Thermal management method, system, frequency converter and variable frequency control device

Abstract

The application provides a heat management method, system, frequency converter and frequency control device. In the heat management system, the predicted junction temperature of each power unit and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature are determined; when the predicted heat capacity margin and the predicted junction temperature of each power unit meet the preset condition, the heat dissipation flow path reconstruction is performed. When the application is applied to the frequency converter, the active redistribution of heat among the power units is realized through the pipeline topology reconstruction, the accurate early triggering of the heat dissipation flow path is realized by using the double condition judgment of the predicted junction temperature and the predicted heat capacity margin, the heat management level and the operation reliability of the frequency converter are effectively improved, and the use experience of the user is improved. The electronic core industry in the new generation information technology industry in the strategic emerging industry covers the related technical field of power semiconductor devices. The heat dissipation control of the power unit of the frequency converter belongs to the power electronic device heat management technology in the electronic core industry.

Description

Technical Field

[0001] This application relates to the field of frequency converter technology, and in particular to a thermal management method, system, frequency converter, and frequency conversion control device. Background Technology

[0002] In related technologies, the heat dissipation management of power units in frequency converters directly affects the operational reliability, output capacity, and service life of the equipment. With the continuous increase in power density, the heat generated by power units is increasing dramatically, and heat dissipation is increasingly becoming a core bottleneck restricting system reliability. If the heat generated by the power unit during operation cannot be dissipated effectively and in a timely manner, it will lead to an increase in junction temperature, which in turn can cause equipment failure, unplanned shutdowns, or even thermal runaway. Summary of the Invention

[0003] In view of this, in order to solve the technical problem that if the heat generated by the power unit during operation cannot be dissipated in a timely and effective manner, it will lead to an increase in junction temperature, which in turn will cause equipment failure, unplanned shutdown or even thermal runaway, this application provides a thermal management method, system, frequency converter and frequency conversion control equipment.

[0004] According to a first aspect of the embodiments of this application, a thermal management method is provided, the thermal management method being applied to a thermal management system, the thermal management system including a system inlet pipeline, a system return pipeline, and at least two power units; The liquid inlet of the first power unit of the thermal management system is connected to the liquid inlet of the system through a first liquid inlet pipe, and the liquid outlet of the first power unit is connected to the liquid return pipe of the system through a first liquid outlet pipe. The liquid inlet of the second power unit of the thermal management system is connected to the liquid inlet of the system through a second liquid inlet pipe, and the liquid outlet of the second power unit is connected to the liquid return pipe of the system through a second liquid outlet pipe. The thermal management system further includes a first bypass pipe and a second bypass pipe. The first bypass pipe is used to connect the liquid inlet of the first power unit to the liquid outlet of the second power unit, and the second bypass pipe is used to connect the liquid inlet of the second power unit to the liquid outlet of the first power unit. The thermal management method includes: Based on the operating data of the first power unit and the second power unit, the predicted junction temperature of the first power unit and the second power unit is determined, as well as the predicted thermal capacity margin of the power unit corresponding to the lower predicted junction temperature. When the predicted heat capacity margin and the predicted junction temperatures of the first power unit and the second power unit meet the conditions, a heat dissipation flow path reconfiguration is performed; wherein, the heat dissipation flow path reconfiguration includes controlling the bypass pipe connected to the liquid outlet of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, and controlling another bypass pipe to be in a cut-off state, controlling the liquid outlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a cut-off state, controlling the liquid inlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, controlling the liquid inlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a cut-off state, and controlling the liquid outlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a conducting state.

[0005] In one alternative implementation, The operating data includes the outlet temperature and load current of the corresponding power unit. The step of determining the predicted junction temperature of the first power unit and the second power unit, and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature, based on the operating data of the first power unit and the second power unit, includes: The operating data is processed based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin.

[0006] In one alternative implementation, The process of processing the operating data based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin, includes: Based on the parameters corresponding to the thermal resistance-capacitance equivalent model and the discretization of the sampling period of the operating data, the state transition matrix and the input matrix are obtained. Based on the state transition matrix, input matrix, and Kalman filter algorithm, prediction and update processing are performed in each sampling period to obtain the predicted junction temperatures of the first power unit and the second power unit.

[0007] In one alternative implementation, The process of processing the operating data based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin, includes: The predicted heat capacity margin is determined based on the predicted radiator temperature of the power unit corresponding to the lower predicted junction temperature and the predicted junction temperature; wherein the predicted radiator temperature is obtained by performing prediction and update processing in each sampling period based on the state transition matrix, the input matrix and the Kalman filter algorithm.

[0008] In one alternative implementation, The determination of the predicted thermal margin based on the predicted radiator temperature of the power unit corresponding to the lower predicted junction temperature and the predicted junction temperature includes: Based on the predicted junction temperature and the corresponding junction temperature threshold and junction heat capacity, the heat absorption capacity value is determined by the junction temperature margin. Based on the predicted temperature of the radiator and the corresponding radiator temperature threshold and radiator heat capacity, the remaining heat absorption capacity of the radiator is determined. The additional heat dissipation is determined based on the current speed percentage of the cooling fan of the power unit corresponding to the lower predicted junction temperature, the coolant flow rate percentage of the radiator, and the preset duration after the heat dissipation flow path reconstruction. The minimum value among the junction temperature margin converted heat absorption capacity, the remaining heat absorption capacity of the radiator, and the additional heat dissipation is determined as the predicted heat capacity margin.

[0009] In one alternative implementation, The thermal management method includes: If it is determined that the preheating heat capacity margin is greater than or equal to the heat capacity margin threshold, and the higher preheating junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is less than the corresponding junction temperature threshold, then it is determined that the predicted heat capacity margin and the predicted junction temperatures of the first power unit and the second power unit meet the conditions.

[0010] In one alternative implementation, The thermal management method includes: After the heat dissipation flow path is reconstructed, after the duration reaches the preset duration, the first bypass pipe and the second bypass pipe are controlled to be cut off, and the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe are controlled to be in the conducting state.

[0011] According to a second aspect of the embodiments of this application, a thermal management system is provided, the thermal management system including a system inlet pipeline, a system return pipeline and at least two power units; The liquid inlet of the first power unit of the thermal management system is connected to the liquid inlet of the system through a first liquid inlet pipe, and the liquid outlet of the first power unit is connected to the liquid return pipe of the system through a first liquid outlet pipe. The liquid inlet of the second power unit of the thermal management system is connected to the liquid inlet of the system through a second liquid inlet pipe, and the liquid outlet of the second power unit is connected to the liquid return pipe of the system through a second liquid outlet pipe. The thermal management system further includes a first bypass pipe and a second bypass pipe. The first bypass pipe is used to connect the liquid inlet of the first power unit to the liquid outlet of the second power unit, and the second bypass pipe is used to connect the liquid inlet of the second power unit to the liquid outlet of the first power unit. The thermal management system further includes a controller configured to implement the thermal management method as described in any one of claims 1-7.

[0012] In one alternative implementation, The thermal management system includes a first inlet three-way valve, wherein the first valve port of the first inlet three-way valve is connected to the first inlet pipeline, the second valve port of the first inlet three-way valve is connected to the inlet of the first power unit, and the third valve port of the first inlet three-way valve is connected to the outlet of the first bypass pipeline; and / or, The thermal management system includes a second inlet three-way valve, wherein the first valve port of the second inlet three-way valve is connected to the second inlet pipeline, the second valve port of the second inlet three-way valve is connected to the inlet of the second power unit, and the third valve port of the second inlet three-way valve is connected to the outlet of the second bypass pipeline; and / or, The thermal management system includes a first liquid outlet three-way valve, wherein the first valve port of the first liquid outlet three-way valve is connected to the first liquid outlet pipeline, the second valve port of the first liquid outlet three-way valve is connected to the liquid outlet of the first power unit, and the third valve port of the first liquid outlet three-way valve is connected to the liquid inlet of the second bypass pipeline; and / or, The thermal management system includes a second liquid outlet three-way valve, the first valve port of the second liquid outlet three-way valve is connected to the second liquid outlet pipeline, the second valve port of the second liquid outlet three-way valve is connected to the liquid outlet of the second power unit, and the third valve port of the second liquid outlet three-way valve is connected to the liquid inlet of the first bypass pipeline.

[0013] In one alternative implementation, The thermal management system includes a bidirectional solenoid valve group, wherein the first solenoid valve of the bidirectional solenoid valve group is used to control the opening or closing of the first bypass pipeline, and the second solenoid valve is used to control the opening or closing of the second bypass pipeline.

[0014] According to a third aspect of the embodiments of this application, a frequency converter is provided, the frequency converter including a thermal management system as described in any of the second aspects.

[0015] According to a fourth aspect of the embodiments of this application, a frequency converter control device is provided, the frequency converter control device including the frequency converter as described in the third aspect.

