A control method for reversible charge-discharge cycle co-electrolysis

Abstract

The application provides a control method for reversible charge-discharge cycle co-electrolysis, which is applied to a charge-discharge monitoring device of an automobile battery and comprises the following steps: obtaining current state information of a lithium battery pack; judging whether to start a temperature monitoring module according to the state information; if yes, monitoring the temperature of the lithium battery pack to obtain first monitoring data; judging whether to start a pressure monitoring module according to the first monitoring data; if yes, monitoring the pressure of the lithium battery pack to obtain second monitoring data; judging whether to start a volume monitoring module according to the second monitoring data; if yes, monitoring the volume of the lithium battery pack to obtain third monitoring data; and increasing or decreasing the current or output power of the lithium battery pack during charging or discharging according to the first, second and third monitoring data. The application solves the technical problem that the existing technology focuses on the temperature monitoring of the lithium battery and cannot directly feed back the change of the battery volume to the user.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery charging and discharging, in particular to a control method for reversible charging and discharging cycle co-electrolysis. BACKGROUND

[0002] With the development of economic society, the demand for energy is also growing; in order to respond to sustainable development, it is imperative to develop new energy and renewable resources.

[0003] For example, electric vehicles mostly use lithium batteries as their energy devices. Lithium batteries are a kind of chemical energy storage devices, which have been widely used and vigorously promoted due to their high specific energy, high output power, excellent rate performance, long cycle life, good safety and other characteristics.

[0004] However, a large amount of heat is generated during the charging and discharging process of lithium batteries, which causes the overall temperature to change, thereby affecting the capacity and performance of the battery, and in some extreme cases, it can also cause thermal runaway, causing major safety accidents, so the charging and discharging process needs to be monitored to ensure that the battery is within a reasonable temperature range.

[0005] The existing technology mainly focuses on monitoring the temperature and battery performance of lithium batteries, and adjusts the current or voltage of the lithium battery during charging or discharging by monitoring the temperature change; which leads to at least one of the following problems: lack of monitoring of the volume change of lithium batteries, users cannot determine whether the lithium battery has expanded or bulged by temperature, which may cause safety accidents. SUMMARY

[0006] The technical problem solved by the present application is that the existing technology mainly focuses on monitoring the temperature and battery performance of lithium batteries, and adjusts the current or voltage of the lithium battery during charging or discharging by monitoring the temperature change, lacks monitoring of the volume change of lithium batteries, and users cannot determine whether the lithium battery has expanded or bulged by temperature, which may cause safety accidents.

[0007] To solve the above problems, the application provides a control method for reversible charge-discharge cycle co-electrolysis, which is applied to an automobile battery charge-discharge monitoring device, and the automobile battery charge-discharge monitoring device comprises a temperature monitoring module, a pressure monitoring module and a volume monitoring module; the control method comprises the following steps: obtaining current state information of a lithium battery pack; determining whether to start the temperature monitoring module according to the state information; if yes, controlling the temperature monitoring module to monitor the temperature of the lithium battery pack and obtaining first monitoring data; determining whether to start the pressure monitoring module according to the first monitoring data; if yes, controlling the pressure monitoring module to monitor the pressure of the lithium battery pack and obtaining second monitoring data; determining whether to start the volume monitoring module according to the second monitoring data; if yes, controlling the volume monitoring module to monitor the volume of the lithium battery pack and obtaining third monitoring data; increasing or decreasing the charging current of the lithium battery pack in a charging state or the output power of the lithium battery pack in a discharging state according to the first monitoring data, the second monitoring data and the third monitoring data, and feeding back to the user.

[0008] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: compared with the related art in which the monitoring of the lithium battery mainly focuses on the temperature and the battery performance, the application can comprehensively monitor the lithium battery pack by sequentially starting the temperature monitoring module, the pressure monitoring module and the volume monitoring module, can obtain the state information of the lithium battery pack in multiple dimensions, can more comprehensively evaluate the safety of the battery, can adjust the charging current of the lithium battery pack or the output power of the lithium battery pack in a discharging state according to the monitoring data, and can feed back to the user at the same time; the dynamic monitoring and control of the charge-discharge process of the lithium battery pack are realized, and the safety and efficiency of the battery use are improved.

[0009] In an example of the application, the automobile battery charge-discharge monitoring device further comprises a protection module; the temperature of the lithium battery pack in a normal working condition is defined as a first temperature; the temperature monitoring module is controlled to monitor the temperature of the lithium battery pack and obtain first monitoring data, which comprises the following steps: obtaining the temperature change rate of the first temperature in a first time period; determining whether the first temperature is in a preset temperature fluctuation interval according to the temperature change rate; if not, sending a first signal to the user and controlling the protection module to perform pre-cooling treatment on the lithium battery pack; monitoring the first temperature multiple times in the future first time period; determining whether the fluctuation difference between the multiple first temperatures obtained in the multiple times of monitoring and the preset temperature fluctuation interval falls into a temperature fluctuation difference interval; if yes, sending the first signal to the user and controlling the temperature monitoring module to periodically monitor the lithium battery pack; if not, sending a second signal to the user and controlling the pressure monitoring module to monitor the pressure of the lithium battery pack; wherein the first signal comprises a safety signal, and the second signal comprises a prompt signal, a pre-warning signal and an alarm signal.

