Small-size high-voltage filter

Abstract

The utility model relates to the technical field of filters, in particular to a small-size high-voltage filter. Aiming at an application scene with strict space limitation, the filter adopts the design of a 6061 aviation aluminum integrated milling shell, a polyether-ether-ketone (PEEK) insulating plate, an output interface formed by combining a gold-plated copper platform with a flexible lead and the like, so that light weight and miniaturization are realized. Main devices comprise a common-mode inductor, a differential-mode capacitor, a common-mode capacitor and a bleeder resistor to form a first-order low-pass filter circuit, EMI interference of 10 kHz to 10 MHz is effectively restrained, and the electromagnetic compatibility requirement (GJB151ACE102) under the working condition of direct current 540V / 50A is met. The size of the product is only 40cm < 3 >, the weight is 128g, and the product has high insulativity, low contact resistance and excellent vibration resistance, and is suitable for the fields with strict requirements on size and reliability, such as aerospace and the like.

Description

Technical Field

[0001] This utility model relates to the field of filter technology, specifically a small-volume high-voltage filter. Background Technology

[0002] A certain system requires the development of a small-volume high-voltage DC filter. Traditional high-voltage filters, due to the need to handle large energy and high voltage, often contain large inductors and capacitors, which typically occupy a significant amount of space, resulting in a large overall filter size. Now, due to strict space constraints for the transmitting and receiving modules, it is essential to minimize the filter's size as much as possible to meet the miniaturization requirements of the overall equipment.

[0003] How to provide miniaturized, lightweight high-voltage filters for applications with strict space constraints is a technical problem that needs to be solved. Utility Model Content

[0004] The problem to be solved is to provide miniaturized, lightweight high-voltage filters for use scenarios with strict space constraints.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a small-volume high-voltage filter, including a housing, an input interface and an output interface on the housing, and an insulating component on the side of the housing with the output interface. The housing contains a first-order low-pass filter circuit, which includes a common-mode inductor L, a differential-mode capacitor C1, a common-mode capacitor C2, a common-mode capacitor C3, and a bleeder resistor R. The input interface and the output interface are respectively connected to the first-order low-pass filter circuit. The bleeder resistor R is connected in parallel with the differential-mode capacitor C1 and then in series with the common-mode inductor L, the common-mode capacitor C2, and the common-mode capacitor C3.

[0006] Preferably, the outer shell is integrally milled from 6061 aerospace aluminum.

[0007] Preferably, the input interface is led out of the housing through an insulating washer, and the input interface uses an aerospace-grade flexible lead wire.

[0008] Preferably, the output interface includes a gold-plated copper platform and output flexible leads.

[0009] Preferably, the common-mode inductor L has an inductance of 0.6mH; the differential-mode capacitor C1 has a capacitance of 0.47μF; the common-mode capacitors C2 and C3 both have a capacitance of 0.047μF; and the bleeder resistor R has a resistance of 2MΩ.

[0010] Preferably, the gold-plated copper platform has a current-carrying cross-sectional area of ​​24 mm2 and a rated current-carrying capacity of 120 A.

[0011] Preferably, the common mode inductor L is made of an ultra-microcrystalline magnetic ring and an enameled wire wound with a thick yellow varnish insulating material.

[0012] Preferably, the differential mode capacitor C1 and the common mode capacitors C2 and C3 are film capacitors with a rated voltage of 800VDC.

[0013] Compared with the prior art, the present invention provides a small-volume high-voltage filter, which has the following advantages:

[0014] This invention achieves miniaturization and lightweight design, with a filter volume of 40cm³ and a weight of 128g, making it suitable for scenarios with strict space constraints. It also features high conductivity and low loss; the gold-plated copper platform reduces contact resistance, achieving a current carrying capacity of 120A (rated 50A) with minimal heat loss; the PEEK insulation board and vacuum-encapsulated polyurethane process ensure electrical safety under high voltage, providing excellent insulation performance; the first-order low-pass filter circuit effectively suppresses EMI interference in the 10kHz–10MHz frequency band, exhibiting strong anti-interference capabilities and meeting GJB 151ACE102 requirements; the operating temperature range is -55℃ to +85℃, and it is vibration-resistant and shock-resistant, making it suitable for extreme environments.

