Power conversion apparatus
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2026-08-13
Smart Images
Figure CN2025113189_13082026_PF_FP_ABST
Abstract
Description
A power conversion device
[0001] This application claims priority to Chinese Patent Application No. 202510142187.7, filed on February 8, 2025, entitled "A Power Conversion Device", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of energy technology, and in particular to a power conversion device. Background Technology
[0003] In power conversion equipment, power modules generate significant heat. To facilitate heat dissipation, phase change heat sinks can be used in power conversion equipment to provide better cooling for the power modules. However, unlike air-cooled or liquid-cooled heat sinks, phase change heat sinks involve the internal cooling medium changing between gas and liquid states. During the gas-liquid circulation of the cooling medium, heat is dissipated from the power modules.
[0004] Because the heat dissipation medium exists in both gaseous and liquid forms, the cooling medium in a phase change heat sink does not completely fill the entire heat sink. After the power conversion equipment is properly installed, the cooling medium inside the phase change heat sink directly contacts all the dies inside the power devices, effectively dissipating heat. However, if the power conversion equipment tilts or falls over, the cooling medium inside the phase change heat sink will no longer be able to directly contact all the dies inside the power module. This will affect the heat dissipation of the power module, increasing the risk of overheating and potentially damaging the power conversion equipment. Summary of the Invention
[0005] This application provides a power conversion device that can protect the power conversion device in the event of tilting or tipping over, thereby improving the reliability of the power conversion device.
[0006] To achieve the above objectives, this application adopts the following technical solution:
[0007] A first aspect of this application provides a power conversion device, which includes a housing, a power module, a heat sink, and a controller. The housing houses the power module, which converts direct current (DC) from a photovoltaic module or a storage battery into alternating current (AC). The heat sink is connected to the power module and is at least partially located outside the housing. The heat sink contains a cooling medium for gas-liquid conversion, and the liquid level of the cooling medium is higher than the bottom of the power module. The power conversion device also includes an accelerometer housed within the housing. The detection result of the accelerometer is used to characterize the tilt angle of the heat sink relative to the horizontal plane when the housing is mounted in the installation position. When the tilt angle of the heat sink relative to the horizontal plane is greater than or equal to an angle threshold, the controller controls the output power of the power conversion device to decrease.
[0008] The power module is connected to a heatsink (phase change heatsink). The cooling medium inside the heatsink circulates between gaseous and liquid states, dissipating heat from the power module. An accelerometer detects the gravitational acceleration of the power conversion device and determines the tilt angle of the heatsink relative to the horizontal plane based on the sensor's readings. This determines the tilt angle of the power conversion device relative to the horizontal plane when mounted. If the tilt angle of the power conversion device is too large (greater than or equal to an angle threshold), the output power of the power conversion device will decrease, causing it to operate at a reduced rate or shut down. Furthermore, when the power conversion device is tilted, the liquid cooling medium inside the heatsink may not be able to effectively dissipate heat from the bare fins inside the power module, resulting in poor heat dissipation from the heatsink. Therefore, after the power conversion equipment is tilted to a certain degree, it is derated or shut down (power value is 0). This reduces the heat generation of the power module, and the heat sink has sufficient heat dissipation capacity to cool the power module with lower heat. This reduces the risk of the power module overheating (over-temperature risk) and also reduces the possibility of damage to the power conversion equipment, thus protecting the power conversion equipment and improving its reliability.
[0009] In one optional implementation, the angle threshold includes a first angle threshold and a second angle threshold; when the tilt angle of the radiator rotating about the first axis is greater than or equal to the first angle threshold, or when the tilt angle of the radiator rotating about the second axis is greater than or equal to the second angle threshold, the controller is used to control the output power of the power conversion device to decrease; wherein the first axis and the second axis are perpendicular to each other and both parallel to the horizontal plane.
[0010] By detecting the gravitational acceleration components of the power conversion device along different coordinate axes using an accelerometer, the tilt angle of the power conversion device's rotation around a first axis and a second axis can be determined. Each tilt angle around the first and second axes has its own corresponding angular threshold. If the tilt angle of the power conversion device around either axis (first or second axis) is too large, the cooling medium inside the heat sink will not be able to effectively dissipate heat from the power module. In this case, derating or shutting down the power conversion device can reduce the heat generated by the power module and protect the device.
[0011] In one optional implementation, after the controller controls the output power of the power conversion device to decrease, if the tilt angle of the radiator rotating about the first axis is less than a first angle threshold and the tilt angle of the radiator rotating about the second axis is less than a second angle threshold, the controller is also used to control the output power of the power conversion device to increase.
[0012] If the power converter is tilted too much, it will operate at a derating rate or shut down. However, once the power converter is restored to its original position (no longer tilted), or if the tilt is small—that is, when the angles of rotation of the heat sink around the first axis and the second axis are both less than their respective angle thresholds—the liquid cooling medium inside the heat sink can effectively dissipate heat for most (or all) of the PCBs inside the power module. In this case, the power output of the power converter can be restored to its initial state, meaning the power converter exits the derating operation state and can operate normally.
[0013] In one alternative implementation, the controller is also configured to output an alarm signal when the tilt angle of the radiator relative to the horizontal plane is greater than or equal to an angle threshold.
[0014] If the tilt angle of the power conversion equipment is too large (greater than or equal to the angle threshold), the controller will not only derate the power conversion equipment or shut it down, but also output an alarm signal. For example, the alarm signal may be sent to the control room so that users in the control room can be aware that the tilt angle of the power conversion equipment is too large and take timely action; another example is that the alarm signal will cause the power conversion equipment to emit an audible warning to alert users that there is an abnormality in the power conversion equipment.
[0015] In one optional embodiment, the power conversion device further includes an angular velocity sensor housed within a housing, the angular velocity sensor being used to detect the angular velocity of the heat sink; when the angular velocity of the heat sink is greater than or equal to an angular velocity threshold, the controller is used to control the output power of the power conversion device to decrease.
[0016] By detecting the angular velocity of the heat sink, which is also the angular velocity of the power conversion device, an angular velocity sensor can be used to determine if the power conversion device has tipped over. If the angular velocity of the power conversion device is greater than or equal to a threshold, the output power of the power conversion device is reduced, meaning the device is derated or shut down. This reduces the heat generated by the power module, lowering the risk of overheating and reducing the likelihood of damage to the power conversion device.
