CN104578345B - Electromagnetic resonance type wireless charging device and control method based on CLL resonant transformation - Google Patents

Abstract

The invention discloses an electromagnetic resonance wireless charging device and a control method based on CLL resonance conversion; a microcontroller acquires a DC bus voltage, and controls the duty cycle of a MOS tube in a bidirectional AC/DC rectifier module to realize the input of the DC bus voltage. Stable; the microcontroller controls the switching of the MOS tube in the CLL resonant conversion module to invert the DC power into AC power; the coupling resonant coil at the transmitting end emits the inverter energy of the CLL resonant conversion module and transmits it to the coupling resonant coil at the receiving end; After receiving the high-frequency alternating current, the end-coupling resonant coil is rectified by the AC/DC rectifier module at the receiving end, and the battery is charged after voltage stabilization and filtering; the microcontroller obtains the terminal voltage and charging current of the battery, and controls the CLL resonance conversion module MOS tube The duty cycle, to achieve the set charging current and overcharge protection function. It can work under zero-voltage and zero-current switching, effectively reduces switching loss, improves energy transmission efficiency, and reduces the volume of the wireless transmission device.

Description

Electromagnetic resonance wireless charging device and control method based on CLL resonance conversion

technical field

The present invention relates to the field of wireless charging, in particular to an electromagnetic resonance wireless charging device and control method based on CLL resonance conversion.

Background technique

The world is facing more and more serious environmental crisis and energy crisis, the decreasing of fossil fuels and the increasing seriousness of environmental problems have attracted global attention. Electric vehicles have many advantages such as energy saving and environmental protection. Vigorously developing electric vehicles has become one of the important ways to solve the crisis and is an inevitable trend in the future development of the automobile industry. Large-scale electric vehicles as mobile energy storage equipment will be an important pillar of the third industrial revolution (Energy Internet). Now the development of electric vehicles is facing a series of problems such as high battery cost, lower energy density than fossil energy, and high quality. Wireless charging technology provides a new way for the development of electric vehicles. Electric vehicles are charged through wireless charging to avoid direct electrical contact, which can effectively reduce possible accidents during charging. At the same time, large-scale construction of wireless charging parking spaces and garages enables people to charge electric vehicles at home or in parking lots at any time without having to go to special charging stations for charging. The electromagnetic resonance wireless charging method is not sensitive to horizontal displacement, so that electric vehicles can be charged while driving on the road, which can greatly reduce the capacity of electric vehicle batteries, making electric vehicles more portable and practical.

At present, there are three implementation methods of wireless energy transmission, namely electromagnetic induction wireless charging method, electromagnetic resonance wireless charging method, and far-field radiation wireless charging method. Among them, the electromagnetic induction wireless charging method uses the principle of a separate transformer. When the primary coil of the charging device passes through a certain frequency of alternating current, the secondary coil will generate a certain current through the principle of electromagnetic induction, thereby transferring energy from the transmitter. To the receiving end, wireless power transmission is realized. The principle of this method is simple, easy to implement, and the short-distance energy transmission efficiency is very high, even up to 99%. However, the disadvantage of this method is that the transmission distance is too short, generally at the centimeter or even millimeter level. Efficiency drops significantly. The electromagnetic resonance wireless charging method utilizes the principle of resonance. When the energy transmitting device and the energy receiving device are adjusted to a unified resonance frequency, the two devices resonate, and they can exchange energy with each other, thereby transferring energy from the transmitting end to the receiving end. wireless power transmission. This method has less electromagnetic radiation, less impact on living organisms, less impact on electronic products of other frequencies, moderate transmission distance, generally at the decimeter level, strong penetrating ability to obstacles of non-metallic materials, and small metal material obstacles The impact of objects on it is also very small, and it can supply energy to multiple receiving ends at the same time. When the horizontal displacement or rotation angle is generated between the receiving end coil and the transmitting end coil, the system transmission efficiency changes very little; but the disadvantage is that the transmission efficiency It is not as good as the electromagnetic induction wireless charging method. Due to the limitation of the switching device, the transmission power is not high, and the system resonance frequency is too high. The far-field radiation wireless charging method uses the principle that microwaves or laser beams can carry energy for transmission. The transmitter converts electrical energy into microwaves or laser beams and emits them. Using the high penetration of the two, the receiver receives microwaves or laser beams. Convert it back into electrical energy to realize wireless energy transmission. This method has an extremely long transmission distance, which can reach more than several kilometers, and has good orientation; but the disadvantages are that the power transmission frequency is high, the efficiency is low, and the microwave device will have strong electromagnetic pollution problems, which may affect human health. Laser devices The electro-optical and photoelectric conversion efficiency is very low, and the transmitting end device and the receiving end device must be within the visible range of each other, and there is no obstacle in the middle.

