Derating method and derating device for energy storage system

Abstract

The invention provides a derating method and a derating device for an energy storage system. The derating method comprises the step of reducing the input power of the photovoltaic module according to a photovoltaic derating rule when the fan state information is judged to be abnormal and the current temperature information is greater than the safe temperature information of the power device. After a preset time, whether the temperature of the energy storage system continues to rise or not is judged, when the surface temperature information of the protection shell is larger than the safe touch temperature of the protection shell, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage conversion module is reduced according to a conversion derating rule. Thus, when it is judged that the fan module is abnormal, operation continues through derating instead of direct shutdown, and the service life of the energy storage system is prolonged. Besides, in the derating process, the input power of the photovoltaic module is preferentially reduced, the output power of the energy storage converter module is ensured to be unchanged, the use experience of a user is ensured, and when it is judged that the temperature continues to rise, the output power of the energy storage converter module is reduced, and the safety is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage battery technology, and in particular to a derating method and derating device for an energy storage system. Background Technology

[0002] Balcony photovoltaic (PV) energy storage inverters typically employ natural heat dissipation to meet IP65 protection standards, ensuring long-term outdoor operation. However, at high power densities, internal power devices (MOSFETs, IGBTs, magnetic components, etc.) are prone to becoming hotspots. To improve internal heat distribution, some designs incorporate small fans as internal airflow turbulence devices to enhance heat dissipation uniformity.

[0003] However, wind turbines typically have a lifespan of less than 10 years, while energy storage inverters are designed to have a lifespan exceeding 10 years. When a wind turbine fails, the temperature of local hot spots will rise significantly, and the surface temperature of the casing will also increase. If this temperature exceeds the touchable temperature threshold stipulated by safety regulations, it may pose a safety hazard and fail to meet the lifespan requirements of balcony photovoltaic energy storage inverters. Summary of the Invention

[0004] This invention provides a derating method and device for an energy storage system. By continuing operation under derating when an abnormality is detected in the wind turbine module, instead of shutting it down directly, the lifespan of the energy storage system is extended. Furthermore, during the derating process, the input power of the photovoltaic module is reduced first, ensuring that the output power of the energy storage converter module remains constant, thus guaranteeing a good user experience. If further temperature increases are detected, the output power of the energy storage converter module is reduced, improving safety.

[0005] In a first aspect, embodiments of the present invention provide a derating method for an energy storage system, the energy storage system comprising a wind turbine module, power devices, a photovoltaic module, a protective casing, and an energy storage converter module, characterized in that...

[0006] The system acquires the wind turbine status information of the wind turbine module. When the wind turbine status information is found to be abnormal, the system acquires the current temperature information of the power device. When the current temperature information is greater than the safe temperature information of the power device, the system reduces the input power of the photovoltaic module according to the photovoltaic derating rules, and keeps the output power of the energy storage converter module constant.

[0007] After a preset time, it is determined whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective shell is greater than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise. Then, the output power of the energy storage converter module is reduced according to the converter derating rule.

[0008] Optionally, reducing the input power of the photovoltaic module according to the photovoltaic derating rules includes:

[0009] Obtain the photovoltaic derating factor of the photovoltaic module, and obtain the temperature difference of the power devices between the current temperature information and the safe temperature information;

[0010] The input power of the photovoltaic module is reduced based on the photovoltaic derating factor and the temperature difference of the power devices.

[0011] Optionally, obtaining the photovoltaic derating factor of the photovoltaic module includes:

[0012] Establish a device temperature rise model for the power device, and determine the device equivalent thermal resistance based on the device temperature rise model;

[0013] The device heat loss ratio of the photovoltaic module is determined, and the photovoltaic derating factor of the photovoltaic module is determined based on the device equivalent thermal resistance and the device heat loss ratio.

[0014] Optionally, reducing the output power of the energy storage converter module according to the converter derating rule includes:

[0015] Obtain the derating factor of the energy storage converter module, and obtain the temperature difference between the surface temperature information and the protective shell temperature at the safe touch temperature;

[0016] The output power of the energy storage converter module is reduced based on the converter derating factor and the temperature difference of the protective casing.

