CN108375797A - A kind of system that foreign bodies detection is carried out by sample rate current phase difference - Google Patents
A kind of system that foreign bodies detection is carried out by sample rate current phase difference Download PDFInfo
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- CN108375797A CN108375797A CN201810159314.4A CN201810159314A CN108375797A CN 108375797 A CN108375797 A CN 108375797A CN 201810159314 A CN201810159314 A CN 201810159314A CN 108375797 A CN108375797 A CN 108375797A
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- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/02—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with propagation of electric current
- G01V3/06—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with propagation of electric current using ac
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Abstract
The invention discloses a kind of systems carrying out foreign bodies detection by sample rate current phase difference, including regulated power supply, inverter, sample circuit, detection coil, capacitance and controller；Sample circuit is used to sample the current zero crossing of the current signal of inverter output；Controller is more than the resonant frequency predeterminated frequency of detection coil and capacitance for controlling the output frequency of inverter in advance, determines the phase difference between the voltage signal and current signal of inverter output；It is additionally operable to obtain the current zero crossing of the voltage signal of inverter output, and is corresponded to according to the current zero crossing of sampling and calculate current phase difference, when current phase difference is less than phase difference and the phase difference being less than is more than preset value, determine that there are foreign matters in detected environment.As it can be seen that detecting system can be placed in wireless charging system by the application, the presence of foreign matter can be found in time, prevents the raising of temperature in wireless charging system, so as to avoid the generation of fire, improve the safety and reliability of wireless charging system.
Description
Technical field
The present invention relates to foreign bodies detection fields, and foreign bodies detection is carried out by sample rate current phase difference more particularly to a kind of
System.
Background technology
With the development of wireless charging technology, the application field of wireless charging system is more and more extensive.Currently, wireless charging
The basic principle of system is magnetic resonance or magnetic induction, so, in the prior art, wireless charging system transmits energy by magnetic field
Amount, to realize the charging of charging equipment.The charge power of general charging equipment is bigger, and the magnetic field for transmitting energy is stronger.But
During wireless charging, if there are the foreign matters such as metal to fall into high-intensity magnetic field, vortex can be generated in high-intensity magnetic field, so as to cause temperature
Degree increases, and even can cause fire when serious, reduce the safety and reliability of wireless charging system.
Therefore, how to provide it is a kind of solve above-mentioned technical problem scheme be that those skilled in the art needs to solve at present
The problem of.
Invention content
The object of the present invention is to provide a kind of systems carrying out foreign bodies detection by sample rate current phase difference, can send out in time
The presence of existing foreign matter, prevents the raising of temperature in wireless charging system, so as to avoid the generation of fire, improves wireless charging
The safety and reliability of system.
In order to solve the above technical problems, being by what sample rate current phase difference carried out foreign bodies detection the present invention provides a kind of
System, including regulated power supply, inverter, sample circuit, detection coil, capacitance and the reverse frequency for controlling the inverter
Controller, wherein：
The output plus terminal of the regulated power supply is connect with the input positive terminal of the inverter, and the output of the regulated power supply is negative
End is connect with the input negative terminal of the inverter, and the inverter is connect with the controller, the output plus terminal of the inverter
It is connect with the first sampling end of the sample circuit, the output end of the sample circuit is connect with the controller, the sampling
Second sampling end of circuit is connect with the first end of the detection coil, and the of the second end of the detection coil and the capacitance
One end connects, and the second end of the capacitance is connect with the output negative terminal of the inverter；
The sample circuit is used to sample the current zero crossing of the current signal of the inverter output；The controller is used
It is more than the resonant frequency predeterminated frequency of the detection coil and the capacitance in the output frequency for controlling the inverter in advance, really
Phase difference between the voltage signal and current signal of the fixed inverter output；It is additionally operable to obtain the electricity of the inverter output
The current zero crossing of signal is pressed, and is corresponded to according to the current zero crossing of sampling and calculates current phase difference, when the current phase difference
When being more than preset value less than the phase difference and the phase difference that is less than, determine that there are foreign matters in detected environment.
Preferably, which further includes choke induction, the output of the first end of the choke induction and the regulated power supply
Negative terminal connects, and the second end of the choke induction is connect with the input negative terminal of the inverter.
Preferably, which further includes alarm, and the control terminal of the alarm is connect with the controller, the control
Device is used for when there are when foreign matter, control the alarm to send out alarm in determining detected environment.
Preferably, the alarm is specially indicator light or buzzer.
