Battery charging and discharging constant voltage control method and device, battery charging and discharging system and medium

Abstract

The invention provides a battery charging and discharging constant-voltage control method and device, a battery charging and discharging system and a medium, is applied to the technical field of battery management, and is used for solving the problem of current response lag when a battery constant-voltage control method approaches a reference voltage in the prior art. Comprising the following steps: when a battery voltage deviation between a charge-discharge voltage and a reference voltage is in a dynamic compensation interval, determining a current compensation voltage according to the battery voltage deviation, a charge-discharge duration and a voltage compensation parameter corresponding to a control parameter of a voltage loop; compensating the reference voltage according to the compensation voltage to obtain a target voltage; the control voltage loop generates a first reference current according to the target voltage and the charging and discharging voltage; the control current loop generates a first control parameter according to the charging and discharging current and the first reference current; and controlling the charging and discharging current of the battery according to the first control parameter. By dynamically compensating the reference voltage, the current can quickly respond when the battery approaches the reference voltage, and the charging efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a battery charging and discharging constant voltage control method, device, battery charging and discharging system and medium. Background Art

[0002] Battery constant-voltage control technology is of great significance in the fields of power electronics and battery management systems, particularly in new energy vehicle power batteries and energy storage systems. Traditional battery constant-voltage control systems typically employ a cascaded dual-loop closed-loop architecture: the outer loop regulates voltage, while the inner loop tracks current. This architecture is widely used in various charging and discharging modes, including constant-current-constant-voltage (CC-CV), constant-power-constant-voltage (CP-CV), and constant-resistance-constant-voltage (CR-CV).

[0003] In practical applications, traditional control methods gradually encounter performance bottlenecks as the battery voltage approaches the target value. Specifically, the voltage loop output command drops sharply as the voltage error decreases, causing the current loop to lose effective regulation power. For example, when the deviation between the battery charge and discharge voltage and the reference voltage enters the small signal range, the voltage loop output change rate decreases significantly, resulting in a slower current response and a longer current stabilization time.

[0004] Therefore, the existing battery constant voltage control method has the problem of current response hysteresis when the current approaches the reference voltage. Summary of the Invention

[0005] The present application provides a battery charging and discharging constant voltage control method, device, battery charging and discharging system and medium, which are used to solve the problem of current response lag when the battery constant voltage control method in the prior art is close to the reference voltage.

[0006] The technical solutions provided in this application are as follows:

[0007] On the one hand, the present application provides a battery charging and discharging constant voltage control method, which is applied to a battery charging and discharging system with a voltage loop as an outer loop and a current loop as an inner loop, comprising:

[0008] Obtaining the battery's reference voltage and current charge and discharge information; wherein the charge and discharge information includes charge and discharge voltage, charge and discharge current, and charge and discharge duration;

[0009] When the battery voltage deviation between the charge and discharge voltage and the reference voltage is within a dynamic compensation range, a current compensation voltage is determined based on the battery voltage deviation, the charge and discharge duration, and a voltage compensation parameter corresponding to a control parameter of the voltage loop; the reference voltage is compensated based on the compensation voltage to obtain a target voltage; and the voltage loop is controlled to generate a first reference current based on the target voltage and the charge and discharge voltage.

[0010] The control current loop generates a first control parameter according to the charge and discharge current and the first reference current;

[0011] The charge and discharge current of the battery is controlled according to the first control parameter.

[0012] Optionally, after obtaining the battery's reference voltage and current charge and discharge information, the following steps are also included:

[0013] Get the control parameters of the voltage loop;

[0014] Inputting the control parameters of the voltage loop into a preset parameter matching model to obtain voltage compensation parameters output by the parameter matching model; wherein the voltage compensation parameters include a first threshold coefficient, a second threshold coefficient, and a dynamic gain parameter; and the second threshold coefficient is greater than the first threshold coefficient;

[0015] Determine a first extreme value based on a product of a first threshold coefficient and a reference voltage, and determine a second extreme value based on a product of a second threshold coefficient and the reference voltage;

[0016] Determine an interval that is not less than the first extreme value and less than the second extreme value as a dynamic compensation interval;

[0017] An interval smaller than the first extreme value or not smaller than the second extreme value is determined as a steady-state maintaining interval.

[0018] Optionally, determining the current compensation voltage according to the voltage compensation parameters corresponding to the battery voltage deviation, the charge and discharge time, and the control parameters of the voltage loop includes:

[0019] Based on the battery voltage deviation and the boundary point of the dynamic compensation interval, the relative deviation rate of the battery voltage deviation within the dynamic compensation interval is calculated;

[0020] Calculate the current transient gain based on the charge and discharge duration, the preset voltage loop control frequency, and the dynamic gain parameter corresponding to the voltage loop control parameter;

[0021] The product of the relative deviation rate and the transient gain is used as the compensation voltage.

[0022] Optionally, after the voltage control loop generates the first reference current according to the target voltage and the charge and discharge voltage, the method further includes:

[0023] Calculating the compensation current based on the control parameters of the current loop, the control parameters of the voltage loop, and the compensation voltage within a preset time;

[0024] Compensating the first reference current according to the compensation current to obtain a predicted current;

[0025] The control current loop generates a second control parameter according to the charge and discharge current and the predicted current;

[0026] The charge and discharge current of the battery is controlled according to the second control parameter.

