Input current determination method, maximum power point tracking method and vehicle

Abstract

The embodiment of the invention provides an input current determination method, a maximum power point tracking method and a vehicle. The method comprises the following steps: acquiring an inductive current of an energy storage inductor in an electric energy conversion circuit; determining an input current of the electric energy conversion circuit according to the inductive current; and controlling the photovoltaic module connected with the input end of the electric energy conversion circuit to work at the maximum power point according to the input current of the electric energy conversion circuit. The input current of the input end of the electric energy conversion circuit is determined through the inductive current, an input end current sampling circuit does not need to be additionally arranged on the basis of an existing inductive current sampling circuit, the influence of parasitic capacitance and inductance in the input end current sampling circuit on a sampling result can be effectively reduced, and the accuracy of the determined input current is improved. When the maximum power point tracking is realized according to the input current, the accuracy of the maximum power point tracking can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic systems, and in particular to an input current determination method, a maximum power point tracking method, and a vehicle. Background Art

[0002] As the heart and brain of the photovoltaic power generation system, the photovoltaic inverter has the important mission of converting the DC power generated by the photovoltaic array into safe and stable AC power and outputting it to the power grid. max Whether a PV power plant operates at its maximum power point (MPP) directly impacts its overall profitability. Based on the VI curve characteristics of photovoltaics, it is usually necessary to first connect the PV power plant to a DC-DC converter for MPPT output before supplying power to downstream devices such as batteries or energy storage converters.

[0003] Maximum power point tracking (MPPT) requires precise detection of the photovoltaic (PV) output current (i.e., the DC-DC converter's input current) to ensure accuracy. Related technologies employ a sampling circuit on the PV side to sample and detect the input current. However, filtering and parasitic parameters in the sampling circuit can affect the collected input current, leading to inaccurate results. Summary of the Invention

[0004] Embodiments of the present application provide an input current determination method, a maximum power point tracking method, and a vehicle for accurately detecting the input current of an electric energy conversion circuit, thereby improving the accuracy of maximum power point tracking.

[0005] In a first aspect, an embodiment of the present application provides a method for determining an input current, the method comprising: obtaining an inductor current of an energy storage inductor in an electric energy conversion circuit;

[0006] The input current of the power conversion circuit is determined according to the inductor current.

[0007] In one possible implementation, obtaining the inductor current of an energy storage inductor in an electric energy conversion circuit includes:

[0008] Sampling the current of the energy storage inductor in the power conversion circuit based on a first sampling frequency to obtain a sampling value of the inductor current, wherein the first sampling frequency is not lower than the switching frequency of the power conversion circuit;

[0009] The inductor current is determined according to the inductor current sampling value.

[0010] In one possible implementation, determining the inductor current according to the inductor current sampling value includes:

[0011] The inductor current corresponding to the current processing period is determined according to the inductor current sampling value obtained during the current processing period, and the current processing period is not less than the switching period of the power conversion circuit.

[0012] In a possible implementation, determining the inductor current corresponding to the current processing period according to the inductor current sampling value obtained during the current processing period includes:

[0013] The inductor current corresponding to the current processing period is determined according to the average current of all the inductor current sampling values ​​in the current processing period.

[0014] In one possible implementation, determining the inductor current corresponding to the current processing period according to the average current of all inductor current sampling values ​​within the current processing period includes:

[0015] Obtain the inductor temperature corresponding to the current processing cycle;

[0016] Correct the average current according to the inductor temperature;

[0017] The inductor current corresponding to the current processing period is determined according to the corrected average current.

[0018] In a possible implementation, obtaining the inductor temperature corresponding to the current processing cycle includes:

[0019] Sampling the temperature of the energy storage inductor in the electric energy conversion circuit based on the second sampling frequency to obtain an inductor temperature sampling value;

[0020] The inductor temperature corresponding to the current processing period is determined according to the inductor temperature sampling value obtained during the current processing period.

[0021] In one possible implementation, the average current is corrected according to the inductor temperature, including:

[0022] The inductance of the energy storage inductor is corrected according to the inductor temperature to obtain the corrected inductance;

[0023] A corrected average current is obtained according to the corrected inductance and the average current.

[0024] In a possible implementation, the inductance of the energy storage inductor is corrected according to the inductor temperature to obtain the corrected inductance, including:

[0025] According to the inductor temperature, determine the inductor compensation amount corresponding to the inductor temperature;

[0026] According to the inductance compensation amount, the corrected inductance is determined.

[0027] In a possible implementation, determining an inductance compensation amount corresponding to the inductor temperature according to the inductor temperature includes:

[0028] Obtain the inductor current corresponding to the previous current processing cycle;

[0029] According to the inductor current and inductor temperature corresponding to the previous current processing cycle, the corresponding inductor compensation amount is searched in the preset mapping relationship, and the preset mapping relationship represents the relationship between the inductor current, temperature and compensation amount.

[0030] In a possible implementation, obtaining a corrected average current according to the corrected inductance and the average current includes:

[0031] Determine the disconnection time of the switch tube serving as the main power tube in the power conversion circuit according to the corrected inductance and the average current;

[0032] Based on the disconnection time, the corrected average current is determined.

[0033] In one possible implementation, determining the off-time of a switch tube serving as a main power tube in the power conversion circuit according to the corrected inductance and the average current includes:

[0034] Determine the current change of the inductor during the current processing cycle based on the average current;

[0035] The disconnection time is determined according to the corrected inductance and current change.

[0036] In one possible implementation, the average current includes at least one sub-average value, where the sub-average value is the average value of all inductor current sampling values ​​collected when the power conversion circuit is in the same state. Determining a current change of the inductor during a current processing cycle based on the average current includes:

[0037] The maximum value of all sub-average values ​​in the average current is taken as the current variation of the energy storage inductor during the current processing cycle.