[0017] Optionally, obtaining the derating factor of the energy storage converter module includes:

[0018] Establish a temperature rise model for the protective enclosure, and determine the equivalent thermal resistance of the protective enclosure based on the temperature rise model.

[0019] Determine the heat loss ratio of the casing of the energy storage converter, and determine the derating factor of the energy storage converter module based on the equivalent thermal resistance of the casing and the equivalent thermal resistance of the casing.

[0020] Optionally, after reducing the output power of the energy storage converter module according to the converter derating rule, the method further includes:

[0021] Determine the photovoltaic power reduction of the photovoltaic module according to the photovoltaic derating rules, obtain the photovoltaic rated power of the photovoltaic module, and determine the photovoltaic limit power of the photovoltaic module after derating based on the photovoltaic rated power and the photovoltaic power reduction.

[0022] Determine the power reduction of the energy storage converter module according to the power derating rule, obtain the rated power of the energy storage converter module, and determine the power limit of the energy storage converter module after derating based on the rated power and the power reduction.

[0023] The minimum value between the photovoltaic power limit and the converter power limit is taken as the output power of the energy storage system.

[0024] Optionally, after obtaining the current temperature information of the power device, the method further includes:

[0025] When the current temperature information is greater than the limit temperature information of the power device, the power of the power device is reduced.

[0026] Optionally, obtaining the photovoltaic derating factor of the photovoltaic module includes:

[0027] Obtain a safety factor, and determine the actual photovoltaic derating factor of the photovoltaic module based on the safety factor and the photovoltaic derating factor;

[0028] The step of reducing the input power of the photovoltaic module based on the photovoltaic derating factor and the temperature difference of the power devices includes:

[0029] The input power of the photovoltaic module is reduced based on the actual photovoltaic derating factor and the temperature difference of the power devices.

[0030] Optionally, obtaining the derating factor of the energy storage converter module includes:

[0031] Obtain a safety factor, and determine the actual derating factor of the energy storage converter module based on the safety factor and the derating factor.

[0032] The method of reducing the output power of the energy storage converter module based on the converter derating factor and the temperature difference of the protective casing includes:

[0033] The output power of the energy storage converter module is reduced based on the actual converter derating factor and the temperature difference of the protective casing.

[0034] Secondly, embodiments of the present invention also provide a derating device for an energy storage system. The energy storage system includes a wind turbine module, power devices, a photovoltaic module, a protective casing, and an energy storage converter module. The derating device comprises:

[0035] The first acquisition module is used to acquire the fan status information of the fan module, and when it is determined that the fan status information is abnormal, acquire the current temperature information of the power device.

[0036] The first derating module is used to reduce the input power of the photovoltaic module according to the photovoltaic derating rules when the current temperature information is greater than the safe temperature information of the power device, and to keep the output power of the energy storage converter module unchanged.

[0037] The second derating module is used to determine whether the temperature of the energy storage system continues to rise after a preset time. If the surface temperature of the protective shell is greater than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rule.

[0038] In summary, this embodiment of the invention acquires the fan status information of the fan module. When an abnormality is detected in the fan status information, it acquires the current temperature information of the power devices. If the current temperature exceeds the safe temperature of the power devices, the input power of the photovoltaic module is reduced according to the photovoltaic derating rules, while maintaining the output power of the energy storage converter module unchanged. After a preset time, it is determined whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing exceeds the safe touch temperature of the protective casing, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rules. In this way, when an abnormality is detected in the fan module, it continues to operate through derating instead of shutting down directly, extending the service life of the energy storage system. Furthermore, during the derating process, the input power of the photovoltaic module is reduced first to ensure that the output power of the energy storage converter module remains unchanged, ensuring the user experience. When it is determined that the temperature continues to rise, the output power of the energy storage converter module is reduced, improving safety. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating a derating method for an energy storage system provided in an embodiment of the present invention;

[0040] Figure 2 This is a flowchart illustrating another energy storage system derating method provided in an embodiment of the present invention;

[0041] Figure 3 This is a flowchart illustrating another energy storage system derating method provided in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the structure of a derating device for an energy storage system provided in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings in the embodiments of this invention, through specific implementation methods. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort fall within the protection scope of this invention.

