Direct current filter
By connecting multiple filtering and suppression modules in series, the problem of excessive volume of the traditional surge suppression and protection integrated filter components is solved, and efficient surge suppression and filtering effects are achieved in a small space, which is suitable for small space high-power equipment.
Patent Information
- Application Number
- CN202422145520.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-09-02
AI Technical Summary
The traditional integrated surge suppression and protection filter assembly is large in size and is difficult to be suitable for equipment with small space and high power.
A DC filter is designed to achieve rapid release of surges, suppress low-frequency differential mode interference and high-frequency common mode interference through series suppression module, first-stage differential mode filter module, second-stage common mode filter module and surge suppression module, and slow down the impact of large energy rapid pulses on the back-end circuit.
It can meet the surge suppression and filtering requirements of high-power equipment in a small space, reduce the use space, and be suitable for application scenarios in a small space, while improving the stability and safety of the equipment.
Smart Images
Figure CN222996431U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of filters, and in particular to a DC filter. Background Art
[0002] With the continuous development of electronic devices and systems, their external usage environments have become increasingly complex. The comprehensive requirements for the protection and filtering of backend devices have also been improved, and the demand for integrated protection and filtering design has received increasing attention. Through the integrated protection and filtering design, the safety and stability of electronic devices in harsh working environments are improved. The integrated protection and filtering design starts from the overall application to solve the problem of effectively suppressing surge voltages and currents in transient situations, such as lightning strikes and power switch operations, thereby protecting the safety of devices and data. In addition to suppressing surge voltages and currents, the integrated surge suppression and protection filter component also has a filtering function. It can filter out noise interference in the system, such as power supply noise and electromagnetic radiation, thereby ensuring the stable operation of electronic and electrical devices. This is essential for the stable operation of electronic and electrical systems. With the development of new technologies such as new energy and smart grids, the demand for integrated surge suppression and protection filter components will be increasing.
[0003] Currently, traditional solutions mainly aim to complete functions and mostly use multiple devices in series, resulting in a relatively large volume of the integrated surge suppression and protection filter component, which is not suitable for devices with small spaces and high power. Utility Model Content
[0004] In order to make the integrated surge suppression and protection filter component suitable for devices with small spaces and high power, this application provides a DC filter.
[0005] In a first aspect, a DC filter provided by this application adopts the following technical solution:
[0006] A DC filter includes a suppression module, a first-stage differential-mode filtering module, a second-stage common-mode filtering module, and a surge suppression module. The suppression module, the first-stage differential-mode filtering module, the second-stage common-mode filtering module, and the surge suppression module are connected in series in sequence. The free end of the surge suppression module is connected to the device to be protected. The suppression module is used to receive surge voltages and discharge surges. The first-stage differential-mode filtering module is used to suppress low-frequency differential-mode interference. The second-stage common-mode filtering module is used to filter out high-frequency common-mode interference.
[0007] By adopting the above technical solution, the suppression module, the first differential-mode filtering module, the second common-mode filtering module, and the surge suppression module are connected in series. The suppression module can quickly discharge the surge and meet the time response requirements. The first differential-mode filtering module can effectively suppress low-frequency differential-mode interference. The second common-mode filtering module can reduce the insertion loss performance and effectively filter out high-frequency common-mode interference suppression. Finally, combined with the surge suppression module, sampling and feedback are realized, and they cooperate together to complete surge suppression, slow down the impact of large-energy fast pulses on the backend circuit, and make full use of the differential-mode inductor through parameter matching to effectively delay the impact of fast pulses; through the cooperation of these four modules, while meeting the functional requirements, the superposition of multiple devices is also reduced, the occupied space is decreased, and it is applicable to application scenarios with small space.
[0008] In a possible implementation manner, the suppression module is a transient voltage suppression diode, and the power of the transient voltage suppression diode is 100 watts.
