Power electronic transformer

Abstract

The invention relates to the field of solid-state transformers, in particular to a power electronic transformer which comprises an outer shell, the outer shell is composed of four stand columns and five panels, and the panels on the two sides are provided with shutter structures used for achieving inside and outside ventilation of the outer shell; the right front portion is in an opening state, and lifting lugs are arranged at the corners of the top and used for hanging and conveying of equipment. The converter, the connecting line, the low-voltage direct-current bus and the inverter are all embedded in the outer shell; the converter is used for realizing electrical isolation and voltage level conversion, converting a power frequency alternating current input by a unit level into a direct current through a converter silicon carbide module and then inverting the direct current into a high-frequency alternating current, and the output end of the converter is fixedly connected with the connecting line; according to the power electronic transformer, abnormal signals such as electric arc flashes in equipment are rapidly captured through the visual sensor, the sealing door is automatically triggered to be locked, and the situation that an operator opens the sealing door unknowingly is prevented.

Description

Technical Field

[0001] This invention relates to the field of solid-state transformer technology, specifically to a power electronic transformer. Background Technology

[0002] As a new type of core equipment for power conversion, power electronic transformers have advantages over traditional power transformers, such as high-efficiency power conversion, electrical isolation, and flexible power regulation. Their core function is to realize multi-stage power conversion from medium-voltage AC to medium-voltage DC to low-voltage DC to load AC, accurately converting the medium-voltage AC power of the power grid into AC power that meets the needs of various loads, while ensuring the stability, security, and efficiency of power transmission. They are one of the key core equipment for the construction of modern smart grids.

[0003] The existing equipment lacks a coordinated arc warning and locking structure involving visual sensors, electric actuators, pistons, and the bladder, making it unable to detect arc flash signals generated by internal discharge. When abnormal conditions such as weak insulation or minor discharge occur inside the equipment, the locking mechanism cannot be automatically activated, and the sealed door can still be opened normally. If operators open the sealed door without their knowledge, it can easily lead to safety accidents such as electric shock and burns, which does not comply with the safety operation standards for electrical equipment. Summary of the Invention

[0004] The present invention provides a power electronic transformer to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a power electronic transformer, comprising an outer casing consisting of four columns and five panels, with louvered structures on both side panels for ventilation inside and outside the casing; the front is open, and lifting lugs are provided at the top corners for hanging and transporting the equipment; The converter, connecting lines, low-voltage DC bus, and inverter are all embedded inside the housing; the converter is used to achieve electrical isolation and voltage level conversion, further converting the unit-level low-voltage DC into a unified low-voltage DC, and its output terminal is fixedly connected to the connecting lines. The end of the connecting line furthest from the converter is connected to the low-voltage DC bus, which is used to connect the output terminals of all DAB units in parallel to the V low-voltage DC bus to achieve power convergence; the bottom of the low-voltage DC bus is connected to the inverter, which is used to invert the V low-voltage DC into industrial frequency AC power to supply AC loads. An adjustment section, located on the outside of the outer casing, is used to facilitate the closing and opening of the front opening of the outer casing. The connecting part is located at the top of the inner cavity of the outer shell and is used for a series of transmission processes after the door is opened; The heat dissipation unit is located on the top of the outer casing to increase the overall heat dissipation range of the equipment, while also cleaning up dust that falls on the top and ensuring the equipment's heat dissipation efficiency.

[0006] Preferably, a hinge is fixedly connected to the outer side of the front column of the outer casing, and a sealing door is rotatably installed on the side of the hinge away from the front column of the outer casing to close the front opening of the outer casing; a transverse groove is provided on the outer side of the sealing door to provide installation and operation space for the adjustment part.

[0007] Preferably, a vision sensor is fixedly installed at the rear of the sealed door.

[0008] Preferably, the adjustment part includes an outer plate, which is fixedly installed on the front of the top panel of the outer shell. A groove is formed on the outer side of the outer plate, and a recess is formed in the center of the groove. A first magnetic block is fixedly connected in the recess. The groove is fitted with a sliding rod. A groove is provided on the top of the sliding rod near the first magnetic block. A second magnetic block is fixedly connected in the groove. The second magnetic block and the first magnetic block are magnetically attracted to each other to achieve the positioning of the sliding rod. The front end of the groove is provided with a notch for the sliding bar to slide out and for the sealing door to open.