Among the above three wireless charging methods, the electromagnetic resonance wireless charging method has a moderate transmission distance, high transmission efficiency, strong penetrability to non-metallic material obstacles, and good penetrability to small metal material obstacles. Very good, the horizontal displacement and rotation angle between the receiving end coil and the transmitting end coil have little influence on its transmission efficiency, the electromagnetic radiation is small, and the impact on electronic products of other frequencies is small, and it can supply energy to multiple loads of the same frequency, etc. Many advantages make it the first choice for wireless charging methods for electric vehicles. The resonant frequency of the electromagnetic resonance wireless charging method is generally between several hundred kilohertz to several megahertz. Such a high switching frequency causes a large switching loss, which not only reduces the power of the overall strong magnetic coupling resonant wireless charging system. The transmission efficiency will be reduced, and the switching device will be heated, and even safety accidents will occur.

Contents of the invention

The purpose of the present invention is to solve the above problems, to provide an electromagnetic resonance wireless charging device and control method based on CLL resonant conversion. The resonant frequency of the terminal resonant circuit is consistent with the three, which not only realizes the wireless energy transmission of electromagnetic resonance, but also realizes the zero-voltage and zero-current switching inversion of the high-frequency inverter at the same time. The switching loss of the switching tube is effectively reduced, and the energy transmission efficiency is improved; and since the inverter can work at a higher frequency, the volume of the wireless transmission device is reduced.

In order to achieve the above object, the present invention adopts the following technical solutions:

A soft-switching electromagnetic resonance wireless charging device based on CLL resonance conversion, including a microcontroller, an AC/DC rectifier module, a transmitter voltage stabilization filter capacitor, a CLL resonance conversion module, a transmitter coupling resonance coil, a receiver coupling resonance coil, a receiver Terminal resonant circuit capacitor, receiving terminal AC/DC rectifier module, receiving terminal voltage stabilization filter capacitor, battery and three-phase power supply;

The input end of the AC/DC rectification module is connected to a three-phase power supply, and the output end is connected to a CLL resonant conversion module after being connected in parallel with a transmitter voltage stabilizing filter capacitor;

The output end of the CLL resonant conversion module is connected to a transmitting end coupling resonant coil, and the inductance and capacitance in the CLL resonant conversion module and the transmitting end coupling resonant coil form a transmitting end resonant circuit;

The coupling resonant coil at the transmitting end and the coupling resonant coil at the receiving end realize the coupling effect,

The receiving end coupling resonant coil is connected in series with the receiving end resonant circuit capacitor and then connected to the receiving end AC/DC rectifier module;

The receiving-end coupling resonant coil and the receiving-end resonant circuit capacitance form a receiving-end resonant circuit, which receives energy transmitted by the resonant coupling magnetic field;

The output terminal of the AC/DC rectifier module at the receiving end is connected in parallel with the voltage stabilizing filter capacitor at the receiving end to charge the battery; the voltage stabilizing filter capacitor at the receiving end filters the DC power obtained by the AC/DC rectifier module at the receiving end to filter out the high-frequency AC part;

The switches of the MOS tubes in the AC/DC rectification module and the CLL resonant conversion module are controlled by the driving signal of the microcontroller, so that the high-frequency inverter frequency of the CLL resonant conversion module, the resonant frequency of the resonant circuit at the transmitting end and the resonant circuit at the receiving end The resonant frequencies of the three are the same, and the circuits at the transmitting end and the receiving end reach resonance.

The AC/DC rectification module is a bidirectional AC/DC rectification module, which is a three-phase bridge full-control rectification circuit composed of 6 MOS transistors Q ₁ -Q ₆ ; the duty cycle of the MOS transistor is controlled by a microcontroller to realize Adjustment of DC side voltage V _in .

The voltage stabilizing filter capacitor at the transmitting end includes two capacitors C _i1 and C _i2 connected in series to filter the direct current obtained by the bidirectional AC/DC rectification module and to filter out high-frequency AC signals.

The CLL resonant conversion module is an H full-bridge circuit; it includes four MOS transistors Q ₁₁ -Q ₁₄ , and each MOS transistor is connected in parallel with a diode, respectively D ₁₁ -D ₁₄ , and each MOS transistor has a corresponding parasitic capacitance , which are C ₁₁ -C ₁₄ respectively; 4 MOS transistors and their parallel diodes and capacitors constitute the 4 vertical bridge arms of the H bridge; the middle horizontal bridge arm includes two inductors L ₁ and L ₂ connected in series, inductor L ₁ and After L ₂ is connected in series, it is connected in parallel with the inductor L ₀ , and the whole after the parallel connection is connected in series with the capacitor C ₁ . The resonant capacitor C ₁ and the resonant inductance L ₁ are connected in series to form a series resonant circuit, and the resonant frequency f ₁ is generated by the resonance of L ₁ and C ₁ . The resonant capacitor C ₁ and the parallel equivalent resonant inductance L _eq of the inductance L ₁ and L ₀ form another series resonant circuit, where The resonant frequency f ₂ is generated by the resonance of L _eq and C ₁ , The soft switching technology can be _realized in the range _of frequency f1 and f2, thereby reducing the switching loss of the four MOS transistors _Q11 - _Q14 .

