Bearing structure for high-low-voltage conversion circuit

A bearing structure for a high-low-voltage conversion circuit is disclosed and includes an insulation carrier, a first conductor layer, a second conductor layer, a first trench and a first insulation material. The first conductor layer and the second conductor layer are coated on the first surface and the second surface of the insulation carrier, respectively. A voltage difference is formed between the first conductor layer and the second conductor layer. The first trench is disposed on the first surface and surrounds an outer peripheral edge of the first conductor layer. The first conductor layer is extended from the first surface into the first trench, and the outer peripheral edge of the first conductor layer is located at a bottom of the first trench. The first insulation material covers the outer peripheral edge of the first conductor layer and is filled in the first trench.

FIELD OF THE INVENTION

The present disclosure relates to a bearing structure, and more particularly to a bearing structure for a high-low-voltage conversion circuit, so as to avoid the corona and partial discharge due to a high electric field strength on the outer peripheral edge of the conductor.

BACKGROUND OF THE INVENTION

With the development of the economy, the demand for electricity has increased sharply. Moreover, the safety requirements for electricity consumption are also getting higher and higher. Taking a common application of medium-voltage solid-state transformers as an example, a plurality of power conversion modules are disposed in a single system cabinet. Each power conversion module needs to be carried on an isolation carrier and be integrated into the system cabinet. Since a high-low voltage conversion circuit is contained in this kind of power conversion module, when the high-voltage circuit and the low-voltage circuit of the high-low conversion circuit are isolated through the isolation carrier, the isolation carrier is further spatially corresponding to a high electric field strength formed due to the voltage difference. Therefore, in order to carry under the action of high electric field strength, the isolation carrier has to avoid the repeated breakdown and extinction phenomenon of partial discharge caused by the structural defects.

In the conventional power conversion module of the solid-state transformer, the high-voltage circuit and the low-voltage circuit are disposed and corresponding to the conductor layer with a uniform electric field, respectively. However, under the action of high electric field strength, the phenomenon of the corona and partial discharge is generated easily on the outer peripheral edge of the conductor layer.

Therefore, there is a need of providing a bearing structure configured to carry a high-low-voltage conversion circuit with high electric field strength, wherein the outer peripheral edge of the conductor layer is sealed through the design of the trench, so as to solve the problem of excessive electric field strength generated due to the outer peripheral edge of the conductor layer on the insulation carrier, avoid the occurrence of corona and partial discharge, and obviate the drawbacks encountered by the prior arts.

SUMMARY OF THE INVENTION

An object of the present disclosure is to provide a bearing structure configured to carry a high-low-voltage conversion circuit with high electric field strength. By sealing the outer edge of the conductor layer through the design of the trench, the problem of excessive electric field strength generated due to the outer peripheral edge of the conductor layer on the insulation carrier is solved. Moreover, the occurrence of corona and partial discharge is avoided.

Another object of the present disclosure is to provide a bearing structure configured to carry and isolate a high-voltage circuit and a low-voltage circuit. The bearing structure is made of an insulation material with a dielectric strength greater than 18 kV/mm. When a high-voltage circuit and a low-voltage circuit with a voltage difference ranged from 10 kV to 30 kV are isolated through the bearing structure, the outer peripheral edge of the conductor layer is sealed by the trench and the insulation material. A distance is maintained between the outer peripheral edge of the conductor layer and an outer surface of the insulation material and greater than 0.6 mm. An air electric field strength on the outer surface of the insulation material is reduced and less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge of the conductor layer under the high electric field strength. In addition, when the trench and the insulation material are disposed on a peripheral wall formed by the protruding portion, it allows the bearing structure to form an upper half shell or a lower half shell. For example, two bearing structures are utilized to form two symmetrical half shells and assembled as a bearing housing. The high-voltage circuit is sandwiched between the two symmetrical half shells, and the low-voltage circuit is placed outside the bearing housing, so as to achieve a unit assembly of the power conversion module with small volume. It facilitates to ensure the safety of the solid-state transformer application and enhance the competitiveness of the product.

A further object of the present disclosure is to provide a bearing structure configured to carry a power conversion module with high electric field strength. The bearing structure having the outer peripheral edge of the conductor layer sealed through the designed trench is allowed to be applied to the bearing housing, which are detached into two symmetrical half shells. The insulation material is filled into the trench by fluid dispensing, which is easily integrated into the manufacturing process of the two symmetrical half shells carrying the power conversion module. The entire space is not increased. Thus, the safety specifications and the convenience of the bearing housing for the power conversion module are improved effectively.

