Solar inverter with heat dissipation structure

Abstract

The present application relates to the technical field of solar energy, and discloses a solar inverter with a heat dissipation structure, which comprises a casing, a heat dissipation fan, a wiring terminal, a ventilation grille, a control element, a transformer, a power inversion module, heat dissipation fins and a photovoltaic panel. The control element is coupled with a toothed air duct control system, which generates toothed channel thermal resistance values and grille resistance values based on toothed inlet temperature, toothed outlet temperature, toothed channel pressure difference and power inversion module electric power state through a toothed thermal resistance construction module. Two heat dissipation fan rotation speeds are distributed according to the toothed channel thermal resistance values and the temperature difference between the two toothed outlet temperatures through a double-fan bias control module. When the grille resistance reaches a trigger condition, the two heat dissipation fans form an alternating rotation speed pulse through a grille resistance cleaning module, and the allowed output power of the power inversion module is linked and controlled through an inversion output coordination module.

Description

Technical Field

[0001] This invention relates to the field of solar energy technology, specifically to a solar inverter with a heat dissipation structure. Background Technology

[0002] Existing solar inverters with heat dissipation structures typically include a casing, ventilation grilles, cooling fans, terminals, control components, a transformer, a power inverter module, heat sink fins, and photovoltaic panels. During operation, the DC power generated by the photovoltaic panels is input to the casing via the terminals. The power inverter module, under the control of the control components, performs inversion processing and outputs AC power after electrical isolation and voltage matching through the transformer. During inversion, the heat generated by the power inverter module is conducted to the heat sink fins attached to its sides. The cooling fan, in conjunction with the ventilation grilles on both sides of the casing, forms a directional cooling airflow, allowing outside air to enter the casing through the ventilation grilles, flow through the heat sink fins and the area surrounding the power inverter module, and then be exhausted by the cooling fan, thus completing the heat dissipation from inside the inverter.

[0003] However, in existing technologies, controllers typically start, stop, or adjust the speed of cooling fans based on the internal temperature of the casing or the temperature of the power inverter module. This control relies primarily on a single temperature condition and fails to combine the airflow temperature at the inlet of the heat sink fins, the airflow temperature at the outlet of the heat sink fins, the pressure difference in the fin channel, and the power state of the power inverter module into a unified control basis. This makes it difficult to promptly identify the correlation between the heat exchange state of the heat sink fins and the obstruction state of the ventilation grille. Furthermore, the two cooling fans usually operate at the same speed or according to a fixed pattern, making it difficult to create a speed offset between the left and right fans based on the temperature difference at the outlets of the heat sink fins. This results in airflow distribution not adjusting to the heat dissipation state of the power inverter module when localized heat concentration occurs in the directional cooling duct. Additionally, when obstruction occurs at the ventilation grille, existing control methods typically rely on increasing the cooling fan speed or decreasing the inverter output power. There is a lack of alternating clearing actions triggered by the grille obstruction value, and a lack of a scheme to coordinate the rate of change in the power inverter module output during the clearing action. Therefore, it is difficult to establish continuous linkage control between the ventilation grille, cooling fans, heat sink fins, and power inverter module. Summary of the Invention

[0004] This invention provides a solar inverter with a heat dissipation structure, which solves the problems mentioned in the background art.

[0005] This invention provides the following technical solution: a solar inverter with a heat dissipation structure, including a housing, ventilation grilles on both sides of the outer side of the housing, cooling fans on both sides of the top of the housing, the ventilation grilles and cooling fans working together to form a directional heat dissipation airflow, a wiring terminal on one side of the top of the housing, control components installed on the outer wall of the housing, a transformer installed on one side of the inner wall of the housing, a power inverter module installed inside the housing, heat dissipation fins attached to both sides of the power inverter module, thermal conduction connection between the power inverter module and the heat dissipation fins, and a photovoltaic panel installed on the outside of the housing;

[0006] The air duct status acquisition module is used to acquire the inlet temperature of the heat dissipation fins on the side near the ventilation grille, the outlet temperature of the heat dissipation fins on the side near the cooling fan, the pressure difference of the heat dissipation fin channel before and after the inter-tooth channel, and the power data of the power inverter module.

[0007] The toothed plate thermal resistance construction module is used to generate the toothed plate channel thermal resistance value and grid resistance value based on the toothed plate inlet temperature, toothed plate outlet temperature, toothed plate channel pressure difference and power inverter module power data.

[0008] The dual-fan bias control module is used to determine the base speed of the two cooling fans based on the thermal resistance value of the toothed channel, and to generate the execution speed of the left cooling fan and the execution speed of the right cooling fan based on the temperature difference at the toothed outlets on both sides of the cooling toothed plate.

[0009] The grid obstruction cleaning module is used to determine whether the airflow channel between the ventilation grid and the heat dissipation toothed plate has reached the cleaning trigger condition based on the grid obstruction value and the toothed plate channel thermal resistance value, and to control the two cooling fans to form alternating speed pulses when the cleaning trigger condition is reached.

[0010] The inverter output coordination module is used to control the allowable output power of the power inverter module based on the thermal resistance value of the gear channel, the gear outlet temperature, the grid resistance value, the operating status of the cooling fan, and the continuous resistance status.

[0011] The present invention has the following beneficial effects:

[0012] 1. This solution incorporates a toothed plate thermal resistance construction module within the control unit. This allows the control unit to generate toothed plate channel thermal resistance and grid resistance values ​​based on toothed plate inlet temperature, toothed plate outlet temperature, toothed plate channel pressure difference, DC input voltage, DC input current, AC output voltage, and AC output current. The toothed plate channel thermal resistance value characterizes the heat transfer state of the heat dissipation teeth within the directional heat dissipation duct, while the grid resistance value characterizes the airflow resistance state between the ventilation grid and the heat dissipation teeth. Thus, the control unit no longer relies solely on a single temperature for heat dissipation control. Instead, it incorporates the heat input of the power inverter module, the temperature changes at both ends of the heat dissipation teeth, and the toothed plate channel pressure difference into the same sampling window, enabling the heat dissipation control to correspond to the actual operating state of the directional heat dissipation duct within the chassis.