[0017] By incorporating an angular velocity sensor, the accelerometer can assist the power conversion device in detecting its status, enabling the device to quickly implement protective measures such as derating or shutdown. For example, in the event of a power conversion device rapidly tipping over, the device may not yet have reached a significant tilt angle, and the controller may not be able to determine the degree of tilt based on the accelerometer's readings. However, the angular velocity sensor can detect a significant angular velocity, indicating a tipping event. Based on the angular velocity sensor's detection, the power conversion device can react quickly, for instance, by entering derating mode or shutting down immediately.
[0018] If the power conversion equipment tilts slowly, the cooling medium inside the radiator will not instantly lose its ability to dissipate heat from multiple bare dies. Therefore, the power conversion equipment can be put into derating operation or shut down directly after the acceleration sensor detects that the tilt of the power conversion equipment is too large.
[0019] In one optional implementation, the angular velocity threshold includes a first angular velocity threshold and a second angular velocity threshold; when the angular velocity of the radiator rotating about the third axis is greater than or equal to the first angular velocity threshold, or when the angular velocity of the radiator rotating about the fourth axis is greater than or equal to the second angular velocity threshold, the controller is used to control the output power of the power conversion device to decrease; wherein the third axis and the fourth axis are perpendicular to each other and both parallel to the horizontal plane.
[0020] By detecting the angular velocity sensor, the angular velocities of the power conversion equipment when rotating around the third and fourth axes can be obtained. Each of the angular velocities has its own corresponding threshold. If the angular velocity of the power conversion equipment rotating around either axis (the third or fourth axis) is too high, the power conversion equipment will be derated or shut down, which improves the response speed of the power conversion equipment in implementing protection measures and protects the power conversion equipment.
[0021] In one optional embodiment, the power conversion device further includes a circuit board and a temperature sensor housed within a housing. The temperature sensor and the acceleration sensor are both fixed to the same side of the circuit board. The temperature sensor is used to detect the temperature of the circuit board. The temperature sensor is located outside the power module. There are no other devices between the temperature sensor and the acceleration sensor. The temperature sensor is also used to detect the temperature of the acceleration sensor.
[0022] Because accelerometers (e.g., in chip form) have a temperature drift problem, their detection results will deviate when operating at different temperatures. This is especially true when power conversion equipment is used as an inverter, where the operating temperature of the accelerometer varies by tens of degrees Celsius (°C). The temperature drift problem has a significant impact on the detection results of the accelerometer. In this case, by detecting the temperature around the accelerometer using a temperature sensor, and consulting the temperature compensation table based on the temperature sensor's detection results, the detection results can be compensated accordingly, thereby improving the accuracy of the accelerometer's detection results.
[0023] In one alternative implementation, when the temperature value detected by the temperature sensor is greater than or equal to a temperature threshold, the controller controls the output power of the power conversion device to decrease.
[0024] Temperature sensors can also detect the internal temperature of the power conversion device's housing or the temperature of its circuit board. Even if the power conversion device is not tilted or tipped over, if the internal temperature of the power conversion device or the temperature of its circuit board is too high (the temperature detected by the temperature sensor is greater than or equal to the temperature threshold), the power conversion device will be derated or shut down to protect it.
[0025] In one alternative embodiment, the power module is fixed to the circuit board and located between the circuit board and the heat sink, and both the temperature sensor and the acceleration sensor are fixed to the side of the circuit board away from the heat sink.
[0026] The circuit board is used to carry multiple electronic components inside the housing. Electronic components such as temperature sensors and acceleration sensors are placed on the side of the circuit board away from the heat sink. This ensures that the temperature sensors and acceleration sensors do not interfere with the connection between the heat sink and the power module, which is beneficial for the heat sink to dissipate heat from the power module. This improves the heat dissipation effect of the power module and reduces the possibility of unstable operation of the power conversion equipment.
[0027] In one optional embodiment, the heat sink includes a substrate and a heat pipe. The substrate is fixed to a housing, and the internal space of the substrate has a cooling medium for gas-liquid conversion. The heat pipe is fixed to one of the surfaces of the substrate, and the internal channel of the heat pipe communicates with the internal space of the substrate. The housing has a mounting port, and both the substrate and the heat pipe are located outside the housing. The power module passes through the mounting port and is connected to the surface of the substrate opposite to the heat pipe. Alternatively, the substrate is located inside the housing and connected to the power module, and the heat pipe extends out of the housing through the mounting port.
[0028] In this process, the liquid coolant accumulates inside the substrate. When heated by the power module, the liquid coolant turns into a gaseous state. At least a portion of the gaseous coolant flows into the heat sink. Since the heat sink is located entirely or partially outside the housing, it can exchange heat with the air outside the housing. After cooling, the gaseous coolant inside the heat sink turns back into a liquid state. At least a portion of the liquid coolant flows back into the substrate, where it continues to absorb heat from the power module, turns back into a gaseous state, and then dissipates heat in the heat sink. This cycle is repeated to achieve continuous heat dissipation for the power module. Attached Figure Description
[0029] Figure 1 is a schematic diagram of a photovoltaic energy storage system provided in an embodiment of this application;
[0030] Figure 2 is a schematic diagram of a power conversion device provided in an embodiment of this application;
[0031] Figure 3 is a schematic diagram of the internal structure of a power conversion device provided in an embodiment of this application;
[0032] Figure 4 is a schematic diagram of the internal structure of another power conversion device provided in an embodiment of this application;
[0033] Figure 5 is a schematic diagram of a heat sink provided in an embodiment of this application;
[0034] Figure 6 is a structural schematic diagram of a power module provided in an embodiment of this application;
[0035] Figure 7 is a schematic diagram of the internal structure of a power module provided in an embodiment of this application;
[0036] Figure 8 is a schematic diagram of the liquid level of a cooling medium provided in an embodiment of this application;
[0037] Figure 9 is a schematic diagram of the liquid level of another cooling medium provided in an embodiment of this application;
[0038] Figure 10 is a schematic diagram of the liquid level of another cooling medium provided in an embodiment of this application;
[0039] Figure 11 is a schematic diagram showing the positions of a first axis and a second axis according to an embodiment of this application;
[0040] Figure 12 is a schematic diagram of a radiator rotating about a first axis according to an embodiment of this application;
[0041] Figure 13 is a schematic diagram of the positions of the third and fourth axes provided in an embodiment of this application.
