Self-heating method, system and equipment of power battery system and storage medium

Abstract

The invention discloses a self-heating method, device and equipment of a power battery system and a computer readable storage medium, and the method comprises the steps: determining to enter a self-heating mode according to the collected voltage and temperature of a single cell; if it is determined that the battery enters the self-heating mode, negative electrode potential values of the single battery cells are obtained, the number of the single battery cells is multiple, and the negative electrode potential values of the single battery cells are the minimum value of the negative electrode potential values of the multiple single battery cells; and according to the negative electrode potential value, controlling the self-heating rate and frequency so as to perform self-heating on the power battery system, thereby solving the problem that the self-heating rate and frequency which are researched and confirmed in advance are preset into a product in the related technology, and the product quality is influenced. The technical problem that overcharge and lithium precipitation easily occur when self-heating is started when a heating condition is met is solved, a control strategy of self-heating rate and frequency is dynamically adjusted, it is ensured that a battery cell is always in a safe use range, and safety problems are reduced.

Description

Technical Field

[0001] The present application relates to the field of battery heating technology, and in particular to a self-heating method, system, device and computer-readable storage medium for a power battery system. Background Art

[0002] The new energy vehicle industry is developing rapidly, and the requirements for the performance of lithium batteries are getting higher and higher. The capacity and power of lithium batteries are significantly reduced at low temperatures, which seriously affects the endurance and power performance of the vehicle. Improving the low-temperature performance of batteries can be improved from the level of active materials and electrolytes, but the cost and development cycle are high. External heating of the battery cell is also a feasible solution, but it requires additional heating films, heating wires, water cooling pipes and other components, resulting in additional component costs and layout space requirements, and the energy utilization rate of external heating is low. The battery cell self-heating solution does not require additional components, can be implemented with existing battery cells, does not require additional layout space, and has a high energy utilization rate. It has become a new heating method.

[0003] The current self-heating scheme generally adopts the self-heating rate and frequency confirmed by research in advance, preset in the product, and starts self-heating when the heating conditions are met. However, for market products, there are inconsistencies in the temperature of hundreds of cells in the battery system, and it is impossible to fully cover the monitoring. Especially for 800V battery systems, the number of single cells in series is generally twice that of traditional 400V battery packs, and the consistency difference of the cells is further increased. The self-heating rate and frequency confirmed by research in advance are preset in the product, and self-heating is started when the heating conditions are met, which is prone to safety problems such as overcharging and lithium precipitation. Summary of the invention

[0004] The present application provides a self-heating method, device, equipment and computer-readable storage medium for a power battery system, which can solve the technical problem in the prior art that self-heating rate and frequency confirmed by prior research are used, preset in the product, and self-heating is started when the heating conditions are met, which easily leads to overcharging and lithium deposition.

[0005] In a first aspect, an embodiment of the present application provides a self-heating method for a power battery system, the self-heating method for a power battery system comprising:

[0006] According to the collected voltage and temperature of the single battery cell, determine to enter the self-heating mode;

[0007] If it is determined to enter the self-heating mode, the negative electrode potential value of the single cell is obtained, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value of the negative electrode potential values ​​of the multiple single cells;

[0008] According to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system.

[0009] In combination with the first aspect, in one embodiment, controlling the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system includes:

[0010] If it is determined that the negative electrode potential value is greater than the first preset negative electrode potential value, controlling the self-heating ratio to increase according to the first preset growth mode and controlling the self-heating frequency to increase according to the second preset growth mode, so as to self-heat the power battery system;

[0011] The first preset growth mode includes the self-heating frequency linearly increasing from 0 Hz at 200 Hz / 5 min until 1400 Hz and maintaining the frequency;

[0012] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0013] In combination with the first aspect, in one embodiment, if it is determined to enter the self-heating mode, after obtaining the negative electrode potential value of the single battery cell, the method further includes:

[0014] If it is determined that the negative electrode potential value is less than or equal to the first preset negative electrode potential value and greater than the second preset negative electrode potential value, controlling the self-heating frequency to increase according to the second preset increase mode to self-heat the power battery system;

