Bypass switching control method under multi-path MPPT working condition

Abstract

The invention discloses a bypass switching control method under a multi-path MPPT (Maximum Power Point Tracking) working condition, relates to the technical field of photovoltaic inverter control, and solves the problems of generating capacity loss and possible damage of a hardware circuit caused by a bypass switch in the prior art. The method comprises the following steps: acquiring a voltage value of a photovoltaic side in each path of MPPT topology and screening out a maximum value; switching a bypass mode or a non-bypass mode according to a comparison result of the maximum value and a first threshold value, independently controlling the working condition of each path of MPPT topology, and confirming a direct current bus voltage instruction value according to a preset strategy so as to enable the total input power of all MPPT topologies under the Bypass working condition to be maximum; the voltage at the two ends of the direct-current bus capacitor is controlled to be the direct-current bus voltage instruction value through the control algorithm, the problem that the generating capacity is reduced due to the fact that multiple Bypass working voltages are controlled by the same direct-current bus is solved, cost is reduced, and damage to a hardware circuit due to existence of a bypass switch is avoided.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic inverter control technology, and in particular to a bypass switching control method under multi-channel MPPT working conditions. Background Art

[0002] Most common inverters today are two-stage inverters, consisting of a front-stage DC / DC circuit and a back-stage DC / AC circuit. In a two-stage inverter topology, the front-stage DC / DC circuit primarily provides an operating voltage for the back-stage DC / AC circuit, referred to as the DC bus voltage Vdc. The back-stage circuit uses SPWM control to convert the DC bus voltage Vdc into the desired output AC voltage Vac. Because SPWM control cannot raise the output voltage Vac to the inverter's required value when Vdc is too low, the front-stage DC / DC circuit uses a boost circuit to raise the DC bus voltage Vdc. However, if the input voltage of the front-stage DC / DC circuit is too high, using the boost circuit will cause the DC bus voltage Vdc to be raised too high, making it difficult to control and placing higher hardware requirements. Therefore, the concept of bypass circuitry was introduced. A mechanical switch bypasses some components in the boost circuit, allowing the DC input voltage to be used directly as the input voltage for the DC / AC circuit without boosting it. Figure 2 shows a two-stage inverter topology with a bypass switch.

[0003] At present, the existing technical solutions for the bypass switching strategy of multiple MPPTs are mostly simultaneous switching of multiple channels, that is, multiple MPPTs work in Boost conditions at the same time or multiple MPPTs work in Bypass conditions at the same time. At this time, the photovoltaic side (i.e. PV) input voltage working in Bypass conditions is consistent with the DC bus voltage. However, the different configurations and environments of the input photovoltaic panels will cause some input photovoltaic panels to be unable to operate at the maximum power point, resulting in a loss of power generation.

[0004] In addition, in actual use, the bypass switch may be accidentally closed or closed due to external interference or human error, causing damage to the boost circuit. At the same time, the inrush current caused by the mechanical switch at the moment of closing and opening may damage the hardware circuit, and the frequent opening and closing of the mechanical switch also poses the risk of hardware damage. Summary of the Invention

[0005] The purpose of this application is to overcome the problems in the prior art that due to the simultaneous switching of multiple MPPT bypasses, the configuration and environment of the input photovoltaic panels are different, which may cause some input photovoltaic panels to be unable to operate at the maximum power point, resulting in loss of power generation, and the bypass switch may cause damage to the hardware circuit. A bypass switching control method under multi-channel MPPT working conditions is provided, which aims to realize multi-channel MPPT working in Boost working condition or Bypass working condition respectively by controlling the switch tube in the Boost circuit, saving the use of bypass switches, avoiding damage to the hardware circuit by the bypass switch, and also improving power generation.

