Control method of fan, inverter and energy storage system

Abstract

The application discloses a fan control method, an inverter and an energy storage system. The control method is used for the inverter, obtaining operation data of the inverter under different environments and in multiple operation modes, the operation data including temperature data, voltage data, power data and current data, the temperature data being temperature data of multiple temperature detection points; solving the correlation coefficients of the temperature of the inverter and the external environment temperature of the inverter, the voltage and the power according to the operation data and a fitting algorithm; solving the target coefficient of the speed duty ratio of the fan according to the operation data and the correlation coefficients; constructing a speed duty ratio control equation of the fan according to the target coefficient; solving the target speed of the fan according to the speed duty ratio control equation, the maximum speed of the fan and the current operation data of the inverter; and controlling the fan to work according to the target speed. In this way, intelligent control of the fan under different working conditions can be realized, the normal operation of the inverter is ensured, and energy waste is avoided.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a fan control method, an inverter, and an energy storage system. Background Technology

[0002] An inverter is a device that converts direct current (DC) to alternating current (AC) or one form of DC to another. It is widely used in various electronic devices, power systems, and renewable energy systems (such as solar and wind power systems). Because inverters generate heat during operation, fans are needed for cooling to ensure normal operation and extend their lifespan. However, due to variations in the internal layout and components of the inverter, fan speeds can easily become unstable, leading to energy waste. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application provides a fan control method, an inverter, and an energy storage system.

[0004] The fan control method of this application is used in an inverter, and the control method includes:

[0005] The inverter is used to acquire operating data under different environments and in multiple operating modes. The operating data includes temperature data, voltage data, power data and current data of multiple temperature detection points in the inverter. The location of the temperature detection points is related to the device layout of the inverter.

[0006] Based on the operating data and the fitting algorithm, the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, voltage, and power are calculated respectively.

[0007] The correlation coefficient and the target coefficient of the fan speed duty cycle are calculated based on the operating data.

[0008] Construct a speed duty cycle control equation for the fan based on the target coefficients;

[0009] The target speed of the fan is determined based on the speed duty cycle control equation, the maximum speed of the fan, and the current operating data of the inverter.

[0010] The fan is controlled to operate according to the target rotational speed.

[0011] In some embodiments, the temperature detection points include the air inlet location, the air outlet location, the resonant converter location, and the power factor correction module location; the voltage data includes at least one of AC terminal voltage and battery terminal voltage; the current data includes at least one of AC terminal current and battery terminal current; and the power data includes at least one of AC terminal power and battery terminal power.

[0012] In some implementations, the target fan speed is determined based on the speed duty cycle control equation, the maximum fan speed, and the current operating data of the inverter, including:

[0013] If any temperature in the current temperature data is greater than or equal to a preset temperature threshold, the highest speed of the fan is used as the target speed; or

[0014] If all temperatures in the current temperature data are less than the preset temperature threshold, the current battery terminal voltage, AC terminal voltage, battery terminal power, and temperature at the air inlet position are input into the speed duty cycle control equation to solve for the fan speed duty cycle.

[0015] The target rotational speed is determined based on the rotational speed duty cycle and the maximum rotational speed of the fan.

[0016] In some embodiments, controlling the fan to operate according to the target rotational speed includes:

[0017] Within the range of the fan's minimum and maximum speeds, the fan is controlled to operate at the target speed; or

[0018] If the target rotational speed is greater than the fan's maximum rotational speed, control the fan to operate at the maximum rotational speed; or

[0019] If the target rotational speed is less than the minimum rotational speed of the fan, the fan is controlled to operate at the minimum rotational speed.

[0020] In some embodiments, the calculation expression of the speed duty cycle control equation includes:

[0021] D_FAN_Control(VLVDC,PLVDC,Ta,Vac):=(VLVDC-48) 2 ·K_Vdc+PLVDC·K_Pdc+Ta·K_Temp+(264-Vac)·K_Vac

[0022] Wherein, VLVDC is the battery terminal voltage, PLVDC is the battery terminal power, Ta is the temperature at the air inlet, Vac is the AC terminal voltage, K_Vdc is the target coefficient of fan speed duty cycle and battery terminal voltage, K_Pdc is the target coefficient of fan speed duty cycle and battery terminal power, K_Temp is the target coefficient of fan speed duty cycle and air inlet temperature, and K_Vac is the target coefficient of fan speed duty cycle and AC terminal voltage.

