Cooling control method and device for fan in energy storage system

Abstract

The invention discloses a cooling control method and device for a fan in an energy storage system, and relates to the technical field of photovoltaic energy storage inverter systems. The method comprises the following steps: acquiring an electrical parameter of a power module and a temperature value of a radiator in the energy storage system; determining operation loss of a power device in the power module based on the electrical parameters, and determining real-time junction temperature of the power device based on the operation loss and a temperature value; and comparing the real-time junction temperature and the temperature value of the radiator with corresponding preset temperature threshold values, and adaptively adjusting the duty ratio of a pulse width modulation signal of a fan for driving the radiator according to a comparison result so as to control the rotating speed of the fan, so that the real-time junction temperature and the temperature value of the radiator are maintained in a preset balance interval. By means of the technical scheme, accurate dynamic adjustment of the rotating speed of the draught fan can be achieved, and operation noise and energy consumption are reduced to the maximum extent while the thermal safety margin of equipment is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic energy storage inverter systems, and particularly relates to a cooling control method and device for a fan in an energy storage system. BACKGROUND

[0002] The current speed of an external cooling fan of a photovoltaic grid-connected inverter or energy storage inverter system mainly adopts a direct control logic based on the power of the inverter and the temperature of the core components. Although this control method can achieve basic cooling function, it has significant limitations: first, the control strategy is mostly a simple threshold trigger adjustment, which lacks fine adaptation to dynamic operating conditions of the system; second, the fan is often in a high-frequency full-speed operating state, which leads to prominent noise pollution problems, especially in household and commercial distributed scenarios, and the user experience is poor; third, the speed regulation response lags behind the actual cooling demand fluctuations, which may cause "overcooling" or "undercooling" phenomena, affecting the operating efficiency of the equipment and shortening the service life of the fan. These problems make it difficult for the existing scheme to meet the application requirements of household and commercial users for low noise, high reliability and intelligent operation and maintenance of the energy storage system. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a cooling control method and device for a fan in an energy storage system, which can achieve precise dynamic regulation of the fan speed, maximize the reduction of operating noise and energy consumption while ensuring the thermal safety margin of the equipment, and effectively realize low noise, high reliability and intelligent dynamic control of photovoltaic grid-connected inverters or energy storage inverters in household and commercial scenarios. The specific scheme is as follows:

[0004] In a first aspect, the present application discloses a cooling control method for a fan in an energy storage system, comprising:

[0005] obtaining an electrical parameter of a power module and a temperature value of a radiator in the energy storage system;

[0006] determining the operating loss of a power device in the power module based on the electrical parameter, and determining the real-time junction temperature of the power device based on the operating loss and the temperature value of the radiator;

[0007] comparing the real-time junction temperature and the temperature value of the radiator with corresponding preset temperature thresholds respectively, and adaptively adjusting the duty cycle of a pulse width modulation signal of a fan driving the radiator according to the comparison results, to control the speed of the fan, so that the real-time junction temperature and the temperature value of the radiator are maintained within a preset balance interval.

[0008] Optionally, the electrical parameter of the power module in the energy storage system is obtained, comprising:

[0009] Obtaining a first electrical parameter, a second electrical parameter and a third electrical parameter in a power module in an energy storage system;

[0010] The first electrical parameter includes an input voltage and an inductor current of a BOOST circuit on a photovoltaic side in the power module, the second electrical parameter includes an input voltage and an inductor current of a DCDC circuit on a battery side in the power module, and the third electrical parameter includes a phase voltage and a phase current on an alternating current side in the power module.

[0011] Optionally, the operation loss of the power device in the power module is determined based on the electrical parameters, and the operation loss of the power device in the power module is determined based on the electrical parameters.

[0012] A loss model including conduction loss and switching loss is constructed according to characteristic parameters of the power device.

[0013] The conduction loss and the switching loss of the power device are respectively determined based on the loss model and the real-time sampled electrical parameters.

[0014] The operation loss is determined based on the conduction loss and the switching loss.

[0015] Optionally, the loss model including conduction loss and switching loss is constructed according to characteristic parameters of the power device, and the loss model including conduction loss and switching loss is constructed according to characteristic parameters of the power device.

[0016] According to the data manual of the power device, the relationship between the conduction voltage drop and the collector current is fitted into a first-order curve to obtain a conduction loss curve.

[0017] The relationship between the switching loss and the collector current, the driving resistance, the conduction voltage drop and the junction temperature is fitted into a second-order curve to obtain a switching loss curve.

[0018] Correspondingly, the conduction loss and the switching loss of the power device are respectively determined based on the loss model and the real-time sampled electrical parameters, and the conduction loss and the switching loss of the power device are respectively determined based on the loss model and the real-time sampled electrical parameters.

[0019] A conduction loss calculation formula is determined based on the conduction loss curve, and a switching loss calculation formula is determined based on the switching loss curve.

[0020] The conduction loss and the switching loss of the power device are respectively determined by using the conduction loss calculation formula, the switching loss calculation formula and the real-time sampled electrical parameters.