[0015] This utility model of a small-volume high-voltage filter is mainly used to filter the power supply of 540V transmitting and receiving modules, suppress EMI interference of 10kHz to 10MHz, reduce power supply interference and interference, and at the same time ensure that the power supply can meet the electromagnetic compatibility requirements of CE102 power line conducted interference in GJB 151A. Attached Figure Description

[0016] Figure 1 This is a front view of the structure of this utility model;

[0017] Figure 2 This is a rear view of the structure of this utility model;

[0018] Figure 3 This is a left view of the structure of this utility model;

[0019] Figure 4 for Figure 2 Top view;

[0020] Figure 5 This is a schematic diagram illustrating the principle of this utility model;

[0021] Explanation of reference numerals in the attached diagram: 1. Outer casing; 2. Input interface; 21. Negative terminal; 22. Positive terminal; 3. Insulating washer; 4. Gold-plated copper platform; 5. Output flexible lead; 6. Insulating component. Detailed Implementation

[0022] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model:

[0023] In order to solve the problems in the background technology, such as Figures 1-4 This utility model provides a small-volume high-voltage filter, including a housing 1. The housing 1 is integrally milled from 6061 aerospace aluminum. 6061 aluminum alloy is a lightweight material, and the milled housing made from it significantly reduces the overall weight while maintaining strength. Aluminum alloy has excellent thermal conductivity, and the surface is electroplated with nickel, which not only improves corrosion resistance but also enhances the appearance. The housing 1 is milled from a single piece of aluminum, and the integrated design ensures structural strength while achieving lightweighting of the filter. The housing 1 is provided with an input interface 2 and an output interface. The input interface 2 includes a negative terminal 21 and a positive terminal 22. Both the negative terminal 21 and the positive terminal 22 are led out of the housing 1 through insulating washers 3. Both the negative terminal 21 and the positive terminal 22 use aerospace-grade soft leads. The use of aerospace-grade soft leads in the input interface 2, led out of the housing 1 through the inner hole of the insulating washers 3, provides high insulation strength and is more reliable under high voltage and high power conditions. The output interface includes a gold-plated copper platform 4 and a flexible output lead 5. The gold-plated copper platform 4 and the flexible output lead 5 are combined. The gold-plated copper platform 4 significantly reduces contact resistance, improves conductivity, and has a strong current-carrying capacity. The current-carrying cross-sectional area of ​​the gold-plated copper platform 4 is 24 mm², and its rated current-carrying capacity is 120A. The flexible output lead 5 is an aerospace-grade ultra-flexible conductor with a multi-strand silver-plated copper wire core, possessing excellent flexibility and conductivity. The gold-plated copper platform 4 is manufactured using precision casting and machining technology to ensure a smooth, defect-free surface, thereby improving contact area and conductivity. The gold plating on the copper platform significantly reduces contact resistance and improves conductivity; the current-carrying cross-sectional area of ​​the gold-plated copper platform 4 is approximately 24 mm². 2 Under normal circumstances, it can carry a current of 120A, while the rated current of the equipment is 50A, which shows that the current has sufficient margin and the heat loss is minimal.

[0024] The housing 1 contains a first-order low-pass filter circuit, which includes a common-mode inductor L, a differential-mode capacitor C1, a common-mode capacitor C2, a common-mode capacitor C3, and a bleeder resistor R. Input interface 2 and output interface 2 are connected to the first-order low-pass filter circuit. The bleeder resistor R is connected in parallel with the differential-mode capacitor C1, and then in series with the common-mode inductor L, common-mode capacitor C2, and common-mode capacitor C3. The common-mode inductor L has an inductance of 0.6mH and is made of enameled wire wound with a microcrystalline magnetic ring and thick yellow varnish insulation material. The differential-mode capacitor C1 has a capacitance of 0.47μF; the common-mode capacitors C2 and C3 both have a capacitance of 0.047μF. The differential-mode capacitors C1, C2, and C3 are film capacitors with a rated voltage of 800VDC. The bleeder resistor R has a resistance of 2MΩ.

[0025] The side where the output interface is located is covered with insulating material 6. The insulating material 6 uses polyetheretherketone (PEEK) as the whole surface insulation material of the shell to ensure reliability under space constraints.

[0026] The electrical schematic diagram of this utility model is shown below. Figure 5 The main components include a 0.6mH common-mode inductor L, a 0.47μF differential-mode capacitor C1, two 0.047μF common-mode capacitors (C2 and C3), and a 2MΩ bleeder resistor R, forming a first-order low-pass filter. High-dV / dt flat film capacitors and high-energy-density metallized film capacitors are used as differential-mode and common-mode capacitors, respectively, suitable for DC filtering and surge current resistance, with a rated voltage of 800VDC. They maintain stability under sudden high-energy surges, absorb and process high-frequency spikes, effectively suppress high-frequency noise and interference, and reduce damage to other components. The common-mode inductor L is made by tightly winding a microcrystalline magnetic ring with varnish and then winding it into enameled wire. The microcrystalline magnetic ring has extremely high initial permeability and low core loss. Varnish is a high-performance insulating material that plays a crucial insulating role in the filter, effectively preventing electrical short circuits between the magnetic ring and other components. By employing a single-stage π-shaped low-pass combined network and selecting appropriate components and parameters, the desired frequency response and attenuation characteristics can be achieved.