[0010] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: by monitoring the temperature change rate and the fluctuation difference value, a signal is sent to the user when the temperature is abnormal and the protection module is started for pre-cooling processing, and the pressure monitoring module is started for multiple times of monitoring in the future first time period to further determine whether to start the pressure monitoring module. The temperature monitoring of the lithium battery pack is provided with specific methods and processes, and the accuracy and reliability of temperature monitoring are improved. At the same time, through accurate temperature monitoring and timely pre-cooling processing, the safety risk caused by battery overheating can be effectively prevented, and the signal sent to the user can enable the user to timely understand the battery state and take corresponding measures.

[0011] In an example of the present application, determining whether the fluctuation difference value formed between the plurality of first temperatures obtained in multiple monitoring and the preset temperature fluctuation interval falls within the temperature fluctuation difference interval comprises: obtaining the temperature data of the lithium battery pack in the future first time period, denoted as the second temperature; comparing the second temperature with the temperature threshold to obtain a first comparison result; determining whether the second temperature is between the highest temperature threshold and the lowest temperature threshold according to the first comparison result; if not, determining that the lithium battery pack is in a first dangerous state and executing a first emergency plan.

[0012] In an example of the present application, comparing the second temperature with the temperature threshold to obtain a first comparison result comprises: regionally dividing the lithium battery pack according to the first comparison result; dividing at least one lithium battery higher than the highest temperature threshold into a first battery pack, and the remaining lithium batteries into a second battery pack; wherein the first battery pack is a high-temperature region.

[0013] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: regionally dividing the lithium battery pack can be more targeted for monitoring and processing. For example, when it is monitored that the temperature of part of the batteries is too high, the high-temperature region can be quickly located, the batteries in the region are cooled or other measures are taken, and the surrounding batteries are monitored to prevent temperature spread; in this way, the processing efficiency can be improved and the impact on the entire battery pack can be reduced.

[0014] In an example of the present application, determining that the lithium battery pack is in a first dangerous state and executing a first emergency plan comprises: obtaining the current remaining power and power consumption rate of the lithium battery pack; performing cooling processing on the lithium battery pack; determining whether the lithium battery pack has the possibility to complete the remaining journey after the cooling processing; if not, sending a second signal to the user to control the driving speed of the automobile to reduce to the minimum speed specified for the current section, and sending a help signal to the relevant department; if yes, controlling the protection module to continuously cool the lithium battery pack to the first temperature, obtaining the road conditions of the remaining journey in the historical period, and controlling the automobile to start the cruise control mode according to the remaining power.

[0015] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: when the lithium battery pack is in a dangerous state, the driving state of the automobile is reasonably controlled according to the residual power and the power consumption rate, and more choices and protection can be provided for the user.

[0016] In an example of the present application, the pressure of the lithium battery pack in a normal condition is defined as a first pressure; the pressure monitoring module includes a plurality of anchor points arranged on the outer surface of the lithium battery pack for measuring the surface flatness of the lithium battery pack; the control pressure monitoring module monitors the pressure of the lithium battery pack, including: obtaining the first flatness data of each anchor point; when it is determined that the lithium battery pack is in a first dangerous state, controlling the plurality of anchor points to monitor the lithium battery pack in a future first time period to obtain second flatness data; generating outer surface change data of the lithium battery pack according to the first flatness data and the second flatness data; determining whether a second processing strategy needs to be performed on the lithium battery pack according to the outer surface change data; if yes, controlling the protection module to perform pressure relief processing on the lithium battery pack.

[0017] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: through monitoring the flatness of the outer surface of the lithium battery pack and timely pressure relief processing, problems such as battery deformation, liquid leakage and even explosion caused by abnormal pressure of the lithium battery pack can be effectively prevented, for example, when an abnormal pressure is found, the system can generate outer surface change data and determine whether to perform pressure relief processing according to the data.

[0018] In an example of the present application, the outer surface change data of the lithium battery pack is generated according to the first flatness data and the second flatness data, including: determining whether the anchor point is in the first battery pack according to the second flatness data of each anchor point; if yes, controlling the protection module to execute a second emergency plan, marking the lithium battery pack corresponding to the anchor point as a high-temperature and high-pressure area, setting the remaining lithium battery packs around it as a temperature spread area, and controlling the volume monitoring module to monitor the lithium battery pack; wherein the second emergency plan includes performing pressure relief processing on the high-temperature and high-pressure area, and starting the liquid cooling function to cool the lithium battery.

[0019] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: executing the second emergency plan can quickly respond to the problem of the high-temperature and high-pressure area and prevent the fault from spreading; for example, when a high temperature and high pressure are monitored in a certain battery, the system can immediately mark the area as a dangerous area and monitor and protect the surrounding batteries; at the same time, starting the liquid cooling function for cooling operation can quickly reduce the battery temperature and reduce the safety risk; in addition, sending an alarm to the user can enable the user to timely understand the situation and take corresponding measures.

