Wireless charging system and operating method thereof
By short-circuiting the midpoint of the full-bridge rectifier bridge arm of the power receiver in the wireless charging system, the problems of power receiver protection and transmitter shutdown delay are solved, and the protection mechanism is triggered in a timely manner to avoid receiver damage.
Patent Information
- Application Number
- CN202510612441.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-08-08
AI Technical Summary
In a wireless charging system, when the protection mechanism of the power receiver is triggered, the shutdown delay of the power transmitter causes the receiver to be damaged, and fast wireless communication increases costs.
The protection mechanism is triggered by short-circuiting the two bridge arms midpoints of the full-bridge rectifier at the control circuit of the power receiver device, so that the voltage across the midpoint of the bridge arms is zero, which is reflected to the full-bridge inverter output of the power transmitter.
Reduces the delay between the protection of the power receiver device and the protection of the power transmitter device, ensuring that the power transmitter timely recognizes the protection status of the receiver and avoids damage to the receiver.
Smart Images
Figure CN120454334A_ABST
Abstract
Description
Technical Field
[0001] This case relates to a wireless charging system and its operating method, and more particularly to a wireless charging system based on wireless power transmission and its operating method. Background Art
[0002] In wireless power transmission technology, the power transmitter and power receiver are two separate components, with energy transferred from the power transmitter to the power receiver without the need for wiring. The power transmitter and power receiver typically collaborate using wireless communication to regulate transmission power and perform operations such as feedback and protection. In such cases, if a protection mechanism on the power receiver side is triggered, the power receiver typically requests the power transmitter to shut down via wireless communication.
[0003] However, the load of a wireless charger is often a battery, and communication between the power transmitter and receiver doesn't need to be extremely fast. This can cause a delay between the protection of the power receiver and the shutdown of the power transmitter. If, during protection, only the power receiver is shut down while the power transmitter remains operational, this can damage the receiver. Furthermore, requiring the wireless communication rate to be as fast as possible increases the cost of the wireless communication component.
[0004] Therefore, how to provide a power receiver device is an important issue in the art. Summary of the Invention
[0005] One embodiment of the present disclosure provides a wireless charging system. The wireless charging system includes a power transmitter device and a power receiver device. The power transmitter device includes a transmitter coil, a transmitter compensation network, a full-bridge inverter, and a transmitter controller. The full-bridge inverter is electrically connected to the transmitter coil via the transmitter compensation network. The transmitter controller is electrically connected to the full-bridge inverter. The power receiver device is configured to receive wireless power transmitted by the power transmitter device. The power receiver device includes a receiver coil, a receiver compensation network, a full-bridge rectifier, and a control circuit. The full-bridge rectifier is electrically connected to the receiver coil via the receiver compensation network. The control circuit is electrically connected to the full-bridge rectifier. The control circuit is configured to control the operation of the full-bridge rectifier. When a protection mechanism for the power receiver device is triggered, the control circuit short-circuits the midpoints of the two bridge arms of the full-bridge rectifier, causing the voltage across the midpoints of the two bridge arms to be zero. The zero voltage across the midpoints of the two bridge arms is reflected at the output of the full-bridge inverter of the power transmitter device, thereby triggering the protection mechanism of the power transmitter device.
[0006] In some embodiments, when the midpoints of the two bridge arms of the full-bridge rectifier are short-circuited, the output power of the full-bridge rectifier is zero, thereby achieving load protection.
[0007] In some embodiments, the control circuit is used to control the operation of the full-bridge rectifier according to the wireless signal from the power transmitter device. The zero voltage across the midpoint of the two bridge arms is used to increase or decrease the output current of the transmitter to trigger the protection mechanism of the power transmitter device.
[0008] In some embodiments, if the transmitter compensation network of the power transmitter device and the receiver compensation network of the power receiver device are topologies in which the main diagonal is zero or near zero, the output current of the full-bridge inverter is reduced, and the reduced output current is used to trigger the undercurrent protection mechanism for the power transmitter device. If the transmitter compensation network of the power transmitter device and the receiver compensation network of the power receiver device are topologies in which the secondary diagonal is zero or near zero, the output current of the full-bridge inverter is increased, and the increased output current is used to trigger the overcurrent protection mechanism of the power transmitter device.
[0009] In some embodiments, a full-bridge rectifier includes two upper switches and two lower switches. A control circuit is configured to control the two upper switches and the two lower switches. When a protection mechanism for the power receiver device is triggered, the control circuit is configured to perform the following steps: setting the two lower switches to an on state and the two upper switches to an off state; or setting the two upper switches to an on state and the two lower switches to an off state.
