阅读说明：本技术 一种集成emi滤波的高功率密度dc/dc电源模块 (High-power-density DC/DC power module integrated with EMI filtering ) 是由 谯涛 张振伟 李自明 于 2021-08-20 设计创作，主要内容包括：本发明涉及一种集成EMI滤波的高功率密度DC/DC电源模块,涉及功率变换模块、加固型便携式终端技术领域。本发明基于高功率密度DC-DC变换器,从加固型便携式终端类设备供电需求出发,实现了单模块集DC/DC功率变换模块及EMI滤波为一体,可广泛应用于对电磁兼容特性要求较高的加固型便携式终端类整机设备中,节省整机的空间、简化设备的维修时长和难度,提高设备的电磁兼容性、测试性和可靠性。(The invention relates to a high-power-density DC/DC power module integrated with EMI filtering, and relates to the technical field of power conversion modules and reinforced portable terminals. The invention is based on a high-power-density DC-DC converter, realizes that a single module integrates a DC/DC power conversion module and EMI filtering into a whole from the power supply requirement of reinforced portable terminal equipment, can be widely applied to reinforced portable terminal equipment with higher requirement on electromagnetic compatibility characteristics, saves the space of the whole equipment, simplifies the maintenance time and difficulty of the equipment, and improves the electromagnetic compatibility, the testability and the reliability of the equipment.)

1. An EMI filtered integrated high power density DC/DC power module, comprising: the EMI filtering module, the input protection module and the power conversion module; the EMI filtering module includes: an input EMI filter circuit and an output EMI filter circuit;

after the input voltage is subjected to EMI filtering by the input EMI filter circuit, when the input voltage is normal, the input protection module is switched on to realize input reverse connection prevention protection, input low-voltage alarm and input voltage protection, then the input voltage is subjected to direct-current voltage output by the power conversion module and is subjected to output EMI filter circuit to supply power to a rear-stage load.

2. The module of claim 1, wherein the EMI filter module filters out mutual interference between the power bus and the DC/DC power module and between the output and the load by using a combination of an X capacitor, a Y capacitor, and a common mode inductor.

3. The module as claimed in claim 2, wherein the input protection module realizes input low voltage alarm and under voltage protection through the voltage regulator tube ZD2 and the optocoupler triode, and provides input protection for the whole machine and feeds back the input low voltage in time, so that the whole machine can make load adjustment in time in terms of power supply strategy.

4. The module of claim 3, wherein the input EMI filter circuit is implemented by an X capacitor, a Y capacitor and a two-stage common mode inductor, the X capacitor is connected in parallel between the positive and negative electrodes of the input bus for implementing differential mode interference suppression on the low frequency band, the Y capacitor is respectively connected in parallel between the input positive and the input negative and the input case for transmitting the high frequency interference of the input bus to the whole machine housing, the common mode inductor adopts two different specification parameters and is connected in series on the input bus for implementing filtering on different frequency bands and suppressing mutual interference between the power conversion module and the external input of the equipment.

5. The module of claim 4, wherein the output EMI filter circuit is implemented by an X capacitor, a Y capacitor and a high-frequency common-mode inductor, and is used for filtering 18V voltage isolated and output by the power conversion module and electric equipment, and the X capacitor is connected between the positive electrode and the negative electrode of the output line in parallel to realize differential mode interference suppression of a low-frequency band; the Y capacitors are respectively connected in parallel between the output positive line and the output negative line and between the output negative line and the output positive line and the output negative line, and the high-frequency interference of the output positive line and the output negative line is transmitted to the whole machine shell; the common mode inductor is connected in series on the output line to achieve suppression of high-frequency band common mode interference, and the common mode inductor adopts two different specification parameters to achieve effective filtering of different frequency bands and suppress mutual interference between a power supply and an output load.

6. The module of claim 5, wherein the reverse connection protection circuit is used for realizing reverse connection protection of the input, and the circuit is not conducted after the input positive and negative polarities are reversed; the input over-voltage and under-voltage protection circuit is used for ensuring that the input voltage works within a safe voltage range, and when the input voltage is under-voltage, the circuit is not conducted, and when the input voltage is over-voltage, the circuit is not conducted.

7. The module of claim 6, wherein the input over-voltage and under-voltage protection circuit comprises a voltage sampling circuit, a reference circuit and an alarm circuit, wherein the voltage sampling circuit is connected between the positive and negative of the input bus to sample the input voltage, a voltage regulator tube ZD2 is used as the reference circuit, a light coupling triode is used as the alarm circuit, when the input voltage is within a set value range, the voltage regulator tube ZD2 breaks down, the circuit is in an operating state, and the output of the light coupling triode is in a low-resistance state; when the input voltage is lower than a set value, the voltage regulator tube ZD2 is not broken down, the circuit is in a non-working state, and the output of the optical coupling triode is in a high-resistance state.

