Power conversion device, health state determination method for heat dissipation module of power conversion device, and system

Abstract

A power conversion device, a health state determination method for a heat dissipation module of the power conversion device, and a system. The power conversion device comprises: a power unit comprising a power module and a heat dissipation module, wherein the heat dissipation module is used for dissipating heat from the power module; and a controller for acquiring indicator values of a specified operating state indicator of the power unit multiple times, and determining the health state of the heat dissipation module on the basis of the multiple indicator values corresponding to the specified operating state indicator, wherein during multiple acquisitions of the indicator values of the specified operating state indicator of the power unit, the operating state of the heat dissipation module changes, and the heat dissipation capability of the heat dissipation module differs before and after the operating state changes. In this way, the health state of the heat dissipation module of the power conversion device can be conveniently determined.

Description

Methods and systems for determining the health status of power conversion devices and their heat dissipation modules

[0001] This disclosure claims priority to Chinese Patent Application No. 2024117351403, filed on November 28, 2024, entitled "Method and System for Determining the Health Status of Power Conversion Device and its Heat Dissipation Module", the entire contents of which are incorporated herein by reference. Technical Field

[0002] The embodiments of this disclosure relate to a method and system for determining the health status of a power conversion device and its heat dissipation module. Background Technology

[0003] In power conversion devices, power electronic components (such as IGBTs and MOSFETs) generate a lot of heat when they are working. Therefore, heat dissipation modules are usually installed in power conversion devices to ensure that the power electronic components can operate within a suitable temperature range, thereby reducing the risk of performance degradation or component damage caused by overheating to a certain extent.

[0004] However, as the power conversion device operates for longer periods, the performance of the heat dissipation module will decrease. Therefore, determining the health status of the heat dissipation module is crucial. Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0006] This disclosure provides a power conversion device, including: a power unit, comprising a power module and a heat dissipation module; wherein the heat dissipation module is used to dissipate heat from the power module; a controller is used to repeatedly acquire the index values ​​of a specified operating state indicator of the power unit, and determine the health status of the heat dissipation module based on the multiple index values ​​corresponding to the specified operating state indicator; wherein, during the repeated acquisition of the index values ​​of the specified operating state indicator of the power unit, the operating state of the heat dissipation module changes, and the heat dissipation capacity of the heat dissipation module is different before and after the change in operating state.

[0007] This disclosure provides a method for determining the health status of a heat dissipation module in a power conversion device. The power conversion device includes a power unit; the power unit includes a power module and a heat dissipation module; the heat dissipation module is used to dissipate heat from the power module; the method includes: repeatedly acquiring the index values ​​of a specified operating status indicator of the power unit; wherein, during the repeated acquisition of the index values ​​of the specified operating status indicator of the power unit, the operating status of the heat dissipation module changes, and the heat dissipation capacity of the heat dissipation module is different before and after the change in operating status; and determining the health status of the heat dissipation module based on multiple index values ​​corresponding to the specified operating status indicator.

[0008] This disclosure provides an energy system including the power conversion device described in any of the above embodiments.

[0009] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood.

[0010] In several embodiments provided in this disclosure, the power conversion device includes a power unit and a controller. The power unit includes a power module and a heat dissipation module. The controller can repeatedly acquire the values ​​of specified operating status indicators of the power unit, and determine the health status of the heat dissipation module based on the multiple indicator values ​​corresponding to the specified operating status indicators. Since the operating state of the heat dissipation module changes during the repeated acquisition of the specified operating status indicators of the power unit, the values ​​of the multiple indicators will vary to some extent. Therefore, the controller can conveniently determine the health status of the heat dissipation module of the power conversion device.

[0011] Brief description of the attached figures

[0012] To more clearly illustrate the embodiments of this disclosure or the technical solutions in general, the accompanying drawings used in the embodiments or general description will be briefly introduced below. Obviously, the drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0013] Figure 1 is a schematic diagram of a power conversion device provided in an embodiment of this disclosure.

[0014] Figure 2 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0015] Figure 3 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0016] Figure 4 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0017] Figure 5 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0018] Figure 6 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0019] Figure 7 is a schematic diagram of the process by which the controller determines the health status of the heat dissipation module according to an embodiment of this disclosure.

[0020] Figure 8 is a schematic diagram of a photovoltaic system provided in an embodiment of this disclosure. Detailed Implementation

[0021] The technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments.

[0022] In the description of the embodiments of this disclosure, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Please refer to Figure 1. This disclosure provides a power conversion device. The power conversion device includes a power unit and a controller. The power unit includes a power module and a heat dissipation module. The heat dissipation module is used to dissipate heat from the power module.

[0024] The controller is used to acquire the values ​​of specified operating status indicators of the power unit multiple times, and determine the health status of the heat dissipation module based on the multiple indicator values ​​corresponding to the specified operating status indicators. During the process of acquiring the values ​​of specified operating status indicators of the power unit multiple times, the working state of the heat dissipation module changes, and the heat dissipation capacity of the heat dissipation module is different before and after the change in working state.

[0025] A power conversion device is a device used to convert electrical energy into a different form. Specifically, a power conversion device can be a bidirectional inverter used to convert between direct current (DC) and alternating current (AC). Alternatively, a power conversion device can be a DC-DC converter used to convert between different voltage levels of DC power. For example, a DC-DC converter can boost or buck DC power. In some embodiments, the power conversion device can be a photovoltaic inverter or an energy storage converter. This embodiment does not impose specific limitations.

[0026] The power unit consists of a power module and a heat dissipation module.

[0027] A power module is a module composed of multiple power electronic components. These power electronic components include, but are not limited to, semiconductor switching elements such as insulated-gate bipolar transistors (IGBTs) or metal-oxide-semiconductor field-effect transistors (MOSFETs). This embodiment does not impose specific limitations on these components.

[0028] During the operation of a power conversion device, the power electronic components in the power module, such as the aforementioned semiconductor switching elements, will close or open at a high frequency, thereby generating significant heat. Therefore, installing a heat dissipation module helps ensure stable operation of the power module.

[0029] A heat dissipation module is a device used to remove the heat generated by the power module during operation in order to keep the power module within its normal operating temperature range.

[0030] In some embodiments, the heat dissipation module dissipates heat from the power module through an air cooling mechanism, or through a liquid cooling mechanism. This embodiment does not limit this to any particular method.

[0031] A heat dissipation module can operate in various states during normal operation. Changes in these states alter the module's heat dissipation capacity. Specifically, the heat dissipation module includes specified heat dissipation parameters. These parameters take different values ​​depending on the module's operating state.

[0032] For example, when the heat dissipation module is based on an air-cooling mechanism, it includes a fan. Correspondingly, the specified heat dissipation parameters of the heat dissipation module include the fan speed. When the fan is at a first fan speed, the heat dissipation module can be considered to be in a first operating state. When the fan is at a second fan speed, the heat dissipation module can be considered to be in a second operating state. The difference between the first and second fan speeds results in different heat dissipation capabilities of the heat dissipation module in the first and second operating states.

[0033] Alternatively, when the heat dissipation module is based on a liquid cooling mechanism, it includes a liquid cooling pump. Accordingly, the specified heat dissipation parameters of the heat dissipation module include the rotational speed of the liquid cooling pump. When the liquid cooling pump is at a first rotational speed, the heat dissipation module can be considered to be in a first operating state. When the liquid cooling pump is at a second rotational speed, the heat dissipation module can be considered to be in a second operating state. The difference between the first and second rotational speeds results in different heat dissipation capacities for the heat dissipation module in the first and second operating states.

[0034] The specified operating status indicators of the power unit are used to represent the operating status of the power unit. Specifically, the specified operating status indicators may include the power module status indicators of the power module or the heat dissipation module status indicators of the heat dissipation module. Of course, the specified operating status indicators of the power unit may also include both the power module status indicators of the power module and the heat dissipation module status indicators of the heat dissipation module.

[0035] Power module status indicators are used to represent the operating status of the power module. These indicators include, but are not limited to, the power module's temperature and power output. Correspondingly, the indicator values ​​can include the power module's power output or its temperature.

[0036] The status indicators of the heat dissipation module are used to represent the operating status of the heat dissipation module. These indicators may include specified heat dissipation parameters and other relevant metrics. Correspondingly, the values ​​for these indicators may include the values ​​of the heat dissipation parameters of the heat dissipation module.

[0037] The health status of a heat dissipation module can be used to assess its overall performance or condition. Specifically, the health status of a heat dissipation module can include whether any components within the module are malfunctioning. For example, a heat dissipation module may include a cooling assembly. When the cooling assembly malfunctions, the heat dissipation module's health status can be considered abnormal. Alternatively, a heat dissipation module may include a flow guiding structure. Blockage of the flow guiding structure can also be considered a malfunction of the heat dissipation module. This embodiment does not impose specific limitations. In some embodiments, when a heat dissipation module malfunctions, it is in an abnormal state.

[0038] A controller is a device used to manage and control the operation of a power conversion device.

[0039] The controller can acquire the values ​​of specified operating status indicators of the power unit multiple times. Furthermore, during these multiple acquisitions, the operating state of the heat dissipation module changes. These changes in the heat dissipation module's operating state cause corresponding changes in the acquired values ​​of the specified operating status indicators. Therefore, based on multiple indicator values, the operating state of the heat dissipation module can be determined.

[0040] In some embodiments, the controller can actively control the operating state of the heat dissipation module while repeatedly acquiring the values ​​of specified operating state indicators of the power unit. Alternatively, the heat dissipation module can also change its operating state under the control of other control units while repeatedly acquiring the values ​​of specified operating state indicators of the power unit. This embodiment does not impose specific limitations here.

[0041] In some embodiments, determining the health status of the heat dissipation module based on the values ​​of multiple indicators corresponding to a specified operating status indicator includes: determining the health status of the heat dissipation module by the value change characteristics of the multiple indicators corresponding to the specified operating status indicator.

[0042] The value change characteristics of multiple indicators corresponding to a specified operating status indicator can be used to describe the relationship between the changing values ​​of multiple indicators obtained for a specific operating status indicator. This relationship can include the trend, magnitude, or rate of change of the multiple indicator values.

[0043] In some embodiments, when the variation characteristics of multiple indicator values ​​do not conform to the expected variation characteristics of the expected multiple indicator values, the heat dissipation module can be considered to be in an abnormal state. Alternatively, when the variation characteristics of multiple indicator values ​​are not significantly different from the expected variation characteristics of the expected multiple indicator values, the heat dissipation module can be considered to be in a good state. Thus, the health status of the heat dissipation module can be determined.

[0044] In some embodiments, the specified operating status indicators include the temperature of the power module; repeatedly acquiring the values ​​of the specified operating status indicators of the power unit includes: acquiring a first measured temperature value of the power module before the operating state of the heat dissipation module changes, and a second measured temperature value of the power module after the operating state of the heat dissipation module changes, while the power module is operating at a specified power value; correspondingly, determining the health status of the heat dissipation module by the value change characteristics of multiple indicator values ​​corresponding to the specified operating status indicators includes: determining the health status of the heat dissipation module based on the measured temperature change between the first measured temperature value and the second measured temperature value.

[0045] In this embodiment, the specified operating status indicators include the temperature of the power module.

[0046] The power module's temperature indicates its thermal state during operation. Specifically, the power module's temperature can be detected by a temperature sensor and obtained by the controller from the sensor. Alternatively, the power module's temperature can be obtained using other methods.

[0047] The specified power value can be a constant value, ensuring stable heat generation from the power module. By monitoring the power module's temperature while it operates at the specified power value, temperature fluctuations caused by power variations can be reduced. Of course, when the power module operates within a certain power range, if the heat generation variation is small, the specified power value can be any value within that range. This embodiment does not impose specific limitations.