[0009] In a possible implementation manner, the first differential-mode filtering module includes a first capacitor, a second capacitor, a first inductor, and a second inductor. One end of the first capacitor is connected to the first inductor, and the other end of the first capacitor is connected to the second inductor. One end of the second capacitor is connected to the free end of the first inductor, and the other end of the second capacitor is connected to the free end of the second inductor. The first capacitor is connected in parallel with the suppression module.
[0010] In a possible implementation manner, the second common-mode filtering module includes a first-stage sub-module and a second-stage sub-module. The first-stage sub-module and the second-stage sub-module are connected in parallel. The first-stage sub-module and the first differential-mode filtering module are connected in parallel. The first-stage sub-module is used to suppress high-frequency common-mode interference, and the second-stage sub-module is used to suppress high-frequency common-mode interference.
[0011] In a possible implementation manner, the first-stage sub-module includes a third inductor, a third capacitor, and a fourth capacitor. One end of the third inductor close to the second-stage sub-module is connected in parallel with the third capacitor and the fourth capacitor, and the common end of the third capacitor and the fourth capacitor is grounded.
[0012] In a possible implementation manner, the second-stage sub-module includes a fourth inductor, a fifth capacitor, and a sixth capacitor. One end of the fourth inductor far from the first-stage sub-module is connected in parallel with the fifth capacitor and the sixth capacitor, and the common end of the fifth capacitor and the sixth capacitor is grounded.
[0013] In a possible implementation manner, it further includes a protective housing with one end open and a protective cover adapted to the opening. The protective housing and the protective cover are used to shield interference in the environment.
[0014] In a possible implementation, a partition is provided inside the protective housing, and the partition divides the protective housing into multiple compartments.
[0015] In summary, the present application includes at least one of the following beneficial technical effects:
[0016] The suppression module, the first-stage differential-mode filtering module, the second-stage common-mode filtering module, and the surge suppression module are connected in series. The suppression module can quickly discharge the surge and meet the time response requirements. The first-stage differential-mode filtering module can effectively suppress low-frequency differential-mode interference. The second-stage common-mode filtering module can reduce the insertion loss performance and effectively filter out high-frequency common-mode interference suppression. Finally, in combination with the surge suppression module, sampling and feedback are realized, and they cooperate together to complete surge suppression, slow down the impact of large-energy fast pulses on the backend circuit, and make full use of the differential-mode inductor through parameter matching to effectively delay the impact of fast pulses; through the cooperation of these four modules, while meeting the functional requirements, the superposition of multiple devices is also reduced, the usage space is reduced, and it is suitable for application scenarios with small spaces. Description of the Drawings
[0017] Figure 1 It is a structural block diagram of the DC filter provided by the embodiment of the present application.
[0018] Figure 2 It is a partial circuit structure diagram of the DC filter provided by the embodiment of the present application.
[0019] Figure 3 It is a partial circuit structure diagram of the DC filter provided by the embodiment of the present application.
[0020] Figure 4 It is a schematic structural diagram of the DC filter provided by the embodiment of the present application.
[0021] Figure 5 It is an internal structural schematic diagram of the DC filter provided by the embodiment of the present application.
[0022] Description of the reference numerals: 1, protective housing; 2, protective cover; 3, partition; 10, suppression module; 20, first-stage differential-mode filtering module; 30, second-stage common-mode filtering module; 40, surge suppression module; 50, equipment to be protected. Detailed Embodiments
[0023] With the increasing requirements for transient surge protection, it is currently mainly solved by an integrated protection and filtering component. One common solution is to connect three devices, namely a protector, a filter, and a surge suppressor, in series to form an integrated protection and filtering component to complete the functions of surge suppression and protection filtering. Another common solution is to use the cumulative connection of component functions to complete the design functions of the circuit. Although the multi-device accumulation in the second solution can complete the functions, the matching and mutual influence between different circuits are not fully considered, and the expected protection effect may not be achieved.
[0024] This application proposes a DC filter for realizing the integration of surge suppression and protection. By comprehensively considering the characteristics of the suppression circuit and the filtering circuit and making a comprehensive match with the surge suppression circuit, the comprehensive matching of the protection circuit, the filtering circuit, and the surge suppression circuit is realized. At the same time, a comprehensive design is carried out based on the actual application scenario.
