Vehicle end coil electricity taking and signal acquisition multiplexing circuit for wireless charging
By designing a multiplexed circuit, the precise monitoring and effective utilization of coil current in the wireless charging system is achieved, which solves the problem that it is difficult for vehicle-side converters to achieve effective power acquisition and accurate sampling at the same time, and improves the intelligent control capability and stability of the system.
Patent Information
- Application Number
- CN202421334250.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-06-12
AI Technical Summary
In existing wireless charging systems, it is difficult for vehicle-end converters to achieve effective power acquisition and accurate current peak sampling at the same time in compact and efficient circuits, resulting in increased system complexity and insufficient intelligent control of the charging process.
A multiplexed circuit is designed to convert the coil-induced AC current into DC through a rectifier bridge, and combined with filtered rectifier voltage stabilization circuit and transistor and other components, the precise monitoring and effective utilization of coil current is achieved, while providing a stable power supply and necessary feedback signals.
It realizes accurate monitoring and effective utilization of coil current, provides stable current and voltage for auxiliary power systems, and provides strong support for the intelligent control of wireless charging systems, reducing system complexity and improving the intelligent level of the charging process.
Smart Images
Figure CN222691444U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of wireless charging, and in particular to a vehicle-end coil power taking and signal acquisition multiplexing circuit for wireless charging. Background Art
[0002] Wireless charging technology, especially systems based on the principle of magnetic field coupling, has become a standard means of modern wireless energy transmission due to its remarkable efficiency and convenience. Such systems rely on a pair of carefully designed coupling coils, namely the ground-end (transmitter) coil and the vehicle-end (receiver) coil, to achieve contactless transmission of electrical energy through the coupling of spatial magnetic fields. Specifically, the ground-end coil generates an alternating magnetic field driven by a power source, which is sensed by the vehicle-end coil and converted into alternating current. Subsequently, the alternating current is converted into stable direct current through circuit processing such as rectification and filtering to supply loads such as on-board equipment or battery systems.
[0003] In the wireless charging system, the vehicle-side converter, as a core component, is not only responsible for efficiently receiving and converting electrical energy, but also needs to integrate a variety of auxiliary subsystems to ensure the safety and efficient operation of the charging process. These subsystems usually include current / voltage sampling circuits, communication interface circuits, and drive control circuits, etc. They each undertake key tasks, such as real-time monitoring of charging status, achieving two-way communication between the vehicle and the ground, and accurately controlling power conversion. These auxiliary systems all require independent power supply to ensure their continuous and stable operation during the wireless charging process.
[0004] There are many ways to solve the existing power supply problems. One common approach is to use the on-board battery system to directly power the auxiliary power system, but this may increase the complexity of the system, especially in the pursuit of miniaturization and lightweight of vehicle-side converters. The additional configuration of batteries not only increases weight and cost, but may also introduce additional energy management issues. Another solution is to directly draw power from the vehicle-side coil and use the wireless energy received by the coil to power the auxiliary power system. This method complies with the principle of miniaturization design and avoids the need for additional energy storage equipment.
[0005] However, relying solely on the coil for power extraction not only requires the circuit to have efficient power extraction capabilities, but also must be able to monitor the coil current in real time to implement the necessary control strategies. The controller needs to perform key control measures such as overcurrent protection (such as preventing overheating or damage through load reduction operations) based on the size of the coil current. Therefore, the design of the vehicle-side converter faces a key challenge: how to simultaneously achieve effective power extraction from the coil and accurate current peak sampling in a compact and efficient circuit, so as to provide a reliable power supply for the auxiliary power system and provide the necessary feedback signals for the control system to ensure the overall performance and safety of the wireless charging system.
[0006] In summary, the development of a multiplexed circuit that can take into account both coil power extraction and peak sampling functions is of great significance for improving the miniaturization of wireless charging systems, reducing system complexity, and enhancing intelligent control of the charging process. Utility Model Content
[0007] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a vehicle-end coil power supply and signal acquisition multiplexing circuit for wireless charging that can realize stable power supply and accurate current monitoring of the auxiliary power system.