8. The module of claim 7, wherein the power conversion module is configured to separately convert the wide-range input voltage of 9V to 36V filtered by the input EMI filter circuit into a stable 18V dc output voltage for providing an external power input to a terminal device; the power conversion module is connected as a separate component to the input and output.

9. The module of claim 8, wherein each of the DC/DC power modules is installed in a closed metal housing, the power input aerial pins and the grounding posts are installed at the input end of the metal housing, and the ground resistance between the aerial pins and the grounding posts is within 10m Ω by using a conductive rubber material; the power output connector is arranged at the output end of the metal shell, the output cable uses a shielding cable, and the shielding layer is grounded in double points; the input EMI filter circuit, the power conversion module, the input protection module and the output EMI filter circuit are respectively and independently processed in different cavities.

10. A method of operating a DC/DC power supply module as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of power conversion modules and reinforced portable terminals, in particular to a high-power-density DC/DC power module integrated with EMI filtering.

Background

In recent years, in order to meet the relevant regulations on the electromagnetic compatibility characteristics of military equipment, the ruggedized portable terminal generally implements the electromagnetic compatibility characteristic control and power isolation conversion functions by a scheme of matching an EMI filter with a DC/DC power supply module.

The scheme of matching the EMI filter with the DC/DC power supply module occupies more equipment space, and the separate installation of the two modules has an unsatisfactory control effect on the radiation index of the RE102, so that a great amount of time is needed for adjustment and adaptation after the complete machine design is completed. With the development trend of high performance, small volume, light weight and the like of the reinforced portable terminal, the whole portable terminal has brand-new requirements on high integration and miniaturization design of internal modules, and particularly has urgent requirements on a high-power-density DC/DC power module of power supply integrated EMI filtering.

Disclosure of Invention

Technical problem to be solved

The technical problem to be solved by the invention is as follows: how to provide power supply with rated power not less than 150W for the whole equipment of the reinforced portable terminal and the like, and simultaneously realize EMI filtering, effectively reduce mutual interference between a power module and the whole machine, and enhance the electromagnetic compatibility characteristic of the whole machine.

(II) technical scheme

In order to solve the above technical problem, the present invention provides an EMI filter integrated high power density DC/DC power module, comprising: the EMI filtering module, the input protection module and the power conversion module; the EMI filtering module includes: an input EMI filter circuit and an output EMI filter circuit;

after the input voltage is subjected to EMI filtering by the input EMI filter circuit, when the input voltage is normal, the input protection module is switched on to realize input reverse connection prevention protection, input low-voltage alarm and input voltage protection, then the input voltage is subjected to direct-current voltage output by the power conversion module and is subjected to output EMI filter circuit to supply power to a rear-stage load.

Preferably, the EMI filter module can filter mutual interference between the power supply bus and the DC/DC power module and between the output terminal and the load by using the combined action of the X capacitor, the Y capacitor, and the common mode inductor.

Preferably, the input protection module realizes input low voltage alarm and under-voltage protection through the voltage regulator tube ZD2 and the optocoupler triode, provides input protection for the whole machine and feeds back input low voltage in time, so that the whole machine can make load adjustment in time on a power supply strategy.

Preferably, the input EMI filter circuit is implemented by an X capacitor, a Y capacitor, and a two-stage common mode inductor, the X capacitor is connected in parallel between the positive and negative electrodes of the input bus for implementing differential mode interference suppression on the low frequency band, the Y capacitor is connected in parallel between the input positive and the input negative and the input case, respectively, and transmits the high frequency interference of the input bus to the whole machine housing, the common mode inductor adopts two different specification parameters, and is connected in series on the input bus to implement filtering on different frequency bands, and suppress mutual interference between the power conversion module and the external input of the device.

Preferably, the output EMI filter circuit is implemented by an X capacitor, a Y capacitor, and a high-frequency common mode inductor, and filters 18V voltage isolated and output by the power conversion module and the electric equipment, and the X capacitor is connected in parallel between the positive and negative electrodes of the output line to implement differential mode interference suppression on the low frequency band; the Y capacitors are respectively connected in parallel between the output positive line and the output negative line and between the output negative line and the output positive line and the output negative line, and the high-frequency interference of the output positive line and the output negative line is transmitted to the whole machine shell; the common mode inductor is connected in series on the output line to achieve suppression of high-frequency band common mode interference, and the common mode inductor adopts two different specification parameters to achieve effective filtering of different frequency bands and suppress mutual interference between a power supply and an output load.

