JP7420671B2 - Synchronous resonance transmission system, synchronous resonance transmission control method, and program for synchronous resonance transmission control - Google Patents

Description

The present invention relates to a contactless power transmission system (wireless power transmission system), and in particular to a synchronous resonant transmission system, a synchronous resonant transmission control method, and a synchronous resonant transmission system that can efficiently transmit contactless power even over long transmission distances. Concerning programs for transmission control.

Since the Massachusetts Institute of Technology (MIT) proposed it in 2005, research on wireless power transmission using sinusoidal electromagnetic waves has been active (see Patent Documents 1 and 2). For example, as described in Patent Document 2, in the conventional wireless power transmission system, the resonant frequency 2π√LC of the power feeding side resonant circuit (LC circuit) and the resonant frequency 2π√LC of the power receiving side resonant circuit (LC circuit) are made to match. It is based on the theory of exchange. In conventional wireless power transmission systems, it is better not to cause resonance (multiple resonance) between the power supply side resonant circuit and the power reception side resonant circuit, as new resonance occurs when the power supply side resonant circuit and power reception side resonant circuit interact with each other. There was technical common sense.

In addition, the power supply circuits (0-order circuits) in the frequency band of 10 kHz to 50 GHz described in Patent Documents 1 and 2 convert the commercial power supply into DC using a switching power supply, and then perform switching using a large number of power semiconductor elements such as PWM. This was a wasteful configuration that equivalently converted to alternating current. This wasteful configuration causes power losses such as resistance losses in power semiconductor elements and switching losses that rapidly increase as the frequency increases. Furthermore, the switching element is likely to be destroyed by the induced back electromotive force generated in the coil, or by excessive voltage rise due to resonance, and the higher the frequency and the greater the power, the more difficult it becomes to design the circuit.

In view of the problems of the prior art described in Patent Documents 1 and 2, the present inventors proposed a contactless transmission device based on non-AC theory that takes heavy resonance into consideration and focuses on transient response (Patent Document 1) (See 3). However, the invention described in Patent Document 3 has a problem in that the transmission efficiency is extremely reduced when the interval (transmission distance) between the power transmitting side coil and the power receiving side coil is 40 mm or more. Particularly in practical use, contactless power transmission with a transmission distance of 300 mm or more is long-awaited. However, when the transmission distance is 300 mm or more, a loose coupling state occurs where the equivalent coupling coefficient k<0.08 between the power transmitting side coil and the power receiving side coil. According to the inventors' preliminary study experiments, in a loosely coupled state where k<0.08, the time from the start of resonance to the maximum transmission timing becomes longer, and the resonant voltage is attenuated by the parasitic resistance of the circuit. A problem has been discovered in which the transmission voltage decreases when the resonance is temporarily cut off at the maximum transmission timing, and sufficient power cannot be transmitted in a single mutual induction transmission.

US Patent Application Publication No. 2008/0278264 Patent No. 5549745 World Intellectual Property Organization International Bureau International Publication No. 2020/039594 Pamphlet

In view of the above-mentioned problems, the present invention provides a synchronous resonant transmission system that can effectively provide contactless power supply even when the transmission distance is 40 mm or more, or even 300 mm or more, and a synchronous resonant transmission system that operates this synchronous resonant transmission system. An object of the present invention is to provide a synchronous resonance transmission control method and a synchronous resonance transmission control program that causes a computer system to execute the synchronous resonance transmission control method.