[0042] Figure reference numerals: 100-Photovoltaic-storage system; 10-Photovoltaic module; 20-Power conversion equipment; 201-Photovoltaic inverter; 202-Energy storage converter; 30-Prefabricated substation; 40-Boosting station; 50-Power grid; 60-Energy storage battery; 1-Housing; 11-Air outlet; 12-Mounting port; 2-Power module; 21-Encapsulation shell; 22-Backing plate; 23-Bare die; 3-Circuit board; 31-Inductor; 32-Controller; 4-Heat exchanger; 5-Radiator; 51-Substrate; 511-Cooling medium; 52-Heat pipe; 521-Heat sub-pipe; 5211-Flow channel; 53-Buffer plate; 6-Blowing structure; 7-Heat shroud; 71-Air inlet; 72-Exhaust outlet; 8-Position sensor; 81-Acceleration sensor; 82-Angular velocity sensor; 9-Temperature sensor; 01-First axis; 02-Second axis; 03-Third axis; 04-Fourth axis; 05-Reference axis. Detailed Implementation
[0043] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0044] In the accompanying drawings of the embodiments of this application, solid structures such as parts and components are represented by guide lines; structures composed of multiple parts are represented by brackets; and hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with arrows.
[0045] Figure 1 illustrates an exemplary structure of a photovoltaic energy storage system 100 (solar photovoltaic energy storage power generation system), including a photovoltaic system and an energy storage system. Referring to Figure 1, in the photovoltaic system, photovoltaic modules 10 directly convert solar energy into electrical energy using the photovoltaic effect. The photovoltaic modules 10 typically include multiple cells connected in series or parallel to achieve a certain output power. A photovoltaic inverter 201 converts the direct current (DC) from the photovoltaic modules 10 into alternating current (AC), and sends the AC to a prefabricated substation 30 corresponding to the photovoltaic inverter 201 for voltage transformation. The prefabricated substation 30 can convert the low-voltage AC output from the photovoltaic inverter 201 into medium-voltage AC, and then transmit the AC to a step-up substation 40 and to the power grid 50 or other loads.
[0046] Referring to Figure 1, in the energy storage system, the energy storage battery 60 can store unstable electrical energy and convert direct current (DC) to alternating current (AC) through the power conversion system (PCS) 202. After passing through the prefabricated substation 30 corresponding to the energy storage battery 60, it delivers stable electrical energy to the power grid 50 or other loads. Furthermore, the power conversion system 202 can also convert AC power from the power grid 50 to DC power to charge the energy storage battery 60, and then store the electrical energy within the energy storage battery 60.
[0047] This application provides a power conversion device 20. FIG2 exemplarily illustrates the structure of a power conversion device 20, wherein the power conversion device 20 is used to convert one of alternating current (AC) and direct current (DC) to the other. In one embodiment, the power conversion device 20 may be a photovoltaic inverter 201 (refer to FIG1 for supplementary reference). In this embodiment, the power conversion device 20 (photovoltaic inverter 201) is used in a photovoltaic system, and the power conversion device 20 (photovoltaic inverter 201) is used to convert DC power from photovoltaic module 10 into AC power and output it to the grid 50 or other loads.
[0048] In another embodiment, the power conversion device 20 may be an energy storage converter 202 (see Figure 1 for reference). In this embodiment, the power conversion device 20 (energy storage converter 202) is used in an energy storage system, and it converts direct current (DC) from the energy storage battery 60 into alternating current (AC) and outputs it to the power grid 50 or other loads. Furthermore, the power conversion device 20 (energy storage converter 202) can also convert AC from the power grid 50 into DC to charge the energy storage battery 60.
[0049] Figure 3 illustrates the internal structure of the power conversion device 20 in Figure 2. Referring to Figures 2 and 3, the power conversion device 20 includes a housing 1, a power module 2, and a circuit board 3. The housing 1 has space for housing devices and apparatus. The circuit board 3 can be a printed circuit board (PCB), which is fixed within the internal space of the housing 1. The power module 2 converts direct current (DC) from the photovoltaic module 10 or the energy storage battery 60 into alternating current (AC). The power module 2 is located within the housing 1 and fixed to the circuit board 3; that is, both the circuit board 3 and the power module 2 are located within the housing 1. In some embodiments, only one power module 2 is provided; in other embodiments, multiple power modules 2 are provided.
[0050] In addition to the power module 2, other electronic components (e.g., capacitors, inductors 31, controllers 32, etc.) may also be disposed on the circuit board 3. In some embodiments, these other electronic components may be disposed on different surfaces of the circuit board 3 from the power module 2. In other embodiments, these other electronic components may be disposed on the same surface of the circuit board 3 as the power module 2. In still other embodiments, some of these other electronic components may be disposed on the same surface of the circuit board 3 as the power module 2, while others may be disposed on different surfaces of the circuit board 3. This application does not impose specific limitations on this.
[0051] To cool the interior of the housing 1, in some embodiments, the power conversion device 20 further includes a heat exchanger 4. The heat exchanger 4 is disposed outside the housing 1 and fixed to the side wall of the housing 1. The housing 1 is provided with multiple air vents 11, and the heat exchange channels of the heat exchanger 4 communicate with the interior space of the housing 1 through the multiple air vents 11. A driving component (e.g., a fan or blower) may also be provided inside the housing 1. This driving component is not shown in the accompanying drawings. The driving component can blow air from inside the housing 1 into the heat exchanger 4 from one air vent 11, where it exchanges heat with the air outside the housing 1, and then returns to the housing 1 from another air vent 11, thereby cooling the interior of the housing 1. In other embodiments, the power conversion device 20 may not include the heat exchanger 4.
[0052] Furthermore, the power module 2 is the component in the power conversion device 20 that generates significant heat. Referring to Figures 3 and 4, the power conversion device 20 also includes a heat sink 5. The heat sink 5 and the power module 2 are arranged in a direction parallel to the X-axis (the X-axis, Y-axis, and Z-axis are perpendicular to each other). The heat sink 5 can provide targeted heat dissipation for the power module 2, thereby improving the heat dissipation efficiency of the power conversion device 20. When the power conversion device 20 also includes a heat exchanger 4, the heat exchanger 4 and the heat sink 5 are arranged in a direction parallel to the Z-axis. In order to enable the heat sink 5 to connect to the power module 2, the housing 1 is provided with a mounting port 12, and the power module 2 is located on the surface of the circuit board 3 facing the mounting port 12.