[0044] Figure 1This is a flowchart illustrating a derating method for an energy storage system provided in an embodiment of the present invention. This embodiment is applicable to situations where a wind turbine module in an energy storage system fails. The method can be executed by the derating device provided in this embodiment, which can be implemented using software and / or hardware. See also... Figure 1 The method of reducing the amount includes:

[0045] S110. Obtain the fan status information of the fan module. When the fan status information is determined to be abnormal, obtain the current temperature information of the power device.

[0046] Specifically, the energy storage system includes a wind turbine module, power devices, a photovoltaic module, a protective casing, and an energy storage converter module. The power devices are internal components of the energy storage system, such as insulated-gate bipolar transistors (IGBTs), primarily used as high-speed switches. By controlling the rapid switching on and off of the IGBTs, the direct current (DC) released from the battery is converted into alternating current (AC) required by the power grid. Alternatively, power devices can also be metal-oxide-semiconductor field-effect transistors (MOSFETs) and magnetic devices, etc. This embodiment of the invention does not limit the specific power devices used. The photovoltaic module converts light energy into electrical energy, which can be directly output to the load or input to charge the energy storage battery. The energy storage converter module converts the DC power from the energy storage battery into AC power to supply power to the user-side load. The protective casing is located on the outermost side of the energy storage system to protect the internal components. The wind turbine module is used for heat dissipation of the entire energy storage system. Currently, if the wind turbine module fails, it leads to poor heat dissipation within the energy storage system, causing a significant increase in localized temperatures and a rise in the surface temperature of the protective casing. When these temperatures reach a certain level, they pose a safety hazard, reducing the lifespan of the energy storage system and lowering its safety. Therefore, in this embodiment of the invention, the wind turbine module's status information is acquired. When the wind turbine status information is normal, the energy storage system operates at full power. When the wind turbine status information is abnormal, such as when the wind turbine module fails and cannot operate, it indicates a risk of temperature rise during subsequent operation of the energy storage system. Therefore, a temperature sensor placed near the power device is used to detect the current temperature information of the power device. The wind turbine status information includes the wind turbine module's rotational speed or current feedback information, etc. When the wind turbine module's rotational speed or current feedback information is zero, it can be considered that the wind turbine module has failed.

[0047] S120. When the current temperature information is greater than the safe temperature information of the power device, reduce the input power of the photovoltaic module according to the photovoltaic derating rules, and keep the output power of the energy storage converter module unchanged.

[0048] Specifically, the current temperature information of the power devices is compared with their safe temperature information. If the current temperature is higher than the safe temperature, the input power of the photovoltaic module is reduced according to the photovoltaic derating rules to lower the temperature of the energy storage system, while maintaining the output power of the energy storage converter module. This ensures a good user experience and extends the lifespan of the energy storage system compared to existing technologies that shut down the system when the temperature is high. If the current temperature is lower than the safe temperature, the energy storage system is operating at normal temperature, and both the input power of the photovoltaic module and the output power of the energy storage converter module can remain constant.

[0049] S130. After a preset time, determine whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing is greater than the safe touch temperature of the protective casing, it is determined that the temperature of the energy storage system continues to rise. Then, reduce the output power of the energy storage converter module according to the converter derating rule.

[0050] Specifically, after reducing the input power of the photovoltaic module, the temperature of the energy storage system may continue to rise. Therefore, after a preset time of reducing the input power of the photovoltaic module, the surface temperature of the protective casing is measured to determine whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing is higher than the safe touch temperature of the protective casing, it indicates that the temperature of the energy storage system continues to rise. Reducing the input power of the photovoltaic module alone cannot reduce the temperature of the energy storage system. Therefore, according to the converter derating rules, the output power of the energy storage converter module is reduced to lower the temperature of the energy storage system, ensuring that the energy storage system operates within a safe temperature range and improving the safety of its use.

[0051] It should be noted that the safe touch temperature is the touchable temperature threshold specified by safety regulations (such as IEC 62109, IEC 62368). Furthermore, this embodiment of the invention does not limit the specific value of the preset time; those skilled in the art can set it as needed.

