Electric vehicle wireless electric energy transmission device based on cloud energy storage and control method

Abstract

The invention provides an electric vehicle wireless electric energy transmission device based on cloud energy storage and a control method, and relates to the technical field of electric vehicles and wireless charging. The device comprises a pre-stage transmitting end and a post-stage receiving end, wherein the pre-stage transmitting end consists of a Buck converter, an inverter bridge, an LCC compensation network and a primary side transmitting coil; the post-stage receiving end consists of a secondary side receiving coil, a diode rectifier bridge and an output capacitor; wherein the pre-stage transmitting end is placed on a cloud energy storage electric vehicle for rescue and is used for reducing, inverting and compensating the voltage of a storage battery according to a selected charging mode and transmitting energy stored in the cloud energy storage electric vehicle to the post-stage receiving end; and the rear-stage receiving end is placed on the electric vehicle waiting for rescue and is used for receiving the energy from the front-stage transmitting end and charging a storage battery in the electric vehicle waiting for rescue by using the received energy. According to the invention, the to-be-rescued time of the electric vehicles can be shortened, and wireless power transmission between the electric vehicles can be safely realized.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicles and wireless charging technology, and in particular to a wireless power transmission device and a control method for an electric vehicle based on cloud energy storage. Background Art

[0002] New energy vehicles represented by electric vehicles are one of the effective means to solve environmental pollution and fossil energy consumption. However, the related infrastructure of electric vehicles, such as charging piles and charging stations, is difficult to keep up with the development speed of electric vehicles. Therefore, the research and development of electric vehicle charging related devices can accelerate the development of electric vehicles and alleviate environmental pollution and fossil energy consumption.

[0003] The traditional method of charging electric vehicles uses a wired vehicle-to-vehicle charging device, but due to the need for physical connection, the wired vehicle-to-vehicle charging device has certain safety hazards during operation, especially in severe weather conditions, the connection line may increase the risk of electric shock due to aging and cracking. At the same time, the wired charging method limits the use scenarios of electric vehicles, because the charging process requires the vehicle to stop at the charging station, and is limited by the length of the charging cable, which is not conducive to fast charging and mobile charging. In addition, in some special environments or emergency situations, such as natural disaster sites, wired charging methods may not be possible or difficult to deploy quickly. Cloud energy storage is a typical model of public energy storage sharing structure, which can comprehensively utilize centralized energy storage facilities or aggregate distributed energy storage resources to provide energy storage services to users. Cloud energy storage can enable electric vehicles with exhausted battery energy to rely on electric vehicles with relatively sufficient battery energy to exchange electric vehicle energy anytime, anywhere, and on demand, forming shared electric vehicle energy storage resources, and pay related service fees according to usage needs and agreements. However, cloud energy storage still faces some technical difficulties in the actual application of wireless charging of electric vehicles, such as the lack of endurance of electric vehicles, large equipment size, and the need for a fixed charging range and location. Therefore, there is an urgent need for an electric vehicle wireless power transmission device based on cloud energy storage to solve the problem of lack of endurance of electric vehicles. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a wireless power transmission device and a control method for electric vehicles based on cloud energy storage, which can realize wireless power transmission between electric vehicles.

[0005] The first aspect of the present invention provides a wireless power transmission device for electric vehicles based on cloud energy storage, the device comprising: a front-stage transmitting end and a rear-stage receiving end; wherein the front-stage transmitting end is placed on the cloud energy storage electric vehicle used for rescue; the rear-stage receiving end is placed on the electric vehicle waiting for rescue;

[0006] The front-stage transmitting end is used to step down, invert and compensate the battery voltage in the cloud energy storage electric vehicle according to the charging mode selected by the owner of the electric vehicle waiting for rescue, and use the mutual inductance coil to send the energy stored in the cloud energy storage electric vehicle to the rear-stage receiving end;

[0007] The latter receiving end is used to receive energy from the former transmitting end by using the mutual inductance coil, and to charge the storage battery in the electric vehicle waiting for rescue by using the received energy;

[0008] Furthermore, the front-stage transmitting end includes: a Buck buck converter, an inverter bridge, an LCC compensation network and a primary-side transmitting coil; wherein the output end of the Buck buck converter is connected to the input end of the inverter bridge; the output end of the inverter bridge is connected to the input end of the LCC compensation network; the output end of the LCC compensation network is connected to the input end of the primary-side transmitting coil;

[0009] The Buck step-down converter is used to reduce the battery voltage U in the cloud energy storage electric vehicle. i The voltage is stepped down and the DC voltage obtained by the step-down is used as the output voltage U of the Buck converter. 1 ;

[0010] The inverter bridge is used to convert the output voltage U of the Buck step-down converter 1 Converted into AC square wave voltage U ab ; wherein the inverter bridge is a full-bridge structure composed of 4 MOSFETs;

[0011] The LCC compensation network is used to compensate the circuit of the front-stage transmitting end; wherein the LCC compensation network is composed of a compensation inductor L p1 , series compensation capacitor C p1 And parallel compensation capacitor C p2 The T-shaped circuit is formed;

[0012] The primary side transmitting coil is used to send the energy stored in the cloud energy storage electric vehicle to the subsequent receiving end; wherein the primary side transmitting coil is a mutual inductance coil L 1 ;

[0013] Furthermore, the post-stage receiving end includes: a secondary side receiving coil, a diode rectifier bridge and an output capacitor C o ; wherein the output end of the secondary side receiving coil is connected to the input end of the diode rectifier bridge; the output end of the diode rectifier bridge is connected to the output capacitor C o The input terminal is connected to

[0014] The secondary side receiving coil is used to sense the energy emitted by the primary side transmitting coil; wherein the secondary side receiving coil is a mutual inductance coil L2 ;

[0015] The diode rectifier bridge is used to connect the mutual inductance coil L 2 The induced AC voltage is converted into a DC voltage; wherein the diode rectifier bridge is a full-wave rectifier circuit composed of 4 diodes;

[0016] The output capacitor C o , used to filter out the voltage ripple in the DC voltage, and connect the filtered DC voltage to the battery of the electric vehicle waiting for rescue for charging;

[0017] A second aspect of the present invention provides a method for controlling wireless power transmission of an electric vehicle based on cloud energy storage, the method comprising the following steps:

[0018] Step 1: The electric car owner waiting for rescue sends a distress signal using a mobile device, and matches the cloud energy storage electric car for rescue according to the distress signal;

[0019] Step 2: The cloud energy storage electric vehicle arrives at the location of the electric vehicle waiting for rescue according to the distress signal, and sets up a cloud energy storage-based electric vehicle wireless power transmission device;

[0020] Step 3: The owner of the electric vehicle waiting for rescue selects a charging mode of constant voltage charging mode or constant current charging mode, and uses the electric vehicle wireless power transmission device based on cloud energy storage to charge the electric vehicle waiting for rescue according to the selected charging mode;

[0021] Step 4: After charging is completed, the electric car owner waiting for rescue pays the charging service fee to the cloud energy storage electric car owner;

