CN113472089A - Electric vehicle wireless charging system and control method - Google Patents

Electric vehicle wireless charging system and control method Download PDF

Info

Publication number
CN113472089A
CN113472089A CN202110819575.6A CN202110819575A CN113472089A CN 113472089 A CN113472089 A CN 113472089A CN 202110819575 A CN202110819575 A CN 202110819575A CN 113472089 A CN113472089 A CN 113472089A
Authority
CN
China
Prior art keywords
control module
inverter
current
wireless charging
ground
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110819575.6A
Other languages
Chinese (zh)
Inventor
孟浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Anjie Wireless Technology Suzhou Co ltd
Original Assignee
Anjie Wireless Technology Suzhou Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Anjie Wireless Technology Suzhou Co ltd filed Critical Anjie Wireless Technology Suzhou Co ltd
Priority to CN202110819575.6A priority Critical patent/CN113472089A/en
Publication of CN113472089A publication Critical patent/CN113472089A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
    • B60L53/12—Inductive energy transfer
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/80—Circuit arrangements or systems for wireless supply or distribution of electric power involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/14—Plug-in electric vehicles

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The invention provides an electric vehicle wireless charging system and a control method, wherein the electric vehicle wireless charging system comprises: the device comprises a power factor correction module, an inverter, a ground terminal control module, a transmitting coil, a receiving coil, a vehicle terminal control module and a rectifier. According to the wireless charging system for the electric automobile, the DC/DC module is not arranged, and the PFC and the INV meet the voltage requirement of the system, so that the system efficiency is optimized, and the system cost and the volume are reduced. Meanwhile, when the wireless charging system for the electric automobile regulates the current of the transmitting coil, the inverter can be ensured to be in a soft switching state, so that the high frequency of a power conversion device is facilitated.

