Energy storage system heat dissipation control parameter calibration method, heat dissipation method and energy storage system

Abstract

This application discloses a method for calibrating heat dissipation control parameters, a heat dissipation method, and an energy storage system. Under a preset ambient temperature, the energy storage system is controlled to operate at full power with the heat dissipation device operating at its maximum heat dissipation power. After thermal equilibrium is reached, the temperature detection value is recorded as the first thermal equilibrium temperature. Using the first thermal equilibrium temperature as the initial trigger temperature, a temperature testing procedure is performed: after the system cools to the ambient temperature, it operates at full power with the heat dissipation device turned off. When the temperature detection value rises to the trigger temperature, the system switches to the maximum heat dissipation power to obtain the peak temperature. Based on the peak temperature, a heat dissipation power upper limit switching temperature threshold is determined, and a first correspondence between the temperature detection value and the heat dissipation power is established. This application incorporates the influence of system thermal inertia into the calibration process of the first correspondence through actual measurement, which helps to avoid the problem of temperature overshoot exceeding the device's safe range due to thermal inertia and helps to reduce the controller's computational load and calibration workload.

Description

Technical Field

[0001] This application relates to the field of thermal management technology for energy storage systems, and in particular to a method for calibrating heat dissipation control parameters, a heat dissipation method, and an energy storage system for an energy storage system. Background Technology

[0002] With the rapid expansion of new energy sources, the installed capacity and power density of energy storage systems are continuously increasing. Energy storage systems contain various heat-generating components, such as switching transistors, diodes, and capacitors. These components generate a significant amount of heat during operation, and improper temperature control can lead to overheating and failure, affecting the system's reliability and lifespan. Forced air cooling has become the mainstream heat dissipation solution due to its controllable cost and simple structure.

[0003] Energy storage systems typically employ a temperature-segmented control strategy for heat dissipation: when the temperature is low, the cooling device operates at low power or is shut down to reduce energy consumption and noise; when the temperature rises to a certain threshold, the cooling device switches to high power operation to provide stronger heat dissipation capacity. The key to this control strategy lies in determining the temperature threshold at which the cooling device switches from low power to high power.

[0004] In existing technologies, the heat dissipation switching temperature threshold is typically set directly based on the device's maximum operating temperature as stated in the datasheet, with a certain safety margin. However, this approach does not fully consider the system's thermal inertia. In practical applications, when the temperature reaches the switching threshold and triggers the heat dissipation device to switch to high-power operation, due to the system's thermal inertia, the temperature will not drop immediately but will continue to rise for a period of time before starting to decrease, resulting in a temperature overshoot. If the switching temperature threshold is set too high, the temperature peak may exceed the device's safe operating range, leading to device failure; if the switching temperature threshold is set too low, the heat dissipation device will prematurely enter high-power operation, increasing energy consumption and noise, and reducing the lifespan of the heat dissipation device. Summary of the Invention

[0005] This application provides a method for calibrating heat dissipation control parameters, a heat dissipation method, and an energy storage system. It incorporates the influence of system thermal inertia into the calibration process of the correspondence between temperature detection values ​​and heat dissipation power, thereby reducing the problem of temperature overshoot exceeding the device's safe range due to failure to consider thermal inertia.

[0006] In a first aspect, this application provides a method for calibrating heat dissipation control parameters of an energy storage system. The energy storage system includes a heat dissipation device, a first heating device, and a temperature detection device for detecting the temperature of the first heating device. The heat dissipation control parameters include a first correspondence between the temperature detection value of the temperature detection device and the heat dissipation power of the heat dissipation device. The calibration method includes: controlling the energy storage system to operate at full power under a preset ambient temperature, and controlling the heat dissipation device to operate at the upper limit of the heat dissipation power; after the energy storage system reaches thermal equilibrium, recording the temperature detection value of the temperature detection device as the first thermal equilibrium temperature; and performing a temperature test step, the temperature test step including: controlling the energy storage system to shut down; after the energy storage system cools down to the ambient temperature, controlling the energy storage system to operate at full power, and controlling the heat dissipation device to shut down. When the temperature detection value rises to the trigger temperature, the heat dissipation device is controlled to switch to the upper limit of the heat dissipation power. The peak temperature reached by the temperature detection value after switching the heat dissipation power is obtained. The initial value of the trigger temperature is the first thermal equilibrium temperature. If the peak temperature is greater than or equal to the over-temperature protection threshold, the trigger temperature is reduced and the temperature test step is re-executed. If the peak temperature is less than the over-temperature protection threshold, the trigger temperature is confirmed as the upper limit of the heat dissipation power switching temperature threshold. The first correspondence is established, wherein the heat dissipation start temperature threshold corresponds to the lower limit of the heat dissipation power, the upper limit of the heat dissipation power switching temperature threshold corresponds to the upper limit of the heat dissipation power, and between the heat dissipation start temperature threshold and the upper limit of the heat dissipation power switching temperature threshold, the heat dissipation power increases monotonically as the temperature detection value increases.

[0007] In one or more embodiments, the energy storage system further includes a second heating device, and the calibration method further includes: controlling the operation of the heat dissipation device using the first correspondence relationship, and controlling the second heating device to operate at full power; after the energy storage system reaches thermal equilibrium, obtaining the actual temperature of the second heating device; if the actual temperature is greater than or equal to the expected operating temperature of the second heating device, increasing the heat dissipation power of the heat dissipation device, and after the energy storage system reaches thermal equilibrium, obtaining the actual temperature again until the actual temperature is less than the expected operating temperature; if the actual temperature is less than the expected operating temperature, recording the current temperature detection value and the current heat dissipation power of the heat dissipation device as an optimized control point; and adjusting the first correspondence relationship based on the optimized control point.

[0008] In one or more embodiments, the heat dissipation control parameters further include a derating trigger temperature and a second correspondence between the derating trigger temperature and the operating power of the energy storage system. The calibration method further includes: controlling the energy storage system to operate at full power under the expected derating ambient temperature, and controlling the heat dissipation device to operate at the upper limit of the heat dissipation power. After the energy storage system reaches thermal equilibrium, the temperature detection value is recorded as the second thermal equilibrium temperature. Based on the upper limit switching temperature threshold of the heat dissipation power, the second thermal equilibrium temperature, and the over-temperature protection threshold, a derating temperature starting value is determined. Starting from the derating temperature starting value and ending at the over-temperature protection threshold, multiple derating levels are divided. The derating trigger temperature corresponding to each derating level and the operating power of the energy storage system corresponding to each derating level are determined, and the second correspondence is obtained. The derating trigger temperature is used to trigger the energy storage system to adjust its operating power based on the second correspondence when the temperature detection value rises. The operating power of the energy storage system corresponding to each derating trigger temperature decreases as the temperature increases.

[0009] In one or more embodiments, the temperature interval between two adjacent derating trigger temperatures is equal. The heat dissipation control parameters further include a power recovery temperature and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The calibration method further includes: obtaining the temperature interval; determining a hysteresis value based on the temperature interval; determining multiple power recovery temperatures and the operating power of the energy storage system corresponding to each power recovery temperature based on the hysteresis value and the multiple derating trigger temperatures, thereby obtaining the third correspondence. The power recovery temperature is used to trigger the energy storage system to adjust its operating power based on the third correspondence when the temperature detection value decreases. The operating power of the energy storage system corresponding to each power recovery temperature decreases as the temperature increases.

[0010] In one or more embodiments, the temperature detection device includes a plurality of temperature detection devices, and the method for calibrating the temperature detection value includes: acquiring temperature data detected by the plurality of temperature detection devices; determining temperature data within a preset temperature range; and determining the maximum value among the temperature data within the preset temperature range as the temperature detection value.

[0011] In one or more embodiments, the calibration method further includes: sequentially controlling the energy storage system to operate under multiple preset conditions, and obtaining the actual temperature of the first heating device and the temperature detection value of the temperature detection device under the multiple preset conditions; establishing a fourth correspondence between the actual temperature and the temperature detection value based on the actual temperature and the temperature detection value, wherein the actual temperature and the temperature detection value satisfy the following formula: T tcn =a·Tn +b, Among them, T tcn T represents the actual temperature. n Let a be the temperature detection value, b be the first fitting parameter, and b be the second fitting parameter. Based on the fourth correspondence, the physical failure temperature threshold of the first heating device is corrected to obtain the over-temperature protection threshold.

[0012] Secondly, embodiments of this application also provide a heat dissipation method for an energy storage system. The energy storage system includes a heat dissipation device, a first heating device, and a temperature detection device for detecting the temperature of the first heating device. The heat dissipation method includes: acquiring heat dissipation control parameters, the heat dissipation control parameters including a first correspondence between the temperature detection value of the temperature detection device and the heat dissipation power of the heat dissipation device, the first correspondence being established using a calibration method as described in any one of the first aspects; acquiring the temperature detection value of the temperature detection device; obtaining a target heat dissipation power based on the temperature detection value and the first correspondence; and controlling the heat dissipation device to operate based on the target heat dissipation power.

[0013] In one or more embodiments, the heat dissipation control parameters further include a second correspondence between the derating trigger temperature and the operating power of the energy storage system, and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The heat dissipation method further includes: determining the target operating power of the energy storage system based on the temperature detection value, the second correspondence, and the third correspondence; and controlling the operation of the energy storage system based on the target operating power.

[0014] Thirdly, embodiments of this application also provide an energy storage system, including: a heat dissipation device, a first heating device, a temperature detection device, and a control device. The heat dissipation device is used to dissipate heat from the energy storage system; the temperature detection device is used to detect the temperature of the first heating device; the control device includes: a processor, and a memory communicatively connected to the processor; the memory stores computer program instructions executable by the processor, which, when executed by the processor, cause the control device to perform the method described in any of the first aspects.

[0015] Fourthly, embodiments of this application provide a computer storage medium storing instructions or programs that, when executed by at least one processor, cause the at least one processor to perform the method described in any of the first aspects above.

[0016] Fifthly, embodiments of this application also provide a computer program product, the computer program product including a computer program stored on a computer-readable storage medium, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the method described in the first aspect above.

[0017] The beneficial effects of this application are as follows: This application determines the switching temperature threshold of the upper limit of heat dissipation power through actual measurement. During the calibration process, it simulates the worst-case scenario of the heat dissipation device switching from the off state to the operation of the upper limit of heat dissipation power. The influence of system thermal inertia is incorporated into the calibration process of the first correspondence, thereby reducing the problem of temperature overshoot exceeding the safe range of the device due to the lack of consideration of thermal inertia in the prior art. At the same time, a monotonically increasing correspondence between temperature detection value and heat dissipation power is established, so that the heat dissipation power can be automatically adjusted with temperature changes. There is no need to calibrate control parameters separately for different operating conditions, realizing adaptive temperature control under all operating conditions. Moreover, the control device only needs to look up a table or perform interpolation calculations to obtain the target heat dissipation power during operation, without the need to solve the thermal network model in real time, which significantly reduces the computational load and calibration workload of the controller. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0019] Figure 1 This is a structural block diagram of the energy storage system provided in this application; Figure 2 This is a structural block diagram of the control device provided in this application; Figure 3 This is a flowchart of the heat dissipation control parameter calibration method provided in this application; Figure 4 This is a schematic diagram of the temperature change curves from multiple tests in the temperature testing steps provided in this application; Figure 5 This is a schematic diagram of the safe speed versus temperature curve provided in this application; Figure 6 This is a schematic diagram of the safe speed and temperature curves collected in actual testing, provided in this application; Figure 7 This is a schematic diagram of the rotational speed versus temperature curve proposed within the safety boundary provided in this application; Figure 8 This is a schematic diagram of the proposed rotational speed and temperature curves collected during the actual test provided in this application; Figure 9 This is a schematic diagram of a speed versus temperature curve after adding optimized control points, as provided in this application. Figure 10This is a schematic diagram of another speed and temperature curve after adding optimized control points, as provided in this application; Figure 11 This is a schematic diagram of the derating temperature range provided in this application; Figure 12 A flowchart of the heat dissipation method provided in this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described clearly and in detail below with reference to the accompanying drawings. Obviously, the embodiments in this application are only some embodiments, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0021] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.

[0022] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0023] With the rapid expansion of new energy sources, the installed capacity and power density of energy storage systems are continuously increasing. Energy storage systems contain various heat-generating components, such as switching transistors, diodes, and capacitors. These components generate a large amount of heat during operation, and improper temperature control can lead to overheating and failure, affecting the system's reliability and lifespan. Forced air cooling has become the mainstream heat dissipation solution due to its controllable cost and simple structure.

[0024] Existing fan speed control and thermal management strategies for energy storage air-cooled systems mainly suffer from the following technical solutions and their shortcomings: The first solution adopts an experience-based threshold-based coarse derating strategy. The basic approach is to pre-set fixed wind speed and temperature thresholds. When the monitored temperature reaches the set threshold, power derating is performed according to a predetermined ratio. This solution relies entirely on engineering experience for threshold selection and derating ratios, resulting in two significant drawbacks: First, derating control lacks theoretical basis and quantitative analysis of safety boundaries. It fails to incorporate the thermal capacity characteristics of the devices and actual operating conditions, making it difficult to accurately control the derating range. Excessive derating reduces system power utilization, while insufficient derating fails to eliminate over-temperature risks. The safety margin setting relies entirely on the engineer's subjective judgment and cannot be quantitatively verified. Second, this solution has weak adaptability to changes in operating conditions. When the load fluctuates or the ambient temperature changes, the fixed thresholds cannot cover the safety boundaries under all operating conditions. For different models of equipment or different specifications of heat sinks, trial-and-error parameter adjustments are required, leading to low development efficiency.

