CN111146874A - Wireless charging foreign matter detection method - Google Patents
Wireless charging foreign matter detection method Download PDFInfo
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- CN111146874A CN111146874A CN202010152297.9A CN202010152297A CN111146874A CN 111146874 A CN111146874 A CN 111146874A CN 202010152297 A CN202010152297 A CN 202010152297A CN 111146874 A CN111146874 A CN 111146874A
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- 238000001514 detection method Methods 0.000 title abstract description 8
- 230000010355 oscillation Effects 0.000 claims abstract description 47
- 238000000034 method Methods 0.000 claims abstract description 18
- 239000000126 substance Substances 0.000 claims description 2
- 239000002184 metal Substances 0.000 description 3
- 230000008092 positive effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
- H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/60—Circuit arrangements or systems for wireless supply or distribution of electric power responsive to the presence of foreign objects, e.g. detection of living beings
Abstract
The invention relates to a wireless charging foreign matter type identification method, which comprises the steps of obtaining a current change value delta Q _ i of a resonance circuit and an oscillation frequency value Q _ f of the resonance circuit; and judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency value Q _ f. By adopting the technical scheme, on the premise that the wireless charging transmitter does not wake up the receiver while transmitting energy, the detection circuit detects the characteristic value parameters of voltage, current and frequency of the resonant circuit to judge the type of an object in a working area so as to determine whether to continue working.
Description
Technical Field
The invention relates to the field of wireless charging, in particular to a wireless charging foreign matter detection method.
Background
The wireless charging technology is widely applied at present and can be divided into two charging modes, namely high-power wireless charging and low-power wireless charging. The low-power wireless charging is usually in an electromagnetic induction type, and the high-power wireless charging is usually in a resonant type. Because the charging device and the electric device which are charged wirelessly transmit energy by adopting a magnetic field, the charging device and the electric device do not need to be connected by wires, and therefore, the charger and the electric device do not need to be exposed with conductive contacts.
Because there is the magnetic field of constantly changing on the charging device of wireless charging, when there is the metallic foreign object in its work area, can lead to the metallic object to produce the vortex phenomenon, lead to the metallic object temperature to increase, cause the danger of catching fire, increase energy loss.
Disclosure of Invention
The invention provides a method for identifying the type of a wireless charging foreign matter, which comprises the steps of obtaining a current change value delta Q _ i of a resonant circuit and an oscillation frequency Q _ f of the resonant circuit; and judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f.
Further, the current variation value Δ Q _ i is the difference value between two current values Δ Q _ i1 and Δ Q _ i2 in the interval time Δ t,
Δ Q _ i2- Δ Q _ i 1;
the difference between the two frequency values Δ Q _ f1 and Δ Q _ f2, which are the oscillation frequency of the resonant circuit during the interval Δ t, reflects the oscillation characteristics of the resonant circuit, which changes when a foreign object or receiver is present in the magnetically effective range of the resonant circuit.
Further, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency Q _ f includes:
and if the oscillation frequency Q _ f is greater than a first frequency preset value Q _ fth1 or the current change value delta Q _ i is greater than a first current preset value delta Q _ ith1, the wireless charging receiver is arranged in the working area.
Further, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency Q _ f includes:
if the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2 or the current change value delta Q _ i is smaller than a second preset current value delta Q _ ith2, foreign matters exist in the working area.
Further, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency Q _ f includes:
and if the oscillation frequency Q _ f is greater than or equal to a second frequency preset value Q _ fth2 and the current change value delta Q _ i is smaller than a second current preset value delta Q _ ith2, acquiring a voltage change value delta Q _ v.
Further, if the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2, or the voltage variation Δ Q _ v is larger than the second preset voltage value Δ Q _ vth2, or the current variation Δ Q _ i is larger than the second preset current value Δ Q _ ith 2; if any one of the three conditions is met, foreign matters exist in the working area.
Further, when the oscillation frequency Q _ f is less than the second frequency preset value Q _ fth2,
or the voltage change value deltaq _ v is greater than the second preset voltage value deltaq _ vth2,
or the current change value delta Q _ i is larger than the second current preset value delta Q _ ith 2;
and if the three conditions are not met, judging that the working area is in an idle state.
Further, when the working area is judged to be in an idle state, the algorithm is ended.
Further, the method is performed on the premise that the charging transmitter does not wake up the charging receiver.
The application also provides a wireless charging device which comprises a resonant circuit and the method for identifying the type of the wireless charging foreign matter by using any one of the technical schemes.
The invention has the advantages and positive effects that: by adopting the technical scheme, on the premise that the wireless charging transmitter does not wake up the receiver while transmitting energy, the detection circuit detects the characteristic value parameters of voltage, current and frequency of the resonant circuit to judge the type of an object in a working area so as to determine whether to continue working.
