Electrical system of electric propulsion unit of aircraft
By using electrically insulating spacers with embossed portions in the electrical system of the aircraft electrical propulsion unit, the complexity of partial discharge and insulation distance maintenance is solved, and the closer layout of the electrical conductors and more flexible environmental adaptability are achieved.
Patent Information
- Application Number
- CN202380059197.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-08-11
- Filing Date
- 2023-08-04
- Publication Date
- 2025-03-28
AI Technical Summary
In the electric propulsion unit of the aircraft, local discharge problems caused by high voltage circuits, and in the case of altitude changes and environmental pollution, the insulation distance and leakage path are maintained in the complexity of the insulation path.
An electrically insulated spacer is employed with a relief portion, which defines a leakage path between the two electrical conductors along the spacer, so that the leakage path passes through the relief portion, thereby increasing the length of the leakage path, avoiding partial discharge, and simplifying modification of the insulated flat support.
It is achieved without increasing insulation distance, allowing electrical conductors to be closer together, reducing weight and complexity, while making it easier to adjust the spacer to accommodate new conditions when the environment changes.
Smart Images
Figure CN119731083A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an electrical system of an electric propulsion unit of an aircraft, an electric propulsion unit having such an electrical system and an aircraft having such an electric propulsion unit. The invention also relates to a method for manufacturing an electrical system of a propulsion unit of an aircraft. Background Art
[0002] Electric propulsion or hybrid aircraft (electric propulsion and thermal propulsion), whether the aircraft is vertical take-off and landing (VTOL), short take-off and landing (STOL) or conventional take-off and landing (CTOL), constitute a very promising future market with great prospects and needs in the intra-city and inter-city transportation of goods and people. Therefore, the electric propulsion unit of these aircraft is at least partially realized by one or more electric motors, the number of which varies according to the architecture of the aircraft.
[0003] These electric propulsion units use circuits with higher voltage levels, which creates problems with partial discharges at high altitudes. In fact, in the air, partial discharges can first occur between two electrical conductors at different electrical potentials when the distance in the air between the two conductors is not enough (i.e. less than the minimum insulation distance). Partial discharges can also occur on the material along one or more electrical insulation members extending between the two electrical conductors. Therefore, the two components must be separated from each other by a distance greater than the minimum leakage distance along a leakage path on one or more insulating members. For example, since the oxygen level decreases with altitude, the minimum leakage distance along the material is greater than the minimum air insulation distance at a rate that increases with altitude.
[0004] Furthermore, the quest for weight reduction has driven the search for solutions that bring components closer together. In the case of electronic boards with electrical conductors that carry positive and negative potentials, respectively, of a DC supply voltage (which can reach several hundred volts), compliance with air insulation distances and leakage distances on the material imposes severe restrictions on the wiring in the electronic board.
[0005] It may therefore be desirable to provide an electrical system for an aircraft propulsion unit that enables overcoming at least some of the above-mentioned problems and constraints. Summary of the invention
[0006] Therefore, an electrical system of an electric propulsion unit of an aircraft is proposed, characterized in that the electrical system comprises:
[0007] an electric circuit comprising an electrically insulating planar support and two electric conductors fixed to the planar support, the two electric conductors being designed to have different respective electric potentials during operation of the electric circuit, the two electric conductors being separated from each other by an air-insulating distance; and
[0008] An electrically insulating spacer extending between the two electrical conductors above the flat support and having a relief to define a leakage path along the spacer between the two electrical conductors, the leakage path passing through the relief.
[0009] Like this, by passing through the embossed part, the leakage path is no longer straight but "compressed", which means that as long as the air insulation distance is sufficient, the electrical conductors can be closer together. In other words, the embossed part of the component increases the length of the leakage path with the same air insulation distance, so that two electrical conductors can be closer together without the risk of partial discharge. In addition, the use of the spacer makes it possible to avoid the use of the embossed part of the electrically insulating flat support. In fact, for example, when the electrically insulating flat support is a printed circuit board, machining the electrically insulating flat support may be complicated and expensive. In addition, in the event of an error, or when the environment of the electrical system changes (for example, when the operating altitude of the aircraft changes), or when the electronic system is modified to make the potential difference higher, or when the pollution and / or humidity level is different from the pollution and / or humidity level envisioned, etc., it may be complicated to modify the insulating flat support. On the other hand, it is easy to replace the spacer to replace the spacer with a new spacer that is more suitable for the new environment.
[0010] The present invention may also include one or more of the following optional features in any technically possible combination:
[0011] Preferably, the spacer is made of at least one of the following: polyaramid, polyamide 6-6, polysulfone and polyetheretherketone.