A first aspect of the present invention provides a primary side LC having (a) a power transmission side capacitor, a power transmission side coil connected in parallel to the power transmission side capacitor, and a power transmission side detector that detects a change in the current flowing through the power transmission side coil. (b) a DC power supply; an excitation circuit having an input element that inputs a DC voltage supplied from the DC power supply stepwise between one terminal and the other terminal of a power transmission capacitor; and (c) a power transmission coil. (d) a secondary side LC circuit having a power receiving side coil facing the power receiving side coil, a power receiving side capacitor connected in parallel to the power receiving side coil, and a power receiving side detector that detects a change in the voltage between the terminals of the power receiving side capacitor; (e) A load circuit that connects the terminals of the capacitor and has a load that receives electrostatic energy accumulated in the power receiving capacitor from the power receiving capacitor, and (e) a primary side that sends a control signal for switching to the control terminal of the input element. After the power receiving side detector detects that the voltage between the terminals of the switching element drive circuit and (f) the power receiving side capacitor exceeds a predetermined value, the power transmitting side detector detects the timing when the current flowing to the power transmitting side coil reaches its peak. The gist of the present invention is that it is a synchronous resonant transmission system including an arithmetic logic circuit that controls a primary side switching element drive circuit so as to supply a DC voltage from a DC power supply when detected.

A second aspect of the present invention relates to a synchronous resonant transmission control method for controlling the operation of the synchronous resonant transmission system described in the first aspect of the present invention. That is, the synchronous resonance type transmission control method according to the second aspect of the present invention includes the steps of the power receiving side detector detecting that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value, and the step of detecting that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value; The present invention is characterized in that it includes a step of supplying DC voltage from a DC power source when a power transmission side detector detects a timing at which the voltage reaches a peak.

A synchronous resonance transmission control program for realizing the synchronous resonance transmission control method described in the second aspect of the present invention is stored in a computer-readable recording medium, the recording medium is read by a computer system, The synchronous resonance type transmission control method of the present invention can be executed by a computer system. That is, the synchronous resonance type transmission control program according to the third aspect of the present invention includes a command that causes the power receiving side detector to detect that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value, and a command that causes the power receiving side detector to detect that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value. The present invention is characterized by causing the computer system to execute a series of instructions including an instruction to supply DC voltage from the DC power source when the power transmission side detector detects the timing at which the current peaks.

According to the present invention, a synchronous resonant transmission system is capable of effectively contactless power feeding even when the transmission distance is 40 mm or more, or even 300 mm or more, and a synchronous resonant transmission control that operates this synchronous resonant transmission system. It is possible to provide a method and a synchronous resonant transmission control program that causes a computer system to execute the synchronous resonant transmission control method.

1 is a schematic diagram showing a schematic structure of a synchronous resonant transmission system according to a typical embodiment of the present invention. FIG. 2 is a block diagram mainly illustrating the drive control circuit shown in FIG. 1. FIG. FIG. 1 is a circuit diagram schematically showing a drive control circuit and a power receiving circuit that constitute an example of a synchronous resonance type transmission system according to an embodiment. 1 is a flowchart showing an outline of an operation flow of a synchronous resonant transmission system according to an embodiment. FIG. 7 is a waveform diagram showing an operation of periodically repeating an operation of supplying power from a power source until the voltage amplitude on the power receiving side reaches a maximum. As a comparative example, it is a waveform diagram showing how the resonant voltage is attenuated due to the parasitic resistance of the circuit when power is not supplied from the start of resonance to the maximum transmission timing. FIG. 3 is a diagram illustrating how the amount of transmitted power changes over elapsed time, comparing the present invention and the reference technology. 1 is a bird's-eye view schematically illustrating an example of an interval control mechanism that adjusts the interplane interval (transmission interval) between coils when the synchronous resonance transmission system according to an embodiment is applied to charging the battery of an electric vehicle (EV). be.

Next, typical embodiments of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar symbols. However, it should be noted that the drawings are schematic, and the relationship between the thickness and planar dimensions, the ratio of the thickness of each member, etc. are different from the actual one. Therefore, the specific thickness and dimensions should be determined with reference to the following explanation. Furthermore, it goes without saying that the drawings include portions with different dimensional relationships and ratios.

Further, the embodiments shown below are representative embodiments illustrating devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material and shape of the component parts. , structure, arrangement, etc. are not specified below. The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims. Furthermore, the directions "left and right" and "up and down" in the following explanation are simply defined for convenience of explanation, and do not limit the technical idea of the present invention. Therefore, for example, if you rotate the page 90 degrees, "left and right" and "up and down" will be read interchangeably, and if you rotate the page 180 degrees, "left" will become "right" and "right" will become "left." Of course it will. Similarly, the direction of the spiral spiral as shown in FIG. 8 is merely a selection for the convenience of explanation, and depending on the actual design circumstances, it is also possible to select right-handed winding as left-handed winding, and left-handed winding as right-handed winding. be.

