Abstract:
An inductive charging system for vehicles includes a power receiving (PR) device disposed in a vehicle, and a power sourcing (PS) device disposed in a charging equipment separated from the vehicle.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 13/276,131, filed on Oct. 18, 2011, entitled “INDUCTIVE CHARGING METHOD FOR VEHICLES”, and claiming the priority benefit of Taiwan patent application number 100128812 filed on Aug. 12, 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an inductive charging method for vehicles, particularly to the method which utilizes a frequency converter power sourcing (PS) module in a PS device to connect with a signal control circuit and a power source and series connected power receiving (PR) modules in a PR device to connect with a bleeder circuit and a PR output terminal, allowing vehicles to be wirelessly charged and identified, make comparisons of voltages, adjust power and transmit data, thus achieving the effect of convenience in use and prevention of electricity leakage and theft. 
     2. Description of the Prior Art 
     Generally, most of electric vehicles are equipped with storage batteries inside. Such vehicles need to be charged when electricity in the storage batteries run out or is insufficient to use. Yet such charging method requires electric connections of vehicles with power lines and sockets. When charging stations are installed, it is very likely to cause leakages of electricity which may lead to electric shocks or problems of power consumption due to wet sockets with rainwater, in addition to possibilities that someone steals electricity from these sockets illegally. Therefore, as inductive charging technology has been developed and applied, and systems that transmit power inductively rely on DC power input to driving coils at the PS end to transmit electric energy to PR coils through AC electromagnetic waves, following procedures of rectification, filter and voltage stabilization, to provide DC power to electromechanical systems at the rear of the PR end, some firms try to apply the inductive charging technology in charging of electric vehicles. 
     However, electromechanical systems require high-voltage DC power to operate, and there is no way to raise the voltage at the PR output end with the inductive charging technology due to the following two reasons: 
     (1) the voltage outputted from the PR end originates from that of PR coils following procedures of rectification, filter and stabilization. As each of these procedures will result in voltage reduction following processing, if the output voltage is required to be raised at the PR end, the voltage of the PR coil at the initial end must be raised remarkably and rectifying components at the rear end are required to resist high voltage. Since high-voltage resistant components are very expensive and difficult to manufacture, this will cause much difficulty and too high costs in practice. 
     (2) if high voltage is needed on the PR coil, it indicates that it is necessary to provide high driving voltage on the PS coil to emit electric power. Under such circumstance, driving components at the PS end must be components capable of driving high voltage. Since the components of such kind are very expensive and difficult to manufacture, this will cause much difficulty and too high costs in practice. 
     Thus, how to overcome the problems and advantages of high cost and high difficulty in raising output voltage at the PR end with inductive charging technology of conventional use is what the firms engaged in this field need urgently to research and improve. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to enable the PS device to transmit electric power wirelessly through frequency converter PS modules and to enable series connected PR modules of the PR device to receive electric power, so as to increase the total voltage to charge vehicles. By using shunts and bleeder circuits, the PR microprocessor can receive the total output voltage that has been shunted for comparison without installing high-voltage resistant components. As it is unnecessary to make wired connections, there is no possibility for water to go into charging sockets. Besides, it can perform activities related to identification, stored value or deductions through data transmission, thus achieving the purposes of lower cost, convenience for use and preventability of electricity leakages and thefts. 
     A secondary purpose of the present invention is to enable PS microprocessors of first frequency converter PS sub-modules in the frequency converter PS module to perform power adjustment by frequency conversion via the coil voltage detection circuit, so as to ensure that the output power is the same as the preset power and to prevent situations of too low or high voltage from occurring. This can avoid the problems of causing the PR modules of the PR device unable to be charged or in danger following receipt of electric power, thus achieving the purposes of stable and safe charging. 
     Another object of the present invention is to enable PR microprocessors of the first PR sub-modules to make comparisons of voltages by using the bleeder circuit following receipt of electric power and series connection of the PR modules. If the shunted total voltage is not equal to the voltage of the preset multiples, the PR microprocessor of the first PR sub-module will transmit PS status error codes to the corresponding first frequency converter PS sub-module, which will further transmit these codes to a signal control circuit. The signal control circuit will send signals to other first frequency converter PS sub-module to suspend power supply and stop charging immediately at occurrence of unstable, too high or low voltage, thus achieving the purpose of protecting systems. 