[0052] In summary, this embodiment of the invention acquires the fan status information of the fan module. When an abnormality is detected in the fan status information, it acquires the current temperature information of the power devices. If the current temperature exceeds the safe temperature of the power devices, the input power of the photovoltaic module is reduced according to the photovoltaic derating rules, while maintaining the output power of the energy storage converter module unchanged. After a preset time, it is determined whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing exceeds the safe touch temperature of the protective casing, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rules. In this way, when an abnormality is detected in the fan module, it continues to operate through derating instead of shutting down directly, extending the service life of the energy storage system. Furthermore, during the derating process, the input power of the photovoltaic module is reduced first to ensure that the output power of the energy storage converter module remains unchanged, ensuring the user experience. When it is determined that the temperature continues to rise, the output power of the energy storage converter module is reduced, improving safety.

[0053] Optionally, in yet another embodiment, Figure 2 This is a schematic flowchart illustrating another energy storage system derating method provided in an embodiment of the present invention. See also... Figure 2 The method of reducing the amount includes:

[0054] S210. Obtain the fan status information of the fan module. When the fan status information is determined to be abnormal, obtain the current temperature information of the power device.

[0055] S220. When the current temperature information is greater than the safe temperature information of the power device, obtain the photovoltaic derating factor of the photovoltaic module and the temperature difference of the power device between the current temperature information and the safe temperature information. Based on the photovoltaic derating factor and the temperature difference of the power device, reduce the input power of the photovoltaic module and keep the output power of the energy storage converter module unchanged.

[0056] Specifically, when the current temperature of the power device exceeds its safe temperature range, the photovoltaic derating factor of the photovoltaic module is obtained. In one embodiment, the photovoltaic derating factor can be obtained using a device temperature rise model. For example, a device temperature rise model is established for the power device, which can be T... dev =T amb +R dev ×P dev Among them, T dev For the current temperature information of the power device, T amb For ambient temperature information, R dev P is the device equivalent thermal resistance of the power device. dev This represents the known power loss of the power device. The current temperature information T of the power device is also provided. dev Ambient temperature information T amband the known power loss P of the power device. dev Since all quantities are known, the equivalent thermal resistance of the photovoltaic module can be calculated based on the device temperature rise model. Furthermore, by measuring the input and output power of the photovoltaic module under different operating conditions using a power meter, the device heat loss ratio of the photovoltaic module can be calculated, and the photovoltaic derating factor of the photovoltaic module can be calculated based on the first thermal model. Specifically, the first thermal model can be k1 = 1 / R. dev ×α pv Where k1 is the derating factor of the photovoltaic module, and R... dev α is the device equivalent thermal resistance of the power device. pv This refers to the heat loss ratio of the photovoltaic module's components. Therefore, based on the equivalent thermal resistance and heat loss ratio of the components, the photovoltaic derating factor of the photovoltaic module can be determined. It can be understood that the photovoltaic derating factor represents the reduction in the input power of the photovoltaic module required for every 1°C increase in the temperature of the power components.

[0057] After determining the derating factor for the photovoltaic (PV) module, the temperature difference between the power devices and the current and safe temperature information is obtained. Based on the derating factor and the power device temperature difference, the input power of the PV module is reduced. Specifically, the derating rule is k1×(T dev -T safe ), where T dev For the current temperature information of the power meter device, T safe This provides the safe temperature information for the power devices. Based on the temperature difference of the power devices and the photovoltaic derating factor, the required reduction in input power of the photovoltaic module when the temperature of the power devices is lowered to the safe temperature is determined. Simultaneously, the output power of the energy storage converter module remains constant, thus ensuring a good power experience for users. Compared to existing technologies that directly shut down the energy storage system when the temperature is high, this extends the lifespan of the energy storage system.

[0058] S230. After a preset time, determine whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing is greater than the safe touch temperature of the protective casing, determine that the temperature of the energy storage system continues to rise. Then, obtain the derating factor of the energy storage converter module and obtain the temperature difference between the surface temperature and the safe touch temperature of the protective casing. Based on the derating factor and the temperature difference of the protective casing, reduce the output power of the energy storage converter module.