[0010] In some embodiments, the full-bridge rectifier includes a switch electrically connected between the midpoints of the two bridge arms, wherein the control circuit is used to control the switch, and when the protection mechanism for the power receiver device is triggered, the control circuit is used to set the switch to an on state.
[0011] In some embodiments, the power receiver device further includes a sensing circuit electrically connected to the control circuit. A sensing signal generated by the sensing circuit is used to trigger a protection mechanism of the power receiver device. The sensing circuit is an output current sensing circuit, an output voltage sensing circuit, an output power sensing circuit, or a temperature sensing circuit.
[0012] In some embodiments, the protection mechanism is an over-current protection mechanism, an over-voltage protection mechanism, an over-power protection mechanism, or an over-temperature protection mechanism.
[0013] Another embodiment of the present disclosure provides an operating method for a wireless charging system. The wireless charging system includes a power transmitter device and a power receiver device. The power transmitter device includes a transmitter coil, a transmitter compensation network, a full-bridge inverter, and a transmitter controller. The full-bridge inverter is electrically connected to the transmitter coil via the transmitter compensation network. The transmitter controller is electrically connected to the full-bridge inverter. The power receiver device includes a receiver coil, a receiver compensation network, a full-bridge rectifier, a control circuit, and a sensing circuit. The full-bridge rectifier is electrically connected to the receiver coil via the receiver compensation network. The control circuit is electrically connected to the full-bridge rectifier and the sensing circuit. The operating method includes the following steps: The sensing circuit detects a physical variable of the power receiver device to generate a sensing signal. The control circuit determines whether the sensing signal triggers a protection mechanism for the power receiver device. If the sensing signal triggers the protection mechanism for the power receiver device, the control circuit short-circuits the midpoints of the two bridge arms of the full-bridge rectifier, causing the voltage across the midpoints of the two bridge arms to be zero. The zero voltage across the midpoints of the two bridge arms is reflected to the output of the full-bridge inverter of the power transmitter device, thereby triggering the protection mechanism of the power transmitter device.
[0014] In some embodiments, when the midpoints of the two bridge arms of the full-bridge rectifier are short-circuited, the output power of the full-bridge rectifier is zero, thereby achieving load protection.
[0015] In summary, when the protection mechanism of the power receiver device disclosed herein is triggered, the output current of the full-bridge inverter is reduced or increased by short-circuiting the midpoints of the two bridge arms of the full-bridge rectifier, so that the output of the power transmitter device has an identifiable and obvious change, thereby reducing the delay between the protection of the power receiver device and the protection of the power transmitter device. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] To make the above and other objects, features, advantages and embodiments of the present disclosure more apparent and understandable, the accompanying drawings are described as follows:
[0017] Figure 1 FIG. 1 is a schematic diagram of a wireless charging system according to an embodiment of the present disclosure.
[0018] Figure 2 FIG. 1 is a schematic diagram of a wireless power transmission system according to an embodiment of the present disclosure.
[0019] Figure 3 According to an embodiment of the present disclosure Figure 2 Schematic diagram of the state space model of the wireless power transfer system.
[0020] Figure 4 FIG. 1 is a schematic diagram of a wireless power transmission system according to an embodiment of the present disclosure.
[0021] Figure 5FIG. 1 is a schematic diagram of a wireless power transmission system according to an embodiment of the present disclosure.
[0022] Figure 6 FIG. 1 is a flow chart of an operating method according to an embodiment of the present disclosure.
[0023] In order to make the above and other objects, features, advantages and embodiments of the present disclosure more obvious and understandable, the accompanying drawings are described as follows:
[0024] 100, 200, 400, 500: Wireless charging system
[0025] 110: Power transmitter device
[0026] 111: AC to DC converter
[0027] 112, 212, 412, 512: Full-bridge inverter
[0028] 113,213,413,513: Transmitter compensation network
[0029] 114: Control circuit
[0030] 115: Sensing circuit
[0031] 120: Power Receiver Device
[0032] 122,222,422,522: Receiver compensation network
[0033] 123,223,423,523: Full-bridge rectifier
[0034] 124: Control circuit
[0035] 125: Sensing circuit
[0036] 130: Load
[0037] 600: Method
[0038] 610: Power Transmitter Device
[0039] 601,612,614,616,618: Steps
[0040] 620: Power Receiver Device
[0041] 622,624,626,628,629: Steps
[0042] C in ,C out :capacitance
[0043] I1: output current
[0044] I2: input current
[0045] L1: Transmitter coil
[0046] L2: Receiver coil
[0047] S 11 ,S 13 :On switch
[0048] S 12 ,S 14 :Down switch
[0049] S 21 ,S 23 :On switch
[0050] S 22 ,S 24 :Down switch
[0051] S CD :switch
[0052] A, B, C, D: nodes
[0053] V AB ,V CD :Voltage
[0054] C41, C42: capacitors
[0055] L51: Inductor
[0056] C21, C52, C53: capacitors DETAILED DESCRIPTION
[0057] The following are detailed descriptions of the embodiments with accompanying drawings, but the embodiments provided are not intended to limit the scope of the present disclosure, and the description of the structural operation is not intended to limit its execution order. Any structure recombined by the elements to produce a device with equal technical effects is within the scope of the present disclosure. In addition, the illustrations are for illustrative purposes only and are not drawn according to the original size. For ease of understanding, the same or similar elements in the following description will be illustrated with the same symbols. The terms used throughout the specification and claims, unless otherwise specified, generally have the ordinary meaning of each term used in this field, in the content disclosed herein and in the special content. In addition, the words "comprise", "include", "have", "contain", etc. used in this article are all open terms, which mean "including but not limited to". In addition, "and / or" used in this article includes any one or more items in the relevant enumerated items and all combinations thereof.