[0053] In one embodiment, referring to FIG3, the heat sink 5 is located outside the housing 1, and the power module 2 is connected to the heat sink 5 through the mounting port 12 (either through contact or through a heat-conducting component). It should be noted that in this embodiment, the power module 2 is also disposed inside the housing 1. For example, the heat sink 5 is close to the side wall of the mounting port 12 of the housing 1, and the heat sink 5 blocks the mounting port 12. The power module 2 passing through the mounting port 12 does not mean that the power module 2 extends out of the housing 1 through the mounting port 12, but rather that the power module 2 extends to the mounting port 12, and the connection position between the power module 2 and the heat sink 5 is located at the mounting port 12.
[0054] The heat sink 5 includes a substrate 51 and a heat pipe 52. In the embodiment shown in FIG3, both the substrate 51 and the heat pipe 52 are located outside the housing 1. The substrate 51 is fixed on the housing 1 and the mounting port 12 is sealed. The power module 2 is connected to the substrate 51, and the heat pipe 52 is fixed on the surface of the substrate 51 away from the power module 2.
[0055] In some other embodiments, the heat sink 5 may be partially located inside the housing 1 and connected to the power module 2, while the other part extends outside the housing 1. For example, FIG4 exemplarily illustrates the internal structure of another power conversion device 20. Referring to FIG4, the substrate 51 is located inside the housing 1 and connected to the power module 2, and the heat sink 52 extends outside the housing 1 through the mounting port 12.
[0056] Figure 5 illustrates an exemplary structure of a heat sink 5. Referring to Figure 5, the substrate 51 can be a hollow plate-like structure. The substrate 51 contains a cooling medium 511 for gas-liquid conversion. Since the power conversion device 20 is mounted at the installation location (e.g., mounted on a support rod or wall), the cooling medium 511 is concentrated at the bottom of the substrate 51. A heat dissipation pipe 52 is fixed to one of the surfaces of the substrate 51, and the internal channel of the heat dissipation pipe 52 communicates with the internal space of the substrate 51. In the embodiment shown in Figure 5, the heat sink 52 includes a plurality of heat sink sub-pipes 521, which are arranged at intervals along a direction parallel to the Y-axis (in some embodiments, heat sink fins are provided between two adjacent heat sink sub-pipes 521). Each heat sink sub-pipe 521 is a flat tube and has a plurality of flow channels 5211. Each flow channel 5211 is connected to the internal space of the substrate 51. That is, the internal channel of the heat sink 52 includes the plurality of flow channels 5211 of each heat sink sub-pipe 521, or in other words, the plurality of flow channels 5211 of the plurality of heat sink sub-pipes 521 together form the internal channel of the heat sink 52.
[0057] In the embodiment shown in Figure 5, each heat dissipation sub-tube 521 is a microchannel flat tube, and each heat dissipation sub-tube 521 includes multiple flow channels 5211. In some other embodiments, each heat dissipation sub-tube 521 is a single-channel flat tube, and this type of heat dissipation sub-tube 521 has only one flow channel 5211 inside. In some other embodiments, the heat dissipation tube 52 can also be a complete pipe, and in this embodiment, the heat sink 5 includes only one heat dissipation tube 52.
[0058] The cooling medium 511 can switch between gaseous and liquid states. The liquid cooling medium 511 is stored in the substrate 51. When heated by the power module 2, the liquid cooling medium 511 turns into a gaseous state. At least part of the gaseous cooling medium 511 flows into the heat sink 52. Since the heat sink 52 is located outside the housing 1 in whole or in part, it can exchange heat with the air outside the housing 1. After cooling, the gaseous cooling medium 511 in the heat sink 52 turns back into a liquid cooling medium 511. The liquid cooling medium 511 flows back into the substrate 51, then absorbs the heat from the power module 2, turns back into a gaseous cooling medium 511, and flows into the heat sink 52 to dissipate heat. This cycle is repeated to achieve continuous heat dissipation for the power module 2.
[0059] In some embodiments, to allow more liquid coolant 511 to flow back into the substrate 51, the heat sink 5 may further include a busbar 53. A heat pipe 52 is located between the substrate 51 and the busbar 53. The busbar 53 may be a hollow plate-like structure, with its internal space communicating with the internal channels of the heat pipe 52. That is, one end of the heat pipe 52 is connected to the substrate 51, and the other end is connected to the busbar 53. The gaseous coolant 511 within the heat pipe 52 can flow into the busbar 53 and become liquid coolant 511 within it. Furthermore, after becoming liquid, the gaseous coolant 511 within the heat pipe 52 can also flow into the busbar 53. The liquid coolant 511 in the busbar 53 accumulates at the bottom of the busbar 53 and then flows back into the substrate 51 from the heat pipe 52.
[0060] In some other embodiments (not shown in the figures), the heat sink 52 may also be inclined so that the cooling medium 511 inside the heat sink 52 can flow smoothly back to the substrate 51 in a liquid state.
[0061] Referring back to Figures 3 or 4, to facilitate heat exchange between the radiator 5 and the air outside the housing 1, the power conversion device 20 may further include a blowing structure 6 (e.g., a fan or blower). The blowing structure 6 is located outside the housing 1 and can blow air towards the radiator 5. In embodiments where the power conversion device 20 also includes a heat exchanger 4, the blowing structure 6 also blows air onto the heat exchanger 4, thereby cooling the radiator 5 and the heat exchanger 4. For example, after the power conversion device 20 is installed in a designated position, the blowing structure 6 is located below the radiator 5 and the heat exchanger 4. In some other embodiments, the power conversion device 20 may not include the blowing structure 6.
[0062] Furthermore, referring to Figures 3 or 4, the power conversion device 20 may also include a heat sink 7. The heat sink 7 is located outside the housing 1 and covers the radiator 5, heat exchanger 4, and air blowing structure 6. The heat sink 7 may be provided with an air inlet 71 and an air outlet 72. The air blowing structure 6 is closer to the air inlet 71, and the radiator 5 and heat exchanger 4 are located between the air inlet 71 and the air outlet 72. Referring to Figure 5, the air blown into the heat sink 7 from the air inlet 71 flows between two adjacent heat dissipation sub-pipes 521 and is then blown out from the air outlet 72.
