Non-contact power supply having built-in coupling detection device and coupling detection method thereof

• US 7,843,707 B2
• Filed: 12/20/2007
• Issued: 11/30/2010
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chen, Po-Shen, Chen, Mu-Ping, Chen, Wan-Pei, Chen, Ching-Piao, Yang, Ming-Che
• Primary Examiner(s): Sterrett; Jeffrey L
• Application Number:
  US11/962,038
• Publication Number:
  US 20080157909A1
• Time in Patent Office: 1,076 Days
• Field of Search: 363/17, 363/98, 363/132
• US Class Current: 363/17
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop

Abstract

The configurations of a non-contact power supply and a coupling detection method thereof are provided. The proposed non-contact power supply includes a detachable transformer including a primary side, a current sensor coupled to the primary side and sensing a primary side current and a controller coupled to the current sensor, receiving the current and determining whether the power supply is under a coupling status according to the current.

Claims

1. A non-contact power supply, comprising:

a detachable transformer comprising;

a primary side; and

a secondary side;

a current sensor coupled to the primary side and sensing a primary side current;

a controller generating a switching signal, coupled to the current sensor and comprising a built-in program for manipulating the power supply and initializing the power supply at a detecting mode;

a first rectifying apparatus coupled to an external AC power source in parallel and outputting a first DC voltage;

a switch module coupled to the first rectifying apparatus, the primary side and the controller, receiving the first DC voltage and the switching signal and outputting a first AC voltage to the primary side; and

a second rectifying apparatus coupled to the secondary side, receiving a second AC voltage and generating a second DC voltage,

wherein the transformer is under a coupling status when the current is smaller than a first current value, and then the controller makes the power supply switch to a power transmission mode;

the transformer is under a separate status when the current is larger than a second current value, and then the controller makes the power supply switch to the detecting mode;

the switch module works under a first switching frequency to generate a high level of the first AC voltage, and the switch module works under a second switching frequency to generate a low level of the first AC voltage.

2. A power supply according to claim 1 further comprising a built-in coupling detection device having the current sensor and the controller, wherein the switch module is an inverter.

3. A power supply according to claim 1, wherein the external AC power source is a commercial power and the second switching frequency is higher than the first switching frequency.

4. A power supply according to claim 1, wherein the switching signal is a low frequency switching signal when the switch module works under the first switching frequency, and the switching signal is one of a high frequency switching signal and a high frequency intermittent switching signal when the switch module works under the second switching frequency.

5. A power supply according to claim 1, wherein the second current value is larger than the first current value.

6. A power supply according to claim 1, wherein the primary side comprises a first terminal and a second terminal, the first rectifying apparatus comprises a first output terminal and a second output terminal, and the switch module comprises:

a first power switch having a first terminal coupled to the first output terminal, a second terminal coupled to the second terminal of the primary side and a control terminal;

a second power switch having a first terminal coupled to the second terminal of the first power switch, a second terminal coupled to the second output terminal and a control terminal;

a third power switch having a first terminal coupled to the first terminal of the first power switch, a second terminal coupled to the first terminal of the primary side and a control terminal; and

a fourth power switch having a first terminal coupled to the second terminal of the third power switch, a second terminal coupled to the second terminal of the second power switch and a control terminal,

wherein the control terminals of the first to the fourth switches are all coupled to the controller for receiving the control signal.

7. A power supply according to claim 6 further comprising a first and a second capacitors, wherein the first capacitor is coupled to the first terminal of the primary side and the second terminal of the third switch in series, and the second capacitor is coupled to the secondary side in parallel.

8. A power supply according to claim 7, wherein the first rectifying apparatus further comprises a first diode apparatus having at least one first diode and coupled to the external AC power source in parallel, and a third capacitor coupled to the first diode apparatus and

a switch module coupled to an external AC power source, the primary side and the controller, and outputting a first AC voltage to the primary side,

wherein the transformer is under the coupling status when the current is smaller than a first current value, and then the controller makes the power supply switch to a power transmission mode;

the transformer is under a separate status when the current is larger than a second current value, and then the controller makes the power supply switch to a detecting mode;

the switch module works under a first switching frequency to generate a high level of the first AC voltage, and the switch module works under a second switching frequency to generate a low level of the first AC voltage.

9. A power supply according to claim 6 further comprising a first capacitor, wherein the first capacitor is coupled to the first terminal of the primary side and the second terminal of the third switch in series.

10. A power supply according to claim 9, wherein the first rectifying apparatus further comprises a first diode apparatus having at least one first diode and coupled to the external AC power source in parallel, and a second capacitor coupled to the first diode apparatus and the switch module in parallel, the second rectifying apparatus comprises a second diode apparatus having at least one second diode and coupled to the secondary side in parallel, and a third capacitor coupled to the second diode apparatus and a load in parallel.