[0020] In an example of the present application, the control volume monitoring module monitors the lithium battery pack, comprising: establishing a three-dimensional volume model for the lithium battery pack; grid processing the lithium battery pack to obtain the coordinates of any cubic on the lithium battery pack; controlling the control volume monitoring module to monitor at least one cubic located in a high temperature and high pressure area to obtain third monitoring data; determining whether the battery safety degree of the cubic corresponding lithium battery in a future first time period meets the charge and discharge standard according to the third monitoring data; if not, cutting off the power supply of the cubic corresponding lithium battery and reducing the output power of the remaining lithium batteries arranged around the lithium battery.

[0021] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: the three-dimensional volume model establishment and grid processing of the lithium battery pack can more accurately monitor the volume change of the battery, and through volume monitoring, the problems such as battery swelling can be found in time, when the safety degree of the lithium battery corresponding to a cubic does not meet the charge and discharge standard, the power supply is cut off and the output power of the surrounding lithium batteries is reduced, which can effectively prevent fault propagation and ensure the overall safety of the equipment.

[0022] In an example of the present application, the control volume monitoring module monitors at least one cubic located in a high temperature and high pressure area, comprising: controlling the inner cell of the lithium battery as a source boundary; controlling the shell of the lithium battery as a target boundary; controlling the inner cell swelling directly acting on the shell; controlling the shell as a boundary constraint of the volume swelling of the lithium battery; obtaining the relationship between the volume of the cubic and the temperature in a future first time period; dynamically adjusting the output power of the lithium battery according to the relationship.

[0023] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: by controlling the inner cell and the shell of the lithium battery as the source boundary and the target boundary, and obtaining the relationship between the volume of the cubic and the temperature, the volume change trend of the battery can be more accurately predicted, and according to this relationship, the output power can be dynamically adjusted, which can avoid the performance decline and safety risk caused by the volume swelling of the battery.

[0024] After adopting the technical scheme of the present application, the following technical effects can be achieved:

[0025] (1) The combination of the temperature monitoring module, the pressure monitoring module and the volume monitoring module can provide accurate early warning for the user, the temperature monitoring module monitors the temperature of the battery in real time, the control center makes corresponding processing strategy according to the temperature, and the user has enough time to take measures, such as stopping using, maintaining the battery, etc., to reduce the safety risk;

[0026] (2) It can help to more accurately diagnose the fault type and cause of the battery. For example: if the temperature rises but the pressure and volume change little, it may be a heat dissipation problem; if the pressure and volume change significantly while the temperature is normal, it may be internal structure damage;

[0027] (3) The control center is connected with the user through the network, the user can obtain the real-time state information of the battery at any time and any place through the mobile terminal, which is not limited by time and space, and once the abnormal data is monitored, the alarm generating unit can quickly send an alarm to notify the user. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0029] Figure 1 A flowchart of a control method of reversible charge-discharge cycle co-electrolysis provided by the embodiment of the present application;

[0030] Figure 2 A module connection diagram of a control system of reversible charge-discharge cycle co-electrolysis provided by the embodiment of the present application.

[0031] Explanation of reference signs:

[0032] 100, control system; 10, temperature monitoring module; 20, pressure monitoring module; 30, volume monitoring module; 40, control center. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0036] Referring to Figure 1 , Figure 1 A flowchart of a control method for reversible charge-discharge cycle co-electrolysis provided by an embodiment of the present application is shown. Specifically, a control method for reversible charge-discharge cycle co-electrolysis, the control method is applied to an automobile battery charge-discharge monitoring device, the automobile battery charge-discharge monitoring device comprises a temperature monitoring module, a pressure monitoring module and a volume monitoring module; the control method comprises:

[0037] S1: obtaining current state information of the lithium battery pack;

[0038] S2: determining whether to start the temperature monitoring module according to the state information;

[0039] S21: if yes, controlling the temperature monitoring module to monitor the temperature of the lithium battery pack and obtaining first monitoring data;

[0040] S22: if no, determining that the lithium battery pack meets the safe working condition and maintaining the current output power of the lithium battery pack;

[0041] S3: determining whether to start the pressure monitoring module according to the first monitoring data;

[0042] S31: if the pressure monitoring module is started, controlling the pressure monitoring module to monitor the pressure of the lithium battery pack and obtaining second monitoring data;

[0043] S32: if the pressure monitoring module is not started, determining that the current pressure of the lithium battery pack meets the safe working condition;

[0044] S4: determining whether to start the volume monitoring module according to the second monitoring data;

[0045] S41: if the volume monitoring module is started, controlling the volume monitoring module to monitor the volume of the lithium battery pack and obtaining third monitoring data;

[0046] S42: if the volume monitoring module is not started, determining that the current volume change of the lithium battery pack meets the safe working condition;

[0047] S5: increasing or decreasing the charging current of the lithium battery pack in the charging state or the output power of the lithium battery pack in the discharging state according to the first monitoring data, the second monitoring data and the third monitoring data, and feeding back to the user.