[0027] Optionally, the compensation current is calculated based on the control parameters of the current loop, the control parameters of the voltage loop, and the compensation voltage within a preset time, including:

[0028] The ratio of the integral time constant of the current loop to the integral time constant of the voltage loop is used as the current regulation coefficient;

[0029] Determining a compensation voltage change rate within the first time period according to the preset compensation voltage within the first time period;

[0030] The product of the current regulation coefficient and the compensation voltage change rate is taken as the compensation current.

[0031] Optionally, after obtaining the battery's reference voltage and current charge and discharge information, the following steps are also included:

[0032] When it is detected that the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a steady-state maintenance range, the voltage loop is controlled to generate a second reference current according to the reference voltage and the charge and discharge voltage;

[0033] The control current loop generates a third control parameter according to the charge and discharge current and the second reference current;

[0034] The charge and discharge current of the battery is controlled according to the third control parameter.

[0035] Optionally, when the battery voltage deviation changes from the dynamic compensation interval to the steady-state maintenance interval and the battery voltage deviation is less than the first extreme value,

[0036] Within a preset second time period, a compensation voltage of a first extreme value is determined; the compensation voltage is attenuated according to an exponential attenuation strategy to obtain an attenuated compensation voltage; the reference voltage is compensated according to the attenuated compensation voltage to obtain a target voltage; the voltage loop is controlled to generate a first reference current according to the target voltage and the charge and discharge voltage; the current loop is controlled to generate a first control parameter according to the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter.

[0037] On the other hand, the present application provides a battery charge and discharge constant voltage control device, comprising:

[0038] A data acquisition unit is used to obtain the reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, charge and discharge current, and charge and discharge time;

[0039] a first voltage loop control unit, configured to determine, when a battery voltage deviation between the charge / discharge voltage and the reference voltage is within a dynamic compensation range, a current compensation voltage based on the battery voltage deviation, the charge / discharge duration, and a voltage compensation parameter corresponding to a voltage loop control parameter; compensate the reference voltage based on the compensation voltage to obtain a target voltage; and control the voltage loop to generate a first reference current based on the target voltage and the charge / discharge voltage;

[0040] a first current loop control unit, configured to control the current loop to generate a first control parameter according to the charge and discharge current and the first reference current;

[0041] The first charge and discharge control unit is used to control the charge and discharge current of the battery according to the first control parameter.

[0042] On the other hand, the present application provides a battery charging and discharging system, comprising: a voltage loop, a current loop, a charging and discharging device, and the above-mentioned battery charging and discharging constant voltage control device;

[0043] The input end of the voltage loop is connected to the battery charge and discharge constant voltage control device, and the output end of the voltage loop is connected to the input end of the current loop; the output end of the current loop is connected to the battery charge and discharge constant voltage control device; the battery charge and discharge constant voltage control device is connected to the charge and discharge device, and the charge and discharge device is connected to the battery;

[0044] The battery charge and discharge constant voltage control device is used to obtain a reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, the charge and discharge current, and the charge and discharge duration; when the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a dynamic compensation range, the current compensation voltage is determined based on the battery voltage deviation, the charge and discharge duration, and the voltage compensation parameter corresponding to the control parameter of the voltage loop; the reference voltage is compensated according to the compensation voltage to obtain a target voltage; the voltage loop is controlled to generate a first reference current based on the target voltage and the charge and discharge voltage; the current loop is controlled to generate a first control parameter based on the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter;

[0045] The voltage loop is used to generate a first reference current according to the target voltage and the current charge and discharge voltage;

[0046] The current loop is used to generate a first control parameter according to the current charge and discharge current and the first reference current;

[0047] The charging and discharging device is used to regulate the charging and discharging current of the battery.

[0048] On the other hand, the present application also provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed by a processor, the battery charging and discharging constant voltage control method provided by the present application is implemented.

[0049] The beneficial effects of this application are as follows:

[0050] In this application, by introducing a dynamic compensation interval, when the voltage deviation is within a preset range, the reference voltage is compensated in real time in combination with the charge and discharge time and the voltage compensation parameters, so that the closed-loop control system can output a larger voltage signal, promote the rapid adjustment of the current, and ensure that the current can respond quickly when the battery is close to the reference voltage, thereby improving the charging efficiency. In addition, as the charging and discharging process progresses, the system can adaptively adjust the compensation intensity to prevent voltage overshoot caused by over-compensation in the early stage and response lag caused by insufficient compensation in the late stage, thus achieving a balance between dynamic response and system stability. Through the active intervention of the voltage loop, the control sensitivity attenuation problem of the current loop under small voltage deviations is effectively alleviated, so that the dual closed-loop system maintains efficient current tracking capabilities within the full range of operating conditions, providing an effective means for battery charge and discharge control.

[0051] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description or be understood by practicing the present application. The purposes and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 This is a schematic flow chart of an overview of a constant voltage control method for battery charging and discharging in an embodiment of the present application;

[0054] Figure 2 This is a schematic diagram of a specific flow chart of current loop control based on predicted current in an embodiment of the present application;

[0055] Figure 3 This is a schematic diagram of a specific flow chart of a method for controlling constant voltage of battery charge and discharge in a steady-state maintenance interval according to an embodiment of the present application;

[0056] Figure 4 This is a functional structural diagram of a battery charge and discharge constant voltage control device in an embodiment of the present application;

[0057] Figure 5 Schematic diagram of the overall framework of the battery charging and discharging system in the embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and beneficial effects of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] It should be noted that the terms "first," "second," etc., mentioned in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that such terms are interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0060] The present invention provides a battery charging and discharging constant voltage control method, which is applied to a battery charging and discharging system with a voltage loop as an outer loop and a current loop as an inner loop. Figure 1 As shown, the overview process of the battery charging and discharging constant voltage control method provided in the embodiment of the present application is as follows:

[0061] Step 101: Obtain the reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, charge and discharge current, and charge and discharge time.