Description

Electric vehicle wireless charging system and control method
Technical Field
The invention relates to the technical field of wireless charging of electric automobiles, in particular to a wireless charging system of an electric automobile and a control method.
Background
The electric automobile adopts the high-energy-density battery pack as a power source, but is limited by the capacity of the battery pack, the driving distance of the electric automobile is short, and meanwhile, the battery pack has long charging time and imperfect charging station configuration, thereby becoming the biggest bottleneck restricting the rapid development of the electric automobile.
There are generally two ways to supplement the electric energy for the battery pack of the electric vehicle: wired charging and wireless charging. The wired charging adopts the metal connection of a cable, a charging plug and a charging socket to supplement electric energy for the battery pack, but the problems of line aging, poor contact and the like also exist, and the reliability and the safety of power supply are greatly reduced. The wireless charging is performed by taking an alternating magnetic field as a medium for electric energy transmission, so that the problems of wired charging can be avoided, and in addition, the wireless charging also conforms to the trend of intelligent development of electric automobiles, and is expected to become a mainstream mode of electric automobile charging.
At present, in an existing wireless charging system, a transmitting side has a three-stage structure with a voltage regulation function, which is a PFC, a DC/DC and a full-bridge inverter, and the voltage regulation mainly based on the PFC + DC/DC is mainly adopted in the control so as to meet the energy transmission under different couplings. However, multi-stage energy transfer is detrimental to system efficiency, while also increasing system cost and volume. Therefore, it is necessary to provide a further solution to the above problems.
Disclosure of Invention
The invention aims to provide a wireless charging system of an electric automobile and a control method thereof, so as to overcome the defects in the prior art.
In order to solve the technical problems, the technical scheme of the invention is as follows:
an electric vehicle wireless charging system, comprising: the system comprises a power factor correction module, an inverter, a ground terminal control module, a transmitting coil, a receiving coil, a vehicle terminal control module and a rectifier;
the power factor correction module is connected with the transmitting coil through the inverter;
the rectifier is connected with the receiving coil;
the transmitting coil and the receiving coil are coupled with each other;
the ground control module is respectively connected with the power factor correction module, the inverter and the transmitting coil, carries out data transmission with the vehicle control module, and controls the phase difference of the current in the transmitting coil and the output voltage current of the inverter according to the data sent by the vehicle control module;
and the vehicle end control module adjusts the driving duty ratio of the rectifier according to data fed back by the ground end control module, and stops adjusting the driving duty ratio of the rectifier when the phase angle of the inverter is smaller than a preset value of the ground end control module, and increases the required current sent to the ground end control module.
As an improvement of the wireless charging system of the electric automobile, the inverter is a full-bridge inverter, and the ground control module controls the current in the transmitting coil by controlling the phase shift angle of the full-bridge inverter.
As an improvement of the wireless charging system of the electric automobile, the ground control module controls the current in the transmitting coil by controlling the output voltage of the power factor correction module.
As an improvement of the wireless charging system for the electric vehicle, the ground control module controls the current in the transmitting coil by controlling the phase shift angle of the full-bridge inverter, and when the phase angle of the full-bridge inverter is adjusted to be minimum and cannot reach the current data required by the vehicle control module, the ground control module continues to control the current in the transmitting coil by controlling the output voltage of the power factor correction module.
As an improvement of the wireless charging system for the electric vehicle, the inverter is a full-bridge inverter, the phase difference of the full-bridge inverter is the phase difference between the output current of the full-bridge inverter and the midpoint voltage of the bridge arm of the full-bridge inverter, and the ground control module controls the phase difference of the full-bridge inverter by controlling the phase shift angle of the full-bridge inverter.
As an improvement of the wireless charging system for the electric vehicle, the ground control module has a preset inverter voltage and current phase angle value, the preset inverter voltage and current phase angle value corresponds to a lowest value for ensuring that the inverter is in a soft switching state, and when the full-bridge inverter voltage and current phase angle value is less than the preset inverter voltage and current phase angle value, the ground control module increases the phase difference of the full-bridge inverter by controlling the phase shift angle of the full-bridge inverter.
As an improvement of the wireless charging system of the electric vehicle, the data fed back by the ground control module comprises: the current of the transmitting coil, whether the current of the transmitting coil reaches the required current of the receiving coil or not and whether the real-time phase angle of the full-bridge inverter reaches the preset inverter voltage and current phase angle value or not.