[0021] Optionally, the expression of the conduction loss curve is:

[0022] (1);

[0023] wherein, the conduction voltage drop is the collector current is For conduction resistance, This represents the initial saturation pressure drop;

[0024] The expression for the switching loss curve is:

[0025] (2);

[0026] (3);

[0027] (4);

[0028] (5);

[0029] in, The switching loss is mentioned above. The driving resistor, The junction temperature is... , , , These are the constants after fitting.

[0030] Optionally, the formula for calculating the conduction loss is:

[0031] (6);

[0032] in, The conduction loss is... The switching cycle time. For the effective value current, This is the average current.

[0033] The formula for calculating the switching loss is as follows:

[0034] (7);

[0035] in, The switching loss is mentioned above. This is the actual driving resistance value. For reference drive resistor value, This represents the actual conduction voltage drop. For reference conduction voltage drop, This is the actual junction temperature value. This is a reference junction temperature value.

[0036] Optionally, determining the real-time junction temperature of the power device based on the operating losses and the temperature value of the heat sink includes:

[0037] Based on the aforementioned operating losses and the temperature value of the radiator, using Determine the real-time junction temperature of the power device;

[0038] in, The real-time junction temperature, For the aforementioned operating losses, The junction-to-case thermal resistance of the power device is... The temperature value of the radiator. Temperature protection values ​​that take into account tolerance and margin.

[0039] Optionally, comparing the real-time junction temperature and the temperature value of the heat sink with corresponding preset temperature thresholds includes:

[0040] A first junction temperature threshold and a second junction temperature threshold are set for the real-time junction temperature; the first junction temperature threshold is greater than the second junction temperature threshold.

[0041] A first radiator temperature threshold and a second radiator temperature threshold are set for the temperature value of the radiator; the first radiator temperature threshold is greater than the second radiator temperature threshold.

[0042] Based on the comparison results of the first parameter and the second parameter, an adjustment command for the duty cycle of the pulse width modulation signal of the wind turbine is generated.

[0043] Wherein, the first parameter comparison result is the comparison result between the real-time junction temperature and the first secondary junction temperature threshold and the second secondary junction temperature threshold, respectively, and the second parameter comparison result is the comparison result between the temperature value of the heat sink and the first secondary heat sink temperature threshold and the second secondary heat sink temperature threshold, respectively.

[0044] Optionally, based on the comparison results, the duty cycle of the pulse width modulation signal driving the fan of the radiator is adaptively adjusted, including:

[0045] When the real-time junction temperature is greater than or equal to the first junction temperature threshold, or when the temperature value of the heat sink is greater than or equal to the first heat sink temperature threshold, the temperature is determined to be in a high state, and the duty cycle is increased by a first preset step size.

[0046] When the real-time junction temperature is greater than the second junction temperature threshold and less than the first junction temperature threshold, and the temperature value of the heat sink is greater than the second heat sink temperature threshold and less than the first heat sink temperature threshold, the temperature is determined to be in the equilibrium range, and the duty cycle remains unchanged.

[0047] When the conditions for determining the high temperature are not met, and the conditions for determining the equilibrium range are not met, the temperature is determined to be in a low temperature state, and the duty cycle is reduced by a second preset step size.

[0048] Secondly, this application discloses a cooling control device for a fan in an energy storage system, comprising:

[0049] The signal acquisition module is used to acquire the electrical parameters of the power modules and the temperature values ​​of the heat sink in the energy storage system.

[0050] A real-time calculation module is used to determine the operating losses of the power devices in the power module based on the electrical parameters, and to determine the real-time junction temperature of the power devices based on the operating losses and the temperature value of the heat sink.

[0051] An adaptive adjustment module is used to compare the real-time junction temperature and the temperature value of the radiator with the corresponding preset temperature thresholds, and based on the comparison results, adaptively adjust the duty cycle of the pulse width modulation signal driving the fan of the radiator to control the speed of the fan so that the real-time junction temperature and the temperature value of the radiator are maintained within a preset balance range.

[0052] The beneficial effects of this application are as follows: By calculating the real-time junction temperature by combining the operating losses of power devices with the heat sink temperature, the heating trend can be predicted in advance and the cooling strategy adjusted before the power devices actually overheat. This internal heat source prediction based on the loss model, compared with traditional control that relies solely on external heat sink temperature triggering, can reflect changes in heat dissipation demand earlier and more accurately, thus fundamentally avoiding the phenomenon of "overheating" or "underheating" caused by response lag, and ensuring that the control response is synchronized with the heat dissipation demand. The solution makes a comprehensive decision by comparing the real-time junction temperature and the heat sink temperature values ​​with preset thresholds, realizing simultaneous monitoring of the core heat source (power devices) and the state of the heat dissipation system (heat sink). The fan speed is increased only when either or both indicate that heat dissipation needs to be strengthened; otherwise, if there is sufficient margin for temperature rise, the speed is actively reduced. This fine adjustment based solely on actual heat demand breaks the convention of fans running at high speed all year round, minimizing fan operating noise and unnecessary energy consumption, and is particularly suitable for the stringent requirements of low noise and high energy efficiency in residential and industrial / commercial scenarios.