[0048] A change in the operating state of the heat dissipation module indicates a change in its heat dissipation capacity. While the power module maintains a specified power level, the heat generated by the power module remains relatively constant. However, changes in the heat dissipation capacity of the heat dissipation module will cause changes in its temperature. Therefore, the health status of the heat dissipation module can be determined by observing these temperature changes.

[0049] Specifically, the controller can first obtain the temperature of the power module before the operating state of the heat dissipation module changes, i.e., the first measured temperature value. When the operating state of the heat dissipation module changes, the controller obtains the temperature of the power module again, i.e., the second measured temperature value.

[0050] Furthermore, the controller can calculate the absolute value of the difference between the first measured temperature value and the second measured temperature value to obtain the measured temperature change.

[0051] If the heat dissipation module is in good condition, the power module's temperature will change as expected when its heat dissipation capacity changes as anticipated. Conversely, if the heat dissipation module is in an abnormal state, such as when its airflow structure is blocked or the cooling components fail, the power module's temperature change may not be as expected.

[0052] Therefore, the controller can compare the measured temperature change with the expected temperature change. If the difference is within the allowable range, the heat dissipation module can be considered to be in good health. If the difference exceeds the allowable range, the heat dissipation module may be malfunctioning and requires further inspection or maintenance.

[0053] In some embodiments, the power module corresponds to a predicted temperature change; the predicted temperature change represents the expected temperature change of the power module when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the power module is operating at a specified power value. Accordingly, based on the measured temperature change between the first measured temperature value and the second measured temperature value, the health status of the heat dissipation module is determined, including: if the absolute value of the difference between the measured temperature change and the predicted temperature change is less than a specified temperature change threshold, the heat dissipation module is considered to be in good condition; or, if the absolute value of the difference between the measured temperature change and the predicted temperature change is greater than the specified temperature change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the measured temperature change and the predicted temperature change is equal to the specified temperature change threshold, the heat dissipation module is considered to be in an abnormal state.

[0054] The projected temperature change can be used to reflect the heat dissipation performance of the heat dissipation module under good conditions, serving as a reference for judging the health status of the heat dissipation module. In some embodiments, the projected temperature change can be preset in memory, and the controller can read the projected temperature change from memory and compare it with the measured temperature change. Alternatively, the projected temperature change can also be stored in the cloud and obtained by the controller from the cloud in real time.

[0055] In some embodiments, when the power module is running at different specified power values, if the operating state of the heat dissipation module changes, the expected temperature change may be different when the power module is running at different specified power values ​​because the heat generated by the power module may vary depending on the specified power value.

[0056] Therefore, in some embodiments, the controller can pre-set multiple expected temperature changes and, in the process of determining the health status of the heat dissipation module, match the corresponding expected temperature changes by specifying a power value.

[0057] In some embodiments, the expected temperature change can be obtained through historical data, simulation experiments, or by establishing a thermal resistance model. This embodiment does not impose specific limitations.

[0058] The specified temperature change threshold can be a preset temperature threshold, used to measure the difference between the measured temperature change and the expected temperature change.

[0059] If the absolute value of the difference between the measured and expected temperature changes is less than a specified temperature change threshold, the measured temperature change is considered to be the same as or close to the expected temperature change, and the heat dissipation module can be deemed to be in good health. Conversely, if the absolute value of the difference is greater than the specified temperature change threshold, a significant difference is considered to exist, and the heat dissipation module is deemed to be in an abnormal health state. Furthermore, if the absolute value of the difference is equal to the specified temperature change threshold, the heat dissipation module is also deemed to be in an abnormal health state.

[0060] In some embodiments, the number of power modules is multiple. Accordingly, each power module has a corresponding first measured temperature, a second measured temperature, and a measured temperature change. If the absolute value of the difference between the measured temperature change and the expected temperature change of all power modules is less than a specified temperature change threshold, the heat dissipation module can be considered to be in good health. If the absolute value of the difference between the measured temperature change and the expected temperature change of any power module is greater than the specified temperature change threshold, the heat dissipation module can be considered to be in abnormal health. If the absolute value of the difference between the measured temperature change and the expected temperature change of any power module is equal to the specified temperature change threshold, the heat dissipation module can be considered to be in abnormal health.

[0061] As exemplarily shown in Figure 2, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0062] Step S110: The power conversion device is in operation.

[0063] Step S120: Obtain the specified power value of the power module.

[0064] Step S130: Obtain the first measured temperature value of the power module.

[0065] Step S140: Change the fan speed. At this time, the working state of the heat dissipation module changes.

[0066] Step S150: Obtain the second measured temperature value of the power module.

[0067] Step S160: Determine the health status of the heat dissipation module based on the measured temperature change between the first measured temperature value and the second measured temperature value.

[0068] In some embodiments, during the process of repeatedly acquiring the values ​​of specified operating status indicators of the power unit, in response to changes in the operating state of the heat dissipation module, the power of the power module is controlled and adjusted to maintain the temperature of the power module at a specified temperature value; the specified operating status indicator includes the power of the power module; correspondingly, repeatedly acquiring the values ​​of specified operating status indicators of the power unit includes: acquiring a first measured power value of the power module before the change of the operating state of the heat dissipation module, and a second measured power value of the power module after the change of the operating state of the heat dissipation module; correspondingly, determining the health status of the heat dissipation module by the value change characteristics of multiple indicator values ​​corresponding to the specified operating status indicator includes: determining the health status of the heat dissipation module based on the measured power change between the first measured power value and the second measured power value.

[0069] In this embodiment, the specified operating status indicators include the power of the power module.

[0070] During the process of repeatedly acquiring the specified operating status indicators of the power unit, the operating state of the heat dissipation module can be changed. Specifically, the operating state of the heat dissipation module can be changed by adjusting the specified heat dissipation parameters. To maintain the temperature of the power module at a preset specified temperature value, the power of the power module will be adjusted accordingly to change the heat generation of the power module.

[0071] The amount and method of changing the specified heat dissipation parameters of the heat dissipation module can be preset and controlled by a controller or other control unit. For example, the heat dissipation module may include a fan. The specified heat dissipation parameter of the heat dissipation module is the fan speed. During the process of repeatedly acquiring the index values ​​of the specified operating status indicators of the power unit, the fan speed can be set to increase by 100 rpm. Alternatively, the fan speed can be set to decrease by 200 rpm. Of course, the fan speed can also be set to 100 rpm before repeatedly acquiring the index values ​​of the specified operating status indicators of the power unit, and then changed to 300 rpm during the process of repeatedly acquiring the index values ​​of the specified operating status indicators of the power unit. This embodiment does not impose specific limitations here.

[0072] When the specified heat dissipation parameters of the heat dissipation module are changed, the temperature of the power module can be maintained at the preset specified temperature value by adjusting the power of the power module.

[0073] The power of the power module can be controlled and adjusted by the controller. Specifically, the controller can dynamically adjust the power of the power module based on changes in the heat dissipation capacity of the heat sink. For example, when the heat dissipation capacity of the heat sink decreases, the controller can reduce the power of the power module to reduce the heat generated by the power module. When the heat dissipation capacity of the heat sink increases, the controller can increase the power of the power module to increase the heat generated by the power module. This allows the temperature of the power module to be maintained at a specified value.

[0074] Alternatively, the power of the power module can be controlled and adjusted by other control units. For example, the power module can have its own dedicated power module control unit, which adjusts the power of the power module by using real-time temperature data and an automatic control algorithm to maintain a constant temperature.

[0075] Maintaining a constant temperature for the power module can reduce the impact of temperature changes on determining the health status of the heat dissipation module to some extent, allowing the controller to determine the health status of the heat dissipation module by measuring the actual power change of the power module.

[0076] The specified temperature value refers to the temperature of the power module before and after the change in the operating state of the heat dissipation module. The specified temperature value can be a pre-set temperature. Alternatively, it can be the temperature actually measured by a temperature sensor before repeatedly acquiring the specified operating status indicators of the power unit.

[0077] The first measured power value is the power of the power module before its operating state changes and before any control or adjustment is applied. The second measured power value is the power after the operating state of the heat dissipation module changes, and after control and adjustment are applied to maintain a constant power module temperature.

[0078] When the heat dissipation module is in good condition, if its operating state changes, the power module needs to adjust according to the expected power change to maintain a constant temperature. Conversely, if the heat dissipation module is in an abnormal state, the power change of the power module may not be as expected.

[0079] Therefore, the controller can compare the measured power change with the expected power change. If the difference is within the allowable range, the heat dissipation module can be considered to be in good health. If the difference exceeds the allowable range, the heat dissipation module may be malfunctioning and requires further inspection or maintenance.

[0080] In some embodiments, the power module corresponds to a predicted power change; the predicted power change represents the power that the power module is expected to need to adjust when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the temperature of the power module is maintained at a specified temperature value; correspondingly, based on the measured power change between the first measured power value and the second measured power value, the health status of the heat dissipation module is determined, including: if the absolute value of the difference between the measured power change and the predicted power change is less than a specified power change threshold, the heat dissipation module is considered to be in good condition; or, if the absolute value of the difference between the measured power change and the predicted power change is greater than the specified power change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the measured power change and the predicted power change is equal to the specified power change threshold, the heat dissipation module is considered to be in an abnormal state.

[0081] The expected power change can be used to reflect the heat dissipation performance of the heat dissipation module under good conditions, and can serve as a reference for judging the health status of the heat dissipation module.

[0082] In this embodiment, the expected power change can be preset in memory, and the controller can read the expected power change from memory and compare it with the measured power change. Alternatively, the expected power change can also be stored in the cloud and obtained by the controller in real time from the cloud.

[0083] In some embodiments, the operating state of the heat dissipation module changes when the specified temperature value of the power module is different, and the amount of power change required for the power module to maintain a constant temperature may also be different. Therefore, the controller can preset multiple expected power change amounts and match the corresponding expected power change amounts to the specified temperature values ​​during the process of determining the health status of the heat dissipation module.

[0084] In some embodiments, the expected power change can be obtained through historical data, simulation experiments, or by establishing a thermal resistance model. This embodiment does not specifically limit this.

[0085] The specified power change threshold is a preset threshold used to measure the difference between the measured power change and the expected power change. If the absolute value of the difference between the measured and expected power changes is less than the specified power change threshold, the measured power change is considered close to the expected power change, and the heat dissipation module can be considered to be in good health. Conversely, if the absolute value of the difference is greater than the specified power change threshold, the measured power change is considered to have a significant difference from the expected value, and the heat dissipation module can be considered to be in an abnormal health state. Additionally, if the absolute value of the difference between the measured and expected power changes is equal to the specified power change threshold, the heat dissipation module can also be considered to be in an abnormal health state.

[0086] In some embodiments, the number of power modules is multiple. Correspondingly, each power module has a first measured power value, a second measured power value, and a measured power change. When the absolute value of the difference between the measured power change and the expected power change of all power modules is less than a specified power change threshold, the heat dissipation module is considered to be in good health. When the absolute value of the difference between the measured power change and the expected power change of any power module is greater than the specified power change threshold, the heat dissipation module is considered to be in abnormal health. Furthermore, when the absolute value of the difference between the measured power change and the expected power change of any power module is equal to the specified power change threshold, the heat dissipation module is considered to be in abnormal health.

[0087] As exemplarily shown in Figure 3, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0088] Step S210: The power conversion device is in operation.

[0089] Step S220: Obtain the first measured power value of the power module.

[0090] Step S230: Change the fan speed. At this time, the working state of the heat dissipation module changes.