[0008] The technical solution adopted by the utility model is that the circuit includes a coil power supply part and a coil current sampling part.
[0009] The coil power supply part includes
[0010] The coil power port for taking power from the coil,
[0011] Other power ports that serve as backup power sources to supply power to the auxiliary power system, and
[0012] An electrostatic discharge protection circuit disposed between the coil power intake port and the other power intake ports;
[0013] The coil current sampling part includes
[0014] Coil current sampling port,
[0015] A rectifier bridge consisting of four diodes that converts AC to DC.
[0016] A filter rectifier voltage stabilizing circuit composed of a number of resistors, a number of capacitors and a number of voltage stabilizing diodes, and
[0017] Coil current ADC interface for connecting to the ADC port of the peripheral controller;
[0018] The coil power supply part and the coil current sampling part are connected through a transistor, the collector of the transistor is connected to the rectifier bridge, the emitter of the transistor is connected to the coil power port, the front end of the coil current sampling port draws power from the coil through a current transformer, and an overvoltage protection circuit composed of a fifth diode and a sixth diode is arranged at the output end of the coil current sampling part.
[0019] The above scheme shows that the alternating current from the coil mutual inductance is converted into direct current through the rectifier bridge, and the coil power supply and peak sampling functions are cleverly integrated into the same circuit. Through a series of links such as transformer sampling, rectification filtering, power supply control, peak holding, overvoltage protection and signal conditioning, the accurate monitoring and effective utilization of the coil current are achieved, providing stable current and voltage for the auxiliary power system, and providing strong support for the intelligent control of the wireless charging system. At the same time, through reasonable circuit layout and protection measures, the stable operation of the system and the safety of the equipment are ensured.
[0020] Furthermore, the electrostatic discharge protection circuit includes a first protection diode and a second protection diode connected in series between the coil power supply port and the other power supply ports and connected in positive and negative directions, and the first protection diode and the second protection diode are connected through a fourth resistor. It can be seen that the first protection diode and the second protection diode can be set to avoid damage from Shuntai high voltage and ensure the safety of the power supply interface.
[0021] Furthermore, the filtering, rectifying and voltage-stabilizing circuit includes a first capacitor connected at both ends of the rectifier bridge, a third resistor and a sixth resistor connected in series with the first capacitor, a fifth resistor connected in parallel with the first capacitor, and a peak holder connected in parallel at both ends of the first capacitor and composed of a second zener diode and a third capacitor. The base of the transistor is connected to the first zener diode, the emitter is connected to the second capacitor, the collector is connected to the first resistor, and the base and collector of the transistor are connected to the second resistor. It can be seen that the first capacitor eliminates the high-frequency ripple in the steamed bun waveform and smoothes it into a relatively stable direct current, providing a purer current sampling signal for the subsequent circuit; the third resistor and the sixth resistor play a voltage divider role, and the fifth resistor plays a shunt role; when the coil current reaches a peak value, the peak holder can record the peak voltage and keep the voltage unchanged when the coil current decreases subsequently, providing the system with reference information of the maximum value of the coil current; the first resistor is proportional to the current extracted by the coil current through the mutual inductor, and the voltage across it reflects the size of the coil current. The second resistor is designed to have a large resistance value (such as 100kΩ), so that the collector operating point of the transistor mainly depends on the voltage on the first resistor, rather than other interference factors; the transistor is used as a switching element, and its base is stabilized at 12V through a voltage regulator diode. When the coil current is large and the voltage on the first resistor exceeds 12V, the transistor is turned on, allowing the coil power port to provide 12V voltage to the auxiliary power system. When the coil has no current or insufficient energy, the voltage of the first resistor is lower than 12V, the transistor is cut off, and the auxiliary power system is powered by the backup power supply of other power ports. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is the circuit schematic diagram of the utility model
[0023] Figure 2 It is a simulation waveform diagram of several signals in the utility model. DETAILED DESCRIPTION
[0024] like Figure 1 and Figure 2 As shown, the utility model circuit includes a coil power supply part and a coil current sampling part.