[0015] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0016] In combination with the first aspect, in one embodiment, if it is determined to enter the self-heating mode, after obtaining the negative electrode potential value of the single battery cell, the method further includes:

[0017] If it is determined that the negative electrode potential value is less than a second preset negative electrode potential value, stopping the self-heating mode within a preset time period;

[0018] If it is detected that the current negative electrode potential value is greater than the second preset negative electrode potential value outside the preset time period, re-determining to enter the self-heating mode;

[0019] According to the current negative electrode potential value, controlling the self-heating rate and frequency to self-heat the power battery system;

[0020] Alternatively, controlling the self-heating frequency to increase according to a second preset increasing manner to self-heat the power battery system;

[0021] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0022] In combination with the first aspect, in one implementation, if it is determined that the self-heating mode is entered, obtaining the negative electrode potential value of the single battery cell includes:

[0023] By presetting the reference electrode and the single cell voltage sampling circuit, the negative electrode potential value of each single cell is monitored and collected in real time;

[0024] The negative electrode potential value of the single battery cell is obtained by collecting the negative electrode potential of each of the battery cells.

[0025] In combination with the first aspect, in one implementation, determining to enter the self-heating mode according to the collected voltage and temperature of the single battery cell includes:

[0026] Real-time collection of the voltage and temperature of the single battery cell;

[0027] If it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, it is determined to enter a self-heating mode.

[0028] In combination with the first aspect, in one embodiment, after controlling the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system, the method further includes:

[0029] If it is detected that the temperature of the single battery cell is greater than or equal to the second preset temperature, the self-heating mode is exited.

[0030] In a second aspect, an embodiment of the present application provides a self-heating device for a power battery system, wherein the self-heating device for the power battery system comprises:

[0031] A determination module, used to determine whether to enter a self-heating mode according to the collected voltage and temperature of the single battery cell;

[0032] an acquisition module, configured to acquire the negative electrode potential value of the single cell if it is determined that the self-heating mode is entered, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value of the negative electrode potential values ​​of the multiple single cells;

[0033] The control and self-heating module is used to control the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system.

[0034] In a third aspect, an embodiment of the present application provides a self-heating device for a power battery system, wherein the self-heating device for the power battery system comprises a processor, a memory, and a self-heating program for the power battery system stored in the memory and executable by the processor, wherein when the self-heating program for the power battery system is executed by the processor, the steps of the self-heating method for the power battery system as described above are implemented.

[0035] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, characterized in that a self-heating program of a power battery system is stored on the computer-readable storage medium, wherein when the self-heating program of the power battery system is executed by a processor, the steps of the self-heating method of the power battery system as described above are implemented.

[0036] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0037] By determining to enter the self-heating mode based on the collected voltage and temperature of the single battery cell; if it is determined to enter the self-heating mode, obtaining the negative electrode potential value of the single battery cell, wherein the number of the single battery cells is multiple, and the negative electrode potential value of the single battery cell is the minimum value of the negative electrode potential values ​​of the multiple single battery cells; according to the negative electrode potential value, controlling the self-heating rate and frequency to self-heat the power battery system, this solves the technical problem in related technologies that the self-heating rate and frequency that are confirmed by prior research are used, preset in the product, and overcharging and lithium deposition are prone to occur when self-heating is started when the heating conditions are met. The control strategy of the self-heating rate and frequency is dynamically adjusted to ensure that the battery cells are always in a safe use range and reduce safety issues. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of the first embodiment of the self-heating method of the power battery system of the present application;

[0039] Figure 2 This is a flow chart of a second embodiment of the self-heating method for a power battery system of the present application;

[0040] Figure 3 This is a schematic flow chart of a third embodiment of the self-heating method for a power battery system of the present application;

[0041] Figure 4 This is a functional module diagram of an embodiment of a self-heating device of a power battery system of the present application;

[0042] Figure 5 This is a schematic diagram of the hardware structure of the self-heating device of the power battery system involved in the embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] First, some technical terms in the present application are explained to facilitate those skilled in the art to understand the present application.