[0091] Step S240: Change the power of the power module so that the temperature of the power module is maintained at a specified temperature value.

[0092] Step S250: Obtain the second measured power value of the power module.

[0093] Step S260: Determine the health status of the heat dissipation module based on the measured power change between the first measured power value and the second measured power value.

[0094] In some embodiments, the heat dissipation module has specified heat dissipation parameters; changes in the specified heat dissipation parameters cause changes in the operating state of the heat dissipation module; during the process of repeatedly acquiring the index values ​​of the specified operating state indicators of the power unit, the power of the power module is controlled to change, and in response to the change in the power of the power module, the specified heat dissipation parameters of the heat dissipation module are controlled to change so that the temperature of the power module is maintained at a specified temperature value; the specified operating state indicators include the specified heat dissipation parameters of the heat dissipation module; correspondingly, repeatedly acquiring the index values ​​of the specified operating state indicators of the power unit includes: acquiring a first heat dissipation parameter value of the specified heat dissipation parameters before the change in the operating state of the heat dissipation module, and a second heat dissipation parameter value of the specified heat dissipation parameters after the change in the operating state of the heat dissipation module; correspondingly, the health status of the heat dissipation module is determined by the value change characteristics of the multiple index values ​​corresponding to the specified operating state indicators, including: determining the health status of the heat dissipation module based on the amount of change in heat dissipation parameters between the first heat dissipation parameter value and the second heat dissipation parameter value.

[0095] In this embodiment, the specified operating status indicators include the specified heat dissipation parameters of the heat dissipation module.

[0096] During the process of repeatedly acquiring the specified operating status indicators of the power unit, the power of the power module may change first. To maintain the temperature of the power module at a preset specified temperature value, the specified heat dissipation parameters of the heat dissipation module will be adjusted accordingly to change the heat dissipation capacity of the heat dissipation module.

[0097] The amount and method of power module power change can be preset and executed by the controller or other control unit. For example, during the process of repeatedly acquiring the value of a specified operating status indicator of the power unit, the power module power can be set to increase by 100kW. Alternatively, the power module power can be set to decrease by 50kW. Of course, the power module power can also be set to 50kW before repeatedly acquiring the value of the specified operating status indicator of the power unit, and then changed to 100kW during the process of repeatedly acquiring the value of the specified operating status indicator of the power unit. This embodiment does not impose specific limitations here.

[0098] When the power of the power module changes, the temperature of the power module can be maintained at a preset specified temperature value by adjusting the specified heat dissipation parameters of the heat dissipation module.

[0099] The specified heat dissipation parameters of the heat dissipation module can be adjusted by the controller. Specifically, the controller can dynamically adjust the specified heat dissipation parameters of the heat dissipation module based on changes in the power of the power module. For example, when the power of the power module decreases, the controller can reduce the heat dissipation capacity of the heat dissipation module by adjusting the specified heat dissipation parameters. When the power of the power module increases, the controller can increase the heat dissipation capacity of the heat dissipation module by adjusting the specified heat dissipation parameters. This allows the temperature of the power module to be maintained at a specified value.

[0100] Alternatively, the specified heat dissipation parameters of the heat dissipation module can also be controlled and adjusted by other control units. For example, the heat dissipation module can be equipped with a separate control unit, which adjusts the specified heat dissipation parameters of the heat dissipation module by acquiring the temperature of the power module in real time and combining it with an automatic control algorithm to maintain the temperature of the power module at a constant level.

[0101] Maintaining a constant temperature for the power module can reduce the impact of temperature changes on determining the health status of the heat dissipation module to some extent, allowing the controller to determine the health status of the heat dissipation module by measuring the changes in specified heat dissipation parameters.

[0102] The first heat dissipation parameter value is the specified heat dissipation parameter before the power module's power is changed and before the heat dissipation module is controlled and adjusted. The second heat dissipation parameter value is the specified heat dissipation parameter after the power module's power is changed, in order to maintain a constant power module temperature.

[0103] When the heat dissipation module is in good condition, it needs to adjust its parameters according to the expected changes in the power module's output to maintain a constant temperature. Conversely, if the heat dissipation module is in an abnormal state, the changes in its parameters may not be as expected.

[0104] Therefore, the controller can compare the measured changes in heat dissipation parameters with the expected changes. If the difference is within the allowable range, the heat dissipation module can be considered to be in good health. If the difference exceeds the allowable range, the heat dissipation module may be malfunctioning and requires further inspection or maintenance.

[0105] In some embodiments, the heat dissipation module corresponds to a predicted parameter change; the predicted heat dissipation parameter change represents the expected adjustment of the heat dissipation parameter when the power of the power module changes, assuming the heat dissipation module is in a good state and the temperature of the power module is maintained at a specified temperature value; correspondingly, the health status of the heat dissipation module is determined based on the heat dissipation parameter change between the first heat dissipation parameter value and the second heat dissipation parameter value, including: if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is less than a specified parameter change threshold, the heat dissipation module is considered to be in a good state; or, if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is greater than the specified parameter change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is equal to the specified parameter change threshold, the heat dissipation module is considered to be in an abnormal state.

[0106] The expected changes in heat dissipation parameters can be used to reflect the heat dissipation performance of the heat dissipation module under good conditions, serving as a reference for judging the health status of the heat dissipation module. In some embodiments, the expected changes in heat dissipation parameters can be preset in memory, and the controller can read the expected changes in heat dissipation parameters from memory and compare them with the actual changes in heat dissipation parameters. Alternatively, the expected changes in heat dissipation parameters can also be stored in the cloud and obtained by the controller from the cloud in real time.

[0107] In some embodiments, when the power of the power module changes, the amount of change in the heat dissipation parameters that the heat dissipation module needs to adjust may also be different in order to maintain the temperature of the power module at a specified temperature value.

[0108] Therefore, in some embodiments, the controller can pre-set multiple expected changes in heat dissipation parameters, and in the process of determining the health status of the heat dissipation module, match the corresponding expected changes in heat dissipation parameters by specifying temperature values.

[0109] In some embodiments, the expected changes in heat dissipation parameters can be obtained through historical data, simulation experiments, or by establishing a thermal resistance model. This embodiment does not specifically limit this.

[0110] The specified threshold for the change in heat dissipation parameters is a preset threshold used to measure the difference between the change in heat dissipation parameters and the expected change in heat dissipation parameters.

[0111] If the absolute value of the difference between the change in heat dissipation parameters and the expected change in heat dissipation parameters is less than the specified threshold for parameter change, the change in heat dissipation parameters can be considered close to the expected change, and the heat dissipation module can be considered to be in good health. Conversely, if the absolute value of the difference between the change in heat dissipation parameters and the expected change in heat dissipation parameters is greater than the specified threshold for parameter change, the heat dissipation module can be considered to be in an abnormal health state. Furthermore, if the absolute value of the difference between the change in heat dissipation parameters and the expected change in heat dissipation parameters is equal to the specified threshold for parameter change, the heat dissipation module can be considered to be in an abnormal health state.

[0112] In some embodiments, there are multiple power modules. Correspondingly, each power module has a first heat dissipation parameter value, a second heat dissipation parameter value, and a heat dissipation parameter change amount. When the absolute value of the difference between the heat dissipation parameter change amount of all power modules and the expected heat dissipation parameter change amount is less than a specified parameter change amount threshold, the heat dissipation module can be considered to be in a good health state. When the absolute value of the difference between the heat dissipation parameter change amount of any power module and the expected heat dissipation parameter change amount is greater than the specified parameter change amount threshold, the heat dissipation module can be considered to be in an abnormal health state. Furthermore, when the absolute value of the difference between the heat dissipation parameter change amount of any power module and the expected heat dissipation parameter change amount is equal to the specified parameter change amount threshold, the heat dissipation module can be considered to be in an abnormal health state.

[0113] As exemplarily shown in Figure 4, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0114] Step S310: The power conversion device is in operation.

[0115] Step S320: Obtain the first heat dissipation parameter value of the heat dissipation module.

[0116] Step S330: Change the power of the power module.

[0117] Step S340: Change the fan speed to maintain the power module temperature at a specified value. At this time, the operating state of the heat dissipation module changes.

[0118] Step S350: Obtain the second heat dissipation parameter value of the heat dissipation module.

[0119] Step S360: Determine the health status of the heat dissipation module based on the change in heat dissipation parameters between the first and second heat dissipation parameter values.

[0120] In some embodiments, the operating status indicators include the temperature of the power module; the multiple indicator values ​​are multiple measured temperature values ​​of the power module; correspondingly, the health status of the heat dissipation module is determined by specifying the value change characteristics of the multiple indicator values ​​corresponding to the operating status indicators, including: determining the health status of the heat dissipation module based on the temperature change rate of the multiple measured temperature values.

[0121] In this embodiment, the specified operating status indicators include the temperature of the power module.

[0122] The specified power value can be a constant value, keeping the heat generated by the power module stable. By acquiring the temperature of the power module while it operates at the specified power value, the interference from temperature changes caused by power variations can be reduced to some extent.

[0123] The rate of temperature change of a power module can be expressed as the amount of temperature change per unit time, reflecting the speed at which the power module temperature rises or falls.

[0124] When the working state of the heat dissipation module changes and its heat dissipation capacity changes, the temperature of the power module will change over time while maintaining the same power operation.

[0125] The health status of the heat dissipation module can be determined by the rate of temperature change of the power module over time. Specifically, when the heat dissipation module is in an abnormal state, the rate of temperature change when its operating state changes may be slow. For example, in a heat dissipation module that includes a fan and an air duct, if the air duct is blocked, even if the fan speed increases normally as instructed by the controller, the temperature drop rate will be somewhat slow due to the blockage. Conversely, when the heat dissipation module is in a good state, its temperature will change at the expected rate when its operating state changes.

[0126] Therefore, the controller can compare the measured rate of temperature change with the predicted rate of temperature change. If the difference is within the allowable range, the heat dissipation module can be considered to be in good health. If the difference exceeds the allowable range, the heat dissipation module may be malfunctioning and requires further inspection or maintenance.

[0127] In this way, the power conversion device can monitor the health status of the heat dissipation module more precisely. Compared with simply comparing the amount of temperature change, the rate of temperature change can more sensitively reflect the performance changes of the heat dissipation module, promptly detect potential heat dissipation problems, and ensure the stable operation of the power conversion device to a certain extent.

[0128] In some embodiments, repeatedly acquiring the values ​​of specified operating state indicators of the power unit includes: acquiring a first measured temperature value of the power module before the operating state of the heat dissipation module changes, and a second measured temperature value of the power module after the operating state of the heat dissipation module changes, while the power module is operating at a specified power value; correspondingly, determining the health status of the heat dissipation module based on the temperature change rate of the multiple measured temperature values ​​includes: identifying the ratio of the measured temperature change amount between the first and second measured temperature values ​​to the temperature change duration as the temperature change rate; wherein the temperature change duration is the time between the moment the operating state of the heat dissipation module changes and the moment the temperature of the power module changes to the second measured temperature value.

[0129] In this embodiment, the rate of temperature change can be obtained by the ratio of the absolute value of the difference between the first and second measured temperature values ​​to the duration of temperature change. When the operating state of the heat dissipation module changes, the temperature of the power module starts to change from the first measured temperature value and stabilizes at the second measured temperature value. The duration of temperature change is the time it takes for the power module to change from the first measured temperature value to stabilize at the second measured temperature value.

[0130] In some embodiments, while the power module maintains a specified power value during operation, the controller can acquire the power module's temperature multiple times within a specified time period after the heat dissipation module's operating state changes, obtaining multiple target measured temperature values. Further, the health status of the heat dissipation module is determined based on the rate of change of the multiple target measured temperature values.