11. A non-contact power supply, comprising:

a detachable transformer comprising;

a primary side;

a current sensor coupled to the primary side and sensing a primary side current;

a controller coupled to the current sensor, receiving the current and determining whether the power supply is under a coupling status according to the current; and

predetermined value when the power supply is under the separate status.

12. A power supply according to claim 11, wherein the controller comprises a built-in program for manipulating the power supply and initializing the power supply at the detecting mode.

13. A power supply according to claim 12, wherein the transformer further comprises a secondary side, the primary side and the secondary side are close to each other within a coupling distance when the power supply is under the coupling status, and the primary side and the secondary side are separate from each other more than a the switch module in parallel, the second rectifying apparatus comprises a second diode apparatus having at least one second diode and coupled to the secondary side in parallel, and a fourth capacitor coupled to the second diode apparatus and a load in parallel.

14. A coupling detection method for a non-contact power supply, wherein the non-contact power supply comprises a detachable transformer having a primary side, a secondary side, a current sensor, a controller, a first rectifying apparatus coupled to an external AC power source in parallel and outputting a first DC voltage, a switch module coupled to the first rectifying apparatus, the primary side and the controller, receiving the first DC voltage and a switching signal generated by the controller and outputting a first AC voltage to the primary side, wherein the switch module driven by the switching signal works under a first switching frequency and generates a high level of the first AC voltage when the non-contact power supply is under a power transmission mode, and the switch module driven by the switching signal works under a second switching frequency and generates a low level of the first AC voltage when the non-contact power supply is under a detecting mode, a second rectifying apparatus coupled to the secondary side, receiving a second AC voltage and generating a second DC voltage, and a load coupled to the second rectifying apparatus and receiving the second DC voltage, comprising the steps of:

(a) sensing a primary side current via the current sensor; and

(b) determining whether the transformer is under a coupling status according to the current by the controller.

15. A method according to claim 14 further comprising a step of:

(c) repeatedly executing the step (a) to the step (b).

16. A method according to claim 14, wherein the controller comprises a built-in program for manipulating the non-contact power supply, the step (a) further comprises a step of (a0) initializing the non-contact power supply at the detecting mode, and the step (b) further comprises the steps of:

(b1) switching the power supply to the power transmission mode via the controller when the current is smaller than a first current value; and

(b2) switching the power supply to the detecting mode via the controller when the current is larger than a second current value.

17. A method according to claim 16, wherein the primary side and the secondary side are close to each other within a coupling distance when the power supply is under the coupling status, and the primary side and the secondary side are separate from each other more than a predetermined value when the power supply is under a separate status.

18. A method according to claim 14, wherein the non-contact power supply further comprises a first capacitor, the switch module comprises a first and a second output terminals, the primary side has a first and a second terminals, the first capacitor is coupled to the first output terminal of the switch module and the first terminal of the primary side in series, and the second output terminal of the switch module is coupled to the second terminal of the primary side.

19. A method according to claim 14, wherein the switch module working under the first switching frequency makes the switching signal be a low frequency switching signal, and the switch module working under the second switching frequency makes the switching signal be one of a high frequency switching signal and a high frequency intermittent switching signal.

20. A method according to claim 14, wherein the non-contact power supply further comprises a first and a second capacitors, the switch module comprises a first and a second output terminals, the primary side has a first and a second terminals, the first capacitor is coupled to the first output terminal of the switch module and the first terminal of the primary side in series, the second capacitor is coupled to the secondary side in parallel, and the second output terminal of the switch module is coupled to the second terminal of the primary side.

21. A coupling detection method for a non-contact power supply, wherein the non-contact power supply comprises a detachable transformer having a primary side and a secondary side, a current sensor, a controller, a first rectifying apparatus coupled to an external AC power source in parallel and outputting a first DC voltage, a switch module coupled to the first rectifying apparatus, the primary side and the controller, receiving the first DC voltage and a switching signal generated by the controller and outputting a first AC voltage to the primary side, wherein the switch module driven by the switching signal works under a first switching frequency and generates a high level of the first AC voltage when the non-contact power supply is under a power transmission mode, and the switch module driven by the switching signal works under a second switching frequency and generates a low level of the first AC voltage when the non-contact power supply is under a detecting mode, a second rectifying apparatus coupled to the secondary side, receiving a second AC voltage and generating a second DC voltage, and a load coupled to the second rectifying apparatus and receiving the second DC voltage, comprising the steps of:

(a) initializing the power supply at the detecting mode;

(b) sensing a primary side current via the current sensor; and

(c) determining whether the primary side and the secondary side are coupled according to the current by the controller.

22. A method according to claim 21, wherein the controller comprises a built-in program for manipulating the non-contact power supply, and the step (c) further comprises the steps of:

(c1) switching the power supply to the power transmission mode via the controller when the current is smaller than a first current value causing the transformer under a coupling status; and

(c2) switching the power supply to the detecting mode via the controller when the current is larger than a second current value causing the transformer under a separate status.

23. A method according to claim 21 further comprising a step of:

(d) repeatedly executing the step (b) to the step (c).