[0022] The specific method of step 1 is as follows: the owner of the electric car waiting for rescue uses a mobile device to send a distress signal to all the cloud energy storage electric cars within the communication range of the mobile device; all owners of the cloud energy storage electric cars that receive the distress signal choose whether to go to the rescue, and if so, choose to agree to the rescue on the mobile device and drive to the location of the electric car waiting for rescue; if not, choose to refuse the rescue on the mobile device; when the owner of a cloud energy storage electric car chooses to agree to the rescue, the distress signals received by the remaining cloud energy storage electric cars except the cloud energy storage electric car are invalid;

[0023] The distress signal includes: the location and power requirement of the electric vehicle waiting for rescue;

[0024] The step 2 further comprises:

[0025] Step 2.1: Align the passenger door of the cloud energy storage electric vehicle with the main driver's door of the electric vehicle waiting for rescue in parallel, and maintain the preset distance;

[0026] Step 2.2: Place the front-stage transmitting end of the electric vehicle wireless power transmission device based on cloud energy storage inside the co-pilot door of the electric vehicle with cloud energy storage; place the rear-stage receiving end of the electric vehicle wireless power transmission device based on cloud energy storage inside the main driver's door of the electric vehicle waiting for rescue;

[0027] Step 2.3: Use wireless power transmission technology to pair the front-stage transmitter and the rear-stage receiver to complete the setting of the electric vehicle wireless power transmission device based on cloud energy storage;

[0028] The step 3 further comprises:

[0029] Step 3.1: Set the output voltage reference value U oref Or the reference value of the output current I oref ;

[0030] Step 3.2: Calculate the load current effective value I using the load parameter identification method o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; where R e0 is the fundamental component of the equivalent resistance on the rectifier bridge side; ωL e0 is the fundamental component of the equivalent inductance on the rectifier bridge side;

[0031] Step 3.3: The electric car owner waiting for rescue selects the charging mode as constant voltage charging mode or constant current charging mode and starts charging;

[0032] Step 3.4: Obtain the battery voltage U in the cloud energy storage electric vehicle i As input voltage;

[0033] Step 3.5: According to the reference value U of the output voltage oref Or the reference value of the output current I oref Calculate the output reference voltage U of the Buck converter 1ref ;

[0034] Step 3.6: Obtain the current I of the primary side transmitting coil by sampling coil , and according to the current I coil and input voltage U i Calculate the output voltage U of the Buck converter 1 ;

[0035] Step 3.7: Use the inverter bridge to adjust the output voltage U of the Buck converter 1 Invert to get AC square wave voltage Uab , and the AC square wave voltage U ab The LCC compensation network is input, and then the AC square wave voltage passing through the LCC compensation network is applied to the primary-side transmitting coil. The primary-side transmitting coil transmits the electric energy of the battery in the cloud energy storage electric vehicle to the secondary-side receiving coil in the form of a magnetic field;

[0036] Step 3.8: Based on the principle of electromagnetic induction, the secondary side receiving coil senses the electromotive force, and the sensed electromotive force is rectified into direct current through a diode rectifier bridge and then filtered, and the filtered output voltage or output current is used to start charging the electric vehicle waiting for rescue;

[0037] Step 3.9: Based on the output reference voltage U of the Buck converter 1ref 、Buck step-down converter output voltage U 1 , load voltage effective value U o , output voltage reference value U oref , load current effective value I o and the reference value of the output current I oref , using PI controller and error regulator to adjust the output voltage of Buck converter;

[0038] Step 3.10: Based on the selected charging mode, the output voltage of the adjusted Buck converter and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 , recalculate the load current effective value or the load voltage effective value, obtain the corrected load voltage effective value or the load current effective value, and then calculate the corrected load equivalent resistance;

[0039] Step 3.11: Determine whether the current charging process is stable. If it is not stable, use the load parameter identification method to recalculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; Update the output voltage of the Buck converter and return to step 3.9; if stable; maintain the current charging state;

[0040] Step 3.12: When the battery power of the electric vehicle waiting for rescue reaches the demand of the owner, the charging is terminated;

[0041] The method for identifying the load parameters in step 3.2 is: obtain the parallel compensation capacitor C by sampling p2 The voltage U Cp2 and the current I of the primary transmitting coil coil, and use fast Fourier transform FFT to calculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 ; Specifically include the following steps:

[0042] Step S1: Use parallel compensation capacitor C p2 The voltage U Cp2 and the current I of the primary transmitting coil coil , calculate the equivalent current of the rectifier bridge under the fundamental wave And the equivalent current of the rectifier bridge under the third harmonic

[0043]

[0044] Where x represents the serial number of the harmonic component, and when x=0, it represents the fundamental component; When the voltage applied to the diode rectifier bridge is The equivalent current of the rectifier bridge at ; C p2 The voltage of the equivalent circuit at the xth harmonic; ω represents the angular frequency, and ω = 2πf, f represents the frequency; M is the mutual inductance coefficient between the primary side transmitting coil and the secondary side receiving coil; C p1 is the series compensation capacitor; R Cp1 C p1 The equivalent resistance of 1 is the mutual inductance coil of the primary side transmitting coil; R 1 For L 1 The equivalent resistance of; j represents the imaginary unit; The xth harmonic flows through L 1 The current;

[0045] Step S2: Use the equivalent current of the rectifier bridge under the fundamental wave And the equivalent current of the rectifier bridge under the third harmonic Calculate the effective value of the load current I o ;

[0046]

[0047] Where θ is the phase angle;

[0048] Step S3: Calculate the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 ;

[0049]

[0050] Where L 2 is the mutual inductance coil of the secondary side receiving coil; R 2 For L 2 The equivalent parasitic resistance of; C and E are both intermediate variables, and there are:

[0051]

[0052] where θ 0 is the phase angle of the fundamental wave; θ 0 =ω 0 t, and ω 0 is the angular frequency of the fundamental wave; t is time; U Cp20 C p2 Fundamental voltage of the equivalent circuit; I coil0 For the flow through L 1 The fundamental current;

[0053] Step S4: Using the rectifier bridge equivalent current under the fundamental wave and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 Calculate the equivalent input voltage fundamental component of the diode rectifier bridge

[0054]

[0055] Step S5: Using the equivalent input voltage fundamental component of the rectifier bridge Calculate the load voltage effective value U o ;

[0056]

[0057] Step S6: Using the load current effective value I o And load voltage effective value U o Calculate the load equivalent resistance R L ;

[0058] The step 3.9 further comprises:

[0059] Step 3.9.1: Calculate the output reference voltage U of the Buck converter 1ref The output voltage U of the Buck converter 1 The difference between ΔU 1 , if the difference ΔU 1 If the error is within the preset range or does not exist, it means that the current charging process is stable and the current state should be maintained for charging. 1 If it does not meet the preset error range, the difference ΔU 1 As the voltage error of Buck converter;

[0060] Step 3.9.2: If the charging mode is constant voltage charging mode, calculate the load voltage effective value U o And the reference value of the output voltage U oref The difference ΔU o ; If the charging mode is constant current charging mode, calculate the load current effective value I o and the reference value of the output current I oref The difference ΔI o ; If the difference ΔU o Or the difference ΔI o If the error is within the preset range or does not exist, the current state is maintained for charging; if the difference ΔU o Or the difference ΔI o If it does not meet the preset error range, the difference ΔU o Or the difference ΔI o As load error;