[0053] Furthermore, the cooling control device, equipment, and storage medium for a fan in an energy storage system provided in this application correspond to the cooling control method for the fan in the aforementioned energy storage system, and have the same effect. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0055] Figure 1 This is a flowchart of a cooling control method for a fan in an energy storage system disclosed in this application;

[0056] Figure 2 This is a block diagram of a photovoltaic energy storage inverter system.

[0057] Figure 3 Flowchart of an adaptive control method for photovoltaic energy storage inverter system based on loss and thermal balance;

[0058] Figure 4 This is a schematic diagram of the cooling control device for a fan in an energy storage system disclosed in this application;

[0059] Figure 5 This is a structural diagram of an electronic device disclosed in this application. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Currently, the cooling fan speed of photovoltaic / energy storage inverters is mostly controlled by simple thresholds based on power and temperature, which has limitations: the strategy is crude and difficult to adapt to dynamic operating conditions; the fan often runs at high frequency and full speed, resulting in high noise, which affects the user experience in residential and industrial applications; and the response lag causes over / under-cooling, reducing efficiency and shortening lifespan.

[0062] Therefore, this application provides a cooling control scheme for a fan in an energy storage system, which can achieve adaptive adjustment of the fan duty cycle and has significant advantages in noise reduction, energy saving and reliability, and is suitable for residential and commercial photovoltaic energy storage application scenarios.

[0063] This invention discloses a cooling control method for a fan in an energy storage system, see [link to relevant documentation]. Figure 1 As shown, the method includes:

[0064] Step S11: Obtain the electrical parameters of the power module and the temperature values ​​of the heat sink in the energy storage system.

[0065] This step is implemented through an ADC (Analog to Digital) real-time sampling unit, which aims to collect key status data in real time to provide accurate decision-making basis for subsequent operation status analysis, adaptive strategy generation, and wind turbine adjustment execution.

[0066] Specifically, the ADC real-time sampling unit is responsible for acquiring multiple types of signals, including the electrical parameters of the power module and the temperature values ​​of the heat sink. In one specific implementation, the real-time sampling process for the electrical parameters includes: acquiring the first electrical parameter, the second electrical parameter, and the third electrical parameter from the power module in the energy storage system.

[0067] The first electrical parameters include the input voltage and inductor current of the BOOST circuit on the photovoltaic side of the power module. The photovoltaic side is the side of the inverter connected to the photovoltaic array and is used for energy harvesting. Since the output voltage on the photovoltaic side varies drastically with the intensity of sunlight and is usually low, it is boosted to the high-voltage DC bus voltage level required by the inverter through the BOOST circuit. The collected first electrical parameters can be used for MPPT (Maximum Power Point Tracking) control, input power calculation, and input parameters for calculating the power transistor losses on the BOOST side, etc.

[0068] The second electrical parameter includes the input voltage and inductor current of the DC-DC circuit on the battery side of the power module. The current is measured on the side of the inverter connected to the energy storage battery pack, and through a bidirectional DC-DC converter, it is responsible for the bidirectional flow of energy (charging and discharging), maintaining the stability of the DC bus voltage. Collecting this second electrical parameter can be used for battery charging and discharging power control and as input parameters for calculating the power transistor losses on the DC-DC side.

[0069] The third electrical parameter includes the phase voltage and phase current on the AC side of the power module. The AC side connects to the power grid or load and is responsible for converting DC power to AC power to achieve grid connection or power supply. Collecting the third electrical parameter enables the inverter energy storage system to perform bidirectional power control and calculate power transistor losses during inversion or rectification, etc.

[0070] In another specific implementation, for the heat dissipation system, the heat sink temperature is sampled and monitored in real time. Therefore, the temperature value of the heat sink obtained by the ADC real-time sampling unit can be used as the input comparison for threshold determination and thermal balance nonlinear mapping relationship.

[0071] The collected parameter data are converted by an ADC and then sent to a digital signal processor (DSP) as the basic input for subsequent steps. In this way, through comprehensive, real-time data acquisition, quantitative input can be provided for the "adaptive strategy based on multi-parameter coupling" in subsequent steps. This breaks the limitations of traditional fixed-speed control of wind turbines, ensuring that wind turbine regulation shifts from "experience-driven" to "data-driven," fundamentally resolving the contradictions of "insufficient heat dissipation" or "excessive energy consumption" in traditional control.

[0072] Step S12: Based on the electrical parameters, determine the operating losses of the power devices in the power module, and based on the operating losses and the temperature value of the heat sink, determine the real-time junction temperature of the power devices.

[0073] In this step, firstly, based on the collected electrical parameters, the operating losses of the power devices in the power module are calculated in real time. The purpose is to quantify the energy loss of the wind turbine under its current operating state, providing a basis for subsequent adjustments to control parameters based on minimizing losses. The specific details will be described in detail in the following embodiments of the invention, and will not be repeated here.

[0074] Furthermore, based on the calculated operating losses and the heat sink temperature value collected in step S11, combined with the heat dissipation characteristics of the power device, the real-time junction temperature of the power device is calculated. This temperature is the most indicative of whether the component will overheat.

[0075] Specifically, the real-time junction temperature of power devices is determined by the formula... Confirmed. Among them, The real-time junction temperature, For real-time calculation of operating losses, Let be the junction-to-case thermal resistance of the power device, and be a constant determined based on the power device's datasheet. This refers to the actual measured temperature of the radiator. Temperature protection values ​​that take into account tolerance and margin are generally referenced. .