As shown in FIG. 1, a synchronous resonance type transmission system according to an embodiment of the present invention transmits wavelet-shaped electromagnetic energy without contact to a vehicle 31c having a power receiving circuit 27b, by using synchronous resonance to transmit wavelet-shaped electromagnetic energy to a power feeding circuit 29b. This is a transmission system that efficiently supplies power from "Wavelet-like" means temporally localized damped oscillations. The power receiving circuit 27b includes a load (storage battery) 6. The synchronous resonance type transmission system according to one embodiment includes a power feeding circuit 29b that non-contactly feeds wavelet-like electromagnetic energy to a power receiving circuit 27b, and a primary side that is connected to the power feeding circuit 29b and sends commands to the power feeding circuit 29b. It mainly includes an operating section 33, a power receiving board 12, a power receiving circuit 27b, a secondary side communication section 22, and a secondary side operating section 23, which are mounted in the vehicle 31c in opposition to the power feeding circuit 29b.

Various structures and mechanisms can be adopted for the primary operation section 33, and for example, the primary operation section 33 may include an imaging device. In an embodiment including an imaging device, a mechanism can be provided in which the vehicle height of the vehicle 31c is automatically linked using an artificial intelligence (AI) function from the image of the vehicle 31c taken by the imaging device. In FIG. 1, the power transmitting coil _L1 on the power feeding circuit 29b side and the power receiving coil _L2 on the vehicle 31c side face each other, and wavelet-shaped electromagnetic energy is transferred from the power transmitting coil _L1 to the power receiving coil _L2 without contact. Although a schematic diagram showing that the power is transmitted to the power receiving coil _L2 without contact is shown, this is merely an example. It is also possible to conduct contactless power feeding from the power transmitting coil L ₁ to the power receiving coil L ₂ at the rear of the vehicle 31c as shown in FIG. 8, which will be described later. Furthermore, various modifications are possible; for example, a method may be adopted in which power is supplied from the power transmitting side coil _L1 to the power receiving side coil _L2 in a non-contact manner at the front, side, or ceiling of the vehicle.

As shown in FIG. 1, the power supply circuit 29b includes a power supply board 11 that houses the power transmission coil _L1 in a disc-shaped dielectric, a drive control circuit 34a that controls the power supply current flowing through the power transmission coil _L1 , and a secondary power supply circuit 29b. The primary side communication unit 21 receives information on the power receiving circuit 27b side, such as the voltage between the terminals of the power receiving side capacitor _C2 , from the side communication unit 22 and transmits it to the drive control circuit 34a. The primary communication unit 21 can exchange various information necessary for contactless power supply with the secondary communication unit 22. The power feeding circuit 29b and the power receiving circuit 27b transmit and receive wavelet-shaped electromagnetic energy to each other via the power transmitting coil L ₁ and the power receiving coil L ₂ to synchronize the resonance vibration phases of the two LC resonance circuits. "Synchronized resonance" is one aspect of heavy resonance, and is a synchronized resonance type transmission system according to an embodiment in which the maximum voltage of the power receiving side resonant circuit and the timing at which the current of the power feeding side resonant circuit reaches the maximum are synchronized. In addition, there is double resonance (double resonance) of the vibration phase between the two LC resonance circuits.

An example of the primary side LC circuit 2b and the secondary side LC circuit 3b that realize synchronous resonance is shown in FIG. As shown in FIG. 3, the primary side LC circuit 2b constituting the power supply side resonant circuit is connected in parallel to the power transmission side capacitor C ₁ that stores electrostatic energy, and the power transmission side capacitor C 1 , and the power transmission side capacitor C ₁ is connected in parallel to the power transmission side capacitor C ₁ . This is an LC resonant circuit that includes a power transmitting coil L ₁ that stores electrostatic energy generated as magnetic energy, and a detector (power transmitting detector) 28 that detects changes in the current flowing through the power transmitting coil L ₁ . The primary side LC circuit 2b may further include a power transmission control element _Q2 as a switching element connected in series with the power transmission side coil _L1 . The power transmission control element Q ₂ in the circuit illustrated in FIG. 3 is a circuit element that assists the circuit operation of the power transmission side capacitor C ₁ to efficiently store electrostatic energy. It is not an essential circuit element.