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0046] In a first aspect, an embodiment of the present application provides a self-heating method for a power battery system.

[0047] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the self-heating method of the power battery system of the present application. Figure 1 As shown, the self-heating method of the power battery system includes:

[0048] Step S10: determining to enter the self-heating mode according to the collected voltage and temperature of the single battery cell;

[0049] Exemplarily, each single cell in the power battery system is monitored by the BMS, and when the voltage and temperature of any single cell are detected, the voltage and temperature of the single cell are collected. When the voltage of the single cell is less than the preset voltage, and the temperature of the single cell is less than the preset temperature, it is determined to enter the self-heating mode. Battery self-heating utilizes the characteristic that low temperature causes increased internal resistance. By installing a device that can generate an oscillating current at both ends of the battery, the current passes through a cell with a large internal resistance, thereby generating a large amount of heat inside the battery, and ultimately causing the battery temperature to rise rapidly. The battery heating method does not require additional hardware costs, and the heating efficiency is high and uniform.

[0050] Specifically, determining to enter the self-heating mode based on the collected voltage and temperature of the single battery cell includes: collecting the voltage and temperature of the single battery cell in real time; if it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, then determining to enter the self-heating mode.

[0051] Exemplarily, the voltage and temperature of the single cell are collected in real time, the collected voltage of the single cell is compared with the preset voltage range, and the temperature of the single cell is compared with the first preset temperature; if the voltage of the single cell is within the first preset voltage range, and the temperature of the single cell is less than or equal to the first preset temperature, it is determined to enter the self-heating mode. For example, if the voltage of the single cell is within the first preset voltage range of 0-0.05V, and the temperature of the single cell is less than or equal to the first preset temperature of -10°C, it is determined to enter the self-heating mode.

[0052] Step S20: if it is determined to enter the self-heating mode, then obtaining the negative electrode potential value of the single cell, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value among the negative electrode potential values ​​of the multiple single cells;

[0053] Exemplarily, if it is determined to enter the self-heating mode, the negative electrode potential value of each single cell is obtained, the negative electrode potential values ​​of multiple single cells are compared, and the minimum value among the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell. The acquisition method includes pre-installing a voltage detection device in each single cell, and obtaining the negative electrode potential value of each single cell through the voltage detection device in each single cell.

[0054] Specifically, if it is determined to enter the self-heating mode, the negative electrode potential value of the single cell is obtained, including: real-time monitoring and collecting the negative electrode potential value of each single cell through a preset reference electrode and a preset single cell voltage sampling circuit in each single cell; and obtaining the negative electrode potential value of the single cell through the collected negative electrode potential of each cell.

[0055] Exemplarily, a reference electrode is pre-installed in each elevator battery cell, and the negative electrode potential value of each battery cell is monitored and collected in real time through the reference electrode and the single cell voltage sampling circuit. The negative electrode potential values ​​of multiple single cells are obtained and compared, and the minimum value of the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell.

[0056] Step S30: According to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system.

[0057] Exemplarily, according to the acquired negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system. For example, when the acquired negative electrode potential value is less than the first preset potential value, the heating frequency is controlled to increase from 0 to 1000 Hz, and the self-heating rate is controlled to increase from 0 to 5C to self-heat the power battery system.

[0058] Specifically, the self-heating rate and frequency are controlled according to the negative electrode potential value to self-heat the power battery system, including: if it is determined that the negative electrode potential value is greater than the first preset negative electrode potential value, the self-heating rate is controlled to increase according to a first preset growth method and the self-heating frequency is controlled to increase according to a second preset growth method to self-heat the power battery system; the first preset growth method includes the self-heating frequency linearly increasing from 0HZ at 200HZ / 5min to 1400HZ and maintaining it; the second preset growth method includes the self-heating rate linearly increasing from 0C at 1C / 5min to 5C and maintaining it.