[0048] Preferably, the temperature of the lithium battery pack in the normal working condition is defined as the first temperature; the pressure of the lithium battery pack in the normal working condition is defined as the first pressure; and the volume of the lithium battery pack in the normal working condition is defined as the first volume.

[0049] Preferably, the temperature monitoring module 10 collects temperature data every second and sends it to the control center 40; the pressure monitoring module 20 collects internal pressure data and external pressure data every ten seconds and sends it to the control center 40; the volume monitoring module 30 performs a three-dimensional scan of the lithium battery pack every thirty seconds and sends the scan data to the control center 40.

[0050] Specifically, a plurality of monitoring devices are arranged on the automobile to monitor the automobile in real time during charging or discharging; by monitoring the temperature, internal pressure, external pressure and volume change, the current state of the lithium battery pack is gradually analyzed, and feedback is given to the user in combination with the state of the lithium battery pack, so as to assist the user to understand the state of the lithium battery pack during charging or discharging, so that the user can take emergency action in time according to the monitoring data, and reduce the phenomenon of swelling or bulging of the automobile during charging or discharging.

[0051] Preferably, the lithium battery pack is arranged in the battery mounting position of the automobile, and the lithium battery pack is composed of a plurality of lithium batteries.

[0052] Further, the automobile battery charging and discharging monitoring device further comprises a protection module; the control temperature monitoring module monitors the temperature of the lithium battery pack to obtain first monitoring data, including:

[0053] obtaining the temperature change rate of the first temperature in the first time period;

[0054] determining whether the first temperature is in the preset temperature fluctuation interval according to the temperature change rate;

[0055] If yes, a first signal is sent to the user, and the temperature monitoring module is controlled to periodically monitor the lithium battery pack;

[0056] If no, a second signal is sent to the user, and a first processing strategy is executed;

[0057] monitoring the first temperature multiple times in the future first time period;

[0058] determining whether the fluctuation difference between the plurality of first temperatures obtained in the multiple times of monitoring and the preset temperature fluctuation interval falls into a temperature fluctuation difference interval;

[0059] If no, a second signal is sent to the user, and the pressure monitoring module is controlled to monitor the pressure of the lithium battery pack;

[0060] The first signal includes a safety signal, and the second signal includes a prompt signal, a warning signal and an alarm signal.

[0061] Preferably, the first processing strategy includes sending a prompt signal to the user, controlling the pressure monitoring module 20 to monitor the internal pressure and external pressure received by the lithium battery, and controlling the protection module to perform a cooling treatment on the lithium battery pack.

[0062] Wherein, the first temperature at a certain time in the future can be predicted more accurately by the temperature change rate, the development trend of the battery temperature is judged in advance, the battery management strategy can be adjusted in real time according to the temperature change, the vehicle can be ensured to run safely, and the safety risks such as thermal runaway of the battery of the vehicle at high temperature and the performance decline of the battery at low temperature can be prevented.

[0063] Further, since the performance and safety of the lithium battery are very sensitive to temperature, first, the temperature change rate of the lithium battery pack in the first time period is obtained, the development trend of the first temperature at a certain time in the future is predicted in advance, whether the first temperature is in the preset temperature fluctuation interval is judged by the temperature change rate, the temperature of the lithium battery pack is dynamically adjusted to keep it in a suitable temperature range, and the change of the temperature can be quantitatively evaluated by setting the preset temperature fluctuation interval and the temperature fluctuation difference interval, so as to more accurately judge the working state of the battery.

[0064] Further, whether the fluctuation difference between the plurality of first temperatures obtained in the plurality of times of monitoring and the preset temperature fluctuation interval falls into the temperature fluctuation difference interval is judged, comprising:

[0065] Obtain the temperature data of the lithium battery pack in the future first time period, denoted as second temperature;

[0066] Compare the second temperature with the temperature threshold to obtain a first comparison result;

[0067] Judge whether the second temperature is between the highest temperature threshold and the lowest temperature threshold according to the first comparison result;

[0068] If not, it is determined that the lithium battery pack is in a first dangerous state, and a first emergency plan is executed.

[0069] Further, the second temperature is compared with the temperature threshold to obtain a first comparison result, comprising:

[0070] According to the first comparison result, the lithium battery pack is divided into regions;

[0071] At least one lithium battery higher than the highest temperature threshold is divided into a first battery pack, and the remaining lithium batteries are a second battery pack;

[0072] Wherein, the first battery pack is a high temperature region.

[0073] Specifically, when the second temperature of the lithium battery pack in the future first time period is greater than or less than the temperature threshold, it is determined that the lithium battery pack is in a dangerous state; at the same time, the lithium batteries in the lithium battery pack are divided into regions according to the second temperature, i.e. the lithium batteries higher than the highest temperature threshold are divided into a first battery pack corresponding to a high temperature region, and the remaining lithium batteries are a second battery pack.

[0074] Preferably, the first battery group is a high-temperature area, and the second battery group is a normal-temperature area.