As an improvement of the wireless charging system for an electric vehicle of the present invention, the wireless charging system for an electric vehicle further comprises: the ground compensation module is connected between the inverter and the transmitting coil, and the vehicle end compensation unit is connected between the receiving coil and the rectifier.
As an improvement of the wireless charging system of the electric automobile, the rectifier comprises two parallel-connected paths, a diode and a MOSFET which are connected in series are arranged in any path, and the driving duty ratio of the rectifier at the moment
Figure BDA0003171384460000031
Wherein alpha is more than or equal to 180 degrees and less than or equal to 360 degrees, namely D is more than or equal to 0.5 and less than or equal to 1.
In order to solve the technical problems, the technical scheme of the invention is as follows:
a control method of an electric vehicle wireless charging system comprises the following steps:
s1, the vehicle end control module sends the current value required by the transmitting coil to the ground end control module;
s2, the ground control module controls the current in the transmitting coil and the phase difference of the voltage and the current output by the inverter according to the data sent by the vehicle control module;
s3, the ground end control module feeds back the state of the transmitting side to the vehicle end control module;
s4, when the phase difference of the voltage and the current output by the inverter is larger than or equal to a preset value and the current of the transmitting coil reaches the current value required by the receiving coil, the vehicle end control module adjusts the driving duty ratio of the rectifier to change the output power, otherwise, the step S5 is executed;
s5, stopping adjusting the driving duty ratio of the rectifier by the vehicle end control module, and increasing the required current value sent to the receiving coil;
s6, when the driving duty ratio of the rectifier is more than or equal to 0.5, the target power is reached, and the state is kept; otherwise, step S5 is executed.
Compared with the prior art, the invention has the beneficial effects that: according to the wireless charging system for the electric automobile, the DC/DC module is not arranged, and the PFC and the INV meet the voltage requirement of the system, so that the system efficiency is optimized, and the system cost and the volume are reduced. Meanwhile, when the wireless charging system for the electric automobile regulates the current of the transmitting coil, the inverter can be ensured to be in a soft switching state, so that the high frequency of a power conversion device is facilitated.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a block diagram of an embodiment of a wireless charging system for an electric vehicle according to the present invention;
FIG. 2 is a circuit diagram of an embodiment of a wireless charging system for an electric vehicle according to the present invention;
fig. 3 is a schematic diagram of a midpoint voltage UAB of a bridge arm of an inverter, an output current Iinv phase angle, and an inverter phase shift angle in an embodiment of the wireless charging system for an electric vehicle according to the present invention;
FIG. 4 shows an example of a driving waveform of a lower tube MOSFET of a rectifier, an input/output current waveform and a waveform of a bridge arm midpoint voltage Uab of the rectifier according to the wireless charging system of an electric vehicle of the present invention;
FIG. 5 is a schematic diagram of an input impedance Zrec of a rectifier and an input impedance Zin of a ground compensation module in an embodiment of the wireless charging system for an electric vehicle according to the invention;
FIG. 6 is a graph showing the variation of the real part and the imaginary part of the rectifier input impedance Zrec with the driving duty ratio D of the MOSFET under the rectifier in an embodiment of the wireless charging system for electric vehicles according to the present invention;
FIG. 7 is a diagram illustrating an influence of a MOSFET under a rectifier on an impedance angle of an input impedance of a ground compensation module when a driving duty ratio D of the MOSFET is changed according to an embodiment of the wireless charging system for an electric vehicle of the present invention;
fig. 8 is a flowchart illustrating a method of controlling a wireless charging system of an electric vehicle according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 and 2, an embodiment of the present invention provides a wireless charging system for an electric vehicle, including: the system comprises a power factor correction module 10, an inverter 20, a ground compensation module 30, a transmitting coil 40, a receiving coil 50, a vehicle-end compensation module 60, a rectifier 70, a ground control module 80 and a vehicle-end control module 90.
A power factor correction module (PFC)10 is connected to the transmitting coil 40 via an inverter 20. The power factor correction module 10 is connectable to an external power source, and is capable of increasing the power factor of the system to reduce loss of switching power and converting single-phase or three-phase power input from the external power source into an adjustable dc voltage output.
Further, the ground control module 80 may control the output voltage of the pfc module 10 according to the requirement, so as to change the magnitude of the input voltage of the inverter 20. The output voltage of the pfc module 10 has a certain range, for example, 600V to 800V, and the pfc module 10 outputs the lowest value of the output voltage range as a start value, which is always used as the output voltage before the pfc module 10 receives no voltage regulation command from the ground control module 80.
The inverter 20 is configured to convert the dc power output by the power factor correction module 10 into ac power with a certain frequency, and then output the ac power to the transmitting coil 40 after being compensated by the ground compensation module 30. In one embodiment, inverter 20 is a full bridge inverter. The full-bridge inverter comprises two parallel circuits, wherein each circuit comprises two MOSFETs connected in series.