[0058] To prevent the power transmitter from continuing to operate after the power receiver's protection mechanism has been triggered, the power transmitter needs to identify whether the power receiver's protection mechanism has been triggered. In some cases, when the power receiver's output to the load changes and reaches an overcurrent threshold or overvoltage protection threshold, the voltage or current flowing through the receiver coil changes, affecting the power transmitter's output. However, the power transmitter's output can also be affected by (i) changes in the position between the receiver and transmitter coils; and / or (ii) the load. For example, if the load remains unchanged and the position between the receiver and transmitter coils changes, the mutual inductance between the receiver and transmitter coils changes, causing the power transmitter's output to change. For another example, if the position between the receiver and transmitter coils remains unchanged and the load changes, the power receiver's output to the load changes, causing the power transmitter's output to change. In these situations, the power transmitter's output can vary over a wide range. In this case, the power transmitter's output can still be adjusted via a control feedback loop. In other words, even if the power transmitter's output varies within the aforementioned range, it is impossible to identify whether the power receiver's output has experienced an overcurrent or overvoltage condition. That is, the corresponding protection threshold of the power transmitter cannot be set to a fixed value within this range.
[0059] Therefore, the present disclosure provides a wireless charging system and a power receiver device to solve the above problems. Figure 1 , Figure 1 FIG is a schematic diagram of a wireless charging system 100 according to an embodiment of the present disclosure. Figure 1 As shown, the wireless charging system 100 includes a power transmitter device 110 and a power receiver device 120. In some embodiments, the power transmitter device 110 is configured to transfer energy to the power receiver device 120 without wiring, thereby transferring electrical energy to the power receiver device 120 based on wireless power transmission to power a load 130 of the power receiver device 120.
[0060] In some embodiments, the power receiver device 120 and the power transmitter device 110 can establish wireless communication and transmit information about the load 130 of the power receiver device 120 via wireless communication, thereby enabling the control circuit of the power transmitter device 110 to operate based on the information about the load 130 and thereby transmit corresponding wireless power to the power receiver device 120. In some embodiments, the power transmitter device 110 can be an electronic device, such as a wireless charging pad, a wireless charging stand, a wireless charging base, or other power transmitting device. In some embodiments, the power receiver device 120 can be an electronic device, such as a mobile device, a wearable device, an electric toothbrush, the power receiving portion of an electric vehicle, or other power receiving and transmitting device.
[0061] In some embodiments, the power transmitter device 110 includes an AC-DC converter 111, a full-bridge inverter 112, a transmitter compensation network 113, a control circuit 114, a sensing circuit 115, a capacitor C in and transmitter coil L1. In some embodiments, the control circuit 114 is electrically connected to the full-bridge inverter 112 to control the operation of the full-bridge inverter 112. In some embodiments, the control circuit 114 is electrically connected to the AC-DC converter 111 to control the operation of the AC-DC converter 111. In some embodiments, the control circuit 114 may include a processor, a microprocessor, and / or a microcontroller. In some embodiments, the power transmitter device 110 further includes a communication circuit, and the control circuit 114 is capable of wireless communication via the communication circuit.
[0062] In some embodiments, the AC-DC converter 111 converts AC power into DC power and transmits the DC power to the capacitor C. in Provides a stable DC input to the full-bridge inverter 112. In some embodiments, the AC-DC converter 111 may be an AC-DC converter with a power factor correction function.
[0063] In some embodiments, the full-bridge inverter 112 is electrically connected to the output terminal of the AC-DC converter 111 and the capacitor C in , to convert DC input into AC output. In some embodiments, the AC output of the full-bridge inverter 112 is transmitted to the transmitter coil L1 via the transmitter compensation network 113 , causing the transmitter coil L1 to generate a time-varying electromagnetic field based on the AC current, thereby transferring energy to the power receiver device 120 .
