Long-distance wireless charging system for electric vehicles using OOFDMA and Leslie prism

Abstract

To provide an electric vehicle remote wireless charging system using OOFDMA and Risley prisms, which reduces time to find exact locations of a PRX and a photovoltaic cell panel.SOLUTION: An electric vehicle remote wireless charging system using OOFDMA and Risley prisms is provided. The system includes: a receiver that transmits its location and size information on a photovoltaic cell panel as a power request signal through V2I; and a transmitter that controls power transmission based on the received information on the power request signal, controls a distance between the prisms according to the location of the receiver and the size of the photovoltaic cell panel, transmits transmission power information (powerinfo) for all laser signals to be received by the photovoltaic cell panel, and rotates the Risley prisms by a predetermined angle, wherein the transmitter, after generating the transmission power information for each wavelength by OOFDM, transmits the signals to areas where the power transmission is available when rotation by the predetermined angle is performed using the prisms.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a long-distance wireless charging system for electric vehicles using OOFDMA and a Lesley prism, and more particularly to a long-distance wireless charging system for electric vehicles using OOFDMA and a Lesley prism, which uses OOFDM, WDMA and a Lesley prism to send pilot signals in multiple directions at once. [Background technology]

[0002] In the conventional method of supplying power to electric vehicles using HILPB, when the PRX requests the necessary power along with its position on the GPS, the PTX sends out a pilot signal limited to the laser strength of MPE Class 1 in all directions where power can be supplied, and the PRX predicts the maximum received power from the pilot signal and selects the PTX with the highest power supply efficiency based on this.

[0003] Here, HILPB (High Intensity Laser Power Beaming) is a technology that transmits power using a high-intensity laser, and it operates by wirelessly transmitting power from a remote location using a laser beam to supply power to an electric vehicle. Also, PRX is an abbreviation of Power Receiver, which refers to a device that receives power in an electric vehicle. PRX requests the necessary power along with its position on the GPS. PTX is an abbreviation of Power Transmitter, which refers to a device that supplies power. PTX transmits a pilot signal limited to the laser intensity of MPE Class 1 in all directions where it can supply power. MPE is an abbreviation of Maximum Permissible Exposure, which means the maximum permissible exposure. MPE Class 1 is the output level of a laser device, and indicates a grade that limits the laser intensity to a certain level for safe use. The laser intensity of MPE Class 1 is used as a pilot signal to supply safe wireless power.

[0004] Due to GPS errors, not only the exact location of the PRX, but also the exact location of the photovoltaic panel is unknown. Since the photovoltaic panel must be supplied with HILPB at its most central part to obtain the highest efficiency, the PTX transmits pilot signals in all directions that the HILPB can transmit in order to accurately find the central part of the photovoltaic panel mounted on the PRX, converts the pilot signals into power, and selects the direction that can receive the most power.

[0005] The pilot signal can be sent in one direction at a time, and the number of directions in which the pilot signal is sent increases in proportion to the direction in which the power supply device PTX sends out the HILPB. This lengthens the time for sending out the pilot signal, and shortens the time for sending out the HILPB by the pilot signal sending time. Since the time spent at the intersection is limited, in order to receive more power, it is necessary to shorten the time to find the exact position of the PRX and the photovoltaic panel. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Publication No. 2019-0136361 (December 10, 2019) Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide an electric vehicle long-distance wireless charging system using OOFDMA and Leslie prism, which shortens the time to find the exact location of PRX and photovoltaic panel. [Means for solving the problem]

[0008] According to the present invention, in a long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism, the system includes a receiver that transmits position and photovoltaic panel size information as a power request signal via V2I, and a transmitter that adjusts the transmission of power based on the received power request signal, adjusts the distance between the prisms according to the receiver's position and the size of the photovoltaic panel, transmits transmission power information (powerinfo) so that the laser signal is fully received by the photovoltaic panel, and rotates the Leslie prism by a certain angle. The transmitter generates information about the transmission power for each wavelength using OOFDM, and transmits a signal to an area where power can be transmitted after rotating a certain angle using the prism.