[0062] In practical applications, the reference voltage is the voltage that the battery needs to reach after charging and discharging. The reference voltage is generally input by the user through an external device. In addition, by obtaining the battery's identification information, the battery model is determined based on the battery identification information. The reference voltage can be obtained by querying the battery model in a pre-stored database of corresponding battery models and reference voltages. The charge and discharge voltage refers to the potential difference between the two ends of the battery during the charging or discharging process, reflecting the battery's immediate energy state. The charge and discharge current refers to the amount of charge passing through the battery per unit time during the charging or discharging process. The charge and discharge duration is the duration of a single charge and discharge process of the battery. The charge and discharge voltage and charge and discharge current can be collected using the preset voltage sensor and current sensor and obtained through analog-to-digital conversion.

[0063] Step 102: When the battery voltage deviation between the charge and discharge voltage and the reference voltage is in the dynamic compensation range, the current compensation voltage is determined according to the battery voltage deviation, the charge and discharge time, and the voltage compensation parameters corresponding to the control parameters of the voltage loop; the reference voltage is compensated according to the compensation voltage to obtain a target voltage; and the voltage loop is controlled to generate a first reference current according to the target voltage and the charge and discharge voltage.

[0064] In practical applications, the battery voltage deviation can be obtained by subtracting the charge and discharge voltage from the reference voltage. Since the control parameters of the voltage loop controller in the voltage loop are different, the corresponding voltage regulation capabilities are different. Therefore, the corresponding voltage compensation parameters can be determined according to the control parameters of the voltage loop. The voltage loop controller in the voltage loop can adopt a PI controller or a PID controller. When the voltage loop controller is a PI controller, the control parameters of the voltage loop include proportional gain and integral gain. When the voltage loop controller is a PID controller, the control parameters of the voltage loop include proportional gain, integral gain and differential gain. The current compensation voltage is calculated based on the battery voltage deviation, charge and discharge time and voltage compensation parameters. The sum of the compensation voltage and the reference voltage is used as the target voltage to achieve compensation for the reference voltage. Taking the voltage loop controller as a PI controller as an example, the difference between the target voltage and the charge and discharge voltage is input into the voltage loop controller, and the voltage controller calculates the first reference current based on the preset proportional gain and integral gain. The first reference current is to adjust the battery charge and discharge voltage to the compensated reference voltage, which is the battery charge and discharge current value expected by the system.

[0065] Step 103: The control current loop generates a first control parameter according to the charge and discharge current and the first reference current.

[0066] In practical applications, the current loop controller in the current loop can adopt a PI controller or a PID controller. When the current loop controller is a PI controller, the control parameters of the current loop include proportional gain and integral gain. When the current loop controller is a PID controller, the control parameters of the current loop include proportional gain, integral gain, and differential gain. Taking the current loop controller as a PI controller as an example, the battery current deviation calculated by subtracting the current charge and discharge current from the first reference current is input into the current loop controller, and the current controller calculates the first control parameter based on the preset proportional gain and integral gain. The first control parameter is an operating parameter that needs to be adjusted by the battery charge and discharge device in order to adjust the battery charge and discharge current to the first reference current. The type of the first control parameter depends on the control mode of the battery charge and discharge device. When the control mode of the battery charge and discharge device is variable frequency control, the type of the first control parameter is frequency. When the control mode of the battery charge and discharge device is variable duty cycle control, the type of the first control parameter is duty cycle.

[0067] Step 104: Control the charge and discharge current of the battery according to the first control parameter.

[0068] In practical applications, control signals for various switching devices in the battery charging and discharging device are generated according to the first control parameter, so as to control the battery charging and discharging device through the control signals.

[0069] In this way, by introducing a dynamic compensation interval, when the voltage deviation is within a preset range, the reference voltage is compensated in real time by combining the charge and discharge duration with the voltage compensation parameters. This allows the closed-loop control system to output a larger voltage signal, driving rapid current adjustment to ensure that the current responds quickly when the battery approaches the reference voltage, thereby improving charging efficiency. In addition, as the charge and discharge process progresses, the system can adaptively adjust the compensation intensity to prevent voltage overshoot caused by initial overcompensation and response lag caused by insufficient compensation at the end, achieving a balance between dynamic response and system stability. Through active intervention in the voltage loop, the control sensitivity attenuation problem of the current loop under small voltage deviations is effectively alleviated, enabling the dual closed-loop system to maintain efficient current tracking capabilities across the entire operating range, providing an effective means for battery charge and discharge control, and is of great value in extending battery life and improving system energy efficiency.

[0070] In a possible implementation, after obtaining the reference voltage and current charge and discharge information of the battery, the method further includes:

[0071] First, obtain the control parameters of the voltage loop;

[0072] Then, the control parameters of the voltage loop are input into a preset parameter matching model to obtain voltage compensation parameters output by the parameter matching model; wherein the voltage compensation parameters include a first threshold coefficient, a second threshold coefficient, and a dynamic gain parameter; and the second threshold coefficient is greater than the first threshold coefficient;

[0073] Next, determining a first extreme value based on a product of the first threshold coefficient and the reference voltage, and determining a second extreme value based on a product of the second threshold coefficient and the reference voltage;

[0074] Finally, an interval that is not less than the first extreme value and less than the second extreme value is determined as a dynamic compensation interval; and an interval that is less than the first extreme value or not less than the second extreme value is determined as a steady-state maintenance interval.

