A voltage doubler rectifier for a high-voltage power supply for electro-pneumatic propulsion

Abstract

The present invention is applicable to the field of power electronics, and discloses a voltage doubler rectifier for an electro-aerodynamic propulsion high-voltage power supply, comprising: a three-dimensional heat dissipation structure, the three-dimensional heat dissipation structure comprising: two PCB boards, two high-voltage diodes and a high-voltage capacitor; wherein the two PCB boards comprise a first PCB board and a second PCB board, and the two high-voltage diodes comprise a first high-voltage diode and a second high-voltage diode; the cathode of the second high-voltage diode is connected to the anode of the first high-voltage diode through the second PCB board; the cathode of the first high-voltage diode is connected to two series-connected high-voltage capacitors through the first PCB board, and is connected to the anode of the second high-voltage diode. The use of a three-dimensional structure helps to increase the heat dissipation area, reduce the weight of the heat dissipation device and the heat dissipation material, realize the reduction of the weight of the voltage doubler rectifier circuit, and achieve the ultimate purpose of reducing the weight of the LCC converter, thereby meeting the requirements of lightweight design of aircraft.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and in particular relates to a voltage doubling rectifier used for a high-voltage power supply of an electro-aerodynamic propulsion system. Background Art

[0002] Electroaerodynamic propulsion is a new type of propulsion method. Different from the traditional mechanical movement to generate thrust, the thrust comes from the "ion wind" generated by high voltage ionized air. At the same time, the aircraft using this propulsion method has the characteristic of lightweight. Electroaerodynamic propulsion relies on a high-power-density high-voltage power supply, and the voltage doubler rectifier is an important component of the high-voltage power supply, which affects important parameters such as the power density of the circuit.

[0003] The voltage-doubling rectifier in the traditional LCC converter is mounted on the PCB board by surface mount welding, which makes the contact area with the air small and is not conducive to the heat dissipation of the high-voltage device. In order to ensure its reliability, heat dissipation measures such as heat sinks and fans need to be added, which increases the weight of the converter and is not conducive to the lightweight design of electroaerodynamic propulsion aircraft. The PCB board used by the voltage-doubling rectifier increases the weight of the voltage-doubling rectifier part. Summary of the invention

[0004] An embodiment of the present invention provides a voltage doubler rectifier for an electro-aerodynamic propulsion high-voltage power supply, aiming to solve the problem of the existing lack of a voltage doubler rectifier for an electro-aerodynamic propulsion high-voltage power supply with the overall lightweight of the converter as the optimization purpose.

[0005] An embodiment of the present invention provides a voltage doubler rectifier for an electro-aerodynamic propulsion high-voltage power supply, the voltage doubler rectifier comprising: a three-dimensional heat dissipation structure, the three-dimensional heat dissipation structure comprising: two PCB boards, two high-voltage diodes and a high-voltage capacitor; wherein the two PCB boards comprise a first PCB board and a second PCB board, and the two high-voltage diodes comprise a first high-voltage diode and a second high-voltage diode;

[0006] The cathode of the second high-voltage diode is connected to the anode of the first high-voltage diode through the second PCB board;

[0007] The cathode of the first high-voltage diode is connected to the two high-voltage capacitors connected in series through the first PCB board, and is connected to the anode of the second high-voltage diode.

[0008] Preferably, the voltage doubler rectifier further comprises: a solidifiable insulating glue and a solidifiable thermally conductive silicone grease;

[0009] The solidifiable insulating adhesive is arranged at each metal contact point;

[0010] The solidifiable thermally conductive silicone grease is arranged on the outer shell of the three-dimensional heat dissipation structure.

[0011] Preferably, the voltage doubler rectifier satisfies at least one of the following conditions:

[0012] The solidifiable insulating adhesive is encapsulated by encapsulating each metal contact point;

[0013] The thermal resistance of the solidifiable thermally conductive silicone grease is smaller than the thermal resistance of the first high-voltage diode and the second high-voltage diode.

[0014] Preferably, the copper foil width of the PCB board is calculated using the following formula:

[0015] ;

[0016] in, is the thickness of the copper foil of the PCB board, is the thermal conductivity of the high voltage diode pin, is the thermal conductivity of the copper foil of the PCB board, is the pin diameter of the high voltage diode.

[0017] Preferably, the thickness of the curable insulating adhesive is calculated using the following formula:

[0018] ;

[0019] in, V out is the output voltage, V is_max is the maximum insulation voltage of the insulation material.

[0020] Preferably, whether the solidifiable thermally conductive silicone grease needs to be used is determined by:

[0021] Calculate the thermal resistance of the high-voltage diode pins and the thermal resistance of the high-voltage diode solder;

[0022] Calculate the thermal resistance of the copper foil of the PCB board under natural convection conditions;

[0023] Calculate the temperature rise of equivalent thermal resistance;

[0024] When the temperature rise of the equivalent thermal resistance is less than the minimum allowable temperature rise of the high-voltage diode PN junction, there is no need to add solidifiable thermal grease;

[0025] When the temperature rise of the equivalent thermal resistance is greater than or equal to the minimum allowable temperature rise of the high-voltage diode PN junction, it is necessary to add solidifiable thermal grease.

[0026] Preferably, the thermal resistance of the high-voltage diode pin is calculated in the following manner:

[0027] ;

[0028] The specific method for calculating the high-voltage diode solder thermal resistance is as follows:

[0029] ;

[0030] in, is the pin length of the high voltage diode, is the thermal conductivity of the high voltage diode pin, is the pin diameter of the high voltage diode, is the thermal conductivity of the high voltage diode solder, is the thickness of the copper foil of the PCB board, d 1 is the solder thickness.

[0031] Preferably, the thermal resistance of the copper foil of the PCB board under natural convection conditions is calculated in the following manner:

[0032] ;

[0033] in The length of the copper foil on the PCB, which is the length required for connecting components to form a complete circuit; is the natural convection heat transfer coefficient of air, is the width of the copper foil on the PCB board, is the thickness of the copper foil on the PCB.

[0034] Preferably, the temperature rise of the equivalent thermal resistance is calculated in the following manner:

[0035] ;

[0036] in, ;

[0037] in, is the thermal resistance from the diode PN junction to the case, is the thermal resistance from case to air, is the thermal resistance of the high voltage diode, is the high voltage diode solder thermal resistance, is the thermal resistance of the copper foil of the PCB board under natural convection conditions, is the temperature rise of the equivalent thermal resistance, is the diode loss, R eq is the equivalent thermal resistance of the diode itself.

[0038] Preferably, when the temperature rise of the equivalent thermal resistance is greater than or equal to the minimum allowable temperature rise of the PN junction of the high-voltage diode, the thickness of the solidifiable thermal conductive silicone grease to be increased is specifically determined in the following manner:

[0039] ;

[0040] The above formula states , and for:

[0041] ;

[0042] ;

[0043] ;

[0044] in is the radius of the high-voltage diode case, is the high voltage diode case length, is the thermal resistance from the high voltage diode PN junction to the case, is the thermal resistance from case to air, is the thermal resistance of the high voltage diode, is the high voltage diode solder thermal resistance, is the thermal resistance of the copper foil of the PCB board under natural convection conditions, is the high voltage diode loss, is the air natural convection coefficient, is the maximum allowable temperature rise.

[0045] Beneficial effects achieved by the present invention: The present invention discloses a voltage doubler rectifier for an electroaerodynamic propulsion high-voltage power supply, including: a three-dimensional heat dissipation structure. The three-dimensional structure is used to increase the heat dissipation area of ​​the voltage doubler rectifier, reduce the weight of the heat dissipation device and the heat dissipation material, and achieve the reduction of the weight of the voltage doubler rectifier circuit, achieving the ultimate goal of reducing the weight of the LCC converter, thereby meeting the requirements of lightweight design of aircraft. Furthermore, the voltage doubler rectifier also includes a solidifiable insulating glue and a solidifiable thermal conductive silicone grease, and the solidifiable insulating glue is arranged at each metal contact point; the solidifiable thermal conductive silicone grease is located in the outer shell of the three-dimensional heat dissipation structure. Furthermore, the copper foil existing on the PCB board of the voltage doubler rectifier circuit is utilized and the surface area of ​​the copper foil is designed so that it is used for the conduction and heat dissipation of the heat of the voltage doubler rectifier. At the same time, the thickness of the heat dissipation silicone grease is designed to further achieve the reduction of the weight of the voltage doubler rectifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A structural diagram of a voltage doubler rectifier provided in an embodiment of the present invention;