[0064] In some embodiments, the sensing circuit 115 is configured to sense the output current I1 of the full-bridge inverter 112 to generate a sensing signal. In some embodiments, the sensing circuit 115 is a current sensing circuit. In some embodiments, the control circuit 114 determines whether the protection mechanism of the power receiver device 120 is triggered based on the sensing signal generated by the sensing circuit 115.
[0065] In some embodiments, the power receiver device 120 includes a receiver compensation network 122, a full-bridge rectifier 123, a control circuit 124, and a sensing circuit 125. In some embodiments, the control circuit 124 is electrically connected to the full-bridge rectifier 123 to control the operation of the full-bridge rectifier 123. In some embodiments, the control circuit 124 may include a processor, a microprocessor, and / or a microcontroller. In some embodiments, the control circuit 124 may include a transmitter controller. In some embodiments, the power receiver device 120 further includes a communication circuit, through which the control circuit 124 can wirelessly communicate with the power transmitter device 110. In some embodiments, via wireless communication, the power receiver device 120 can transmit information about the load 130 to the power transmitter device 110, thereby enabling the power transmitter device 110 to deliver power accordingly.
[0066] In some embodiments, the receiver coil L2 is magnetically coupled to the transmitter coil L1, and the receiver coil L2 generates an induced current according to the time-varying electromagnetic field. The induced current flows through the receiver compensation network 122 to the full-bridge rectifier 123. The full-bridge rectifier 123 rectifies the induced current to output a DC current, and then transmits the DC current to the full-bridge rectifier 123 through the capacitor C. out Provides a stable DC output to the load 130 .
[0067] In some embodiments, the sensing circuit 125 is used to sense a physical variable of the power receiver device 120 (e.g., the output current, output voltage, or output power of the full-bridge rectifier 123, or the temperature of the power receiver device 120) to generate a sensing signal. In some embodiments, the sensing circuit 125 includes an output current sensing circuit, an output voltage sensing circuit, an output power sensing circuit, and / or a temperature sensing circuit. In some embodiments, the control circuit 124 receives the sensing signal generated by the sensing circuit 125 and determines whether the sensing signal triggers a protection mechanism of the power receiver device 120. In some embodiments, the protection mechanism of the power receiver device 120 includes an overcurrent protection mechanism, an overvoltage protection mechanism, an overpower protection mechanism, and / or an overtemperature protection mechanism.
[0068] In some embodiments, the architecture of the full-bridge inverter 112, the transmitter compensation network 113, the transmitter coil L1, the receiver coil L2, the receiver compensation network 122, and the full-bridge rectifier 123 can be considered a wireless power transmission system. In some embodiments, the compensation network of the wireless power transmission system (e.g., the transmitter compensation network 113 and the receiver compensation network 122) has a main diagonal zero or near-zero topology to implement the output of the wireless power transmission system as a constant current source. In other embodiments, the compensation network of the wireless power transmission system has a sub-diagonal zero or near-zero topology to implement the output of the wireless power transmission system as a constant voltage source.
[0069] See also Figure 2 . Figure 2 FIG is a schematic diagram of a wireless power transmission system 200 according to an embodiment of the present disclosure. Figure 2 As shown, the wireless power transmission system 200 includes a full-bridge inverter 212, a transmitter compensation network 213, a transmitter coil L1, a receiver coil L2, a receiver compensation network 222 and a full-bridge rectifier 223. In some embodiments, Figure 2 The full-bridge inverter 212, the transmitter compensation network 213, the transmitter coil L1, the receiver coil L2, the receiver compensation network 222 and the full-bridge rectifier 223 of the wireless power transmission system 200 correspond to Figure 1 The full-bridge inverter 112 , the transmitter compensation network 113 , the transmitter coil L1 , the receiver coil L2 , the receiver compensation network 122 and the full-bridge rectifier 123 are shown.
[0070] In some embodiments, the full-bridge inverter 212 includes an upper switch S 11 and S 13 With the lower switch S 12 and S 14 In some embodiments, the upper switch S of the full-bridge inverter 212 is 11 and S 13 With the lower switch S 12 and S 14 The state (eg, on state or off state) of the Figure 1 In some embodiments, the upper switch S 11 With the lower switch S 14 is in the on state, and the upper switch S 12 With the lower switch S 13 In the off state, the output current I1 of the full-bridge inverter 212 flows in the first direction. In some embodiments, the upper switch S 11 With the lower switch S 14 is in the off state, and the upper switch S 12 With the lower switch S 13 In the on state, the output current I1 of the full-bridge inverter 212 flows in a second direction opposite to the first direction. In some embodiments, the first direction is counterclockwise and the second direction is clockwise. In this way, the full-bridge inverter 212 can provide the AC output current I1.
