RESONANCE-TYPE CONTACTLESS POWER SUPPLY, INTEGRATED CIRCUIT AND CONSTANT VOLTAGE CONTROLLING METHOD THEREFOR

• US 20160013663A1
• Filed: 07/14/2015
• Published: 01/14/2016
• Est. Priority Date: 07/14/2014
• Status: Active Grant

• Current Assignee: Silergy Semiconductor Technology (Hangzhou) Ltd. (Silergy Corporation)
• Original Assignee: Silergy Semiconductor Technology (Hangzhou) Ltd. (Silergy Corporation)
• Inventors: Zhang, Wang, Yu, Feng
• Granted Patent: US 10,601,248 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The present disclosure relates to a resonance-type contactless power supply, an integrated circuit and a constant voltage control method. The resonance-type contactless power supply includes an inverter, a transmitter-side resonant circuit, a receiver-side resonant circuit, a rectifier circuit, and an output capacitance. In this resonance-type contactless power supply, the inverter receives electric energy, which is transferred to the rectifier circuit in a first state and is not transferred to the rectifier circuit in a second state. By switching between the first state and the second state, the resonance-type contactless power supply is controlled to provide a relatively constant voltage, and can be electrically coupled directly to a constant-voltage-type load.

Claims

1. A resonance-type contactless power supply comprising:

an inverter configured to receive electric energy and output an AC current with a self-inductance resonance frequency;

a transmitter-side resonant circuit comprising a transmitting coil for receiving said AC current from said inverter;

a receiver-side resonant circuit comprising a receiving coil which is separated from but electrically coupled to said transmitting coil in a contactless manner, and configured to receive electric energy from said transmitting coil;

a rectifier circuit being electrically coupled to said receiver-side resonant circuit;

an output capacitance being connected in parallel at an output of said rectifier circuit;

a state switching circuit configured to control said receiver-side resonant circuit to output said AC current to said rectifier circuit in said first state, and to connect an input port of said rectifier circuit to ground in said second state; and

a control circuit configured to switch said state switching circuit between said first state and said second state so that said rectifier circuit outputs a constant output voltage.

2. The resonance-type contactless power supply according to claim 1, wherein said state switching circuit comprises:

a first switch being electrically coupled between a first terminal of said input port of said rectifier circuit and ground; and

a second switch being electrically coupled between a second terminal of said input port of said rectifier circuit and ground;

wherein said control circuit outputs a switching control signal in response to a feedback voltage which is in proportion to said output voltage of said rectifier circuit, for turning on or off said first switch and said second switch simultaneously.

3. The resonance-type contactless power supply according to claim 2, wherein said control circuit increases an on time of said first switch and said second switch in each cycle when said feedback voltage increases so as to decrease a time period of said first state, and decreases said on time of said first switch and said second switch in each cycle when said feedback voltage decreases so as to increase said time period of said first state.

4. The resonance-type contactless power supply according to claim 2, wherein said control circuit comprises:

an error amplifier circuit configured to receive said feedback voltage and a reference voltage and to provide an error compensation signal;

a comparator configured to compare said error compensation signal with a triangular wave signal to provide a pulse-width modulation signal; and

a driving circuit configured to provide said switching control signal for said first switch and said second switch in response to said pulse-width modulation signal.

5. The resonance-type contactless power supply according to claim 1, wherein said transmitting coil and said receiving coil are configured to be coupled to each other in a predetermined coupling coefficient, and when operating in said self-inductance resonance frequency, a mutual inductance between said transmitting coil and said receiving coil is equal to an equivalent load impedance of a rated load in said first state.

6. A resonance-type contactless power supply comprising:

an inverter configured to receive electric energy and output an AC current with a self-inductance resonance frequency in a first state, and to stop its operation in a second state;

a transmitter-side resonant circuit comprising a transmitting coil for receiving said AC current from said inverter;

a receiver-side resonant circuit comprising a receiving coil which is separated from but electrically coupled to said transmitting coil in a contactless manner, and configured to receive electric energy from said transmitting coil;

a rectifier circuit being electrically coupled to said receiver-side resonant circuit;

an output capacitance being connected in parallel at an output of said rectifier circuit; and

a control circuit configured to switch said inverting circuit between said first state and said second state so that said rectifier circuit outputs a constant voltage.

7. The resonance-type contactless power supply according to claim 6, wherein said control circuit is configured to switch said inverter circuit between said first state and said second state in response to a feedback voltage, so as to decrease a time period during which said inverter circuit maintains in said first state when said feedback voltage increases, and to increase said time period during which said inverter circuit maintains in said first state when said feedback voltage decreases.