[0038] In a possible implementation, determining the disconnection duration according to the corrected inductance and current change includes:

[0039] The disconnection time is calculated according to the working mode of the power conversion circuit, the corrected inductance and the current change.

[0040] In a possible implementation, calculating the disconnection duration according to the operating mode of the power conversion circuit, the corrected inductance, and the current change includes:

[0041] Determine the electromotive force across the inductor according to the operating mode of the power conversion circuit;

[0042] The disconnection time is calculated based on the electromotive force across the inductor, the corrected inductance, and the current change.

[0043] In a possible implementation, the operating mode of the electric energy conversion circuit includes at least one of a boost mode, a buck mode, and a boost / buck mode.

[0044] In a possible implementation, determining the corrected average current according to the disconnection duration includes:

[0045] The disconnection time is compared with a reference time to determine a comparison result, wherein the reference time is related to the duty cycle of the switch tube serving as the main power tube in the power conversion circuit;

[0046] Based on the comparison result, a corrected average current is determined according to the average current.

[0047] In one possible implementation, determining a corrected average current based on the comparison result and the average current includes:

[0048] When the disconnection time is not less than the reference time, determining that the corrected average current is equal to the average current;

[0049] When the disconnection time is shorter than the reference time, a correction coefficient is determined according to the disconnection time and the switching cycle, and a corrected average current is determined according to the correction coefficient and the average current.

[0050] In a possible implementation, the first sampling frequency is 4N1 times the switching frequency, where N1 is a positive integer.

[0051] In a possible implementation, the first sampling frequency satisfies that the sampling moment determined at the first sampling frequency includes the midpoint of the conduction interval of the switch tube serving as the main power tube in the power conversion circuit.

[0052] In a possible implementation, the current processing period is N2 times the switching period, where N2 is a positive integer.

[0053] In one possible implementation, determining the input current of the power conversion circuit according to the inductor current includes:

[0054] When the working mode of the power conversion circuit is the boost mode, the input current of the power conversion circuit is equal to the inductor current;

[0055] When the working mode of the power conversion circuit is the step-down mode, determining the input current of the power conversion circuit according to the conversion efficiency of the power conversion circuit and the inductor current;

[0056] When the operation mode of the power conversion circuit is the step-up / step-down mode, the input current of the power conversion circuit is determined according to the switching cycle of the power conversion circuit and the inductor current.

[0057] In a possible implementation, the power conversion circuit is a DC-DC converter.

[0058] In one possible implementation, the DC-DC converter is a four-switch voltage converter.

[0059] In a second aspect, an embodiment of the present application provides a maximum power point tracking method, the method comprising:

[0060] Obtaining the inductor current in the power conversion circuit;

[0061] Determine the input current of the power conversion circuit according to the inductor current;

[0062] According to the input current of the electric energy conversion circuit, the photovoltaic component connected to the input end of the electric energy conversion circuit is controlled to operate at the maximum power point.

[0063] In a third aspect, an embodiment of the present application provides an input current determination device, the device including a data acquisition module and a data processing module;

[0064] A data acquisition module is used to obtain the inductor current of the energy storage inductor in the power conversion circuit;

[0065] The data processing module is used to determine the input current of the power conversion circuit according to the inductor current.

[0066] In a fourth aspect, an embodiment of the present application provides a computer device, including: a memory, a processor;

[0067] Memory stores computer-executable instructions;

[0068] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0069] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementation methods of the first aspect.

[0070] In a sixth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the first aspect and / or various possible implementation methods of the first aspect.

[0071] In the seventh aspect, an embodiment of the present application provides a vehicle, comprising an electric energy conversion circuit and a processing module, wherein the processing module is connected to the electric energy conversion circuit and is used to execute the above first aspect and / or various possible implementation methods of the first aspect.

[0072] The input current determination method, maximum power point tracking method, and vehicle provided in the embodiments of the present application obtain the inductor current of the energy storage inductor in the electric energy conversion circuit; determine the input current of the electric energy conversion circuit based on the inductor current; and control the photovoltaic assembly connected to the input end of the electric energy conversion circuit to operate at the maximum power point based on the input current of the electric energy conversion circuit. By determining the input current of the input end of the electric energy conversion circuit through the inductor current, there is no need to set up an input end current sampling circuit on the basis of the existing inductor current sampling circuit, which can effectively reduce the influence of parasitic capacitance and inductance in the input end current sampling circuit on the sampling result and improve the accuracy of the determined input current. When the maximum power point tracking is achieved based on the input current, the accuracy of the maximum power point tracking can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0074] Figure 1 A schematic diagram of input current sampling points provided in one embodiment;

[0075] Figure 2 A schematic diagram of a method for determining input current provided in one embodiment Figure 1 ;

[0076] Figure 3 A schematic structural diagram of a DC-DC converter provided in one embodiment;

[0077] Figure 4 A schematic diagram of sampling points provided in one embodiment;

[0078] Figure 5 A schematic diagram of an operating mode of a DC-DC converter provided in one embodiment;

[0079] Figure 6 A schematic diagram of the states of input current and inductor current provided in one embodiment;

[0080] Figure 7 A schematic diagram of a method for determining input current provided in one embodiment Figure 2 ;

[0081] Figure 8 A schematic diagram of a method for determining input current provided in one embodiment Figure 3 ;

[0082] Figure 9 A schematic diagram of a method for determining input current provided in one embodiment Figure 4 ;

[0083] Figure 10 A schematic structural diagram of a photovoltaic system provided in one embodiment;

[0084] Figure 11 A schematic flow chart of a maximum power point tracking method provided in one embodiment;

[0085] Figure 12 A schematic structural diagram of a maximum power point tracking system provided in one embodiment;

[0086] Figure 13 A schematic diagram of the structure of the computer device provided in this application.

