A photovoltaic panel reverse self-heating snow removal system and method

Abstract

This invention discloses a photovoltaic panel reverse self-heating snow removal system and method, relating to the fields of photovoltaic power generation and automatic maintenance technology. It includes a status monitoring unit for real-time acquisition of electrical output parameters and external environmental parameters of the photovoltaic module array; and a power control unit, whose input is connected to the energy source and whose output is connected to the DC bus of the photovoltaic module array. This invention constructs a full-process control logic of "monitoring and judgment – ​​safety isolation – reverse injection – monitoring and reset," providing a low-impedance path for reverse current using a switching unit without altering the original power generation topology. This effectively overcomes the blocking effect of traditional anti-reverse current diodes, achieving safe, controllable, and uniform injection of reverse current into the photovoltaic module cell string, thus addressing the lack of systematic solutions in existing technologies.

Description

Technical Field

[0001] This invention relates to photovoltaic power generation and automatic maintenance technology, specifically to a photovoltaic panel reverse self-heating snow removal system and method. Background Technology

[0002] In cold and snowy regions, snow accumulation on the surface of photovoltaic modules can severely hinder the absorption of light energy, leading to a sharp reduction in power generation or even zero. Existing snow removal methods, such as manual sweeping and mechanical scraping, suffer from low efficiency, high cost, damage to the module surface, and insufficient automation. In recent years, the idea of ​​using electric heating to melt snow has emerged. However, existing technical solutions mostly rely on external heating films, heating cables, or require complex external power supply systems, which have drawbacks such as high energy consumption, low integration, uneven heating, and poor compatibility with the original photovoltaic power generation system.

[0003] In particular, the "reverse self-heating" technology, which utilizes the photovoltaic panel itself as a heat source, has attracted much attention because it can achieve energy closed loop and system self-consistency. However, this technology has long faced a fundamental engineering challenge: how to safely, controllably, and uniformly inject reverse current into the photovoltaic panel battery string without changing the original power generation topology or adding complex external heating circuits, while effectively overcoming the blocking effect of traditional anti-reverse current diodes. Existing publicly available technologies lack independent bypass on / off control mechanisms and strict safety isolation handshake procedures. Forcibly injecting reverse current can easily lead to diode damage, module overvoltage breakdown, or inverter failure, failing to provide a complete, reliable, and economical system solution.

[0004] To address these issues, the applicant proposes a photovoltaic panel reverse self-heating snow removal system and method. Summary of the Invention

[0005] The purpose of this invention is to provide a photovoltaic panel reverse self-heating snow removal system and method to solve the problems of existing reverse self-heating technology which is difficult to safely overcome the blocking of anti-reverse current diodes to achieve uniform heating without changing the topology, lack of independent bypass on / off control and safety isolation handshake process, and easy damage to diodes, photovoltaic module overvoltage breakdown or inverter failure due to forced injection of reverse current, and there is no reliable system solution yet.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic panel reverse self-heating snow removal system, comprising:

[0007] The status monitoring unit is used to collect the electrical output parameters and external environmental parameters of the photovoltaic module array in real time;

[0008] A power control unit has its input end connected to the energy source and its output end connected to the DC bus of the photovoltaic module array. The power control unit has a first operating mode and a second operating mode. In the first operating mode, the power control unit is used to execute a maximum power point tracking algorithm to deliver photovoltaic power to the load or the power grid. In the second operating mode, the power control unit is used as a controllable DC power source to draw power from the energy source and output reverse power to the DC bus.

[0009] A number of switching units are respectively set in the output circuit of each photovoltaic module in the photovoltaic module array; each switching unit is controlled by a control signal and can switch between a shutdown state and a conduction state; in the shutdown state, the switching unit is used to allow the photovoltaic module to output the power generation current normally and block the reverse current; in the conduction state, the switching unit is used to provide a low impedance path for the reverse heating current to flow through the internal cells of the photovoltaic module.

[0010] The system control unit is communicatively connected to the status monitoring unit, the power control unit, and all on / off units. The system control unit is used to determine whether the preset snow removal conditions are met based on the data collected by the status monitoring unit. If the preset snow removal conditions are met, the system control unit controls the power control unit to switch to the second working mode and controls all on / off units to switch to the on state, so as to force the reverse current to flow evenly through each photovoltaic module to generate Joule heat.