[0025] The following is a further detailed description of this application in conjunction with the attached Figures 1-5 drawings.
[0026] An embodiment of this application discloses a DC filter. Referring to Figure 1 , the DC filter includes a suppression module 10, a first-stage differential-mode filtering module 20, a second-stage common-mode filtering module 30, and a surge suppression module 40. The above-mentioned suppression module 10, the above-mentioned first-stage differential-mode filtering module 20, the above-mentioned second-stage common-mode filtering module 30, and the above-mentioned surge suppression module 40 are connected in series in sequence. The free end of the above-mentioned surge suppression module 40 is connected to the device 50 to be protected. The above-mentioned suppression module 10 is used to receive the surge voltage and discharge the surge. The above-mentioned first-stage differential-mode filtering module 20 is used to suppress low-frequency differential-mode interference. The above-mentioned second-stage common-mode filtering module 30 is used to filter out high-frequency common-mode interference.
[0027] Referring to Figure 2 , further, the above-mentioned suppression module 10 is a transient voltage suppression diode, and the power of the transient voltage suppression diode is 100 watts.
[0028] In the embodiment provided by this application, the suppression module 10 is mainly composed of TVS. The TVS selects a 100-watt high-power suppression diode, which can quickly discharge the surge. And a bidirectional TVS is adopted. The response time of the TVS is in the nanosecond level, which can meet the time response requirements.
[0029] Referring to Figure 2 , further, the above-mentioned first-stage differential-mode filtering module 20 includes a first capacitor, a second capacitor, a first inductor, and a second inductor. One end of the above-mentioned first capacitor is connected to the above-mentioned first inductor, the other end of the above-mentioned first capacitor is connected to the above-mentioned second inductor, one end of the above-mentioned second capacitor is connected to the free end of the above-mentioned first inductor, the other end of the above-mentioned second capacitor is connected to the free end of the above-mentioned second inductor, and the above-mentioned first capacitor is connected in parallel with the above-mentioned suppression module 10.
[0030] The first - order differential - mode filtering module 20 is a π - type filtering circuit composed of a first capacitor C1, a second capacitor C2, a first inductor L1, and a second inductor L2. The π - type filtering circuit can effectively suppress low - frequency differential - mode interference. In the embodiment provided in this application, the differential - mode inductors, namely the above - mentioned first inductor and second inductor, are made of high - flux magnetic cores, and can pass transient large currents and are not easily saturated.
[0031] Further, the above - mentioned second - order common - mode filtering module 30 includes a first - stage sub - module and a second - stage sub - module. The first - stage sub - module and the second - stage sub - module are in parallel. The first - stage sub - module and the first - order differential - mode filtering module 20 are in parallel. The first - stage sub - module is used to suppress high - frequency common - mode interference, and the second - stage sub - module is used to suppress high - frequency common - mode interference. The first - stage sub - module includes a third inductor, a third capacitor, and a fourth capacitor. One end of the third inductor close to the second - stage sub - module is in parallel with the third capacitor and the fourth capacitor, and the common terminal of the third capacitor and the fourth capacitor is grounded. The second - stage sub - module includes a fourth inductor, a fifth capacitor, and a sixth capacitor. One end of the fourth inductor far from the first - stage sub - module is in parallel with the fifth capacitor and the sixth capacitor, and the common terminal of the fifth capacitor and the sixth capacitor is grounded.
[0032] The second - order common - mode filtering module 30 is composed of a first - stage sub - module and a second - stage sub - module. The input signal passes through the first - stage sub - module and the second - stage sub - module once, which can meet the requirements of higher insertion loss and effectively suppress interference at the same time.
[0033] The second - order common - mode filtering module 30 includes a first - stage sub - module composed of a third inductor L3, a third capacitor C3, and a fourth capacitor C4 and a second - stage sub - module composed of a fourth inductor L4, a fifth capacitor C5, and a sixth capacitor C6. The first - stage sub - module is also a first - stage common - mode filtering circuit, and the second - stage sub - module is also a second - stage common - mode filtering circuit. By using a two - stage reverse - filtering circuit, the insertion - loss performance is reduced, and high - frequency common - mode interference is effectively filtered and suppressed.