The inductance L ₂ is the coupling resonant coil of the transmitting end, which forms the resonant circuit of the transmitting end with the capacitor C ₁ and the inductors L ₀ and L ₁ , and uses the high coupling between the coupling resonant coil of the transmitting end and the coupling resonant coil of the receiving end to emit high-frequency AC energy .

The AC/DC rectification module at the receiving end is a single-phase full-bridge rectification circuit composed of four diodes D ₁ -D ₄ , which rectifies the received high-frequency AC into DC.

The microcontroller generates a pulse width modulated PWM signal for controlling the switch of the MOS tube;

The microcontroller also includes a voltage detection circuit, and the voltage detection circuit sends the collected battery pack terminal voltage, charging current and input DC bus voltage to the CPU of the microcontroller through an analog-to-digital conversion port.

A control method for a soft-switching electromagnetic resonance type wireless charging device based on CLL resonance conversion, comprising the following steps:

In the first step, the microcontroller obtains the voltage of the input DC bus through the voltage detection circuit, and controls the duty cycle of the MOS transistors Q ₁ -Q ₆ in the bidirectional AC/DC rectifier module to stabilize the input DC bus voltage;

In the second step, the microcontroller inverts the direct current into alternating current by controlling the switching of the MOS transistors Q ₁₁ -Q ₁₄ in the CLL resonant conversion module;

In the third step, the coupling resonant coil at the transmitting end emits the inverter energy of the CLL resonant conversion module, and transmits it to the coupling resonant coil at the receiving end through the high-frequency resonance coupling magnetic field;

Step 4: After receiving the high-frequency alternating current, the coupled resonant coil at the receiving end is rectified by the AC/DC rectifier module at the receiving end, and then stabilized and filtered by the voltage stabilizing filter capacitor at the receiving end, and finally charges the battery;

In the fifth step, the microcontroller obtains the terminal voltage and charging current of the battery through the voltage detection circuit, and controls the duty ratio of the MOS tube of the CLL resonant conversion module to realize the set charging current and overcharge protection function.

In the second step, the microcontroller controls the switching frequency of the MOS transistors Q ₁₁ -Q ₁₄ in the CLL resonant conversion module to be set between the frequencies f ₁ and f ₂ to realize zero-voltage, zero-current switching inversion.

Beneficial effects of the present invention:

The switching frequency of MOS transistors Q ₁₁ -Q ₁₄ of the CLL resonant conversion module is set at f ₁ (fixed resonant frequency of resonant capacitor C ₁ and resonant inductance L ₁ ) and f ₂ (resonant capacitor C ₁ , resonant inductance L ₁ , L ₀ Between the fixed frequency), realize zero-voltage, zero-current switching inversion, effectively reducing the switching loss.

By using CLL resonant conversion, there are two resonant frequencies, which expands the resonant frequency range, realizes the zero-voltage switching (ZVS) of the switch tube and the zero-current switching (ZCS) of the secondary rectifier diode in the full load range, and eliminates the diode The reverse recovery loss reduces the circulation loss at light load and improves the light load efficiency.

Since the high-frequency inverter frequency of the CLL resonant conversion module, the resonant frequency of the resonant circuit at the transmitting end and the resonant frequency of the resonant circuit at the receiving end are consistent, the circuits at the transmitting end and the receiving end resonate, which greatly strengthens the coupling resonance at the transmitting end The degree of coupling between the coil and the coupling resonant coil at the receiving end improves energy transmission efficiency.

Due to the realization of zero voltage and zero current switching, the inverter can work at a higher frequency, which effectively improves the transmission efficiency of the coupling coil and reduces the circuit volume;

Part of the energy converted by the CLL resonance is fed back to the power grid through the conversion of the bidirectional AC/DC rectifier module instead of being consumed, which reduces energy waste and improves work efficiency.

Description of drawings

Fig. 1 is the composition schematic diagram of the present invention;

Fig. 2 is the main circuit diagram of CLL resonant conversion;

Figure 3 is the main working mode of CLL resonant conversion; among them, Figure 3(a) is the explanatory diagram of the circuit working state 1; Figure 3(b) is the explanatory diagram of the circuit working state 2; Figure 3(c) is the circuit working state The explanatory figure of state 3; Fig. 3 (d) is the explanatory figure of circuit working state 4; Fig. 3 (e) is the explanatory figure of circuit working state 5; Fig. 3 (f) is the explanatory figure of circuit working state 6;

Figure 4 is the key working waveform of CLL resonant conversion;

Among them, 1. Microcontroller; 2. Bidirectional AC/DC rectifier module; 3. Transmitter voltage stabilization filter capacitor; 4. CLL resonant conversion module; 5. Transmitter coupling resonance coil; 6. Receiver coupling resonance coil; 7. 1. Resonant circuit capacitor at the receiving end; 8. AC/DC rectifier module at the receiving end; 9. Voltage stabilization filter capacitor at the receiving end; 10. Battery; 11. Three-phase power supply.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, it is a soft-switching electromagnetic resonance wireless charging device based on CLL resonance conversion, including a microcontroller 1, an AC/DC rectification module 2, a transmitter voltage stabilization filter capacitor 3, a CLL resonance conversion module 4, and a transmitter Coupling resonant coil 5, receiving end coupling resonant coil 6, receiving end resonant circuit capacitor 7, receiving end AC/DC rectifier module 8, receiving end voltage stabilizing filter capacitor 9, storage battery 10 and three-phase power supply 11;