[0025] The coil power supply part includes
[0026] The coil power supply port JK1 is used to take power from the coil.
[0027] Other power ports JK2 that serve as backup power sources to supply power to the auxiliary power system, and
[0028] An electrostatic discharge protection circuit provided between the coil power intake port JK1 and the other power intake port JK2;
[0029] The coil current sampling part includes
[0030] Coil current sampling ports I_Coil_A, I_Coil_B,
[0031] The rectifier bridge consists of four diodes D1 to D4 that convert AC to DC.
[0032] A filter rectifier voltage stabilizing circuit composed of a number of resistors, a number of capacitors and a number of voltage stabilizing diodes, and
[0033] Coil current ADC interface JK3 used to connect to the ADC port of the peripheral controller;
[0034] The coil power supply part and the coil current sampling part are connected through a transistor Q1, the collector of the transistor Q1 is connected to the rectifier bridge, the emitter of the transistor Q1 is connected to the coil power port JK1, the front ends of the coil current sampling ports I_Coil_A and I_Coil_B draw power from the coil through a current transformer, and an overvoltage protection circuit composed of a fifth diode D5 and a sixth diode D6 is provided at the output end of the coil current sampling part.
[0035] The electrostatic discharge protection circuit includes a first protection diode E1 and a second protection diode E2 connected in series between the coil power port JK1 and the other power port JK2 and connected in positive and negative directions, and the first protection diode E1 and the second protection diode E2 are connected through a fourth resistor R4. The filtering, rectifying and voltage stabilizing circuit includes a first capacitor C1 connected to both ends of the rectifier bridge, a third resistor R3 and a sixth resistor R6 connected in series with the first capacitor C1, a fifth resistor R5 connected in parallel with the first capacitor C1, and a peak holder connected in parallel at both ends of the first capacitor C1 and composed of a second voltage stabilizing diode Z2 and a third capacitor C3, the base of the transistor Q1 is connected to the first voltage stabilizing diode Z1, the emitter is connected to the second capacitor C2, the collector is connected to the first resistor R1, and the base and collector of the transistor Q1 are connected to the second resistor R2.
[0036] The specific working process of the utility model is as follows:
[0037] 1. Coil current sampling and extraction:
[0038] The current transformer connected to the coil current sampling ports I_Coil_A and I_Coil_B draws power from the vehicle-end coil and converts the large current in the coil into a smaller alternating current according to a preset ratio (e.g., 200:1). The frequency of the current is the same as the coil current, which is 85kHz in this embodiment.
[0039] Rectifier bridge D1~D4: converts the AC current output by the transformer into a unidirectional steamed bun waveform to prepare for subsequent filtering and voltage conversion.
[0040] The first capacitor C1 acts as a filter: it eliminates the high-frequency ripple in the steamed bun waveform and smoothes it into a relatively stable direct current, providing a purer current sampling signal for subsequent circuits.
[0041] 2. Power control and voltage stabilization:
[0042] The first resistor R1 and the second resistor R2 act as voltage dividers: R1 is proportional to the current extracted by the coil current through the transformer, and the voltage across it reflects the magnitude of the coil current. R2 is designed to have a large resistance value (such as 100kΩ), so that the collector operating point of Q1 mainly depends on the voltage on R1, rather than other interference factors.
[0043] Transistor Q1: As a switching element, its base is stabilized at 12V through the first voltage-stabilizing diode Z1. When the coil current is large and the voltage on R1 exceeds 12V, Q1 is turned on, allowing the coil power port JK1 to provide 12V voltage to the auxiliary power system. When the coil has no current or insufficient energy, and the R1 voltage is lower than 12V, Q1 is turned off, and the auxiliary power system is powered by the backup power supply of JK2.