[0075] In practical applications, the first threshold coefficient refers to the ratio of the lower threshold that triggers dynamic compensation of the reference voltage. The second threshold coefficient refers to the ratio of the upper threshold that triggers dynamic compensation of the reference voltage. The dynamic gain parameter refers to the gain amplification factor within the dynamic compensation interval. The parameter matching model can be a neural network model. The parameter matching model can be trained based on a preset training set. The training set includes control parameters of different voltage loops (such as proportional gain, integral gain, and differential gain) and corresponding standard voltage compensation parameters. After determining the voltage compensation parameters, the battery charge and discharge process is divided into a dynamic compensation interval and a steady-state maintenance interval based on the first threshold coefficient, the second threshold coefficient, and the reference voltage. The product of the first threshold coefficient and the reference voltage is used as the first extreme value, and the product of the second threshold coefficient and the reference voltage is used as the second extreme value. The dynamic compensation interval refers to the interval in which the battery voltage deviation is greater than or equal to the first extreme value and less than the second extreme value. There are two steady-state maintenance intervals: the first steady-state maintenance interval corresponds to the initial stage of charge and discharge, where the battery voltage deviation is less than the first extreme value; and the second steady-state maintenance interval corresponds to the final stage of charge and discharge, where the battery voltage deviation is greater than or equal to the second extreme value. The dynamic compensation interval is a small signal interval corresponding to the deviation between the charge and discharge voltage of the battery and the reference voltage.

[0076] In specific implementation, the current compensation voltage is determined according to the voltage compensation parameters corresponding to the battery voltage deviation, charge and discharge time, and the control parameters of the voltage loop. The following methods may be used, but are not limited to:

[0077] First, based on the battery voltage deviation and the boundary point of the dynamic compensation interval, the relative deviation rate of the battery voltage deviation within the dynamic compensation interval is calculated.

[0078] In practical applications, the relative deviation rate quantifies the relative position of the battery voltage deviation within the dynamic compensation interval. The boundary point of the dynamic compensation interval can be selected as the second extreme value, that is, the product of the second threshold coefficient and the reference voltage. The relative deviation rate of the battery voltage deviation within the dynamic compensation interval can be calculated using the following formula (1).

[0079] δ=(1-ΔV / α2V_ref) (1)

[0080] Wherein, δ is the relative deviation rate, ΔV is the battery voltage deviation, α2 is the second threshold coefficient, and V_ref is the reference voltage.

[0081] Then, the current transient gain is calculated based on the charge and discharge duration, the preset control frequency of the voltage loop, and the dynamic gain parameter corresponding to the control parameter of the voltage loop.

[0082] In practical applications, transient gain reflects the system's dynamic response to voltage deviations. Within the dynamic compensation range, the transient gain gradually increases over time, causing the compensation voltage to rise rapidly. Based on the charge and discharge duration, the preset voltage loop control frequency, and the dynamic gain parameters corresponding to the voltage loop control parameters, the current transient gain can be calculated using the following formula (2).

[0083] G(t)=k·(1-e^(-t·f)(2)

[0084] Where G(t) is the transient gain, k is the dynamic gain parameter, f is the control frequency of the voltage loop, and t is the charge and discharge time.

[0085] Finally, the product of the relative deviation rate and the transient gain is used as the compensation voltage.

[0086] In practical applications, the compensation voltage can be determined by the product of the relative deviation rate and the transient gain, and is calculated using the following formula (3).

[0087] ΔV_comp(t)=G(t)·δ(3)

[0088] Where G(t) is the transient gain, δ is the relative deviation rate, and ΔV_comp(t) is the compensation voltage.

[0089] By calculating the relative deviation rate of the battery voltage deviation relative to the dynamic compensation range, the system can quantify the distance between the current state and the compensation boundary, achieving nonlinear adjustment of the compensation amount. This avoids the over-compensation or under-compensation issues often associated with traditional fixed-gain compensation, precisely matching the compensation voltage to actual demand. Furthermore, the transient gain incorporates the cumulative effect of battery charge and discharge time into the compensation calculation, allowing the system to maintain moderate compensation during the initial charging phase to prevent voltage overshoot, while increasing compensation during the dynamic compensation range to maintain current response, achieving a dynamic balance between response speed and stability.

[0090] In one possible implementation, see Figure 2 As shown, after the control voltage loop generates the first reference current according to the target voltage and the charge and discharge voltage, it also includes:

[0091] Step 201: Calculate a compensation current based on a control parameter of a current loop, a control parameter of a voltage loop, and a compensation voltage within a preset time.

[0092] Specifically, the compensation current may be calculated based on the control parameters of the current loop, the control parameters of the voltage loop, and the compensation voltage within a preset time, in the following manners, but not limited to:

[0093] First, the ratio of the integral time constant of the current loop to the integral time constant of the voltage loop is used as the current regulation coefficient.

[0094] Then, according to the preset compensation voltage in the first time period, the compensation voltage change rate in the first time period is determined.

[0095] Finally, the product of the current regulation coefficient and the compensation voltage change rate is taken as the compensation current.