     To achieve the purposes described above, an embodiment of the invention discloses an inductive charging system for vehicles, and includes a power receiving (PR) device disposed in a vehicle, and a power sourcing (PS) device disposed in a charging equipment separated from the vehicle. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of the circuit according to the present invention. 
         FIG. 2  is a block diagram of the circuit of the first frequency converter power sourcing module according to the present invention. 
         FIG. 3  is a block diagram of the circuit of the first and third power receiving modules according to the present invention. 
         FIG. 4  is a block diagram of the circuit of the second power receiving module according to the present invention. 
         FIG. 5  is a flow chart illustrating operation of the power sourcing device according to the present invention (I). 
         FIG. 6  is a flow chart illustrating operation of the power sourcing device according to the present invention (II). 
         FIG. 7  is a flow chart illustrating operation of the power sourcing device according to the present invention (III). 
         FIG. 8  is a flow chart illustrating operation of the power receiving device according to the present invention. 
         FIG. 9  is a three-dimensional appearance drawing according to one preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     To achieve the aforesaid objects and functions as well as the techniques adopted in the present invention and its fabrication, examples of the preferred embodiments of the present invention are given below to illustrate features and functions of the present invention in detail by referring to the accompanying drawings. 
     Refer to  FIGS. 1 ,  2 ,  3  and  4 , which are block diagrams of the circuits of the first frequency converter PS sub-module, of the first and third PR sub-modules and of the second PR sub-module according to the present invention. As shown clearly in these figures, the inductive charging method for vehicles comprises a PS device  1  and a PR device  2 , wherein: 
     The PS device  1  includes a frequency converter PS module  11 , in which two or more first frequency converter PS sub-modules  1101  are installed in parallel, and each of the first frequency converter PS sub-modules  1101  includes a PS microprocessor  111  in which the operating program, control program, data code analysis software and other related programs are installed. The PS microprocessors  111  are electrically connected with a PS driving unit  112 , a signal analysis circuit  113 , a coil voltage detection circuit  114  and a PS unit  115  respectively, wherein the PS driving unit  112  is equipped with a MOSFET driver  1121 , which is connected with the PS microprocessor  111 , a high-side MOSFET component  1122  and a low-side MOSFET component  1123  respectively, so as to further connect to a resonance circuit  116 , and the high-side MOSFET component  1122  is electrically linked the PS unit  115 ; the signal analysis circuit  113  and coil voltage detection circuit  114  is electrically connected to the resonance circuit  116 , which is connected with a PS coil  1161  that may transmit power energy and data signals. Each of the first frequency converter PS sub-module  1101  is connected in series with the a signal control circuit  12  and a power source  13 , while the signal control circuit  12  is electrically connected with the PS microprocessor  111  of the first frequency converter PS sub-module  1101 , and the PS unit  115  and PS driving unit  112  of the first frequency converter PS sub-module  1101  are connected in parallel with the power source  13 . 