[0009] The transmitter generates information regarding the transmission power for each wavelength using OOFDM, and then sends it to the prism. Pilot signals are then sent out in multiple directions simultaneously due to differences in the laser refractive index depending on the wavelength.

[0010] The receiver analyzes the information on the transmitted power received from the transmitter to determine the position of the laser and predict the maximum receivable power.

[0011] The receiver receives power by selecting multiple transmitters via a laser power beam (HILPB), which selects a transmitter capable of supplying the required power and proceeds with wireless charging.

[0012] The receiver then identifies the position of the Power ID that is relatively closest to the center of the PV array using the Device ID among the transmission power information of the transmitter, and calculates the distance / reception angle between the transmitter and the PV array using the distribution of the Power IDs to select a transmitter as a power supply source. Effect of the Invention

[0013] The present invention has the advantage of reducing the time required to find the exact location of the receiver (PRX) and the photovoltaic panel. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 shows an electric vehicle long-distance wireless charging system that uses OOFDM, WDMA and a Leslie prism to send pilot signals in multiple directions at once in accordance with one embodiment of the present invention. [Diagram 2] A diagram to explain the operation of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism in accordance with one embodiment of the present invention. [Diagram 3] A diagram showing a pilot signal used in the PTX of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism in accordance with one embodiment of the present invention. [Figure 4] A diagram for explaining the detailed configuration and operation of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism according to one embodiment of the present invention. [Diagram 5] A diagram illustrating a Flip OFDMA encoder of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism in accordance with one embodiment of the present invention. [Figure 6] A diagram illustrating a Flip OFDMA decoder of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism in accordance with one embodiment of the present invention. [Figure 7] FIG. 1 is a conceptual diagram of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism according to one embodiment of the present invention applied to a traffic light at an intersection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] FIG. 1 is a diagram showing an electric vehicle long-distance wireless charging system that uses OOFDM, WDMA, and a Leslie prism to transmit pilot signals in multiple directions at once according to one embodiment of the present invention.

[0016] As shown in Fig. 1, the long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism includes a receiver 100 that transmits its own position information and photovoltaic panel size information as a power request signal via V2I, and a transmitter 200 that adjusts the power transmission based on the received information of the power request signal, adjusts the distance between the prisms according to the receiver's position and the photovoltaic panel size, transmits transmission power information (powerinfo) so that the laser signal is fully received by the photovoltaic panel, and rotates the Leslie prism by a certain angle. The transmitter 200 generates information about the transmission power for each wavelength using OOFDM, and transmits the signal to an area where power can be transmitted after rotating a certain angle using the prism.

[0017] The transmitter according to this embodiment generates information about the transmission power for each wavelength using OOFDM, and then sends it to a prism, where pilot signals are sent in multiple directions simultaneously due to differences in the laser refractive index depending on the wavelength. This transmitter uses a prism to transmit signals to a wide area. When the prism rotates 360 degrees once, the signal is transmitted to an area where power can be transmitted. It is sufficient for only one signal to reach the PV cell, and large wavelength intervals and rotation intervals are used.

[0018] In the electric vehicle long-distance wireless charging system using OOFDMA and Leslie prism according to the present embodiment, a unique Device ID is assigned to each transmitter, and a unique Power ID is assigned to each angle and wavelength. The receiving side uses only the Device ID and Power ID, and excludes the RSSI. This is because the RSSI is not constant due to the characteristics of OOFDM and various wavelengths, and continues to change. Conventionally, the optimum power supply source was selected using the RSSI, but in one embodiment of the present invention, the receiving side uses only the Device ID and Power ID. Here, RSSI is an abbreviation for "Received Signal Strength Indicator" and is an index indicating the strength of a signal received in a wireless communication system. RSSI is measured by a device that receives a wireless signal, and is generally expressed in dBm (decibels in milliwatts). In a wireless communication system, this signal strength can be measured to determine the signal quality of communication or to select the optimum power supply source. That is, conventionally, a method of selecting the optimum power supply source using RSSI has been applied. However, in one embodiment of the present invention, since the RSSI is not constant but constantly changes due to the characteristics of OOFDM and various wavelengths, the receiving side uses only the Device ID and Power ID, excluding the RSSI. The Device ID is an identifier uniquely assigned to each transmitter, and the Power ID is an identifier uniquely assigned to each wavelength. This allows the receiving side to distinguish and select each power supply source through the identifier without being affected by fluctuations in signal strength.