[0059] Exemplarily, if it is determined that the negative electrode potential value is greater than the first preset negative electrode potential value of 0.05V, the self-heating rate is controlled to increase linearly from 0HZ at 200HZ / 5min to 1400HZ and maintained according to the first preset growth method, and the self-heating frequency is controlled to increase linearly from 0C at 1C / 5min to 5C and maintained according to the second preset growth method, so as to self-heat the power battery system.

[0060] Specifically, after controlling the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system, the method further includes: if it is detected that the temperature of the single battery cell is greater than or equal to a second preset temperature, exiting the self-heating mode.

[0061] Exemplarily, if it is detected that the temperature of the single battery cell is greater than or equal to the second preset temperature of 85 degrees, the self-heating mode is exited and the self-heating rate and frequency are no longer controlled.

[0062] In the present embodiment, it is determined to enter the self-heating mode based on the collected voltage and temperature of the single battery cell; if it is determined to enter the self-heating mode, the negative electrode potential value of the single battery cell is obtained, wherein the number of the single battery cells is multiple, and the negative electrode potential value of the single battery cell is the minimum value of the negative electrode potential values ​​of the multiple single battery cells; according to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system, which solves the technical problem that the related technology uses the self-heating rate and frequency confirmed by prior research, presets them in the product, and the self-heating is easily overcharged and lithium precipitation occurs when the heating conditions are met. The control strategy of the self-heating rate and frequency is dynamically adjusted to ensure that the battery cell is always in a safe use range and reduce safety problems.

[0063] In one embodiment, referring to Figure 2 , Figure 2 This is a flow chart of the second embodiment of the self-heating method of the power battery system of the present application. Figure 2 As shown, the self-heating method of the power battery system includes:

[0064] Step S21: determining to enter the self-heating mode according to the collected voltage and temperature of the single battery cell;

[0065] Exemplarily, each single cell in the power battery system is monitored by the BMS, and when the voltage and temperature of any single cell are detected, the voltage and temperature of the single cell are collected. When the voltage of the single cell is less than the preset voltage, and the temperature of the single cell is less than the preset temperature, it is determined to enter the self-heating mode. Battery self-heating utilizes the characteristic that low temperature causes increased internal resistance. By installing a device that can generate an oscillating current at both ends of the battery, the current passes through a cell with a large internal resistance, thereby generating a large amount of heat inside the battery, and ultimately causing the battery temperature to rise rapidly. The battery heating method does not require additional hardware costs, and the heating efficiency is high and uniform.

[0066] Specifically, determining to enter the self-heating mode based on the collected voltage and temperature of the single battery cell includes: collecting the voltage and temperature of the single battery cell in real time; if it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, then determining to enter the self-heating mode.

[0067] Exemplarily, the voltage and temperature of the single cell are collected in real time, the collected voltage of the single cell is compared with the preset voltage range, and the temperature of the single cell is compared with the first preset temperature; if the voltage of the single cell is within the first preset voltage range, and the temperature of the single cell is less than or equal to the first preset temperature, it is determined to enter the self-heating mode. For example, if the voltage of the single cell is within the first preset voltage range of 0-0.05V, and the temperature of the single cell is less than or equal to the first preset temperature of -10°C, it is determined to enter the self-heating mode.

[0068] Step S22: if it is determined to enter the self-heating mode, then obtaining the negative electrode potential value of the single cell, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value among the negative electrode potential values ​​of the multiple single cells;

[0069] Exemplarily, if it is determined to enter the self-heating mode, the negative electrode potential value of each single cell is obtained, the negative electrode potential values ​​of multiple single cells are compared, and the minimum value among the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell. The acquisition method includes pre-installing a voltage detection device in each single cell, and obtaining the negative electrode potential value of each single cell through the voltage detection device in each single cell.

[0070] Specifically, if it is determined to enter the self-heating mode, the negative electrode potential value of the single cell is obtained, including: real-time monitoring and collecting the negative electrode potential value of each single cell through a preset reference electrode and a preset single cell voltage sampling circuit in each single cell; and obtaining the negative electrode potential value of the single cell through the collected negative electrode potential of each cell.