[0016] The technical solutions provided by the embodiments of this application may include the following beneficial effects: In this application, the thermal management system includes a system inlet pipe, a system return pipe, and at least two power units. In the thermal management system, the predicted junction temperature of each power unit and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature are first determined. When the predicted heat capacity margin and the predicted junction temperature of each power unit meet preset conditions, a heat dissipation flow path reconfiguration is performed—by controlling the liquid outlet pipe of the high-temperature power unit to be cut off and the bypass pipe to be opened, and the liquid inlet pipe of the low-temperature power unit to be cut off and the liquid outlet pipe to be opened, the cooling medium, after absorbing heat in the high-temperature power unit, does not flow directly back to the system return pipe, but flows into the low-temperature power unit through the bypass pipe. The excess heat dissipation capacity of the low-temperature power unit's radiator is used to perform secondary cooling on the high-temperature medium before it flows back to the system return pipe. In this application, using the predicted junction temperature and preheating heat capacity margin of the power unit as the decision basis for thermal path reconfiguration, the overheating risk can be predicted before the junction temperature actually reaches the dangerous threshold, and the heat dissipation flow path reconfiguration action can be triggered in advance. Furthermore, this application connects the outlet of the high-temperature power unit with the inlet of the low-temperature power unit by setting a bypass pipe in the pipeline and controlling its on / off state. This allows the cooling medium of the high-temperature power unit to be further cooled as it flows through the low-temperature power unit, achieving directional heat transfer between units. This fully utilizes the idle cooling capacity of the low-temperature power units within the system, overcoming the limitations of independent heat dissipation in related technologies, effectively eliminating local hot spots, and improving the overall heat dissipation efficiency of the system. In other words, when this application is applied to a frequency converter, it achieves active heat redistribution between power units through pipeline topology reconfiguration, and uses a dual-condition judgment based on predicted junction temperature and predicted heat capacity margin to achieve precise early triggering of the heat dissipation flow path, effectively improving the thermal management level and operational reliability of the frequency converter, and enhancing the user experience.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a schematic diagram of a thermal management system according to an exemplary embodiment.

[0022] Figure 2 This is a schematic diagram illustrating a thermal management method according to an exemplary embodiment.

[0023] Figure 3 This is a schematic diagram illustrating a thermal management method according to another exemplary embodiment.

[0024] Figure 4 This is a schematic diagram illustrating a thermal management method according to another exemplary embodiment.

[0025] Figure 5 This is a block diagram illustrating a closed-loop thermal management architecture according to an exemplary embodiment. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various aspects of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0028] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0031] In order to address the technical problem in the prior art that if the heat generated by the power unit during operation cannot be dissipated in a timely and effective manner, it will lead to an increase in junction temperature, which in turn will cause equipment failure, unplanned shutdown, or even thermal runaway, this application provides a thermal management method, system, frequency converter, and frequency conversion control equipment.

[0032] In this application, the thermal management system includes a system inlet pipe, a system return pipe, and at least two power units. The thermal management system first determines the predicted junction temperature of each power unit and the predicted thermal capacity margin of the power unit corresponding to the lower predicted junction temperature. When the predicted thermal capacity margin and the predicted junction temperature of each power unit meet preset conditions, a heat dissipation flow path reconfiguration is performed—by controlling the shut-off of the outlet pipe and the opening of the bypass pipe of the high-temperature power unit, and the shut-off of the inlet pipe and the opening of the outlet pipe of the low-temperature power unit, the cooling medium, after absorbing heat in the high-temperature power unit, does not directly return to the system return pipe, but flows into the low-temperature power unit through the bypass pipe. The excess heat dissipation capacity of the low-temperature power unit's radiator is used to perform secondary cooling of the high-temperature medium before it returns to the system return pipe. In this application, using the predicted junction temperature and preheating thermal capacity margin of the power unit as the decision-making basis for thermal path reconfiguration allows for the prediction of overheating risks before the junction temperature actually reaches the dangerous threshold, triggering the heat dissipation flow path reconfiguration action in advance. Furthermore, this application connects the outlet of the high-temperature power unit with the inlet of the low-temperature power unit by setting a bypass pipe in the pipeline and controlling its on / off state. This allows the cooling medium of the high-temperature power unit to be further cooled as it flows through the low-temperature power unit, achieving directional heat transfer between units. This fully utilizes the idle cooling capacity of the low-temperature power units within the system, overcoming the limitations of independent heat dissipation in related technologies, effectively eliminating local hot spots, and improving the overall heat dissipation efficiency of the system. In other words, when this application is applied to a frequency converter, it achieves active heat redistribution between power units through pipeline topology reconfiguration, and uses a dual-condition judgment based on predicted junction temperature and predicted heat capacity margin to achieve precise early triggering of the heat dissipation flow path, effectively improving the thermal management level and operational reliability of the frequency converter, and enhancing the user experience.

[0033] In one exemplary embodiment, reference Figure 1 , Figure 2 and Figure 5 As shown, a thermal management system and a thermal management method are provided, as well as a frequency converter equipped with the thermal management system. In this embodiment, the thermal management system includes a system inlet pipe 4, a system return pipe 5, and at least two power units.

[0034] Each power unit may include a power device and a heat sink. The power device (such as an IGBT module) is the source of heat, generating a large amount of heat during operation due to conduction and switching losses. Its junction temperature directly determines the safe operating boundary of the power device. The heat sink is installed below, to the side, or in other locations, without limitation. A thermally conductive medium may be coated between the contact surface between the heat sink and the power device to conduct the heat generated by the power device to the heat sink substrate. The heat sink has a coolant flow path inside, in which a cooling medium (such as water or an aqueous ethylene glycol solution) flows, carrying away the heat absorbed by the heat sink substrate through convection heat transfer. Each power unit has an independent inlet and outlet. The inlet is connected to the inlet of the coolant flow path inside the heat sink, and the outlet is connected to the outlet of the flow path, for connection to the coolant circulation loop.

[0035] Among them, the system inlet pipe 4 is the common liquid supply channel for the cooling medium to flow from the main circulation pump 8 or the external cold source into each power unit, and the system return pipe 5 is the common liquid return channel for the cooling medium to flow back to the main circulation pump 8 or the external cold source after the cooling medium absorbs heat and rises in temperature through each power unit.

[0036] In this embodiment, the two power units in the thermal management system can be referred to as the first power unit 11 and the second power unit 21, respectively. The first power unit 11 and the second power unit 21 can be adjacent power units or non-adjacent power units, and there is no limitation on this. When the two are adjacent, the length of the relevant pipelines can be shortened, making the installation of the relevant pipelines easier and reducing costs.

[0037] The first power unit 11 has its inlet connected to the system's inlet pipe 4 via a first inlet pipe, and its outlet connected to the system's return pipe 5 via a first outlet pipe, thus achieving a conventional heat dissipation flow path for the cooling medium corresponding to the first power unit 11. Similarly, the second power unit 21 has its inlet connected to the system's inlet pipe 4 via a second inlet pipe, and its outlet connected to the system's return pipe 5 via a second outlet pipe, thus achieving a conventional heat dissipation flow path for the cooling medium corresponding to the second power unit 21.

[0038] The thermal management system further includes a first bypass pipe 91 and a second bypass pipe 92.

[0039] The first bypass pipe 91 is used to connect the liquid inlet of the first power unit 11 and the liquid outlet of the second power unit 21. For example, the liquid inlet of the first bypass pipe 91 is connected to the liquid outlet of the second power unit 21, and the liquid outlet of the first bypass pipe 91 is connected to the liquid inlet of the first power unit 11.

[0040] The second bypass pipe 92 is used to connect the liquid inlet of the second power unit 21 with the liquid outlet of the first power unit 11. For example, the liquid inlet of the second bypass pipe 92 is connected to the liquid outlet of the first power unit 11, and the liquid outlet of the second bypass pipe 92 is connected to the liquid inlet of the second power unit 21.

[0041] The first bypass pipe 91 and the second bypass pipe 92 are cross-connected, meaning that the liquid inlet of each power unit can not only be connected to the system liquid inlet pipe 4, but also to the liquid outlet of another power unit through a corresponding bypass pipe. This cross-connection structure allows the liquid outlet of any power unit to be directly guided to the liquid inlet of another power unit through the corresponding bypass pipe, thereby realizing the series connection of the coolant flow paths of the two power unit radiators.

[0042] It should be noted that the term "connected" in this embodiment can refer to direct connection or indirect connection, and is not limited in this respect. For example, "connected" between A and B can mean that A is directly connected to B, or it can mean that A is connected to B through another device C, and is not limited in this respect.

[0043] In this embodiment, the thermal management method includes: S110. Based on the operating data of the first power unit 11 and the second power unit 21, determine the predicted junction temperature of the first power unit 11 and the second power unit 21, and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature. S120. If the predicted heat capacity margin and the predicted junction temperature of the first power unit 11 and the second power unit 21 meet the conditions, the heat dissipation flow path is reconstructed.

[0044] In step S110, the operating data may include the outlet temperature and load current of the corresponding power unit. In this embodiment, the thermal management system may include two types of sensors to continuously collect operating data of each power unit at a set sampling frequency (e.g., 5kHz). The temperature sensor may be installed on the outlet pipe of the radiator of each power unit, or it may be located at the outlet of the radiator; the specific location is not limited. It is used to monitor the temperature of the coolant discharged from the power unit and is recorded as the outlet temperature. The current sensor may be installed in the output circuit of each power unit to collect the load current I(t) (in A) flowing through the power unit in real time, which is used for subsequent calculations of parameters such as power loss. The load current is a fundamental parameter for calculating power loss—the larger the load current, the greater the power loss and the more severe the heat generation.

[0045] It should be noted that the temperature sensor can be a platinum resistance temperature sensor (such as a PT100 temperature sensor), an NTC thermistor, or a fiber optic temperature sensor, etc., without limitation, as long as it can monitor the outlet liquid temperature. The current sensor can be a Hall current sensor (a current detection device based on the Hall effect principle), a fluxgate current sensor, or a fiber optic current sensor, etc., without limitation, as long as it can monitor the load current.

[0046] In this embodiment, the thermal management system may further include an intelligent decision control unit, which can be based on a processor (e.g., a DSP microprocessor) and uses a thermal resistance-capacitance equivalent model (RC equivalent model, which can equate the heat conduction path from the power device to the cooling medium to a series network of thermal resistance and thermal capacity) and a Kalman filter algorithm to fuse real-time monitored operating data such as outlet temperature and load current to predict the junction temperature and thermal capacity margin of the power unit. That is, this step can process the operating data based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit 11 and the second power unit 21, as well as the predicted thermal capacity margin.