The secondary LC circuit 3b constituting the power receiving side resonant circuit is connected in parallel to the power receiving side coil _L2 that stores magnetic energy, and the power receiving side coil _L2 , and converts the magnetic energy sent from the power receiving side coil _L2 into electrostatic energy. This is an LC resonant circuit that has a power receiving side capacitor C ₂ that accumulates power as a power receiving side capacitor C ₂ and a detector (power receiving side detector) 29 that detects a change in the voltage between the terminals of the power receiving side capacitor C 2 . The secondary LC circuit 3b may further include a power receiving control element _Q3 as a switching element connected in series with the power receiving coil _L2 . The power receiving coil L ₂ of the secondary LC circuit 3b is spaced apart from the power transmitting coil L ₁ and receives magnetic energy from the power transmitting coil L ₁ . The power receiving control element _Q3 provided in the secondary LC circuit 3b is a circuit element for efficiently controlling the synchronized resonance of the vibration phase between the primary LC circuit 2b and the secondary LC circuit 3b. , is not an essential circuit element for the synchronous resonant transmission system according to one embodiment. The power transmitting coil L ₁ of the primary LC circuit 2b stores the electrostatic energy sent from the power transmitting capacitor C ₁ as magnetic energy, and at the same time circulates this magnetic energy to the power transmitting capacitor C ₁ . It is magnetically coupled to the power receiving coil L ₂ of the LC circuit 3b and transmits and receives magnetic energy to and from the power receiving coil L ₂ .

As shown in FIG. 3, an excitation circuit (5, Q ₁ ) that excites damped vibration in the primary LC circuit 2b is connected to the primary LC circuit 2b. The excitation circuit (5, Q ₁ ) includes a DC power supply 5 and an input element Q ₁ that performs switching for switching transmission of the DC voltage supplied from the DC power supply 5. The excitation circuit (5, Q ₁ ) is connected in parallel to both ends of the power transmission capacitor C ₁ , and the DC power supply 5 inputs a DC voltage stepwise to the power transmission capacitor C ₁ to excite damped vibration. A primary side switching element drive circuit 340a that sends a switching control signal to the control terminal of the input element Q ₁ is connected to the control terminal of the input element Q ₁ of the excitation circuit (5, Q ₁ ). A load 6 that receives electrostatic energy accumulated in the power receiving capacitor C ₂ from the power receiving capacitor C ₂ in a circuit that connects the terminals of the power receiving capacitor C ₂ is connected to the secondary LC circuit 3 b. A load circuit is constituted by a circuit having a load 6 connected between the terminals of the power receiving side capacitor _C2 . Furthermore, this load circuit may have a configuration in which a load transfer control element Q ₄ is connected in series between the power receiving side capacitor C ₂ and the load 6 as a switching element. The load transfer control element _Q4 is a circuit element that assists in efficiently controlling the synchronous resonance of the vibration phase between the primary side LC circuit 2b and the secondary side LC circuit 3b, but according to one embodiment. It is not an essential circuit element for a synchronous resonant transmission system.

In the embodiment shown in FIG. 1, the distance between the power transmitting coil _L1 and the power receiving coil _L2 is determined by, for example, a hydraulic vertical mechanism, an electromagnetic vertical mechanism, a moving mechanism such as a ball spiral rotated by a step motor, etc. can be adjusted by various mechanisms. FIG. 1 is an example, and it is also possible to omit the power feeding board 11 that houses the power transmitting coil L ₁ and use the power transmitting coil L ₁ in a bare state. The power receiving side coil _L2 is housed in a power receiving board 12 made of a disc-shaped dielectric material. However, it is also possible to omit the power reception board 12 that houses the power reception side coil _L2 and use the power reception side coil _L2 in a bare state. Wavelet-shaped electromagnetic energy from the power transmitting coil _L1 is supplied to the power receiving coil _L2 by electromagnetic induction so that the vibration phases of the power feeding side resonant circuit and the power receiving side resonant circuit have multiple resonances (synchronous resonance). be done.