[0047] Figure 2 This is a circuit diagram of a voltage doubler rectifier according to an embodiment of the present invention;

[0048] Figure 3 This is a thermal resistance principle diagram of a voltage doubler rectifier according to an embodiment of the present invention.

[0049] Reference numerals: first PCB board 1 , second PCB board 2 , first high-voltage diode 3 , second high-voltage diode 4 , high-voltage capacitor 5 , curable insulating glue 6 and curable thermal conductive silicone grease 7 . DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0052] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0053] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the terms used in this specification include any and all combinations of the relevant listed items.

[0054] like Figure 1 As shown, the present invention provides a lightweight integrated transformer for high voltage power supply of electro-aerodynamic propulsion, such as Figure 1 As shown, the transformer includes: a three-dimensional heat dissipation structure, the three-dimensional heat dissipation structure includes: two PCB boards, two high-voltage diodes and a high-voltage capacitor 5; wherein the two PCB boards include a first PCB board 1 and a second PCB board 2, and the two high-voltage diodes include a first high-voltage diode 3 and a second high-voltage diode 4;;

[0055] The cathode of the second high-voltage diode 4 is connected to the anode of the first high-voltage diode 3 through the second PCB board 2 , and the cathode of the first high-voltage diode 3 is connected to the anode of the second high-voltage diode 4 after being connected to two high-voltage capacitors 5 connected in series through the first PCB board 1 .

[0056] Specifically, in the present invention, the first PCB board 1 is an upper PCB board, and the second PCB board is a lower PCB board.

[0057] Beneficial effects achieved by the present invention: The present invention discloses a voltage doubler rectifier for an electroaerodynamic propulsion high-voltage power supply, including: a three-dimensional heat dissipation structure. The three-dimensional structure helps to increase the heat dissipation area of ​​the voltage doubler rectifier, reduce the weight of the heat dissipation device and the heat dissipation material, achieve a reduction in the weight of the voltage doubler rectifier circuit, and achieve the ultimate goal of reducing the weight of the LCC converter, thereby meeting the lightweight design requirements of the aircraft.

[0058] like Figure 1 As shown, the voltage doubler rectifier also includes: a solidifiable insulating glue 6 and a solidifiable thermally conductive silicone grease 7; the solidifiable insulating glue 6 is located at each metal contact point; the solidifiable thermally conductive silicone grease 7 is located at the outer shell of the first high-voltage diode 3 and the second high-voltage diode 4; the solidifiable insulating glue 6 is encapsulated in a potting manner to wrap each metal contact point, and the thermal resistance of the solidifiable thermally conductive silicone grease 7 is less than the outer shell thermal resistance of the first high-voltage diode 3 and the second high-voltage diode 4.

[0059] Above Figure 1 The designed PCB copper foil width and the solidifiable thermal grease thickness are used as a heat sink and reduce the weight of the heat sink. In the present invention, the PCB copper foil width, the thickness of the solidifiable insulating glue, and the thickness of the solidifiable thermal grease are reasonably designed to meet the heat dissipation and lightweight design requirements.

[0060] The specific design plan is as follows:

[0061] 1) The width of the copper foil in the PCB board is:

[0062] ;

[0063] in, is the thickness of the copper foil of the PCB board, is the thermal conductivity of the high voltage diode pin, is the thermal conductivity of the copper foil of the PCB board, is the pin diameter of the high voltage diode.

[0064] 2) The thickness of the curable insulating adhesive is:

[0065] .

