CN214543820U

CN214543820U - Reconfigurable current type wireless power transmission system with impedance matching

Info

Publication number: CN214543820U
Application number: CN202120339670.1U
Authority: CN
Inventors: 程瑜华; 刘椿武; 徐慧; 王高峰; 李文钧
Original assignee: Hangzhou Dianzi University; Hangzhou Dianzi University Wenzhou Research Institute Co Ltd
Current assignee: Hangzhou Dianzi University; Hangzhou Dianzi University Wenzhou Research Institute Co Ltd
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2021-10-29
Anticipated expiration: 2031-02-03

Abstract

The utility model discloses a reconfigurable current type wireless power transmission system with impedance matching; which comprises a transmitting end and a receiving end. The receiving end comprises a receiving coil, a matching inductor Ls and a matching capacitor Cp. One end of the receiving coil is connected to a first input end of a load RL through a switching tube M4, and is connected to the first input end of the load RL through a matching inductor Ls and a switching tube M3 which are connected in series; the other end of the receiving coil is connected to a second input terminal of the load RL. The matching capacitor Cp and the switching tube M1 which are connected in series are connected in parallel at two ends of the receiving coil and the matching inductor Ls or connected in parallel at two ends of the receiving coil. The matching capacitor C2 and the switch tube M2 which are connected in series are connected in parallel at two ends of the receiving coil. The utility model discloses introduce L type impedance matching network in reconfigurable current type wireless power transmission system for reconfigurable current type wireless power transmission system can work near maximum transmission power.

Description

Reconfigurable current type wireless power transmission system with impedance matching

Technical Field

The utility model belongs to the technical field of wireless chargeable sensor network energy supply, concretely relates to take impedance matching's restructural current type wireless power transmission system.

Background

The voltage resonance type system and the current resonance type system are respectively suitable for scenes that the coupling distance or the load value is small and large, namely the receiving end voltage is large and small. In the application context of implantable medical devices, sensors, radio frequency identification devices, wireless charging devices, and the like, the problem of receiving power variation at a receiving end due to coupling conditions (including relative distance, relative direction, and the like) of a coil, a circuit resonance state, or a change in load is faced. The reconfigurable current type system is based on detection of the Voltage amplitude of the receiving end, so that the system works in a Voltage resonance mode when the Voltage of the receiving end is large, and works in a current resonance mode when the Voltage of the receiving end is small, the system is enabled to obtain higher energy transmission Efficiency (PTE) and Voltage Conversion Efficiency (VCE) respectively, meanwhile, the transmission distance and the load range of the system are expanded, and the system can be applied to scenes with large transmission distance and load change.

However, when the reconfigurable current-mode system works in a voltage resonance mode, the Power Delivered Load (PDL) and the energy transmission efficiency PTE of the system cannot be kept optimal due to the difference between different loads, and even the PDL and the PTE are both minimum values, which cannot satisfy the energy provided by the system required by the Load. In order to solve the problem, a technical scheme and a circuit structure are provided, wherein the technical scheme and the circuit structure are combined based on the fact that when a reconfigurable current type system works in a voltage resonance mode, an impedance matching technology is combined, so that when the system operates in the voltage resonance mode, the system can output the maximum power under any load, the maximum power transmission efficiency is ensured, and meanwhile, the performance of the system operating in the current resonance mode cannot be influenced.

Disclosure of Invention

The utility model provides a take impedance matching's restructural electric current type wireless power transmission system.

The utility model discloses a transmitting terminal and receiving terminal. The receiving end comprises a receiving coil L2, a matching inductor Ls, a matching capacitor Cp, a switching tube M1, a switching tube M2, a switching tube M3, a switching tube M4 and a capacitor C2. One end of the receiving coil L2 is connected to the first input end of the load RL through the switching tube M4, and is connected to the first input end of the load RL through the matching inductor Ls and the switching tube M3 which are connected in series; the other end of the receiving coil L2 is connected to a second input terminal of the load RL. The matching capacitor Cp and the switching tube M1 connected in series are connected in parallel to both ends of the receiving coil L2 and the matching inductor Ls or connected in parallel to both ends of the receiving coil L2. The capacitor C2 and the switch tube M2 connected in series are connected in parallel at two ends of the receiving coil L2.

Preferably, the inductance value of the matching inductor Ls and the capacitance value of the matching capacitor Cp are determined according to various working parameters, so that the wireless power transmission power is maximized.

Preferably, the transmitting terminal comprises a signal source, a compensation capacitor C1 and a transmitting coil L1 which are connected in series.

The utility model has the advantages as follows:

1. the utility model discloses introduce L type impedance matching network in reconfigurable current type wireless power transmission system for reconfigurable current type wireless power transmission system can work near maximum transmission power.

2. The utility model discloses based on reconfigurable current type wireless power transmission system, through combining impedance matching network for the system only needs the components and parts parameter of adjustment impedance matching network with voltage mode during operation, just can all realize maximum power transmission under different load conditions.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention;

FIG. 2 is an equivalent circuit diagram of the present invention operating in voltage mode;

fig. 3 is an equivalent circuit diagram of the present invention operating in the current mode.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, a reconfigurable current type wireless power transmission system with impedance matching includes a transmitting end and a receiving end. The transmitting end comprises a signal source, a compensation capacitor C1 and a transmitting coil L1 which are connected in series; the receiving end comprises a receiving coil L2, a matching inductor Ls, a matching capacitor Cp, a switching tube M1, a switching tube M2, a switching tube M3, a switching tube M4, a capacitor C2 and a load R_L. The parasitic resistance of the transmitting coil L1 is denoted as resistance R1. The parasitic resistance of the transmitting coil L2 is denoted as resistance R2; the parasitic capacitance of the load RL is denoted as the capacitance CL. One end of the receiving coil L2 is connected to the first input end of the load RL through the switching tube M4, and is connected to the first input end of the load RL through the matching inductor Ls and the switching tube M3 which are connected in series; the other end of the receiving coil L2 is connected to a second input terminal of the load RL. The matching capacitor Cp and the switching tube M1 connected in series are connected in parallel to both ends of the receiving coil L2 and the matching inductor Ls or connected in parallel to both ends of the receiving coil L2 (in fig. 1, the matching capacitor Cp and the switching tube M1 are connected in parallel to both ends of the receiving coil L2 and the matching inductor Ls, which only represents one scheme, but is not necessarily an option scheme). The matching capacitor C2 and the switch tube M2 which are connected in series are connected in parallel at two ends of the receiving coil L2. The matching inductor Ls and the matching capacitor Cp form an L-shaped impedance matching network. The inductance value of the matching inductor Ls and the capacitance value of the matching capacitor Cp are determined according to various working parameters, so that the wireless power transmission power is maximized. The switch tube M1, the switch tube M2, the switch tube M3 and the switch tube M4 are controlled to be opened and closed by an external control circuit; the controller in the control circuit can be a single chip microcomputer.

By adjusting the parameter values of the matching inductor Ls and the matching capacitor Cp, different loads RL can be operated near the maximum power.

The work principle of the reconfigurable current type wireless power transmission system with the band rejection matching function is as follows:

firstly, the voltage V at two ends of a receiving end coil is detected through an envelope detection circuit_RAmplitude is detected, and the mode selection circuit judges the voltage V output by the receiving coil_RRelative to a reference voltage (V)_ref) When the system is in the Current Mode, the control circuit in the Current Mode generates corresponding switching signals CM _ GATE and CM _ charge to control the on/off of the switching transistor M2 and the switching transistor M4; the switch tube M2 will be in a set period (N x T)_p，T_pThe system working period is adopted, and N generally takes a value of 3-20) is circularly switched on and off; when the switch tube M2 is turned on, the switch tube M4 is turned off, and L is at the moment₂C₂The network accumulates energy as it passes through (N-1/4) T_pAfter time accumulation, all energy is stored in the inductor L₂At this time, CM _ GATE controls the switch transistor M2 to be turned off, CM _ charge controls the switch transistor M4 to be turned on, and the inductor L controls the switch transistor M4 to be turned on₂The upper current cannot change abruptly and flows to the load through the switch tube M4, so that L is the only discharge path₂C₂Supplying power to the load in the form of an equivalent current source, the charging phase being at T_pCompleted within/4 time; when operating in voltage mode, both M2 and M4 are on, L₂C₂The network delivers energy to the load in the form of an equivalent voltage source.

On the basis of a reconfigurable current mode resonant wireless power supply system, an L-type impedance matching network is combined, and any load value can be matched to be an optimal value, so that the maximum power transmission of the system under any load condition when the system works in a voltage mode is realized, and R is used in practical application_L>R_eqr,optIs more common; the utility model discloses a L-II type impedance matching structure. The working principle is as follows: firstly, the voltage amplitude V of the receiving end is detected by an envelope detection circuit_RDetecting, and selecting V via mode selection circuit_RAnd a reference voltage V_ref(generally 3V)Making a comparison when V_R>V_refWhen the system is operated in the VM mode, the switch M1 is turned on, the switches M2 and M4 are turned off, and the equivalent circuit is as shown in fig. 2; when V is_R<V_refWhen the system is running in CM mode, the switch M2 is turned on, the switches M1 and M3 are turned off, and the equivalent circuit is shown in fig. 3. When the system operates in the VM mode, at the time when VM _ GATE is high, M1 is turned on, M2 and M4 are turned off, and the VM mode control circuit is triggered, when the compensation capacitor C is turned on_pVoltage V across_CpGreater than the voltage V across the load_LWhen M3 is conducting power to the load.

When the voltage amplitude V of the receiving end of the system_RWhen the system is smaller, the system will work in CM mode, at this time, the CM mode control circuit will be triggered, the switch tubes M1 and M3 are cut off, and when M2 is turned off and V is turned off_RGreater than V during the jump_LWhen CM _ charge is brought low, M4 is turned on to supply power to the load.

Claims

1. The reconfigurable current type wireless power transmission system with impedance matching comprises a sending end and a receiving end; the method is characterized in that: the receiving end comprises a receiving coil L2, a matching inductor Ls, a matching capacitor Cp, a switching tube M1, a switching tube M2, a switching tube M3, a switching tube M4 and a capacitor C2; one end of the receiving coil L2 is connected to the first input end of the load RL through the switching tube M4, and is connected to the first input end of the load RL through the matching inductor Ls and the switching tube M3 which are connected in series; the other end of the receiving coil L2 is connected to a second input terminal of the load RL; the matching capacitor Cp and the switching tube M1 which are connected in series are connected in parallel at two ends of the receiving coil L2 and the matching inductor Ls or connected in parallel at two ends of the receiving coil L2; the matching capacitor C2 and the switch tube M2 which are connected in series are connected in parallel at two ends of the receiving coil L2.

2. The band rejection impedance matched reconfigurable current mode wireless power transfer system of claim 1, wherein: the transmitting end comprises a signal source, a compensation capacitor C1 and a transmitting coil L1 which are connected in series.