[0071] In some embodiments, the full-bridge rectifier 223 includes an upper switch S 21 and S 23 With the lower switch S 22 and S 24In some embodiments, the upper switch S of the full-bridge rectifier 223 is 21 and S 23 With the lower switch S 22 and S 24 The state (eg, on state or off state) of the Figure 1 In some embodiments, the upper switch S 21 With the lower switch S 24 is in the on state, and the upper switch S 22 With the lower switch S 23 In the off state, the input current I2 of the full-bridge rectifier 223 flows in the first direction. In some embodiments, the upper switch S 21 With the lower switch S 24 is in the off state, and the upper switch S 22 With the lower switch S 23 In the on state, the input current I2 of the full-bridge rectifier 223 flows in a second direction opposite to the first direction. In this way, the full-bridge rectifier 223 performs rectification.
[0072] In some embodiments, when a power receiver device (e.g., Figure 1 When the protection mechanism of the power receiver device 120 is triggered, the control circuit (eg, Figure 1 The control circuit 124 (e.g., the control circuit 124) short-circuits the midpoints of the two bridge arms of the full-bridge rectifier 223 (i.e., nodes C and D), causing the voltage across nodes C and D of the full-bridge rectifier 223 to decrease to zero. Due to the compensation network topology and the magnetic coupling between the receiver coil L2 and the transmitter coil L1, when the voltage across nodes C and D of the full-bridge rectifier 223 decreases to zero, the output of the full-bridge inverter 212 (e.g., the output current I1) exhibits a noticeable and recognizable change.
[0073] In some embodiments, the method of short-circuiting the midpoints of the two bridge arms of the full-bridge rectifier 223 (ie, nodes C and D) can be to switch the upper switch S 21 With S 23 Set it to the on state and turn on the lower switch S 22 With S 24 In this embodiment, the full-bridge rectifier 223 may not include the switch S CD .
[0074] In some embodiments, the method of short-circuiting the midpoints of the two bridge arms of the full-bridge rectifier 223 (ie, nodes C and D) can be to switch the lower switch S 22 With S 24 Set it to the on state and turn on the upper switch S 21 With S 23In this embodiment, the full-bridge rectifier 223 may not include the switch S CD .
[0075] In some embodiments, the full-bridge rectifier 223 may include a switch S connected between the midpoints of the two bridge arms of the short-circuited full-bridge rectifier 223 (ie, nodes C and D). CD In some embodiments, the switch S may be switched to short-circuit the midpoints of the two bridge arms of the full-bridge rectifier 223 (ie, nodes C and D). CD Set to the on state. At this time, the upper switch S 21 With S 23 and down switch S 22 With S 24 In some embodiments, in normal operation, the switch S CD is set to the off state.
[0076] In some embodiments, the transmitter compensation network 213 and the receiver compensation network 222 are configured with a zero or near-zero topology (e.g., series / series, parallel / parallel, etc.) on the main diagonal to implement the output of the wireless power transmission system as a constant current source. In other embodiments, the transmitter compensation network 213 and the receiver compensation network 222 are configured with a zero or near-zero topology (e.g., series / parallel, parallel / series, LC / series, LCC / series, etc.) on the secondary diagonal to implement the output of the wireless power transmission system as a constant voltage source.
[0077] See also Figure 3 . Figure 3 According to an embodiment of the present disclosure Figure 2 Schematic diagram of the state space model of the wireless power transmission system 200. Figure 3 As shown, the voltage V AB represents the voltage across nodes A and B (ie, the midpoints of the two bridge arms of the full-bridge inverter 212), and I1 represents the output current of the full-bridge inverter 212. CD represents the voltage across nodes C and D (ie, the midpoints of the two bridge arms of the full-bridge rectifier 223), and I2 represents the input current of the full-bridge rectifier 223. In some embodiments, the input and output of wireless power can be represented by the following matrix.
[0078]
[0079] In the above formula, A represents the matrix, a 11 ~a 22 represents the coefficient.
[0080] In a topology where the main diagonal is zero, a 11 with a 22is zero, the input and output of wireless power can be represented by the following matrix.
[0081]
[0082] In a topology where the main diagonal is approximately zero, a 11 with a 22 Approximately zero, the input and output of wireless power can be expressed by the following matrix.
[0083]
[0084] In the above formula, a 11 Much smaller than a 12 , and a 22 Much smaller than a 21 .
[0085] In a topology with zeros on the secondary diagonal, a 12 with a 21 is zero, the input and output of wireless power can be represented by the following matrix.
