Wireless charging control system and method

Abstract

The application discloses a wireless charging control system and method. The control system comprises a receiving end coil, a compensation network, a controllable rectifier and a controller. The controller is electrically connected with the controllable rectifier, is used for controlling the controllable rectifier to work in a short circuit state, acquiring a synchronization signal of an input current of the controllable rectifier, controlling the controllable rectifier to be in a controllable rectifier output state, adjusting a direct current output voltage and stabilizing the direct current output voltage to a target voltage, adjusting a phase angle of an output current of the controllable rectifier after a constant voltage load is turned on, and stabilizing the direct current output voltage to the target voltage. When an equivalent resistance of the constant voltage load fluctuates, the phase angle of the output current of the controllable rectifier and a control frequency of the phase angle adjustment are dynamically adjusted. The technical scheme of the embodiment of the application can dynamically adjust the direct current output voltage and the control frequency of the phase angle adjustment by controlling the phase angle of the output current, so that the direct current output voltage is stabilized to the target voltage.

Description

Technical Field

[0001] This invention relates to wireless charging technology, and more particularly to a wireless charging control system and method. Background Technology

[0002] With the explosive growth of electric vehicles, charging technology has become one of the breakthroughs in innovation and development in the electric vehicle field. Emerging wireless charging technology is gradually replacing traditional wired charging technology and becoming the preferred charging method.

[0003] In existing technologies, wireless charging receivers use LCC compensation networks, which can meet the constant current output current requirement but cannot generate a stable constant voltage output current, thus having significant limitations in terms of the types of loads they can adapt to.

[0004] Therefore, how to generate a stable constant voltage output current in the wireless charging system for electric vehicles has become an urgent problem to be solved in the industry. Summary of the Invention

[0005] This invention provides a wireless charging control system and method to achieve a stable constant voltage output current to the load in a wireless charging system.

[0006] According to one aspect of the present invention, a wireless charging control system is provided, comprising:

[0007] The receiving coil is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current.

[0008] The compensation network is electrically connected to both ends of the receiving coil; it is used to output a constant current.

[0009] A controllable rectifier, the input of which is electrically connected to a compensation network, and the output of which is connected to a constant voltage load;

[0010] The controller, electrically connected to the controllable rectifier, is used to control the controllable rectifier to operate in a short-circuit state, obtain a synchronization signal based on the input current of the controllable rectifier, control the controllable rectifier to switch from the short-circuit state to the controllable rectifier output state, control the controllable rectifier circuit according to the synchronization signal, adjust the DC output voltage and stabilize it to the target voltage; after the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage to the target voltage; when the equivalent resistance of the constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle.

[0011] Optionally, the controllable rectifier is equipped with a controllable rectifier circuit;

[0012] The controllable rectifier circuit includes a first diode, a second diode, a third diode, a fourth diode, a first field-effect transistor, and a second field-effect transistor;

[0013] The first terminal of the first diode is electrically connected to the second terminal of the third diode, and the first terminal of the controlled rectifier circuit is connected between the first terminal of the first diode and the second terminal of the third diode; the first terminal of the second diode is electrically connected to the second terminal of the fourth diode, and the fourth terminal of the controlled rectifier circuit is connected between the first terminal of the second diode and the second terminal of the fourth diode; the second terminals of the first diode and the second diode are electrically connected to the second terminal of the controlled rectifier circuit; the first terminals of the third diode and the first terminals of the fourth diode are electrically connected to the third terminal of the controlled rectifier circuit.

[0014] The first and second terminals of the first field-effect transistor are connected in parallel to the first and second terminals of the third diode; the first and second terminals of the second field-effect transistor are connected in parallel to the first and second terminals of the fourth diode.

[0015] Optionally, the control terminals of both the first and second field-effect transistors are electrically connected to the controller.

[0016] Optionally, the compensation network includes: a first capacitor, a second capacitor, a third capacitor, a first inductor, and a second inductor.

[0017] The first terminal of the first capacitor is electrically connected to one end of the receiving coil, and the second terminal of the first capacitor is electrically connected to the first terminal of the first inductor. The second terminal of the first inductor is electrically connected to the first terminal of the controllable rectifier circuit. The first terminal of the second capacitor is electrically connected to the other end of the receiving coil, and the second terminal of the second capacitor is electrically connected to the first terminal of the second inductor. The second terminal of the second inductor is electrically connected to the fourth terminal of the controllable rectifier circuit. The third capacitor is connected in parallel between the second terminals of the first capacitor and the second terminal of the second capacitor.

[0018] According to another aspect of the present invention, a wireless charging control method is provided, applicable to a wireless charging control system. The wireless charging control system includes: a receiving coil, a compensation network, and a controllable rectifier. The receiving coil is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current. The compensation network is electrically connected to both ends of the receiving coil and is used to output a constant current. The input end of the controllable rectifier is electrically connected to the compensation network, and the output end is connected to a constant voltage load.

[0019] Wireless charging control methods include:

[0020] The controllable rectifier is controlled to operate in a short-circuit state, and a synchronization signal is obtained based on the input current of the controllable rectifier; wherein, the synchronization signal includes: current resonant frequency and current zero-crossing information;

[0021] Control the controllable rectifier to switch from a short-circuit state to a controllable rectifier output state;

[0022] The output voltage of the controllable rectifier circuit is controlled according to the synchronization signal and stabilized to the target voltage.

[0023] After the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage at the target voltage.

[0024] When the equivalent resistance of a constant voltage load fluctuates, the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle are dynamically adjusted.

