CN110729978A - High-frequency common mode rejection circuit and electrical apparatus - Google Patents
High-frequency common mode rejection circuit and electrical apparatus Download PDFInfo
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- CN110729978A CN110729978A CN201910876139.5A CN201910876139A CN110729978A CN 110729978 A CN110729978 A CN 110729978A CN 201910876139 A CN201910876139 A CN 201910876139A CN 110729978 A CN110729978 A CN 110729978A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/0115—Frequency selective two-port networks comprising only inductors and capacitors
Abstract
The invention provides a high-frequency common mode rejection circuit which comprises a common mode choke coil, a first filter capacitor group, a second filter capacitor group and a resonant circuit, wherein the input end of the first filter capacitor group is connected with the input end of the choke coil, the common end of the first filter capacitor group is connected with a mains supply, the input end of the second filter capacitor group is connected with the output end of the common mode choke coil, the output ends of the first filter capacitor group and/or the second filter capacitor group are/is connected with the input end of the resonant circuit, and the output end of the resonant circuit is grounded. The invention utilizes the LC parallel resonance characteristic and the Y capacitor to form a band elimination circuit in series, inhibits the high-frequency common mode interference from passing through a bypass, improves the high-frequency common mode filtering effect of the filter, reduces the stage number and the magnetic ring of the filter and effectively reduces the cost of circuit devices.
Description
Technical Field
The invention relates to the technical field of household appliances, in particular to a high-frequency common-mode rejection circuit and an appliance.
Background
The common mode filter is used for filtering common mode interference generated by electrical equipment so as to meet the requirements of electromagnetic compatibility standards. A common structure of the common-mode filter includes a common-mode capacitor (also referred to as Y capacitor) and a common-mode inductor, and common-mode interference is reduced by a common-mode impedance of the common-mode inductor and a bypass effect of the common-mode capacitor. The common mode filter is generally used for conducting electromagnetic interference, and the action frequency band is 150 kHz-30 MHz.
The high-frequency band (5 MHz-30 MHz) conducted electromagnetic interference exceeds the standard, which is a common problem encountered in the electromagnetic compatibility test, for the high-frequency band common mode interference, it is usually necessary to select a nanocrystalline or amorphous common mode choke coil with better high-frequency impedance characteristic, and increase the filter stage number to enhance the high-frequency band common mode filtering performance (further increase a common mode choke coil and a pair of Y capacitors), as shown in fig. 1, there is still a certain degree of common mode interference, and the device cost is greatly increased.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a high-frequency common mode rejection circuit and an electric appliance, which can reject high-frequency common mode interference in the electric appliance, improve the high-frequency common mode filtering effect of a filter, reduce the number of stages and magnetic rings of the filter and effectively reduce the cost of circuit devices.
The purpose of the invention is realized by the following technical scheme in two aspects:
in a first aspect, the present invention provides a high-frequency common mode rejection circuit, which includes a common mode choke coil, a first filter capacitor bank, a second filter capacitor bank, and a resonant circuit, wherein an input terminal of the first filter capacitor bank is connected to an input terminal of the choke coil, a common terminal of the first filter capacitor bank is connected to a commercial power, an input terminal of the second filter capacitor bank is connected to an output terminal of the common mode choke coil, an output terminal of the first filter capacitor bank and/or the second filter capacitor bank is connected to an input terminal of the resonant circuit, and an output terminal of the resonant circuit is grounded.
Further, the resonant circuit is connected between the second filter capacitor bank and ground.
Further, the resonant circuit comprises a first resonant capacitor, a second resonant capacitor, a first resonant inductor and a second resonant inductor, wherein the input end of the first resonant capacitor is connected with the input end and the common end of the first resonant inductor are connected with the output end of one filter capacitor in the second filter capacitor bank, the input end of the second resonant capacitor is connected with the input end and the common end of the second resonant inductor are connected with the output end of another filter capacitor in the second filter capacitor bank, and the output ends of the first resonant capacitor, the second resonant capacitor, the first resonant inductor and the second resonant inductor are all grounded.
