Integrated medium voltage propulsion frequency converter, system and cooling dehumidification method

Abstract

The application discloses an integrated medium-voltage propulsion frequency converter, a system and a cooling and dehumidifying method, and relates to the technical field of underwater electric propulsion devices. The integrated medium-voltage propulsion frequency converter comprises a shell, a plurality of frequency conversion loop devices and a cooling and dehumidifying system; the internal space of the shell comprises a device cabin and an air duct cabin which are separated from each other; the cooling and dehumidifying system comprises a driving fan, a heat dissipation device and a condenser; the driving fan drives air to circulate between the device cabin and the air duct cabin; the heat dissipation device receives hot air from the device cabin and cools the hot air; the condenser receives air from the inside of the air duct cabin and condenses and dehumidifies the air, and the air after condensation and dehumidification can flow back to the device cabin. Based on the technical scheme disclosed by the application, the internal air of the frequency converter is isolated from the external high-humidity environment, efficient cooling and active dehumidification are combined, condensation is prevented, the electromagnetic compatibility and low-noise performance of the equipment are improved, the power density of the system is improved, and cable connection is simplified.

Description

Technical Field

[0001] This invention relates to the field of underwater electric propulsion technology, specifically to an integrated medium-voltage propulsion frequency converter, system, and cooling and dehumidification method. Background Technology

[0002] With the development of new energy ships, high-efficiency, high-power-density electric propulsion systems have become an important development direction for marine power systems. As a key component of marine electric propulsion systems, the increased power density of frequency converters leads to a sharp increase in heat generation per unit volume. Simultaneously, the marine environment, characterized by high humidity and high salt spray, places higher demands on the heat dissipation and moisture-proof performance of propulsion frequency converters.

[0003] Currently, medium-voltage high-power propulsion systems, due to their high voltage levels and complex insulation and heat dissipation requirements, typically employ a separate design for the motor and frequency converter. This design suffers from drawbacks such as dispersed equipment layout and complex connecting cables. Regarding heat dissipation, existing propulsion frequency converters often use fans installed on the cabinet walls to reduce internal air temperature. However, this method easily reduces the equipment's electromagnetic compatibility performance and generates significant noise pollution. Furthermore, when the air inside the frequency converter interacts with the external humid environment, condensation is likely to occur, increasing the risk of short circuits. To prevent condensation, some frequency converters use internal heaters. However, this increases the internal air temperature of the frequency converter, potentially causing internal electrical components to fail due to overheating. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an integrated medium-voltage drive frequency converter, system and cooling and dehumidification method to solve the technical problem that the heat dissipation and anti-condensation measures of the frequency converter in the prior art are independent and have a single effect, making it difficult to achieve efficient heat dissipation and active dehumidification at the same time.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an integrated medium-voltage drive frequency converter, comprising: The shell, whose internal space includes at least mutually separated device compartments and air duct compartments; Multiple frequency conversion circuit devices are arranged inside the device compartment; and The cooling and dehumidification system is configured as an internal circulation loop connecting the device compartment and the air duct compartment respectively; The cooling and dehumidification system includes a drive fan, a heat dissipation device, and a condenser. The drive fan is configured to drive air to circulate between the device compartment and the air duct compartment along the internal circulation loop. The heat dissipation device is disposed in the air duct compartment, which receives hot air from the device compartment and cools it. The condenser is configured to receive air from inside the air duct compartment and condense and dehumidify it, and the air outlet of the condenser is connected to the device compartment so that the condensed and dehumidified air can flow back to the device compartment.

[0006] In some embodiments, the device compartment and the air duct compartment are located on opposite sides of the internal space of the housing, and the device compartment and the air duct compartment are separated by an internal partition.

[0007] In some embodiments, the device compartment includes a plurality of sub-compartments, any two adjacent sub-compartments are separated by structural reinforcing ribs, and the plurality of sub-compartments include at least one inverter compartment for accommodating frequency conversion circuit devices and at least one condenser compartment for accommodating the condenser.

[0008] In some embodiments, the plurality of sub-compartments include a plurality of inverter compartments and two condenser compartments. The plurality of inverter compartments are arranged side by side, and the two condenser compartments are respectively arranged on opposite sides of the plurality of inverter compartments. A ventilation structure is provided between any two adjacent sub-compartments.