[0047] It should be noted that the thermal resistance-capacitance equivalent model equates the heat conduction path from the power device to the cooling medium as a series network of thermal resistance and thermal capacity—thermal resistance describes the magnitude of the resistance during heat transfer, while thermal capacity describes the heat storage capacity. This model is used to describe the thermal characteristics of power devices and forms the basis for predictions in the Kalman filter algorithm.

[0048] The Kalman filter algorithm is an optimal state estimation algorithm used to suppress measurement noise and model errors, achieving optimal estimation of states that cannot be directly measured (such as junction temperature). This algorithm integrates the physical predictions provided by the thermal resistance-capacitance equivalent model with the heatsink temperature measured by a temperature sensor, outputting an optimal estimate of the junction temperature. Based on this optimal estimate, it recursively predicts the junction temperature at future times, thus obtaining the predicted junction temperature.

[0049] For example, the outlet temperature and load current of the first power unit 11 can be processed based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm (other data that can be used in the processing are not limited here), thereby obtaining the predicted junction temperature of the first power unit 11, which can be denoted as the first predicted junction temperature. Similarly, the outlet temperature and load current of the second power unit 21 can be processed based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm (other data that can be used in the processing are not limited here), thereby obtaining the predicted junction temperature of the second power unit 21, which can be denoted as the second predicted junction temperature. If the first predicted junction temperature is greater than the second predicted junction temperature, the second predicted junction temperature can be determined as the lower predicted junction temperature, and then the predicted thermal capacity margin of the second power unit 21 can be determined. If the second predicted junction temperature is greater than the first predicted junction temperature, the first predicted junction temperature can be determined as the lower predicted junction temperature, and then the predicted thermal capacity margin of the first power unit 11 can be determined.

[0050] It's important to note that junction temperature is the highest operating temperature of the PN junction inside a power device. It's the most critical indicator for assessing the health and safety margin of a power device, directly determining its output capability and lifespan. Predicted junction temperature reflects the temperature rise trend of each power unit over a future period, used to identify potential overheating risks in advance. Predicted thermal margin reflects the upper limit of the additional heat absorption capacity of a power unit corresponding to a lower predicted junction temperature under current heat dissipation conditions, used to determine whether the power unit can handle additional heat loads.

[0051] In step S120, the intelligent decision control unit of the thermal management system can make a comprehensive judgment on the predicted heat capacity margin and the predicted junction temperatures of the first power unit 11 and the second power unit 21. When the predicted junction temperature of the high-temperature power unit is at risk of overheating and the predicted heat capacity margin of the low-temperature power unit is sufficient to handle the additional heat, the heat dissipation flow path can be reconfigured to avoid unnecessary control processing and to prevent the low-temperature power unit from overheating.

[0052] If it is determined that the predicted thermal capacity margin is greater than or equal to the thermal capacity margin threshold, and the higher predicted junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is less than the corresponding junction temperature threshold, then it is determined that the predicted thermal capacity margin and the predicted junction temperatures of the first power unit 11 and the second power unit 21 meet the conditions.

[0053] The thermal margin threshold is the minimum standard for determining whether a low-temperature power unit has sufficient excess cooling capacity. Only when the predicted thermal margin of the power unit reaches or exceeds this threshold is it considered that the power unit has sufficient safety margin to handle the additional heat load from the high-temperature power unit and will not exceed its junction temperature limit due to handling additional heat. This threshold can be preset based on the power unit's heat capacity, radiator performance, and safety margin requirements; its specific value is not limited. For example, 40% to 60% of the maximum heat absorption capacity corresponding to the junction temperature threshold of the power unit can be determined as the aforementioned thermal margin threshold.

[0054] A predicted junction temperature greater than or equal to the corresponding junction temperature threshold means that the predicted junction temperature of the high-temperature power unit has reached or exceeded the preset junction temperature safety boundary. This indicates that the power unit will face the risk of exceeding the junction temperature limit in the near future, requiring proactive thermal management intervention. This junction temperature threshold can be determined by the specifications and safe operation requirements of the power device, and its specific value is not limited.

[0055] A lower predicted junction temperature than the corresponding junction temperature threshold means that the current predicted junction temperature of the cryogenic power unit is still within a safe range, providing a temperature margin to handle additional heat. This junction temperature threshold can be the same as the high-temperature judgment threshold mentioned above, or it can be set to a different value depending on the specific control strategy and the different specifications of the power unit. For example, a lower threshold can be set to determine whether the cryogenic module is in a "sufficiently cold" state, ensuring that the cryogenic module still has sufficient safety margin after handling additional heat.

[0056] When all three conditions are met simultaneously, the heat dissipation flow path reconfiguration action can be triggered. The comprehensive judgment of the three conditions avoids blindly switching when the heat dissipation of the low-temperature power unit is close to saturation, which could cause the power device to overheat, and also avoids unnecessary control operations when the high-temperature power unit has not yet reached a dangerous state.

[0057] In this step, the heat dissipation flow path reconfiguration may include controlling the bypass pipe connected to the liquid outlet of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, and controlling another bypass pipe to be in a cut-off state, controlling the liquid outlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a cut-off state, controlling the liquid inlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, controlling the liquid inlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a cut-off state, and controlling the liquid outlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a conducting state.

[0058] The control logic for reconfiguring the heat dissipation flow path is as follows, taking the first power unit 11 as a high-temperature power unit (i.e., its predicted junction temperature is relatively high) and the second power unit 21 as a low-temperature power unit (i.e., its predicted junction temperature is relatively low): The system controls the inlet pipe of the second power unit 21 to be in a cut-off state, cutting off the normal channel for the system inlet pipe 4 to supply liquid to the second power unit 21. The system controls the outlet pipe of the first power unit 11 to be in a cut-off state, cutting off the channel for the liquid from the first power unit 11 to flow directly back to the system return pipe 5. The system controls the bypass pipe (i.e., the second bypass pipe 92) connected to the outlet of the first power unit 11 to be in a conductive state, allowing the liquid from the first power unit 11 to flow directly into the inlet of the second power unit 21 through the second bypass pipe 92. The system controls the other bypass pipe (i.e., the first bypass pipe 91) to be in a cut-off state, preventing the bypass path between the inlet of the first power unit 11 and the outlet of the second power unit 21 from interfering with the flow direction of the cooling medium. The system controls the inlet pipe of the first power unit 11 to be in a conductive state, allowing the system inlet pipe 4 to still supply liquid to the first power unit 11. The liquid outlet pipeline of the second power unit 21 is kept in a conductive state so that the liquid outlet of the second power unit 21 can flow back to the system return pipeline 5 normally.

[0059] After the above control measures are implemented, the flow path of the cooling medium is reconfigured: Under normal conditions (parallel cooling mode): the first path consists of the system inlet pipe 4, the radiator of the first power unit 11, and the system return pipe 5; the second path consists of the system inlet pipe 4, the radiator of the second power unit 21, and the system return pipe 5. The two power units are independently connected in parallel for cooling, and the cooling media of each radiator do not interfere with each other.

[0060] After the heat dissipation flow path is reconfigured (series heat dissipation mode): the system inlet pipe 4, the heat sink of the first power unit 11 (the cooling medium absorbs the heat generated by the first power device and heats up), the heat sink of the second power unit 21 (utilizing the excess cooling capacity of the second heat sink to perform secondary cooling of the high-temperature medium), and the system return pipe 5. At this time, the first power unit 11 and the second power unit 21 form a series-connected heat dissipation loop. The liquid outlet of the first power unit 11 no longer flows directly back to the system return pipe 5, but flows into the inlet of the second power unit 21 through the second bypass pipe 92, is further cooled in the heat sink of the second power unit 21, and is then discharged into the system return pipe 5. Since the second power unit 21 is under a low load, its heat sink and cooling medium still have sufficient heat absorption capacity to absorb the remaining heat in the liquid outlet of the first power unit 11 without causing it to overheat. Thus, the excess heat of the first power unit 11 is directed to the second power unit 21 for coordinated dissipation, realizing the active redistribution of heat between power modules.

[0061] In this embodiment, the cross-connected bypass lines ensure that regardless of which power unit becomes the high-temperature power unit and which becomes the low-temperature power unit, the thermal management system can directly guide the liquid flow from the outlet of the high-temperature power unit to the inlet of the low-temperature power unit by opening the corresponding bypass lines and cutting off the corresponding inlet and outlet lines. When the roles of the high-temperature power unit and the low-temperature power unit are interchanged, it is only necessary to symmetrically control the opening of the first bypass line 91 and the cutting off of the second bypass line 92, and switch the state of each inlet and outlet line accordingly, without changing the pipeline hardware structure. For example, when the second power unit 21 is a high-temperature power unit and the first power unit 11 is a low-temperature power unit, the liquid inlet pipe of the first power unit 11 can be controlled to be cut off, the liquid outlet pipe of the second power unit 21 can be controlled to be cut off, the first bypass pipe 91 can be controlled to be open, the second bypass pipe 92 can be controlled to be cut off, the liquid inlet pipe of the second power unit 21 can be controlled to be open, and the liquid outlet pipe of the first power unit 11 can be controlled to be open. This allows the liquid from the second power unit 21 to flow into the first power unit 11 through the first bypass pipe 91 for secondary cooling.