In accordance with an aspect of the present disclosure, a bearing structure is provided and configured to carry a high-low-voltage conversion circuit. The bearing structure includes an insulation carrier, a first conductor layer, a second conductor layer a first trench and a first insulation material. The insulation carrier includes a first surface and a second surface opposite to each other. The first conductor layer and a second conductor layer are coated on the first surface and the second surface, respectively. A voltage difference is formed between the first conductor layer and the second conductor layer. The first trench is disposed on the first surface and surrounds an outer peripheral edge of the first conductor layer. The first conductor layer is extended from the first surface into the first trench, and the outer peripheral edge of the first conductor layer is located at a bottom of the first trench. The first insulation material covers the outer peripheral edge of the first conductor layer and is filled in the first trench.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, spatially relative terms, such as “upper,” “lower,” “top,” “bottom” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. When an element is referred to as being “connected,” or “coupled,” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Although the wide numerical ranges and parameters of the present disclosure are approximations, numerical values are set forth in the specific examples as precisely as possible. In addition, although the “first,” “second,” “third,” and the like terms in the claims be used to describe the various elements can be appreciated, these elements should not be limited by these terms, and these elements are described in the respective embodiments are used to express the different reference numerals, these terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. Besides, “and/or” and the like may be used herein for including any or all combinations of one or more of the associated listed items. Alternatively, the word “about” means within an acceptable standard error of ordinary skill in the art-recognized average. In addition to the operation/working examples, or unless otherwise specifically stated otherwise, in all cases, all of the numerical ranges, amounts, values and percentages, such as the number for the herein disclosed materials, time duration, temperature, operating conditions, the ratio of the amount, and the like, should be understood as the word “about” decorator. Accordingly, unless otherwise indicated, the numerical parameters of the present invention and scope of the appended patent proposed is to follow changes in the desired approximations. At least, the number of significant digits for each numerical parameter should at least be reported and explained by conventional rounding technique is applied. Herein, it can be expressed as a range between from one endpoint to the other or both endpoints. Unless otherwise specified, all ranges disclosed herein are inclusive.

FIG.1is a perspective view illustrating a bearing structure utilized to form a bearing housing according to an embodiment of the present disclosure.FIG.2is a cross-section view illustrating the bearing structure utilized to form the bearing housing and configured to carry a high-low-voltage conversion circuit according to the embodiment of the present disclosure.FIG.3is a perspective view illustrating the bearing structure utilized to form the bearing housing with the upper half shell and the lower half shell disassembled according to the embodiment of the present disclosure. In the embodiment, a bearing structure1aor a bearing structure1bis configured to carry a high-low-voltage conversion circuit. Preferably but not exclusively, the bearing housing1formed by the bearing structure1aand the bearing structure1bis applied in the field of the solid state transformer (SST), so as to simplify the carrying and assembling procedures of the power conversion module in the solid state transformer. At the same time, it ensures that each unit of the power conversion module meets the safety specifications and avoids the phenomenon of corona and partial discharge caused by the high electric field strength. Certainly, the present disclosure is not limited thereto. Preferably but not exclusively, in the embodiment, the bearing structure1ais an upper half shell, the bearing structure1bis a lower half shell, and the upper half shell and the lower half shell are symmetrical and assembled with each other to form a bearing housing1having an accommodation space10. In an embodiment, the bearing housing1includes a front opening101and a rear opening102. The front opening101and the rear opening102are in fluid communication with each other through the accommodation space10, so as to facilitates the bearing housing1to accommodate a high-voltage circuit HV and provide the functions of ventilation and heat dissipation. Certainly, the present disclosure is not limited thereto. Notably, in case of that the bearing housing1is utilized to carry one unit of the high-low-voltage conversion circuit, the high-voltage circuit HV is sandwiched between the upper half shell of the bearing structure1aand the lower half shell of the bearing structure1b, and the low-voltage circuit LV is disposed on an outer side of the bearing housing1. Preferably but not exclusively, the low-voltage circuit LV is disposed on the top of the upper half shell of the bearing structure1a. Certainly, the present disclosure is not limited thereto. In other embodiments, a plurality of units of the power conversion modules are carried on a plurality of bearing housings1, respectively, and then stacked with each other. In that, the high-voltage circuit HV accommodated with a bearing housing1and the low-voltage circuit LV disposed outside another bearing housing1have a voltage difference formed between the lower half shell of the bearing structure1b. In other words, the bearing structure1aand the bearing structure1bof the present disclosure are not limited to be served as an upper half shell or a lower half shell, and described here firstly.