[0025] The second approach is based on a multi-order thermal network model to calculate the device junction temperature in real time. The technical approach of this approach is as follows: construct a multi-order RC thermal resistance network model (such as the Foster model or Cauer model) between the device and the heat sink, collect operating parameters such as load current, bus voltage, and ambient temperature in real time, use a high-frequency iterative algorithm to solve the heat conduction differential equations, estimate the instantaneous junction temperature of the power device, and use this as a feedback signal to adjust the system output power in a closed loop. Despite its theoretical completeness, this scheme faces three prominent challenges in engineering implementation: First, the workload and technical difficulty of parameter calibration are extremely high. The multi-order thermal network model involves dozens of thermal resistance and thermal capacity parameters, each of which needs to be calibrated individually under specific conditions using specialized thermal testing equipment. Furthermore, these parameters are highly sensitive to assembly processes and batch consistency of heat sinks; parameter deviations can lead to model mismatch, making it difficult to guarantee the control accuracy of mass-produced products. Second, this scheme places stringent demands on the computational resources of the microcontroller unit (MCU), requiring repeated solutions to multivariate differential equations within millisecond-level control cycles. This places high demands on the MCU's computing power, memory capacity, and interrupt response speed, significantly increasing hardware costs and making it impossible to implement on low-cost, general-purpose MCU platforms. Third, the model estimation is an open-loop prediction, lacking direct correction from measured temperature values. The estimation error will gradually accumulate and amplify with prolonged operation, potentially leading to two failure modes: excessive derating limiting system output capabilities, or insufficient derating causing device temperatures to exceed safe ranges.

[0026] In existing technologies, the heat dissipation switching temperature threshold is typically set directly based on the device's operating temperature as stated in the datasheet, with a certain safety margin. This approach does not fully consider the system's thermal inertia. In practical applications, when the temperature reaches the switching threshold and triggers the heat dissipation device to switch to high-power operation, due to the system's thermal inertia, the temperature will not drop immediately but will continue to rise for a period of time before starting to decrease, resulting in a temperature overshoot. If the switching temperature threshold is set too high, the temperature peak may exceed the device's safe operating range, leading to device failure; if the switching temperature threshold is set too low, the heat dissipation device will prematurely enter high-power operation, increasing energy consumption and noise, and reducing the lifespan of the heat dissipation device.

[0027] To address the aforementioned technical issues, embodiments of this application provide a method for calibrating heat dissipation control parameters, a heat dissipation method, and an energy storage system. The method determines the upper limit of heat dissipation power switching temperature threshold through actual measurement calibration, fully considers the thermal inertia characteristics of the system, and establishes a monotonically increasing correspondence between temperature detection values ​​and heat dissipation power, thereby achieving adaptive temperature control under all operating conditions.

[0028] To facilitate understanding of the methods provided in the embodiments of this application, the energy storage system provided in the embodiments of this application will first be described in detail.

[0029] Please see Figure 1 , Figure 1 A structural block diagram of the energy storage system 100 provided in this application is shown. The energy storage system 100 includes a heat dissipation device 10, a first heating device 20, a temperature detection device 30, and a control device 40.

[0030] The heat dissipation device 10 is used to dissipate heat from the energy storage system 100. In this application, the heat dissipation device 10 can employ various heat dissipation methods. In a preferred embodiment, the heat dissipation device 10 is a fan, employing forced air cooling to dissipate heat from the energy storage system 100. The fan generates airflow by rotating, carrying away heat from the surface of the heat-generating components, thus achieving forced convection cooling. The heat dissipation power of the heat dissipation device 10 is characterized by its fan speed; the higher the speed, the greater the airflow through the heat sink per unit time, and the greater the heat dissipation power. In this application, the fan speed is typically expressed as a percentage of the rated speed, which refers to the ratio of the fan's current speed to its rated speed; for example, 30%, 55%, and 70% respectively indicate that the fan is operating at 30%, 55%, and 70% of its rated speed, corresponding to the heat dissipation power level of the heat dissipation device at the corresponding proportion.

[0031] In another embodiment, the heat dissipation device 10 can be a water-cooled heat dissipation device, which removes heat by circulating coolant between the radiator and the heat exchanger. The water-cooled heat dissipation device includes a water pump, a radiator, a heat exchanger, and coolant piping. The water pump drives the coolant to circulate; as the coolant flows through the radiator, it absorbs heat from the heat-generating components, and then dissipates the heat to the external environment as it flows through the heat exchanger. The heat dissipation power of the water-cooled system is controlled by adjusting the water pump speed or the coolant flow rate. Compared to air cooling, water cooling offers higher heat dissipation efficiency and lower noise, but its cost and system complexity are correspondingly higher.

[0032] In another embodiment, the heat dissipation device 10 can be a heat pipe heat dissipation device, which utilizes the phase change cycle of the working fluid inside the heat pipe to achieve efficient heat conduction. One end of the heat pipe is in contact with the heat-generating device, where the working fluid absorbs heat and evaporates; the other end of the heat pipe is connected to the heat dissipation fins, where the working fluid releases heat and condenses. The condensate flows back to the evaporation end through capillary action, forming a cycle. Heat pipe heat dissipation can be used in conjunction with air cooling or water cooling to further improve heat dissipation performance.

[0033] In another embodiment, the heat dissipation device 10 can employ a combination of air cooling and water cooling to form a hybrid heat dissipation system. Water cooling is used for areas with high power density, while air cooling is used for areas with low power density, achieving a balance between cost and performance.

[0034] This application primarily uses forced air cooling with a fan as an example, but the method is equally applicable to other heat dissipation methods. For water cooling systems, the heat dissipation power corresponds to the water pump speed or flow rate; for heat pipe systems using a fan, the heat dissipation power corresponds to the fan speed.

[0035] The first heating device 20 is a heating device in the energy storage system 100 that is equipped with a temperature detection device. The energy storage system 100 contains multiple types of heating devices, which generate heat during operation due to factors such as Joule heat generated by current passing through conductors, switching losses, and dielectric losses. The first heat-generating device 20 includes, but is not limited to: switching transistors, such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated-gate bipolar transistors (IGBTs), which generate conduction and switching losses during switching; diodes, such as fast recovery diodes and Schottky diodes, which generate voltage drop losses during forward conduction; capacitors, such as electrolytic capacitors and film capacitors, which generate heat due to equivalent series resistance during charging and discharging; inductors, such as power inductors and transformers, which generate copper and iron losses when current flows through them; transformers, which generate winding and core losses during energy transfer; and busbars or high-current connecting copper busbars, which generate Joule heat when high current flows through them. The operating temperature of these heat-generating devices directly affects their performance and lifespan. Taking a MOSFET as an example, its on-resistance increases with temperature, leading to increased conduction losses and forming a thermal positive feedback effect. When the device temperature exceeds its rated operating temperature, the device parameters will drift, and thermal runaway may even occur, leading to permanent damage to the device. Therefore, accurate monitoring and control of the temperature of the first heating device 20 is crucial to ensuring the safe and reliable operation of the energy storage system 100.

[0036] The temperature detection device 30 is used to detect the temperature of the first heating device 20. The temperature detection device 30 includes multiple temperature detection devices arranged at different locations inside the energy storage system 100 to monitor the temperature of different heating areas.

[0037] The preferred temperature sensing device is a negative temperature coefficient thermistor (NTC) temperature sensor. The resistance of an NTC temperature sensor decreases as temperature increases; the temperature can be calculated by measuring the resistance value. NTC temperature sensors offer advantages such as high sensitivity, fast response, and low cost, making them suitable for large-scale deployment in energy storage systems.

[0038] In other embodiments, the temperature sensing device can also be a positive temperature coefficient thermistor (PTC) temperature sensor, a thermocouple, a resistance temperature detector (RTD) such as PT100 or PT1000, or an integrated temperature sensor chip. Different types of temperature sensors have different temperature measurement ranges, accuracies, and response characteristics, and can be selected according to specific application requirements.

[0039] Control device 40 refers to the processing unit that performs unified scheduling and control of the overall operating logic of the energy storage system. For details, please refer to [link / reference]. Figure 2 , Figure 2 The schematic diagram illustrates the structure of a control device provided in some embodiments of this application. In this application, the control device 40 includes at least one processor 41 and a memory 42 connected in communication. Figure 2 Taking a bus system connection and a processor 41 as an example. Understandably, the various components in the control device 40 are coupled together through a bus system, which is used to achieve communication between the components. It is easy to understand that the bus system, in addition to the data bus, can also include a power bus, a control bus, and a status signal bus, etc. However, for clarity and brevity, in... Figure 2 The general refers to all buses as bus systems. This is understandable. Figure 2 The structures shown in the embodiments are merely illustrative and do not limit the structure of the control device described above. For example, the control device may also include components that are more... Figure 2 The structure shown has more or fewer components, or has the same as Figure 2 The diagram shows different configurations of the structure.

[0040] Specifically, processor 41 provides computational and control capabilities to support control device 40 in executing corresponding business logic, such as supporting control device 40 in executing the methods provided in the embodiments of this application, or executing the steps in any possible implementation of the methods provided in the embodiments of this application. Those skilled in the art will understand that processor 41 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0041] The memory 42, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, instructions, and modules, such as the programs, instructions, and modules corresponding to the methods in the embodiments of this application. In some embodiments, the memory 42 may include a program storage area and a data storage area. The program storage area may store the operating system, applications required for at least one function, and the data storage area may store data created according to the use of the processor 41. The processor 41 executes various functional applications and data processing of the control device 40 by running the non-transitory software programs, instructions, and modules stored in the memory 42 to implement the methods provided in the embodiments of this application, or to perform the steps in any possible implementation of the methods provided in the embodiments of this application. In some embodiments of this application, the memory 42 may include high-speed random access memory and may also include non-transitory memory. For example, at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 42 may also include memory remotely located relative to the processor 41, which may be connected to the processor 41 via a communication network. It is understood that examples of the above-mentioned communication networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0042] As can be understood from the foregoing, the implementing entity of any method provided in the embodiments of this application can be any suitable type of control device 40 with certain computing and control capabilities, such as the aforementioned control device 40. In some feasible implementations, any method provided in the embodiments of this application can be implemented by a processor executing computer program instructions stored in memory.

[0043] In this application, the control device 40 determines the switching temperature threshold of the upper limit of heat dissipation power through actual measurement. During the calibration process, it simulates the worst scenario of the heat dissipation device switching from the off state to the operation of the upper limit of heat dissipation power. The influence of system thermal inertia is incorporated into the calibration process of the first correspondence, thereby reducing the problem of temperature overshoot exceeding the safe range of the device due to the lack of consideration of thermal inertia in the prior art. At the same time, a monotonically increasing correspondence between the temperature detection value and the heat dissipation power is established, so that the heat dissipation power can be automatically adjusted with temperature changes. There is no need to calibrate the control parameters separately for different operating conditions, realizing adaptive temperature control under all operating conditions. Moreover, the control device only needs to look up the table or perform interpolation calculations to obtain the target heat dissipation power during operation, without the need to solve the thermal network model in real time, which significantly reduces the computational load and calibration workload of the controller.

[0044] The following will describe in detail the heat dissipation control parameter calibration method and heat dissipation method provided in this application embodiment, with reference to the exemplary application of the control device 40. This method is applied to the aforementioned control device. Specifically, the execution subject of this method is one or at least two processors of the control device. Please refer to... Figure 3 The calibration method includes, but is not limited to, the following steps S10 to S40.

[0045] Step S10: Under the preset ambient temperature, control the energy storage system to operate at full power and control the heat dissipation device to operate at the upper limit of heat dissipation power. After the energy storage system reaches thermal equilibrium, record the temperature detection value of the temperature detection device as the first thermal equilibrium temperature.

[0046] The preset ambient temperature refers to the ambient temperature conditions under which the calibration is performed. In one embodiment, the preset ambient temperature can be approximately 25°C (normal temperature) to allow testing to be conducted under a more stable environmental reference.

[0047] Full power operation refers to the operating state of an energy storage system when it operates at the maximum allowable power. At this time, the heat dissipation of each heat-generating device in the system reaches its maximum value, which is the worst heat dissipation scenario for the energy storage system.

[0048] The upper limit of heat dissipation power refers to the maximum heat dissipation capacity that a heat dissipation device is allowed to achieve during normal operation. For fans, the upper limit of heat dissipation power corresponds to 100% of the rated speed.

[0049] Thermal equilibrium refers to a state where, under current operating conditions and heat dissipation power, the heat generated and the heat dissipated are equal or nearly equal. At this point, the temperature reading remains constant or fluctuates only slightly over a certain period and can be considered stable. Heat generated P heat This represents the heat generated by the first heating device, specifically the heat dissipation P. diss This indicates the amount of heat removed by the heat dissipation device. The thermal equilibrium temperature represents the temperature of the first heating element or the temperature reading that eventually stabilizes under a specific operating condition.

[0050] The first thermal equilibrium temperature is the temperature value given by the temperature detection device after the energy storage system is operating at full power and the heat dissipation device is operating at its maximum heat dissipation capacity, after thermal equilibrium has been reached. It can be denoted as T. eq This temperature reflects the lowest steady-state temperature level that the system can achieve under maximum heat dissipation capacity, serving as a starting point reference for subsequently determining the switching temperature threshold for the upper limit of heat dissipation power.