[0131] The specified duration represents a preset time period after the operating state of the heat dissipation module changes. Specifically, this preset time period can be the time between the change in the operating state of the heat dissipation module and the temperature of the power module stabilizing. Within the specified duration, the controller can acquire the temperature of the power module multiple times to obtain multiple target measured temperature values.

[0132] The controller can also record the measurement time difference between two target measured temperatures. Furthermore, the controller can obtain the rate of temperature change by calculating the ratio of the difference between any two target measured temperature values ​​to the corresponding measurement time difference. Of course, the controller can also first calculate the rate of change of multiple temperatures for multiple combinations of two target measured temperature values. Furthermore, the controller can measure the central trend of the multiple temperature change rates and identify it as the rate of temperature change. This embodiment does not impose specific limitations here.

[0133] In some embodiments, the rate of temperature change corresponds to a predicted rate of temperature change; the predicted rate of temperature change represents the predicted rate of temperature change of the power module when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the power module maintains a specified power value. Accordingly, the health status of the heat dissipation module is determined based on the rate of temperature change of multiple target measured temperature values, including: determining that the heat dissipation module is in good condition when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is less than a specified rate of change threshold; or, determining that the heat dissipation module is in an abnormal state when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is greater than the specified rate of change threshold; or, determining that the heat dissipation module is in an abnormal state when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is equal to the specified rate of change threshold.

[0134] In this embodiment, the rate of temperature change corresponds to the expected rate of temperature change. The expected rate of temperature change reflects the heat dissipation performance of the heat dissipation module under normal conditions and serves as a reference for judging the health status of the heat dissipation module.

[0135] In some embodiments, the expected rate of temperature change can be preset in memory, and the controller can read the expected rate of temperature change from memory and compare it with the rate of change of the actual temperature value. Alternatively, the expected rate of temperature change can also be stored in the cloud and retrieved by the controller in real time.

[0136] In some embodiments, the operating state of the heat dissipation module changes when the power module operates at different specified power values. Since the heat generated by the power module may vary depending on the specified power value, the expected temperature change rate of the power module may also differ. Therefore, the controller can preset multiple expected temperature change rates and match the corresponding expected temperature change rate to the specified power value during the process of determining the health status of the heat dissipation module.

[0137] In some embodiments, the expected rate of temperature change can be obtained through historical data, simulation experiments, or by establishing a thermal resistance model. This embodiment does not specifically limit this.

[0138] The specified rate of change threshold is a preset threshold used to measure the difference between the actual rate of temperature change and the expected rate of temperature change. When the absolute value of the difference between the actual and expected rates of temperature change is less than the specified rate of change threshold, the actual and expected rates of temperature change can be considered similar, and the heat dissipation module can be considered to be in good health. Conversely, when the absolute value of the difference between the actual and expected rates of temperature change is greater than the specified rate of change threshold, the actual and expected rates of temperature change can be considered to differ significantly, and the heat dissipation module can be considered to be in an abnormal health state. Furthermore, when the absolute value of the difference between the actual and expected rates of temperature change is equal to the specified rate of change threshold, the heat dissipation module can be considered to be in an abnormal health state.

[0139] In some embodiments, there are multiple power modules. Correspondingly, each power module has multiple target measured temperature values ​​and temperature change rates. When the absolute value of the difference between the temperature change rate and the expected temperature change rate of all power modules is less than a specified rate change threshold, the heat dissipation module is considered to be in good health. When the absolute value of the difference between the temperature change rate and the expected temperature change rate of any power module is greater than the specified rate change threshold, the heat dissipation module is considered to be in an abnormal health state. Furthermore, when the absolute value of the difference between the temperature change rate and the expected temperature change rate of any power module is equal to the specified rate change threshold, the heat dissipation module is considered to be in an abnormal health state.

[0140] As exemplarily shown in Figure 5, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0141] Step S410: The power conversion device is in operation.

[0142] Step S420: Obtain the first measured temperature value of the power module.

[0143] Step S430: Change the fan speed to maintain the power module temperature at a specified value. At this time, the operating state of the heat dissipation module changes.

[0144] Step S440: Obtain the second measured temperature value of the power module.

[0145] Step S450: Calculate the slope of temperature change based on the first measured temperature value and the second measured temperature value.

[0146] Step S460: Determine the health status of the heat dissipation module based on the slope of the temperature change.

[0147] In some embodiments, the specified operating status indicators include the temperature of the power module; acquiring the indicator values ​​of the specified operating status indicators of the power unit multiple times includes: acquiring a first measured temperature value of the power module before the operating state of the heat dissipation module changes, and a second measured temperature value of the power module after the operating state of the heat dissipation module changes; correspondingly, determining the health status of the heat dissipation module based on the multiple indicator values ​​corresponding to the specified operating status indicators includes: inferring the measured change in thermal resistance of the heat conduction path corresponding to the power module before and after the operating state of the heat dissipation module changes based on the first measured temperature value, the second measured temperature value, and the power of the power module; and determining the health status of the heat dissipation module by the measured change in thermal resistance.

[0148] The health status of the heat dissipation module can be determined by analyzing the thermal resistance of the heat conduction path corresponding to the power module. Specifically, the health status of the heat dissipation module can be determined by comparing the thermal resistance of the heat conduction path corresponding to the power module with the expected thermal resistance when the heat dissipation module is in good condition.

[0149] Please refer to Formula 1 for the calculation method of the thermal resistance of the heat conduction path corresponding to the power module. th =(T p -T a ) / P loss (1)

[0150] Among them, R th T represents the thermal resistance of the power conversion device. p This refers to the temperature of the power module. (T) a P represents the ambient temperature. loss This represents the power loss value of the power module.

[0151] As can be seen from Equation 1, the thermal resistance of the heat conduction path corresponding to the power module is related to the ambient temperature. Adding an ambient temperature detection device to the power conversion device to obtain the ambient temperature would not only increase the structural complexity of the power conversion device but also increase its cost.

[0152] Therefore, considering that changes in the operating state of the heat dissipation module will affect the thermal resistance of the power conversion device, the change in thermal resistance of the heat conduction path before and after the change in the operating state of the heat dissipation module during the operation of the power module to maintain a specified power value can offset the influence of ambient temperature. Thus, the health status of the heat dissipation module can be determined more accurately without adding an ambient temperature detection device.

[0153] For the calculation method of the change in thermal resistance of the power conversion device caused by the change in the operating state of the heat dissipation module, please refer to Formula 2. thΔ=|T1-T2| / P loss’ (2)

[0154] Among them, R thΔ T represents the change in thermal resistance of the power conversion device. T1 is the temperature of the power module before the change in the operating state of the heat dissipation module. T2 is the temperature of the power module after the change in the operating state of the heat dissipation module. a P represents the ambient temperature. loss’ The power loss value for maintaining a specified power value when the power module is running.

[0155] As can be seen from Formula 2, while the power module maintains a specified power value, the change in thermal resistance can be calculated by acquiring the temperature of the power module. Therefore, in this embodiment, the specified operating status indicator includes the temperature of the power module.

[0156] By taking the first measured temperature value of the power module before the change of the heat dissipation module's operating state, and the second measured temperature value of the power module after the change of the heat dissipation module's operating state, and combining this with the specified power value of the power module, the change in measured thermal resistance of the corresponding heat conduction path of the power module before and after the change of the heat dissipation module's operating state can be inferred.

[0157] In some embodiments, the method for inferring the measured thermal resistance change includes: calculating the power loss value based on the power of the power module; and determining the ratio of the absolute value of the measured temperature change between the first measured temperature value and the second measured temperature value to the power loss value as the measured thermal resistance change of the heat conduction path corresponding to the power module.

[0158] The power loss value can be obtained by multiplying the efficiency coefficient of the power module by the power of the power module.

[0159] Therefore, when the measured change in thermal resistance matches the expectation, the heat dissipation module can be considered to be in good condition. When the measured change in thermal resistance differs from the expectation, the heat dissipation module can be considered to be in an abnormal condition.

[0160] In some embodiments, during the process of repeatedly acquiring the index values ​​of a specified operating state indicator of the power unit, the power of the power module changes; the specified operating state indicator also includes the power of the power module; correspondingly, repeatedly acquiring the index values ​​of the specified operating state indicator of the power unit further includes: acquiring a first measured power value of the power module's power before the change of the heat dissipation module's operating state, and a second measured power value of the power module's power after the change of the heat dissipation module's operating state; correspondingly, calculating the power loss value based on the power module's power includes: determining the power loss value through the first measured power value and the second measured power value.

[0161] In some cases, power conversion devices can be used in photovoltaic power generation systems. Specifically, a power conversion device has a DC side and an AC side. The DC side of the power conversion device is used to connect to the photovoltaic modules. The AC side of the power conversion device is used to connect to the power grid.

[0162] Because the output power of photovoltaic modules changes over time due to factors such as light intensity and ambient temperature, the maximum output power of the power conversion device is also limited by the change in the output power of the photovoltaic modules over time. Therefore, during the process of repeatedly obtaining the specified operating status index values ​​of the power unit, if the power of the control power module is to be stably maintained at a specified power value, the specified power value needs to be constrained by the minimum output power of the photovoltaic modules during this process, thus affecting the power generation of the photovoltaic power generation system.

[0163] Therefore, in this embodiment, the power of the power module is allowed to change. Specifically, the power of the power module can change at a certain slope under normal operating conditions. Thus, to determine the health status of the heat dissipation module, the power of the power module is also included as an operating status indicator.

[0164] Because the power of the power module changes, the theoretical formula for calculating the change in thermal resistance becomes relatively complex and is affected to some extent by the ambient temperature. Therefore, in some embodiments, the calculation can be performed using an approximation mechanism based on Formula 2.

[0165] Please refer to Formula 2. Because the power of the power module changes before and after the change in the operating state of the heat dissipation module, the temperature difference between the power module and the heat dissipation module before and after the change in operating state further increases. That is, the numerator value in Formula 2 will increase. Therefore, for the power loss value substituted into Formula 2, the larger of the first and second measured power values ​​can be appropriately selected to increase the denominator value.

[0166] In some embodiments, determining the power loss value by taking a first measured power value and a second measured power value includes: calculating the power loss value based on the target measured power value that is larger between the first measured power value and the second measured power value.

[0167] The target measured power value is the larger of the first and second measured power values. The power loss value can be obtained by multiplying the target measured power value by the efficiency coefficient.

[0168] In some embodiments, determining the power loss value using a first measured power value and a second measured power value includes: calculating the power loss value based on a central trend measurement of the first measured power value and the second measured power value.

[0169] The central tendency measure can be the median or average of the first and second measured power values, etc. This embodiment does not impose specific limitations here.

[0170] In some embodiments, the controller may also add a fixed compensation value to the central trend measurement of the first and second measured power values ​​or the target measured power value. This compensation value can be obtained through one or more methods such as theoretical derivation, historical data, or simulation experiments. This embodiment does not impose specific limitations here.

[0171] In some embodiments, the power conversion device has a predicted thermal resistance change; the predicted thermal resistance change represents the predicted change in the thermal resistance of the heat conduction path corresponding to the power module when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in a good condition; determining the health status of the heat dissipation module by measuring the thermal resistance change includes: determining that the heat dissipation module is in a good condition if the absolute value of the difference between the measured thermal resistance change and the predicted thermal resistance change is less than a specified thermal resistance change threshold; or, determining that the heat dissipation module is in an abnormal condition if the absolute value of the difference between the measured thermal resistance change and the predicted thermal resistance change is greater than the specified thermal resistance change threshold; or, determining that the heat dissipation module is in an abnormal condition if the absolute value of the difference between the measured thermal resistance change and the predicted thermal resistance change is equal to the specified thermal resistance change threshold.