FIGS.4A and4Bare partial exploded views illustrating the upper half shell of the bearing housing formed by the bearing structure according to the embodiment of the present disclosure.FIG.5is an enlarged view showing the region P1inFIG.2. In the embodiment, the bearing structure1ais configured to form an upper half shell. The bearing structure1aincludes an insulation carrier10a, a first conductor layer31a, a second conductor layer41a, a first trench51aand a first insulation material71a. The insulation carrier10aincludes a first surface11aand a second surface12aopposite to each other. Preferably but not exclusively, the first conductor layer31aand the second conductor layer41aare the zinc metal coating layers and coated on the first surface11aand the second surface12a, respectively. Moreover, a voltage difference is formed between the first conductor layer31aand the second conductor layer41a. Notably, in the embodiment, the high-voltage circuit HV is disposed on a first aluminum plate21over the first conductor layer31a, and the first aluminum plate21is spatially corresponding to the first conductor layer31a, so that the electric field generated by the high-voltage circuit HV is uniformized through the action of the first conductor layer31a. Similarly, the low-voltage circuit LV is disposed on a second aluminum plate22over the second conductor layer41a, and the second aluminum plate22is spatially corresponding to the second conductor layer41a, so that the electric field generated by the low-voltage circuit LV is uniformized through the action of the second conductor layer41a. In other words, the voltage difference of the high-voltage circuit HV and the low-voltage circuit LV is formed between the first conductor layer31aand the second conductor layer41a. Certainly, the types of the high-voltage circuit HV formed on the first surface11aand the low-voltage circuit LV formed on the second surface12aare not limited in the present disclosure. In the embodiment, the voltage difference formed between the high-voltage circuit HV and the low-voltage circuit LV is ranged from 10 kV to 30 kV, but the present disclosure is not limited there.

Notably, in the embodiment, the first trench51ais disposed on the first surface11aand surrounds an outer peripheral edge32aof the first conductor layer31a. Preferably but not exclusively, in the embodiment, the first conductor layer31ais coated on the first surface11aand extended into the first trench51a, so that the outer peripheral edge32aof the first conductor layer31ais located at a bottom52aof the first trench51a. In the embodiment, the first insulation material71acovers the outer peripheral edge32aof the first conductor layer31aand filled in the first trench51a. In the embodiment, the voltage difference formed between the high-voltage circuit HV and the low-voltage circuit LV is ranged from 10 kV to 30 kV. The first insulation material71ais one selected from the group consisting of an epoxy resin, a silicone rubber, a silicone resin and a polyurethane. Moreover, the first insulation material71ahas a dielectric strength greater than 18 kV/mm. Preferably but not exclusively, in the embodiment, the first insulation material71ais filled into the first trench51aby fluid dispensing, so that an outer surface72aof the first insulation material71ais coplanar with the opening of the first trench51a. Thereby, the outer peripheral edge32aof the first conductor layer31ais sealed through the first trench51aand the first insulation material71a, and a distance D1is maintained between the outer peripheral edge32aof the first conductor layer31aand the outer surface72aof the first insulation material71aand greater than 0.6 mm. According to the result of the partial discharge test, an air electric field strength on the outer surface72aof the first insulation material71ais less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge32aof the first conductor layer31aunder the high electric field strength.

In the embodiment, the bearing structure1ais constructed on the upper half shell of the supporting housing1, and the bearing structure1afurther includes a first protruding portion13a, which is protruded from the first surface11ain a direction (i.e., the reverse Z axial direction) away the second surface12a. The first trench51ais disposed on the first protruding portion13a. The first conductor layer31ais coated and disposed on the first surface11aand a lateral wall131aand a top surface132aof the first protruding portion13a, and extended into the bottom52aof the first trench51a. Since the first trench51ais disposed on the first protruding portion13a, when the first insulation material71ais filled into the first trench51aby fluid dispensing, the lateral-wall structure of the first protruding portion13ais helpful of performing the fluid dispensing, and preventing the fluid that is not solidified to form the first insulation material71afrom overflowing everywhere. Preferably but not exclusively, in an embodiment, the outer surface72aof the first insulation material71aand the top surface132aof the first protruding portion13aare coplanar. Certainly, the present disclosure is not limited thereto.