[0062] In related technologies, each power unit is independently connected in parallel for heat dissipation, and the heat dissipation channels are isolated from each other. The heat dissipation capacity of the low-temperature power unit cannot be used to assist in the heat dissipation of the high-temperature power unit. This embodiment uses a cross-connected bypass pipeline to guide the liquid outlet of the high-temperature power unit to the liquid inlet of the low-temperature power unit. This allows the cooling medium to flow sequentially through the heat sinks of both the high-temperature and low-temperature power units, forming a series heat dissipation loop. That is, the liquid outlet of the high-temperature power unit is further cooled in the heat sink of the low-temperature power unit before flowing back to the system. Thus, the excess heat of the high-temperature power unit is directionally "transported" to the low-temperature power unit for coordinated dissipation, overcoming the limitations of the independent heat dissipation architecture of related technologies. This fully utilizes the idle cooling capacity of the low-temperature power unit within the system and effectively eliminates localized hot spots.

[0063] Moreover, this embodiment uses the predicted junction temperature of the power unit, rather than the current measured temperature, as the basis for decision-making. The thermal resistance-capacitance equivalent model equates the heat conduction path from the power device to the cooling medium as a series network of thermal resistance and thermal capacitance, describing the physical laws of heat transfer. The Kalman filter algorithm integrates the predicted value of this physical model with the measured value of the temperature sensor, suppressing measurement noise and model errors, outputting the optimal estimate of the junction temperature, and recursively predicting the junction temperature at future times. As a result, the thermal management system can predict the risk of overheating before the junction temperature actually reaches the dangerous threshold, transforming thermal management from the traditional "post-event response" to "proactive sensing," effectively responding to transient thermal shocks caused by sudden load changes.

[0064] Furthermore, the thermal path reconfiguration in this embodiment is not triggered solely by a single temperature threshold, but simultaneously satisfies three conditions: the predicted thermal margin is greater than or equal to the thermal margin threshold (the low-temperature power unit has sufficient excess cooling capacity), the higher predicted junction temperature is greater than or equal to the corresponding junction temperature threshold (the high-temperature power unit has a clear risk of overheating), and the lower predicted junction temperature is less than the corresponding junction temperature threshold (the low-temperature power unit is within a safe temperature range). This mechanism avoids blindly switching when the low-temperature power unit's own heat dissipation is close to saturation, which could lead to overheating, and also avoids unnecessary control operations when the high-temperature power unit has not yet reached a dangerous state, making the triggering of thermal path reconfiguration more precise and safer.

[0065] In other words, this embodiment achieves active heat redistribution among power modules, advanced sensing of transient thermal shocks, precise triggering of heat dissipation flow path reconstruction, and flexible switching of bidirectional reconstruction through the coordinated cooperation of cross-configured bypass pipelines and predictive control strategies. This effectively improves the thermal management level and operational reliability of the thermal management system composed of multiple heat dissipation units and the frequency converter equipped with the thermal management system, thereby enhancing the user experience.

[0066] In one exemplary embodiment, reference Figure 1 , Figure 3 and Figure 5 As shown, a thermal management system and a thermal management method are provided, as well as a frequency converter equipped with the thermal management system. In this embodiment, the thermal management method may include: S210. Based on the operating data of the first power unit 11 and the second power unit 21, determine the predicted junction temperature of the first power unit 11 and the second power unit 21, and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature. S220. Under the condition that the predicted heat capacity margin and the predicted junction temperature of the first power unit and the second power unit meet the conditions, the heat dissipation flow path is reconstructed. S230. After the heat dissipation flow path reconstruction is completed, and after the duration reaches the preset duration, the thermal management system is controlled to return to the state before the heat dissipation flow path reconstruction.

[0067] It should be noted that steps S210 and S220 of this embodiment can refer to steps S110 and S120 of other embodiments, and will not be repeated here.

[0068] In step S230, the preset duration is the pre-set duration for maintaining the series flow path after the heat dissipation flow path reconstruction. This duration should not be too long to avoid the low-temperature power unit bearing additional heat load for a long time, causing its own temperature to rise continuously or even exceed the temperature limit. However, its specific value is not limited and can be set according to the actual situation. For example, the preset duration can be 5 minutes to 15 minutes, and can be 10 minutes in particular.

[0069] In this step, after the heat dissipation flow path reconstruction is completed and the duration reaches the preset duration, the thermal management system can be controlled to return to the state before the heat dissipation flow path reconstruction. This may include controlling the first bypass pipe 91 and the second bypass pipe 92 to be in a cut-off state, and controlling the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe, and the second liquid outlet pipe to be in a conductive state. When the first bypass pipe 91 and the second bypass pipe 92 are both in a cut-off state, and the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe, and the second liquid outlet pipe are all in a conductive state, the cooling medium returns to the initial parallel heat dissipation mode. The liquid inlet of each power unit is connected to the system liquid inlet pipe 4 through its respective liquid inlet pipe, and the liquid outlet of each power unit is connected to the system return liquid pipe 5 through its respective liquid outlet pipe. The two power units independently dissipate heat in parallel, and the cooling medium of each radiator does not interfere with each other. At this point, the thermal management system completes the complete switch from the series heat dissipation mode to the parallel heat dissipation mode.

[0070] The exit mechanism in this embodiment enables the thermal management system to switch orderly between the two modes of "series heat dissipation" and "parallel heat dissipation". This avoids the temperature accumulation of the low-temperature power unit due to long-term exposure to additional heat load, and also reserves sufficient cooling margin for the next heat flow reconstruction. This avoids protection failure due to the depletion of the thermal capacity margin of the low-temperature power unit, and ensures the long-term sustainable operation of the thermal management system.

[0071] In addition, in this embodiment, if the predicted heat capacity margin and the predicted junction temperature of the first power unit 11 and the second power unit 21 do not meet the conditions when the thermal management system is in normal working condition, it means that the thermal management system does not need to reconfigure the heat dissipation flow path, or the thermal management system cannot reconfigure the heat dissipation flow path. At this time, the current state can be maintained. For example, the first bypass pipe 91 and the second bypass pipe 92 are both in the cut-off state, and the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe are all in the conducting state. The thermal management system is in the parallel heat dissipation mode.

[0072] It should be noted that if the predicted heat capacity margin and the predicted junction temperatures of the first power unit 11 and the second power unit 21 do not meet the conditions, the thermal management system can also perform other actions based on the specific circumstances of the predicted junction temperatures and preheating heat capacity margin. For example, if it is determined that the preheating heat capacity margin is less than the heat capacity margin threshold, and the higher preheating junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is less than the corresponding junction temperature threshold, a low-level alarm can be output to inform the user that the junction temperature of the high-temperature power unit is about to exceed the limit, but the low-temperature power unit cannot handle the heat dissipation, thus facilitating the user to take appropriate measures. As another example, if it is determined that the preheating heat capacity margin is less than the heat capacity margin threshold, and the higher preheating junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is also greater than or equal to the corresponding junction temperature threshold, a high-level alarm can be output to inform the user that the junction temperatures of both the high-temperature and low-temperature power units are about to exceed the limit, thus facilitating the user to take appropriate measures.

[0073] In one exemplary embodiment, reference Figure 1 , Figure 4 and Figure 5 As shown, a thermal management system and a thermal management method are provided, as well as a frequency converter equipped with the thermal management system. In this embodiment, the operating data is processed based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit 11 and the second power unit 21, and the predicted thermal capacity margin, which may include: S111. Discretize the parameters and sampling period of the running data based on the thermal resistance-capacitance equivalent model to obtain the state transition matrix and input matrix; S112. Based on the state transition matrix, input matrix and Kalman filter algorithm, perform prediction processing and update processing in each sampling period to obtain the predicted junction temperature of the first power unit 11 and the second power unit 21. S113. Determine the predicted heat capacity margin based on the predicted radiator temperature and predicted junction temperature of the power unit corresponding to the lower predicted junction temperature.

[0074] In step S111, the thermal resistance-capacitance equivalent model equates the heat conduction path from the power device to the cooling medium as a series network of thermal resistance and thermal capacitance. Each power module defines the following physical quantities: junction temperature Tj (to be estimated), heat sink temperature Th (to be estimated), junction-to-heat sink thermal resistance Rjc, heat sink-to-ambient thermal resistance Rca, junction thermal capacitance Cj, and heat sink thermal capacitance Ch. Junction temperature refers to the temperature of the PN junction inside the power device chip and is a core indicator of device thermal safety.

[0075] It should be noted that the sampling period Ts (e.g., 0.2ms) is the time interval between two consecutive data acquisitions, corresponding to a sampling frequency of 5kHz. The sampling period serves as the time base for the Kalman filter algorithm's discretization recursion. It converts the continuous physical process into discrete digital signals and represents the cycle of a complete data acquisition, state prediction, and measurement update at each time step. The determination of the state transition matrix A and the input matrix B depends only on the physical parameters (Rjc, Rca, Cj, Ch) of the RC equivalent model and the sampling period Ts, and does not depend on the specific values ​​of the junction temperature Tj or the heatsink temperature Th. A shorter sampling period results in a higher accuracy of the discretized model in approximating the continuous physical process, but also places higher demands on the controller's computational power.

[0076] In this step, a continuous-time state-space model of the second-order RC equivalent model of each power module can be established first. Then, the above continuous-time state-space model is discretized according to the sampling period Ts to obtain the state transition matrix A and the input matrix B.

[0077] Specifically, the form is as follows: , .

[0078] In step S112, the Kalman filter algorithm is an optimal state estimation algorithm used to suppress measurement noise and model errors, achieving optimal estimation of states that cannot be directly measured (such as junction temperature). This algorithm performs a complete prediction and update recursion once within each sampling period Ts.

[0079] The Kalman filtering algorithm (also known as the Kalman filter) sequentially performs prediction and update steps in each sampling period.

