CN104202013B

CN104202013B - A kind of active EMI filter and electric power controller

Info

Publication number: CN104202013B
Application number: CN201410416528.7A
Authority: CN
Inventors: 裴昌盛; 朱勇发; 骆孝龙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2014-08-21
Filing date: 2014-08-21
Publication date: 2017-03-08
Anticipated expiration: 2034-08-21
Also published as: CN104202013A

Abstract

The embodiment of the invention discloses a kind of active Electromagnetic disturbs electromagnetic interface filter, including auxiliary source circuit, current detection circuit, see-saw circuit and noise injection circuit, the wave filter also includes differential mode capacitor and differential mode inductance, the earth impedance of positive supply lines and negative supply lines is inconsistent, differential mode capacitor is connected between positive supply lines and negative supply lines, differential mode inductance is connected in positive supply lines and negative supply lines on the higher supply lines of earth impedance, one end connection auxiliary source circuit and the connecting node of the supply lines, the connecting node of other end connection differential mode capacitor and the supply lines.Differential mode capacitor can increase the impedance of the higher supply lines of the earth impedance, make more low frequency common Noise Circuits converge to the relatively low supply lines of earth impedance by differential mode capacitor.The embodiment of the invention also discloses a kind of electric power controller, including above-mentioned active EMI filter.Using the present invention, the filtration result that low frequency common noise current can be strengthened and the stability for improving active EMI filter.

Description

A kind of active EMI filter and electric power controller

Technical field

The present invention relates to electronic technology field, more particularly to a kind of active EMI filter and electric power controller.

Background technology

In general, active EMI filter includes the injection of auxiliary source circuit, current detection circuit, amplifying circuit and noise Circuit and the differential mode capacitor being serially connected between positive supply lines and negative supply lines, the common mode noise signal on generally positive and negative supply lines are being passed Defeated to before auxiliary source circuit, can be convergeed on the relatively low supply lines of earth impedance by differential mode capacitor, and then be transferred to successively auxiliary Help source circuit low impedance path, the earth terminal of amplifying circuit and noise injection circuit.The defect of this scheme is：Low frequency Noise signal is difficult to flow into the relatively low supply lines of earth impedance by differential mode capacitor from the higher supply lines of earth impedance, so as to lead On the supply lines for causing earth impedance higher, the noise signal filtration result of low frequency is restricted.

Content of the invention

A kind of active EMI filter and electric power controller is embodiments provided, low frequency common can be strengthened and made an uproar The filtration result of acoustoelectric current.

Embodiment of the present invention first aspect provides a kind of active EMI filter, including auxiliary source circuit, current detecting electricity Road, see-saw circuit and noise injection circuit, the wave filter also include the first differential mode inductance, wherein：

The noise inputs end of positive supply lines, the auxiliary source in the first input end connection power line of the auxiliary source circuit The noise inputs end of supply lines is born in the second input connection power line of circuit, and the first output end of the auxiliary source circuit connects The power end of the see-saw circuit is connect, the first output end of the auxiliary source circuit exports the work of the see-saw circuit Make voltage, the second output end of the auxiliary source circuit connects the positive input terminal of the see-saw circuit, the auxiliary source electricity Second output end on road exports the reference voltage of the see-saw circuit；

The first input end of the current detection circuit connects the power input of the positive supply lines, the current detecting Second input of circuit connects the power input of the negative supply lines, the first output end connection of the current detection circuit The positive input terminal of the see-saw circuit, the second output end of the current detection circuit connect the see-saw circuit Negative input end, the current detection circuit are used for the first common mode noise current signal of detection, and first common-mode noise is electric Stream signal is transformed into voltage signal and exports to the see-saw circuit；

The output end of the see-saw circuit connects the input of the noise injection circuit, the see-saw circuit For being amplified processing to the voltage signal that the current detection circuit is exported, and by the electricity through enhanced processing Pressure signal output gives the noise injection circuit；

The noise injection circuit at least includes a direct current letter intercepted between the see-saw circuit and protecting field Number electric capacity, the noise injection circuit is serially connected between the see-saw circuit and protecting field, for by described through putting The big voltage signal for processing is back to noise inputs end by protecting field；

The noise inputs end of the noise inputs end of the positive supply lines and the negative supply lines passes through the first differential mode capacitor phase Even, one end of first differential mode capacitor connects the positive supply lines, and the other end connects the negative supply lines；

When the earth impedance of the positive supply lines is higher than the earth impedance of the negative supply lines, first differential mode inductance It is serially connected on the positive supply lines, one end of first differential mode inductance connects the first input end of the auxiliary source circuit, institute The other end for stating the first differential mode inductance connects the connecting node of first differential mode capacitor and the positive supply lines；Described first is poor Mould inductance is used for increasing the earth impedance of the positive supply lines so that the second common mode noise current signal passes through first differential mode Electric capacity is convergeed on the negative supply lines, and is transferred to protecting field by the negative supply lines, to realize institute by protecting field State the second common mode noise current signal and be back to noise inputs end；

When the earth impedance of the negative supply lines is higher than the earth impedance of the positive supply lines, first differential mode inductance It is serially connected on the negative supply lines, one end of first differential mode inductance connects the second input of the auxiliary source circuit, institute The other end for stating the first differential mode inductance connects the connecting node of first differential mode capacitor and the negative supply lines；Described first is poor Mould inductance is used for increasing the earth impedance of the negative supply lines so that the second common mode noise current signal passes through first differential mode Electric capacity is convergeed on the positive supply lines, and is transferred to protecting field by the positive supply lines, to realize institute by protecting field State the second common mode noise current signal and be back to noise inputs end.

In conjunction with a first aspect, in the first possible embodiment, the induction reactance of first differential mode inductance is at least institute State the first differential mode capacitor 10 times of capacitive reactance.

In conjunction with the first possible embodiment of first aspect and first aspect, in second possible embodiment In, the wave filter also includes bandwidth-limited circuit, and the first input end of the bandwidth-limited circuit connects the current detecting First output end of circuit, the second input of the bandwidth-limited circuit connect the second output of the current detection circuit End, the first output end of the bandwidth-limited circuit connect the positive input terminal of the see-saw circuit, the bandpass filtering electricity Second output end on road connects the negative input end of the see-saw circuit, and the bandwidth-limited circuit is used for examining the electric current The voltage signal of slowdown monitoring circuit output carries out bandpass filtering treatment, makes voltage signal of the frequency in preset range by the band logical Filter circuit is input to the see-saw circuit, so that the voltage signal frequency obtained after bandpass filtering treatment is not as little as So that the operational amplifier saturation in the see-saw circuit is failed, also up to do not make the operational amplifier produce high frequency and swash Swing.

In conjunction with second possible embodiment of first aspect, in the third possible embodiment, the band logical Filter circuit includes the first electric capacity, the second electric capacity, first resistor, second resistance and 3rd resistor, wherein：

First output end of the current detection circuit is connected with the positive input terminal of the see-saw circuit, and is led to successively Cross the second output end that first electric capacity of series connection and the first resistor connect the current detection circuit；The electric current inspection Second output end of slowdown monitoring circuit passes sequentially through second electric capacity of series connection and the second resistance connection anti-phase amplification electricity The negative input end on road；The 3rd resistor is connected to the second output end of the current detection circuit and the see-saw circuit Negative input end between.