[0061] Step 3.9.3: Input the voltage error of the Buck buck converter into the PI controller to obtain the output value of the PI controller; input the load error into the error regulator to obtain the error compensation value of the error regulator; then add the output value of the PI controller to the error compensation value obtained by the error regulator to obtain the PWM duty cycle D and feed it back to the Buck buck converter to recalculate the output voltage of the Buck buck converter;

[0062] The method for recalculating the load current effective value or the load voltage effective value described in step 3.10 is: if the selected charging mode is the constant voltage charging mode, a linear control relationship between the output voltage of the Buck buck converter and the load voltage effective value in the constant voltage charging mode is constructed, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0 , calculate the corrected load voltage effective value;

[0063] The linear control relationship between the output voltage of the Buck converter and the effective value of the load voltage in the constant voltage charging mode is:

[0064]

[0065] Where L p1 To compensate for inductance;

[0066] If the selected charging mode is the constant current charging mode, a linear control relationship between the output voltage of the Buck buck converter and the effective value of the load current in the constant current charging mode is established, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0, calculate the corrected load current effective value;

[0067] The linear control relationship between the output voltage of the Buck converter and the effective value of the load current in the constant current charging mode is:

[0068]

[0069] Where A and B are both intermediate variables, and there are:

[0070]

[0071] Where Z in is the equivalent input impedance seen from the output end of the inverter bridge; Z p3 is the third harmonic component of the equivalent impedance of the primary-side transmitting coil; Z s3 is the third harmonic component of the equivalent impedance of the secondary side receiving coil; and:

[0072]

[0073] Z s3 =j3ω(L 2 +L e3 )+R 2 +R e3

[0074] Where ωL e3 is the equivalent inductance third harmonic component of the secondary side receiving coil; R e3 is the third harmonic component of the equivalent resistance of the secondary side receiving coil.

[0075] The beneficial effects of adopting the above technical solution are:

[0076] The device of the present invention realizes energy transfer through power electronic conversion technology. Compared with the traditional vehicle-to-vehicle charging device with wired connection, the device of the present invention uses a transmitting coil and a receiving coil, so that there is no physical connection between the two electric vehicles during charging, thereby ensuring the safety, convenience and connectivity of the electric vehicle wireless power transmission device.

[0077] The device of the present invention adopts an LCC compensation structure to design the front-stage transmitting end in the wireless power transmission device of an electric vehicle, and adopts a magnetic integration structure on the primary side and a non-compensation network on the secondary side, thereby reducing the volume of the additional compensation inductor. The size of the secondary side is relatively compact, thereby reducing the weight of the electric vehicle.

[0078] The device of the present invention applies a load parameter identification method in the rear-stage receiving end of the electric vehicle wireless power transmission device. Since the non-pure resistive input impedance characteristics of the rectifier are taken into consideration, the relationship between the rectifier input impedance and the load is not derived, but the equivalent output resistance is obtained through the output current and the output voltage, which simplifies the relationship between the rectifier input impedance and the load and reduces the calculation complexity of the digital controller.

[0079] The device of the present invention utilizes a primary-side linear control strategy to simplify the control model into a linear one, which facilitates the design of a controller in the process of charging using the device of the present invention, including a PI controller and an error regulator, so that the controller has a good linear relationship with the output variable, thereby improving the control accuracy of the wireless power transmission device.

[0080] In summary, the present invention applies the concept of cloud energy storage to define an electric car with sufficient power. The method of the present invention effectively shortens the time for an electric car owner who is waiting for rescue to be rescued, thereby alleviating the anxiety of the owner and accelerating the development of electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 Schematic diagram of a wireless power transmission device for electric vehicles based on cloud energy storage in this embodiment;

[0082] Figure 2 This is a flow chart of a method for controlling wireless power transmission of an electric vehicle based on cloud energy storage in this embodiment;

[0083] Figure 3 A flow chart of charging an electric vehicle using a wireless power transmission device based on cloud energy storage in this embodiment;

[0084] Figure 4 is a flow chart of the primary side linear control method in this embodiment;

[0085] Figure 5 This is a block diagram of the primary side linear control in this implementation;

[0086] Figure 6 is an equivalent circuit diagram of the primary-side transmitting coil end and the secondary-side receiving coil end in this embodiment;

[0087] Figure 7 Schematic diagram of the position relationship between the primary side, secondary side coils and compensation inductance in this embodiment. DETAILED DESCRIPTION

[0088] In order to facilitate the understanding of the present application, the specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.

[0089] In this embodiment, a wireless power transmission device for electric vehicles based on cloud energy storage is provided. Figure 1 As shown, the device includes: a front-stage transmitting end and a rear-stage receiving end; wherein the front-stage transmitting end is placed on a cloud energy storage electric vehicle used for rescue; and the rear-stage receiving end is placed on an electric vehicle waiting for rescue.

[0090] The front-stage transmitting end is used to step down, invert and compensate the battery voltage in the cloud energy storage electric vehicle according to the charging mode selected by the electric vehicle owner waiting for rescue, and use the mutual inductance coil to send the energy stored in the cloud energy storage electric vehicle to the rear-stage receiving end.

[0091] In this embodiment, the cloud energy storage electric vehicle used for rescue transfers the energy stored in its own battery to the electric vehicle waiting for rescue according to the distress signal, and the cloud energy storage electric vehicle used for rescue is composed of electric vehicles with relatively abundant electric energy.

[0092] The latter receiving end is used to receive energy from the former transmitting end by using the mutual inductance coil, and to charge the storage battery in the electric vehicle waiting for rescue by using the received energy.

[0093] The front-stage transmitting end includes: a Buck buck converter, an inverter bridge, an LCC compensation network and a primary-side transmitting coil; wherein the output end of the Buck buck converter is connected to the input end of the inverter bridge; the output end of the inverter bridge is connected to the input end of the LCC compensation network; and the output end of the LCC compensation network is connected to the input end of the primary-side transmitting coil.

[0094] The Buck step-down converter is used to reduce the battery voltage U in the cloud energy storage electric vehicle. i The voltage is stepped down and the DC voltage obtained by the step-down is used as the output voltage U of the Buck converter. 1 .

[0095] The inverter bridge is used to convert the output voltage U of the Buck step-down converter 1 Converted into AC square wave voltage U ab ; wherein the inverter bridge is a full-bridge structure composed of 4 MOSFETs.

[0096] In this embodiment, if Figure 1 As shown, the inverter bridge adopts a full-bridge structure composed of 4 MOSFETs, which are respectively denoted as: Q1 ,Q 2 ,Q 3 ,Q 4 .

[0097] The LCC compensation network is used to compensate the circuit of the front-stage transmitting end.