[0080] First, the prediction steps: Prior state estimation: k|k-1 = A · k-1|k-1 + B · P k-1 ,in k|k-1 It uses the optimal estimate from the previous time step combined with the model's prediction of the current state vector. k-1|k-1 It is the optimal estimate from the previous moment.

[0081] Prior covariance: P k|k-1 = A · P k-1|k-1 · A + Q, P k|k-1 It is the prior estimation error covariance matrix, P k-1|k-1 Q is the posterior covariance of the previous time step, and Q is the process noise covariance matrix.

[0082] Second, update steps: Kalman gain: K k = P k|k-1 · H · (H · P k|k-1 · H + R) - ¹, K k The Kalman gain (2×1 vector) determines the degree of confidence in the measured values; H = [0, 1] is the observation matrix; and R is the measurement noise variance.

[0083] Posterior state estimation: k|k = k|k-1 + K k · (z k - H · k|k-1 ), k|k This is the current best estimate, including the predicted junction temperature. j And predicting radiator temperature h .

[0084] Posterior covariance: P k|k = (I - K k · H) · P k|k-1 P k|k This is the updated error covariance matrix.

[0085] In this step, the current optimal predicted junction temperature is used as the basis. j The system calculates the predicted junction temperature for the next n sampling periods by repeatedly recursively applying the state equation (excluding measurement update steps), thus obtaining the predicted junction temperature for each power unit. j Similarly, the predicted radiator temperature for each power unit can be obtained. h .

[0086] In step S113, the predicted radiator temperature is obtained by performing prediction and update processing in each sampling period based on the state transition matrix, the input matrix, and the Kalman filter algorithm. That is, the predicted radiator temperature can be obtained in step S112.

[0087] In this step, the heat absorption capacity value can be determined based on the predicted junction temperature, the corresponding junction temperature threshold, and the junction heat capacity. For example, the difference between the current predicted junction temperature and the safety threshold is calculated: This value reflects the additional temperature rise that the power unit can withstand. The corresponding heat absorption capacity is calculated using the junction heat capacity Cj: This item directly measures the upper limit of heat absorption under junction temperature constraints, preventing the junction temperature from exceeding the limit.

[0088] The remaining heat absorption capacity of the radiator can also be determined based on the predicted radiator temperature, the corresponding radiator temperature threshold, and the radiator heat capacity. For example, the sensible heat capacity that can be absorbed can be calculated based on the radiator heat capacity Ch and the current predicted radiator temperature: This value represents how much heat the radiator can still store without overheating.

[0089] Additional heat dissipation can also be determined based on the current percentage of the cooling fan speed of the power unit's radiator corresponding to the lower predicted junction temperature, the percentage of coolant flow in the radiator, and the preset duration after the heat dissipation flow path reconfiguration. For example, fan speed margin: ΔSfan = 1 Sfan, this value multiplied by the increase in cooling power Pfan,max at full fan speed (pre-calibrated by fan characteristics), yields the increase in cooling power Pfan,extra = ΔSfan · Pfan,max that can be achieved by fan acceleration. Similarly, the coolant flow margin: ΔFflow = 1 Fflow is the increase in heat dissipation power Pflow that can be obtained by increasing the flow rate, extra = ΔFflow. Pflow,max.

[0090] Within a preset duration Δt after the heat dissipation flow path is reconfigured, the additional heat that can be dissipated by the above two items is Qforced=(Pfan,extra+Pflow,extra). Δt.

[0091] Then, the minimum value among the junction temperature margin converted heat absorption capacity, the radiator's remaining heat absorption capacity, and the additional heat dissipation is determined as the predicted heat capacity margin.

[0092] The final predicted heat capacity margin is taken as the minimum of the three values ​​as a conservative estimate: Qmargin=min(Qj, Qheat, Qforced) That is, the predicted heat capacity margin is the smaller of the junction temperature margin converted heat absorption capacity (to prevent the junction temperature from exceeding the limit), the remaining heat absorption capacity of the radiator, and the additional heat dissipation. The higher this value, the more capable the corresponding power unit is of receiving additional heat load from high-temperature power units. The intelligent decision control unit (e.g., the controller) uses this to determine whether to select it as the target power unit for "borrowing heat for heat dissipation".

[0093] In this embodiment, the thermal resistance-capacitance equivalent model equates the heat conduction path from the power device to the cooling medium as a series network of thermal resistance and thermal capacitance, describing the physical laws of heat transfer. The Kalman filter algorithm, as a model-based optimal state estimator, can fuse the predicted values ​​from the physical model with the measured values ​​from the temperature sensor, achieving optimal estimation of the junction temperature under inaccurate power loss input and measurement conditions. This combination combines the determinism of the physical model with the accuracy of the measured data, effectively suppressing measurement noise and model errors. Based on this, this embodiment calculates the predicted junction temperature for future moments by repeatedly recursively applying the state equation based on the current optimal junction temperature estimate, enabling the prediction of overheating risks before the junction temperature actually reaches the dangerous threshold. Compared to related technologies that rely on threshold triggering schemes based on current measured temperature values, this embodiment transforms thermal management from "post-event response" to "proactive sensing," effectively addressing transient thermal shocks caused by sudden load changes.

[0094] Moreover, the predicted heat capacity margin in this embodiment considers three dimensions simultaneously: junction temperature margin converted heat absorption capacity (based on the difference between the predicted junction temperature and the junction temperature threshold, and the junction heat capacity, measuring the upper limit of heat absorption under junction temperature constraints to prevent the junction temperature from exceeding the limit), the remaining heat absorption capacity of the radiator (based on the difference between the predicted radiator temperature and the radiator temperature threshold, and the radiator heat capacity, measuring how much heat the radiator itself can still store without overheating), and additional heat dissipation (based on the current fan speed percentage and coolant flow rate percentage, combined with the preset duration after the heat dissipation flow path reconstruction, measuring the additional heat dissipation that can be achieved by accelerating the fan and increasing the flow rate), taking the minimum value of the three as a conservative estimate. This mechanism ensures that when the low-temperature power unit undertakes additional heat loads, the junction temperature and radiator temperature are within a safe range, and there is sufficient forced heat dissipation regulation capacity as a backup, avoiding the risk of overheating due to undertaking additional heat, and avoiding blind switching when the low-temperature power unit's own heat dissipation is close to saturation, thus improving the accuracy and safety of thermal management decisions.

[0095] In one exemplary embodiment, reference is made to the figure. Figure 1 As shown, a thermal management system and a thermal management method are provided, as well as a frequency converter equipped with the thermal management system. In this embodiment, the thermal management system may include a first liquid inlet three-way valve 12. The first valve port of the first liquid inlet three-way valve 12 is connected to a first liquid inlet pipeline, the second valve port of the first liquid inlet three-way valve 12 is connected to the liquid inlet of a first power unit 11, and the third valve port of the first liquid inlet three-way valve 12 is connected to the liquid outlet of a first bypass pipeline 91. Based on this method, when reconfiguring the heat dissipation flow path, the first power unit 11 can be connected to the first liquid inlet pipeline or the first bypass pipeline 91 by adjusting the state of each valve port of the first liquid inlet three-way valve 12.

[0096] For example, when a heat dissipation flow path reconfiguration is required, if the predicted junction temperature of the first power unit 11 is low, the first port of the first inlet three-way valve 12 can be shut off, and the second and third ports of the first inlet three-way valve 12 can be opened, thereby connecting the first bypass pipe 91 with the inlet of the first power unit 11. In this case, after the cooling medium passes through the high-temperature second power unit 21, it can enter the first power unit 11 through the first bypass pipe 91, thus achieving a series connection of their heat dissipation flow paths. When a heat dissipation flow path reconfiguration is not required, the first and second ports of the first inlet three-way valve 12 can be opened, and the third port of the first inlet three-way valve 12 can be shut off, thereby disconnecting the flow path between the first bypass pipe 91 and the inlet of the first power unit 11. In this case, the cooling medium can directly enter the first power unit 11 through the first inlet pipe, thus achieving a parallel connection of the heat dissipation flow paths of the first power unit 11 and the second power unit 21.

[0097] The thermal management system may also include a second inlet three-way valve 22. The first port of the second inlet three-way valve 22 is connected to the second inlet pipeline, the second port of the second inlet three-way valve 22 is connected to the inlet of the second power unit 21, and the third port of the second inlet three-way valve 22 is connected to the outlet of the second bypass pipeline 92. Based on this method, when reconfiguring the heat dissipation flow path, the second power unit 21 can be connected to the second inlet pipeline or the second bypass pipeline 92 by adjusting the state of each port of the second inlet three-way valve 22.

[0098] For example, when a heat dissipation flow path reconfiguration is required, if the predicted junction temperature of the second power unit 21 is low, the first port of the second inlet three-way valve 22 can be shut off, and the second and third ports of the second inlet three-way valve 22 can be opened, thereby connecting the second bypass pipe 92 with the inlet of the second power unit 21. In this case, after the cooling medium passes through the high-temperature first power unit 11, it can enter the second power unit 21 through the second bypass pipe 92, thus achieving a series connection of their heat dissipation flow paths. When a heat dissipation flow path reconfiguration is not required, the first and second ports of the second inlet three-way valve 22 can be opened, and the third port of the second inlet three-way valve 22 can be shut off, thereby disconnecting the flow path between the second bypass pipe 92 and the inlet of the second power unit 21. In this case, the cooling medium can directly enter the second power unit 21 through the second inlet pipe, thus achieving a parallel connection of the heat dissipation flow paths of the first power unit 11 and the second power unit 21.

