the ratio of the rising total value / the falling total value to get the change trend ratio;

[0031] Preset the intervals of trend ratios corresponding to the change trend ratios, and set an average rate additional coefficient corresponding to the intervals of trend ratios of each group; match the change trend ratios calculated for each battery during the current discharge process with the intervals of trend ratios of each group, so as to obtain the average rate additional coefficient corresponding to each battery, and multiply the calculated internal resistance change average rate of each battery by the obtained average rate additional coefficient to obtain the internal resistance change additional rate of each battery during the current discharge process;

[0032] The threshold addition rate corresponding to the internal resistance change addition rate of each battery is preset, and the ratio of the internal resistance change addition rate of each battery during the current discharge duration / the threshold addition rate is calculated to obtain the internal resistance evaluation index hyc of each battery during the current discharge duration.

[0033] Optionally, the use status of each battery is determined, specifically:

[0034] Extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process, set the weight coefficients corresponding to the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc, respectively, multiply the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process by the corresponding set weight coefficients, and then sum them to obtain the health evaluation index jks of each battery in the current discharge process;

[0035] A threshold index of the health assessment index jks corresponding to each battery is preset. If the health assessment index jks of a battery during the current discharge process is higher than the preset threshold index, the battery usage status higher than the preset threshold index is judged as unqualified, otherwise it is judged as qualified.

[0036] Optionally, execute corresponding steps for processing, specifically:

[0037] M1: Extract the health assessment index jks of each marked battery, and calculate the difference between the index and the preset threshold index to obtain the hidden danger difference of each marked battery, preset the interval of each group of hidden danger differences corresponding to the hidden danger difference, set a health hazard level corresponding to each group of hidden danger difference interval, where the health hazard level includes a sub-health level and an alarm health level; match the hidden danger difference of each marked battery with the interval of each group of hidden danger differences to obtain the health hazard level corresponding to each marked battery; execute the corresponding steps based on the specific health hazard level of the marked battery.

[0038] Optionally, corresponding steps are performed based on the specific health hazard level of the marked battery, specifically:

[0039] M2: If the health hazard level is a sub-health level, the health assessment index jks of the marked battery during the next discharge and capacity verification process is analyzed. If it is still determined to be a sub-health level, the sub-health level is upgraded to an alarm health level.

[0040] Optionally, executing corresponding steps based on the specific health hazard level of the marked battery also includes:

[0041] M3: If the health hazard level is the alarm health level, extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of the marked battery and use them as the length, width and height of the three-dimensional rectangle respectively to construct a three-dimensional rectangular model corresponding to the marked battery;

[0042] Extracting the three-dimensional rectangular model corresponding to each type of battery fault from the pre-built fault database;

[0043] The similarity between the three-dimensional rectangular model of the marked battery and the three-dimensional rectangular models of each type of fault is calculated using the Euclidean distance, and the three-dimensional rectangular models of each type of fault are sorted from small to large according to the similarity, and the fault types corresponding to the first three groups of three-dimensional rectangular models are selected from the left as the type of fault cause of the marked battery;

[0044] Taking the location of the marked battery as the starting point, the operation and maintenance personnel closest to the starting point are obtained as the processing personnel, and an alarm signal is immediately sent to the processing personnel. The alarm signal includes the changes of the marked battery, its location, the health assessment index jks, the three-dimensional rectangular model and similar fault causes.

[0045] In summary, the present application includes at least one of the following beneficial technical effects:

[0046] The present invention continuously collects the voltage, temperature and internal resistance parameters of the battery during the discharge process, and analyzes them respectively to obtain the voltage evaluation index, temperature evaluation index and internal resistance evaluation index of the battery during the discharge process, further extracts the voltage evaluation index, temperature evaluation index and internal resistance evaluation index, sets their respective weight coefficients, multiplies them and sums them to obtain the health evaluation index, presets the threshold index of the health evaluation index, compares the health evaluation index of each battery with the threshold index, and judges it as unqualified if it is higher than the threshold index, otherwise it is qualified, thereby comprehensively evaluating the use status of the battery, solving the problem that it is difficult to comprehensively and accurately evaluate the health status of the battery in the prior art, and lacks multi-parameter comprehensive analysis and quantitative evaluation means;