The transmitter coil 40 and the receiver coil 50 form a coupling mechanism. The transmitting coil 40 transmits the alternating current electric energy in the form of an alternating magnetic field, and the receiving coil 50 coupled with the transmitting coil induces an alternating current in the alternating magnetic field, so that the conversion from the magnetic energy to the electric energy is realized.
The ground control module 80 may employ the current I of the transmitting coil 40pFull bridge inverter output current IinvInverter 20 bridge arm midpoint voltage UAB. In addition, the ground control module 80 is configured to control the inverter 20 according to the inverter arm midpoint voltage UABAnd an output current IinvJudging whether the full-bridge inverter is in a soft switching state, and feeding the current state of the transmitting side back to the vehicle-end control module 90 through wireless communication, so that the vehicle-end control module 90 adjusts the current value I of the request coil issued to the ground-end control module 80 in real timep-reAnd rectifier 70 tube MOSFET drive duty cycle.
Specifically, the ground control module 80 is connected to the power factor correction module 10, the inverter 20, and the transmitting coil 40, respectively. The ground control module 80 performs data transmission with the vehicle control module 90, and controls the phase difference between the current in the transmitting coil 40 and the output voltage and current of the inverter 20 according to the data fed back by the vehicle control module 90. As described above, the wireless charging system for an electric vehicle according to the present invention can ensure that the inverter 20 is in a soft-switching state when the current of the transmitting coil 40 is adjusted, and is further advantageous for achieving a high frequency of the power conversion device.
For controlling the current in the transmit coil 40.
Transmitting coil 40 current I in coupling mechanismpThe following relationship is associated with the inverter 20 output voltage:
Figure BDA0003171384460000071
therefore, the transmitting coil can be changed by controlling the output voltage of the PFC module 10, i.e., the input voltage of the inverter 20 and the phase shift angle of the inverter 2040 current Ip。
Thus, the ground control module 80 can receive the current value I of the demand coil sent by the vehicle control module 90 through wireless communicationp-reAnd the bridge arm midpoint voltage U is adjusted by controlling the full-bridge inverter to shift the phase or changing the output voltage of the power factor correction module 10ABSo as to achieve the coil current value I required by the vehicle end control module 90p-re。
In one embodiment, when the inverter 20 is a full-bridge inverter, the ground control module 80 controls the current in the transmitting coil 40 by controlling the phase shift angle of the full-bridge inverter. Meanwhile, the ground control module 80 controls the current in the transmitting coil 40 by controlling the output voltage of the power factor correction module 10.
At this time, the ground control module 80 firstly controls the current in the transmitting coil 40 by controlling the phase angle of the full-bridge inverter, and when the phase angle of the full-bridge inverter is adjusted to be minimum and cannot reach the current data required by the vehicle-end control module 90, the ground control module 80 continues to control the current in the transmitting coil 40 by controlling the output voltage of the power factor correction module 10.
A phase difference with respect to the control inverter 20 output voltage current.
Considering that the ground control module 80 adjusts the bridge arm midpoint voltage UAB by controlling the full-bridge inverter to shift the phase or changing the output voltage of the power factor correction module 10, it is necessary to ensure that the inverter 20 is in a soft-switching state. Therefore, the ground control module 80 needs to control the phase difference of the output voltage current of the inverter 20 to realize soft switching of the inverter 20.
Specifically, the ground control module 80 may collect the transmit coil 40 current IpFull bridge inverter output current IinvAnd inverter 20 bridge arm midpoint voltage UABAnd can be based on the collected bridge arm midpoint voltage UABAnd an inverter current IinvAnd calculating the phase relation of the two.
As shown in fig. 3, the inverter 20 is represented by a bridge arm midpoint voltage UABAnd an output current IinvPhase angle and inverter 20 phase shifting angle. Bridge arm midpoint voltage UABAnd an output current IinvThe phase angle refers to the phase difference between the rising edge of the midpoint voltage of the bridge arm and the positive zero crossing point of the inverter current, and the phase angle is used
Figure BDA0003171384460000081
And (4) showing. The phase shift angle of the inverter 20 means a phase difference between a falling edge of a negative voltage and a rising edge of a positive voltage in the output voltage of the inverter 20, and is represented by θ.
Considering that the inverter 20 output voltage leads the output current is an important condition for achieving soft switching of the inverter 20, i.e., the phase angle
Figure BDA0003171384460000082
It is an important condition for achieving soft switching of the inverter 20, and therefore can be based on
Figure BDA0003171384460000083
The angle determines the soft switching state of the inverter 20.
Therefore, the ground control module 80 can control the phase shift angle θ of the inverter 20, so as to control the bridge arm midpoint voltage U of the inverter 20ABAnd an output current IinvPhase angle
Figure BDA0003171384460000084
And also to vary the magnitude of the output voltage of the inverter 20. The theoretical adjustable range of the phase shift angle theta of the inverter 20 is 180-0 degrees, and the phase shift angle theta is adjusted from large to small in the system control process.