Preferably, the sample circuit includes AC current transformer, resistance, comparator, pull-up resistor and DC power supply,
Wherein：
First sampling end of the first input end of the AC current transformer as the sample circuit, the alternating current
Second sampling end of second input terminal of current transformer as the sample circuit, the first output of the AC current transformer
End is connect with the input positive terminal of the first end of the resistance and the comparator respectively, and the second of the AC current transformer is defeated
Outlet is connect with the input negative terminal of the second end of the resistance and the comparator respectively, common end grounding, the comparator
Output end connect with the first end of the pull-up resistor, output end of the common end as the sample circuit, the pull-up
The second end of resistance is connect with the output end of the DC power supply.
Preferably, the controller is also particularly useful for where the rising edge for the voltage signal for obtaining the inverter output
Current time, and acquire the current time where the rising edge of the comparator output signal, calculate it is corresponding two it is current when
Between current time difference, when the current time difference be less than the phase difference corresponding time difference and time difference for being less than be more than it is pre-
If when the time, determining that there are foreign matters in detected environment.
Preferably, the controller is also particularly useful for where the failing edge for the voltage signal for obtaining the inverter output
Current time, and acquire the current time where the failing edge of the comparator output signal, calculate it is corresponding two it is current when
Between current time difference, when the current time difference be less than the phase difference corresponding time difference and time difference for being less than be more than it is pre-
If when the time, determining that there are foreign matters in detected environment.
Preferably, the sample circuit further includes limiting filter circuit, the first input end of the limiting filter circuit with
The first end of the resistance connects, and the second input terminal of the limiting filter circuit is connect with the second end of the resistance, public
End ground connection, the first output end of the limiting filter circuit are connect with the input positive terminal of the comparator altogether, the current limliting filtering
The second output terminal of circuit is connect with the input negative terminal of the comparator.
Preferably, the limiting filter circuit includes the first current-limiting resistance, the second current-limiting resistance, the first filter capacitor and the
Two filter capacitors, wherein：
The first end of first current-limiting resistance is connect with the first end of first filter capacitor, and common end is as institute
State the first input end of limiting filter circuit, the first end of the second end of first filter capacitor and second current-limiting resistance
Connection, second input terminal of the common end as the limiting filter circuit, the second end of first current-limiting resistance with it is described
The first end of second filter capacitor connects, first output end of the common end as the limiting filter circuit, second filter
The second end of wave capacitance is connect with the second end of second current-limiting resistance, common end as the limiting filter circuit
Two output ends.
Preferably, the detection coil includes N winding displacement circles, includes the even number coil of axial symmetry distribution per winding displacement circle,
And the inner ring outlet of opposite, the one of coil of area equation, direction of winding of two adjacent coils connects another coil
Outside outlet, wherein N is positive integer.
The present invention provides a kind of system carrying out foreign bodies detection by sample rate current phase difference, including it is regulated power supply, inverse
Become device, sample circuit, detection coil, capacitance and controller.The principle of system detectio foreign matter：Regulated power supply provides stable voltage
To inverter, and by the reverse frequency of controller control inverter, keep the load of inverter in running order, inversion here
The load of device is to form resonant ring by detection coil and capacitance.If there are the foreign matters such as metal to fall into detection coil, can detect
Vortex is generated in coil, the phase difference between voltage signal and current signal to influence inverter output.
The application first passes through resonant frequency certain frequency of the output frequency more than resonant ring of controller control inverter in advance,
Determine the phase difference between the voltage signal and current signal of inverter output.Then, the application is inverse by sampling circuit samples
Become the current zero crossing of the current signal of device output；And the current zero passage of the voltage signal of inverter output is obtained by controller
Point, to the corresponding current phase difference both calculated, when current phase difference is less than phase difference and the phase difference being less than is more than setting
When value, illustrate that there are foreign matters in detected environment.As it can be seen that detecting system can be placed in but be not limited only to high-intensity magnetic field ring by the application
In border, such as wireless charging system, the presence of foreign matter can be found in time, prevents the raising of temperature in wireless charging system, to
The generation for avoiding fire improves the safety and reliability of wireless charging system.
Description of the drawings
It to describe the technical solutions in the embodiments of the present invention more clearly, below will be to institute in the prior art and embodiment
Attached drawing to be used is needed to be briefly described, it should be apparent that, the accompanying drawings in the following description is only some implementations of the present invention
Example, for those of ordinary skill in the art, without creative efforts, can also obtain according to these attached drawings
Obtain other attached drawings.