[0047] The present invention marks and processes the batteries judged as unqualified. First, the difference between the marked battery health assessment index and the preset threshold index is calculated to obtain the hidden danger difference, the hidden danger difference interval and the corresponding health hidden danger level are preset, the health hidden danger level of the battery is obtained by matching, and targeted processing is performed according to the matched health hidden danger level, which solves the problem of low intelligence level in the prior art that when the battery is found to be abnormal, corresponding processing cannot be performed according to the degree of battery abnormality;

[0048] The present invention re-analyzes the health assessment index of the marked battery during the next discharge and capacity verification process when the health risk level is sub-healthy. If it is still determined to be sub-healthy, it will be upgraded to the alarm health level, thus realizing dynamic monitoring and hierarchical management of the battery health status, timely discovering potential problems and taking more stringent monitoring measures;

[0049] The present invention constructs a three-dimensional rectangular model by extracting the voltage evaluation index, temperature evaluation index and internal resistance evaluation index of the marked battery when the health hazard level is the alarm health level, and calculates the similarity with the three-dimensional rectangular model of each type of fault in the fault database, and screens out the most similar fault type as the type fault cause of the marked battery. At the same time, taking the location of the marked battery as the starting point, the nearest operation and maintenance personnel are obtained as the processing personnel and an alarm signal is immediately issued, which helps the operation and maintenance personnel to quickly and accurately understand the battery fault situation, prepare maintenance tools and plans in advance, improve fault handling efficiency, reduce the impact of battery faults on the power system, and ensure stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Further details, features and advantages of the present application are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0051] Figure 1 It is a principle block diagram of the present invention. DETAILED DESCRIPTION

[0052] Several embodiments of the present application will be described in more detail below with reference to the accompanying drawings so that those skilled in the art can implement the present application. The present application can be embodied in many different forms and purposes and should not be limited to the embodiments described herein. These embodiments are provided to make the present application comprehensive and complete, and to fully convey the scope of the present application to those skilled in the art. The embodiments do not limit the present application.

[0053] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0054] Example 1

[0055] See also Figure 1 As shown, the online discharge capacity control system of the station DC battery group includes a discharge capacity control module, a parameter monitoring module and an alarm processing module;

[0056] The discharge core capacity module includes a test preset unit, a load supplement unit and a load configuration unit;

[0057] The test preset unit is used to preset the automatic execution time of the discharge core capacity; it is set according to the actual load conditions of the substation and the characteristics of the battery, for example, the automatic execution time is set to be executed once every 3 months; and after the preset automatic execution time is reached, the battery is first divided into X sections; where X>4, the specific number of sections is set by the technician; then the X sections of batteries and the DCDC module are connected; after connection, the switch of the battery outlet diode in parallel is turned on, and the grouping switch of the DCDC module is closed at the same time, and the DCDC module raises the voltage of the X sections of batteries to be higher than the bus voltage, so that the X groups of batteries give priority to powering the bus, and the discharge operation is performed according to the preset standard; the preset standard is 0.1C discharge for 10 hours;

[0058] The load supplement unit is used to determine that the output power is insufficient and start the charger to supplement the power if the battery output power is lower than the preset power during the capacity-reducing process; maintain the stability of the discharge capacity-reducing process and ensure the normal power supply of the DC load;

[0059] The load configuration unit is used to discharge the core capacity in parallel with the real load and the dummy load by using the preset core capacity parameters when the real load in the substation cannot meet the discharge operation according to the preset standard; the core capacity parameters include discharge core capacity current, time, internal resistance calibration, equalization charge cut-off voltage, access bus voltage, discharge static time, charge static time, single core capacity cut-off voltage and dummy load current, etc.;

[0060] It should be noted that if the real load in the station is insufficient, the dummy load will be diverted according to the settings. For example, if it is calculated that the dummy load needs to share 5A current so that the total discharge current reaches the standard value, the system will automatically adjust the dummy load (ceramic resistor box) access resistance value to achieve dummy load diversion discharge, and the electric energy will be reasonably distributed among the DC system, real load and dummy load; changing the traditional all-dummy load discharge core capacity mode, reducing energy waste and safety risks;