The input end of the bidirectional AC/DC rectification module 2 is connected to the three-phase power supply 11, and the output end is connected to the CLL resonant conversion module 4 after being connected in parallel with the transmitting end voltage stabilization filter capacitor 3; the output end of the CLL resonant conversion module 4 is connected to the transmitting end coupling resonant coil 5 , the coupling resonant coil 5 at the transmitting end and the coupling resonant coil 6 at the receiving end realize the coupling effect,

The receiving end coupling resonant coil 6 is connected in series with the receiving end resonant circuit capacitor 7 and then connected to the receiving end AC/DC rectifier module 8; the receiving end coupling resonant coil 6 and the receiving end resonant circuit capacitor 7 form a receiving end resonant circuit, and the receiving end is transmitted by the resonant coupling magnetic field. energy; the output end of the AC/DC rectification module 8 at the receiving end is connected in parallel with the voltage stabilizing filter capacitor 9 at the receiving end to charge the battery 10 .

Bi-directional AC/DC rectification module 2 is a three-phase bridge full-control rectification circuit composed of 6 MOS tubes. In the circuit, MOS tubes Q ₁ and Q ₄ form a pair of bridge arms, and MOS tubes Q ₃ and Q ₆ form another pair of bridge arms. MOS tubes Q ₅ and Q ₂ form the third pair of bridge arms. The six MOS tubes are sequentially controlled by the microcontroller drive circuit, and the conduction sequence is MOS tubes Q ₁ -Q ₂ -Q ₃ -Q ₄ -Q ₅ - Q ₆ forms a rectification circuit to rectify the AC power input by the three-phase power supply 11 .

The voltage stabilizing filter capacitor 3 at the transmitter is two capacitors C _i1 and C _i2 connected in series, the positive pole of C _i1 is connected to the high voltage side of the output of the rectifier circuit, the positive pole of C _i2 is connected to the negative pole of C _i1 , and the negative pole of C _i2 is connected to the output of the rectifier circuit On the low-voltage side, two capacitors are connected in parallel with the bidirectional AC/DC rectifier module 2 after being connected in series.

The CLL resonant conversion module 4 includes an H full bridge, a resonant capacitor C ₁ and resonant inductors L ₀ and L ₁ . The H full-bridge includes a single-phase full-bridge circuit composed of four MOS transistors Q ₁₁ -Q ₁₄ and four capacitors C ₁₁ -C _14. The capacitors C ₁₁ -C ₁₄ are connected in parallel with the MOS transistors Q ₁₁ -Q ₁₄ respectively. In the full-bridge circuit, MOS tubes Q ₁₁ and Q ₁₃ form a pair of bridge arms, MOS tubes Q ₁₂ and Q ₁₄ form another pair of bridge arms, and the four MOS tubes are controlled by the drive circuit of the controller, and MOS tubes Q ₁₁ and Q ₁₄ Receive a set of driving signals, and MOS transistors Q ₁₂ and Q ₁₃ receive another set of driving signals to form an inverter circuit. The middle transverse bridge arm includes two inductors L ₁ and L ₂ connected in series, and the inductors L ₁ and L ₂ are connected in parallel with the inductor L ₀ after being connected in series, and the whole after the parallel connection is connected in series with the capacitor C ₁ . The resonant capacitor C ₁ and the resonant inductance L ₁ are connected in series to form a series resonant circuit, and the resonant frequency f ₁ is generated by the resonance of L ₁ and C ₁ . The resonant capacitor C ₁ and the parallel equivalent resonant inductance L _eq of the inductance L ₁ and L ₀ form another series resonant circuit, where The resonant frequency f ₂ is generated by the resonance of L _eq and C ₁ , The soft switching technology can be _realized in the range _of frequency f1 and f2, thereby reducing the switching loss of the four MOS transistors _Q11 - _Q14 .

The transmitting end couples the resonant coil 5, that is, the inductance L ₂ , and the capacitor C ₁ , the inductances L ₀ and L ₁ form a series resonant circuit, which is the resonant circuit of the transmitting end. The coupling resonant coil 6 at the receiving end, that is, the inductance L ₃ , and the capacitor C ₂ form a series resonant circuit, which is the resonant circuit at the receiving end. The wireless transmission of energy is realized by utilizing the resonance of the resonant circuit at the transmitting end and the resonant circuit at the receiving end.

The AC/DC rectification module 8 at the receiving end is a single-phase full-bridge rectification circuit composed of four diodes D ₁ -D ₄ , which rectifies the high-frequency alternating current received by the resonant circuit at the receiving end. The diode D in the single-phase full-bridge rectification circuit ₁ and D ₃ form a pair of bridge arms, and diodes D ₂ and D ₄ form another pair of bridge arms. After rectification, a relatively stable direct current is obtained after the voltage stabilization and filtering by the voltage stabilization filter capacitor 9 at the receiving end, that is, the capacitor C _o . Capacitor C _o is connected in parallel to the output end of the single-phase full-bridge rectifier circuit, wherein the anode of capacitor C _o is connected to the high voltage side of the circuit output. The DC power after the voltage stabilization and filtering charges the storage battery 10 .