[0059] Specifically, after reducing the input power of the photovoltaic module, the temperature of the energy storage system may continue to rise. Therefore, after a preset time of reducing the input power of the photovoltaic module, the surface temperature of the protective casing is used to determine whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing is greater than the safe touch temperature of the protective casing, it indicates that the temperature of the energy storage system continues to rise, and in this case, simply reducing the input power of the photovoltaic module cannot reduce the temperature of the energy storage system. Therefore, after a preset time, if the surface temperature of the protective casing is determined to be greater than the safe touch temperature of the protective casing, the derating factor of the energy storage converter module is obtained. For example, in one embodiment, the derating factor of the energy storage converter module can be obtained using a casing temperature rise model. Specifically, a casing temperature rise model is established, which can be T... case =T amb +R case ×P total Among them, T case To protect the surface temperature information of the casing, T amb For ambient temperature information, R case To protect the equivalent thermal resistance of the casing, P total This represents the total known power loss of the photovoltaic module and the energy storage converter module. The surface temperature information T of the protective casing is also provided. case Ambient temperature information T amb The total known power loss P of the photovoltaic module and the energy storage converter module. total Since all quantities are known, the equivalent thermal resistance of the protective casing can be calculated based on the casing temperature rise model. Furthermore, by measuring the input and output power of the energy storage converter under different operating conditions using a power meter, the casing heat loss ratio of the energy storage converter module can be calculated, and the converter derating factor of the energy storage converter module can be calculated based on the second thermal model. Specifically, the second thermal model can be k2 = 1 / R. case ×α pcs Where k2 is the derating factor of the energy storage converter module, and R... case To protect the equivalent thermal resistance of the casing, α pcs Let be the heat loss ratio of the energy storage converter module's casing. Therefore, based on the casing heat loss ratio and the equivalent thermal resistance of the casing, the derating factor of the energy storage converter module can be determined. It can be understood that the derating factor represents the reduction in the output power of the energy storage converter module for every 1°C increase in the temperature of the protective casing.

[0060] After determining the derating factor for the energy storage converter module, the surface temperature information of the protective casing and the temperature difference between the protective casing and the safe touch temperature are obtained. Based on the derating factor and the temperature difference of the protective casing, the output power of the energy storage converter module is reduced. Specifically, the photovoltaic derating rule is k2×(T case -Tmax ), where T case To protect the surface temperature information of the casing, T max To protect the safe touch temperature of the casing, the required reduction in output power of the energy storage converter module is determined based on the temperature difference of the protective casing and the derating factor of the optical converter. This reduction in output power ensures the energy storage system operates within a safe temperature range, thus improving its operational safety.

[0061] Optionally, in yet another embodiment, Figure 3 This is a schematic flowchart illustrating another energy storage system derating method provided in an embodiment of the present invention. See also... Figure 3 The method of reducing the amount includes:

[0062] S310. Obtain the fan status information of the fan module. When the fan status information is determined to be abnormal, obtain the current temperature information of the power device.

[0063] S320. When the current temperature information is greater than the safe temperature information of the power device, obtain the safety factor, determine the actual photovoltaic derating factor of the photovoltaic module based on the safety factor and the photovoltaic derating factor, obtain the temperature difference of the power device between the current temperature information and the safe temperature information, reduce the input power of the photovoltaic module based on the actual photovoltaic derating factor and the temperature difference of the power device, and keep the output power of the energy storage converter module unchanged.

[0064] Specifically, in this embodiment of the invention, after calculating the equivalent thermal resistance of the photovoltaic module using a device temperature rise model, and determining the photovoltaic derating factor of the photovoltaic module based on the equivalent thermal resistance and the device heat loss ratio, a safety factor is introduced. The actual photovoltaic derating factor of the photovoltaic module is determined by multiplying the safety factor and the photovoltaic derating factor. In this way, it can be ensured that the photovoltaic derating rule calculated in the end is applicable even in extreme environments. The safety factor can be 0.7 × 0.9.

[0065] It should be noted that, in this embodiment of the invention, after obtaining the current temperature information of the power device, the method further includes reducing the power of the power device when the current temperature information exceeds the limit temperature information of the power device. Specifically, the limit temperature information of the power device is the temperature at which the power device will be damaged, wherein the limit temperature information is greater than the safe temperature information. Therefore, by reducing the power of the power device when the current temperature information exceeds the limit temperature information, damage to the power device due to the current temperature exceeding the limit temperature information is avoided, further improving the safety and reliability of the energy storage system.