The power supply panel 11 is installed or buried on the ground so that the upper surface of the power supply panel 11 is arranged parallel to the lower surface of the power reception panel 12. In the state before power supply work, the upper surface of the power supply board 11 is arranged parallel to the flat surface 30 on the ground, and the vehicle 31c is set to be able to drive on a uniform flat surface and enter. The power supply circuit 29b is provided in a parking space, for example, and supplies wavelet-like electromagnetic energy to the power receiving board 12 mounted on the vehicle 31c by facing the power receiving board 12 while the vehicle 31c is parked. In the case where data on the transmission distance d of the synchronous resonance type transmission system according to one embodiment has been acquired, if a case occurs where there is a limit distance that can be transmitted due to special circumstances, the relationship between the vehicle height of the vehicle 31c In some cases, the transmission distance d does not fall within the limit distance. In such a case, the top surface of the power feed board 11 may be installed so as to protrude above the ground. If the top surface of the power feed board 11 protrudes above the ground, both wheels of the vehicle 31c entering the power feed field may be , the vehicle 31c may be guided to enter so as to straddle the upper surface of the power supply board 11.

The load 6 is a storage battery, and stores wavelet-shaped electromagnetic energy supplied from the power supply circuit 29b via the power receiving board 12. The vehicle 31c is, for example, a hybrid electric vehicle (HEV), a plug-in electric vehicle (PEV), or an electric vehicle (EV), and runs on electromagnetic energy stored in a storage battery as the load 6. For example, the primary side operation unit 33 generates a power supply start signal indicating the start of power supply or a power supply stop signal indicating the stop of power supply by operating an operation panel (not shown) by an external person (operator). The signal is output to the power supply circuit 29b. Alternatively, a signal from an IoT system such as a sensor may be received, and a power supply start signal or a power supply stop signal may be automatically output from the primary operation unit 33 to the power supply circuit 29b using an AI function. When the primary operation unit 33 determines the vehicle height of the vehicle 31c using the AI function, data on the vehicle height of the vehicle 31c is also transmitted to the drive control circuit 34a of the power supply circuit 29b.

The drive control circuit 34a is connected to a transmission data storage device 342a, a program storage device 342b, and an output device 343, respectively, as shown in FIG. It includes an arithmetic logic circuit 341 that performs drive control to synchronize and resonate the vibration phases of the power receiving side resonance circuits. The arithmetic logic circuit 341 of the drive control circuit 34a determines that after the power receiving side detector 29 detects that the voltage between the terminals of the power receiving side capacitor _C2 exceeds a predetermined value, the current flowing through the power sending side coil _L1 reaches a peak. The power transmission side detector 28 detects the timing and calculates the timing necessary for synchronized resonance of the vibration phase.

That is, the arithmetic logic circuit 341 controls the primary side switching element drive circuit 340a to supply DC voltage from the DC power supply 5 at a timing when synchronous resonance is possible, and controls the primary side LC circuit 2b and the secondary side LC circuit 340a. The vibration phases of the two LC resonance circuits of the circuit 3b are synchronized to resonate. When a power supply start signal is input from the primary side operation unit 33, the arithmetic logic circuit 341 of the drive control circuit 34a transmits wavelet-shaped electromagnetic energy from the primary side LC circuit 2b to 2 at the set synchronous resonance timing. The current of the power supply panel 11 is controlled so as to supply power to the next side LC circuit 3b without contact. The arithmetic logic circuit 341 receives information indicating that the voltage across the terminals of the power receiving capacitor _C2 exceeds a predetermined value, which is transmitted from the secondary LC circuit 3b, and information transmitted from the primary LC circuit 2b. Information on the timing at which the current flowing through the LC circuit 2b reaches its peak is acquired, and processing is performed to calculate the optimal drive timing at which the transmission efficiency due to synchronous resonance of the vibration phase between the power supply board 11 and the power reception board 12 is maximized. .