Fig. 1 is a kind of structural representation of system carrying out foreign bodies detection by sample rate current phase difference provided by the invention
Figure；
Fig. 2 is a kind of output voltage current waveform figure applied to inverter in Fig. 1 provided by the invention；
Fig. 3 is a kind of structural schematic diagram applied to sample circuit in Fig. 1 provided by the invention；
Fig. 4 is a kind of output waveform figure applied to sample circuit in Fig. 3 provided by the invention；
Fig. 5 is a kind of structural schematic diagram applied to detection coil in Fig. 1 provided by the invention.
Specific implementation mode
Core of the invention is to provide a kind of system carrying out foreign bodies detection by sample rate current phase difference, can send out in time
The presence of existing foreign matter, prevents the raising of temperature in wireless charging system, so as to avoid the generation of fire, improves wireless charging
The safety and reliability of system.
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is
A part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art
The every other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.
Fig. 1 is please referred to, Fig. 1 is a kind of system carrying out foreign bodies detection by sample rate current phase difference provided by the invention
Structural schematic diagram.
The system includes regulated power supply 1, inverter 2, sample circuit 3, detection coil L, capacitance C and for controlling inverter
The controller 4 of 2 reverse frequency, wherein：
The output plus terminal of regulated power supply 1 is connect with the input positive terminal of inverter 2, the output negative terminal of regulated power supply 1 and inversion
The input negative terminal of device 2 connects, and inverter 2 is connect with controller 4, the output plus terminal of inverter 2 and the first sampling of sample circuit 3
End connection, the output end of sample circuit 3 are connect with controller 4, the second sampling end of sample circuit 3 and the first of detection coil L
End connection, the second end of detection coil L are connect with the first end of capacitance C, the second end of capacitance C and the output negative terminal of inverter 2
Connection；
Sample circuit 3 is used to sample the current zero crossing of the current signal of the output of inverter 2；Controller 4 for controlling in advance
The output frequency of inverter 2 processed is more than the resonant frequency predeterminated frequency of detection coil L and capacitance C, determines the electricity that inverter 2 exports
Press the phase difference between signal and current signal；It is additionally operable to obtain the current zero crossing for the voltage signal that inverter 2 exports, and root
It is corresponded to according to the current zero crossing of sampling and calculates current phase difference, when current phase difference is less than phase difference and the phase difference that is less than is more than
When preset value, determine that there are foreign matters in detected environment.
It should be noted that advance in the application and it is default set in advance, unless according to actual conditions need
It changes, otherwise need not reset.
Specifically, the system provided by the present application for carrying out foreign bodies detection by sample rate current phase difference can be applied to but not
It is only limitted in strong magnetic field circumstance, mainly wireless charging system.The system include regulated power supply 1, inverter 2, sample circuit 3,
Detection coil L, capacitance C and controller 4.Here regulated power supply 1 can be that inverter 2 provide stable DC, except this it
Outside, regulated power supply 1 can also have the function of overvoltage protection, under-voltage protection, open-phase protection, short-circuit overload protection etc..
Then, the direct current that regulated power supply 1 provides is transformed into alternating current by inverter 2, and output is to by detection coil L and electricity
Hold the resonant ring of C compositions.The application is controlled the output frequency of inverter 2 by controller 4, to make resonant ring work.Resonant ring
The size of resonant frequency determine that this resonant frequency is intrinsic frequency by the inductance value of detection coil L and the capacitance of capacitance C.
Fig. 2 is please referred to, Fig. 2 is a kind of output voltage current waveform figure applied to inverter in Fig. 1 provided by the invention.
In Fig. 2, it is the output voltage waveforms of inverter 2 to mark the waveform of blue, and it is the output current of inverter 2 to mark the waveform of green
Waveform.When resonant ring works, the output frequency of inverter 2 is more than the resonant frequency of resonant ring, at this point, resonant ring can be in integrally
Perception, the phase for the voltage signal that inverter 2 exports can be ahead of the phase of the current signal of its output.The application is by controller
4 output frequencies for controlling inverter 2 in advance are more than the resonant frequency certain frequency of resonant ring, so that it is determined that the voltage signal of output
Phase difference between current signal.Then the output power of inverter 2 is：POutput=VOutput*IOutput*cosφ；Wherein, VOutputIt is inverse
Become the voltage that device 2 exports, IOutputFor the electric current that inverter 2 exports, φ be inverter 2 voltage signal and the current signal that export it
Between phase difference.