     The PR device  2  contains a PR module  21  in which a first PR sub-module  2101  and a second PR sub-module  2102 , together with one or more third PR sub-modules  2103  placed in series between them, are installed in series to match the first frequency converter PS sub-module  1101 . The first PR sub-module  2101 , second PR sub-module  2102  and third PR sub-modules  2103  are equipped with a PR microprocessor  211  respectively to install the operating program, control programs and other necessary software programs. The PR microprocessor  211  is connected with a voltage detection circuit  212 , an AM carrier modulation circuit  214 , a breaker protection circuit  215 , a voltage-stabilizing circuit  216  and a DC step-down transformer  217  respectively, wherein the voltage detection circuit  212  and DC step-down transformer  217  is connected in parallel with a rectifying filter circuit  213 , which, together with the breaker protection circuit  215  and voltage-stabilizing circuit  216 , is connected in series with a resonance circuit  218  and a PR coil  2181 . The PR microprocessor  211  and AM carrier modulation circuit  214  are connected in series with the resonance circuit  218 , while the breaker protection circuit  215  is connected in series with a resistor, a P-type MOSFET component and an N-type MOSFET component, so as to electrically connect with the PR microprocessor  211  via the N-type MOSFET component and with the voltage stabilizing circuit  216  via the P-type MOSFET; the voltage detection circuit  212 , breaker protection circuit  215  and DC step-down transformer  217  connect to the rectifying filter circuit  213  respectively, and the rectifying filter circuit  213  and AM carrier modulation circuit  214  are electrically connected with the resonance circuit  218 . Thus, the resonance circuit  218  is electrically connected with the PR coil  2181 , while the first PR sub-module  2101 , second PR sub-module  2102  and third PR sub-modules  2103  are connected in series via the voltage stabilizing circuit  216 , and the second PR sub-module  2102  is electrically connected to a PR output terminal  23  via the voltage stabilizing circuit  216 . The voltage stabilizing circuit  216  is shunted by a bleeder circuit  22 , and then connected electrically to the PR microprocessor  211  of the first PR sub-module  2101 . 
     There may be a different number, such as two, three, four, seven or twenty, of the first frequency converter PS sub-modules  1101  installed in the frequency converter PS module  11  of the PS device  1 . If that number is two, the first PR sub-module  2101  and second PR sub-module  2102  are required to be installed in the PR module  21  of the PR device  2 ; if that number is three or more, the first PR sub-module  2101 , second PR sub-module  2102  and one or more third PR sub-modules  2103  will be installed in the PR module  21 , and the number of the third PR sub-modules  2103  to be installed decreases progressively with the number of the installed first frequency converter PS sub-modules  1101 . The following descriptions are given by taking installation of four first frequency converter PS sub-modules  1101  in the frequency converter PS module  11  as an example. They are only intended to illustrate correspondence of the frequency converter PS modules  11  to the PR module  21  for charging and data transmission, and shall not be construed as limiting the appended patent claims of the present invention. It is hereby stated that all modifications and equivalent structural changes made without departing from the spirit and art of the present invention shall be included in the patent claims of the present invention. 
     The PR microprocessor  211  of the PR module  21  is electrically connected with the AM carrier modulation circuit  214  and breaker protection circuit  215  to operate and control data signals, and is electrically linked with the voltage stabilizing circuit  216  to secure stable transmission of data signals through time sequence arrangements. Then, the data code analysis software installed in the PS microprocessor  111  of the frequency converter PS module  11  is used to ensure that data codes of data signals can also be transferred stably in the process of power transmission from an inductive type power source, so as to minimize power losses in that process and prevent quick changes in load currents of the PR module  21  from affecting data code analysis by the PS microprocessor  111 . In addition, the circuit used for power conversion is installed separately from that for data transmission in the PR module  21 , which helps increase the maximal transmission power from the power supply system. 