[0013] 2. This solution incorporates a dual-fan bias control module within the control unit. This module enables the base speed determination unit to determine the base speed of the two cooling fans based on the thermal resistance of the toothed channel. The left and right fan bias units generate target speeds for the left and right cooling fans based on the temperature difference between the outlet temperatures of the left and right toothed channels. Furthermore, the speed slope limiting unit restricts speed variations between consecutive sampling windows. As a result, the two cooling fans can distribute their speeds around the temperature difference between the outlets on both sides of the cooling toothed channel. This ensures that the cooling fan closer to the heat concentration side receives the corresponding suction intensity, while maintaining compatibility between the cooling fan speed variation process and the airflow state of the directional cooling channel.

[0014] 3. This solution incorporates a grille obstruction clearing module and an inverter output coordination module within the control unit. The obstruction trigger judgment unit determines whether the clearing trigger condition between the ventilation grille and the heat dissipation fins is met based on the grille obstruction value and the thermal resistance value of the fin channel. The clearing pulse generation unit controls the left and right cooling fans to generate alternating speed pulses, while the power gradual change coordination unit limits the output change rate of the power inverter module during the clearing pulse execution. After clearing, the clearing result verification unit rereads the grille obstruction value and the fin channel thermal resistance value. The inverter output coordination module calculates the allowable output power based on the fin channel thermal resistance value, fin outlet temperature, grille obstruction value, cooling fan execution status, and continuous obstruction status. Thus, ventilation grille obstruction identification, alternating fan clearing, power inverter module output limitation, and fault interlocking can form a continuous control chain within the control unit, ensuring that the cooling duct status and inverter output status remain linked. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the overall partial structure of the present invention;

[0017] Figure 3This is a schematic diagram of the overall partial structure of the present invention;

[0018] Figure 4 This is a schematic diagram of the overall process of the control component built into the toothed duct coupling control system of the present invention.

[0019] Figure 5 This is a schematic diagram of the data processing flow of the toothed plate thermal resistance construction module of the present invention;

[0020] Figure 6 This is a schematic diagram of the control flow of the grid obstruction cleaning module of the present invention.

[0021] In the diagram: 1. Housing; 2. Cooling fan; 3. Terminal block; 4. Ventilation grille; 5. Control components; 6. Transformer; 7. Power inverter module; 8. Heat sink fins; 9. Photovoltaic panel. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The solar inverter with heat dissipation structure involved in the present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figures 1-6 The solar inverter shown includes a housing 1, wherein ventilation grilles 4 are provided on both sides of the exterior of the housing 1, and cooling fans 2 are installed on both sides of the top of the housing 1. The ventilation grilles 4 and the cooling fans 2 work together to form a directional heat dissipation airflow channel, which can provide a stable installation support and outdoor protection for the electrical components inside the inverter using the housing 1, and ensure that the ventilation grilles 4 and the cooling fans 2 work together to build a stable heat dissipation channel. A photovoltaic panel 9 is provided on the exterior of the housing 1.

[0024] It also includes a wiring terminal 3, which is fixedly installed on one side of the top of the housing 1. The inner end of the wiring terminal 3 extends into the inner cavity of the housing 1. The wiring terminal 3 is used to realize a fast electrical connection between the inverter and the photovoltaic panel 9 grid line.

[0025] It also includes a control component 5, which is fixedly installed on the outer wall of the housing 1 and electrically connected to the cooling fan 2 and the power inverter module 7 respectively. The control component 5 is used to centrally control the inverter operation parameters of the inverter, the start, stop and speed regulation of the cooling fan 2, so as to realize the fully automated temperature control and grid-connected operation of the equipment.

[0026] It also includes a transformer 6, which is fixedly installed inside the casing 1 on one side and is electrically connected to the power inverter module 7.

[0027] It also includes a power inverter module 7, which is fixedly installed inside the housing 1. The power inverter module 7 is electrically connected to the wiring terminal 3, the transformer 6, and the control component 5 respectively.

[0028] It also includes heat dissipation fins 8, which are symmetrically attached to both sides of the power inverter module 7. The power inverter module 7 and the heat dissipation fins 8 are thermally connected. The toothed surfaces of the heat dissipation fins 8 are oriented towards the airflow direction of the directional heat dissipation channel. The heat dissipation fins 8 can increase the heat exchange area of ​​the power inverter module 7, enhance the heat conduction and diffusion effect, and achieve rapid heat removal in conjunction with the directional heat dissipation channel.

[0029] During operation, after the equipment is started, the controller 5 drives the power inverter module 7 and the transformer 6 to enter the working state. The DC power generated by the photovoltaic panel 9 is input to the inverter through the terminal 3. After electrical isolation and voltage matching are completed by the transformer 6, the power inverter module 7 converts it into AC power that meets the grid connection standard, and then outputs it through the terminal 3. During the operation of the equipment, the power inverter module 7 generates working heat. The heat dissipation fins 8 that are attached to the device quickly conduct and diffuse the heat into the surrounding air. When the internal temperature of the casing 1 reaches the temperature control threshold set by the controller 5, the controller 5 drives the cooling fan 2 to start. Together with the ventilation grilles 4 on both sides of the casing, they form a directional heat dissipation air duct. The external cold air enters the inner cavity of the casing through the ventilation grilles 4, flows through the heat-generating devices and the heat dissipation fins 8 to remove the heat, and is then quickly discharged to the outside of the casing by the cooling fan 2.

[0030] The control unit 5 incorporates a toothed duct coupling control system. This system, during the operation of the power inverter module 7, controls the speed distribution of the cooling fan 2, the output limitation of the power inverter module 7, and the obstruction clearing action at the ventilation grille 4 based on the temperature and pressure difference of the airflow channels on both sides of the heat dissipation toothed fins 8 and the power output status of the power inverter module 7. The toothed duct coupling control system is formed by sequentially connecting a duct status acquisition module, a toothed fin thermal resistance construction module, a dual-fan bias control module, a grille obstruction clearing module, and an inverter output coordination module.

[0031] The airflow status acquisition module first obtains the inlet temperature of the heat dissipation fin 8 near the ventilation grille 4 using the fin inlet temperature acquisition unit, and then obtains the outlet temperature of the heat dissipation fin 8 near the cooling fan 2 using the fin outlet temperature acquisition unit. The pressure difference between the fins is obtained through the fin pressure difference acquisition unit, and the DC input voltage, DC input current, AC output voltage, and AC output current of the power inverter module 7 are read through the inverter power acquisition unit to obtain a sampling data packet corresponding to the directional cooling airflow, the heat dissipation fin 8, and the power inverter module 7. This sampling data packet is sent to the fin thermal resistance construction module, enabling subsequent calculations to be based on the actual airflow state of the heat dissipation fin 8.