[0086]
[0087] In a topology where the main diagonal is approximately zero, a 12 with a 21 Approximately zero, the input and output of wireless power can be expressed by the following matrix.
[0088]
[0089] In the above formula, a 12 Much smaller than a 11 , and a 21 Much smaller than a 22 .
[0090] See also Figure 4 . Figure 4 FIG. 4 is a schematic diagram of a wireless power transmission system 400 according to an embodiment of the present disclosure. Figure 4 As shown, the wireless power transmission system 400 includes a full-bridge inverter 412, a transmitter compensation network 413, a transmitter coil L1, a receiver coil L2, a receiver compensation network 422 and a full-bridge rectifier 423. In some embodiments, Figure 4 The full-bridge inverter 412, the transmitter compensation network 413, the transmitter coil L1, the receiver coil L2, the receiver compensation network 422 and the full-bridge rectifier 423 of the wireless power transmission system 400 correspond to Figure 2 The full-bridge inverter 212 , the transmitter compensation network 213 , the transmitter coil L1 , the receiver coil L2 , the receiver compensation network 222 and the full-bridge rectifier 223 are shown.
[0091] The network topology of power transmission system 400 is a zero or near-zero topology on the main diagonal. Specifically, transmitter compensation network 413 includes capacitor C41 connected in series with transmitter coil L1, and receiver compensation network 422 includes capacitor C42 connected in series with receiver coil L2. The compensation network topology of power transmission system 400 is a series / series topology. In some embodiments, the input and output of power transmission system 400 can be expressed by the following formulas.
[0092]
[0093] In the above formula, M represents the transformer's mutual inductance, and ω represents the operating frequency. Based on this formula, the following formula can be derived.
[0094]
[0095] In the above formula, it can be seen that in the topology where the main diagonal is zero or near zero, the output current I1 of the full-bridge inverter 412 and the voltage V across the nodes C and D (the midpoints of the two bridge arms of the full-bridge rectifier 423) are CD Therefore, when the midpoints of the two bridge arms of the full-bridge rectifier 423 are short-circuited, the voltage V CD The output current I1 of the full-bridge inverter 412 will be significantly reduced (e.g., reduced to zero), and the output current I1 of the full-bridge inverter 412 will also be significantly reduced. Therefore, the significantly reduced output current I1 of the full-bridge inverter 412 can trigger the under-current protection. In other words, the zero voltage at the midpoint of the two bridge arms of the full-bridge rectifier 423 is reflected in the output of the full-bridge inverter 412, thereby triggering the protection mechanism of the power transmitter device.
[0096] exist Figure 4 In the embodiment, since the compensation network topology of the wireless power transmission system 400 is a topology with a zero or near-zero main diagonal, the output of the wireless power transmission system 400 is implemented as a constant current source. In this topology, even if the midpoints of the two bridge arms of the full-bridge rectifier 423 are short-circuited, according to the above formula, the input current I2 of the full-bridge rectifier 423 is still determined by the voltage V across nodes A and B (the midpoints of the two bridge arms of the full-bridge inverter 412). AB Therefore, the upper switch S in the full-bridge rectifier 423 21 、S 23 and down switch S 22 、S 24 Or switch S CD There will be no current stress issues.
[0097] See also Figure 5 . Figure 5 FIG is a schematic diagram of a wireless power transmission system 500 according to an embodiment of the present disclosure. Figure 5As shown, the wireless power transmission system 500 includes a full-bridge inverter 512, a transmitter compensation network 513, a transmitter coil L1, a receiver coil L2, a receiver compensation network 522 and a full-bridge rectifier 523. In some embodiments, Figure 5 The full-bridge inverter 512, the transmitter compensation network 513, the transmitter coil L1, the receiver coil L2, the receiver compensation network 522 and the full-bridge rectifier 523 of the wireless power transmission system 500 correspond to Figure 2 The full-bridge inverter 212 , the transmitter compensation network 213 , the transmitter coil L1 , the receiver coil L2 , the receiver compensation network 222 and the full-bridge rectifier 223 are shown.
[0098] The network topology of power transmission system 500 is a zero or near-zero sub-diagonal topology. Specifically, transmitter compensation network 513 includes inductor L51, capacitors C51, and C52. Receiver compensation network 522 includes capacitor C53 connected in series with receiver coil L2. The network topology of power transmission system 500 is an LCC / series topology. In some embodiments, the input and output of power transmission system 500 can be expressed by the following equations.
[0099]
[0100] In the above formula, M represents the mutual inductance of the transformer, L x represents the inductance value of inductor L51. Based on the above formula, the following formula can be derived.