[0061] The parameter monitoring module is used to collect the operating parameters of X batteries during the discharge process through preset sensors and conduct a comprehensive evaluation, so as to obtain the health assessment index jks corresponding to each battery during the current discharge process; the operating parameters include voltage, temperature and internal resistance; based on the health assessment index jks corresponding to each battery during the current discharge process, the use status of each battery is determined; the use status includes qualified and unqualified;

[0062] It should be noted that the voltage, temperature and internal resistance parameters of the battery are continuously collected through sensors installed on each battery (such as voltage sensor, temperature sensor, internal resistance sensor). These sensors convert physical quantities into electrical signals and transmit them to the parameter monitoring module.

[0063] Internal resistance is an important indicator of the health of the battery. As the battery ages, the plates corrode, or the active substances fall off, the internal resistance will gradually increase.

[0064] Comprehensively evaluate the voltage parameters of each battery during the discharge process, specifically:

[0065] According to the type and technical specifications of X batteries, a voltage standard curve of each battery during the discharge process is pre-constructed; for example, for lead-acid batteries, the voltage drops slowly at the beginning of discharge, and the voltage drop rate gradually accelerates as the depth of discharge increases, and the voltage drops rapidly near the end of discharge;

[0066] Extract the voltage value of each battery at each sampling moment during the current discharge process, and calculate the difference with the voltage value at the same moment in the corresponding voltage standard curve and take the absolute value to obtain the voltage deviation value of each battery at each sampling moment during the current discharge process;

[0067] The actual allowable value corresponding to the preset voltage deviation value is set to 0.1V; if the voltage deviation value calculated at a certain sampling moment in each battery is higher than the preset actual allowable value, the voltage deviation value higher than the actual allowable value is marked as an abnormal fluctuation value;

[0068] The number of abnormal fluctuation values ​​of each battery during the continuous discharge process is counted, which is recorded as the number of abnormal pressure hg1; at the same time, the average of each group of abnormal fluctuation values ​​of each battery during the continuous discharge process is calculated, and the calculated average is recorded as the average value of abnormal pressure hg2;

[0069] The voltage change rate is calculated for the voltage values ​​of each battery at adjacent sampling moments during the current discharge process; that is, the difference between the voltage values ​​at adjacent sampling moments is calculated, and the absolute value of the difference is taken and divided by the time between adjacent sampling moments; each group of voltage change rates calculated for each battery during the current discharge process is compared with a set reference change rate, and the reference change rate is obtained by extracting the voltage change rate corresponding to two groups of adjacent time points in the voltage standard curve, as the reference change rate corresponding to the voltage change rate of each battery at each adjacent sampling moment;

[0070] If a certain group of voltage change rates of each battery in the current discharge process is higher than the corresponding reference change rate, the voltage change rate higher than the corresponding reference change rate is marked as an abnormal change rate; the number of abnormal change rates of each battery in the discharge process is counted as the number of abnormal changes, the number of abnormal changes is multiplied by the duration between adjacent sampling moments, and the multiplication result is used as the abnormal voltage duration hg3 of each battery;

[0071] According to the formula The number of abnormal pressure hg1, the average value of abnormal pressure hg2 and the duration of abnormal pressure hg3 of each battery are weighted and calculated to obtain the voltage evaluation index hya corresponding to each battery; , as well as They respectively represent the number of allowed abnormal pressures, the preset actual allowed value corresponding to the voltage deviation value, and the allowed duration of abnormal pressures; the number of allowed abnormal pressures and the allowed duration of abnormal pressures are set by technical personnel; t1, t2, and t3 are the influence weight factors corresponding to the number of abnormal pressures hg1, the average value of abnormal pressures hg2, and the duration of abnormal pressures hg3, respectively;

[0072] It should be noted that for voltage parameters, the battery health status is quantified into specific values ​​or indicators by calculating various values ​​and performing formulaic evaluation. This quantification result makes it easier for operation and maintenance personnel to intuitively understand the battery performance status, and is also conducive to the automation and intelligence of battery management.