[0023] In some embodiments, the control method further includes:

[0024] Obtain the current operating mode of the inverter;

[0025] The fan is started when the current operating mode is AC charging mode and the current operating data meets the first preset condition; or

[0026] When the current operating mode is inverter discharge mode and the current operating data meets the second preset condition, the fan is started.

[0027] In some implementations, the first preset condition includes one of the following: the battery terminal current of the inverter is greater than or equal to a first preset current threshold, the temperature at the location of the power factor correction module is greater than or equal to a first temperature threshold, and the temperature at the location of the resonant converter is greater than or equal to a second temperature threshold.

[0028] The second preset condition includes one of the following: the battery terminal power is greater than the first power threshold, the temperature at the location of the power factor correction module is greater than or equal to the first temperature threshold, and the temperature at the location of the resonant converter is greater than or equal to the second temperature threshold.

[0029] In some embodiments, when the operating mode is charging mode and the temperature at the air inlet is less than a third temperature threshold, the maximum operating speed of the fan is 75% of the highest speed; or

[0030] When the operating mode is charging mode, the temperature at the air inlet is greater than the fourth temperature threshold, and the charging current is greater than the first current threshold, the fan speed is set to the highest speed.

[0031] In some embodiments, the inverter includes a temperature sensor located at the temperature detection point to acquire operating data of the inverter under different environments and in multiple operating modes, including:

[0032] The temperature at the temperature detection point is collected using the temperature sensor and the temperature acquisition device, respectively.

[0033] The temperature collected by the temperature acquisition device is corrected against the temperature collected by the temperature sensor to obtain the temperature data.

[0034] In some implementations, the operating modes include at least a plurality of modes selected from AC charging, inverter charging, inverter discharging, PV charging, AC charging and PV charging, AC charging and inverter discharging, and PV charging and inverter discharging.

[0035] In some implementations, the fitting algorithm includes at least one of linear fitting, Gaussian fitting, or smoothing curves.

[0036] The inverter according to the embodiments of this application includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor implements the control method described above.

[0037] The energy storage system of this application includes the inverter.

[0038] The control method, inverter, and energy storage system of this application acquire operating data such as temperature, voltage, power, and current data from multiple temperature detection points operating in different environments and various working modes. Based on the operating data and a fitting algorithm, the correlation coefficients between the inverter's temperature and the external ambient temperature, voltage, and power are calculated to obtain the influence of these factors on the inverter's temperature. The correlation coefficients are then calibrated with the fan's duty cycle to obtain target coefficients. A control equation for the fan's duty cycle is constructed based on the target coefficients, establishing a mapping relationship between the fan's duty cycle and the external ambient temperature, voltage, and power. Thus, the target fan speed can be calculated based on the duty cycle control equation, the fan's maximum speed, and the inverter's current operating data to control the fan's operation. This achieves intelligent fan control under different operating conditions, states, and power device differences, ensuring normal inverter operation while avoiding energy waste.

[0039] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0040] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0041] Figure 1 This is a flowchart illustrating the fan control method according to an embodiment of this application.

[0042] Figure 2This is a schematic diagram of the inverter module according to the embodiments of this application.

[0043] Figure 3 This is a schematic diagram illustrating the relationship between battery terminal voltage and fan speed duty cycle in an embodiment of this application.

[0044] Figure 4-8 This is a flowchart illustrating the fan control method according to an embodiment of this application. Detailed Implementation

[0045] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0046] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection or an integral connection; a mechanical connection or an electrical connection or a connection that allows communication; a direct connection or an indirect connection through an intermediate medium; or a connection within two components or an interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] Please see Figure 1 This application provides a fan control method for an inverter, the control method including:

[0049] 01. Obtain operating data of the inverter under different environments and in multiple operating modes. The operating data includes temperature data, voltage data, power data and current data of multiple temperature detection points in the inverter. The location of the temperature detection points is related to the device layout of the inverter.

[0050] 02. Based on the operating data and fitting algorithm, calculate the correlation coefficients between the inverter temperature and the external ambient temperature, voltage, and power of the inverter.

[0051] 03. Calculate the correlation coefficient and the target coefficient of the fan speed duty cycle based on the operating data;

[0052] 04. Construct the fan speed duty cycle control equation based on the target coefficient;

[0053] 05. Solve for the target fan speed based on the speed duty cycle control equation, the fan's maximum speed, and the inverter's current operating data;

[0054] 06. Control the fan operation according to the target speed.