[0101]
[0102] From the above formula, it can be seen that in a topology where the secondary diagonal is zero or near-zero, the output current I1 of the full-bridge inverter 512 is proportional to the input current I2 of the full-bridge rectifier 523. Therefore, when the midpoints of the two bridge arms of the full-bridge rectifier 523 are short-circuited, the input current I2 of the full-bridge rectifier 523 increases significantly, and the output current I1 of the full-bridge inverter 512 also increases significantly. Therefore, the significantly increased output current I1 of the full-bridge inverter 512 can trigger the overcurrent protection. In other words, the zero voltage at the midpoints of the two bridge arms of the full-bridge rectifier 523 is reflected at the output of the full-bridge inverter 512, thereby triggering the protection mechanism of the power transmitter device.
[0103] exist Figure 5 In the embodiment, since the network topology of the wireless power transmission system 500 is a zero or near-zero sub-diagonal topology, the output of the wireless power transmission system 500 is implemented as a constant voltage source. In such a topology, when the midpoints of the two bridge arms of the full-bridge rectifier 523 are short-circuited, the input current I2 of the full-bridge rectifier 523 will be larger, so it is necessary to consider the upper switch S in the full-bridge rectifier 523. 21 、S 23and down switch S 22 、S 24 Or switch S CD current stress.
[0104] It should be noted that the compensation network architecture disclosed herein is for illustration only. Depending on the design of the compensation network circuit, the output current protection of the full-bridge inverter on the power transmitter side may also be equivalent to the voltage or current protection of other components, and the present disclosure should not be limited thereto.
[0105] See also Figure 6 . Figure 6 FIG. 6 is a flow chart of an operating method 600 according to an embodiment of the present disclosure. Figure 6 As shown, method 600 includes steps 601 , 612 , 614 , 616 , 618 , 622 , 624 , 626 , 628 and 629 .
[0106] In step 601, the power transmitter device 610 establishes wireless communication with the power receiver device 620. In some embodiments, the power transmitter device 610 and the power receiver device 620 each include communication circuitry, such as Bluetooth communication circuitry, cellular network-based communication circuitry, or other wireless communication circuitry. In some embodiments, the control circuitry of the power transmitter device 610 establishes wireless communication with the control circuitry of the power receiver device 620 via the communication circuitry. In some embodiments, the power receiver device 620 transmits load information and other required parameters to the power transmitter device 610 via wireless communication, enabling the power transmitter device 610 to operate according to the information transmitted by the power receiver device 620. Thus, in steps 612 and 622, the power transmitter device 610 and the power receiver device 620 operate normally.
[0107] In step 614 , the sensing circuit in the power transmitter device 610 detects the current output by the full-bridge inverter.
[0108] In step 624, the sensing circuit in the power receiver device 620 detects a physical variable in the power receiver device 620 to generate a sensing signal. In some embodiments, the physical variable may be the output current, output voltage, output power provided by the full-bridge rectifier to the load, and / or the temperature of the power receiver device 620.
[0109] In step 626, the control circuitry in the power receiver device 620 determines whether the sensed signal triggers a protection mechanism. In some embodiments, the protection mechanism may be overcurrent protection, overvoltage protection, overpower protection, and / or overtemperature protection. If so, the process proceeds to step 628. If not, the process proceeds to step 624.
[0110] In step 628, the control circuit in the power receiver device 620 shorts the midpoints of the two bridge arms of the full-bridge rectifier. This causes the midpoint voltage of the two bridge arms of the full-bridge rectifier to be zero, resulting in a noticeable change in the output of the full-bridge inverter in the power transmitter device 610.
[0111] In step 616, the control circuit in the power transmitter device 610 determines whether the output current of the full-bridge inverter is outside the current limit range. In some embodiments, the upper limit of the current limit range may be set based on an overcurrent protection mechanism, and the lower limit of the current limit range may be set based on an undercurrent protection mechanism. If yes in step 616, the process proceeds to step 618. If no, the process proceeds to step 614.
[0112] In step 618 , the power transmitter device 610 suspends operation.
[0113] In step 629 , the power receiver device 620 suspends operation.
[0114] In summary, when the protection mechanism of the power receiver device disclosed herein is triggered, the midpoint voltage of the two bridge arms of the full-bridge rectifier is made zero by short-circuiting the midpoints of the two bridge arms of the full-bridge rectifier, thereby causing the output of the power transmitter device to have a recognizable and obvious change, thereby reducing the delay between the protection of the power receiver device and the protection of the power transmitter device.
[0115] Although the present disclosure has been disclosed in the form of embodiments as described above, it is not intended to limit the present disclosure. Any person skilled in the art may make various changes and modifications without departing from the concept and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the claims.
