Battery heating method and device for active balancing energy storage and interconnection system

Abstract

The application discloses a battery heating method and device of an active equalization energy storage parallel system, and belongs to the field of energy storage battery management. The method comprises the following steps: adjusting and controlling the voltage of an embedded capacitor according to the adjusting current of an auxiliary power supply which is electrically connected with the input end of the embedded capacitor of the active equalization energy storage parallel system, so that the embedded capacitor is in a steady voltage state; when the embedded capacitor is in the steady voltage state, generating a heating current for heating the battery of each branch according to the excitation signals applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage parallel system. The application can heat the battery of the active equalization energy storage parallel system without adding new elements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage battery management, and particularly relates to a battery heating method and device of an active equalization energy storage parallel system. BACKGROUND

[0002] With the continuous and rapid increase of the proportion of renewable energy installation, the intermittence and instability of fluctuating new energy make the power system increasingly dependent on energy storage, so that new energy storage has become a key technology for building a new power system. Under this background, active equalization energy storage parallel battery clusters are used for energy storage, thereby meeting the demand for large capacity of the energy storage system.

[0003] In related technologies, in order to ensure that the battery can still maintain good performance, safety and long service life in a low temperature environment, the battery needs to be heated, and the traditional heating method often needs additional heating elements or complex heating circuits. These heating methods not only have safety hazards, but also cause electromagnetic interference to surrounding electronic equipment.

[0004] Therefore, there is an urgent need for a battery heating method and device of an active equalization energy storage parallel system to solve the above technical problems. SUMMARY

[0005] The present application provides a battery heating method and device of an active equalization energy storage parallel system, which can heat the battery of the active equalization energy storage parallel system without adding new elements. The technical solution is as follows:

[0006] On the one hand, a battery heating method of an active equalization energy storage parallel system is provided, and the method comprises:

[0007] According to the adjustment current of the auxiliary power supply electrically connected to the input end of the embedded capacitor of the active equalization energy storage parallel system, the voltage of the embedded capacitor is adjusted and controlled, so that the embedded capacitor is in a stable voltage state;

[0008] When the embedded capacitor is in a stable voltage state, according to the excitation signal applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage parallel system, a heating current for heating the battery of each branch is generated.

[0009] On the other hand, a battery heating device of an active equalization energy storage parallel system is provided, and the device comprises:

[0010] The control module is configured to adjust and control the voltage of the embedded capacitor according to the adjustment current of the auxiliary power supply electrically connected to the input end of the embedded capacitor of the active equalization energy storage parallel system, so that the embedded capacitor is in a stable voltage state;

[0011] The generating module is configured to generate a heating current for heating each branch battery according to an excitation signal applied to both sides of a half-bridge switch of each branch of the active equalization energy storage and parallel system when the embedded capacitor is in a steady state.

[0012] In another aspect, a computer device is provided, which comprises a memory and a processor, the memory is configured to store a computer program, and the processor is configured to execute the computer program stored in the memory to implement the steps of the battery heating method and device of the active equalization energy storage and parallel system.

[0013] The technical solution provided by the application can bring at least the following beneficial effects: the embedded converter is used to apply a variable-frequency and variable-amplitude excitation signal to the switching device, thereby generating an alternating heating current. This method does not require a complex pulse generation and control circuit, reduces the design difficulty and cost of the system, improves the battery life, avoids the electromagnetic interference caused by the instantaneous impact of the pulse current, and affects the normal operation of the surrounding electronic equipment. At the same time, this method is simple to control, easy to implement, does not require the addition of new components, and is suitable for the active equalization energy storage and parallel system. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0015] Figure 1 is a flow chart of the battery heating method of the active equalization energy storage and parallel system provided by an embodiment of the application;

[0016] Figure 2 is a circuit schematic diagram of the active equalization energy storage and parallel system provided by an embodiment of the application;

[0017] Figure 3 is a heating mode circuit schematic diagram of the active equalization energy storage and parallel system provided by an embodiment of the application;

[0018] Figure 4 is a voltage regulation flow chart of the embedded capacitor provided by an embodiment of the application;

[0019] Figure 5 is a voltage schematic diagram of the embedded converter of the active equalization energy storage and parallel system provided by an embodiment of the application;

[0020] Figure 6is a heating current simulation curve and a heating current function curve solved by an embodiment of the present application.