[0009] In some embodiments, the drive fan includes: A first fan, configured in a one-to-one correspondence with each inverter compartment, is installed within the corresponding inverter compartment and is used to draw hot air from the corresponding inverter compartment into the air duct compartment; and The second fan is arranged in a one-to-one correspondence with the condenser chamber and is installed in the corresponding condenser chamber to draw the cooled air in the air duct chamber into the corresponding condenser chamber.

[0010] In some embodiments, the air duct chamber is provided with a plurality of air duct partitions, which divide the air duct chamber into a plurality of independent air duct sections; the plurality of air duct sections correspond to the plurality of inverter chambers respectively and are configured to receive hot air from the corresponding inverter chamber respectively.

[0011] In some embodiments, each of the air duct sections is separated from the corresponding inverter compartment by an internal partition; the heat dissipation device is a water-cooled plate radiator, and one side of the water-cooled plate radiator is provided with multiple fins, which extend and are close to the internal partition.

[0012] In some embodiments, at least one of the frequency conversion circuit devices has an integrated water-cooled plate inside; the housing is also provided with a water inlet and outlet interface, one end of which is connected to the water-cooled plate through a pipe, and the other end of which can be connected to an external circulating water circuit.

[0013] In a second aspect, the present invention also provides an integrated medium-pressure propulsion system, including an integrated medium-pressure propulsion frequency converter as described in the first aspect, and a propulsion motor electrically connected to the frequency converter circuit device.

[0014] Thirdly, the present invention also provides a cooling and dehumidification method for an integrated medium-voltage drive frequency converter as described in the first aspect, comprising the following steps: Hot air from the drive unit compartment enters the air duct compartment; Controlling the flow of hot air through the heat dissipation device to achieve heat exchange and cooling; The cooled air is controlled to flow through the condenser to achieve condensation and dehumidification; The dehumidified, dry, and cold air is controlled to flow back into the device compartment, forming an internal circulation.

[0015] Compared with the prior art, the present invention provides an integrated medium-pressure propulsion frequency converter, system and cooling and dehumidification method, which separates the device compartment and the air duct compartment inside the frequency converter housing and constructs an internal circulation loop connecting the two compartments. The drive fan drives the air to circulate in the loop, thereby completing the cooling of the frequency converter circuit devices and the active control of the internal air humidity.

[0016] Thus, on the one hand, the internal circulation mode isolates the air inside the inverter from the high-humidity marine environment outside, preventing condensation. This eliminates the need for traditional heater-based anti-condensation solutions, thus avoiding the risk of internal temperature rise and component thermal failure. On the other hand, the heat dissipation device and condenser work together to achieve efficient cooling and active dehumidification in one cycle. This not only improves the electromagnetic compatibility and low noise of the equipment but also overcomes the shortcomings of heater solutions, which are limited in effectiveness and have thermal side effects. Furthermore, the integrated structure significantly increases the system power density and simplifies cable connections. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the frequency converter in one embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of a frequency converter in one embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the device compartment in one embodiment of the present invention; Figure 4 This is a schematic diagram of the internal structure of the device compartment in one embodiment of the present invention; Figure 5This is a perspective view of the inverter structure in one embodiment of the present invention; Figure 6 This is a perspective view of the inverter structure in one embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the principle of cooling and dehumidification of the propulsion system in one embodiment of the present invention; Figure 8 This is a schematic flowchart of a frequency converter cooling and dehumidification method in one embodiment of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1. Manual operation side; 2. Housing; 21. Door panel; 22. Water inlet / outlet interface; 23. Drain outlet; 3. Heat dissipation device; 31. Fin; 4. Component compartment; 41. Inverter compartment; 42. Condensation compartment; 5. Air duct compartment; 51. Air duct section; 6. Internal partition; 7. Structural reinforcing rib; 71. Ventilation structure; 8. Variable frequency circuit components; 81. Incoming busbar; 82. Pre-charge component; 83. Inverter module; 831. Inverter module support; 84. Secondary circuit component; 85. Outgoing busbar; 86. Voltage sensor; 87. Voltage divider resistor; 88. Transformer; 9. Water collector; 10. Drive fan; 101. First fan; 102. Second fan; 11. Condenser; 12. Condensate pipe; 13. Air duct partition; 14. Propulsion motor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To address the aforementioned technical problems, this invention provides an integrated medium-voltage drive frequency converter, system, and cooling and dehumidification method. By isolating the air inside the frequency converter from the external high-humidity environment, combined with efficient cooling and active dehumidification, it achieves anti-condensation, improves the electromagnetic compatibility and low noise performance of the equipment, increases the system power density, and simplifies cable connections.