[0087] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0088] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various information or data, but these elements are not limited by these terms. These terms are only used to distinguish the first information from another information. For example, without departing from the scope of this application, the first action information may be referred to as the second action information, and similarly, the second action information may be referred to as the first action information. Both the first action information and the second action information are action information, but they are not the same action information.

[0090] First, let’s explain the terms involved in this application:

[0091] Photovoltaic (PV) power generation systems, also known as photovoltaics (PV), use the photovoltaic effect of photovoltaic cells to directly convert solar radiation into electrical energy. The PV side refers to the photovoltaic panels in a PV system, which are primarily responsible for converting solar energy into direct current (DC).

[0092] Maximum power point tracking (MPPT) is a technology commonly used in wind turbines and photovoltaic solar systems. Its purpose is to achieve maximum power output under various circumstances.

[0093] A DC-to-DC converter (also known as a DC-DC converter) is a circuit or electromechanical device that converts electrical energy. It can convert a direct current (DC) power supply into a DC (or near-DC) power supply of a different voltage.

[0094] Boost mode: boost mode; Buck mode: buck mode; Buck-Boost mode: boost and buck coexisting mode.

[0095] Midpoint: refers to the middle moment in the on-time period of the switch tube when the switch tube in the switching power supply is controlled by pulse width modulation (PWM), that is, the midpoint moment of the high level of the PWM waveform.

[0096] ADC sampling data: This refers to the process of converting a continuously changing analog signal into a discrete digital signal through an analog-to-digital converter (ADC). ADC sampling is the process of discretizing the analog signal at a certain sampling frequency and then converting it into a digital signal.

[0097] DMA transfer, Direct Memory Access, a technology that allows hardware to transfer data directly between memories.

[0098] As the heart and brain of the photovoltaic power generation system, the photovoltaic inverter has the important mission of converting the DC power generated by the photovoltaic array into safe and stable AC power and outputting it to the power grid. max Whether a PV power plant operates at its maximum power point (MPP) directly impacts its overall profitability. Based on the VI curve characteristics of photovoltaics, it is usually necessary to first connect the PV power plant to a DC-DC converter for MPPT output before supplying power to downstream devices such as batteries or energy storage converters.

[0099] Maximum power point tracking requires precise detection of the output current of the photovoltaic (PV) side (i.e., the input current of the DC-DC converter) to ensure the accuracy of maximum power point tracking. In related technologies, a sampling circuit is set on the PV side to sample and detect the input current. Figure 1 The four-switch circuit shown in the figure uses a sampling circuit connected to the input current sampling point for current sampling. However, due to the filtering and parasitic parameters (including parasitic capacitance and parasitic inductance) in the sampling circuit, the collected input current will be affected, resulting in inaccurate collection results. In addition, a photovoltaic system typically includes multiple photovoltaic input channels. If a sampling current is set for each photovoltaic channel to sample the output current (the input current of the DC-DC converter), it will increase the cost and complexity of the system.

[0100] In order to solve the above technical problems, the present invention provides a method for determining input current. Figure 2 As shown, the method includes:

[0101] Step 202, obtaining the inductor current of the energy storage inductor in the power conversion circuit;

[0102] Step 204 : determining the input current of the power conversion circuit according to the inductor current.

[0103] The power conversion circuit refers to the circuitry within a switching power supply that implements power conversion. It converts one type of power into another, including DC-to-DC, DC-to-AC, and AC-to-DC. The power conversion circuit includes an input and an output. Exemplarily, the power conversion circuit is a four-switch voltage converter, specifically a four-switch DC-DC converter.

[0104] Energy storage inductors are used in power conversion circuits to store and release energy to maintain a stable output voltage. During the operation of the power conversion circuit, digital control of the circuit requires the acquisition of the inductor current. The inductor current can be the instantaneous value flowing through the inductor, or a representative current value determined by current values ​​collected over a period of time, such as the maximum current or average current. Similarly, the input current can be determined as an instantaneous value or a current value over a period of time.

[0105] In an energy conversion circuit, DC or AC voltage is converted to DC or AC voltage by repeatedly switching on and off the switching transistors in the circuit. Therefore, as an inductor that stores and releases energy, there is a certain correlation between the current flowing through it and the current on the input side. The input current can be determined by detecting the inductor current. For example, in existing photovoltaic systems, the input current and inductor current are sampled separately, with the inductor current used for DC-DC digital control and the input current used for display monitoring and MPPT power tracking. Therefore, without setting up an input current sampling circuit, the input current can be determined from the inductor current.

[0106] For example, Figure 3 For the four-switch voltage converter shown in FIG, the input current can be considered equal to the inductor current, and the magnitude of the detected inductor current can be considered as the magnitude of the input current. Alternatively, the input current can be determined by the inductor current according to the operating mode of the power conversion circuit. Figure 3 In the four-switch voltage converter shown, when the DC-DC converter is in boost mode, if the inductor current is in continuous mode, the input current is equal to the inductor current at the midpoint. If it is in discontinuous mode, the inductor current can be converted to an equivalent value based on the time percentage. By ensuring that the DC-DC output voltage is always lower than the minimum voltage for effective photovoltaic operation, when the DC-DC converter is in buck mode, if the inductor current is in continuous mode, the input current is equal to the inductor current at the midpoint. If it is in discontinuous mode, the inductor current can be converted to an equivalent value based on the time percentage.

[0107] In the method provided in the above embodiment, the inductor current of the energy storage inductor in the power conversion circuit is obtained; based on the inductor current, the input current of the power conversion circuit is determined; and based on the input current of the power conversion circuit, the photovoltaic assembly connected to the input end of the power conversion circuit is controlled to operate at the maximum power point. By determining the input current of the input end of the power conversion circuit using the inductor current, there is no need to set up an input end current sampling circuit based on the existing inductor current sampling circuit. This can effectively reduce the impact of parasitic capacitance and inductance in the input end current sampling circuit on the sampling results, and improve the accuracy of the determined input current. When implementing maximum power point tracking based on the input current, the accuracy of maximum power point tracking can be effectively improved.

