Current output control method and device, power equipment and storage medium

Abstract

The application discloses a current output control method and device, a power device and a storage medium, and belongs to the technical field of power control. The method comprises the following steps: acquiring a first current; obtaining a charge accumulation value based on the first current; in the case that the charge accumulation value is greater than or equal to a charge limit value, outputting a second current until the charge accumulation value is less than or equal to an initial value before charge accumulation is performed, and stopping outputting the second current; wherein the first current is smaller than the second current. According to the application, the smaller first current is converted into the larger second current for output, so that the problem of poor sampling accuracy under a small current working condition can be reduced, and the system control accuracy is improved.

Description

Technical Field

[0001] This application belongs to the field of power control technology, and in particular relates to a current output control method, device, power equipment and storage medium. Background Technology

[0002] In fields such as motor control, energy storage, and new energy grid connection, small current commands are needed to regulate charge or energy for scenarios such as battery equalization management, dynamic estimation of remaining capacity, microgrid power regulation, and smooth control of charging and discharging processes.

[0003] Executing small current commands requires current sampling to achieve closed-loop control and command correction. In related technologies, current sampling techniques mainly employ Hall effect sensors, shunt resistors, or magnetoresistive sensors. After signal conditioning through analog front-end circuitry, the signal is digitized via an analog-to-digital converter. However, limited by factors such as sensor resolution, noise in the analog front-end circuitry, and the effective bit depth of the analog-to-digital converter, sampling results often exhibit significant deviations or fluctuations when the measured current is small, leading to insufficient system control accuracy. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a current output control method, device, power equipment, and storage medium to reduce the problem of poor sampling accuracy under low current conditions and improve the system control accuracy.

[0005] In a first aspect, this application provides a current output control method, including: Obtain the first current; The charge accumulation value is obtained based on the first current; If the charge accumulation value is greater than or equal to the charge limit, a second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current.

[0006] According to the current output control method of this application, a first current is acquired; a charge accumulation value is obtained based on the first current; and a second current is output when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current. This embodiment of the application uses charge accumulation and charge release to convert a smaller first current into a larger second current for output. Considering the influence of hardware sampling errors, the sampling accuracy is higher under high current conditions compared to low current conditions, thus reducing the problem of poor sampling accuracy under low current conditions. The second current is output until the charge accumulation value falls back to the initial value before accumulation, making the first current and the second current equivalent in terms of total charge output. This allows for an equivalent control process while reducing the problem of poor sampling accuracy under low current conditions, thereby improving the system control accuracy.

[0007] According to one embodiment of this application, obtaining the charge accumulation value based on the first current includes: Obtain the gradient coefficients; The product of the first current and the gradient coefficient is used as the accumulated gradient; The charge accumulation value is obtained based on the accumulation gradient.

[0008] In this embodiment, the product of the first current and the gradient coefficient is used as the accumulation gradient for charge accumulation. This allows the charge accumulation rate to be adjusted according to actual operating conditions, reducing the impact on control stability caused by excessively rapid accumulation leading to prematurely reaching the limit, or the impact on response time caused by excessively slow accumulation. This improves the stability and efficiency of the system under different current conditions.

[0009] According to one embodiment of this application, the method further includes: Obtain the accumulation time when the charge accumulation value is greater than or equal to the charge limit; If the output task duration of the first current is greater than the accumulation duration, the difference between the second current and the first current is obtained; The amount of attenuation of the charge accumulation value is obtained based on the difference.

[0010] In this embodiment, when the output duration of the first current is longer than the accumulation duration, charge decay is performed based on the difference between the second current and the first current, thereby enabling the charge decay to match the continuous charge accumulation process and improving the accuracy of the control process.

[0011] According to one embodiment of this application, obtaining the attenuation amount of the charge accumulation value based on the difference includes: Obtain the gradient coefficients, and determine the decay gradient based on the difference and the gradient coefficients; The attenuation amount of the charge accumulation value is obtained based on the attenuation gradient.

[0012] In this embodiment, the attenuation gradient is determined by combining the difference between the second current and the first current and the gradient coefficient. This allows the rate of charge attenuation to be adjusted according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0013] According to one embodiment of this application, the method further includes: If the output duration of the first current is less than or equal to the accumulation duration, the attenuation of the charge accumulation value is obtained based on the second current.

[0014] In this embodiment, by performing charge decay based on the second current when the output task duration of the first current is less than or equal to the accumulation duration, the charge decay process is matched with the actual output of the second current, thereby improving the accuracy of the control process.

[0015] According to one embodiment of this application, the attenuation amount of obtaining the charge accumulation value based on the second current includes: Obtain the gradient coefficients and determine the attenuation gradient based on the second current and the gradient coefficients; The attenuation amount of the charge accumulation value is obtained based on the attenuation gradient.