[0076] Step S13: Compare the real-time junction temperature and the temperature value of the radiator with the corresponding preset temperature thresholds, and based on the comparison results, adaptively adjust the duty cycle of the pulse width modulation signal driving the fan of the radiator to control the speed of the fan so that the real-time junction temperature and the temperature value of the radiator are maintained within the preset balance range.

[0077] This step determines whether the temperature is safe. On one hand, it assesses the calculated core temperature of the power device, i.e., the real-time junction temperature; on the other hand, it assesses the collected heatsink temperature. By setting appropriate temperature thresholds for both temperatures and comparing them, the temperature status is determined based on the comparison results. Then, based on the temperature status, the duty cycle of the fan's pulse width modulation signal is adjusted by setting a step size to control the signal strength of the fan speed, thereby adjusting the fan speed. In this way, by judging both the junction temperature (the temperature of the power device itself) and the temperature value (the temperature of the heatsink), dual protection is provided for fan control, avoiding "overheating" or "underheating." For example, if the junction temperature of the power device is just right, but the heatsink is already hot, it indicates high subsequent heat dissipation pressure, and accelerating the fan in advance is safer; conversely, if both are low, the fan speed is reduced to decrease noise, meeting the low-noise requirements of residential scenarios.

[0078] In one specific implementation, junction temperature threshold protection is set: a first junction temperature threshold and a second junction temperature threshold are set for the real-time junction temperature; the first junction temperature threshold is greater than the second junction temperature threshold. For example, taking an IGBT (Insulated Gate Bipolar Transistor) as an example of a power device, the first junction temperature threshold is... (If configurable) The second junction temperature threshold is (If configurable) ).

[0079] The real-time junction temperature is compared with both the first and second junction temperature thresholds, and the comparison result is the first parameter comparison result. Based on the first parameter comparison result, an adjustment command for the duty cycle of the fan's pulse width modulation signal can be generated.

[0080] For example, if This indicates that the junction temperature is too high under these conditions, requiring an increase in the external fan drive duty cycle to reduce the junction temperature; if This indicates that the junction temperature is in a dynamic relative equilibrium range under this condition, maintaining the external fan drive duty cycle; if This indicates that the junction temperature is relatively low under this condition, and there is a margin for temperature rise, which can reduce the duty cycle of the external fan drive.

[0081] In another specific implementation, the radiator temperature threshold is determined by setting a first radiator temperature threshold and a second radiator temperature threshold for the radiator's temperature value; the first radiator temperature threshold is greater than the second radiator temperature threshold. Specifically, the measured temperature value of the radiator in the photovoltaic energy storage system is recorded as follows: Based on the nonlinear relationship of thermal balance, the radiator threshold is set as follows: the temperature threshold of the first-stage radiator is... (If configurable) The temperature threshold of the second heat sink is... (If configurable) ).

[0082] The temperature value of the radiator is compared with the temperature threshold values ​​of the first and second radiators, respectively, and the comparison result is the second parameter comparison result. Based on the second parameter comparison result, an adjustment command for the duty cycle of the pulse width modulation signal of the fan can be generated.

[0083] For example, if This indicates that the radiator temperature is too high in this state, therefore it is necessary to increase the duty cycle of the external fan drive to reduce the radiator temperature to reach an equilibrium range; if This indicates that the radiator temperature is in a dynamic relative equilibrium range under this state, maintaining the external fan drive duty cycle; if This indicates that the radiator temperature is relatively low in this state, and there is a margin for temperature rise, so the duty cycle of the external fan drive can be reduced.

[0084] In this embodiment, two threshold judgment protections are performed for the two implementation methods described above: when the junction temperature and radiator temperature are in a relatively balanced range, the external fan drive is maintained. When the junction temperature and radiator temperature are too low, the duty cycle of the external fan drive can be reduced, which can reduce operating noise and energy consumption in real time. When the junction temperature and radiator temperature are too high, the duty cycle of the external fan drive can be increased to protect the machine's temperature rise performance. A step value can be set for increasing or decreasing the external fan drive, and the step duty cycle can be 5%.

[0085] Specifically, when the real-time junction temperature is greater than or equal to the first secondary junction temperature threshold, or when the temperature of the heat sink is greater than or equal to the first secondary heat sink temperature threshold, the temperature is determined to be in a high-temperature state, and the duty cycle is increased by a first preset step size; when the real-time junction temperature is greater than the second secondary junction temperature threshold and less than the first secondary junction temperature threshold, and the temperature of the heat sink is greater than the second secondary heat sink temperature threshold and less than the first secondary heat sink temperature threshold, the temperature is determined to be in a balanced range, and the duty cycle remains unchanged; when the conditions for determining the high-temperature state are not met, and the conditions for determining the balanced range are not met, the temperature is determined to be in a low-temperature state, and the duty cycle is decreased by a second preset step size.