[0172] The expected change in thermal resistance can be used to reflect the thermal performance of the heat dissipation module under good conditions, serving as a reference for judging the health status of the heat dissipation module. This change in thermal resistance corresponds to the heat conduction path of the power module.

[0173] In this embodiment, the expected change in thermal resistance can be preset in memory. The controller can read the expected change in thermal resistance from memory and compare it with the measured change in thermal resistance. Alternatively, the expected change in thermal resistance can be stored in the cloud and retrieved by the controller in real time.

[0174] The expected change in thermal resistance can be obtained through historical data, simulation experiments, or by establishing a thermal resistance model. This embodiment does not impose specific limitations on this.

[0175] The specified thermal resistance change threshold is a preset threshold used to measure the difference between the measured thermal resistance change and the expected thermal resistance change. When the absolute value of the difference between the measured and expected thermal resistance changes is less than the specified thermal resistance change threshold, the measured and expected thermal resistance changes can be considered similar, thus indicating that the heat dissipation module is in good condition. Conversely, when the absolute value of the difference between the measured and expected thermal resistance changes is greater than the specified thermal resistance change threshold, a significant difference can be considered, indicating that the heat dissipation module is in an abnormal state. Furthermore, when the absolute value of the difference between the measured and expected thermal resistance changes is equal to the specified thermal resistance change threshold, the heat dissipation module can be considered to be in an abnormal state.

[0176] In some embodiments, there are multiple power modules. Accordingly, each power module has a corresponding first measured temperature value, a second measured temperature value, and a corresponding power. Therefore, for each power module, the change in thermal resistance of its corresponding heat conduction path can be calculated. When the absolute value of the difference between the measured thermal resistance change and the expected thermal resistance change of all power modules' corresponding heat conduction paths is less than a specified thermal resistance change threshold, the heat dissipation module can be considered to be in good health. If the absolute value of the difference between the measured thermal resistance change and the expected thermal resistance change of any power module's corresponding heat conduction path is greater than the specified thermal resistance change threshold, the heat dissipation module can be considered to be in an abnormal health state. Furthermore, if the absolute value of the difference between the measured thermal resistance change and the expected thermal resistance change of any power module's corresponding heat conduction path is equal to the specified thermal resistance change threshold, the heat dissipation module can be considered to be in an abnormal health state.

[0177] As exemplarily shown in Figure 6, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0178] Step S510: The power conversion device is in operation.

[0179] Step S520: Obtain the first measured temperature value of the power module.

[0180] Step S530: Change the fan speed. At this time, the operating state of the heat dissipation module changes.

[0181] Step S540: Obtain the second measured temperature value of the power module.

[0182] Step S550: Calculate the measured change in thermal resistance of the heat conduction path corresponding to the power module.

[0183] Step S560: Determine the health status of the heat dissipation module based on the measured change in thermal resistance.

[0184] Please refer to Figure 1. In some embodiments, the heat dissipation module includes a cooling component and a flow guiding structure. The cooling component is used to drive the cooling medium through the heat dissipation surface of the power module under the guidance of the flow guiding structure to dissipate heat from the power module. The cooling power of the cooling component is different before and after the working state of the heat dissipation module changes. The health status of the heat dissipation module is determined based on the values ​​of multiple indicators corresponding to the specified operating status indicators, including: determining the health status of the flow guiding structure based on the values ​​of multiple indicators corresponding to the specified operating status indicators.

[0185] Cooling components are used to reduce the temperature of power conversion devices. Accordingly, the specified heat dissipation parameters of the heat dissipation module can be the operating parameters of the cooling components.

[0186] For example, a cooling assembly may include components such as a fan. Accordingly, a specified heat dissipation parameter for the heat dissipation module may be the fan speed. Thus, the heat dissipation module can adjust the fan speed to utilize airflow to cool the power module. Alternatively, the cooling assembly may also include components such as a liquid cooling pump. Accordingly, a specified heat dissipation parameter for the heat dissipation module may be the liquid cooling pump speed. Thus, the heat dissipation module can adjust the fan speed to utilize the flow of coolant to cool the power module.

[0187] A flow-guiding structure is a structure used to guide the cooling medium. For example, when a heat dissipation module cools a power module using an air-cooling mechanism, the cooling components include a fan, the flow-guiding structure includes air ducts, and the cooling medium includes air. Alternatively, when a heat dissipation module cools a power module using a liquid-cooling mechanism, the cooling components include a cooling pump, the flow-guiding structure includes pipes for conveying coolant, and the cooling medium is coolant.

[0188] Cooling power can be used to describe the ability of a cooling component to remove heat from a heat source by driving the flow of cooling medium during operation.

[0189] In some embodiments, the cooling component includes a liquid cooling pump, and the speed of the liquid cooling pump before the change of the operating state of the heat dissipation module is different from the speed of the liquid cooling pump after the change of the operating state of the heat dissipation module, resulting in different cooling power before and after the change of the operating state of the heat dissipation module. Alternatively, the cooling component includes a fan, and the speed of the fan before the change of the operating state of the heat dissipation module is different from the speed of the fan after the change of the operating state of the heat dissipation module, also resulting in different cooling power before and after the change of the operating state of the heat dissipation module.

[0190] In some embodiments, the type of cooling medium used in the cooling assembly differs before and after the change in the operating state of the heat dissipation module. Different types of cooling media have different thermal conductivity, which will result in different cooling power outputs of the cooling assembly before and after the change in the heat dissipation module's operating state. For example, the cooling assembly may include components such as a fan and a liquid-cooled pump, forming a hybrid cooling system. The cooling assembly may use air as the cooling medium before the change in the heat dissipation module's operating state, and then change the cooling medium to a coolant to alter the heat dissipation module's operating state.

[0191] In this embodiment, the health status of the heat dissipation module may include the health status of the airflow guiding structure. The health status of the airflow guiding structure may include whether any blockages have occurred in the airflow guiding structure of the heat dissipation module. For example, whether dust or other blockages have accumulated in the airflow guiding structure.

[0192] In some embodiments, the number of power modules is multiple; the cooling component drives the cooling medium through different flow paths to dissipate heat from different power modules; the specified operating status indicators include the power module status indicators of each power module; correspondingly, based on the multiple index values ​​corresponding to the specified operating status indicators, the health status of the flow guiding structure is determined, including: determining the health status of at least a portion of the flow guiding structure traversed by the flow path corresponding to the power module according to the multiple index values ​​of the power module status indicators of each of at least two power modules.

[0193] The heat dissipation surface of the power module can be the surface of the power module itself. Alternatively, when the power module is connected to a heat sink and dissipates heat through the heat sink, the heat dissipation surface of the power module can also represent the heat sink. This embodiment does not impose any specific limitations.

[0194] A flow path can represent the area through which the cooling medium flows as it dissipates heat from the power module. For example, a flow path may include at least a portion of the flow-guiding structure through which the cooling medium flows and the heat dissipation surface of the power module.

[0195] Because multiple power modules are located in different positions within the heat dissipation module, the positional relationships between different power modules and the cooling components vary. Therefore, different power modules correspond to different flow paths. Based on the values ​​of multiple power module status indicators for each power module, the health status of the flow path corresponding to that power module can be determined. The health status of the flow path includes issues such as blockages or deformations in the guide structures traversed by the flow path. This embodiment does not impose specific limitations on these issues.

[0196] For example, in a scenario where the heat dissipation module uses a liquid cooling mechanism to cool the power module, the cooling components include a liquid cooling pump, the flow guiding structure includes pipes for transmitting coolant, and the cooling medium includes coolant. When the heat dissipation surfaces of different power modules are connected to the liquid cooling pump via different pipes, the flow path corresponding to a power module may include the pipe connecting to the heat dissipation surface of that power module. Accordingly, based on the values ​​of multiple indicators of the power module status index for each power module, the health status of the pipes corresponding to that power module can be determined.

[0197] Alternatively, if at least two power modules' heat dissipation surfaces are connected to the liquid cooling pump via the same pipe, the flow path corresponding to the power module can be represented as the local pipe through which the coolant dissipates heat from the power module. Accordingly, based on the values ​​of multiple power module status indicators, the health status of the corresponding local pipe can be determined.

[0198] In some embodiments, when the heat dissipation module dissipates heat from the power module using an air-cooling mechanism, the cooling component includes a fan, the airflow guiding structure is an air duct, and the cooling medium is air. When the power module and fan can be correspondingly positioned, and the power module is dissipated heat through a corresponding air duct, the flow path corresponding to the power module can be represented as the air duct corresponding to that power module. Accordingly, based on the values ​​of multiple indicators of the power module's status, the health status of the air duct corresponding to the power module can be determined.

[0199] Alternatively, at least two power modules can share the same airflow duct for heat dissipation. Since the different power modules are positioned differently within the heat dissipation module, their relative positions to the air inlet and outlet of the airflow duct differ. This causes the heat generated by the power modules to be discharged from the power conversion device through different flow paths. Specifically, the heat generated by each power module will be discharged from the power conversion device using a portion of the airflow duct. Therefore, in this case, the flow path corresponding to a power module can be represented as the local airflow duct through which the air dissipating heat from that power module passes. Accordingly, based on the values ​​of multiple indicators of the power module's status, the health status of the local airflow corresponding to that power module can be determined.

[0200] As exemplarily shown in Figure 7, in one embodiment provided in this disclosure, the heat dissipation module includes a fan and an air duct. Accordingly, the controller can perform the following steps to determine the health status of the heat dissipation module.

[0201] Step S610: The power conversion device is in operation.

[0202] Step S620: Obtain the indicator values ​​of the power module indicators of multiple power modules.

[0203] Step S630: Change the fan speed. At this time, the operating state of the heat dissipation module changes.

[0204] Step S640: Obtain the indicator values ​​of the power module indicators of multiple power modules.

[0205] Step S660: Based on the values ​​of multiple indicators corresponding to each power module, determine the health status of the part of the air duct that the flow path corresponding to the power module passes through.

[0206] In some embodiments, the controller is further configured to reduce the upper limit of the output power of the power conversion device when it is determined that there is an abnormal heat dissipation in the heat dissipation module, so as to reduce the heat generated by the power module and thereby alleviate the burden on the heat dissipation module. The upper limit of the output power may represent the highest output power that the power conversion device is set to operate at.

[0207] In some embodiments, the controller may also lower the temperature protection threshold of the power conversion device, meaning that the protection mechanism will be triggered at a lower temperature to prevent the temperature from rising further and causing damage to the device.

[0208] Of course, the controller can also simultaneously reduce the upper limit of the output power of the power conversion device and the temperature protection threshold of the power conversion device. This embodiment is not limited to this.

[0209] This disclosure provides a method for determining the health status of a heat dissipation module in a power conversion device. The power conversion device includes a power unit; the power unit includes a power module and a heat dissipation module; the heat dissipation module is used to dissipate heat from the power module; the method includes: repeatedly acquiring the index values ​​of a specified operating status index of the power unit; wherein, during the repeated acquisition of the index values ​​of the specified operating status index of the power unit, the operating status of the heat dissipation module changes, and the heat dissipation capacity of the heat dissipation module is different before and after the change in operating status; and determining the health status of the heat dissipation module based on the multiple index values ​​corresponding to the specified operating status index.

[0210] In some embodiments, determining the health status of the heat dissipation module based on the values ​​of multiple indicators corresponding to a specified operating status indicator includes: determining the health status of the heat dissipation module by the value change characteristics of the multiple indicators corresponding to the specified operating status indicator.