[0016] In this embodiment, by combining the second current and the gradient coefficient to determine the attenuation gradient, the rate of charge attenuation can be adjusted according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0017] According to one embodiment of this application, the method further includes: The decay time when the charge accumulation value is less than or equal to the initial value is obtained, and the accumulation time when the charge accumulation value is greater than or equal to the charge limit is obtained; When the duration of the first current output task is greater than the sum of the decay duration and the accumulation duration, the charge accumulation value is obtained based on the first current, and when the charge accumulation value is greater than or equal to the charge limit, the second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops.

[0018] In this embodiment, by re-executing the charge accumulation and charge decay process based on the second control command when the output task duration of the first current is greater than the sum of the decay duration and the accumulation duration, it is possible to realize the charge accumulation and decay cycle of multiple control cycles based on the output task duration of the first current, under the premise of satisfying the equivalence of the total charge output. This not only shortens the difference between the output task duration of the first current and the output duration of the second current, but also reduces the waiting time for outputting the second current, thereby improving control efficiency and control equivalence.

[0019] Secondly, this application provides a current output control device, comprising: The acquisition module is used to acquire the first current; The collection module is used to obtain the charge accumulation value based on the first current; An output module is configured to output a second current when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current.

[0020] According to the current output control device of this application, a first current is acquired; a charge accumulation value is obtained based on the first current; and a second current is output when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current. This embodiment of the application uses a charge accumulation and charge release method to convert a smaller first current into a larger second current for output. Considering the influence of hardware sampling errors, the sampling accuracy is higher under high current conditions compared to low current conditions, thus reducing the problem of poor sampling accuracy under low current conditions. The output of the second current stops when the charge accumulation value falls back to the initial value before accumulation, making the first current and the second current equivalent in terms of total charge output. This allows for an equivalent control process while reducing the problem of poor sampling accuracy under low current conditions, thereby improving the system control accuracy.

[0021] Thirdly, this application provides a power device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described current output control method.

[0022] Fourthly, this application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described current output control method.

[0023] Fifthly, this application provides a chip, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the above-described current output control method.

[0024] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects: According to the current output control method of this application, a first current is acquired; a charge accumulation value is obtained based on the first current; and a second current is output when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current. This embodiment of the application uses charge accumulation and charge release to convert a smaller first current into a larger second current for output. Considering the influence of hardware sampling errors, the sampling accuracy is higher under high current conditions compared to low current conditions, thus reducing the problem of poor sampling accuracy under low current conditions. The second current is output until the charge accumulation value falls back to the initial value before accumulation, making the first current and the second current equivalent in terms of total charge output. This allows for an equivalent control process while reducing the problem of poor sampling accuracy under low current conditions, thereby improving the system control accuracy.

[0025] In some embodiments, by using the product of the first current and the gradient coefficient as the accumulation gradient for charge accumulation, the rate of charge accumulation can be adjusted according to the actual operating conditions. This reduces the impact on control stability caused by excessively rapid accumulation leading to prematurely reaching the limit, or the extension of response time due to excessively slow accumulation, thereby improving the stability and efficiency of the system under different current conditions.

[0026] In some embodiments, by performing charge decay based on the difference between the second current and the first current when the output duration of the first current is greater than the accumulation duration, the charge decay can be matched with the continuous charge accumulation process, thereby improving the accuracy of the control process.

[0027] In some embodiments, the attenuation gradient is determined by combining the difference between the second current and the first current and the gradient coefficient, which can adjust the charge attenuation rate according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0028] In some embodiments, by performing charge decay based on the second current when the output duration of the first current is less than or equal to the accumulation duration, the charge decay process is matched with the actual output of the second current, thereby improving the accuracy of the control process.

[0029] In some embodiments, the attenuation gradient is determined by combining the second current and the gradient coefficient, which can adjust the charge attenuation rate according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0030] In some embodiments, by re-executing the charge accumulation and charge decay process based on the second control command when the output task duration of the first current is greater than the sum of the decay duration and the accumulation duration, it is possible to realize a charge accumulation and decay cycle of multiple control cycles based on the output task duration of the first current, under the premise of satisfying the equivalence of the total charge output. This not only shortens the difference between the output task duration of the first current and the output duration of the second current, but also reduces the waiting time for outputting the second current, thereby improving control efficiency and control equivalence.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic flowchart of the current output control method provided in the embodiments of this application; Figure 2 This is a schematic diagram illustrating the equivalent principle of the first control instruction and the second control instruction provided in the embodiments of this application; Figure 3 This is one of the schematic diagrams of the application scenarios provided in the embodiments of this application; Figure 4 This is a second schematic diagram of an application scenario provided in the embodiments of this application; Figure 5 This is a schematic diagram of the current output control device provided in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of the power equipment provided in the embodiments of this application. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0035] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0036] In the field of modern power electronics and energy control, current regulation is required for the operation of motor control, energy storage systems, and new energy grid connection. For example, in the fields of energy storage systems and new energy grid connection, for scenarios such as battery equalization management, microgrid power regulation, and smooth control of charging and discharging processes, small current commands are needed to regulate charge or energy due to load characteristics, energy transmission efficiency, and system safety requirements.

