EMI circuit of multi-power-supply DC power supply conversion module

Abstract

The invention discloses a multi-power-supply direct-current power supply conversion module EMI circuit which comprises a rectifying circuit used for being connected with at least one power supply and two stages of pi-type filter circuits connected with the rectifying circuit, the power supply is provided with a ground wire, and each stage of pi-type filter circuit comprises a common-mode inductor, an X capacitor bank and a Y capacitor bank. The X capacitor bank is provided with at least one group of 1 [mu] F capacitors used for filtering differential-mode high-frequency interference of the power supply, and the pi-type filter circuit and the Y capacitor bank are used for suppressing common-mode electromagnetic interference; according to the two-stage pi-type filter circuit and the common mode inductor, a fundamental frequency signal and a corresponding frequency multiplication signal of electromagnetic interference of a DC / DC power module product can be effectively suppressed, so that the operation of the DC / DC power module meets the electromagnetic compatibility RE102 requirement.

Description

Technical Field

[0001] This invention relates to the field of power supply architecture for DC / DC power conversion modules, specifically to an EMI circuit for a multi-power supply DC power conversion module. Background Technology

[0002] With the diversification of power supply architectures and the proliferation of input / output ports in power conversion, coupled with the large operating frequency bandwidth of DC / DC power conversion modules, the electromagnetic environment has become relatively complex, leading to increasingly stringent requirements for product electromagnetic compatibility. Conventional DC / DC power conversion modules typically employ only simple Y-type capacitors or other designs in their chassis, which cannot meet the EMC RE102 requirements. Furthermore, conventional DC / DC power conversion module circuits cannot suppress the electromagnetic interference generated at its source; suppression can only be achieved through its transmission path. Therefore, an EMI circuit for a multi-power supply DC power conversion module is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide an EMI circuit for a multi-power supply DC power conversion module to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an EMI circuit for a multi-power supply DC power conversion module, comprising a rectifier circuit for connection to at least one power supply and a two-stage π-type filter circuit connected to the rectifier circuit. The rectifier circuit consists of four groups of diodes D1-D4, capacitor C1, resistor R1, capacitor C2, Zener diode D4, resistor R2, resistor R3, and field-effect transistor Q1. Each group of diodes is connected to a power supply, and the power supply has its own ground wire. Each stage of the π-type filter circuit includes a common-mode inductor, an X capacitor group, and a Y capacitor group. The X capacitor group has at least one 1μF capacitor for filtering the differential-mode high-frequency interference inherent in the power supply. The π-type filter circuit and the Y capacitor group are used to suppress common-mode electromagnetic interference.

[0005] Preferably, the output terminal of the rectifier circuit is connected to a bidirectional voltage limiting and protection circuit, which consists of at least one set of bidirectional Zener diodes connected to the power supply.

[0006] Preferably, the gate of the field-effect transistor Q1 is connected to a resistor R2, a resistor R4 is connected between the drain and source of the field-effect transistor Q1, and the drain of the field-effect transistor Q1 is connected to a common-mode inductor.

[0007] Preferably, the power supply is a 28VDC power supply, and a 1μF capacitor C85 is provided between the positive and negative terminals of the power supply.

[0008] The beneficial effects of this invention are: the two-stage π-type filter circuit and common-mode inductor of this invention can effectively suppress the fundamental frequency signal and corresponding harmonic signal of electromagnetic interference in DC / DC power module products, eliminate high-frequency interference in the output power supply to ensure a relatively clean power supply, and suppress electromagnetic interference coupling and conduction to the product's input and output cables and spatial radiation to the outside of the product, so that the DC / DC power module works in accordance with the electromagnetic compatibility RE102 requirements. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the present invention.

[0010] In the diagram: 1. Power supply; 2. Rectifier circuit; 3. Bidirectional Zener diode; 4. X capacitor bank; 5. Y capacitor bank; 6. Common mode inductor; 7. Second π filter circuit; 8. Ground wire. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Please see Figure 1 This invention provides a technical solution: an EMI circuit for a multi-power DC power conversion module, comprising a rectifier circuit 2 connected to at least one power supply 1 and a two-stage π-type filter circuit connected to the rectifier circuit 2. The output terminal of the rectifier circuit 2 is connected to a bidirectional voltage limiting and protection circuit, which consists of at least one set of bidirectional Zener diodes 3 connected to the power supply 1. The power supply 1 is a 28VDC power supply, and a 1μF capacitor C85 is provided between the positive and negative terminals of the power supply 1. The rectifier circuit 2 consists of four sets of diodes D1-D4, capacitor C1, resistor R1, capacitor C2, Zener diode D4, resistor R2, resistor R3, and MOSFET Q1. Each set of diodes is connected to one power supply... A power supply 1 is connected, the gate of a field-effect transistor Q1 is connected to a resistor R2, a resistor R4 is connected between the drain and source of the field-effect transistor Q1, and the drain of the field-effect transistor Q1 is connected to a common-mode inductor. The power supply 1 has a ground wire 8. Each π-type filter circuit includes a common-mode inductor, an X capacitor group 4, and a Y capacitor group 5. The X capacitor group 4 has at least one 1μF capacitor for filtering the differential-mode high-frequency interference of the power supply 1. The π-type filter circuit and the Y capacitor group 5 are used to suppress common-mode electromagnetic interference. The two π-type filter circuits respectively include a first π-type filter circuit and a second π-type filter circuit 7. Both the first π-type filter circuit and the second π-type filter circuit 7 include a common-mode inductor, an X capacitor group 4, and a Y capacitor group 5.