[0025] Optionally, the controllable rectifier includes a controllable rectifier circuit, which includes a first diode, a second diode, a third diode, a fourth diode, a first field-effect transistor (FET), and a second field-effect transistor (FET). The first terminal of the first diode is electrically connected to the second terminal of the third diode, the first terminal of the second diode is electrically connected to the second terminal of the fourth diode, the second terminal of the first diode is electrically connected to the second terminal of the second diode, and the first terminal of the third diode is electrically connected to the first terminal of the fourth diode. The first and second terminals of the first FET are connected in parallel to the first and second terminals of the third diode. The first and second terminals of the second FET are connected in parallel to the first and second terminals of the fourth diode.

[0026] Adjusting the phase angle of the output current of the controllable rectifier includes:

[0027] Controlling the on / off state of the first and second field-effect transistors in the controllable rectifier adjusts the phase angle of the output current of the controllable rectifier.

[0028] Optionally, when both the first and second field-effect transistors in the controllable rectifier are turned on, the phase angle of the output current of the controllable rectifier is adjusted to 0°, and the controllable rectifier operates in a short-circuit state.

[0029] When both the first and second field-effect transistors in the controllable rectifier are turned off, the phase angle of the output current of the controllable rectifier is adjusted to 90°, and the controllable rectifier operates in the uncontrolled rectifier output state.

[0030] When the first and second field-effect transistors in the controllable rectifier are alternately turned on, the phase angle of the output current of the controllable rectifier is adjusted to between 0° and 90°, and the controllable rectifier operates in the controllable rectification output state.

[0031] Optionally, before dynamically adjusting the control frequency for adjusting the phase angle of the output current of the controllable rectifier when the equivalent resistance of the constant voltage load fluctuates, the following method is also included:

[0032] Calculate the equivalent resistance of the load based on the target voltage and load power;

[0033] The time constant and control frequency are calculated based on the load equivalent resistance and bus capacitance.

[0034] Optionally, before controlling the controllable rectifier to operate in a short-circuit state and obtaining a synchronization signal based on the input current of the controllable rectifier, the method further includes:

[0035] The communication signal is sent to the transmitter controller, causing the transmitter coil to generate a high-frequency magnetic field.

[0036] Optionally, after dynamically adjusting the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle when the equivalent resistance of the constant voltage load fluctuates, the system further includes:

[0037] Wireless charging is complete when the load connection is disconnected or the load is turned off.

[0038] The controllable rectifier switches from the controllable rectifier output state to the short-circuit state and remains in standby mode.

[0039] This invention provides a wireless charging system with a controllable rectifier. A controller regulates the operating state and frequency of the controllable rectifier. When the rectifier is in a short-circuit state, the system acquires the synchronization signal of the input current and determines it as the operating frequency. The controller then controls the rectifier to operate in a controllable rectification output state, adjusting the phase angle of the output current based on the synchronization signal to stabilize the DC output voltage at the target voltage. When a constant-voltage load is activated, the wireless charging system provides constant-voltage charging. When the equivalent resistance of the constant-voltage load fluctuates, the system dynamically adjusts the phase angle based on the calculated control frequency to achieve stable constant-voltage output. This constant-voltage output wireless charging system can adapt to different types of constant-voltage loads and, under controllable conditions, achieves constant-voltage output while reducing controller memory consumption.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a structural diagram of a wireless charging control system provided according to an embodiment of the present invention;

[0043] Figure 2This is a structural diagram of a controllable rectifier circuit in a wireless charging control system according to an embodiment of the present invention;

[0044] Figure 3 This is a structural diagram of a compensation network in a wireless charging control system according to an embodiment of the present invention;

[0045] Figure 4 This is a flowchart of a wireless charging control method provided according to an embodiment of the present invention;

[0046] Figure 5 This is a circuit diagram of the controllable rectifier in the wireless charging control system provided according to an embodiment of the present invention when the controllable rectifier is operating in a short-circuit state.

[0047] Figure 6 This is a circuit diagram of the controllable rectifier in the wireless charging control system provided by the embodiment of the present invention when the controllable rectifier is operating in the uncontrolled rectifier output state.

[0048] Figure 7 This is a circuit diagram of a wireless charging control system according to an embodiment of the present invention, showing the controllable rectifier operating in the controllable rectifier output state.

[0049] Figure 8 This is a circuit diagram of a controllable rectifier operating in a controllable rectifier output state in another wireless charging control system according to an embodiment of the present invention.

[0050] Figure 9 This is a flowchart of another wireless charging control method provided according to an embodiment of the present invention;

[0051] Figure 10 The input current i of the controllable rectifier provided according to an embodiment of the present invention is... reci Output current i reco and input voltage v rec Waveform diagram of the relationship between them;

[0052] Figure 11 This is a flowchart of another wireless charging control method provided according to an embodiment of the present invention;

[0053] Figure 12 This is a flowchart of another wireless charging control method provided according to an embodiment of the present invention. Detailed Implementation

[0054] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0055] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0056] This invention provides a wireless charging control system. Figure 1 This is a structural diagram of a wireless charging control system provided in an embodiment of the present invention. Figure 1 As shown, the wireless charging control system includes: a receiver coil 10, a compensation network 20, a controllable rectifier 30, and a controller 40.

[0057] The receiving coil 10 is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current.

[0058] The compensation network 20 is electrically connected to both ends of the receiving coil 10; it is used to output a constant current.

[0059] The input terminal of the controllable rectifier 30 is electrically connected to the compensation network 20, and the output terminal is connected to a constant voltage load.

[0060] The controller 40 is electrically connected to the controllable rectifier 30 and is used to control the controllable rectifier 30 to operate in a short-circuit state, obtain a synchronization signal based on the input current of the controllable rectifier 30, control the controllable rectifier 30 to switch from the short-circuit state to the controllable rectifier output state, control the controllable rectifier circuit according to the synchronization signal, adjust the DC output voltage and stabilize it to the target voltage; after the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier 30 to stabilize the DC output voltage to the target voltage; when the equivalent resistance of the constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier 30 and the control frequency for adjusting the phase angle.