[0096] In practical applications, the current regulation coefficient reflects the relative relationship between the current loop and the voltage loop in terms of dynamic response characteristics. The current regulation coefficient can be calculated using the following formula (4). The compensation voltage change rate reflects the temporal trend and speed of the compensation voltage change. The compensation voltage change rate can be calculated using the following formula (5). The compensation current can be calculated using the following formula (6).

[0097] k ff =τi / τv (4)

[0098]

[0099] I ff(t) =k ff ·ρ (6)

[0100] Among them, k ff is the current regulation coefficient; τi is the integral time constant of the current loop; τv is the integral time constant of the voltage loop; ρ is the compensation voltage change rate; I ff(t) is the compensation current.

[0101] Step 202: Compensate the first reference current according to the compensation current to obtain a predicted current.

[0102] In practical applications, the sum of the compensation current and the first reference current is used as the predicted current to correct the first reference current in advance and offset the hysteresis effect of the voltage loop.

[0103] Step 203: The control current loop generates a second control parameter according to the charge and discharge current and the predicted current.

[0104] In practical applications, taking a PI controller as an example, the battery current deviation, calculated by subtracting the charge and discharge current from the predicted current, is input into the current loop controller. The current controller then calculates a second control parameter based on preset proportional gain and integral gain. This second control parameter is an operating parameter of the battery charging and discharging device that needs to be adjusted to offset the hysteresis effect of the voltage loop in order to adjust the battery charge and discharge current to the predicted current. The type of the second control parameter also depends on the control method of the battery charging and discharging device and can be either frequency or duty cycle.

[0105] Step 204: Control the charge and discharge current of the battery according to the second control parameter.

[0106] In practical applications, control signals for various switching devices in the battery charging and discharging device are generated according to the second control parameter, so as to control the battery charging and discharging device through the control signals.

[0107] In this way, a dynamic feedforward channel is constructed in the current loop. By analyzing the changing trend of the compensation voltage in real time, the subsequent current demand is predicted and the current set value is corrected in advance, forming a timing coordination mechanism of dual-loop control.

[0108] In one possible implementation, see Figure 3 As shown, after obtaining the battery's reference voltage and current charge and discharge information, it also includes:

[0109] Step 301: When it is monitored that the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a steady-state maintenance interval, the voltage loop is controlled to generate a second reference current according to the reference voltage and the charge and discharge voltage.

[0110] Step 302: Control the current loop to generate a third control parameter according to the charge and discharge current and the second reference current.

[0111] Step 303: Control the charge and discharge current of the battery according to the third control parameter.

[0112] In practical applications, when the battery voltage deviation is within the steady-state maintenance range, assuming both the voltage loop controller and the current loop controller are PI controllers, the difference between the reference voltage and the charge / discharge voltage is input into the voltage loop controller. The voltage controller then calculates a second reference current based on a preset proportional gain and integral gain. The second reference current is used to adjust the battery charge / discharge voltage to the uncompensated reference voltage, the desired battery charge / discharge current value for the system. The battery current deviation calculated by subtracting the current charge / discharge current from the second reference current is then input into the current loop controller. The current controller then calculates a third control parameter based on a preset proportional gain and integral gain. The third control parameter is an operating parameter of the battery charge / discharge device that needs to be adjusted to adjust the battery charge / discharge current to the second reference current. The type of the third control parameter also depends on the control method of the battery charge / discharge device and can be either frequency or duty cycle. The first, third, and second control parameters are of the same type. Control signals for each switching device in the battery charge / discharge device are generated based on the third control parameter, thereby controlling the battery charge / discharge device through the control signals.

[0113] In this way, when the battery charge and discharge voltage approaches the reference voltage further, the compensation of the reference voltage is stopped, and the control voltage loop generates a second reference current according to the reference voltage and the charge and discharge voltage, ensuring that the constant voltage mode can be accurately implemented.

[0114] In a possible implementation, when the battery voltage deviation changes from the dynamic compensation interval to the steady-state maintenance interval and the battery voltage deviation is less than the first extreme value,

[0115] Within a preset second time period, a compensation voltage of a first extreme value is determined; the compensation voltage is attenuated according to an exponential attenuation strategy to obtain an attenuated compensation voltage; the reference voltage is compensated according to the attenuated compensation voltage to obtain a target voltage; the voltage loop is controlled to generate a first reference current according to the target voltage and the charge and discharge voltage; the current loop is controlled to generate a first control parameter according to the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter.

[0116] In practical applications, the second preset time is the time required for the current compensation voltage to decay to a value less than the preset voltage according to the exponential decay strategy. When the battery voltage deviation changes from the dynamic compensation interval to the steady-state maintenance interval, and the battery voltage deviation is less than the first extreme value, the compensation voltage is not immediately set to zero, but the "smooth compensation withdrawal" process is started. The current compensation is determined and the compensation withdrawal flag is set. The sum of the attenuated compensation voltage and the reference voltage is used as the target voltage. When the attenuated compensation voltage drops to the preset voltage value, it is forced to zero and the compensation withdrawal flag is cleared. Attenuating the compensation voltage according to the exponential decay strategy to obtain the attenuated compensation voltage can be achieved by the following formula (7).

[0117] ΔV_comps(t)=ΔV_comp(t0)*exp(–(t–t0) / τ_down)(7)

[0118] Where τ_down is the compensation time constant; ΔV_comp(t0) is the compensation voltage corresponding to the first extreme value, ΔV_comps(t) is the attenuated compensation voltage, t is the current time, and t0 is the time corresponding to the battery voltage deviation switching from the dynamic compensation range to the steady-state maintenance range.