[0055] This application also provides an inverter, including a fan, a processor, and a memory. The memory stores a computer program. When the computer program is executed by the processor, the processor implements the aforementioned fan control method. That is, the processor can acquire operating data of the inverter under different environments and in multiple operating modes. The operating data includes temperature data, voltage data, power data, and current data from multiple temperature detection points in the inverter. The location of the temperature detection points is related to the device layout of the inverter. Based on the operating data and a fitting algorithm, the processor calculates the correlation coefficients between the inverter's temperature and the external ambient temperature, voltage, and power. The processor can also calculate the target coefficients of the correlation coefficients and the fan's speed duty cycle based on the operating data. Based on the target coefficients, it constructs a control equation for the fan's speed duty cycle. Based on the speed duty cycle control equation, the fan's maximum speed, and the inverter's current operating data, it calculates the target speed of the fan and controls the fan's operation based on the target speed.

[0056] In the control method and inverter of this application, operating data such as temperature, voltage, power, and current data from multiple temperature detection points under different environments and operating in multiple modes are acquired. Correlation coefficients between the inverter's temperature and the external ambient temperature, voltage, and power are calculated based on the operating data and a fitting algorithm, thus revealing the influence of these factors on the inverter's temperature. The correlation coefficients are then calibrated with the fan's duty cycle to obtain target coefficients. A fan duty cycle control equation is constructed based on the target coefficients, establishing a mapping relationship between the fan's duty cycle and the external ambient temperature, voltage, and power. This allows for the calculation of the fan's target speed based on the duty cycle control equation, the fan's maximum speed, and the inverter's current operating data, thereby controlling the fan's operation. This enables intelligent fan control under different operating conditions, states, and power device variations, ensuring normal inverter operation while avoiding energy waste.

[0057] Please see Figure 2Specifically, the inverter can be an energy storage inverter. As those skilled in the art will understand, an energy storage inverter is a device connected between an energy storage battery and the power grid, capable of bidirectional energy conversion. It can store direct current (DC) generated from renewable energy sources (such as solar and wind power) and convert the stored electrical energy into alternating current (AC) output when needed to meet the electricity demands of households, businesses, or the power grid. The inverter may include power devices such as fans, input common-mode, PV modules, PV capacitors, PV inductors, LLC capacitors, LV_LCC, LV sampling circuits, LLC transformers, resonant inductors, resonant capacitors, PFC, PFC inductors, bus capacitors, HV_LLC, input common-mode, and output common-mode, as well as ports such as AC terminals, battery terminals, and PV input terminals. The fans may include a first fan and a second fan. The first fan draws air from the outside into the inverter, and the second fan exhausts air from the inverter for heat dissipation. Understandably, the layout of the various components in the inverter can be configured as needed; that is, the layout of the various components in the inverter is not limited.

[0058] The inverter also includes multiple temperature detection points, each equipped with a temperature sensor to detect the temperature at that point. These temperature detection points can be located at the positions of the first fan, second fan, PFC, HV_LLC, PV, or LV_LLC, etc. Specifically, a temperature detection point near the first fan detects the external ambient temperature of the inverter; a point near the second fan detects the internal ambient temperature (the highest internal temperature); a point near the first fan detects the external ambient temperature; a point at the PFC detects the PFC temperature; a point at the PV detects the PFC temperature; a point at the HV_LLC detects the HV_LLC temperature; and a point at the LV_LLC detects the LV_LLC temperature. It is understood that the temperature detection points are not limited to these locations; their arrangement can be based on the layout and number of components, and their distribution is not unique.

[0059] Temperature sensors can be, but are not limited to, thermocouples, resistance temperature detectors (RTDs), semiconductor temperature sensors, etc. For example, in this embodiment, a thermocouple can be used as an example for temperature sensor description. It is understood that thermocouples have a wide range of applications, can measure high and low temperatures and situations with rapid temperature changes, and are low in cost and do not require a power supply.

[0060] Please refer to further information. Figure 2In this embodiment, to improve the heat dissipation efficiency of the inverter, the layout of the components inside the inverter can be as follows: the output common mode, FPC, and HV_LLC are arranged side by side to form a first row, and the PV and LV_LLC are arranged side by side to form a second row. The first and second rows are spaced apart to form an air duct, and the direction of the air duct is along the length of the inverter. The fan may include a first fan and a second fan, which are located on the two short sides of the inverter and are positioned directly opposite the air duct.