[0099] The thermal management system may also include a first liquid outlet three-way valve 13. The first valve port of the first liquid outlet three-way valve 13 is connected to the first liquid outlet pipeline, the second valve port of the first liquid outlet three-way valve 13 is connected to the liquid outlet of the first power unit 11, and the third valve port of the first liquid outlet three-way valve 13 is connected to the liquid inlet of the second bypass pipeline 92. Based on this method, when reconfiguring the heat dissipation flow path, the first power unit 11 can be connected to the first liquid outlet pipeline or the second bypass pipeline 92 by adjusting the state of each valve port of the first liquid outlet three-way valve 13.

[0100] For example, when the heat dissipation flow path needs to be reconfigured, if the predicted junction temperature of the first power unit 11 is high, the first valve port of the first liquid outlet three-way valve 13 can be cut off, and the second and third valve ports of the first liquid outlet three-way valve 13 can be opened, so that the second bypass pipe 92 is connected to the liquid outlet of the first power unit 11. At this time, after the cooling medium passes through the high-temperature first power unit 11, it no longer directly enters the first liquid outlet pipe, but enters the second power unit 21 through the second bypass pipe 92, thereby realizing the series connection of the heat dissipation flow paths of the two. When there is no need to reconfigure the heat dissipation flow path, the first and second valve ports of the first liquid outlet three-way valve 13 can be opened, and the third valve port of the first liquid outlet three-way valve 13 can be cut off, thereby disconnecting the flow path between the second bypass pipe 92 and the liquid outlet of the first power unit 11. At this time, the cooling medium discharged by the first power unit 11 can directly enter the system return pipe 5 through the first liquid outlet pipe, thereby realizing the parallel connection of the heat dissipation flow paths of the first power unit 11 and the second power unit 21.

[0101] The thermal management system may also include a second liquid outlet three-way valve 23. The first valve port of the second liquid outlet three-way valve 23 is connected to the second liquid outlet pipeline, the second valve port of the second liquid outlet three-way valve 23 is connected to the liquid outlet of the second power unit 21, and the third valve port of the second liquid outlet three-way valve 23 is connected to the liquid inlet of the first bypass pipeline 91. Based on this method, when reconfiguring the heat dissipation flow path, the second power unit 21 can be connected to the second liquid outlet pipeline or the first bypass pipeline 91 by adjusting the state of each valve port of the second liquid outlet three-way valve 23.

[0102] For example, when the heat dissipation flow path needs to be reconfigured, if the predicted junction temperature of the second power unit 21 is high, the first valve port of the second liquid outlet three-way valve 23 can be cut off, and the second and third valve ports of the second liquid outlet three-way valve 23 can be opened, so that the first bypass pipe 91 is connected to the liquid outlet of the second power unit 21. At this time, after the cooling medium passes through the high-temperature second power unit 21, it no longer directly enters the second liquid outlet pipe, but enters the first power unit 11 through the first bypass pipe 91, thereby realizing the series connection of the heat dissipation flow paths of the two. When there is no need to reconfigure the heat dissipation flow path, the first and second valve ports of the second liquid outlet three-way valve 23 can be opened, and the third valve port of the second liquid outlet three-way valve 23 can be cut off, thereby disconnecting the flow path between the first bypass pipe 91 and the liquid outlet of the second power unit 21. At this time, the cooling medium discharged by the second power unit 21 can directly enter the system return pipe 5 through the second liquid outlet pipe, thereby realizing the parallel connection of the heat dissipation flow paths of the first power unit 11 and the second power unit 21.

[0103] It should be noted that the above three-way valves can be installed simultaneously or at least one can be installed; there is no limitation on this. When the above three-way valves are installed simultaneously, the series and parallel connection of the heat dissipation flow path between the first power unit 11 and the second power unit 21 can be switched by controlling the state of the valve ports of each of the above three-way valves.

[0104] In addition, in this embodiment, the thermal management system may also include a bidirectional solenoid valve assembly 3. The first solenoid valve 31 of the bidirectional solenoid valve assembly 3 is used to control the opening or closing of the first bypass line 91, and the second solenoid valve 32 is used to control the opening or closing of the second bypass line 92. It should be noted that the first solenoid valve 31 and the second solenoid valve 32 can be two anti-parallel unidirectional solenoid valves.

[0105] For example, when a heat dissipation flow path reconfiguration is required, if the predicted junction temperature of the first power unit 11 is high, the first solenoid valve 31 can be controlled to shut off, and the second solenoid valve 32 can be controlled to open. This allows the first bypass pipe 91 to shut off, while the second bypass pipe 92 remains open. At this time, after the cooling medium passes through the high-temperature first power unit 11, it enters the second power unit 21 through the second bypass pipe 92, thus achieving a series connection of their heat dissipation flow paths.

[0106] For example, when a heat dissipation flow path reconfiguration is required, if the predicted junction temperature of the second power unit 21 is high, the second solenoid valve 32 can be controlled to shut off, while the first solenoid valve 31 can be controlled to open. This allows the second bypass pipe 92 to shut off, while the first bypass pipe 91 remains open. At this time, after the cooling medium passes through the high-temperature second power unit 21, it enters the first power unit 11 through the first bypass pipe 91, thus connecting their heat dissipation flow paths in series.

[0107] For example, when the heat dissipation flow path reconfiguration is not required, the first solenoid valve 31 and the second solenoid valve 32 can be controlled to shut off, thereby cutting off both the first bypass pipe 91 and the second bypass pipe 92. At this time, the heat dissipation flow of the first power unit 11 and the second power unit 21 is in parallel.

[0108] This embodiment achieves flexible switching and precise control of the heat dissipation flow path between power units by setting a three-way valve and / or a two-way solenoid valve group 3. When the predicted junction temperature of the high-temperature power unit meets the conditions, the on / off state of the corresponding three-way valve or the conduction and cutoff of the two-way solenoid valve group 3 is controlled, so that the cooling medium absorbs heat from the high-temperature power unit and flows into the low-temperature power unit through the bypass pipeline for secondary cooling, forming a series heat dissipation loop, realizing the directional guidance of heat from the high-temperature module to the low-temperature module; when there is no need for heat dissipation flow path reconstruction, each valve returns to its normal state, so that each power unit resumes independent parallel heat dissipation. The three-way valve integrates the switching function of multiple independent valves in related technologies into a single valve body, reducing the number of valves and the complexity of pipeline connections, and simplifying the system structure; the two-way solenoid valve group 3 can realize rapid independent on / off control of the bypass pipeline, with a fast response, and can form multiple switching redundancy schemes in combination with the three-way valve. The two work together to effectively utilize the surplus cooling capacity of each power unit in the system, eliminate local hot spots, improve the overall efficiency and reliability of the thermal management system, and further enhance the user experience.

[0109] In one exemplary embodiment, reference Figures 1 to 5 As shown, a thermal management system and method are provided, as well as a frequency converter equipped with the thermal management system. In this embodiment, the thermal management system may include a power unit cluster 30, a dynamic thermal path execution unit 20, a multi-dimensional sensing layer 40, and an intelligent decision control unit 10, etc., to form a closed-loop thermal management architecture. The power unit cluster 30 may include multiple power units connected in parallel, each power unit integrating a heat sink at its bottom and having an independent liquid inlet and outlet.

[0110] During normal operation, all power units achieve parallel heat dissipation through a common system inlet pipe and system return pipe 5, forming a heat source network. When the thermal management system detects a risk of local overheating, this cluster can dynamically participate in heat flow reconfiguration. The dynamic thermal path execution unit 20 is the core of the physical implementation, including a bidirectional solenoid valve group 3 between adjacent power units, three-way valves on the inlet and outlet sides of the power units, a main circulation pump 8, and an external radiator 6, etc. By opening and closing the solenoid valves and switching the three-way valves, the flow path of the coolant (i.e., the cooling medium) can be reconfigured from a standard parallel mode to a series mode between power units, realizing the physical transport of heat from the high-temperature power unit to the low-temperature power unit.

[0111] The multi-dimensional sensing layer 40 deploys two types of sensors to continuously collect operating data from each power unit at a sampling frequency of 5kHz: a PT100 temperature sensor is installed in the outlet pipe of the radiator of each power unit to monitor the outlet temperature of the coolant; a Hall current sensor is installed in the current output circuit of each power unit to collect the load current I(t) (in A) flowing through the power unit in real time, which is used to calculate the real-time power loss. The specific calculation formula is P(t)=I²·RDS(on)+Psw, where RDS(on) is the on-resistance (which can be corrected with temperature), and Psw is the switching loss (obtained through experimental calibration or by looking up a table based on current and bus voltage). The intelligent decision control unit 10 uses a DSP microprocessor as its core and integrates the operating data collected by the sensing layer in real time based on the thermal resistance-capacitance equivalent model (RC equivalent model, also known as RC network) and Kalman filtering algorithm to predict the temperature rise trend in advance, accurately identify the transient thermal shock caused by load changes, and completely eliminate the hysteresis of traditional threshold control.

[0112] In the Kalman filter prediction and thermal capacity margin assessment (each power unit operates independently), the following physical quantities are defined for each power unit: T j Junction temperature (°C, under estimated conditions); T h Radiator temperature (°C, under estimated conditions); I(t): Load current, measured by a Hall current sensor installed in the output circuit of each power module (unit: A). P(t): Power loss, calculated from the load current: P = I²·R DS(on) + P sw； R jc : Thermal resistance from junction to heat sink (K / W); R ca Thermal resistance from the heatsink to the environment (K / W, affected by fan speed and airflow). C j Junction heat capacity (J / K); C h Heat capacity of the radiator (J / K); T s Sampling period (0.2ms, corresponding to 5kHz); z k : Radiator temperature measurement at time k (actual measurement with PT100); State vector x k = [T j,k , T h,k ] ; The Kalman filtering algorithm (also known as the Kalman filter) sequentially performs prediction and update steps in each sampling period. For details, please refer to other embodiments, which will not be elaborated here.