[0051] Specifically, the control device sets the heat dissipation device to its maximum heat dissipation power and adjusts the energy storage system to full-power operation. The control device continuously collects temperature readings and calculates the fluctuation range of the temperature readings within a preset time period. If the fluctuation range is less than a preset fluctuation threshold, the temperature readings are considered to be stable, indicating that the energy storage system is in thermal equilibrium. The fluctuation range can be the difference between the maximum and minimum temperature readings within the preset time period, or the absolute value of the rate of temperature change within the preset time period. After determining that the temperature readings are stable, the current temperature reading is recorded as the first thermal equilibrium temperature. It is understandable that if the first thermal equilibrium temperature exceeds the acceptable temperature range of the first heating device, it is not advisable to proceed with the subsequent calibration process, and a reliable upper limit reference will be difficult to obtain for the subsequent speed regulation curve.

[0052] Step S20: Perform the temperature test procedure, which includes: controlling the energy storage system to shut down, waiting for the energy storage system to cool down to the ambient temperature, controlling the energy storage system to operate at full power and controlling the heat dissipation device to shut down, when the temperature detection value rises to the trigger temperature, controlling the heat dissipation device to switch to the upper limit of heat dissipation power, obtaining the peak temperature reached by the temperature detection value after switching the heat dissipation power, and the initial value of the trigger temperature is the first thermal equilibrium temperature.

[0053] The trigger temperature refers to the temperature point at which the control device switches the heat dissipation device from a closed or low-power state to the upper limit of the heat dissipation power when the temperature detection value rises to that value.

[0054] Peak temperature refers to the highest temperature value reached by the temperature sensor before it drops back down after switching to the maximum heat dissipation power.

[0055] Specifically, the energy storage system is first shut down to allow it to cool naturally to near ambient temperature, minimizing the residual heat from the previous test. Then, the system is run at full power again with the cooling system off (fan speed at 0), allowing it to heat up under near-unforced cooling conditions. When the temperature reaches the current trigger temperature, the cooling system is immediately switched to its maximum power output. Temperature readings are continuously recorded until the temperature decreases and stabilizes, at which point the peak temperature observed after the switch is extracted.

[0056] The initial trigger temperature is set to the first thermal equilibrium temperature obtained in step S10. The first thermal equilibrium temperature corresponds to the steady-state temperature under the upper limit of heat dissipation power. If this temperature is used as the switching point, after the heat dissipation device switches from off to the upper limit of heat dissipation power, the temperature detection value may continue to rise for a period of time due to the acceleration process and the heat capacity of the whole machine. If the resulting peak temperature is lower than the over-temperature protection threshold, the trigger temperature can be used as a candidate value for the upper limit of heat dissipation power switching temperature threshold; if the peak temperature is too high, the trigger temperature needs to be lowered and the test repeated.

[0057] Under forced cooling conditions, the heat dissipation P diss The temperature is determined by both Newton's law of cooling and the relationship between airflow velocity and air volume. The following derivation is used to qualitatively explain the formation mechanism of temperature overshoot after the cooling device switches, as well as the key factors affecting the magnitude of the overshoot, providing a theoretical basis for calibrating the trigger temperature using experimental methods.

[0058] For forced air cooling systems, Newton's law of cooling can be written as: P diss =h·A·(T) s -T env ); Among them, P diss The total heat dissipation of the system is equal to the total heat generation under steady state, in W; h is the convective heat transfer coefficient between the device surface and the cooling air, in W / m²; A is the effective heat transfer area, in m², a constant value under fixed hardware structure; T s T represents the steady-state temperature of the heating element's surface, expressed in °C. env The ambient temperature of the cooling air is expressed in °C.

[0059] Within the normal operating range of the fan, the air volume of the fan is approximately linearly proportional to its speed. V = k v ·n; Where V is the volumetric airflow within the duct, measured in m³ / s; k v The speed-airflow ratio coefficient is determined by the characteristics of the fan body and the airflow resistance characteristics, and is a constant value after the fixed system is calibrated; n is the fan speed, in r / min.

[0060] The face velocity v inside the duct is the ratio of the air volume to the effective flow area S of the duct, that is: v = V / S; Where S is constant under a fixed structure. According to the engineering correlation of forced convection heat transfer, the convective heat transfer coefficient h and the surface wind velocity v satisfy a power-law relationship: h = C·v m ; Where C is a constant related to air properties and heat exchange surface characteristics, and m is the wind speed index.

[0061] The speed-up process of a heat dissipation device directly affects the speed at which its heat dissipation capacity is built up. The mechanical speed-up process of a fan can be equivalent to an inertial element with a rise time. Let the real-time speed be n(t), and the rated speed nmax be reached after a rise time tr. In engineering, this can be approximated as a ramp rise. When t≥tr, n(t)=nmax, and when 0≤t≤tr, n(t)=nmax·(t / tr).

[0062] The rise time tr is determined by the characteristics of the fan motor, the drive circuit, and the airflow resistance, and is an inherent dynamic parameter of the fan.

[0063] Within the normal operating range of the fan, the volumetric airflow is approximately linearly proportional to the fan speed; therefore, the real-time volumetric airflow is: V(t) = k v ·n(t) The wind speed on the duct surface is: v(t) = V(t) / S = (k v / S)·n(t); Substituting the real-time wind speed, we obtain the time-varying convective heat transfer coefficient: ; Maximum heat transfer coefficient at rated speed for: ; Substituting the above equation into the expression for h(t), we can simplify it to its per-unit form: ; According to Newton's law of cooling, the real-time heat dissipation power is determined by both the time-varying heat coefficient and the real-time temperature difference: P diss (t)=h(t)·A·[T z (t)-T env ]; Among them, T z (t) represents the real-time surface temperature of the device.

[0064] The increase in heat dissipation power is driven by two factors. The first is the heat exchange improvement term: h(t) increases monotonically with fan speed, which is the dominant factor in improving heat dissipation capacity. The second is the temperature difference amplification term: the temperature continues to rise after switching, [T] z (t)-T env The temperature continues to increase, further boosting the heat dissipation power until it reaches its peak.

[0065] The temperature change of the device is determined by both the net heat absorption power and the total heat capacity of the device. The transient thermal balance equation is: ; Wherein, Cth is the equivalent heat capacity of the whole machine, in units of J / ℃, which characterizes the overall heat storage capacity of the device, heat sink, and structural components; This represents the rate of temperature change.

[0066] The time of the switching instruction trigger is taken as the zero point of time (t=0, at which point T) z (t)=T eq The entire temperature response process is divided into three stages.

[0067] The first stage is the continuous upward phase, corresponding to 0 < t < t. peak After the switching command is triggered, the fan starts to increase its speed, and h(t) gradually increases. However, in the initial stage of speed increase, the heat transfer coefficient is still at a low level, satisfying h(t) < h max Since the initial temperature is T eq Substituting into the heat dissipation formula, we get: P diss (t)=h(t)·A·(T eq -T env )<h max ·A·(T eq -T env ) = P heat ; That is, the heat dissipation power is still less than the total power loss, and the net heat absorption power P heat -Pd iss Since h(t) > 0, the rate of temperature change is positive, and the device temperature continues to rise. During this stage, h(t) continues to increase, the net heat absorption power gradually decreases, so the rate of temperature rise gradually decreases, the temperature acceleration is negative, and the temperature curve shows an upward convex shape.

[0068] The second stage is the temperature peak point, corresponding to t = t peak When the heat transfer coefficient increases to a critical value, the heat dissipation power is exactly equal to the power loss, the net heat absorption power is 0, the rate of temperature change drops to 0, and the temperature reaches its highest point T. max : P heat =P diss (t peak )=h(t peak )·A·(T max -T env ); ; This point marks the inflection point where the temperature changes from rising to falling. T max With trigger temperature T eq The difference is the temperature overshoot: ΔT max =T max -T eq ; The third stage is the steady-state phase after a decline, corresponding to t > t. peak After the peak point, the fan speed continues to rise or has reached full speed, h(t) continues to increase, the heat dissipation power exceeds the power loss, the net heat absorption power becomes negative, the rate of temperature change turns negative, the device temperature begins to decrease, and eventually stabilizes at the equilibrium temperature T corresponding to 100% fan speed. eq From the perspective of energy conservation, temperature overshoot equals the net heat absorbed by the device during the rise phase divided by the total heat capacity of the system. ; The magnitude of the overshoot is determined by the overall heat capacity of the machine, the fan speed-up time, and the initial temperature difference. A larger heat capacity and a slower fan speed-up result in a larger overshoot. Therefore, the ideal latest switching point relationship can be derived as follows: T OTP -T eq =ΔT max Among them, T OTP This is the over-temperature protection threshold.

[0069] The above derivation provides a qualitative physical framework and quantitative logical relationship for temperature overshoot, but the parameters are difficult to obtain precisely in actual engineering. Accurate analytical solutions are lacking for convective heat transfer parameters. The heat transfer constant C, wind speed index m, and speed-volume coefficient kv are coupled with factors such as turbulent flow in the duct, radiator fin processing precision, assembly gaps, and air temperature and humidity, resulting in significant errors in purely theoretical calculations, making it difficult to meet the reliability requirements of thermal protection alone. The actual fan acceleration process is not an ideal ramp; it is also affected by the drive circuit, motor characteristics, and air pressure load, making the dynamic process complex and requiring high precision modeling costs. The equivalent heat capacity of the entire unit includes distributed heat storage from multiple components such as the power chip, packaging structure, radiator, printed circuit board, and equipment housing. The heat distribution among these components is uneven, and the theoretical and actual values ​​of the equivalent heat capacity are prone to deviation. In view of these factors, an engineering approach combining theoretical qualitative guidance with experimental quantitative calibration is adopted, determining the acceptable trigger temperature through actual measurements.

[0070] Step S30: If the peak temperature is greater than or equal to the over-temperature protection threshold, the trigger temperature is reduced and the temperature test step is repeated. If the peak temperature is less than the over-temperature protection threshold, the trigger temperature is confirmed as the upper limit switching temperature threshold for heat dissipation power.

[0071] Over-temperature protection threshold T OTP This is the temperature threshold used by the control device to determine whether shutdown protection is required. Its value can be predetermined before calibration, taking into account the physical failure temperature of the first heating device and the detection deviation.

[0072] Heat dissipation power limit switching temperature threshold T last It is the upper limit anchor point in the first correspondence, that is, when the temperature detection value rises to the upper limit of the heat dissipation power switching temperature threshold, the heat dissipation power should be at the upper limit value of the heat dissipation power.

[0073] Specifically, the peak temperature obtained in step S20 is compared with the over-temperature protection threshold. If the peak temperature is greater than or equal to the over-temperature protection threshold, it indicates that the current trigger temperature is too high, and the overshoot after switching may be close to the device's safety boundary. In this case, the trigger temperature is appropriately reduced, for example, by decreasing it by a certain number of degrees Celsius in fixed steps, and then the temperature test steps are repeated to observe the peak temperature again. If the peak temperature is less than the over-temperature protection threshold, it indicates that after switching at this trigger temperature, the temperature peak can still remain below the over-temperature protection threshold. Therefore, this trigger temperature is confirmed as the upper limit switching temperature threshold for heat dissipation power.

[0074] Please see Figure 4 . Figure 4 The diagram illustrates the temperature change curves from multiple tests during the temperature testing process. After heating to the trigger temperature with the heat dissipation off, switching to the maximum heat dissipation power often results in a brief continued rise in temperature, followed by a drop and a tendency towards the full-speed thermal equilibrium temperature. If a test peak value is too high, the trigger temperature is lowered and the test is repeated until the peak value meets the requirements.

[0075] In one test example, the ambient temperature was approximately 25°C. The fan speed was initially fixed at 100%, and the machine was adjusted to operate at maximum heat output. After thermal equilibrium was reached, the highest thermal equilibrium temperature was approximately 67°C. The machine was then turned off and allowed to cool to ambient temperature. The fan speed was then fixed at 0%, and the machine was adjusted to operate at maximum heat output until the temperature reached 67°C. The fan speed was then adjusted back to 100%. During the test, the temperature readings were observed to ensure they did not exceed the over-temperature protection threshold. The highest temperature during the test did not exceed the threshold related to the failure of the first heating element, and the temperature subsequently dropped back to near thermal equilibrium. Therefore, 67°C can be confirmed as the upper limit switching temperature threshold for heat dissipation power. During the test, if the temperature rise meter or temperature readings approach the over-temperature protection threshold, the machine should be shut down first to reduce the risk of thermal runaway.

[0076] Step S40: Establish a first correspondence, wherein the heat dissipation start temperature threshold corresponds to the lower limit of heat dissipation power, the heat dissipation power upper limit switching temperature threshold corresponds to the upper limit of heat dissipation power, and between the heat dissipation start temperature threshold and the heat dissipation power upper limit switching temperature threshold, the heat dissipation power increases monotonically as the temperature detection value increases.

[0077] The first correspondence is the mapping relationship between the temperature detection value and the heat dissipation power of the heat dissipation device. In the implementation where the heat dissipation device is a fan, this mapping relationship can be expressed as the correspondence between the rotation speed of the heat dissipation device and the temperature detection value, i.e., the wind speed and temperature curve.