Further, the first filter capacitor bank comprises a first filter capacitor and a second filter capacitor, the second filter capacitor bank comprises a third filter capacitor and a fourth filter capacitor, the first filter capacitor and the second filter capacitor are connected in parallel, the third filter capacitor and the fourth filter capacitor are connected in parallel, and the first filter capacitor, the second filter capacitor, the third filter capacitor and the fourth filter capacitor are all Y capacitors.
Further, the resonant circuit comprises a resonant capacitor and a resonant inductor, and the resonant capacitor and the resonant inductor are connected in parallel.
Further, the first resonant inductor and the second resonant inductor are both 100uH i-inductors.
Further, the first resonant inductor and the second resonant inductor are both 100uH inductors.
Further, the first resonance capacitor and the second resonance capacitor are both capacitors of 0.1nF-30 nF.
Further, the first resonance capacitance and the second resonance capacitance are both capacitances of 10 nF.
Furthermore, a magnetic ring is sleeved at the wire inlet of the mains supply, and the magnetic ring is one of a high-conductivity manganese-zinc ferrite magnetic ring, a nanocrystalline magnetic ring and an amorphous magnetic ring with a high low-frequency-band impedance value.
In a second aspect, the present invention also provides an electrical appliance, which includes the high-frequency common mode rejection circuit of the first aspect.
The invention has the beneficial effects that: the invention provides a high-frequency common mode rejection circuit which is used for an electric appliance, and utilizes the LC parallel resonance characteristic of a resonance circuit to be connected with a filter capacitor in series to form a band rejection circuit, so that the high-frequency common mode interference is rejected to pass through a bypass, the high-frequency common mode filtering effect of a filter is improved, the number of stages and magnetic rings of the filter are reduced, and the cost of circuit devices is effectively reduced.
Drawings
The invention is further illustrated by means of the attached drawings, but the embodiments in the drawings do not constitute any limitation to the invention, and for a person skilled in the art, other drawings can be derived on the basis of the following drawings without inventive effort.
Fig. 1 is a schematic circuit diagram of a conventional two-stage filter circuit.
Fig. 2 is a schematic circuit configuration diagram of a high-frequency common mode rejection circuit according to embodiment 1 of the present invention.
Fig. 3 is a schematic circuit configuration diagram of a high-frequency common mode rejection circuit according to embodiment 2 of the present invention.
Fig. 4 is a graph of conducted EMI test results obtained based on the two-stage filter circuit described in fig. 1.
Fig. 5 is a graph of conducted EMI test results obtained based on the high frequency common mode rejection circuit described in fig. 2.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the description of the embodiments of the invention herein.
The high-frequency band (5 MHz-30 MHz) conducted electromagnetic interference exceeds the standard, which is a common problem encountered in the electromagnetic compatibility test, for the high-frequency band common mode interference, it is usually necessary to select a nanocrystalline or amorphous common mode choke coil with better high-frequency impedance characteristic, and increase the filter stage number to enhance the high-frequency band common mode filtering performance (further increase a common mode choke coil and a pair of Y capacitors), as shown in fig. 1, there is still a certain degree of common mode interference, and the device cost is greatly increased.
Example 1.
To solve the above problems, this embodiment provides a high-frequency common mode rejection circuit, as shown in fig. 2, which includes a magnetic loop, a common mode choke coil, a first filter capacitor CY1, a second filter capacitor CY2, a third filter capacitor CY3, a fourth filter capacitor CY4, and a resonant circuit, where the resonant circuit includes a first resonant capacitor C1, a second resonant capacitor C2, a first resonant inductor L1, and a second resonant inductor L2, the magnetic loop is connected to the power supply line, the input end of the second filter capacitor CY2 is connected to the live line of the power supply and the common end is connected to the first input end of the common mode choke coil, the input end of the first filter capacitor CY1 is connected to the zero line of the power supply and the common end is connected to the second input end of the common mode choke coil, the output end of the first filter capacitor CY1 is connected to the output end of the second filter capacitor CY2 and the common end is grounded, the first output end of the common mode choke coil is connected to the input end of the fourth filter capacitor CY4, the second output end of the common mode choke coil is connected to the input end 3, the output end of the third filter capacitor CY3 is connected to the input end of the first resonant capacitor C1, the common end of the third filter capacitor CY3 is connected to the input end of the second resonant capacitor C2, the output end of the fourth filter capacitor CY4 is connected to the input end of the second resonant capacitor C2, the common end of the fourth filter capacitor CY4 is connected to the input end of the second resonant inductor L2, and the output ends of the first resonant capacitor C1, the second resonant capacitor C2, the second resonant capacitor C2 and the second resonant inductor L2 are all grounded.