[0113] The state transition matrix A and the input matrix B are obtained by discretizing the RC parameters and the sampling period, and their specific forms are as follows: , .

[0114] In this embodiment, the current optimal predicted junction temperature is based on the Kalman filter output. j And the current best predicted temperature estimate of the heat sink h The system calculates the predicted junction temperature for the next n sampling periods by repeatedly applying the recursive state equation (excluding measurement update steps), for example, predicting the junction temperature 5 seconds later. This process utilizes the identified RC equivalent model, which can identify potential temperature rise trends in advance.

[0115] The thermal management system uses the predicted junction temperature of each power unit as a reference. j Radiator Predicted Temperature Estimation h The fan speed percentage (Sfan, current speed / maximum speed) and coolant flow percentage (Fflow, current flow / maximum flow) are combined with a preset junction temperature safety threshold (hereinafter referred to as junction temperature threshold). (As determined by the device datasheet) and the maximum allowable temperature of the heatsink. (Determined by the material's maximum temperature), calculate the "heat capacity margin" of the power unit—that is, the additional heat it can absorb without causing itself to overheat (expressed as equivalent heat power or equivalent temperature rise). This involves three steps: Junction temperature margin converted to heat absorption capacity: Calculate the difference between the current predicted junction temperature and the safe threshold. This value reflects the additional temperature rise that the power unit can withstand. The corresponding heat absorption capacity is calculated using the junction heat capacity Cj: This item directly measures the upper limit of heat absorption under junction temperature constraints, preventing the junction temperature from exceeding the limit.

[0116] Remaining heat absorption capacity of the radiator: Calculate the sensible heat capacity that can be absorbed based on the radiator's heat capacity Ch and the current predicted radiator temperature. This value represents how much heat the radiator can still store without overheating.

[0117] Additional heat dissipation. For example, fan speed margin: ΔSfan = 1 Sfan, this value multiplied by the heat dissipation power increment Pfan,max at full fan speed (pre-calibrated by fan characteristics), yields the heat dissipation power increase Pfan,extra = ΔSfan · Pfan,max that can be achieved by fan acceleration. Similarly, coolant flow margin: ΔFflow = 1 Fflow is the increase in heat dissipation power Pflow that can be obtained by increasing the flow rate, extra = ΔFflow. Pflow,max. Within a preset duration Δt after the heat dissipation flow path is reconfigured, the additional heat that can be dissipated by the above two items is Qforced = (Pfan,extra + Pflow,extra). Δt.

[0118] The final predicted heat capacity margin is taken as the minimum of the three values ​​as a conservative estimate: Qmargin=min(Qj, Qheat, Qforced) That is, the predicted heat capacity margin is the smaller of the junction temperature margin converted heat absorption capacity value (to prevent the junction temperature from exceeding the limit), the remaining heat absorption capacity value of the radiator, and the additional heat dissipation. The higher this value, the more capable the corresponding power unit is of receiving additional heat load from the high-temperature power unit. Based on this, the intelligent decision control unit 10 (e.g., the controller) determines whether to select it as the target power unit for "heat dissipation through a bypass".

[0119] If the thermal margin of the low-temperature power unit is sufficient (i.e., the predicted thermal margin is greater than or equal to the thermal margin threshold), and the higher predicted junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is less than the corresponding junction temperature threshold, then the thermal management system will automatically trigger a heat dissipation flow path reconfiguration (referred to as thermal flow reconfiguration) before the junction temperature of the high-temperature power unit (i.e., the power unit corresponding to the higher predicted junction temperature) actually exceeds the limit, and perform the following steps: Close the first valve port of the liquid outlet three-way valve of the high-temperature power unit (i.e., cut off the first valve port of the liquid outlet three-way valve of the high-temperature power unit), and close the first valve port of the liquid inlet three-way valve of the low-temperature power unit (i.e., control the first valve port of the liquid inlet three-way valve of the low-temperature power unit). Open the second solenoid valve 32 of the bidirectional solenoid valve between the high-temperature power unit and the low-temperature power unit, and control the third valve port of the outlet three-way valve of the high-temperature power unit to be open (i.e., switch the outlet three-way valve of the high-temperature power unit to the heat flow guiding position. The forced coolant path is changed to "system inlet pipe 4 → high-temperature power unit heat absorption → second bypass pipe 92 → low-temperature power unit → system return pipe 5 → external radiator 6 → water tank 7 → main circulation pump 8", which utilizes the high-efficiency heat dissipation capacity of the low-temperature power unit to transfer heat.

[0120] It should be noted that in this embodiment, Dynamic Thermal Path Reconfiguration refers to the technical means of changing the physical connection topology of the cooling medium among multiple heat dissipation units in real time by switching electronic valves (such as switching from parallel to series), thereby changing the heat flow path.

[0121] Thermal capacity margin: refers to the capacity of a power module under low load conditions, where its heat sink and cooling medium have not yet reached the thermal equilibrium limit, and it still has the capacity to absorb additional heat load without overheating.

[0122] Thermal resistance-capacitance equivalent model: a physical model used to simulate the thermal characteristics of power modules, which compares the heat conduction process to the resistance and capacitance in a circuit, and is used for mathematical modeling of thermal states.

[0123] In contrast, frequency converters in related technologies typically only respond passively after the temperature actually exceeds the limit, lacking the ability to predict heat proactively based on physical models. Furthermore, they cannot actively redistribute heat among power units, making it difficult to effectively cope with transient load shocks and optimize the system's lifecycle performance. With the increasing demands for high reliability and energy efficiency in industrial automation, there is an urgent need for a system and method that can integrate multi-dimensional sensing, predict thermal shocks in advance, and implement adaptive collaborative compensation measures.

[0124] While some technical solutions have achieved a certain level of intelligence, they generally suffer from the following problems: Passive and singular heat dissipation mode: Most solutions rely solely on unidirectional heat dissipation to the environment, failing to utilize the "cooling margin" of the low-temperature modules inside the system, making it difficult to eliminate local hot spots when their own heat dissipation is saturated; Lagging control strategies: Self-repair mechanisms are mostly based on static thresholds or simple linear adjustments, lacking the ability to predict and actively intervene based on physical models (such as Kalman filtering), making it difficult to effectively cope with transient thermal shocks; Lack of multi-objective coordination: There is a lack of a global decision-making mechanism that deeply integrates "heat flow reconstruction" with multiple objectives such as "energy efficiency, quietness, and lifespan", making it difficult to achieve the optimal balance of overall system performance while ensuring safety.

[0125] In this embodiment, a "power unit-level active heat flux directional flow" mechanism based on dynamic thermal circuit reconfiguration is proposed, specifically including: Hardware architecture innovation: Breakthrough in related technologies, this inverter features an isolated architecture with independent parallel heat dissipation for the power units. Switchable connecting pipes (including bidirectional solenoid valves or three-way valve assemblies) are added between adjacent power units to construct a cross-module heat exchange link; Control Logic: The system monitors the status of each power unit in real time. When it detects that a high-temperature power unit has reached its heat dissipation saturation, while a nearby low-temperature power unit has thermal capacity margin, the following actions are automatically executed: Cut off the circuit where high-temperature power units directly discharge into the environment; Open the connecting valve to connect the cooling medium outlet of the high-temperature power unit in series with the inlet of the low-temperature power unit; The heat is forced to flow through the high-efficiency heat dissipation channel of the low-temperature power unit, and the large temperature difference is used to accelerate heat dissipation.

[0126] This allows for the directional guidance of heat between modules, effectively eliminating local hot spots and solving the heat dissipation bottleneck problem of a single module by utilizing the excess cooling capacity of the low-temperature power unit through "borrowing" pathways.

[0127] This embodiment designs a transient thermal shock proactive defense strategy based on Kalman filtering, as follows: Predictive Model Construction: Abandoning the threshold-triggered mode of related technologies, a Kalman filter algorithm is used to establish a thermal state observer for the power unit. Based on the thermal resistance-capacitance (RC) equivalent network of the power unit, real-time load current and temperature noise data are integrated to perform optimal unbiased estimation of the junction temperature change trend. Advanced intervention mechanism: Based on the prediction results, the system automatically triggers dual coordinated actions before the junction temperature actually reaches the junction temperature threshold; Heat flow redirection: Activate the above-mentioned "dynamic thermal path reconfiguration" mechanism in advance to establish a thermal bridge across power units; Therefore, this embodiment can overcome the thermal inertia hysteresis of related technologies, transform the temperature control response from "passive response" to "active defense", and significantly suppress junction temperature fluctuations caused by sudden load changes.

[0128] This embodiment also constructs a globally optimal decision engine under multi-objective constraints, as detailed below: Multi-objective optimization model: Establish an optimization function with temperature standard deviation (thermal balance), total heat dissipation energy consumption (energy efficiency), and operating sound pressure level (quietness) as joint objectives, and set the junction temperature safety upper limit as a hard constraint condition.

[0129] Global solution strategy: Using intelligent optimization algorithms, the optimal combination of fan speed, liquid cooling flow rate, thermal bridge switching status and load distribution ratio is calculated in real time while meeting safety constraints.

[0130] Dynamic balancing mechanism: The system no longer solely pursues the lowest temperature, but automatically seeks the optimal solution between cooling effect, energy consumption cost, and noise level. For example, it prioritizes low-energy "heat flow reconfiguration" methods to assist in heat dissipation, rather than blindly increasing fan speed.

[0131] Therefore, this embodiment can break through the limitations of related technologies that "sacrifice energy consumption and noise for cooling", and achieve the overall optimal combination of system energy efficiency, quietness and reliability.