[0011] A photovoltaic panel reverse self-heating snow removal system includes:

[0012] The status monitoring unit is used to collect the electrical output parameters and external environmental parameters of the photovoltaic module array in real time;

[0013] A power control unit has its input end connected to the energy source and its output end connected to the DC bus of the photovoltaic module array. The power control unit has a first operating mode and a second operating mode. In the first operating mode, the power control unit is used to execute a maximum power point tracking algorithm to deliver photovoltaic power to the load or the power grid. In the second operating mode, the power control unit is used as a controllable DC power source to draw power from the energy source and output reverse power to the DC bus.

[0014] A number of switching units are respectively set in the output circuit of each photovoltaic module in the photovoltaic module array; each switching unit is controlled by a control signal and can switch between a shutdown state and a conduction state; in the shutdown state, the switching unit is used to allow the photovoltaic module to output the power generation current normally and block the reverse current; in the conduction state, the switching unit is used to provide a low impedance path for the reverse heating current to flow through the internal cells of the photovoltaic module.

[0015] The system control unit is communicatively connected to the status monitoring unit, the power control unit, and all on / off units. The system control unit is used to determine whether the preset snow removal conditions are met based on the data collected by the status monitoring unit. If the preset snow removal conditions are met, the system control unit controls the power control unit to switch to the second working mode and controls all on / off units to switch to the on state, so as to force the reverse current to flow evenly through each photovoltaic module to generate Joule heat.

[0016] A method for snow removal using a photovoltaic panel with reverse self-heating includes the following steps:

[0017] S1. Multidimensional status monitoring and trigger judgment: Receive the electrical output parameters and external environmental parameters of the photovoltaic module array collected by the status monitoring unit, and generate a snow removal command when it is determined that the electrical output parameters and external environmental parameters meet the preset snow removal conditions;

[0018] S2. System safety isolation and mode switching: In response to the snow removal command, disconnect the electrical connection between the photovoltaic module array and the inverter, and control the power control unit to switch from the first working mode to the second working mode;

[0019] S3. Reverse current injection and uniform heating: In the second working mode, the power control unit is controlled to obtain electrical energy from the energy end and output reverse electrical energy to the DC bus, while all switching units are controlled to switch to the on state, so as to force the reverse current to flow through the internal cells of the photovoltaic module to generate Joule heat.

[0020] S4. Dynamic process monitoring and automatic reset: During the heating process, the feedback parameters characterizing the snow melting progress are monitored in real time. When it is determined that the feedback parameters meet the snow removal termination conditions, the power control unit is controlled to stop reverse output, all on / off units are restored to the off state, and the system is controlled to return to the normal power generation standby state.

[0021] Further, in step S1, determining that the electrical output parameters and external environmental parameters meet the preset snow removal conditions includes:

[0022] Acquire real-time power data from the electrical output parameters, and ambient temperature data and weather forecast data from the external environmental parameters;

[0023] Pre-defined logic judgment operations are performed on the real-time power data, ambient temperature data, and weather forecast data;

[0024] If the real-time power data is lower than the first power threshold, and the ambient temperature data is lower than the freezing point threshold, or the weather forecast data indicates snowfall, then the preset snow removal conditions are determined to be met.

[0025] Further, in step S2, disconnecting the electrical connection between the photovoltaic module array and the inverter includes:

[0026] Generate a system safety isolation command and send it to the inverter;

[0027] Receive the disconnection confirmation signal returned by the inverter;

[0028] The step of controlling the power control unit to switch from the first operating mode to the second operating mode is executed only after receiving the disconnection confirmation signal.

[0029] Further, in step S3, controlling the power control unit to obtain electrical energy from the energy source includes:

[0030] Obtain the remaining power data of the energy source;

[0031] Determine whether the remaining battery power is less than a preset battery power threshold;

[0032] If so, the power control unit is controlled to draw power from an external power source or the grid interface, and the period of outputting reverse power is limited to low-cost power supply periods or periods of low electricity prices.

[0033] If not, the power control unit is controlled to draw power from the energy storage battery unit.

[0034] Further, in step S3, controlling all on / off units to switch to the on state includes:

[0035] Send synchronous heating preparation command to all on / off units;

[0036] Receive status confirmation signals returned by each on / off unit;

[0037] Count the number of on / off units that return confirmation signals;

[0038] The power control unit is controlled to start outputting reverse electrical energy only when the quantity reaches a preset proportional threshold.