[0021] Please see Figure 1 , Figure 1 This is a schematic diagram of the overall structure of an integrated medium-voltage propulsion frequency converter according to one embodiment of the present invention. The integrated medium-voltage propulsion frequency converter can be configured in an annular cylindrical shape, so that the outer diameter of the frequency converter can be consistent with the outer diameter of the propulsion motor 14, thereby facilitating the integrated installation of the two.

[0022] In practical applications, the back of the frequency converter can be fitted snugly against the housing of the propulsion motor 14, leaving space in its center to accommodate the motor's main shaft. This arrangement reduces the overall size of the propulsion system, helps increase its power density, simplifies the overall layout of the ship's electrical system, and also simplifies the cable connection between the frequency converter and the motor.

[0023] It should be noted that in this embodiment, the front and back of the inverter can be determined according to its relative position to the operator. That is, the front of the inverter can be defined as the manual operation side 1, while its back can be understood as the side away from the operator. This definition will be used in the following text and will not be repeated.

[0024] In some embodiments, please refer to Figure 2 The integrated medium-pressure drive frequency converter includes a housing 2, multiple frequency conversion circuit devices 8, and a cooling and dehumidification system. The housing 2 forms the framework of the external outline and internal space of the frequency converter, and is therefore configured as an annular cylindrical shape. A door panel 21 is provided on the front of the housing 2, while a heat dissipation device 3 is provided on its back. The internal space of the housing 2 is at least divided into independent device compartments 4 and air duct compartments 5.

[0025] For example, the housing 2 has a component compartment 4 and an air duct compartment 5 inside. The component compartment 4 and the air duct compartment 5 can be respectively arranged on opposite sides of the internal space of the housing 2. For example, the component compartment 4 can be located on the front of the frequency converter, while the air duct compartment 5 can be located on the back of the frequency converter. The component compartment 4 and the air duct compartment 5 can be physically separated by an internal partition 6 to ensure isolation between the two different functional areas. At the same time, multiple frequency converter circuit components 8 are arranged in the component compartment 4.

[0026] In some embodiments, the device compartment 4 can be further divided into multiple sub-compartments. Any two adjacent sub-compartments can be separated by structural reinforcing ribs 7, so that each sub-compartment can meet different functional requirements and ensure the mechanical strength of the overall structure of the device compartment 4. Each sub-compartment may include an inverter compartment 41 and a condenser compartment 42. The inverter compartment 41 may be equipped with the aforementioned frequency conversion circuit device 8, while the condenser compartment 42 may be equipped with a condenser 11.

[0027] For example, such as Figure 3As shown, the multiple sub-compartments may include multiple inverter compartments 41 and two condenser compartments 42. The multiple inverter compartments 41 can be arranged side by side, while the two condenser compartments 42 can be respectively located on opposite sides of all the inverter compartments 41. For example, the device compartment 4 can be divided into six sub-compartments from left to right, of which the four middle sub-compartments can be configured as inverter compartments 41, and the two compartments located on opposite sides of the four inverter compartments 41 (i.e., the leftmost and rightmost ends) can be configured as condenser compartments 42. At the same time, in order to ensure that air can circulate between the sub-compartments, a ventilation structure 71 is provided between any two adjacent sub-compartments (including between inverter compartments 41 and between inverter compartments 41 and condenser compartments 42), for example, ventilation ducts can be opened on the structural reinforcing ribs 7.

[0028] In some embodiments, please refer to Figure 4 The frequency conversion circuit device 8 is the core component that completes the power conversion and control functions. It may include an incoming busbar 81, a pre-charge component 82, an inverter module 83, a secondary circuit component 84, an outgoing busbar 85, a voltage sensor 86, a voltage divider resistor 87, and a transformer 88, etc.