In conjunction with second possible embodiment of first aspect, in the 4th kind of possible embodiment, the band logical Filter circuit includes the 3rd electric capacity, the 4th electric capacity, the 4th resistance, the 5th resistance and the 6th resistance, wherein：

Second output end of the current detection circuit passes sequentially through the 3rd electric capacity of series connection and the 4th resistance Connect the negative input end of the see-saw circuit；The connecting node of the 3rd electric capacity and the 4th resistance passes sequentially through string 5th resistance of connection and the first output end of current detection circuit and the see-saw circuit described in the 4th capacitance connection Positive input terminal；6th resistance is connected to the second output end of the current detection circuit and the see-saw circuit Between negative input end.

In conjunction with second possible embodiment of first aspect, in the 5th kind of possible embodiment, the band logical Filter circuit includes the 5th electric capacity, the 6th electric capacity, the 7th resistance, the 8th resistance and the 9th resistance, wherein：

First output end of the current detection circuit connects the positive input terminal of the see-saw circuit, while leading to successively Cross the negative input end that the 5th electric capacity of series connection and the 7th resistance connect the see-saw circuit；The current detecting Second output end of circuit passes sequentially through the 6th electric capacity of series connection and the 8th resistance connects the see-saw circuit Negative input end；9th resistance is connected to the second output end of the current detection circuit and the see-saw circuit Between negative input end.

Embodiment of the present invention second aspect provides a kind of active EMI filter, including auxiliary source circuit, current detecting electricity Road, voltage-current converting circuit and noise injection circuit, the wave filter also include the second differential mode inductance, wherein：

The noise inputs end of positive supply lines, the auxiliary source in the first input end connection power line of the auxiliary source circuit The noise inputs end of supply lines is born in the second input connection power line of circuit, and the first output end of the auxiliary source circuit connects The power end of the voltage-current converting circuit is connect, for providing operating voltage for the voltage-current converting circuit, described Second output end of auxiliary source circuit connects the negative input end of the voltage-current converting circuit, for for the voltage-to-current Translation circuit provides reference voltage；

The first input end of the current detection circuit connects the noise inputs end of the positive supply lines, the current detecting Second input of circuit connects the noise inputs end of the negative supply lines, the first output end connection of the current detection circuit The positive input terminal of the voltage-current converting circuit, the second output end of the current detection circuit connect the voltage-to-current The negative input end of translation circuit, the current detection circuit are used for detecting on the positive supply lines and negative supply lines of the power line 3rd common mode noise current, and by the 3rd common mode noise current for detecting be converted to voltage signal export to described electricity piezo-electric Stream translation circuit；

The output end of the voltage-current converting circuit connects the input of the noise injection circuit, the electricity piezo-electric Stream translation circuit is used for carrying out voltage-current transformation process to the voltage signal of current detection circuit output, obtains electric current Signal, and the current signal is exported to the noise injection circuit；

The noise injection circuit at least include one intercept between the voltage-current converting circuit and protecting field straight The electric capacity of stream signal, the noise injection circuit are serially connected between output end and the protecting field of the voltage-current converting circuit, For the 3rd current signal injection protecting field for exporting the voltage-current converting circuit；

The power input of the power input of the positive supply lines and the negative supply lines passes through the second differential mode capacitor phase Even, one end of second differential mode capacitor connects the positive supply lines, and the other end connects the negative supply lines；

When the earth impedance of the positive supply lines is higher than the earth impedance of the negative supply lines, second differential mode inductance It is serially connected on the positive supply lines, one end of second differential mode inductance connects the power input of the positive supply lines, described The other end of the second differential mode inductance connects the connecting node of second differential mode capacitor and the positive supply lines, second differential mode Inductance is used for increasing the earth impedance of the positive supply lines, makes the 4th common mode noise current not detected by current detection circuit Convergeed on the negative supply lines by second differential mode capacitor, and protecting field is transferred to by the negative supply lines；

When the earth impedance of the negative supply lines is higher than the earth impedance of the positive supply lines, second differential mode inductance It is serially connected on the negative supply lines, one end of second differential mode inductance connects the power input of the negative supply lines, described The other end of the second differential mode inductance connects the connecting node of second differential mode capacitor and the negative supply lines, second differential mode Inductance is used for increasing the earth impedance of the negative supply lines, makes the 4th common mode noise current not detected by current detection circuit Convergeed on the positive supply lines by second differential mode capacitor, and protecting field is transferred to by the positive supply lines.

In conjunction with second aspect, in the first possible embodiment, the induction reactance of second differential mode inductance is at least institute State the second differential mode capacitor 10 times of capacitive reactance.

The embodiment of the present invention third aspect provide a kind of electric power controller, the electric power controller by circuit with Load and external power source form loop, and the electric power controller includes slow to open module, direct current transformation module and as first party Active EMI filter described in the first to five kind of possible embodiment of face and first aspect, wherein described active EMI filter Ripple device be connected to described slow open between module and the direct current transformation module, when the direct current transformation module works, in the line Common mode noise current is produced on road, and the active EMI filter is used for filtering the common mode noise current on the circuit.

Embodiment of the present invention fourth aspect provide a kind of electric power controller, the electric power controller by circuit with Load and external power source form loop, and the electric power controller includes slow to open module, direct current transformation module and as second party Active EMI filter described in the possible embodiment of the first of face and second aspect, wherein described active EMI filter Be connected to described slow open between module and the direct current transformation module, when the direct current transformation module works, on the circuit Common mode noise current is produced, the active EMI filter is used for filtering the common mode noise current on the circuit.

In the embodiment of the present invention, the common mode noise current on supply lines for making earth impedance higher by differential mode capacitor is converged To the relatively low supply lines of earth impedance, auxiliary source circuit carries out voltage stabilizing process to the voltage obtained from external power source, is active EMI Wave filter provides stable voltage, while provide one for the common mode noise current on the relatively low supply lines of earth impedance being transferred to The low impedance path of see-saw circuit earth terminal.Common mode noise current without the low impedance path is by current detecting electricity Road is transformed into the input that voltage signal is transferred to see-saw circuit, and see-saw circuit is amplified same to the voltage signal When output common mode noise current, the common mode noise current through noise injection circuit inject protecting field, it is to avoid other equipment is caused Electromagnetic interference, so as to reach EMI filter effect.Differential mode inductance is concatenated on the higher supply lines of earth impedance, increase further The impedance of the supply lines, makes the common mode noise current of low frequency also can converge to the relatively low power supply of earth impedance by differential mode capacitor Line, so as to strengthen filter effect of the active EMI filter to low frequency common noise current.

Description of the drawings

The technical scheme being illustrated more clearly that in the embodiment of the present invention, below by accompanying drawing to be used needed for embodiment It is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, general for this area For logical technical staff, without having to pay creative labor, other accompanying drawings can also be obtained according to these accompanying drawings.

The structure composition schematic diagram of one embodiment of the active EMI filter that Fig. 1 is provided for the present invention；

The circuit diagram of one embodiment of the active EMI filter that Fig. 2 is provided for the present invention；

The circuit diagram of another embodiment of the active EMI filter that Fig. 3 is provided for the present invention；

The structure composition schematic diagram of another embodiment of the active EMI filter that Fig. 4 is provided for the present invention；

The circuit diagram of an embodiment of bandwidth-limited circuit in the active EMI filter that Fig. 5 is provided for the present invention；

Fig. 6 is the circuit diagram of another embodiment of bandwidth-limited circuit in active EMI filter shown in Fig. 5；

Fig. 7 is the circuit diagram of the another embodiment of bandwidth-limited circuit in active EMI filter shown in Fig. 5；

The structure composition schematic diagram for having an embodiment of the active EMI filter that Fig. 8 is provided for the present invention.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation is described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.It is based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not made Embodiment, belongs to the scope of protection of the invention.

