Abstract:
A wireless power supply system and a self adaptive regulation method thereof. The method includes the following steps: detecting an operating mode of an electric power sending unit ( 210 ); judging whether the electric power sending unit coincides with a normal operation condition of the wireless power supply system ( 200 ) according to the detected operating mode; determining according to a judging result whether to regulate a main oscillating frequency of an oscillating circuit ( 213 ) or not, so as to make the main oscillating frequency of the oscillating circuit be maintained between the resonant frequency of a sending coil ( 214 ) and the resonant frequency of a receiving coil ( 221 ). The main oscillating frequency of the oscillating circuit is regulated automatically, so as to make the main oscillating frequency be close to the resonant frequency of coils in the electric power sending unit and a receiving unit ( 220 ) all the time and make the system maintain a stable power output to ensure the normal operation of the wireless power supply system.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to wireless power supplying technologies, and in particular, to an adaptive adjustment method of a wireless power supplying system and the corresponding wireless power supplying system. 
       TECHNICAL BACKGROUND 
       [0002]    Wireless technologies have been used in the field of information application such as wireless transmission of signals for a long time, but the power transmission characteristic of such technologies has not been properly developed. An electronic device for daily use must be equipped with a dedicated power adapter to electrically connect to the Alternating Current (AC) utility power supply, or be equipped with a battery providing electrical energy to the electronic device. However, since the existing power adapter needs to use a power line to electrically connect to the electronic device, it is extremely inconvenient due to the limitation of the power line when the electronic device is moving. With the development of technology, the wireless power supplying technology has been developed to transmit electrical energy to the electronic device in a wireless manner. Reference is now made to  FIG. 1 , which depicts a schematic diagram of an existing wireless power supplying system. As shown in  FIG. 1 , the existing wireless power supplying system  100  includes an electric power transmitting unit  110  and an electric power receiving unit  120 . The electric power transmitting unit  110  generally includes a power supply  111 , a control circuit  112 , an oscillating circuit  113  and a transmitting coil  114 . The electric power receiving unit  120  generally includes a receiving coil  121  and a rectifying and filtering circuit  122 . The power supply  111  of the electric power transmitting unit  110  is used for converting the AC utility power supply voltage to a Direct Current (DC) voltage required for each of the circuits in the electric power transmitting unit  110  (e.g., the control circuit  112  and the oscillating circuit  113 ), the oscillating circuit  113  is used to generate a frequency signal, the control circuit  112  is electrically connected to the oscillating circuit  113  to control a master frequency f 0  of the frequency signal generated by the oscillating circuit  113 , and the transmitting coil  114  generates a resonance frequency f 1  based on the master frequency f 0  of the frequency signal so as to output the electric power. The receiving coil  121  of the electric power receiving unit  120  is electromagnetically coupled to the transmitting coil  114  to receive the electric power outputted by the electric power transmitting unit  110 , so as to generate an AC voltage having a certain resonance frequency f 2 , and the rectifying and filtering circuit  122  is used for converting that AC voltage to the DC voltage. 
         [0003]    However, in order to enable the wireless power supplying system  100  to be operated stably, the master frequency f 0  of the frequency signal generated by the control oscillating circuit  113 , the resonance frequency f 1  of the transmitting coil  114  and the resonance frequency f 2  of the receiving coil  121  should be ideally equal (i.e. f 0 =f 1 =f 2 ), so that the transmitting coil  114  and the receiving coil  121  can be electromagnetically coupled deeply, so as to generate the electrical energy at the electric power receiving unit  120  to implement wireless power supplying. However, in fact, due to the influences of physical characteristics, application environments and qualities of electrical elements and the like, there exists a shift between the resonance frequency f 1  of the transmitting coil  114  and the resonance frequency f 2  of the receiving coil  121 , which causes a big difference and mismatch between the resonance frequency f 1  of the transmitting coil  114  and the resonance frequency f 2  of the receiving coil  121 , and the deep electromagnetic coupling may not be enabled, and therefore the output power of the wireless power supplying system  100  is unstable, that is, the wireless power supplying system cannot operate normally. 