[0019] In addition, the receiver according to the present embodiment analyzes information regarding the transmitted power received from the transmitter to grasp the position of the laser, predicts the maximum receivable power, and selects a transmitter capable of supplying the required power and proceeds with wireless charging. In this way, the receiver receives power by selecting multiple transmitters via a high intensity laser power beam (HILPB).

[0020] For reference, HILPB uses a high-power laser system to concentrate power in the form of a beam. This laser beam retains its energy while passing through the air and transmits the power towards a receiver or receiving device. The receiver can contain this power, convert it and use or store it as electrical energy. The core of HILPB is the concentration of a high-intensity laser beam. A high-power laser is used to generate the beam and effectively concentrate the laser light to transmit power to a remote location. For this, optical and tracking systems can be used to minimize the loss of the reflection path and maintain the stability of the beam. HILPB can be used to provide power in remote areas or places with limited mobility. It can be used in a variety of applications, including charging electric vehicles, powering space exploration equipment, and remotely operating meters. Wireless power transmission overcomes the constraints of cable connections, enabling efficient and convenient power supply.

[0021] The receiver then identifies the position of the Power ID that is relatively closest to the center of the PV array using the Device ID among the transmission power information of the transmitter, and calculates the distance / reception angle between the transmitter and the PV array using the distribution of the Power IDs to select a transmitter as a power supply source.

[0022] The receiver according to the present embodiment can recognize / select the power ID closest to the center of the PV array using the received power ID, and can grasp the position of the received power ID on the PV array. Also, the receiver can select the optimal transmitter by calculating the distance / reception angle between the transmitter and the PV array using the power ID distribution.

[0023] In one embodiment of the present invention, OOFDMA is a combination of OOFDM (Optical Orthogonal Frequency Division Multiplexing) and WDMA (Wavelength Division Multiple Access), and OOFDMA can combine the multiple frequency bands of OOFDM and the multiple access of WDMA to enable efficient data transfer between multiple users.

[0024] Although the OOFDM according to this embodiment undergoes a more complicated signal processing process than the unipolar OCDMA, it can generate 48-bit power information as 24 optical signals and transmit more power information in a short period of time.

[0025] WDMA is an optical communication method that uses multiple laser wavelengths simultaneously, and allows simultaneous transmission and reception of optical signals in proportion to the number of wavelengths used.

[0026] In addition, in the Leslie prism, multiple prisms use the same central axis, but by varying the prism characteristics, refractive index, rotation speed, etc., it is possible to generate patterns with various intervals and shapes. Therefore, in the electric vehicle long-distance wireless charging system of this embodiment, information regarding the PTX transmission power for each wavelength is generated using OOFDM, and then sent to a prism, allowing pilot signals to be transmitted in multiple directions simultaneously due to differences in the laser refractive index depending on the wavelength.

[0027] One embodiment of the present invention relates to a long-distance wireless charging system for electric vehicles using OOFDM and a Leslie prism, which transmits pilot signals in multiple directions at once using OOFDM, WDMA, and a Leslie prism. Information regarding the PTX transmission power for each wavelength is generated using OOFDM and then sent to the prism, and pilot signals are transmitted in multiple directions simultaneously due to differences in the laser refractive index depending on the wavelength, making it possible to transmit pilot signals in more directions in a shorter time by using three optical technologies at once.

[0028] FIG. 2 is a diagram for explaining the operation of a long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to one embodiment of the present invention.