[0012] Furthermore, preferably, the relief portion comprises at least one groove.
[0013] Furthermore, preferably, the groove has a rectangular cross-sectional profile.
[0014] Furthermore, preferably, the groove has a trapezoidal cross-sectional profile.
[0015] Furthermore, preferably, the width of the groove is equal to at least 20% of the length of the smallest leakage path in order to avoid partial discharges between two electrical conductors on the spacer.
[0016] Furthermore, preferably, the height of the groove amounts to at least 25% of the length of the smallest leakage path in order to avoid partial discharges between two electrical conductors on the spacer.
[0017] An electric propulsion unit for an aircraft is also proposed, comprising the electrical system according to the invention.
[0018] An aircraft comprising an electric propulsion unit according to the invention is also proposed.
[0019] A method of manufacturing an electrical system of an electric propulsion unit of an aircraft is also proposed, the method comprising:
[0020] - obtaining an electric circuit having an electrically insulating flat support and two electric conductors fixed to the flat support, the two electric conductors being designed to have different respective electric potentials during operation of the electric circuit, the two electric conductors being separated from each other by an air insulating distance; the method further comprising:
[0021] - adding an electrically insulating spacer such that the electrically insulating spacer extends above the flat support between the two electrical conductors, the spacer having a relief to define a leakage path along the spacer between the two electrical conductors, the leakage path passing through the relief.
[0022] Preferably, the method comprises:
[0023] - calculating a minimum insulation distance between two electrical conductors, for example based on at least one of: a maximum potential difference between the two electrical conductors during operation of the circuit, a maximum altitude the aircraft is designed to reach, a maximum pollution level the aircraft is designed to pass, and a maximum humidity level the aircraft is designed to pass; obtaining a circuit, wherein the two electrical conductors are separated by an air insulation distance, the air insulation distance being greater than or equal to the minimum insulation distance;
[0024] - calculating the length of the minimum leakage path according to the highest altitude the aircraft is designed to reach, for example according to the minimum insulation distance and a coefficient that varies with altitude, by which the minimum insulation distance must be multiplied to obtain the length of the minimum leakage path; and
[0025] The relief of the spacer is designed such that the length of the leakage path is greater than or equal to the length of the smallest leakage path. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The invention will be better understood from the following description, given by way of example only and with reference to the accompanying drawings, in which:
[0027] - Figure 1 is a top view of an electronic board according to the invention of an electrical system of an electric propulsion unit of an aircraft, the electronic board having a spacer between two electrical conductors,
[0028] - Figure 2 is a cross-sectional view of a first embodiment of a groove in a spacer,
[0029] - Figure 3 is a cross-sectional view of a second embodiment of a groove in a spacer,
[0030] - Figure 4 is a cross-sectional view of two grooves in the second embodiment,
[0031] - Figure 5 No spacers are used. Figure 1 Similar views, and
[0032] - Figure 6 is a block diagram illustrating steps in a method for mounting electrical insulation according to the present invention. DETAILED DESCRIPTION
[0033] Reference Figure 1 , an example of an electrical system 100 of a propulsion unit of an aircraft according to the invention will now be described.
[0034] The electrical system 100 firstly comprises an electrical circuit 102 including an electrically insulating flat support 104 , such as a printed circuit board.
[0035] The electrical system 100 further comprises two electrical conductors 106, 108 fixed to the flat support 104, the two electrical conductors being designed to assume two different respective potentials during operation of the circuit 102. For example, the two electrical conductors are electrical terminals designed to be respectively connected to respective bus bars and to respectively assume a positive potential and a negative potential of a DC supply voltage (e.g. greater than 100 V). Alternatively, the electrical conductors 106, 108 may be bus bars (e.g. for transmitting a DC supply voltage), studs, contactors or even measuring probes.
[0036] The two electrical conductors 106, 108 are separated from each other by an air insulation distance DI. The insulation distance DI is defined as the shortest straight-line distance between the two conductors 106, 108 in air.
[0037] In order to avoid partial discharge through air, the insulation distance DI must be greater than the minimum insulation distance DI 最小 , the minimum insulation distance is calculated in advance, for example, based on at least one of the following: the maximum potential difference between two operating conductors of the circuit, the highest altitude that the aircraft is designed to reach, the maximum pollution level and the maximum humidity level that the aircraft is designed to pass. Typically, the electrical conductors 106, 108 are such that the insulation distance DI is equal to the minimum insulation distance DI 最小 .