Fig. 1 is referred to, is the structure composition schematic diagram of an embodiment of the active EMI filter that the present invention is provided.As Fig. 1 Shown, the active EMI filter includes auxiliary source circuit 11, current detection circuit 12, see-saw circuit 13, noise injection electricity Road 14, the first differential mode capacitor Cd1 and the first differential mode inductance Ld1, wherein：

The noise inputs end of positive supply lines, auxiliary source circuit 11 in the first input end connection power line of auxiliary source circuit 11 The second input connection power line in bear supply lines noise inputs end, auxiliary source circuit 11 the first output end connection anti-phase The power end of amplifying circuit 13, operating voltage Vcc of the first output end output see-saw circuit 13 of auxiliary source circuit 11, auxiliary The positive input terminal of the second output end connection see-saw circuit 13 of source circuit 11 is helped, the second output end of auxiliary source circuit 11 is defeated Go out the reference voltage Vref of see-saw circuit 13；

The first input end of current detection circuit 12 connects the power input of positive supply lines, and the of current detection circuit 12 The power input of supply lines, the first output end connection see-saw circuit 13 of current detection circuit 12 are born in the connection of two inputs Positive input terminal, current detection circuit 12 the second output end connection see-saw circuit 13 negative input end, current detecting electricity Road 12 be used for detect the first common mode noise current signal, and by the first common mode noise current signal be transformed into voltage signal export to See-saw circuit 13；

The input of the output end connection noise injection circuit 14 of see-saw circuit 13, it is right that see-saw circuit 13 is used for The voltage signal that current detection circuit 12 is exported is amplified processing, and the voltage signal through enhanced processing is exported to noise Injection circuit 14；

Noise injection circuit 14 at least includes a direct current signal intercepted between see-saw circuit and protecting field PGND Electric capacity, noise injection circuit 14 is serially connected between see-saw circuit 13 and protecting field PGND, for will be through enhanced processing Voltage signal noise inputs end is back to by protecting field PGND；

The positive noise inputs end of supply lines is connected by the first differential mode capacitor Cd1 with the noise inputs end of negative supply lines, the One end of one differential mode capacitor Cd1 connects positive supply lines, and supply lines is born in other end connection；

When the earth impedance of positive supply lines is higher than the earth impedance for bearing supply lines, the first differential mode inductance Ld1 is just serially connected in On supply lines, the first input end of one end connection auxiliary source circuit 11 of the first differential mode inductance Ld1, the first differential mode inductance Ld1's The other end connects the connecting node of the first differential mode capacitor Cd1 and positive supply lines；First differential mode inductance Ld1 is used for increasing positive supply lines Earth impedance so that the second common mode noise current signal is convergeed on negative supply lines by the first differential mode capacitor Cd1, and is passed through Negative supply lines is transferred to protecting field, to realize, by protecting field, the second common mode noise current signal is back to noise inputs end；

When the earth impedance of negative supply lines is higher than the earth impedance of positive supply lines, the first differential mode inductance Ld1 is serially connected in negative On supply lines, the second input of one end connection auxiliary source circuit of the first differential mode inductance Ld1, the first differential mode inductance Ld1's is another One end connects the connecting node of the first differential mode capacitor Cd1 and negative supply lines；First differential mode inductance Ld1 is used for increasing negative supply lines Earth impedance so that the second common mode noise current signal is convergeed on positive supply lines by the first differential mode capacitor Cd1, and by just Supply lines is transferred to protecting field, to realize, by protecting field PGND, the second common mode noise current signal is back to noise inputs End.

In implementing, power line includes that positive supply lines and negative supply lines, positive supply lines and negative supply lines each include to make an uproar Vocal input end and power input, the earth impedance of wherein positive supply lines and negative supply lines are inconsistent, in the present embodiment, are just supplying Concatenate the first differential mode capacitor Cd1 between the noise inputs end of electric wire and the noise inputs end of negative supply lines, and in earth impedance relatively Position on high supply lines between the first differential mode capacitor Cd1 and auxiliary source circuit concatenates the first differential mode inductance Ld1.First differential mode Inductance Ld1 can increase the impedance of the higher supply lines of earth impedance further, enable the common mode noise current of more low frequencies from right Impedance higher supply lines in ground converges to the relatively low supply lines of earth impedance through the first differential mode capacitor Cd1, then through auxiliary In source circuit 11, the connected low impedance path of the supply lines relatively low with earth impedance is transferred to the ground connection of see-saw circuit End, the common mode noise current for wherein convergeing to the relatively low supply lines of earth impedance through the first differential mode capacitor Cd1 are the second common mode Noise current, is the first common mode noise current without the common mode noise current of the low impedance path in auxiliary source circuit 11, In the present embodiment, the second common mode noise current accounts for the major part of the common mode noise current flowed into from the noise inputs end of power line. In the second common mode noise current while low impedance path in auxiliary source circuit 11, the first common mode noise current continues to exist Direction on supply lines toward power input is transmitted, and is detected by current detection circuit 12.Current detection circuit 12 will be detected The first common mode noise current be transformed into voltage signal, the voltage signal is exported to see-saw circuit 13.Anti-phase amplification electricity 13 pairs, the road voltage signal carries out anti-phase amplification, the voltage signal after being amplified, the output end voltage of see-saw circuit 13 For the voltage signal after the amplification, output end current is equal to the second common mode noise current for flowing into its earth terminal.Anti-phase amplification electricity The output end current on road 13 is injected into protecting field PGND through noise injection circuit 14, it is to avoid cause electromagnetic interference to other equipment, Complete the EMI filtering of the present embodiment.

Specifically, the induction reactance of the first differential mode inductance Ld1 should be bigger than the capacitive reactance of the first differential mode capacitor Cd1, and at least described the 10 times of the capacitive reactance of one differential mode capacitor.

Fig. 2 is referred to, is the circuit diagram of an embodiment of the active EMI filter that the present invention is provided.Wherein Fig. 2 with Illustrate as a example by the earth impedance of the higher than negative supply lines of the earth impedance of positive supply lines.As shown in Fig. 2 bearing supply lines to connect work Make ground GND, the active EMI filter may include auxiliary source circuit 11, current detection circuit 12, see-saw circuit 13, noise Injection circuit 14, the first differential mode capacitor Cd1 and the first differential mode inductance Ld1, may also include Transient Voltage Suppressor TVS, wherein：

First differential mode capacitor Cd1 is serially connected between the noise inputs end of positive supply lines and the noise inputs end of negative supply lines, First differential mode inductance Ld1 is serially connected on positive supply lines, and the first of one end connection auxiliary source circuit 11 of the first differential mode inductance Ld1 is defeated Enter end, the other end connects the connecting node of the first differential mode capacitor Cd1 and positive supply lines.First differential mode inductance Ld1 can increase further The impedance of big positive supply lines, enables the common mode noise current of more low frequencies to converge from positive supply lines through the first differential mode capacitor Cd1 To supply lines is born, then the electric wire 1 in the auxiliary source circuit 11 is transferred to the earth terminal of see-saw circuit 13.