[0078] Heat dissipation start-up temperature threshold T start This is the temperature at which the heat dissipation device transitions from being off or in standby mode to operating at its lower limit of heat dissipation power. The lower limit of heat dissipation power can be determined based on the minimum stable rotational speed V specified in the heat dissipation device's datasheet. minDetermine, for example, a certain percentage of the rated speed.

[0079] Monotonic increase means that as the temperature detection value increases, the corresponding target heat dissipation power does not decrease. Specifically, for any two temperature points T1 and T2 in the first correspondence, if T2 > T1, then the heat dissipation power corresponding to T2 is not less than the heat dissipation power corresponding to T1. This mapping relationship can be implemented as a piecewise linear, polygonal, or smooth curve. A piecewise linear relationship means that the heat dissipation power increases linearly with temperature in different temperature ranges, and the slopes of adjacent ranges can be different. A polygonal line is composed of multiple straight line segments connected end-to-end, with inflection points corresponding to specific temperature and power combinations. A smooth curve means that the heat dissipation power changes continuously with temperature and the derivative exists, without obvious inflection points. All of the above implementation forms satisfy the monotonicity requirement and can be selected according to the control accuracy requirements and implementation complexity.

[0080] According to Newton's law of cooling, with a constant heat dissipation structure, the greater the temperature difference between the heat-generating device and the ambient temperature, the greater the heat that a unit of airflow can remove. Under the same operating conditions, when the heat generation is constant, a larger airflow results in a lower thermal equilibrium temperature, and a smaller airflow results in a higher thermal equilibrium temperature. Therefore, there is a one-to-one correspondence between a certain rotational speed and a certain thermal equilibrium temperature; the two are negatively correlated. Under the premise of meeting safety boundaries, a relatively higher operating temperature can be achieved at a relatively lower rotational speed of the heat dissipation device, thereby reducing overall machine noise.

[0081] Taking a specific operating condition as an example: when the first heating element stabilizes at the expected temperature, the cooling device rotates at 60% of its rated speed; the thermal equilibrium temperature corresponding to the upper limit of the cooling power is 75℃; at 30% speed, the thermal equilibrium temperature is 130℃. Under this condition, the usable speed adjustment range is approximately 100% to 60% of the rated speed. The thermal equilibrium temperature corresponding to the upper limit of the cooling power can be called the lower temperature at full speed, and the speed at 60% of the rated speed can be called the speed required to reach the expected temperature. The higher the output power of the energy storage system, the greater the heat generation, and the higher the minimum speed required to maintain the temperature of the first heating element at the expected temperature.

[0082] Specifically, after confirming the upper limit of heat dissipation power switching temperature threshold, consult the heat dissipation device specifications to determine the lower limit of heat dissipation power V. min Based on noise, power consumption, and startup requirements, a heat dissipation startup temperature threshold T is determined. start Between the heat dissipation start-up temperature threshold and the heat dissipation power upper limit switching temperature threshold, a first correspondence is obtained by fitting the data based on the principle that the heat dissipation power monotonically increases with the temperature detection value. The fitting can be performed using piecewise linear methods, without the need to construct a complex thermal resistance network model. Excessive precision is unnecessary during fitting, allowing for subsequent adjustments by adding optimization control points through actual measurements.

[0083] Please see Figures 5 to 7 . Figure 5The temperature threshold T is shown by switching between the upper limit of heat dissipation power. last A defined safe operating speed and temperature curve is provided, which includes only two operating states: when the temperature detection value is below the upper limit of heat dissipation power, a switching temperature threshold T is established. last When the temperature rises to the upper limit of the heat dissipation power, the cooling device remains off or in standby mode; when the temperature detection value rises to the upper limit of the heat dissipation power, the switching temperature threshold T is activated. last When the heat dissipation device switches to the upper limit of heat dissipation power (i.e., 100% speed), the curve reflects the latest switching point obtained from the calibration of steps S20 to S30, which is the upper limit anchor point for establishing the first correspondence in the future. Figure 6 The safe speed versus temperature curves collected in actual testing are shown. These curves are compared with... Figure 5 The logic shown is consistent: the vertical axis represents the fan speed percentage, and the horizontal axis represents the temperature reading. The curve switches between the maximum cooling power and the temperature threshold T. last The speed changes from low to 100% to provide a safety boundary reference for the subsequent formulation of a continuous monotonic curve. Figure 7 The proposed speed versus temperature curves within the safety boundaries are shown, and the switching temperature threshold T is determined after confirming the upper limit of heat dissipation power. last Then, consult the heat dissipation device specifications to determine the lower limit value of heat dissipation power V. min The cooling start-up temperature threshold T is determined based on noise, power consumption, and the startup requirements of the cooling device. start At the heat dissipation start-up temperature threshold T start Switching temperature threshold T with upper limit of heat dissipation power last Between these values, a continuous speed-temperature curve was obtained by fitting the data based on the principle that the heat dissipation power monotonically increases with the temperature detection value. The temperature detection value is below the heat dissipation start-up temperature threshold T. start At that time, the heat dissipation device maintains the lower limit value of heat dissipation power V. min Running; temperature detection value is at the heat dissipation start-up temperature threshold T. start Switching temperature threshold Tl with upper limit of heat dissipation power ast During this period, the heat dissipation power increases monotonically with temperature; when the temperature detection value reaches the upper limit of the heat dissipation power, the switching temperature threshold T is activated. last At this point, the heat dissipation power rises to its upper limit. Piecewise linear methods can be used for fitting, without the need to construct a complex thermal resistance network model. Excessive refinement is not pursued at this stage, allowing for subsequent adjustments by adding optimization control points based on actual measurements. Figure 8 This diagram illustrates the relationship between the target fan speed and temperature, as collected during actual testing. The vertical axis represents the fan speed percentage, and the horizontal axis represents the temperature reading. The curve trend is similar to... Figure 7 The proposed curves shown are consistent and reflect the correspondence between the temperature detection value and the speed of the heat dissipation device under the actual operating conditions, which can serve as the basis for adding optimization control points in the future.

[0084] Since the first correspondence is monotonically increasing, when the heat generation increases or the heat dissipation conditions worsen, leading to an increase in the temperature detection value, the target heat dissipation power increases accordingly; conversely, when the heat generation decreases or the heat dissipation conditions improve, leading to a decrease in the temperature detection value, the target heat dissipation power decreases accordingly. High-temperature environments, low-temperature environments, and situations where heat dissipation is obstructed due to dust accumulation in the air duct can be respectively equated to situations where the heat dissipation decreases or increases under the same heat dissipation power. The system can find the corresponding heat dissipation power combination point on the first correspondence based on the temperature detection value until the temperature tends to stabilize, or the heat dissipation weakens to the point where it is difficult to suppress the temperature rise and triggers the over-temperature protection threshold.

[0085] Energy storage systems often involve the combined effects of multiple factors, including the power grid, photovoltaic systems, and batteries. If a separate wind speed curve is created for each factor and the highest wind speed value is used, the calibration workload increases with the number of factors. By using the highest temperature data collected from each temperature sensor as a unified input, a single monotonically increasing curve can cover multiple heat sources, eliminating the need for individual calibration for each combination of operating conditions. During operation, the control device uses the current temperature detection value to look up a table or interpolate to obtain the target heat dissipation power and drives the cooling device to operate.

[0086] In this embodiment, by measuring the temperature rise to the trigger temperature under full power and cooling-off conditions, and then switching to the upper limit of cooling power, the temperature overshoot caused by the heat sink's rise time and the overall heat capacity is incorporated into the calibration. This helps to obtain a cooling power upper limit switching temperature threshold that matches the actual thermal inertia. Compared to directly setting the switching point based solely on the temperature margin in the specifications, this embodiment simulates a harsher scenario during the calibration phase, where the cooling sink switches from the off state to the upper limit of cooling power. This reduces the risk of temperature overshoot exceeding the device's safe range after switching cooling power and also reduces the possibility of the cooling sink prematurely entering high-power operation due to an excessively low switching point. After establishing a monotonically increasing first correspondence, the target cooling power only needs to be determined by looking up a table or interpolating based on the temperature detection value during operation. There is no need to solve multi-order thermal network models in real time, which helps to reduce the computational load on the controller. When the operating conditions, ambient temperature, or cooling conditions change, the change in the temperature detection value can automatically drive the cooling power to adjust along a curve. A single curve can cover a wide operating range, which helps to reduce the workload of adjusting parameters one by one according to the operating conditions and improves the adaptive capability under all operating conditions.

[0087] In some embodiments, the energy storage system further includes a second heating device, and the calibration method includes, but is not limited to, steps S51 to S53. The second heating device refers to a heating device in the energy storage system that does not have a dedicated temperature detection device, or whose temperature is difficult for the main controller to directly read, such as some diodes or magnetic components. These devices are often related to the operating conditions of the first heating device with temperature detection, and their heat generation varies with the same set of operating conditions.

[0088] Step S51: Use the first correspondence to control the operation of the heat dissipation device and control the second heating device to operate at full power. After the energy storage system reaches thermal equilibrium, obtain the actual temperature of the second heating device.

[0089] The actual temperature of the second heating element can be obtained through external temperature measurement methods. For example, a temperature recorder and thermocouple can be used, attached to the surface of the second heating element or a key thermal node, and the temperature measured is recorded as T. tc A thermocouple is a sensor that uses the thermoelectric potential generated at the contact point between two different metal conductors to measure temperature. It features a wide temperature measurement range and fast response speed, making it suitable for temporary temperature measurement of heating devices that do not have dedicated temperature sensing devices during the calibration stage.

[0090] The full-power operating condition of the second heating device refers to the operating state in which the heat output of the second heating device reaches or approaches the maximum heat output level that may occur in the system.

[0091] Expected operating temperature T pred This refers to the upper limit of the temperature that the second heating device is expected to control. It can be selected by combining its derating requirements, the temperature rise differences under different ambient temperatures, and the safety margin.

[0092] Specifically, the control device adjusts the heat dissipation device according to the established first correspondence, while simultaneously adjusting the system to a condition that emphasizes the heat contribution of the second heating device. Once both the detected temperature and the actual temperature of the second heating device have stabilized, the actual temperature T is read. tc and the expected operating temperature T pred Compare.

[0093] Step S52: If the actual temperature is greater than or equal to the expected operating temperature of the second heating device, increase the heat dissipation power of the heat dissipation device, and after the energy storage system reaches thermal equilibrium, re-obtain the actual temperature until the actual temperature is less than the expected operating temperature. If the actual temperature is less than the expected operating temperature, record the current temperature detection value and the current heat dissipation power of the heat dissipation device as the optimization control point.

[0094] When T tc Still higher than or equal to T pred If the temperature is too high, it indicates that the heat dissipation power obtained according to the original first correspondence is insufficient to control the second heating device below the expected operating temperature. At this point, the heat dissipation power can be increased by a preset step size. After thermal equilibrium is reached again, the actual temperature should be checked, and this process should be repeated until T... tc ≤T pred Record the current temperature reading T at this point. MAX_A With current heat dissipation power V need To form the optimal control point A(T) MAX_A V needThe optimized control point characterizes the heat dissipation power required to ensure the safety of the secondary heating device at this temperature detection level. This point is equivalent to finding a measurable switching anchor point for the secondary heating device.

[0095] Please see Figures 8 to 10 According to Table 1, in one example, a diode without a temperature sensor is added to the circuit, that is, the second heating device is this diode. Table 1 records the ambient temperature, actual diode temperature, temperature data of each temperature sensing device, and fan speed at various times in this example. Specifically, the test started at 16:00, with an ambient temperature of approximately 26.9℃ and a fan speed of 30% of its rated speed. The temperature data of the five temperature sensing devices were 28℃, 30℃, 34℃, 28℃, and 31℃, respectively. Running according to the originally planned speed and temperature curve, by 16:22, the actual diode temperature had risen to 88℃, the ambient temperature was approximately 29.2℃, and the fan speed was 55% of its rated speed. The temperature data of the five temperature sensing devices were 32℃, 41℃, 41℃, 56℃, and 38℃, respectively. By 16:31, the actual diode temperature was close to stable at approximately 88.5℃, the fan speed remained at 55% of its rated speed, and the temperature data of the five temperature sensing devices were 32℃, 41℃, 41℃, 56℃, and 39℃, respectively. The highest value was taken as the temperature detection value, i.e., the temperature detection value was approximately 56℃. Figure 8 The curve shows that the corresponding fan speed is 55% of the rated speed. The actual diode temperature of 88.5℃ is higher than the expected operating temperature of 85℃, exceeding it by approximately 3.5℃. This indicates that the originally planned fan speed at 55% of the temperature curve is insufficient to keep the diode below the expected operating temperature. To find the optimal heat dissipation power, at 16:32, the heat dissipation device speed was manually increased to 70% of the rated speed. By 16:46, the temperature stabilized, and the actual diode temperature dropped to approximately 83℃, lower than the expected operating temperature of 85℃. At this time, the temperature data from the five temperature sensors were 31℃, 40℃, 39℃, 52℃, and 38℃, respectively, meaning the detected temperature was approximately 52℃. Subsequently, the speed was adjusted back to 60% of the rated speed. By 16:47, the actual temperature had risen to approximately 86.72℃, higher than the expected operating temperature. Therefore, it can be confirmed that 70% fan speed and a detected temperature of approximately 52℃ are the optimal heat dissipation power combination points that meet the expected operating temperature requirements of this diode, i.e., the optimized control point A (52℃, 70%).