[0009] Preferably, the top of the inner cavity of the tank is provided with a sliding groove and an arc-shaped groove, the arc-shaped groove is located at the center of the tank and its shape is adapted to the sliding bar to adapt to the deflection action of the sliding bar. There are two slides, which are respectively located at the front and center of the slide body. A spring is fixedly connected to the top of the inner cavity of the slide. A fitting block is fixedly connected to the end of the spring away from the slide. The fitting block is slidably adapted to the slide. The bottom of the fitting block is adapted to the top of the slide bar for positioning and limiting the slide bar.

[0010] Preferably, the transverse groove is equipped with a slider, and a bearing sleeve is fixedly connected to the side of the slider away from the transverse groove. A handle is rotatably installed inside the bearing sleeve through a bearing, and the handle is fixedly connected to a slide bar for adjusting the deflection direction and movement distance of the slide bar.

[0011] Preferably, the connecting part includes a connecting strip, and a through strip is fixedly connected to the bottom end of the connecting strip. The through strip passes through the center part of the front of the outer shell and is fixedly connected to the rear part of the sealing door. A square groove is provided at the top of the inner cavity of the outer shell. The sidewall of the square groove is slidably adapted to the connecting strip. Sealing plates are fixedly connected to the front and rear sides of the connecting strip, and the sealing plates are fixed in the square groove.

[0012] Preferably, a fixing tube is fixedly installed on the outer side of the center of the front part of the outer shell, an electric push rod is fixedly installed on the outer side of the fixing tube, and a piston is fixedly connected to the output end of the electric push rod, the piston being slidably adapted to the inside of the fixing tube; A spherical groove is provided at the rear of the sealing door, and a bladder is fixedly connected to the inner wall of the fixing tube, with the bladder positioned inside the spherical groove.

[0013] Preferably, the heat dissipation part includes a plug plate, which sequentially passes through the upper panel and the outer plate of the outer shell and extends to the outside. A mating plate is fixedly connected to the front end of the plug plate, and the bottom of the plug plate is fixedly connected to the top end of the connecting strip. A collection frame is fixedly connected to the top of the inner cavity of the outer shell, and a fixing rod is fixedly connected to the back of the outer shell. An integrated plate is slidably adapted to the outside of the fixing rod. The front end of the integrated plate is fixedly connected to the collection frame. A nut is threadedly connected to the outside of the fixing rod for limiting and fixing the integrated plate.

[0014] Preferably, the top of the outer shell is provided with a triangular groove, and the part of the outer shell with the triangular groove is trapezoidal. The trapezoidal structure is provided with filter holes, and the bottom of the triangular groove is provided with a second inclined groove for the rearward movement of impurities. The filter holes are used to discharge excess heat from the top of the outer shell and to filter impurities. A telescopic plate is fixedly connected to the bottom of the sealing plate, and a cleaning brush is fixedly connected to the bottom of the telescopic plate for sweeping impurities on the second inclined groove into the collection frame. A cotton body is fixedly connected to the outside of the telescopic plate, and the side of the cotton body away from the telescopic plate is squeezed and adapted to the outer shell.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The sealed door is firmly fixed through multiple limiting and magnetic structures. The handle can be moved, rotated and hidden flexibly. The operation steps are simple, which not only avoids the risk of bumps caused by the exposed handle, but also ensures that the sealed door is not easy to loosen after it is closed, thus improving the overall sealing performance of the equipment.

[0016] 2. When the sealed door is opened, the filter hole blockage is automatically released, increasing the heat release efficiency. This allows the high-temperature hot air accumulated inside the equipment to be completely dissipated, effectively preventing the equipment from being damaged due to overheating and extending the equipment's service life.