[0061] Specifically, the wireless charging control system is configured on the vehicle-mounted end. When the transmitting coil located in the ground charging area generates a high-frequency magnetic field, an induced current will be generated in the receiving coil 10 on the vehicle-mounted end based on the principle of electromagnetic induction. The compensation network 20 can be an LCC compensation network. The input end of the compensation network 20 is electrically connected to the two ends of the receiving coil 10, so that the induced current generated by the receiving coil 10 flows into the compensation network 20, and a constant current output can be achieved when the compensation network 20 outputs it. The input end of the controllable rectifier 30 is electrically connected to the compensation network 20, and the output end is electrically connected to the constant voltage load, so that the constant current output by the compensation network 20 is input into the controllable rectifier 30. After rectification and regulation, a constant voltage current can be output to the constant voltage load for charging. Furthermore, the current and voltage can be adjusted to the appropriate values ​​according to the type of constant voltage load to stably output to the constant voltage load.

[0062] The controller 40 is electrically connected to the control terminal of the controllable rectifier 30 and is used to control the operating state of the controllable rectifier 30. When no constant voltage load is connected to the wireless charging system and wireless charging of the constant voltage load is not required, the controller 40 controls the controllable rectifier 30 to operate in a short-circuit state. When wireless charging of the constant voltage load is required, the controller 40 obtains the synchronization signal of the current input to the controllable rectifier 30 through the sampling circuit connected to the wireless charging system, so that the controller 40 controls the controllable rectifier 30 to operate in a controllable rectification output state. The current synchronization signal may include current zero-crossing information and the current resonant frequency; based on the synchronization signal, the current oscillation waveform image can be obtained. After obtaining the current synchronization signal, the controller 40 controls the operating frequency of the controllable rectifier 30 to be the same as the current oscillation frequency, so as to rectify and regulate the current output constant voltage current to the constant voltage load. The controller 40 adjusts the phase angle of the output current of the controllable rectifier 30 to stabilize the DC output current voltage value to the target voltage, after which the constant voltage load is turned on. During wireless charging, when the equivalent resistance of the constant voltage load fluctuates and the actual voltage value of the DC output current exceeds the threshold range of the target voltage, the controller 40 calculates a suitable control frequency for adjusting the phase angle based on the relevant parameters of the current system, and dynamically adjusts the phase angle of the output current of the controllable rectifier 30 to stabilize the actual voltage value of the DC output current near the target voltage, thereby achieving constant voltage output. Furthermore, while satisfying the constant voltage output requirement, the phase angle is adjusted to the optimal value, reducing the memory consumption of the controller and saving resources.

[0063] This embodiment designs a wireless charging system with a controllable rectifier. A controller regulates the operating state and frequency of the controllable rectifier. When the controllable rectifier operates in a short-circuit state, the system acquires the synchronization signal of the input current and determines it as the operating frequency. The controller controls the controllable rectifier to operate in a controllable rectification output state, adjusting the phase angle of the output current based on the synchronization signal to stabilize the DC output voltage of the controllable rectifier at the target voltage. When a constant voltage load is activated, the wireless charging system charges the load at a constant voltage. When the equivalent resistance of the constant voltage load fluctuates, the system dynamically adjusts the phase angle based on the calculated control frequency to achieve a stable constant voltage output. This constant voltage output wireless charging system can adapt to different types of constant voltage loads and, under controllable conditions, achieves constant voltage output while reducing controller memory consumption.

[0064] Optional, Figure 2 This is a structural diagram of a controllable rectifier circuit in a wireless charging control system provided by an embodiment of the present invention. This embodiment details the specific structure of the controllable rectifier in the above embodiments. Figure 2 As shown, the controllable rectifier is equipped with a controllable rectifier circuit;

[0065] The controllable rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first field-effect transistor Q1, and a second field-effect transistor Q2;

[0066] The first terminal of the first diode D1 is electrically connected to the second terminal of the third diode D3. The first terminal X1 of the controlled rectifier circuit is connected between the first terminal of the first diode D1 and the second terminal of the third diode D3. The first terminal of the second diode D2 is electrically connected to the second terminal of the fourth diode D4. The fourth terminal X4 of the controlled rectifier circuit is connected between the first terminal of the second diode D2 and the second terminal of the fourth diode D4. The second terminals of the first diode D1 and the second diode D2 are electrically connected to the second terminal X2 of the controlled rectifier circuit. The first terminals of the third diode D3 and the first terminal of the fourth diode D4 are electrically connected to the third terminal X3 of the controlled rectifier circuit.

[0067] The first and second terminals of the first field-effect transistor Q1 are connected in parallel to the first and second terminals of the third diode D3; the first and second terminals of the second field-effect transistor Q2 are connected in parallel to the first and second terminals of the fourth diode D4.

[0068] Specifically, the controllable rectifier includes a controllable rectifier circuit for adjusting the phase angle of the output current, ensuring the output current is a DC constant-voltage output current adapted to the constant-voltage load. In the controllable rectifier circuit, the first diode D1 and the third diode D3 are connected in series, the second diode D2 and the fourth diode D4 are connected in series, and the second terminal of the first diode D1 and the first terminal of the third diode D3 are connected in parallel to the second terminal of the second diode D2 and the first terminal of the fourth diode D4. The circuit composed of four diodes forms an uncontrolled rectifier circuit, which can rectify the input current at a fixed frequency to obtain a DC output current. In this embodiment, the first field-effect transistor Q1 is connected in parallel across the two terminals of the third diode D3, and the second field-effect transistor Q2 is connected in parallel across the two terminals of the fourth diode D4, forming a controllable rectifier circuit. The controllable rectifier circuit can control the magnitude of the input current phase angle and the control frequency of the phase angle adjustment, thereby dynamically and in real time adjusting the phase angle when the equivalent resistance of the constant-voltage load fluctuates during charging, ensuring that the voltage value of the DC output current remains stable near the target voltage.