[0039] Furthermore, in step S3, controlling the power control unit to output reverse electrical energy further includes:

[0040] Obtain the reverse withstand voltage threshold and safety margin of a single module in the photovoltaic module array;

[0041] Calculate the maximum allowable total reverse voltage of the system;

[0042] The output of the power control unit is adjusted so that the absolute value of the reverse voltage applied to the DC bus is dynamically limited within the range of the maximum total reverse voltage.

[0043] Furthermore, in step S4, the feedback parameter characterizing the snow melting progress includes at least one of the following:

[0044] The total heating current of the DC bus, the current balance of each branch, the heating duration, or the snow coverage obtained through image recognition.

[0045] Further, in step S4, determining that the feedback parameter meets the snow removal termination condition includes any one of the following:

[0046] The total heating current is monitored to rise and stabilize above the preset snow melting completion current threshold for a set duration;

[0047] The monitoring showed that the heating duration had reached the maximum permissible safe duration;

[0048] Alternatively, image recognition can be used to confirm that the snow cover has dropped to zero or below a preset low threshold.

[0049] Further, in step S4, the control system returns to the normal power generation standby state, including:

[0050] Control the power control unit to switch back to the first operating mode;

[0051] Generate a power generation recovery command to close the electrical connection between the photovoltaic module array and the inverter;

[0052] The maximum power point tracking algorithm is executed to restore normal power generation of the system.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] This invention proposes a complete, closed-loop, and automated reverse self-heating snow removal solution for photovoltaic panels. By constructing a full-process control logic of "monitoring and judgment - safety isolation - reverse injection - monitoring and reset", it provides a low-impedance path for reverse current using switching units without changing the original power generation topology. This effectively overcomes the blocking effect of traditional anti-reverse current diodes and realizes safe, controllable, and uniform injection of reverse current into the photovoltaic module cell string, solving the lack of systematic solutions in existing technologies.

[0055] This invention fully utilizes and upgrades the core power equipment of existing photovoltaic systems. It only requires replacing the conventional controller with a power control unit with bidirectional flow function and using the switching unit to replace the traditional bypass diode to achieve the snow removal function. This design avoids the complex installation of external heating film, heating cable and independent power supply system, greatly reducing the additional hardware cost and construction difficulty, while maintaining the original neat appearance and high integration of the photovoltaic array.

[0056] This invention establishes multiple safety mechanisms to ensure reliable operation during snow removal. By designing a strict safety sequence logic of "first isolating the power grid, then switching modes, and finally powering on for heating," the risk of reverse high voltage impacting the inverter or backflow into the power grid is effectively avoided. At the same time, by utilizing the real-time status feedback of the switching unit and the dynamic voltage limiting function of the power control unit, the system can instantly identify anomalies and prevent local overheating or component overvoltage breakdown, thus ensuring the safety of the power grid, energy storage equipment, and photovoltaic modules themselves.

[0057] This invention combines intelligent decision-making with efficient energy management. Based on an intelligent judgment algorithm that integrates multi-source data such as sunlight, temperature, power, and weather forecasts, the system can accurately identify snow accumulation and avoid accidental startup. During the heating process, by monitoring feedback parameters such as total heating current, current balance, or snow coverage in real time, the system can adaptively adjust the heating strategy and automatically terminate and resume power generation the moment the snow is cleared. This closed-loop control strategy improves thermal energy utilization, recovers power generation losses with lower energy consumption, and enhances the overall operational efficiency of photovoltaic power plants in cold regions. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0059] Figure 1 This is a schematic diagram of the overall process provided for an embodiment of the present invention;

[0060] Figure 2 This is a schematic diagram of step S1 provided in an embodiment of the present invention;

[0061] Figure 3 This is a schematic diagram of step S2 provided in an embodiment of the present invention;

[0062] Figure 4 This is a flowchart illustrating step S3 provided in an embodiment of the present invention;

[0063] Figure 5 This is a schematic diagram of step S4 provided in an embodiment of the present invention. Detailed Implementation

[0064] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0065] As attached Figure 1 To be continued Figure 5 As shown:

[0066] Example 1:

[0067] This embodiment provides a specific hardware architecture for a photovoltaic panel reverse self-heating snow removal system. This system can be flexibly applied to various photovoltaic arrays composed of several photovoltaic modules connected in series (e.g., a 5 kW array composed of 10 modules connected in series).