[0066] S330. After a preset time, determine whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective casing is greater than the safe touch temperature of the protective casing, determine that the temperature of the energy storage system continues to rise. Then, obtain the safety factor, determine the actual derating factor of the energy storage converter module based on the safety factor and the derating factor, and obtain the temperature difference between the surface temperature and the safe touch temperature of the protective casing. Based on the actual derating factor and the temperature difference of the protective casing, reduce the output power of the energy storage converter module.

[0067] Specifically, in this embodiment of the invention, after calculating the equivalent thermal resistance of the energy storage converter module's casing using a casing temperature rise model, and determining the converter derating factor of the energy storage converter module based on the equivalent thermal resistance and the casing heat loss ratio, a safety factor is introduced. The actual converter derating factor of the energy storage converter module is determined by multiplying the safety factor and the converter derating factor. In this way, it can be ensured that the finally calculated converter derating rule is applicable even in extreme environments. The safety factor can be 0.7 × 0.9.

[0068] S340. Determine the reduced photovoltaic power of the photovoltaic module according to the photovoltaic derating rules, obtain the rated photovoltaic power of the photovoltaic module, and determine the limited photovoltaic power of the photovoltaic module after derating based on the rated photovoltaic power and the reduced photovoltaic power.

[0069] Specifically, after reducing the input power of the photovoltaic module for a preset time, the temperature of the energy storage system continues to rise. The temperature is further reduced by decreasing the output power of the energy storage converter module. In this case, both the input power of the photovoltaic module and the output power of the energy storage converter module are reduced. Thus, the final output of the energy storage system can be limited based on the minimum final power of either the photovoltaic module or the energy storage converter module. For example, based on the photovoltaic derating rules, the current temperature information of the power devices is determined. The required reduction in input power (i.e., photovoltaic derating power) of the photovoltaic module when the temperature drops to a safe level is determined. The rated photovoltaic power of the photovoltaic module is then obtained, and the derating-limited photovoltaic power is determined based on the rated photovoltaic power and the photovoltaic derating power.

[0070] S350. Determine the reduced power of the energy storage converter module according to the converter derating rule, obtain the rated power of the energy storage converter module, determine the derating power limit of the energy storage converter module based on the rated power and the reduced power, and take the minimum value between the photovoltaic power limit and the converter power limit as the output power of the energy storage system.

[0071] Similarly, based on the derating rules, the surface temperature of the protective casing is determined. When this temperature drops to a safe touch temperature, the energy storage converter module needs to reduce its output power, i.e., the converter reduction power. The rated power of the energy storage converter module is obtained. Based on the rated power and the reduced power, the drated converter limit power of the energy storage converter module is determined. The minimum of the photovoltaic limit power and the converter limit power is used as the output power of the energy storage system. For example, the photovoltaic limit power is 400KW (500KW-100KW), and the converter limit power is 300KW (500KW-200KW). In this process, the reduced output power of the energy storage converter module is greater than the reduced input power of the photovoltaic module. If the output of the energy storage system is limited to the photovoltaic limit power of 400KW, the reduced output power of the energy storage converter module will be insufficient, failing to solve the problem of the protective casing temperature rise. Therefore, by using the minimum of the photovoltaic limit power and the converter limit power as the output power of the energy storage system, the reliability of the energy storage system is ensured.

[0072] Based on the same inventive concept, embodiments of the present invention also provide a derating device for an energy storage system. Figure 4 This is a schematic diagram of the structure of a derating device for an energy storage system provided in an embodiment of the present invention. See also... Figure 4 The dereasing device includes:

[0073] The first acquisition module 100 is used to acquire the fan status information of the fan module, and when it is determined that the fan status information is abnormal, it acquires the current temperature information of the power device.

[0074] The first derating module 200 is used to reduce the input power of the photovoltaic module according to the photovoltaic derating rules when the current temperature information is greater than the safe temperature information of the power device, and to keep the output power of the energy storage converter module unchanged.

[0075] The second derating module 300 is used to determine whether the temperature of the energy storage system continues to rise after a preset time. If the surface temperature of the protective shell is greater than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rule.