[0066] V out is the output voltage.

[0067] 3) Whether the solidifiable thermal grease is needed is determined by the following method:

[0068] Step S10, calculating the thermal resistance of the high-voltage diode pin and the thermal resistance of the high-voltage diode solder;

[0069] Step S20, calculating the thermal resistance of the copper foil of the PCB board under natural convection conditions;

[0070] Step S30, calculating the temperature rise of the equivalent thermal resistance;

[0071] Step S40, when the temperature rise of the equivalent thermal resistance is less than the minimum allowable temperature rise of the PN junction of the high-voltage diode, it is not necessary to add the solidifiable thermal conductive silicone grease;

[0072] Step S40: When the temperature rise of the equivalent thermal resistance is greater than or equal to the minimum allowable temperature rise of the PN junction of the high-voltage diode, it is necessary to add solidifiable thermal conductive silicone grease.

[0073] Among them, in step S10, the thermal resistance of the high-voltage diode pin is calculated in the following manner:

[0074] ;

[0075] The specific method for calculating the high-voltage diode solder thermal resistance is as follows:

[0076] ;

[0077] in, is the pin length of the high voltage diode, is the thermal conductivity of the high voltage diode pin, is the pin diameter of the high voltage diode, is the thermal conductivity of the high voltage diode solder, is the thickness of the copper foil of the PCB board, d 1 is the solder thickness.

[0078] In step S20, the thermal resistance of the copper foil of the PCB board under natural convection conditions is calculated as:

[0079] ;

[0080] in The length of the copper foil on the PCB, which is the length required for connecting components to form a complete circuit; is the natural convection heat transfer coefficient of air, is the width of the copper foil on the PCB board, is the thickness of the copper foil on the PCB. ;

[0081] ;

[0082] ;

[0083] ;

[0084] in is the air density, is the air expansion coefficient, is the acceleration due to gravity, is the temperature difference between the average temperature of the copper foil and the ambient temperature, is the air diffusion velocity perpendicular to the PCB board, is the specific heat capacity of air, is the air viscosity coefficient, is the thermal conductivity of air, is the Nusselt number, is the Grashof number, is the Prandtl number.

[0085] In step S30, the temperature rise of the equivalent thermal resistance is calculated as:

[0086] ;

[0087] in, ;

[0088] in, is the thermal resistance from the diode PN junction to the case, is the thermal resistance from case to air, is the thermal resistance of the high voltage diode, is the high voltage diode solder thermal resistance, is the thermal resistance of the copper foil of the PCB board under natural convection conditions, is the temperature rise of the equivalent thermal resistance, is the diode loss, R eq is the equivalent thermal resistance of the diode itself.

[0089] In step S40, when the temperature rise of the equivalent thermal resistance is greater than or equal to the minimum allowable temperature rise of the high-voltage diode PN junction, the thickness of the solidifiable thermal conductive silicone grease to be increased is specifically determined in the following manner:

[0090] ;

[0091] The above formula states , and for:

[0092] ;

[0093] ;

[0094] ;

[0095] in is the radius of the high-voltage diode case, is the high voltage diode case length, is the thermal resistance from the high voltage diode PN junction to the case, is the thermal resistance from case to air, is the thermal resistance of the high voltage diode, is the high voltage diode solder thermal resistance, is the thermal resistance of the copper foil of the PCB board under natural convection conditions, is the high voltage diode loss, is the air natural convection coefficient, is the maximum allowable temperature rise.

[0096] like Figure 2 As shown, Figure 1 The schematic diagram of the voltage doubler rectifier circuit is shown in.

[0097] like Figure 3 As shown, Figure 1 The thermal resistance relationship diagram of the voltage doubler rectifier is shown in .