[0069] Optionally, the control electrodes of both the first field-effect transistor Q1 and the second field-effect transistor Q2 are electrically connected to the controller. The first field-effect transistor Q1 and the second field-effect transistor Q2 can be N-type MOSFETs. The controller can control the conduction or cutoff of the first field-effect transistor Q1 and the second field-effect transistor Q2 by outputting level signals to their control electrodes, thereby adjusting the phase angle of the output current and achieving constant voltage output.

[0070] Optional, Figure 3 This is a structural diagram of the compensation network in a wireless charging control system provided by an embodiment of the present invention. This embodiment refines the specific structure of the compensation network in the above embodiments. Figure 3 As shown, the compensation network includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, and a second inductor L2.

[0071] Specifically, the first terminal of the first capacitor C1 is electrically connected to one end of the receiving coil 10, and the second terminal of the first capacitor C1 is electrically connected to the first terminal of the first inductor L1; the second terminal of the first inductor L1 is electrically connected to the first terminal of the controllable rectifier 30; the first terminal of the second capacitor C2 is electrically connected to the other end of the receiving coil 10, and the second terminal of the second capacitor C2 is electrically connected to the first terminal of the second inductor L2; the second terminal of the second inductor L2 is electrically connected to the fourth terminal of the controllable rectifier 30; and the third capacitor C3 is connected in parallel between the second terminals of the first capacitor C1 and the second terminals of the second capacitor C2.

[0072] Specifically, the compensation network can be an LCC compensation network. When the ground-based transmitting coil generates a high-frequency magnetic field, the vehicle-mounted receiving coil generates an induced current based on the principle of electromagnetic induction, which is then output to the compensation network. By changing the operating frequency, the parameter values ​​of the first capacitor C1, the second capacitor C2, the third capacitor C3, the first inductor L1, and the second inductor L2 are changed, thereby achieving a constant current source output.

[0073] This invention also provides a wireless charging control method. Figure 4 This is a flowchart of a wireless charging control method provided in an embodiment of the present invention. See also... Figure 1 and Figure 4 This wireless charging control method is applicable to a wireless charging control system, which includes: a receiving coil, a compensation network, and a controllable rectifier. The receiving coil is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current. The compensation network is electrically connected to both ends of the receiving coil and is used to output a constant current. The input end of the controllable rectifier is electrically connected to the compensation network, and the output end is connected to a constant voltage load.

[0074] The wireless charging control method includes:

[0075] S110. Control the controllable rectifier to operate in a short-circuit state and obtain a synchronization signal based on the input current of the controllable rectifier; wherein, the synchronization signal includes: current resonant frequency and current zero-crossing information.

[0076] Specifically, the synchronization signal of the input current of the controllable rectifier can include the current resonant frequency and the current zero-crossing information. Since the input current of the controllable rectifier is an AC signal, the current zero-crossing information is the time information when the current value is zero during the periodic oscillation of the AC signal, thus obtaining the starting point of one oscillation cycle of the AC signal. The current resonant frequency can include the frequency and amplitude of the AC signal oscillation, thus obtaining the oscillation waveform of the AC signal. The controller keeps the controllable rectifier circuit in a short-circuit state, preventing it from outputting voltage to the constant voltage load. The synchronization signal of the controllable rectifier input current can be obtained using a sampling circuit connected to an external wireless charging system to obtain the oscillation information.

[0077] S120: Control the controllable rectifier to switch from short-circuit state to controllable rectifier output state.

[0078] Specifically, after receiving the synchronization signal of the input current of the controllable rectifier, the controller controls the operating state of the controllable rectifier to switch from the short-circuit state to the controllable rectifier output state, controls the operating frequency of the controllable rectifier, and enables the controllable rectifier to regulate the voltage of the output current.

[0079] S130: Control the output voltage of the controllable rectifier circuit according to the synchronization signal and stabilize it to the target voltage.

[0080] Specifically, the target voltage is the required voltage adapted to the connected constant voltage load. The controllable rectifier operates in controllable rectification output mode, and its DC output voltage is adjusted to rise from zero to the target voltage. A target voltage threshold range is set near the target voltage. This threshold range represents the acceptable charging voltage for the constant voltage load, and it varies for different constant voltage loads. For example, the target voltage threshold range can be ±5V of the target voltage. When the controller gradually increases the voltage of the controllable rectifier's output current and stabilizes within the target voltage threshold range, it can be considered that the voltage of the controllable rectifier's output current has met the requirement of stabilizing to the target voltage.

[0081] S140. After the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage at the target voltage.

[0082] Specifically, after the voltage value of the controllable rectifier output current stabilizes at the target voltage, the constant voltage load connected to the output terminal of the controllable rectifier is turned on and connected to the circuit to begin wireless charging of the constant voltage load battery. After the constant voltage load is connected to the circuit, the DC output voltage of the controllable rectifier output current will change. The controller adjusts the DC output voltage to the target voltage threshold range by controlling the phase angle of the controllable rectifier output current and stabilizes it within the target voltage threshold range. This ensures that the DC output voltage remains within the target voltage threshold range throughout the charging process of the constant voltage load, thus providing the DC voltage required for charging the constant voltage load battery.