[0037] For example, in energy storage systems, battery balancing management can maintain battery pack performance and extend battery life. Energy storage systems consist of multiple batteries connected in series or parallel. Due to slight differences in the internal resistance and capacity of individual cells, uneven charge and discharge can occur during long-term charging and discharging. If not addressed promptly, this can lead to overcharging and over-discharging of some cells, severely impacting the overall performance and safety of the battery pack. To achieve battery balancing, a small current command needs to be sent to the balancing circuit. Through this small current charging and discharging compensation, the difference in charge and discharge capacity between individual cells is gradually reduced. The precision of this small current control directly determines the balancing effect, thus affecting the charging and discharging efficiency and battery cycle life of the entire energy storage system. In the scenario of dynamic estimation of the remaining capacity of an energy storage system, small current commands are also needed to simulate energy consumption under different loads, and the remaining capacity estimation model is calibrated using small current sampling data.

[0038] In the field of renewable energy grid integration, microgrid power regulation can ensure the stable operation of the power grid. Due to the intermittent and fluctuating nature of renewable energy generation such as photovoltaic and wind power, their grid connection can impact the voltage and frequency of the power grid. Therefore, it is necessary to send small-current commands through the microgrid control system to regulate the power output of energy storage devices and flexible loads, achieving a dynamic balance between renewable energy generation and grid load. For example, when photovoltaic power generation is excessive, the microgrid control system will issue a small-current charging command to control the energy storage device to absorb the excess energy; when photovoltaic power generation is insufficient, it will issue a small-current discharging command to control the energy storage device to supplement the power gap in the grid. Furthermore, in the scenario of smooth control during the charging and discharging process of renewable energy grid integration, whether it is the slow charging control of electric vehicle charging piles or the charging and discharging regulation of distributed energy storage, small-current commands are needed to achieve smooth energy transfer and reduce the damage caused by sudden current changes to the power grid, energy storage equipment, and electrical loads.

[0039] Executing small current commands requires accurate current sampling. By accurately acquiring small current signals, the execution effect of the command can be fed back, and control parameters can be adjusted in a timely manner to ensure that charge or energy regulation achieves the expected goals. In related technologies, current sampling technology mainly employs solutions such as Hall effect sensors, shunt resistors, or magnetoresistive sensors. The working principle is that the sensor detects changes in the magnetic field or voltage generated by the current. After signal filtering, amplification, and conditioning processing by the analog front-end circuit, the analog signal is converted into a digital signal by an analog-to-digital converter and transmitted to the controller to complete the control logic calculations.

[0040] However, limited by factors such as sensor resolution, noise in the analog front-end circuit, and the effective bit depth of the analog-to-digital converter (ADC), sampling results often exhibit significant deviations or fluctuations when the measured current is small, leading to insufficient system control accuracy. For example, the magnetic field or voltage change signals generated by small currents are weak and exceed the sensor's sensing range, easily causing sampled signal distortion. During signal conditioning, the analog front-end circuit introduces circuit noise, and since the amplitude of small current signals is inherently small, noise easily interferes with them, further amplifying sampling deviations. The effective bit depth of the ADC determines the digital quantization accuracy; for weak small current analog signals, quantization errors are prone to occur, resulting in significant deviations in small current sampling results. Insufficient sampling accuracy can lead to poor balancing performance and shortened battery life in energy storage battery equalization management; power imbalance and increased grid fluctuations in microgrid power regulation; and unstable energy transmission and increased equipment losses in charge-discharge control. Therefore, a solution is needed to reduce the poor sampling accuracy under low-current conditions.

[0041] Based on this, embodiments of this application provide a current output control method, apparatus, power equipment, and storage medium. The current output control method, apparatus, power equipment, and storage medium provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios.

[0042] The current output control method provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the current output control method. The electronic device mentioned in this application embodiment can be a digital controller in a power electronic converter, such as a microcontroller unit (MCU), digital signal processor (DSP), or field-programmable gate array (FPGA), etc. It can also be a control unit integrated in power equipment such as a motor driver, energy storage converter, photovoltaic inverter, or charging pile, or a main control chip or equalization control unit in a battery management system (BMS), or a power regulation controller in a microgrid energy management system, etc. The current output control method provided in this application embodiment is described below using an electronic device as the execution subject.

[0043] like Figure 1 As shown, the current output control method includes steps 110, 120 and 130.

[0044] Step 110: Obtain the first current.

[0045] In this embodiment, a first current can be obtained according to a control command. The control command carries the desired output current parameter information, i.e., the first current. The first current is an initial target current determined according to control requirements, and its magnitude is determined based on the specific application scenario and control objective. The control command may also include an output task duration, for example, the control command is "output a current of 0.1A for a duration of 110s". Here, "output duration 110s" is the output task duration of the first current.