[0029] An EV arrives at an intersection and stops to wait for a traffic light. At this time, the electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism according to the present embodiment broadcasts its own location information and size information of the photovoltaic panel to the surroundings as a power request signal using V2I to receive power. Here, V2I is an abbreviation of Vehicle-to-Infrastructure and indicates communication between an automobile and infrastructure. V2I refers to a technology for exchanging and transmitting information and data between an automobile and road infrastructure facilities. As a result, an automobile can perform various functions such as road safety, driving efficiency, and service improvement through interaction with infrastructure. V2I can improve the safety and convenience of an automobile through communication with infrastructure facilities such as traffic signals, street lights, highway toll systems, and parking management systems.

[0030] PTX, a power supply device at an intersection such as a traffic light or street light, receives a power request signal via V2I. PTX generates PowerInfo by combining Device ID, a unique number that identifies the power supply device, Angle ID, which indicates the rotation angle based on the center of the prism, Max Power, which indicates the maximum power that can be transmitted, and CRC information, which determines data loss.

[0031] The transmitter PTX adjusts the distance between the prisms according to the position of the receiver PRX and the size of the photovoltaic panel, and transmits PowerInfo so that all the laser refracted through the prism is received by the photovoltaic panel.

[0032] After sending out PowerInfo, the Leslie prism is rotated by a specified angle. The receiver PRX analyzes the PowerInfo received from the photovoltaic panel, determines the position of the laser by wavelength based on the center of the photovoltaic panel, and predicts the maximum receivable power based on this.

[0033] Here, PowerInfo is Device ID+Angle ID+Powr ID+Max Power+CRC, and 48-bit=4PAM*16 Subchannels=24 Symbols.

[0034] The receiver PRX selects a transmitter PTX that can receive the required power based on the power predicted by receiving the power for a certain period of time. Since the HILPB can receive power from one or more transmitters PTX, if the HILPB does not receive enough power from one transmitter PTX, the receiver PRX can simultaneously select multiple transmitters PTX to receive power.

[0035] FIG. 3 is a diagram illustrating a pilot signal used in a transmitter (PTX) of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism according to one embodiment of the present invention.

[0036] The pilot signal used by the transmitter (PTX) consists of four parts: device ID, angle ID, max power, and CRC.

[0037] The Device ID is a unique number for identifying a PTX and uses 16 bits.

[0038] The Risley prism consists of three wedge prisms, one thick and one thin.

[0039] The central axes of all three prisms are aligned, and the three prisms rotate independently of each other around the central axis to generate various scanning patterns.

[0040] The Angle ID is a 16-bit representation of the angle by which each Risley prism is rotated around the central axis.

[0041] The max power is the maximum power of the CW laser that the PTX can transmit, expressed in watts (watts), and uses 8 bits.

[0042] CRC (Cyclic Redundancy Check) is generated by applying CRC-8 to 40 bits corresponding to device ID, angle ID, and max power to generate 8 bits of checksum data. PRX generates a checksum using CRC-8 on the received 40 bits and compares it with the received 8 bits of CRC to check for data corruption that occurred during data transmission.

[0043] In addition, in Fig. 3, MSB is an abbreviation of "Most Signification Bit" and means the bit that represents the most significant digit. This refers to the rightmost bit in a binary number. For example, in the 8-bit binary number 11011010, the leftmost bit, 1, is the MSB.

[0044] LSB is an abbreviation for "Least Significant Bit" and refers to the bit that represents the least significant digit. It refers to the bit located to the right of a binary number. For example, in the 8-bit binary number 11011010, the right-most bit, 0, is the LSB. MSB and LSB indicate the position and importance of a bit string and can affect the interpretation and representation of data.

[0045] FIG. 4 is a diagram for explaining the detailed configuration and operation of a long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to one embodiment of the present invention.

[0046] In the long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to the present embodiment, the spacing between the Leslie prisms is adjusted by a spacing adjustment device according to the distance between PTX and PRX and the size of the photovoltaic panel in the Leslie prism configuration. In this case, if the distance between PTX and PRX is short or the size of the photovoltaic panel is large, the spacing between the prisms is narrowed to increase the size of the pattern. Conversely, if the distance between PTX and PRX is long or the size of the photovoltaic panel is small, the spacing between the prisms is widened to decrease the size of the pattern.

