Inductive power supply and operating method thereof with variable capacitance and rectification control

Abstract

This invention relates to an inductive power supply, comprising: a power supply end, including a power supply coil, wherein the power supply end is in a power transmission state or a self-resonant state; and a power receiving end, receiving power from the power supply end in an inductive manner, including a power receiving coil; a plurality of power receiving drive modules, each including a power receiving capacitor, a power receiving switch circuit, and a power receiving driver; a power receiving controller, providing drive signals of the plurality of power receiving coils to the plurality of power receiving drive modules; and a signal processor, continuously receiving the power receiving resonance signal on the power receiving coil and providing it to the power receiving controller, wherein, when the power supply end is in a self-resonant state, the power receiving controller adjusts the number of activated power receiving drive modules according to the distance between the power supply coil and the power receiving coil.

Claims

1. An inductive power supply, comprising: a power supply terminal connected to a power source, and including: a power supply coil having a first node and a second node at its two ends; and a power supply drive module including a power supply resonant capacitor, a power supply switching circuit, and a power supply driver, wherein, The power supply switching circuit is connected to the power supply and electrically connected between the power supply resonant capacitor and the power supply driver. The power supply resonant capacitor is also electrically connected to the first node and resonates with the power supply coil. A power supply controller is electrically connected to the power supply drive module and provides a power supply drive signal to the power supply drive module, causing the power supply driver to drive the power supply switching circuit according to the power supply drive signal. The power supply controller enables or disables the power supply drive module through the power supply drive signal to control the power supply terminal to be in a power transmission state or a self-resonant state. A power receiving terminal is configured to receive power from the power supply terminal in an inductive manner and includes: a power receiving coil electromagnetically coupled to the power supply coil, and having a first node and a second node at its two ends respectively. A plurality of powered drive modules are connected in parallel, wherein each powered drive module includes a powered capacitor, a powered switch circuit and a powered driver. The powered switch circuit is connected to an output terminal of the inductive power supply and is electrically connected between the powered capacitor and the powered driver. The powered capacitor is also electrically connected to the first node of the powered coil. A power receiving controller is electrically connected to the plurality of power receiving drive modules and provides a plurality of power receiving coil drive signals to the plurality of power receiving drive modules respectively. In each power receiving drive module, the power receiving driver drives the power receiving coil switching circuit according to the power receiving coil drive signal. A first signal processor is electrically connected to the first node of the power receiving coil and the power receiving controller, and continuously receives a power receiving resonant signal on the power receiving coil and provides it to the power receiving controller. When the resonant frequency of the power receiving resonant signal is lower than a preset frequency, the power receiving controller determines that the power supply terminal is in the self-resonant state. When the power supply terminal is in the self-resonant state, the power receiving controller obtains a distance between the power supply coil and the power receiving coil according to the resonant frequency, and adjusts the number of activated power receiving drive modules according to the distance.

2. The inductive power supply as claimed in claim 1, wherein the power receiver controller presets a first frequency and a second frequency, wherein the first frequency is the resonant frequency of the power receiving resonant signal when the power supply coil and the power receiving coil are closest, and the second frequency is the resonant frequency of the power receiving resonant signal when the power supply coil and the power receiving coil are at a set maximum induction distance, and the power receiver controller further calculates the distance between the power supply coil and the power receiving coil based on the proportional relationship between the detected resonant frequency of the power receiving resonant signal and the first frequency and the second frequency.

3. The inductive power supply as claimed in claim 1, wherein the receiving end further includes an auxiliary rectifier electrically connected to the receiving coil and the receiving controller, for rectifying the electrical energy of the receiving coil to provide DC power for the operation of the receiving controller.

4. The inductive power supply as claimed in claim 3, wherein the power receiving end further includes a plurality of blocking switches, each of the blocking switches being electrically connected between the corresponding power receiving switch circuit and the output terminal of the inductive power supply, and being controlled by the power receiving controller, wherein the blocking switch is turned off by the controller when the voltage at the output terminal of the inductive power supply is abnormal.

5. The inductive power supply as claimed in claim 4, wherein after the power receiver receives the DC power supplied by the auxiliary rectifier, an initial state of each of the powered drive modules is to stop operating, and an initial state of each of the blocking switches is to open.