[0086] It should be noted that when either the junction temperature or the heatsink temperature is too high or too low, while the other is within a balanced range, the duty cycle can be adjusted according to priority or weighted rules (for example, if the junction temperature is too high, the duty cycle should be increased first). It is evident that the junction temperature is the core temperature of the power device, directly determining whether the component will burn out, and therefore has the highest priority; the heatsink temperature, representing the temperature of the heat dissipation medium, reflects the load on the heat dissipation device, and has the second highest priority; the core objective of adjustment should first ensure that the component is not damaged (junction temperature safety), then ensure that the heat dissipation is not overloaded, and only lastly consider noise reduction and energy saving.

[0087] It is evident that if the conditions for determining a high temperature state and the conditions for determining a balanced range are not met, i.e., if any of the following conditions are met, the temperature is determined to be in a low temperature state, and the duty cycle is reduced by a second preset step size: (a) the real-time junction temperature is less than or equal to the second junction temperature threshold, and the radiator temperature is less than or equal to the second radiator temperature threshold; (b) the real-time junction temperature is less than or equal to the second junction temperature threshold, and the radiator temperature is greater than the second radiator temperature threshold and less than the first radiator temperature threshold; (c) the radiator temperature is less than or equal to the second radiator temperature threshold, and the real-time junction temperature is greater than the second junction temperature threshold and less than the first junction temperature threshold.

[0088] In summary, based on the actual real-time calculation and determination of junction temperature and the determination of heat sink temperature detection threshold, a nonlinear mapping relationship between power transistor device temperature, heat sink temperature margin and fan PWM duty cycle can be established. Figure 2 The demonstration showcases its specific execution and judgment process. Based on the judgment result, a real-time PWM control optimization strategy with a set step size is adopted to achieve precise dynamic adjustment of the fan speed. When the adaptive real-time temperature adjustment reaches the equilibrium range, the duty cycle is maintained. When it is outside the equilibrium range, adaptive dynamic adjustment is implemented.

[0089] Specifically, the process begins with the ADC unit acquiring voltage, current, and temperature data in real time. After processing by the power device loss calculation unit, the real-time junction temperature of the power device is calculated. Then, the temperature status judgment stage proceeds, processing the data into three states based on the relationship between the real-time junction temperature and the heatsink temperature relative to a preset threshold:

[0090] If the real-time junction temperature is greater than or equal to the first junction temperature threshold, or the radiator temperature is greater than or equal to the first radiator temperature threshold, the state is determined to be "too high". The fan duty cycle is controlled to increase by the first preset step size, so that the fan speed is increased. Then the process loops back to the ADC sampling stage until the state is balanced.

[0091] If the real-time junction temperature and the heat sink temperature are both within the balance range between their respective first and second thresholds, the state is determined to be "balanced". At this time, the junction temperature of the power device and the state of the heat sink are relatively stable, and the process ends.

[0092] If the real-time junction temperature is less than or equal to the second junction temperature threshold and the radiator temperature is less than or equal to the second radiator temperature threshold, or if the real-time junction temperature is less than or equal to the second junction temperature threshold and the second radiator temperature threshold is less than or equal to the radiator temperature value and the first radiator temperature threshold, or if the radiator temperature value is less than or equal to the second radiator temperature threshold and the second junction temperature threshold is less than or equal to the real-time junction temperature and the first junction temperature threshold, the state is determined to be "too low". The fan duty cycle is controlled to decrease by the second preset step size to reduce the fan speed. The process then loops back to the ADC sampling stage until the state is balanced.

[0093] As can be seen, the entire process achieves dynamic adjustment of the fan speed through real-time sampling, junction temperature calculation, and status determination, in order to maintain the temperature stability of the power devices.

[0094] The beneficial effects of this application are as follows: By calculating the real-time junction temperature by combining the operating losses of power devices with the heat sink temperature, the heating trend can be predicted in advance and the cooling strategy adjusted before the power devices actually overheat. This internal heat source prediction based on the loss model, compared with traditional control that relies solely on external heat sink temperature triggering, can reflect changes in heat dissipation demand earlier and more accurately, thus fundamentally avoiding the phenomenon of "overheating" or "underheating" caused by response lag, and ensuring that the control response is synchronized with the heat dissipation demand. The solution makes a comprehensive decision by comparing the real-time junction temperature and the heat sink temperature values ​​with preset thresholds, realizing simultaneous monitoring of the core heat source (power devices) and the state of the heat dissipation system (heat sink). The fan speed is increased only when either or both indicate that heat dissipation needs to be strengthened; otherwise, if there is sufficient margin for temperature rise, the speed is actively reduced. This fine adjustment based solely on actual heat demand breaks the convention of fans running at high speed all year round, minimizing fan operating noise and unnecessary energy consumption, and is particularly suitable for the stringent requirements of low noise and high energy efficiency in residential and industrial / commercial scenarios.

[0095] Based on the above embodiments, in a specific implementation, the process of determining the operating losses of power devices in the power module based on the electrical parameters is described, specifically including the following steps:

[0096] Step 1: Based on the characteristic parameters of the power device, construct a loss model that includes conduction loss and switching loss;

[0097] Step 2: Based on the loss model and the real-time sampled electrical parameters, determine the conduction loss and switching loss of the power device, respectively;

[0098] Step 3: Determine the operating loss based on the conduction loss and the switching loss.