[0071] Exemplarily, a reference electrode is pre-installed in each elevator battery cell, and the negative electrode potential value of each battery cell is monitored and collected in real time through the reference electrode and the single cell voltage sampling circuit. The negative electrode potential values ​​of multiple single cells are obtained and compared, and the minimum value of the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell.

[0072] Step S23: If it is determined that the negative electrode potential value is less than or equal to the first preset negative electrode potential value and greater than the second preset negative electrode potential value, the self-heating frequency is controlled to increase according to the second preset growth method to self-heat the power battery system; the second preset growth method includes the self-heating rate linearly increasing from 0C at 1C / 5min until 5C and maintaining it.

[0073] Exemplarily, if it is determined that the negative electrode potential value is less than or equal to the first preset negative electrode potential value of 0.05V, and greater than the second preset negative electrode potential value of 0V, the self-heating frequency is controlled to increase according to the second preset increase method, and the self-heating rate increases linearly from 0C at 1C / 5min to 5C and maintained to self-heat the power battery system.

[0074] In the present embodiment, it is determined to enter the self-heating mode based on the collected voltage and temperature of the single battery cell; if it is determined to enter the self-heating mode, the negative electrode potential value of the single battery cell is obtained, wherein the number of the single battery cells is multiple, and the negative electrode potential value of the single battery cell is the minimum value of the negative electrode potential values ​​of the multiple single battery cells; according to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system, which solves the technical problem that the related technology uses the self-heating rate and frequency confirmed by prior research, presets them in the product, and the self-heating is easily overcharged and lithium precipitation occurs when the heating conditions are met. The control strategy of the self-heating rate and frequency is dynamically adjusted to ensure that the battery cell is always in a safe use range and reduce safety problems.

[0075] In one embodiment, referring to Figure 2 , Figure 2 This is a flow chart of the second embodiment of the self-heating method of the power battery system of the present application. Figure 2 As shown, the self-heating method of the power battery system includes:

[0076] Step S31: determining to enter the self-heating mode according to the collected voltage and temperature of the single battery cell;

[0077] Exemplarily, each single cell in the power battery system is monitored by the BMS, and when the voltage and temperature of any single cell are detected, the voltage and temperature of the single cell are collected. When the voltage of the single cell is less than the preset voltage, and the temperature of the single cell is less than the preset temperature, it is determined to enter the self-heating mode. Battery self-heating utilizes the characteristic that low temperature causes increased internal resistance. By installing a device that can generate an oscillating current at both ends of the battery, the current passes through a cell with a large internal resistance, thereby generating a large amount of heat inside the battery, and ultimately causing the battery temperature to rise rapidly. The battery heating method does not require additional hardware costs, and the heating efficiency is high and uniform.

[0078] Specifically, determining to enter the self-heating mode based on the collected voltage and temperature of the single battery cell includes: collecting the voltage and temperature of the single battery cell in real time; if it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, then determining to enter the self-heating mode.

[0079] Exemplarily, the voltage and temperature of the single cell are collected in real time, the collected voltage of the single cell is compared with the preset voltage range, and the temperature of the single cell is compared with the first preset temperature; if the voltage of the single cell is within the first preset voltage range, and the temperature of the single cell is less than or equal to the first preset temperature, it is determined to enter the self-heating mode. For example, if the voltage of the single cell is within the first preset voltage range of 0-0.05V, and the temperature of the single cell is less than or equal to the first preset temperature of -10°C, it is determined to enter the self-heating mode.

[0080] Step S32: if it is determined to enter the self-heating mode, obtaining the negative electrode potential value of the single cell, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value among the negative electrode potential values ​​of the multiple single cells;

[0081] Exemplarily, if it is determined to enter the self-heating mode, the negative electrode potential value of each single cell is obtained, the negative electrode potential values ​​of multiple single cells are compared, and the minimum value among the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell. The acquisition method includes pre-installing a voltage detection device in each single cell, and obtaining the negative electrode potential value of each single cell through the voltage detection device in each single cell.