[0032] The slat inlet temperature acquisition unit is located inside the housing 1 and near the ventilation grille 4, with its measuring end facing the airflow area before entering the inter-tooth channel of the heat dissipation slats 8. When the power inverter module 7 receives power input from the photovoltaic panel 9 and enters the inverter preparation state, the control unit 5 causes the slat inlet temperature acquisition unit to acquire the slat inlet temperature at a fixed sampling period, which is any preset value between 1 and 5 seconds. The data acquired by the slat inlet temperature acquisition unit is not directly used for fan start / stop; it is first written into the sampling buffer of the control unit 5.

[0033] The toothed fin outlet temperature acquisition unit is located inside the housing 1 and close to the cooling fan 2. The temperature measuring end of the toothed fin outlet temperature acquisition unit faces the airflow area after exiting the inter-tooth channel of the cooling fin 8. The toothed fin outlet temperature acquisition unit and the toothed fin inlet temperature acquisition unit use the same sampling period. The control unit 5 reads the toothed fin inlet temperature and toothed fin outlet temperature at the same sampling time, so that the two temperature data have the same time reference.

[0034] The toothed plate pressure difference acquisition unit consists of a first pressure tap, a second pressure tap, and a micro-pressure sensor. The first pressure tap is located on the side of the heat dissipation tooth 8 near the ventilation grille 4, and the second pressure tap is located on the side of the heat dissipation tooth 8 near the cooling fan 2. The first and second pressure taps are connected to the micro-pressure sensor through pressure guide channels. After reading the output of the micro-pressure sensor, the control unit 5 obtains the toothed plate channel pressure difference. The toothed plate channel pressure difference is used to characterize the airflow resistance state formed by the ventilation grille 4, the gap between the teeth of the heat dissipation tooth 8, and the suction side of the cooling fan 2.

[0035] The inverter power acquisition unit is connected to the voltage detection terminal and current detection terminal of the power inverter module 7. When the power inverter module 7 performs maximum power point tracking, grid-connected output, or off-grid output, the inverter power acquisition unit reads the DC input voltage, DC input current, AC output voltage, and AC output current, and converts the DC input voltage and DC input current into inverter input power data, and the AC output voltage and AC output current into inverter output power data. The control unit 5 uses the inverter input power data and inverter output power data to determine the calculation basis for the heat transfer from the power inverter module 7 to the heat sink 8.

[0036] After receiving the sampling data packet generated by the air duct status acquisition module, the toothed channel thermal resistance construction module first calculates the heat input generated by the power inverter module 7 within the current sampling window using the heat input calculation unit. Then, the toothed channel thermal resistance calculation unit constructs the toothed channel thermal resistance value from the toothed inlet temperature, toothed outlet temperature, and heat input. The grid resistance calculation unit compares the toothed channel pressure difference with the initial clean pressure difference to obtain the grid resistance value. Finally, the status latching unit writes the toothed channel thermal resistance value and the grid resistance value into the status register area of ​​the control unit 5. The dual-fan bias control module reads the toothed channel thermal resistance value to determine the base speed of the cooling fan 2, and the grid resistance cleaning module reads the grid resistance value to determine whether the ventilation grid 4 has entered the cleaning action.

[0037] The heat input calculation unit is located within the control unit 5 and is connected to the power sampling data of the power inverter module 7. The heat input calculation unit reads the DC input voltage, DC input current, AC output voltage, and AC output current at each sampling window. It multiplies the DC input voltage and DC input current to obtain the input power of the current sampling window, and multiplies the AC output voltage and AC output current to obtain the output power of the current sampling window. The difference between the input power and the output power is then used as the heat input for the current sampling window. When the difference between the input power and the output power is less than zero, the heat input calculation unit records the heat input for the current sampling window as zero. The heat input calculation unit calculates according to the following formula:

[0038]

[0039] in, Let be the heat input of the t-th sampling window. Let be the DC input voltage of the t-th sampling window. Let be the DC input current of the t-th sampling window. Let be the AC output voltage of the t-th sampling window. Let be the AC output current of the t-th sampling window. After the heat input calculation unit completes the calculation, it transmits the heat input to the toothed channel thermal resistance calculation unit and simultaneously writes it into the data area to be written in the status latch unit.

[0040] The toothed channel thermal resistance calculation unit is located within the control unit 5. This unit receives the heat input from the heat input calculation unit and reads the toothed inlet and outlet temperatures from the airflow status acquisition module. The toothed inlet temperature corresponds to the position before the airflow enters the inter-tooth channel of the heat dissipation tooth 8, and the toothed outlet temperature corresponds to the position after the airflow exits the inter-tooth channel of the heat dissipation tooth 8. The toothed channel thermal resistance calculation unit first calculates the temperature difference between the toothed outlet temperature and the toothed inlet temperature, then divides this temperature difference by the sum of the heat input and the zero-prevention constant to obtain the toothed channel thermal resistance value for the current sampling window. The zero-prevention constant is pre-written into the control unit 5 to ensure the calculation process remains executable when the heat input is zero or close to zero. The toothed channel thermal resistance calculation unit calculates according to the following formula:

[0041]

[0042] in, Let be the thermal resistance value of the toothed channel in the t-th sampling window. Let be the toothed blade exit temperature of the t-th sampling window. Let be the inlet temperature of the toothed blade in the t-th sampling window. Let ε be the thermal input for the t-th sampling window, and ε be a zero-prevention constant. After the toothed channel thermal resistance calculation unit completes the calculation, it transmits the toothed channel thermal resistance value to the state latch unit, which then allows the dual-fan bias control module to read it in subsequent sampling windows.