[0063] Figure 6 illustrates an exemplary positional relationship between a power module 2 and a heat sink 5. Referring to Figure 6, the substrate 51 protrudes downwards toward the heat pipe 52. After the heat sink 5 is mounted on the housing 1, the power module 2 is connected to the substrate 51 of the heat sink 5. Multiple power modules 2 are provided, and all of them can be located below the heat pipe 52. In some embodiments, a portion of each power module 2 is located below the heat pipe 52, while another portion is positioned opposite to the heat pipe 52. In other embodiments, the substrate 51 does not protrude significantly below the heat pipe 52. In this embodiment, the multiple power modules 2 are not located below the heat pipe 52, but rather all are positioned opposite to the heat pipe 52.
[0064] Figure 7 illustrates an exemplary internal structure of a power module 2. Referring to Figure 7, the power module 2 includes a package shell 21, a substrate 22, and at least one die 23. The substrate 22 can be any structure capable of supporting the die 23; for example, the substrate 22 can be a direct bond ceramic plate (DBC). In the embodiment shown in Figure 7, multiple dies 23 are provided and all are fixed to the substrate 22.
[0065] After the power module 2 is connected to the heat sink 5, the liquid level of the coolant 511 in the heat sink 5 is higher than the bottom of the power module 2. The relationship between the liquid level of the coolant 511 and the position of the power module 2 is compared after the power conversion device 20 is installed according to the installation requirements. At this time, the liquid level of the coolant 511 is higher than the bottom of the power module 2, meaning that the power module 2 is at least partially positioned opposite the coolant 511. For example, Figure 8 exemplarily shows the liquid level position of the coolant 511. Referring to Figure 8, the liquid level (L1) of the coolant 511 is higher than the bottom (L2) of the power module 2, and the liquid level (L1) of the coolant 511 is also higher than the top (L3) of the power module 2. In this case, the coolant 511 is directly facing all the dies 23, and each die 23 can dissipate heat through the gas-liquid conversion of the coolant 511. At this time, the heat dissipation effect of the heat sink 5 is optimal.
[0066] When the power conversion device 20 tilts or falls over, the liquid surface of the liquid coolant 511 inside the heat sink 5 will tilt, making it impossible for the coolant 511 to better dissipate heat for the power module 2. For example, Figure 9 shows another liquid surface position of the coolant 511. Referring to Figure 9, when the heat sink 5 tilts or falls over along the F1 direction in Figure 6, the liquid surface of the coolant 511 inside the heat sink 5 will be as shown in Figure 9. A portion of the bare dies 23 (the shaded portion of the bare dies 23) cannot dissipate heat through the coolant 511, or in other words, the coolant 511 has poor heat dissipation capacity for that portion (shaded portion) of the bare dies 23. For example, Figure 10 shows the liquid level of another type of cooling medium 511. Referring to Figure 10, when the radiator 5 is tilted along the F2 direction in Figure 6, the liquid level of the cooling medium 511 in the radiator 5 will be as shown in Figure 10. Some of the bare plates 23 (shaded bare plates 23) will not be able to dissipate heat through the cooling medium 511, or in other words, the cooling medium 511 has poor heat dissipation capacity for this part (shaded part) of the bare plates 23.
[0067] It is understood that Figure 8 shows the liquid level of the cooling medium 511 when the power conversion device 20 is not tilted or tipped over, while Figures 9 and 10 show the liquid level of the cooling medium 511 when the power conversion device 20 is tilted or tipped over. In some other embodiments, if the liquid level of the cooling medium 511 is not higher than all the bare dies 23 when the power conversion device 20 is not tilted or tipped over, then when the power conversion device 20 is tilted or tipped over, even more bare dies 23 will not be able to effectively dissipate heat through the cooling medium 511.
[0068] In other words, if the power conversion device 20 tilts or falls over, the heat dissipation capacity of the heat sink 5 will decrease, affecting the heat dissipation of the power module 2, which may cause the power module 2 to overheat and thus affect the normal operation of the power conversion device 20.
[0069] To address the aforementioned issues, referring back to Figures 3 or 4, the power conversion device 20 further includes a position sensor 8 housed within the housing 1. The position sensor 8 includes an acceleration sensor 81, which is fixed to the circuit board 3. For example, the acceleration sensor 81 and other electronic components are positioned on the side of the circuit board 3 away from the heat sink 5, ensuring that the acceleration sensor 81 does not interfere with the connection between the heat sink 5 and the power module 2, thus facilitating heat dissipation from the heat sink 5 for the power module 2. The acceleration sensor 81 can detect acceleration, and the detection result is used to characterize the tilt angle of the heat sink 5 relative to the horizontal plane when the housing 1 is mounted in the installation position. In other words, the tilt angle of the heat sink 5 relative to the horizontal plane can be determined based on the detection result of the acceleration sensor 81. For instance, the controller 32 of the power conversion device 20 (which may be a control chip on the circuit board 3) acquires the detection result of the acceleration sensor 81 and calculates the tilt angle of the heat sink 5 using trigonometric functions based on the detection result of the acceleration sensor 81.
[0070] Because the power conversion device 20 is tilted, the liquid cooling medium 511 inside the heat sink 5 may not be able to effectively dissipate heat for all the bare dies 23 inside the power module 2 (e.g., as shown in Figures 9 and 10), resulting in poor heat dissipation of the heat sink 5. Therefore, when the power conversion device 20 is tilted, if the tilt angle of the heat sink 5 relative to the horizontal plane reaches (greater than or equal to) an angle threshold, the controller 32 controls the output power of the power conversion device 20 to decrease. For example, the controller 32 makes the output power value of the power conversion device 20 less than the target power value, where the target power value is the power value output by the output terminal of the power conversion device 20 when the power conversion device 20 is operating normally (e.g., without tilting or tipping). In this process, the output power of the power conversion device 20 is reduced, that is, the power conversion device 20 is put into a derating operation state or directly shut down (power value is 0). This reduces the heat generation of the power module 2, and the heat dissipation capacity of the heat sink 5 is sufficient to dissipate heat from the power module 2, which has a lower heat generation. This reduces the risk of the power module 2 overheating (over-temperature risk) and also reduces the possibility of damage to the power conversion device 20, thus protecting the power conversion device 20 and improving its reliability.