[0061] The bus capacitor, PFC inductor, HV_MCU, resonant capacitor, resonant inductor, LLC transformer, and HV sampling circuit are arranged side-by-side and spaced apart in the air duct between the first and second rows. The bus capacitor is positioned close to the second fan. The PV capacitor and PV inductor are arranged side-by-side and spaced apart on one side of the PV fan. The LV_MCU, LLC capacitor, and LV sampling circuit are arranged side-by-side and spaced apart on one side of the LV_LLC fan, forming a row with the PV capacitor and PV inductor. The input common-mode circuit is located on the PV fan side near the second fan, and the output common-mode circuit is located on the FPC fan side near the second fan.

[0062] The AC side includes an AC input terminal and an AC output terminal. The AC input terminal, PV input terminal, and battery terminal are arranged sequentially and alternately along one of the long sides of the inverter. The AC input terminal is positioned near the second fan, and the AC output terminal is located on the other long side of the inverter, also near the second fan. The AC output terminal and AC input terminal are used to connect to an AC power source or AC load. The battery terminal is used to connect to an energy storage battery. The PV input terminal connects to the solar module and converts the DC power generated by the solar module into AC power.

[0063] Please refer to further information. Figure 2 The energy storage device is equipped with four temperature detection points, namely T inlet T outlet T PFC T LLC , among which, T inlet Place it near the first fan (air inlet) to detect the incoming airflow, i.e., the ambient temperature outside the inverter, T. outlet It is placed near the second fan (at the air inlet) to detect the temperature of various internal components before they flow out, and it is also the highest internal temperature point, i.e., the internal ambient temperature of the inverter. PFc Place it in the location with the highest heat output, such as the PFC or HV_LLC. LLC Place it in the area of ​​the PV or LV_LLC module where the heat is highest. The temperature sensor may include four sensors, each located at T... inlet T outlet T PFC T LLCThese four temperature detection points are used to detect the temperature at each of these points.

[0064] The processor can be electrically connected to each component in each inverter to obtain the inverter's operating parameters in real time. Temperature data can be obtained by the processor from temperature sensors, while voltage, power, and current data can be detected from ports such as the AC input, AC output, PV input, and battery. Thus, the temperature data obtained by the processor can include temperature data from multiple temperature detection points in the inverter, including the air inlet, air outlet, resonant converter, and power factor correction module. Voltage data includes, but is not limited to, AC terminal voltage and battery terminal voltage; current data includes, but is not limited to, AC terminal current and battery terminal current; and power data includes AC terminal power and battery terminal power. Furthermore, it can be understood that power data can be obtained directly or calculated based on voltage and current.

[0065] The internal temperature change of an inverter is related to the external ambient temperature, current, voltage, and power. Therefore, in order to accurately reflect the correlation between the internal temperature change of the inverter and the ambient temperature, current, voltage, and power, in step 01, multiple inverters can be operated in different environments and in various operating modes to obtain operating data. The more operating data, the more accurate the correlation between the internal temperature of the inverter and the ambient temperature, current, voltage, and power.

[0066] It should be noted that the environment can include, but is not limited to, normal temperature, high temperature, vacuum, and alternating high and low temperature environments. The working modes can include, but are not limited to, AC charging, inverter discharging, PV charging, AC charging + PV charging, AC charging + inverter discharging, and PV charging + inverter discharging.

[0067] After obtaining the operating data, the processor can use a fitting algorithm and the operating data to fit at least one of the following correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, (input / output) voltage, (input / output) power, and (input / output) current: For example, the processor can fit the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature and input power using the fitting algorithm; alternatively, the processor can fit the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, DC voltage, and power using the fitting algorithm and the operating data; still another example is that the processor can fit the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, AC voltage, DC voltage, and power using the fitting algorithm and the operating data. In this embodiment, the example of fitting the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, AC voltage, DC voltage, and power will be used for explanation. Specifically, the correlation coefficients between the fitted temperature and the inverter's DC voltage (K_Vdc_Initial), the correlation coefficients between the temperature and the inverter's power (K_Pdc_Initial), the correlation coefficients between the fitted temperature and the inverter's external ambient temperature (K_Temp_Initial), and the correlation coefficients between the fitted temperature and the inverter's AC voltage (K_Vac_Initial).