[0119] Outside the preset second time period, the voltage control loop generates a second reference current based on the reference voltage and the charge and discharge voltage; the current control loop generates a third control parameter based on the charge and discharge current and the second reference current; and the charge and discharge current of the battery is controlled according to the third control parameter, that is, only the reference voltage is used for closed-loop control, and no compensation voltage is output.

[0120] In this way, a smooth transition of the compensation voltage is achieved by introducing an exponential decay strategy. When the battery voltage deviation switches from the dynamic compensation interval to the steady-state maintenance interval, the step change of the compensation amount is converted into a continuous gradual change process to avoid sudden changes in the compensation amount and reduce stress impact on the device.

[0121] Based on the above embodiments, the present application provides a battery charge and discharge constant voltage control device, see Figure 4As shown, the battery charge and discharge constant voltage control device 400 provided in the embodiment of the present application includes at least:

[0122] The data acquisition unit 401 is used to obtain the reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, charge and discharge current, and charge and discharge time;

[0123] A first voltage loop control unit 402 is configured to determine, when a battery voltage deviation between the charge / discharge voltage and the reference voltage is within a dynamic compensation range, a current compensation voltage based on the battery voltage deviation, the charge / discharge duration, and a voltage compensation parameter corresponding to a voltage loop control parameter; compensate the reference voltage based on the compensation voltage to obtain a target voltage; and control the voltage loop to generate a first reference current based on the target voltage and the charge / discharge voltage;

[0124] A first current loop control unit 403, configured to control the current loop to generate a first control parameter according to the charge and discharge current and the first reference current;

[0125] The first charge and discharge control unit 404 is configured to control the charge and discharge current of the battery according to a first control parameter.

[0126] In a possible implementation, the battery charge and discharge constant voltage control device 400 further includes:

[0127] The parameter determination unit 405 is used to obtain the control parameters of the voltage loop; input the control parameters of the voltage loop into a preset parameter matching model to obtain the voltage compensation parameters output by the parameter matching model; wherein the voltage compensation parameters include a first threshold coefficient, a second threshold coefficient and a dynamic gain parameter; the second threshold coefficient is greater than the first threshold coefficient; the first extreme value is determined based on the product of the first threshold coefficient and the reference voltage, and the second extreme value is determined based on the product of the second threshold coefficient and the reference voltage; an interval greater than or equal to the first extreme value and less than the second extreme value is determined as a dynamic compensation interval; and an interval less than the first extreme value and greater than or equal to the second extreme value is determined as a steady-state maintenance interval.

[0128] In a possible implementation, the first voltage loop control unit 402 in the battery charge and discharge constant voltage control device 400 is specifically configured to:

[0129] Based on the battery voltage deviation and the boundary point of the dynamic compensation interval, the relative deviation rate of the battery voltage deviation within the dynamic compensation interval is calculated;

[0130] Calculate the current transient gain based on the charge and discharge duration, the voltage loop control frequency, and the dynamic gain parameters corresponding to the voltage loop control parameters;

[0131] The product of the relative deviation rate and the transient gain is used as the compensation voltage.

[0132] In a possible implementation, the battery charge and discharge constant voltage control device 400 further includes:

[0133] The predicted current determination unit 406 is configured to calculate a compensation current based on the control parameters of the current loop, the control parameters of the voltage loop, and the compensation voltage within a preset time; and to compensate the first reference current according to the compensation current to obtain a predicted current;

[0134] A second current loop control unit 407, configured to control the current loop to generate a second control parameter according to the charge and discharge current and the predicted current;

[0135] The second charge and discharge control unit 408 is configured to control the charge and discharge current of the battery according to the second control parameter.

[0136] In a possible implementation, the predicted current determination unit 406 in the battery charge and discharge constant voltage control device 400 is specifically configured to:

[0137] The ratio of the integral time constant of the current loop to the integral time constant of the voltage loop is used as the current regulation coefficient;

[0138] Determining a compensation voltage change rate within the first time period according to the preset compensation voltage within the first time period;

[0139] The product of the current regulation coefficient and the compensation voltage change rate is taken as the compensation current.

[0140] In a possible implementation, the battery charge and discharge constant voltage control device 400 further includes:

[0141] The second voltage loop control unit 409 is configured to control the voltage loop to generate a second reference current according to the reference voltage and the charge and discharge voltage when the battery voltage deviation between the charge and discharge voltage and the reference voltage is detected to be in a steady-state maintenance interval;

[0142] A third current loop control unit 410 is configured to control the current loop to generate a third control parameter according to the charge and discharge current and the second reference current;

[0143] The third charge and discharge control unit 411 is configured to control the charge and discharge current of the battery according to a third control parameter.

[0144] In a possible implementation, the battery charge and discharge constant voltage control device 400 further includes:

[0145] The attenuation transition unit 412 is used to determine the compensation voltage of the first extreme value within a preset second time period when the battery voltage deviation changes from the dynamic compensation interval to the steady-state maintenance interval and the battery voltage deviation is less than the first extreme value; attenuate the compensation voltage according to the exponential attenuation strategy to obtain an attenuated compensation voltage; compensate the reference voltage according to the attenuated compensation voltage to obtain a target voltage; control the voltage loop to generate a first reference current according to the target voltage and the charge and discharge voltage; control the current loop to generate a first control parameter according to the charge and discharge current and the first reference current; and control the charge and discharge current of the battery according to the first control parameter.