       SUMMARY OF THE INVENTION 
       [0004]    An object of the present invention is to provide an adaptive adjustment method of a wireless power supplying system, which is capable of automatically adjusting the master frequency, so that the master frequency is always close to the resonance frequency of the transmitting coil of the electric power transmitting unit and the resonance frequency of the receiving coil of the electric power receiving unit, which can stabilize the power output of the system so as to achieve a relatively stable system. 
         [0005]    The object of the present invention is also to provide a wireless power supplying system having an adaptive adjustment function, which is capable of automatically adjusting the master frequency, so that the master frequency is always close to the resonance frequency of the transmitting coil of the electric power transmitting unit and the resonance frequency of the receiving coil of the electric power receiving unit, which can stabilize the power output of the system so as to achieve a relatively stable system. 
         [0006]    To achieve above advantages, it is provided an adaptive adjustment method of a wireless power supplying system, the wireless power supplying system comprises an electric power transmitting unit, the electric power transmitting unit includes a power supply, an oscillating circuit, a control circuit and a transmitting coil, the oscillating circuit generates a frequency signal having a master frequency, an induction between the transmitting coil and a receiving coil of an electric power receiving unit generates an electrical energy, the adaptive adjustment method comprises: a step for detecting an operating status of the electric power transmitting unit and determining, based on the detected operating status, whether the electric power transmitting unit satisfies a condition of a normal operation of the wireless power supplying system; and a step for determining, based on the above determination result, whether to adjust the master frequency of the oscillating circuit so that the master frequency of the oscillating circuit is between a resonance frequency of the transmitting coil and a resonance frequency of the receiving coil. 
         [0007]    Preferably, the step for detecting an operating status of the electric power transmitting unit and determining, based on the detected operating status, whether the electric power transmitting unit satisfies a condition of the normal operation of the wireless power supplying system comprises: a step A for detecting an amplitude of present current in the transmitting coil; and a step B for determining whether the present current in the transmitting coil is within a normal operating current range of the transmitting coil in a normal operation of the wireless power supplying system. 
         [0008]    Preferably, the step for determining, based on the above determination result, whether to adjust the master frequency of the oscillating circuit so that the master frequency of the oscillating circuit is between a resonance frequency of the transmitting coil and a resonance frequency of the receiving coil comprises: a step C for determining, based on above determination result in the step B, whether to adjust the master frequency of the oscillating circuit so that the present current in the transmitting coil is within its normal operating current range. 
         [0009]    Preferably, the normal operating current range of the transmitting coil is between a permitted minimum current value and a permitted maximum current value. 
         [0010]    Preferably, the step B includes: a step B 1  for determining whether the present current in the transmitting coil is larger than the permitted minimum current value in its normal operating current range and is less than the permitted maximum current value in its normal operating current range; and a step B 2  for determining that the present current in the transmitting coil is within its normal operating current range when the above determination result in the step B 1  shows that the present current in the transmitting coil is larger than the permitted minimum current value in its normal operating current range and is less than the permitted maximum current value in its normal operating current range; otherwise, determining that the present current in the transmitting coil is not within its normal operating current range. 
         [0011]    Preferably, in the step C, if it is necessary to adjust the master frequency of the oscillating circuit so that the present current in the transmitting coil is within its normal operating current range, the step C further includes: a step C 1  for increasing the master frequency of the oscillating circuit by one fixed frequency offset; a step C 2  for detecting the current in the transmitting coil, and employing this current as a positively-adjusted current; a step C 3  for determining whether the positively-adjusted current is larger than the present current in the transmitting coil before the master frequency is adjusted, and a step C 4  for employing the positively-adjusted current as the present current in the transmitting coil when the above determination result in the step C 3  shows that the positively-adjusted current is larger than the present current in the transmitting coil and returning to the step B; otherwise, decreasing the master frequency of the oscillating circuit by two fixed frequency offsets, detecting the current in the transmitting coil, employing this current as a negatively-adjusted current, employing the negatively-adjusted current as the present current in the transmitting coil, and returning to the step B. 