[0047] In this embodiment, the RTX converts the pilot signal PowerInfo into a signal to be used for transmission by encoding it using the Flip OFDMA technique. Then, an analog laser is generated using an external optical modulator (EOM) and a laser diode (LD) based on the analog signal generated using the DAC.

[0048] Analog laser signals generated by performing the same task simultaneously at multiple laser wavelengths are combined into one signal via an optical coupler. The laser signal transmitted to the Leslie prism is refracted according to its wavelength each time it passes through the prism before being sent out.

[0049] After the laser signal is emitted, the Leslie prism is rotated by a predetermined angle.

[0050] The PRX converts the received laser signal using a photovoltaic panel into an analog signal using a TIA, then converts it into a digital signal using an ADC, and uses Flip OFDMA to decode it and generate PowerInfo.

[0051] After receiving all the PowerInfo sent by PTX at various angles, select the PTX with the most number of the same Device ID and Angle ID. The ratio of the number of device IDs sent by PTX to the number of device IDs received by PRX indicates the reception rate at which HILPB arrives at the PV panel when it is sent. The more the same Device ID and Angle ID, the greater the HILPB received by the photovoltaic panel.

[0052] Using Max Power and the reception rate, the maximum receivable power can be predicted.

[0053] The angle ID indicates whether the prism central axis and the PV panel central axis coincide with each other. If the prism central axis is moved in a direction with more of the same angle ID, the possibility that the two central axes will coincide with each other increases.

[0054] The photovoltaic panel can use all the received HILPB for power conversion as long as the amount of light it can receive is not exceeded. If the power received from one PTX is insufficient, multiple PTXs can be selected to receive the required amount of power.

[0055] FIG. 5 is a diagram illustrating a Flip OFDMA encoder of a long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to one embodiment of the present invention.

[0056] As shown in FIG. 5, the flip OFDMA encoder according to the present embodiment performs the processes of serial-to-parallel conversion, multiple amplitude constrained coding mapping (M-PAM mapping), subchannel mapping, N-order inverse discrete Hartley transform (N-order IDHT), inverse modulation (flip), and parallel-to-serial conversion.

[0057] Serial-to-Parallel conversion is the process of converting data transmitted in serial format into a parallel format that can process multiple bits of data at once.

[0058] M-PAM Mapping is a mapping process of Multi-Pulse Amplitude Modulation (MPM), which converts digital data into a multi-amplitude signal by converting input bits into various amplitude levels.

[0059] Subchannel mapping is the process of dividing data into multiple subchannels in a multiple access scheme, such as Frequency Division Multiple Access (FDMA) or Time Division Multiple Access (TDMA).

[0060] The N-order Inverse Discrete Hartley Transform (N-order IDHT) is an N-order Inverse Discrete Fourier Transform (IDHT), a process that converts a given frequency domain signal into the time domain. The N-order IDHT is used to reconstruct a time domain signal in N-dimensional space.

[0061] Flip is a process of returning data to its original order, i.e., reversing a previously performed operation.

[0062] Parallel-to-serial is the process of converting parallel data into serial data. It means lining up multiple pieces of data in a single line and converting them into a serial form.

[0063] FIG. 6 is a diagram illustrating a Flip OFDMA decoder of a long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to one embodiment of the present invention.

[0064] The flip OFDMA decoder according to this embodiment performs the processes of serial-to-parallel conversion, de-flip, N-order discrete Hartley transform (N-order DHT), subchannel mapping, multiple amplitude conditional coding mapping (M-PAM mapping), and parallel-to-serial conversion.

[0065] Serial-to-Parallel is the process of converting data transmitted in serial form into parallel form. This can be used to increase data transmission speeds. Serial data transmits only one bit at a time, but parallel data allows multiple bits to be transmitted simultaneously.

[0066] De-Flip is the reverse process of the Flip process. Flip is the process of modulating data in a specific way, while De-Flip is the process of returning the modulated data to its original form.

[0067] N-order Discrete Hartley Transform (N-order DHT) is a transform technique used in digital signal processing. DHT transforms a time domain signal into a frequency domain. N-order DHT means that a given signal is transformed by N-dimensional Hartley transform.