[0096] Table 1. Test data for diodes

[0097] Step S53: Adjust the first correspondence based on the optimized control points.

[0098] Specifically, the optimized control point is added to the original first correspondence, and the overall relationship is kept monotonically increasing, so that the curve passes through or covers the optimized control point A(T). MAX_A V need Please see ). Figure 9 and Figure 10 The adjusted curve rises above the original planned curve, passing through this point, and still reaches the upper limit of heat dissipation power at the temperature threshold of the upper limit switching temperature.

[0099] The adjusted first correspondence, based on the original safety boundary of the first heating device, also considers the heat dissipation requirements of the second heating device. Since the operating conditions of the two types of devices are related, the temperature of the second heating device can be indirectly constrained by temperature detection values ​​through a single optimization point calibration. When the heat generation is lower than the full-power operating condition, the thermal equilibrium temperature is usually lower, and the system will fall to a lower heat dissipation power combination point along a monotonic curve. As the heat generation continues to increase, the temperature rise will drive the heat dissipation power to rise along the curve until it reaches the heat dissipation power V corresponding to the optimized control point. need .

[0100] The wind speed curve obtained through calibration under this operating condition is also applicable to various operating environments, including high temperature, low temperature, and environments with obstructed heat dissipation (such as dust accumulation on the fan). High temperature environments and environments with obstructed heat dissipation can be equated to situations where the heat dissipation is reduced under the same heat dissipation power, while low temperature environments can be equated to situations where the heat dissipation is increased under the same heat dissipation power. Regardless of changes in environmental conditions, the heat dissipation power will automatically find the corresponding combination point based on the temperature detection value in the first correspondence until the temperature stabilizes or the heat dissipation is insufficient to suppress the temperature rise and trigger the over-temperature protection threshold. In this embodiment, for the second heating device without a dedicated temperature sensor, the protection range of the first correspondence is expanded without increasing the main control temperature measurement channel by measuring the actual temperature and recalibrating the optimized control point. In addition, the addition of optimized points still maintains a monotonically increasing trend, which helps to automatically increase the heat dissipation power when the heat generation increases. Moreover, the calibration workload is relatively controllable, and optimized points can be added in the same way when adding similar heat sources in the future, which is convenient for maintenance and expansion.

[0101] In some embodiments, the heat dissipation control parameters also include derating trigger temperature and a second correspondence between derating trigger temperature and the operating power of the energy storage system. The calibration method also includes, but is not limited to, the following steps S61 to S63.

[0102] When the ambient temperature rises, the temperature difference between the cooling air and the device decreases for the same heat dissipation power, and the heat dissipation decreases accordingly. According to Newton's law of cooling, the heat dissipation P... diss With temperature difference (T) s -T env It is directly proportional to the ambient temperature T. envAn increase in temperature leads to a decrease in the temperature difference. Under the condition of constant heat generation, the surface temperature T of the device will decrease. s The corresponding increase is necessary. If the thermal equilibrium temperature under full-power operation rises to a level that is difficult to suppress below the over-temperature protection threshold using only the upper limit of heat dissipation power, then the operating power of the energy storage system needs to be reduced to decrease heat generation. The operating power of the energy storage system refers to the electrical power output or received by the system, including inverter output power, charging power, and discharging power. The magnitude of the operating power directly determines the heat generation of the power devices. Without a separate ambient temperature sensor, the rise in thermal equilibrium temperature can indirectly reflect the rise in ambient temperature. This embodiment uses the rise in temperature detection values ​​to indirectly perceive this risk and calibrates the derating parameters accordingly.

[0103] Step S61: Under the expected derating ambient temperature, control the energy storage system to operate at full power and control the heat dissipation device to operate at the upper limit of heat dissipation power. After the energy storage system reaches thermal equilibrium, record the temperature detection value as the second thermal equilibrium temperature.

[0104] The expected derating ambient temperature refers to the ambient temperature level at which the system needs to undergo high-temperature derating treatment. This temperature level can be selected by combining the expected high-temperature operating conditions in the application scenario and the temperature rise characteristics of the devices in high-temperature environments. For example, 45°C can be chosen, corresponding to typical operating conditions in high-temperature summer or poorly ventilated environments.

[0105] The second thermal equilibrium temperature is the measured value of the thermal equilibrium temperature when the energy storage system is operating at full power and at the upper limit of its heat dissipation capacity under the expected derating ambient temperature. Compared to the first thermal equilibrium temperature at room temperature, the second thermal equilibrium temperature is at a higher temperature level. According to Newton's law of cooling, when the ambient temperature rises from room temperature (e.g., 25°C) to the expected derating ambient temperature (e.g., 45°C), the ambient temperature rises by approximately 20°C. Under the same heat generation and heat dissipation capacity, the device surface temperature will also rise by approximately 20°C accordingly. Therefore, the second thermal equilibrium temperature can be used as an indirect criterion for determining whether the temperature detection value has entered the derating range. That is, when the thermal equilibrium level of the temperature detection value exceeds the second thermal equilibrium temperature during operation, it can be determined that the ambient temperature has reached or exceeded the expected derating ambient temperature, and derating control needs to be initiated.

[0106] Specifically, the energy storage system is placed at the expected derating ambient temperature, for example, by placing it in a temperature-controlled environmental test chamber or testing it in an actual high-temperature environment. The energy storage system is controlled to operate at full power, and the heat dissipation device is set to the upper limit of its heat dissipation power. The control device continuously collects temperature detection values ​​and monitors the fluctuation range of the temperature detection values ​​within a preset time period. When the fluctuation range is less than a preset fluctuation threshold, it is determined that the temperature detection value tends to stabilize, that is, the energy storage system is in thermal equilibrium, and the temperature detection value at this time is recorded as the second thermal equilibrium temperature.

[0107] Step S62: Determine the starting value of the derating temperature based on the upper limit switching temperature threshold of heat dissipation power, the second thermal equilibrium temperature and the over-temperature protection threshold.

[0108] Derating initial value T der This is the starting temperature at which the power reduction is triggered during the temperature rise. The selection of this temperature must be based on the premise that the heat dissipation capacity has been fully utilized, reserving a sufficient temperature range for power adjustment. This avoids premature derating that would affect system output, or delayed derating that would result in insufficient adjustment space before protection action.

[0109] Understandably, the upper limit switching temperature threshold for heat dissipation power is the temperature point determined in step S30. When the temperature detection value reaches this point, the heat dissipation device switches to the upper limit of heat dissipation power. If the initial value of the derating temperature is lower than this threshold, derating begins before the heat dissipation power reaches the upper limit, and power derating is initiated before the heat dissipation adjustment space is fully utilized, posing a risk of insufficient system output due to premature derating. The second thermal equilibrium temperature reflects the thermal equilibrium temperature detection value under the conditions of expected derating ambient temperature, full-power operation, and upper limit of heat dissipation power. If the initial value of the derating temperature is lower than the second thermal equilibrium temperature, when the system is running at full power under the expected derating ambient temperature, the temperature detection value after thermal equilibrium has reached or exceeded the initial value of the derating temperature, triggering derating control and preventing the system from operating at its rated output. The over-temperature protection threshold is the temperature limit at which the control device executes shutdown protection. If the initial value of the derating temperature is higher than or equal to the over-temperature protection threshold, there is no temperature adjustment range between derating control and over-temperature protection. Once the temperature reaches the initial value of the derating temperature, shutdown protection is triggered, making it difficult to lower the temperature through power adjustment, and the derating function becomes ineffective. In addition, a sufficient temperature margin should be maintained between the derating temperature threshold and the over-temperature protection threshold. This margin is used to divide the system into multiple derating levels, with each level corresponding to a derating trigger temperature and an operating power. This allows for a gradual reduction in operating power, and after each derating level, the system is given sufficient time to observe the temperature response, preventing an imbalance between output and safety due to insufficient or excessive derating. The margin can be determined based on the number of derating levels and the temperature intervals. For example, if the plan is to divide the system into 3 derating levels with a 5°C interval between each level, the margin should not be less than 15°C. Please refer to [link / reference]. Figure 11 derating temperature initial value T der The switching temperature threshold T can fall within the upper limit of heat dissipation power. last Second thermal equilibrium temperature T eq_der With over-temperature protection threshold T OTP Within the feasible interval of common constraints.

[0110] In one example, the over-temperature protection threshold is 135°C. The expected thermal equilibrium temperature at full power operation under a derating ambient temperature of 45°C, with the heat dissipation device operating at its maximum heat dissipation power, is approximately 100°C, i.e., the second thermal equilibrium temperature is 100°C. The difference between the over-temperature protection threshold and the second thermal equilibrium temperature is 35°C. This allows for a derating temperature approximately 15°C below the over-temperature protection threshold, setting the initial derating temperature to 120°C. This value simultaneously satisfies the constraints of not falling below the maximum heat dissipation power switching temperature threshold, not falling below the second thermal equilibrium temperature, and maintaining a 15°C adjustment margin between the over-temperature protection threshold and the thermal equilibrium temperature.

[0111] Step S63: Starting from the derating temperature start value and ending at the over-temperature protection threshold, divide the system into multiple derating levels, determine the derating trigger temperature corresponding to each derating level, the operating power of the energy storage system corresponding to each derating level, and obtain a second correspondence. The derating trigger temperature is used to trigger the energy storage system to adjust its operating power based on the second correspondence when the temperature detection value rises. The operating power of the energy storage system corresponding to each derating trigger temperature decreases as the temperature increases.

[0112] The second correspondence describes the mapping between derating trigger temperature and the operating power of the energy storage system, and consists of multiple derating levels. Each derating level corresponds to a derating trigger temperature and a permissible operating power. Let the number of derating levels be M, and the temperature interval between two adjacent derating trigger temperatures be ΔT. step_der ,but: T OTP -T der = M×ΔT step_der ; Number of derating gears M and temperature interval ΔT step_der The temperature margin between the over-temperature protection threshold and the derating temperature initiation value can be flexibly selected. Based on this, multiple derating levels can be defined between the derating temperature initiation value and the over-temperature protection threshold, and the derating trigger temperature and operating power corresponding to each derating level can be determined. As the derating trigger temperature increases, the corresponding allowable operating power P... run Gradually reduce the power until it reaches a low power level or zero power when approaching the over-temperature protection threshold. Continuing the example above, the over-temperature protection threshold T... OTP =135℃, initial derating temperature T der =120℃, the difference between the two is 15℃. Divided into 5℃ intervals, i.e. ΔT step_der =5℃, the number of derating levels M = (T OTP -T der ) / ΔT step_der =15℃ / 5℃=3. The derating trigger temperatures corresponding to the three derating levels are as follows: the derating trigger temperature T for the first derating level. der1 =T der=120℃, the derating trigger temperature T of the second derating setting. der2 =T der +ΔT step_der =120℃ + 5℃ = 125℃, the derating trigger temperature T for the third derating setting. der3 =T der +2×ΔT step_der =120℃ + 10℃ = 130℃. Correspondingly, the three derating levels correspond to approximately 66%, 33%, and 0% of the rated power, respectively. Specifically, when the temperature detection value is below 120℃, the operating power remains at 100% of the rated power; when the temperature detection value reaches 120℃, the operating power is reduced to 66% of the rated power using the first derating level; when the temperature detection value reaches 125℃, the operating power is further reduced to 33% of the rated power using the second derating level; when the temperature detection value reaches 130℃, the operating power is reduced to 0% using the third derating level, i.e., the charging / discharging of the energy storage system or the inverter output is stopped; when the temperature detection value reaches 135℃, over-temperature protection is triggered, and the control device executes shutdown protection.

[0113] During operation, when the detected temperature rises and exceeds a certain derating trigger temperature, the control device adjusts the operating power to the target value corresponding to that derating level according to a second correspondence, in order to reduce heat generation. The more derating levels there are, the finer the power adjustment and the smoother the temperature response. However, too many derating levels will increase the number of threshold comparisons, so the control accuracy and implementation complexity must be considered comprehensively.

[0114] After determining each derating level and its corresponding derating trigger temperature and operating power, the control device can execute derating control during operation. As the temperature detection value rises, the temperature detection value successively surpasses each derating trigger temperature, and the operating power of the energy storage system gradually decreases according to the derating level. This control logic does not require establishing a thermal network model; it only needs to compare the temperature detection value with a preset threshold to complete the derating judgment. The control logic mainly uses table lookup comparison and does not require solving thermal differential equations within the control cycle, resulting in a relatively small amount of computation within the control cycle.

[0115] In this embodiment, when the heat dissipation power, even at its upper limit, is insufficient to suppress the temperature rise in a high-temperature environment, further heat generation is reduced by dividing the derating levels and performing tiered derating. This helps to indirectly perceive the high-temperature risk using temperature detection values, even in the absence of an ambient temperature sensor. The selection of the derating temperature starting value comprehensively considers three boundary conditions: the upper limit switching temperature threshold for heat dissipation power, the second thermal equilibrium temperature, and the over-temperature protection threshold. An adjustable power step is reserved before the over-temperature protection action, reducing the possibility of directly triggering shutdown protection due to late derating. The second correspondence structure is simple; the control device can determine the target operating power through temperature threshold comparison and table lookup, which helps to achieve high-temperature protection on resource-constrained controllers and provides an adjustable power step before the over-temperature protection action. Compared to a fixed-ratio coarse derating, this embodiment divides the derating levels by quantified temperature intervals and determines the derating trigger temperature and operating power corresponding to each derating level. The derating range corresponds to the temperature level, which helps to provide a power adjustment response that matches the actual thermal state under different high-temperature conditions, reducing the possibility of insufficient output due to excessive derating or over-temperature caused by insufficient derating.