[0043] The grille resistance calculation unit is located within the control unit 5. This unit reads the differential pressure in the toothed channel output by the air duct status acquisition module. The differential pressure in the toothed channel is formed by the pressure difference between the side of the heat dissipation toothed 8 near the ventilation grille 4 and the side of the heat dissipation toothed 8 near the cooling fan 2. During the initial stable operation phase of the equipment, the grille resistance calculation unit records the initial clean pressure difference, which corresponds to the differential pressure in the toothed channel when the cooling fan 2 is at its rated speed, the power inverter module 7 is at its rated output state, and the ventilation grille 4 is not obstructed. After the equipment enters subsequent operation, the grille resistance calculation unit reads the differential pressure in the toothed channel at each sampling window, calculates the difference between the differential pressure and the initial clean pressure difference, and then divides this difference by the sum of the initial clean pressure difference and the zero-prevention constant to obtain the grille resistance value for the current sampling window. The grille resistance calculation unit calculates according to the following formula:

[0044]

[0045] in, Let be the grid resistance value of the t-th sampling window. Let be the pressure difference of the toothed channel in the t-th sampling window. ε represents the initial clean pressure differential, and ε is the zero-prevention constant. After the grid resistance calculation unit completes the calculation, it transmits the grid resistance value to the status latch unit, which then allows the grid resistance cleaning module to read it in subsequent sampling windows.

[0046] The state latch unit is located within the control unit 5 and is connected to the heat input calculation unit, the toothed channel thermal resistance calculation unit, and the grid resistance calculation unit. In each sampling window, the state latch unit receives the heat input, toothed channel thermal resistance, and grid resistance value, and simultaneously receives the toothed inlet temperature, toothed outlet temperature, and toothed channel pressure difference. The state latch unit uses the sampling window number as the writing order, writing the heat input, toothed channel thermal resistance, grid resistance value, toothed inlet temperature, toothed outlet temperature, and toothed channel pressure difference within the same sampling window into the state register area. When writing new sampling window data, the state latch unit retains data from multiple consecutive sampling windows, ensuring that the toothed channel thermal resistance value and grid resistance value read by the dual-fan bias control module, grid resistance clearing module, and inverter output coordination module have the same sampling time source. After the state latch unit completes the writing, it provides the tooth channel thermal resistance value to the dual-fan bias control module, the grid resistance value to the grid resistance cleaning module, and the tooth channel thermal resistance value and grid resistance value to the inverter output coordination module.

[0047] The dual-fan bias control module is located within the control unit 5. This module receives the thermal resistance value of the toothed channel from the state latching unit in the toothed channel thermal resistance construction module, and receives the outlet temperatures of the left and right toothed channels from the air duct status acquisition module. The dual-fan bias control module first determines the base speed of the two cooling fans 2 based on the thermal resistance value of the toothed channel using the base speed determination unit. Then, it generates the target speeds of the left and right cooling fans 2 based on the temperature difference between the outlet temperatures of the left and right toothed channels using the left and right fan bias units. Subsequently, it limits the variation of the target speeds of the left and right cooling fans 2 within a continuous sampling window using the speed slope limiting unit. Finally, it outputs drive signals to the left and right cooling fans 2 respectively through the fan drive output unit. After completing the drive, the fan drive output unit writes the executed speeds of the left and right cooling fans 2 into the state register area of ​​the control unit 5, enabling the inverter output coordination module to coordinately control the power inverter module 7 based on the execution state of the cooling fans 2.

[0048] The basic speed determination unit is located within the control unit 5 and is connected to the state latching unit in the toothed fin thermal resistance construction module. The basic speed determination unit reads the toothed fin channel thermal resistance value in each sampling window. The toothed fin channel thermal resistance value is calculated by the toothed fin thermal resistance construction module based on the toothed fin inlet temperature, toothed fin outlet temperature, and heat input. The toothed fin channel thermal resistance value corresponds to the heat dissipation state of the heat dissipation fin 8 in the directional heat dissipation duct. The basic speed determination unit pre-stores the corresponding data between the toothed fin channel thermal resistance value and the basic speed. After the power inverter module 7 is started, the control unit 5 causes the basic speed determination unit to read the toothed fin channel thermal resistance value in the sampling window sequence and obtain the basic speed of the current sampling window from the corresponding data based on the toothed fin channel thermal resistance value. The basic speed determination unit increases the basic speed when the toothed fin channel thermal resistance value continuously increases and decreases the basic speed when the toothed fin channel thermal resistance value continuously decreases and the toothed fin outlet temperature reaches the recovery condition. After completing the basic speed determination, the basic speed determination unit transmits the basic speed to the left and right fan bias units.

[0049] The left and right fan biasing units are located within the control unit 5. These units receive the base speed output from the base speed determination unit and read the outlet temperatures of the left and right fan fins. The left fan fin outlet temperature corresponds to the airflow temperature at the outlet of the cooling fin 8 closest to the left cooling fan 2, and the right fan fin outlet temperature corresponds to the airflow temperature at the outlet of the cooling fin 8 closest to the right cooling fan 2. The left and right fan biasing units first calculate the temperature difference between the left and right fan fin outlet temperatures, then multiply this temperature difference by the temperature difference-speed coefficient to obtain the speed bias. When the left fan fin outlet temperature is greater than the right fan fin outlet temperature, the left and right fan biasing units increase the speed bias of the left cooling fan 2 by the base speed and decrease the speed bias of the right cooling fan 2 by the base speed; conversely, when the right fan fin outlet temperature is greater than the left fan fin outlet temperature, the right fan 2 increases the speed bias by the base speed and decreases the speed bias of the left cooling fan 2 by the base speed. The left and right fan offset units limit the calculated speeds to ensure that the target speeds of both the left and right cooling fans are between the minimum and maximum allowable speeds. The left and right fan offset units calculate according to the following formula:

[0050]

[0051] in, Let be the target rotational speed of cooling fan 2 on the s-th side in the t-th sampling window. When s is l, it represents cooling fan 2 on the left side; when s is r, it represents cooling fan 2 on the right side. , , Let be the base rotational speed for the t-th sampling window. The coefficient of rotational speed due to temperature difference. Let be the outlet temperature of the left toothed plate in the t-th sampling window. Let be the exit temperature of the right toothed plate in the t-th sampling window. Minimum permissible speed, For the maximum permissible speed, clip(⋅) indicates that the calculation result is limited to between the minimum and maximum permissible speeds. After the left and right fan offset units complete the calculation, they transmit the target speeds of the left cooling fan 2 and the right cooling fan 2 to the speed slope limiting unit.