[0071] Regarding the tilt angle of the power conversion device 20 (i.e., the tilt angle of the heat sink 5), the tilt angle of the heat sink 5 rotating around the first axis 01 and the tilt angle of the heat sink 5 rotating around the second axis 02 can be detected. Figure 11 exemplarily shows the positions of the first axis 01 and the second axis 02, wherein the first axis 01 and the second axis 02 are perpendicular to each other and both parallel to the horizontal plane; that is, the first axis 01 and the second axis 02 are two mutually perpendicular horizontal axes. It should be noted that the horizontal plane refers to a plane perpendicular to the direction of gravity. For example, after the power conversion device 20 is normally installed (without tilting), the top and bottom of the housing 1 of the power conversion device 20 are arranged along the direction of gravity (parallel to the Z-axis), and the arrangement direction of the top and bottom of the housing 1 is perpendicular to the horizontal plane. In the embodiment shown in Figure 11, the first axis 01 is parallel to the X-axis, and the second axis 02 is parallel to the Y-axis; in some other embodiments, the first axis 01 is parallel to the Y-axis, and the second axis 02 is parallel to the X-axis, or the first axis 01 and the second axis 02 are any two mutually perpendicular horizontal axes. For ease of explanation, Figure 11 also includes a reference axis 05, which is parallel to the Z-axis. That is, the first axis 01, the second axis 02, and the reference axis 05 are perpendicular to each other.
[0072] Taking the radiator 5 rotating around the first axis 01 as an example, Figure 12 exemplarily shows the situation after the radiator 5 rotates around the first axis 01. Referring to Figure 12, the solid reference axis 05 is the position of the reference axis 05 when the radiator 5 is not rotating (the position of the reference axis 05 in Figure 11), and the dashed reference axis is the position of the reference axis 05 after the radiator 5 rotates. The angle α1 between the solid reference axis 05 and the dashed reference axis 05 is the tilt angle of the radiator 5 rotating around the first axis 01. Similarly, the tilt angle of the radiator 5 rotating around the second axis 02 can also be obtained, which will not be specifically described in this application.
[0073] Accelerometer 81 (e.g., a triaxial accelerometer) can detect the components of the gravitational acceleration of the power conversion device 20 on different coordinate axes (e.g., the X-axis, Y-axis, and Z-axis). Based on the detection results of accelerometer 81, the tilt angle of the power conversion device 20 about the first axis 01 and the tilt angle of the power conversion device 20 about the second axis 02 can be determined. The tilt angles of the power conversion device 20 about the first axis 01 and the tilt angles about the second axis 02 can each have corresponding angle thresholds. For example, the angle thresholds include a first angle threshold (the tilt angle threshold of the radiator 5 about the first axis 01) and a second angle threshold (the tilt angle threshold of the radiator 5 about the second axis 02). If the tilt angle of the power conversion device 20 around any axis (first axis 01 or second axis 02) is too large, for example, if the tilt angle of the heat sink 5 around the first axis 01 is greater than or equal to a first angle threshold, or if the tilt angle of the heat sink 5 around the second axis 02 is greater than or equal to a second angle threshold, the liquid cooling medium 511 inside the heat sink 5 will not be able to effectively dissipate heat for the power module 2. In this case, reducing the output power of the power conversion device 20 (derating operation or shutdown) can reduce the heat generation of the power module 2 and protect the power conversion device 20.
[0074] Furthermore, in some embodiments, when the tilt angle of the power conversion device 20 is too large, the controller 32, in addition to controlling the power conversion device 20 to operate at a reduced rate, can also output an alarm signal. That is, when the tilt angle of the heat sink 5 relative to the horizontal plane is greater than or equal to an angle threshold, the controller 32 outputs an alarm signal. For example, the alarm signal may be transmitted to the control room, so that the user in the control room can be aware that the tilt angle of the power conversion device 20 is too large and take timely action; or, for example, the alarm signal may cause the power conversion device 20 to emit an audible or visual warning to alert the user that the power conversion device 20 is malfunctioning, facilitating further operation by the user. For example, the user can adjust the position of the power conversion device 20 based on the alarm signal output by the controller 32 to resolve the malfunction of the power conversion device 20.
[0075] In some embodiments, if the position of the power conversion device 20 is restored (not tilted), or if the tilt of the power conversion device 20 is small, that is, if the tilt angle of the heat sink 5 about the first axis O1 is less than a first angle threshold and the tilt angle of the heat sink 5 about the second axis O2 is less than a second angle threshold, the liquid cooling medium 511 inside the heat sink 5 can effectively dissipate heat for most (or all) of the bare dies 23 inside the power module 2. In this case, the controller 32 can also control the output power of the power conversion device 20 to increase. For example, the controller 32 can control the output power of the power conversion device 20 to return to its initial state, that is, the controller 32 makes the output power value of the power conversion device 20 equal to the target power value, and the power conversion device 20 exits the derating operation state, at which point the power conversion device 20 can operate normally.
[0076] If the power conversion device 20 tipes over, the power conversion device 20 (or the heat sink 5) will generate a large angular velocity. Therefore, to further protect the power conversion device 20, the angular velocity of the heat sink 5 can also be detected. In some embodiments, referring back to FIG3 or FIG4, the position sensor 8 further includes an angular velocity sensor 82, which can detect rotational angular velocity using the Coriolis force. In the embodiment shown in FIG3 or FIG4, the accelerometer 81 and the angular velocity sensor 82 can be packaged in a single package, existing as a single chip. In other embodiments, the accelerometer 81 and the angular velocity sensor 82 are two separate structures, and there is a gap between the accelerometer 81 and the angular velocity sensor 82. Referring to FIG3 or FIG4, the angular velocity sensor 82 is fixed to the circuit board 3, for example, fixed to the side of the circuit board 3 away from the heat sink 5, so that the angular velocity sensor 82 does not affect the connection between the heat sink 5 and the power module 2, which is beneficial for the heat sink 5 to dissipate heat from the power module 2.
[0077] The angular velocity of the heat sink 5, and thus the angular velocity of the power conversion device 20, can be obtained through the detection of the angular velocity sensor 82. For example, the angular velocity sensor 82 transmits the detection result to the controller 32 of the power conversion device 20, which can then determine the angular velocity of the power conversion device 20 based on the detection result. In the event of the power conversion device 20 tipping over, the angular velocity sensor 82 detects a significant angular velocity and determines that the power conversion device 20 has tipped over. Specifically, if the angular velocity of the power conversion device 20 reaches (or is greater than or equal to) an angular velocity threshold, the controller 32 can reduce the output power of the power conversion device 20, i.e., de-rated operation or shutdown. This reduces the heat generation of the power module 2, lowering the risk of overheating and reducing the possibility of damage to the power conversion device 20.