When detection coil L works, magnetic field intensity is will produce, the magnetic field intensity generated can be according to detection coil L certainly
The structure of body and the electric current for flowing through detection coil L determine.When the application is fallen into view of foreign matters such as metals in detection coil L, meeting
Vortex is generated, the electric current for flowing through detection coil L is caused to increase, thus when detection coil L includes multiple coils, each coil
Magnetic field can become strong, and then convenient for sensing the foreign matters such as the metal fallen into detection coil L.
It, can be due to consuming energy from the vortex generated in detection coil L when the foreign matters such as metal fall into detection coil L
Amount, to increase the output power of inverter 2.Due to resonant ringInduction reactance=2* π * f*l, wherein f
For the resonant frequency of resonant ring, c is the capacitance of capacitance C, and l is the electrodynamic capacity of detection coil L, so the equivalent resistance of resonant ring
It is anti-only related with resonant frequency, in the case that the voltage signal that resonant frequency, inverter 2 export is constant,
POutput'=VOutput*IOutput* cos φ ' ＞ POutput=VOutput*IOutput* cos φ namely φ ' ＜ φ, wherein POutput' it is metal
The output power of inverter 2 when equal foreign matters fall into detection coil L, when φ ' is that the foreign matters such as metal fall into detection coil L, inverter 2
Phase difference between the voltage signal and current signal of output.
When the application falls into detection coil L using foreign matters such as metals, voltage signal and current signal that inverter 2 exports it
Between phase difference reduce principle, by sample circuit 3 sample inverter 2 export current signal current zero crossing, and will
The current zero crossing of sampling is sent to controller 4.Then, the current mistake for the voltage signal that inverter 2 exports is obtained by controller 4
Zero, according to the current zero crossing of voltage signal calculating current phase difference corresponding with the current zero crossing of current signal.
When the current phase difference between the voltage signal and current signal that inverter 2 exports is less than its phase determined in advance
Difference, and when the phase difference being less than is more than the value set, determine that there are foreign matters in detected environment.That is, it is contemplated that real
In the situation of border, voltage signal and current signal that inverter 2 exports can fluctuate in smaller range, so, the application is provided with
One error permissible value is determined and is deposited in detected environment when controller 4 detects that the phase difference being less than is more than error permissible value
The generation of fire is avoided, wireless charging is improved to improve the accuracy that foreign matter detection system detects foreign matter in foreign matter
The safety and reliability of system.
The present invention provides a kind of system carrying out foreign bodies detection by sample rate current phase difference, including it is regulated power supply, inverse
Become device, sample circuit, detection coil, capacitance and controller.The principle of system detectio foreign matter：Regulated power supply provides stable voltage
To inverter, and by the reverse frequency of controller control inverter, keep the load of inverter in running order, inversion here
The load of device is to form resonant ring by detection coil and capacitance.If there are the foreign matters such as metal to fall into detection coil, can detect
Vortex is generated in coil, the phase difference between voltage signal and current signal to influence inverter output.
The application first passes through resonant frequency certain frequency of the output frequency more than resonant ring of controller control inverter in advance,
Determine the phase difference between the voltage signal and current signal of inverter output.Then, the application is inverse by sampling circuit samples
Become the current zero crossing of the current signal of device output；And the current zero passage of the voltage signal of inverter output is obtained by controller
Point, to the corresponding current phase difference both calculated, when current phase difference is less than phase difference and the phase difference being less than is more than setting
When value, illustrate that there are foreign matters in detected environment.As it can be seen that foreign matter detection system can be placed in but be not limited only to strong magnetic by the application
In the environment of field, such as wireless charging system, the presence of foreign matter can be found in time, prevents the raising of temperature in wireless charging system,
So as to avoid the generation of fire, the safety and reliability of wireless charging system is improved.
On the basis of the above embodiments：
As a kind of preferred embodiment, which further includes choke induction, first end and the regulated power supply 1 of choke induction
The connection of output negative terminal, the second end of choke induction connect with the input negative terminal of inverter 2.
Further, it is contemplated that the reverse frequency that controller 4 controls inverter 2 is higher, and accuracy of detection is better, general control
The reverse frequency that device 4 controls inverter 2 is million grades, and still, higher reverse frequency can cause the output current of regulated power supply 1
Fluctuation reduces so the application connects choke induction between output negative terminal and the input negative terminal of inverter 2 of regulated power supply 1
Due to the fluctuation of the output current of regulated power supply 1 caused by high-frequency inversion, the sampling precision of sample circuit 3 is improved, to
Improve the accuracy of detection of detecting system.