[0068] It should be noted that the fitting algorithm may include, but is not limited to, at least one of linear fitting, Gaussian fitting, or smooth curves.

[0069] Furthermore, the processor can set known quantities based on the operating data to solve for the target coefficients of the correlation coefficients and the fan speed duty cycle. The known quantities include the average battery terminal voltage, average battery power, average ambient temperature, and AC terminal voltage range during inverter operation. The target coefficients can include the target coefficients K_Vdc (fan speed duty cycle and battery terminal voltage), K_Pdc (fan speed duty cycle and battery terminal power), K_Temp (fan speed duty cycle and ambient temperature), and K_Vac (fan speed duty cycle and AC terminal voltage).

[0070] The target coefficients for the fan speed duty cycle and battery terminal voltage are: K_Vdc = K_Vdc_Initial / average battery terminal voltage; K_Pdc = K_Pdc_Initial / average battery power; K_Temp = K_Temp_Initial / average external ambient temperature; and K_Vac = K_Vac_Initial / (upper limit AC terminal voltage - lower limit AC terminal voltage).

[0071] For example, in some cases, based on operating data and fitting algorithms, the correlation coefficients K_Vdc_Initial = 0.3 between temperature and inverter DC voltage, K_Pdc_Initial = 0.1 between temperature and inverter power, K_Temp_Initial = 0.3 between temperature and inverter ambient temperature, and K_Vac_Initial = 0.4 between temperature and inverter AC voltage are fitted. If the average battery terminal voltage is 42.7 ohms, the average battery power is 2200 ohms, the average ambient temperature is 35 ohms, the upper limit of AC terminal voltage is 264 ohms, and the lower limit of AC terminal voltage is 185 ohms, then substituting these values ​​into the calculation formula yields:

[0072] K_Vdc = 0.3 / 42.7 = 7.0258 * 10 -3

[0073] K_Pdc = 0.1 / 2200 = 4.5455 * 10 -5

[0074] K_Temp = 0.3 / 35 = 8.5714 * 10 -3

[0075] K_Vac=0.4 / (264-185)=5.0633*10 -3

[0076] The speed duty cycle control equation is used to solve for the fan's speed duty cycle. During fan control, the processor can acquire the current operating data in real time and substitute the data related to the speed duty cycle control equation into the current operating data to calculate the fan's speed duty cycle. Based on the speed duty cycle and the fan's maximum speed, the target speed is calculated to control the fan to operate at the target speed.

[0077] Thus, through the implementation method of this application, intelligent control of fans under different external ambient temperatures, different states, power device differences, and different usage environments can be achieved.

[0078] In some embodiments, the calculation expression for the speed duty cycle control equation may include:

[0079] D_FAN_Control(VLVDC,PLVDC,Ta,Vac):=(VLVDC-48) 2 ·K_Vdc+PLVDC·K_Pdc+Ta·K_Temp+(264-Vac)·K_Vac

[0080] Wherein, VLVDC is the battery terminal voltage, PLVDC is the battery terminal power, Ta is the ambient temperature at the air inlet, Vac is the AC terminal voltage, K_Vdc is the target coefficient of fan speed duty cycle and battery terminal voltage, K_Pdc is the target coefficient of fan speed duty cycle and battery terminal power, K_Temp is the target coefficient of fan speed duty cycle and air inlet temperature, and K_Vac is the target coefficient of fan speed duty cycle and AC terminal voltage.

[0081] Please see Figure 3 The figure shows the battery terminal voltage versus fan speed duty cycle fitting curves obtained by fitting the speed duty cycle control equation when the inverter is running under different operating conditions.

[0082] Please see Figure 4 In some implementations, 01 includes;

[0083] 011, the temperature at the temperature detection point is collected by temperature sensor and temperature acquisition device respectively;

[0084] 012, the temperature collected by the temperature acquisition device is corrected against the temperature collected by the temperature sensor to obtain temperature data.

[0085] In some implementations, the processor can be used to acquire the temperature of a temperature detection point through a temperature sensor and a temperature acquisition device, respectively; and to correct the temperature acquired by the temperature acquisition device against the temperature acquired by the temperature sensor to obtain temperature data.

[0086] It should be noted that the temperature detected by the temperature sensor may be inaccurate due to variations in the environment, particularly in extreme conditions (such as high-temperature environments). Therefore, this application also includes an additional temperature acquisition device. This device can accurately measure the temperature at various locations within the inverter. When the inverter operates in different environments and multiple modes, the processor can acquire temperature data from both the temperature sensor and the temperature acquisition device, and then use the data acquired by the temperature acquisition device to correct the temperature data acquired by the temperature sensor.