[0098] The LCC compensation network consists of a compensation inductor L p1 , series compensation capacitor C p1 And parallel compensation capacitor C p2 The T-shaped circuit is composed of a T-shaped structure; the left branch of the T-shaped structure is the compensation inductor; the right branch of the T-shaped structure is the series compensation capacitor C p1 ; The lower branch of the T-type structure is the parallel compensation capacitor C p2 ,like Figure 1 shown.

[0099] The primary side transmitting coil is used to send the energy stored in the cloud energy storage electric vehicle to the subsequent receiving end; wherein the primary side transmitting coil is a mutual inductance coil L 1 .

[0100] The latter receiving end includes: a secondary side receiving coil, a diode rectifier bridge and an output capacitor C o ; wherein the output end of the secondary side receiving coil is connected to the input end of the diode rectifier bridge; the output end of the diode rectifier bridge is connected to the output capacitor C o The input terminal is connected.

[0101] The secondary side receiving coil is used to sense the energy emitted by the primary side transmitting coil; wherein the secondary side receiving coil is a mutual inductance coil L 2 .

[0102] The diode rectifier bridge is used to connect the mutual inductance coil L 2 The induced AC voltage is converted into a DC voltage; wherein the diode rectifier bridge is a full-wave rectifier circuit composed of 4 diodes.

[0103] In this embodiment, if Figure 1 As shown, the function of the diode rectifier bridge is to convert the alternating current (AC) induced by the receiving coil into direct current (DC). In wireless power transmission, the rectifier bridge usually consists of four diodes forming a full-wave rectifier circuit, which are denoted as: D 1 ,D 2 ,D 3 ,D 4 , so that both the positive and negative half cycles of AC can be converted into DC. This can maximize the use of the inductively generated electrical energy and improve the energy conversion efficiency of the system. The selection of the rectifier bridge is crucial to the efficiency and reliability of the system.

[0104] The output capacitor C o , which is used to filter out the voltage ripple in the DC voltage and connect the filtered DC voltage to the battery of the electric vehicle waiting for rescue for charging.

[0105] In this embodiment, if Figure 1 As shown, the wireless power transmission in the wireless power transmission device of electric vehicles needs to go through step-down, inversion, compensation, coil mutual inductance, rectification and filtering to complete the transmission of wireless power. Step-down refers to using a Buck step-down converter to step down the battery voltage of the cloud energy storage electric vehicle; inversion refers to converting the voltage obtained after step-down into an AC square wave voltage; compensation refers to using an LCC compensation network to compensate the entire front-stage transmitting circuit for the primary side coil; coil mutual inductance refers to the mutual induction of the transmitting coil and the receiving coil; rectification refers to converting the AC square wave voltage induced by the receiving coil into a DC voltage; filtering refers to converting the DC voltage obtained by rectification into a more stable DC voltage for output.

[0106] A method for controlling wireless power transmission of an electric vehicle based on cloud energy storage in this embodiment is as follows: Figure 2 As shown, the method comprises the following steps:

[0107] Step 1: The electric car owner waiting for rescue uses a mobile device to send a distress signal, and matches the cloud energy storage electric car for rescue based on the distress signal.

[0108] The specific method of step 1 is: the owner of the electric car waiting for rescue uses a mobile device to send a distress signal to all cloud-storage energy electric cars within the communication range of the mobile device; all owners of the cloud-storage energy electric cars that receive the distress signal choose whether to go for rescue, and if so, choose to agree to the rescue on the mobile device and drive to the location of the electric car waiting for rescue; if not, choose to refuse rescue on the mobile device; when the owner of a cloud-storage energy electric car chooses to agree to the rescue, the distress signals received by the remaining cloud-storage energy electric cars except for the cloud-storage energy electric car are invalid.

[0109] The distress signal includes: the location and power demand of the electric vehicle waiting for rescue.

[0110] In this embodiment, first, according to user needs, a help signal is sent to nearby electric vehicles that can quickly reach the rescue site through wireless communication devices such as smart phones, mobile phone apps with information transmission functions, etc. After the rescue vehicle owner responds, he drives the electric vehicle to the rescue site.

[0111] Step 2: The cloud energy storage electric vehicle arrives at the location of the electric vehicle waiting for rescue according to the distress signal, and sets up a cloud energy storage-based electric vehicle wireless power transmission device.

[0112] Step 2.1: Align the passenger door of the cloud energy storage electric vehicle parallel to the main driver's door of the electric vehicle waiting for rescue, and maintain the preset distance.

[0113] In this embodiment, if Figure 3 As shown, after the owner of the cloud energy storage electric vehicle responds, he drives the cloud energy storage electric vehicle to the rescue site and adjusts the relative position of the two vehicles to the position with the maximum efficiency of wireless power transmission, so as to facilitate the subsequent use of the wireless power transmission device loaded on the electric vehicle to wirelessly charge the waiting rescue vehicle. Specifically, the cloud energy storage electric vehicle is parked on the side of the main driver's door of the waiting rescue electric vehicle, and the co-driver's door of the cloud energy storage electric vehicle is aligned with the main driver's door of the waiting rescue electric vehicle, ensuring that the distance between the two doors is small and in a parallel state, preferably not more than 30cm, so that the wireless power transmission efficiency can be maximized.

[0114] Step 2.2: Place the front-stage transmitting end in the electric vehicle wireless power transmission device based on cloud energy storage inside the co-pilot door of the electric vehicle with cloud energy storage; place the rear-stage receiving end in the electric vehicle wireless power transmission device based on cloud energy storage inside the main driver's door of the electric vehicle waiting for rescue.

[0115] In this embodiment, a primary transmitting coil is placed inside the co-driver's door of the cloud energy storage electric vehicle, and a secondary receiving coil is placed inside the main driver's door of the electric vehicle waiting for rescue.

[0116] Step 2.3: Use wireless power transmission technology to pair the front-end transmitter and the back-end receiver to complete the setting of the electric vehicle wireless power transmission device based on cloud energy storage.

[0117] In this embodiment, by turning on the wireless power transmission function, the two vehicles are waiting to transmit their respective parameter information, including charging voltage, coil inductance, mutual inductance coefficient, etc.

[0118] Step 3: The owner of the electric car waiting for rescue selects a charging mode as a constant voltage charging mode or a constant current charging mode, and uses the electric car wireless power transmission device based on cloud energy storage to charge the electric car waiting for rescue according to the selected charging mode.

[0119] In this embodiment, after the parameter transfer is completed, it is necessary to select the charging mode as constant voltage charging or constant current charging mode. Trigger the switch to start wireless charging, and use the wireless power transmission device to transfer the energy of the cloud energy storage electric vehicle to the waiting rescue electric vehicle, which consists of load parameter identification and primary side linear control.

[0120] Step 3.1: Set the output voltage reference value U oref Or the reference value of the output current I oref .

[0121] In this embodiment, if Figure 4 and Figure 5 As shown, by setting a reference value of the output voltage or current, the output of the wireless power transmission device for electric vehicles based on cloud energy storage can be ensured to be within the expected range, thereby maintaining stability and reliability when charging using the wireless power transmission device for electric vehicles based on cloud energy storage.