[0075] It should be noted that by dividing the lithium battery group into the first battery group and the second battery group, and by the first comparison result, the relative change degree between lithium batteries at different positions can be found out, so as to more accurately evaluate the working state of the battery group; even if each lithium battery itself may not reach the preset dangerous temperature threshold, but the abnormal difference between the parameter first comparison results can also indicate the uneven heating condition existing in the lithium battery group, which is helpful to find potential faults or safety hazards in advance.

[0076] Further, the lithium battery group is determined to be in the first dangerous state, and a first emergency plan is executed, including:

[0077] obtaining the current residual capacity and power consumption rate of the lithium battery group;

[0078] cooling the lithium battery group;

[0079] determining whether the lithium battery group has the possibility to complete the remaining journey after the cooling treatment;

[0080] if not, sending a second signal to the user to control the driving speed of the automobile to reduce to the minimum speed specified for the current section, and sending a help signal to the relevant department;

[0081] if yes, controlling the protection module to continuously cool the lithium battery group to the first temperature, obtaining the road conditions of the remaining journey in the historical period, and controlling the automobile to start the cruise control mode according to the residual capacity.

[0082] For example, during the driving of the vehicle, the first temperature of the lithium battery pack changes with the driving condition; the preset temperature fluctuation interval is defined as 20-40℃, and the temperature fluctuation difference interval is ±5℃; under normal driving conditions, the temperature of the battery of the vehicle may fluctuate around 30℃; however, if the vehicle is driving at high speed or climbing for a long time, the load of the battery increases, and the temperature tends to rise; therefore, obtaining the temperature change rate of the first temperature in the first time period can predict the change of the battery temperature of the vehicle on the future road section in advance; for example, setting the reference temperature as 35℃, when the first temperature is not in the preset fluctuation interval, and the fluctuation difference between the first temperature obtained by monitoring multiple times in the future first time period and the preset temperature fluctuation interval also does not fall into the temperature fluctuation difference interval, for example, the temperatures continuously monitored by the temperature monitoring module 10 are 38℃, 40℃ and 31℃, and the fluctuation differences of the subsequent temperatures are 3℃, 5℃ and -4℃ respectively, which fall into the temperature fluctuation difference interval ±5℃, indicating that the current battery temperature fluctuates, but is still within the normal range, at this time the vehicle can continue to operate normally, but some measures may need to be taken, such as reducing the air conditioning power, adjusting the motor output power, etc., and a prompt signal needs to be sent to the user; further, if it is found again that the temperature of the lithium battery pack continues to rise to 45℃, which exceeds the preset temperature fluctuation interval, and the fluctuation difference also exceeds the temperature difference fluctuation interval, at this time the first emergency plan should be executed, according to the current remaining capacity and power consumption rate of the lithium battery pack, whether the vehicle can complete the remaining journey is predicted, if it can, the temperature of the lithium battery pack in the high temperature area is reduced to the normal working temperature, the control center 40 and the user terminal interact to obtain the road condition information between the current position and the target position, calculate the best driving speed according to the remaining capacity, control the vehicle to start the cruise control mode, so as to avoid frequent braking or acceleration, so as to save the power and maintain the output power of the battery; if not, the vehicle speed is reduced to the minimum speed specified on the current road section, and a help signal is sent.

[0083] Further, the pressure monitoring module 20 includes a plurality of anchor points arranged on the outer surface of the lithium battery pack for measuring the flatness of the surface of the lithium battery pack; the control pressure monitoring module monitors the pressure of the lithium battery pack, including:

[0084] obtaining first flatness data of each anchor point;

[0085] when it is determined that the lithium battery pack is in the first dangerous state, controlling the plurality of anchor points to monitor the lithium battery pack in the future first time period to obtain second flatness data;

[0086] generating outer surface change data of the lithium battery pack according to the first flatness data and the second flatness data;

[0087] determining whether the lithium battery pack needs a second processing strategy according to the outer surface change data;

[0088] If yes, the control protection module performs pressure relief processing on the lithium battery pack.

[0089] Preferably, the first flatness data is measured when the lithium battery pack is in a normal working state.

[0090] Preferably, the second processing strategy includes sending a warning signal to the user and controlling the volume monitoring module 30 to monitor the lithium battery pack.

[0091] Further, the outer surface change data of the lithium battery pack is generated according to the first flatness data and the second flatness data, specifically including:

[0092] According to the second flatness data of each anchor point, it is determined whether the anchor point is in the first battery pack;

[0093] If yes, the control protection module executes a second emergency plan, marks the lithium battery corresponding to the anchor point as a high-temperature and high-pressure area, sets the remaining lithium batteries around it as a temperature spread area, and controls the volume monitoring module to monitor the lithium battery pack.

[0094] Preferably, the second emergency plan includes pressure relief processing on the high-temperature and high-pressure area, and starting the liquid cooling function to cool the lithium battery.