[0068] In this embodiment, the specific hardware selection and connection relationships of each functional unit are as follows:

[0069] The status monitoring unit consists of an environmental sensor (for detecting temperature, light intensity, and humidity), a DC-side meter (for detecting voltage, current, and power), and an optional meteorological data interface, enabling multi-dimensional data acquisition.

[0070] The power control unit specifically selects a controller with bidirectional energy flow capability (such as a bidirectional maximum power point tracking controller or a bidirectional DC / DC converter). This unit integrates a bidirectional conversion circuit and supports switching between two operating modes via software configuration: in the first operating mode, it executes a conventional maximum power point tracking algorithm to deliver photovoltaic power to the load or energy storage device; in the second operating mode, it acts as a controllable constant voltage or constant current source, drawing power from the energy source and outputting a preset reverse DC power to the DC bus.

[0071] The switching unit specifically employs a distributed intelligent control module, with each module corresponding to one another in the output circuit of each photovoltaic module (typically connected in parallel between the positive and negative terminals of the module's output). Each switching unit integrates a low-on-resistance power switching device (such as a metal-oxide-semiconductor field-effect transistor), a high-precision current sampling circuit, a local microcontroller, and a communication interface. In normal power generation mode (off state), this unit allows forward current to flow through the photovoltaic module while blocking reverse current; in heating mode (on state), the local microcontroller receives a command to force the power switching device to fully conduct, forming an extremely low-impedance path, forcing a large reverse current to flow through the cell strings inside the photovoltaic module, thereby effectively overcoming the blocking effect of traditional anti-reverse current diodes.

[0072] Depending on the application scenario, the energy source can be configured as an energy storage battery pack, a public power grid interface, or a diesel generator interface.

[0073] The functions of the system control unit can be integrated into the host computer management system of the power control unit, or implemented through an independent controller. It establishes communication connections with all on / off units through a communication bus and interacts with the inverter or load management device.

[0074] Special Note: The system architecture constructed in this embodiment has high topology adaptability, and its core control logic and hardware connection method are not limited to grid-connected or off-grid inverters. Whether it is a grid-connected system connected to the public power grid, an independently operating off-grid system, or a hybrid microgrid system, the reverse self-heating snow removal function can be realized through the hardware architecture described in this embodiment. Only adaptive adjustments need to be made to the system control strategy for different topologies.

[0075] Example 2:

[0076] This embodiment provides a specific execution flow of a photovoltaic panel reverse self-heating snow removal method. This method can be applied to any type of system (grid-connected or off-grid) as described in Embodiment 1. Its core lies in strict timing control and multiple judgment logic, aiming to solve the safety hazards mentioned in the background art.

[0077] The method in this embodiment specifically includes the following steps:

[0078] Step S1: Multi-dimensional state monitoring and trigger judgment

[0079] The system collects the electrical output parameters of the photovoltaic array and external environmental parameters in real time.

[0080] The specific judgment logic is as follows: when the real-time power is lower than the first power threshold, and the ambient temperature is lower than the freezing point threshold, or when weather forecast data indicates snowfall, the preset snow removal conditions are met, and a snow removal command is generated. This step, through multi-source data fusion, effectively avoids invalid startup caused by misjudgment of a single parameter.

[0081] Step S2: System security isolation and mode switching

[0082] In response to the snow removal command, the system first executes a strict safety isolation procedure:

[0083] For grid-connected systems: Send a shutdown command to the grid-connected inverter and wait to receive a "disconnection confirmation signal" from the inverter. Subsequent operations will only be performed after receiving this disconnection confirmation signal.

[0084] For off-grid systems: send a disconnect command to the load-side contactor (if the load is sensitive to reverse voltage), or confirm that the load has been switched to bypass power supply mode to ensure that reverse current does not flow through the sensitive load.

[0085] After completing the above isolation confirmation, the system controls the power control unit to switch from the first operating mode to the second operating mode (such as constant voltage output mode) and sets the target reverse voltage value (this value is lower than the component's allowable reverse withstand voltage threshold and safety margin). Simultaneously, a "prepare to heat" command is sent to all on / off units. This step establishes the ironclad safety rule of "isolate first, confirm, then heat."