[0029] For example, the incoming busbar 81 can be located at both ends outside the inverter and can be used to connect to a medium-voltage power supply. The outgoing busbar 85 can be distributed around the perimeter of the housing 2 and extend towards the rear end of the inverter (i.e., the side that is in contact with the propulsion motor 14) to facilitate electrical connection with the propulsion motor 14.

[0030] The inverter compartment 41 can house inverter modules 83, transformers 88, and connecting copper busbars, among other components. The inverter module 83 can be fixed to the structural reinforcing rib 7 via an inverter module support 831. The condenser compartment 42 can house a pre-charging assembly 82, a water collector 9, a secondary circuit assembly 84, a voltage sensor 86, a voltage divider resistor 87, a condenser 11, and condensate pipes 12, among other components. The secondary circuit assembly 84 is the control core, primarily composed of a controller, filter, temperature and humidity controller, contactor, and various terminal blocks.

[0031] Furthermore, at least one frequency converter circuit device 8 integrates a water-cooled plate inside. For example, components with high heat generation, such as the inverter module 83 and the pre-charge component 82, can integrate water-cooled plates (not shown in the figure). Correspondingly, a water collector 9 can be installed inside the condensation chamber 42. The water collector 9 can be used to collect the cooling water flowing through each water-cooled plate. At the same time, an inlet / outlet water interface 22 can be installed on the housing 2. One end of the inlet / outlet water interface 22 can be connected to the water collector 9 through a pipe, and then connected to each water-cooled plate. The other end can be used to connect to an external circulating water circuit, thereby removing the heat generated by the corresponding frequency converter circuit device 8 through water cooling, achieving water cooling heat dissipation.

[0032] In some embodiments, please refer to Figure 5-6 The integrated medium-pressure drive frequency converter may further include a cooling and dehumidification system disposed inside the housing 2. This system can be configured as an internal circulation loop connecting the aforementioned component compartment 4 and the air duct compartment 5. It may include a drive fan 10, a heat dissipation device 3, and the aforementioned condenser 11. The drive fan 10 can be disposed in the component compartment 4, and can drive air to circulate between the component compartment 4 and the air duct compartment 5 along the internal circulation loop. The heat dissipation device 3 can be disposed in the air duct compartment 5, and can receive and cool the hot air from the component compartment 4. The condenser 11 can be disposed in the component compartment 4, and can receive and dehumidify the air from inside the air duct compartment 5. The air outlet of the condenser 11 can be connected to the component compartment 4, allowing the dehumidified air to flow back to the component compartment 4.

[0033] For example, such as Figure 5 As shown, the drive fan 10 may include a first fan 101 and a second fan 102. The first fan 101 can be configured in a one-to-one correspondence with the inverter compartment 41, and can be installed within the corresponding inverter compartment 41, for example, it can be fixedly installed on the internal partition 6, and can be positioned above the inverter module 83 within the corresponding inverter compartment 41. The air inlet of the first fan 101 can face the heat-generating components such as the inverter module 83, and its air outlet can connect to the ventilation duct compartment 5, thereby enabling the first fan 101 to draw hot air from the corresponding inverter compartment 41 into the ventilation duct compartment 5.

[0034] Meanwhile, the second fan 102 can be configured in a one-to-one correspondence with the condenser chamber 42, and can be installed in the corresponding condenser chamber 42 or fixedly mounted on the internal partition 6. The air inlet of the second fan 102 can face the air outlet of the heat dissipation device 3, and the air outlet of the second fan 102 can connect to the corresponding condenser chamber 42, so that the second fan 102 can draw the cooled air in the air duct chamber 5 into the corresponding condenser chamber 42.

[0035] It should be noted that in this embodiment, each inverter compartment 41 may be equipped with an inverter module 83, and each inverter module 83 may be equipped with the aforementioned first fan 101 above it; similarly, each condenser compartment 42 may be equipped with a second fan 102, and the first fan 101 and the second fan 102 may be respectively arranged on the upper and lower sides of the device compartment 4.