Preferably, the reverse connection protection circuit is used for realizing reverse connection protection of input, and the circuit is not conducted after the positive polarity and the negative polarity of the input are reversed; the input over-voltage and under-voltage protection circuit is used for ensuring that the input voltage works within a safe voltage range, and when the input voltage is under-voltage, the circuit is not conducted, and when the input voltage is over-voltage, the circuit is not conducted.

Preferably, the input overvoltage and undervoltage protection circuit comprises a voltage sampling circuit, a reference circuit and an alarm circuit, wherein the voltage sampling circuit is connected between the positive and negative of an input bus to sample input voltage, a voltage regulator tube ZD2 is used as the reference circuit, and an optocoupler triode is used as the alarm circuit; when the input voltage is lower than a set value, the voltage regulator tube ZD2 is not broken down, the circuit is in a non-working state, and the output of the optical coupling triode is in a high-resistance state.

Preferably, the power conversion module is configured to isolate and convert the wide-range input voltage of 9V to 36V filtered by the input EMI filter circuit into a stable 18V dc output voltage, so as to provide an external power supply input for a terminal device; the power conversion module is connected as a separate component to the input and output.

Preferably, each module in the DC/DC power supply module is arranged in a closed metal shell, the power input aerial plug and the grounding column are arranged at the input end of the metal shell, and the grounding resistance between the aerial plug and the grounding column is within 10m omega by using a conductive rubber material; the power output connector is arranged at the output end of the metal shell, the output cable uses a shielding cable, and the shielding layer is grounded in double points; the input EMI filter circuit, the power conversion module, the input protection module and the output EMI filter circuit are respectively and independently processed in different cavities.

The invention also provides a working method of the DC/DC power supply module.

(III) advantageous effects

The invention is based on a high-power-density DC-DC converter, realizes that a single module integrates a DC/DC power conversion module and EMI filtering into a whole from the power supply requirement of reinforced portable terminal equipment, can be widely applied to reinforced portable terminal equipment with higher requirement on electromagnetic compatibility characteristics, saves the space of the whole equipment, simplifies the maintenance time and difficulty of the equipment, and improves the electromagnetic compatibility, the testability and the reliability of the equipment.

Drawings

FIG. 1 is a schematic block diagram of a high power density DC/DC power module based on integrated EMI filtering according to the present invention;

fig. 2 is a schematic diagram of a high power density DC/DC power module cavity structure based on integrated EMI filtering according to the present invention.

Detailed Description

In order to make the objects, contents, and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be made in conjunction with the accompanying drawings and examples.

The invention designs a high-power-density DC/DC power supply module based on integrated EMI filtering, integrates a power conversion module and an EMI filtering module, accords with the miniaturized application of a portable terminal, and can be widely applied to reinforced portable terminal equipment.

The invention provides a high-power-density DC/DC power module based on integrated EMI filtering, which is designed for a reinforced portable device with the power of the whole machine within 150W and comprises an EMI filtering module, an input protection module and a power conversion module, wherein the whole module is arranged in a closed metal shell, the EMI filtering module realizes the EMI filtering function and improves the electromagnetic compatibility of the whole device; the input protection module realizes the reverse connection protection function, the low-voltage alarm function and the power loop switching-off function; the power conversion module realizes wide-voltage DC-DC isolation conversion and provides stable output voltage for the rear end.

The EMI filtering module comprises an input EMI filtering circuit and an output EMI filtering circuit, the input EMI filtering circuit is realized by an X capacitor, a Y capacitor and a two-stage common mode inductor, the X capacitor is connected in parallel between the positive electrode and the negative electrode of an input bus to realize the differential mode interference suppression of a low frequency band, the Y capacitor is respectively connected in parallel between the input positive shell and the input shell as well as between the input negative shell and the input shell, the high frequency interference of the input bus is transmitted to the whole machine shell, the interference of a high frequency component to a system is reduced, the common mode inductor adopts two different specification parameters and is connected in series on the input bus to realize the effective filtering of different frequency bands, the mutual interference between the power conversion module and the external input of equipment is effectively suppressed, the voltage input to the power conversion module is ensured to be in a low interference state, and other electric equipment of the system is enabled to be in a safe and reliable working state; the output EMI filter circuit is realized by an X capacitor, a Y capacitor and a high-frequency common-mode inductor, the 18V voltage isolated and output by the power conversion module is filtered by electric equipment, and the X capacitor is connected between the anode and the cathode of an output line in parallel to realize the differential mode interference suppression of a low-frequency band; the Y capacitors are respectively connected in parallel between the output positive line and the output negative line and between the output negative line and the output positive line and the output negative line, and high-frequency interference of the output positive line and the output negative line is transmitted to the whole machine shell, so that interference of high-frequency components on a system is reduced; the common mode inductor is connected in series on the output line to achieve suppression of high-frequency band common mode interference, the common mode inductor adopts two different specification parameters to achieve effective filtering of different frequency bands, mutual interference between a power supply and an output load is effectively suppressed, voltage output to the load is guaranteed to be in a low interference state, other electric equipment of the system is enabled to be in a safe and reliable working state, and therefore reliability and safety of the system are improved. The 18V voltage isolated and output by the power conversion module is filtered, so that the switching frequency and the harmonic waves of the PWM control circuit can be effectively inhibited from entering the electric equipment, the backward flow interference of the electric equipment to the power conversion module is reduced, the power supply stability of the electric equipment can be ensured, the power protection circuit can be protected, the electric equipment is in a better working state, and the reliability and the safety of a system are improved.