[0044] 3. Peak hold and overvoltage protection:
[0045] Peak Holder (Z2, C3): When the coil current reaches its peak value, the circuit composed of Z2 and C3 can record the peak voltage and keep the voltage unchanged when the coil current decreases, providing the system with reference information of the maximum value of the coil current.
[0046] The fifth diode D5 and the sixth diode D6 for overvoltage protection are connected in series at the output end of the circuit. When the output voltage is too high, the diodes are turned on to form a bypass to prevent the excessive voltage from damaging subsequent circuits or equipment.
[0047] 4. Signal conditioning and data processing:
[0048] Coil current ADC interface JK3 (I_Coil_ADC interface): Send the coil current signal (optionally with conditioning circuit or voltage follower to further optimize signal quality) after the above processing to the ADC port of the peripheral microcontroller or DSP controller. The controller (microcontroller / DSP) receives the coil current signal through the ADC port, digitizes it and performs further data processing and analysis. This information can be used to monitor the coil current status in real time, implement control strategies such as overcurrent protection and power adjustment, and ensure the safe and efficient operation of the wireless charging system.
[0049] like Figure 2 As shown, when the transformer takes a coil current signal as input ( Figure 2 When the wireless charging system is operating normally, the voltage of the first resistor R1 will be stable above 12V ( Figure 2 Therefore, the coil power port works normally and outputs a stable 12V voltage ( Figure 2 Finally, the coil current ADC interface JK3 (I_Coil_ADC interface) will output a voltage signal related to the peak value of the coil current ( Figure 2 Waveform 4 in Figure 1).
[0050] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A vehicle-end coil power supply and signal acquisition multiplexing circuit for wireless charging, characterized in that: The multiplexing circuit includes a coil power supply part and a coil current sampling part. The coil power supply part includes The coil power supply port (JK1) that takes power from the coil. Other power ports (JK2) that serve as backup power sources to supply power to the auxiliary power system, and An electrostatic discharge protection circuit is arranged between the coil power supply port (JK1) and the other power supply ports (JK2); The coil current sampling part includes Coil current sampling port (I_Coil_A, I_Coil_B), A rectifier bridge consisting of four diodes (D1 to D4) converts AC to DC. A filter rectifier voltage stabilizing circuit composed of a number of resistors, a number of capacitors and a number of voltage stabilizing diodes, and Coil current ADC interface (JK3) for connecting to the ADC port of the peripheral controller; The coil power supply part and the coil current sampling part are connected via a transistor (Q1), the collector of the transistor (Q1) is connected to the rectifier bridge, the emitter of the transistor (Q1) is connected to the coil power supply port (JK1), the front end of the coil current sampling port (I_Coil_A, I_Coil_B) draws power from the coil via a current transformer, and an overvoltage protection circuit composed of a fifth diode (D5) and a sixth diode (D6) is arranged at the output end of the coil current sampling part.
2. According to claim 1, a vehicle-end coil power supply and signal acquisition multiplexing circuit for wireless charging is characterized in that: The electrostatic discharge protection circuit comprises a first protection diode (E1) and a second protection diode (E2) which are connected in series between the coil power supply port (JK1) and the other power supply port (JK2) and are connected in positive and negative directions. The first protection diode (E1) and the second protection diode (E2) are connected via a fourth resistor (R4).
3. The vehicle-end coil power supply and signal acquisition multiplexing circuit for wireless charging according to claim 1 is characterized in that: The filtering, rectifying and voltage-stabilizing circuit comprises a first capacitor (C1) connected at both ends of the rectifying bridge, a third resistor (R3) and a sixth resistor (R6) connected in series with the first capacitor (C1), a fifth resistor (R5) connected in parallel with the first capacitor (C1), and a peak holder connected in parallel with both ends of the first capacitor (C1) and composed of a second voltage-stabilizing diode (Z2) and a third capacitor (C3); the base of the transistor (Q1) is connected to the first voltage-stabilizing diode (Z1), the emitter is connected to the second capacitor (C2), the collector is connected to the first resistor (R1), and the base and collector of the transistor (Q1) are connected to the second resistor (R2).