[0006] In a first aspect, a bypass switching control method under multi-channel MPPT working conditions is provided, which is used to control a parallel circuit of a multi-channel MPPT topology, and the control method includes:

[0007] S100, obtaining the voltage values of the photovoltaic side in each MPPT topology, and screening out the maximum voltage value among the voltage values;

[0008] S200, comparing the maximum voltage value with a preset first threshold value, if the maximum voltage value is greater than the first threshold value, switching to the bypass mode, if the maximum voltage value is less than the first threshold value, switching to the non-bypass mode, wherein, in the bypass mode, at least one MPPT topology operates in the bypass condition, and in the non-bypass mode, all MPPT topologies operate in the boost condition;

[0009] S300, in bypass mode, comparing the absolute value of the difference between the voltage value in each MPPT topology and the maximum voltage value with a preset second threshold value; if the absolute value is greater than the second threshold value, the MPPT topology operates in a Boost condition; if the absolute value is less than the second threshold value, the MPPT topology operates in a Bypass condition;

[0010] S400: Determine the DC bus voltage command value according to a preset strategy so that the total input power of all MPPT topologies in the Bypass working condition is maximized;

[0011] S500: The MPPT topology operating under the Boost condition calculates the duty cycle through the voltage and current loop to raise the output voltage to the DC bus voltage command value; the MPPT topology operating under the Bypass condition is controlled by the DC bus voltage;

[0012] S600 , looping through steps S200 - S500 to perform bypass switching control.

[0013] In some possible implementations, the parallel circuit of the multi-channel MPPT topology is obtained by connecting multiple single-channel MPPT topologies in parallel, wherein the single-channel MPPT topologies all adopt a two-stage inverter topology without bypass, wherein no bypass means no bypass switch, and the bypass switch includes an ordinary switch or MOS tube, IGBT and other components.

[0014] In some possible implementations, the single-channel MPPT topology includes a photovoltaic side, a DC bus, and a voltage output side, wherein the positive electrode of the photovoltaic side is connected in series with a first inductor and a diode and then connected to the DC bus, the DC bus is connected in series with a first switch tube and a second inductor and then connected to the first end of the voltage output side, the DC bus is connected to the second end of the voltage output side through the second switch tube, the negative electrode of the photovoltaic side is connected to the end of the second inductor away from the voltage output side through the third switch tube, the negative electrode of the photovoltaic side is connected to the second end of the voltage output side through the fourth switch tube, a first capacitor is connected between the positive and negative electrodes of the photovoltaic side, and a second capacitor is connected between the DC bus and the negative electrode of the photovoltaic side, wherein the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube form an H-bridge circuit (i.e., a full-bridge inverter circuit), which is used to convert the DC power across the second capacitor into AC power on the voltage output side.

[0015] In some possible implementations, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, and the fifth switch tube are all MOSFETs or IGBTs.

[0016] In some possible implementations, under the Bypass operating condition, the fifth switch tube is blocked, the photovoltaic side and the DC bus are directly connected, and the photovoltaic side voltage is the same as the DC bus voltage; under the Boost operating condition, the fifth switch tube, the diode, the first capacitor and the first inductor constitute a Boost circuit, and the boost chopping is achieved through the duty cycle of the fifth switch tube. When the duty cycle increases, the output voltage increases, and when the duty cycle decreases, the output voltage decreases.

[0017] In some possible implementations, the preset strategy includes: if the difference between the maximum value and the minimum value of the input voltage in all MPPT topologies under the Bypass condition is less than a third threshold, then the minimum value of the input voltage in all MPPT topologies under the Bypass condition is used as the DC bus voltage command value; otherwise, the maximum value of the input voltage in all MPPT topologies under the Bypass condition is used as the DC bus voltage command value.

[0018] In some possible implementations, the third threshold is any value between 4V and 6V.

[0019] In a second aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method described in the first aspect.

[0020] In a third aspect, a computer-readable storage medium is provided, wherein the computer-readable medium stores program code for execution by a device, the program code including steps for executing the method in any one of the implementations of the first aspect.

[0021] In a fourth aspect, an electronic device is provided, comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements a method as in any one of the implementations of the first aspect described above.

[0022] This application has the following beneficial effects:

[0023] 1. This application determines whether each MPPT topology is generating power or not by comparing the voltage of the MPPT topology with the current maximum operating voltage of each MPPT topology, thereby avoiding the situation where all MPPT topologies are in the Bypass operating state, solving the problem of reduced power generation caused by the operating voltages of multiple Bypasses being controlled by the same DC bus, thereby improving the overall power generation. In addition, it saves the use of bypass switch components and reduces costs, and avoids the damage to the hardware circuit caused by the boost circuit being damaged due to the bypass switch being mistakenly closed due to external interference or human error, and avoids the damage to the hardware circuit caused by the impact current caused by the bypass switch at the moment of closing and opening.