[0083] S150: When the equivalent resistance of a constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle.

[0084] Specifically, during the charging process, as the battery charge gradually increases, the required charging power for the constant-voltage load decreases, causing fluctuations in the equivalent resistance of the constant-voltage load. At this time, the DC output voltage of the controllable rectifier may exceed the target voltage threshold range, making it impossible to maintain constant-voltage charging for the constant-voltage load. During the fluctuation of the constant-voltage load's equivalent resistance, the controller controls the phase angle of the controllable rectifier's output current and adjusts the frequency of the output current to stabilize the DC output voltage value after the AC signal is converted to a DC signal within the target voltage threshold range.

[0085] Because the equivalent resistance of a constant-voltage load fluctuates dynamically during charging, the phase angle of the controllable rectifier's output current needs to be adjusted in real time using a preset control frequency. Furthermore, dynamically adjusting the preset control frequency during charging ensures sufficient power for the constant-voltage load while reducing memory consumption caused by the controller operating at inappropriate frequencies, thus saving resources and achieving superior constant-voltage output control in the wireless charging system.

[0086] Optionally, this embodiment refines the method features of step S140 in the above embodiments. See also... Figure 2 The controllable rectifier includes a controllable rectifier circuit, which includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first field-effect transistor Q1, and a second field-effect transistor Q2. The first terminal of the first diode D1 is electrically connected to the second terminal of the third diode D3, the first terminal of the second diode D2 is electrically connected to the second terminal of the fourth diode D4, the second terminal of the first diode D1 is electrically connected to the second terminal of the second diode D2, and the first terminal of the third diode D3 is electrically connected to the first terminal of the fourth diode D4. The first and second terminals of the first field-effect transistor Q1 are connected in parallel to the first and second terminals of the third diode D3; the first and second terminals of the second field-effect transistor Q2 are connected in parallel to the first and second terminals of the fourth diode D4.

[0087] Adjusting the phase angle of the output current of the controllable rectifier includes:

[0088] Controlling the on / off state of the first and second field-effect transistors in the controllable rectifier adjusts the phase angle of the output current of the controllable rectifier.

[0089] Specifically, the control electrodes of the first field-effect transistor Q1 and the second field-effect transistor Q2 in the controllable rectifier circuit are both electrically connected to the controller. The controller outputs corresponding level signals to the control electrodes of the first field-effect transistor Q1 and the second field-effect transistor Q2 to control the first field-effect transistor Q1 and the second field-effect transistor Q2 to turn on or off, thereby adjusting the phase angle of the output current of the controllable rectifier and outputting a constant DC voltage output current to the constant voltage load.

[0090] When the first field-effect transistor Q1 and the second field-effect transistor Q2 are in different states, the controllable rectifier operates in different states. Optionally, when both the first and second field-effect transistors in the controllable rectifier are turned on, the phase angle of the output current of the controllable rectifier is adjusted to 0°, and the controllable rectifier operates in a short-circuit state.

[0091] When both the first and second field-effect transistors in the controllable rectifier are turned off, the phase angle of the output current of the controllable rectifier is adjusted to 90°, and the controllable rectifier operates in the uncontrolled rectifier output state.

[0092] When the first and second field-effect transistors in the controllable rectifier are alternately turned on, the phase angle of the output current of the controllable rectifier is adjusted to between 0° and 90°, and the controllable rectifier operates in the controllable rectification output state.

[0093] Specifically, Figure 5 This is a circuit diagram of the controllable rectifier in the wireless charging control system provided in this embodiment of the invention when it is operating in a short-circuit state. Figure 6 This is a circuit diagram of the controllable rectifier in the wireless charging control system provided in this embodiment of the invention, when it operates in the uncontrolled rectifier output state. Figure 7 This is a circuit diagram of a wireless charging control system provided in an embodiment of the present invention, showing the controllable rectifier operating in the controllable rectifier output state. Figure 8 This is a circuit diagram showing the controllable rectifier operating in a controllable rectifier output state in another wireless charging control system provided by an embodiment of the present invention. Wherein, "×" indicates that the corresponding diode and / or field-effect transistor is in the off state. For example... Figure 5 As shown, the controller outputs a high-level signal to the control electrodes of the first MOSFET Q1 and the second MOSFET Q2, turning on both MOSFETs Q1 and Q2, thus adjusting the phase angle of the output current of the controllable rectifier to 0°. The input current of the controllable rectifier enters from the first terminal X1, passes through the first MOSFET Q1 and the second MOSFET Q2 in sequence, and is output from the fourth terminal X4. The current does not pass through the diodes. At this time, the controllable rectifier operates in a short-circuit state. Figure 6 As shown, the controller outputs a low-level signal to the control electrodes of the first MOSFET Q1 and the second MOSFET Q2, turning off both MOSFETs Q1 and Q2, thus adjusting the phase angle of the controlled rectifier output current to 90°. The forward input current of the controlled rectifier enters from the first terminal X1, passes through the first diode D1, and is output from the second terminal X2 to the bus capacitor, then enters from the third terminal X3, passes through the fourth diode D4, and is output from the fourth terminal X4. The reverse input current enters from the fourth terminal X4, passes through the second diode D2, and is output from the second terminal X2 to the bus capacitor, then enters from the third terminal X3, passes through the third diode D3, and is output from the first terminal X1. At this time, the controlled rectifier operates in an uncontrolled rectifier output state. Figure 7 As shown, the controller outputs a low-level signal to the first MOSFET Q1 and a high-level signal to the control electrode of the second MOSFET Q2, turning off the first MOSFET Q1 and turning on the second MOSFET Q2. At this time, the forward current enters from the first terminal X1 of the controllable rectifier circuit, passes through the first diode D1, and is output from the second terminal X2 to the bus capacitor. It then enters from the third terminal X3, passes through the second MOSFET Q2, and is output from the fourth terminal X4. The reverse input current is cut off. Therefore, the controllable rectifier operates in a controllable rectification output state. Figure 8 As shown, the controller outputs a high-level signal to the first MOSFET Q1 and a low-level signal to the control electrode of the second MOSFET Q2, controlling the first MOSFET Q1 to conduct and the second MOSFET Q2 to turn off. At this time, the reverse current is input from the fourth terminal X4 of the controllable rectifier circuit, passes through the second diode D2, and is output from the second terminal X2 to the bus capacitor. It then enters from the third terminal X3, passes through the first MOSFET Q1, and is output from the first terminal X1; while the forward input current is cut off. Therefore, the controllable rectifier operates in a controllable rectification output state.