[0146] It should be noted that the principle of solving the technical problem by the battery charge and discharge constant voltage control device 400 provided in the embodiment of the present application is similar to the battery charge and discharge constant voltage control method provided in the embodiment of the present application. Therefore, the implementation of the battery charge and discharge constant voltage control device 400 provided in the embodiment of the present application can refer to the implementation of the battery charge and discharge constant voltage control method provided in the embodiment of the present application, and the repeated parts will not be repeated.

[0147] Based on the above embodiments, the present application provides a battery charging and discharging system. Figure 5 As shown, the battery charging and discharging system 500 provided in the embodiment of the present application at least includes: a voltage loop 501, a current loop 502, a charging and discharging device 503 and the above-mentioned battery charging and discharging constant voltage control device 400;

[0148] The input end of the voltage loop 501 is connected to the battery charge and discharge constant voltage control device 400, and the output end of the voltage loop 501 is connected to the input end of the current loop 502; the output end of the current loop 502 is connected to the battery charge and discharge constant voltage control device 400; the battery charge and discharge constant voltage control device 400 is connected to the charge and discharge device 503, and the charge and discharge device 503 is connected to the battery;

[0149] The battery charge and discharge constant voltage control device 400 is used to obtain a reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, the charge and discharge current, and the charge and discharge duration; when the battery voltage deviation between the charge and discharge voltage and the reference voltage is in the dynamic compensation range, the current compensation voltage is determined based on the battery voltage deviation, the charge and discharge duration, and the voltage compensation parameter corresponding to the control parameter of the voltage loop 501; the reference voltage is compensated according to the compensation voltage to obtain a target voltage; the voltage loop 501 is controlled to generate a first reference current according to the target voltage and the charge and discharge voltage; the current loop 502 is controlled to generate a first control parameter according to the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter;

[0150] The voltage loop 501 is used to generate a first reference current according to the target voltage and the current charge and discharge voltage;

[0151] The current loop 502 is used to generate a first control parameter according to the current charge and discharge current and the first reference current;

[0152] The charge and discharge device 503 is used to adjust the charge and discharge current of the battery.

[0153] The following describes the computer-readable storage medium provided in an embodiment of the present application. The computer-readable storage medium provided in an embodiment of the present application stores computer instructions, which, when executed by a processor, implement the battery charge and discharge constant-voltage control method provided in an embodiment of the present application. Specifically, the computer instructions can be built into or installed in a battery charge and discharge constant-voltage control device. In this way, the battery charge and discharge constant-voltage control device can implement the battery charge and discharge constant-voltage control method provided in an embodiment of the present application by executing the built-in or installed computer instructions.

[0154] In addition, the battery charge and discharge constant voltage control method provided in the embodiment of the present application can also be implemented as a program product, which includes a program code. When the program product can be run on a battery charge and discharge constant voltage control device, the program code is used to enable the battery charge and discharge constant voltage control device to execute the battery charge and discharge constant voltage control method provided in the embodiment of the present application.

[0155] The program product provided in the embodiments of the present application may adopt any combination of one or more readable media, wherein the readable medium may be a readable signal medium or a readable storage medium, and the readable storage medium may be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any combination of the above. Specifically, more specific examples of readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, RAM, ROM, Erasable Programmable Read Only Memory (EPROM), optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0156] The program product provided in the embodiments of the present application may be a CD-ROM and include program code, and may also be run on a computing device. However, the program product provided in the embodiments of the present application is not limited thereto. In the embodiments of the present application, the readable storage medium may be any tangible medium containing or storing a program, and the program may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0157] It should be noted that although several units or subunits of the device are mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, depending on the embodiment of the application, the features and functions of two or more units described above can be embodied in a single unit. Conversely, the features and functions of a single unit described above can be further divided and embodied by multiple units.

[0158] Furthermore, although the operations of the method of the present application are described in a particular order in the accompanying drawings, this does not require or imply that the operations must be performed in this particular order, or that all illustrated operations must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0159] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0160] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include such modifications and variations.

Claims

1. A constant voltage control method for battery charging and discharging, characterized in that: Applied to battery charging and discharging systems with a voltage loop as the outer loop and a current loop as the inner loop, including: Obtaining the reference voltage and current charge and discharge information of the battery; wherein the charge and discharge information includes the charge and discharge voltage, charge and discharge current, and charge and discharge time; When the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a dynamic compensation range, determining a current compensation voltage according to the battery voltage deviation, the charge and discharge duration, and a voltage compensation parameter corresponding to a control parameter of the voltage loop; compensating the reference voltage according to the compensation voltage to obtain a target voltage; and controlling the voltage loop to generate a first reference current according to the target voltage and the charge and discharge voltage; controlling the current loop to generate a first control parameter according to the charge and discharge current and the first reference current; The charge and discharge current of the battery is controlled according to the first control parameter.

2. The battery charge and discharge constant voltage control method according to claim 1, wherein: After obtaining the battery's reference voltage and current charge and discharge information, it also includes: Obtaining control parameters of the voltage loop; Inputting the control parameters of the voltage loop into a preset parameter matching model to obtain voltage compensation parameters output by the parameter matching model; wherein the voltage compensation parameters include a first threshold coefficient, a second threshold coefficient, and a dynamic gain parameter; and the second threshold coefficient is greater than the first threshold coefficient; Determine a first extreme value based on a product of a first threshold coefficient and a reference voltage, and determine a second extreme value based on a product of a second threshold coefficient and the reference voltage; determining an interval that is not less than the first extreme value and less than the second extreme value as a dynamic compensation interval; An interval smaller than the first extreme value or not smaller than the second extreme value is determined as a steady-state maintaining interval.