[0046] In some embodiments, the control command may be generated by a host controller, a user input module, or a preset control program, and transmitted to the electronic device via a communication interface. Upon receiving the control command, the electronic device can parse and obtain the first current.

[0047] It should be noted that when the initial current is less than the preset current threshold, the system is considered to be in a low-current operating condition, and subsequent charge accumulation and conversion steps need to be initiated. The current threshold can be determined experimentally based on factors such as the actual hardware's sampling resolution and the allowable relative error range.

[0048] Since the first current is a current parameter under low-current operating conditions, in actual hardware sampling, the low-current signal is easily affected by factors such as quantization errors of the sampling circuit, noise interference, and sensor resolution limitations, leading to a decrease in sampling accuracy. Therefore, directly controlling based on the first current may result in insufficient control accuracy.

[0049] Step 120: Obtain the charge accumulation value based on the first current.

[0050] In this embodiment of the application, the first current can be integrated over time to simulate the accumulation process of charge in the virtual container. Therefore, during the charge accumulation process, no hardware sampling is required, thereby reducing the sampling error problem under low current conditions.

[0051] Once the first current is obtained, charge accumulation calculations can be performed based on the first current. For example, the first current I can be used to calculate the charge accumulation. ref1 The virtual quantized charge accumulation value ∑Q is the product of the accumulation time t1 and the accumulation duration t1. collect , i.e. ∑Q collect= I ref1 ·t1.

[0052] Alternatively, a timed interrupt method can be used to periodically accumulate charge, triggering the charge accumulation once per cycle, i.e., Q. n= Q n-1 +I ref1 ·Δt, where Q n Q represents the current amount of charge accumulated. n-1 Δt represents the charge accumulation value at the previous moment, and Δt represents the duration of the period.

[0053] Step 130: When the charge accumulation value is greater than or equal to the charge limit, output a second current until the charge accumulation value is less than or equal to the initial value before charge accumulation, then stop outputting the second current; wherein, the first current is less than the second current.

[0054] In this embodiment, the charge limit can be a preset value or the maximum capacity value for charge accumulation. When the charge accumulation value reaches or exceeds the charge limit, it indicates that the charge accumulation through the first current has completed sufficient energy accumulation, and a second current can be output. The second current is greater than the first current, thus allowing the sampling accuracy of the second current to be greater than that of the first current. Therefore, by converting the first current into a second current output, the problem of poor sampling accuracy with small currents can be reduced, improving the accuracy of the control process. The magnitude of the second current can be preset or is the maximum current value supported by the hardware in the electronic device.

[0055] During the output of the second current, charge decay can be performed; for example, it can be based on the second current I. ref2 The product of the decay time t2 gradually increases the accumulated charge value ∑Q. collect The charge is gradually reduced until the accumulated charge value is less than or equal to the initial value before charge accumulation. Then the output of the second current is stopped, so that the total charge accumulation corresponding to the first current is equal to the total charge decay corresponding to the second current, that is, the equivalent relationship between the first current and the second current in terms of total charge output is achieved.

[0056] In some embodiments, the initial value before charge accumulation can be a zero-charge state or a preset reference charge amount. If the initial value is zero, the second current is stopped when the charge accumulation value decays to zero; if the initial value is a non-zero reference value, the second current is stopped when the charge accumulation value decays to that reference value.

[0057] It should be noted that the above-described process of charge accumulation and decay can be repeated periodically. When the accumulated charge value decays to the initial value, if the first current output task duration has not ended or a new first current is received, the charge accumulation process can be restarted and step 130 can be executed.

[0058] The following is combined Figure 2 Explain the principle that the first current and the second current are equivalent. For example... Figure 2 As shown, the upper waveform corresponds to the output curve of the first current, and the lower waveform corresponds to the output curve of the second current. The horizontal axis represents time T, and the vertical axis represents current I. ref1 I represents the first current. ref2 This indicates the second current, which is greater than the first current.

[0059] During the output task duration of the first current, with the first current I ref1 The output, the total output charge is equal to the first current I. ref1 The product of the output task duration and the second current I. ref2The total output charge is the charge accumulation value obtained based on the first current, which is equal to the total charge required for the task of outputting the first current. Therefore, the first control command and the second control command are equivalent in terms of total charge.

[0060] from Figure 2 As can be seen, the upper waveform is a high-frequency, low-amplitude pulse sequence that is continuously output to meet the requirements of small current control; the lower waveform is a relatively low-frequency, high-amplitude pulse sequence that, by extending the duration of each output T1, T2 and T3, makes the total charge of each output equal to the total charge of the first current in the corresponding time period.

[0061] The following description uses the application of the current output control method of this application to an energy storage system as an example. Figure 3 As shown, the energy storage system includes an energy storage control box, multi-level battery packs, and equalization control units within each battery pack.

[0062] The energy storage control box is the main controller of the energy storage system. It can establish a communication connection with the equalization control unit in each battery pack through the communication bus to realize the issuance of control commands and the transmission of status data.