Alternatively, auxiliary source circuit 11 may include triode Q1, resistance R10, resistance R11, resistance R12, resistance R13, electricity Hold C7, electric capacity C8, electric capacity C9, voltage-stabiliser tube ZD1 and diode D1, wherein：

The colelctor electrode of triode Q1 connects positive supply lines, and the base for meeting triode Q1 by resistance R11 by resistance R10 Pole, the base stage of triode Q1 connect GND by voltage-stabiliser tube ZD1, and the emitter stage of triode Q1 passes through the resistance being sequentially connected in series R12 and resistance R13 connect GND；The negative pole of voltage-stabiliser tube ZD1 connects the base stage of triode Q1, and positive pole connects GND and negative confession The power input 2 of electric wire；Electric capacity C7 is in parallel with voltage-stabiliser tube ZD1；The emitter stage of the termination triode Q1 of electric capacity C8, termination activities Ground GND；Electric capacity C9 is connected between the common node of resistance R12 and resistance R13 and GND；The positive pole of diode D1 connects The emitter stage of triode Q1, negative pole connect the base stage of triode Q1；The emitter stage of triode Q1 draws the first of auxiliary source circuit 12 Output end, is that see-saw circuit 13 provides operating voltage Vcc, and the common node of resistance R12 and resistance R13 draws auxiliary source electricity Second output end on road 14, is that see-saw circuit 13 provides reference voltage V_Ref.

In implementing, the electric wire 1 in auxiliary source circuit connects negative supply lines and GND, is to bear being total on supply lines Mode noise electric current provides a low impedance path so that bears most of common mode noise current on supply lines and arrives through 1 stream of electric wire The earth terminal of see-saw circuit 13.In the present embodiment, the common-mode noise of negative supply lines is convergeed to through the first differential mode capacitor Cd1 Electric current is the second common mode noise current, and the common mode noise current without the low impedance path in auxiliary source circuit 11 is common for first Mode noise electric current.Wherein the second common mode noise current accounts for the big portion of the common mode noise current flowed into from the noise inputs end of power line Point.In the second common mode noise current while electric wire 1 in auxiliary source circuit 11, the first common mode noise current continues supplying Direction on electric wire toward power input is transmitted, and is detected by current detection circuit 12.

Alternatively, current detection circuit 12 may include that the electric current with a two armature winding Np and secondary windings Ns is mutual Sensor CT1 and resistance R14, two of which armature winding Np are serially connected on the positive supply lines and negative supply lines of power line respectively, The two ends that two armature winding Np are connected with the power input of positive and negative supply lines and one end of secondary windings Ns of the same name each other End, the Same Name of Ends of secondary windings Ns connect the negative input end of see-saw circuit 13, and the other end of secondary windings Ns is reversed mutually to be amplified The positive input terminal of circuit 13, resistance R14 are in parallel with secondary windings Ns.

In being embodied as, extract in the signal that two armature winding Np of Current Transmit 1 are transmitted from power line First common mode noise current, and induced-current is formed on secondary windings Ns, the induced-current forms pressure at resistance R14 two ends Drop, so as to be converted to voltage signal by current signal.The two ends of secondary windings Ns are defeated with two of see-saw circuit 13 respectively Enter end to be connected, the voltage signal is input to see-saw circuit 13.

Alternatively, see-saw circuit 13 may include operational amplifier A 1 and electric capacity C10, and wherein operational amplifier A 1 is same The mutually non-same polarity of secondary windings Ns and the second output end of auxiliary source circuit 11, computing in input termination current detection circuit 12 The Same Name of Ends of secondary windings Ns in the anti-phase input termination current detection circuit 12 of amplifier A1；The output end of operational amplifier A 1 Noise injection circuit 14 is connect, and the inverting input of operational amplifier A 1 is connect by electric capacity C10；The power end of operational amplifier A 1 The first output end of auxiliary source circuit 11 is connect, the ground connection termination GND of operational amplifier A 1, due in auxiliary source circuit 11 Electric wire 1 also connect GND, the common mode noise current for therefore flowing into electric wire 1 can be transferred to the earth terminal of operational amplifier A 1.

Operational amplifier A 1 and the 8th electric capacity C8 constitute one and introduce degenerative inverting amplifier, to current detection circuit The voltage signal of 11 outputs carries out anti-phase amplification, and the output end voltage of operational amplifier A 1 is the voltage signal after amplifying, defeated Go out to hold electric current to be then equal to the electric current for flowing into 1 earth terminal of operational amplifier A.

Specifically, noise injection circuit 14 is capacitive circuit, it may include the electric capacity C11 and resistance R15 of series connection, wherein resistance R15 is connected with the output end of operational amplifier A 1, and electric capacity C11 meets protecting field PGND.Export from the output end of operational amplifier A 1 Common mode noise current be injected into protecting field through noise injection circuit 14, it is to avoid other equipment is interfered, so as to reach EMI filter effect.

Transient Voltage Suppressor TVS can be connected with the output end of operational amplifier A 1 and negative supply lines, wherein transient voltage The connecting node of suppressor TVS and negative supply lines is Wei Yu current detection circuit 12 and auxiliary source circuit 11 between.Transient voltage presses down Device TVS processed plays surge protective action, the voltage clamp of two interpolars can be made pre- in one when two interpolars are subject to instantaneous high pressure to impact Definite value, effectively protects operational amplifier A 1 from the damage of various surge pulse.

Alternatively, passive filter circuit (not shown) may also include in the active EMI filter, passive filter circuit can It is made up of passive devices such as RC circuit, common mode inductance or differential mode inductances, is mainly used in filtering the high frequency noise current on power line. The input of passive filter circuit can be connected between the noise inputs end of power line and auxiliary source circuit 11, or is connected to Between the power input of power line and current detection circuit 12；The output termination protecting field PGND of passive filter circuit, will be from The high-frequency noise circuit output that input is flowed into is to protecting field PGND.

Alternatively, the active EMI filter may also include and is connected with noise injection circuit 14 and see-saw circuit 13 Biasing circuit (not shown), biasing circuit can according to the output current of see-saw circuit 13 adjust see-saw circuit 13 Quiescent point, it is to avoid see-saw circuit 13 produce distortion.

In the embodiment of the present invention, the common mode noise current on positive supply lines is made to converge to negative supply lines by differential mode capacitor, Auxiliary source circuit carries out voltage stabilizing process to the voltage obtained from external power source, is that active EMI filter provides stable voltage, with When be bear supply lines on common mode noise current provide a low impedance path for being transferred to see-saw circuit earth terminal.Without The common mode noise current for crossing the low impedance path is transformed into voltage signal by current detection circuit and is transferred to see-saw circuit Input, the voltage signal is amplified see-saw circuit while output common mode noise current, the common mode noise current Protecting field is injected through noise injection circuit, it is to avoid electromagnetic interference is caused to other equipment, so as to reach EMI filter effect.Just Differential mode inductance is concatenated on supply lines, increase the impedance of positive supply lines further, the common mode noise current of more low frequencies is made by poor Mould electric capacity converges to negative supply lines, so as to strengthen filter effect of the active EMI filter to low frequency common noise current.