The input protection module comprises a reverse connection protection circuit and an input overvoltage and undervoltage protection circuit, and is used for realizing input reverse connection protection, input low-voltage alarm and input voltage protection, providing input protection for the whole machine and feeding back low-voltage input in time, so that the whole machine can make load adjustment in time on a power supply strategy, and preventing the reliability of the whole machine from being reduced due to overlarge input current. The reverse connection protection circuit realizes input reverse connection protection, the circuit is not conducted after the positive and negative polarities of the input are reversely connected, and the reverse connection voltage cannot cause product damage; the input over-voltage and under-voltage protection circuit is used for ensuring the work when the input voltage is in a safe voltage range, when the input voltage is under-voltage, the circuit is not conducted, the product is ensured not to work when the input voltage is low, large current cannot be generated to damage an external power supply or the product, when the input voltage is over-voltage, the circuit is not conducted, and the product is protected from sending high voltage to be damaged; the input overvoltage and undervoltage protection circuit comprises a voltage sampling circuit, a reference circuit and an alarm circuit, wherein the voltage sampling circuit is connected between the positive and negative of an input bus to sample input voltage, a voltage regulator tube ZD2 is used as the reference circuit, and an optocoupler triode is used as the alarm circuit, when the input voltage is within a set value range (default is more than 18V), the voltage regulator tube ZD2 is broken down, the circuit is in a working state, and the output of the optocoupler triode is in a low-resistance state; when the input voltage is lower than a set value (18V by default), the voltage-regulator tube ZD2 is not broken down, the circuit is in a non-working state, and the output of the optocoupler triode is in a high-resistance state; the state of the optocoupler triode can be used as an alarm signal to provide input low-voltage feedback for the input protection of the whole machine in time, so that the whole machine can make load adjustment in time on a power supply strategy, and the situation that the reliability of the whole machine is reduced due to overlarge input current is prevented.

The power conversion module comprises a primary current sampling circuit, a flyback active clamp power conversion circuit, an output synchronous rectification circuit, an output voltage and current sampling circuit, an output protection circuit and a PWM control circuit, is used for isolating and converting the input voltage of 9V-36V wide range filtered by the input EMI filter circuit into stable 18V direct current output voltage, and can be used for providing external power supply input for portable terminal equipment. The power conversion module is used as an independent component to be connected with input and output, the input voltage range is 9-36V, the output is 18V/150W, the standby power consumption is low (the typical value is not more than 0.3W), the conversion efficiency is high (the typical value is not less than 90%), the input and the output are isolated, and the power conversion module has the functions of remote control on-off, adjustable output voltage, input under-voltage protection, output overcurrent protection, output overvoltage protection, output short-circuit protection, over-temperature protection and the like. The power conversion module has lower static power consumption, the power loss is not more than 0.3W in the standby state of the portable terminal, and the power conversion module has the characteristics of low standby power consumption and high conversion efficiency, thereby well solving the heating problem. Can be used to implement the provision of external power supply input to the portable terminal device.

A closed metal shell integrally mounts the modules together, the module size is no more than 125 x 35 x 22.5mm (no projection); the power input aerial plug and the grounding column are arranged at the input end of the module shell, and the grounding resistance between the aerial plug and the grounding column is ensured to be within 10m omega by using a conductive rubber material; the power output connector is arranged at the output end of the module shell, the output cable uses a shielding cable, and the shielding layer is grounded in double points; the input EMI filter circuit, the power conversion module, the input protection module and the output EMI filter circuit are respectively and independently processed in a cavity, mutual radiation interference among an input bus, the power conversion module and an output load can be effectively inhibited by the structural mode, a good cold conduction and heat dissipation environment is provided for the power conversion module, and the power conversion module can well meet the items such as CE102 and RE102 required by electromagnetic compatibility. The method can be widely applied to a portable terminal power supply system or other systems with higher requirements on electromagnetic compatibility. Therefore, in order to improve maintainability, testability and reliability of the reinforced portable terminal, enhance the EMI characteristics of equipment and reduce the design size of the whole machine, the high-power-density DC/DC power module integrated with EMI filtering becomes a good solution.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.