[0017] 3. It can quickly detect abnormal signals such as electric arc flashes inside the equipment and automatically trigger the sealing door to lock, preventing operators from opening the sealing door without their knowledge, effectively avoiding safety hazards such as electric shock and electric arc injuries, and at the same time serving as a danger warning.

[0018] 4. When the sealing door is closed and reset, the cleaning components can be driven simultaneously to clean the beveled edge of the outer shell and the area around the filter holes, and automatically push the filtered impurities to the collection frame. Cleaning can be completed with simple disassembly, which greatly simplifies the maintenance process and reduces the labor intensity of operators. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the external structure of a power electronic transformer according to the present invention.

[0020] Figure 2 This is a schematic diagram of the internal structure of the power electronic transformer of the present invention.

[0021] Figure 3 This is a schematic cross-sectional view of the adjustment part of the present invention.

[0022] Figure 4 This is a schematic diagram of the planar structure of the adjustment part of the present invention after a cross-sectional view.

[0023] Figure 5 This is a cross-sectional view of the external plate in the adjustment section of the present invention.

[0024] Figure 6 This is a cross-sectional enlarged structural diagram of the slider in the adjustment section of the present invention.

[0025] Figure 7 This is an enlarged structural schematic diagram of the interlocking block in the adjustment section of the present invention.

[0026] Figure 8 This is a schematic diagram of the handle in the adjustment part of the present invention.

[0027] Figure 9 This is a schematic diagram of the structure of the vision sensor in the power electronic transformer of the present invention.

[0028] Figure 10 This is an enlarged cross-sectional view of the bladder in the power electronic transformer of the present invention.

[0029] Figure 11 This is a vertical cross-sectional view of the connecting part of the present invention.

[0030] Figure 12 This is a vertical cross-sectional view of the heat dissipation part of the present invention.

[0031] Figure 13 This is a schematic diagram of the integrated board in the heat dissipation section of the present invention.

[0032] Figure 14 This is an enlarged structural schematic diagram of the second inclined groove in the heat dissipation part of the present invention.

[0033] Figure 15 This is an enlarged structural schematic diagram of the telescopic plate in the heat dissipation section of the present invention.

[0034] In the diagram: 1. Outer casing; 2. Converter; 3. Connecting wire; 4. Low-voltage DC bus; 5. Inverter; 6. Hinge; 7. Sealing door; 8. Horizontal groove; 9. Adjustment section; 10. Connection section; 11. Heat dissipation section; 91. External plate; 92. Groove; 93. Magnetic block No. 1; 94. Sliding rod; 95. Spring; 96. Fitting block; 97. Arc groove; 98. Sliding block; 99. Bearing sleeve; 90. Handle; 12. Vision sensor; 13. Fixing tube; 14. Electric push rod; 15. Piston; 16. Capsule body; 101. Connecting strip; 102. Sealing plate; 103. Through strip; 111. Insert sealing plate; 112. Connecting plate; 113. Collection frame; 114. Fixing rod; 115. Integrated plate; 116. Triangular groove; 117. Filter hole; 118. No. 2 bevel groove; 119. Telescopic plate; 110. Cleaning brush; 121. Cotton body; 122. Nut. Detailed Implementation

[0035] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Please see Figures 1 to 15 The present invention provides a technical solution: Example 1, such as Figure 1 , Figure 2 , Figure 9 and Figure 10 As shown, the outer casing 1 serves as the mounting carrier and protective enclosure for the entire power electronic transformer. It consists of four uprights and five panels, which are fixedly connected to form a closed installation space. The side panels of the outer casing 1 are equipped with louver structures to assist in heat dissipation and accelerate the dissipation of heat inside the outer casing 1. Lifting lugs are provided at the top corners of the outer casing 1 and are fixedly connected to the top panel of the outer casing 1 for hoisting and transporting the equipment, facilitating the handling and installation of the equipment.