[0122] Step 3.2: Calculate the load current effective value I using the load parameter identification method o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; where R e0 is the fundamental component of the equivalent resistance on the rectifier bridge side; ωL e0 It is the fundamental component of the equivalent inductance on the rectifier bridge side.

[0123] In this embodiment, load parameter identification is mainly performed by obtaining the voltage across the compensation capacitor and the transmitting coil current through a sampling circuit, and obtaining the fundamental component and the third harmonic component through a fast Fourier transform FFT, ignoring the fifth harmonic component and above, and then substituting them into the corresponding formula to obtain the load current and voltage, and the load equivalent resistance can be obtained through the voltage and current.

[0124] The method for identifying the load parameters is: obtaining the parallel compensation capacitor C by sampling p2 The voltage U Cp2 and the current I of the primary transmitting coil coil , and use fast Fourier transform FFT to calculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 ; Specifically include the following steps:

[0125] In this embodiment, if Figure 6 As shown, an equivalent circuit of an LCC compensation circuit, a primary-side transmitting coil, and a secondary-side receiving coil considering parasitic parameters is constructed. is the AC square wave voltage obtained after inversion, is the input current obtained after inversion, L p1 To compensate for the inductance, R Lp1 For L p1 The equivalent parasitic resistance, C p2 is the parallel compensation capacitor, R Cp2 C p2The equivalent parasitic resistance of C p2 and R Cp2 The voltage across the terminals, For L p1 The current, C p1 is the series compensation capacitor, R Cp1 C p1 The equivalent parasitic resistance, L 1 The mutual inductance coil used for the primary side transmitting coil, R 1 For L 1 The equivalent parasitic resistance, L 2 is the mutual inductance coil used by the secondary side receiving coil, R 2 For L 2 The equivalent parasitic resistance, Z M For L 1 and L 2 The mutual inductance impedance, Z MS For L p1 and L 2 The mutual inductance impedance, is the input voltage of the diode rectifier bridge, is the input current of the diode rectifier bridge, L ex is the equivalent inductance of the load, R ex is the equivalent resistance of the load; Z in is the equivalent input impedance seen from the output end of the inverter bridge; Z p is the equivalent impedance of the primary side transmitting coil; where L p1 , C p1 and C p2 It forms the LCC compensation network on the primary side.

[0126] Step S1: Use parallel compensation capacitor C p2 The voltage U Cp2 and the current I of the primary transmitting coil coil , calculate the equivalent current of the rectifier bridge under the fundamental wave And the equivalent current of the rectifier bridge under the third harmonic

[0127]

[0128] Where x represents the serial number of the harmonic component, and when x=0, it represents the fundamental component; When the voltage applied to the diode rectifier bridge is The equivalent current of the rectifier bridge at ; C p2 The voltage of the equivalent circuit at the xth harmonic; ω represents the angular frequency, and ω = 2πf, f represents the frequency; M is the mutual inductance coefficient between the primary side transmitting coil and the secondary side receiving coil; C p1 is the series compensation capacitor; RCp1 C p1 The equivalent resistance of 1 is the mutual inductance coil of the primary side transmitting coil; R 1 For L 1 The equivalent resistance of; j represents the imaginary unit; The xth harmonic flows through L 1 of current.

[0129] Step S2: Use the equivalent current of the rectifier bridge under the fundamental wave And the equivalent current of the rectifier bridge under the third harmonic Calculate the effective value of the load current I o .

[0130]

[0131] Where θ is the phase angle.

[0132] Step S3: Calculate the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 .

[0133]

[0134]

[0135] Where L 2 is the mutual inductance coil of the secondary side receiving coil; R 2 For L 2 The equivalent parasitic resistance of; C and E are both intermediate variables, and there are:

[0136]

[0137]

[0138] where θ 0 is the phase angle of the fundamental wave; θ 0 =ω 0 t, and ω 0 is the angular frequency of the fundamental wave; t is time; U Cp20 C p2 Fundamental voltage of the equivalent circuit; I coil0 For the flow through L 1 The fundamental current.

[0139] Step S4: Using the rectifier bridge equivalent current under the fundamental wave and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 Calculate the fundamental component of the equivalent input voltage of the diode rectifier bridge

[0140]

[0141] Step S5: Using the equivalent input voltage fundamental component of the rectifier bridge Calculate the load voltage effective value U o .

[0142]

[0143] Step S6: Using the load current effective value I o And load voltage effective value U o Calculate the load equivalent resistance R L .

[0144]

[0145] In this embodiment, in the above formulas (1)-(9), since the parasitic resistance parameter is small, the parasitic resistance can be ignored for calculation.

[0146] In this embodiment, if Figure 7 As shown, various inductors and coils are placed, among which the compensation inductor L p1 and mutual inductance coil L 1 Sharing a ferrite reduces the size of the compensation network. p1 and mutual inductance coil L 1 When aligned, the two are decoupled. In addition, the compensation inductor L p1 , mutual inductance coil L 1 and L 2 Made of Litz wire LitZ, its material is copper, and its magnetic permeability is close to the magnetic permeability of air, so the compensation inductance L p1 For mutual inductance coil L 1 and L 2 The influence of is negligible. Figure 3 When aligned and offset in the x direction, Z MS = 0. Therefore, during wireless power transmission, the two doors need to be kept approximately parallel, thus ensuring Z MS =0.

[0147] Step 3.3: The electric car owner waiting for rescue selects a charging mode of constant voltage charging mode or constant current charging mode and starts charging.

[0148] Step 3.4: Obtain the battery voltage U in the cloud energy storage electric vehicle i as input voltage.

[0149] Step 3.5: According to the reference value U of the output voltage oref Or the reference value of the output current I orefCalculate the output reference voltage U of the Buck converter 1ref .

[0150] In this embodiment, the primary side linear control refers to the Buck converter output voltage U 1 With the output current I o Or output voltage U o Linearization processing, by controlling the output voltage U of the Buck step-down converter 1 Realize constant voltage or constant current wireless power transmission.

[0151] Step 3.6: Obtain the current I of the primary side transmitting coil by sampling coil , and according to the current I coil and input voltage U i Calculate the output voltage U of the Buck converter 1 .

[0152]

[0153] Among them I coil0 For the flow through L 1 The fundamental current; ω is the angular frequency; L p1 To compensate for the inductance.

[0154] Step 3.7: Use the inverter bridge to adjust the output voltage U of the Buck converter 1 Invert to get AC square wave voltage U ab , and the AC square wave voltage U ab The LCC compensation network is input, and then the AC square wave voltage passing through the LCC compensation network is applied to the primary side transmitting coil. The primary side transmitting coil transmits the electric energy of the battery in the cloud energy storage electric vehicle to the secondary side receiving coil in the form of a magnetic field.

[0155] Step 3.8: Based on the principle of electromagnetic induction, the secondary side receiving coil senses the electromotive force, and the induced electromotive force is rectified into direct current through a diode rectifier bridge and then filtered, and the filtered output voltage or output current is used to start charging the electric vehicle waiting for rescue.