Drawings
FIG. 1 is a schematic flow diagram of the present invention.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
In one embodiment, the invention provides a method for identifying a type of a wireless charging foreign object, which includes the steps of obtaining a current change value delta Q _ i of a resonant circuit and an oscillation frequency Q _ f of the resonant circuit; and judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f.
According to this embodiment, since the wireless charging transmitter transmits energy to the outside in the form of electromagnetic waves through the coil of the resonant circuit, when the wireless charging receiver is located in the working area, the current variation value Δ Q _ i and the oscillation frequency Q _ f do not fluctuate greatly, but when a metal foreign object is placed in the working area, the current variation value Δ Q _ i and the oscillation frequency Q _ f fluctuate, and the state of the object in the charging area can be determined by detecting the changes of the two parameters, so as to provide a reference for the further operation of the wireless charging receiver.
As an explanation of the above embodiment, the current variation value Δ Q _ i is a difference between two current values Δ Q _ i1 and Δ Q _ i2 during the interval time Δ t,
Δ Q _ i2- Δ Q _ i 1;
the oscillation frequency Q _ f is an oscillation frequency of the resonance circuit, which reflects an oscillation characteristic of the resonance circuit, and is changed when a foreign substance or a receiver is present in a magnetically effective range of the resonance circuit.
The interval time can be adjusted for the detection accuracy, and the sampling value accuracy is improved through the control of the interval time.
Further, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency Q _ f includes:
and if the oscillation frequency Q _ f is greater than a first frequency preset value Q _ fth1 or the current change value delta Q _ i is greater than a first current preset value delta Q _ ith1, the wireless charging receiver is arranged in the working area.
According to the above judgment mode, the wireless charging receiver is judged to be in the working area, and the wireless charging receiver can start to work through detection.
In another case, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency variation Q _ f includes:
if the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2 or the current change value delta Q _ i is smaller than a second preset current value delta Q _ ith2, foreign matters exist in the working area.
When at least meeting one judgment condition in the technical scheme, the foreign matter in the working area is judged, and the work of the wireless charging emitter is stopped, so that the foreign matter is prevented from being heated to cause energy, and meanwhile, the potential safety hazard is reduced.
It is to be noted that, for different kinds of foreign matters, the influences on the oscillation frequency Q _ f and the voltage variation value Δ Q _ v are different, and when the foreign matter existing in the working area is a coil which is not matched with the wireless charging transmitter, the influence on the frequency variation value Q _ f is small, and the influence on the voltage variation value Δ Q _ v is large; when the foreign matter existing in the working area is a metal foreign matter, such as a coin, a metal button and the like which are common in life, the influence on the oscillation frequency Q _ f and the voltage change value Δ Q _ v is large, so that the specific foreign matter type can be judged by setting a judgment threshold value related to the foreign matter type, for example, setting the threshold value of the oscillation frequency Q _ f as Q _ fth3 and the threshold value of the voltage change value Δ Q _ v as Δ Q _ vth3, so that the specific type of the foreign matter can be judged according to the above rule, and different feedback can be given to a user, for example, when a wireless charging receiver of another brand is placed on a wireless charging transmitter of one brand, or a device with the wireless charging receiver is provided, the mismatching is prompted, and the energy loss is avoided. When the foreign matter is the coin of entity, can stop wireless charging emitter's work, avoid overheated danger that brings.
Further, the determining the type of the object in the working area according to the current variation value Δ Q _ i and the oscillation frequency Q _ f includes:
and if the oscillation frequency Q _ f is greater than or equal to a second frequency preset value Q _ fth2 and the current change value delta Q _ i is smaller than a second current preset value delta Q _ ith2, acquiring a voltage change value delta Q _ v.
In this case, by acquiring one more parameter, the actual working state can be obtained more accurately.
On the basis of the previous step, it is further determined that, if the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2, or the voltage variation Δ Q _ v is greater than the second preset voltage value Δ Q _ vth2, or the current variation Δ Q _ i is greater than the second preset current value Δ Q _ ith 2; if any one of the three conditions is met, foreign matters exist in the working area.
In order to determine the idle state, that is, no foreign object exists in the working area or the wireless charging receiver, if the oscillation frequency Q _ f is less than a second preset frequency value Q _ fth2, the voltage variation Δ Q _ v is greater than the second preset voltage value Δ Q _ vth2, and the current variation Δ Q _ i is greater than the second preset current value Δ Q _ ith 2; and if the three conditions are not met, judging that the working area is in an idle state.
In the present embodiment, the three parameters of the frequency variation Δ Q _ f, the voltage variation Δ Q _ v, and the current variation Δ Q _ i are simultaneously determined to identify whether the battery is in an idle state, thereby preventing a problem of determination error and a problem of incapability of charging due to fluctuation of individual parameters.
In the above embodiment, when it is determined that the working area is empty, the algorithm is terminated.