[0037] Converter 2, connecting line 3, low-voltage DC bus 4, and inverter 5 are all embedded inside housing 1 and fixedly connected to the inner wall of housing 1 by brackets. Converter 2 is used to achieve electrical isolation and voltage level conversion, further converting the unit-level low-voltage DC to a unified low-voltage DC. Its output terminal is fixedly connected to connecting line 3 through a connector. The connection adopts a sealed structure to prevent poor circuit contact. The end of connecting line 3 away from converter 2 is fixedly connected to low-voltage DC bus 4, which is used to connect the output terminals of all DAB units in parallel to 750V low-voltage DC bus 4 to achieve power convergence and ensure power supply stability.

[0038] The bottom of the low-voltage DC bus 4 is fixedly connected to the inverter 5, which is used to invert 750V low-voltage DC into industrial frequency AC power to supply AC loads and realize the conversion and transmission of electrical energy. The adjustment part 9 is located on the outside of the outer shell 1 and is fixedly connected to the outer shell 1. It is used to realize the convenient closing and opening of the front opening of the outer shell 1, which is easy to operate. The connection part 10 is located on the top of the inner cavity of the outer shell 1 and is fixedly connected to both the outer shell 1 and the sealing door 7. It is used for a series of transmission processes after the door is opened, which links the heat dissipation part 11 to operate. The heat dissipation part 11 is located on the top of the outer shell 1 and is fixedly connected to the outer shell 1 and the connection part 10. It is used to increase the overall heat dissipation range of the equipment and at the same time realize the cleaning of dust on the top, ensuring the heat dissipation efficiency of the equipment and avoiding dust accumulation from affecting the operation of the equipment.

[0039] A hinge 6 is bolted to the outer side of the front column of the outer casing 1. The hinges 6 are symmetrically arranged to provide rotational support for the sealing door 7. The sealing door 7 is rotatably installed on the side of the hinge 6 away from the front column of the outer casing 1 via a bearing. The sealing door 7 is adapted to the front opening of the outer casing 1 and is used to close the front opening of the outer casing 1 to prevent dust and debris from entering the interior of the outer casing 1 and to ensure the safe operation of the internal components. A transverse groove 8 is provided on the outer side of the sealing door 7. The transverse groove 8 extends along the length of the sealing door 7 to provide installation and operation space for the adjustment part 9 and to ensure that the adjustment part 9 can move flexibly.

[0040] A vision sensor 12 is fixedly installed at the rear of the sealed door 7 by bolts. The vision sensor 12 is electrically connected to the electric push rod 14 and is used to detect the electric arc generated inside the outer casing 1 due to air ionization and rapid temperature rise. It can capture abnormal signals of the equipment in time, ensure the safe operation of the equipment, and avoid safety accidents.

[0041] A fixed tube 13 is bolted to the outer side of the front center of the outer casing 1. The fixed tube 13 has a tubular structure and is used to accommodate the piston 15 and the bladder 16. An electric push rod 14 is bolted to the outer side of the fixed tube 13. The electric push rod 14 is electrically connected to the vision sensor 12 and is used to receive signals from the vision sensor 12 and drive the piston 15 to move. The output end of the electric push rod 14 is bolted to the piston 15. The piston 15 slides within the fixed tube 13 and can slide back and forth along the inner wall of the fixed tube 13 to compress the gas inside the fixed tube 13. A spherical groove is provided at the rear of the sealing door 7, and the spherical groove is adapted to the bladder 16. The bladder 16 is glued to the inner wall of the fixed tube 13 and is located in the spherical groove. It is used to inflate when compressed to lock the sealing door 7. The bladder 16 is not in the spherical groove when it is not inflated.

[0042] Example 2, as follows Figure 3 , Figure 4 , Figure 5 , Figure 6, Figure 7 and Figure 8 As shown, the adjustment unit 9 includes an outer plate 91, a slider 94, a first magnetic block 93, a spring 95, a fitting block 96, a slider 98, a bearing sleeve 99, and a handle 90. All components work together to realize the opening and closing and the limiting fixation of the sealing door 7.

[0043] The outer plate 91 is fixedly installed on the front of the top panel of the outer shell 1 by bolts, and fits tightly with the top panel of the outer shell 1, providing a mounting carrier for other components of the adjustment part 9; a groove 92 is provided on the outer side of the outer plate 91, which extends along the length of the outer plate 91 to accommodate the slider 94 and other components; a groove is provided in the center of the groove 92, and a first magnetic block 93 is fixedly connected in the groove by adhesive, which is used to cooperate with the second magnetic block to realize the positioning of the slider 94.