[0063] Battery packs, such as battery pack 1, battery pack 2, battery pack 3 through battery pack n, are energy storage units of the energy storage system. Each battery pack integrates a corresponding equalization control unit and battery pack, forming an independent subsystem that can achieve equalization control within the pack.

[0064] The equalization control unit serves as the execution entity for the current output control method, with one equalization control unit configured for each battery pack. The equalization control unit receives control commands from the energy storage control box and executes the steps outlined in this application to achieve equalization current control of the battery packs. The equalization control units are cascaded via an equalization bus, providing a data exchange channel for coordinated equalization among multiple battery packs.

[0065] In this scenario example, the energy storage control box can generate a balancing current command, i.e., a control command, based on parameters such as the voltage difference and remaining charge of the battery pack. This balancing current command instructs the output of a smaller balancing current value to achieve fine-grained balancing adjustment.

[0066] After receiving the control command, the equalization control unit accumulates charge based on the first current, without having to directly output a small current and sample it, thus reducing the control deviation caused by sampling errors under low current conditions.

[0067] When the accumulated charge value is greater than or equal to the charge limit, the equalization control unit controls the battery to output an equalization current with a second current. This achieves the same control effect as with a small current by equipping the total charge. Due to the improved sampling accuracy of the hardware sampling module under high current conditions, the accuracy of the equalization current output can be enhanced.

[0068] The following comparison illustrates the application of the current output control method and a conventional control method. For example, if the control command specifies a first current of 1A and an output task duration of 110s, but due to sampling errors, the actual sampled equalization current is only 0.95A, then under the conventional control method, the final equalization charge would be 110 * 0.95 = 104.5 A·s. However, if the current output control method of this application is used, with the initial value Qint_sum set to 0 before charge accumulation, the second current to 10A, the accumulation gradient to 1A / s, and the charge limit Q... limt If the current is 100A·s, then after an accumulation period of 100s, the output current will be 10A.

[0069] Since the output task duration has not ended when the second current is output, it can be decayed according to the decay gradient of 1-10=-9A. It takes about 11.11s to decay to 0. Since the actual output current value is 10A, the sampling error will be smaller than that of 1A. Therefore, the actual sampled current value during the output of the second current is 9.9A. So the final balanced charge is 11.11·9.9=109.989A·s.

[0070] It can be seen that the control command indicates the first current to be 1A, the output task duration is 110s, and the theoretical balanced charge is 110·1=110A. Under the traditional control method, the final balanced charge is 104.5A·s. Using the current output control method of this application, the final balanced charge is 109.989A·s. The error of the current output control method of this application is smaller.

[0071] The following description uses the application of the current output control method of this application to a photovoltaic grid-connected system as an example. Figure 4 As shown, the photovoltaic grid-connected system includes an AC power grid, multiple inverters, a DC bus, and a photovoltaic energy storage array.

[0072] Inverter 1-n connects one end to the AC power grid and the other end to the DC bus to achieve bidirectional conversion between AC and DC power. The inverter can convert the DC power supplied to the DC bus by the photovoltaic array into AC power and send it into the AC power grid.

[0073] The photovoltaic energy storage array includes n energy storage subsystems, and each energy storage subsystem includes an energy storage control box, a balance control unit, and a battery pack.

[0074] The equalization control unit serves as the execution entity for the current output control method, with one equalization control unit configured for each battery pack. The equalization control unit receives control commands from the energy storage control box and executes the steps outlined in this application to achieve equalization current control of the battery pack's components.

[0075] When the photovoltaic array generates electricity by connecting to the AC grid, excess energy is distributed to each battery pack via the DC bus. At this time, the remaining charge, voltage, and other parameters of each battery pack may differ, requiring the activation of equalization control. The energy storage control box can generate control commands based on the detected differences in battery pack status. After receiving the control commands, the equalization control unit accumulates charge based on the first current, without needing to directly output a small current and sample it, thus reducing control deviations caused by sampling errors under low-current conditions.

[0076] When the accumulated charge value is greater than or equal to the charge limit, the equalization control unit controls the battery to output an equalization current with a second current. This achieves the same control effect as with a small current by equipping the total charge. Due to the improved sampling accuracy of the hardware sampling module under high current conditions, the accuracy of the equalization current output can be enhanced.

[0077] It should be noted that the current output control method of this application embodiment can also be applied to other power electronics and energy control fields, such as motor control, and to other scenarios, such as smooth control of charging and discharging processes, dynamic estimation of remaining capacity, etc. This application embodiment does not limit these applications.

[0078] According to the current output control method of this application, a first current is acquired; a charge accumulation value is obtained based on the first current; and a second current is output when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current. This embodiment of the application uses charge accumulation and charge release to convert a smaller first current into a larger second current for output. Considering the influence of hardware sampling errors, the sampling accuracy is higher under high current conditions compared to low current conditions, thus reducing the problem of poor sampling accuracy under low current conditions. The output of the second current stops when the charge accumulation value falls back to the initial value before accumulation, making the first current and the second current equivalent in terms of total charge output. This allows for an equivalent control process while reducing the problem of poor sampling accuracy under low current conditions, thereby improving the system control accuracy.