[0108] In one embodiment, obtaining an inductor current in an electric energy conversion circuit includes:

[0109] Sampling the current of the energy storage inductor in the power conversion circuit based on a first sampling frequency to obtain a sampling value of the inductor current, wherein the first sampling frequency is not lower than the switching frequency of the power conversion circuit;

[0110] The inductor current is determined according to the inductor current sampling value.

[0111] The first sampling frequency refers to the sampling frequency of the inductor current. Current sampling is achieved by setting the first sampling frequency of the inductor current sampling circuit. The switching frequency of the power conversion circuit refers to the conduction control frequency of the switch in the power conversion circuit. Typically, to better implement DC-DC digital control, the current flowing through the inductor must be sampled at least once within a switching cycle. Therefore, the first sampling frequency should not be lower than the switching frequency of the power conversion circuit.

[0112] In one embodiment, the first sampling frequency is 4N1 times the switching frequency, where N1 is a positive integer. That is, the current is sampled at least 4 times in one switching cycle, and the sampling time in each switching cycle is the same. Figure 4 In the PWM carrier shown, if N1 is 1, four samples are taken during each switching cycle, each at points 1, 2, 3, and 4. The resulting inductor current samples are more representative. By setting the first sampling frequency to 4N1 times the switching frequency, the accuracy impact of current waveform phase and amplitude offsets introduced by sampling line filtering and parasitic parameters can be reduced.

[0113] It should be noted that regardless of the power conversion circuit's mode, when the inductor current is continuous, the input current is equal to the inductor current at the midpoint. Therefore, when setting the first sampling frequency, the first sampling frequency satisfies the requirement that the sampling moment determined at the first sampling frequency includes the midpoint of the conduction interval of the switch transistor serving as the main power transistor in the power conversion circuit.

[0114] After obtaining the inductor current sample values ​​collected by the sampling circuit, the inductor current is determined based on the sample values. Specifically, the sample values ​​can be used directly as the inductor current. This allows multiple inductor currents to be determined. In practical applications, to reduce computational complexity, high-frequency acquisition of the inductor current is unnecessary. Therefore, the sample values ​​can be processed to determine a single inductor current based on the sample values ​​over a period of time.

[0115] Among them, a period of time is taken as a current processing cycle. After a current processing cycle, the inductor current corresponding to the current processing cycle is determined based on the inductor current sampling value obtained during the current processing cycle. Among them, the current processing cycle is not less than the switching cycle of the power conversion circuit, which can effectively reduce the amount of calculation.

[0116] The current processing cycle is typically pre-set. The first sampling frequency is no less than the switching frequency, the first sampling period is no greater than the switching period, and the current processing cycle is no less than the switching period. Thus, the current processing cycle includes multiple inductor current sampling values. In one embodiment, to ensure a consistent number of inductor current sampling values ​​within each current processing cycle and consistent sampling times within a switching cycle, the current processing cycle is set to N2 times the switching period, where N2 is a positive integer.

[0117] When determining the inductor current corresponding to the current processing cycle, the maximum value among multiple inductor current sampling values ​​can be used as the inductor current, and the inductor current can also be calculated based on multiple inductor current sampling values. The relationship between the inductor current sampling value and the inductor current is related to the state of the inductor current. In combination with the state of the inductor current, the inductor current is determined from the inductor current sampling value. The state of the inductor current refers to the state of the current flowing through the inductor. For example, for Figure 3 The four-switch DC-DC converter shown in the figure has three operating modes. The state of the switch tube is different in each operating mode. Figure 5 The working mode of the converter and the state of the switch tube are shown in Table 1. Correspondingly, the inductor current has three states: continuous, discontinuous and critical, corresponding to Figure 6 Line (1), Line (2) and Line (3).

[0118] In the method provided in the above embodiment, the inductor current is sampled by a set first sampling frequency, and the inductor current within the current processing cycle is determined by collecting multiple inductor current sampling values. This can effectively reduce the computational complexity of subsequent data processing and output a more accurate input current value.

[0119] Table 1 Converter operating mode and switch status

[0120]

[0121] In one embodiment, the average current of all the inductor current sampling values ​​within the current processing period can be directly used as the inductor current corresponding to the current processing period.

[0122] The inductor current sampling value is directly obtained through the sampling circuit, and the determined inductor current is equivalent to being measured. However, because the inductor's inductance varies nonlinearly with different currents and temperatures, there will be a certain degree of error in the actual inductor current and inductance. If you need to use the inductor inductance and inductor current for circuit analysis and determine the input current, you must determine the actual inductor inductance and inductor current at each moment.

[0123] In one embodiment, Figure 7As shown, the inductor current corresponding to the current processing period is determined based on the average current of all inductor current sampling values ​​in the current processing period, and further includes:

[0124] Step 702, obtaining the inductor temperature corresponding to the current processing cycle;

[0125] Step 704, correcting the average current according to the inductor temperature;

[0126] Step 706 : Determine the inductor current corresponding to the current processing period according to the corrected average current.

[0127] The inductor temperature corresponding to the current processing period refers to the inductor temperature obtained during the current processing period, which may be directly obtained through a sensor or the like, or may be determined after sampling the inductor temperature multiple times.

[0128] In one embodiment, obtaining the inductor temperature corresponding to the current processing cycle includes:

[0129] Sampling the temperature of the energy storage inductor in the electric energy conversion circuit based on the second sampling frequency to obtain an inductor temperature sampling value;

[0130] The inductor temperature corresponding to the current processing period is determined according to the inductor temperature sampling value obtained during the current processing period.