8. The resonance-type contactless power supply according to claim 6, wherein said control circuit comprises:

an error amplifier circuit configured to receive said feedback voltage which is in proportion to an output voltage of said rectifier circuit and a reference voltage and to provide an error compensation signal;

a comparator configured to compare said error compensation signal with a triangular wave signal to provide a pulse-width modulation signal; and

an inverter controller configured to switch between said first state and said second state in response to said pulse-width modulation signal, and to provide an inverter control signal which has said self-inductance resonance frequency in said first state and stops an operation of said inverter in said second state.

9. The resonance-type contactless power supply according to claim 6, wherein said transmitting coil and said receiving coil are configured to be coupled to each other in a predetermined coupling coefficient, and when operating in said self-inductance resonance frequency, a mutual inductance between said transmitting coil and said receiving coil is equal to an equivalent load impedance of a rated load in said first state.

10. An integrated circuit for a resonance-type contactless power supply comprising:

a rectifier circuit;

a state switching circuit configured to control a receiver-side resonant circuit to output an AC current to said rectifier circuit in a first state, and to connect an input terminal of said rectifier circuit to ground in a second state; and

a control circuit configured to switch said state switching circuit between said first state and said second state so that said rectifier circuit outputs a constant output voltage.

11. The integrated circuit according to claim 10, wherein said state switching circuit comprises:

a first switch being electrically coupled between a first terminal of said input port of said rectifier circuit and ground; and

a second switch being electrically coupled between a second terminal of said input port of said rectifier circuit and ground, wherein said control circuit outputs a switching control signal in response to a feedback voltage which is in proportion to said output voltage of said rectifier circuit, for turning on or off said first switch and said second switch simultaneously.

12. The integrated circuit according to claim 10, wherein said control circuit increases an on time of said first switch and said second switch in each cycle when said feedback voltage increases so as to decrease a time period of said first state, and decreases said on time of said first switch and said second switch in each cycle when said feedback voltage decreases so as to increase said time period of said first state.

13. The integrated circuit according to claim 10, wherein said control circuit comprises:

an error amplifier circuit configured to receive said feedback voltage and a reference voltage and to provide an error compensation signal;

a comparator configured to compare said error compensation signal with a triangular wave signal to provide a pulse-width modulation signal; and

a driving circuit configured to provide a switching control signal for said first switch and said second switch in response to said pulse-width modulation signal.

14. An integrated circuit for a resonance-type contactless power supply comprising:

an inverter configured to receive electric energy and output an AC current with a self-inductance resonance frequency in a first state, and to stop its operation in a second state; and

a control circuit configured to switch said inverting circuit between said first state and said second state so that said resonance-type contactless power supply outputs a constant output voltage.

15. The integrated circuit according to claim 14, wherein said control circuit is configured to switch said inverter circuit between said first state and said second state in response to a feedback voltage, so as to decrease a time period during which said inverter circuit maintains in said first state when said feedback voltage increases, and to increase said time period during which said inverter circuit maintains in said first state when said feedback voltage decreases.

16. The integrated circuit according to claim 14, wherein said control circuit comprises:

an error amplifier circuit configured to receive a feedback voltage which is in proportion to an output voltage of said resonance-type contactless power supply and a reference voltage and to provide an error compensation signal;

a comparator configured to compare said error compensation signal with a triangular wave signal to provide a pulse-width modulation signal; and

an inverter controller configured to switch between said first state and said second state in response to said pulse-width modulation signal and to provide an inverter control signal which has said self-inductance resonance frequency in said first state and stops an operation of said inverter in said second state.

17. A constant voltage control method for a resonance-type contactless power supply comprising an inverter, a transmitter-side resonant circuit, a receiver-side resonant circuit, a rectifier circuit and an output capacitor, comprising:

switching said resonance-type contactless power supply between said first state and said second state so that said resonance-type contactless power supply outputs a constant voltage,

wherein said inverter receives electric energy, which is transferred to said rectifier circuit in a first state and is not transferred to said rectifier circuit in a second state.

18. The constant voltage control method according to claim 17, wherein said receiver-side resonant circuit outputs an AC current to said rectifier circuit in said first state, and an input terminal of said rectifier circuit is grounded in said second state.

19. The constant voltage control method according to claim 17, wherein said inverter circuit receives electric energy and outputs an AC current with a self-inductance resonance frequency in said first state, and said inverter stops its operation in said second state.