[0116] In some embodiments, the temperature interval between two adjacent derating trigger temperatures is equal, and the heat dissipation control parameters also include the power recovery temperature and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The calibration method also includes, but is not limited to, the following steps S64 to S66.

[0117] Step S64: Obtain the temperature interval.

[0118] The temperature interval ΔTstep_der is the difference between two adjacent derating trigger temperatures. In step S63, multiple derating trigger temperatures are divided between the derating temperature start value and the over-temperature protection threshold in an equally spaced manner. The equally spaced division can be determined by the difference between the over-temperature protection threshold and the derating temperature start value and the number of derating levels.

[0119] Step S65: Determine the hysteresis value based on the temperature interval.

[0120] Hysteresis ΔT hys_der This is used to create hysteresis during temperature decrease, reducing frequent switching of operating power between adjacent derating levels. The hysteresis value should meet the following requirements: ΔT hys_der ≤ ΔT step_der ; If the hysteresis value is greater than the temperature interval, the power recovery temperature and derating trigger temperature ranges of two adjacent derating levels will overlap. In actual operation, some derating levels may never trigger power recovery, rendering that derating level ineffective. The hysteresis value can be selected based on a combination of system temperature fluctuation amplitude and control requirements. For systems with large temperature fluctuation amplitudes, the hysteresis value can be appropriately increased to reduce false triggering; for systems with small temperature fluctuation amplitudes, the hysteresis value can be appropriately decreased to accelerate power recovery response, for example, using 2℃.

[0121] Step S66: Based on the hysteresis value and multiple derating trigger temperatures, determine multiple power recovery temperatures and the operating power of the energy storage system corresponding to each power recovery temperature to obtain a third correspondence. The power recovery temperature is used to trigger the energy storage system to adjust its operating power based on the third correspondence when the temperature detection value decreases. The operating power of the energy storage system corresponding to each power recovery temperature decreases as the temperature increases.

[0122] The power recovery temperature can be obtained by subtracting the hysteresis value from the corresponding derating trigger temperature. The third correspondence describes the mapping between the power recovery temperature and the operating power, and corresponds to the derating level in the second correspondence. Each power recovery temperature corresponds to a derating level and the operating power at that derating level. When the temperature detection value drops and falls below a certain power recovery temperature, the operating power is allowed to be restored to the operating power of the derating level corresponding to that power recovery temperature.

[0123] Taking the above example: the over-temperature protection threshold is 135℃, the derating temperature start value is 120℃, and three derating levels are divided in 5℃ intervals, so the derating trigger temperatures are 120℃, 125℃, and 130℃ respectively. When the temperature detection value rises, if the temperature detection value reaches 120℃, the operating power is adjusted to approximately 66% of the rated power according to the first derating level; if the temperature detection value reaches 125℃, the operating power is adjusted to approximately 33% of the rated power according to the second derating level; if the temperature detection value reaches 130℃, the operating power is adjusted to 0% according to the third derating level; if the temperature detection value reaches 135℃, the over-temperature protection is triggered. The hysteresis value can be taken as 2℃, so the power recovery temperatures corresponding to the above three derating levels are 118℃, 123℃, and 128℃ respectively. When the temperature detection value drops, if the temperature detection value is below 128℃, the operating power is allowed to recover from 0% to approximately 33% of the rated power; if the temperature detection value is below 123℃, the operating power is allowed to recover to approximately 66% of the rated power; if the temperature detection value is below 118℃, the operating power is allowed to recover to 100% of the rated power.

[0124] Number of depreciation gears M, step size ΔT step_der and hysteresis ΔT hys_derAll parameters can be adjusted according to the above relationships. It is understood that the more derating levels there are, the smoother the power adjustment. Furthermore, in this embodiment, hysteresis logic for temperature rise derating and temperature fall recovery is constructed using equal temperature intervals and hysteresis no greater than the interval. This ensures a one-to-one correspondence between the power recovery temperature in the third correspondence and the derating level in the second correspondence, helping to reduce power switching caused by temperature fluctuations near the threshold and improving operational stability. The derating logic primarily uses comparison and table lookup, finding the combination point of wind speed, power, and temperature without complex heat calculation fitting. This results in lower computational complexity. Compared to open-loop thermal model estimation, the derating logic with hysteresis has a higher tolerance for temperature sampling fluctuations and does not rely on iterative solutions, making it less prone to error accumulation during long-term operation.

[0125] In some embodiments, the temperature detection device includes multiple temperature detection devices, and the determination of the temperature detection value includes, but is not limited to, the following steps S71 to S72.

[0126] Step S71: Obtain temperature data detected by multiple temperature sensing devices.

[0127] Multiple temperature sensing devices monitor different heat-generating areas. Temperature data refers to the temperature readings from each of these devices.

[0128] The control device periodically reads temperature data from each temperature sensor. The acquisition frequency can be set according to the control cycle, for example, several to tens of times per second. The temperature data can be transmitted to the control device via analog signal lines or a digital communication bus.

[0129] Step S72: Determine the temperature data within the preset temperature range.

[0130] The preset temperature range is used to determine whether the temperature data detected by each temperature sensing device is normal. Temperature data exceeding this preset temperature range is considered abnormal data, such as obviously unreasonable readings caused by sensor failure, open circuit, or short circuit, and will not be included in the determination of subsequent temperature detection values. The preset temperature range can be set comprehensively by combining the effective range of the temperature sensing device, the allowable operating temperature range of the first heating device, and the reasonable temperature rise range in the system's historical operation, or it can be determined based on engineering experience.

[0131] In one embodiment, the preset temperature range is set to -50°C to 100°C. Specifically, the control device compares each temperature data obtained in step S71 with the preset temperature range one by one, filtering out temperature data that falls within the preset temperature range; temperature data that does not fall within the preset temperature range is discarded or marked as invalid. For example, if the reading of a certain temperature detection device is less than -50°C or greater than 100°C, the reading is determined to be abnormal data, discarded, and subsequently not used in determining the temperature detection value.

[0132] Step S73: Determine the maximum value among the temperature data within the preset temperature range as the temperature detection value.

[0133] After obtaining multiple temperature data points within a preset temperature range, the maximum value is selected as the temperature detection value. This maximum value is then used as the input for subsequent lookup of the first correspondence and for determining whether derating has been initiated.

[0134] Energy storage system operation often involves the superposition of multiple factors such as the power grid, photovoltaics, and batteries. If a separate wind speed curve is created for each factor or each measuring point, and the highest wind speed value is taken during operation, the calibration workload will increase with the number of factors. After removing outlier data, the highest temperature among the valid measuring points can be directly taken, which simplifies the input from the data source. This allows a single primary correspondence to cover the hottest spots in multiple heat-generating areas, eliminating the need for individual calibration for each combination of operating conditions. At the same time, it can reduce the risk of abnormal readings triggering high heat dissipation power or derating.

[0135] In this embodiment, effective temperature data is first filtered according to a preset temperature range, and then the maximum value among them is used as the control input. This helps to identify the most serious thermal risk points of the system and reduce the interference of abnormal measurement points on temperature control decisions. It also reduces the complexity of parallel calibration of multiple curves and makes it easier to use the same set of correspondences when adding new measurement points in the future.

[0136] Due to structural, cost, and heat dissipation limitations, temperature sensing devices are generally not mounted directly on the chip surface or die of the heat-generating device, but rather in an adjacent location. Specific mounting locations may include: the surface of the heatsink to which the heat-generating device is connected, in contact with the heatsink via thermal grease or a thermal pad; the copper trace of the printed circuit board to which the heat-generating device is soldered, indirectly sensing the device temperature using the thermal conductivity of the copper; the surface of the heat-generating device's package; or embedded within the internal structure of the heatsink. This mounting method results in the temperature data read by the temperature sensing device not being directly equivalent to the actual temperature of the heat-generating device. Taking a MOSFET as an example, its junction temperature refers to the actual operating temperature of the semiconductor junction region inside the MOSFET. It is the most direct physical quantity for measuring the thermal state of the device and a key parameter determining whether the device is within its safe operating range. Because the junction region is located inside the chip and cannot be directly measured by an external sensor, there is a certain difference between the temperature read by the temperature sensing device and the junction temperature. Furthermore, the heat inside the heat-generating device must pass through multiple layers of thermal resistance, such as from the chip to the package, from the package to the heatsink, and from the heatsink to the sensor, before reaching the temperature sensing device. Therefore, the detected temperature may lag behind the actual device temperature, and there may be numerical deviations. Therefore, in some embodiments, the calibration method also includes, but is not limited to, the following steps S81 to S83.

[0137] Step S81: Sequentially control the energy storage system to be in multiple preset operating conditions, and obtain the actual temperature of the first heating device and the temperature detection value of the temperature detection device under multiple preset operating conditions.

[0138] Multiple preset operating conditions refer to artificially set combinations of operating states of the energy storage system, used to generate temperature changes in the primary heating device to cover a wide temperature range. Preset operating conditions may include, but are not limited to: operating conditions at different output power levels, such as 30%, 50%, 80%, and 100% of rated power; operating conditions at different charging and discharging modes, such as charging mode, discharging mode, and grid-connected mode; operating conditions at different heat dissipation power, such as the heat dissipation device operating at 30%, 60%, and 100% of rated speed; or combinations of the above factors. By collecting data under multiple operating conditions, the correspondence between temperature detection values ​​and actual temperatures at different temperature levels can be obtained, improving the fitting accuracy. The actual temperature can be measured using a temperature recorder and thermocouples at key locations of the primary heating device, denoted as T. tc1 T tc2 T tc3 ... T tcn As a relatively accurate reference for the device temperature, n is an integer greater than or equal to 1. Simultaneously, the temperature detection values ​​T1, T2, T3, ..., T6 given by the temperature detection device are recorded. n .

[0139] Step S82: Based on the actual temperature and the temperature detection value, establish a fourth correspondence between the actual temperature and the temperature detection value, where the actual temperature T... tcn With temperature detection value T n Satisfy the following formula: T tcn =a·T n +b; Among them, T tcn T represents the actual temperature. n Let be the temperature detection value, 'a' be the first fitting parameter, and 'b' be the second fitting parameter.

[0140] The first fitting parameter 'a' is the slope in the linear relationship, used to characterize the proportional relationship between the actual temperature and the temperature detection value. Since heat needs to be transferred through multiple layers of thermal resistance, such as the chip, package, heat sink, and temperature detection device, the temperature detection value is usually lower than the actual temperature of the device, and the temperature difference between the two often increases with the increase of temperature. Therefore, the first fitting parameter 'a' is usually greater than 1; the larger 'a' is, the greater the actual temperature rise corresponding to the same increase in temperature detection value, that is, the more obvious the proportional deviation between the detection point and the heating point.

[0141] The second fitting parameter b is the intercept in the linear relationship, used to characterize the inherent deviation of the actual temperature relative to the temperature detection value. This deviation mainly comes from the difference in installation position between the temperature detection device and the heating device, the contact thermal resistance, and the fixed temperature difference on the heat conduction path. This means that even in the lower temperature range, there may still be an approximately constant difference between the actual temperature and the temperature detection value. The value of b can be positive or negative, and its sign and magnitude depend on the arrangement of the measuring points and the heat transfer path.

[0142] The first fitting parameter a and the second fitting parameter b can be obtained by univariate linear regression from multiple sets of data collected in step S81, and can be fine-tuned according to engineering needs, so as to convert the temperature detection value read by the control device into an actual temperature estimate that is closer to the true thermal state of the device.

[0143] In one fitting example, the temperature relationship of the power MOSFETs in the photovoltaic inverter branch of the energy storage system was calibrated. Measured data were collected under various preset operating conditions, and Table 2 lists some of the data points.

[0144] Table 2 Record Table of Actual Temperatures and Temperature Measurement Values

[0145] As shown in Table 2, when the detected temperature is 26.09℃, the corresponding actual temperature of the first MOSFET is approximately 27.56℃, with a temperature difference of approximately 1.47℃; when the detected temperature is 36.49℃, the corresponding actual temperature of the first MOSFET is approximately 41.55℃, with a temperature difference of approximately 5.06℃; and when the detected temperature is 66.17℃, the corresponding actual temperature of the first MOSFET is approximately 73.71℃, with a temperature difference of approximately 7.54℃. It is evident that as the temperature increases, the difference between the detected temperature and the actual temperature tends to increase.

[0146] After performing a univariate linear regression fitting on the actual temperature and temperature detection values ​​of the first MOSFET at all test points in Table 2, the fourth correspondence is obtained as follows: T MOS =1.1·T n +0.85; Among them, T MOS T represents the actual temperature of the first MOSFET. n This is the temperature reading.

[0147] For diodes monitored by the same temperature sensing device, using the same fitting method, the relationship between the actual diode temperature and the detected temperature value is obtained as follows: T 二极管 =1.153·T n +16.455; Considering the need to protect multiple devices in practical engineering applications, and the fact that the slope of the fitted curve may decrease with temperature changes in the high-temperature range, the parameters can be adjusted appropriately. For example, setting the slope parameter to 1.14 and the intercept parameter to 15 yields a uniform actual temperature T. tc With temperature detection value T n The fourth correspondence between them: T tc =1.14·T n +15; The slope of 1.14 was selected to take into account the temperature rise characteristics of different devices and the trend of the fitting curve in the high temperature range; the intercept of 15℃ was selected to take into account the difference in installation position between the temperature detection device and the heating device and the heat transfer path.