[0024] 2. This application compares all the current working voltages under the Bypass operating condition. If they are all close, a certain point is selected as the DC bus voltage command value. At the same time, considering the general MPPT curve characteristics on this basis, the minimum value among the close working voltages is selected as the DC bus voltage command value. To a certain extent, this solves the problem of reduced power generation caused by multiple Bypass working voltages being controlled by the same DC bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings that constitute a part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application.

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 This is a flow chart of the bypass switching control method under multi-channel MPPT working conditions of Example 1 of the present application;

[0028] Figure 2 This is a topology diagram of a two-stage inverter with a bypass switch in the prior art;

[0029] Figure 3 1 is a parallel circuit diagram of a multi-channel MPPT topology in the bypass switching control method under a multi-channel MPPT working condition in Example 1 of the present application;

[0030] Figure 4 This is a single-channel MPPT topology diagram in the bypass switching control method under the multi-channel MPPT working condition of Example 1 of the present application;

[0031] Figure 5 This is a schematic diagram of the internal structure of the electronic device of Example 4 of the present application. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1

[0034] like Figure 1 As shown, the bypass switching control method under multi-channel MPPT working conditions involved in Example 1 of the present application specifically includes the following steps:

[0035] In this embodiment, the bypass switching control method under multi-channel MPPT working conditions is used to control the parallel circuit of multi-channel MPPT topology, such as Figure 3 As shown, the parallel circuit of the multi-channel MPPT topology is obtained by connecting multiple single-channel MPPT topologies in parallel.

[0036] In this embodiment, a two-stage inverter topology without a bypass switch (including ordinary switches or MOS tubes, IGBTs and other components) is adopted. Figure 4As shown, a single-channel MPPT topology includes a photovoltaic side, a DC bus, and a voltage output side, wherein the positive electrode of the photovoltaic side PV is connected in series with a first inductor L1 and a diode D and then connected to the DC bus, the DC bus is connected in series with a first switch tube Q1 and a second inductor L2 and then connected to the first end of the voltage output side VOUT, the DC bus is connected to the second end of the voltage output side VOUT through the second switch tube Q2, the negative electrode of the photovoltaic side PV is connected to the end of the second inductor L2 away from the voltage output side VOUT through the third switch tube Q3, and the negative electrode of the photovoltaic side PV is connected to the DC bus through the fourth switch tube Q4. A first capacitor C1 is connected to the second end of the voltage output side VOUT, and a second capacitor C2 is connected between the positive and negative electrodes of the photovoltaic side PV. The DC bus is connected to the negative electrode of the photovoltaic side PV. The first switching tube Q1, the second switching tube Q2, the third switching tube Q3, the fourth switching tube Q4, and the fifth switching tube Q5 are all MOSFETs or IGBTs. The first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fourth switching tube Q4 form an H-bridge circuit, which is used to convert DC power across the second capacitor C2 into AC power for the voltage output side VOUT.

[0037] When the DC / DC converter needs to operate in Boost mode, the circuit on the left side of the DC bus, consisting of the fifth switch Q5, diode D, first capacitor C1, and first inductor L1, forms a Boost circuit. Boost chopping is achieved by controlling the duty cycle of the fifth switch Q5. When the duty cycle increases, the output voltage increases, and when the duty cycle decreases, the output voltage decreases. When the DC / DC converter needs to operate in Bypass mode, the fifth switch Q5 is disabled, and a direct connection is established between the photovoltaic side (i.e., the PV input side) and the DC bus. Boost chopping is not performed, and the PV side input voltage is now the same as the DC bus output voltage.

[0038] like Figure 4 As shown, it is a single-channel MPPT topology diagram, which can be extended to a parallel circuit of multiple MPPT topologies on this basis. In this embodiment, the MPPT working mode is defined as two modes. The first is the bypass mode. In this mode, at least one MPPT topology works in the bypass condition (that is, at least one does not perform boost chopping); the second is the non-bypass mode. In this mode, all MPPT topologies work in the boost condition (that is, all DC / DC conversion circuits work and perform boost chopping). In this case, each MPPT works normally independently. Since the focus of this application is to solve the problem that when multiple channels work in the bypass condition, the input voltage is controlled by the DC bus voltage and cannot reach the maximum power point, the control method of the second mode (that is, the non-bypass mode) is not discussed in this embodiment.