[0027] The filter's internal potting material is polyurethane. After potting, a vacuum is applied at 40°C to eliminate air bubbles, ensuring complete filling and improved insulation. It maintains good performance even at 85°C. Because polyurethane is an elastomer, it has low residual internal stress and good shock absorption, enhancing the product's resistance to vibration and impact.

[0028] In a first-order π-type low-pass filter circuit, L is a series common-mode inductor, C1 is a parallel differential-mode capacitor, C2 / C3 are common-mode capacitances to ground, and R is a bleeder resistor. The common-mode inductor L suppresses common-mode interference, and core losses are reduced through a microcrystalline magnetic ring and highly insulated enameled wire. The differential-mode capacitor C1 filters differential-mode noise, and a high dV / dt thin-film capacitor is selected to handle surge current. The common-mode capacitors C2 / C3 further attenuate common-mode interference and are connected in parallel at the input / output terminals. The bleeder resistor R releases residual charge, improving system safety. Input interface 2 (positive 22, negative 21) is connected via a flexible lead, and an insulating washer 3 ensures high-voltage isolation.

[0029] The main technical specifications of the filter of this utility model are as follows:

[0030] 1) Rated operating voltage: 540VDC;

[0031] 2) Rated operating current: 50A;

[0032] 3) Test voltage: Line-to-line test voltage 1500VDC, 5s; Line-to-ground test voltage: 1500VDC, 5s;

[0033] 4) Insulation resistance: Line-to-ground 500VDC, 60s, greater than 500MΩ;

[0034] 5) Insertion loss: In a 50Ω system without load, the reference values ​​for insertion loss are shown in the table below; Frequency (MHz) 0.01 0.1 0.5 15 10; Common mode (dB) / 82 12 83 530; Differential mode (dB) / 41 0 15 25 20;

[0035] 6) Operating temperature: -55℃~+85℃.

[0036] This utility model features a small-volume high-voltage filter with a volume of 40cm². 3 Weighing only 128g, this compact and lightweight design allows for operation at 540VDC and 27kW power, effectively suppressing EMI interference from the 540V transmitter and receiver power supply in the 10kHz–10MHz range. Its innovative design, featuring an integrated 6061 aluminum casing, PEEK insulation, gold-plated copper platform, and high-voltage film capacitors, solves the problems of large size and weight inherent in traditional high-voltage filters. Internally, it employs a vacuum encapsulation process, combined with an ultra-microcrystalline magnetic ring common-mode inductor and a π-shaped filter network, ensuring stable operation at 540VDC / 50A while significantly suppressing high-frequency interference. The product combines miniaturization, high reliability, and environmental adaptability, making it widely applicable in aerospace, military electronics, and other fields with stringent space and performance requirements.

[0037] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A small-volume high-voltage filter, characterized in that: The device includes a housing (1), which has an input interface (2) and an output interface. The side of the housing (1) with the output interface is also provided with an insulating component (6). The housing (1) contains a first-order low-pass filter circuit, which includes a common-mode inductor L, a differential-mode capacitor C1, a common-mode capacitor C2, a common-mode capacitor C3, and a bleeder resistor R. The input interface (2) and the output interface are respectively connected to the first-order low-pass filter circuit. The bleeder resistor R is connected in parallel with the differential-mode capacitor C1 and then connected in series with the common-mode inductor L, the common-mode capacitor C2, and the common-mode capacitor C3.

2. The small-volume high-voltage filter according to claim 1, characterized in that: The outer shell (1) is integrally milled from 6061 aviation aluminum.

3. The small-volume high-voltage filter according to claim 1, characterized in that: The input interface (2) is led out of the outer casing (1) through the insulating washer (3), and the input interface (2) adopts aviation-grade soft lead wire.

4. The small-volume high-voltage filter according to claim 1, characterized in that: The output interface includes a gold-plated copper platform (4) and output soft leads (5).

5. The small-volume high-voltage filter according to claim 1, characterized in that: The common-mode inductor L has an inductance of 0.6mH; the differential-mode capacitor C1 has a capacitance of 0.47μF; the common-mode capacitors C2 and C3 both have a capacitance of 0.047μF; and the bleeder resistor R has a resistance of 2MΩ.

6. The small-volume high-voltage filter according to claim 4, characterized in that: The gold-plated copper platform (4) has a current-carrying cross-sectional area of ​​24 mm2 and a rated current-carrying capacity of 120 A.

7. The small-volume high-voltage filter according to claim 1, characterized in that: The common mode inductor L is made of an ultra-microcrystalline magnetic ring and an enameled wire wound with yellow varnish insulation material.

8. The small-volume high-voltage filter according to claim 1, characterized in that: Differential mode capacitor C1 and common mode capacitors C2 and C3 are film capacitors with a rated voltage of 800VDC.

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