[0098] The present invention proposes a voltage doubler rectifier for a high-voltage power supply for electro-aerodynamic propulsion, aiming to realize a lightweight design of a voltage doubler rectifier circuit in an LCC converter, so as to effectively reduce the weight of the converter. In the present invention, the use of a three-dimensional structure helps to increase the heat dissipation area and reduce the weight of the heat dissipation device and the heat dissipation material; the copper foil existing on the PCB board of the voltage doubler rectifier circuit is utilized and the surface area of ​​the copper foil is designed so that it can be used for the conduction and heat dissipation of the heat of the voltage doubler rectifier, and the thickness of the heat dissipation silicone grease is designed to realize the reduction of the weight of the voltage doubler rectifier circuit, so as to achieve the ultimate goal of reducing the weight of the LCC converter, thereby meeting the requirements of lightweight design of aircraft.

[0099] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0100] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A voltage doubler rectifier for a high voltage power supply for electro-aerodynamic propulsion, characterized in that: The voltage doubler rectifier comprises: a three-dimensional heat dissipation structure, which comprises: two PCB boards, two high-voltage diodes and a high-voltage capacitor; wherein the two PCB boards comprise a first PCB board and a second PCB board, and the two high-voltage diodes comprise a first high-voltage diode and a second high-voltage diode; The cathode of the second high-voltage diode is connected to the anode of the first high-voltage diode through the second PCB board; The cathode of the first high-voltage diode is connected to the two high-voltage capacitors connected in series through the first PCB board, and is connected to the anode of the second high-voltage diode; The voltage doubler rectifier further comprises: a solidifiable insulating glue and a solidifiable thermally conductive silicone grease; The solidifiable insulating glue is arranged at each metal contact point; the solidifiable thermal conductive silicone grease is arranged on the outer shells of the first high-voltage diode and the second high-voltage diode; Whether the solidifiable thermal conductive silicone grease is needed is determined by the following method: Calculate the thermal resistance of the high-voltage diode pins and the thermal resistance of the high-voltage diode solder; Calculate the thermal resistance of the copper foil of the PCB board under natural convection conditions; Calculate the temperature rise of equivalent thermal resistance; When the temperature rise of the equivalent thermal resistance is less than the minimum allowable temperature rise of the high-voltage diode PN junction, there is no need to add solidifiable thermal grease; When the temperature rise of the equivalent thermal resistance is greater than or equal to the minimum allowable temperature rise of the high-voltage diode PN junction, it is necessary to add solidifiable thermal conductive silicone grease; The temperature rise of equivalent thermal resistance is calculated in the following way: ； in: ； is the thermal resistance from the diode PN junction to the case, is the thermal resistance from case to air, is the thermal resistance of the high voltage diode, is the high voltage diode solder thermal resistance, is the thermal resistance of the copper foil of the PCB board under natural convection conditions, R eq is the equivalent thermal resistance of the diode itself, is the temperature rise of the equivalent thermal resistance, is the diode loss.

2. A voltage doubler rectifier for a high voltage power supply for electro-aerodynamic propulsion according to claim 1, characterized in that: The voltage doubler rectifier satisfies at least one of the following conditions: The solidifiable insulating adhesive is encapsulated by encapsulating each metal contact point; The thermal resistance of the solidifiable thermally conductive silicone grease is smaller than the thermal resistance of the first high-voltage diode and the second high-voltage diode.

3. A voltage doubler rectifier for a high voltage power supply for electro-aerodynamic propulsion according to claim 1, characterized in that: The thermal resistance of the high-voltage diode pin is calculated in the following way: ； The specific method for calculating the high-voltage diode solder thermal resistance is as follows: ； in, is the pin length of the high voltage diode, is the thermal conductivity of the high voltage diode pin, is the pin diameter of the high voltage diode, is the thermal conductivity of the high voltage diode solder, is the thickness of the copper foil of the PCB board, d 1 is the solder thickness.

4. A voltage doubler rectifier for a high voltage power supply for electro-aerodynamic propulsion according to claim 1, characterized in that: The specific method for calculating the thermal resistance of the copper foil of the PCB board under natural convection conditions is as follows: ； in The length of the copper foil on the PCB, which is the length required for connecting components to form a complete circuit; is the natural convection heat transfer coefficient of air, is the width of the copper foil on the PCB board, is the thickness of the copper foil on the PCB.

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