[0079] In some embodiments, obtaining the charge accumulation value based on the first current includes: Obtain the gradient coefficients; The product of the first current and the gradient coefficient is used as the accumulated gradient. The charge accumulation value is obtained based on the accumulation gradient.

[0080] In this embodiment, the gradient coefficient is a parameter used to adjust the charge accumulation rate, which can be pre-calibrated or dynamically adjusted according to actual operating conditions such as hardware performance, control response speed requirements, control type, and current operating range.

[0081] In some embodiments, the gradient coefficient can be adjusted according to the magnitude of the first current. When the first current is small, using a fixed charge accumulation rate may result in an excessively long charge accumulation time, prolonging the overall control response time. Therefore, the gradient coefficient can be increased to improve the charge accumulation rate and shorten the time required to reach the charge limit. When the first current is large, if the accumulation rate is too fast, the charge may reach the limit quickly, resulting in a short current switching cycle and affecting the stability of the control. Therefore, the gradient coefficient can be reduced to decrease the charge accumulation rate.

[0082] In some embodiments, the gradient coefficient can also be calibrated based on historical operating data. For example, by statistically analyzing the system response time under different current conditions, a mapping table between the gradient coefficient and the current value can be established. During operation, the mapping table can be queried based on the first current to obtain the corresponding gradient coefficient. The mapping table can be experimentally determined and stored in a storage unit, or it can be updated during operation based on an online learning algorithm. Of course, the gradient coefficient can also be manually set by the user through a human-machine interface, or issued by the upper-level controller according to the upper-level control strategy; this embodiment does not limit this.

[0083] In this embodiment, the first current I can be ref1 With gradient coefficients The product of these factors is used as the accumulation gradient for charge accumulation, i.e., the single charge collection value Q. int_once =I ref1 · It can accumulate charge based on the time interval of the control execution, such as once per second, until it reaches the accumulated charge value ∑Q. collect .

[0084] In this embodiment, the product of the first current and the gradient coefficient is used as the accumulation gradient for charge accumulation. This allows the charge accumulation rate to be adjusted according to actual operating conditions, reducing the impact on control stability caused by excessively rapid accumulation leading to prematurely reaching the limit, or the impact on response time caused by excessively slow accumulation. This improves the stability and efficiency of the system under different current conditions.

[0085] In some embodiments, the method further includes: Obtain the accumulation time when the charge accumulation value is greater than or equal to the charge limit; If the output duration of the first current is greater than the accumulation duration, obtain the difference between the second current and the first current; The amount of charge accumulation decay is obtained from the difference.

[0086] In this embodiment, the accumulation time refers to the time interval from the start of the charge accumulation process until the charge accumulation value first reaches or exceeds the charge limit.

[0087] In some embodiments, the accumulation duration when the charge accumulation value is greater than or equal to the charge limit can be obtained by a timer or clock module. For example, the timer can be started at the same time as the charge accumulation begins, and the timer can be stopped when the charge accumulation value is greater than or equal to the charge limit. The current value of the timer is then read as the accumulation duration.

[0088] When the output duration of the first current exceeds the accumulation duration, it means that the output duration of the first current has not yet ended when the accumulated charge value is greater than or equal to the charge limit. For example, if a control command to output the first current is received at 12:20:15, with an output duration of 80 seconds, then accumulation begins at 12:20:15. Assuming an accumulation duration of 60 seconds, if the accumulated charge value is greater than or equal to the charge limit at 12:21:15, and there are still 20 seconds of output duration remaining, charge accumulation will continue. In this case, triggering the output of the second current will attenuate the accumulated charge value. Therefore, the accumulated charge value will continue to accumulate based on the first current and will be attenuated based on the second current.

[0089] For example, the attenuation can be based on the second current I. ref2 The product of the decay time t2 gradually increases the accumulated charge value ∑Q. collect The decay can be achieved through cumulative reduction, or by using the product of the second current and the gradient coefficient as the decay gradient. Since the charge accumulation value will continue to accumulate based on the first current during the decay process, it is necessary to combine the accumulation amount and the decay amount to obtain the decay amount for charge decay.

[0090] Specifically, the difference between the second current and the first current is obtained, and the attenuation of the charge accumulation value is obtained based on the difference. For example, the attenuation Q1 = (I ref2- I ref1 )·t, where t represents the decay time.

[0091] In this embodiment, when the output duration of the first current is longer than the accumulation duration, charge decay is performed based on the difference between the second current and the first current, thereby enabling the charge decay to match the continuous charge accumulation process and improving the accuracy of the control process.

[0092] In some embodiments, obtaining the attenuation of the charge accumulation value based on the difference includes: Obtain the gradient coefficients and determine the decay gradient based on the difference and the gradient coefficients; The decay amount of the charge accumulation value is obtained based on the decay gradient.