[0034] The design principle of the second - order common - mode filtering module 30 is a passive multi - order LC low - pass filter. It is composed of a common - mode inductor, a differential - mode inductor, a common - mode capacitor, and a differential - mode capacitor, and is a passive two - way network. One end of it is the power supply, and the other end is the load. The second - order common - mode filtering module 30 plays the role of two low - pass filters. One is to suppress common - mode interference, and the other is to suppress differential - mode interference. The second - order common - mode filtering module 30 can effectively suppress large differential - mode interference and complete common - mode interference suppression.
[0035] Refer to Figure 3, the surge suppression module 40 is mainly composed of a U1 high-efficiency switching surge suppressor and corresponding configuration circuits (start-up circuit, drive control circuit, amplification circuit, and output sampling circuit), and can effectively suppress surges. Among them, the start-up circuit is mainly composed of R1 and M1, the drive control circuit is mainly composed of M2, and the output sampling circuit is mainly composed of L5, R2, and C9 to achieve sampling and feedback, and cooperate with each other to complete surge suppression.
[0036] When the input voltage is normal, the overvoltage surge suppression circuit is in a through state, and the input voltage is output through the ideal diode. The output voltage follows the input voltage. When an overvoltage surge occurs on the input side (100V / 50ms), the overvoltage surge suppression circuit starts to work in a step-down mode, clamping the output voltage at 34V. The ideal diode outputs 34V. When an overvoltage surge occurs on the input side, the output voltage can be stabilized within 34 - 36V. It meets the power consumption requirements of the subsequent 36V power supply module. When a 100V surge is input, the surge suppression circuit can maintain the output voltage at 34V.
[0037] The above-mentioned DC filter effectively cooperates with the inductor and the actual discharge circuit in use to slow down the impact of large-energy fast pulses on the subsequent circuit. By making full use of the differential-mode inductor through parameter matching, it can effectively delay the impact of fast pulses.
[0038] Refer to Figures 4-5 , further, the above-mentioned DC filter further includes a protective housing 1 with one end open and a protective cover 2 adapted to the opening. The protective housing 1 and the protective cover 2 are used to shield interference in the environment. A partition 3 is provided inside the protective housing 1, and the partition 3 divides the protective housing 1 into multiple compartments.
[0039] In a specific example, the positional relationship between the various modules in the protective housing 1 of the above-mentioned DC filter adopts a linear circuit layout design, which can effectively avoid the problem of spatial coupling of high-frequency interference. The protective housing 1 can be divided into two compartments by the partition 3. In one compartment, a suppression module 10, a first-stage differential-mode filtering module 20, and a second-stage common-mode filtering module 30 are arranged, and in the other compartment, a surge suppression module 40 is arranged, following the principle that protective devices are in the front and devices with low withstand voltage are in the back. When a transient signal occurs, the device can quickly reduce the impedance between the signal path and the ground and conduct, thereby ensuring that the subsequent circuit components are not damaged by the impact of transient and high-energy interference. At the same time, it has strong interference suppression ability, obvious insertion loss advantage, can reduce large interference, and has obvious surge suppression ability. In other embodiments, the protective housing 1 can be divided into four compartments by the partition 3, and a suppression module 10, a first-stage differential-mode filtering module 20, a second-stage common-mode filtering module 30, and a surge suppression module 40 are respectively arranged in each compartment.
[0040] In the embodiments provided by this application, the structure of the above-mentioned protective housing 1 adopts a chamfered design to reduce stress concentration, and weight is reduced through the design of the output holes, which can not only ensure the effectiveness of transmission but also ensure good shielding performance and consider lightweight design. For the inductors in the protection cabin, a fixing method using glue dispensing and special fixing buckles is adopted to avoid performance changes caused by vibration.