         [0012]    Preferably, before the step B, the method further comprises: a step D 1  for determining whether the present current in the transmitting coil exceeds the permitted maximum current value in the normal operating current range of the transmitting coil; and a step D 2  for issuing an alarm or turning off the wireless power supplying system automatically when the above determination result in the step D 1  shows that the present current in the transmitting coil exceeds the permitted maximum current value; otherwise, performing the step B. 
         [0013]    The present invention also provides an adaptive adjustment method of a wireless power supplying system, the wireless power supplying system comprises an electric power transmitting unit and an electric power receiving unit, the electric power transmitting unit includes an oscillating circuit and a transmitting coil, the oscillating circuit generates a frequency signal having a master frequency, the electric power receiving unit comprises a receiving coil, an induction between the transmitting coil and the receiving coil generates an electrical energy, the adaptive adjustment method comprises: a step E for detecting a change of an operating status of the electric power transmitting unit; and a step F for controlling an adjustment of the master frequency according to the change of the operating status of the electric power transmitting unit, so that the master frequency is always close to the changed resonance frequency of the transmitting coil of the electric power transmitting unit and to the changed resonance frequency of the receiving coil of the electric power receiving unit, thereby stabilizing the power output of the system. The present invention further provides a wireless power supplying system having an adaptive adjustment function, comprises: an electric power transmitting unit and an electric power receiving unit. The electric power transmitting unit includes a power supply, an oscillating circuit, a control circuit and a transmitting coil, wherein the power supply is used for converting an AC utility power supply voltage into a DC voltage required for each of the circuits, the oscillating circuit is used for generating a frequency signal having a master frequency, the control circuit is electrically connected to the oscillating circuit to adjust the master frequency of the oscillating circuit, and the transmitting coil generates an oscillation frequency based on the master frequency of the oscillating circuit to transmit the electrical energy. The electric power receiving unit is used for receiving the electrical energy transmitted by the electric power transmitting unit. The control circuit includes a current detection circuit, a determination circuit and a processor. The current detection circuit is used for detecting the present current in the transmitting coil, the determination circuit is used for determining whether the present current in the transmitting coil is within a normal operating current range of the transmitting coil in a normal operation of the wireless power supplying system, and the processor is electrically connected to the determination circuit and the oscillating circuit, to determine, based on the above determination result, whether to adjust the master frequency of the oscillating circuit so that the present current in the transmitting coil is within its normal operating current range. 
         [0014]    The adaptive adjustment method of the wireless power supplying system and the wireless power supplying system with the adaptive adjustment function of the present invention can automatically adjust the master frequency so that the master frequency is always close to the resonance frequency of the transmitting coil and to the resonance frequency of the receiving coil, therefore the power output of system can be maintained stably, which ensures the wireless power supplying system to be operated stably. 
         [0015]    The above illustration is only an overview of the technical solution of the present invention, in order to be able to better understand the technical means of the present invention so as to be implemented in accordance with the contents of the specification, and in order to allow the above and other purposes, features, and advantages of the present invention to be more apparent, the following preferred embodiments will be discussed in conjunction with accompanying drawings as follows. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  is a schematic diagram of an existing wireless power supplying system. 
           [0017]      FIG. 2  is a schematic diagram of a wireless power supplying system having an adaptive adjustment function according to an embodiment of the present invention. 
           [0018]      FIG. 3  is a schematic diagram of an adaptive adjustment method of a wireless power supplying system according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    To further illustrate the technical means of the present invention taken to achieve a predetermined purpose of the invention and the effectiveness thereof, specific embodiments, structures, features and effectiveness of the wireless power supplying system having an adaptive adjustment function and its adaptive adjustment method according to the present invention will be described in detail as follows in conjunction with the accompanying drawings and preferred embodiments. 
         [0020]    Reference is now made to  FIG. 2 , which depicts a schematic diagram of a wireless power supplying system having an adaptive adjustment function according to an embodiment of the present invention. As shown in  FIG. 2 , a wireless power system  200  is similar to the wireless power supplying system  100  as shown in  FIG. 1 , and also includes an electric power transmitting unit  210  and an electric power receiving unit  220 . The electric power transmitting unit  210  includes a power supply  211 , a control circuit  212 , an oscillating circuit  213  and a transmitting coil  214 , and the electric power receiving unit  220  includes a receiving coil  221  and a rectifying and filtering circuit  222 . These electronic elements are similar to the electronic elements as shown in  FIG. 1 , and will not be discussed in detail here. 
