Pre-stage controlled wireless charging system with optimal impedance and control method of pre-stage controlled wireless charging system

Abstract

The invention provides a preceding-stage-controlled wireless charging system with optimal impedance and a control method of the preceding-stage-controlled wireless charging system, and relates to the technical field of wireless charging. Wherein the controllable constant-current alternating-current source output end I is connected with one end of the transmitting end resonance compensation capacitor, the other end of the transmitting end resonance compensation capacitor is connected with one end of the transmitting coil, and the other end of the transmitting coil is connected with the controllable constant-current alternating-current source output end II; two ends of the receiving coil are respectively connected with one end of the receiving end resonance compensation capacitor and the input end II of the diode rectifier; the other end of the receiving end resonance compensation capacitor is connected with a diode rectifier input end I; the output anode end and the output cathode end of the diode rectifier are respectively connected with the input anode end and the input cathode end of the DC-DC converter; the output anode end and the output cathode end of the DC-DC converter are respectively connected with the anode end and the cathode end of a load; and a control signal end and a communication port of the transmitting end controller are connected with a control signal end of the controllable constant-current alternating-current source and a communication port of the transmitting end wireless communication module.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and in particular to a wireless charging system with optimal impedance controlled by a front stage and a control method thereof. Background Art

[0002] With the popularity of electronic devices, wireless charging technology has attracted widespread attention due to its convenience. However, existing wireless charging systems have many problems that seriously limit their performance and application.

[0003] When it comes to impedance matching, wireless charging systems are susceptible to factors such as coil distance and misalignment, which can cause changes in mutual inductance and, in turn, alter the system's optimal load impedance. Traditional systems struggle to automatically identify and adjust for these changes, resulting in reduced energy transfer efficiency. For example, if a phone's position on a wireless charging pad is slightly offset, charging efficiency decreases significantly, resulting in wasted energy and prolonged charging times.

[0004] Communication lag also significantly impacts wireless charging systems. Existing technologies often control output voltage by adjusting equivalent impedance in the final stage, but this relies heavily on communication. The inevitable lag in communication can lead to control delays, making it impossible to respond promptly to load changes, further reducing charging efficiency and even affecting charging stability.

[0005] Furthermore, traditional methods have shortcomings in output voltage response speed. When the load changes, such as when multiple devices are wirelessly charging simultaneously, traditional systems cannot quickly adjust the output voltage, resulting in device charging anomalies and affecting the user experience.

[0006] Therefore, it is urgent to develop a wireless charging system that can automatically identify the optimal load impedance, reduce the impact of communication lag, and have a fast output voltage response capability. The optimal impedance control wireless charging system and related methods proposed in this patent are designed to address these problems and have important practical significance for improving the performance of wireless charging systems and promoting the development of wireless charging technology. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the present invention provides a wireless charging system with optimal impedance controlled by a front stage and a control method thereof;

[0008] A wireless charging system with optimal impedance controlled by a front stage, comprising: a controllable constant current AC source, a transmitting end resonant capacitor, a transmitting coil, a transmitting end controller, a transmitting end wireless communication module, a receiving coil, a receiving end resonant capacitor, a diode rectifier, a DC-DC converter, a receiving end controller, and a receiving end wireless communication module;

[0009] The output terminal 1 of the controllable constant-current AC source is connected to one end of the transmitting-end resonant compensation capacitor, the other end of the transmitting-end resonant compensation capacitor is connected to one end of the transmitting coil, and the other end of the transmitting coil is connected to the output terminal 2 of the controllable constant-current AC source; the two ends of the receiving coil are respectively connected to one end of the receiving-end resonant compensation capacitor and the input terminal 2 of the diode rectifier; the other end of the receiving-end resonant compensation capacitor is connected to the input terminal 1 of the diode rectifier; the output anode terminal and the output cathode terminal of the diode rectifier are respectively connected to the input anode terminal and the input cathode terminal of the DC-DC converter; the output anode terminal and the output cathode terminal of the DC-DC converter are respectively connected to the anode terminal and the cathode terminal of the load;

[0010] The control signal terminal of the transmitter controller is connected to the control signal terminal of the controllable constant current AC source;

[0011] The communication port of the transmitter controller is connected to the communication port of the transmitter wireless communication module;

[0012] The communication port of the receiving-end wireless communication module is connected to the communication port of the receiving-end controller, the sampling port of the receiving-end controller is connected to the output cathode end of the diode rectifier and the input cathode end of the DC-DC converter; the control signal end of the receiving-end controller is connected to the control signal end of the DC-DC converter.