[0132] In other words, this embodiment constructs an active directional heat flow channel by regulating the heat at the power unit level, "transferring" the excess heat load of the high-temperature power unit to the low-temperature power unit with surplus cooling capacity for coordinated dissipation, thus breaking through the physical bottleneck of unidirectional heat dissipation limited by ambient temperature difference in related technologies. This "borrowed heat dissipation" mechanism not only directly reduces the peak junction temperature of the high-temperature power unit, but also eliminates local hot spots by utilizing system-level heat capacity sharing, significantly extending the average service life of the power module.

[0133] Moreover, this embodiment integrates Kalman filtering, which has the ability to predict temperature rise trends in advance, completely overcoming the response lag defects caused by thermal inertia in related technology threshold control. Through a proactive defense strategy, the system triggers active thermal flow regulation and load migration before the temperature rise is caused by sudden load changes, shortening the temperature control response time, effectively suppressing junction temperature fluctuations, and ensuring the thermal stability of the frequency converter under high-frequency dynamic conditions.

[0134] Furthermore, the multi-objective constraint optimization engine constructed in this embodiment uses temperature standard deviation, total heat dissipation energy consumption, and operating sound pressure level as joint objective functions. Under the premise of satisfying the hard constraint of safe junction temperature, it solves the global optimal strategy in real time, breaking the single path dependence of related technologies that "sacrifice energy consumption and noise for cooling". By prioritizing the use of low-cost heat flow reconstruction methods to assist heat dissipation, the system successfully finds the Pareto optimal balance point between energy efficiency, quietness, and thermal balance, realizing efficient, quiet, and reliable intelligent thermal management and improving the user experience.

[0135] In one exemplary embodiment, a variable frequency control device (not shown in the figure) is provided, which may include the frequency converter in the above embodiments. The variable frequency control device may be, for example, an air conditioning unit, a fan, a refrigerator, etc., and is not limited thereto.

[0136] Because of the aforementioned frequency converter, this variable frequency control device can accurately trigger the heat dissipation flow path in advance by using the dual-condition judgment of predicted junction temperature and predicted heat capacity margin, which effectively improves the thermal management level and operational reliability of the variable frequency control device and enhances the user experience.

[0137] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0138] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0139] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A thermal management method, characterized in that, The thermal management method is applied to a thermal management system, which includes a system inlet pipeline, a system return pipeline, and at least two power units. The liquid inlet of the first power unit of the thermal management system is connected to the liquid inlet of the system through a first liquid inlet pipe, and the liquid outlet of the first power unit is connected to the liquid return pipe of the system through a first liquid outlet pipe. The liquid inlet of the second power unit of the thermal management system is connected to the liquid inlet of the system through a second liquid inlet pipe, and the liquid outlet of the second power unit is connected to the liquid return pipe of the system through a second liquid outlet pipe. The thermal management system further includes a first bypass pipe and a second bypass pipe. The first bypass pipe is used to connect the liquid inlet of the first power unit to the liquid outlet of the second power unit, and the second bypass pipe is used to connect the liquid inlet of the second power unit to the liquid outlet of the first power unit. The thermal management method includes: Based on the operating data of the first power unit and the second power unit, the predicted junction temperature of the first power unit and the second power unit is determined, as well as the predicted thermal capacity margin of the power unit corresponding to the lower predicted junction temperature. When the predicted heat capacity margin and the predicted junction temperatures of the first power unit and the second power unit meet the conditions, a heat dissipation flow path reconfiguration is performed; wherein, the heat dissipation flow path reconfiguration includes controlling the bypass pipe connected to the liquid outlet of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, and controlling another bypass pipe to be in a cut-off state, controlling the liquid outlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a cut-off state, controlling the liquid inlet pipe of the power unit corresponding to the higher predicted junction temperature to be in a conducting state, controlling the liquid inlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a cut-off state, and controlling the liquid outlet pipe of the power unit corresponding to the lower predicted junction temperature to be in a conducting state.

2. The thermal management method according to claim 1, characterized in that, The operating data includes the outlet temperature and load current of the corresponding power unit. The step of determining the predicted junction temperature of the first power unit and the second power unit, and the predicted heat capacity margin of the power unit corresponding to the lower predicted junction temperature, based on the operating data of the first power unit and the second power unit, includes: The operating data is processed based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin.

3. The thermal management method according to claim 2, characterized in that, The process of processing the operating data based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin, includes: Based on the parameters corresponding to the thermal resistance-capacitance equivalent model and the discretization of the sampling period of the operating data, the state transition matrix and the input matrix are obtained. Based on the state transition matrix, input matrix, and Kalman filter algorithm, prediction and update processing are performed in each sampling period to obtain the predicted junction temperatures of the first power unit and the second power unit.

4. The thermal management method according to claim 3, characterized in that, The process of processing the operating data based on the thermal resistance-capacitance equivalent model and the Kalman filter algorithm to determine the predicted junction temperature of the first power unit and the second power unit, as well as the predicted thermal capacity margin, includes: The predicted heat capacity margin is determined based on the predicted radiator temperature of the power unit corresponding to the lower predicted junction temperature and the predicted junction temperature; wherein the predicted radiator temperature is obtained by performing prediction and update processing in each sampling period based on the state transition matrix, the input matrix and the Kalman filter algorithm.

5. The thermal management method according to claim 4, characterized in that, The determination of the predicted thermal margin based on the predicted radiator temperature of the power unit corresponding to the lower predicted junction temperature and the predicted junction temperature includes: Based on the predicted junction temperature and the corresponding junction temperature threshold and junction heat capacity, the heat absorption capacity value is determined by the junction temperature margin. Based on the predicted temperature of the radiator and the corresponding radiator temperature threshold and radiator heat capacity, the remaining heat absorption capacity of the radiator is determined. The additional heat dissipation is determined based on the current speed percentage of the cooling fan of the power unit corresponding to the lower predicted junction temperature, the coolant flow rate percentage of the radiator, and the preset duration after the heat dissipation flow path reconstruction. The minimum value among the junction temperature margin converted heat absorption capacity, the remaining heat absorption capacity of the radiator, and the additional heat dissipation is determined as the predicted heat capacity margin.

6. The thermal management method according to any one of claims 1-5, characterized in that, The thermal management method includes: If it is determined that the preheating heat capacity margin is greater than or equal to the heat capacity margin threshold, and the higher preheating junction temperature is greater than or equal to the corresponding junction temperature threshold, and the lower predicted junction temperature is less than the corresponding junction temperature threshold, then it is determined that the predicted heat capacity margin and the predicted junction temperatures of the first power unit and the second power unit meet the conditions.

7. The thermal management method according to any one of claims 1-5, characterized in that, The thermal management method includes: After the heat dissipation flow path is reconstructed, after the duration reaches the preset duration, the first bypass pipe and the second bypass pipe are controlled to be cut off, and the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe are controlled to be in the conducting state.

8. A thermal management system, characterized in that, The thermal management system includes a system inlet pipeline, a system return pipeline, and at least two power units; The liquid inlet of the first power unit of the thermal management system is connected to the liquid inlet of the system through a first liquid inlet pipe, and the liquid outlet of the first power unit is connected to the liquid return pipe of the system through a first liquid outlet pipe. The liquid inlet of the second power unit of the thermal management system is connected to the liquid inlet of the system through a second liquid inlet pipe, and the liquid outlet of the second power unit is connected to the liquid return pipe of the system through a second liquid outlet pipe. The thermal management system further includes a first bypass pipe and a second bypass pipe. The first bypass pipe is used to connect the liquid inlet of the first power unit to the liquid outlet of the second power unit, and the second bypass pipe is used to connect the liquid inlet of the second power unit to the liquid outlet of the first power unit. The thermal management system further includes a controller configured to implement the thermal management method as described in any one of claims 1-7.

9. The thermal management system according to claim 8, characterized in that, The thermal management system includes a first inlet three-way valve, wherein the first valve port of the first inlet three-way valve is connected to the first inlet pipeline, the second valve port of the first inlet three-way valve is connected to the inlet of the first power unit, and the third valve port of the first inlet three-way valve is connected to the outlet of the first bypass pipeline; and / or, The thermal management system includes a second inlet three-way valve, wherein the first valve port of the second inlet three-way valve is connected to the second inlet pipeline, the second valve port of the second inlet three-way valve is connected to the inlet of the second power unit, and the third valve port of the second inlet three-way valve is connected to the outlet of the second bypass pipeline; and / or, The thermal management system includes a first liquid outlet three-way valve, wherein the first valve port of the first liquid outlet three-way valve is connected to the first liquid outlet pipeline, the second valve port of the first liquid outlet three-way valve is connected to the liquid outlet of the first power unit, and the third valve port of the first liquid outlet three-way valve is connected to the liquid inlet of the second bypass pipeline; and / or, The thermal management system includes a second liquid outlet three-way valve, the first valve port of the second liquid outlet three-way valve is connected to the second liquid outlet pipeline, the second valve port of the second liquid outlet three-way valve is connected to the liquid outlet of the second power unit, and the third valve port of the second liquid outlet three-way valve is connected to the liquid inlet of the first bypass pipeline.

10. The thermal management system according to claim 8 or 9, characterized in that, The thermal management system includes a bidirectional solenoid valve group, wherein the first solenoid valve of the bidirectional solenoid valve group is used to control the opening or closing of the first bypass pipeline, and the second solenoid valve is used to control the opening or closing of the second bypass pipeline.

11. A frequency converter, characterized in that, The frequency converter includes the thermal management system as described in any one of claims 8-9.

12. A frequency converter control device, characterized in that, The frequency converter control device includes the frequency converter as described in claim 11.

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