[0156] Step 3.9: Based on the output reference voltage U of the Buck converter 1ref 、Buck step-down converter output voltage U 1 , load voltage effective value U o , output voltage reference value U oref , load current effective value I o and the reference value of the output current I oref , the output voltage of the Buck converter is adjusted using a PI controller and an error regulator.

[0157] In this embodiment, in the process of using an electric vehicle wireless power transmission device based on cloud energy storage for electric vehicle rescue charging, in order to ensure accurate control of the output of the device, this embodiment adjusts the output voltage of the Buck step-down converter by setting a PI controller and an error regulator, thereby achieving load voltage regulation and improving the stability of the charging process.

[0158] Step 3.9.1: Calculate the output reference voltage U of the Buck converter 1ref The output voltage U of the Buck converter 1 The difference between ΔU 1 , if the difference ΔU 1 If the error is within the preset range or does not exist, it means that the current charging process is stable and the current state should be maintained for charging. 1 If it does not meet the preset error range, the difference ΔU 1 As the voltage error of the Buck converter.

[0159] Step 3.9.2: If the charging mode is constant voltage charging mode, calculate the load voltage effective value U o And the reference value of the output voltage U oref The difference ΔU o ; If the charging mode is constant current charging mode, calculate the load current effective value I o and the reference value of the output current I oref The difference ΔI o ; If the difference ΔU o Or the difference ΔI o If the error is within the preset range or does not exist, the current state is maintained for charging; if the difference ΔU o Or the difference ΔI o If it does not meet the preset error range, the difference ΔU o Or the difference ΔI o as load error.

[0160] Step 3.9.3: Input the voltage error of the Buck buck converter into the PI controller to obtain the output value of the PI controller; input the load error into the error regulator to obtain the error compensation value of the error regulator; then add the output value of the PI controller and the error compensation value obtained by the error regulator to obtain the PWM duty cycle D and feed it back to the Buck buck converter to recalculate the output voltage of the Buck buck converter.

[0161] In this embodiment, the difference ΔU 1Input to the PI controller, where the PI controller consists of two parts: the proportional part P: adjusts according to the instantaneous value of the error to provide a fast response; the integral part I: adjusts according to the accumulation of the error over time to eliminate the steady-state error. If the system contains an additional error regulator, such as feedforward control or an additional feedback link, the error regulator will also generate a compensation value based on the system state or error; the output of the PI controller is added to the compensation value of the error regulator to obtain the final PWM duty cycle.

[0162] Step 3.10: Based on the selected charging mode, the output voltage of the adjusted Buck converter and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 , recalculate the load current effective value or the load voltage effective value to obtain the corrected load voltage effective value or load current effective value, and then calculate the corrected load equivalent resistance.

[0163] The method for recalculating the load current effective value or the load voltage effective value is as follows: if the selected charging mode is the constant voltage charging mode, a linear control relationship between the output voltage of the Buck buck converter and the load voltage effective value in the constant voltage charging mode is constructed, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0 , calculate the corrected load voltage effective value;

[0164] The linear control relationship between the output voltage of the Buck converter and the effective value of the load voltage in the constant voltage charging mode is:

[0165]

[0166] Where L p1 To compensate for the inductance.

[0167] In this embodiment, in the constant voltage charging mode, the output voltage of the Buck buck converter and the load voltage effective value are linearized, and then the constant voltage wireless power transmission is realized by controlling the output voltage of the Buck buck converter. Specifically, the equivalent input impedance R e0 +ωL e0 , establish the relationship between the output voltage of the Buck buck converter and the effective value of the load voltage, and adjust the duty cycle of the Buck buck converter to make the output voltage constant and realize constant voltage charging. It is worth noting that in all the calculation processes in the above constant voltage charging mode, the parasitic resistance parameters are small and can be ignored.

[0168] If the selected charging mode is the constant current charging mode, a linear control relationship between the output voltage of the Buck buck converter and the effective value of the load current in the constant current charging mode is established, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0 , calculate the corrected load current effective value.

[0169] The linear control relationship between the output voltage of the Buck converter and the effective value of the load current in the constant current charging mode is:

[0170]

[0171] Where A and B are both intermediate variables, and there are:

[0172]

[0173]

[0174] Where Z in is the equivalent input impedance seen from the output end of the inverter bridge; Z p3 is the third harmonic component of the equivalent impedance of the primary-side transmitting coil; Z s3 is the third harmonic component of the equivalent impedance of the secondary side receiving coil; and:

[0175]

[0176]

[0177] Z s3 =j3ω(L 2 +L e3 )+R 2 +R e3 (17)

[0178] Where ωL e3 is the equivalent inductance third harmonic component of the secondary side receiving coil; R e3 is the third harmonic component of the equivalent resistance of the secondary side receiving coil.

[0179] In this embodiment, in the constant current charging mode, the output voltage and output current of the Buck buck converter are linearized, and then the constant current wireless power transmission is realized by controlling the output voltage of the Buck buck converter. According to the relationship between the output voltage of the Buck buck converter and the effective value of the load current, the duty cycle of the Buck buck converter is adjusted so that the output voltage of the Buck buck converter is constant, thereby ensuring that the output voltage of the Buck buck converter is constant and realizing constant current charging. It is worth noting that in all the calculation processes in the above constant current charging mode, since the parasitic resistance parameters are small, they can be ignored.

[0180] In this embodiment, the output voltage of the adjusted Buck converter is inverted by using an inverter bridge, and the AC square wave voltage U ab The LCC compensation network is input, and then the AC square wave voltage passing through the LCC compensation network is applied to the primary side transmitting coil. The primary side transmitting coil transmits the electric energy of the battery in the cloud energy storage electric vehicle to the secondary side receiving coil in the form of a magnetic field.

[0181] Step 3.11: Determine whether the current charging process is stable. If it is not stable, use the load parameter identification method to recalculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; Update the output voltage of the Buck converter and return to step 3.9; if stable; maintain the current charging state.

[0182] In this embodiment, in order to determine whether the current charging process is stable, it is possible to observe whether the output voltage fluctuates within the expected range and whether the ripple is within the design allowable range. If the output voltage is stable without continuous oscillation or drift, it indicates that the system is stable. If the output voltage is unstable, the load parameter identification method is used to recalculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 , and use the adjusted output voltage of the Buck buck converter to update the output voltage U of the Buck buck converter 1 Then return to step 3.9.

[0183] In this embodiment, it is determined whether the charging process is stable, and the condition for determining whether the charging process is stable is whether the load parameters are reasonable. Specifically, a relatively accurate load parameter can be obtained after multiple iterations. If it is unstable, the parameter identification is continued. If it is stable, the current charging state is maintained. Applying PWM to the Buck circuit is used to control the output voltage U of the Buck circuit. 1 , thereby stabilizing the output voltage at U 1ref At the same time, the secondary side output voltage or output current is also stabilized at U according to the mode selection. oref or I oref Specifically, if U o with U oref or I o with I oref If there is an error between the output voltage U o With its reference value U oref Or output current I o With its reference value I oref If there is no error, the parameter identification is completed. In addition, it is also necessary to determine whether the electric vehicle wireless power transmission device based on cloud energy storage can meet the power required by the charging load.