[0036] Based on this, each condenser compartment 42 can be equipped with a condenser 11, and the air outlet of the second fan 102 can be directed towards the air inlet of the condenser 11, so that the air discharged by the second fan 102 can enter the condenser 11 for condensation and dehumidification. With this configuration, the air condensed and dehumidified by the condenser 11 can be discharged from the air outlet of the condenser 11 and flow back to the corresponding condenser compartment 42. Since the air in the device compartment 4 can circulate through the ventilation structure 71 between the various sub-compartments, the air that has been cooled and dehumidified can flow into each inverter compartment 41, thereby achieving efficient cooling of the inverter circuit devices 8 in each inverter compartment 41 on the basis of active dehumidification.

[0037] Furthermore, to drain the condensate generated during the operation of the condenser 11, the frequency converter is also equipped with a drain outlet 23. The position of the drain outlet 23 can be flexibly set as needed, for example, it can be set on the aforementioned door panel 21. At the same time, a condenser pipe can also be installed in each condensation chamber 42. One end of the condenser pipe can be connected to the condenser 11, and the other end can be connected to the aforementioned drain outlet 23, thereby facilitating the discharge of the condensate collected by the condenser 11 to the outside of the frequency converter.

[0038] In some embodiments, please refer to Figure 6 The air duct compartment 5 is equipped with multiple air duct baffles 13, which can divide the air duct compartment 5 into multiple independent air duct sections 51. At this time, the multiple air duct sections 51 can correspond to the multiple inverter compartments 41 mentioned above. Taking one air duct section 51 as an example, the opposite sides of the air duct section 51 in the extension direction can respectively form an air inlet side and an air outlet side. The air inlet side can be directly connected to the air outlet of the first fan 101 in the corresponding inverter compartment 41, while the air outlet side can be independently connected to the air inlet of the second fan 102, or the air outlet sides of each air duct section 51 can be combined and then connected to the air inlet of the second fan 102. With this configuration, each air duct section 51 can receive hot air from the corresponding inverter compartment 41. This hot air can flow along the corresponding air duct section 51 and finally flow back to the condenser compartment 42 under the action of the second fan 102.

[0039] In some embodiments, each air duct section 51 is separated from the corresponding inverter compartment 41 by an internal partition 6. Meanwhile, the aforementioned heat dissipation device 3 is installed in the air duct compartment 5, which can be used to cool the flowing hot air in each air duct section 51.

[0040] For example, such as Figure 6As shown, the heat dissipation device 3 can be configured as a water-cooled plate radiator. The water-cooled plate radiator can be installed on the inner side of the back of the inverter, with multiple fins 31 on one side (i.e., the side closer to the device compartment 4). Each fin 31 can extend towards the side where the device compartment 4 is located and approach the aforementioned internal partition 6, thereby greatly increasing the heat exchange area between the fins 31 and the air within a limited space. With this configuration, when hot air from the inverter compartment 41 enters the corresponding air duct section 51, it must flow through these fins 31 and exchange heat with them, thereby achieving a cooling effect.

[0041] Please see Figure 7 The present invention also provides an integrated medium-pressure propulsion system, which may include the integrated medium-pressure propulsion frequency converter in any of the above embodiments, and a propulsion motor 14 electrically connected to the frequency converter circuit device 8.

[0042] For example, the overall shape of the integrated medium-voltage propulsion inverter can be configured as an annular cylinder, with its outer diameter set to be substantially consistent with the outer diameter of the propulsion motor 14. The back of the inverter (i.e., the side with the water-cooled heat sink) can directly fit against the end face of the propulsion motor 14's housing and achieve a rigid connection using bolts or other fasteners. Simultaneously, the central portion of the inverter's annular structure is left open to accommodate the propulsion motor 14's main shaft. This configuration allows for a tight, "sleeve-like" or "side-by-side" mounting method, achieving a high degree of mechanical integration between the inverter and the motor, making the entire propulsion system a compact and robust integrated unit.

[0043] It should be noted that because the frequency converter and the propulsion motor 14 are directly mounted, the electrical distance between them is significantly shortened. Specifically, the output busbar 85 of the integrated medium-voltage propulsion frequency converter can be arranged around the perimeter of the housing 2 and extend towards its rear end (i.e., the side that is in contact with the propulsion motor 14). After the frequency converter and the propulsion motor 14 are mechanically connected, the output busbar 85 corresponds precisely to the wiring terminal position on the periphery of the housing 2 of the propulsion motor 14, thus enabling direct electrical connection via copper busbars or short cables.