Microcontroller 1 acquires the voltage of the input DC bus through the voltage detection circuit, and controls the duty cycle of MOS transistors Q ₁ -Q ₆ to stabilize the input DC bus voltage; microcontroller 1 controls the MOS transistor in the CLL resonance conversion module 4 The switching of Q ₁₁ -Q ₁₄ inverts the direct current into alternating current. In particular, when the switching frequency of the MOS transistors Q ₁₁ -Q ₁₄ is between the resonant frequencies f ₁ and f ₂ , zero voltage and zero current switching inversion is realized. The coupling resonant coil 5 at the transmitting end emits the resonance energy of the CLL resonance conversion 4, and transmits it to the coupling resonant coil 6 at the receiving end through the high-frequency resonance coupling magnetic field. The three resonant frequencies are the same, so the circuits of the transmitting end and the receiving end resonate, which greatly strengthens the coupling degree between the coupling resonant coil of the transmitting end and the coupling resonant coil of the receiving end, and improves the energy transmission efficiency. After the high-frequency alternating current received by the receiving end is rectified by the AC/DC rectifying module 8 at the receiving end, the voltage is stabilized and filtered by the voltage stabilizing filter capacitor 9 at the receiving end, and the battery 10 is charged to realize wireless energy transmission. The microcontroller 1 acquires the terminal voltage and charging current of the storage battery 10 through the voltage detection circuit, and controls the MOS transistor of the CLL resonant conversion module 4 to realize the set charging current and charging protection functions.

The microcontroller 1 generates a pulse width modulation PWM signal, and the output end of the pulse width modulation PWM signal is connected to the MOS transistors Q ₁ -Q ₆ of the bidirectional AC/DC rectification module 2 and the MOS transistors Q ₁₁ - of the CLL resonant conversion module 4 through the driving circuit Q ₁₄ is used to control the switch of the MOS tube; the microcontroller 1 also includes a voltage detection circuit, and the voltage detection circuit sends the collected battery pack terminal voltage, charging current and input DC bus voltage to the microcontroller through the analog-to-digital conversion port the CPU.

Figure 2-4 further explains the working principle of CLL resonance conversion. Figure 2 is the main circuit diagram of CLL resonance conversion. Figure 3 is an illustration of the main working process of CLL resonance conversion. Figure 4 is the main waveform of CLL resonance conversion. The work of CLL resonant conversion is divided into six working states.

Figure 2 is the circuit diagram of the CLL resonant conversion in the overall system. In the actual resonant circuit, in order to make the switching device MOS tube work in the zero-voltage and zero-current switching state, it should be ensured that the resonant circuit works in the inductive region. Therefore, the switch should be The switching frequency of the MOS tube of the device is set between f ₁ (the fixed resonance frequency of the resonant capacitor C ₁ and the resonant inductance L ₁ ) and f ₂ (the fixed frequency of the resonant capacitor C ₁ , the resonant inductance L ₁ , and L ₀ ). At the same time, Figure 2 also specifies the positive direction of the voltage and current values involved in Figure 4. The working state and working process of the CLL resonant conversion will be further explained based on Figure 2-4 below:

Working state 1: corresponding to Fig. 3(a), time t ₁ -t ₃ in Fig. 4 . At time t ₀ before time t ₁ , MOS transistors Q ₁₁ and Q ₁₄ have been turned on at zero voltage, until time t ₁ , the resonant circuit current i _l changes from a negative value to a positive value, and the voltage across C ₁ When U _C1 reaches the reverse maximum value, the current of the resonant circuit starts to flow forward, U _C1 becomes larger, and the capacitor C ₁ starts to discharge until the time _t2 , the voltage U _C1 of the capacitor C ₁ is zero, and the discharge of the capacitor C ₁ is completed. Under the effect of the voltage V _in , the capacitor C ₁ starts to charge until the time t ₃ , when this state ends.

Working state 2: corresponding to Fig. 3(b), time t ₃ -t ₄ in Fig. 4 . At time t ₃ , MOS transistors Q ₁₁ and Q ₁₄ are turned off. At this time, the current i _l flowing through the resonant circuit charges the capacitors C ₁₁ and C ₁₄ connected in parallel with the MOS transistors Q ₁₁ and Q ₁₄ , so that the two ends of the switching devices MOS transistors Q ₁₁ and Q ₁₄ have very low dv/ dt, thereby reducing the switching loss and realizing the zero-voltage turn-off of the switching devices MOS transistors Q ₁₁ and Q ₁₄ . Then the current i _l flowing through the resonant circuit charges the capacitors C ₁₁ and C ₁₄ connected in parallel with the MOS transistors Q ₁₁ and Q ₁₄ , so that the voltages U _C11 and U _C14 of the capacitors C ₁₁ and C ₁₄ increase from zero, and The maximum voltage V _in is reached at time t ₄ . At the same time, the current i _l flowing through the resonant circuit discharges the capacitors C ₁₂ and C ₁₃ connected in parallel with the MOS transistors Q ₁₂ and Q ₁₃ , so that the voltage U _C12 and U _C13 of the capacitors C ₁₂ and C ₁₃ change from the maximum voltage V _in begins to decrease and reaches zero voltage at t4 _. At this point, the state ends.