[0021] Figure 7 is an excitation signal waveform diagram provided by an embodiment of the present application.

[0022] Figure 8 is a heating current and excitation signal amplitude and frequency change relationship diagram provided by an embodiment of the present application.

[0023] Figure 9 is a battery heating device structure diagram of an active equalization energy storage and parallel system provided by an embodiment of the present application.

[0024] Figure 10 is a hardware architecture diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0026] As described above, in the field of battery heating technology, the traditional heating method has many limitations. The external heating method will cause a large amount of heat to be lost in the conduction process, and the heating efficiency is low. The long-term use of pulse heating will significantly shorten the battery life, and therefore is not suitable for active equalization energy storage and parallel system.

[0027] Based on this, the idea of the present application is to use the system's built-in converter to apply a frequency and amplitude variable switching function on the switching device, thereby inducing an alternating current heating current. This method is simple to control, easy to implement, and does not require the addition of new components, and is suitable for active equalization energy storage and parallel system.

[0028] The specific implementation of the above idea is described below.

[0029] Please refer to Figure 1 The battery heating method of the active equalization energy storage and parallel system provided by the embodiments of the present application comprises:

[0030] Step 100, adjust and control the voltage of the built-in capacitor according to the adjustment current of the auxiliary power supply electrically connected to the input end of the built-in capacitor of the active equalization energy storage and parallel system, so that the built-in capacitor is in a stable voltage state.

[0031] Step 102, when the embedded capacitor is in a steady state, according to the excitation signal applied on both sides of the half-bridge switch of each branch of the active equalization energy storage and parallel system, a heating current for heating each branch battery is generated.

[0032] In the embodiment of the present application, the embedded converter is used to apply the excitation signal with variable frequency and amplitude on the switching device, so as to induce the alternating heating current. This method not only does not need complex pulse generation and control circuit, reduces the design difficulty and cost of the system, and improves the battery life, but also avoids the electromagnetic interference and other compatibility problems caused by the instantaneous impact of the pulse current, and affects the normal operation of the surrounding electronic equipment. At the same time, the method is simple to control, easy to implement, and does not need to add new components, which is suitable for the active equalization energy storage and parallel system.

[0033] The execution mode of each step is described below. Figure 1

[0034] Firstly, for step 100, the voltage of the embedded capacitor is adjusted and controlled according to the adjusting current of the auxiliary power supply which is electrically connected with the input end of the embedded capacitor of the active equalization energy storage and parallel system, so that the embedded capacitor is in a steady state.

[0035] As Figure 2 As shown in the schematic diagram of the active equalization energy storage and parallel system circuit provided by the embodiment of the present application, the active equalization energy storage and parallel system is improved by topology on the basis of the centralized energy storage converter, only a small capacity and low cost embedded converter is added to connect different battery clusters, so as to form a series-parallel current regulation. It has the following advantages: 1. The embedded converter only needs to transmit part of the battery charging and discharging power, and still ensures fewer devices; 2. The embedded converter adopts a non-isolated structure, and realizes the stability of the embedded capacitor voltage through energy balance control, and saves the isolation transformer. Therefore, on the basis of realizing the parallel loop current suppression and active regulation of the charging and discharging current among the battery clusters, the embedded converter increases the power density and reduces the cost.