     Refer to  FIGS. 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  and  8 , which are the circuit block diagram of the present invention and circuit block diagrams of the first frequency converter PS sub-module as well as first, second and third PR sub-modules, and flow charts illustrating operation of the PS device (I), (H) and of the PR device according to the present invention. As shown clearly in these figures, operation of the PS device  1  includes the following steps:
         ( 100 ) PS device  1  standby, switch off power output from first frequency converter PS sub-modules  1101  and eliminate system status markings in the PS microprocessor  111 .   ( 101 ) PS device  1  detects if there is any PR device  2  in the induction range by using the first frequency converter PS sub-module  1101  that corresponds to the first PR sub-module  2101  of the PR device  2 . Proceed to step ( 102 ) if a startup code is received from the PR device  2 ; otherwise, proceed to step ( 100 ).   ( 102 ) PS microprocessor  111  of the first frequency converter PS sub-module  1101  corresponding to the first PR sub-module  2101  checks the ID code of the PR device  2  and decides if it is on the list of authorized power receivers. If yes, proceed to step ( 103 ); otherwise, proceed to step ( 107 ).   ( 103 ) PS microprocessor  111  of the first frequency converter PS sub-module  1101  corresponding to the first PR sub-module  2101  decides if the PR device  2  is in the state of normal power supply by checking its power receiving status data code. If yes, proceed to step ( 106 ); otherwise, proceed to step ( 104 ).   ( 104 ) Mark the system status of the PR device  2  as incorrect in the PS microprocessor  111  of the first frequency converter PS sub-module  1101  corresponding to the first PR sub-module  2101 .   ( 105 ) Deliver the incorrect system status in the PS microprocessor  111  of the first frequency converter PS sub-module  1101  via the signal control circuit  12  to the PS microprocessors  111  of other first frequency converter PS sub-modules  1101  for handling.   ( 106 ) Check other system status markings delivered by the signal control circuit  12  in the PS microprocessors  111  of other first frequency converter PS sub-modules  1101  and decide if other first frequency converter PS sub-modules  1101  supply power normally. If yes, proceed to step ( 108 ); otherwise, proceed to step ( 107 ).   ( 107 ) Cut off power output from the first frequency converter PS sub-modules  1101  and proceed to step ( 100 ).   ( 108 ) PS microprocessors  111  of the first frequency converter PS sub-modules  1101  check the power currently received by using power status data codes from the PR device  2  and compare it with the preset power; if the currently received power is larger than the preset power, proceed to step ( 109 ); if it is smaller than the preset power, proceed to step ( 110 ); if it equals the preset power, proceed step ( 111 ).   ( 109 ) Increase the working frequency of the output that should be adjusted from the corresponding PS microprocessor  111  to the PS driving unit  112  to reduce the output frequency through frequency conversion, and then proceed to step ( 111 ).   ( 110 ) Reduce the working frequency of the output that should be adjusted from the corresponding PS microprocessor  111  to the PS driving unit  112  to increase the output frequency through frequency conversion.   ( 111 ) PS microprocessors  111  check if output power of the corresponding first frequency converter PS sub-modules  1101  has reached the preset upper limit, if yes, proceed to step ( 112 ); otherwise, proceed to step ( 113 ).   ( 112 ) PS microprocessors  111  of other first frequency converter PS sub-modules  1101  mark the system status of the PS device  1  as incorrect if the output power has reached the preset upper limit, and then proceed to step ( 105 ).   ( 113 ) PS microprocessors  111  continue to supply electricity and proceed to step ( 102 ).       

     Additionally, operation of the PR device  2  comprises the following steps:
         ( 200 ) First PR sub-module  2101  of the PR device  2  receives a detection signal from the PS device  1  and feeds back a startup code to the corresponding first frequency converter PS sub-module  1101  in the PS device  1 .   ( 201 ) First PR sub-module  2101  of the PR device  2  transmits an identification code to the corresponding first frequency converter PS sub-module  1101  in the PS device  1 .   ( 202 ) First PR sub-module  2101  of the PR device  2  sends a power supply status data code to the corresponding first frequency converter PS sub-module  1101  in the PS device  1 .   ( 203 ) First PR sub-modules  2101 , second PR sub-modules  2102  and third PR sub-modules  2103  send data codes of the received power status to the corresponding first frequency converter PS sub-modules  1101  of the PS device  1 .   ( 204 ) First PR sub-module  2101  checks if the voltage of the PR output terminal  23  is equal to the preset voltage by using the bleeder circuit  22 . If yes, proceed to step ( 205 ); otherwise, mark the incorrect status and proceed to step ( 202 ).   ( 205 ) First PR sub-module  2101 , second PR sub-module  2102  and third PR sub-modules  2103  of the PR device  2  continue to receive electric power and proceed to step ( 201 ).       

     When the PR device  2  enters into the inductive range of the PS device  1 , the first PR sub-module  2101  of the PR device  2  is only required to align with any of the nearby first frequency converter PS sub-modules  1101  for subsequent processing, as the PR device  2  can rotate its direction. The first PR sub-module  2101  of the PR device  2  receives a detection signal and feeds back a startup code, and then delivers an identification code. Since the identification code contains information on users and stored value, etc, the corresponding first frequency converter PS sub-module  1101  in the PS device  1  will compare and decide if the PR device  2  is on the list of authorized power receivers following receipt of the identification code. It will start the power supply after having identified the paid users, thus preventing electricity from being stolen by illegal persons. 