[0041] The above DC filter has strong electromagnetic interference resistance ability, can effectively isolate noise, protect the equipment from external interference, and ensure the normal operation of the equipment system or provide accuracy guarantee. The DC filter can also reduce energy waste, effectively reduce the internal energy consumption of the load, reduce the power consumption of the protected equipment 50, and thus save energy costs for users.
[0042] The DC filter takes into account the overload and overvoltage protection performance, can effectively reduce the changes caused by the increase of the load current, and thus better protects the power supply system and equipment. The DC filter integrates multiple functions, including overcurrent protection, overvoltage protection, noise suppression and surge suppression. Therefore, under the condition of certain size and capacity, the protection range is wider and it is more convenient to use. The DC filter can quickly respond to spike and surge suppression, effectively protect electrical equipment, and is stable and reliable. The DC filter can be conveniently installed inside the electrical equipment and occupies little space.
[0043] The implementation principle of a DC filter in an embodiment of this application is as follows: by setting a suppression module 10, a first-stage differential mode filtering module 20, a second-stage common mode filtering module 30 and a surge suppression module 40, the suppression of differential mode interference and common mode interference of signals is achieved. At the same time, through a certain design in the protective housing 1, the volume of the DC filter is reduced, making the DC filter applicable to more scenarios.
[0044] The above are all the preferred embodiments of this application. It does not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of this application should be covered within the protection scope of this application.
Claims
1. A DC filter, characterized in that: The invention comprises a suppression module (10), a primary differential mode filter module (20), a secondary common mode filter module (30) and a surge suppression module (40); the suppression module (10), the primary differential mode filter module (20), the secondary common mode filter module (30) and the surge suppression module (40) are sequentially connected in series; a free end of the surge suppression module (40) is connected to a protected device (50); the suppression module (10) is used to receive a surge voltage and discharge a surge; the primary differential mode filter module (20) is used to suppress low-frequency differential mode interference; and the secondary common mode filter module (30) is used to filter out high-frequency common mode interference.
2. The DC filter according to claim 1, characterized in that: The suppression module (10) is a transient voltage suppression diode, and the power of the transient voltage suppression diode is 100 watts.
3. The DC filter according to claim 1, characterized in that: The first-level differential mode filtering module (20) comprises a first capacitor, a second capacitor, a first inductor and a second inductor, one end of the first capacitor is connected to the first inductor, the other end of the first capacitor is connected to the second inductor, one end of the second capacitor is connected to the free end of the first inductor, the other end of the second capacitor is connected to the free end of the second inductor, and the first capacitor is connected in parallel with the suppression module (10).
4. The DC filter according to claim 1, characterized in that: The secondary common-mode filtering module (30) comprises a first-stage submodule and a second-stage submodule, the first-stage submodule and the second-stage submodule are connected in parallel, the first-stage submodule and the primary differential-mode filtering module (20) are connected in parallel, the first-stage submodule is used to suppress high-frequency common-mode interference, and the second-stage submodule is used to suppress high-frequency common-mode interference.
5. The DC filter according to claim 4, characterized in that: The first-stage submodule includes a third inductor, a third capacitor and a fourth capacitor. One end of the third inductor close to the second-stage submodule is connected in parallel with the third capacitor and the fourth capacitor. A common end of the third capacitor and the fourth capacitor is grounded.
6. The DC filter according to claim 4, characterized in that: The second-stage submodule includes a fourth inductor, a fifth capacitor and a sixth capacitor. One end of the fourth inductor away from the first-stage submodule is connected in parallel with the fifth capacitor and the sixth capacitor. A common end of the fifth capacitor and the sixth capacitor is grounded.
7. The DC filter according to claim 1, characterized in that: It also comprises a protective shell (1) with an opening at one end and a protective cover (2) adapted to the opening, wherein the protective shell (1) and the protective cover (2) are used to shield interference in the environment.
8. The DC filter according to claim 7, characterized in that: A partition (3) is provided inside the protective shell (1), and the partition (3) divides the protective shell (1) into a plurality of compartments.