[0073] Comprehensively evaluate the temperature parameters of each battery during the discharge process, specifically:

[0074] According to the type and technical specifications of each battery, preset the maximum allowable temperature of each battery during the discharge process; for example, the best operating temperature of a general lead-acid battery is around 25°C, and the maximum allowable temperature is 40°C. The temperature thresholds of different types of batteries will vary and need to be set according to the specific battery characteristics;

[0075] Extract the temperature value of each battery during the current discharge process, and construct the temperature change curve of each battery. Map the preset maximum allowable temperature value as the threshold line in the temperature change curve, mark the part of the temperature change curve that is higher than the threshold line, count the duration corresponding to the marked part and accumulate it to obtain the high temperature duration; at the same time, identify the highest point in the temperature change curve, and use the temperature value corresponding to the highest point as the peak temperature value;

[0076] Extract the temperature values ​​of each battery at each time point during the current discharge process, calculate the average value, and use the calculated average value as the average temperature value; mark the high temperature duration, peak temperature value and average temperature value corresponding to each battery as hp1, hp2 and hp3 respectively;

[0077] According to the formula The high temperature duration hp1, peak temperature value hp2 and average temperature value hp3 of each battery are weighted and calculated to obtain the temperature evaluation index hyb corresponding to each battery; and They represent the high temperature allowable duration and the maximum allowable temperature value respectively; g1, g2 and g3 are the influence weight factors of the high temperature duration hp1, the peak temperature value hp2 and the average temperature value hp3 respectively;

[0078] It should be noted that the temperature assessment index is obtained by weighted calculation of the three temperature indicators, which realizes the quantitative evaluation of the thermal state of the battery. The quantitative result is convenient for unified management and comparison in the battery management system. Whether it is between different batteries in the same battery pack or between battery packs in different sites or equipment, the temperature assessment index can be used to intuitively understand the differences in battery thermal health.

[0079] Comprehensively evaluate the internal resistance parameters of each battery during the continuous discharge process, specifically:

[0080] Extract the internal resistance value of each battery at each time point during the current discharge process, and calculate the internal resistance change rate at adjacent time points, that is, through the formula Calculate and get, where r is the internal resistance change rate, is the internal resistance value at the right time point among adjacent time points, is the internal resistance value at the left time point among adjacent time points;

[0081] The average value of the internal resistance change rate of each group of batteries calculated during the current discharge process is calculated to obtain the average internal resistance change rate of each battery during the current discharge process;

[0082] Arrange the internal resistance change rates of each group calculated for each battery in chronological order, and then calculate the difference between two adjacent groups of internal resistance change rates for each group of internal resistance change rates corresponding to each battery, that is, subtract the internal resistance change rate on the left from the internal resistance change rate on the right of the two adjacent groups of internal resistance change rates. If the difference calculation result of a group is negative, take the absolute value as the descending difference; if the difference calculation result of a group is positive, take it as the ascending difference;

[0083] Sum up all the rising differences and falling differences respectively to get the total rising value and the total falling value, and calculate the ratio of the rising total value / the falling total value to get the change trend ratio;

[0084] The intervals of trend ratios of each group corresponding to the preset change trend ratio are set, and an average rate additional coefficient is set to correspond to the intervals of each group of trend ratios; the range of the average rate additional coefficient is set at 1.137-1.1275, and the larger the change trend ratio is, the higher the average rate additional coefficient is obtained by the corresponding matching; the change trend ratio calculated by each battery in the current discharge process is matched with the intervals of each group of trend ratios, so as to obtain the average rate additional coefficient corresponding to each battery, and the calculated internal resistance change average rate of each battery is multiplied by the obtained average rate additional coefficient to obtain the internal resistance change additional rate of each battery in the current discharge process;

[0085] According to the battery type of each battery, the threshold additional rate corresponding to the internal resistance change additional rate of each battery is preset, and the ratio of the internal resistance change additional rate of each battery during the current discharge duration / the threshold additional rate is calculated to obtain the internal resistance evaluation index hyc of each battery during the current discharge duration;

[0086] It should be noted that the internal resistance evaluation index is obtained by calculating the ratio of the internal resistance change addition rate to the threshold addition rate, thereby realizing a standardized evaluation of the internal resistance health status of each battery cell. This enables a battery pack containing multiple batteries to quickly and intuitively identify which batteries have relatively good internal resistance health status and which batteries may have major problems, thus facilitating operation and maintenance personnel to make overall management and maintenance decisions for the battery pack.