Claims
1. A wireless charging system, characterized in that: Include: a power transmitter device; a transmitter coil; a transmitter compensation network; a full-bridge inverter electrically connected to the transmitter coil via the transmitter compensation network; and a transmitter controller electrically connected to the full-bridge inverter; and A power receiver device, for receiving wireless power transmitted by the power transmitter device, comprising: Power Receiver Device a receiver coil; a receiver compensation network; a full-bridge rectifier electrically connected to the receiver coil via the receiver compensation network; and A control circuit is electrically connected to the full-bridge rectifier and is used to control the operation of the full-bridge rectifier. When a protection mechanism for the power receiver device is triggered, the control circuit short-circuits the midpoints of the two bridge arms of the full-bridge rectifier to make the voltage across the midpoints of the two bridge arms zero. The zero voltage across the midpoints of the two bridge arms is reflected to the output of the full-bridge inverter of the power transmitter device, thereby triggering a protection mechanism of the power transmitter device.
2. The wireless charging system according to claim 1, wherein: When the midpoints of the two bridge arms of the full-bridge rectifier are short-circuited, the output power of the full-bridge rectifier is zero, thereby achieving load protection.
3. The wireless charging system according to claim 2, wherein: The control circuit is used to control the operation of the full-bridge rectifier according to the wireless signal from the power transmitter device. The zero voltage across the midpoints of the two bridge arms is used to increase or decrease the output current of the transmitter to trigger the protection mechanism of the power transmitter device.
4. The wireless charging system according to claim 3, wherein: If the transmitter compensation network of the power transmitter device and the receiver compensation network of the power receiver device are in a topology with a main diagonal of zero or close to zero, an output current of the full-bridge inverter is reduced, and the reduced output current is used to trigger an under-current protection mechanism for the power transmitter device; and If the transmitter compensation network of the power transmitter device and the receiver compensation network of the power receiver device are in a topology with a diagonal line of zero or close to zero, an output current of the full-bridge inverter increases, and the increased output current is used to trigger an overcurrent protection mechanism of the power transmitter device.
5. The wireless charging system according to claim 1, wherein: The full-bridge rectifier includes two upper switches and two lower switches, wherein the control circuit is configured to control the two upper switches and the two lower switches, and wherein when the protection mechanism for the power receiver device is triggered, the control circuit is configured to: Setting the two lower switches to an on state and setting the two upper switches to an off state; or The two upper switches are set to an on state, and the two lower switches are set to an off state.
6. The wireless charging system according to claim 1, wherein: The full-bridge rectifier includes a switch electrically connected between the midpoints of the two bridge arms, wherein the control circuit is used to control the switch, and wherein when the protection mechanism for the power receiver device is triggered, the control circuit is used to set the switch to an on state.
7. The wireless charging system according to claim 1, wherein: The power receiver device also includes: A sensing circuit is electrically connected to the control circuit, wherein a sensing signal generated by the sensing circuit is used to trigger the protection mechanism of the power receiver device, and wherein the sensing circuit is an output current sensing circuit, an output voltage sensing circuit, an output power sensing circuit or a temperature sensing circuit.
8. The wireless charging system according to claim 7, wherein: The protection mechanism is an over-current protection mechanism, an over-voltage protection mechanism, an over-power protection mechanism or an over-temperature protection mechanism.
9. A method for operating a wireless charging system, characterized in that: The wireless charging system includes a power transmitter device and a power receiver device, wherein the power transmitter device includes a transmitter coil, a transmitter compensation network, a full-bridge inverter, and a transmitter controller, wherein the full-bridge inverter is electrically connected to the transmitter coil via the transmitter compensation network, wherein the transmitter controller is electrically connected to the full-bridge inverter, wherein the power receiver device includes a receiver coil, a receiver compensation network, a full-bridge rectifier, a control circuit, and a sensing circuit, wherein the full-bridge rectifier is electrically connected to the receiver coil via the receiver compensation network, wherein the control circuit is electrically connected to the full-bridge rectifier and the sensing circuit, and wherein the operating method includes: The sensing circuit detects a physical variable of the power receiver device to generate a sensing signal; determining, by the control circuit, whether the sensing signal triggers a protection mechanism for the power receiver device; and If the sensing signal triggers the protection mechanism for the power receiver device, the control circuit short-circuits the midpoints of the two bridge arms of the full-bridge rectifier, causing the voltage across the midpoints of the two bridge arms to be zero. The zero voltage across the midpoints of the two bridge arms is reflected to the output of the full-bridge inverter of the power transmitter device, thereby triggering a protection mechanism of the power transmitter device.
10. The operating method according to claim 9, wherein: When the midpoints of the two bridge arms of the full-bridge rectifier are short-circuited, the output power of the full-bridge rectifier is zero, thereby achieving load protection.