[0099] In this embodiment, the power device is taken as an IGBT, and the same applies to other power devices. Based on the datasheet and measured parameters, a power device loss model is constructed in a digital signal processor (DSP). First, the two types of heat generation are identified: conduction loss and switching loss. Therefore, the process of constructing the loss model includes constructing conduction loss curves and switching loss curves respectively. Subsequently, the conduction and switching losses of the power device can be directly calculated in real time based on these curves. Specifically:

[0100] 1) According to the datasheet of the power device, the relationship between the on-state voltage drop and the collector current is fitted to a linear curve to obtain the conduction loss curve.

[0101] The expression for the conduction loss curve is:

[0102] (1);

[0103] in, For the on-state voltage drop in the IGBT datasheet, The collector current is a current parameter obtained from real-time sampling by the ADC. The on-resistance of the IGBT (can be calculated by fitting from the IGBT datasheet; it is a constant). This is the initial saturation voltage drop (which can be calculated by fitting from the IGBT datasheet; it is a constant).

[0104] 2) Fit the relationship between the switching loss and the collector current, drive resistance, on-state voltage drop and junction temperature to a quadratic curve to obtain the switching loss curve;

[0105] The expression for the switching loss curve is:

[0106] (2);

[0107] (3);

[0108] (4);

[0109] (5);

[0110] in, The switching loss is mentioned above. The driving resistor, The junction temperature is... , , , These are the constants after fitting.

[0111] The switching loss Esw can include the turn-on loss Eon and the turn-off loss Eoff, i.e., Esw = Eon + Eoff. Eon and Eoff can be calculated separately. Based on the Esw in the IGBT datasheet, quadratic curves are fitted to Esw and Ic, Rg, Vce, and Tj respectively. , , , All are constants of the quadratic curve fitted according to the manual. For example, the quadratic curve fitted according to the manual of a typical seventh-generation IGBT from an international semiconductor company yields the following:

[0112] , , ; , , ;

[0113] , , ; , , .

[0114] Furthermore, the power device losses are calculated in real time. Based on the fitted parameter model, the conduction loss and switching loss of the IGBT are calculated respectively. Specifically, the conduction loss calculation formula is determined based on the conduction loss curve, and the switching loss calculation formula is determined based on the switching loss curve; using the conduction loss calculation formula, the switching loss calculation formula, and the real-time sampled electrical parameters, the conduction loss and switching loss of the power device are determined respectively.

[0115] The formula for calculating the conduction loss is as follows:

[0116] (6);

[0117] in, The conduction loss is... The switching cycle time; For the effective value current, The average current is calculated from the current parameters sampled by the ADC.

[0118] The formula for calculating the switching loss is as follows:

[0119] (7);

[0120] The above expressions consider the effects of the drive resistance Rg, turn-on and turn-off voltage Vce, and junction temperature Tj on switching losses, respectively. The switching loss is mentioned above. This is the actual driving resistance value. This is the reference drive resistance value for the fitting curve from the IGBT datasheet. This represents the actual conduction voltage drop. The reference on-state voltage drop is used for fitting the curve from the IGBT datasheet. This is the actual junction temperature value. This is the reference junction temperature value for the fitting curve from the IGBT datasheet.

[0121] Finally, the total IGBT loss is calculated as the sum of the conduction loss and the switching loss, i.e. .

[0122] like Figure 3The diagram illustrates an exemplary photovoltaic energy storage inverter system block diagram. As an example, the inverter system has three external fans forcibly cooling the entire system. Each external fan is a 4-wire system, containing VCC, GND, PWM, and FB signals. These represent the positive and negative power supplies (VCC and GND) to the external fans, respectively. PWM controls the fan speed via duty cycle, and FB is the fan speed feedback signal. In the system block diagram, the "rectangular frame in the middle" can be considered the heat sink of the energy storage inverter system. Typically, the power transistors for the photovoltaic input BOOST, the battery DC-DC converter, and the bidirectional DC-AC converter are connected to the heat sink for cooling. The three external fans provide forced air cooling to the heat sink, improving the system's cooling capacity. The block diagram contains a schematic of the control loop. The hardware samples and monitors the voltage and inductor current of the component input BOOST, the voltage and inductor current of the battery DC-DC converter, the bus voltage, and the phase voltage and phase current of the AC side in real time. The data is sent to the digital signal processor (DSP) for basic power calculation and control, loss model construction, real-time loss calculation and analysis, and the determination of temperature margin threshold based on real-time loss and heat sink temperature sampling values. The nonlinear relationship of thermal balance is analyzed to adjust the duty cycle of the external fan, thereby controlling the fan speed. Real-time adaptive adjustment keeps the system in a relatively balanced state.

[0123] As can be seen, by constructing a real-time loss model for power devices, covering conduction losses and switching losses, and calculating the quantized loss values ​​of each power device in real time, a dynamic loss and thermal balance relationship is established. This includes the nonlinear mapping relationship between power device temperature, heat sink temperature margin, and fan PWM duty cycle. Combined with PWM control optimization strategies, precise dynamic adjustment of fan speed is achieved. While ensuring the thermal safety margin of the equipment, operating noise and energy consumption are minimized, effectively realizing low-noise, high-reliability, and intelligent dynamic control of photovoltaic grid-connected inverters or energy storage inverter systems in residential and industrial / commercial applications.