[0086] Step S3: Reverse current injection and uniform heating

[0087] In the second operating mode, the system controls the power control unit to obtain electrical energy from the energy source and apply a reverse voltage to the DC bus. The system sends a synchronous heating preparation command to all switching units, counts the number of switching units that return status confirmation signals, and only controls all switching units to synchronously switch to the on state after the number of confirmations reaches a preset proportional threshold. At this time, the reverse current is forced to flow sequentially through the cell strings of each photovoltaic module, using the Joule effect to rapidly heat the cells themselves.

[0088] The heating monitoring strategy is as follows: real-time monitoring of total current changes and current balance of each branch; if an abnormal current is detected in a branch, the branch is determined to be faulty and the output is immediately cut off to prevent local overheating.

[0089] Step S4: Dynamic process monitoring and automatic reset

[0090] The system calculates feedback parameters that characterize the snow melting progress in real time.

[0091] The termination condition is determined by any of the following:

[0092] (1) The total heating current rises and stabilizes above the preset threshold for a set duration;

[0093] (2) The heating duration reaches the maximum permissible safe duration;

[0094] (3) Image recognition confirmed that the snow cover rate dropped to zero.

[0095] When any of the above conditions are met, the system performs a reset operation: the control power control unit stops reverse output -> all switching units are restored to the off state -> the electrical connection between the photovoltaic module array and the inverter / load is closed -> the control power control unit switches back to the first operating mode -> the system resumes normal power generation or supply.

[0096] Example 3:

[0097] This embodiment provides an application method for a photovoltaic panel reverse self-heating snow removal system in an off-grid, independent operation scenario. This embodiment is applied to communication base stations, pastoral monitoring stations, or off-grid residential photovoltaic systems in remote areas without grid connection, focusing on solving snow removal problems under energy-constrained conditions.

[0098] In this embodiment, the system topology is as follows: the photovoltaic module array is directly connected to the off-grid bidirectional power control unit, which simultaneously manages the charging and discharging of the energy storage battery pack and the DC bus voltage, and is connected to a DC load or an off-grid inverter at the back end.

[0099] The snow removal method in this embodiment has been adapted for off-grid environments:

[0100] During the triggering and judgment phase, the system, based on the assessment of snow accumulation conditions, adds priority judgments on the remaining power of the energy storage battery pack and the current load power demand. The triggering logic is adjusted to generate a snow removal command only when the snow accumulation conditions are met and the remaining power of the energy storage battery pack is greater than the "snow removal reserved threshold" (e.g., remaining power percentage greater than 40%). If the power is insufficient, the system enters a "low-power keep-alive mode," suspending snow removal to prevent the system from paralyzing due to depletion of power during snow removal.

[0101] During the safety isolation phase, in response to snow removal commands, the system performs safety isolation for the off-grid topology: if the DC load is sensitive to reverse voltage, the load-side contactor is temporarily disconnected, or the load is switched to a bypass circuit directly powered by the energy storage battery pack. After confirming that the load isolation is complete, the power control unit is forcibly switched from "PV charging / inverter mode" to "battery discharging / reverse constant current source mode".

[0102] During the reverse current injection phase, considering the limited battery capacity of the off-grid system, the system adopts a "dynamic current-limiting heating" strategy. The system dynamically sets the upper limit of the reverse current based on the current remaining battery charge (for example, outputting the rated current when the remaining charge is high and reducing the current when the remaining charge is low) to avoid a sudden drop in bus voltage due to high current causing system protection shutdown. At the same time, the battery terminal voltage is monitored in real time, and heating is immediately suspended if the voltage drops to the minimum protection threshold.

[0103] During the dynamic process monitoring and reset phase, the termination judgment logic adds a "power depletion warning" as a mandatory termination condition: if the remaining battery power drops to a critical value (e.g., 20%) during the heating process, heating will be forcibly stopped immediately regardless of whether the snow has been cleared. Furthermore, in off-grid scenarios, once the module output power is detected to have recovered to a level sufficient to charge the battery (even if the snow has not been completely cleared), high-power heating can be terminated in advance, switching to micro-current heating using the photovoltaic power generated by the photovoltaic system itself, thus achieving self-replenishment of energy.