Moreover, in the embodiment, the bearing structure1afurther includes a second trench61aand a second insulation material81a. The second trench61ais disposed on the second surface12aand surrounds an outer peripheral edge42aof the second conductor layer41a. Preferably but not exclusively, in the embodiment, the second conductor layer41ais coated on the second surface12aand extended into the second trench61a, so that the outer peripheral edge42aof the second conductor layer41ais located at a bottom62aof the second trench61a. In the embodiment, the second insulation material81ais filled in the second trench61a, and covers the outer peripheral edge42aof the second conductor layer41a. Similarly, the bearing structure1afurther includes a second protruding portion14a, which is protruded from the second surface12ain a direction (i.e. the Z axial direction) away the first surface11a. The second trench61ais disposed on the second protruding portion14a. The second conductor layer41ais coated and disposed on the second surface12aand a lateral wall141aand a top surface142aof the second protruding portion14a, and extended into the bottom62aof the second trench61a. Since the second trench61ais disposed on the second protruding portion14a, when the second insulation material81ais filled into the second trench61aby fluid dispensing, the lateral-wall structure of the second protruding portion14ais helpful of performing the fluid dispensing, and preventing the fluid that is not solidified to form the second insulation material81afrom overflowing everywhere. Preferably but not exclusively, in an embodiment, the outer surface82aof the second insulation material81aand the top surface142aof the second protruding portion14aare coplanar. Preferably but not exclusively, in the embodiment, the voltage difference formed between the high-voltage circuit HV and the low-voltage circuit LV is ranged from 10 kV to 30 kV. The second insulation material81ais one selected from the group consisting of an epoxy resin, a silicone rubber, a silicone resin and a polyurethane. Moreover, the second insulation material81ahas a dielectric strength greater than 18 kV/mm. Since the outer peripheral edge42aof the second conductor layer41ais sealed through the second trench61aand the second insulation material81a, and a distance D2is maintained between the outer peripheral edge42aof the second conductor layer41aand the outer surface82aof the second insulation material81aand greater than 0.6 mm. According to the result of the partial discharge test, an air electric field strength on the outer surface82aof the second insulation material81ais less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge42aof the second conductor layer41aunder the high electric field strength.

Notably, in the embodiment, the heights of the first protruding portion13aand/or the second protruding portion14aare adjustable according to the practical requirements. In other embodiments, the first protruding portion13aand/or the second protruding portion14aare omitted. In an embodiment, the first trench51ais recessed directly from the first surface11atoward the second surface12a(i.e. in the Z axial direction). Moreover, the first conductor layer31ais coated and disposed on the first surface11a, and extended directly from the first surface11ato the bottom52aof the first trench51a. In that, the first insulation material71acovers the outer peripheral edge32aof the first conductor layer31a, and the outer peripheral edge32aof the first conductor layer31ais sealed. Preferably but not exclusively, in an embodiment, the outer surface72aof the first insulation material71ais substantially coplanar with the first surface11a. In another embodiment, the second trench61ais recessed directly from the second surface12atoward the first surface11a(i.e. in the reverse Z axial direction). Moreover, the second conductor layer41ais coated and disposed on the second surface12a, and extended directly from the second surface12ato the bottom62aof the second trench61a. In that, the second insulation material81acovers the outer peripheral edge42aof the second conductor layer41a, and the outer peripheral edge42aof the second conductor layer41ais sealed. Preferably but not exclusively, in an embodiment, the outer surface82aof the second insulation material81ais substantially coplanar with the second surface12a. Certainly, the present disclosure is not limited thereto, and not redundantly described herein.