[0211] In some embodiments, the specified operating status indicators include the temperature of the power module; repeatedly acquiring the values ​​of the specified operating status indicators of the power unit includes: acquiring a first measured temperature value of the power module before the operating state of the heat dissipation module changes, and a second measured temperature value of the power module after the operating state of the heat dissipation module changes, while the power module is operating at a specified power value; correspondingly, determining the health status of the heat dissipation module by the value change characteristics of multiple indicator values ​​corresponding to the specified operating status indicators includes: determining the health status of the heat dissipation module based on the measured temperature change between the first measured temperature value and the second measured temperature value.

[0212] In some embodiments, the power module corresponds to a predicted temperature change; the predicted temperature change represents the expected temperature change of the power module when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the power module is operating at a specified power value. Accordingly, based on the measured temperature change between the first measured temperature value and the second measured temperature value, the health status of the heat dissipation module is determined, including: if the absolute value of the difference between the measured temperature change and the predicted temperature change is less than a specified temperature change threshold, the heat dissipation module is considered to be in good condition; or, if the absolute value of the difference between the measured temperature change and the predicted temperature change is greater than the specified temperature change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the measured temperature change and the predicted temperature change is equal to the specified temperature change threshold, the heat dissipation module is considered to be in an abnormal state.

[0213] In some embodiments, during the process of repeatedly acquiring the values ​​of specified operating status indicators of the power unit, in response to changes in the operating state of the heat dissipation module, the power of the power module is controlled and adjusted to maintain the temperature of the power module at a specified temperature value; the specified operating status indicator includes the power of the power module; correspondingly, repeatedly acquiring the values ​​of specified operating status indicators of the power unit includes: acquiring a first measured power value of the power module before the change of the operating state of the heat dissipation module, and a second measured power value of the power module after the change of the operating state of the heat dissipation module; correspondingly, determining the health status of the heat dissipation module by the value change characteristics of multiple indicator values ​​corresponding to the specified operating status indicator includes: determining the health status of the heat dissipation module based on the measured power change between the first measured power value and the second measured power value.

[0214] In some embodiments, the power module corresponds to a predicted power change; the predicted power change represents the power that the power module is expected to adjust when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the temperature of the power module is maintained at a specified temperature value; correspondingly, based on the measured power change between the first measured power value and the second measured power value, the health status of the heat dissipation module is determined, including: if the absolute value of the difference between the measured power change and the predicted power change is less than a specified power change threshold, the heat dissipation module is considered to be in good condition; or, if the absolute value of the difference between the measured power change and the predicted power change is greater than the specified power change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the measured power change and the predicted power change is equal to the specified power change threshold, the heat dissipation module is considered to be in an abnormal state.

[0215] In some embodiments, the heat dissipation module has specified heat dissipation parameters; changes in the specified heat dissipation parameters cause changes in the operating state of the heat dissipation module; during the process of repeatedly acquiring the index values ​​of the specified operating state indicators of the power unit, the power of the power module is controlled to change, and in response to the change in the power of the power module, the specified heat dissipation parameters of the heat dissipation module are controlled to change so that the temperature of the power module is maintained at a specified temperature value; the specified operating state indicators include the specified heat dissipation parameters of the heat dissipation module; correspondingly, repeatedly acquiring the index values ​​of the specified operating state indicators of the power unit includes: acquiring a first heat dissipation parameter value of the specified heat dissipation parameters before the change in the operating state of the heat dissipation module, and a second heat dissipation parameter value of the specified heat dissipation parameters after the change in the operating state of the heat dissipation module; correspondingly, the health status of the heat dissipation module is determined by the value change characteristics of the multiple index values ​​corresponding to the specified operating state indicators, including: determining the health status of the heat dissipation module based on the amount of change in heat dissipation parameters between the first heat dissipation parameter value and the second heat dissipation parameter value.

[0216] In some embodiments, the heat dissipation module corresponds to a predicted parameter change; the predicted heat dissipation parameter change represents the expected adjustment of the heat dissipation parameter when the power of the power module changes, assuming the heat dissipation module is in a good state and the temperature of the power module is maintained at a specified temperature value; correspondingly, the health status of the heat dissipation module is determined based on the heat dissipation parameter change between the first heat dissipation parameter value and the second heat dissipation parameter value, including: if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is less than a specified parameter change threshold, the heat dissipation module is considered to be in a good state; or, if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is greater than the specified parameter change threshold, the heat dissipation module is considered to be in an abnormal state; or, if the absolute value of the difference between the heat dissipation parameter change and the predicted parameter change is equal to the specified parameter change threshold, the heat dissipation module is considered to be in an abnormal state.

[0217] In some embodiments, the operating status indicators include the temperature of the power module; correspondingly, acquiring the values ​​of the specified operating status indicators of the power unit multiple times includes: acquiring the temperature of the power module multiple times within a specified time after the working state of the heat dissipation module changes while the power module is maintaining a specified power value, thereby obtaining multiple target measured temperature values; correspondingly, determining the health status of the heat dissipation module by the value change characteristics of the multiple indicator values ​​corresponding to the specified operating status indicators includes: determining the health status of the heat dissipation module based on the temperature change rate of the multiple target measured temperature values.

[0218] In some embodiments, the rate of temperature change corresponds to a predicted rate of temperature change; the predicted rate of temperature change represents the predicted rate of temperature change of the power module when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in good condition and the power module maintains a specified power value. Accordingly, the health status of the heat dissipation module is determined based on the rate of temperature change of multiple target measured temperature values, including: determining that the heat dissipation module is in good condition when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is less than a specified rate of change threshold; or, determining that the heat dissipation module is in an abnormal state when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is greater than the specified rate of change threshold; or, determining that the heat dissipation module is in an abnormal state when the absolute value of the difference between the rate of temperature change and the predicted rate of temperature change is equal to the specified rate of change threshold.

[0219] In some embodiments, the specified operating status indicators include the temperature of the power module; repeatedly acquiring the indicator values ​​of the specified operating status indicators of the power unit includes: acquiring a first measured temperature value of the power module before the operating state of the heat dissipation module changes, and a second measured temperature value of the power module after the operating state of the heat dissipation module changes; correspondingly, determining the health status of the heat dissipation module based on the multiple indicator values ​​corresponding to the specified operating status indicators includes: inferring the measured thermal resistance change of the power conversion device before and after the operating state of the heat dissipation module changes based on the first measured temperature value, the second measured temperature value, and the power of the power module; and determining the health status of the heat dissipation module by the measured thermal resistance change.

[0220] In some embodiments, based on the first measured temperature value, the second measured temperature value, and the power of the power module, the measured thermal resistance change of the power conversion device before and after the change in the working state of the heat dissipation module is inferred, including: calculating the power loss value based on the power of the power module; and identifying the ratio of the absolute value of the measured temperature change between the first measured temperature value and the second measured temperature value to the power loss value as the measured thermal resistance change.

[0221] In some embodiments, during the process of repeatedly acquiring the index values ​​of a specified operating state indicator of the power unit, the power of the power module changes; the specified operating state indicator also includes the power of the power module; correspondingly, repeatedly acquiring the index values ​​of the specified operating state indicator of the power unit further includes: acquiring a first measured power value of the power module's power before the change of the heat dissipation module's operating state, and a second measured power value of the power module's power after the change of the heat dissipation module's operating state; correspondingly, calculating the power loss value based on the power module's power includes: determining the power loss value through the first measured power value and the second measured power value.

[0222] In some embodiments, determining the power loss value using a first measured power value and a second measured power value includes: calculating the power loss value based on the target measured power value that is larger between the first measured power value and the second measured power value; or, calculating the power loss value based on a central trend measurement of the first measured power value and the second measured power value.

[0223] In some embodiments, the power conversion device has a projected thermal resistance change; the projected thermal resistance change represents the projected change in the thermal resistance of the power conversion device when the operating state of the heat dissipation module changes, assuming the heat dissipation module is in a good condition; determining the health status of the heat dissipation module by measuring the thermal resistance change includes: determining that the heat dissipation module is in a good condition if the absolute value of the difference between the measured thermal resistance change and the projected thermal resistance change is less than a specified thermal resistance change threshold; or, determining that the heat dissipation module is in an abnormal condition if the absolute value of the difference between the measured thermal resistance change and the projected thermal resistance change is greater than the specified thermal resistance change threshold; or, determining that the heat dissipation module is in an abnormal condition if the absolute value of the difference between the measured thermal resistance change and the projected thermal resistance change is equal to the specified thermal resistance change threshold.

[0224] In some embodiments, the heat dissipation module includes a cooling component and a flow guiding structure; the cooling component is used to drive the cooling medium through the heat dissipation surface of the power module under the guidance of the flow guiding structure to dissipate heat from the power module; the cooling power of the cooling component is different before and after the working state of the heat dissipation module changes; the health status of the heat dissipation module is determined based on the values ​​of multiple indicators corresponding to the specified operating state indicators, including: determining the health status of the flow guiding structure based on the values ​​of multiple indicators corresponding to the specified operating state indicators.

[0225] In some embodiments, the number of power modules is multiple; the cooling component drives the cooling medium through different flow paths to dissipate heat from different power modules; the specified operating status indicators include the power module status indicators of each power module; correspondingly, based on the multiple index values ​​corresponding to the specified operating status indicators, the health status of the flow guiding structure is determined, including: determining the health status of at least a portion of the flow guiding structure traversed by the flow path corresponding to the power module according to the multiple index values ​​of the power module status indicators of each of at least two power modules.

[0226] In some embodiments, the heat dissipation module dissipates heat from the power module through an air cooling mechanism, or the heat dissipation module dissipates heat from the power module through a liquid cooling mechanism.

[0227] In some embodiments, the method for detecting the health status of the power conversion device further includes: reducing the upper limit of the output power of the power conversion device and / or reducing the temperature protection threshold of the power conversion device when it is determined that the heat dissipation module has an abnormal heat dissipation. That is, when it is determined that the heat dissipation module has an abnormal heat dissipation, the detection method provided in this disclosure embodiment further includes at least one of reducing the upper limit of the output power of the power conversion device and reducing the temperature protection threshold of the power conversion device.

[0228] For a description of the method for determining the health status of the heat dissipation module of the power conversion device, please refer to other embodiments in this disclosure. This embodiment will not be elaborated further here.

[0229] Referring to Figure 8, this disclosure also provides an energy system. This energy system includes the power conversion device as described in any of the embodiments of this disclosure.

[0230] In some embodiments, the power conversion device may be a photovoltaic inverter. The photovoltaic inverter has a DC side and an AC side. The DC side of the power conversion device is used to connect to a DC source. The AC side of the power conversion device is used to connect to the power grid. The DC source may be a photovoltaic module or an energy storage battery. This embodiment is not limited thereto.

[0231] Of course, if the energy system includes photovoltaic modules, the power conversion device can also be a maximum power point tracking (MPPT) controller in the photovoltaic system. This embodiment is not limited to this.

[0232] For a description of the energy system, please refer to other embodiments in this disclosure; this embodiment will not be elaborated upon further here.

[0233] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0234] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this disclosure, and are not intended to limit the scope of this disclosure.

[0235] It is understood that in the various embodiments of this disclosure, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure.

[0236] It is understood that the various embodiments described in this disclosure can be implemented individually or in combination, and the embodiments of this disclosure are not limited in this respect.