When the oscillation frequency Q _ f is less than the second preset frequency value Q _ fth2,
or the voltage change value deltaq _ v is greater than the second preset voltage value deltaq _ vth2,
or the current change value delta Q _ i is larger than the second current preset value delta Q _ ith 2;
and if the three conditions are not met, judging that the working area is in an idle state.
Further, when the working area is judged to be in an idle state, the algorithm is ended.
Further, the method is performed on the premise that the charging transmitter does not wake up the charging receiver.
The application also provides a wireless charging device which comprises a resonant circuit and the method for identifying the type of the wireless charging foreign matter by using any one of the technical schemes.
The invention has the advantages and positive effects that: by adopting the technical scheme, on the premise that the wireless charging transmitter does not wake up the receiver while transmitting energy, the detection circuit detects the characteristic value parameters of voltage, current and frequency of the resonant circuit to judge the type of an object in a working area so as to determine whether to continue working.
Fig. 1 shows an embodiment that can implement the above technical solution, first obtaining a current variation value Δ Q _ i and an oscillation frequency f of a resonant circuit;
and when the Q _ f is larger than the Q _ fth1 or the delta Q _ i is smaller than the delta Q _ ith1, the wireless charging receiver is judged to be in the working area.
If the above condition is not satisfied, it is determined whether Δ Q _ f < Δ Q _ fth1 or Δ Q _ i < Δ Q _ ith1 is satisfied, and if so, it is determined that the foreign object is present.
If the condition is not met, namely Q _ f is more than or equal to Q _ fth2 or delta Q _ i is less than delta Q _ ith2, acquiring a voltage change value delta Q _ v;
judging that Q _ f is less than Q _ fth2, or delta Q _ v is more than delta Q _ vth2, or delta Q _ i is more than delta Q _ ith 2;
if any condition is met, judging that the foreign matter is in the working area; if the condition does not satisfy any of the above conditions, the working area is determined to be empty.
And finishing the algorithm.
While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.
Claims (10)
1. A wireless charging foreign matter type identification method is characterized in that:
acquiring a current change value delta Q _ i of a resonant circuit and an oscillation frequency Q _ f of the resonant circuit;
and judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f.
2. The method of claim 1, wherein: the current variation value deltaq _ i is within the interval time deltat,two current values Δ Q _ i1And Δ Q _ i2The difference value of (a) to (b),
that is, Δ Q _ i ═ Δ Q _ i2-ΔQ_i1；
The oscillation frequency Q _ f is an oscillation frequency of the resonance circuit, which reflects an oscillation characteristic of the resonance circuit, and is changed when a foreign substance or a receiver is present in a magnetically effective range of the resonance circuit.
3. The method of claim 2, wherein: the judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f comprises:
if the oscillation frequency Q _ f is greater than a first preset frequency value Q _ fth1Or the current change value delta Q _ i is larger than a first current preset value delta Q _ ith1And if the wireless charging receiver is in the working area, the wireless charging receiver is in the working area.
4. The method of claim 2, wherein: the judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f comprises:
if the oscillation frequency Q _ f is less than a second preset frequency value Q _ fth2Or the current change value delta Q _ i is smaller than a second current preset value delta Q _ ith2If so, the foreign matter is in the working area.
5. The method of claim 2, wherein: the judging the type of the object in the working area according to the current change value delta Q _ i and the oscillation frequency Q _ f comprises:
if the oscillation frequency Q _ f is greater than or equal to a second preset frequency Q _ fth2And the current variation value delta Q _ i is smaller than a second current preset value delta Q _ ith2Then, the voltage variation value Δ Q _ v is acquired.
6. The method of claim 5, wherein: when the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2Or the voltage variation value delta Q _ v is larger than the second voltageSet value delta Q _ vth2Or the current variation value delta Q _ i is larger than the second current preset value delta Q _ ith2(ii) a If any one of the three conditions is met, foreign matters exist in the working area.
7. The method of claim 5, wherein: when the oscillation frequency Q _ f is smaller than a second preset frequency value Q _ fth2，
Or the voltage change value delta Q _ v is larger than the second preset voltage value delta Q _ vth2，
Or the current change value delta Q _ i is larger than the second current preset value delta Q _ ith2；
And if the three conditions are not met, judging that the working area is in an idle state.
8. The method of claim 6, wherein: and when the working area is in the idle state, ending the algorithm.
9. The method according to any of claims 1-7, wherein: the method is performed on the premise that the charging transmitter does not wake up the charging receiver.
10. A wireless charging apparatus comprising a resonance circuit, characterized in that the method for identifying a type of a foreign object by wireless charging according to any one of claims 1 to 8 is applied.
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| CN202010152297.9A CN111146874A (en) | 2020-03-06 | 2020-03-06 | Wireless charging foreign matter detection method |
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| CN202010152297.9A CN111146874A (en) | 2020-03-06 | 2020-03-06 | Wireless charging foreign matter detection method |
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