Fig. 3 is referred to, is the circuit diagram of another embodiment of the active EMI filter that the present invention is provided.Wherein Fig. 3 Illustrated as a example by bearing earth impedance of the earth impedance of supply lines higher than positive supply lines.As shown in figure 3, positive supply lines connects work Make ground GND, the active EMI filter may include auxiliary source circuit 11, current detection circuit 12, see-saw circuit 13, noise Injection circuit 14, the first differential mode capacitor Cd1 and the first differential mode inductance Ld1, may also include Transient Voltage Suppressor TVS, wherein：

First differential mode capacitor Cd1 is serially connected between the noise inputs end of positive supply lines and the noise inputs end of negative supply lines, First differential mode inductance Ld1 is serially connected on negative supply lines, and the second of one end connection auxiliary source circuit 11 of the first differential mode inductance Ld1 is defeated Enter end, the other end connects the connecting node of the first differential mode capacitor Cd1 and negative supply lines.First differential mode inductance Ld1 can increase further The big impedance for bearing supply lines, enables the common mode noise current of more low frequencies to converge from negative supply lines through the first differential mode capacitor Cd1 To positive supply lines, then the electric wire 2 in the auxiliary source circuit 11 is transferred to the earth terminal of see-saw circuit 13.

Auxiliary source circuit 11 may include triode Q2, resistance R16, resistance R17, resistance R18, resistance R19, electric capacity C11, electricity Hold C12, voltage-stabiliser tube ZD2 and diode D2, the emitter stage of triode Q2 passes sequentially through the resistance R16 and resistance R17 of series connection and just connects Supply lines, the base stage of triode Q2 connect positive supply lines by voltage-stabiliser tube ZD2, and pass sequentially through resistance R18 and resistance R19 connect negative Supply lines, the connecting node of the colelctor electrode connecting resistance R18 and resistance R19 of triode Q2；The positive pole of voltage-stabiliser tube ZD2 meets triode Q2 Base stage, negative pole connects positive supply lines；Electric capacity C11 is connected between the emitter stage of positive supply lines and triode Q2；Electric capacity C12 connects Between the common node and positive supply lines of resistance R16 and resistance R17；The positive pole of diode D2 connects the base stage of triode Q2, bears Pole connects the emitter stage of triode Q2；The emitter stage of triode Q2 draws the first output end of auxiliary source circuit 11, is anti-phase amplification Circuit 13 provides operating voltage Vcc, and the common node of resistance R16 and resistance R17 draws the second output end of auxiliary source circuit 11, Reference voltage V is provided for see-saw circuit 13_Ref.

In implementing, the electric wire 2 in auxiliary source circuit connects positive supply lines and GND, is being total on positive supply lines Mode noise electric current provides a low impedance path so that on positive supply lines, most of common mode noise current is arrived through 2 stream of electric wire The earth terminal of see-saw circuit.In the present embodiment, the common-mode noise electricity of positive supply lines is convergeed to through the first differential mode capacitor Cd1 Flow for the second common mode noise current, be the first common-mode noise without the common mode noise current of the electric wire 2 in auxiliary source circuit 11 Electric current.Wherein the second common mode noise current accounts for the major part of the common mode noise current flowed into from the noise inputs end of power line.? While electric wire 2 of second common mode noise current in auxiliary source circuit 11, the first common mode noise current continues in supply lines The upper direction toward power input is transmitted, and is detected by current detection circuit 12.

Specifically, current detection circuit 12, see-saw circuit 13, noise injection circuit 14 and Transient Voltage Suppressor The concrete structure of TVS can be identical with embodiment illustrated in fig. 2 with function, will not be described here.

In the embodiment of the present invention, converge to by differential mode capacitor the common mode noise current on negative supply lines and just power Line, auxiliary source circuit carry out voltage stabilizing process to the voltage obtained from external power source, are that active EMI filter provides stable electricity Pressure, while provide a Low ESR road for being transferred to see-saw circuit earth terminal for the common mode noise current on positive supply lines Footpath.Voltage signal is transformed into by current detection circuit without the common mode noise current of the low impedance path and is transferred to anti-phase putting The input of big circuit, the voltage signal is amplified see-saw circuit while output common mode noise current, and the common mode is made an uproar Acoustic-electric flows through noise injection circuit injection protecting field, it is to avoid cause electromagnetic interference to other equipment, so as to reach EMI filtering effect Really.Differential mode inductance is concatenated on negative supply lines, is increased the impedance for bearing supply lines further, is made the common mode noise current of more low frequencies Positive supply lines is convergeed to by differential mode capacitor, the filtering of low frequency common noise current is imitated so as to strengthen the active EMI filter Really.

Fig. 4 is referred to, is the structure composition schematic diagram of another embodiment of the active EMI filter that the present invention is provided.Such as Shown in Fig. 4, on the basis of Fig. 1, the active EMI filter may also include bandwidth-limited circuit 15, wherein：

First output end of the first input end connection current detection circuit of bandwidth-limited circuit 15, bandwidth-limited circuit 15 The second input connection current detection circuit 12 the second output end, bandwidth-limited circuit 15 the first output end connection anti-phase The positive input terminal of amplifying circuit 13, the negative input end of the second output end connection see-saw circuit 13 of bandwidth-limited circuit 15, Bandwidth-limited circuit 15 is used for carrying out bandpass filtering treatment to the voltage signal that current detection circuit 12 is exported, and makes frequency default In the range of voltage signal see-saw circuit 13 is input to by bandwidth-limited circuit so that after bandpass filtering treatment To voltage signal frequency so that the operational amplifier saturation in see-saw circuit 13 is failed, put up to computing yet Big device produces high frequency and agitates.

Alternatively, as shown in figure 5, bandwidth-limited circuit 15 may include the first electric capacity C1, the second electric capacity C2, first resistor R1, second resistance R2 and 3rd resistor R3, wherein：

First output end of current detection circuit 12 is connected with the positive input terminal of see-saw circuit 13, and passes sequentially through string First electric capacity C1 of connection and first resistor R1 connect the second output end of current detection circuit 12；The second of current detection circuit 12 Output end passes sequentially through the negative input end that the second electric capacity C2 of series connection and second resistance R2 connect see-saw circuit 13；3rd electricity Resistance R3 is connected between the second output end of current detection circuit 12 and the negative input end of see-saw circuit 13.

Alternatively, as shown in fig. 6, bandwidth-limited circuit 15 may include the 3rd electric capacity C3, the 4th electric capacity C4, the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6, wherein：

The 3rd electric capacity C3 and the 4th resistance R4 connection that second output end of current detection circuit 12 passes sequentially through series connection is anti- The negative input end of phase amplifying circuit 13；The connecting node of the 3rd electric capacity C3 and the 4th resistance R4 passes sequentially through the 5th resistance of series connection R5 and the 4th electric capacity C4 connection the first output end of current detection circuit 12 and the positive input terminal of see-saw circuit 13；6th electricity Resistance R6 is connected between the second output end of current detection circuit and the negative input end of see-saw circuit.

Alternatively, as shown in fig. 7, bandwidth-limited circuit 15 may include the 5th electric capacity C5, the 6th electric capacity C6, the 7th resistance R7, the 8th resistance R8 and the 9th resistance R9, wherein：

The positive input terminal of the first output end connection see-saw circuit 13 of current detection circuit 12, while pass sequentially through string 5th electric capacity C5 of connection and the 7th resistance R7 connects the negative input end of see-saw circuit 13；The second of current detection circuit 12 is defeated Go out the negative input end that end passes sequentially through the 6th electric capacity C6 and the 8th resistance R8 connection see-saw circuit 13 of series connection；9th resistance R9 is connected between the second output end of current detection circuit 12 and the negative input end of see-saw circuit 13.