[0237] Unless otherwise stated, all technical and scientific terms used in the embodiments of this disclosure have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure. The term "and / or" as used in this disclosure includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0238] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0239] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0240] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0241] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0242] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A power conversion device, characterized by, The method comprises: a power unit comprising a power module and a heat dissipation module, wherein the heat dissipation module is configured to dissipate heat for the power module; a controller configured to acquire multiple values of a specified operating state indicator of the power unit, and determine a health state of the heat dissipation module based on the multiple values of the specified operating state indicator; wherein the working state of the heat dissipation module changes during the acquisition of the multiple values of the specified operating state indicator, and the heat dissipation capacity of the heat dissipation module is different before and after the change of the working state.

2. The power conversion device of claim 1, wherein, The determination of the health state of the heat dissipation module based on the multiple values of the specified operating state indicator comprises: determining the health state of the heat dissipation module through the value change characteristics of the multiple values of the specified operating state indicator.

3. The power conversion device of claim 2, wherein, The specified operating state indicator comprises the temperature of the power module. The acquisition of the multiple values of the specified operating state indicator of the power unit comprises: acquiring a first measured temperature value of the temperature of the power module before the change of the working state of the heat dissipation module, and a second measured temperature value of the temperature of the power module after the change of the working state of the heat dissipation module, during the maintenance of the power module at a specified power value. Correspondingly, the determination of the health state of the heat dissipation module through the value change characteristics of the multiple values of the specified operating state indicator comprises: determining the health state of the heat dissipation module based on the measured temperature change between the first measured temperature value and the second measured temperature value.

4. The power conversion device of claim 3, wherein, The power module corresponds to a predicted temperature change; the predicted temperature change represents a predicted temperature change of the power module when the working state of the heat dissipation module changes, under the condition that the heat dissipation module is in a good state and the power module is maintained at a specified power value. Correspondingly, the determination of the health state of the heat dissipation module based on the measured temperature change between the first measured temperature value and the second measured temperature value comprises: in the case that the absolute value of the difference between the measured temperature change and the predicted temperature change is less than a specified temperature change threshold, it is determined that the heat dissipation module is in a good state; or in the case that the absolute value of the difference between the measured temperature change and the predicted temperature is greater than the specified temperature change threshold, it is determined that the heat dissipation module is in an abnormal state.

5. The power conversion device of claim 2, wherein, During the acquisition of the multiple values of the specified operating state indicator of the power unit, the power of the power module is controlled and adjusted to maintain the temperature of the power module at a specified temperature value in response to the change of the working state of the heat dissipation module. The specified operating state indicator comprises the power of the power module; correspondingly, the acquisition of the multiple values of the specified operating state indicator of the power unit comprises: acquiring a measured first power value of the power of the power module before the change of the working state of the heat dissipation module, and acquiring a measured second power value of the power of the power module after the change of the working state of the heat dissipation module. Correspondingly, the health status of the heat dissipation module is determined by the value variation characteristic of the multiple indicator values corresponding to the specified operating state indicator, including: determining the health status of the heat dissipation module based on a measured power variation between the first measured power value and the second measured power value.

6. The power conversion device of claim 5, wherein, The power module corresponds to a predicted power variation; the predicted power variation represents that, when the operating state of the heat dissipation module changes, the power module is predicted to adjust the power under the condition that the heat dissipation module is in a good state and the temperature of the power module is maintained at the specified temperature value. Correspondingly, the health status of the heat dissipation module is determined based on a measured power variation between the first measured power value and the second measured power value, including: In the case that the absolute value of the difference between the measured power variation and the predicted power variation is less than a specified power variation threshold, it is determined that the heat dissipation module is in a good state; or, In the case that the absolute value of the difference between the measured power variation and the predicted power variation is greater than the specified power variation threshold, it is determined that the heat dissipation module is in an abnormal state.

7. The power conversion device of claim 2, wherein, The heat dissipation module has a specified heat dissipation parameter; the change of the specified heat dissipation parameter causes the operating state of the heat dissipation module to change; During the multiple times of acquiring the indicator values of the specified operating state indicator of the power unit, the power of the power module is controlled to change, and in response to the change of the power of the power module, the specified heat dissipation parameter of the heat dissipation module is controlled to change so as to maintain the temperature of the power module at a specified temperature value; The specified operating state indicator includes the specified heat dissipation parameter of the heat dissipation module; correspondingly, the multiple times of acquiring the indicator values of the specified operating state indicator of the power unit include: acquiring a first heat dissipation parameter value of the specified heat dissipation parameter before the operating state of the heat dissipation module changes, and a second heat dissipation parameter value of the specified heat dissipation parameter after the operating state of the heat dissipation module changes; Correspondingly, the health status of the heat dissipation module is determined by the value variation characteristic of the multiple indicator values corresponding to the specified operating state indicator, including: determining the health status of the heat dissipation module based on a measured power variation between the first measured power value and the second measured power value.

8. The power conversion device of claim 7, wherein, The heat dissipation module corresponds to a predicted parameter variation; the predicted heat dissipation parameter variation represents that, when the power of the power module changes, the heat dissipation module is predicted to adjust the heat dissipation parameter variation under the condition that the heat dissipation module is in a good state and the temperature of the power module is maintained at the specified temperature value. Correspondingly, the health status of the heat dissipation module is determined based on a heat dissipation parameter variation between the first heat dissipation parameter value and the second heat dissipation parameter value, including: In the case that the absolute value of the difference between the heat dissipation parameter variation and the predicted parameter variation is less than a specified parameter variation threshold, it is determined that the heat dissipation module is in a good state; Or, In the case that the absolute value of the difference between the heat dissipation parameter variation and the predicted parameter variation is greater than the specified parameter variation threshold, it is determined that the heat dissipation module is in an abnormal state. In a case where an absolute value of a difference between the heat dissipation parameter variation amount and the predicted parameter variation amount is greater than a specified parameter variation threshold, it is determined that the heat dissipation module is in an abnormal state.

9. The power conversion device of claim 2, wherein, The operating state indicators include temperatures of the power modules; and the multiple indicator values are multiple measured temperature values of the power modules. Correspondingly, the health state of the heat dissipation module is determined according to a value variation characteristic of the multiple indicator values of the specified operating state indicators, including: determining the health state of the heat dissipation module according to a temperature value variation rate of the multiple measured temperature values.

10. The power conversion device of claim 9, wherein The multiple indicator values of the specified operating state indicators of the power unit are obtained, including: obtaining a first measured temperature value of a temperature of the power module before a working state of the heat dissipation module is changed, and a second measured temperature value of the temperature of the power module after the working state of the heat dissipation module is changed, during a process in which the power module maintains a specified power value; Correspondingly, the health state of the heat dissipation module is determined according to a temperature value variation rate of the multiple measured temperature values, including: determining the temperature value variation rate as a ratio between a measured temperature variation amount and a temperature variation time length, the measured temperature variation amount being between the first measured temperature value and the second measured temperature value; and the temperature variation time length being a time length between a time when the working state of the heat dissipation module is changed and a time when the temperature of the power module changes to the second measured temperature value.

11. The power conversion device of claim 9, wherein, The temperature value variation rate corresponds to a predicted temperature variation rate; the predicted temperature variation rate represents a predicted variation rate of the temperature of the power module when the working state of the heat dissipation module is changed, in a case where the heat dissipation module is in a good state and the power module maintains a specified power value; Correspondingly, the health state of the heat dissipation module is determined according to a temperature value variation rate of the multiple target measured temperature values, including: In a case where an absolute value of a difference between the temperature value variation rate and the predicted temperature variation rate is less than a specified rate variation threshold, it is determined that the heat dissipation module is in a good state; Or, In a case where an absolute value of a difference between the temperature value variation rate and the predicted temperature variation rate is greater than a specified rate variation threshold, it is determined that the heat dissipation module is in an abnormal state.

12. The power conversion device of claim 1, wherein, The specified operating state indicators include temperatures of the power modules; The multiple indicator values of the specified operating state indicators of the power unit are obtained, including: obtaining a first measured temperature value of a temperature of the power module before a working state of the heat dissipation module is changed, and a second measured temperature value of the temperature of the power module after the working state of the heat dissipation module is changed; Correspondingly, based on the multiple indicator values of the specified operating state indicators, the health status of the heat dissipation module is determined, including: according to the first measured temperature value, the second measured temperature value, and the power of the power module, the measured thermal resistance change amount of the heat conduction path corresponding to the power module before and after the working state of the heat dissipation module changes is inferred; the health status of the heat dissipation module is determined through the measured thermal resistance change amount.

13. The power conversion device of claim 12, wherein, According to the first measured temperature value, the second measured temperature value, and the power of the power module, the measured thermal resistance change amount of the heat conduction path corresponding to the power module before and after the working state of the heat dissipation module changes is inferred, including: According to the power of the power module, a power loss value is calculated; The absolute value of the measured temperature change amount between the first measured temperature value and the second measured temperature value is determined as the ratio of the power loss value.

14. The power conversion device of claim 13, wherein, During the process of acquiring the indicator values of the specified operating state indicators of the power unit multiple times, the power of the power module changes; the specified operating state indicators also include the power of the power module; Correspondingly, acquiring the indicator values of the specified operating state indicators of the power unit multiple times also includes: acquiring a first measured power value of the power of the power module before the working state of the heat dissipation module changes, and a second measured power value of the power of the power module after the working state of the heat dissipation module changes; Correspondingly, calculating the power loss value according to the power of the power module includes: determining the power loss value through the first measured power value and the second measured power value.

15. The power conversion device of claim 14, wherein, The power loss value is determined through the first measured power value and the second measured power value, including: According to the target measured power value with a larger value among the first measured power value and the second measured power value, the power loss value is calculated; or, According to the central tendency measure of the first measured power value and the second measured power value, the power loss value is calculated.

16. A power conversion device according to any one of claims 12 to 15, characterised in that, The power conversion device has a predicted thermal resistance change amount; the predicted thermal resistance change amount represents the predicted change amount of the thermal resistance of the heat conduction path corresponding to the power module when the working state of the heat dissipation module changes under the condition that the heat dissipation module is in good condition; The health status of the heat dissipation module is determined through the measured thermal resistance change amount, including: In the case where the absolute value of the difference between the measured thermal resistance change amount and the predicted thermal resistance change amount is less than a specified thermal resistance change threshold, it is determined that the heat dissipation module is in good condition; Or, In the case where the absolute value of the difference between the measured thermal resistance change amount and the predictive thermal resistance change amount is greater than a specified thermal resistance change threshold, it is determined that the heat dissipation module is in an abnormal state.

17. The power conversion device of claim 1, wherein, The heat dissipation module includes a cooling assembly and a flow guide structure; the cooling assembly is used to drive the cooling medium to pass through the heat dissipation surface of the power module under the guidance of the flow guide structure to dissipate heat from the power module; before and after the working state of the heat dissipation module changes, the cooling power of the cooling assembly is not the same; The health state of the heat dissipation module is determined based on the multiple values of the specified operating state indicators, including: the health state of the flow guide structure is determined based on the multiple values of the specified operating state indicators.

18. The power conversion device of claim 17, wherein, The number of the power modules is multiple; the cooling assembly drives the cooling medium to pass through different flow paths to dissipate heat for different power modules; The specified operating state indicators include power module state indicators of each power module; accordingly, the health state of the flow guide structure is determined based on the multiple values of the specified operating states indicators, including: The health state of at least part of the flow guide structure through which the flow path corresponding to the power module passes is determined according to the multiple values of the power module state indicators of each power module in the at least two power modules.

19. The power conversion device of any one of claims 1 to 18, wherein, The heat dissipation module dissipates heat for the power modules through an air cooling mechanism, or the heat dissipation module dissipates heat for the power modules through a liquid cooling mechanism.

