Filter circuit for aviation 28V DC power supply module

Abstract

The invention discloses a filter circuit for an aviation 28V direct current power supply module. The filter circuit comprises a filter circuit on the input side of the power supply module and a filter circuit on the output side of the power supply module. The method has the advantages that the input and output sides of the aviation 28V direct-current power supply module are subjected to filtering design, the method is easy to implement and high in stability, the conduction and radiation emission level of the power supply module can be effectively reduced, and the scheme iteration cost and the identification test risk in the aviation equipment development stage are effectively reduced.

Description

Technical Field

[0001] The invention relates to an aviation 28V direct current power supply module, in particular to a filter circuit used for the aviation 28V direct current power supply module. Background Art

[0002] In avionics equipment, due to its 28V DC power supply characteristics, a large number of power conversion modules are used from 28V DC to 28V DC or low voltage DC. Due to the sharp increase in the switching frequency and module power of the PWM drive, the conduction and radiation interference problems caused by the high-order harmonics with a base frequency of 200kHz-500kHz are endless, such as the common JZF919 constant current converter. In the current filter circuit design of power modules, finished filters are often used to suppress their interference problems, but finished filters generally only have large insertion losses in the 10kHz-30MHz frequency band, and have poor noise suppression capabilities above 30MHz, which cannot meet the radiation emission requirements of the GJB 151 series, and seriously affect the electromagnetic environment effects of the aircraft in the actual combat environment. Summary of the invention

[0003] The purpose of the present invention is to solve the problems in the prior art and provide a novel filter circuit for an aviation 28V DC power supply module.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a technical solution: a filter circuit for an aviation 28V DC power supply module, comprising: a filter circuit on the input side of the power supply module and a filter circuit on the output side of the power supply module.

[0005] As a preferred solution for the filter circuit of the aviation 28V DC power module, the filter circuit on the input side of the power module has capacitors C1 and C2, the first end of C1 is connected to 28V+, and the first end of capacitor C2 is connected to 28V-.

[0006] As a preferred solution for the filter circuit of the aviation 28V DC power supply module, the filter circuit on the input side of the power supply module has capacitors C3, C4, C5 and a common-mode inductor LX1. The first end of capacitor C3 is connected to 28V+, the second end of capacitor C3 is connected to 28V-, the first input end of common-mode inductor LX1 is connected to 28V+, the first output end of common-mode inductor LX1 is connected to the first end of capacitor C4, the second input end of common-mode inductor LX1 is connected to 28V-, the second output end of common-mode inductor LX1 is connected to the first end of capacitor C5, and the second ends of capacitors C4 and C5 are both connected to the chassis ground.

[0007] As a preferred solution for the filter circuit of the aviation 28V DC power supply module, the filter circuit on the input side of the power supply module has a differential mode inductor L1, a differential mode inductor L2 and a common mode inductor LX2. The first terminal of the differential mode inductor L1 is connected to the first end of the capacitor C4, the second terminal of the differential mode inductor L1 is connected to the first input end of the common mode inductor LX2, the first terminal of the differential mode inductor L2 is connected to the first end of the capacitor C5, the second terminal of the differential mode inductor L2 is connected to the second input end of the common mode inductor LX2, and the first output end of the common mode inductor LX2 is connected to the VIN+ end of the power supply module.

[0008] As a preferred solution for the filter circuit of the aviation 28V DC power module, the filter circuit on the input side of the power module has capacitors C6, C7 and C8. The first ends of capacitors C6, C7 and C8 are all connected to 28V+, and the second ends of capacitors C6, C7 and C8 are all connected to 28V-.

[0009] As a preferred solution for the filter circuit of the aviation 28V DC power module, the filter circuit on the output side of the power module has capacitors C9, C10, C11 and a common-mode inductor LX3. The first ends of capacitors C9, C10 and C11 are all connected to the VOUT+ end of the power module, and the second ends of capacitors C9, C10 and C11 are all connected to the VOUT- end of the power module.

[0010] As a preferred solution for the filter circuit of the aviation 28V DC power module, the filter circuit on the output side of the power module has capacitors C12 and C13, the first end of capacitor C12 is connected to the first output end of the common-mode inductor LX3, the first output end of capacitor C13 is connected to the second output end of the common-mode inductor LX3, and the second ends of capacitors C12 and C13 are both connected to the chassis ground.