[0044] A sliding rod 94 is fitted inside the groove 92. The sliding rod 94 can slide back and forth along the groove 92 to drive the sealing door 7 to open and close. A groove is provided on the top of the sliding rod 94 near the first magnetic block 93. A second magnetic block is fixedly connected in the groove. The second magnetic block and the first magnetic block 93 are magnetically attracted to each other to achieve precise positioning of the sliding rod 94 and ensure that the sealing door 7 can be closed stably. A notch is provided at the front end of the groove 92. The notch is adapted to the sliding rod 94 for sliding out of the sliding rod 94 and opening of the sealing door 7 to ensure that the sealing door 7 can be opened smoothly.

[0045] The top of the inner cavity of the groove body 92 is provided with a sliding groove and an arc-shaped groove 97. The arc-shaped groove 97 is located in the center of the groove body 92 and its shape is adapted to the sliding rod 94 to adapt to the deflection action of the sliding rod 94 and ensure that the sliding rod 94 can deflect flexibly. There are two sliding grooves, which are respectively located in the front and center of the groove body 92. The top of the inner cavity of the sliding groove is fixedly connected to a spring 95 by welding for the elastic reset of the fitting block 96. The end of the spring 95 away from the sliding groove is fixedly connected to the fitting block 96 by welding. The fitting block 96 slides and adapts to the sliding groove and can slide up and down along the sliding groove. The bottom of the fitting block 96 is adapted to the top of the sliding rod 94 to position and limit the sliding rod 94, prevent the sliding rod 94 from moving at will, and ensure that the sealing door 7 is stable and reliable after closing.

[0046] The transverse groove 8 is equipped with a slider 98, which can slide left and right along the transverse groove 8. A bearing sleeve 99 is fixedly connected to the side of the slider 98 away from the transverse groove 8 by welding. The bearing sleeve 99 is used to install a handle 90. The handle 90 is installed inside the bearing sleeve 99 by rotating the bearing. The handle 90 can rotate flexibly around the bearing sleeve 99. The handle 90 is fixedly connected to the slide bar 94 and is used to adjust the deflection direction and movement distance of the slide bar 94, so as to facilitate the operator to control the opening and closing of the sealing door 7.

[0047] Example 3, as follows Figure 12 , Figure 13 , Figure 14 and Figure 15 As shown, the bottom end of the connecting strip 101 is fixedly connected to the through strip 103 by welding. The through strip 103 passes through the center part of the front of the outer shell 1 and is fixedly connected to the rear part of the sealing door 7 by bolts, so as to ensure that the connecting strip 101 can move synchronously when the sealing door 7 is opened and closed. A square groove is provided on the top of the inner cavity of the outer shell 1. The square groove extends along the length of the outer shell 1. The side wall of the square groove is slidably adapted to the connecting strip 101, and the connecting strip 101 can slide back and forth along the square groove. Sealing plates 102 are fixedly connected to the front and rear sides of the connecting strip 101 by adhesive bonding. The sealing plates 102 are fixed in the square groove and fit tightly against the inner wall of the square groove to seal the square groove and prevent dust and moisture from entering the square groove, so as to avoid affecting the sliding of the connecting strip 101.

[0048] The heat dissipation unit 11 includes a sealing plate 111, a docking plate 112, a collection frame 113, a fixing rod 114, an integrated plate 115, a nut 122, a telescopic plate 119, a cleaning brush 110, and a cotton body 121. The components work together to achieve heat dissipation and dust removal from the top of the equipment.

[0049] The insert sealing plate 111 passes through the upper panel and the outer plate 91 of the outer shell 1 and extends to the outside. The insert sealing plate 111 is slidably adapted to the upper panel and the outer plate 91 of the outer shell 1 and can slide back and forth. The front end of the insert sealing plate 111 is fixedly connected to the mating plate 112 by welding, which is used to limit the movement of the insert sealing plate 111 and prevent the insert sealing plate 111 from completely entering the interior of the outer shell 1. The bottom of the insert sealing plate 111 is fixedly connected to the top end of the connecting strip 101 by welding and can move synchronously with the connecting strip 101 to realize the sealing and opening of the filter hole 117.