[0095] Specifically, a plurality of anchor points are arranged on the outer surface of the lithium battery pack, and a plurality of measurement points are selected, which are marked as M1, M2, M3, …, Mn, respectively. The surface flatness data of each measurement point of the lithium battery pack under normal working conditions is measured and marked as D1, D2, D3, …, Dn, respectively. The flatness data of the plurality of measurement points obtained by monitoring after a future first time period is Q1, Q2, Q3, …, Qn, respectively. The outer surface change data of the lithium battery pack is generated according to the first flatness data and the second flatness data, that is, the change amount of the flatness of each measurement point is ΔMt=Qt-Dt, where t={1, 2, 3, …, n}. The change of the flatness of the plurality of measurement points of the lithium battery pack within the future first time period is compared with formula 1, formula 1:

[0096] ;

[0097] It can be determined whether the lithium battery pack meets the safe working condition within the future first time period;

[0098] If not, the position of each anchor point and the region where the first battery pack is located are fitted, and then the anchor points falling into the first battery pack, i.e., the high-temperature region, are screened out, and the anchor points and the region are divided into a high-temperature and high-pressure area, and the remaining lithium batteries around it are set as a temperature spread area.

[0099] wherein, ΔMtmin is the flatness change lower limit, ΔMtmax is the flatness change upper limit, C is the change coefficient, and t is the future first time period.

[0100] Further, the above is the internal pressure detection caused by the surface flatness change of the internal chemical reaction of the lithium battery. In addition to the above monitoring of the internal pressure of the lithium battery pack, the external pressure received by the lithium battery pack is also monitored. The influence of pressure on the lithium battery is multifaceted. Appropriate pressure can make the positive and negative electrode plates and the separator in the battery contact closely, improve the battery charge and discharge reaction interface, reduce the battery internal resistance and polarization, thereby improving the cycle stability and high-rate charge and discharge performance of the battery. Too low pressure will reduce the electrode reaction area, deteriorate the reaction interface, increase the battery internal resistance and polarization, and reduce the battery capacity. After long cycle, it will also cause the electrode material to fall off from the current collector, which will seriously affect the battery life. Too high pressure will destroy the pore structure of the electrode material and the separator, deteriorate the reaction interface, and increase the battery internal resistance, thereby causing rapid attenuation of the battery capacity, and in severe cases, it will also cause internal short circuit of the battery, and risks such as thermal runaway. When the external pressure of 0.05MPa-0.5MPa is applied to the lithium battery pack, it helps to improve the cycle stability of the battery and the life of the battery, thereby improving the battery capacity.

[0101] For the monitoring of the external pressure of the lithium battery pack, the present application will not be described in detail here. The basic idea is similar to the idea of monitoring the internal pressure of the lithium battery pack.

[0102] Further, the control volume monitoring module monitors the lithium battery pack, including:

[0103] A three-dimensional volume model is established for the lithium battery pack.

[0104] The lithium battery pack is gridded to obtain the coordinates of any cube on the lithium battery pack.

[0105] The control volume monitoring module monitors at least one cube located in a high-temperature and high-pressure area to obtain third monitoring data.

[0106] According to the third monitoring data, it is determined whether the battery safety degree of the lithium battery corresponding to the cube in the future first time period meets the charge and discharge standard.

[0107] If not, an alarm signal is sent to the user, the power supply to the lithium battery corresponding to the cube is cut off, and the output power of the remaining lithium batteries arranged around the lithium battery is reduced.

[0108] For example, the shape of the lithium battery pack is input into the control center, which then generates its corresponding three-dimensional volume model. The lithium battery pack is then meshed, treating each lithium battery as a cube and obtaining its coordinate position within the lithium battery pack. If several cubes are detected in a high-temperature, high-pressure region, the control center can pinpoint their positions and take appropriate action against the lithium batteries.

[0109] Furthermore, the volume monitoring module monitors at least one cube located in the high-temperature and high-pressure region, including:

[0110] Control the internal cells of the lithium battery as the source boundary;

[0111] The casing of the lithium battery is used as the target boundary;

[0112] Controlling the expansion of the internal battery cell directly affects the outer casing;

[0113] The casing serves as a boundary constraint for the volume expansion of the lithium battery;

[0114] Obtain the relationship between the volume of the cube and temperature during the first time period in the future;

[0115] The output power of the lithium battery is dynamically adjusted based on the changing relationship.

[0116] Based on practical considerations, the internal battery cell is considered the source of volume changes and other effects. When the internal battery cell undergoes a chemical reaction leading to expansion, this is the starting point of volume change. The lithium battery casing is controlled as the target boundary, limiting the expansion range of the internal battery cell. When the internal battery cell expands, it directly acts on the casing. For example, if the internal battery cell increases in volume due to temperature rise or other reasons, it will exert pressure on the casing, which may lead to changes in the volume of the lithium battery. The casing acts as a boundary constraint for the volume expansion of the lithium battery, ensuring that the expansion is within a certain range. The relationship between the volume change of the cube and temperature in the first time period in the future is obtained. Through monitoring and data analysis, the trend of lithium battery volume change with increasing temperature can be derived. The output power of the lithium battery is dynamically adjusted based on this relationship. If the volume changes too rapidly with temperature, it indicates that there may be a safety risk to the battery, and its output power is reduced to reduce heat generation and further volume changes. Furthermore, the vehicle charging and discharging monitoring device also has a road condition prediction module connected to the user's mobile terminal. The road condition prediction module predicts the road condition type for the vehicle in the first time period in the future, specifically including:

[0117] If the road is uphill or has speed changes, the control center will increase the output power of the lithium battery pack in the normal temperature range to reduce the load on the high temperature range. Together with the high temperature range, the battery pack will provide power to the vehicle and provide a stable amount of electricity to the high temperature range, allowing the high temperature range to be quickly recharged.