[0011] Compared with the prior art, the beneficial effects of the present invention are at least that: by performing filtering design on the input and output sides of the aviation 28V DC power supply module, a simple and stable filtering method is achieved, which can effectively reduce the conduction and radiation emission levels of the power supply module, and effectively reduce the solution iteration cost and identification test risk in the aviation equipment development stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. Implementation

[0013] The present invention is further described in detail below by means of specific embodiments in combination with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0014] See also Figure 1, the figure shows a filter circuit for an aviation 28V DC power supply module.

[0015] The power module has a VIN+ terminal, a VIN- terminal, a VOUT+ terminal, a VOUT- terminal, a CNT terminal, and a CASE terminal. In this embodiment, the power module uses a JZF919 constant current converter.

[0016] The filter circuit on the input side of the power module is used to filter the input of the power module, with the purpose of improving the filtering effect of the on-board power supply and solving the problem of the power module noise being emitted outward through the input line.

[0017] The filter circuit on the input side of the power module has capacitors C1 and C2. The first terminal of capacitor C1 is connected to 28V+. The first terminal of capacitor C2 is connected to 28V-. The second ends of capacitors C1 and C2 are both connected to the chassis ground. Among them, capacitors C1 and C2 are used for common mode filtering of the on-board power supply. In this embodiment, capacitors C1 and C2 are selected as 4.7nF / 2kV capacitors.

[0018] Furthermore, the filter circuit on the input side of the power module has capacitors C3, C4, C5 and a common-mode inductor LX1. The first terminal of capacitor C3 is connected to 28V+. The second terminal of capacitor C3 is connected to 28V-. Among them, capacitor C3 is used for differential mode filtering of the on-board power supply. The first input terminal of common-mode inductor LX1 is connected to 28V+. The first output terminal of common-mode inductor LX1 is connected to the first end of capacitor C4. The second input terminal of common-mode inductor LX1 is connected to 28V-. The second output terminal of common-mode inductor LX1 is connected to the first end of capacitor C5. The second ends of capacitors C4 and C5 are both connected to the chassis ground. Among them, capacitor C4 and capacitor C5 are used for common-mode filtering of the power module. In this embodiment, capacitor C3 uses 4.7uF / 100V, capacitors C4 and C5 use 4.7nF / 2kV capacitors, and common-mode inductor LX1 uses 10mH common-mode inductor.

[0019] Furthermore, the filter circuit on the input side of the power module has a differential mode inductor L1, a differential mode inductor L2 and a common mode inductor LX2. The first terminal of the differential mode inductor L1 is connected to the first end of the capacitor C4. The second terminal of the differential mode inductor L1 is connected to the first input end of the common mode inductor LX2. The first terminal of the differential mode inductor L2 is connected to the first end of the capacitor C5. The second terminal of the differential mode inductor L2 is connected to the second input end of the common mode inductor LX2. The first output end of the common mode inductor LX2 is connected to the VIN+ end of the power module. Among them, the common mode inductor LX2 is used for common mode filtering of the power module. Among them, the differential mode filter branch formed by the differential mode inductor L1 and the differential mode inductor L2 is located between the common mode inductor LX2 and the capacitor C4 and the capacitor C5, and is used for differential mode filtering of the power supply and the power module. In this embodiment, the differential mode inductors L1 and L2 use 68uH differential mode inductors, and the common mode inductor LX2 uses 1000ohm@100MHz common mode inductors.

[0020] Further, the filter circuit on the input side of the power module has capacitor C6, capacitor C7 and capacitor C8. The first ends of capacitor C6, capacitor C7 and capacitor C8 are all connected to 28V+. The second ends of capacitor C6, capacitor C7 and capacitor C8 are all connected to 28V-. Capacitor C6, capacitor C7 and capacitor C8 are located between the common mode inductor LX2 and the VIN+ and VIN- ends of the power module, and are used for differential mode filtering and power supply energy storage of the power module. In this embodiment, capacitor C6 uses a 10uF / 100V capacitor, capacitor C7 uses a 100nF / 100V capacitor, and capacitor C8 uses a 220uF / 100V electrolytic capacitor.