6. The inductive power supply as claimed in claim 1, wherein the power receiver controller sets the time elapsed between two consecutive positive and negative voltage conversions of the power received resonant signal as a resonant period, and when the resonant period falls within the range of a preset resonant period, calculates a first time position at 1 / 4 of the resonant period and a second time position at 3 / 4 of the resonant period, and the power receiver controller further controls the duty cycle of an upper switch and a lower switch of each power received drive module according to the output demand of the inductive power supply, wherein the center point of the conduction time of one of the upper switch and the lower switch of each power received drive module controlled by the power receiver controller corresponds to the first time position, and the center point of the conduction time of the other switch of the upper switch and the lower switch corresponds to the second time position.

7. The inductive power supply as claimed in claim 1, wherein the number of powered drive modules is two to form a half-bridge architecture, or the number of powered drive modules is four to form a full-bridge architecture.

8. A method of operating an inductive power supply, comprising the steps of: (S1) providing a power supply terminal and a power receiving terminal of the inductive power supply, wherein the power supply terminal includes a power supply coil, at least one power supply drive module and a power supply controller, the at least one power supply drive module includes a power supply resonant capacitor, a power supply switching circuit and a power supply driver, the power receiving terminal includes a power receiving coil, a plurality of power receiving drive modules, a power receiving controller and a first power receiving signal processor, each power receiving drive module includes a power receiving capacitor, a power receiving switching circuit and a power receiving driver; (S2) using the power supply controller to provide a power supply drive signal to the power supply drive module, so that the power supply driver drives the power supply switching circuit according to the power supply drive signal, and using the power receiving controller to provide a plurality of power receiving drive signals to the power receiving drive module respectively, so that the power receiving driver in each power receiving drive module drives the power receiving switching circuit according to the power receiving drive signal; (S3) The power supply controller enables or disables the power supply drive module via the power supply drive signal to control the power supply terminal to be in a power transmission state or a self-resonant state accordingly; (S4) The first power receiving signal processor continuously receives a power receiving resonance signal on the power receiving coil and provides it to the power receiving controller; and (S5) When the resonant frequency of the power receiving resonance signal is lower than a preset frequency, the power receiving controller determines that the power supply terminal is in the self-resonant state, and when the power supply terminal is in the self-resonant state, the power receiving controller obtains a distance between the power supply coil and the power receiving coil based on the resonant frequency of the power receiving resonance signal on the power receiving coil, and adjusts the number of activated power receiving drive modules according to the size of the distance.

9. The operating method as described in claim 8, wherein the power receiver controller presets a first frequency and a second frequency, wherein the first frequency is the resonant frequency of the power receiving resonant signal when the power supply coil and the power receiving coil are closest, and the second frequency is the resonant frequency of the power receiving resonant signal when the power supply coil and the power receiving coil are at a set maximum sensing distance, and the power receiver controller further calculates the distance between the power supply coil and the power receiving coil based on the proportional relationship between the detected resonant frequency of the power receiving resonant signal and the first frequency and the second frequency.

10. The method of operation as described in claim 8, wherein the power receiving end further includes an auxiliary rectifier electrically connected to the power receiving coil and the power receiving controller, for rectifying the power of the power receiving coil to provide DC power to the power receiving controller for operation.

11. The method of operation as described in claim 10, wherein the power receiving end further includes a plurality of blocking switches, each of the blocking switches being electrically connected between a corresponding power receiving switch circuit and an output terminal of the inductive power supply, and being controlled by the power receiving controller, wherein the blocking switch is turned off by the controller when the voltage at the output terminal of the inductive power supply is abnormal.

12. The method of operation as described in claim 11, wherein after the power receiving controller receives the DC power provided by the auxiliary rectifier, an initial state of each power receiving drive module is to stop operating, and an initial state of each blocking switch is to open.

13. The method of operation as described in claim 8, wherein step (S2) further comprises: the power receiver controller setting the time elapsed between two consecutive positive and negative voltage conversions of the power receiver resonant signal as a resonant period, and when the resonant period is within the range of a preset resonant period, calculating a first time position at 1 / 4 of the resonant period and a second time position at 3 / 4 of the resonant period, the power receiver controller further controlling the duty cycle of an upper switch and a lower switch of each power receiver drive module according to the output demand of the inductive power supply, wherein the center point of the time of a conduction time of one of the upper switch and the lower switch of each power receiver drive module controlled by the power receiver controller corresponds to the first time position, and the center point of the time of a conduction time of the other switch of the upper switch and the lower switch corresponds to the second time position.

14. The method of operation as described in claim 8, wherein the number of electrically driven modules is two to form a half-bridge architecture, or the number of electrically driven modules is four to form a full-bridge architecture.

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