Further, the ground control module 80 may preset an inverter 20 voltage current phase angle value ψ, which is the lowest value that ensures soft switching of the inverter 20. Thus, the ground control module 80 may collect the present voltage-current phase angle of the inverter 20
Figure BDA0003171384460000091
When compared with the preset phase angle psi
Figure BDA0003171384460000096
The ground control module 80 controls the phase shift angle theta of the inverter 20 to increase the phase angle
Figure BDA0003171384460000097
Thereby ensuring that the inverter 20 is in a soft switching state, i.e. ensuring that the present voltage and current phase angle of the inverter 20
Figure BDA0003171384460000094
The preset phase angle phi is not less than psi.
The rectifier 70 is connected to the receiving coil 50 via the end-of-vehicle compensation module 60. The vehicle-end compensation module 60 compensates the ac power in the receiving coil 50 and outputs the compensated ac power to the rectifier 70, and the rectifier 70 converts the ac power into dc power and supplies the dc power to the load. In one embodiment, the ground compensation module 30 and the vehicle compensation module 60 adopt a symmetrical LCC topology. Rectifier 70 is referred to as a controlled full bridge rectifier 70, in which case the full bridge rectifier 70 includes two parallel paths with diodes and MOSFETs in series in either path.
The vehicle-side control module 90 adjusts the driving duty ratio of the rectifier 70 according to the data fed back by the ground-side control module 80, and stops adjusting the driving duty ratio of the rectifier 70 when the phase angle of the inverter 20 is smaller than the preset value of the ground-side control module 80, and increases the required current sent to the ground-side control module 80. Thus, the inverter 20 can be further ensured to be in a soft switching state through the control regulation of the vehicle-end control module 90.
Specifically, the ground control module 80 feeds back the current state of the transmitting side including, but not limited to, the current I of the transmitting coil 40 to the vehicle control module 90 via wireless communication in each communication cyclepWhether the required coil current value I is reachedp-reCurrent voltage current phase angle of inverter 20
Figure BDA0003171384460000095
Whether a preset phase angle psi is reached, etc.
The vehicle-end control module 90 adjusts the current value I of the demand coil issued to the ground-end control module 80 in real time according to the received feedback informationp-reAnd rectifier 70 tube MOSFET drive duty cycle.
As shown in FIG. 4, the present invention provides a controllable rectifier 70 lower tube MOSFET drive waveform, input/output current waveform and rectifier 70 bridge arm midpoint voltage UabWaveform, formula for drive duty cycle of tube MOSFET in rectifier 70
Figure BDA0003171384460000101
And calculating, wherein alpha is more than or equal to 180 degrees and less than or equal to 360 degrees, namely D is more than or equal to 0.5 and less than or equal to 1.
As shown in FIG. 5, the present invention provides a controllable rectifier 70 having an input impedance ZrecAnd the input impedance Z of the ground compensation module 30inSchematic representation. By fundamental analysis, the input current of the controllable rectifier 70 leads the input voltage, i.e. the input impedance Z of the controllable rectifierrecThe formula is as follows:
Figure BDA0003171384460000102
in the above equation, D is the driving duty cycle of the tube MOSFET in the rectifier 70, and Rbat is the equivalent load impedance.
As shown in FIG. 6, the present invention provides a rectifier 70 with an input impedance ZrecThe real and imaginary parts of (a) are a function of the MOSFET drive duty cycle D under the rectifier 70.
Input impedance Z of ground compensation module 30inIs closely related to the reflected impedance from the receiving side to the transmitting side, which is in turn affected by the input impedance Z of the rectifier 70recThus the input impedance Z of the ground compensation module 30inIs a function of the drive duty cycle D of the tube MOSFETs under rectifier 70, i.e. Zin＝f(D)；
As shown in fig. 7, the input impedance Z of the ground compensation module 30 when the duty ratio D of the MOSFET under the controlled rectifier 70 is changedinThe impedance angle of (c).
Since the driving duty ratio D of the tube MOSFET in the rectifier 70 of the present application varies from large to small, i.e., the starting value of D is 1, it is adjusted to 0.5. As can be seen from fig. 8, when the duty ratio D of the MOSFET driving circuit under the rectifier 70 is decreased, the input impedance Z of the ground compensation module 30 is decreasedinThe impedance angle of (2) also becomes smaller, and accordinglyVoltage current phase angle of ground inverter 20
Figure BDA0003171384460000103
It becomes smaller and affects the soft switching state of the inverter 20.
Therefore, the implementation of soft switching of the transmit side inverter 20 is affected by the inverter 20 phase shift angle θ and the receive side controlled rectifier down tube MOSFET drive duty cycle D. Therefore, the ground control module 80 is required to feed the current state of the transmitting side back to the vehicle control module 90 through wireless communication in each communication period, and the ground control module 80 and the vehicle control module 90 are matched to realize soft switching of the inverter 20.
Based on the same technical concept, the invention also provides a control method of the wireless charging system of the electric automobile, which comprises the following steps:
s1, the vehicle end control module sends the current value required by the transmitting coil to the ground end control module;
s2, the ground control module controls the current in the transmitting coil and the phase difference of the voltage and the current output by the inverter according to the data sent by the vehicle control module;
s3, the ground end control module feeds back the state of the transmitting side to the vehicle end control module;