[0038] The electrical system 100 further comprises an electrically insulating spacer 110 extending above the planar support 104 between the two electrical conductors 106, 108. The spacer 110 has a relief 112 to define a leakage path LF along the spacer 110 between the two electrical conductors 106, 108, the leakage path LF passing through the relief 112. The leakage path LF is defined as the shortest distance between the two conductors 106, 108 extending over the spacer 110.
[0039] To avoid partial discharge along the spacer 110, the length of the leakage path LF must be greater than the minimum leakage path LF. 最小 The length of the minimum leakage path is equal to the insulation distance multiplied by a factor (greater than 1) that increases with altitude. Thus, the coefficient corresponding to the altitude that the aircraft is designed to reach is used to calculate the minimum leakage path LF 最小 Length.
[0040] Therefore, the embossed portion 112 is designed so that the length of the leakage path LF is equal to or greater than (preferably equal to) the minimum leakage path LF. 最小 Length.
[0041] For example, the relief 112 comprises at least one groove 114 (two grooves in the example shown), which groove is, for example, linear and perpendicular to the leakage path LF.
[0042] The spacer is made of, for example, at least one of the following: polyarylamide (commonly referred to as PAA), polyamide 6-6 (abbreviated as PA66), polysulfone (commonly referred to as PSU) and polyetheretherketone (commonly referred to as PEEK GLx, where x ranges from 1 to 30).
[0043] Reference Figure 2 Each groove 114 may have a rectangular cross-sectional profile. Preferably, according to standard EN60664-1 "Isolation_système_basse_tension", the width L of the groove 114 is equal to the minimum leakage path LF 最小 at least 20% of the length of the groove, and / or the height H of the groove is equal to the minimum leakage path LF 最小 at least 25% of the length.
[0044] Reference Figure 3 , each groove 114 may also have a trapezoidal cross-sectional profile. Preferably, as described above, the width L of the groove 114 (the dimension of the base of the trapezoid, at the bottom of the groove 114) is equal to the minimum leakage path LF 最小at least 20% of the length of the groove, and / or the height H of the groove is equal to the minimum leakage path LF 最小 at least 25% of
[0045] Figure 4 The following situation is shown: the size of the groove 114 is designed so that the length of the leakage path LF is equal to the minimum leakage path LF 最小 The insulation distance DI is equal to the minimum insulation distance DI 最小 In this case, take into account the minimum insulation distance DI 最小 and the minimum leakage path LF 最小 Depending on the aircraft operating conditions (maximum potential difference, altitude, etc.), the electrical conductors 106, 108 are placed as close together as possible to avoid partial discharges.
[0046] Reference Figure 5 In the absence of the spacer 110, the two electrical conductors 106, 108 would have to be spaced farther apart to comply with the minimum leakage path LF 最小 , in the example shown, the minimum leakage path is the minimum insulation distance DI 最小 1.5 times of.
[0047] Reference Figure 6 , the method 600 for manufacturing the electrical system 100 may, for example, include the following steps.
[0048] In step 602, the minimum insulation distance DI between the two electrical conductors 106, 108 is calculated, for example, according to at least one of the following: 最小 : the maximum potential difference between the two electrical conductors 106, 108 during operation of the circuit 102, the maximum altitude the aircraft is designed to reach, the maximum pollution level the aircraft is designed to pass, and the maximum humidity level the aircraft is designed to pass.
[0049] In step 604, the circuit 102 is obtained without the spacer 110, wherein the two electrical conductors 106, 108 are separated by an insulation distance DI in the air, and the insulation distance is greater than or equal to the minimum insulation distance DI 最小 For example, where the spacer 110 is intended to replace a previous spacer present between the electrical conductors 106 , 108 (the previous spacer being no longer suitable, for example, for the new environment of the electrical system 100 ), step 604 may include removing the previous spacer.
[0050] In step 606, the maximum altitude that the aircraft is designed to reach, for example, according to the minimum insulation distance DI 最小 and the coefficient that varies with altitude to calculate the minimum leakage path LF 最小 Length, minimum insulation distance DI 最小Multiply this factor to obtain the minimum leakage path LF 最小 Length.
[0051] In step 608, the relief portion 112 of the spacer 110 is designed so that once the spacer is added to the circuit 102, the length of the leakage path LF is greater than or equal to the minimum leakage path LF 最小 Length.
[0052] In step 610, a spacer 110 having a previously designed relief 112 is added to the circuit 102 so that the spacer extends between the two electrical conductors 106, 108 over the planar support 104. Thus, a leakage path DF between the two electrical conductors 106, 108 along the spacer 110 passes through the relief 112.