[0044] Meanwhile, regarding thermal management, as mentioned earlier, the heat-generating components inside the frequency converter (such as the inverter module 83) are integrated with water-cooled plates, and a water-cooled heat sink is installed on the back of the frequency converter. When the frequency converter and the propulsion motor 14 are installed in close contact, their cooling systems can be effectively integrated. For example, the external circulating water path that provides cooling water to the frequency converter can first flow through the water-cooled heat sink of the frequency converter and then be guided to the cooling jacket of the propulsion motor 14, or vice versa, forming a unified and efficient series or parallel cooling loop. This arrangement avoids the need to set up separate cooling systems for the two devices, helps to simplify the piping layout of the ship, and further improves the integration and power density of the propulsion system.

[0045] In summary, the integrated medium-pressure propulsion system provided by the embodiments of the present invention, by integrating the above-mentioned integrated medium-pressure propulsion frequency converter with the propulsion motor 14 in terms of mechanical, electrical and thermal management, helps to improve the power density, reliability, electromagnetic compatibility and environmental adaptability of the system, and simplifies the overall layout of the ship and cable connections.

[0046] Please see Figure 8 The present invention also provides a cooling and dehumidification method for an integrated medium-voltage propulsion frequency converter, which can be applied to the integrated medium-voltage propulsion frequency converter in any of the above embodiments, and includes the following steps: Step 1: The hot air in the drive unit compartment 4 is drawn into the air duct compartment 5. Specifically, when the inverter is operating, the inverter module 83, transformer 88, and other inverter circuit components 8 in the inverter compartment 41 generate a large amount of heat, causing the air temperature inside the inverter compartment 41 to rise. At this time, the first fan 101 installed on the internal partition 6 of each inverter compartment 41 can forcibly extract the hot air accumulated in the inverter compartment 41 and send it into the air duct section 51 corresponding to that inverter compartment 41 in the air duct compartment 5 through the ventilation opening on the internal partition 6 (i.e., the air outlet of the first fan 101). Since each inverter compartment 41 has its own independent first fan 101 and independent air duct section 51, mutual interference of hot air between different inverter compartments 41 can be avoided, achieving precise heat dissipation.

[0047] Step Two: Controlling the flow of hot air through the heat dissipation device 3 to achieve heat exchange and cooling. Specifically, the hot air sent into the air duct section 51, under the pressure of the first fan 101, flows through the densely distributed fins 31 on the surface of the water-cooled plate radiator. At this time, the external circulating water circuit continuously supplies the water-cooled plate radiator with cooler water through the inlet / outlet interface 22, the water collector 9, and the internal channels of the water-cooled plate. The heat in the hot air is efficiently transferred to the water-cooled plate through the fins 31 and then carried away by the cooling water, thereby significantly reducing the temperature of the air itself. After this step, the hot air is cooled to a lower temperature. At the same time, because the water-cooled plate radiator has extremely high heat exchange efficiency, it can quickly remove the heat from the hot air, thus ensuring that the internal temperature of the frequency converter can be maintained within a safe range.

[0048] Step 3: Control the flow of cooled air through condenser 11 to achieve condensation dehumidification. Specifically, the cooled air gathers inside the air duct chamber 5. At this time, the second fan 102, installed on the internal partition 6 of the condenser chamber 42, starts, drawing the low-temperature air from the air duct chamber 5 into the condenser chamber 42. Under the blowing of the second fan 102, this low-temperature air first flows through the condenser 11 installed at the air outlet of the second fan 102. When the air flows over the even cooler surface of the condenser 11, the water vapor in the air quickly condenses into water droplets, adhering to the fins 31 or coils of the condenser 11. These condensates collect under gravity and are eventually guided to the drain outlet 23 on the door panel 21 and discharged outside the inverter through the condensate pipe 12 connected to the condenser 11, thus achieving active and efficient dehumidification of the internal air.