s4, when the phase difference of the voltage and the current output by the inverter is larger than or equal to a preset value and the current of the transmitting coil reaches the current value required by the receiving coil, the vehicle end control module adjusts the driving duty ratio of the rectifier to change the output power, otherwise, the step S5 is executed;
s5, stopping adjusting the driving duty ratio of the rectifier by the vehicle end control module, and increasing the required current value sent to the receiving coil;
s6, when the driving duty ratio of the rectifier is more than or equal to 0.5, the target power is reached, and the state is kept; otherwise, step S5 is executed.
The following describes a technical solution of the control method of the wireless charging system for an electric vehicle, with reference to a specific embodiment.
As shown in fig. 8, the control method of the wireless charging system for an electric vehicle of the present embodiment includes the following steps:
s1, the vehicle end control module sends a required coil current value I to the ground end control modulep-re。
S2, the ground control module controls the full-bridge inverter phase shift angle theta and the output voltage of the power factor correction module to enable the transmitting coil current to flow to the required coil current value Ip-reAdjusting;
the phase shift angle theta of the full-bridge inverter refers to the phase difference between the falling edge of a negative voltage and the rising edge of a positive voltage in the output voltage of the inverter, the theoretical adjustable range is 180-0 degrees, and the phase shift angle theta is adjusted from large to small in the system control process.
The transmitting coil current reaches the required coil current value I by adjusting the phase shift angle theta of the full-bridge inverterp-reIn the process of (1), the voltage current phase angle of the inverter
Figure BDA0003171384460000124
Is enlarged, which is helpful for the inverter to realize soft switching;
the ground control module adjusts the current I of the transmitting coil by controlling the output voltage of the power factor correction module and the phase shift angle theta of the full-bridge inverterpWhen the phase shift angle theta of the full-bridge inverter cannot be adjusted, namely the phase shift angle theta reaches an adjustable minimum value, the output voltage of the power factor correction module is adjusted;
the power factor correction module outputs the lowest value of the output voltage range as an initial value, and the initial value is always used as the output voltage before the power factor correction module does not receive a voltage regulation command of the ground control module;
s3, the ground control module collects the phase angle of the voltage and the current of the inverter
Figure BDA0003171384460000125
And the current transmitting coil current IpAnd the current state of the transmitting side is fed back to the vehicle end control module.
Wherein the voltage-current phase angle of the inverter
Figure BDA0003171384460000121
The phase difference between the rising edge of the midpoint voltage of the bridge arm of the inverter and the positive zero crossing point of the inverter current is referred to;
the transmit side current state includes but is not limited to: current of the current transmitting coil IpWhether the required coil current value I is reachedp-reCurrent voltage and current phase angle of inverter
Figure BDA0003171384460000122
Whether the preset phase angle psi is reached.
Transmitting coil current IpThe required value of the vehicle end control module is achieved, and the soft switching requirement of the inverter is met, namely the judgment condition is met:
Figure BDA0003171384460000123
and S4, when the judgment condition is met, the vehicle end control module adjusts the driving duty ratio D of the MOSFET under the rectifier to change the output power.
The driving duty ratio D of the rectifier lower tube MOSFET is changed from large to small, and the adjusting range is [0.5,1 ].
As can be seen from FIG. 8, when the driving duty ratio D of the MOSFET under the rectifier becomes smaller, the input impedance Z of the ground compensation moduleinWill also become smaller, correspondingly the inverter voltage current phase angle
Figure BDA0003171384460000131
Will be reduced to further affect the soft switch of the inverter, so the ground control module will collect the voltage and current phase angle of the inverter in real time
Figure BDA0003171384460000132
And feeds back the information to the vehicle end control module.
S5, once the MOFET driving duty ratio under the rectifier is adjusted to make the inverter voltage current phase angle
Figure BDA0003171384460000133
If the phase angle phi is less than the preset phase angle psi, stopping adjusting the driving duty ratio D of the rectifier, and simultaneously increasing the current value I of the demand coil sent to the ground terminal control modulep-reThereby reducing the phase shift angle theta of the inverter and increasing the voltage current phase angle of the inverter
Figure BDA0003171384460000134
When the driving duty ratio D of the mosfet under the rectifier reaches the adjustable minimum value and the system has not yet reached the output requirement, step S5 is also executed: stopping adjusting the rectifier drive duty cycle D while increasing the demanded coil current value I sent to the ground control modulep-reThereby increasing the output power;
and S6, when the judgment condition D is satisfied and is not less than 0.5 and the target power is reached, the state is maintained and the system output requirement is satisfied.
In conclusion, the wireless charging system for the electric vehicle is not provided with the DC/DC module, and the PFC and the INV meet the voltage requirement of the system, so that the system efficiency is optimized, and the system cost and the volume are reduced. Meanwhile, when the wireless charging system for the electric automobile regulates the current of the transmitting coil, the inverter can be ensured to be in a soft switching state, so that the high frequency of a power conversion device is facilitated.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (10)