[0104] This embodiment demonstrates that even in extreme environments without grid support, the present invention can still achieve effective snow removal using limited energy storage resources through refined energy management and security isolation logic.

[0105] Example 4:

[0106] This embodiment provides an application method for a photovoltaic panel reverse self-heating snow removal system in a high-efficiency intelligent scenario. This embodiment introduces a visual feedback mechanism, suitable for large-scale distributed photovoltaic systems (whether grid-connected or off-grid) with extremely high power generation efficiency requirements.

[0107] In this embodiment, the status monitoring unit also includes a visible light / infrared dual-spectrum camera mounted on top of the bracket for real-time image capture of the photovoltaic module surface. The on / off unit not only supports global synchronous conduction but also supports grouped independent control (e.g., dividing a large array into multiple groups, each managed by an independent power control unit submodule).

[0108] During the triggering and judgment phase, in addition to the usual power and temperature judgments, the system uses image processing algorithms to calculate the snow coverage rate. Snow removal is only started when the coverage rate is greater than a preset threshold (such as 30%), avoiding false starts caused by a small amount of loose snow and reducing unnecessary energy consumption.

[0109] During the reverse current injection phase, the system identifies areas with thicker snow accumulation (such as the lower half of the module or shaded areas) based on image recognition results. The system control unit obtains the reverse withstand voltage threshold and safety margin of each individual module in the photovoltaic module array and calculates the maximum allowable total reverse voltage. Subsequently, it controls the corresponding power control unit submodule to output different reverse voltages or sends conduction commands with different duty cycles to the switching units of the corresponding areas. For example, a higher reverse voltage (e.g., -45 volts) is applied to areas with thick snow accumulation, and a lower reverse voltage (e.g., -30 volts) is applied to areas with thin snow accumulation, while ensuring that the absolute values ​​of all voltages are dynamically limited within the maximum total reverse voltage range. This "on-demand heating" strategy avoids overheating and energy waste in snow-free areas, significantly improving the energy efficiency ratio.

[0110] During the dynamic process monitoring and reset phase, the termination condition no longer relies solely on current changes. Instead, it prioritizes image recognition confirming that the snow coverage has fallen below a preset low threshold (e.g., 5%) as the primary termination criterion, while simultaneously using current stability as a double confirmation. If the image shows that the snow has been cleared but the current has not yet reached the threshold (potentially due to sensor malfunction), the system prioritizes the visual result and terminates heating to prevent overheating.

[0111] This embodiment achieves truly intelligent snow removal by introducing visual feedback and refined zone control, further improving the system's adaptability and operational efficiency.

[0112] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic panel reverse self-heating snow removal system, characterized in that, include: The status monitoring unit is used to collect the electrical output parameters and external environmental parameters of the photovoltaic module array in real time; A power control unit has its input end connected to the energy source and its output end connected to the DC bus of the photovoltaic module array. The power control unit has a first operating mode and a second operating mode. In the first operating mode, the power control unit is used to execute a maximum power point tracking algorithm to deliver photovoltaic power to the load or the power grid. In the second operating mode, the power control unit is used as a controllable DC power source to draw power from the energy source and output reverse power to the DC bus. A number of switching units are respectively set in the output circuit of each photovoltaic module in the photovoltaic module array; each switching unit is controlled by a control signal and can switch between a shutdown state and a conduction state; in the shutdown state, the switching unit is used to allow the photovoltaic module to output the power generation current normally and block the reverse current; in the conduction state, the switching unit is used to provide a low impedance path for the reverse heating current to flow through the internal cells of the photovoltaic module. The system control unit is communicatively connected to the status monitoring unit, the power control unit, and all on / off units. The system control unit is used to determine whether the preset snow removal conditions are met based on the data collected by the status monitoring unit. If the preset snow removal conditions are met, the system control unit controls the power control unit to switch to the second working mode and controls all on / off units to switch to the on state, so as to force the reverse current to flow evenly through each photovoltaic module to generate Joule heat.

2. A method for reverse self-heating snow removal using photovoltaic panels, applied to the system described in claim 1, characterized in that, Includes the following steps: S1. Multidimensional status monitoring and trigger judgment: Receive the electrical output parameters and external environmental parameters of the photovoltaic module array collected by the status monitoring unit, and generate a snow removal command when it is determined that the electrical output parameters and external environmental parameters meet the preset snow removal conditions; S2. System safety isolation and mode switching: In response to the snow removal command, disconnect the electrical connection between the photovoltaic module array and the inverter, and control the power control unit to switch from the first working mode to the second working mode; S3. Reverse current injection and uniform heating: In the second working mode, the power control unit is controlled to obtain electrical energy from the energy end and output reverse electrical energy to the DC bus, while all switching units are controlled to switch to the on state, so as to force the reverse current to flow through the internal cells of the photovoltaic module to generate Joule heat. S4. Dynamic process monitoring and automatic reset: During the heating process, the feedback parameters characterizing the snow melting progress are monitored in real time. When it is determined that the feedback parameters meet the snow removal termination conditions, the power control unit is controlled to stop reverse output, all on / off units are restored to the off state, and the system is controlled to return to the normal power generation standby state.

3. The photovoltaic panel reverse self-heating snow removal method according to claim 2, characterized in that, In step S1, determining that the electrical output parameters and external environmental parameters meet the preset snow removal conditions includes: Acquire real-time power data from the electrical output parameters, and ambient temperature data and weather forecast data from the external environmental parameters; Pre-defined logic judgment operations are performed on the real-time power data, ambient temperature data, and weather forecast data; If the real-time power data is lower than the first power threshold, and the ambient temperature data is lower than the freezing point threshold, or the weather forecast data indicates snowfall, then the preset snow removal conditions are determined to be met.

4. The photovoltaic panel reverse self-heating snow removal method according to claim 2, characterized in that, In step S2, disconnecting the electrical connection between the photovoltaic module array and the inverter includes: Generate a system safety isolation command and send it to the inverter; Receive the disconnection confirmation signal returned by the inverter; The step of controlling the power control unit to switch from the first operating mode to the second operating mode is executed only after receiving the disconnection confirmation signal.

5. A photovoltaic panel reverse self-heating snow removal method according to claim 2, characterized in that, In step S3, controlling the power control unit to obtain electrical energy from the energy source includes: Obtain the remaining power data of the energy source; Determine whether the remaining battery power is less than a preset battery power threshold; If so, the power control unit is controlled to draw power from an external power source or the grid interface, and the period of outputting reverse power is limited to low-cost power supply periods or periods of low electricity prices. If not, the power control unit is controlled to draw power from the energy storage battery unit.

6. A photovoltaic panel reverse self-heating snow removal method according to claim 2, characterized in that, In step S3, controlling all on / off units to switch to the on state includes: Send synchronous heating preparation command to all on / off units; Receive status confirmation signals returned by each on / off unit; Count the number of on / off units that return confirmation signals; The power control unit is controlled to start outputting reverse electrical energy only when the quantity reaches a preset proportional threshold.

7. A photovoltaic panel reverse self-heating snow removal method according to claim 2, characterized in that, In step S3, controlling the power control unit to output reverse electrical energy further includes: Obtain the reverse withstand voltage threshold and safety margin of a single module in the photovoltaic module array; Calculate the maximum allowable total reverse voltage of the system; The output of the power control unit is adjusted so that the absolute value of the reverse voltage applied to the DC bus is dynamically limited within the range of the maximum total reverse voltage.

8. A method for reverse self-heating snow removal using photovoltaic panels according to claim 2, characterized in that, In step S4, the feedback parameter characterizing the snow melting progress includes at least one of the following: The total heating current of the DC bus, the current balance of each branch, the heating duration, or the snow coverage obtained through image recognition.

9. A method for reverse self-heating snow removal using photovoltaic panels according to claim 2, characterized in that, In step S4, determining that the feedback parameter meets the snow removal termination condition includes any one of the following: The total heating current is monitored to rise and stabilize above the preset snow melting completion current threshold for a set duration; The monitoring showed that the heating duration had reached the maximum permissible safe duration; Alternatively, image recognition can be used to confirm that the snow cover has dropped to zero or below a preset low threshold.

10. A method for reverse self-heating snow removal using photovoltaic panels according to claim 2, characterized in that, In step S4, the control system returns to the normal power generation standby state, including: Control the power control unit to switch back to the first operating mode; Generate a power generation recovery command to close the electrical connection between the photovoltaic module array and the inverter; The maximum power point tracking algorithm is executed to restore normal power generation of the system.

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