[0082] Specifically, if it is determined to enter the self-heating mode, the negative electrode potential value of the single cell is obtained, including: real-time monitoring and collecting the negative electrode potential value of each single cell through a preset reference electrode and a preset single cell voltage sampling circuit in each single cell; and obtaining the negative electrode potential value of the single cell through the collected negative electrode potential of each cell.

[0083] Exemplarily, a reference electrode is pre-installed in each elevator battery cell, and the negative electrode potential value of each battery cell is monitored and collected in real time through the reference electrode and the single cell voltage sampling circuit. The negative electrode potential values ​​of multiple single cells are obtained and compared, and the minimum value of the negative electrode potential values ​​of the multiple single cells is determined, and the minimum value is used as the negative electrode potential value of the single cell.

[0084] Step S33: if it is determined that the negative electrode potential value is less than the second preset negative electrode potential value, stopping the self-heating mode within a preset time period;

[0085] Exemplarily, if it is determined that the negative electrode potential value is less than the second preset negative electrode potential value 0V, the self-heating mode is stopped within the preset time, and the self-heating rate and frequency are not controlled. For example, the self-heating mode is stopped for 5 minutes, or 10 minutes.

[0086] Step S34: if it is detected that the current negative electrode potential value is greater than the second preset negative electrode potential value outside the preset time period, re-determining to enter the self-heating mode;

[0087] Exemplarily, after stopping the self-heating mode for 5 minutes or 10 minutes, if it is detected that the current cathode potential value is greater than the second preset cathode potential value 0V, it is determined to re-enter the self-heating mode.

[0088] Step S35: controlling the self-heating rate and frequency according to the current negative electrode potential value to self-heat the power battery system;

[0089] Exemplarily, if it is determined that the current negative electrode potential value is greater than the first preset negative electrode potential value of 0.05V, the self-heating rate is controlled to increase linearly from 0HZ at 200HZ / 5min to 1400HZ and maintained according to the first preset growth method, and the self-heating frequency is controlled to increase linearly from 0C at 1C / 5min to 5C and maintained according to the second preset growth method, so as to self-heat the power battery system.

[0090] Step S36: Alternatively, the self-heating frequency is controlled to increase according to a second preset growth method to self-heat the power battery system; the second preset growth method includes the self-heating rate increasing linearly from 0C at 1C / 5min to 5C and maintaining it.

[0091] Exemplarily, if it is determined that the current negative electrode potential value is less than or equal to the first preset negative electrode potential value of 0.05V, and greater than the second preset negative electrode potential value of 0V, the self-heating frequency is controlled to increase according to the second preset increase method, and the self-heating rate increases linearly from 0C at 1C / 5min to 5C and maintained to self-heat the power battery system.

[0092] In the present embodiment, it is determined to enter the self-heating mode based on the collected voltage and temperature of the single battery cell; if it is determined to enter the self-heating mode, the negative electrode potential value of the single battery cell is obtained, wherein the number of the single battery cells is multiple, and the negative electrode potential value of the single battery cell is the minimum value of the negative electrode potential values ​​of the multiple single battery cells; according to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system, which solves the technical problem that the related technology uses the self-heating rate and frequency confirmed by prior research, presets them in the product, and the self-heating is easily overcharged and lithium precipitation occurs when the heating conditions are met. The control strategy of the self-heating rate and frequency is dynamically adjusted to ensure that the battery cell is always in a safe use range and reduce safety problems.

[0093] In a second aspect, an embodiment of the present application also provides a self-heating device for a power battery system.

[0094] In one embodiment, referring to Figure 4 , Figure 4 This is a functional module diagram of an embodiment of a self-heating device for a power battery system of the present application. Figure 4 As shown, the self-heating device of the power battery system includes:

[0095] A determination module 10 is used to determine whether to enter a self-heating mode according to the collected voltage and temperature of the single battery cell;

[0096] An acquisition module 20, configured to acquire the negative electrode potential value of the single cell if it is determined that the self-heating mode has been entered, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value of the negative electrode potential values ​​of the multiple single cells;

[0097] The control and self-heating module 30 is used to control the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system.