[0050] A collection frame 113 is bolted to the top of the inner cavity of the outer shell 1. The collection frame 113 is used to collect impurities and dust swept by the cleaning brush 110. A fixing rod 114 is welded to the back of the outer shell 1. The fixing rod 114 provides installation support for the integrated plate 115. The integrated plate 115 is slidably fitted on the outer side of the fixing rod 114. The integrated plate 115 can slide back and forth along the fixing rod 114. The front end of the integrated plate 115 is bolted to the collection frame 113 to move the collection frame 113 and facilitate cleaning of the collection frame 113. A nut 122 is threaded to the outer side of the fixing rod 114. The nut 122 is pressed and fitted with the integrated plate 115 to limit and fix the integrated plate 115 and prevent it from moving at will.

[0051] A triangular groove 116 is provided on the top of the outer casing 1. The portion of the outer casing 1 with the triangular groove 116 is trapezoidal. Filter holes 117 are provided on this trapezoidal structure. The filter holes 117 are evenly distributed and are used to dissipate excess heat from the top of the outer casing 1 and to filter impurities, preventing impurities from entering the interior of the outer casing 1. A second inclined groove 118 is provided at the bottom of the triangular groove 116. The second inclined groove 118 is inclined and is used to guide impurities backward, facilitating their entry into the collection frame 113. The bottom of the sealing plate 111 is fixedly connected by welding. There is a telescopic plate 119, which is telescopic and adapts to the movement of the sealing plate 111; a cleaning brush 110 is fixedly connected to the bottom of the telescopic plate 119 by adhesive bonding. The cleaning brush 110 fits snugly with the second bevel groove 118 and is used to sweep impurities on the second bevel groove 118 into the collection frame 113; a cotton body 121 is fixedly connected to the outside of the telescopic plate 119 by adhesive bonding. The side of the cotton body 121 away from the telescopic plate 119 is squeezed and fitted with the outer shell 1 and is used to clean the bevel of the outer shell 1 to prevent dust accumulation.

[0052] The working principle of this invention is as follows: First, converter 2 and inverter 5 are started respectively, so that the multiple DC outputs after CHB cascade rectification are sent to the corresponding high-frequency isolated DAB (dual active bridge) modules, i.e., converter 2. The DAB modules achieve electrical isolation through high-frequency transformers and simultaneously complete efficient DC-DC conversion, further stepping down the medium-voltage DC to low-voltage DC. The low-voltage DC outputs of all DAB modules are combined to the 750V low-voltage DC bus 4 through connecting line 3, completing power concentration and providing a stable DC power supply for the subsequent inverter. The 750V DC power from the low-voltage DC bus 4 is sent to the DC / AC inverter and inverted into AC power that meets the load requirements, completing the complete power conversion and power supply process from "medium-voltage AC - medium-voltage DC - low-voltage DC - load AC".

[0053] When the equipment is running, the operator holds handle 90 to close the sealing door 7, and then moves handle 90 to both sides along the groove 92, simultaneously moving slider 98, which is connected to handle 90 through bearing sleeve 99, outward along the transverse groove 8. When slider 94 moves to the center position of groove 92, slider 94 first exerts an upward squeezing force on fitting block 96, causing spring 95 at the top of fitting block 96 to be in a compressed state, until the top of slider 94 moves to a position that matches the bottom of fitting block 96; then, under the action of elastic restoring force of spring 95, fitting block 96 and slider 94 fit together, achieving initial positioning and limiting of slider 94.