[0131] The second sampling frequency refers to the frequency at which the inductor temperature is sampled. The second sampling frequency can be equal to the first sampling frequency. In this case, a single sampling frequency is set to sample all parameters required for the circuit, such as the inductor temperature, inductor current, and other required circuit parameters, at each sampling moment. The second sampling frequency can also be different from the first sampling frequency, set based on the required sampling frequency for the inductor temperature and need not be equal to the first sampling frequency for the inductor current. The second sampling frequency is typically also less than the switching frequency, meaning that the inductor temperature is sampled at least once during each switching cycle.

[0132] All inductor temperature sampling values ​​obtained during the current processing period are processed to obtain the inductor temperature during the current processing period. Specifically, the maximum value, the most frequently occurring value, or the average value of all inductor temperature sampling values ​​can be used as the inductor temperature during the current processing period.

[0133] By acquiring the inductor temperature through sampling, the inductor current can be corrected based on the temperature data collected from the power conversion circuit in the prior art.

[0134] After determining the inductor temperature within a current processing cycle, the average inductor current determined within the current processing cycle is corrected based on the inductor temperature within the current processing cycle to eliminate the effect of temperature on the inductor temperature and improve the accuracy of the determined inductor current. Specifically, the inductor current corresponding to the inductor temperature within each current processing cycle can be directly determined based on the relationship between temperature and current.

[0135] In one embodiment, the average current is corrected based on the inductor temperature, including:

[0136] The inductance of the energy storage inductor is corrected according to the inductor temperature to obtain the corrected inductance;

[0137] A corrected average current is obtained according to the corrected inductance and the average current.

[0138] Inductance refers to its ability to store energy, which varies with the inductor's temperature. The effect of inductor temperature on inductor current is actually due to the effect of temperature on inductance. Therefore, the inductor compensation value corresponding to the inductor temperature is determined based on the inductor temperature; and the corrected inductance is determined based on the inductor compensation value.

[0139] The corrected inductance is relative to the known inductance of the inductor. This means there is an error between the actual inductance of the inductor in the circuit and the known inductance, where the known inductance is a known parameter of the inductor. The inductor temperature during the current processing cycle is used to determine the difference between the actual inductance and the known inductance, thereby correcting the inductance. The corrected average current is calculated using the corrected inductance and the average current.

[0140] In one embodiment, determining an inductor compensation amount corresponding to the inductor temperature according to the inductor temperature includes:

[0141] Obtaining the inductor current corresponding to the previous current processing cycle, where the previous current processing cycle is the cycle immediately preceding the current processing cycle;

[0142] According to the inductor current and inductor temperature corresponding to the previous current processing cycle, the corresponding inductor compensation amount is searched in the preset mapping relationship, and the preset mapping relationship represents the relationship between the inductor current, temperature and compensation amount.

[0143] The inductor current corresponding to the previous current processing cycle refers to the inductor current finally determined in the previous current processing cycle. For example, if the current processing cycle is the kth cycle, the previous current processing cycle refers to the k-1th cycle. The inductor current corresponding to the previous current processing cycle is typically a more accurate current value after correction, eliminating the effects of inductor temperature.

[0144] A preset mapping relationship is data, determined through inductor testing, that characterizes the relationship between the inductor's current, temperature, and compensation value. This mapping relationship can be in the form of a table or other format. In actual applications, inductors are pre-tested to determine the relationship between current, temperature, and inductance for similar inductors. When correcting the inductor's inductance, the inductor's compensation value corresponding to the current inductor temperature and current is determined by searching the table, thereby determining the corrected inductor's inductance.

[0145] In the method provided in the above embodiment, temperature-based correction of the inductor current can reduce the impact of current waveform phase and amplitude offsets introduced by sampling circuit filtering and parasitic parameters. Furthermore, a more accurate input current can be determined based on the inductor current under different power conversion circuit topologies.

[0146] In one embodiment, Figure 8 As shown, according to the corrected inductance and average current, the corrected average current is obtained, including:

[0147] Step 802: Determine the off time of the switch tube serving as the main power tube in the power conversion circuit according to the corrected inductance and the average current;

[0148] Step 804: Determine the corrected average current according to the disconnection duration.

[0149] The switching tube used as the main power tube in the power conversion circuit is a MOSFET or an IGBT, which is controlled by PWM.

[0150] For the power conversion circuit, it realizes different functions by controlling the on and off of the switch tube. In different working modes of the power conversion circuit, the switch tube has different working states. Among them, the working mode of the conversion circuit includes at least one of the boost mode, the buck mode and the boost / buck mode. For example, for Figure 3 The four-switch DC-DC converter shown in FIG. 1 has an operating mode and a status of a switch tube as shown in Table 1.

[0151] When a DC-DC converter is in continuous conduction, the inductor current remains above zero during a switching cycle. This means the inductor current never resets, and the inductor flux never returns to zero. Main power transistor status: During a switching cycle, the main power transistor periodically switches on and off to control the current through the inductor. Because the inductor current remains above zero, the main power transistor must withstand a certain reverse voltage when turned off.

[0152] When a DC-DC converter is in discontinuous conduction, the inductor current will be interrupted within a switching cycle, meaning the inductor current drops to zero, and the inductor is "reset." Main power transistor state: During the switching cycle, the main power transistor also periodically switches on and off. However, after the inductor current drops to zero, the main power transistor remains off for a period of time until the next switching cycle begins. During this period, the inductor current is zero, and the main power transistor is not subject to reverse voltage.

[0153] When the DC-DC converter is in critical conduction, the minimum inductor current is exactly zero within a switching cycle. In this mode, the turn-on and turn-off timings of the main power transistor are very critical and require precise control to ensure that the inductor current is exactly zero at its minimum value.

[0154] From this, we can see that the magnitude of the inductor current is actually related to the on-time and off-time of the switch. The on-time of the switch can be determined by the switching period and duty cycle of the PWM control. However, since the switch is connected in parallel with a diode, freewheeling occurs. Therefore, the actual off-time of the switch needs to be determined by analyzing the actual parameters across the inductor, such as the voltage.