[0087] Determine the usage status of each battery, specifically:

[0088] Extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process, set the weight coefficients corresponding to the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc, respectively, multiply the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process by the corresponding set weight coefficients, and then sum them to obtain the health evaluation index jks of each battery in the current discharge process;

[0089] A threshold index of the health assessment index jks corresponding to each battery is preset. If the health assessment index jks of a battery during the current discharge process is higher than the preset threshold index, the battery usage status higher than the preset threshold index is judged as unqualified, otherwise it is judged as qualified;

[0090] The alarm processing module is used to mark the storage battery whose usage status is judged as unqualified and execute corresponding steps for processing;

[0091] Specifically:

[0092] M1: extract the health assessment index jks of each marked battery, and calculate the difference between the index and the preset threshold index to obtain the hidden danger difference of each marked battery, preset the interval of each group of hidden danger differences corresponding to the hidden danger difference, set each group of hidden danger difference interval to correspond to a health hidden danger level, where the health hidden danger level includes sub-health level and alarm health level; the greater the hidden danger difference, the greater the possibility of matching the alarm health level; match the hidden danger difference of each marked battery with the interval of each group of hidden danger differences, so as to obtain the health hidden danger level corresponding to each marked battery; if the health hidden danger level is the sub-health level, execute step M2, if the health hidden danger level is the alarm health level, execute step M3;

[0093] M2: If the health hazard level is a sub-health level, the health assessment index jks of the marked battery during the next discharge and capacity verification process is analyzed. If it is still determined to be a sub-health level, the sub-health level is upgraded to an alarm health level;

[0094] M3: If the health hazard level is the alarm health level, extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of the marked battery and use them as the length, width and height of the three-dimensional rectangle respectively to construct a three-dimensional rectangular model corresponding to the marked battery;

[0095] Extracting the three-dimensional rectangular model corresponding to each type of battery fault from a pre-built fault database; that is, extracting the voltage evaluation index, temperature evaluation index and internal resistance evaluation index when each type of battery fault occurs, and using them as the length value, width value and height value of the three-dimensional rectangular model;

[0096] The similarity between the three-dimensional rectangular model of the marked battery and the three-dimensional rectangular models of each type of fault is calculated using the Euclidean distance, and the three-dimensional rectangular models of each type of fault are sorted from small to large according to the similarity, and the fault types corresponding to the first three groups of three-dimensional rectangular models are selected from the left as the type of fault cause of the marked battery;

[0097] Taking the location of the marked battery as the starting point, the operation and maintenance personnel closest to the starting point are obtained as the processing personnel, and an alarm signal is immediately sent to the processing personnel. The alarm signal includes the change of the marked battery, the location, the health assessment index jks, the three-dimensional rectangular model and similar fault causes;

[0098] It should be noted that the difference (hidden danger difference) between the marked battery health assessment index and the preset threshold index is calculated, and the health hazard level (sub-health level and alarm health level) is determined according to the interval of the hidden danger difference, so as to achieve a more detailed classification of the health status of unqualified batteries. This classification method can not only quickly distinguish the severity of battery problems, but also the greater the hidden danger difference, the greater the possibility of corresponding alarm health level, making the classification more reasonable and accurate, which helps operation and maintenance personnel take targeted measures.