Working state 3: corresponding to Fig. 3(c), time t ₄ -t ₆ in Fig. 4 . _At time t4, the voltages U _C12 and U _C13 of the capacitors C ₁₂ and C ₁₃ reach zero voltage, so that the diodes D ₁₂ and D ₁₃ of the parallel switching devices at both ends of the MOS transistors Q ₁₂ and Q ₁₃ are turned on, and the voltage flowing through the resonant circuit The current i _l is fed back to the power grid via diodes D ₁₂ and D _13. During the period of this working state, due to the parallel connection of switching devices, the diodes D ₁₂ and D ₁₃ at both ends of the MOS transistors Q ₁₂ and Q ₁₃ are kept conducting, and are connected in parallel with the diodes The voltages U _Q12 and U _Q13 at both ends of the MOS transistors Q ₁₂ and Q ₁₃ remain zero until the moment t ₅ when the MOS transistors Q ₁₂ and Q ₁₃ are turned _on and the state of the circuit remains unchanged. ₁₃ freewheeling, the voltages U _Q12 and U _Q13 at both ends of the MOS transistors Q ₁₂ and Q ₁₃ remain zero, realizing the zero-voltage turn-on of the switching devices MOS transistors Q ₁₂ and Q ₁₃ . Until the current reverses at time t ₆ , the diodes D ₁₂ and D ₁₃ are cut off, and this state ends.

Working state 4: corresponding to Fig. 3(d), time t ₆ -t ₈ in Fig. 4 . _At the previous moment t5, the MOS transistors _Q12 and _Q13 have been turned _on under the condition of zero voltage, and at the moment t6, the current i _l of the resonant circuit changes from a positive value to a negative value, and the voltage U across the capacitor _C1 When _C1 reaches the maximum positive value, the current of the resonant circuit starts to flow in the negative direction, U _C1 becomes smaller, and the capacitor _C1 starts to discharge until the time _t7 , the voltage U _C1 of the capacitor _C1 is zero, and the discharge of the capacitor _C1 ends. Under the action of the voltage _Vin , the capacitor _C1 begins to charge until the time _t8 , when this state ends.

Working state 5: corresponding to Fig. 3(e), time t ₈ -t ₉ in Fig. 4 . At time t ₈ , the MOS transistors Q ₁₂ and Q ₁₃ are turned off. At this time, the current i _l flowing through the resonant circuit charges the capacitors C ₁₂ and C ₁₃ connected in parallel with the MOS transistors Q ₁₂ and Q ₁₃ , so that the two ends of the switching devices MOS transistors Q ₁₂ and Q ₁₃ have very low dv/ dt, thereby reducing the switching loss and realizing the zero-voltage turn-off of the switching devices MOS transistors Q ₁₂ and Q ₁₃ . Then the current i _l flowing through the resonant circuit charges the capacitors C ₁₂ and C ₁₃ connected in parallel with the MOS transistors Q ₁₂ and Q ₁₃ , so that the voltages U _C12 and U _C13 of the capacitors C ₁₂ and C ₁₃ increase from zero, and The maximum voltage V _in is reached at time t ₉ . At the same time, the current i _l flowing through the resonant circuit discharges the capacitors C ₁₁ and C ₁₄ connected in parallel with the MOS transistors Q ₁₁ and Q ₁₄ , so that the voltage U _C11 and U _C14 of the capacitors C ₁₁ and C ₁₄ change from the maximum voltage V _in begins to decrease and reaches zero voltage at _t9 . At this point, the state ends.

Working state 6: corresponding to Fig. 3(f), time t ₉ -t ₁₁ in Fig. 4 . At time t ₉ , the voltages U _C11 and U _C14 of capacitors C ₁₁ and C ₁₄ reach zero voltage, which makes the diodes D ₁₁ and D ₁₄ connected in parallel to the two ends of the switching device MOS transistors Q ₁₁ and Q ₁₄ conduct, and the current flowing through the resonant circuit The current i _l is fed back to the power grid through diodes D ₁₁ and D _14. During this period of time in this working state, since the diodes D ₁₁ and D ₁₄ connected in parallel to the two ends of the switching device MOS transistors Q ₁₁ and Q ₁₄ are kept conducting, they are connected in parallel with the diodes The voltages U _Q11 and U _Q14 at both ends of the MOS transistors Q ₁₁ and Q ₁₄ remain zero until the moment t ₁₀ when the MOS transistors Q ₁₁ and Q ₁₄ are turned _on and the circuit status remains unchanged. ₁₄ freewheeling, the voltages U _Q11 and U _Q14 at both ends of the MOS transistors Q ₁₁ and Q ₁₄ remain zero, realizing the zero-voltage turn-on of the switching devices MOS transistors Q ₁₁ and Q ₁₄ . Until the moment t ₁₁ the current reverses, the diodes D ₁₁ and D ₁₄ are cut off, and this state ends. So far, a complete working cycle of the CLL resonant transformation is over, and the circuit returns to the working state 1 of the next working cycle, and the cycle repeats.