[0155] In one embodiment, determining the disconnection duration of a switch tube serving as a main power tube in the power conversion circuit according to the corrected inductance and the average current includes:

[0156] Determine the current change of the inductor during the current processing cycle based on the average current;

[0157] The disconnection time is determined according to the corrected inductance and current change.

[0158] The average current is the average value of the current value obtained by sampling the inductor current. By sampling the current flowing through the inductor in real time, the current change at both ends of the inductor is analyzed. In one embodiment, the first sampling frequency is 4N1 times the switching frequency, and the current processing cycle is N2 times the switching cycle, then 4N1×N2 data will be obtained in one current processing cycle. Since the circuit state of the power conversion circuit in one switching cycle is different, and the circuit state changes cyclically with the switching cycle, the point corresponding to a sampling moment in one switching cycle is taken as a state point, such as Figure 6 The state corresponding to point 1 in each switching cycle is the same, and the state corresponding to point 2 is also the same. When the first sampling frequency is 4N1 times the switching frequency, there are 4N1 state points in one switching cycle. The current processing cycle is N2 times the switching cycle, and the current at each state point is sampled N2 times.

[0159] For example, when N1=1, that is, Figure 6Sampling is performed at midpoints 1, 2, 3, and 4, resulting in N2 data at each point. For each state point, the average of all collected inductor current sampling values ​​is calculated as the sub-average value. The maximum value of all sub-average values ​​in the average current is taken as the current change of the inductor during the current processing cycle. In one embodiment, the formula for the current change is as follows:

[0160] dI=max(2I 3_avg ,I 1_avg ,I 2_avg ,I 4_avg );

[0161] Where dI is the current change, I 1_avg is the average current at point 1, I 2_avg is the average current at point 2, I 3_avg is the average current at point 3, I 4_avg is the average current at point 4.

[0162] The disconnection duration is calculated differently when the power conversion circuit is in different operating modes. In one embodiment, the disconnection duration is calculated based on the operating mode of the power conversion circuit, the corrected inductance, and the current change.

[0163] The electromotive force at both ends of the inductor is determined by the working mode of the power conversion circuit; the disconnection time is calculated based on the electromotive force at both ends of the inductor, the corrected inductance, and the current change. Figure 3 The four-switch DC-DC converter shown in the figure, when in Buck mode or Buck-Boost mode, the electromotive force across the inductor is V out +V D , accordingly, the disconnection duration is:

[0164]

[0165] Among them, T2 is the disconnection time of the switch tube as the main power tube, L cps is the corrected inductance, V out is the output voltage of the power conversion circuit, V D is the forward voltage drop of the parallel diodes.

[0166] When in -Boost mode, the electromotive force across the inductor is V out -V in -V D , accordingly, the disconnection duration is:

[0167]

[0168] Among them, V inThe input voltage of the power conversion circuit. The input and output voltages of the power conversion circuit are detected and acquired in real time by a voltage sampling circuit. It should be noted that the sampling frequency of the input and output voltages is not limited; multiple sampling values ​​may be present within a current processing cycle. If multiple sampling values ​​are present, the input and output voltages are determined based on these multiple sampling values.

[0169] In the method provided in the above embodiment, the electromotive force across the inductor is analyzed by the collected current to calculate the actual disconnection time of the switch tube, which can more accurately determine the working state of the circuit and the relationship between the actual inductor current and the measured value.

[0170] In one embodiment, determining the corrected average current based on the disconnection duration includes:

[0171] The disconnection time is compared with a reference time to determine a comparison result, wherein the reference time is related to the duty cycle of the switch tube serving as the main power tube in the power conversion circuit;

[0172] Based on the comparison result, a corrected average current is determined according to the average current.

[0173] The reference duration is the theoretical off-time of the switch tube under PWM control, which is determined based on the switching cycle and on-time of the switch tube. The reference duration is determined based on the switching cycle and duty cycle of the switch tube. Specifically, on-time T1 = T SW *Duty, where T SW is the switching period, Duty is the duty cycle, and the reference duration is T SW *(1-Duty).

[0174] When the disconnection time is not less than the reference time, the corrected average current is determined to be equal to the average current; when the disconnection time is less than the reference time, the correction coefficient is determined based on the disconnection time and the switching cycle, and the corrected average current is determined based on the correction coefficient and the average current.

[0175] The correction coefficient is determined based on the disconnection time and the switching cycle, and is determined by pre-collected data. When in use, the correction coefficient corresponding to the disconnection time is directly found, and the average current is corrected to determine the inductor current.

[0176] In one embodiment, Figure 9 As shown, the input current of the power conversion circuit is determined according to the inductor current, including:

[0177] Step 902: When the working mode of the power conversion circuit is the boost mode, the input current of the power conversion circuit is equal to the inductor current;

[0178] Step 904: When the working mode of the power conversion circuit is the buck mode, determine the input current of the power conversion circuit according to the conversion efficiency of the power conversion circuit and the inductor current;

[0179] Step 906 : When the operation mode of the power conversion circuit is the step-up / step-down mode, determine the input current of the power conversion circuit according to the switching cycle of the power conversion circuit and the inductor current.

[0180] In Boost mode, since the input and output are always connected, the input current is equal to the inductor current. In Buck mode, the inductor current can always flow through the output, so the energy conservation law can be used to calculate the input current: I in_avg =I L_avg_cps *V out_avg / η*V in_avg , where I L_avg_cps is the inductor current, and η is the conversion efficiency of the power conversion circuit. In Buck-boost mode, the inductor current and the input current are connected only in the conduction phase, so I in_avg =I L_avg_cps *T1 / T SW .