[0052] The speed slope limiting unit is located within the control unit 5. This unit receives the target speeds of the left and right cooling fans 2 from the left and right fan offset units, and reads the executed speeds of the left and right cooling fans 2 from the previous sampling window. The unit calculates the speed change between the target speed of the left cooling fan 2 and the executed speed of the left cooling fan 2 in the previous sampling window, as well as the speed change between the target speed of the right cooling fan 2 and the executed speed of the right cooling fan 2 in the previous sampling window. The unit compares the speed change with a preset slope limit. When the speed change exceeds the preset slope limit, the unit limits the executed speed of the current sampling window to the executed speed of the previous sampling window plus the preset slope limit. When the speed change is less than a negative value of the preset slope limit, the unit limits the executed speed of the current sampling window to the executed speed of the previous sampling window minus the preset slope limit. When the speed change is within the preset slope limit range, the unit uses the target speed as the executed speed of the current sampling window. The speed slope limiting unit is calculated according to the following formula:

[0053]

[0054] in, Let be the operating speed of cooling fan 2 on the s-th side in the t-th sampling window. The execution speed of cooling fan 2 on the s-th side in the (t-1)-th sampling window. Let the target rotational speed of cooling fan 2 on the s-th side of the t-th sampling window be , To preset the slope limit, clip(⋅) means limiting the change in rotational speed to a certain value. to Between. After the speed slope limiting unit completes the calculation, it transmits the operating speed of the left cooling fan 2 and the operating speed of the right cooling fan 2 to the fan drive output unit.

[0055] The fan drive output unit is located within the control unit 5 and is connected to the drive ends of the two cooling fans 2. The fan drive output unit receives the execution speeds of the left and right cooling fans 2 from the speed slope limiting unit. The fan drive output unit converts the execution speed of the left cooling fan 2 into a left fan drive signal and outputs the left fan drive signal to the left cooling fan 2; the fan drive output unit also converts the execution speed of the right cooling fan 2 into a right fan drive signal and outputs the right fan drive signal to the right cooling fan 2. Under the action of the corresponding drive signals, the two cooling fans 2 draw airflow from inside the housing 1 along the direction from the ventilation grille 4 to the cooling fan 2, causing the airflow to pass through the inter-tooth channels of the heat dissipation fins 8. After outputting the drive signal, the fan drive output unit writes the execution speeds of the left and right cooling fans 2 into the status register area of ​​the control unit 5 and provides the written execution speeds to the inverter output coordination module. When any cooling fan 2 fails to run at the specified speed, the fan drive output unit writes the abnormal state of the corresponding cooling fan 2 into the status register area of ​​the control unit 5, enabling the inverter output coordination module to read the abnormal state and control the output of the power inverter module 7.

[0056] The grille obstruction cleaning module is located within the control unit 5. This module receives the grille obstruction value and the toothed channel thermal resistance value output by the state latching unit in the toothed thermal resistance construction module, and also receives the base speed output by the dual-fan bias control module. The grille obstruction cleaning module first determines whether the airflow channel between the ventilation grille 4 and the heat dissipation toothed fin 8 meets the cleaning triggering conditions through the obstruction trigger judgment unit. Then, it sends a power change limiting command to the power inverter module 7 through the power gradual change coordination unit. Subsequently, it controls the left and right cooling fans 2 to form alternating speed pulses through the cleaning pulse generation unit. Finally, the cleaning result verification unit rereads the grille obstruction value and the toothed channel thermal resistance value after the cleaning pulse ends. The cleaning result verification unit writes the verification result into the state register area of ​​the control unit 5, enabling the dual-fan bias control module to restore the speed distribution based on the verification result, and enabling the inverter output coordination module to control the output of the power inverter module 7 based on the verification result.

[0057] The blocking trigger judgment unit is located within the control unit 5 and is connected to the state latching unit in the toothed plate thermal resistance construction module. The blocking trigger judgment unit reads the grid blocking value and the toothed plate channel thermal resistance value in each sampling window. The grid blocking value is calculated by the grid blocking calculation unit based on the toothed plate channel pressure difference and the initial clean pressure difference. The toothed plate channel thermal resistance value is calculated by the toothed plate channel thermal resistance calculation unit based on the toothed plate inlet temperature, toothed plate outlet temperature, and heat input. The blocking trigger judgment unit compares the grid blocking value of the current sampling window with the blocking trigger threshold and compares the toothed plate channel thermal resistance value of the current sampling window with the toothed plate channel thermal resistance value of the previous sampling window. When the grid blocking value continuously reaches the blocking trigger threshold and the toothed plate channel thermal resistance value rises synchronously within the corresponding sampling window, the blocking trigger judgment unit generates a cleaning trigger command. When the grid blocking value does not reach the blocking trigger threshold, the blocking trigger judgment unit does not generate a cleaning trigger command and writes the judgment result into the state register area of ​​the control unit 5. After the blocking trigger judgment unit generates the cleanup trigger command, it transmits the cleanup trigger command to the power gradual change coordination unit and the cleanup pulse generation unit.

[0058] The power variation coordination unit is located within the control unit 5 and is connected to the control terminal of the power inverter module 7. After receiving the cleanup trigger command output by the blocking trigger judgment unit, the power variation coordination unit first reads the current output state of the power inverter module 7 and then sends a power variation limiting command to the power inverter module 7. Upon receiving the power variation limiting command, the power inverter module 7 limits the rise and fall rates of the AC output power during the cleanup pulse execution. The power variation coordination unit completes the issuance of the power variation limiting command before the cleanup pulse generation unit begins controlling the two cooling fans 2, ensuring that the power inverter module 7 maintains controlled output changes during the alternating speed changes of the cooling fans 2. The power variation coordination unit keeps the power variation limiting command valid until the cleanup result verification unit completes verification, and releases the power variation limiting command after the cleanup result verification unit outputs a recovery control command. When the cleanup result verification unit outputs a continuous blocking state, the power variation coordination unit continues to maintain the power variation limiting command and transmits the continuous blocking state to the inverter output coordination module.