In the whole working process of CLL resonant conversion, in order to ensure that the four MOS transistors Q ₁₁ -Q ₁₄ normally realize zero-voltage switching, the dead time t _d should be carefully selected, and the MOS transistors must be turned on in working state 1 and working state 6 . If the dead time is too short, the zero-voltage turn-on cannot be realized because the parallel buffer capacitor of the MOS transistor has not been discharged. If the dead time is too long, the buffer capacitor will start to charge because the resonant current reaches zero voltage and starts to flow in the reverse direction. Zero voltage turn-on cannot be achieved. Therefore, the dead time t _d must be carefully selected.

Below in conjunction with above-mentioned content, beneficial effect of the present invention is described further:

(1) In the description of working states 2-6, the process of CLL resonant conversion to realize zero-voltage turn-on and zero-voltage turn-off of MOS transistors Q ₁₁ -Q ₁₄ is explained. In this process, the use of hard switches is reduced. unnecessary waste of energy;

(2) Use soft switching circuit to realize zero-voltage turn-on and zero-voltage turn-off, reduce the loss of switching devices caused by high-frequency inverter, reduce the heat generation of switching devices, reduce the design difficulty of heat dissipation of switching devices, and improve the use of switching devices time;

(3) The use of soft switching circuit reduces the loss of high-frequency inverter to the switching device, so that the switching frequency of the switching device can be further improved, and the inverter can work at a higher frequency, which will improve the coupling coil High transmission efficiency and reduce the volume of the system;

(4) In the description of working states 3 and 6, part of the energy of CLL resonant conversion is fed back to the power grid through the freewheeling diode and bidirectional AC/DC conversion instead of being consumed, which effectively reduces the loss of the system.

A control method for a soft-switching electromagnetic resonance type wireless charging device based on CLL resonance conversion, comprising the following steps:

In the first step, the microcontroller obtains the voltage of the input DC bus through the voltage detection circuit, and controls the duty cycle of the MOS transistors Q ₁ -Q ₆ in the bidirectional AC/DC rectifier module to stabilize the input DC bus voltage;

In the second step, the microcontroller controls the switching of MOS transistors Q ₁₁ -Q ₁₄ in the CLL resonant conversion module to invert the DC power into AC power; the microcontroller controls the switching frequency of the MOS transistors Q ₁₁ -Q ₁₄ in the CLL resonant conversion module Work between f ₁ and f ₂ to realize zero-voltage, zero-current switching inversion.

In the third step, the coupling resonant coil at the transmitting end emits the inverter energy of the CLL resonant conversion module, and transmits it to the coupling resonant coil at the receiving end through the high-frequency resonance coupling magnetic field;

Step 4: After receiving the high-frequency alternating current, the coupled resonant coil at the receiving end is rectified by the AC/DC rectifier module at the receiving end, and then stabilized and filtered by the voltage stabilizing filter capacitor at the receiving end, and finally charges the battery;

In the fifth step, the microcontroller obtains the terminal voltage and charging current of the battery through the voltage detection circuit, and controls the duty ratio of the MOS tube of the CLL resonant conversion module to realize the set charging current and overcharge protection function.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (7)

1. the electromagentic resonance formula wireless charging device based on CLL resonant transformation, is characterized in that, including AC/DC rectification module；

The input of described AC/DC rectification module connects three phase mains, connects after outfan parallel connection transmitting terminal filtering capacitance of voltage regulation CLL resonant transformation module；

The outfan of described CLL resonant transformation module is connected with transmitting terminal coupled resonance coil, the electricity in CLL resonant transformation module Electrification holds and forms transmitting terminal resonance circuit with transmitting terminal coupled resonance coil；

Coupling realized by transmitting terminal coupled resonance coil and receiving terminal coupled resonance coil；

Receiving terminal AC/DC rectification module is connected after receiving terminal coupled resonance coil series connection receiving terminal resonant-circuit capacitor；

Described receiving terminal coupled resonance coil constitutes receiving terminal resonance circuit with receiving terminal resonant-circuit capacitor, receives by resonance coupling Close the energy that magnetic field transmission comes；

Charge for accumulator after the outfan parallel connection receiving terminal filtering capacitance of voltage regulation of described receiving terminal AC/DC rectification module；Receive The unidirectional current that end filtering capacitance of voltage regulation obtains to receiving terminal AC/DC rectification module is filtered, and filters off high-frequency ac part；