The first filter capacitor CY1, the second filter capacitor CY2, the third filter capacitor CY3 and the fourth filter capacitor CY4 are Y capacitors, the first filter capacitor CY1 and the second filter capacitor CY2 are first filter capacitor sets, the third filter capacitor CY3 and the fourth filter capacitor CY4 are second filter capacitor sets, the resonant circuit can be connected with the first filter capacitor sets in series or connected with the second filter capacitor sets in series, or the resonant point circuits are divided into two sets and respectively connected with the first filter capacitor sets and the second filter capacitor sets in series, a band elimination circuit is formed by the filter Y capacitors and the resonant circuits in the filter capacitor sets, high-frequency common-mode interference is inhibited from passing through a bypass, and the high-frequency common-mode filtering effect of the filter is improved.
The first resonant inductor L1 and the second resonant inductor L2 in the present invention may be h-shaped inductors of 10nH to 300uH, and are composed of an inductor coil and a magnetic core, or an air-core coil. In this embodiment, 100uH inductors are used for the first resonant inductor L1 and the second resonant inductor L2, and the inductors may be connected in parallel by a plurality of small-sized inductors to achieve an equivalent effect of 100uH, for example, 100uH may be achieved by connecting two 50uH inductors in parallel.
The first resonant capacitor C1 and the second resonant capacitor C2 in the present invention may be capacitors of 0.1nF-30nF, in this embodiment, the first resonant capacitor C1 and the second resonant capacitor C2 both use capacitors of 10nF, and the capacitors may be connected in parallel by a plurality of small-sized inductors to achieve an equivalent effect of 5nF, for example, two capacitors of 5nF are connected in parallel to achieve an equivalent effect of 10 nF.
The first resonant capacitor C1 and the second resonant capacitor C2 in this embodiment are also Y capacitors.
The magnetic ring in the embodiment is a high-conductivity manganese-zinc ferrite magnetic ring with a high low-frequency-band impedance value, the high-conductivity manganese-zinc ferrite magnetic ring is very convenient to use, and the high-conductivity manganese-zinc ferrite magnetic ring is directly sleeved on a cable needing filtering and is not grounded like other filtering modes, so that no special requirements are required for structural design and circuit board design, signal distortion is avoided, and the magnetic ring is very suitable for a wire for transmitting high-frequency signals.
The working principle of this embodiment is to utilize LC parallel resonance characteristic and Y electric capacity to establish ties and constitute a band elimination circuit, through electric field in the resonance electric capacity and the magnetic field in the resonance inductance can interconversion, this increases each other and subtracts, the complete compensation to more effective suppression high frequency common mode interference passes through the bypass, promotes the high frequency common mode filtering effect of wave filter.
The high-frequency common mode suppression circuit is suitable for various electrical appliances, and when the high-frequency common mode suppression circuit is used for an air conditioner, the high-frequency common mode interference of the air conditioner can be suppressed to pass through a bypass, the high-frequency common mode filtering effect of a filter is improved, the number of stages and magnetic rings of the filter are reduced, and the device cost of the air conditioner is effectively reduced.
Fig. 4 is a conducted EMI test effect diagram of a conventional two-stage filter circuit at present, where an interference spike appears at a high frequency of 11M, and the margin is 3.09dB, and fig. 5 is a conducted EMI test effect diagram of the high-frequency common mode rejection circuit of this embodiment for an air conditioner, where the interference spike is effectively suppressed near 11M, and the margin is 11 dB.