[0036] Further, when the battery needs to be heated, the energy storage converter (PCS) is in a non-working state, at this time, the input end of the embedded capacitor is switched to the auxiliary power supply and the input end half-bridge is always on, and the topology structure is as shown in Figure 3 The size of the auxiliary power supply is determined by the design value of the embedded capacitor voltage. When the main circuit parameters are calculated, it is stated that the embedded capacitor voltage is 133V, and the margin considered is 1.5-2 times, so a 200V auxiliary power supply is selected in this design.

[0037] ​The embodiment of the present application generates the heating current by applying the excitation signal to the two ends of the half-bridge switch of the active equalization energy storage and connection system, and the generation of the heating current is not only related to the half-bridge switch function, but also related to the embedded capacitor voltage, and the stability of the embedded capacitor voltage is the prerequisite for generating the excitation voltage.

[0038] Therefore, the embodiment of the present application controls the voltage of the embedded capacitor by adjusting the current of the auxiliary power supply, and comprises the following steps: calculating the time-domain expression of the voltage of the embedded capacitor according to the average value of the current of the auxiliary power supply, the average value of the switch function of the half-bridge switch and the average value of the charging and discharging current of the branch battery; and performing Laplace transform on the time-domain expression of the voltage to obtain the adjustment current of the auxiliary power supply for adjusting the voltage of the embedded capacitor.

[0039] Specifically, the time-domain expression of the voltage of the embedded capacitor is established by the following formula:

[0040]

[0041] In the formula, C is the capacitance value of the embedded capacitor; V is the average value of the variable; V is the average value of the voltage of the embedded capacitor; I is the average value of the current of the auxiliary power supply; s is the average value of the switch function of the jth battery-side half-bridge switch; and I is the average value of the charging and discharging current of the jth battery. sc T sc T T j1 T j T

[0042] Further, the auxiliary power supply current controller as shown in the formula is designed to adjust the voltage of the embedded capacitor, and the adjustment current is calculated by the following formula: Figure 4

[0043] In the formula, I(s) is the adjustment current of the auxiliary power supply; K is the proportional control coefficient of the voltage of the embedded capacitor; K is the integral control coefficient of the voltage of the embedded capacitor; V is the small signal value of the voltage of the embedded capacitor; V is the reference value of the non-steady-state quantity of the voltage of the embedded capacitor; I is the steady-state current of the auxiliary power supply; C is the capacitance value of the embedded capacitor; and s is the Laplace operator. P I sc

[0044]

[0045] ​​​​​​​​​​​​​​​For step 102, when the embedded capacitor is in a steady state, a heating current for heating each branch battery is generated according to an excitation signal applied to both sides of a half-bridge switch of each branch of the active equalization energy storage system.

[0046] In the embodiment of the application, the heating current is generated by the following steps: a time-domain expression of an excitation voltage generated by the excitation signal is established according to a signal parameter of the excitation signal and a voltage of the embedded capacitor; a time-domain expression of the heating current generated by the excitation signal is established according to the time-domain expression of the excitation voltage and an open-circuit voltage of the branch battery; the time-domain expression of the heating current is solved and calculated, and a specific expression of the heating current is established according to the voltage of the embedded capacitor in the steady state; an influence parameter is determined according to the specific expression of the heating current, and the excitation signal is adjusted according to the influence parameter to generate the heating current for heating each branch battery.

[0047] Specifically, when the actual excitation signal is, an alternating excitation voltage generated is:

[0048] V cj (t) = V sc × Asin(ωt + ψ j )

[0049] In the formula, V sc is a stable voltage of the embedded capacitor; A is an amplitude of the excitation signal; ω is an angular frequency of the excitation signal, ψ j is a phase of the jth excitation signal; V cj (t) is an excitation voltage generated by the jth excitation signal at t.

[0050] A time-domain expression of the corresponding heating current is established by the following formula:

[0051]

[0052] In the formula, I j is the heating current generated by the jth excitation signal; r is a battery internal resistance; L is a battery filter inductance; V OCVj is an open-circuit voltage of the battery.