[0093] In this embodiment, the gradient coefficient used to calculate the attenuation can be the same as the gradient coefficient used to calculate the charge accumulation value. The second current I can be... ref2 With the first current I ref1 The difference and gradient coefficient between The product of these two factors is used as the decay gradient, and the decay amount of the charge accumulation value is obtained based on the decay gradient.

[0094] That is, the single-time attenuation Q2 = (I ref2- I ref1 )· The total attenuation can be obtained by accumulating multiple individual attenuation values ​​according to the attenuation time interval, such as once per second.

[0095] In this embodiment, the attenuation gradient is determined by combining the difference between the second current and the first current and the gradient coefficient. This allows the rate of charge attenuation to be adjusted according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0096] In some embodiments, the method further includes: If the output duration of the first current is less than or equal to the accumulation duration, the attenuation of the charge accumulation value is obtained based on the second current.

[0097] In this embodiment, when the output duration of the first current is less than or equal to the accumulation duration, it indicates that the output duration of the first current has ended when the charge accumulation value is greater than or equal to the charge limit. The attenuation amount is equal to the second current I. ref2 The decay amount is obtained by multiplying the decay time t2 by the decay gradient, or by multiplying the second current by the gradient coefficient.

[0098] In this embodiment, by performing charge decay based on the second current when the output duration of the first current is less than or equal to the accumulation duration, the charge decay process is matched with the actual output of the second current, thereby improving the accuracy of the control process.

[0099] In some embodiments, obtaining the attenuation of the charge accumulation value based on the second current includes: Obtain the gradient coefficients and determine the attenuation gradient based on the second current and the gradient coefficients; The decay amount of the charge accumulation value is obtained based on the decay gradient.

[0100] In this embodiment, the second current I can be ref2 and gradient coefficients The product of these two factors serves as the attenuation gradient. Based on this gradient, the attenuation amount of the accumulated charge is obtained, i.e., the single attenuation amount Q2 = I. ref2 · The total attenuation can be obtained by accumulating multiple individual attenuation values ​​according to the attenuation time interval, such as once per second.

[0101] In this embodiment, by combining the second current and the gradient coefficient to determine the attenuation gradient, the rate of charge attenuation can be adjusted according to actual operating conditions, thereby improving the stability and efficiency of the system under different current conditions.

[0102] In some embodiments, the method further includes: The decay time is obtained when the charge accumulation value is less than or equal to the initial value, and the accumulation time is obtained when the charge accumulation value is greater than or equal to the charge limit. If the duration of the first current output task is greater than the sum of the decay duration and the accumulation duration, the charge accumulation value is obtained based on the first current. When the charge accumulation value is greater than or equal to the charge limit, the second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops.

[0103] In this embodiment, the decay time refers to the time interval from the start of the charge decay process until the charge limit first decays to the initial value before charge accumulation.

[0104] In some embodiments, the decay duration can be obtained through a timer or clock module. For example, a timer can be started at the same time as charge decay begins, and the timer can be stopped when the charge limit is less than or equal to the initial value before charge accumulation. The current value of the timer is then read as the decay duration.

[0105] In this embodiment, the sum of the decay duration and the accumulation duration represents the time of one control conversion cycle. If the output task duration of the first current is greater than the sum of the decay duration and the accumulation duration, it means that the task of outputting the first current has not been completed. The total amount of charge actually output by the second current is less than the total amount of charge required by the first current output task. Therefore, it is necessary to continue to accumulate charge based on the first current. When the charge accumulation value is greater than or equal to the charge limit, the second current is continued to be output until the charge accumulation value is again less than or equal to the initial value before charge accumulation. That is, the control cycle of charge accumulation and decay is repeated once.

[0106] By repeatedly executing the above process, under the action of a first current output task with a long duration, multiple equivalent large current control cycles can replace small current control.

[0107] In this embodiment, by re-executing the charge accumulation and charge decay process based on the second control command when the output task duration of the first current is greater than the sum of the decay duration and the accumulation duration, it is possible to realize the charge accumulation and decay cycle of multiple control cycles based on the output task duration of the first current, under the premise of satisfying the equivalence of the total charge output. This not only shortens the difference between the output task duration of the first current and the output duration of the second current, but also reduces the waiting time for outputting the second current, thereby improving control efficiency and control equivalence.

[0108] The current output control method provided in this application can be executed by a current output control device. This application uses an example of a current output control device executing the current output control method to illustrate the current output control device provided in this application.

[0109] This application also provides a current output control device.

[0110] like Figure 5 As shown, the current output control device includes: The acquisition module 510 is used to acquire the first current; Collection module 520 is used to obtain the charge accumulation value based on the first current; The output module 530 is used to output a second current when the charge accumulation value is greater than or equal to the charge limit value, until the charge accumulation value is less than or equal to the initial value before charge accumulation, and then stop outputting the second current; wherein the first current is less than the second current.