[0078] Regarding the angular velocity of the power conversion device 20 (i.e., the angular velocity of the heat sink 5), the angular velocity of the heat sink 5 rotating about the third axis 03 and the angular velocity of the heat sink 5 rotating about the fourth axis 04 can be detected. Figure 13 exemplarily shows the positions of the third axis 03 and the fourth axis 04, wherein the third axis 03 and the fourth axis 04 are perpendicular to each other and both parallel to the horizontal plane; that is, the third axis 03 and the fourth axis 04 are two mutually perpendicular horizontal axes. In the embodiment shown in Figure 13, the third axis 03 is parallel to the X-axis, and the fourth axis 04 is parallel to the Y-axis; in some other embodiments, the third axis 03 is parallel to the Y-axis, and the fourth axis 04 is parallel to the X-axis, or the third axis 03 and the fourth axis 04 are any two mutually perpendicular horizontal axes. Referring to Figure 13, direction F3 is one direction of rotation of the heat sink 5 about the third axis 03, direction F4 is another direction of rotation of the heat sink 5 about the third axis 03; direction F5 is one direction of rotation of the heat sink 5 about the fourth axis 04, and direction F6 is another direction of rotation of the heat sink 5 about the fourth axis 04.
[0079] The angular velocity sensor 82 (e.g., a multi-axis gyroscope) can detect the angular velocities of the power conversion device 20 when it rotates around the third axis 03 and the fourth axis 04. Each of these angular velocities can have its own corresponding angular velocity threshold, such as a first angular velocity threshold and a second angular velocity threshold. If the angular velocity of the power conversion device 20 rotating around either axis (the third axis 03 or the fourth axis 04) is too high—that is, if the angular velocity of the heat sink 5 rotating around the third axis 03 is greater than or equal to the first angular velocity threshold, or if the angular velocity of the heat sink 5 rotating around the fourth axis 04 is greater than or equal to the second angular velocity threshold—the output power of the power conversion device 20 is reduced. In this case, the power conversion device 20 operates at a derating rate or is shut down to protect it.
[0080] By setting up an angular velocity sensor 82, the accelerometer 81 can assist in detecting the status of the power conversion device 20, enabling the power conversion device 20 to quickly execute a series of protective measures such as derating operation or shutdown. For example, in the event of a rapid tilt of the power conversion device 20, the device may not yet have reached a large tilt angle, and the controller 32 cannot determine whether the tilt of the device 20 is excessive based on the detection results of the accelerometer 81. However, the angular velocity sensor 82 can detect that the device 20 has generated a large angular velocity. The controller 32 can then determine that the device 20 is tilting, and based on the detection results of the angular velocity sensor 82, the device 20 can react quickly, entering a derating operation state or shutting down directly.
[0081] If the power conversion device 20 tilts slowly, the cooling medium 511 inside the heat sink 5 does not instantly lose its ability to dissipate heat from the multiple bare dies 23. In this case, the rotation of the power conversion device 20 has little impact on the heat dissipation capacity of the heat sink 5. Therefore, the power conversion device 20 can be allowed to rotate or tilt to a certain degree, and the acceleration sensor 81 can be used to determine that the tilt of the power conversion device 20 is too large before putting the power conversion device 20 into derating operation or shutting it down directly.
[0082] Specifically, if the angular velocity sensor 82 detects a large angular velocity and causes the power conversion device 20 to enter a derating operation state, and if the position of the power conversion device 20 is restored (not tilted), or if the tilt of the power conversion device 20 is small, and the accelerometer 81 determines that the tilt angle of the heat sink 5 around the first axis 01 is less than the first angle threshold, and the tilt angle of the heat sink 5 around the second axis 02 is less than the second angle threshold, then the power conversion device 20 can exit the derating operation state and can then operate normally.
[0083] Both the accelerometer 81 and the angular velocity sensor 82 suffer from temperature drift. When they operate at different temperatures, their detection results will deviate. This is especially true when the power conversion device 20 functions as an inverter, where the operating temperature of the accelerometer 81 varies by tens of degrees Celsius (°C), making the temperature drift significantly impact its detection results. In some embodiments, referring back to Figures 3 and 4, the power conversion device 20 further includes a temperature sensor 9 housed within the housing 1. The temperature sensor 9 is located outside the power module 2 and is fixed to the circuit board 3.
[0084] Referring to Figures 3 and 4, when the accelerometer 81 and the angular velocity sensor 82 are integrated into a single position sensor 8, the position sensor 8 (including the accelerometer 81 and the angular velocity sensor 82) is arranged adjacent to the temperature sensor 9. That is, no other electronic components are placed between the accelerometer 81 and the temperature sensor 9, and similarly, no other electronic components are placed between the angular velocity sensor 82 and the temperature sensor 9, enabling the temperature sensor 82 to detect the temperatures of both the accelerometer 81 and the angular velocity sensor 82. In other embodiments, if the accelerometer 81 and the angular velocity sensor 82 are two independent structures, then both the accelerometer 81 and the angular velocity sensor 82 are arranged adjacent to the temperature sensor 9. That is, no other electronic components are placed between the accelerometer 81 and the temperature sensor 9, and no other electronic components are placed between the angular velocity sensor 82 and the temperature sensor 9. For example, the accelerometer 81 and the angular velocity sensor 82 are located on different sides of the temperature sensor 9. In this example, the temperature sensor 82 can also detect the temperatures of both the accelerometer 81 and the angular velocity sensor 82.
[0085] It should be noted that when temperature sensor 82 detects the temperatures of accelerometer 81 and angular velocity sensor 82, it means that temperature sensor 82 can detect the temperatures surrounding accelerometer 81 and angular velocity sensor 82. Since temperature sensor 82 is relatively close to both accelerometer 81 and angular velocity sensor 81, the temperature around accelerometer 81 detected by temperature sensor 82 can be used to characterize the temperature of accelerometer 81, and the temperature around angular velocity sensor 82 detected by temperature sensor 82 can be used to characterize the temperature of angular velocity sensor 82.
[0086] Temperature sensor 9 detects the temperature around acceleration sensor 81 and angular velocity sensor 82. The controller 32 of power conversion device 20 can query the temperature compensation table of acceleration sensor 81 based on the detection results of temperature sensor 9, and perform corresponding temperature compensation on the detection results of acceleration sensor 81 and angular velocity sensor 82, thereby improving the accuracy of the detection results of acceleration sensor 81.