[0076] The first derating module 200 is specifically used to obtain the photovoltaic derating factor of the photovoltaic module and the temperature difference between the power devices and the current temperature information and the safe temperature information; based on the photovoltaic derating factor and the temperature difference of the power devices, the input power of the photovoltaic module is reduced.

[0077] The first derating module 200 is also used to establish a device temperature rise model for the power device, determine the device equivalent thermal resistance of the power device based on the device temperature rise model, determine the device heat loss ratio of the photovoltaic module, and determine the photovoltaic derating factor of the photovoltaic module based on the device equivalent thermal resistance and the device heat loss ratio.

[0078] The second derating module 300 is specifically used to obtain the derating coefficient of the energy storage converter module, and to obtain the surface temperature information and the temperature difference between the protective shell and the safe touch temperature. Based on the derating coefficient and the temperature difference of the protective shell, the output power of the energy storage converter module is reduced.

[0079] The second derating module 300 is also used to establish a temperature rise model of the protective enclosure, determine the equivalent thermal resistance of the protective enclosure based on the temperature rise model, determine the heat loss ratio of the energy storage converter enclosure, and determine the derating factor of the energy storage converter module based on the equivalent thermal resistance of the enclosure.

[0080] The derating device also includes an output determination module, which is used to determine the photovoltaic power reduction of the photovoltaic module according to the photovoltaic derating rules, obtain the photovoltaic rated power of the photovoltaic module, determine the photovoltaic limit power of the photovoltaic module after derating based on the photovoltaic rated power and the photovoltaic power reduction, determine the converter power reduction of the energy storage converter module according to the converter derating rules, obtain the converter rated power of the energy storage converter module, determine the converter limit power of the energy storage converter module after derating based on the converter rated power and the converter power reduction, and take the minimum value between the photovoltaic limit power and the converter limit power as the output power of the energy storage system.

[0081] The first derating module 200 is also used to reduce the power of the power device when the current temperature information is greater than the limit temperature information of the power device.

[0082] The first derating module 200 is also used to obtain a safety factor, determine the actual photovoltaic derating factor of the photovoltaic module based on the safety factor and the photovoltaic derating factor, and reduce the input power of the photovoltaic module based on the actual photovoltaic derating factor and the temperature difference of the power devices.

[0083] The second derating module 300 is also used to obtain a safety factor, determine the actual derating factor of the energy storage converter module based on the safety factor and the converter derating factor, and reduce the output power of the energy storage converter module based on the actual derating factor and the temperature difference of the protective casing.

[0084] In summary, this embodiment of the invention acquires the fan status information of the fan module through a first acquisition module. When the fan status information is determined to be abnormal, the current temperature information of the power device is acquired. When the current temperature information is higher than the safe temperature information of the power device, the first derating module reduces the input power of the photovoltaic module according to the photovoltaic derating rules, while maintaining the output power of the energy storage converter module unchanged. The second derating module determines whether the temperature of the energy storage system continues to rise after a preset time. If the surface temperature information of the protective shell is higher than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rules. In this way, when the fan module is determined to be abnormal, it continues to operate through derating instead of shutting down directly, thus extending the service life of the energy storage system. In addition, during the derating process, the input power of the photovoltaic module is reduced first to ensure that the output power of the energy storage converter module remains unchanged, ensuring the user experience. When it is determined that the temperature continues to rise, the output power of the energy storage converter module is reduced, thus improving safety.

[0085] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A derating method for an energy storage system, the energy storage system comprising a wind turbine module, power devices, a photovoltaic module, a protective casing, and an energy storage converter module, characterized in that, The system acquires the wind turbine status information of the wind turbine module. When the wind turbine status information is found to be abnormal, the system acquires the current temperature information of the power device. When the current temperature information is greater than the safe temperature information of the power device, the system reduces the input power of the photovoltaic module according to the photovoltaic derating rules, and keeps the output power of the energy storage converter module constant. After a preset time, it is determined whether the temperature of the energy storage system continues to rise. If the surface temperature of the protective shell is greater than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise. Then, the output power of the energy storage converter module is reduced according to the converter derating rule.