[0053] Obviously, an electrical system such as the one described above increases the length of the leakage path over a shorter distance in air which eventually equals the minimum insulation distance.
[0054] It should also be noted that the present invention is not limited to the embodiments described above. In fact, those skilled in the art will appreciate that various modifications may be made to the embodiments described above in light of the teachings just disclosed.
[0055] For example, step 606 and / or step 608 may be performed before step 604 .
[0056] In the above detailed description of the present invention, the terms used should not be interpreted as limiting the present invention to the embodiments disclosed in this specification, but should be interpreted as including all equivalents of the embodiments disclosed in this specification, which are anticipated by those skilled in the art by applying his general knowledge to the implementation methods of the teachings just disclosed.
Claims
1. An electrical system (100) of an electric propulsion unit of an aircraft, characterized in that: The electrical system comprises: - an electric circuit (102) comprising an electrically insulating flat support (104) and two electric conductors (106, 108) fixed to the flat support, the two electric conductors (106, 108) being designed to have different respective electrical potentials during operation of the electric circuit (102), the two electric conductors (106, 108) being separated from each other by an air insulation distance (DI); and - an electrically insulating spacer (110) extending between the two electrical conductors (106, 108) above the flat support (104) and having a relief (112) to define a leakage path (DF) along the spacer (110) between the two electrical conductors (106, 108), the leakage path (DF) passing through the relief (112).
2. The electrical system (100) according to claim 1, wherein: The spacer is made of at least one of the following: polyaramid, polyamide 6-6, polysulfone, and polyetheretherketone.
3. The electrical system (100) according to claim 1 or 2, wherein: The relief portion (112) includes at least one groove (114).
4. The electrical system (100) according to claim 3, wherein: The groove (114) has a rectangular cross-sectional profile.
5. The electrical system (100) according to claim 3, wherein: The groove (114) has a trapezoidal cross-sectional profile.
6. The electrical system (100) according to any one of claims 3 to 5, wherein: The width (L) of the groove (114) is equal to the minimum leakage path (LF 最小 ) to avoid partial discharges between the two electrical conductors (106, 108) on the spacer (110).
7. The electrical system (100) according to any one of claims 3 to 6, wherein: The height (H) of the groove (114) is equal to the minimum leakage path (LF 最小 ) to avoid partial discharges between the two electrical conductors (106, 108) on the spacer (110).
8. An electric propulsion unit for an aircraft, the electric propulsion unit comprising an electrical system according to any one of claims 1 to 7.
9. An aircraft comprising an electric propulsion unit according to claim 8.
10. A method (600) of manufacturing an electrical system (100) of an electric propulsion unit of an aircraft, the method comprising: - obtaining (604) an electric circuit (102) having an electrically insulating flat support (104) and two electric conductors (106, 108) fixed to the flat support, the two electric conductors (106, 108) being designed to have different respective electric potentials during operation of the electric circuit (102), the two electric conductors (106, 108) being separated from each other by an air insulation distance (DI); The method further comprises: - Adding (610) an electrically insulating spacer (110) so that the electrically insulating spacer extends between the two electrical conductors (106, 108) above the flat support (104), and the spacer (110) has a relief (112) to define a leakage path (DF) along the spacer (110) between the two electrical conductors (106, 108), the leakage path (DF) passing through the relief (112).
11. The method (600) of claim 10, comprising: - calculating (602) a minimum insulation distance (DI) between the two electrical conductors (106, 108), for example according to at least one of the following: 最小 ): a maximum potential difference between the two electrical conductors (106, 108) during operation of the circuit (102), a maximum altitude that the aircraft is designed to reach, a maximum pollution level that the aircraft is designed to pass through, and a maximum humidity level that the aircraft is designed to pass through; obtaining (604) the circuit (102), wherein the two electrical conductors (106, 108) are separated by the air insulation distance (DI), and the air insulation distance is greater than or equal to the minimum insulation distance (DI 最小 ); - According to the maximum altitude that the aircraft is designed to reach, for example, according to the minimum insulation distance (DI 最小 ) and the coefficient that varies with altitude to calculate (606) the minimum leakage path (LF 最小 ) length, the minimum insulation distance (DI 最小 ) must be multiplied by the coefficient to obtain the minimum leakage path (LF 最小 )’s length; and - designing (608) the relief portion (112) of the spacer (110) such that the length of the leakage path (LF) is greater than or equal to the minimum leakage path (LF 最小 )'s length.