FIGS.6A and6Bare partial exploded views illustrating the lower half shell of the bearing housing formed by the bearing structure according to the embodiment of the present disclosure.FIG.7is an enlarged view showing the region P2inFIG.2. In the embodiment, the bearing structure1bis configured to form a lower half shell. The bearing structure1bincludes an insulation carrier10b, a first conductor layer31b, a second conductor layer41b, a first trench51band a first insulation material71b. The insulation carrier10bincludes a first surface11band a second surface12bopposite to each other. Preferably but not exclusively, the first conductor layer31band the second conductor layer41bare coated on the first surface11band the second surface12b, respectively. Moreover, a voltage difference is formed between the first conductor layer31band the second conductor layer41b. Notably, in the embodiment, the high-voltage circuit HV is accommodated within the bearing housing1, and spatially corresponding to the first conductor layer31bcoated on the first surface11bof the insulation carrier10b, so that the electric field generated by the high-voltage circuit HV is uniformized through the action of the first conductor layer31b. On the other hand, when the two bearing housings1with the power conversion modules carried thereon are stacked with each other, the second conductor layer41bcoated on the second surface12bof the insulation carrier10bof the upper bearing housing1is spatially opposite to the low-voltage circuit LV disposed on the outer side of the lower bearing housing.1, so that the electric field generated by the low-voltage circuit LV outside the lower bearing housing1can be uniformized through the action of the second conductor layer41bof the upper bearing housing1. In other words, the voltage difference of the high-voltage circuit HV and the low-voltage circuit LV is formed between the first conductor layer31band the second conductor layer41b.

In the embodiment, the bearing structure1bincludes a first protruding portion13b, which is protruded from the first surface11bin a direction (i.e., the Z axial direction) away the second surface12b. The first trench51bis disposed on the first protruding portion13b. The first conductor layer31bis coated and disposed on the first surface11band a lateral wall131band a top surface132bof the first protruding portion13b, and extended into the bottom52bof the first trench51b. In the embodiment, the first insulation material71bcovers the outer peripheral edge32bof the first conductor layer31band filled in the first trench51b. In the embodiment, the voltage difference formed between the high-voltage circuit HV and the low-voltage circuit LV is ranged from 10 kV to 30 kV. The first insulation material71bis one selected from the group consisting of an epoxy resin, a silicone rubber, a silicone resin and a polyurethane. Moreover, the first insulation material71bhas a dielectric strength greater than 18 kV/mm. Preferably but not exclusively, in the embodiment, the first insulation material71bis filled into the first trench51bby fluid dispensing, so that an outer surface72bof the first insulation material71bis coplanar with the top surface132bof the first protruding portion13b. Thereby, the outer peripheral edge32bof the first conductor layer31bis sealed through the first trench51band the first insulation material71b, and a distance D3is maintained between the outer peripheral edge32bof the first conductor layer31band the outer surface72bof the first insulation material71band greater than 0.6 mm. According to the result of the partial discharge test, an air electric field strength on the outer surface72bof the first insulation material71bis less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge32bof the first conductor layer31bunder the high electric field strength.

Similarly, in the embodiment, the bearing structure1bincludes a second protruding portion14b, which is protruded from the second surface12bin a direction (i.e. the reverse Z axial direction) away the first surface11b. The second trench61bis disposed on the second protruding portion14b. The second conductor layer41bis coated and disposed on the second surface12band a lateral wall141band a top surface142bof the second protruding portion14b, and extended into the bottom62bof the second trench61b. The second insulation material81bis filled into the second trench61bby fluid dispensing, and the outer surface82bof the second insulation material81band the top surface142bof the second protruding portion14bare coplanar. Preferably but not exclusively, in the embodiment, the voltage difference formed between the high-voltage circuit HV and the low-voltage circuit LV is ranged from 10 kV to 30 kV. The second insulation material81bis one selected from the group consisting of an epoxy resin, a silicone rubber, a silicone resin and a polyurethane. Moreover, the second insulation material81bhas a dielectric strength greater than 18 kV/mm. Since the outer peripheral edge42bof the second conductor layer41bis sealed through the second trench61band the second insulation material81b, and a distance D4is maintained between the outer peripheral edge42bof the second conductor layer41band the outer surface82bof the second insulation material81band greater than 0.6 mm. According to the result of the partial discharge test, an air electric field strength on the outer surface82bof the second insulation material81bis less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge42bof the second conductor layer41bunder the high electric field strength.