[0124] Accordingly, this application also discloses a cooling control device for a fan in an energy storage system, see [link to relevant documentation]. Figure 4 As shown, the device includes:

[0125] The signal acquisition module 11 is used to acquire the electrical parameters of the power module and the temperature value of the heat sink in the energy storage system.

[0126] The real-time calculation module 12 is used to determine the operating loss of the power device in the power module based on the electrical parameters, and to determine the real-time junction temperature of the power device based on the operating loss and the temperature value of the heat sink.

[0127] The adaptive adjustment module 13 is used to compare the real-time junction temperature and the temperature value of the radiator with the corresponding preset temperature thresholds, and according to the comparison results, adaptively adjust the duty cycle of the pulse width modulation signal of the fan driving the radiator to control the speed of the fan so that the real-time junction temperature and the temperature value of the radiator are maintained within a preset balance range.

[0128] For more detailed information on the working process of each of the above modules, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0129] Therefore, the above-described scheme in this embodiment, by calculating the real-time junction temperature by combining the operating losses of the power devices with the heat sink temperature, can predict the heating trend and adjust the cooling strategy in advance based on electrical parameters before the power devices actually overheat. This internal heat source prediction based on the loss model, compared with traditional control that relies solely on external heat sink temperature triggering, can reflect changes in heat dissipation demand earlier and more accurately, thus fundamentally avoiding the "overheating" or "underheating" phenomenon caused by response lag, and ensuring that the control response is synchronized with the heat dissipation demand. The scheme makes a comprehensive decision by comparing the real-time junction temperature and the heat sink temperature values ​​with preset thresholds, realizing simultaneous monitoring of the core heat source (power devices) and the state of the heat dissipation system (heat sink). The fan speed is increased only when either or both indicate that heat dissipation needs to be strengthened; otherwise, if there is sufficient margin for temperature rise, the speed is actively reduced. This fine adjustment based solely on actual heat demand breaks the convention of the fan running at high speed all year round, maximizing the reduction of fan operating noise and unnecessary energy consumption, which is particularly suitable for the strict requirements of low noise and high energy efficiency in residential and industrial and commercial scenarios.

[0130] Furthermore, embodiments of this application also disclose an electronic device, Figure 5 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0131] Figure 5 This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of this application. Specifically, the electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the cooling control method for the fan in the energy storage system disclosed in any of the foregoing embodiments. Alternatively, the electronic device 20 in this embodiment may specifically be a computer.

[0132] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0133] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk, or optical disk, etc. The resources stored on it can include an operating system 221, computer programs 222, and data 223, etc. The data 223 can include various types of data. The storage method can be temporary storage or permanent storage.

[0134] The operating system 221 is used to manage and control the various hardware devices on the electronic device 20 and the computer program 222, which may be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program capable of performing the cooling control method for the fan in the energy storage system executed by the electronic device 20 as disclosed in any of the foregoing embodiments, the computer program 222 may further include computer programs capable of performing other specific tasks.

[0135] Furthermore, this application also discloses a computer-readable storage medium, which includes random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, magnetic disks, optical disks, or any other form of storage medium known in the art. The computer program, when executed by a processor, implements the cooling control method for the fan in the aforementioned energy storage system. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0136] Furthermore, embodiments of this application also provide a computer program product, including a computer program / instruction, which, when executed by a processor, implements any of the above-described methods for cooling control of the fan in the energy storage system.

[0137] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0138] The steps of the cooling control method or algorithm for the fan in the energy storage system described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0139] Finally, 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0140] The cooling control method and device for a fan in an energy storage system provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method of cooling control of a wind turbine in an energy storage system, characterized by, The method comprises the following steps: acquiring electrical parameters of a power module in an energy storage system and temperature values of a heat sink; determining an operating loss of a power device in the power module based on the electrical parameters, and determining a real-time junction temperature of the power device based on the operating loss and the temperature values of the heat sink; comparing the real-time junction temperature and the temperature values of the heat sink with corresponding preset temperature thresholds respectively, and adaptively adjusting a duty cycle of a pulse width modulation signal of a fan driving the heat sink according to a comparison result to control a rotating speed of the fan, so that the real-time junction temperature and the temperature values of the heat sink are maintained within a preset balance interval.

2. The method of claim 1, wherein, The method of acquiring the electrical parameters of the power module in the energy storage system comprises the following steps: acquiring first electrical parameters, second electrical parameters and third electrical parameters in the power module in the energy storage system; wherein the first electrical parameters comprise an input voltage and an inductor current of a BOOST circuit on a photovoltaic side of the power module, the second electrical parameters comprise an input voltage and an inductor current of a DCDC circuit on a battery side of the power module, and the third electrical parameters comprise phase voltages and phase currents on an alternating current side of the power module.

3. The method of claim 1, wherein the wind turbine is a wind turbine of an energy storage system. The method of determining the operating loss of the power device in the power module based on the electrical parameters comprises the following steps: constructing a loss model containing conduction loss and switching loss according to characteristic parameters of the power device; determining the conduction loss and the switching loss of the power device respectively based on the loss model and the real-time sampled electrical parameters; determining the operating loss based on the conduction loss and the switching loss.