In being embodied as, by changing the resistance of resistance and/or the capacitance of electric capacity in bandwidth-limited circuit 15, can obtain The frequency range of needs, such as 10kHz-10MHz.

It should be noted that bandwidth-limited circuit 15 can be any active circuit with band-pass filtering function or passive Three kinds of circuits in circuit, the including but not limited to embodiment of the present invention cited by Fig. 5-7.

It is capacitive load as noise injection circuit 14 is usually capacitive circuit, the i.e. load of see-saw circuit 13.And See-saw circuit 13 is usually negative-feedback circuit, and loop gain is very high, and now the noise signal of underfrequency may cause The output saturation of see-saw circuit 13, so that whole active EMI filter cannot work；And the too high noise signal of frequency Easily make see-saw circuit 13 that self-oscillation is produced, these noise signals can not be not only filtered, is produced new noise on the contrary, leads Cause the less stable of feedback-type active electromagnetic interface filter.Bandwidth-limited circuit 15 in the present embodiment can be by underfrequency or mistake High signal is filtered, and makes to be input to the voltage signal of see-saw circuit 13 in default frequency range, anti-phase so as to solve Amplifying circuit saturation distortion and the problem of vibration, improve the stability of the active EMI filter.

Alternatively, the active EMI filter may also include and is connected with noise injection circuit 44 and see-saw circuit 43 Biasing circuit (not shown), biasing circuit can according to the output current of see-saw circuit 43 adjust see-saw circuit 13 Quiescent point, it is to avoid see-saw circuit 43 produce distortion.

In the embodiment of the present invention, the common mode noise current on supply lines for making earth impedance higher by differential mode capacitor is converged To the relatively low supply lines of earth impedance, auxiliary source circuit carries out voltage stabilizing process to the voltage obtained from external power source, is active EMI Wave filter provides stable voltage, while provide one for the common mode noise current on the relatively low supply lines of earth impedance being transferred to The low impedance path of see-saw circuit earth terminal.Common mode noise current without the low impedance path is by current detecting electricity Road is transformed into the input that voltage signal is transferred to see-saw circuit, and see-saw circuit is amplified same to the voltage signal When output common mode noise current, the common mode noise current through noise injection circuit inject protecting field, it is to avoid other equipment is caused Electromagnetic interference, so as to reach EMI filter effect.Connection bandpass filtering electricity between current detection circuit and see-saw circuit Road, makes common mode noise current of the frequency not in the preset range reach see-saw circuit, so as to solve anti-phase to amplify electricity Road saturation distortion and the problem of vibration, improve the stability of the active EMI filter.

Fig. 8 is referred to, is the structure composition schematic diagram of the another embodiment of the active EMI filter that the present invention is provided.Such as Shown in Fig. 8, the active EMI filter may include auxiliary source circuit 81, current detection circuit 82, voltage-current converting circuit 83, Noise injection circuit 84, the second differential mode capacitor Cd2 and the second differential mode inductance Ld2, wherein：

The noise inputs end of positive supply lines, auxiliary source circuit 82 in the first input end connection power line of auxiliary source circuit 81 The second input connection power line in bear supply lines noise inputs end, auxiliary source circuit 82 the first output end connection electricity The power end of piezo-electric stream translation circuit 83, for providing operating voltage Vcc, auxiliary source circuit for voltage-current converting circuit 83 The negative input end of 81 the second output end connection voltage-current converting circuit 81, for providing for voltage-current converting circuit 83 Reference voltage Vref.

The first input end of current detection circuit 82 connects the noise inputs end of positive supply lines, and the of current detection circuit 82 The noise inputs end of supply lines, the first output end connection voltage-current transformation of current detection circuit 82 are born in the connection of two inputs The positive input terminal of circuit 83, the negative input end of the second output end connection voltage-current converting circuit 83 of current detection circuit 82, Current detection circuit 82 is used for detecting the 3rd common mode noise current on the positive supply lines and negative supply lines of power line, and will detect To common mode noise current be converted to voltage signal and export to voltage-current converting circuit 83；

The input of the output end connection noise injection circuit 84 of voltage-current converting circuit 83, voltage-current transformation electricity Road 83 is used for carrying out voltage-current transformation process to the voltage signal that current detection circuit 82 is exported, and obtains current signal, and will The current signal is exported to noise injection circuit 84；

Noise injection circuit 84 at least includes a direct current signal intercepted between voltage-current converting circuit and protecting field Electric capacity, noise injection circuit 84 is serially connected between the output end of voltage-current converting circuit 83 and protecting field PGND, for will The current signal injection protecting field PGND that voltage-current converting circuit 83 is exported；

The positive power input of supply lines is connected by the second differential mode capacitor Cd2 with the power input of negative supply lines, the One end of two differential mode capacitor Cd2 connects positive supply lines, and supply lines is born in other end connection；

When the earth impedance of positive supply lines is higher than the earth impedance for bearing supply lines, the second differential mode inductance Ld2 is just serially connected in On supply lines, one end of the second differential mode inductance Ld2 connects the power input of positive supply lines, and the second differential mode inductance Ld2's is another End connects the connecting node of the second differential mode capacitor Cd2 and positive supply lines, and the second differential mode inductance Ld2 is used for increasing the right of positive supply lines Ground impedance, makes the 4th common mode noise current not detected by current detection circuit 82 converge to by the second differential mode capacitor Cd2 On negative supply lines, and protecting field PGND is transferred to by bearing supply lines；

When the earth impedance of negative supply lines is higher than the earth impedance of positive supply lines, the second differential mode inductance Ld2 is serially connected in negative On supply lines, the power input of supply lines is born in one end connection of the second differential mode inductance Ld2, and the second differential mode inductance Ld2's is another End connects the connecting node of the second differential mode capacitor Cd2 and negative supply lines, and the second differential mode inductance Ld2 is used for increasing the right of negative supply lines Ground impedance, makes the 4th common mode noise current not detected by current detection circuit 82 converge to by the second differential mode capacitor Cd2 On positive supply lines, and protecting field PGND is transferred to by positive supply lines.

In implementing, common mode noise current is flowed into from the noise inputs end of power line, in positive supply lines and negative supply lines Upper co-propagate.The present embodiment adopts feed forward type structure, and current detection circuit 82 is connected to the noise inputs end of power line, common mode When noise current is transmitted on the power line, most of common mode noise current is detected and is converted into voltage by current detection circuit 82 Signal, other common mode noise current then continue to transmit toward power input direction on the power line.The power input of positive supply lines It is connected by differential mode capacitor Cd2 with the power input of negative supply lines, other common mode noise current can pass through differential mode capacitor Cd2 Converge on the relatively low supply lines of earth impedance, then a low impedance path in the auxiliary source circuit 81 be transferred to voltage- The earth terminal of current conversion circuit 83.In the present embodiment, the common mode noise current that current detection circuit 82 is detected is common for the 3rd Mode noise electric current, the low impedance path in the auxiliary source circuit 81 are transferred to the earth terminal of voltage-current translation circuit 83 Common mode noise current is the 4th common mode noise current, and wherein the 3rd common mode noise current is accounted for and flowed into from the noise inputs end of power line Common mode noise current major part.