Example 2.
The difference between this embodiment and embodiment 1 is that the resonant circuit in this embodiment only uses one i-shaped resonant inductor L of 200uH and one Y-shaped resonant capacitor C of 20nF in parallel, the input terminal of the resonant inductor L is connected to the input terminal of the resonant capacitor C, the common terminal of the resonant inductor L is connected to the output terminal of the third filter capacitor CY3 and the output terminal of the fourth filter capacitor CY4, and the resonant inductor L and the resonant capacitor C are grounded.
The embodiment only adopts one inductor and one capacitor, so that the complexity of circuit design can be reduced, and the cost of the device can be saved.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (11)
1. The utility model provides a high frequency common mode rejection circuit, includes common mode choke, first filter capacitor group and second filter capacitor group, its characterized in that still includes resonant circuit, the input of first filter capacitor group is connected the commercial power is connected to the input and the common port of choke, the input of second filter capacitor group is connected common mode choke's output, the output of first filter capacitor group and/or second filter capacitor group is connected resonant circuit's input, resonant circuit's output ground connection.
2. A high frequency common mode rejection circuit as in claim 1 wherein said resonant circuit is connected between said second bank of filter capacitors and ground.
3. A high frequency common mode rejection circuit as claimed in claim 1, wherein said resonant circuit comprises a first resonant capacitor, a second resonant capacitor, a first resonant inductor and a second resonant inductor, said first resonant capacitor having an input terminal connected to said first resonant inductor and a common terminal connected to an output terminal of one of said second set of filter capacitors, said second resonant capacitor having an input terminal connected to said second resonant inductor and a common terminal connected to an output terminal of another one of said second set of filter capacitors, said first resonant capacitor, said second resonant capacitor, said first resonant inductor and said second resonant inductor having output terminals connected to ground.
4. The high-frequency common mode rejection circuit according to claim 1, wherein said first filter capacitor set comprises a first filter capacitor and a second filter capacitor, said second filter capacitor set comprises a third filter capacitor and a fourth filter capacitor, said first filter capacitor and said second filter capacitor are connected in parallel, said third filter capacitor and said fourth filter capacitor are connected in parallel, and said first filter capacitor, said second filter capacitor, said third filter capacitor and said fourth filter capacitor are Y capacitors.
5. A high frequency common mode rejection circuit as in claim 1 wherein said resonant circuit is an LC resonant circuit including a resonant capacitor and a resonant inductor, said resonant capacitor and said resonant inductor being connected in parallel.
6. A high frequency common mode rejection circuit as claimed in claim 3, wherein said first resonant inductor and said second resonant inductor are both i-inductors of 10nH to 300 uH.
7. The high-frequency common mode rejection circuit according to claim 5, wherein said first resonant inductor and said second resonant inductor are both I-shaped inductors of 100 uH.
8. A high frequency common mode rejection circuit as in claim 3 wherein said first resonant capacitor and said second resonant capacitor are each a capacitor of 0.1nF to 30 nF.
9. A high frequency common mode rejection circuit as in claim 5 wherein said first resonant capacitor and said second resonant capacitor are each 10nF capacitors.
10. The high-frequency common mode rejection circuit as claimed in claim 1, wherein a magnetic ring is connected to the line inlet of the utility power, and the magnetic ring is one of a high-conductivity manganese-zinc ferrite magnetic ring, a nanocrystalline magnetic ring and an amorphous magnetic ring with a high impedance value at a low frequency band.