[0184] Step 3.12: When the power level of the battery in the electric vehicle waiting for rescue reaches the demand of the owner, the charging is terminated.

[0185] Step 4: After charging is completed, the electric car owner waiting for rescue pays the charging service fee to the cloud energy storage electric car owner.

[0186] In this embodiment, after charging is completed, the owner of the rescued electric car needs to pay a certain service fee to the owner of the cloud energy storage electric car who comes to rescue.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. A wireless power transmission device for electric vehicles based on cloud energy storage, characterized in that: The device comprises: a front-stage transmitting end and a rear-stage receiving end; wherein the front-stage transmitting end is placed on a cloud energy storage electric vehicle used for rescue; and the rear-stage receiving end is placed on an electric vehicle waiting for rescue; The front-stage transmitting end is used to step down, invert and compensate the battery voltage in the cloud energy storage electric vehicle according to the charging mode selected by the owner of the electric vehicle waiting for rescue, and use the mutual inductance coil to send the energy stored in the cloud energy storage electric vehicle to the rear-stage receiving end; The latter receiving end is used to receive energy from the former transmitting end by using the mutual inductance coil, and to charge the storage battery in the electric vehicle waiting for rescue by using the received energy.

2. According to claim 1, a wireless power transmission device for electric vehicles based on cloud energy storage is characterized in that: The front-stage transmitting end includes: a Buck buck converter, an inverter bridge, an LCC compensation network and a primary-side transmitting coil; wherein the output end of the Buck buck converter is connected to the input end of the inverter bridge; the output end of the inverter bridge is connected to the input end of the LCC compensation network; the output end of the LCC compensation network is connected to the input end of the primary-side transmitting coil; The Buck step-down converter is used to reduce the battery voltage U in the cloud energy storage electric vehicle. i Step down the voltage, and use the DC voltage obtained by the step-down as the output voltage U1 of the Buck converter; The inverter bridge is used to convert the output voltage U1 of the Buck step-down converter into an AC square wave voltage U ab ; wherein the inverter bridge is a full-bridge structure composed of 4 MOSFETs; The LCC compensation network is used to compensate the circuit of the front-stage transmitting end; wherein the LCC compensation network is composed of a compensation inductor L p1 , series compensation capacitor C p1 And parallel compensation capacitor C p2 The T-shaped circuit is formed; The primary-side transmitting coil is used to send the energy stored in the cloud energy storage electric vehicle to the subsequent receiving end; wherein the primary-side transmitting coil is a mutual inductance coil L1.

3. According to claim 2, a wireless power transmission device for electric vehicles based on cloud energy storage is characterized in that: The latter receiving end includes: a secondary side receiving coil, a diode rectifier bridge and an output capacitor C o ; wherein the output end of the secondary side receiving coil is connected to the input end of the diode rectifier bridge; the output end of the diode rectifier bridge is connected to the output capacitor C o The input terminal is connected to The secondary side receiving coil is used to sense the energy transmitted by the primary side transmitting coil; wherein the secondary side receiving coil is a mutual inductance coil L2; The diode rectifier bridge is used to convert the AC voltage induced by the mutual inductance coil L2 into a DC voltage; wherein the diode rectifier bridge is a full-wave rectifier circuit composed of four diodes; The output capacitor C o , which is used to filter out the voltage ripple in the DC voltage and connect the filtered DC voltage to the battery of the electric vehicle waiting for rescue for charging.

4. A method for controlling wireless power transmission of electric vehicles based on cloud energy storage, which is implemented by a wireless power transmission device of electric vehicles based on cloud energy storage, characterized in that: The method comprises the following steps: Step 1: The electric car owner waiting for rescue sends a distress signal using a mobile device, and matches the cloud energy storage electric car for rescue according to the distress signal; Step 2: The cloud energy storage electric vehicle arrives at the location of the electric vehicle waiting for rescue according to the distress signal, and sets up the electric vehicle wireless power transmission device based on cloud energy storage; Step 3: The owner of the electric vehicle waiting for rescue selects a charging mode of constant voltage charging mode or constant current charging mode, and uses the electric vehicle wireless power transmission device based on cloud energy storage to charge the electric vehicle waiting for rescue according to the selected charging mode; Step 4: After charging is completed, the electric car owner waiting for rescue pays the charging service fee to the cloud energy storage electric car owner.

5. According to claim 4, a method for controlling wireless power transmission of electric vehicles based on cloud energy storage is characterized in that: The specific method of step 1 is as follows: the owner of the electric car waiting for rescue uses a mobile device to send a distress signal to all the cloud energy storage electric cars within the communication range of the mobile device; all owners of the cloud energy storage electric cars that receive the distress signal choose whether to go to the rescue, and if so, choose to agree to the rescue on the mobile device and drive to the location of the electric car waiting for rescue; if not, choose to refuse the rescue on the mobile device; when the owner of a cloud energy storage electric car chooses to agree to the rescue, the distress signals received by the remaining cloud energy storage electric cars except the cloud energy storage electric car are invalid; The distress signal includes: the location and power requirement of the electric vehicle waiting for rescue.

6. According to claim 5, a method for controlling wireless power transmission of electric vehicles based on cloud energy storage is characterized in that: The step 2 further comprises: Step 2.1: Align the passenger door of the cloud energy storage electric vehicle with the main driver's door of the electric vehicle waiting for rescue in parallel, and maintain the preset distance; Step 2.2: Place the front-stage transmitting end of the electric vehicle wireless power transmission device based on cloud energy storage inside the co-pilot door of the electric vehicle with cloud energy storage; place the rear-stage receiving end of the electric vehicle wireless power transmission device based on cloud energy storage inside the main driver's door of the electric vehicle waiting for rescue; Step 2.3: Use wireless power transmission technology to pair the front-end transmitter and the back-end receiver to complete the setting of the electric vehicle wireless power transmission device based on cloud energy storage.