     As slight error of inductance occurs indifferent PS coils  1161  in the process of manufacturing, this may lead to different power output from the frequency converter PS modules  11  of the PS device  1  in standby mode. However, the output power can be adjusted to be equal to the preset value through the aforesaid method to avoid too low or high power output that may cause the PR device  2  unable to be charged or in danger. 
     The first frequency converter PS sub-modules  1101  of the PS device  1  are equipped with the PS coils  1161  respectively to produce preset energy output of the same power following adjustment of power output by the first frequency converter PS sub-modules  1101 . When facing the PS coils  1161  properly, the PR coils  2181  of the PR device  2  can receive preset energy output of the same power, making the total voltage produced by series connection equal to the voltage of the preset multiples; if deflecting from the PS coils  1161 , the PR coils  2181  in the second PR sub-modules  2102  and third PR sub-modules  2103  will receive energy output of the power that is lower than scheduled, making the total voltage produced by series connection lower than the voltage of preset multiples; under such circumstance, the voltage output from the stabilizing circuit  216  of the second PR sub-module  2102  to the PR output terminal  23  will be shunted and transferred to the bleeder circuit  22  for shunt handling. Then, the shunted total voltage will be outputted to the PR microprocessor  211  of the first PR sub-module  2101 , which will compare the shunted total voltage with that of the preset multiples. If the voltages are the same, there will be no action; otherwise the PR microprocessor  211  will emit a PR status error code through the AM carrier modulation circuit  214  and PR coil  2181  to the corresponding first frequency converter PS sub-module  1101  in the PS device  1 . 
     Following receipt of the error code by the PS coil  1161 , the corresponding first frequency converter PS sub-module  1101  corresponding to the first PR sub-module  2101  of the PS device  1  analyzes the error code using the signal analysis circuit  113  and processes it in the PS microprocessor  111 , and then transmits the error code to the signal control circuit  12 , which will send a system status signal to other first PR sub-modules  2101  to mark the system status of the PR device  2  as incorrect and make the frequency converter PS modules  111  terminate power supply. In this way, charging will be suspended promptly under the conditions of unstable, higher or lower voltages, thus achieving the purpose of protecting the system. 
     Besides, after the first PR sub-modules  2101 , second PR sub-modules  2102  and third PR sub-modules  2103  transmit status data codes of received electric power to the corresponding first frequency converter PS sub-modules  1101  in the PS module  1 , the PS microprocessors  111  of the first frequency converter PS sub-modules  1101  will check the power currently received by the PR terminal respectively and compare it with the preset power. If the currently received power is higher than the preset power, the PS microprocessor  111  will increase the working frequency of the corresponding PS driving unit  112  that needs to be adjusted to lower the output power through frequency conversion; if the currently received power is lower than the preset power, the PS microprocessor  111  will reduce the working frequency of the corresponding PS driving unit  112  that needs to be adjusted to increase the output power through frequency conversion; if the currently received power equals the preset power, no adjustment is made to ensure that the power received by the PR device  2  is equal to the preset power; furthermore, it can check if output power has reached or exceeded the preset upper limit for the PS device  1 ; it will continue to supply electric power if the preset upper limit is not reached; if the preset upper limit is reached for the PS device  1 , the first frequency converter PS sub-modules  1101  whose output power has reached the preset upper limit will mark the system status of the PS device  1  as incorrect and transfer the status through the signal control circuit  12  to the microprocessors  111  of other first frequency converter PS sub-modules  1101  for processing to make the PS device  1  stop power supply. 
     The PS coils  1161  of the PS device  1  and PR coils  2181  of the PR device  2  as described above may be arranged like a rectangle, triangle, straight line or cross or any other shape, as long as these coils of two kinds can face each other properly to carry out mutual induction and transmission between them, and shall not be construed as limiting the appended patent claims of the present invention. It is hereby stated that all modifications and equivalent structural changes made without departing from the spirit and art of the present invention shall be included in the patent claims of the present invention. 