[0099] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Online discharge nuclear capacity system of station DC battery group, characterized by: include: Discharge core capacity module: including test preset unit, load supplement unit and load configuration unit; The test preset unit is used to preset the automatic execution time of the discharge core capacity, and after reaching the preset automatic execution time, the battery is first divided into X sections; then the X sections of batteries and the DCDC module are connected, and the discharge operation is performed according to the preset standard; The load supplement unit is used to determine that the output power is insufficient and start the charger to supplement the power if the battery output power is lower than the preset power during the capacity verification process; The load configuration unit is used to discharge the nuclear capacity in parallel with the real load and the dummy load by using the preset nuclear capacity parameters when the real load in the substation cannot meet the discharge operation according to the preset standard; Parameter monitoring module: collects the operating parameters of X batteries during the discharge process and conducts a comprehensive evaluation to obtain the health assessment index jks corresponding to each battery during the current discharge process; the operating parameters include voltage, temperature and internal resistance; based on the health assessment index jks corresponding to each battery during the current discharge process, the use status of each battery is determined; the use status includes qualified and unqualified; Determine the usage status of each battery, specifically: Extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process, set the weight coefficients corresponding to the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc, respectively, multiply the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of each battery in the current discharge process by the corresponding set weight coefficients, and then sum them to obtain the health evaluation index jks of each battery in the current discharge process; A threshold index of the health assessment index jks corresponding to each battery is preset. If the health assessment index jks of a battery during the current discharge process is higher than the preset threshold index, the battery usage status higher than the preset threshold index is judged as unqualified, otherwise it is judged as qualified; Alarm processing module: mark the batteries whose usage status is judged as unqualified and execute corresponding steps for processing; Execute the corresponding steps to process, specifically: M1: extract the health assessment index jks of each marked battery, and calculate the difference between the index and the preset threshold index to obtain the hidden danger difference of each marked battery, preset the interval of each group of hidden danger difference corresponding to the hidden danger difference, set each group of hidden danger difference interval to correspond to a health hidden danger level, where the health hidden danger level includes a sub-health level and an alarm health level; match the hidden danger difference of each marked battery with the interval of each group of hidden danger difference, so as to obtain the health hidden danger level corresponding to each marked battery; execute the corresponding steps based on the specific health hidden danger level of the marked battery; M2: If the health hazard level is a sub-health level, the health assessment index jks of the marked battery during the next discharge and capacity verification process is analyzed. If it is still determined to be a sub-health level, the sub-health level is upgraded to an alarm health level; M3: If the health hazard level is the alarm health level, extract the voltage evaluation index hya, temperature evaluation index hyb and internal resistance evaluation index hyc of the marked battery and use them as the length, width and height of the three-dimensional rectangle respectively to construct a three-dimensional rectangular model corresponding to the marked battery; Extracting the three-dimensional rectangular model corresponding to each type of battery fault from the pre-built fault database; The similarity between the three-dimensional rectangular model of the marked battery and the three-dimensional rectangular models of each type of fault is calculated using the Euclidean distance, and the three-dimensional rectangular models of each type of fault are sorted from small to large according to the similarity, and the fault types corresponding to the first three groups of three-dimensional rectangular models are selected from the left as the type of fault cause of the marked battery; Taking the location of the marked battery as the starting point, the operation and maintenance personnel closest to the starting point are obtained as the processing personnel, and an alarm signal is immediately sent to the processing personnel. The alarm signal includes the change of the marked battery, the location, the health assessment index jks, the three-dimensional rectangular model, and the type and cause of the failure of the marked battery.

2. The online discharge capacity-reducing system of the station DC battery pack according to claim 1 is characterized in that: Comprehensively evaluate the voltage parameters of each battery during the discharge process, specifically: Pre-constructing a voltage standard curve for each battery during the discharge process; extracting the voltage value of each battery at each sampling moment during the current discharge process, and calculating the difference with the voltage value at the same moment in the corresponding voltage standard curve and taking the absolute value, to obtain the voltage deviation value of each battery at each sampling moment during the current discharge process; The actual allowable value corresponding to the preset voltage deviation value; if the voltage deviation value calculated at a certain sampling moment in each battery is higher than the preset actual allowable value, the voltage deviation value higher than the actual allowable value is marked as an abnormal fluctuation value; The number of abnormal fluctuation values ​​of each battery during the continuous discharge process is counted, which is recorded as the number of abnormal pressure hg1; at the same time, the average of each group of abnormal fluctuation values ​​of each battery during the continuous discharge process is calculated, and the calculated average is recorded as the average value of abnormal pressure hg2; The voltage change rate is calculated for the voltage values ​​of each battery at adjacent sampling moments during the current discharge process; each group of voltage change rates calculated for each battery during the current discharge process are compared with a set reference change rate, which is obtained by extracting the voltage change rate corresponding to two groups of adjacent time points in the voltage standard curve as the reference change rate corresponding to the voltage change rate of each battery at each adjacent sampling moment; If a certain group of voltage change rates of each battery in the current discharge process is higher than the corresponding reference change rate, the voltage change rate higher than the corresponding reference change rate is marked as an abnormal change rate; the number of abnormal change rates of each battery in the discharge process is counted as the number of abnormal changes, the number of abnormal changes is multiplied by the duration between adjacent sampling moments, and the multiplication result is used as the abnormal voltage duration hg3 of each battery; According to the formula The number of abnormal pressure hg1, the average value of abnormal pressure hg2 and the duration of abnormal pressure hg3 of each battery are weighted and calculated to obtain the voltage evaluation index hya corresponding to each battery; , as well as They respectively represent the allowed number of abnormal pressures, the preset actual allowed value corresponding to the voltage deviation value, and the allowed duration of abnormal pressures; t1, t2, and t3 are the influence weight factors corresponding to the number of abnormal pressures hg1, the average abnormal pressure hg2, and the duration of abnormal pressure hg3.