[0098] Further, in one embodiment, the control and self-heating module 30 is used to:

[0099] If it is determined that the negative electrode potential value is greater than the first preset negative electrode potential value, controlling the self-heating ratio to increase according to the first preset growth mode and controlling the self-heating frequency to increase according to the second preset growth mode, so as to self-heat the power battery system;

[0100] The first preset growth mode includes the self-heating frequency linearly increasing from 0 Hz at 200 Hz / 5 min until 1400 Hz and maintaining the frequency;

[0101] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0102] Furthermore, in one embodiment, the self-heating device of the power battery system further includes a new module for:

[0103] If it is determined that the negative electrode potential value is less than or equal to the first preset negative electrode potential value and greater than the second preset negative electrode potential value, controlling the self-heating frequency to increase according to the second preset increase mode to self-heat the power battery system;

[0104] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0105] Furthermore, in one embodiment, the self-heating device of the power battery system further includes a new module for:

[0106] If it is determined that the negative electrode potential value is less than a second preset negative electrode potential value, stopping the self-heating mode within a preset time period;

[0107] If it is detected that the current negative electrode potential value is greater than the second preset negative electrode potential value outside the preset time period, re-determining to enter the self-heating mode;

[0108] According to the current negative electrode potential value, controlling the self-heating rate and frequency to self-heat the power battery system;

[0109] Alternatively, controlling the self-heating frequency to increase according to a second preset increasing manner to self-heat the power battery system;

[0110] The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

[0111] Furthermore, in one embodiment, the acquisition module 20 is used to:

[0112] By using a preset reference electrode and a preset single cell voltage sampling circuit in each single cell, the negative electrode potential value of each single cell is monitored and collected in real time;

[0113] The negative electrode potential value of the single battery cell is obtained by collecting the negative electrode potential of each of the battery cells.

[0114] Furthermore, in one embodiment, the determination module 10 is used to:

[0115] Real-time collection of the voltage and temperature of the single battery cell;

[0116] If it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, it is determined to enter a self-heating mode.

[0117] Furthermore, in one embodiment, the self-heating device of the power battery system further includes a new module for:

[0118] If it is detected that the temperature of the single battery cell is greater than or equal to the second preset temperature, the self-heating mode is exited.

[0119] Among them, the functional implementation of each module in the self-heating device of the above-mentioned power battery system corresponds to the various steps in the embodiment of the self-heating method of the above-mentioned power battery system, and its functions and implementation processes will not be repeated here one by one.

[0120] In a third aspect, an embodiment of the present application provides a self-heating device for a power battery system. The self-heating device for the power battery system may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0121] Reference Figure 5 , Figure 5 Schematic diagram of the hardware structure of the self-heating device of the power battery system involved in the embodiment of the present application. In the embodiment of the present application, the self-heating device of the power battery system may include a processor, a memory, a communication interface and a communication bus.

[0122] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0123] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces for interconnecting devices within the self-heating device of the power battery system, as well as interfaces for interconnecting the self-heating device of the power battery system with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0124] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0125] The processor may be a general-purpose processor, which may call the self-heating program of the power battery system stored in the memory and execute the self-heating method of the power battery system provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the self-heating program of the power battery system is called may refer to the various embodiments of the self-heating method of the power battery system of the present application, which will not be repeated here.

[0126] Those skilled in the art will understand that Figure 5 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0127] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0128] The computer-readable storage medium of the present application stores a self-heating program for a power battery system, wherein when the self-heating program for the power battery system is executed by a processor, the steps of the self-heating method for the power battery system as described above are implemented.

[0129] Among them, the method implemented when the self-heating program of the power battery system is executed can refer to the various embodiments of the self-heating method of the power battery system of the present application, and will not be repeated here.