     Refer to  FIG. 9 , which is a three-dimensional appearance drawing in accordance with one preferred embodiment of the present invention. As shown clearly in this figure, the PR device  2  can be installed on a steering handgrip of a motorcycle, so that the steering handgrip is close to the cylindrical object when the motorcycle stops, allowing the PS device  1  to charge the PR device  2 . 
     The inductive charging method for vehicles as disclosed in the present invention has the advantages as follows when applied practically:
         (1) the PS device  1  relies on the frequency converter PS modules  11  to transfer electric power wirelessly, received by the PR module  21  of the PR device  2 , and the first and second PR sub-modules  2101  and  2102 , or the first and second PR sub-modules  2101  and  2102  as well as one or more third PR sub-modules  2103  are connected in series to increase the total voltage for charging vehicles. Since it is not necessary to install charging sockets, it is impossible for water to enter into the sockets and cause leakage of electricity. Besides, it is not necessary to make wired connections for this method and identification can be conducted through data transmission before charging is started. In addition, this method helps implement operations concerning stored value and deductions.   (2) the PS microprocessors  111  of the first frequency converter PS sub-modules  1101  in the frequency converter PS modules  11  can make frequency converter power adjustments based on power status data codes from the PR device  2  to ensure that the power output is adjusted to be equal to the preset power value, thus avoiding situations of too low or high voltages and preventing charging problems or dangers.   (3) after receipt of electric power and series connection with other components, the PR module  21  of the PR device  2  depends on the PR microprocessor  211  of the first PR sub-module  2101  to make comparisons by using the bleeder circuit  22 . If the shunted total voltage is not equal to the voltage of preset multiples, the first PR sub-module  2101  will send a PR status error data code via the corresponding first frequency converter PS sub-module  1101  to the signal control circuit  12 , which sends a signal to other first frequency converter PS sub-modules  1101  to request suspension of power supply, thus interrupting charging immediately in occurrence of unstable, too high or low voltage.   ( 4 ) it utilizes series connection with the PR module  21  to increase the total voltage for charging vehicles and adopts shunting and the bleeder circuit  22 , allowing the PR microprocessor  211  of the first PR sub-module  2101  to receive the shunted total output voltage and make comparisons without the need to use components of high-voltage specifications.       

     Therefore, the present invention chiefly involves the inductive charging method for vehicles, in which the first frequency converter PS sub-modules  1101  in the frequency converter PS module  11  of the PS device  1  are connected in parallel with the signal control circuit  12  and power source  13 , while the first and second PR sub-modules  2101  and  2102 , or the first PR sub-module  2101 , second PR sub-module  2102  and one or more third PR sub-modules  2103  are connected in series inside the PR devices  2 , and the second PR sub-module  2102  is electrically connected via the voltage stabilizing circuit  216  with the PR output terminal  23 . The voltage stabilizing circuit  216  is connected in series with the bleeder circuit  22  for shunting and further connected with the PR microprocessor  211  of the first PR sub-module  2101 , so as to charge vehicles wirelessly while preventing water from going into sockets to cause leakage of electricity or preventing illegal persons from stealing electricity from charging sockets. This method does not require wired connections and can carry out user identification through data transmission before charging or activities related to stored value and deductions are implemented, thus making it convenient to use in addition to functions of preventing electricity leakage or thefts. However, the above descriptions are given to illustrate preferred embodiments of the present invention and shall not be construed as limiting the appended patent claims of the present invention. It is hereby stated that all modifications and equivalent structural changes made without departing from the spirit and art of the present invention shall be included in the patent claims of the present invention. 
     In summary, the inductive charging method for vehicles as disclosed in the present invention can achieve its functions and objects when applied practically. Therefore, the present invention is really an excellent one with practical applicability and can satisfy the terms and conditions for patentability of a utility model. While the application of patent is filed pursuant to applicable laws, your early approval will be highly appreciated so as to guarantee benefits and rights of the inventor who has worked hard at this invention. For any question, please do not hesitate to inform the inventor by mail, and the inventor will try his best to cooperate with you. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.