20. The power conversion device of any one of claims 1 to 19, wherein, The controller is further configured to reduce the upper limit of the output power of the power conversion device and / or reduce the temperature protection threshold of the power conversion device in the case of identifying that the heat dissipation module has heat dissipation abnormity.

21. A method of determining a health state of a heat dissipation module of a power conversion device, the method comprising: The power conversion device includes a power unit; the power unit includes power modules and a heat dissipation module; the heat dissipation module is used to dissipate heat for the power modules; the method includes: Multiple values of specified operating state indicators of the power unit are acquired; wherein, during the process of acquiring the multiple values of the specified operating state indicators of the power unit, the working state of the heat dissipation module changes, and the heat dissipation capacity of the heat dissipation module is different before and after the change of the working state; The health state of the heat dissipation module is determined based on the multiple values of the specified operation state indicators.

22. The health state determination method according to claim 21, characterized by, The health state of the heat dissipation module is determined based on the multiple values of the specified operational state indicators, including: The health state of the heat dissipation module is determined through the value change characteristics of the multiple values of the specified operating state indicators.

23. The health state determination method according to claim 22, characterized by, The specified operating state indicators include the temperature of the power module; The multiple values of the specified operating state indicators of the power unit are acquired, including: during the process that the power module maintains a specified power value, a first measured temperature value of the temperature of the power module before the change of the working state of the heat dissipation module is acquired, and a second measured temperature value of the temperature of the power module after the change of the working state of the heat dissipation module is acquired; Accordingly, the health state of the heat dissipation module is determined through the value change characteristics of the multiple values corresponding to the specified operating state indicators, including: the health state of the heat dissipation module is determined based on the measured temperature change between the first measured temperature value and the second measured temperature value.

24. The health state determination method according to claim 23, characterized by, The power module corresponds to a predicted temperature change; the predicted temperature change represents the temperature change of the power module predicted to be generated when the working state of the heat dissipation module changes, under the condition that the heat dissipation module is in good condition and the power module maintains a specified power value. Correspondingly, determining the health status of the heat dissipation module based on a measured temperature variation between the first measured temperature value and the second measured temperature value comprises: in the case where the absolute value of the difference between the measured temperature variation and the predicted temperature variation is less than a specified temperature variation threshold, it is determined that the heat dissipation module is in a good state; or in the case where the absolute value of the difference between the measured temperature variation and the predicted temperature variation is greater than the specified temperature variation threshold, it is determined that the heat dissipation module is in an abnormal state.

25. The health state determination method of claim 22, wherein, During the process of acquiring the index value of the specified operating state indicator of the power unit multiple times, the power of the power module is controlled to be adjusted to maintain the temperature of the power module at a specified temperature value in response to a change in the working state of the heat dissipation module; The specified operating state indicator includes the power of the power module. Correspondingly, acquiring the index value of the specified operating state indicator of the power unit multiple times comprises: acquiring a first measured power value of the power of the power module before the change in the working state of the heat dissipation module, and a second measured power value of the power of the power module after the change in the working state of the heat dissipation module; Correspondingly, determining the health status of the heat dissipation module through the value variation characteristics of the multiple index values of the specified operating state indicator comprises: determining the health status of the heat dissipation module based on a measured power variation between the first measured power value and the second measured power value.

26. The health state determination method according to claim 25, characterized by, The power module corresponds to a predicted power variation. The predicted power variation represents the predicted adjusted power of the power module when the working state of the heat dissipation module changes, under the condition that the heat dissipation module is in a good state and the temperature of the power module is maintained at the specified temperature value; Correspondingly, determining the health status of the heat dissipation module based on a measured power variation between the first and second measured power values comprises: in the case where the absolute value of the difference between the measured power variation and the predicted power variation is less than a specified power variation threshold, it is determined that the heat dissipation module is in a good state; or, in the case where the absolute value of the difference between the measured power variation and the predicted power change is greater than the specified power variation threshold, it is determined that the heat dissipation module is in an abnormal state.

27. The health state determination method of claim 22, wherein, The heat dissipation module has a specified heat dissipation parameter; a change in the specified heat dissipation parameter causes a change in the working state of the heat dissipation module; During the process of acquiring the index value of the specified operating state indicator of the power unit multiple time, the power of the power module is controlled to be changed, and in response to the change in the power of the power module, the specified heat dissipation parameter of the heat dissipation module is controlled to be changed to maintain the temperature of the power module at a specified temperature value; The specified operating state indicator includes a specified heat dissipation parameter of the heat dissipation module; accordingly, the multiple indicator values of the specified operating state indicator of the power unit are obtained, including: obtaining a first heat dissipation parameter value of the specified heat dissipation parameter before the working state of the heat dissipation module changes, and a second heat dissipation parameter value of the specified heat dissipation parameter after the working state of the heat dissipation module changes; Accordingly, the health state of the heat dissipation module is determined based on the heat dissipation parameter change amount between the first heat dissipation parameter value and the second heat dissipation parameter value.

28. The health state determination method according to claim 27, wherein, The heat dissipation module corresponds to a predicted parameter change amount; the predicted heat dissipation parameter change amount represents the predicted heat dissipation parameter change amount of the heat dissipation module when the power of the power module changes, under the condition that the heat dissipation module is in a good state and the temperature of the power module is maintained at the specified temperature value; Accordingly, the health state of the heat dissipation module is determined based on the heat dissipation parameter change amount between the first heat dissipation parameter value and the second heat dissipation parameter value. In the case where the absolute value of the difference between the heat dissipation parameter change amount and the predicted parameter change amount is less than a specified parameter change threshold, it is determined that the heat dissipation module is in a good state; Or, In the case where the absolute value of the difference between the heat dissipation parameter change amount and the predicted parameter change amount is greater than a specified parameter change threshold, it is determined that the heat dissipation module is in an abnormal state.

29. The health state determination method of claim 22, wherein, The operating state indicator includes the temperature of the power module; the multiple indicator values are multiple measured temperature values of the power module; Accordingly, the health state of the heat dissipation module is determined based on the temperature value change rate of the multiple measured temperature values.

30. The health state determination method of claim 29, wherein The multiple indicator values of the specified operating state indicator of the power unit are obtained, including: obtaining, during the process in which the power module maintains a specified power value, a first measured temperature value of the temperature of the power module before the working state of the heat dissipation module changes, and a second measured temperature value of the temperature of the power module after the working state of the heat dissipation module changes; Accordingly, the health state of a heat dissipation module is determined based on the temperature value change rate of the multiple measured temperature values, including: calculating the ratio of the measured temperature change amount between the first measured temperature value and the second measured temperature value to the temperature change time length as the temperature value change rate; wherein the temperature change time length is the time length required for the working state of the heat dissipation module to change and the temperature of the power module to change to the second measured temperature value.

31. The health state determination method according to claim 29, wherein, The temperature value change rate corresponds to a predicted temperature change rate; the predicted temperature change rate represents a predicted change rate of the temperature of the power module when the working state of the heat dissipation module changes, in a case that the heat dissipation module is in a good state and the power module maintains a specified power value operation; Correspondingly, determining the health state of the heat dissipation module according to the temperature value change rates of the plurality of target measured temperature values comprises: In a case that an absolute value of a difference between the temperature value change rate and the predicted temperature change rate is less than a specified rate change threshold, it is determined that the heat dissipation module is in a good state; Or, In a case that the absolute value of the difference between the temperature value change rate and the predicted temperature change rate is greater than the specified rate change threshold, it is determined that the heat dissipation module is in an abnormal state.

32. The health state determination method of claim 21, wherein, The specified operating state indicator includes the temperature of the power module; Obtaining a plurality of indicator values of the specified operating state indicator of the power unit comprises: obtaining a first measured temperature value of the temperature of the power module before the working state of the heat dissipation module changes, and a second measured temperature value of the temperature of the power module after the working state of the heat dissipation module changes; Correspondingly, determining the health state of the heat dissipation module based on a plurality of indicator values corresponding to the specified operating state indicator comprises: inferring a measured thermal resistance change amount of the power conversion device before and after the working state of the heat dissipation module changes according to the first measured temperature value, the second measured temperature value and the power of the power module; and determining the health state of the heat dissipation module through the measured thermal resistance change amount.

33. The health state determination method of claim 32, wherein, Inferring a measured thermal resistance change amount of the power conversion device before and after the working state of the heat dissipating module changes according to the first measured temperature value, the second measured temperature value and the power of power module comprises: Calculating a power loss value according to the power of the power module; The absolute value of the measured temperature change amount between the first measured temperature value and the second measured temperature value is determined as the ratio of the power loss value.

34. The health state determination method according to claim 33, wherein, During the process of obtaining a plurality of indicator values of the specified operating state indicator of the power unit, the power of the power module changes; The specified operating state indicator further includes the power of the power module; correspondingly, obtaining a plurality of indicator values of the specified operating state indicator of the power unit further comprises: obtaining a first measured power value of the power of the power module before the working state of the heat dissipation module changes, and a second power value of the power of the power module after the working state of the heat dissipation module changes; Correspondingly calculating a power loss value according to the power of the power module comprises: determining the power loss value through the first measured power value and the second measured power value.

35. The health state determination method of claim 34, wherein, Determining the power loss value through the first measured power value and the second measured power value comprises: Calculating the power loss value according to the target measured power value with a larger value between the first measured power value and the second measured power value; or, The power loss value is calculated according to a central tendency measure of the first measured power value and the second measured power value.

36. The health state determination method according to any one of claims 32 to 35, characterized by, The power conversion device has a predicted thermal resistance variation amount, which represents a predicted variation amount of the thermal resistance of the power conversion device when the working state of the heat dissipation module changes under the condition that the heat dissipation module is in a good state. The health state of the heat dissipation module is determined by the measured thermal resistance variation amount, including: In the case that the absolute value of the difference between the measured thermal resistance variation amount and the predicted thermal resistance variation amount is less than a specified thermal resistance variation threshold, it is determined that the heat dissipation module is in a good state. Or, In the case that the absolute value of the difference between the measured thermal resistance variation amount and the predicted thermal resistance variation amount is greater than a specified thermal resistance variation threshold, it is determined that the heat dissipation module is in an abnormal state.

37. The health state determination method of claim 21, wherein, The heat dissipation module includes a cooling assembly and a flow guide structure; the cooling assembly is used to drive a cooling medium to pass through the heat dissipation surface of the power module under the guidance of the flow guide structure to dissipate heat from the power module; the cooling power of the cooling assembly is different before and after the working state of the heat dissipation module changes; The health state of the heat dissipation module is determined based on the multiple index values corresponding to the specified operating state indicators, including determining the health state of the flow guide structure based on the multiple index values corresponding to the specified operating state indicators.

38. The health state determination method of claim 37, wherein, The number of power modules is multiple; the cooling assembly drives the cooling medium to pass through different flow paths to dissipate heat from different power modules; The specified operating state indicators include power module state indicators of each power module; accordingly, the health state of the flow guide structure is determined based on the multiple index values corresponding to the specified operating state indicators, including: The health state of at least part of the flow guide structure through which the flow path corresponding to the power module passes is determined according to the multiple index values of the power module state indicators of each power module in the at least two power modules.

39. The health condition determining method according to any one of claims 21 to 38, characterized by, The heat dissipation module dissipates heat from the power module through an air cooling mechanism, or the heat dissipation module dissipates heat from the power module through a liquid cooling mechanism.

40. The health condition determining method according to any one of claims 21 to 39, characterized by, Further comprising: In the case that it is determined that the heat dissipation module has heat dissipation abnormalities, the output power upper limit of the power conversion device is reduced, and / or the temperature protection threshold of the power conversion device is reduced.

41. An energy system, comprising: Including: The power conversion device according to any one of claims 1 to 20.

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