The arithmetic logic circuit 341 of the drive control circuit 34a inputs the signal of the vibration characteristics of the electromagnetic energy of the power receiving circuit 27b received by the primary side communication unit 21 via the secondary side communication unit 22, and receives the input shown in FIG. The drive timing of the element Q ₁ and the power transmission control element Q ₂ is determined, and the primary side switching element drive circuit 340a is controlled. The arithmetic logic circuit 341 further determines the drive timing of the power reception control element _Q3 and the load transfer control element _Q4 , transmits information from the primary side communication section 21 to the secondary side communication section 22, and drives the secondary side switching element. Control circuit 340b. The primary side switching element drive circuit 340a controls the input element _Q1 and the power transmission control element _Q2 by sending control signals to the respective control terminals of the input element _Q1 and the power transmission control element _Q2 shown in FIG. At the same time as controlling on/off, it receives a signal from the power transmission side detector 28 and transmits it to the arithmetic logic circuit 341. The secondary side switching element drive circuit 340b sends control signals to the respective control terminals of the power reception control element _Q3 and the load transfer control element _{Q4 shown} in FIG. At the same time as controlling the on/off of the element Q ₄ , it receives a signal from the power receiving side detector 29 and transmits it to the secondary side communication section 22 .

As described above, the arithmetic logic circuit 341 has the maximum transmission efficiency due to synchronous resonance, and the input element Q ₁ , the power transmission control element Q ₂ , the power reception control element Q ₃ and the load transfer control element Q ₄ shown in FIG. The primary side switching element drive circuit 340a and the secondary side switching element drive circuit 340b are controlled so as not to be damaged. Input element Q ₁ , power transmission control element Q ₂ , power reception control element Q ₃ and load transfer control element Q ₄ include FET, static induction transistor (SIT), BJT, GTO thyristor, static induction (SI) thyristor, etc. It is possible to use a power semiconductor device including a thyristor such as. In addition, considering the requirement for low internal resistance, MOSFETs can be used as the input element Q ₁ , the power transmission control element Q ₂ , the power reception control element Q ₃ and the load transfer control element Q ₄ due to their current availability on the market. It is preferable to adopt it.

In the synchronous resonant transmission system according to one embodiment, a drive voltage is step-input to the power supply side resonant circuit at a specific drive timing, and a wavelet-shaped damped vibration is excited. Here, the "driving voltage" is the voltage between the terminals of the DC power supply 5 shown in FIG. 3. This wavelet-shaped damped vibration is periodically excited at a drive period determined by the drive timing, and synchronization of the vibration phases is realized. That is, in the arithmetic logic circuit 341, the primary side LC circuit 2b and the secondary side LC circuit 3b perform synchronous resonance in the phase of vibration of the LC circuit via the power transmission side coil _L1 and the power reception side coil _L2 . The drive control circuit 34a is controlled so as to perform the following operations.

The transmission data storage device 342a can store data on the drive timing and drive cycle of the input element _Q1 in association with data such as the vehicle type and product number, and can have a learning function. In particular, by storing the drive timing data of the input element _Q1 obtained by the procedure shown in the flowchart of FIG. It is possible to provide a learning function that quickly responds to changes in impedance of circuit elements included in the primary side LC circuit 2b, the secondary side LC circuit 3b, etc. due to changes in . Further, the transmission data storage device 342a stores data indicating the relationship between the distance d between the coils (transmission distance) and the drive timing of synchronous resonance, and data indicating the relationship between the equivalent coupling coefficient k and the drive timing. The transmission condition setting circuit 348 reads data indicating the relationship between the transmission distance d and drive timing and data indicating the relationship between the equivalent coupling coefficient k and drive timing from the transmission data storage device 342a, and calculates the equivalent coupling calculated by the coupling coefficient calculation circuit 347. This is a logic circuit that determines the optimal transmission distance d from the coefficient k. Here, the "transmission distance d" means the physical distance between the power transmitting coil L ₁ and the power receiving coil L ₂ as illustrated in FIG. 3, and a specific example of the transmission distance d is schematically illustrated in FIG. 8. has been done.