[0059] The cleaning pulse generation unit is located within the control unit 5 and is connected to the drive ends of the left and right cooling fans 2. The cleaning pulse generation unit receives the cleaning trigger command output by the blocking trigger judgment unit and reads the base speed output by the dual-fan bias control module. The cleaning pulse generation unit first increases the left cooling fan 2 to the cleaning speed while maintaining the right cooling fan 2 at the base speed, creating an enhanced exhaust state within the casing 1 near the left cooling fan 2. Then, the cleaning pulse generation unit increases the right cooling fan 2 to the cleaning speed while maintaining the left cooling fan 2 at the base speed, creating an enhanced exhaust state within the casing 1 near the right cooling fan 2. The cleaning pulse generation unit alternately controls the airflow in the order of enhanced exhaust from the left cooling fan 2 and enhanced exhaust from the right cooling fan 2, causing the airflow entering the ventilation grille 4 to form a time-varying suction effect within the inter-tooth channel of the heat dissipation fins 8, and causing the deposits at the ventilation grille 4 to be disturbed by the airflow difference created by the speed difference of the cooling fans 2. The duration of a single cleaning pulse generated by the cleaning pulse generation unit is a preset value between 3 and 10 seconds, and the number of cleaning pulses in a single cleaning process is a preset value between 2 and 6. After the cleaning pulse generation unit completes the preset number of cleaning pulses, it transmits the cleaning end signal to the cleaning result verification unit and writes the number of cleaning pulses into the status register area of ​​the control unit 5.

[0060] The cleaning result verification unit is located within the control unit 5 and is connected to the state latching unit in the toothed plate thermal resistance construction module. After receiving the cleaning end signal from the cleaning pulse generation unit, the cleaning result verification unit reads the grid resistance value and the toothed plate channel thermal resistance value in the first sampling window after the cleaning pulse ends. The cleaning result verification unit compares the grid resistance value after the cleaning pulse ends with the recovery confirmation threshold. When the grid resistance value is lower than the recovery confirmation threshold, the cleaning result verification unit generates a recovery control command and transmits it to the dual-fan bias control module and the power gradual change coordination unit. After receiving the recovery control command, the dual-fan bias control module reallocates the speeds of the two cooling fans 2 according to the toothed plate channel thermal resistance value and the outlet temperatures of the toothed plates on both sides; after receiving the recovery control command, the power gradual change coordination unit releases the power change restriction command. When the grid resistance value still reaches the resistance trigger threshold, the cleaning result verification unit generates a continuous resistance state and writes the continuous resistance state into the state register area of ​​the control unit 5. After reading the continuous stagnation state, the inverter output coordination module controls the allowable output power of the power inverter module 7 based on the thermal resistance value of the gear channel, the gear outlet temperature, and the continuous stagnation state.

[0061] The inverter output coordination module is located within the control unit 5. This module receives the tooth channel thermal resistance value, grid resistance value, and tooth outlet temperature from the state latching unit in the tooth thermal resistance construction module; it also receives the execution status of the cooling fan 2 from the fan drive output unit in the dual-fan bias control module; and it receives the continuous resistance status from the cleaning result verification unit in the grid resistance cleaning module. The inverter output coordination module first calculates the allowable output power of the power inverter module 7 based on the tooth channel thermal resistance value, tooth outlet temperature, grid resistance value, cooling fan 2 execution status, and continuous resistance status through the output derating calculation unit. Then, it writes the allowable output power into the control register of the power inverter module 7 through the inverter command issuing unit. Subsequently, it controls the power inverter module 7 to stop outputting when the tooth outlet temperature, cooling fan 2 execution status, and continuous resistance status meet the shutdown conditions through the fault lockout unit. Finally, it records the tooth channel thermal resistance value, grid resistance value, tooth outlet temperature, cooling fan 2 execution status, continuous resistance status, allowable output power, and fault lockout status through the operation recording unit.

[0062] The output derating calculation unit is located within the control unit 5. It is connected to the state latching unit in the toothed fin thermal resistance construction module, the fan drive output unit in the dual-fan bias control module, and the cleaning result verification unit in the grille obstruction cleaning module. The output derating calculation unit reads the toothed fin channel thermal resistance value, toothed fin outlet temperature, and grille obstruction value in each sampling window. The toothed fin channel thermal resistance value indicates the heat transfer state of the heat dissipation fin 8 within the directional cooling duct; the toothed fin outlet temperature indicates the temperature state of the airflow after exiting the heat dissipation fin 8; and the grille obstruction value indicates the airflow obstruction state between the ventilation grille 4 and the heat dissipation fin 8. The output derating calculation unit simultaneously reads the execution state and continuous obstruction state of the cooling fan 2. When the execution state of the cooling fan 2 indicates that any cooling fan 2 is not running at the execution speed output by the dual-fan bias control module, the output derating calculation unit participates in the allowable output power calculation according to the execution state of the cooling fan 2; when a continuous obstruction state exists, the output derating calculation unit participates in the allowable output power calculation according to the continuous obstruction state.

[0063] The output derating calculation unit is pre-programmed with rated output power, temperature limit threshold, thermal resistance power coefficient, temperature power coefficient, slack power coefficient, and normalized power upper limit. The output derating calculation unit first determines the thermal resistance limit based on the toothed channel thermal resistance value, then determines the temperature limit based on the portion of the toothed outlet temperature exceeding the temperature limit threshold, and finally determines the slack limit based on the grid slack value. The output derating calculation unit adds the thermal resistance limit, temperature limit, and slack limit to obtain the power limit, and calculates the allowable output power based on the power limit. The output derating calculation unit calculates according to the following formula:

[0064]

[0065]

[0066] in, Let be the power limit for the t-th sampling window. The thermal resistance power coefficient, Let be the thermal resistance value of the toothed channel in the t-th sampling window. The temperature power coefficient, Let be the toothed blade exit temperature of the t-th sampling window. Temperature limit threshold The power factor is the hindrance factor. Let be the grid resistance value of the t-th sampling window. Let be the allowed output power for the t-th sampling window. Rated output power, To normalize the power limit, max(⋅) represents taking the maximum value among the values ​​within the parentheses, and min(⋅) represents taking the minimum value among the values ​​within the parentheses. After the output derating calculation unit completes the calculation, it transmits the allowed output power to the inverter command issuing unit and writes the power limit and allowed output power into the status register area of ​​the control unit 5.

[0067] The inverter command issuing unit is located within the control unit 5 and is connected to the control terminal of the power inverter module 7. The inverter command issuing unit receives the allowable output power from the output derating calculation unit and reads the current output power of the power inverter module 7. The inverter command issuing unit converts the allowable output power into a power limiting command that the power inverter module 7 can execute, and writes the power limiting command into the control register of the power inverter module 7. Upon receiving the power limiting command, the power inverter module 7 adjusts its AC output power according to the power limiting command in the next control cycle, ensuring that the AC output power of the power inverter module 7 does not exceed the allowable output power.

[0068] When the power variation coordination unit in the grid obstruction clearing module maintains the power change limit command in effect, the inverter command issuing unit does not directly change the output power of the power inverter module 7 all at once according to the allowable output power. Instead, it issues power limit commands gradually according to the change rate specified by the power change limit command. After the power variation coordination unit releases the power change limit command, the inverter command issuing unit continues to issue power limit commands to the power inverter module 7 according to the allowable output power calculated by the output derating calculation unit in the current sampling window. After completing the command issuance, the inverter command issuing unit writes the issued allowable output power and issuance time into the status register area of ​​the control unit 5.

[0069] The fault interlocking unit is located within the control unit 5 and is connected to the state latching unit in the toothed plate thermal resistance construction module, the fan drive output unit in the dual-fan bias control module, the cleaning result verification unit in the grid obstruction cleaning module, and the control terminal of the power inverter module 7. The fault interlocking unit reads the toothed plate outlet temperature, toothed plate channel thermal resistance value, cooling fan 2 execution status, and continuous obstruction status in each sampling window. A shutdown temperature threshold, interlocking time threshold, and reset temperature threshold are pre-written into the fault interlocking unit. When the toothed plate outlet temperature reaches the shutdown temperature threshold, the fault interlocking unit sends a shutdown command to the power inverter module 7. When the cooling fan 2 execution status indicates that any cooling fan 2 is not operating at the execution speed, and the continuous obstruction status remains within the continuous sampling window until the interlocking time threshold, the fault interlocking unit sends a shutdown command to the power inverter module 7.

[0070] Upon receiving a shutdown command from the fault lockout unit, the power inverter module 7 stops its AC output. After the power inverter module 7 stops its AC output, the fault lockout unit keeps the cooling fan 2 running in the control unit 5 and continuously reads the toothed sprocket outlet temperature. The fault lockout unit releases the fault lockout state when the toothed sprocket outlet temperature falls below the reset temperature threshold and the continuous blocking state disappears. After releasing the fault lockout state, the fault lockout unit writes the release result to the status register of the control unit 5, enabling the inverter command issuing unit to reissue a power limit command to the power inverter module 7 according to the allowed output power in subsequent sampling windows.

[0071] The operation recording unit is located within the control unit 5 and is connected to the output derating calculation unit, the inverter command issuing unit, and the fault interlocking unit. The operation recording unit reads and records the toothed channel thermal resistance, grid resistance, toothed outlet temperature, cooling fan 2 execution status, continuous resistance status, power limit, allowable output power, issued allowable output power, and fault interlocking status in each sampling window. The operation recording unit writes the data within the same sampling window into the status register area of ​​the control unit 5 according to the sampling window number, enabling the output derating calculation unit, inverter command issuing unit, and fault interlocking unit to perform control based on the data from the same sampling window.

[0072] When the fault lockout unit sends a shutdown command, the operation recording unit writes the thermal resistance value of the toothed channel, the grid resistance value, the toothed outlet temperature, the execution status of the cooling fan 2, the continuous resistance status, the allowable output power, and the fault lockout status within the continuous sampling window before and after the shutdown command is sent into the non-volatile storage area of ​​the control unit 5. After the control unit 5 is powered on again, the operation recording unit provides the fault lockout status in the non-volatile storage area to the fault lockout unit, enabling the fault lockout unit to perform a reset judgment based on the toothed outlet temperature and the continuous resistance status.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A solar inverter with a heat dissipation structure, comprising a housing (1), characterized in that: Ventilation grilles (4) are provided on both sides of the outer side of the casing (1). Cooling fans (2) are installed on both sides of the top of the casing (1). The ventilation grilles (4) and the cooling fans (2) cooperate to form a directional cooling air duct. A terminal block (3) is provided on one side of the top of the casing (1). A control component (5) is installed on the outer wall of the casing (1). A transformer (6) is installed on one side of the inner wall of the casing (1). A power inverter module (7) is installed inside the casing (1). Heat dissipation fins (8) are attached to both sides of the power inverter module (7). The power inverter module (7) and the heat dissipation fins (8) are connected by thermal conduction. A photovoltaic panel (9) is provided on the outside of the casing (1). The control unit (5) is equipped with a toothed duct coupling control system, which includes a duct status acquisition module, a toothed thermal resistance construction module, a dual-fan bias control module, a grid blockage cleaning module, and an inverter output coordination module. The air duct status acquisition module is used to acquire the inlet temperature of the heat dissipation fin (8) on the side near the ventilation grille (4), the outlet temperature of the heat dissipation fin (8) on the side near the cooling fan (2), the pressure difference of the fin channel before and after the inter-fin channel of the heat dissipation fin (8), and the power data of the power inverter module (7). The toothed plate thermal resistance construction module is used to generate the toothed plate channel thermal resistance value and grid resistance value based on the toothed plate inlet temperature, toothed plate outlet temperature, toothed plate channel pressure difference and power inverter module (7). The dual-fan bias control module is used to determine the basic speed of the two cooling fans (2) based on the thermal resistance value of the tooth channel, and to generate the execution speed of the left cooling fan (2) and the execution speed of the right cooling fan (2) based on the temperature difference of the tooth outlet on both sides of the cooling tooth (8). The grid obstruction cleaning module is used to determine whether the airflow channel between the ventilation grid (4) and the heat dissipation tooth (8) has reached the cleaning trigger condition based on the grid obstruction value and the tooth channel thermal resistance value, and to control the two heat dissipation fans (2) to form alternating speed pulses when the cleaning trigger condition is reached; The inverter output coordination module is used to control the allowable output power of the power inverter module (7) based on the thermal resistance value of the toothed channel, the toothed outlet temperature, the grid resistance value, the execution state and continuous resistance state of the cooling fan (2).