[0054] After the initial positioning is completed, the operator holds the handle 90 and rotates it counterclockwise. At this time, the slide bar 94 rotates counterclockwise along the arc groove 97 with the engagement part with the fitting block 96 as the center point until the second magnetic block at the top of the slide bar 94 and the first magnetic block 93 in the groove are on the same vertical line. The two generate an attraction, thereby hiding the handle 90. At the same time, the integrated structure of the handle 90 and the slide bar 94 completes the positioning and fixing of the sealing door 7. Similarly, when the operator holds the handle 90 and resets the slide bar 94 along the front end of the groove 92, the slide bar 94 will also engage with the fitting block 96 in the vertical position. When the operator pulls the door, under the action of external force, the slide bar 94 disengages from the fitting block 96 in that position and slides outward along the notch at the front end of the groove 92, thereby opening the sealing door 7.

[0055] When a slight discharge or weak insulation occurs inside the outer casing 1, the entry of outside air will induce an electric arc flash. At this time, the visual sensor 12 quickly captures the arc flash signal and transmits it to the electric actuator 14. Upon receiving the signal, the control terminal inside the electric actuator 14 immediately activates, driving the piston 15 connected to its output end to move forward along the inner wall of the fixed tube 13. During the forward movement of the piston 15, the gas inside the fixed tube 13 is compressed, causing the bladder 16 to bulge. The bulging bladder 16 tightly fills the spherical groove on the back of the sealing door 7, thus firmly locking the sealing door 7 to the outer casing 1, preventing the operator from unknowingly opening the sealing door 7, and simultaneously alerting the operator to the danger.

[0056] When the sealing door 7 is opened, the connecting strip 103 fixed on its back will pass through the center of the front of the outer shell 1 and extend outward, thereby driving the connecting strip 101 connected to the other end of the connecting strip 103, and driving the sealing plate 111 to move towards the front of the outer shell 1. As the sealing plate 111 moves forward, the filter hole 117 that was originally blocked by it is connected to the outside, thereby increasing the heat release efficiency inside the outer shell 1 and preventing all the high-temperature hot air from escaping from the opening of the outer shell 1.

[0057] When the sealing door 7 is closed again, the sealing plate 111 automatically resets under the elastic force of the sealing plate 102, and at the same time seals the filter hole 117. Subsequently, the telescopic plate 119 fixed to the bottom of the sealing plate 111 moves synchronously to the rear end of the outer shell 1. During the movement, the cleaning brush 110 fixed to the bottom of the telescopic plate 119 continuously fits against the second inclined groove 118 on the top of the outer shell 1, pushing the impurities filtered by the filter hole 117 backward along the second inclined groove 118 until the impurities enter the collection frame 113. At the same time, the cotton body 121 fixed to the outside of the telescopic plate 119 cleans the inclined edge of the outer shell 1 synchronously.

[0058] Finally, loosen the nut 122 and remove the integrated plate 115 from the fixing rod 114 to clean the dust and impurities accumulated inside the collection frame 113.

[0059] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made by those skilled in the art based on the above concepts without creative effort shall fall within the scope of protection of the present invention.

Claims

1. A power electronic transformer, characterized in that, include: The outer casing consists of four columns and five panels. The side panels are equipped with louver structures to allow for ventilation inside and outside the casing. The front is open, and there are lifting lugs at the top corners for hanging and transporting the equipment. The converter, connecting lines, low-voltage DC bus, and inverter are all embedded inside the housing; the converter is used to achieve electrical isolation and voltage level conversion, further converting the unit-level low-voltage DC into a unified low-voltage DC, and its output terminal is fixedly connected to the connecting lines. The end of the connecting line furthest from the converter is connected to the low-voltage DC bus, which is used to connect the output terminals of all DAB units in parallel to the V low-voltage DC bus; the bottom of the low-voltage DC bus is connected to the inverter, which is used to invert the V low-voltage DC into power frequency AC. An adjustment section, located on the outside of the outer casing, is used to facilitate the closing and opening of the front opening of the outer casing. The connecting part is located at the top of the inner cavity of the outer shell and is used for a series of transmission processes after the door is opened; The heat dissipation unit is located on the top of the outer casing to increase the overall heat dissipation range of the equipment and to facilitate the cleaning of dust accumulation on the top. A vision sensor is fixedly installed at the rear of the sealed door; A fixing tube is fixedly installed on the outer side of the center of the front part of the outer shell, and an electric push rod is fixedly installed on the outer side of the fixing tube. A piston is fixedly connected to the output end of the electric push rod, and the piston slides and adapts to the inside of the fixing tube. A spherical groove is provided at the rear of the sealing door, and a bladder is fixedly connected to the inner wall of the fixing tube, with the bladder positioned inside the spherical groove.