[0087] This ensures the accuracy of temperature data, thereby improving the control effect.

[0088] Please see Figure 5 In some implementations, 05 includes:

[0089] 051, if any temperature in the current temperature data is greater than or equal to a preset temperature threshold, the highest fan speed will be used as the target speed; or

[0090] 052. If all temperatures in the current temperature data are lower than the preset temperature threshold, input the current battery terminal voltage, AC terminal voltage, battery terminal power and the temperature at the air inlet position into the speed duty cycle control equation to solve for the fan speed duty cycle.

[0091] 053, the target speed is calculated based on the rotational speed duty cycle and the fan's maximum speed.

[0092] In some implementations, the processor can be used to take the maximum fan speed as the target speed when any temperature in the current temperature data is greater than or equal to a preset temperature threshold, or to input the current battery terminal voltage, AC terminal voltage, battery terminal power, and temperature at the air inlet position into the speed duty cycle control equation to solve for the fan speed duty cycle when all temperatures in the current temperature data are less than the preset temperature threshold; and to solve for the target speed based on the speed duty cycle and the maximum fan speed.

[0093] It should be noted that the preset temperature thresholds for different temperature detection points can be the same or different. For example, in some examples, T inlet T outlet T PFC T LLC Of these four temperature detection points, T inlet The preset temperature threshold can be 60 degrees Celsius, T outlet The preset temperature threshold can be 60 degrees Celsius, T PFC The preset temperature threshold can be 80 degrees Celsius, T LLC The preset temperature threshold can be 80 degrees Celsius. That is, if T inlet ≥60℃ or T outlet ≥60℃ or T PFC ≥80℃ or T LLC If the temperature is ≥80℃, the maximum speed of the fan will be used as the target speed.

[0094] If all temperatures in the current temperature data are lower than the preset temperature threshold, the current battery terminal voltage, AC terminal voltage, battery terminal power, and temperature at the air inlet position are input into the fan speed duty cycle control equation to solve for the duty cycle. The obtained fan speed duty cycle is then multiplied by the fan's maximum speed to obtain the target speed.

[0095] Additionally, it should be noted that to prevent inverter damage due to overheating, each temperature detection point is equipped with an OTP protection point and an OTP recovery point. The OTP protection point is used to trigger OTP protection, and the OTP recovery point is used to disable OTP protection. If the processor detects that the temperature at any temperature detection point exceeds the temperature of the OTP protection point, the OTP protection function is triggered, thereby cutting off the power supply, and the OTP protection function is disabled at the OTP recovery point. The OTP protection point is above a preset temperature threshold.

[0096] In this example, at T inlet T outlet T PFC T LLC The OTP protection point and OTP recovery point among these four temperature detection points are shown in Table 1 below.

[0097] Temperature sensor location OTP protection point OTP Recovery Point <![CDATA[T inlet ]]> 65℃ 60℃ <![CDATA[T outlel ]]> 65℃ 60℃ <![CDATA[T PFC ]]> 90℃ 80℃ <![CDATA[T LLC ]]> 90℃ 80℃

[0098] Table 1

[0099] Please refer to 6. In some embodiments, step 06 includes, including

[0100] 061, when the target speed is within the range of the fan's minimum and maximum speeds, control the fan to operate at the target speed; or

[0101] 062, If the target speed is greater than the fan's maximum speed, control the fan to operate at its maximum speed; or

[0102] 063, when the target speed is less than the minimum speed of the fan, control the fan to operate at the minimum speed.

[0103] In some implementations, the processor controls the fan to operate at a target speed when the target speed is within the range of the fan's minimum and maximum speeds; controls the fan to operate at the maximum speed when the target speed is greater than the fan's maximum speed; and controls the fan to operate at the minimum speed when the target speed is less than the fan's minimum speed.

[0104] For example, in some examples, the minimum fan speed is 2000 rpm and the maximum speed is 5500 rpm. If the target speed is greater than 5500 rpm, the fan is controlled to operate at 5500 rpm; if the target speed is less than 2000 rpm, the fan is controlled to operate at 2000 rpm. If the target speed is in the range of 2000-5500 rpm, the fan is directly controlled to operate at the target speed.