[0053] The specific expression of the heating current is obtained by solving and calculating the above formula as:

[0054]

[0055] In the formula, i j (t) is a specific value of the heating current; V = V sc × A; ω = 2 × π × f, f is a frequency of the excitation signal; n is a total number of the excitation signals.

[0056] It is worth mentioning that, in order to ensure the safety and effectiveness of battery heating, the excitation signal applied to each branch needs to have a phase difference for the case of multiple branches, and when 3 clusters are taken as an example, the heating current specific expression can be obtained:

[0057]

[0058] For n cluster branches, n excitation signals are needed, and the heating current generated by the jth excitation signal is:

[0059]

[0060] Where j = 1, 2, 3, …, n.

[0061] By comparing the coefficients, the second term is dominant, and the above formula can be simplified as:

[0062]

[0063] Corresponding to:

[0064]

[0065] Thus it can be determined that the heating current is related to the frequency and amplitude of the excitation signal, and in the variable alternating current battery heating system, the frequency and amplitude of the heating current are usually obtained by nonlinear programming, and in the present application, no optimal solution is made, only a heating current with controllable frequency and amplitude is designed, and the additional constraints include the maximum current allowed by IGBT selection.

[0066] 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 accompanying drawings.

[0067] A preferred scheme topology of the embedded converter for energy storage is built using MATLAB / Simulink software as shown in the figure, and simulation verification is carried out for the topology, and the simulation parameters are shown in Table 1 as follows:

[0068] Table 1

[0069]

[0070] Figure 5 For the embedded converter voltage, energy balance can be achieved. Figure 6 For the excitation signal with amplitude 0.2 and frequency 100Hz, the branch 1 heating current simulink simulation waveform and the calculated current 1 function waveform can be seen from the waveform that they completely overlap, proving the correctness of the established current model. Figure 7For the excitation signal waveform, the amplitude and frequency of the excitation signal are continuously changed, the excitation signal is started at 0.05s, the amplitude of the excitation signal is 0.1 and the frequency is 50 at 0.05-0.2, the amplitude of the excitation signal is 0.2 and the frequency is 50 at 0.2-0.3, the amplitude of the excitation signal is 0.2 and the frequency is 100 at 0.3-0.4, the amplitude of the excitation signal is 0.3 and the frequency is 100 at 0.4-0.5, and the excitation signal is stopped at 0.5-0.55. Figure 8 For the alternating heating current, the heating current changes with the excitation signal, and it can be seen that the heating current is related to the amplitude and frequency of the excitation signal.

[0071] It is proved by the above examples that the active equalization energy storage parallel system variable current control method implemented in the examples has feasibility and effectiveness, and can realize continuous control of the frequency and amplitude of the heating current.

[0072] Please refer to Figure 9 The battery heating device of the active equalization energy storage parallel system provided in the embodiments of the present application comprises:

[0073] The control module 900 is configured to adjust and control the voltage of the embedded capacitor according to the adjusting current of the auxiliary power supply electrically connected to the input end of the embedded capacitor of the active equalization energy storage parallel system, so that the embedded capacitor is in a steady voltage state.

[0074] The generation module 902 is configured to generate a heating current for heating the battery of each branch when the embedded capacitor is in the steady voltage state, according to the excitation signal applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage parallel system.

[0075] In the embodiments of the present application, the adjusting and controlling of the voltage of the embedded capacitor according to the adjusting current of the auxiliary power supply electrically connected to the input end of the embedded capacitor of the active equalization energy storage parallel system comprises:

[0076] The voltage time domain expression of the embedded capacitor is calculated according to the average value of the current of the auxiliary power supply, the average value of the switching function of the half-bridge switch and the average value of the charging and discharging current of the branch battery.

[0077] The adjusting current of the auxiliary power supply for adjusting the voltage of the embedded capacitor is obtained by Laplace transform processing of the voltage time domain expression.