1. The utility model provides a wireless charging system of electric automobile, its characterized in that, wireless charging system of electric automobile includes: the system comprises a power factor correction module, an inverter, a ground terminal control module, a transmitting coil, a receiving coil, a vehicle terminal control module and a rectifier;
the power factor correction module is connected with the transmitting coil through the inverter;
the rectifier is connected with the receiving coil;
the transmitting coil and the receiving coil are coupled with each other;
the ground control module is respectively connected with the power factor correction module, the inverter and the transmitting coil, carries out data transmission with the vehicle control module, and controls the phase difference of the current in the transmitting coil and the output voltage current of the inverter according to the data sent by the vehicle control module;
and the vehicle end control module adjusts the driving duty ratio of the rectifier according to data fed back by the ground end control module, and stops adjusting the driving duty ratio of the rectifier when the phase angle of the inverter is smaller than a preset value of the ground end control module, and increases the required current sent to the ground end control module.
2. The wireless charging system of claim 1, wherein the inverter is a full-bridge inverter, and the ground control module controls the current in the transmitting coil by controlling a phase shift angle of the full-bridge inverter.
3. The wireless charging system of claim 2, wherein the ground control module controls the current in the transmitting coil by controlling the output voltage of the power factor correction module.
4. The wireless charging system of claim 3, wherein the ground control module first controls the current in the transmitting coil by controlling the phase shift angle of the full-bridge inverter, and when the phase angle of the full-bridge inverter is adjusted to the minimum and cannot reach the current data required by the vehicle control module, the ground control module continues to control the current in the transmitting coil by controlling the output voltage of the power factor correction module.
5. The wireless charging system for the electric vehicle according to claim 1, wherein the inverter is a full-bridge inverter, the phase difference of the full-bridge inverter is a phase difference between an output current of the full-bridge inverter and a midpoint voltage of a bridge arm of the full-bridge inverter, and the ground control module controls the phase difference of the full-bridge inverter by controlling a phase shift angle of the full-bridge inverter.
6. The wireless charging system for electric vehicles according to claim 5, wherein the ground control module has a preset inverter voltage/current phase angle value, the preset inverter voltage/current phase angle value corresponds to the lowest value for ensuring the inverter to be in the soft switching state, and when the full-bridge inverter voltage/current phase angle value < the preset inverter voltage/current phase angle value, the ground control module increases the phase difference of the full-bridge inverter by controlling the phase shift angle of the full-bridge inverter.
7. The wireless charging system of claim 6, wherein the data fed back by the ground control module comprises: the current of the transmitting coil, whether the current of the transmitting coil reaches the required current of the receiving coil or not and whether the real-time phase angle of the full-bridge inverter reaches the preset inverter voltage and current phase angle value or not.
8. The wireless charging system for electric vehicles according to claim 1, further comprising: the ground compensation module is connected between the inverter and the transmitting coil, and the vehicle end compensation unit is connected between the receiving coil and the rectifier.
9. The wireless charging system of claim 1, wherein the rectifier comprises two parallel circuits, each circuit having a series diode and a MOSFET, and the driving duty cycle of the rectifier
Figure FDA0003171384450000031
Wherein alpha is more than or equal to 180 degrees and less than or equal to 360 degrees, namely D is more than or equal to 0.5 and less than or equal to 1.
10. A control method of an electric vehicle wireless charging system is characterized by comprising the following steps:
s1, the vehicle end control module sends the current value required by the transmitting coil to the ground end control module;
s2, the ground control module controls the current in the transmitting coil and the phase difference of the voltage and the current output by the inverter according to the data sent by the vehicle control module;
s3, the ground end control module feeds back the state of the transmitting side to the vehicle end control module;
s4, when the phase difference of the voltage and the current output by the inverter is larger than or equal to a preset value and the current of the transmitting coil reaches the current value required by the receiving coil, the vehicle end control module adjusts the driving duty ratio of the rectifier to change the output power, otherwise, the step S5 is executed;
s5, stopping adjusting the driving duty ratio of the rectifier by the vehicle end control module, and increasing the required current value sent to the receiving coil;
s6, when the driving duty ratio of the rectifier is more than or equal to 0.5, the target power is reached, and the state is kept; otherwise, step S5 is executed.
CN202110819575.6A 2021-07-20 2021-07-20 Electric vehicle wireless charging system and control method Pending CN113472089A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110819575.6A CN113472089A (en) 2021-07-20 2021-07-20 Electric vehicle wireless charging system and control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110819575.6A CN113472089A (en) 2021-07-20 2021-07-20 Electric vehicle wireless charging system and control method