As electric capacity has larger to low frequency signal capacitive reactance, it is poor by second that the common mode noise current of low frequency is difficult to Mould electric capacity Cd2 converges to the relatively low supply lines of earth impedance.It is higher that second mould inductance Ld2 can increase earth impedance further The impedance of supply lines, passes through more low frequency noise current in the common mode noise current not detected by current detection circuit 81 Second differential mode capacitor Cd2 is convergeed on the relatively low supply lines of earth impedance, and is transferred to by the relatively low supply lines of earth impedance Protecting field PGND.

The 3rd common mode noise current for wherein being detected by current detection circuit 82 is converted into after voltage signal and is input to Voltage-current converting circuit 83, then current signal is converted into by voltage-current converting circuit 83, the current signal is noted by noise Enter circuit 84 and be injected into protecting field, it is to avoid other equipment is interfered, so as to reach EMI filter effect.

In being embodied as, the induction reactance of the second differential mode inductance Ld2 should be greater than the capacitive reactance of the second differential mode capacitor Cd2, and at least 10 times of the capacitive reactance of two differential mode capacitor Cd2.

Specifically, the 26S Proteasome Structure and Function of auxiliary source circuit 81 refers to the specific descriptions of Fig. 2 or embodiment illustrated in fig. 3, This does not repeat；

Specifically, the concrete structure and function of current detection circuit 82 and noise injection circuit 84 can be implemented with shown in Fig. 2 Example is identical, will not be described here.

Specifically, voltage-current converting circuit 83 can be using Howland current source circuit or other double-ended current sources electricity Road.

Alternatively, passive filter circuit (not shown) may also include in the active EMI filter, passive filter circuit can It is made up of passive devices such as RC circuit, common mode inductance or differential mode inductances, is mainly used in filtering the high frequency noise current on power line. The input of passive filter circuit can be connected between the noise inputs end of power line and auxiliary source circuit 81, or is connected to Between the power input of power line and current detection circuit 82；The output termination protecting field PGND of passive filter circuit, will be from The high-frequency noise circuit output that input is flowed into is to protecting field PGND.

Alternatively, the active EMI filter may also include and noise injection circuit 84 and 83 phase of voltage-current converting circuit The biasing circuit (not shown) of connection, biasing circuit can according to the output current of voltage-current converting circuit 83 adjust voltage- The quiescent point of current conversion circuit 83, it is to avoid voltage-current converting circuit 83 produces distortion.

In the embodiment of the present invention, auxiliary source circuit carries out voltage stabilizing process to the voltage obtained from external power source, is active EMI Wave filter provides stable voltage；Most of common mode noise signal on power line is become by current detection circuit, voltage-to-current Change circuit and noise injection circuit is injected into protecting field, other common mode noise signals are then convergeing to the relatively low power supply of earth impedance Protecting field is injected by auxiliary source circuit, voltage-current converting circuit and noise injection circuit after line, it is to avoid other equipment is made Become electromagnetic interference, so as to reach EMI filter effect.On the higher supply lines of earth impedance concatenate differential mode inductance, further plus The impedance of the big supply lines, makes the common mode noise current of low frequency also can converge to the relatively low power supply of earth impedance by differential mode capacitor Line, so as to strengthen filter effect of the active EMI filter to low frequency common noise current.

The embodiment of the present invention further correspondingly provides two kinds of electric power controllers, includes the active EMI filter shown in Fig. 1-7 respectively Active EMI filter shown in ripple device and Fig. 8.Wherein electric power controller is formed back with load and external power source by circuit Road, electric power controller also include slow open module and direct current transformation module, wherein active EMI filter be connected to slow open module and Between direct current transformation module, when direct current transformation module works, common mode noise current is produced on the line, active EMI filter is used In filtering the common mode noise current on circuit.

Embodiments described above, does not constitute the restriction to the technical scheme protection domain.Any in above-mentioned enforcement Modification, equivalent and improvement that is made within the spirit and principle of mode etc., should be included in the protection model of the technical scheme Within enclosing.

Claims

1. a kind of active Electromagnetic disturbs electromagnetic interface filter, including auxiliary source circuit, current detection circuit, see-saw circuit and Noise injection circuit, it is characterised in that：The wave filter also includes the first differential mode inductance, wherein：

The noise inputs end of positive supply lines, the auxiliary source circuit in the first input end connection power line of the auxiliary source circuit The second input connection power line in bear supply lines noise inputs end, the auxiliary source circuit the first output end connection institute The power end of see-saw circuit is stated, the first output end of the auxiliary source circuit exports the work electricity of the see-saw circuit Pressure, the second output end of the auxiliary source circuit connect the positive input terminal of the see-saw circuit, the auxiliary source circuit Second output end exports the reference voltage of the see-saw circuit；

The first input end of the current detection circuit connects the power input of the positive supply lines, the current detection circuit The second input connect the power input of the negative supply lines, the first output end connection of the current detection circuit is described The positive input terminal of see-saw circuit, the second output end of the current detection circuit connect the negative defeated of the see-saw circuit Enter end, the current detection circuit is used for the first common mode noise current signal to be detected, and first common mode noise current is believed Number being transformed into voltage signal exports to the see-saw circuit；

The output end of the see-saw circuit connects the input of the noise injection circuit, and the see-saw circuit is used for The voltage signal to current detection circuit output is amplified processing, and the voltage through enhanced processing is believed Number export to the noise injection circuit；

The noise injection circuit at least includes that intercepts the direct current signal between the see-saw circuit and protecting field Electric capacity, the noise injection circuit are serially connected between the see-saw circuit and protecting field, for by the process amplification The voltage signal of reason is back to noise inputs end by protecting field；

The noise inputs end of the positive supply lines is connected by the first differential mode capacitor with the noise inputs end of the negative supply lines, institute The one end for stating the first differential mode capacitor connects the positive supply lines, and the other end connects the negative supply lines；

When the earth impedance of the positive supply lines is higher than the earth impedance of the negative supply lines, the first differential mode inductance concatenation On the positive supply lines, one end of first differential mode inductance connects the first input end of the auxiliary source circuit, and described the The other end of one differential mode inductance connects the connecting node of first differential mode capacitor and the positive supply lines；The first differential mode electricity Feel the earth impedance for increasing the positive supply lines so that the second common mode noise current signal passes through first differential mode capacitor Converge on the negative supply lines, and protecting field is transferred to by the negative supply lines, to realize described the by protecting field Two common mode noise current signals are back to noise inputs end；

When the earth impedance of the negative supply lines is higher than the earth impedance of the positive supply lines, the first differential mode inductance concatenation On the negative supply lines, one end of first differential mode inductance connects the second input of the auxiliary source circuit, and described the The other end of one differential mode inductance connects the connecting node of first differential mode capacitor and the negative supply lines；The first differential mode electricity Feel the earth impedance for increasing the negative supply lines so that the second common mode noise current signal passes through first differential mode capacitor Converge on the positive supply lines, and protecting field is transferred to by the positive supply lines, to realize described the by protecting field Two common mode noise current signals are back to noise inputs end.

2. active Electromagnetic according to claim 1 disturbs electromagnetic interface filter, it is characterised in that first differential mode inductance Impedance is at least 10 times of the capacitive reactance of first differential mode capacitor.