         [0021]    Further, the control circuit  212  further includes a current detection circuit  2121 , a determination circuit  2122 , and a processor  2123 . The current detection circuit  2121  is electrically connected to the transmitting coil  214  to detect present current in the transmitting coil  214 , the determination circuit  2122  is electrically connected to the current detection circuit  2121  to determine whether the present current in the transmitting coil  214  is within a normal operating current range of the transmitting coil  214  in a normal operation of the wireless power supplying system  200 , and the processor  2123  is electrically connected to the determination circuit  2122  and the oscillating circuit  213  to determine, based on the above determination result, whether to adjust the master frequency f 0  of the oscillating circuit  213  so that the master frequency f 0  is between a resonance frequency f 1  of the transmitting coil  214  and a resonance frequency f 2  of the receiving coil  221 , to stabilize the output power of the system. 
         [0022]    The wireless power supplying system  100  having an adaptive adjustment function of the present invention determines whether its resonance frequency f 1  matches with the resonance frequency f 2  of the receiving coil  221  t the current flowed into the transmitting coil  214 . If the resonance frequency f 1  and the resonance frequency f 2  are not matched, then the master frequency f 0  of the oscillating circuit  213  is adjusted so that the master frequency f 0  is between the resonance frequency f 1  of the transmitting coil  214  and the resonance frequency f 2  of the receiving coil  221 , thereby adjusting the output power of the transmitting coil  214 , and at the same time making the master frequency f 0  be maintained close to the resonance frequency f 1  of the transmitting coil  214  and to the resonance frequency f 2  of the receiving coil  221 , thereby enabling the wireless power supplying system  100  to maintain the stable power output and operate stably and normally. 
         [0023]    Further, in order to enable the two coils to be electromagnetic coupled deeply, there is a requirement to define a permitted minimum current value Imin and a permitted maximum current value Imax. When the current I in the coil is greater than the permitted minimum current value Imin and less than the permitted maximum current value Imax, the resonance frequencies of both of the coils are close to each other, the wireless power system  200  can operate normally, and the electric power can be transmitted stably. In other words, the normal operating current range of the coil is between the permitted minimum current value Imin and the permitted maximum current value Imax, and the resonance frequency at which the electric power can be transmitted stably by the coil is between two critical resonance frequencies corresponding to the permitted minimum current value Imin. 
         [0024]    The present invention also provides an adaptive adjustment method of the wireless power system, and the method is to determine whether a frequency offset shall be compensated in the oscillating circuit  213  based on an amplitude of the current flowing in the transmitting coil. By adjusting the master frequency of the oscillating circuit  213 , the inflow current to the transmitting coil  214  is maintained within an appropriate range to meet the operational needs. That is, the adjustment of the master frequency is controlled by the detected and determined operation condition of the electric power transmitting unit  210  (current, electric power, etc.), so that the master frequency is always close to the changed resonance frequency of the coil of the electric power transmitting unit  210  and to the changed resonance frequency of the coil of the electric power receiving unit  220 , thereby stabilizing the power output of the system. 
         [0025]    In particular, reference is now made to  FIG. 3  which depicts a schematic diagram of the adaptive adjustment method of the wireless power supplying system according to an embodiment of the present invention. As shown in  FIG. 3 , the method includes detecting a present current I 1  in the transmitting coil  214  by the current detection circuit  2121 . Then, the determination circuit  2122  determines whether the present current I 1  in the transmitting coil  214  exceeds the permitted maximum current value Imax in the normal operating current range of the transmitting coil. Since the current of the coil is not allowed to exceed the permitted maximum current value during its electromagnetic coupling, it means that the wireless power supplying system  200  is in a dangerous state when the above determination result shows that the present current I 1  in the transmitting coil  214  exceeds the permitted maximum current value Imax, then an alarm should be issued or the wireless power supplying system  200  should be turned off automatically. Otherwise, the determination circuit  2122  continues to determine whether the present current I 1  in the transmitting coil  214  is within its normal operating current range. 