[0078] In the embodiments of the present application, the voltage time domain expression is established by the following formula:

[0079]

[0080] In the formula, C sc is the capacitance value of the embedded capacitor; <> T is the average value of the variable; <V sc(t) T is the average value of the in-cell capacitor voltage, <I(t) T is the average value of the auxiliary power supply current, <s j1 (t) T is the average value of the jth battery-side half-bridge switching function, <I j (t) T is the average value of the jth battery charging and discharging current.

[0081] In the embodiment of the present application, the adjusting current is calculated by the following formula:

[0082]

[0083] In the formula, I(s) is the adjusting current of the auxiliary power supply; K P is the proportional control coefficient of the in-cell capacitor voltage; K I is the integral control coefficient of the in-cell capacitor voltage; is the small signal value of the in-cell capacitor voltage; is the reference value of the in-cell capacitor voltage non-steady-state quantity; I is the steady-state current of the auxiliary power supply; C sc is the capacitance value of the in-cell capacitor; s is the Laplace operator.

[0084] In the embodiment of the present application, the heating current for heating each branch battery is generated according to the excitation signals applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage system, and the method comprises the following steps: establishing a time-domain expression of an excitation voltage generated by the excitation signals according to signal parameters of the excitation signals and the voltage of the in-cell capacitor; establishing a time-domain expression of a heating current generated by the excitation signals according to the time-domain expression of the excitation voltage and the open-circuit voltage of the branch battery; solving and calculating the time-domain expression of the heating current, and establishing a specific expression of the heating current according to the voltage of the in-cell capacitor in a steady state; determining an influence parameter according to the specific expression of the heating current, and adjusting the excitation signals according to the influence parameter to generate the heating current for heating each branch battery.

[0085] In the embodiment of the present application, the time-domain expression of the excitation voltage is established by the following formula:

[0086] V cj (t) = V sc × Asin(ωt + ψ j )

[0087] In the formula, V sc is the steady voltage of the in-cell capacitor; A is the amplitude of the excitation signal; ω is the angular frequency of the excitation signal, ψ j is the phase of the jth excitation signal; V cj(t) is the excitation voltage generated by the jth excitation signal at time t.

[0088] In the embodiment of the application, the time-domain expression of the heating current is established by the following formula:

[0089]

[0090] In the formula, I j is the heating current generated by the jth excitation signal; r is the internal resistance of the battery; L is the filter inductance of the battery; V OCVj is the open-circuit voltage of the battery.

[0091] In the embodiment of the application, the specific expression of the heating current is established by the following formula:

[0092]

[0093] In the formula, i j (t) is the specific value of the heating current; V = V sc x A; ω = 2 x π x f, f is the frequency of the excitation signal; and n is the total number of the excitation signals.

[0094] It should be noted that the battery heating device of the active energy storage and parallel system provided in the above embodiment is only exemplified by the division of the above functional modules, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the battery heating device of the active energy storage and parallel system provided in the above embodiment and the battery heating method and device embodiments of the active energy storage and parallel system belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be described here.

[0095] Embodiments of the present application also provide a computer device, which refers to Figure 10 The computer device includes a processor and a memory, and the memory stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the battery heating method and device of the active energy storage and parallel system provided by each method embodiment.

[0096] Embodiments of the present application also provide a computer readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the battery heating method and device of the active energy storage and parallel system provided by each method embodiment.

[0097] The embodiment of the present application further provides a computer program product, which comprises a computer program, and a processor of a computer device reads the computer program from a computer readable storage medium, and the processor executes the computer program, so that the computer device executes the battery heating method and device of the active balancing energy storage and contact system according to any one of the above embodiments.

[0098] For the convenience of description, the above system or device is described in various modules or units in terms of functions. Of course, the functions of each unit can be implemented in the same or multiple software and / or hardware in the implementation of the present application.

[0099] From the above description of the embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software and the necessary general hardware platform. Based on this understanding, the technical solutions of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in various embodiments or some parts of the embodiments.