[0148] Substituting this relationship, when the temperature detection value is a certain reading, the actual temperature of the device can be estimated using the above formula. Considering the accuracy of temperature measurement and fitting error, in practical applications, the first fitting parameter a and the second fitting parameter b can be manually fine-tuned according to the actual test curve, ensuring that the estimated device temperature calculated from the temperature detection value is not lower than the actual device temperature directly measured by the thermocouple. In this way, when the estimated temperature reaches the protection threshold, the actual temperature of the device is still within the threshold, which can reduce the phenomenon of delayed protection action due to underestimation.

[0149] This step is used to determine the relationship between the temperature that the control device can read and the actual temperature of the components, providing a basis for the conversion of the over-temperature protection threshold.

[0150] Step S83: Based on the fourth correspondence, the physical failure temperature threshold of the first heating device is corrected to obtain the over-temperature protection threshold.

[0151] Physical failure temperature threshold T fail This refers to the temperature limit specified in the device specifications that may cause damage if exceeded. Because there is a discrepancy between the measured temperature and the actual temperature, the physical failure temperature threshold should not be directly used as the over-temperature protection threshold T. OTP In this step, the physical failure temperature threshold is converted or corrected to an over-temperature protection threshold in the temperature detection value coordinate system using the fourth correspondence relationship. The control device will provide timely protection when the temperature detection value reaches this threshold, providing a unified safety upper limit for heat dissipation switching and derating calibration. Regardless of subsequent adjustments to the fan speed curve or derating level, the system should be shut down when the temperature detection value reaches the over-temperature protection threshold to reduce the risk of device damage.

[0152] Taking the power MOSFET in the photovoltaic inverter branch of an energy storage system as an example, if the physical failure temperature of the device is 175℃, the derating reference temperature can be obtained as approximately 131℃ according to the derating standard of about 75%. After further adjusting down by about 10℃, the starting value of the derating temperature is taken as approximately 120℃. Using the fourth correspondence to calculate in reverse, when the actual temperature of the power MOSFET reaches 120℃, the corresponding temperature detection value is approximately: (120-15) / 1.14≈92℃. To further reserve a safety margin, the over-temperature protection threshold corresponding to this branch can be set to approximately 90℃.

[0153] In this embodiment, the correspondence between the detected temperature and the actual temperature is established through multi-condition measurement, and the physical failure temperature is corrected. This helps to compensate for the deviation caused by the sensor installation position, making the over-temperature protection threshold closer to the actual device risk, and providing a basic safety boundary for the entire set of temperature control parameters.

[0154] As another aspect of this application, this application also provides a heat dissipation method for an energy storage system, see reference. Figure 12 Heat dissipation methods include: Step S100: Obtain heat dissipation control parameters, which include a first correspondence between the temperature detection value of the temperature detection device and the heat dissipation power of the heat dissipation device. The first correspondence is established using the calibration method described in any of the preceding embodiments.

[0155] Heat dissipation control parameters are the configuration information used by the control device to achieve temperature control. The first correspondence is the mapping curve between the temperature detection value and the heat dissipation power. This curve has been established through actual measurement during the calibration phase and incorporates factors such as system thermal inertia, heat dissipation device uptime, and safety boundaries.

[0156] After calibration, the thermal control parameters can be stored in the non-volatile memory of the control device, such as flash memory or electrically erasable programmable read-only memory (EEPROM). During power-on initialization of the energy storage system, the control device reads the thermal control parameters from the memory and loads them into the operating memory. If the calibration parameters are updated, they can be rewritten to the memory via the communication interface or configuration tools.

[0157] The storage format for the first correspondence can be chosen based on controller resources and lookup efficiency requirements. One storage method is discrete entries, where the corresponding points of temperature detection values ​​and heat dissipation power are stored in a lookup table at fixed intervals. Intermediate values ​​are calculated during runtime using interpolation. For example, a heat dissipation power value is stored every 5°C, forming a temperature-power entry array. Another storage method is piecewise linear function parameters, dividing the curve into several linear intervals, storing the slope and intercept for each interval. Heat dissipation power is calculated based on the interval where the current temperature falls. Yet another storage method is curve fitting parameters. If the first correspondence can be approximated by a quadratic or cubic polynomial, the polynomial coefficients are stored, and the heat dissipation power is calculated by substituting the temperature during runtime. The table-based lookup method is fast but requires more storage space, while the function-based method requires less space but requires a certain amount of computation. A trade-off should be made based on the actual situation.

[0158] Step S200: Obtain the temperature detection value from the temperature detection device.

[0159] The temperature detection device includes multiple temperature sensing devices arranged in different heat-generating areas of the energy storage system. These temperature sensing devices typically employ negative temperature coefficient thermistors (NTC) temperature sensors.

[0160] The control device reads the output of each temperature sensor at a fixed interval. The acquisition period can be set according to control requirements, for example, 1 to 10 times per second. Too low an acquisition frequency may result in untimely response to temperature changes, while too high an acquisition frequency will increase the processor interrupt load. The temperature change rate and controller resources must be considered comprehensively.

[0161] When the temperature detection device includes multiple temperature sensing elements, the control device acquires the temperature data T1, T2, T3, ..., T from each temperature sensing element. n Where T1 represents the temperature data from the first temperature sensing device, T2 represents the temperature data from the second temperature sensing device, and so on, T... n Representing the n The temperature data of a temperature sensing device, where n is the number of temperature sensing devices and n is an integer greater than or equal to 1.

[0162] After the control device removes abnormal data, it determines the maximum value among all temperature data as the temperature detection value T. MAXTaking the maximum value simplifies control input from the data source, allowing a single primary correspondence to cover the hottest spots in multiple heat-generating regions. Energy storage system operation involves various factors such as grid charging and discharging, photovoltaic input, and battery charging and discharging, resulting in different temperature distributions in different heat-generating regions under varying conditions. If a separate heat dissipation power curve is established for each temperature sensing device, and the maximum value is taken from the output of multiple curves during operation, the calibration workload increases with the number of temperature sensing devices. Directly taking the maximum value of each temperature data point reduces computational complexity by requiring only one subsequent table lookup operation, and also facilitates the continued use of the same primary correspondence when adding new temperature sensing devices.

[0163] Step S300: Based on the temperature detection value and the first correspondence, obtain the target heat dissipation power.

[0164] The control device uses the temperature detection value T MAX As input, the target heat dissipation power Vtgt that should be executed is obtained by querying or calculating in the first correspondence.

[0165] Since the initial correspondence was established during the calibration phase based on a monotonically increasing principle, the target heat dissipation power increases when the temperature detection value rises and decreases when the temperature detection value falls. This monotonicity allows the heat dissipation power to automatically adjust in response to temperature changes. When the heat generation increases or the heat dissipation conditions worsen, causing the temperature detection value to rise, the control device automatically increases the heat dissipation power to enhance heat dissipation capacity. When the heat generation decreases or the heat dissipation conditions improve, causing the temperature detection value to fall, the control device automatically reduces the heat dissipation power to reduce energy consumption and noise.

[0166] Step S400: Control the operation of the heat dissipation device based on the target heat dissipation power.

[0167] The control device converts the target heat dissipation power into a drive signal for the heat dissipation device, driving the heat dissipation device to operate at that power. The conversion method depends on the type of heat dissipation device and its drive method.

[0168] When the cooling device is a fan, the target cooling power is usually expressed as a percentage of the rated speed. The control device converts the target cooling power into the duty cycle of a Pulse Width Modulation (PWM) signal or a target speed command. A PWM signal is a method of controlling average power by adjusting the proportion of high-level time to the entire cycle time. The duty cycle is the ratio of the high-level time to the cycle time in a PWM signal, expressed as a percentage. For example, a 50% duty cycle means that the high-level time accounts for 50% and the low-level time accounts for 50% of one cycle. The average power of the fan motor is approximately proportional to the PWM duty cycle; the larger the duty cycle, the higher the fan speed and the greater the cooling power.

[0169] Specifically, the control device generates a PWM signal with a corresponding duty cycle based on the target heat dissipation power, and drives the fan motor through the output pin. For example, when the target heat dissipation power is 60%, the control device outputs a PWM signal with a 60% duty cycle, and the fan speed reaches approximately 60% of the rated speed. Some fans support closed-loop speed control, with a built-in Hall sensor providing feedback on the actual speed. The control device can adjust the PWM duty cycle based on the deviation between the target speed and the actual speed, ensuring the fan operates stably at the target speed.

[0170] In this embodiment, during the operation phase, only temperature detection values ​​need to be collected and the target heat dissipation power output is output according to the calibrated first correspondence. The control logic is relatively simple, and the operation of the control device mainly involves numerical comparison, table lookup, or simple calculations. There is no need to build a heat estimation model or solve the heat balance equation in real time, which reduces the consumption of controller resources and helps to implement it on a low-cost microcontroller with limited resources. Since the first correspondence has been determined by actual measurement during the calibration phase to switch the upper limit of heat dissipation power, and the temperature overshoot caused by the heat dissipation device's acceleration time and the overall heat capacity is taken into account, the adjustment of heat dissipation power during operation can be completed before the temperature reaches a dangerous level, which helps to reduce the risk of temperature overshoot exceeding the safe range due to thermal inertia. The first correspondence adopts a monotonically increasing mapping. When the heat generation, ambient temperature, or heat dissipation conditions change, the change in temperature detection value will automatically drive the heat dissipation power to adjust along the curve. There is no need to calibrate control parameters separately for different combinations of operating conditions, and a single curve can cover a wide operating range. High-temperature environments and heat dissipation obstruction can be equivalent to the situation where the heat dissipation is reduced under the same heat dissipation power, while low-temperature environments can be equivalent to the situation where the heat dissipation is increased under the same heat dissipation power. The system can find the corresponding heat dissipation power combination point based on the temperature detection value in the first correspondence until the temperature tends to stabilize or the heat dissipation capacity is insufficient and the over-temperature protection threshold is triggered. This helps to respond to changes in ambient temperature without relying on an independent ambient temperature sensor.

[0171] In some embodiments, the heat dissipation control parameters also include a second correspondence between the derating trigger temperature and the operating power of the energy storage system, and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The heat dissipation method also includes, but is not limited to, the following steps S500 to S600.

[0172] Step S500: Determine the target operating power of the energy storage system based on the temperature detection value, the second correspondence, and the third correspondence.

[0173] The derating trigger temperature is the temperature threshold used to trigger a reduction in operating power during a rise in the detected temperature value. The second correspondence describes the mapping between each derating trigger temperature and its corresponding operating power. The power recovery temperature is the temperature threshold used to trigger an increase or recovery in operating power during a fall in the detected temperature value. The third correspondence describes the mapping between each power recovery temperature and its corresponding operating power. There is a hysteresis between the derating trigger temperature and the power recovery temperature. The hysteresis is the temperature difference between the two, used to create hysteresis characteristics and reduce frequent switching of operating power when the temperature fluctuates near the threshold.

[0174] The operating power of an energy storage system refers to the electrical power output or received by the system, such as inverter output power, charging power, and discharging power. The operating power directly determines the heat generated by the internal heat-generating components. Higher operating power results in greater switching losses, diode voltage drop losses, and capacitor charging / discharging losses, leading to a higher total system heat generation. Lowering the operating power can reduce heat generation and lower the temperature.

[0175] While the control device is performing steps S100 to S400 to adjust the heat dissipation power according to the first correspondence, it continuously compares the current temperature detection value with multiple preset derating trigger temperatures and power recovery temperatures to determine whether the operating power of the energy storage system needs to be adjusted.

[0176] When the temperature detection value rises, the control device sequentially determines whether the temperature detection value has reached or exceeded each derating trigger temperature. If the temperature detection value reaches a certain derating trigger temperature, the control device queries the target operating power corresponding to that derating trigger temperature according to the second correspondence relationship, and lowers the operating power of the energy storage system to that target value. In the second correspondence relationship, the operating power corresponding to each derating trigger temperature decreases as the temperature rises; the higher the temperature, the lower the allowable operating power.

[0177] For example, the second correspondence includes three derating levels: derating trigger temperature T der1 =120℃ corresponds to an operating power P1 of 66% of the rated power, and the derating trigger temperature T der2 =125℃ corresponds to an operating power P2 of 33% of the rated power, and the derating trigger temperature T der3 =130℃ corresponds to an operating power P3 of 0%. When the temperature rises from below 120℃ to 120℃, the control device reduces the operating power to 66% of the rated power. If the temperature continues to rise to 125℃, the control device further reduces the operating power to 33% of the rated power. If the temperature continues to rise to 130℃, the control device reduces the operating power to 0%, i.e., stops the charging and discharging of the energy storage system or the inverter output. If the temperature continues to rise to the over-temperature protection threshold T... OTP For example, at 135°C, the control device will perform a shutdown protection, shut down all power devices, and issue an alarm signal.

[0178] When the temperature detection value decreases, the control device sequentially checks whether the temperature detection value is lower than each power recovery temperature. If the temperature detection value is lower than a certain power recovery temperature, the control device queries the target operating power corresponding to that power recovery temperature according to the third correspondence relationship, and adjusts or restores the operating power of the energy storage system to that target value. In the third correspondence relationship, the operating power corresponding to each power recovery temperature also decreases as the temperature increases, but the value of the power recovery temperature is lower than the corresponding derating trigger temperature, and the difference between the two is the hysteresis.