[0013] The wireless charging system with optimal impedance controlled by the front stage is used to implement the following control method, including the following steps:

[0014] Step 1: System initialization:

[0015] Step 1.1: The transmitter controller sets the desired target output voltage U ref , the primary side equivalent internal resistance r1, the secondary side equivalent internal resistance r2, and the output effective value of the controllable constant current AC source I ref and the expected equivalent impedance R of the DC-DC converter ref The initial value of

[0016] Step 1.2: The transmitter controller transmits U to the receiver wireless communication module through the transmitter wireless communication module ref ;

[0017] Step 1.3: The transmitter controller controls the controllable constant current AC source to output an effective value of I ref ; The receiving end controller controls the DC-DC converter output voltage U L Approaching U ref ;

[0018] Step 2: Run data acquisition:

[0019] Step 2.1: The transmitter controller controls the controllable constant current AC source to maintain the output current I1 at the current value; the receiver controller controls the DC-DC converter output voltage U L Also maintain the current value;

[0020] Step 2.2: Receiver Controller Measures I DC ,U DC , and calculate the equivalent input impedance R of the DC-DC converter DC =U DC / I DC ; Then R DC and U DC The value is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module;

[0021] Step 2.3: The transmitter controller calculates the frequency-mutual inductance coefficient: Where ω is the resonant angular frequency and M is the mutual inductance;

[0022] Step 3: Optimize the current working status:

[0023] Step 3.1: Transmitter controller calculates optimal load impedance

[0024] Step 3.2: The transmitter controller calculates the equivalent load impedance of the wireless charging and the equivalent input impedance R of the DC-DC converter. DC Calculate the output current effective value of the controllable constant current AC source by using the current constant current source output current I1

[0025] Step 3.3: Transmitter controller The transmitter controller controls the controllable constant current AC source to output the effective current value I ref ;

[0026] Step 4: Shutdown:

[0027] Step 4.1: If the battery is fully charged, the receiving controller measures I DC If it is zero, the shutdown signal is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed;

[0028] If the transmitter controller receives a shutdown command, the shutdown signal is transmitted to the receiver controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed;

[0029] Step 4.2: Both the transmitter controller and the receiver controller are shut down to stop wireless energy transmission.

[0030] The beneficial effects of adopting the above technical solution are:

[0031] The present invention provides a wireless charging system with optimal impedance controlled by a front stage and a control method thereof, which has the following beneficial effects:

[0032] 1. The present invention can automatically identify the optimal load impedance of the system, and can adapt to the change of the optimal load impedance caused by the change of mutual inductance caused by factors such as coil distance and misalignment, so that the system has the ability to resist external interference.

[0033] 2. This system achieves optimal impedance control by controlling the current in the transmitting coil. Output voltage control does not rely on communication, relying solely on local information from the DC-DC converter. Communication-induced lag has minimal impact on efficiency control, as control can be performed in the previous stage after communication. Compared to existing methods that adjust equivalent impedance in the later stage and voltage in the previous stage, this method offers a faster output voltage response. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 FIG. 4 is a block diagram of the overall structure of the wireless charging system with optimal impedance in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0036] A wireless charging system with optimal impedance controlled by a front stage, such as Figure 1 As shown, it includes: a controllable constant current AC source, a transmitting end resonant capacitor, a transmitting coil, a transmitting end controller, a transmitting end wireless communication module, a receiving coil, a receiving end resonant capacitor, a diode rectifier, a DC-DC converter, a receiving end controller and a receiving end wireless communication module;

[0037] The controllable constant current AC source has an output terminal 1, an output terminal 2, and a control signal port;

[0038] The transmitter-end resonant compensation capacitor has a port 1 and a port 2;

[0039] The transmitting coil has port 1 and port 2;

[0040] The receiving coil has port 1 and port 2;

[0041] The receiving end resonant compensation capacitor has port 1 and port 2;

[0042] The diode rectifier has an input terminal 1, an input terminal 2, an output anode port, and an output cathode port;

[0043] The DC-DC converter has an input anode port, an output cathode port, a control signal port, an output anode port, and an output cathode port;

[0044] The load has an anode port and a cathode port;

[0045] The transmitter controller has a control signal port and a communication port;

[0046] The transmitting end wireless communication module has a communication port;

[0047] The receiving end wireless communication module has a communication port;

[0048] The receiving end controller has a communication port, a sampling port, and a control signal port.