[0039] First, wait for the device to be powered on and working, and MPPT to start tracking. Figure 1As shown, the following bypass switching control method is performed for MPPT tracking:

[0040] S100, obtain the voltage value (i.e., input voltage) on the photovoltaic side of each MPPT topology, and filter out the maximum voltage value among the voltage values. In this embodiment, taking the N-way MPPT two-stage topology as an example, first obtain and record the current working voltage of each MPPT, i.e., the input voltage on the PV side (photovoltaic side), respectively recorded as V pv1 、V pv2 、V pv3 ...V pvn , record the maximum value of the input voltage by comparison and record it as V max , that is, V max V pv1 、V pv2 、V pv3 ...V pvn The maximum value in .

[0041] S200, comparing the maximum voltage value V max and the preset first threshold V set The size of V max >V set , then switch to bypass mode, if V max <V set , then switch to the non-bypass module, that is, comparison, where, in bypass mode, at least one MPPT topology works in the Bypass condition, and in non-bypass mode, all MPPT topologies work in the Boost condition.

[0042] S300: When the MPPT operates in bypass mode, first, a second threshold V is set according to the characteristics of the hardware components. diff , the second threshold V diff It is used to determine whether the difference between the current photovoltaic side voltage (i.e. input voltage) and the maximum value of each photovoltaic side voltage (i.e. input voltage) is too large. diff If the setting is too small, the DC / DC circuit with a larger voltage on the photovoltaic side will work in Boost mode, which may easily cause DC bus jitter and DC bus overvoltage. diff If the setting is too large, the DC / DC circuit input voltage with a smaller photovoltaic side voltage will be pulled up by the DC bus voltage, resulting in lower input power and affecting the power generation. diff Then, the working conditions of each MPPT are judged, that is, the absolute value of the difference between the voltage value in each MPPT topology and the maximum voltage value is compared with the size of the preset second threshold value V. diff , if the absolute value is greater than the second threshold, ie IV pvi -V max Ⅰ>V diff, where i=1, 2, 3...n, the MPPT topology works in Boost mode; if the absolute value is less than the second threshold, that is, IV pvi -V max Ⅰ <V diff , where i=1, 2, 3...n, the MPPT topology of this path works in the Bypass condition, and step S300 is repeated until all N MPPT conditions are confirmed.

[0043] In the Bypass operating condition, the fifth switch tube is blocked, the photovoltaic side and the DC bus are directly connected, and the photovoltaic side voltage is the same as the DC bus voltage. In the Boost operating condition, the fifth switch tube Q5, the diode D, the first capacitor C1 and the first inductor L1 form a Boost circuit, and the boost chopping is realized through the duty cycle of the fifth switch tube Q5. When the duty cycle increases, the output voltage increases, and when the duty cycle decreases, the output voltage decreases.

[0044] S400: Determine the DC bus voltage command value according to a preset strategy so that the total input power of all MPPT topologies in the Bypass working condition is maximized.

[0045] Since the input voltage of the MPPT topology working under the Bypass condition is controlled by the DC bus voltage, it is necessary to confirm a DC bus voltage value that maximizes the total input power of the MPPT topology under the Bypass condition. In this embodiment, the strategy is as follows: if the input voltages of all the paths under the Bypass condition are close, the maximum value minus the minimum value of all the input voltages is subtracted to obtain the difference. If the difference is less than the third threshold, the minimum value V is taken. min As the DC bus voltage command value V dcref If not all input voltages are close, then the maximum value V max As the DC bus voltage command value V dcref Finally, the voltage across the DC bus capacitor is controlled to V dcref By comparing all the current working voltages under the Bypass working condition, if they are all close, a certain point is taken as the bus voltage command value. At the same time, considering the general MPPT curve characteristics on this basis, the minimum value among the close working voltages is selected as the bus voltage command value. To a certain extent, it solves the problem of reduced power generation caused by multiple Bypass working voltages being controlled by the same bus.