3. The battery charge and discharge constant voltage control method according to claim 2, wherein: Determining a current compensation voltage according to the battery voltage deviation, the charge and discharge time, and a voltage compensation parameter corresponding to the control parameter of the voltage loop includes: Calculating a relative deviation rate of the battery voltage deviation within the dynamic compensation interval based on the battery voltage deviation and a boundary point of the dynamic compensation interval; Calculating a current transient gain based on the charge and discharge duration, a preset voltage loop control frequency, and a dynamic gain parameter corresponding to the voltage loop control parameter; The product of the relative deviation rate and the transient gain is used as the compensation voltage.

4. The battery charge and discharge constant voltage control method according to claim 1, wherein: After controlling the voltage loop to generate a first reference current according to the target voltage and the charge and discharge voltage, the method further includes: Calculating a compensation current based on the control parameters of the current loop, the control parameters of the voltage loop, and the compensation voltage within a preset time; Compensating the first reference current according to the compensation current to obtain a predicted current; controlling the current loop to generate a second control parameter according to the charge and discharge current and the predicted current; The charge and discharge current of the battery is controlled according to the second control parameter.

5. The battery charge and discharge constant voltage control method according to claim 4, wherein: Calculating the compensation current based on the control parameter of the current loop, the control parameter of the voltage loop, and the compensation voltage within a preset time includes: The ratio of the integral time constant of the current loop to the integral time constant of the voltage loop is used as the current adjustment coefficient; Determining a compensation voltage change rate within a preset first time period based on the compensation voltage within the first time period; The product of the current adjustment coefficient and the compensation voltage change rate is used as the compensation current.

6. The battery charge and discharge constant voltage control method according to any one of claims 1 to 5, characterized in that: After obtaining the battery's reference voltage and current charge and discharge information, it also includes: When it is detected that the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a steady-state maintenance interval, controlling the voltage loop to generate a second reference current according to the reference voltage and the charge and discharge voltage; controlling the current loop to generate a third control parameter according to the charge and discharge current and the second reference current; The charge and discharge current of the battery is controlled according to the third control parameter.

7. The battery charge and discharge constant voltage control method according to claim 2 or 3, characterized in that: When the battery voltage deviation changes from the dynamic compensation interval to the steady-state maintenance interval and the battery voltage deviation is less than the first extreme value, Determining a compensation voltage of the first extreme value within a preset second time period; attenuating the compensation voltage according to an exponential attenuation strategy to obtain an attenuated compensation voltage; and compensating the reference voltage according to the attenuated compensation voltage to obtain a target voltage; controlling the voltage loop to generate a first reference current according to the target voltage and the charge and discharge voltage; The current loop is controlled to generate a first control parameter according to the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter.

8. A battery charge and discharge constant voltage control device, characterized in that: include: A data acquisition unit, configured to acquire a reference voltage of the battery and current charge and discharge information; wherein the charge and discharge information includes charge and discharge voltage, charge and discharge current, and charge and discharge duration; a voltage loop control unit, configured to, when a battery voltage deviation between the charge and discharge voltage and the reference voltage is within a dynamic compensation range, determine a current compensation voltage based on the battery voltage deviation, the charge and discharge duration, and a voltage compensation parameter corresponding to a control parameter of the voltage loop; compensate the reference voltage based on the compensation voltage to obtain a target voltage; and control the voltage loop to generate a first reference current based on the target voltage and the charge and discharge voltage; a current loop control unit, configured to control the current loop to generate a first control parameter according to the charge and discharge current and the first reference current; A charge and discharge control unit is used to control the charge and discharge current of the battery according to the first control parameter.

9. A battery charging and discharging system, characterized in that: include: A voltage loop, a current loop, a charge and discharge device, and a battery charge and discharge constant voltage control device as claimed in claim 8; The input end of the voltage loop is connected to the battery charge and discharge constant voltage control device, and the output end of the voltage loop is connected to the input end of the current loop; the output end of the current loop is connected to the battery charge and discharge constant voltage control device; the battery charge and discharge constant voltage control device is connected to the charge and discharge device, and the charge and discharge device is connected to the battery; The battery charge and discharge constant voltage control device is used to obtain a reference voltage and current charge and discharge information of a battery; wherein the charge and discharge information includes charge and discharge voltage, charge and discharge current, and charge and discharge duration; when the battery voltage deviation between the charge and discharge voltage and the reference voltage is in a dynamic compensation range, the current compensation voltage is determined according to the battery voltage deviation, the charge and discharge duration, and the voltage compensation parameter corresponding to the control parameter of the voltage loop; the reference voltage is compensated according to the compensation voltage to obtain a target voltage; the voltage loop is controlled to generate a first reference current according to the target voltage and the charge and discharge voltage; the current loop is controlled to generate a first control parameter according to the charge and discharge current and the first reference current; and the charge and discharge current of the battery is controlled according to the first control parameter; The voltage loop is used to generate a first reference current according to the target voltage and the current charge and discharge voltage; The current loop is used to generate a first control parameter according to the current charge and discharge current and the first reference current; The charging and discharging device is used to adjust the charging and discharging current of the battery.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the battery charging and discharging constant voltage control method according to any one of claims 1 to 7 is implemented.

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