[0013] It should be noted that the Y capacitor group 5 mentioned has capacitors C105, C107, C90, C6, C7, C8, C9, C89, C91, C106, and C5; the X capacitor group 4 mentioned has capacitors C85, C86, C3, C4, C104, and C103, with capacitance values ​​of 10μF, 0.047μF, 0.01μF, 8.2nF, 0.1μF, and 0.1μF, respectively. These capacitors effectively filter out high-harmonic interference generated by the operation of the DC / DC power module switching transistors, mainly in the frequency bands around 25MHz, 75MHz, 160MHz, and 1034MHz.

[0014] The EMI circuit of this multi-supply DC power converter module is located between the four power supply channels 1 and the six output power circuits, ensuring that its electromagnetic compatibility test RE102 meets the requirements of GJB151B for application-type circuits. Before voting at the input terminals of the four power supply channels 1, 10μF and 0.1μF Y capacitors are designed for each power supply channel 1 to provide a discharge path for common-mode electromagnetic interference. Through the above measures, the transmission of electromagnetic interference on the 28VDC power supply path can be effectively suppressed, mainly suppressing electromagnetic noise within the frequency bands of 20MHz and 48MHz. Among them, the EMI circuit of this multi-supply DC power converter module effectively suppresses the fundamental frequency signal and corresponding harmonic signal of electromagnetic interference of DC / DC power module products by effectively grounding, designing common-mode inductors and π-type filter circuits on the multi-input and output port circuits of the power converter, so that the DC / DC power module meets the electromagnetic compatibility RE102 requirements.

[0015] The EMI circuit of the multi-power DC power conversion module, laid out on the PCB board, can solve the electromagnetic interference from multiple 28V DC power inputs and the high-frequency interference signals from the DC / DC power conversion module that are coupled and conducted or radiated into the external space of the product through the 28VDC power supply lines. It also solves the problem of interference radiated from the DC / DC power module housing by the spatial environment, and eliminates high-frequency interference from the 6 output power of the DC / DC power conversion module to ensure a cleaner power supply and suppress electromagnetic interference coupling and conduction to the product's input and output cables and spatial radiation to the outside of the product.

[0016] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0017] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be understood that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. In the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a mechanical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Among these, there are various ways of detachable installation, such as by using a combination of plug-in and snap-fit, or by using bolt connections, etc.

[0018] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi- supply DC power conversion module EMI circuit, characterized by: The device includes a rectifier circuit for connection to at least one power supply and a two-stage π-type filter circuit connected to the rectifier circuit. The rectifier circuit consists of four groups of diodes (D1-D4), capacitor C1, resistor R1, capacitor C2, Zener diode D4, resistor R2, resistor R3, and MOSFET Q1. Each group of diodes is connected to a power supply, and the power supply has its own ground wire. Each stage of the π-type filter circuit includes a common-mode inductor, an X capacitor group, and a Y capacitor group. The X capacitor group has at least one 1μF capacitor for filtering differential-mode high-frequency interference inherent in the power supply. The π-type filter circuit and the Y capacitor group are used to suppress common-mode electromagnetic interference.

2. A multi-feed DC power conversion module EMI circuit according to claim 1, wherein: The output terminal of the rectifier circuit is connected to a bidirectional voltage limiting and protection circuit, which consists of at least one set of bidirectional Zener diodes connected to the power supply.

3. The multi-output DC power conversion module EMI circuit of claim 1, wherein: The gate of the field-effect transistor Q1 is connected to a resistor R2, a resistor R4 is connected between the drain and source of the field-effect transistor Q1, and the drain of the field-effect transistor Q1 is connected to a common-mode inductor.

4. The multi-output DC power conversion module EMI circuit of claim 1, wherein: The power supply is a 28VDC power supply, and a 1μF capacitor C85 is provided between the positive and negative terminals of the power supply.

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