[0068] Subchannel mapping refers to data allocation from multiplexed transmission channels to subchannels. Transmission channels divided in various dimensions such as frequency and time are mapped to each subchannel to transmit and process data.

[0069] Multi-amplitude conditional coding mapping (M-PAM Mapping) is a multi-ary pulse amplitude modulation (M-PAM) technique that converts digital data into multiple symbols. M-PAM mapping maps data to different amplitude levels before transmitting, and the original data is restored by decoding the data at the receiving end.

[0070] Parallel-to-serial conversion is the process of converting data transmitted in parallel format into serial format. Parallel data is transmitted in multiple bits simultaneously, while serial data is transmitted one bit at a time. Parallel-to-serial conversion is used to convert parallel data into a processable format for data transmission, storage, etc.

[0071] FIG. 7 is a conceptual diagram of an electric vehicle long-distance wireless charging system using OOFDMA and a Leslie prism according to one embodiment of the present invention, applied to a traffic light at an intersection.

[0072] As shown in Figure 7, the long-distance wireless charging system for electric vehicles using OOFDMA and Leslie prisms according to this embodiment has a traffic light at each of the four corners of an intersection, and a PTX that supplies power via HILPB at each traffic light. When an EV waits for the light to turn on at the intersection, the PRX installed in the EV notifies the EV of its location and the location of the photovoltaic panel via V2I and requests power supply.

[0073] The four PTXs adjust their prisms according to the distance and size of the photovoltaic panel installed in the EV and transmit pilot signals. They transmit pilot signals at every angle where power can be transmitted. Due to GPS and targeting errors, the patterns and numbers of pilot signals received by the photovoltaic panel differ depending on the PTX.

[0074] The pilot signal sent from T3 in Figure 7 was received most frequently by the photocell panel, followed by the pilot signal sent from T2. As for T1, the central axis of the Leslie prism was received at the corner of the photocell panel, so some of the pilot signal was received by the photocell panel.

[0075] In the case of T4, the central axis of the Leslie prism was offset from the photovoltaic panel and the fewest pilot signals were received by the photovoltaic panel.

[0076] The EV selects the PTX from which the most pilot signals are received and requests the transmission of power, and the selected PTX transmits a HILPB to the central axis portion of the prism used when transmitting the pilot signal.

[0077] The EV uses a photovoltaic panel to convert the received HILPB into electricity and charge the battery. When the battery is fully charged or the signal changes, the EV notifies the PTX of the interruption of power transmission via V2I. The PTX that receives this notification interrupts the transmission of power, and the EV moves toward its destination.

[0078] The long-distance wireless charging system for electric vehicles using OOFDMA and Risley prism according to one embodiment of the present invention can be used not only for automobiles but also for airborne flying objects (mobility means) such as drones and UAMs.

Claims

1. In a long-distance wireless charging system for electric vehicles using OOFDMA and Leslie prism, a receiver transmitting information about its location and the size of its photovoltaic panel as a power request signal via V2I; a transmitter for adjusting the power transmission based on the information received from the power request signal, adjusting the distance between the wedge prisms constituting the Leslie prism according to the position of the receiver and the size of the photovoltaic panel, and transmitting transmission power information (powerinfo) so that the pilot signal using a laser is fully received by the photovoltaic panel, The transmitter generates the transmission power information for each wavelength of the laser using OOFDMA, and then transmits the pilot signal to an area where power can be transmitted by rotating the multiple wedge prisms independently of each other by a certain angle.

2. The transmitter generates the transmission power information for each wavelength of the laser using OOFDMA, and then sends it to the Leslie prism, whereby the pilot signal is simultaneously transmitted in multiple directions due to differences in refractive index depending on the wavelength of the laser.

3. The long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism as described in claim 1, characterized in that the receiver analyzes the transmitted power information received from the transmitter, determines the position of the lasers for each wavelength among the lasers based on the center of the photovoltaic panel, and predicts the maximum receivable power.

4. 2. The long-distance wireless charging system for electric vehicles using OOFDMA and a Leslie prism according to claim 1, wherein the receiver receives power via a HILPB.

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