[0021] The filter circuit on the output side of the power module is used to filter the output of the power module in order to solve the problem of the power module noise being emitted outward through the output line.

[0022] The filter circuit on the output side of the power module has capacitors C9, C10, C11 and a common mode inductor LX3. The first terminals of capacitors C9, C10 and C11 are connected to the VOUT+ terminal of the power module. The second terminals of capacitors C9, C10 and C11 are connected to the VOUT- terminal of the power module. Capacitors C9, C10 and C11 are located between the VOUT+ terminal, the VOUT- terminal of the power module and the common mode inductor LX3, and the purpose is to be used for differential mode filtering and power supply energy storage of the power module. In this embodiment, capacitor C9 selects a 220uF / 100V electrolytic capacitor, capacitor C10 selects a 10uF / 100V capacitor, capacitor C11 selects a 100nF / 100V capacitor, and the common mode inductor LX3 selects a 1000ohm@100MHz common mode inductor.

[0023] Further, the filter circuit on the output side of the power module has capacitors C12 and C13. The first terminal of capacitor C12 is connected to the first output terminal of common mode inductor LX3. The first output terminal of capacitor C13 is connected to the second output terminal of common mode inductor LX3. The second terminals of capacitors C12 and C13 are both connected to the chassis ground. Capacitors C12 and C13 are used for common mode filtering of the power module. In this embodiment, C12 and C13 are selected as 1000pF / 2kV capacitors.

[0024] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A filter circuit for an aviation 28V DC power supply module, characterized in that: include: The filter circuit on the input side of the power module and the filter circuit on the output side of the power module.

2. The filter circuit for aviation 28V DC power supply module according to claim 1, characterized in that: The filter circuit on the input side of the power module has capacitors C1 and C2, a first terminal of C1 is connected to 28V+, and a first terminal of capacitor C2 is connected to 28V-.

3. The filter circuit for aviation 28V DC power supply module according to claim 2, characterized in that: The filter circuit on the input side of the power module has capacitors C3, C4, C5 and a common-mode inductor LX1. The first end of capacitor C3 is connected to 28V+, the second end of capacitor C3 is connected to 28V-, the first input end of common-mode inductor LX1 is connected to 28V+, the first output end of common-mode inductor LX1 is connected to the first end of capacitor C4, the second input end of common-mode inductor LX1 is connected to 28V-, the second output end of common-mode inductor LX1 is connected to the first end of capacitor C5, and the second ends of capacitors C4 and C5 are both connected to the chassis ground.

4. The filter circuit for aviation 28V DC power supply module according to claim 3, characterized in that: The filter circuit on the input side of the power module has a differential mode inductor L1, a differential mode inductor L2 and a common mode inductor LX2. The first terminal of the differential mode inductor L1 is connected to the first end of the capacitor C4, the second terminal of the differential mode inductor L1 is connected to the first input end of the common mode inductor LX2, the first terminal of the differential mode inductor L2 is connected to the first end of the capacitor C5, the second terminal of the differential mode inductor L2 is connected to the second input end of the common mode inductor LX2, and the first output end of the common mode inductor LX2 is connected to the VIN+ end of the power module.

5. The filter circuit for aviation 28V DC power supply module according to claim 4, characterized in that: The filter circuit on the input side of the power module has capacitors C6, C7 and C8. The first ends of capacitors C6, C7 and C8 are all connected to 28V+, and the second ends of capacitors C6, C7 and C8 are all connected to 28V-.

6. The filter circuit for an aviation 28V DC power supply module according to claim 1, 3 or 4, characterized in that: The filter circuit on the output side of the power module has capacitors C9, C10, C11 and a common mode inductor LX3. The first ends of capacitors C9, C10 and C11 are all connected to the VOUT+ end of the power module, and the second ends of capacitors C9, C10 and C11 are all connected to the VOUT- end of the power module.

7. The filter circuit for an aviation 28V DC power supply module according to claim 6, characterized in that: The filter circuit on the output side of the power module has capacitors C12 and C13, the first end of capacitor C12 is connected to the first output end of the common mode inductor LX3, the first output end of capacitor C13 is connected to the second output end of the common mode inductor LX3, and the second ends of capacitors C12 and C13 are both connected to the chassis ground.

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