Publications (1)

Publication Number Publication Date
CN113472089A true CN113472089A (en) 2021-10-01

Family

ID=77881323

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110819575.6A Pending CN113472089A (en) 2021-07-20 2021-07-20 Electric vehicle wireless charging system and control method

Country Status (1)

Country Link
CN (1) CN113472089A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114172249A (en) * 2022-01-10 2022-03-11 深圳威迈斯新能源股份有限公司 Automobile wireless charging system and control method thereof
WO2023246420A1 (en) * 2022-06-22 2023-12-28 深圳威迈斯新能源股份有限公司 Wireless charging system and control method therefor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114172249A (en) * 2022-01-10 2022-03-11 深圳威迈斯新能源股份有限公司 Automobile wireless charging system and control method thereof
CN114172249B (en) * 2022-01-10 2023-11-07 深圳威迈斯新能源股份有限公司 Automobile wireless charging system and control method thereof
WO2023246420A1 (en) * 2022-06-22 2023-12-28 深圳威迈斯新能源股份有限公司 Wireless charging system and control method therefor

Similar Documents

Publication Publication Date Title
CN109861532B (en) DC/DC converter and whole vehicle control method based on same
CN110620517B (en) Parallel input and serial output aging power supply device
CN113472089A (en) Electric vehicle wireless charging system and control method
WO2023207049A1 (en) Low-voltage large-current wireless charging system and cooperative control method thereof
CN108879895B (en) Electric automobile energy transmission system and transmission method
CN110768521A (en) Bidirectional high-frequency auxiliary converter system
CN109586421B (en) Induction type wireless power transmission system and multi-adjustment parameter control method
CN115276258B (en) Wireless power transmission system with multiple inverters and multiple rectifiers and control method thereof
CN110544975A (en) single-tube constant-current constant-voltage wireless charging device and control method thereof
CN112373322B (en) Electric automobile bidirectional wireless power transmission topological structure and modulation method
CN215378578U (en) Wireless charging system of electric automobile
CN110492623B (en) Wireless power transmission inverter power supply based on direct control AC-AC converter
CN112311106A (en) Single-stage full-bridge constant-current constant-voltage wireless charging device and control method thereof
CN114312382B (en) System topology suitable for electric automobile wired wireless integrated charging pile
CN217514980U (en) Charging system suitable for electric vehicle
WO2022120663A1 (en) Power converter control method, device, and system
CN112436747B (en) Electric drive system, power assembly and electric automobile
CN114884107A (en) High power density digital control vehicle-mounted charging inversion all-in-one machine
CN111525706A (en) Frequency modulation type phase-locking synchronous rectification control circuit and frequency modulation type phase-locking method
CN111016690B (en) Wireless charging control method and device for electric automobile
CN110492767B (en) Wireless power transmission inversion source based on six-pulse wave controllable rectification
CN211790895U (en) Lightweight wireless charging receiving terminal and wireless charging system
CN113829904B (en) High-power wireless charging system and charging control method thereof
CN112572191B (en) Vehicle-mounted charging system and vehicle with same
CN112572194B (en) Vehicle-mounted charging system and vehicle with same

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination