Switchable compensation wireless power transmission system constant voltage control system and method
By switching between the LCCL-LCCL and LCCL-S resonant compensation topology, the two-stage wireless charging of constant current and constant voltage is achieved using controllable switches, the problem of power supply instability of the radio energy transmission system when load changes or position offset is solved, and the reliability and safety of the system are improved.
Patent Information
- Application Number
- CN202410104589.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-25
- Publication Date
- 2025-07-18
AI Technical Summary
When the load changes or position shifts, it is difficult to maintain the power supply state of constant voltage and constant current, and there is a risk of overcurrent or overvoltage, and the system reliability and safety are insufficient.
By switching between the two resonant compensation topology of LCCL-LCCL and LCCL-S, the connection method of controllable switches S1 and S2 is used to realize two-stage wireless charging of constant current and constant voltage, keeping the circuit resonance state unchanged, and the secondary coil inductance value and capacitance value are not changed.
It realizes constant voltage and constant current power supply when load changes or position shifts, improves the reliability and safety of the system, avoids overcurrent or overvoltage, and has the function of outputting the whole power factor.
Smart Images
Figure CN120342101A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of wireless power transmission, and particularly to a constant voltage control system and method for a switchable compensation wireless power transmission system. Background Art
[0002] Wireless power transmission technology is a new power access mode that realizes the transfer of electric energy from the original device to the power receiving device under completely electrically isolated conditions by means of invisible soft media in space (such as magnetic fields, electric fields, lasers, microwaves, etc.). This technology fundamentally eliminates problems such as device wear, poor contact, and contact sparks brought by the traditional "socket + connector" power supply mode. It is a clean, safe, and flexible new power supply mode and has been selected as one of the top ten future research directions by the US magazine Technology Review.
[0003] The working principle of an inductive power transmission system is that industrial frequency alternating current is rectified into direct current by a rectifier, and the direct current is converted into high-frequency alternating current under the action of a high-frequency inverter. The high-frequency alternating current excites a high-frequency magnetic field on the primary coil, and the secondary energy pickup coil that does not directly contact the primary coil couples the high-frequency magnetic field to induce a co-frequency alternating voltage. The electric energy conversion device in the secondary circuit converts it into the electric energy form required by the load to supply the load, realizing non-contact transmission of energy. Summary of the Invention
[0004] The purpose of this application is to provide a constant voltage control system and method for a switchable compensation wireless power transmission system. Without changing the inductance value and capacitance value of the secondary coil, by switching the topological structure between LCCL-LCCL and LCCL-S two resonant compensation topologies, while maintaining the resonant state of the circuit, realizing two-stage wireless charging of constant voltage and constant current for the load.
[0005] To achieve the above purpose, this application discloses the following technical solutions:
[0006] In a first aspect, this application discloses a constant voltage control system for a switchable compensation wireless power transmission system, including an inverter, a primary compensation coil L f1 , a secondary compensation coil L f2 , a primary coil L1, a secondary coil L2, a compensation capacitor C1 of the primary coil, a compensation capacitor C2 of the secondary coil, a primary compensation capacitor C f1 , a secondary compensation capacitor C f2 , a controllable switch S1, a controllable switch S2, and a rectifier and filter circuit;
[0007] The input end of the inverter is connected to a DC power supply. The first pin of the primary compensation coil L f1 is connected to the first pin of the compensation capacitor C1 and the first pin of the primary compensation capacitor C f1 . The first pin of the primary compensation coil L f1The second pin of is connected to the first pin of the output terminal of the inverter, and the primary compensation capacitor C f1 The second pin of is connected to the second pin of the output terminal of the inverter, and the primary compensation capacitor C f1 The second pin of is connected to the first pin of the primary coil L1, and the second pin of the primary coil L1 is connected to the second pin of the primary compensation capacitor C f1 ;
[0008] The output terminal of the rectifier and filter circuit is connected to the battery, and the first pin of the secondary compensation coil L f2 is connected to the first pin of the rectifier and filter circuit, and the second pin of the secondary compensation coil L f2 is connected to the normally open contact of the controllable switch S2. The first pin of the compensation capacitor C2 and the secondary compensation capacitor C f2 is connected to the normally closed contact of the controllable switch S2. The second pin of the compensation capacitor C2 is connected to the first pin of the secondary coil L2. The second pin of the secondary compensation capacitor C f2 is connected to the normally closed contact of the controllable switch S1. The normally open contact 1 of the controllable switch S1 is connected to the first pin of the secondary compensation coil L f2 The normally open contact 2 of the controllable switch S1 is connected to the first pin of the secondary coil L2 and the second pin of the rectifier and filter circuit.
[0009] In a second aspect, the present application discloses a constant voltage control method for a switchable compensation wireless power transmission system, which is applicable to the switchable compensation wireless power transmission system constant voltage control system as described above. The method includes the following steps:
[0010] Constant current charging: When the normally closed contact of the controllable switch S1 is connected to the normally open contact 1 and the controllable switch S2 is closed, the resonant compensation topology is LCC-LCC;
[0011] Constant voltage charging: When the normally closed contact of the controllable switch S1 is connected to the normally open contact 2 and the controllable switch S2 is disconnected, the resonant compensation topology is LCC-S.
[0012] Preferably, in the constant current charging and the constant voltage charging, parameter design is further included, and the parameter design includes:
[0013] Among them, L1 is the inductance value of the primary coil, L2 is the inductance value of the secondary coil, C1 is the capacitance value of the compensation capacitor of the primary coil, C f1 is the capacitance value of the primary compensation capacitor, L f1 is the inductance value of the primary compensation coil, C2 is the capacitance value of the compensation capacitor of the secondary coil, C f2 is the capacitance value of the secondary compensation capacitor, L f2is the inductance value of the secondary compensation coil, U AB is the output voltage of the inverter, U ab is the secondary output voltage, M is the mutual inductance value of the primary and secondary coils, i1, i2, i f1 and i f2 are the current values of the primary coil L1, the secondary coil L2, the primary compensation coil L f1 , and the secondary compensation coil L f2 respectively, and ω0 is the natural resonant angular frequency of the circuit.
[0014] Preferably, the L1 and C1 branches, and the L2 and C2 branches are equivalent to inductances Le1 and Le2, and the following formula is obtained:
[0015] wherein, Le1 = L f1 , Le2 = L f2 .
[0016] Preferably, in the constant current charging, the output current is:
[0017] Preferably, in the constant voltage charging, the output voltage is: U ab = jωMI1.
[0018] Beneficial effects: This application can meet the power supply requirements of different loads at different times. Specifically, the properties of the LCCL-LCCL resonant compensation circuit enable the wireless charging system to have the following four advantages: 1) When there are position offsets and changes in the power battery's power, the system can maintain the resonant state; 2) The system has a constant current output function and can achieve constant current charging of the power battery; 3) When there are extreme situations such as short circuits or open circuits in the circuit, the primary system will not have overcurrent or overvoltage, and has high reliability and safety; 4) The system can achieve unity power factor output.
[0019] The properties of the LCCL-S resonant compensation circuit enable the wireless charging system to have the following three advantages: 1) When there are position offsets and changes in the power battery's power, the system can maintain the resonant state; 2) The system has a constant voltage output function and can achieve constant voltage charging of the power battery. 3) The system can achieve unity power factor output. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0021] Figure 1 Topological circuit structure diagram of the constant voltage control system for the switchable compensation wireless power transfer system provided by the embodiment of the present application;
[0022] Figure 2 Simulation waveform of the constant current characteristic provided by the embodiment of the present application;
[0023] Figure 3 Constant voltage output voltage waveform diagram provided by the embodiment of the present application. Detailed implementation manners
[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
[0025] In this article, the term "including" is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the elements defined by the statement "including..." do not exclude the presence of additional identical elements in the process, method, article or device including the said elements.
[0026] In the first aspect, the present embodiment discloses a constant voltage control system for a switchable compensation wireless power transfer system as shown in Figure 1 , including an inverter, a primary compensation coil L f1 , a secondary compensation coil L f2 , a primary coil L1, a secondary coil L2, a compensation capacitor C1 of the primary coil, a compensation capacitor C2 of the secondary coil, a primary compensation capacitor C f1 , a secondary compensation capacitor C f2 , a controllable switch S1, a controllable switch S2 and a rectifier filter circuit;
[0027] The input end of the inverter is connected to a DC power supply. The first pin of the primary compensation coil L f1 is connected to the first pin of the compensation capacitor C1 and the first pin of the primary compensation capacitor C f1 . The second pin of the primary compensation coil L f1 is connected to the first pin of the output end of the inverter. The second pin of the primary compensation capacitor C f1 is connected to the second pin of the output end of the inverter. The second pin of the primary compensation capacitor C f1 is connected to the first pin of the primary coil L1. The second pin of the primary coil L1 is connected to the primary compensation capacitor Cf1 is connected to the second pin;
[0028] The output terminal of the rectifying and filtering circuit is connected to the battery, and the first pin of the secondary compensation coil L f2 is connected to the first pin of the rectifying and filtering circuit. The second pin of the secondary compensation coil L f2 is connected to the normally open contact of the controllable switch S2. The first pins of the compensation capacitor C2 and the secondary compensation capacitor C f2 are connected to the normally closed contact of the controllable switch S2. The second pin of the compensation capacitor C2 is connected to the first pin of the secondary coil L2. The second pin of the secondary compensation capacitor C f2 is connected to the normally closed contact of the controllable switch S1. The normally open contact one of the controllable switch S1 is connected to the first pin of the secondary compensation coil L f2 The normally open contact two of the controllable switch S1 is connected to the first pin of the secondary coil L2 and the second pin of the rectifying and filtering circuit.
[0029] In the second aspect, this embodiment discloses a constant voltage control method for a switchable compensation wireless power transmission system, which is applicable to the above-mentioned constant voltage control system of the switchable compensation wireless power transmission system. The method includes the following steps:
[0030] Constant current charging: When the normally closed contact of the controllable switch S1 is connected to the normally open contact one and the controllable switch S2 is closed, the resonant compensation topology is LCC-LCC;
[0031] Constant voltage charging: When the normally closed contact of the controllable switch S1 is connected to the normally open contact two and the controllable switch S2 is disconnected, the resonant compensation topology is LCC-S.
[0032] In the above constant current charging and constant voltage charging, parameter design is also included, and the parameter design includes: Among them, L1 is the inductance value of the primary coil, L2 is the inductance value of the secondary coil, C1 is the capacitance value of the compensation capacitor of the primary coil, C f1 is the capacitance value of the primary compensation capacitor, L f1 is the inductance value of the primary compensation coil, C2 is the capacitance value of the compensation capacitor of the secondary coil, C f2 is the capacitance value of the secondary compensation capacitor, L f2 is the inductance value of the secondary compensation coil, U AB is the output voltage of the inverter, U ab is the secondary output voltage, M is the mutual inductance value of the primary and secondary coils, i1, i2, i f1 and i f2 are the primary coil L1, secondary coil L2, primary compensation coil L f1 , secondary compensation coil L f2The current value, where ω0 is the natural resonant angular frequency of the circuit.
[0033] Equivalent the branches of L1 and C1, and L2 and C2 into inductances Le1 and Le2, the following formula is obtained: where Le1 = L f1 , Le2 = L f2 .
[0034] In the above constant current charging, the output current is: In the above constant voltage charging, the output voltage is: U ab = jωMI1.
[0035] Based on the above, when the resonant compensation topology is LCCL-LCCL, the resistors are switched at 0.06 s, 0.1 s, and 0.14 s, and the resistance values are 100 Ω, 50 Ω, 33 Ω, and 25 Ω in sequence. The current waveform is as Figure 2 shown. It can be seen from the figure that when the resistance changes, the output current of the system changes little, and when the resistance value is low, the current is almost unchanged before and after the resistance switching. Oscillation occurs when the resistance is switched, and it will stabilize at a certain fixed value in a short time. When the power battery is charged, it can be considered that its equivalent internal resistance changes smoothly without poles, so the oscillation shown in the figure will not occur.
[0036] When the resonant compensation topology is LCCL-S, the resistors are switched at 0.06 s, 0.1 s, and 0.14 s, and the resistance values are 100 Ω, 50 Ω, 33 Ω, and 25 Ω in sequence. The voltage waveform is as Figure 3 shown. The output voltage of the system remains almost unchanged before and after the resistance switching. Voltage oscillation occurs when the resistance is switched, and the voltage stabilizes at a certain fixed value in a short time. When the power battery is charged, it can be considered that its equivalent internal resistance changes smoothly without poles, so the oscillation shown in the figure will not occur.
[0037] Finally, it should be noted that the above are only the preferred embodiments of the present application and are not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A constant voltage control system for a switchable compensation wireless power transfer system, characterized in that, including an inverter, a primary compensation coil L f1 , a secondary compensation coil L f2 , a primary coil L1, a secondary coil L2, a compensation capacitor C1 of the primary coil, a compensation capacitor C2 of the secondary coil, a primary compensation capacitor C f1 , a secondary compensation capacitor C f2 , a controllable switch S1, a controllable switch S2, and a rectifying and filtering circuit; The input end of the inverter is connected to a DC power supply, and the first pin of the primary compensation coil L f1 is connected to the compensation capacitor C1 and the first pin of the primary compensation capacitor C f1 ; the second pin of the primary compensation coil L f1 is connected to the first pin of the output end of the inverter; the second pin of the primary compensation capacitor C f1 is connected to the second pin of the output end of the inverter; the second pin of the primary compensation capacitor C f1 is connected to the first pin of the primary coil L1, and the second pin of the primary coil L1 is connected to the second pin of the primary compensation capacitor C f1 . The output terminal of the rectifying and filtering circuit is connected to the battery, and the first pin of the secondary compensation coil L f2 is connected to the first pin of the rectifying and filtering circuit. The second pin of the secondary compensation coil L f2 is connected to the normally open contact of the controllable switch S2. The first pins of the compensation capacitor C2 and the secondary compensation capacitor C f2 are connected to the normally closed contact of the controllable switch S2. The second pin of the compensation capacitor C2 is connected to the first pin of the secondary coil L2. The second pin of the secondary compensation capacitor C f2 is connected to the normally closed contact of the controllable switch S1. One of the normally open contacts of the controllable switch S1 is connected to the first pin of the secondary compensation coil L f2 and the other normally open contact of the controllable switch S1 is connected to the first pin of the secondary coil L2 and the second pin of the rectifying and filtering circuit.
2. A constant voltage control method for a switchable compensation wireless power transfer system, applicable to the constant voltage control system of the switchable compensation wireless power transfer system as described in claim 1, characterized in that, The method includes the following steps: Constant current charging: when the normally closed contact of the controllable switch S1 is connected to the first normally open contact and the controllable switch S2 is closed, the resonant compensation topology is LCC-LCC; Constant voltage charging: when the normally closed contact of the controllable switch S1 is connected to the second normally open contact and the controllable switch S2 is disconnected, the resonant compensation topology is LCC-S.
3. The constant voltage control method for the switchable compensation wireless power transfer system according to claim 2, wherein In the described constant current charging and the described constant voltage charging, parameter design is also included, and the parameter design includes: Among them, L1 is the inductance value of the primary side coil, L2 is the inductance value of the secondary side coil, C1 is the capacitance value of the compensation capacitor of the primary side coil, C f1 is the capacitance value of the primary side compensation capacitor, L f1 is the inductance value of the primary side compensation coil, C2 is the capacitance value of the compensation capacitor of the secondary side coil, C f2 is the capacitance value of the secondary side compensation capacitor, L f2 is the inductance value of the secondary side compensation coil, U AB is the output voltage of the inverter, U ab is the secondary side output voltage, M is the mutual inductance value of the primary and secondary side coils, i1, i2, i f1 and i f2 are the current values of the primary side coil L1, the secondary side coil L2, the primary side compensation coil L f1 , the secondary side compensation coil L f2 respectively, and ω0 is the natural resonant angular frequency of the circuit.
4. The constant voltage control method for a switchable compensation wireless power transmission system according to claim 3, characterized in that, The branches of L1 and C1, and L2 and C2 are equivalent to inductors Le1 and Le2, and the following formula is obtained: Among them, Le1 = L f1 , Le2 = L f2 .
5. The constant voltage control method for a switchable compensation wireless power transfer system according to claim 3, characterized in that, In the constant current charging described above, the output current is:
6. The constant voltage control method for the switchable compensation wireless power transmission system according to claim 3, characterized in that In the constant voltage charging described above, the output voltage is: U ab = jωMI1.