[0094] As the wireless charging process progresses, the battery charge of the constant voltage load increases, and the equivalent resistance of the constant voltage load fluctuates. The controller controls the first field-effect transistor Q1 and the second field-effect transistor Q2 to alternately turn on or off at a certain control frequency, dynamically adjusting the phase angle of the output current of the controllable rectifier to any value between 0° and 90°, and adjusting the voltage value of the DC output current to stabilize near the target voltage, thereby outputting a DC constant voltage output current adapted to the constant voltage load.

[0095] Optional, Figure 9 This is a flowchart of another wireless charging control method provided by an embodiment of the present invention. Based on the above embodiments, this embodiment adds a technical feature prior to the control frequency used to dynamically adjust the phase angle of the output current of the controllable rectifier when the equivalent resistance of the constant voltage load fluctuates. For example... Figure 9 As shown, the wireless charging control method includes:

[0096] S210: Control the controllable rectifier to operate in a short-circuit state and obtain a synchronization signal based on the input current of the controllable rectifier.

[0097] S220 controls the controllable rectifier to switch from a short-circuit state to a controllable rectifier output state.

[0098] S230: Control the output voltage of the controllable rectifier circuit according to the synchronization signal and stabilize it to the target voltage.

[0099] S240. After the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage at the target voltage.

[0100] S250. Calculate the equivalent resistance of the load based on the target voltage and load power.

[0101] Specifically, the load equivalent resistance R Load It can be determined by the target voltage V ref and load power P outCalculations show that the wireless charging control system circuit is in an unloaded state before the constant voltage load is turned on. After the DC output voltage of the controllable rectifier is stabilized to the target voltage threshold range by adjusting the phase angle of the output current, the constant voltage load is turned on. At this time, the equivalent resistance connected to the output terminal of the controllable rectifier changes from infinite to R. Load According to formula R Load =V ref 2 / P out The equivalent resistance value of a constant voltage load can be calculated.

[0102] During the charging process, as the load power P... out As the voltage changes, the equivalent resistance of the constant voltage load will also change. At this time, the DC output voltage of the controllable rectifier will deviate from the target voltage threshold range. The DC output voltage of the controllable rectifier can be determined by the input current i of the controllable rectifier. reci Output current i reco and input voltage v rec Calculated. Figure 10 The input current i of the controllable rectifier provided in this embodiment of the invention is... reci Output current i reco and input voltage v rec A waveform diagram illustrating the relationship between them. For example, as shown... Figure 10 As shown, the input current i reci The waveform is shown as the long dashed line in the figure, and the output current i reco The waveform is shown as the solid line in the figure, and the input voltage v rec The waveform is shown as the short dashed line in the figure. The input current i of the controllable rectifier... reci It can be calculated using the following formula:

[0103]

[0104] Among them, I ga M is the current amplitude of the ground transmitting coil, M is the mutual inductance between the receiver and transmitter, and L is the current amplitude of the ground transmitting coil. va ω is the inductance of the receiver coil, ω is the operating angular frequency of the wireless charging system, and φ is the phase difference between the input voltage and current of the rectifier.

[0105] When the current flows through the controlled rectifier circuit in the controlled rectifier, only the current flowing through the first diode and the second diode will be output to the constant voltage load connected to the output terminal of the controlled rectifier. Therefore, the output current i reco The input current is not zero for 2β time periods within each half-cycle of the input current. When the output current i reco When the input voltage v of the controllable rectifier is 0, rec It is also 0; when the output current i recoWhen the input voltage v of the controllable rectifier is not 0, rec The input voltage is either positive or negative, and alternates between them. Within a 2β time interval of each half-cycle of the input current, the input voltage v... rec Not zero. When β = 0°, i.e., the input voltage v rec When the value is 0, both the first field-effect transistor Q1 and the second field-effect transistor Q2 are turned on, and the controllable rectifier operates as follows: Figure 5 The short-circuit condition shown; when β = 90°, i.e., the input voltage v rec In the input current i reci Throughout the entire cycle, the voltage level is either positive or negative. During this time, both the first field-effect transistor Q1 and the second field-effect transistor Q2 are turned off, and the controllable rectifier operates as follows: Figure 6 The uncontrolled rectifier output state is shown; when β is between 0° and 90°, i.e., the input voltage v rec In the input current i reci During the 2β time period of the cycle, the voltage level is either positive or negative. At this time, the first field-effect transistor Q1 is turned on and the second field-effect transistor Q2 is turned off, or the first field-effect transistor Q1 is turned off and the second field-effect transistor Q2 is turned on. The controllable rectifier operates alternately in this state. Figure 7 and Figure 8 The controllable rectifier output state is shown to adjust the DC output voltage value to the target voltage.