2. A power electronic transformer according to claim 1, characterized in that: A hinge is fixedly connected to the outer side of the front column of the outer casing, and the side of the hinge away from the front column of the outer casing is rotatably connected to the sealing door; a transverse groove is provided on the outer side of the sealing door.

3. A power electronic transformer according to claim 2, characterized in that: The adjustment part includes an outer plate, which is fixedly installed on the front of the top panel of the outer shell. A groove is formed on the outer side of the outer plate, and a recess is formed in the center of the groove. A first magnetic block is fixedly connected in the recess. The groove is fitted with a sliding rod. A groove is provided on the top of the sliding rod near the first magnetic block. A second magnetic block is fixedly connected in the groove. The second magnetic block and the first magnetic block are magnetically attracted to each other to achieve the positioning of the sliding rod. The front end of the groove is provided with a notch for the sliding bar to slide out and for the sealing door to open.

4. A power electronic transformer according to claim 3, characterized in that: The top of the inner cavity of the tank is provided with a sliding groove and an arc-shaped groove. The arc-shaped groove is located at the center of the tank and its shape is adapted to the sliding rod to accommodate the deflection action of the sliding rod. There are two slides, which are respectively located at the front and center of the slide body. A spring is fixedly connected to the top of the inner cavity of the slide. A fitting block is fixedly connected to the end of the spring away from the slide. The fitting block is slidably adapted to the slide. The bottom of the fitting block is adapted to the top of the slide bar for positioning and limiting the slide bar.

5. A power electronic transformer according to claim 3, characterized in that: The transverse groove is equipped with a slider inside. A bearing sleeve is fixedly connected to the side of the slider away from the transverse groove. A handle is rotatably installed inside the bearing sleeve through a bearing. The handle is fixedly connected to a slide bar and is used to adjust the deflection direction and movement distance of the slide bar.

6. A power electronic transformer according to claim 2, characterized in that: The connecting part includes a connecting strip, and a through strip is fixedly connected to the bottom end of the connecting strip. The through strip passes through the center part of the front of the outer shell and is fixedly connected to the rear part of the sealing door. A square groove is provided at the top of the inner cavity of the outer shell. The sidewall of the square groove is slidably adapted to the connecting strip. Sealing plates are fixedly connected to the front and rear sides of the connecting strip, and the sealing plates are fixed in the square groove.

7. A power electronic transformer according to claim 3, characterized in that: The heat dissipation part includes a plug plate, which passes through the upper panel and the outer plate of the outer shell and extends to the outside. A mating plate is fixedly connected to the front end of the plug plate, and the bottom of the plug plate is fixedly connected to the top end of the connecting strip. A collection frame is fixedly connected to the top of the inner cavity of the outer shell, and a fixing rod is fixedly connected to the back of the outer shell. An integrated plate is slidably adapted to the outside of the fixing rod. The front end of the integrated plate is fixedly connected to the collection frame. A nut is threadedly connected to the outside of the fixing rod for limiting and fixing the integrated plate.

8. A power electronic transformer according to claim 7, characterized in that: The top of the outer shell is provided with a triangular groove, and the part of the outer shell with the triangular groove is trapezoidal. The trapezoidal structure is provided with filter holes. The bottom of the triangular groove is provided with a second inclined groove for the backward movement of impurities. The filter holes are used to discharge excess heat from the top of the outer shell and to filter impurities. A telescopic plate is fixedly connected to the bottom of the sealing plate, and a cleaning brush is fixedly connected to the bottom of the telescopic plate for sweeping impurities on the second inclined groove into the collection frame. A cotton body is fixedly connected to the outside of the telescopic plate, and the side of the cotton body away from the telescopic plate is squeezed and adapted to the outer shell.

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