         [0026]    Specifically, the determination circuit  2122  determines whether the present current I 1  in the transmitting coil  214  is greater than the permitted minimum current value Imin of its normal operating current range. When the present current I 1  in the transmitting coil  214  is greater than the permitted minimum current value Imin, it means that the present current I 1  in the transmitting coil  214  is within its normal operating range, and then the wireless power system  200  can be operated stably. Otherwise, when the present current I 1  in the transmitting coil  214  is less than the permitted minimum current value Imin, it means that the present current I 1  is not within the normal operating current range, and then the processor  2123  outputs a control signal to adjust the master frequency f 0  of the oscillating circuit  213 , so that the present current I 1  in the transmitting coil  214  is adjusted to be within its normal operating current range. 
         [0027]    First, the master frequency f 0  of the oscillating circuit  213  is increased by one fixed frequency offset Δf. Then, the present current (namely positively-adjusted current)  12  in the transmitting coil  214  is detected by the current detection circuit  2121 . Next, it is determined whether this present positively-adjusted current I 2  is greater than the present current I 1  in the transmitting coil  214  by the determination circuit  2122 . When the positively-adjusted current I 2  is greater than the present current I 1 , it means that the above adjustment direction for the master frequency f 0  of the oscillating circuit  213  is correct. At this time, the positively-adjusted current I 2  can be used as the present current I 1  in the transmitting coil  214 , and it is continued to determine whether this present current I 1  (i.e. the positively-adjusted current I 2 ) is in the normal operating current range, and if not, the adjustment is conducted continuously. 
         [0028]    In contrast, when the positively-adjusted current I 2  is less than the present current I 1 , it means that the above adjustment direction for the master frequency f 0  of the oscillating circuit  213  is incorrect. Then, the present master frequency f 0  of the oscillating circuit  213  is decreased by two fixed frequency offsets Δf (i.e., reverse-direction adjustment by 2Δf), and the present current (namely negatively-adjusted current)  13  in the transmitting coil  214  is detected, and the negatively-adjusted current I 3  is used as the present current I 1  in the transmitting coil  214 , and then it is also continued to determine whether this present current I 1  (i.e. the negatively-adjusted current I 3 ) is in the normal operating current range, and if not, it continues to adjust again. By analogy, the present current I 1  in the transmitting coil  214  can be gradually adjusted to the normal current range according to present invention, that is, it allows the present current to be between the permitted maximum current value Imax and the permitted minimum current value Imin. 
         [0029]    In summary, the wireless power supplying system and its adaptive adjustment method of the present invention can automatically adjust the master frequency, so that the master frequency is always between the resonance frequency f 1  of the transmitting coil  214  and the resonance frequency f 2  of the receiving coil  222 , thereby allowing the power output of the system to be maintained stably, so as to ensure that the wireless power supplying system can always operate normally and stably. 
         [0030]    The above description is merely the preferred embodiments of the present invention, and it is not intended to act as any form of limitation for the present invention. Although the present invention has been disclosed with the above preferred embodiment, the embodiment is not intended to limit the present invention. Those skilled in the art can amend and modify the above disclosed technical content as equivalent embodiments with equivalent variation, without departing from the scope of the technical solution of the present invention. However, the contents without departing from the technical solution of the present invention, any of simple amendments, equivalent variations and modifications for the above embodiments based on the technical essence of the present invention, should fall into the scope of the technical solution of the present invention. 
       INDUSTRIAL APPLICABILITY OF INVENTION 
       [0031]    The adaptive adjustment method of the wireless power supplying system and the wireless power supplying system with the adaptive adjustment function of the present invention can automatically adjust the master frequency so that the master frequency is always close to the resonance frequency of the transmitting coil and to the resonance frequency of the receiving coil, therefore the power output of system can be maintained stably, which ensures the wireless power supplying system to be operated stably.