[0106] In the output current i reco After filtering by the bus capacitor connected to the output terminal of the controllable rectifier, the output DC current can be calculated using the following formula:

[0107]

[0108] After calculating the DC output current I dc Then, based on the bus capacitance C bus and the equivalent resistance R of a constant voltage load Load The DC output voltage V can be calculated using the following formula. dc :

[0109]

[0110] When the calculated DC output voltage V dc When the voltage is not stable within the target voltage threshold range, the controller adjusts the DC output voltage to the target voltage by controlling the phase angle β of the output current of the controllable rectifier.

[0111] S260. The time constant and control frequency are calculated based on the equivalent resistance of the load and the bus capacitance.

[0112] Specifically, the control frequency f is the frequency at which the controllable rectifier circuit is adjusted, and the time constant τ is the basis for selecting the control frequency f. The time constant τ can be determined by the equivalent resistance R of the constant voltage load. Load and bus capacitor C bus The calculation yields τ = R. Load ·C bus When the control frequency f satisfies 1 / f < 0.1τ, a better control effect of DC output voltage can be obtained. This can not only ensure that the DC output voltage is stable at the target voltage output, but also reduce the memory loss of the controller in adjusting the phase angle β of the controllable rectifier output current, thus saving resources.

[0113] S270. When the equivalent resistance of the constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle.

[0114] Optional, Figure 11 This is a flowchart of another wireless charging control method provided by an embodiment of the present invention. Based on the above embodiments, this embodiment adds technical features prior to controlling the controllable rectifier to operate in a short-circuit state and obtaining a synchronization signal based on the input current of the controllable rectifier. For example... Figure 11 As shown, the wireless charging control method includes:

[0115] S310: Sends a communication signal to the transmitter controller, causing the transmitter coil to generate a high-frequency magnetic field.

[0116] Specifically, when a constant voltage load is connected to the output of a controllable rectifier circuit, the receiver controller transmits a communication signal to the transmitter controller, entering a constant voltage load wireless charging mode, causing the transmitter coil to generate a high-frequency magnetic field. Based on the principle of electromagnetic induction, the receiver coil induces a current, which, after being regulated by a compensation network and a controllable rectifier, outputs a DC voltage that is stabilized at the target voltage, used to charge the constant voltage load.

[0117] S320 controls the controllable rectifier to operate in a short-circuit state and obtains a synchronization signal based on the input current of the controllable rectifier.

[0118] S330 controls the controllable rectifier to switch from a short-circuit state to a controllable rectifier output state.

[0119] S340: Controls the output voltage of the controllable rectifier circuit according to the synchronization signal and stabilizes it to the target voltage.

[0120] S350. After the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage at the target voltage.

[0121] S360. When the equivalent resistance of the constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle.

[0122] Optional, Figure 12 This is a flowchart of another wireless charging control method provided by an embodiment of the present invention. Based on the above embodiments, this embodiment adds the technical feature of dynamically adjusting the control frequency to adjust the phase angle of the output current of the controllable rectifier when the equivalent resistance of the constant voltage load fluctuates. Figure 12 As shown, the wireless charging control method includes:

[0123] S410 controls the controllable rectifier to operate in a short-circuit state and obtains a synchronization signal based on the input current of the controllable rectifier.

[0124] S420 controls the controllable rectifier to switch from a short-circuit state to a controllable rectifier output state.

[0125] S430 controls the output voltage of the controllable rectifier circuit according to the synchronization signal and stabilizes it to the target voltage.

[0126] S440. After the constant voltage load is turned on, adjust the phase angle of the output current of the controllable rectifier to stabilize the DC output voltage at the target voltage.

[0127] S450. When the equivalent resistance of the constant voltage load fluctuates, dynamically adjust the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle.

[0128] S460: Disconnect the load or turn off the load to complete wireless charging.

[0129] Specifically, during wireless charging, when the power of the constant voltage load falls below the power threshold, the connection between the constant voltage load and the controllable rectifier is disconnected, or the constant voltage load is turned off, thus completing the wireless charging process. The power threshold can be the power value at which the constant voltage load battery is fully charged, or the power value at which the constant voltage load battery enters the charging protection state.

[0130] S470, the controllable rectifier switches from the controllable rectifier output state to the short-circuit state and remains in standby mode.

[0131] Specifically, after the wireless charging process is completed, the equivalent resistance connected to the output terminal of the controllable rectifier becomes infinite again, and no output current is needed. Therefore, the controllable rectifier switches from the controllable rectifier output state to the short-circuit state, waiting for the next wireless charging process to switch back from the short-circuit state to the controllable rectifier output state.

[0132] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A wireless charging control system, characterized in that, include: A receiving coil is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current. A compensation network is electrically connected to both ends of the receiving coil; Used to output constant current; A controllable rectifier, wherein the input terminal of the controllable rectifier is electrically connected to the compensation network, and the output terminal is connected to a constant voltage load; A controller, electrically connected to the controllable rectifier, is used to control the controllable rectifier to operate in a short-circuit state, acquire a synchronization signal based on the input current of the controllable rectifier, control the controllable rectifier to switch from the short-circuit state to the controllable rectifier output state, and control the controllable rectifier according to the synchronization signal to adjust the DC output voltage and stabilize it to the target voltage; after the constant voltage load is turned on, the phase angle of the output current of the controllable rectifier is adjusted to stabilize the DC output voltage to the target voltage; when the equivalent resistance of the constant voltage load fluctuates, the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle are dynamically adjusted. Before dynamically adjusting the control frequency that adjusts the phase angle of the output current of the controllable rectifier when the equivalent resistance of the constant voltage load fluctuates, the method further includes: Calculate the equivalent resistance of the load based on the target voltage and load power; The time constant and the control frequency are calculated based on the equivalent resistance of the load and the bus capacitance.