7. The electric vehicle wireless power transmission control method based on cloud energy storage according to claim 6 is characterized in that: The step 3 further comprises: Step 3.1: Set the output voltage reference value U oref Or the reference value of the output current I oref ; Step 3.2: Calculate the load current effective value I using the load parameter identification method o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; where R e0 is the fundamental component of the equivalent resistance on the rectifier bridge side; ωL e0 is the fundamental component of the equivalent inductance on the rectifier bridge side; Step 3.3: The electric car owner waiting for rescue selects the charging mode as constant voltage charging mode or constant current charging mode and starts charging; Step 3.4: Obtain the battery voltage U in the cloud energy storage electric vehicle i As input voltage; Step 3.5: According to the reference value U of the output voltage oref Or the reference value of the output current I oref Calculate the output reference voltage U of the Buck converter 1ref ; Step 3.6: Obtain the current I of the primary side transmitting coil by sampling coil , and according to the current I coil and input voltage U i Calculate the output voltage U1 of the Buck converter; Step 3.7: Use the inverter bridge to invert the output voltage U1 of the Buck converter to obtain an AC square wave voltage U ab , and the AC square wave voltage U ab The LCC compensation network is input, and then the AC square wave voltage passing through the LCC compensation network is applied to the primary-side transmitting coil. The primary-side transmitting coil transmits the electric energy of the battery in the cloud energy storage electric vehicle to the secondary-side receiving coil in the form of a magnetic field; Step 3.8: Based on the principle of electromagnetic induction, the secondary side receiving coil senses the electromotive force, and the sensed electromotive force is rectified into direct current through a diode rectifier bridge and then filtered, and the filtered output voltage or output current is used to start charging the electric vehicle waiting for rescue; Step 3.9: Based on the output reference voltage U of the Buck converter 1ref , Buck converter output voltage U1, load voltage RMS value U o , output voltage reference value U oref , load current effective value I o and the reference value of the output current I oref , using PI controller and error regulator to adjust the output voltage of Buck converter; Step 3.10: Based on the selected charging mode, the output voltage of the adjusted Buck converter and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 , recalculate the load current effective value or the load voltage effective value, obtain the corrected load voltage effective value or the load current effective value, and then calculate the corrected load equivalent resistance; Step 3.11: Determine whether the current charging process is stable. If it is not stable, use the load parameter identification method to recalculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L And the equivalent input impedance R of the rectifier bridge e0 +ωL e0 ; Update the output voltage of the Buck converter and return to step 3.9; if stable; maintain the current charging state; Step 3.12: When the power level of the battery in the electric vehicle waiting for rescue reaches the demand of the owner, the charging is terminated.

8. The electric vehicle wireless power transmission control method based on cloud energy storage according to claim 7 is characterized in that: The method for identifying the load parameters in step 3.2 is: obtain the parallel compensation capacitor C by sampling p2 The voltage U Cp2 and the current I of the primary transmitting coil coil , and use fast Fourier transform FFT to calculate the load current effective value I o , load voltage effective value U o , load equivalent resistance R L and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 ; Specifically include the following steps: Step S1: Use parallel compensation capacitor C p2 The voltage U Cp2 and the current I of the primary transmitting coil coil , calculate the equivalent current of the rectifier bridge under the fundamental wave respectively And the equivalent current of the rectifier bridge under the third harmonic Where x represents the serial number of the harmonic component, and when x=0, it represents the fundamental component; When the voltage applied to the diode rectifier bridge is The equivalent current of the rectifier bridge at ; C p2 The voltage of the equivalent circuit at the xth harmonic; ω represents the angular frequency, and ω = 2πf, f represents the frequency; M is the mutual inductance coefficient between the primary side transmitting coil and the secondary side receiving coil; C p1 is the series compensation capacitor; R Cp1 C p1 The equivalent resistance of L1; L1 is the mutual inductance coil of the primary side transmitting coil; R1 is the equivalent resistance of L1; j represents the imaginary unit; is the current flowing through L1 under the xth harmonic; Step S2: Use the equivalent current of the rectifier bridge under the fundamental wave And the equivalent current of the rectifier bridge under the third harmonic Calculate the effective value of the load current I o ; Where θ is the phase angle; Step S3: Calculate the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 ; Where L2 is the mutual inductance coil of the secondary side receiving coil; R2 is the equivalent parasitic resistance of L2; C and E are both intermediate variables, and: Where θ0 is the phase angle of the fundamental wave; θ0 = ω0t, and ω0 is the angular frequency of the fundamental wave; t is time; U Cp20 C p2 Fundamental voltage of the equivalent circuit; I coil0 is the fundamental current flowing through L1; Step S4: Using the rectifier bridge equivalent current under the fundamental wave and the equivalent input impedance R of the diode rectifier bridge e0 +ωL e0 Calculate the fundamental component of the equivalent input voltage of the diode rectifier bridge Step S5: Using the equivalent input voltage fundamental component of the rectifier bridge Calculate the load voltage effective value U o ; Step S6: Using the load current effective value I o And load voltage effective value U o Calculate the load equivalent resistance R L .

9. The electric vehicle wireless power transmission control method based on cloud energy storage according to claim 8 is characterized in that: The step 3.9 further comprises: Step 3.9.1: Calculate the output reference voltage U of the Buck converter 1ref The difference ΔU1 between the output voltage U1 of the Buck buck converter and the output voltage U1 of the Buck buck converter. If the difference ΔU1 meets the preset error range or does not exist, it means that the current charging process is stable and the current state continues to be maintained for charging; if the difference ΔU1 does not meet the preset error range, the difference ΔU1 is used as the voltage error of the Buck buck converter; Step 3.9.2: If the charging mode is constant voltage charging mode, calculate the load voltage effective value U o And the output voltage reference value U oref The difference ΔU o ; If the charging mode is constant current charging mode, calculate the load current effective value I o and the reference value of the output current I oref The difference ΔI o ; If the difference ΔU o Or the difference ΔI o If the error is within the preset range or does not exist, the current state is maintained for charging; if the difference ΔU o Or the difference ΔI o If it does not meet the preset error range, the difference ΔU o Or the difference ΔI o As load error; Step 3.9.3: Input the voltage error of the Buck buck converter into the PI controller to obtain the output value of the PI controller; input the load error into the error regulator to obtain the error compensation value of the error regulator; then add the output value of the PI controller and the error compensation value obtained by the error regulator to obtain the PWM duty cycle D and feed it back to the Buck buck converter to recalculate the output voltage of the Buck buck converter.

10. The electric vehicle wireless power transmission control method based on cloud energy storage according to claim 9 is characterized in that: The method for recalculating the load current effective value or the load voltage effective value described in step 3.10 is: if the selected charging mode is the constant voltage charging mode, a linear control relationship between the output voltage of the Buck buck converter and the load voltage effective value in the constant voltage charging mode is constructed, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0 , calculate the corrected load voltage effective value; The linear control relationship between the output voltage of the Buck converter and the effective value of the load voltage in the constant voltage charging mode is: Where L p1 To compensate for inductance; If the selected charging mode is the constant current charging mode, a linear control relationship between the output voltage of the Buck buck converter and the effective value of the load current in the constant current charging mode is established, and the linear control relationship, the adjusted output voltage of the Buck buck converter and the equivalent input impedance R of the diode rectifier bridge are used. e0 +ωL e0 , calculate the corrected load current effective value; The linear control relationship between the output voltage of the Buck converter and the effective value of the load current in the constant current charging mode is: Where A and B are both intermediate variables, and there are: Where Z in is the equivalent input impedance seen from the output end of the inverter bridge; Z p3 is the third harmonic component of the equivalent impedance of the primary-side transmitting coil; Z s3 is the third harmonic component of the equivalent impedance of the secondary side receiving coil; and: <h2 style=";text-align:left;direction:ltr">Z<h2 style=";text-align:left;direction:ltr"> s3 <h2 style=";text-align:left;direction:ltr"> =j3ω(L2+L<h2 style=";text-align:left;direction:ltr"> e3 <h2 style=";text-align:left;direction:ltr"> )+R2+R<h2 style=";text-align:left;direction:ltr"> e3 Where ωL e3 is the equivalent inductance third harmonic component of the secondary side receiving coil; R e3 is the third harmonic component of the equivalent resistance of the secondary side receiving coil.

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