4. The method of claim 3, wherein the fan is controlled to cool the energy storage system when the temperature of the energy storage system is greater than the threshold temperature. The method of constructing the loss model containing the conduction loss and the switching loss according to the characteristic parameters of the power device comprises the following steps: fitting a relationship between a conduction voltage drop and a collector current into a first-order curve to obtain a conduction loss curve according to the data manual of the power device; fitting relationships between the switching loss and the collector current, a driving resistor, the conduction voltage drop and a junction temperature into second-order curves to obtain a switching loss curve; Correspondingly, the method of determining the conduction loss and the switching loss of the power device respectively based on the loss model and the real-time sampled electrical parameters comprises the following steps: determining a conduction loss calculation formula based on the conduction loss curve and a switching loss calculation formula based on the switching loss curve; determining the conduction loss and the switching loss of the power device respectively by using the conduction loss calculation formula, the switching loss calculation formula and the real-time sampled electrical parameters.

5. The method of claim 4, wherein the fan is controlled to cool the energy storage system when the temperature of the energy storage system is greater than the threshold temperature. The expression of the conduction loss curve is: （1）； wherein, is the on-voltage drop, is the collector current, is the on-resistance, is the initial saturation voltage drop; The expression of the switching loss curve is: （2）； （3）； （4）； （5）； wherein, is the switching loss, is the drive resistance, is the junction temperature, , , , is the constant after fitting.

6. The method of claim 5, wherein the fan is controlled to cool the energy storage system when the temperature of the energy storage system is greater than the threshold temperature. The conduction loss calculation formula is: （6）； wherein, is the conduction loss, is the switching cycle time, is the root mean square current, is the average current; The switching loss calculation formula is: （7）； wherein, is the switching loss, is the actual drive resistance value, is the reference drive resistance value, is the actual on voltage drop, is the reference on voltage drop, is the actual junction temperature value, is the reference junction temperature value.

7. The method of claim 1, wherein the wind turbine is a wind turbine of an energy storage system. The method of determining the real-time junction temperature of the power device based on the operating loss and the temperature values of the heat sink comprises the following steps: based on the operating loss and the temperature value of the heat sink, determining a real-time junction temperature of the power device by using the power device wherein, is the real-time junction temperature, is the operating loss, is the junction-to-case thermal resistance of the power device, is the temperature value of the heat sink, is the temperature protection value considering tolerances and margins.

8. The method of claim 1 to 7, wherein, The method of comparing the real-time junction temperature and the temperature values of the heat sink with corresponding preset temperature thresholds respectively comprises the following steps: setting a first heavy junction temperature threshold and a second heavy junction temperature threshold for the real-time junction temperature; the first heavy junction temperature threshold is greater than the second heavy junction temperature threshold; a first heavy heat sink temperature threshold and a second heavy heat sink temperature threshold are set for the temperature value of the heat sink; the first heavy heat sink temperature threshold is greater than the second heavy heat sink temperature threshold; an adjustment instruction for a duty cycle of a pulse width modulation signal of the fan is generated based on the first parameter comparison result and the second parameter comparison result; The first parameter comparison result is a size comparison result between the real-time junction temperature and the first heavy junction temperature threshold and the second heavy junction temperature threshold, and the second parameter comparison result is a size comparison result between the temperature value of the heat sink and the first heavy heat sink temperature threshold and the second heavy heat sink temperature threshold.

9. The method of claim 8, wherein the fan is controlled to cool the energy storage system when the temperature of the energy storage system is greater than a predetermined temperature threshold. According to the comparison result, the duty cycle of the pulse width modulation signal of the fan driving the heat sink is adaptively adjusted, including: When the real-time junction temperature is greater than or equal to the first heavy junction temperature threshold, or the temperature value of the heat sink is greater than or equal to the first heavy heat sink temperature threshold, it is determined that the temperature is in a high state, and the duty cycle is increased by a first preset step; When the real-time junction temperature is greater than the second heavy junction temperature threshold and less than the first heavy junction temperature threshold, and the temperature value of the heat sink is greater than the second heavy heat sink temperature threshold and less than the first heavy heat sink temperature threshold, it is determined that the temperature is in an equilibrium interval, and the duty cycle is kept unchanged; When the determination condition of the high state is not met, and the determination condition of the equilibrium interval is not met, it is determined that the temperature is in a low state, and the duty cycle is reduced by a second preset step.

10. A cooling control device for a wind turbine in an energy storage system, characterized in that It includes: A signal acquisition module is configured to acquire an electrical parameter of a power module in an energy storage system and a temperature value of a heat sink; A real-time calculation module is configured to determine an operating loss of a power device in the power module based on the electrical parameter, and determine a real-time junction temperature of the power device based on the operating loss and the temperature value of the heat sink; An adaptive adjustment module is configured to compare the real-time junction temperature and the temperature value of the heat sink with corresponding preset temperature thresholds, respectively, and adaptively adjust a duty cycle of a pulse width modulation signal of a fan driving the heat sink according to the comparison result, so as to control a rotating speed of the fan, so that the real-time junction temperature and the temperature value of the heat sink are maintained in a preset equilibrium interval.

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