[0130] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0131] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0132] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0133] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0134] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0135] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0136] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A self-heating method for a power battery system, characterized in that: The self-heating method of the power battery system comprises: According to the collected voltage and temperature of the single battery cell, determine to enter the self-heating mode; If it is determined to enter the self-heating mode, the negative electrode potential value of the single cell is obtained, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value among the negative electrode potential values ​​of the multiple single cells; According to the negative electrode potential value, the self-heating rate and frequency are controlled to self-heat the power battery system.

2. The self-heating method of the power battery system according to claim 1, characterized in that: The controlling the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system includes: If it is determined that the negative electrode potential value is greater than the first preset negative electrode potential value, controlling the self-heating ratio to increase according to the first preset growth mode and controlling the self-heating frequency to increase according to the second preset growth mode, so as to self-heat the power battery system; The first preset growth mode includes the self-heating frequency linearly increasing from 0 Hz at 200 Hz / 5 min until 1400 Hz and maintaining the frequency; The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

3. The self-heating method of the power battery system according to claim 1, characterized in that: If it is determined to enter the self-heating mode, after obtaining the negative electrode potential value of the single cell, the method further includes: If it is determined that the negative electrode potential value is less than or equal to the first preset negative electrode potential value and greater than the second preset negative electrode potential value, controlling the self-heating frequency to increase according to the second preset increase mode to self-heat the power battery system; The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

4. The self-heating method of the power battery system according to claim 1, characterized in that: If it is determined to enter the self-heating mode, after obtaining the negative electrode potential value of the single cell, the method further includes: If it is determined that the negative electrode potential value is less than a second preset negative electrode potential value, stopping the self-heating mode within a preset time period; If it is detected that the current negative electrode potential value is greater than the second preset negative electrode potential value outside the preset time period, re-determining to enter the self-heating mode; According to the current negative electrode potential value, controlling the self-heating rate and frequency to self-heat the power battery system; Alternatively, controlling the self-heating frequency to increase according to a second preset increasing manner to self-heat the power battery system; The second preset growth mode includes the self-heating rate linearly increasing from 0C at 1C / 5min until it reaches 5C and is maintained.

5. The self-heating method of the power battery system according to claim 1, characterized in that: If it is determined that the self-heating mode is entered, obtaining the negative electrode potential value of the single cell includes: By using a preset reference electrode and a preset single cell voltage sampling circuit in each single cell, the negative electrode potential value of each single cell is monitored and collected in real time; The negative electrode potential value of the single battery cell is obtained by collecting the negative electrode potential of each of the battery cells.

6. The self-heating method of the power battery system according to claim 1, characterized in that: The step of determining to enter the self-heating mode according to the collected voltage and temperature of the single cell includes: Real-time collection of the voltage and temperature of the single battery cell; If it is determined that the collected voltage of the single battery cell is within a preset voltage range, and the temperature of the single battery cell is less than or equal to a first preset temperature, it is determined to enter a self-heating mode.

7. The self-heating method of the power battery system according to claim 1, characterized in that: After controlling the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system, the method further includes: If it is detected that the temperature of the single battery cell is greater than or equal to the second preset temperature, the self-heating mode is exited.

8. A self-heating device for a power battery system, characterized in that: The self-heating device of the power battery system comprises: A determination module, used to determine whether to enter a self-heating mode according to the collected voltage and temperature of the single battery cell; an acquisition module, configured to acquire the negative electrode potential value of the single cell if it is determined that the self-heating mode is entered, wherein the number of the single cells is multiple, and the negative electrode potential value of the single cell is the minimum value of the negative electrode potential values ​​of the multiple single cells; The control and self-heating module is used to control the self-heating rate and frequency according to the negative electrode potential value to self-heat the power battery system.

9. A self-heating device for a power battery system, characterized in that: The self-heating device of the power battery system includes a processor, a memory, and a self-heating program of the power battery system stored in the memory and executable by the processor, wherein when the self-heating program of the power battery system is executed by the processor, the steps of the self-heating method of the power battery system as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a self-heating program for a power battery system, wherein when the self-heating program for the power battery system is executed by a processor, the steps of the self-heating method for a power battery system according to any one of claims 1 to 7 are implemented.

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