[0181] In combination with the methods provided in all the above embodiments, a maximum power point tracking method for a photovoltaic system is provided. Figure 10 The photovoltaic system shown in FIG, in which a four-switch DCDC converter is used to achieve maximum power point tracking. Figure 11 As shown, the method includes:

[0182] Step 1102, obtaining the inductor current of the energy storage inductor in the power conversion circuit;

[0183] Step 1104: determining an input current of the power conversion circuit according to the inductor current;

[0184] Step 1106 : Control the photovoltaic assembly connected to the input end of the power conversion circuit to operate at a maximum power point according to the input current of the power conversion circuit.

[0185] The above maximum power point tracking method is based on Figure 12 The maximum power point tracking system shown in the figure is executed, and the maximum power point tracking system includes: a configuration and sampling module 1201, a sampling data processing module 1202 and an MPPT control module; wherein:

[0186] The configuration and sampling module 1201 includes:

[0187] (1) PWM configuration module: Contains the configuration of the PWM drive of the MOSFET in the DCDC. The frequency of the PMW is fsw, which can make the four switches in different modes; and a 4*fsw synchronous PWM for triggering ADC sampling. The first sampling frequency is 4 times fsw. The sampling point is shown in Figure 5 At the moments numbered 1, 2, 3, and 4, the current duty cycle of the supervisor will be output at the same time;

[0188] (2) ADC configuration module: configures the sampling of physical signals such as voltage V, current I, and temperature T;

[0189] (3) DMA configuration module: configures each sampling result to be transferred by DMA, without triggering additional CPU interrupts, thus reducing CPU overhead;

[0190] (4) ADC sampling module: performs simple preprocessing on the 4x ADC sampling results and outputs them to the sampling data processing module;

[0191] The sample data processing module 1202 includes:

[0192] (1) Average current calculation module: The duty cycle of the current processing cycle and 4*N groups of ADC data are accumulated and summed to calculate the average current, including the average current of voltage, temperature, inductance, and the average current at time 1-4;

[0193] (2) Inductor LUT: Compensates the inductor value during the current processing cycle using a lookup table based on the average current and inductor temperature, and outputs the corrected inductor value.

[0194] (3) Inductor current compensation module: Calculates the on-time T1 and off-time T1 of the main power switch and the compensated inductor current IL_avg_cps using the corrected inductor Lcps, operating mode Mode, duty cycle Duty, voltage Vout, Vin, and current IL_avg;

[0195] (4) Input current calculation module: Calculates the input current Iin_avg_cps based on the inductor current IL_avg_cps, the on-time T1, and the off-time T1, combined with the operating mode Mode;

[0196] The MPPT control module 1203 controls the photovoltaic assembly connected to the input end of the power conversion circuit to operate at a maximum power point according to the input current Iin_avg_cps of the power conversion circuit.

[0197] The method and system provided in the above embodiment can reduce the accuracy impact caused by the phase and amplitude offset of the current waveform introduced by sampling line filtering and parasitic parameters by sampling at 4 times the switching frequency. Under the Buck and buck-boost topologies, the inductor current cannot represent the input current. The embodiment of the present application can calculate the input current relatively accurately without adding an additional high-precision current sensor. The embodiment of the present application covers the current calculation of three DCDC topologies and has a wider applicability. The embodiment of the present application adopts N2 switching cycles, that is, the window average value of 4N2 sampling points for calculation, which reduces the amount of calculation, and can monitor the midpoint current, maximum current, whether the inductor is saturated, etc. according to the current sampling conditions at different times.

[0198] Based on the method provided in the above embodiment, this embodiment further provides a vehicle, which adopts the maximum power point tracking method provided in the above embodiment.

[0199] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0200] In one embodiment, an input current determination device is provided, the device including a data acquisition module and a data processing module;

[0201] A data acquisition module is used to obtain the inductor current of the energy storage inductor in the power conversion circuit;

[0202] The data processing module is used to determine the input current of the power conversion circuit according to the inductor current.

[0203] Figure 13 This is a schematic diagram of the structure of the computer equipment provided in this application. Figure 13 As shown, the electronic device 130 provided in this embodiment includes: at least one processor 1301 and a memory 1302. Optionally, the device 130 also includes a communication component 1303. The processor 1301, the memory 1302, and the communication component 1303 are connected via a bus 1304.

[0204] During the specific implementation process, at least one processor 1301 executes the computer-executable instructions stored in the memory 1302, so that the at least one processor 1301 performs the above method.

[0205] The specific implementation process of the processor 1301 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0206] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0207] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0208] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0209] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0210] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0211] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0212] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0213] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0214] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0215] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0216] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0217] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0218] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A method for determining input current, characterized in that: The method comprises: Obtaining the inductor current of the energy storage inductor in the power conversion circuit; An input current of the power conversion circuit is determined according to the inductor current.

2. The method according to claim 1, characterized in that The obtaining of the inductor current of the energy storage inductor in the electric energy conversion circuit includes: Sampling the current of the energy storage inductor in the power conversion circuit based on a first sampling frequency to obtain an inductor current sampling value, wherein the first sampling frequency is not lower than the switching frequency of the power conversion circuit; The inductor current is determined according to the inductor current sampling value.

3. The method according to claim 2, characterized in that The determining the inductor current according to the inductor current sampling value includes: The inductor current corresponding to the current processing period is determined according to the inductor current sampling value obtained during the current processing period, and the current processing period is not less than the switching period of the power conversion circuit.

4. The method according to claim 3, characterized in that The determining, based on the inductor current sampling value obtained during the current processing period, the inductor current corresponding to the current processing period includes: The inductor current corresponding to the current processing period is determined according to an average current of all the inductor current sampling values ​​in the current processing period.

5. The method according to claim 4, characterized in that The determining, based on the average current of all inductor current sampling values ​​within the current processing period, the inductor current corresponding to the current processing period includes: Obtaining an inductor temperature corresponding to the current processing cycle; Correcting the average current according to the inductor temperature; The inductor current corresponding to the current processing period is determined according to the corrected average current.