2. A solar inverter with a heat dissipation structure according to claim 1, characterized in that: The air duct status acquisition module includes a toothed plate inlet temperature acquisition unit, a toothed plate outlet temperature acquisition unit, a toothed plate differential pressure acquisition unit, and an inverter power acquisition unit. The toothed plate inlet temperature acquisition unit is located inside the housing (1) and close to the ventilation grille (4), with the temperature measuring end of the toothed plate inlet temperature acquisition unit facing the airflow area before entering the inter-tooth channel of the heat dissipation toothed plate (8). The toothed plate outlet temperature acquisition unit is located inside the housing (1) and close to the cooling fan (2), with the temperature measuring end of the toothed plate outlet temperature acquisition unit facing the airflow area after exiting the inter-tooth channel of the heat dissipation toothed plate (8). The toothed plate differential pressure acquisition unit is used to acquire the toothed plate channel differential pressure between the side of the heat dissipation toothed plate (8) close to the ventilation grille (4) and the side of the heat dissipation toothed plate (8) close to the cooling fan (2). The inverter power acquisition unit is connected to the voltage detection end and the current detection end of the power inverter module (7) and is used to acquire the DC input voltage, DC input current, AC output voltage, and AC output current of the power inverter module (7).

3. A solar inverter with a heat dissipation structure according to claim 1, characterized in that: The toothed plate thermal resistance construction module includes a heat input calculation unit, a toothed plate channel thermal resistance calculation unit, a grid resistance calculation unit, and a state latching unit. The heat input calculation unit is used to calculate the heat input based on the DC input voltage, DC input current, AC output voltage, and AC output current of the power inverter module 7; the toothed channel thermal resistance calculation unit is used to generate the toothed channel thermal resistance value based on the toothed inlet temperature, toothed outlet temperature, and heat input. The grid resistance calculation unit is used to generate grid resistance value based on the pressure difference of the toothed channel and the initial clean pressure difference; the status latching unit is used to write the heat input, the thermal resistance value of the toothed channel, the grid resistance value, the toothed inlet temperature, the toothed outlet temperature, and the pressure difference of the toothed channel into the status register area of ​​the control unit (5) according to the sampling window.

4. A solar inverter with a heat dissipation structure according to claim 3, characterized in that: The grid resistance calculation unit records the initial clean pressure difference during the first stable operation phase of the equipment. The initial clean pressure difference corresponds to the tooth channel pressure difference when the cooling fan (2) is at the rated speed, the power inverter module (7) is at the rated output state, and the ventilation grid (4) is not blocked. The grid resistance calculation unit reads the tooth channel pressure difference of the current sampling window during subsequent operation and generates the grid resistance value based on the change of the tooth channel pressure difference of the current sampling window relative to the initial clean pressure difference.

5. A solar inverter with a heat dissipation structure according to claim 1, characterized in that: The dual-fan bias control module includes a base speed determination unit, a left and right fan bias unit, a speed slope limiting unit, and a fan drive output unit. The base speed determination unit is used to determine the base speed of the two cooling fans (2) based on the thermal resistance value of the toothed channel. The left and right fan bias unit is used to generate the target speed of the left cooling fan (2) and the target speed of the right cooling fan (2) based on the temperature difference between the outlet temperature of the left toothed channel and the outlet temperature of the right toothed channel. The speed slope limiting unit is used to limit the change of the target speed of the left cooling fan (2) and the target speed of the right cooling fan (2) between continuous sampling windows. The fan drive output unit is used to drive the left cooling fan (2) and the right cooling fan (2) respectively based on the execution speed of the left cooling fan (2) and the execution speed of the right cooling fan (2) output by the speed slope limiting unit.

6. A solar inverter with a heat dissipation structure according to claim 5, characterized in that: When the outlet temperature of the left toothed blade is greater than that of the right toothed blade, the left and right fan bias units increase the speed bias of the left cooling fan (2) by an amount above the base speed and decrease the speed bias of the right cooling fan (2) by an amount above the base speed. When the outlet temperature of the right toothed blade is greater than that of the left toothed blade, the left and right fan bias units increase the speed bias of the right cooling fan (2) by an amount above the base speed and decrease the speed bias of the left cooling fan (2) by an amount above the base speed. The left and right fan bias units limit the target speed of the left cooling fan (2) and the target speed of the right cooling fan (2) to between the minimum allowable speed and the maximum allowable speed.

7. A solar inverter with a heat dissipation structure according to claim 1, characterized in that: The grid obstruction cleaning module includes an obstruction trigger judgment unit, a power gradual change coordination unit, a cleaning pulse generation unit, and a cleaning result verification unit. The obstruction trigger judgment unit is used to generate a cleaning trigger command based on the grid obstruction value and the tooth channel thermal resistance value within the continuous sampling window. The power gradual change coordination unit is used to send a power change limit command to the power inverter module (7) after the cleaning trigger command is generated. The cleaning pulse generation unit is used to control the left cooling fan (2) and the right cooling fan (2) to form alternating speed pulses based on the cleaning trigger command. The cleaning result verification unit is used to reread the grid obstruction value and the tooth channel thermal resistance value after the alternating speed pulse ends, and generate a recovery control command or a continuous obstruction state based on the reread grid obstruction value.

8. A solar inverter with a heat dissipation structure according to claim 7, characterized in that: After receiving the cleaning trigger command, the cleaning pulse generation unit first increases the left cooling fan (2) to the cleaning speed and maintains the right cooling fan (2) at the base speed, then increases the right cooling fan (2) to the cleaning speed and maintains the left cooling fan (2) at the base speed. The cleaning pulse generation unit alternately controls the left cooling fan (2) to enhance the exhaust and the right cooling fan (2) to enhance the exhaust in sequence. The duration of a single cleaning pulse is a preset value between 3 seconds and 10 seconds, and the number of cleaning pulses in a single cleaning process is a preset value between 2 and 6.

9. A solar inverter with a heat dissipation structure according to claim 1, characterized in that: The inverter output coordination module includes an output derating calculation unit, an inverter command issuing unit, a fault lockout unit, and an operation recording unit. The output derating calculation unit is used to calculate the allowable output power of the power inverter module (7) based on the thermal resistance value of the tooth channel, the tooth outlet temperature, the grid resistance value, the execution state of the cooling fan (2), and the continuous resistance state. The inverter command issuing unit is used to convert the allowable output power into a power limiting command that the power inverter module (7) can execute, and write the power limiting command into the control register of the power inverter module (7). The fault lockout unit is used to send a shutdown command to the power inverter module (7) when the tooth outlet temperature reaches the shutdown temperature threshold, or when the execution state of the cooling fan (2) and the continuous resistance state simultaneously meet the lockout conditions. The operation recording unit is used to record the thermal resistance value of the tooth channel, the grid resistance value, the tooth outlet temperature, the execution state of the cooling fan (2), the continuous resistance state, the allowable output power, and the fault lockout state.

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