[0105] Please see Figure 7 In some implementations, the control method further includes:

[0106] 07. Obtain the current operating mode of the inverter;

[0107] 08. If the current operating mode is AC charging mode and the current operating data meets the first preset condition, start the fan; or

[0108] 09. If the current operating mode is inverter discharge mode and the current operating data meets the second preset condition, start the fan.

[0109] In some implementations, the processor includes acquiring the current operating mode of the inverter; starting the fan if the current operating mode is AC charging mode and the current operating data meets a first preset condition; or starting the fan if the current operating mode is inverter discharging mode and the current operating data meets a second preset condition.

[0110] The first preset condition includes one of the following: the inverter's battery terminal current is greater than or equal to a first preset current threshold; the temperature at the power factor correction module location is greater than or equal to a first temperature threshold; or the temperature at the resonant converter location is greater than or equal to a second temperature threshold. The second preset condition includes one of the following: the battery terminal power is greater than a first power threshold; the temperature at the power factor correction module location is greater than or equal to a first temperature threshold; or the temperature at the resonant converter location is greater than or equal to a second temperature threshold.

[0111] In this way, by setting the fan's start-up conditions, energy waste in low-power environments is avoided, and the inverter's performance is improved.

[0112] Please see Figure 8 In some implementations, the control method further includes:

[0113] 11. When the operating mode is charging mode and the temperature at the air inlet is less than the third temperature threshold, the maximum operating speed of the fan is 75% of the highest speed; or

[0114] 12. When the working mode is charging mode, the temperature at the air inlet is greater than the fourth temperature threshold and the charging current is greater than the first current threshold, the fan speed is set to the highest speed.

[0115] In some implementations, the processor is also configured to set the maximum operating speed of the fan to 75% of the highest speed when the operating mode is charging mode and the temperature at the air inlet is less than a third temperature threshold; or to set the fan speed to the highest speed when the operating mode is charging mode, the temperature at the air inlet is greater than a fourth temperature threshold, and the charging current is greater than a first current threshold.

[0116] It should be noted that the third temperature threshold is less than the fourth temperature threshold. In this embodiment, the third temperature threshold can be 35 degrees Celsius, the fourth temperature threshold can be 40 degrees Celsius, and the first current threshold can be 1A. That is, in charging mode, if the temperature T at the air inlet is... inlet When the temperature is below 35℃, the fan's maximum operating speed is 75% of its highest speed. If the temperature T at the air inlet is... inlet The temperature is above 40℃, the charging current is greater than 1A, and the speed is set to the highest speed.

[0117] Understandably, the temperature T at the air inlet location... inlet The temperature is determined by the external ambient temperature, and the overall temperature of the inverter is greatly affected by the external ambient temperature. The temperature T at the air inlet is a key factor. inlet When the temperature is below the third temperature threshold, the overall temperature of the inverter is mainly affected by the power devices during charging. Therefore, limiting the maximum speed can reduce energy consumption. However, if the ambient temperature is too high, and the inverter is in a high-current charging mode, the overall temperature of the inverter is prone to becoming too high during charging. Therefore, it is necessary to enhance heat dissipation. This ensures efficient heat dissipation when the inverter is in a high-temperature environment and undergoing high-current charging.

[0118] This application also provides an energy storage system, which includes the inverter described in the above embodiments.

[0119] In the energy storage system of this application, operating data is acquired under different environments and in multiple operating modes. The correlation coefficients between the inverter's temperature and the external ambient temperature, voltage, and power are calculated based on the operating data and a fitting algorithm. The target coefficients for the fan's speed duty cycle are calculated based on the operating data. A control equation for the fan's speed duty cycle is constructed based on the target coefficients. The target fan speed is calculated based on the speed duty cycle control equation, the fan's maximum speed, and the inverter's current operating data. The fan is then controlled according to the target speed. This achieves intelligent fan control under different operating conditions, ensuring the inverter's normal operation while avoiding energy waste.