[0046] For example, if there are 4 MPPTs in Bypass mode and the third threshold is 4V, if |V pv1 -V pv2 |<4V,|V pv1 -V pv3 |<4V,|V pv1-V pv4 |<4V,|V pv2 -V pv3 |<4V,|V pv2 -V pv4 |<4V,|V pv3 -V pv4 |<4V, it is considered that all bypass circuit input voltages are close, and the minimum value is taken as the DC bus voltage command value V dcref .

[0047] For example, if there are 4 MPPTs in Bypass mode and the third threshold is 5V, if |V pv1 -V pv2 |<5V,|V pv1 -V pv3 |<5V,|V pv1 -V pv4 |<5V,|V pv2 -V pv3 |<5V,|V pv2 -V pv4 |<5V,|V pv3 -V pv4 |<5V, it is considered that all bypass circuit input voltages are close, and the minimum value is taken as the DC bus voltage command value V dcref .

[0048] For example, if there are 4 MPPTs in Bypass mode and the third threshold is 6V, if |V pv1 -V pv2 |<6V,|V pv1 -V pv3 |<6V,|V pv1 -V pv4 |<6V,|V pv2 -V pv3 |<6V,|V pv2 -V pv4 |<6V,|V pv3 -V pv4 |<6V, it is considered that all bypass circuit input voltages are close, and the minimum value is taken as the DC bus voltage command value V dcref .

[0049] S500, the MPPT topology working under the boost condition calculates the duty cycle through the voltage and current loop to raise the output voltage to the DC bus voltage command value V obtained from the above step S400. dcref; In the MPPT topology working under the Bypass condition, the fifth switch tube Q5 does not generate ripple, the input voltage is controlled by the DC bus, and the input power is directly supplied to the DC bus.

[0050] S600: Repeat steps S200-S500 to continuously cycle through the bypass switching logic control.

[0051] Compared with the common control algorithms in the prior art, the advantage of this embodiment is that, first, by comparing the voltage of the MPPT topology with the current maximum operating voltage of each MPPT topology, it is determined whether each MPPT topology is emitting waves, thereby avoiding the situation where all MPPT topologies are in the Bypass working condition, and realizing independent control of multiple MPPTs to bypass or not. Compared with the common all-MPPT unified control of bypass or not on the market, independent control can make each input work near the maximum power point, so that the equipment has higher power generation efficiency; at the same time, the bypass switch tube is abandoned, reducing costs while avoiding the risk of hardware damage caused by the instantaneous impact of the bypass diode switch, and avoiding the damage to the hardware circuit caused by the boost circuit being damaged due to external interference or human error.

[0052] Example 2

[0053] A computer program product involved in Example 2 of the present application is used to store a computer program. When the computer program runs on a computer, the method in any one of the implementation methods in Example 1 of the present application is implemented.

[0054] Example 3

[0055] A computer-readable storage medium according to embodiment 3 of the present application, wherein the computer-readable storage medium stores program code for execution by a device, the program code including steps for executing the method in any one of the implementations in embodiment 1 of the present application;

[0056] Among them, the computer-readable storage medium can be a read-only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM); the computer-readable storage medium can store program code, and when the program stored in the computer-readable storage medium is executed by the processor, the processor is used to execute the steps of the method in any one of the implementation methods in Example 1 of the present application.

[0057] Example 4

[0058] like Figure 5As shown, an electronic device involved in Example 4 of the present application includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the method in any one of the implementations in Example 1 of the present application;

[0059] Among them, the processor can adopt a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), a graphics processing unit (GPU) or one or more integrated circuits to execute relevant programs to implement the method in any one of the implementation methods in Example 1 of the present application.

[0060] The processor may also be an integrated circuit electronic device with signal processing capabilities. In the implementation process, each step of the method in any one of the implementations in Example 1 of the present application may be completed by hardware integrated logic circuits in the processor or software instructions.

[0061] The above-mentioned processor can also be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or being executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in combination with its hardware, completes the functions required to be executed by the units included in the data processing device of the embodiment of the present application, or executes the method in any one of the implementation modes in Example 1 of the present application.