In described AC/DC rectification module and CLL resonant transformation module, the switch of metal-oxide-semiconductor accepts the control of microcontroller drive signal System, makes high-frequency inversion frequency, the resonant frequency of transmitting terminal resonance circuit and the receiving terminal resonance circuit of CLL resonant transformation module Resonant frequency three is consistent, so that transmitting terminal and receiving terminal circuit reach resonance；

Described CLL resonant transformation module is H full-bridge circuit, including 4 metal-oxide-semiconductor Q₁₁-Q₁₄, each metal-oxide-semiconductor is parallel with two poles Pipe, respectively D₁₁-D₁₄, each metal-oxide-semiconductor is to should have a parasitic capacitance, respectively C₁₁-C₁₄；4 metal-oxide-semiconductors and connected in parallel Diode and electric capacity constitute H bridge 4 vertical brachium pontis；Intermediate lateral brachium pontis includes the two resonant inductance L connecting₁And L₂, electricity Sense L₁And L₂With resonant inductance L after series connection₀Parallel connection, after parallel connection overall again with resonant capacitance C₁Series connection；

Inductance L₂For transmitting terminal coupled resonance coil, with electric capacity C₁With inductance L₁、L₀Composition transmitting terminal resonance circuit, using transmitting terminal Coupled resonance coil is coupled with the height of receiving terminal coupled resonance coil, and high-frequency ac electric flux is launched；

Described receiving terminal AC/DC rectification module is 4 diode D₁-D₄The single-phase full bridge rectification circuit constituting, by the height receiving Frequency AC rectification becomes direct current.

2. the electromagentic resonance formula wireless charging device based on CLL resonant transformation as claimed in claim 1, is characterized in that, described AC/ DC rectification module is two-way AC/DC rectification module；Described two-way AC/DC rectification module is by 6 metal-oxide-semiconductor Q₁-Q₆The three-phase constituting Bridge-type all controlled rectifier circuit；By the dutycycle of microprocessor controls metal-oxide-semiconductor, realize to DC voltage V_inRegulation.

3. the electromagentic resonance formula wireless charging device based on CLL resonant transformation as claimed in claim 2, is characterized in that, described Penetrate two electric capacity C that end filtering capacitance of voltage regulation includes connecting_i1, C_i2, unidirectional current is obtained to two-way AC/DC rectification module and filters Ripple, filters off high frequency ac signal, C_i1Positive pole connect the high-pressure side of two-way AC/DC rectification module output, C_i2Positive pole and C_i1's Negative pole is connected, C_i2Negative pole connect the low-pressure side of two-way AC/DC rectification module output.

4. the electromagentic resonance formula wireless charging device based on CLL resonant transformation as described in Claims 2 or 3, is characterized in that, described CLL resonant transformation module has two kinds of resonant frequencies, and one kind is by resonant capacitance C₁With resonant inductance L₁The resonant frequency producing f₁, that is,Another kind is then by resonant capacitance C₁With resonant inductance L₁、L₀Resonant frequency f producing₂, that is,Wherein L_eqFor inductance L₁、L₀The resonant inductance of parallel equivalent,

5. the electromagentic resonance formula wireless charging device based on CLL resonant transformation as claimed in claim 1, is characterized in that, described micro- Controller produces pulse width modulation (PWM) signal, for controlling the switch of metal-oxide-semiconductor；

Described microcontroller also includes voltage detecting circuit, voltage detecting circuit by gather set of cells terminal voltage, charging current And the voltage of input direct-current bus, the CPU of microcontroller is delivered to by analog digital conversion port.

6. a kind of control method of the electromagentic resonance formula wireless charging device based on CLL resonant transformation as claimed in claim 4, It is characterized in that, comprise the following steps：

The first step, microcontroller obtains the voltage of input direct-current bus by voltage detecting circuit, and controls two-way AC/DC rectification Metal-oxide-semiconductor Q in module₁-Q₆Dutycycle realize stablizing of input direct-current busbar voltage；

Second step, microcontroller passes through to control metal-oxide-semiconductor Q in CLL resonant transformation module₁₁-Q₁₄Switching, DC inverter is struck a bargain Stream electricity；

3rd step, the inversion energy of CLL resonant transformation module is launched by transmitting terminal coupled resonance coil, and passes through harmonic high frequency Shake coupled magnetic field, be transferred to receiving terminal coupled resonance coil；

4th step, receiving terminal coupled resonance coil carries out whole through receiving terminal AC/DC rectification module after receiving high-frequency alternating current Stream, then voltage stabilizing and filtering are carried out by receiving terminal filtering capacitance of voltage regulation, finally accumulator is charged；

5th step, microcontroller obtains terminal voltage and the charging current of accumulator by voltage detecting circuit, and controls CLL resonance The dutycycle of conversion module metal-oxide-semiconductor, realizes the charging current of setting and crosses charging protection function.

7. the control method of the electromagentic resonance formula wireless charging device based on CLL resonant transformation as claimed in claim 6, its feature It is, in described second step, metal-oxide-semiconductor Q in microprocessor controls CLL resonant transformation module₁₁-Q₁₄Switching frequency be operated in frequency f₁ And f₂Between, realize no-voltage, Zero Current Switch inversion.