[0120] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0121] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A fan control method for an inverter, characterized in that, The control method includes: The system acquires operating data of the inverter under different environments and in multiple operating modes. This operating data includes temperature data, voltage data, power data, and current data from multiple temperature detection points within the inverter. The locations of these temperature detection points are related to the inverter's component layout and include the locations of the air inlet, air outlet, resonant converter, and power factor correction module. The voltage data includes AC terminal voltage and battery terminal voltage, the current data includes battery terminal current, and the power data includes battery terminal power. Based on the operating data and the fitting algorithm, the correlation coefficients between the inverter's temperature and the inverter's external ambient temperature, voltage, and power are calculated respectively. The correlation coefficient and the target coefficient of the fan speed duty cycle are calculated based on the operating data. Construct a speed duty cycle control equation for the fan based on the target coefficients; The target speed of the fan is calculated based on the speed duty cycle control equation, the maximum speed of the fan, and the current operating data of the inverter, including: if any temperature in the current temperature data is greater than or equal to a preset temperature threshold, the maximum speed of the fan is used as the target speed; or if all temperatures in the current temperature data are less than the preset temperature threshold, the current battery terminal voltage, AC terminal voltage, battery terminal power, and the temperature at the air inlet are input into the speed duty cycle control equation to obtain the fan speed duty cycle; the target speed is then calculated based on the speed duty cycle and the maximum speed of the fan; and The fan is controlled to operate according to the target rotation speed; The calculation expression for the speed duty cycle control equation includes: D_FAN_Control(VLVDC,PLVDC,Ta,Vac)=(VLVDC-48) 2 ·K_Vdc+PLVDC·K_Pdc+Ta·K_Temp+(264-Vac)·K_Vac Wherein, D_FAN_Control is the fan speed duty cycle, VLVDC is the battery terminal voltage, PLVDC is the battery terminal power, Ta is the temperature at the air inlet, Vac is the AC terminal voltage, K_Vdc is the target coefficient between the fan speed duty cycle and the battery terminal voltage, K_Pdc is the target coefficient between the fan speed duty cycle and the battery terminal power, K_Temp is the target coefficient between the fan speed duty cycle and the temperature at the air inlet, and K_Vac is the target coefficient between the fan speed duty cycle and the AC terminal voltage.

2. The control method according to claim 1, characterized in that, The step of controlling the fan to operate according to the target rotation speed includes: Within the range of the fan's minimum and maximum speeds, the fan is controlled to operate at the target speed; or If the target rotational speed is greater than the fan's maximum rotational speed, control the fan to operate at the maximum rotational speed; or If the target rotational speed is less than the minimum rotational speed of the fan, the fan is controlled to operate at the minimum rotational speed.

3. The control method according to claim 1, characterized in that, The control method further includes: Obtain the current operating mode of the inverter; The fan is started when the current operating mode is AC charging mode and the current operating data meets the first preset condition; or When the current operating mode is inverter discharge mode and the current operating data meets the second preset condition, the fan is started.

4. The control method according to claim 3, characterized in that, The first preset condition includes one of the following: the battery terminal current of the inverter is greater than or equal to a first preset current threshold, the temperature at the location of the power factor correction module is greater than or equal to a first temperature threshold, and the temperature at the location of the resonant converter is greater than or equal to a second temperature threshold. The second preset condition includes one of the following: the battery terminal power is greater than the first power threshold, the temperature at the location of the power factor correction module is greater than or equal to the first temperature threshold, and the temperature at the location of the resonant converter is greater than or equal to the second temperature threshold.

5. The control method according to claim 3, characterized in that, Control methods also include: When the operating mode is charging mode and the temperature at the air inlet is less than the third temperature threshold, the maximum operating speed of the fan is 75% of the highest speed; or When the operating mode is charging mode, the temperature at the air inlet is greater than the fourth temperature threshold, and the charging current is greater than the first current threshold, the fan speed is set to the maximum speed.

6. The control method according to claim 1, characterized in that, The inverter includes a temperature sensor located at the temperature detection point, which acquires operating data of the inverter under different environments and in multiple operating modes, including: The temperature at the temperature detection point is collected using the temperature sensor and the temperature acquisition device, respectively. The temperature collected by the temperature acquisition device is corrected against the temperature collected by the temperature sensor to obtain the temperature data.

7. The control method according to claim 1, characterized in that, The operating modes include AC charging, inverter charging, inverter discharging, PV charging, AC charging + PV charging, AC charging + inverter discharging, and PV charging + inverter discharging.

8. The control method according to claim 1, characterized in that, The fitting algorithm includes at least one of linear fitting and Gaussian fitting.

9. An inverter, characterized in that, It includes a processor and a memory, the memory storing a computer program that, when executed by the processor, causes the processor to implement the control method according to any one of claims 1-8.

10. An energy storage system, characterized in that, Including the inverter as described in claim 9.

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