As a kind of preferred embodiment, which further includes alarm, and the control terminal of alarm is connect with controller 4,
Controller 4 is used for when, there are when foreign matter, control alarm sends out alarm in determining detected environment.
Further, which further includes alarm, when controller 4 determines in detected environment there are when foreign matter, is controlled
Alarm sends out alarm, reminds the user that the presence of foreign matter, user is facilitated to clear up foreign matter.
As a kind of preferred embodiment, alarm is specially indicator light or buzzer.
Specifically, alarm can be indicator light, bright by controlling indicator light, play alarm function.When indicator light is sent out
When alarm, indicator light can become red light from green light, can also become flickering from not flickering, it is of course also possible to be other colors
Conversion or other flicker states conversion.Alarm may be buzzer, be sounded buzzer by controlling buzzer,
Play alarm function.
Certainly, the alarm in the application may be other devices with warning function, and the application is not spy herein
Other restriction.
Fig. 3 is please referred to, Fig. 3 is a kind of structural schematic diagram applied to sample circuit in Fig. 1 provided by the invention, sampling electricity
Road 3 is on the basis of the above embodiments：
As a kind of preferred embodiment, sample circuit 3 includes AC current transformer Lt, resistance R, comparator U, pull-up
Resistance Rs and DC power supply, wherein：
First sampling end of the first input end of AC current transformer Lt as sample circuit 3, AC current transformer
Second sampling end of the second input terminal of Lt as sample circuit 3, the first output end of AC current transformer Lt respectively with electricity
The first end of R and the input positive terminal connection of comparator U are hindered, the second output terminal of AC current transformer Lt is respectively with resistance R's
Second end and the connection of the input negative terminal of comparator U, common end grounding, the output end of comparator U and the first of pull-up resistor Rs
End connection, output end of the common end as sample circuit 3, the second end of pull-up resistor Rs and the output end of DC power supply connect
It connects.
Specifically, sample circuit 3 includes AC current transformer Lt, resistance R, comparator U, pull-up resistor Rs and direct current
Source.AC current transformer Lt can synchronize the sinusoidal current signal induced in detection coil L, and resistance R can be by alternating current
The synchronization sinusoidal current signal that current transformer Lt is induced is transformed into sine voltage signal.Then, by comparator U by transformation just
String voltage signal is made comparisons with 0, when sine voltage signal is more than 0, comparator U actions, output high level, when sinusoidal voltage is believed
When number being less than 0, comparator U exports low level.
Here comparator U output high level is to assist to complete by pull-up resistor Rs and DC power supply, i.e., ought compare
When device U actions, pull-up resistor Rs draws high the output voltage of comparator U to the output voltage of DC power supply, to make comparator U
Realize the output of high level.In addition, the selection of DC power supply is considered as the limitation of the highest pressure voltage of controller 4.
Fig. 4 is please referred to, Fig. 4 is a kind of output waveform figure applied to sample circuit in Fig. 3 provided by the invention.In Fig. 4,
The red signal of label is the sine voltage signal of resistance R transformations, marks the output signal that the signal of green is comparator U.Inspection
The zero crossing of sinusoidal current signal in test coil L is the zero crossing for the current signal that inverter 2 exports, therefore, inverter 2
The zero crossing of the current signal of output correspondingly corresponds to the rising edge and failing edge of comparator U, to by comparing the rising of device U
Edge and failing edge sample out the zero crossing of the current signal of the output of inverter 2.
As a kind of preferred embodiment, controller 4 is also particularly useful for the rising for obtaining the voltage signal that inverter 2 exports
Current time along place, and the current time where the rising edge of comparator U output signals is acquired, it calculates corresponding two and works as
The current time difference of preceding time, when current time difference is less than the phase difference corresponding time difference and the time difference being less than is more than default
Between when, determine that there are foreign matters in detected environment.
Further, it is known that φ=360 ° * (T2-T1)/T=360 ° of * (T2-T1) * f, wherein T2 exports for inverter 2
Voltage signal zero crossing where time (i.e. controller 4 controls the time that switching tube switchs in inverter 2), T1 is and T2
Time where the zero crossing for the current signal that corresponding inverter 2 exports, T are voltage, the current signal that inverter 2 exports
Period.
As it can be seen that f is fixed value, and when the foreign matters such as metal fall into detection coil L, voltage signal and electric current that inverter 2 exports
The difference that phase difference between signal reduces as T2-T1 reduces.When the difference of T2-T1 reduces, it can determine and be detected
There are foreign matters in environment.