[0062] The above are only preferred specific implementations of this application; however, the scope of protection of this application is not limited thereto. Any person skilled in the art who, within the technical scope disclosed in this application, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of this application shall be covered by the scope of protection of this application.

Claims

1. A bypass switching control method under multi-channel MPPT working conditions, characterized in that: A parallel circuit for controlling a multi-channel MPPT topology, the control method comprising: S100, obtaining the voltage values of the photovoltaic side in each MPPT topology, and screening out the maximum voltage value among the voltage values; S200, comparing the maximum voltage value with a preset first threshold value, if the maximum voltage value is greater than the first threshold value, switching to the bypass mode, if the maximum voltage value is less than the first threshold value, switching to the non-bypass mode, wherein, in the bypass mode, at least one MPPT topology operates in the bypass condition, and in the non-bypass mode, all MPPT topologies operate in the boost condition; S300, in bypass mode, comparing the absolute value of the difference between the voltage value in each MPPT topology and the maximum voltage value with a preset second threshold value; if the absolute value is greater than the second threshold value, the MPPT topology operates in a Boost condition; if the absolute value is less than the second threshold value, the MPPT topology operates in a Bypass condition; S400: Determine the DC bus voltage command value according to a preset strategy so that the total input power of all MPPT topologies in the Bypass working condition is maximized; S500: The MPPT topology operating under the Boost condition calculates the duty cycle through the voltage and current loop to raise the output voltage to the DC bus voltage command value; the MPPT topology operating under the Bypass condition is controlled by the DC bus voltage; S600 , looping through steps S200 - S500 to perform bypass switching control.

2. The bypass switching control method under multi-channel MPPT working conditions according to claim 1 is characterized in that: The parallel circuit of the multi-channel MPPT topology is obtained by connecting multiple single-channel MPPT topologies in parallel, wherein the single-channel MPPT topologies all adopt a two-stage inverter topology without bypass.

3. The bypass switching control method under multi-channel MPPT working conditions according to claim 2 is characterized in that: The single-channel MPPT topology includes a photovoltaic side, a DC bus and a voltage output side, wherein the positive pole of the photovoltaic side is connected in series with a first inductor and a diode and then connected to the DC bus, the DC bus is connected in series with a first switch tube and a second inductor and then connected to the first end of the voltage output side, the DC bus is connected to the second end of the voltage output side through the second switch tube, the negative pole of the photovoltaic side is connected to the end of the second inductor away from the voltage output side through the third switch tube, the negative pole of the photovoltaic side is connected to the second end of the voltage output side through the fourth switch tube, a first capacitor is connected between the positive and negative poles of the photovoltaic side, and a second capacitor is connected between the DC bus and the negative pole of the photovoltaic side.

4. The bypass switching control method under multi-channel MPPT working conditions according to claim 3 is characterized in that: The first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the fifth switch tube are all MOSFETs or IGBTs.

5. The bypass switching control method under multi-channel MPPT working conditions according to claim 3 or 4, characterized in that: In the Bypass operating condition, the fifth switch tube is blocked, the photovoltaic side and the DC bus are directly connected, and the photovoltaic side voltage is the same as the DC bus voltage; in the Boost operating condition, the fifth switch tube, the diode, the first capacitor and the first inductor form a Boost circuit, and the boost chopping is achieved through the duty cycle of the fifth switch tube. When the duty cycle increases, the output voltage increases, and when the duty cycle decreases, the output voltage decreases.

6. The bypass switching control method under multi-channel MPPT working conditions according to claim 1 is characterized in that: The preset strategy includes: if the difference between the maximum value and the minimum value of the input voltage in all MPPT topologies under the Bypass condition is less than a third threshold, the minimum value of the input voltage in all MPPT topologies under the Bypass condition is used as the DC bus voltage command value; otherwise, the maximum value of the input voltage in all MPPT topologies under the Bypass condition is used as the DC bus voltage command value.

7. The bypass switching control method under multi-channel MPPT working conditions according to claim 6 is characterized in that: The third threshold is any value between 4V and 6V.

8. A computer program product, characterized in that The computer program product stores computer instructions, and when the computer instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores program codes for execution by a device, wherein the program codes include steps for executing the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the method according to any one of claims 1 to 7.

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