11. An electrical appliance, characterized in that the electrical appliance comprises a high frequency common mode rejection circuit according to any one of claims 1 to 10.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910876139.5A CN110729978A (en) | 2019-09-17 | 2019-09-17 | High-frequency common mode rejection circuit and electrical apparatus |
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| CN201910876139.5A CN110729978A (en) | 2019-09-17 | 2019-09-17 | High-frequency common mode rejection circuit and electrical apparatus |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023110201A1 (en) * | 2021-12-14 | 2023-06-22 | Robert Bosch Gmbh | Device for electrically filtering an input dc voltage of an inverter |
| CN116800284A (en) * | 2023-07-18 | 2023-09-22 | 北京捷星电子科技有限公司 | Bluetooth multimedia radio |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101277056A (en) * | 2007-03-30 | 2008-10-01 | 艾默生网络能源系统有限公司 | Filter circuit |
| CN201528198U (en) * | 2009-09-14 | 2010-07-14 | 宝鸡市瑞通电器有限公司 | Alternating current power supply noise filter |
| CN103138692A (en) * | 2011-11-25 | 2013-06-05 | 英特尔移动通信有限责任公司 | Common mode rejection circuit |
| CN104201920A (en) * | 2014-09-19 | 2014-12-10 | 阳光电源股份有限公司 | Common mode circuit, three-phase inverter and photovoltaic power generation system |
| US20150021994A1 (en) * | 2013-07-18 | 2015-01-22 | The Boeing Company | Power converter having emi filter common to multiple converters |
| CN107482896A (en) * | 2016-06-08 | 2017-12-15 | 珠海格力电器股份有限公司 | Electromagnetic interface filter and EMI power filter access circuit |
| CN107819397A (en) * | 2017-12-06 | 2018-03-20 | 浙江大学 | Input filter and its method to set up include the frequency converter of the input filter |
| CN108419349A (en) * | 2018-02-07 | 2018-08-17 | 福建睿能科技股份有限公司 | Full-bridge high-frequency driving circuit, electric ballast and the lighting apparatus of low EMI |
| CN109565296A (en) * | 2016-10-17 | 2019-04-02 | 密克罗奇普技术公司 | Coaxial data communication with reduced EMI |
-
2019
- 2019-09-17 CN CN201910876139.5A patent/CN110729978A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101277056A (en) * | 2007-03-30 | 2008-10-01 | 艾默生网络能源系统有限公司 | Filter circuit |
| CN201528198U (en) * | 2009-09-14 | 2010-07-14 | 宝鸡市瑞通电器有限公司 | Alternating current power supply noise filter |
| CN103138692A (en) * | 2011-11-25 | 2013-06-05 | 英特尔移动通信有限责任公司 | Common mode rejection circuit |
| US20150021994A1 (en) * | 2013-07-18 | 2015-01-22 | The Boeing Company | Power converter having emi filter common to multiple converters |
| CN104201920A (en) * | 2014-09-19 | 2014-12-10 | 阳光电源股份有限公司 | Common mode circuit, three-phase inverter and photovoltaic power generation system |
| CN107482896A (en) * | 2016-06-08 | 2017-12-15 | 珠海格力电器股份有限公司 | Electromagnetic interface filter and EMI power filter access circuit |
| CN109565296A (en) * | 2016-10-17 | 2019-04-02 | 密克罗奇普技术公司 | Coaxial data communication with reduced EMI |
| CN107819397A (en) * | 2017-12-06 | 2018-03-20 | 浙江大学 | Input filter and its method to set up include the frequency converter of the input filter |
| CN108419349A (en) * | 2018-02-07 | 2018-08-17 | 福建睿能科技股份有限公司 | Full-bridge high-frequency driving circuit, electric ballast and the lighting apparatus of low EMI |
Non-Patent Citations (1)
| Title |
|---|
| 林启瑜: "《实用电工基础》", 28 February 1995 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023110201A1 (en) * | 2021-12-14 | 2023-06-22 | Robert Bosch Gmbh | Device for electrically filtering an input dc voltage of an inverter |
| CN116800284A (en) * | 2023-07-18 | 2023-09-22 | 北京捷星电子科技有限公司 | Bluetooth multimedia radio |
| CN116800284B (en) * | 2023-07-18 | 2024-03-12 | 北京捷星电子科技有限公司 | Bluetooth multimedia radio |
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Application publication date: 20200124 |