Specifically, the application should be sought in advance really according to relational expression φ=360 ° * (T2-T1)/T=360 ° of * (T2-T1) * f
The corresponding time difference T2-T1 of fixed phase difference.In addition, the application obtains the voltage signal of the output of inverter 2 by controller 4
Current time where rising edge, is denoted as T2；Also, the current time where the rising edge of comparator U output signals is acquired, note
Make T1.Then, the current time difference between corresponding T2 and T1 is calculated, when the current time difference between T2 and T1 is less than in advance really
The fixed phase difference corresponding time difference, and when the time difference being less than is more than the time set, determines and exist in detected environment
Foreign matter.
As a kind of preferred embodiment, controller 4 is also particularly useful for the decline for obtaining the voltage signal that inverter 2 exports
Current time along place, and the current time where the failing edge of comparator U output signals is acquired, it calculates corresponding two and works as
The current time difference of preceding time, when current time difference is less than the phase difference corresponding time difference and the time difference being less than is more than default
Between when, determine that there are foreign matters in detected environment.
Specifically, where the failing edge for the voltage signal that the application can also obtain the output of inverter 2 by controller 4
Current time is denoted as T2；Also, the current time where the failing edge of comparator U output signals is acquired, T1 is denoted as.Then, it counts
The current time difference between corresponding T2 and T1 is calculated, when the current time difference between T2 and T1 is less than phase difference pair determining in advance
The time difference answered, and when the time difference being less than is more than the time set, determine that there are foreign matters in detected environment.
As a kind of preferred embodiment, sample circuit 3 further includes limiting filter circuit, and the first of limiting filter circuit is defeated
Enter end to connect with the first end of resistance R, the second input terminal of limiting filter circuit is connect with the second end of resistance R, common end
Ground connection, the first output end of limiting filter circuit are connect with the input positive terminal of comparator U, the second output terminal of limiting filter circuit
It is connect with the input negative terminal of comparator U.
Specifically, sample circuit 3 is also provided with limiting filter circuit between resistance R and comparator U, limits and is input to
The current value of comparator U, and the interference signal for including in transformed sine voltage signal has been filtered out, sample circuit 3 is protected,
Improve the sampling precision of sample circuit 3.
As a kind of preferred embodiment, limiting filter circuit includes the first current-limiting resistance, the second current-limiting resistance, the first filter
Wave capacitance and the second filter capacitor, wherein：
The first end of first current-limiting resistance is connect with the first end of the first filter capacitor, and common end is as current limliting filtered electrical
The first input end on road, the second end of the first filter capacitor are connect with the first end of the second current-limiting resistance, and common end is as limit
The second input terminal of filter circuit is flowed, the second end of the first current-limiting resistance is connect with the first end of the second filter capacitor, public
The first output end as limiting filter circuit, the second end of the second filter capacitor and the second end of the second current-limiting resistance is held to connect
It connects, second output terminal of the common end as limiting filter circuit.
Further, limiting filter circuit includes the first current-limiting resistance, the second current-limiting resistance, the first filter capacitor and second
Filter capacitor.First current-limiting resistance and the second current-limiting resistance limit the current value for being input to comparator U, the first filter capacitor and
Second filter capacitor has filtered out the interference signal for including in transformed sine voltage signal.Certainly, current limliting filters in the application
The structure of circuit may be other structures, and the application is not particularly limited herein.
Fig. 5 is please referred to, Fig. 5 is a kind of structural schematic diagram applied to detection coil in Fig. 1 provided by the invention.
As a kind of preferred embodiment, detection coil L includes N winding displacement circles, includes axial symmetry distribution per winding displacement circle
Even number coil, and the inner ring outlet of opposite, the one of coil of area equation, direction of winding of two adjacent coils connects separately
The outside outlet of one coil, wherein N is positive integer.
Specifically, wireless charging system includes wireless transmitter and wireless receiver, and wireless transmitter includes transmitting coil
And resonant capacitance.During wireless charging, transmitting coil will produce high-intensity magnetic field, and detection coil L can feel on transmitting coil
High voltage should be gone out, if be not pocessed, the high voltage induced can damage foreign matter detection system.Due to wireless charging system
Transmitting coil is typically all parallel, and magnetic field intensity is equal in two parallel points, and in identical magnetic field intensity
Two direction of windings opposite two it is coil-induced go out voltage be opposite, so induction whole after transmitting coil is connected
Voltage is 0V, to reduce influence of the high-intensity magnetic field to foreign matter detection system, improves the accuracy of detection of foreign matter detection system.