[0049] The output terminal 1 of the controllable constant-current AC source is connected to one end of the transmitting-end resonant compensation capacitor, the other end of the transmitting-end resonant compensation capacitor is connected to one end of the transmitting coil, and the other end of the transmitting coil is connected to the output terminal 2 of the controllable constant-current AC source; the two ends of the receiving coil are respectively connected to one end of the receiving-end resonant compensation capacitor and the input terminal 2 of the diode rectifier; the other end of the receiving-end resonant compensation capacitor is connected to the input terminal 1 of the diode rectifier; the output anode terminal and the output cathode terminal of the diode rectifier are respectively connected to the input anode terminal and the input cathode terminal of the DC-DC converter; the output anode terminal and the output cathode terminal of the DC-DC converter are respectively connected to the anode terminal and the cathode terminal of the load;

[0050] The control signal terminal of the transmitter controller is connected to the control signal terminal of the controllable constant current AC source;

[0051] The communication port of the transmitter controller is connected to the communication port of the transmitter wireless communication module;

[0052] The communication port of the receiving-end wireless communication module is connected to the communication port of the receiving-end controller, the sampling port of the receiving-end controller is connected to the output cathode end of the diode rectifier and the input cathode end of the DC-DC converter; the control signal end of the receiving-end controller is connected to the control signal end of the DC-DC converter.

[0053] The output effective value of the controllable constant current AC source is I ref The AC current is measured and the effective value of the current output current I1 is measured; where I ref set externally;

[0054] The output value of the DC-DC converter is U L DC voltage;

[0055] The receiving end controller collects the output voltage U of the diode rectifier DC and current I DC ; Send the output voltage U of the diode rectifier to the receiving wireless communication module DC And the DC-DC converter equivalent input impedance RDC , target output voltage U ref ; Send target output voltage U to DC-DC converter ref ;

[0056] The transmitter controller can receive the output U of the voltage diode rectifier from the transmitter wireless communication module. DC And the DC-DC converter equivalent input impedance R DC , send target output voltage U ref ;

[0057] The wireless charging system with optimal impedance controlled by the front stage is used to implement the following control method, including the following steps:

[0058] Step 1: System initialization:

[0059] Step 1.1: The transmitter controller sets the desired target output voltage U ref , the primary side equivalent internal resistance r1, the secondary side equivalent internal resistance r2, and the output effective value of the controllable constant current AC source I ref and the expected equivalent impedance R of the DC-DC converter ref The initial value of

[0060] Step 1.2: The transmitter controller transmits U to the receiver wireless communication module through the transmitter wireless communication module ref ;

[0061] Step 1.3: The transmitter controller controls the controllable constant current AC source to output an effective value of I ref ; The receiving end controller controls the DC-DC converter output voltage U L Approaching U ref ;

[0062] Step 2: Run data acquisition:

[0063] Step 2.1: The transmitter controller controls the controllable constant current AC source to maintain the output current I1 at the current value; the receiver controller controls the DC-DC converter output voltage U L Also maintain the current value;

[0064] Step 2.2: Receiver Controller Measures I DC ,U DC , and calculate the equivalent input impedance R of the DC-DC converter DC =U DC / I DC ; Then R DC and U DC The value is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module;

[0065] Step 2.3: The transmitter controller calculates the frequency-mutual inductance coefficient: Where ω is the resonant angular frequency and M is the mutual inductance;

[0066] Step 3: Optimize the current working status:

[0067] Step 3.1: Transmitter controller calculates optimal load impedance

[0068] Step 3.2: The transmitter controller calculates the equivalent load impedance of the wireless charging and the equivalent input impedance R of the DC-DC converter. DC Calculate the output current effective value of the controllable constant current AC source by using the current constant current source output current I1

[0069] Step 3.3: Transmitter controller The transmitter controller controls the controllable constant current AC source to output the effective current value I ref ;

[0070] Step 4: Shutdown:

[0071] Step 4.1: If the battery is fully charged, the receiving controller measures I DC If it is zero, the shutdown signal is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed;

[0072] If the transmitter controller receives a shutdown command, the shutdown signal is transmitted to the receiver controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed;

[0073] Step 4.2: Both the transmitter controller and the receiver controller are shut down to stop wireless energy transmission.

[0074] The above description is merely a preferred embodiment of the present disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also encompass other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned inventive concept. For example, a technical solution formed by mutually replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present disclosure.