[0179] Continuing with the example above, if the hysteresis ΔT hys_der =2℃, then the power recovery temperatures are respectively T rec1 =118℃, T rec2 =123℃, T rec3 =128℃. When the temperature drops from 130℃ to 128℃, the control device will restore the operating power from 0% to 33% of the rated power. If the temperature continues to drop to 123℃, the control device will restore the operating power to 66% of the rated power. If the temperature continues to drop to 118℃, the control device will restore the operating power to 100% of the rated power.

[0180] The introduction of hysteresis can reduce frequent switching of operating power caused by small temperature fluctuations near the threshold. Without hysteresis, the derating trigger temperature coincides with the power recovery temperature. When the temperature fluctuates around this threshold, the operating power will repeatedly switch between adjacent levels, leading to unstable output of the energy storage system and increasing the processing burden on the controller. The selection of the hysteresis value needs to comprehensively consider the temperature fluctuation range and control requirements. If the hysteresis value is too small, the hysteresis effect will be insignificant; if the hysteresis value is too large, the power recovery response will be slow.

[0181] The control device compares the temperature detection value with various threshold values ​​and considers the current operating power level to determine whether a power level needs to be switched. This judgment logic primarily relies on conditional comparisons, requiring minimal computation and eliminating the need for complex heat fitting or model solving.

[0182] Step S600: Control the operation of the energy storage system based on the target operating power.

[0183] The control device adjusts or limits the output of the energy storage system based on the target operating power determined in step S500. The adjustment method depends on the topology and operating mode of the energy storage system.

[0184] When the energy storage system operates in inverter output mode, the control device limits the output power by adjusting the inverter's modulation strategy. An inverter is a power electronic device that converts direct current (DC) energy into alternating current (AC) energy. It typically uses pulse width modulation (PWM) technology to control the switching of transistors, generating an AC output with the required frequency and amplitude. The control device can ensure that the inverter's output power does not exceed the target operating power by reducing the modulation amplitude, decreasing the output current command, or limiting the power command.

[0185] When the energy storage system operates in charging mode, the control device limits the charging power of the battery or energy storage unit by adjusting the charging current or charging power command. During charging, electrical energy is input from an external power source and converted into chemical energy or other forms for storage. The charging current generates conduction and switching losses as it flows through the power conversion circuit. Reducing the charging power can reduce these losses and decrease heat generation.

[0186] When the energy storage system operates in discharge mode, the control device limits the discharge power of the battery or energy storage unit by adjusting the discharge current or discharging power command. During discharge, the stored energy is released and output through the power conversion circuit. Discharge current flowing through power devices also generates losses and heat. Reducing the discharge power can correspondingly reduce heat generation.

[0187] The control device can regulate power by modifying the power command register, adjusting the reference values ​​of the current loop or power loop, or sending power limit commands to the power conversion module. The regulation process can be configured with a specific slope or transition time to ensure smooth power changes and reduce the impact on the power grid or load.

[0188] After the operating power is reduced, the heat generated by the power devices inside the energy storage system decreases accordingly. According to the principle of thermal balance, when the heat generated is less than the heat dissipation, the temperature detection value begins to decrease. If the temperature drops below a certain power recovery temperature, the control device increases the operating power according to the logic of step S500, allowing the system to exert its maximum power while maintaining a safe temperature. If even reducing the operating power to the lowest level cannot suppress the temperature rise, and the temperature continues to rise and reaches the over-temperature protection threshold T, then... OTP If the temperature is too high, the control device will perform a shutdown protection, turn off all power switching transistors, cut off the charging and discharging circuit, and issue an over-temperature alarm signal through indicator lights, buzzers, or communication interfaces to prompt the user to check the heat dissipation system or lower the ambient temperature.

[0189] Steps S100 to S600 together constitute a tiered temperature control strategy. Steps S100 to S400 use a first correspondence to automatically adjust the heat dissipation power according to the temperature, covering the operating range from room temperature to higher temperatures. Steps S500 to S600 use a second and third correspondence to tiered derating of the operating power to address extreme high-temperature scenarios or scenarios where the heat dissipation power has reached its upper limit but still faces the risk of overheating or heat dissipation obstruction. The two strategies work in parallel, with the control device simultaneously performing heat dissipation power adjustment and operating power judgment in each control cycle. At lower temperatures, only heat dissipation power adjustment is active, and the operating power remains at its rated value. After the temperature rises to the derating trigger temperature, both heat dissipation power and operating power are adjusted simultaneously to jointly control the temperature within a safe range.

[0190] In this embodiment, when the heat dissipation power has reached its upper limit and there is still a risk of overheating, the operating power is reduced by step-by-step derating with hysteresis to reduce heat generation, forming a dual protection mechanism of heat dissipation regulation and power regulation. This helps maintain the safe operation of the system in high-temperature environments or scenarios where heat dissipation is hindered, and reduces the possibility of shutdown protection due to overheating. Compared with the coarse derating method with a fixed ratio, the step-by-step derating and hysteresis can be set according to a quantitative relationship. The derating range corresponds to the temperature level, and a power regulation response that matches the actual temperature state can be given, reducing the possibility of insufficient system output due to excessive derating or overheating caused by insufficient derating. Compared with the closed-loop estimation method based on the thermal network model, the step-by-step derating logic with hysteresis is based directly on the comparison between the temperature detection value and the preset threshold. It has a higher tolerance for temperature sampling fluctuations, does not rely on the accuracy of model parameters such as thermal resistance and thermal capacity, and is less prone to error accumulation due to model parameter drift during long-term operation, resulting in better operational stability. The number of derating levels, temperature intervals, and hysteresis values ​​can all be flexibly adjusted according to device characteristics and application requirements, making it easy to adapt to energy storage systems of different specifications.

[0191] As another aspect of the embodiments of this application, the embodiments of this application also provide a computer-readable storage medium storing computer-executable instructions for causing an electronic device to perform the methods provided in the embodiments of this application.

[0192] In some embodiments, the storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.

[0193] In some embodiments, executable instructions may take the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0194] As an example, executable instructions may, but do not necessarily, correspond to files in the file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple collaborative files (e.g., a file that stores one or more modules, subroutines, or code sections).

[0195] As an example, executable instructions can be deployed to execute on a single computing device (including devices such as smart terminals and servers), or on multiple computing devices located in one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0196] As another aspect of the embodiments of this application, the embodiments of this application also provide a computer program product, the computer program product including a computer program stored on a computer-readable storage medium, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the method as described in the foregoing embodiments.

[0197] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0198] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general-purpose hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for at least one computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments.

[0199] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for calibrating heat dissipation control parameters of an energy storage system, characterized in that, The energy storage system includes a heat dissipation device, a first heating device, and a temperature detection device for detecting the temperature of the first heating device. The heat dissipation control parameters include a first correspondence between the temperature detection value of the temperature detection device and the heat dissipation power of the heat dissipation device. The calibration method includes: Under a preset ambient temperature, the energy storage system is controlled to operate at full power, and the heat dissipation device is controlled to operate at the upper limit of heat dissipation power. After the energy storage system reaches thermal equilibrium, the temperature detection value of the temperature detection device is recorded as the first thermal equilibrium temperature. Perform a temperature test step, which includes: controlling the energy storage system to shut down; after the energy storage system cools down to the ambient temperature, controlling the energy storage system to operate at full power and controlling the heat dissipation device to shut down; when the temperature detection value rises to the trigger temperature, controlling the heat dissipation device to switch to the upper limit of the heat dissipation power; obtaining the peak temperature reached by the temperature detection value after switching the heat dissipation power; and the initial value of the trigger temperature is the first thermal equilibrium temperature. If the peak temperature is greater than or equal to the over-temperature protection threshold, the trigger temperature is reduced and the temperature test step is re-executed. If the peak temperature is less than the over-temperature protection threshold, the trigger temperature is confirmed as the upper limit switching temperature threshold for heat dissipation power. Establish the first correspondence, wherein the heat dissipation start-up temperature threshold corresponds to the lower limit of heat dissipation power, the heat dissipation power upper limit switching temperature threshold corresponds to the upper limit of heat dissipation power, and between the heat dissipation start-up temperature threshold and the heat dissipation power upper limit switching temperature threshold, the heat dissipation power increases monotonically as the temperature detection value increases.

2. The calibration method according to claim 1, characterized in that, The energy storage system further includes a second heating device, and the calibration method further includes: The first correspondence is used to control the operation of the heat dissipation device and control the second heating device to operate at full power. After the energy storage system reaches thermal equilibrium, the actual temperature of the second heating device is obtained. If the actual temperature is greater than or equal to the expected operating temperature of the second heating device, the heat dissipation power of the heat dissipation device is increased, and after the energy storage system reaches thermal equilibrium, the actual temperature is re-acquired until the actual temperature is less than the expected operating temperature. If the actual temperature is less than the expected operating temperature, the current temperature detection value and the current heat dissipation power of the heat dissipation device are recorded as optimization control points. Based on the optimized control points, the first correspondence is adjusted.

3. The calibration method according to claim 1 or 2, characterized in that, The heat dissipation control parameters also include a derating trigger temperature and a second correspondence between the derating trigger temperature and the operating power of the energy storage system. The calibration method further includes: Under the expected derating ambient temperature, the energy storage system is controlled to operate at full power, and the heat dissipation device is controlled to operate at the upper limit of the heat dissipation power. After the energy storage system reaches thermal equilibrium, the temperature detection value is recorded as the second thermal equilibrium temperature. Based on the heat dissipation power upper limit switching temperature threshold, the second thermal equilibrium temperature, and the over-temperature protection threshold, the derating temperature starting value is determined. Starting from the derating temperature initial value and ending at the over-temperature protection threshold, multiple derating levels are defined. The derating trigger temperature and the operating power of the energy storage system corresponding to each derating level are determined, and the second correspondence is obtained. The derating trigger temperature is used to trigger the energy storage system to adjust its operating power based on the second correspondence when the temperature detection value rises. The operating power of the energy storage system corresponding to each derating trigger temperature decreases as the temperature increases.

4. The calibration method according to claim 3, characterized in that, The temperature interval between two adjacent derating trigger temperatures is equal. The heat dissipation control parameters also include the power recovery temperature and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The calibration method further includes: Obtain the temperature interval; Based on the temperature interval, the hysteresis value is determined; Based on the hysteresis value and the multiple derating trigger temperatures, multiple power recovery temperatures and the operating power of the energy storage system corresponding to each power recovery temperature are determined to obtain the third correspondence. The power recovery temperature is used to trigger the energy storage system to adjust its operating power based on the third correspondence when the temperature detection value decreases. The operating power of the energy storage system corresponding to each power recovery temperature decreases as the temperature increases.

5. The calibration method according to claim 1 or 2, characterized in that, The temperature detection device includes multiple temperature detection components, and the calibration method for the temperature detection value includes: Acquire temperature data detected by the multiple temperature detection devices; Determine the temperature data within the preset temperature range; The maximum value among the temperature data within the preset temperature range is determined as the temperature detection value.

6. The calibration method according to claim 1 or 2, characterized in that, The calibration method further includes: The energy storage system is sequentially controlled to operate under various preset conditions, and the actual temperature of the first heating device and the temperature detection value of the temperature detection device are obtained under various preset conditions. Based on the actual temperature and the detected temperature value, a fourth correspondence is established between the actual temperature and the detected temperature value, wherein the actual temperature and the detected temperature value satisfy the following formula: T tcn =a·T n +b, Among them, T tcn T represents the actual temperature. n The temperature detection value is given by , where a is the first fitting parameter and b is the second fitting parameter; Based on the fourth correspondence, the physical failure temperature threshold of the first heating device is corrected to obtain the over-temperature protection threshold.

7. A heat dissipation method for an energy storage system, characterized in that, The energy storage system includes a heat dissipation device, a first heating device, and a temperature detection device for detecting the temperature of the first heating device. The heat dissipation method includes: Obtain heat dissipation control parameters, the heat dissipation control parameters including a first correspondence between the temperature detection value of the temperature detection device and the heat dissipation power of the heat dissipation device, the first correspondence being established using the calibration method described in any one of claims 1 to 6; Obtain the temperature detection value from the temperature detection device; Based on the temperature detection value and the first correspondence, the target heat dissipation power is obtained; The heat dissipation device is controlled to operate based on the target heat dissipation power.

8. The heat dissipation method according to claim 7, characterized in that, The heat dissipation control parameters also include a second correspondence between the derating trigger temperature and the operating power of the energy storage system, and a third correspondence between the power recovery temperature and the operating power of the energy storage system. The heat dissipation method further includes: Based on the temperature detection value, the second correspondence, and the third correspondence, the target operating power of the energy storage system is determined; The energy storage system is controlled to operate based on the target operating power.

9. An energy storage system, characterized in that, include: A heat dissipation device is used to dissipate heat from the energy storage system; First heating device; A temperature detection device is used to detect the temperature of the first heating device; The control device includes: a processor, and a memory communicatively connected to the processor; The memory stores computer program instructions executable by the processor, which, when executed by the processor, cause the control device to perform the method as described in any one of claims 1 to 8.

10. A computer storage medium, characterized in that, The computer storage medium stores instructions or programs that, when executed by at least one processor, cause the at least one processor to perform the method as described in any one of claims 1 to 8.

Images