3. The online discharge capacity-reducing system of the station DC battery pack according to claim 2 is characterized in that: Comprehensively evaluate the temperature parameters of each battery during the discharge process, specifically: Preset the maximum allowable temperature value of each battery during the discharge process; extract the temperature value of each battery during the current discharge process, and construct a temperature change curve for each battery, map the preset maximum allowable temperature value as a threshold line in the temperature change curve, mark the part of the temperature change curve that is higher than the threshold line, count the duration corresponding to the marked part and accumulate it to obtain the high temperature duration; at the same time, identify the highest point in the temperature change curve, and use the temperature value corresponding to the highest point as the peak temperature value; Extract the temperature values ​​of each battery at each time point during the current discharge process, calculate the average value, and use the calculated average value as the average temperature value; mark the high temperature duration, peak temperature value and average temperature value corresponding to each battery as hp1, hp2 and hp3 respectively; According to the formula The high temperature duration hp1, peak temperature value hp2 and average temperature value hp3 of each battery are weighted and calculated to obtain the temperature evaluation index hyb corresponding to each battery; and They represent the allowable high temperature duration and the maximum allowable temperature value respectively; g1, g2 and g3 are the influence weight factors of high temperature duration hp1, peak temperature value hp2 and average temperature value hp3 respectively.

4. The online discharge capacity-reducing system of the station DC battery pack according to claim 3 is characterized in that: Comprehensively evaluate the internal resistance parameters of each battery during the continuous discharge process, specifically: Extract the internal resistance value of each battery at each time point during the current discharge process, and calculate the internal resistance change rate at adjacent time points, that is, through the formula Calculate and get, where r is the internal resistance change rate, is the internal resistance value at the right time point among adjacent time points, is the internal resistance value at the left time point among adjacent time points; The average value of the internal resistance change rate of each group of batteries calculated during the current discharge process is calculated to obtain the average internal resistance change rate of each battery during the current discharge process; Arrange the internal resistance change rates of each group calculated for each battery in chronological order, and then calculate the difference between two adjacent groups of internal resistance change rates for each group of internal resistance change rates corresponding to each battery, that is, subtract the internal resistance change rate on the left from the internal resistance change rate on the right of the two adjacent groups of internal resistance change rates. If the difference calculation result of a group is negative, take the absolute value as the descending difference; if the difference calculation result of a group is positive, take it as the ascending difference; Sum up all the rising differences and falling differences respectively to get the total rising value and the total falling value, and calculate the ratio of the rising total value / the falling total value to get the change trend ratio; Preset the intervals of trend ratios corresponding to the change trend ratios, and set an average rate additional coefficient corresponding to the intervals of trend ratios of each group; match the change trend ratios calculated for each battery during the current discharge process with the intervals of trend ratios of each group, so as to obtain the average rate additional coefficient corresponding to each battery, and multiply the calculated internal resistance change average rate of each battery by the obtained average rate additional coefficient to obtain the internal resistance change additional rate of each battery during the current discharge process; The threshold addition rate corresponding to the internal resistance change addition rate of each battery is preset, and the ratio of the internal resistance change addition rate of each battery during the current discharge duration / the threshold addition rate is calculated to obtain the internal resistance evaluation index hyc of each battery during the current discharge duration.

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