[0118] If it is a downhill section, the control center controls the generator to generate braking to charge the lithium battery pack.

[0119] If it is a pothole section or a steep section, the suspension parameters of the car are adjusted to avoid the lithium battery pack from being damaged by external impact and to reduce the output power of the lithium battery pack to reduce the additional pressure on the lithium battery pack caused by the vibration of the vehicle when driving on a pothole or steep section, and a warning signal is sent to the user's mobile terminal to remind the user to drive carefully.

[0120] Further, the automobile charging and discharging monitoring device further comprises a weather monitoring module, which is arranged on the user's mobile terminal and is in communication connection with the control center 40, and is used to monitor the weather when the user drives the automobile and judge whether the working environment of the lithium battery pack is met;

[0121] According to the weather monitoring module, it is judged whether the weather change type in the future first time period meets the temperature drop condition;

[0122] If so, it is judged whether the weather change type includes rainy weather or snowy weather;

[0123] If it is judged that the weather change type is rainy weather or snowy weather, the control center controls the protection module to regulate the temperature of the lithium battery pack and starts the temperature compensation function to keep the temperature of the lithium battery pack at the first temperature.

[0124] Please refer to Figure 2The application also provides a control system 100 of reversible charge-discharge cycle co-electrolysis, which can apply the control method in any of the above examples, and the control system 100 comprises a temperature monitoring module 10, a pressure monitoring module 20, a volume monitoring module 30, a control center 40, a data storage function module and a data analysis processing unit; wherein the temperature monitoring module 10 is used for monitoring the temperature of the lithium battery pack during charging or discharging to obtain first monitoring data; is used for monitoring the external pressure and the internal pressure suffered by the lithium battery pack during charging or discharging to obtain second monitoring data; is used for monitoring the volume change of the lithium battery pack during charging or discharging to obtain third monitoring data; the control center 40 increases or decreases the charging current of the lithium battery pack in the charging state or the output power in the discharging state according to the total monitoring data, and feeds back to the user; the data storage function module saves the data of the control center 40 and each monitoring module for subsequent analysis and tracing; the data analysis processing unit can receive and process the data from each monitoring module, and send an alarm to the user through an alarm generation unit; wherein the total monitoring data comprises at least one of the first monitoring data, the second monitoring data and the third monitoring data, and the control center 40 is connected with the mobile terminal of the user through a network, and pushes the monitoring results and alarm information to the user in real time.

[0125] Although the application is disclosed as above, the application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the application, therefore the protection scope of the application should be limited by the scope defined by the claims.