[0087] Furthermore, if the power conversion device 20 also includes a temperature sensor 9, the temperature sensor 9 can also detect the internal temperature of the housing 1 of the power conversion device 20 or the temperature of the circuit board 3. Even if the power conversion device 20 does not tilt or fall over, if the internal temperature of the power conversion device 20 is too high, or if the temperature of the circuit board 3 is too high, and the temperature detected by the temperature sensor 9 reaches (greater than or equal to) the temperature threshold, the output power of the power conversion device 20 will be reduced, causing the power conversion device 20 to enter a derating operation state or be directly shut down, thus protecting the power conversion device 20.
[0088] In other words, when the power conversion device 20 includes a temperature sensor 9, an angular velocity sensor 82, and an acceleration sensor 81, the power conversion device 20 can operate at a derating rate if any one of the following three conditions is met: Condition 1, the temperature detected by the temperature sensor 9 is greater than or equal to the temperature threshold; Condition 2, the angular velocity of the heat sink 5 is greater than or equal to the angular velocity threshold; Condition 3, the tilt angle of the heat sink 5 is greater than or equal to the angle threshold.
[0089] However, if the internal temperature of the power conversion device 20 or the temperature of the circuit board 3 decreases, and the temperature detected by the temperature sensor 9 is lower than the temperature threshold, it is also necessary to determine whether the tilt angle of the heat sink 5 is lower than the angle threshold. If the tilt angle of the heat sink 5 is also lower than the angle threshold, then the power conversion device 20 can exit the derating operation state. Similarly, if the power conversion device 20 also includes a temperature sensor 9, and the tilt angle of the heat sink 5 is lower than the angle threshold, it is also necessary to determine whether the internal temperature of the power conversion device 20 or the temperature of the circuit board 3 has decreased. Only if the temperature detected by the temperature sensor 9 is also lower than the temperature threshold can the power conversion device 20 exit the derating operation state.
[0090] For example, after the power conversion device 20 is derated, the following two conditions must be met simultaneously: Condition 1, the tilt angle of the heat sink 5 is less than the angle threshold. For example, the tilt angle of the heat sink 5 around the first axis 01 is less than the first angle threshold, and the tilt angle of the heat sink 5 around the second axis 02 is less than the second angle threshold; Condition 2, the temperature detected by the temperature sensor 9 is less than the temperature threshold, in order for the output power of the power conversion device 20 to increase (exit derating).
[0091] The above detailed description of the power conversion device 20 and the analysis of its beneficial effects can be applied to the control method of the power conversion device 20, and will not be repeated here in the embodiments of this application.
[0092] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power conversion device, characterized in that, The device includes a housing, a power module, a heat sink, and a controller. The housing is used to house the power module, which converts direct current (DC) from a photovoltaic module or an energy storage battery into alternating current (AC). The heat sink is connected to the power module and is at least partially located outside the housing. The heat sink contains a cooling medium for gas-liquid conversion. The power conversion device also includes an acceleration sensor housed within the housing, the detection result of which is used to characterize the tilt angle of the radiator relative to the horizontal plane when the housing is mounted in the installation position; When the tilt angle of the heat sink relative to the horizontal plane is greater than or equal to an angle threshold, the controller is used to control the output power of the power conversion device to decrease.
2. The power conversion device according to claim 1, characterized in that, The angle threshold includes a first angle threshold and a second angle threshold; When the tilt angle of the radiator about the first axis is greater than or equal to the first angle threshold, or when the tilt angle of the radiator about the second axis is greater than or equal to the second angle threshold, the controller is used to control the output power of the power conversion device to decrease. The first axis and the second axis are perpendicular to each other and both are parallel to the horizontal plane.
3. The power conversion device according to claim 2, characterized in that, After the controller reduces the output power of the power conversion device, if the angle of rotation of the radiator around the first axis is less than the first angle threshold and the angle of rotation of the radiator around the second axis is less than the second angle threshold, the controller is also used to control the output power of the power conversion device to increase.
4. The power conversion device according to any one of claims 1-3, characterized in that, If the angle of inclination of the radiator relative to the horizontal plane is greater than or equal to the angle threshold, the controller is also used to output an alarm signal.
5. The power conversion device according to any one of claims 1-4, characterized in that, The power conversion device also includes an angular velocity sensor housed within the housing, the angular velocity sensor being used to detect the angular velocity of the heat sink; When the angular velocity of the heat sink is greater than or equal to an angular velocity threshold, the controller is used to control the output power of the power conversion device to decrease.
6. The power conversion device according to claim 5, characterized in that, The angular velocity threshold includes a first angular velocity threshold and a second angular velocity threshold; When the angular velocity of the radiator rotating about the third axis is greater than or equal to the first angular velocity threshold, or when the angular velocity of the radiator rotating about the fourth axis is greater than or equal to the second angular velocity threshold, the controller is used to control the output power of the power conversion device to decrease. The third axis and the fourth axis are perpendicular to each other and both are parallel to the horizontal plane.
7. The power conversion device according to any one of claims 1-6, characterized in that, The power conversion device also includes a circuit board and a temperature sensor housed in the housing. The temperature sensor and the acceleration sensor are both fixed to the same side of the circuit board. The temperature sensor is used to detect the temperature of the circuit board. There are no other devices between the temperature sensor and the acceleration sensor. The temperature sensor is also used to detect the temperature of the acceleration sensor.
8. The power conversion device according to claim 7, characterized in that, When the temperature value detected by the temperature sensor is greater than or equal to a temperature threshold, the controller is used to control the output power of the power conversion device to decrease.
9. The power conversion device according to claim 7 or 8, characterized in that, The power module is fixed to the circuit board and located between the circuit board and the heat sink. The temperature sensor and the acceleration sensor are both fixed to the side of the circuit board away from the heat sink.
10. The power conversion device according to any one of claims 1-9, characterized in that, The heat sink includes a base plate and a heat sink pipe. The base plate is fixed to the housing. The internal space of the base plate has a cooling medium for gas-liquid conversion. The heat sink pipe is fixed to one of the plates of the base plate. The internal channel of the heat sink pipe is connected to the internal space of the base plate. The housing has a mounting port, the substrate and the heat sink are both located outside the housing, the power module passes through the mounting port and is connected to the surface of the substrate opposite to the heat sink, or the substrate is located inside the housing and connected to the power module, and the heat sink extends out of the housing through the mounting port.