3. active Electromagnetic according to claim 1 and 2 disturbs electromagnetic interface filter, it is characterised in that：

The wave filter also includes bandwidth-limited circuit, and the first input end of the bandwidth-limited circuit connects the current detecting First output end of circuit, the second input of the bandwidth-limited circuit connect the second output of the current detection circuit End, the first output end of the bandwidth-limited circuit connect the positive input terminal of the see-saw circuit, the bandpass filtering electricity Second output end on road connects the negative input end of the see-saw circuit, and the bandwidth-limited circuit is used for examining the electric current The voltage signal of slowdown monitoring circuit output carries out bandpass filtering treatment, makes voltage signal of the frequency in preset range by the band logical Filter circuit is input to the see-saw circuit, so that the voltage signal frequency obtained after bandpass filtering treatment is not as little as So that the operational amplifier saturation in the see-saw circuit is failed, also up to do not make the operational amplifier produce high frequency and swash Swing.

4. active Electromagnetic according to claim 3 disturbs electromagnetic interface filter, it is characterised in that the bandwidth-limited circuit bag The first electric capacity, the second electric capacity, first resistor, second resistance and 3rd resistor is included, wherein：

First output end of the current detection circuit is connected with the positive input terminal of the see-saw circuit, and passes sequentially through string First electric capacity of connection and the first resistor connect the second output end of the current detection circuit；The current detecting electricity Second output end on road passes sequentially through second electric capacity of series connection and the second resistance connects the see-saw circuit Negative input end；The 3rd resistor is connected to the negative of the second output end of the current detection circuit and the see-saw circuit Between input.

5. active Electromagnetic according to claim 3 disturbs electromagnetic interface filter, it is characterised in that the bandwidth-limited circuit bag The 3rd electric capacity, the 4th electric capacity, the 4th resistance, the 5th resistance and the 6th resistance is included, wherein：

Second output end of the current detection circuit passes sequentially through the 3rd electric capacity of series connection and the 4th resistance connection The negative input end of the see-saw circuit；The connecting node of the 3rd electric capacity and the 4th resistance passes sequentially through series connection 5th resistance and the first output end of current detection circuit and the see-saw circuit described in the 4th capacitance connection are just Input；6th resistance is connected to the negative defeated of the second output end of the current detection circuit and the see-saw circuit Enter between end.

6. active Electromagnetic according to claim 3 disturbs electromagnetic interface filter, it is characterised in that the bandwidth-limited circuit bag The 5th electric capacity, the 6th electric capacity, the 7th resistance, the 8th resistance and the 9th resistance is included, wherein：

First output end of the current detection circuit connects the positive input terminal of the see-saw circuit, while passing sequentially through string 5th electric capacity of connection and the 7th resistance connect the negative input end of the see-saw circuit；The current detection circuit The second output end pass sequentially through the 6th electric capacity of series connection and the 8th resistance connects the negative of the see-saw circuit Input；9th resistance is connected to the negative defeated of the second output end of the current detection circuit and the see-saw circuit Enter between end.

7. a kind of active Electromagnetic disturbs electromagnetic interface filter, including auxiliary source circuit, current detection circuit, voltage-current converting circuit And noise injection circuit, it is characterised in that the wave filter also includes the second differential mode inductance, wherein：

The noise inputs end of positive supply lines, the auxiliary source circuit in the first input end connection power line of the auxiliary source circuit The second input connection power line in bear supply lines noise inputs end, the auxiliary source circuit the first output end connection institute The power end of voltage-current converting circuit is stated, for operating voltage, the auxiliary being provided for the voltage-current converting circuit Second output end of source circuit connects the negative input end of the voltage-current converting circuit, for for the voltage-current transformation Circuit provides reference voltage；

The first input end of the current detection circuit connects the noise inputs end of the positive supply lines, the current detection circuit The second input connect the noise inputs end of the negative supply lines, the first output end connection of the current detection circuit is described The positive input terminal of voltage-current converting circuit, the second output end of the current detection circuit connect the voltage-current transformation The negative input end of circuit, the current detection circuit are used for detecting the 3rd on the positive supply lines and negative supply lines of the power line Common mode noise current, and by the 3rd common mode noise current for detecting be converted to voltage signal export to the voltage-to-current become Change circuit；

The output end of the voltage-current converting circuit connects the input of the noise injection circuit, and the voltage-to-current becomes Circuit is changed for voltage-current transformation process being carried out to the voltage signal that the current detection circuit is exported, obtain current signal, And export the current signal to the noise injection circuit；

The noise injection circuit at least includes a direct current letter intercepted between the voltage-current converting circuit and protecting field Number electric capacity, the noise injection circuit is serially connected between output end and the protecting field of the voltage-current converting circuit, is used for The 3rd current signal that the voltage-current converting circuit is exported injects protecting field；

The power input of the positive supply lines is connected by the second differential mode capacitor with the power input of the negative supply lines, institute The one end for stating the second differential mode capacitor connects the positive supply lines, and the other end connects the negative supply lines；

When the earth impedance of the positive supply lines is higher than the earth impedance of the negative supply lines, the second differential mode inductance concatenation On the positive supply lines, one end of second differential mode inductance connects the power input of the positive supply lines, and described second The other end of differential mode inductance connects the connecting node of second differential mode capacitor and the positive supply lines, second differential mode inductance For increasing the earth impedance of the positive supply lines, pass through the 4th common mode noise current not detected by current detection circuit Second differential mode capacitor is convergeed on the negative supply lines, and is transferred to protecting field by the negative supply lines；

When the earth impedance of the negative supply lines is higher than the earth impedance of the positive supply lines, the second differential mode inductance concatenation On the negative supply lines, one end of second differential mode inductance connects the power input of the negative supply lines, and described second The other end of differential mode inductance connects the connecting node of second differential mode capacitor and the negative supply lines, second differential mode inductance For increasing the earth impedance of the negative supply lines, pass through the 4th common mode noise current not detected by current detection circuit Second differential mode capacitor is convergeed on the positive supply lines, and is transferred to protecting field by the positive supply lines.

8. active Electromagnetic according to claim 7 disturbs electromagnetic interface filter, it is characterised in that second differential mode inductance Induction reactance is at least 10 times of the capacitive reactance of second differential mode capacitor.

9. a kind of electric power controller, the electric power controller form loop by circuit with load and external power source, its spy Levy and be, the electric power controller includes slow to open module, direct current transformation module and as described in any one of claim 1 to 6 Active Electromagnetic interference electromagnetic interface filter, wherein active Electromagnetic interference electromagnetic interface filter is connected to the slow module and described of opening Between direct current transformation module, when the direct current transformation module works, common mode noise current is produced on the circuit, described active Electromagnetic interference electromagnetic interface filter is used for filtering the common mode noise current on the circuit.

10. a kind of electric power controller, the electric power controller form loop by circuit with load and external power source, its spy Levy and be, the electric power controller includes slow to open module, direct current transformation module and as described in any one of claim 7 to 8 Active Electromagnetic interference electromagnetic interface filter, wherein active Electromagnetic interference electromagnetic interface filter is connected to the slow module and described of opening Between direct current transformation module, when the direct current transformation module works, common mode noise current is produced on the circuit, described active Electromagnetic interference electromagnetic interface filter is used for filtering the common mode noise current on the circuit.