In other embodiment, the bearing structures1aand the bearing structure1bof the present disclosure are utilized to carry other circuit modules with the high electric field strength generated therefrom. By sealing the outer edge of the conductor layer through the design of the trench, the problem of excessive electric field strength generated due to the outer peripheral edge of the conductor layer on the insulation carrier is solved, and the occurrence of corona and partial discharge is avoided. Certainly, the bearing structure1aand bearing structure1bdesigned to seal the outer peripheral edges of the conductor layers through the trenches are not limited to the two half shells of the bearing housing1. However, in the case of that the bearing structure1aand the bearing structure1bare utilized to form the two symmetrical half shells of the bearing housing1, the first insulation materials71a,71band the second insulation materials81a,81bare filled into the corresponding first trenches51a,51band the corresponding trenches61a,61bby fluid dispensing, respectively. It allows to integrate the formation processes into the manufacturing processes of the bearing housing1easily. Moreover, the assembly of the bearing hosing1and the power conversion module is not affected. In addition, the first insulation materials71a,71band the second insulation materials81a,81bcooperated with the corresponding first trenches51a,51band the corresponding second trenches61a,61bare disposed in the bearing housing1, so that the entire space is not increased. It is not necessary to add an additional space. Thus, the safety specifications and the convenience of the bearing housing for the power conversion module are improved effectively. The bearing housing1formed by the bearing structure1aand the bearing structure1bis advantageous of sandwiching the high-voltage circuit HV in the accommodation space10therebetween simply. Furthermore, the low-voltage circuit LV is disposed on the outer side of the bearing housing1. In that, a unit assembly of power conversion module with small volume is achieved. It facilitates to ensure the safety of the solid-state transformer application and enhance the competitiveness of the product. On the other hand, in case of that the bearing housing1formed by the bearing structure1aand the bearing structure1bis used to carry the high-low-voltage conversion circuit of the power conversion module in the solid state transformer, it allows to adjust the bearing structure1aand the bearing structure1baccording to the isolation transformer included in the high-low-voltage conversion circuit. Referring toFIGS.1to3and taking the bearing structure1aas an example, in an embodiment, a first recessed region (not shown) is formed on the first surface11acovered by the first conductor layer31a, a second recessed region (not shown) is formed on the second surface12acovered by the second conductor layer41a, and the first recessed region and the second recessed region are spatially corresponding to each other in position. In that, the isolation transformer of the high-low-voltage conversion circuit is disposed correspondingly in the first recessed region and the second recessed region. Similarly, the bearing structure1bis a symmetrical structure of the bearing structure1a, and has the same design. However, it is not an essential feature of the present disclosure, and the effects of sealing outer peripheral edges of the first conductor layers31a,31bor the second conductor layers41a,41bare not influenced. The present disclosure is not limited thereto and not redundantly described hereafter.

In summary, the present disclosure provides a bearing structure configured to carry a high-low-voltage conversion circuit with high electric field strength. By sealing the outer edge of the conductor layer through the design of the trench, the problem of excessive electric field strength generated due to the outer peripheral edge of the conductor layer on the insulation carrier is solved. Moreover, the occurrence of corona and partial discharge is avoided. The bearing structure is made of an insulation material with a dielectric strength greater than 18 kV/mm. When a high-voltage circuit and a low-voltage circuit with a voltage difference ranged from 10 kV to 30 kV are isolated through the bearing structure, the outer peripheral edge of the conductor layer is sealed by the trench and the insulation material. In that, a distance is maintained between the outer peripheral edge of the conductor layer and an outer surface of the insulation material and greater than 0.6 mm. An air electric field strength on the outer surface of the insulation material is reduced and less than 2.0 kV/mm. It avoids the occurrence of corona and partial discharge due to the contact of the air and the outer peripheral edge of the conductor layer under the high electric field strength. In addition, when the trench and the insulation material are disposed on a peripheral wall formed by the protruding portion, it allows the bearing structure to form an upper half shell or a lower half shell. For example, two bearing structures are utilized to form two symmetrical half shells and assembled as a bearing housing. The high-voltage circuit is sandwiched between the two symmetrical half shells, and the low-voltage circuit is placed outside the bearing housing, so as to achieve a unit assembly of the power conversion module with small volume. It facilitates to ensure the safety of the solid-state transformer application and enhance the competitiveness of the product. On the other hand, the bearing structure having the outer peripheral edge of the conductor layer sealed through the designed trench is allowed to be applied to the bearing housing, which are detached into two symmetrical half shells. The insulation material is filled into the trench by fluid dispensing, which is easily integrated into the manufacturing process of the two symmetrical half shells carrying the power conversion module. The entire space is not increased. Thus, the safety specifications and the convenience of the bearing housing for the power conversion module are improved effectively.