2. The method for reducing the rate according to claim 1, characterized in that, The step of reducing the input power of the photovoltaic module according to the photovoltaic derating rules includes: Obtain the photovoltaic derating factor of the photovoltaic module, and obtain the temperature difference of the power devices between the current temperature information and the safe temperature information; The input power of the photovoltaic module is reduced based on the photovoltaic derating factor and the temperature difference of the power devices.

3. The method for reducing the rate according to claim 2, characterized in that, The process of obtaining the photovoltaic derating factor of the photovoltaic module includes: Establish a device temperature rise model for the power device, and determine the device equivalent thermal resistance based on the device temperature rise model; The device heat loss ratio of the photovoltaic module is determined, and the photovoltaic derating factor of the photovoltaic module is determined based on the device equivalent thermal resistance and the device heat loss ratio.

4. The method for reducing the rate according to claim 1, characterized in that, The step of reducing the output power of the energy storage converter module according to the converter derating rule includes: Obtain the derating factor of the energy storage converter module, and obtain the temperature difference between the surface temperature information and the protective shell temperature at the safe touch temperature; The output power of the energy storage converter module is reduced based on the converter derating factor and the temperature difference of the protective casing.

5. The method for reducing the rate according to claim 4, characterized in that, The process of obtaining the derating factor of the energy storage converter module includes: Establish a temperature rise model for the protective enclosure, and determine the equivalent thermal resistance of the protective enclosure based on the temperature rise model. Determine the heat loss ratio of the casing of the energy storage converter, and determine the derating factor of the energy storage converter module based on the equivalent thermal resistance of the casing and the equivalent thermal resistance of the casing.

6. The method for reducing the rate according to claim 1, characterized in that, After reducing the output power of the energy storage converter module according to the converter derating rule, the method further includes: Determine the photovoltaic power reduction of the photovoltaic module according to the photovoltaic derating rules, obtain the photovoltaic rated power of the photovoltaic module, and determine the photovoltaic limit power of the photovoltaic module after derating based on the photovoltaic rated power and the photovoltaic power reduction. Determine the power reduction of the energy storage converter module according to the power derating rule, obtain the rated power of the energy storage converter module, and determine the power limit of the energy storage converter module after derating based on the rated power and the power reduction. The minimum value between the photovoltaic power limit and the converter power limit is taken as the output power of the energy storage system.

7. The method for reducing the rate according to claim 1, characterized in that, After obtaining the current temperature information of the power device, the process also includes: When the current temperature information is greater than the limit temperature information of the power device, the power of the power device is reduced.

8. The method for reducing the rate according to claim 2, characterized in that, The process of obtaining the photovoltaic derating factor of the photovoltaic module includes: Obtain a safety factor, and determine the actual photovoltaic derating factor of the photovoltaic module based on the safety factor and the photovoltaic derating factor; The step of reducing the input power of the photovoltaic module based on the photovoltaic derating factor and the temperature difference of the power devices includes: The input power of the photovoltaic module is reduced based on the actual photovoltaic derating factor and the temperature difference of the power devices.

9. The method for reducing the rate according to claim 4, characterized in that, The process of obtaining the derating factor of the energy storage converter module includes: Obtain a safety factor, and determine the actual derating factor of the energy storage converter module based on the safety factor and the derating factor. The method of reducing the output power of the energy storage converter module based on the converter derating factor and the temperature difference of the protective casing includes: The output power of the energy storage converter module is reduced based on the actual converter derating factor and the temperature difference of the protective casing.

10. A derating device for an energy storage system, the energy storage system comprising a wind turbine module, power devices, a photovoltaic module, a protective housing, and an energy storage converter module, characterized in that, The dereasing device includes: The first acquisition module is used to acquire the fan status information of the fan module, and when it is determined that the fan status information is abnormal, acquire the current temperature information of the power device. The first derating module is used to reduce the input power of the photovoltaic module according to the photovoltaic derating rules when the current temperature information is greater than the safe temperature information of the power device, and to keep the output power of the energy storage converter module unchanged. The second derating module is used to determine whether the temperature of the energy storage system continues to rise after a preset time. If the surface temperature of the protective shell is greater than the safe touch temperature of the protective shell, it is determined that the temperature of the energy storage system continues to rise, and the output power of the energy storage converter module is reduced according to the converter derating rule.

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