Similarly, detection coil L includes a winding displacement circle or multiple rows of coil, and the even number of parallelly distribute on is included per winding displacement circle
Coil, and the inner ring outlet of opposite, the one of coil of area equation, direction of winding of two adjacent coils connects another line
The outside outlet of circle ensure that every winding displacement circle in the direction of winding of two coils substantially symmetrical about its central axis on the contrary, also ensuring every row
The voltage that the current direction of two adjacent coils is opposite in coil, magnetic direction is opposite, induces is positive and negative opposite.As it can be seen that phase
Adjacent two coils, an one positive negative fluxfield is cancelled out each other, it is therefore prevented that influences of the detection coil L to the magnetic field of transmitting coil realizes two
Person does not interfere with each other；Two coils, an one positive negative voltage adjacent simultaneously is cancelled out each other, it is therefore prevented that the voltage that detection coil L is induced
It is excessive to burn out rear side circuit.
In addition, the application can configure more set foreign matter detection systems, it includes a winding displacement circle often to cover in foreign matter detection system
With the circuits such as the inversion sampling mating with a winding displacement circle, the foreign matter detection systems that cover work at the same time more, by the hair of wireless charging system
Ray collar region, so that it is determined that foreign matter falls the general location in transmitting coil.
It should also be noted that, in the present specification, relational terms such as first and second and the like be used merely to by
One entity or operation are distinguished with another entity or operation, without necessarily requiring or implying these entities or operation
Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant meaning
Covering non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only that
A little elements, but also include other elements that are not explicitly listed, or further include for this process, method, article or
The intrinsic element of equipment.In the absence of more restrictions, the element limited by sentence "including a ...", is not arranged
Except there is also other identical elements in the process, method, article or apparatus that includes the element.
The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention.
Various modifications to these embodiments will be apparent to those skilled in the art, as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, of the invention
It is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein phase one
The widest range caused.
Claims (10)
1. a kind of system carrying out foreign bodies detection by sample rate current phase difference, which is characterized in that including regulated power supply, inversion
The controller of device, sample circuit, detection coil, capacitance and the reverse frequency for controlling the inverter, wherein：
The output plus terminal of the regulated power supply is connect with the input positive terminal of the inverter, the output negative terminal of the regulated power supply with
The input negative terminal of the inverter connects, and the inverter is connect with the controller, the output plus terminal of the inverter and institute
The first sampling end connection of sample circuit is stated, the output end of the sample circuit is connect with the controller, the sample circuit
The second sampling end connect with the first end of the detection coil, the first end of the second end of the detection coil and the capacitance
Connection, the second end of the capacitance are connect with the output negative terminal of the inverter；
The sample circuit is used to sample the current zero crossing of the current signal of the inverter output；The controller is for pre-
The output frequency for first controlling the inverter is more than the resonant frequency predeterminated frequency of the detection coil and the capacitance, determines institute
State the phase difference between the voltage signal and current signal of inverter output；It is additionally operable to obtain the voltage letter of the inverter output
Number current zero crossing, and according to the current zero crossing of sampling correspond to calculate current phase difference, when the current phase difference is less than
The phase difference and when the phase difference that is less than is more than preset value, determines that there are foreign matters in detected environment.
2. the system for carrying out foreign bodies detection by sample rate current phase difference as described in claim 1, which is characterized in that the system
Further include choke induction, the first end of the choke induction is connect with the output negative terminal of the regulated power supply, the choke induction
Second end connect with the input negative terminal of the inverter.
3. the system for carrying out foreign bodies detection by sample rate current phase difference as described in claim 1, which is characterized in that the system
Further include alarm, the control terminal of the alarm is connect with the controller, and the controller is used for when determining detected ring
There are when foreign matter, control the alarm to send out alarm in border.
4. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 3, which is characterized in that the report
Alert implement body is indicator light or buzzer.
5. the system according to any one of claims 1-4 for carrying out foreign bodies detection by sample rate current phase difference, feature exist
In, the sample circuit include AC current transformer, resistance, comparator, pull-up resistor and DC power supply, wherein：
First sampling end of the first input end of the AC current transformer as the sample circuit, the alternating current are mutual
Second sampling end of second input terminal of sensor as the sample circuit, the first output end point of the AC current transformer
It is not connect with the input positive terminal of the first end of the resistance and the comparator, the second output terminal of the AC current transformer
Connect respectively with the input negative terminal of the second end of the resistance and the comparator, common end grounding, the comparator it is defeated
Outlet is connect with the first end of the pull-up resistor, output end of the common end as the sample circuit, the pull-up resistor
Second end connect with the output end of the DC power supply.
6. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 5, which is characterized in that the control
Device processed acquires the ratio also particularly useful for the current time where the rising edge for the voltage signal for obtaining the inverter output
Compared with the current time where the rising edge of device output signal, the current time difference of corresponding two current times is calculated, when described
Current time difference is less than the phase difference corresponding time difference and when time difference for being less than is more than preset time, determines detected ring
There are foreign matters in border.
7. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 5, which is characterized in that the control
Device processed acquires the ratio also particularly useful for the current time where the failing edge for the voltage signal for obtaining the inverter output
Compared with the current time where the failing edge of device output signal, the current time difference of corresponding two current times is calculated, when described
Current time difference is less than the phase difference corresponding time difference and when time difference for being less than is more than preset time, determines detected ring
There are foreign matters in border.
8. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 5, which is characterized in that described to adopt
Sample circuit further includes limiting filter circuit, and the first input end of the limiting filter circuit is connect with the first end of the resistance,
Second input terminal of the limiting filter circuit is connect with the second end of the resistance, common end grounding, the current limliting filtering
First output end of circuit is connect with the input positive terminal of the comparator, the second output terminal of the limiting filter circuit with it is described
The input negative terminal of comparator connects.
9. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 8, which is characterized in that the limit
It flows filter circuit and includes the first current-limiting resistance, the second current-limiting resistance, the first filter capacitor and the second filter capacitor, wherein：
The first end of first current-limiting resistance is connect with the first end of first filter capacitor, and common end is as the limit
The first input end of filter circuit is flowed, the second end of first filter capacitor and the first end of second current-limiting resistance connect
It connects, second input terminal of the common end as the limiting filter circuit, the second end of first current-limiting resistance and described the
The first end of two filter capacitors connects, first output end of the common end as the limiting filter circuit, second filtering
The second end of capacitance is connect with the second end of second current-limiting resistance, common end as the limiting filter circuit second
Output end.
10. the system for carrying out foreign bodies detection by sample rate current phase difference as claimed in claim 5, which is characterized in that described
Detection coil includes N winding displacement circles, and the even number coil of axial symmetry distribution, and the face of two adjacent coils are included per winding displacement circle
Product is equal, direction of winding is opposite, the inner ring outlet of one of coil connects the outside outlet of another coil, wherein N is just whole
Number.
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| CN201810159314.4A CN108375797B (en) | 2018-02-26 | 2018-02-26 | System for detecting foreign matters through sampling current phase difference |
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| CN108375797B CN108375797B (en) | 2019-12-27 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2022188170A1 (en) * | 2021-03-12 | 2022-09-15 | 华为技术有限公司 | Foreign object detection apparatus and method, and wireless charging transmitter device |
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| CN106371143A (en) * | 2016-11-07 | 2017-02-01 | 重庆大学 | Foreign body detection method and system based on impedance characteristic |
| CN107134858A (en) * | 2017-06-27 | 2017-09-05 | 青岛鲁渝能源科技有限公司 | Radio energy transmission system and its metal foreign matter detecting method |
| CN107248788A (en) * | 2017-06-15 | 2017-10-13 | 山东大学 | The wireless charging system for electric automobile and method of foreign bodies detection are carried out using phaselocked loop |
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| CN105790324A (en) * | 2014-12-16 | 2016-07-20 | 财团法人车辆研究测试中心 | Wireless charging system and metal foreign body detection method thereof |
| CN106371143A (en) * | 2016-11-07 | 2017-02-01 | 重庆大学 | Foreign body detection method and system based on impedance characteristic |
| CN107248788A (en) * | 2017-06-15 | 2017-10-13 | 山东大学 | The wireless charging system for electric automobile and method of foreign bodies detection are carried out using phaselocked loop |
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Effective date of registration: 20210317 Address after: 518000 room 133-134, No.1 International Students (Longgang) Pioneer Park, Longcheng street, Longgang District, Shenzhen City, Guangdong Province Patentee after: ZONECHARGE (SHENZHEN) WIRELESS POWER SUPPLY TECHNOLOGY Co.,Ltd. Address before: 264003 Mingda West Road, Laishan District, Yantai, Shandong Province, No. 11 Patentee before: ZHONG HUI POWERISE WIRELESS POWER TECHNOLOGY Ltd. |