Claims

1. A wireless charging system with optimal impedance controlled by a front stage, characterized in that: include: Controllable constant current AC source, transmitting end resonant capacitor, transmitting coil, transmitting end controller, transmitting end wireless communication module, receiving coil, receiving end resonant capacitor, diode rectifier, DC-DC converter, receiving end controller and receiving end wireless communication module; The output terminal 1 of the controllable constant-current AC source is connected to one end of the transmitting-end resonant compensation capacitor, the other end of the transmitting-end resonant compensation capacitor is connected to one end of the transmitting coil, and the other end of the transmitting coil is connected to the output terminal 2 of the controllable constant-current AC source; the two ends of the receiving coil are respectively connected to one end of the receiving-end resonant compensation capacitor and the input terminal 2 of the diode rectifier; the other end of the receiving-end resonant compensation capacitor is connected to the input terminal 1 of the diode rectifier; the output anode terminal and the output cathode terminal of the diode rectifier are respectively connected to the input anode terminal and the input cathode terminal of the DC-DC converter; The output anode terminal and the output cathode terminal of the DC-DC converter are connected to the anode terminal and the cathode terminal of the load respectively; The control signal terminal of the transmitter controller is connected to the control signal terminal of the controllable constant current AC source; the communication port of the transmitter controller is connected to the communication port of the transmitter wireless communication module.

2. The wireless charging system with optimal impedance controlled by a front stage according to claim 1, characterized in that: The communication port of the receiving-end wireless communication module is connected to the communication port of the receiving-end controller, the sampling port of the receiving-end controller is connected to the output cathode end of the diode rectifier and the input cathode end of the DC-DC converter; the control signal end of the receiving-end controller is connected to the control signal end of the DC-DC converter.

3. A control method for a wireless charging system with optimal impedance controlled by a front stage, implemented by the wireless charging system with optimal impedance controlled by a front stage according to claim 1, characterized in that: The following steps are involved: Step 1: System initialization: Step 2: Run data acquisition: Step 3: Optimize the current working status: Step 4: Shutdown.

4. The control method of the wireless charging system with optimal impedance of the front-stage control according to claim 3, characterized in that: The step 1 comprises the following steps: Step 1.1: The transmitter controller sets the desired target output voltage U ref , the primary side equivalent internal resistance r1, the secondary side equivalent internal resistance r2, and the output effective value of the controllable constant current AC source I ref and the expected equivalent impedance R of the DC-DC converter ref The initial value of Step 1.2: The transmitter controller transmits U to the receiver wireless communication module through the transmitter wireless communication module ref ; Step 1.3: The transmitter controller controls the controllable constant current AC source to output an effective value of I ref ; The receiving end controller controls the DC-DC converter output voltage U L Approaching U ref .

5. The control method of the wireless charging system with optimal impedance of the front-stage control according to claim 3, characterized in that: The step 2 comprises the following steps: Step 2.1: The transmitter controller controls the controllable constant current AC source to maintain the output current I1 at the current value; the receiver controller controls the DC-DC converter output voltage U L Also maintain the current value; Step 2.2: Receiver Controller Measures I DC ,U DC , and calculate the equivalent input impedance R of the DC-DC converter DC =U DC / I DC ; Then R DC and U DC The value is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module; Step 2.3: The transmitter controller calculates the frequency-mutual inductance coefficient: Where ω is the resonant angular frequency and M is the mutual inductance.

6. The control method of the wireless charging system with optimal impedance of the front-stage control according to claim 3, characterized in that: The step 3 comprises the following steps: Step 3.1: Transmitter controller calculates optimal load impedance Step 3.2: The transmitter controller calculates the equivalent load impedance of the wireless charging and the equivalent input impedance R of the DC-DC converter. DC Calculate the output current effective value of the controllable constant current AC source by using the current constant current source output current I1 Step 3.3: Transmitter controller The transmitter controller controls the controllable constant current AC source to output the effective current value I ref .

7. The control method of the wireless charging system with optimal impedance of the front-stage control according to claim 3, characterized in that: The step 4 comprises the following steps: Step 4.1: If the battery is fully charged, the receiving controller measures I DC If it is zero, the shutdown signal is transmitted to the transmitter controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed; If the transmitter controller receives a shutdown command, the shutdown signal is transmitted to the receiver controller through the transmitter wireless communication module and the receiver wireless communication module, and step 4.2 is executed; Step 4.2: Both the transmitter controller and the receiver controller are shut down to stop wireless energy transmission.

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