[0111] According to the current output control device of this application, a first current is acquired; a charge accumulation value is obtained based on the first current; and a second current is output when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current. This embodiment of the application uses charge accumulation and charge release to convert a smaller first current into a larger second current for output. Considering the influence of hardware sampling errors, the sampling accuracy is higher under high current conditions compared to low current conditions, thus reducing the problem of poor sampling accuracy under low current conditions. The output of the second current stops when the charge accumulation value falls back to the initial value before accumulation, making the first current and the second current equivalent in terms of total charge output. This reduces the problem of poor sampling accuracy under low current conditions while ensuring an equivalent control process, thereby improving the system control accuracy.

[0112] In some embodiments, the collection module 520 is further configured to: Obtain the gradient coefficients; The product of the first current and the gradient coefficient is used as the accumulated gradient. The charge accumulation value is obtained based on the accumulation gradient.

[0113] In some embodiments, the output module 530 is further configured to: Obtain the accumulation time when the charge accumulation value is greater than or equal to the charge limit; If the output duration of the first current is greater than the accumulation duration, obtain the difference between the second current and the first current; The amount of charge accumulation decay is obtained from the difference.

[0114] In some embodiments, the output module 530 is further configured to: Obtain the gradient coefficients and determine the decay gradient based on the difference and the gradient coefficients; The decay amount of the charge accumulation value is obtained based on the decay gradient.

[0115] In some embodiments, the output module 530 is further configured to: If the output duration of the first current is less than or equal to the accumulation duration, the attenuation of the charge accumulation value is obtained based on the second current.

[0116] In some embodiments, the output module 530 is further configured to: Obtain the gradient coefficients and determine the attenuation gradient based on the second current and the gradient coefficients; The decay amount of the charge accumulation value is obtained based on the decay gradient.

[0117] In some embodiments, the output module 530 is further configured to: The decay time is obtained when the charge accumulation value is less than or equal to the initial value, and the accumulation time is obtained when the charge accumulation value is greater than or equal to the charge limit. If the duration of the first current output task is greater than the sum of the decay duration and the accumulation duration, the charge accumulation value is obtained based on the first current. When the charge accumulation value is greater than or equal to the charge limit, the second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops.

[0118] like Figure 6 As shown, this application embodiment also provides a power device 600, including a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the program is executed by the processor 601, it implements the various processes of the above-described current output control method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0119] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described current output control method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0120] The processor is the processor in the power equipment described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0121] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described current output control method.

[0122] The processor is the processor in the power equipment described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0123] This application also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described current output control method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0124] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0125] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0126] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0127] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0128] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0129] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A current output control method, characterized in that, include: Obtain the first current; The charge accumulation value is obtained based on the first current; If the charge accumulation value is greater than or equal to the charge limit, a second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current.

2. The method according to claim 1, characterized in that, The process of obtaining the charge accumulation value based on the first current includes: Obtain the gradient coefficients; The product of the first current and the gradient coefficient is used as the accumulated gradient; The charge accumulation value is obtained based on the accumulation gradient.

3. The method according to claim 1, characterized in that, The method further includes: Obtain the accumulation time when the charge accumulation value is greater than or equal to the charge limit; If the output task duration of the first current is greater than the accumulation duration, the difference between the second current and the first current is obtained; The amount of attenuation of the charge accumulation value is obtained based on the difference.

4. The method according to claim 3, characterized in that, The step of obtaining the attenuation amount of the charge accumulation value based on the difference includes: Obtain the gradient coefficients, and determine the decay gradient based on the difference and the gradient coefficients; The attenuation amount of the charge accumulation value is obtained based on the attenuation gradient.

5. The method according to claim 3, characterized in that, The method further includes: If the output duration of the first current is less than or equal to the accumulation duration, the attenuation of the charge accumulation value is obtained based on the second current.

6. The method according to claim 5, characterized in that, The attenuation amount of obtaining the charge accumulation value based on the second current includes: Obtain the gradient coefficients and determine the attenuation gradient based on the second current and the gradient coefficients; The attenuation amount of the charge accumulation value is obtained based on the attenuation gradient.

7. The method according to claim 1, characterized in that, The method further includes: The decay time when the charge accumulation value is less than or equal to the initial value is obtained, and the accumulation time when the charge accumulation value is greater than or equal to the charge limit is obtained; When the duration of the first current output task is greater than the sum of the decay duration and the accumulation duration, the charge accumulation value is obtained based on the first current, and when the charge accumulation value is greater than or equal to the charge limit, the second current is output until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops.

8. A current output control device, characterized in that, include: The acquisition module is used to acquire the first current; The collection module is used to obtain the charge accumulation value based on the first current; An output module is configured to output a second current when the charge accumulation value is greater than or equal to a charge limit, until the charge accumulation value is less than or equal to the initial value before charge accumulation, at which point the output of the second current stops; wherein the first current is less than the second current.

9. An electrical device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the current output control method as described in any one of claims 1-7.

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