6. The method according to claim 5, characterized in that The obtaining the inductor temperature corresponding to the current processing period includes: Sampling the temperature of the energy storage inductor in the power conversion circuit based on the second sampling frequency to obtain an inductor temperature sampling value; The inductor temperature corresponding to the current processing period is determined according to the inductor temperature sampling value obtained during the current processing period.

7. The method according to claim 5, characterized in that The correcting the average current according to the inductor temperature includes: Correcting the inductance of the energy storage inductor according to the inductor temperature to obtain a corrected inductance; The corrected average current is obtained according to the corrected inductance and the average current.

8. The method according to claim 7, characterized in that The step of correcting the inductance of the inductor according to the inductor temperature to obtain a corrected inductance of the inductor includes: determining an inductance compensation amount corresponding to the inductance temperature according to the inductance temperature; The corrected inductance is determined according to the inductance compensation amount.

9. The method according to claim 8, characterized in that The determining, based on the inductor temperature, an inductor compensation amount corresponding to the inductor temperature includes: Obtain the inductor current corresponding to the previous current processing cycle; According to the inductor current corresponding to the previous current processing cycle and the inductor temperature, a corresponding inductor compensation amount is searched in a preset mapping relationship, where the preset mapping relationship represents a relationship between the inductor current, temperature, and compensation amount.

10. The method according to claim 7, characterized in that The obtaining the corrected average current according to the corrected inductance and the average current includes: determining, according to the corrected inductance and the average current, a disconnection duration of a switch tube serving as a main power tube in the power conversion circuit; The corrected average current is determined according to the disconnection duration.

11. The method according to claim 10, characterized in that The determining, based on the corrected inductance and the average current, the disconnection duration of the switch tube serving as the main power tube in the power conversion circuit includes: determining a current change of the inductor during the current processing cycle according to the average current; The disconnection duration is determined according to the corrected inductance and the current change.

12. The method according to claim 11, characterized in that The average current includes at least one sub-average value, where the sub-average value refers to the average value of all inductor current sampling values ​​collected when the power conversion circuit is in the same state; and determining the current change of the inductor during the current processing cycle based on the average current includes: The maximum value of all sub-average values ​​in the average current is used as the current variation of the energy storage inductor during the current processing cycle.

13. The method according to claim 11, characterized in that The determining the disconnection duration according to the corrected inductance and the current change includes: The disconnection duration is calculated according to the working mode of the power conversion circuit, the corrected inductance and the current change.

14. The method according to claim 13, characterized in that The calculating the disconnection duration according to the working mode of the electric energy conversion circuit, the corrected inductance, and the current change includes: determining the electromotive force across the inductor according to the operating mode of the electric energy conversion circuit; The disconnection duration is calculated according to the electromotive force across the inductor, the corrected inductance, and the current change.

15. The method according to any one of claims 13-14, characterized in that The operating mode of the electric energy conversion circuit includes at least one of a boost mode, a buck mode, and a boost / buck mode.

16. The method according to claim 10, characterized in that The determining the corrected average current according to the disconnection duration includes: Comparing the disconnection time with a reference time to determine a comparison result, wherein the reference time is related to a duty cycle of a switch tube serving as a main power tube in the power conversion circuit; Based on the comparison result, the corrected average current is determined according to the average current.

17. The method according to claim 16, characterized in that The determining the corrected average current based on the comparison result and according to the average current includes: When the disconnection time is not less than the reference time, determining that the corrected average current is equal to the average current; When the disconnection time is shorter than the reference time, a correction coefficient is determined according to the disconnection time and the switching period, and the corrected average current is determined according to the correction coefficient and the average current.

18. The method according to any one of claims 2 to 17, characterized in that The first sampling frequency is 4N1 times the switching frequency, where N1 is a positive integer.

19. The method according to claim 18, characterized in that The first sampling frequency satisfies that the sampling moment determined at the first sampling frequency includes the midpoint of the conduction interval of the switch tube serving as the main power tube in the power conversion circuit.

20. The method according to any one of claims 3 to 17, characterized in that The current processing period is N2 times the switching period, where N2 is a positive integer.

21. The method according to any one of claims 1 to 17, wherein: The step of determining the input current of the power conversion circuit according to the inductor current includes: When the working mode of the power conversion circuit is the boost mode, the input current of the power conversion circuit is equal to the inductor current; When the working mode of the power conversion circuit is the buck mode, determining the input current of the power conversion circuit according to the conversion efficiency of the power conversion circuit and the inductor current; When the operation mode of the power conversion circuit is the step-up / step-down mode, the input current of the power conversion circuit is determined according to the switching period of the power conversion circuit and the inductor current.

22. The method according to any one of claims 1 to 21, characterized in that The electric energy conversion circuit is a DC-DC converter.

23. The method according to claim 22, characterized in that The DC-DC converter is a four-switch voltage converter.

24. A maximum power point tracking method, characterized in that: The method comprises: Obtaining the inductor current in the power conversion circuit; determining an input current of the power conversion circuit according to the inductor current; According to the input current of the power conversion circuit, the photovoltaic assembly connected to the input end of the power conversion circuit is controlled to operate at a maximum power point.

25. An input current determination device, characterized in that: The device includes a data acquisition module and a data processing module; The data acquisition module is used to obtain the inductor current of the energy storage inductor in the power conversion circuit; The data processing module is used to determine the input current of the power conversion circuit according to the inductor current.

26. A computer device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 24.

27. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 24 when executed by a processor.

28. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 24 when executed by a processor.

29. A vehicle, characterized in that: The vehicle includes an electric energy conversion circuit and a processing module, wherein the processing module is connected to the electric energy conversion circuit and is configured to execute the method steps according to any one of claims 1 to 24.

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