2. The wireless charging control system according to claim 1, characterized in that, The controllable rectifier is equipped with a controllable rectifier circuit; The controllable rectifier circuit includes a first diode, a second diode, a third diode, a fourth diode, a first field-effect transistor, and a second field-effect transistor; The first terminal of the first diode is electrically connected to the second terminal of the third diode, and the first terminal of the controllable rectifier circuit is connected between the first terminal of the first diode and the second terminal of the third diode; the first terminal of the second diode is electrically connected to the second terminal of the fourth diode, and the fourth terminal of the controllable rectifier circuit is connected between the first terminal of the second diode and the second terminal of the fourth diode; the second terminals of the first diode and the second diode are electrically connected to the second terminal of the controllable rectifier circuit; the first terminals of the third diode and the fourth diode are electrically connected to the third terminal of the controllable rectifier circuit. The first and second terminals of the first field-effect transistor are connected in parallel to the first and second terminals of the third diode; the first and second terminals of the second field-effect transistor are connected in parallel to the first and second terminals of the fourth diode.

3. The wireless charging control system according to claim 2, characterized in that, The control terminals of both the first and second field-effect transistors are electrically connected to the controller.

4. The wireless charging control system according to claim 1, characterized in that, The compensation network includes: a first capacitor, a second capacitor, a third capacitor, a first inductor, and a second inductor; Wherein, the first terminal of the first capacitor is electrically connected to one end of the receiving coil, and the second terminal of the first capacitor is electrically connected to the first terminal of the first inductor; the second terminal of the first inductor is electrically connected to the first terminal of the controllable rectifier; the first terminal of the second capacitor is electrically connected to the other end of the receiving coil, and the second terminal of the second capacitor is electrically connected to the first terminal of the second inductor; the second terminal of the second inductor is electrically connected to the fourth terminal of the controllable rectifier; and the third capacitor is connected in parallel between the second terminal of the first capacitor and the second terminal of the second capacitor.

5. A wireless charging control method, applicable to a wireless charging control system, characterized in that, The wireless charging control system includes: a receiving coil, a compensation network, and a controllable rectifier. The receiving coil is used to sense the high-frequency magnetic field generated by the transmitting coil and generate an induced current. The compensation network is electrically connected to both ends of the receiving coil and is used to output a constant current. The input end of the controllable rectifier is electrically connected to the compensation network, and the output end is connected to a constant voltage load. The wireless charging control method includes: The controllable rectifier is controlled to operate in a short-circuit state, and a synchronization signal is obtained based on the input current of the controllable rectifier; wherein, the synchronization signal includes: current resonant frequency and current zero-crossing information; Control the controllable rectifier to switch from a short-circuit state to a controllable rectified output state; The output voltage of the controllable rectifier is controlled according to the synchronization signal and stabilized to the target voltage. After the constant voltage load is turned on, the phase angle of the output current of the controllable rectifier is adjusted to stabilize the DC output voltage at the target voltage. When the equivalent resistance of the constant voltage load fluctuates, the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle are dynamically adjusted. Before dynamically adjusting the control frequency that adjusts the phase angle of the output current of the controllable rectifier when the equivalent resistance of the constant voltage load fluctuates, the method further includes: Calculate the equivalent resistance of the load based on the target voltage and load power; The time constant and the control frequency are calculated based on the equivalent resistance of the load and the bus capacitance.

6. The method according to claim 5, characterized in that, The controllable rectifier includes a controllable rectifier circuit, which includes a first diode, a second diode, a third diode, a fourth diode, a first field-effect transistor (FET), and a second field-effect transistor (FET). The first terminal of the first diode is electrically connected to the second terminal of the third diode, the first terminal of the second diode is electrically connected to the second terminal of the fourth diode, the second terminal of the first diode is electrically connected to the second terminal of the second diode, and the first terminal of the third diode is electrically connected to the first terminal of the fourth diode. The first and second terminals of the first FET are connected in parallel to the first and second terminals of the third diode; the first and second terminals of the second FET are connected in parallel to the first and second terminals of the fourth diode. Adjusting the phase angle of the output current of the controllable rectifier includes: The phase angle of the output current of the controllable rectifier is adjusted by controlling the on or off state of the first field-effect transistor and the second field-effect transistor in the controllable rectifier.

7. The method according to claim 6, characterized in that, include: When both the first field-effect transistor and the second field-effect transistor in the controllable rectifier are turned on, the phase angle of the output current of the controllable rectifier is adjusted to 0°, and the controllable rectifier operates in a short-circuit state. When both the first field-effect transistor and the second field-effect transistor in the controllable rectifier are turned off, the phase angle of the output current of the controllable rectifier is adjusted to 90°, and the controllable rectifier operates in an uncontrolled rectified output state. When the first field-effect transistor and the second field-effect transistor in the controllable rectifier are alternately turned on, the phase angle of the output current of the controllable rectifier is adjusted to between 0° and 90°, and the controllable rectifier operates in a controllable rectification output state.

8. The method according to claim 5, characterized in that, Before controlling the controllable rectifier to operate in a short-circuit state and obtaining a synchronization signal based on the input current of the controllable rectifier, the method further includes: The communication signal is sent to the transmitter controller, causing the transmitter coil to generate a high-frequency magnetic field.

9. The method according to claim 5, characterized in that, After dynamically adjusting the phase angle of the output current of the controllable rectifier and the control frequency for adjusting the phase angle when the equivalent resistance of the constant voltage load fluctuates, the method further includes: Wireless charging is complete when the load connection is disconnected or the load is turned off. The controllable rectifier switches from the controllable rectifier output state to the short-circuit state and remains in standby mode.

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