[0049] Step 4: Control the return of dehumidified dry air to the device compartment 4, forming an internal circulation. Specifically, after dehumidification by the condenser 11, the air becomes dry and the temperature is still low. Since the condenser compartment 42 and the inverter compartment 41 are interconnected by the ventilation structure 71 (i.e., ventilation duct) on the structural reinforcing rib 7, the dehumidified dry air will naturally return from the condenser compartment 42 to each inverter compartment 41 under the action of pressure difference. At this point, the air completes a complete cooling and dehumidification internal circulation. Subsequently, the dry air absorbs the heat generated by the inverter circuit device 8 again, becomes hot air, and is drawn back into the air duct compartment 5 by the first fan 101. This cycle repeats continuously, forming a closed-loop, continuous heat transfer and moisture removal process.

[0050] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An integrated medium-voltage drive frequency converter, characterized in that, include: The shell, whose internal space includes at least mutually separated device compartments and air duct compartments; Multiple frequency conversion circuit devices are arranged inside the device compartment; as well as The cooling and dehumidification system is configured as an internal circulation loop connecting the device compartment and the air duct compartment respectively; The cooling and dehumidification system includes a drive fan, a heat dissipation device, and a condenser. The drive fan is configured to drive air to circulate between the device compartment and the air duct compartment along the internal circulation loop. The heat dissipation device is disposed in the air duct compartment, which receives hot air from the device compartment and cools it. The condenser is configured to receive air from inside the air duct compartment and condense and dehumidify it, and the air outlet of the condenser is connected to the device compartment so that the condensed and dehumidified air can flow back to the device compartment.

2. The integrated medium-voltage drive frequency converter according to claim 1, characterized in that, The device compartment and the air duct compartment are located on opposite sides of the internal space of the shell, and are separated by an internal partition.

3. The integrated medium-voltage drive frequency converter according to claim 1, characterized in that, The device compartment includes multiple sub-compartments, and any two adjacent sub-compartments are separated by structural reinforcing ribs. The multiple sub-compartments include at least one inverter compartment for accommodating frequency conversion circuit devices and at least one condenser compartment for accommodating the condenser.

4. The integrated medium-voltage drive frequency converter according to claim 3, characterized in that, The plurality of sub-compartments include a plurality of inverter compartments and two condenser compartments. The plurality of inverter compartments are arranged side by side, and the two condenser compartments are respectively located on opposite sides of the plurality of inverter compartments. A ventilation structure is provided between any two adjacent sub-compartments.

5. The integrated medium-voltage drive frequency converter according to claim 4, characterized in that, The drive fan includes: A first fan, configured in a one-to-one correspondence with each inverter compartment, is installed within the corresponding inverter compartment and is used to draw hot air from the corresponding inverter compartment into the air duct compartment; and The second fan is arranged in a one-to-one correspondence with the condenser chamber and is installed in the corresponding condenser chamber to draw the cooled air in the air duct chamber into the corresponding condenser chamber.

6. The integrated medium-voltage drive frequency converter according to claim 4, characterized in that, The air duct chamber is equipped with multiple air duct partitions, which divide the air duct chamber into multiple independent air duct sections; each of the multiple air duct sections corresponds to a multiple inverter chamber and is configured to receive hot air from the corresponding inverter chamber.

7. The integrated medium-voltage drive frequency converter according to claim 6, characterized in that, Each of the aforementioned air duct sections is separated from the corresponding inverter compartment by an internal partition; the heat dissipation device is a water-cooled plate radiator, and one side of the water-cooled plate radiator is provided with multiple fins, which extend and are close to the internal partition.

8. The integrated medium-voltage drive frequency converter according to claim 1, characterized in that, At least one of the frequency conversion circuit devices has an integrated water-cooled plate inside; the housing is also provided with a water inlet and outlet interface, one end of which is connected to the water-cooled plate through a pipe, and the other end of which can be connected to an external circulating water circuit.

9. An integrated medium-pressure propulsion system, characterized in that, It includes an integrated medium-pressure propulsion frequency converter as described in any one of claims 1-8, and a propulsion motor electrically connected to the frequency converter circuit device.

10. A cooling and dehumidification method for an integrated medium-pressure propulsion frequency converter as described in any one of claims 1-8, characterized in that, Includes the following steps: Hot air from the drive unit compartment enters the air duct compartment; Controlling the flow of hot air through the heat dissipation device to achieve heat exchange and cooling; The cooled air is controlled to flow through the condenser to achieve condensation and dehumidification; The dehumidified, dry, and cold air is controlled to flow back into the device compartment, forming an internal circulation.

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