[0100] Finally, it should be noted that in this document, relational terms such as first and second and third and fourth, and the like can only be used to distinguish one entity or action from another entity or action, without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0101] The above description is only the preferred embodiments of the present application, and it should be pointed out that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be regarded as the protection scope of the present application.

Claims

1. A battery heating method for an active equalization energy storage and interconnection system, characterized by, The method comprises: According to the adjusting current of the auxiliary power supply electrically connected with the input end of the embedded capacitor of the active equalization energy storage and parallel system, the voltage of the embedded capacitor is adjusted and controlled, so that the embedded capacitor is in a steady voltage state; When the embedded capacitor is in a steady voltage state, according to the excitation signal applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage and parallel system, a heating current for heating each branch battery is generated, comprising: According to the signal parameters of the excitation signal and the voltage of the embedded capacitor, a time domain expression of the excitation voltage generated by the excitation signal is established; According to the open circuit voltage of the branch battery and the time domain expression of the excitation voltage, a time domain expression of the heating current generated by the excitation signal is established; The time domain expression of the heating current is solved and calculated, and the specific expression of the heating current is established according to the voltage of the embedded capacitor in the steady voltage state; According to the specific expression of the heating current, the influence parameters are determined, and the excitation signal is adjusted to generate the heating current for heating each branch battery; The time domain expression of the excitation voltage is established by the following formula: wherein is the stable voltage of the embedded capacitor; A is the amplitude of the excitation signal; is the angular frequency of the excitation signal, is the phase of the jth excitation signal; is the excitation voltage generated by the jth excitation signal at time t. The time domain expression of the heating current is established by the following formula: wherein is the heating current generated for the jth excitation signal; r is the battery internal resistance; L is the battery filter inductance; is the battery open circuit voltage; The specific expression of the heating current is established by the following formula: wherein is the heating current value; , f is the frequency of the excitation signal; n is the total number of excitation signals.​ 2. The method of claim 1, wherein, The adjusting current of the auxiliary power supply electrically connected with the input end of the embedded capacitor of the active equalization energy storage and parallel system, comprising: According to the average value of the current of the auxiliary power supply, the average value of the switching function of the half-bridge switch and the average value of the branch battery charging and discharging current, the voltage time domain expression of the embedded capacitor is calculated; The voltage time domain expression is processed by Laplace transform to obtain the adjusting current of the auxiliary power supply for adjusting the voltage of the embedded capacitor.

3. The method of claim 2, wherein, The voltage time domain expression is established by the following formula: wherein C sc is the capacitance value of the embedded capacitor; is the average value of the embedded capacitor voltage, is the average value of the auxiliary power supply current, is the average value of the jth battery-side half-bridge switching function, is the average value of the jth battery charge-discharge current.

4. The method of claim 2, wherein, The adjusting current is calculated by the following formula: wherein is the regulated current of the auxiliary power supply; is the proportional control coefficient of the embedded capacitor voltage; is the integral control coefficient of the embedded capacitor voltage; is the small signal value of the embedded capacitor voltage; is the reference value of the embedded capacitor voltage non-steady state quantity; is the steady state current of the auxiliary power supply; C sc is the capacitance value of the embedded capacitor; is the Laplace operator.

5. A battery heating device for an active equalization energy storage and tie system, comprising: The device is applied to the method of any one of claims 1-4, and the device comprises: A control module is configured to adjust and control the voltage of the embedded capacitor according to the adjusting current of the auxiliary power supply electrically connected with the input end of the embedded capacitor of the active equalization energy storage and parallel system, so that the embedded capacitor is in a steady voltage state; A generation module is configured to generate a heating current for heating each branch battery according to the excitation signal applied to the two sides of the half-bridge switch of each branch of the active equalization energy storage and parallel system when the embedded capacitor is in a steady voltage state.

6. A computer device, comprising: The computer device comprises a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to realize the steps of the method of any one of claims 1-4.

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