Claims

1. A control method of reversible charge-discharge cycle co-electrolysis, characterized by, The control method is applied to an automobile battery charging and discharging monitoring device, which comprises a temperature monitoring module, a pressure monitoring module and a volume monitoring module; the control method comprises: obtaining current state information of a lithium battery pack; determining whether to start the temperature monitoring module according to the state information; if yes, controlling the temperature monitoring module to monitor the temperature of the lithium battery pack and obtaining first monitoring data; determining whether to start the pressure monitoring module according to the first monitoring data; if the pressure monitoring module is started, controlling the pressure monitoring module to monitor the pressure of the lithium battery pack and obtaining second monitoring data; determining whether to start the volume monitoring module according to the second monitoring data; if the volume monitoring module is started, controlling the volume monitoring module to monitor the volume of the lithium battery pack and obtaining third monitoring data; increasing or decreasing the charging current of the lithium battery pack in a charging state or the output power of the lithium battery pack in a discharging state according to the first monitoring data, the second monitoring data and the third monitoring data, and feeding back to the user; the automobile battery charging and discharging monitoring device further comprises a protection module; the temperature of the lithium battery pack in a normal working condition is defined as a first temperature; the control of the temperature monitoring module to monitor the temperature of the lithium battery pack and obtain the first monitoring data comprises: obtaining the temperature change rate of the first temperature in a first time period; determining whether the first temperature is in a preset temperature fluctuation interval according to the temperature change rate; if yes, sending a first signal to the user and controlling the temperature monitoring module to periodically monitor the lithium battery pack; if no, sending a second signal to the user and controlling the protection module to perform pre-cooling treatment on the lithium battery pack; monitoring the first temperature multiple times in a future first time period; determining whether the fluctuation difference value between the multiple first temperatures obtained in the multiple monitoring and the preset temperature fluctuation interval falls into a temperature fluctuation difference value interval; if no, sending a second signal to the user and controlling the pressure monitoring module to monitor the pressure of the lithium battery pack; wherein the first signal comprises a safety signal, and the second signal comprises a prompt signal, a pre-warning signal and an alarm signal; the determination of whether the fluctuation difference value between the multiple first temperatures obtained in the multiple monitoring and the preset temperature fluctuation interval falls into a temperature fluctuation difference value interval comprises: obtaining temperature data of the lithium battery pack in the future first time period, denoted as a second temperature; comparing the second temperature with a temperature threshold to obtain a first comparison result; determining whether the second temperature is between a highest temperature threshold and a lowest temperature threshold according to the first comparison result; if no, determining that the lithium battery pack is in a first dangerous state and executing a first emergency plan; the comparison of the second temperature with a temperature threshold to obtain a first comparison result comprises: regionally dividing the lithium battery pack according to the first comparison result; divide at least one of the lithium batteries higher than the highest temperature threshold into a first battery group, and the rest of the lithium batteries into a second battery group; wherein the first battery group is a high-temperature area; define the pressure of the lithium battery group under normal conditions as a first pressure; the pressure monitoring module comprises a plurality of anchor points arranged on the outer surface of the lithium battery group, for measuring the surface flatness of the lithium battery group; the control of the pressure monitoring module for monitoring the pressure of the lithium battery group, comprising: monitoring the internal pressure of the lithium battery group and the external pressure of the lithium battery group; obtain the first flatness data of each anchor point; when it is determined that the lithium battery group is in the first dangerous state, control the plurality of anchor points to monitor the lithium battery group in the future first time period to obtain second flatness data; generate the outer surface change data of the lithium battery group according to the first flatness data and the second flatness data; the generation of the outer surface change data of the lithium battery group according to the first flatness data and the second flatness data, comprising: determine whether the anchor point is in the first battery group according to the second flatness data of each anchor point; if yes, control the protection module to execute a second emergency plan, mark the anchor point corresponding to the lithium battery group as a high-temperature and high-pressure area, and the rest of the lithium battery group around it as a temperature spread area, and control the volume monitoring module to monitor the lithium battery group; wherein the second emergency plan includes pressure relief treatment for the high-temperature and high-pressure area, and starting liquid cooling function to cool the lithium battery; determine whether a second processing strategy is needed for the lithium battery group according to the outer surface change data; if yes, control the protection module to perform pressure relief treatment on the lithium battery group; The automobile charging and discharging monitoring device is also provided with a road condition prediction module connected with the mobile terminal of the user; the road condition prediction module predicts the road condition type of the automobile in the future first time period, specifically including: if it is a potholed section or a steep section, adjust the suspension parameters of the automobile to avoid damage to the lithium battery group caused by external impact, and reduce the output power of the lithium battery group to reduce the additional pressure on the lithium battery group caused by the vibration of the vehicle driving on the potholed or steep section, and send a warning signal to the mobile terminal of the user to remind the user to drive carefully; The automobile charging and discharging monitoring device further comprises a weather monitoring module, which is arranged on the mobile terminal of the user and is in communication connection with the control center 40, and is used for monitoring the weather when the user drives the automobile and judging whether the working environment of the lithium battery group is met; determine whether the weather change type in the future first time period meets the temperature drop condition according to the weather monitoring module; if yes, determine whether the weather change type includes rainy weather or snowy weather; If the weather change type is determined to be rainy weather or snowy weather, the control center controls the protection module to regulate the temperature of the lithium battery pack, starts the temperature compensation function, and keeps the temperature of the lithium battery pack at the first temperature; The control of the volume monitoring module on the lithium battery pack includes: A three-dimensional volume model is established for the lithium battery pack; The lithium battery pack is gridded to obtain the coordinates of any cube on the lithium battery pack; The volume monitoring module is controlled to monitor at least one cube located in the high-temperature and high-pressure area to obtain the third monitoring data; According to the third monitoring data, it is determined whether the battery safety degree of the lithium battery corresponding to the cube in the future first time period meets the charge and discharge standard; If not, the lithium battery corresponding to the cube is cut off, and the output power of the remaining lithium batteries arranged around the lithium battery is reduced.

2. The control method according to claim 1, characterized by, The determination that the lithium battery pack is in a first dangerous state includes: The current residual capacity and power consumption rate of the lithium battery pack are obtained; The lithium battery pack is cooled; It is determined whether the lithium battery pack has the possibility to complete the remaining journey after the cooling treatment; If not, the second signal is sent to the user, the driving speed of the automobile is controlled to reduce to the minimum speed specified by the current road section, and a help signal is sent to the relevant department; If yes, the protection module is controlled to continuously cool the lithium battery pack to the first temperature, the road conditions of the remaining journey in the historical period are obtained, and the automobile is controlled to start the cruise control mode according to the residual capacity.

3. The control method according to claim 2, characterized by, The control of the volume monitoring module on at least one cube located in the high-temperature and high-pressure area includes: The inner cell of the lithium battery is controlled as the source boundary; The shell of the lithium battery is controlled as the target boundary; The inner cell is controlled to expand directly on the shell; The shell is controlled as the boundary constraint of the volume expansion of the lithium battery; The relationship between the volume of the cube and the temperature in the future first time period is obtained; According to the change relationship, the output power of the lithium battery is dynamically adjusted.

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