Generally, the transmission distance d of the synchronous resonant transmission system according to one embodiment may be initially unknown. If data on the limit of the transmission distance d of the synchronous resonance transmission system has been acquired, the transmission condition setting circuit 348 determines whether the transmission distance d is within the limit data in consideration of the vehicle height of the vehicle 31c that is the purpose of power supply. A command is sent to the transmission interval control circuit 340c so as to fall within the range of . When the primary side operation unit 33 determines the vehicle height of the vehicle 31c using the AI function, it also takes into account the vehicle height data of the vehicle 31c and determines the travel distance required for the interval control mechanism that controls the transmission distance d. Command.

As shown in FIG. 2, the arithmetic logic circuit 341 includes an arithmetic sequence control circuit 344, a primary side current measurement control circuit 345, a secondary side voltage measurement control circuit 346, a coupling coefficient calculation circuit 347, and a transmission condition setting circuit. It mainly consists of a circuit 348, an A bus 349a, and a B bus 349b. The arithmetic sequence control circuit 344 controls the sequence of arithmetic processing. The A bus 349a and the B bus 349b supply information and information to each of the calculation sequence control circuit 344, the primary side current measurement control circuit 345, the secondary side voltage measurement control circuit 346, the coupling coefficient calculation circuit 347, and the transmission condition setting circuit 348. It is used to convey commands.

When the power supply stop signal is input from the primary side operation unit 33, the drive control circuit 34a controls the primary side switching element drive circuit 340a so as not to start the power supply or to stop the power supply. The drive control circuit 34a operates the primary side switching element drive circuit 340a so that the drive voltage is step-input to the power supply side resonant circuit at the drive timing determined by the synchronous resonance drive timing calculated by the arithmetic logic circuit 341. By driving the primary side switching element drive circuit 340a, wavelet-shaped electromagnetic energy is fed from the power feeding circuit 29b to the power receiving circuit 27b. The primary current measurement control circuit 345 controls the power transmission side detector 28 to measure changes in the current flowing through the power transmission side coil _L1 , and receives information from the power transmission side detector 28. The timing at which the current flowing through the power transmission coil _L1 reaches its peak can be detected by the power transmission side detector 28, as shown in FIG. The power transmission side detector 28 is not limited to an ammeter. Since there is a certain phase difference between voltage and current, even if the voltage is measured, the timing at which the current flowing through the power transmission coil _L1 reaches its peak can be detected.

The drive control circuit 34a connects the _primary side communication unit 21, the secondary side communication unit 22, and the secondary side so that the power reception side detector 29 shown in FIG. The operation of the power receiving side detector 29 is controlled via the side switching element drive circuit 340b. Furthermore, the drive control circuit 34a transmits information about the change in the voltage between the terminals of the power receiving capacitor _C2 from the power receiving side detector 29 to the secondary switching element drive circuit 340b, the secondary communication unit 22, and the primary communication unit 22. The received information is received via the unit 21. The drive control circuit 34a further detects that the voltage between the terminals of the power receiving capacitor _C2 exceeds a predetermined value based on the voltage across the terminals of the power receiving capacitor _C2 . It is transmitted to the drive circuit 340a and also controls the secondary side switching element drive circuit 340b.

For the arithmetic logic circuit 341, it is possible to configure a computer system using a microprocessor (MPU) or the like implemented as a microchip. In addition, as the arithmetic logic circuit 341 that makes up the computer system, there are digital signal processors (DSPs) that have enhanced arithmetic operation functions and specialize in signal processing, and microcontrollers that are equipped with memory and peripheral circuits and are designed to control embedded devices. microcomputer) etc. may also be used. Alternatively, the main CPU of a current general-purpose computer may be used for the arithmetic logic circuit 341. Furthermore, some or all of the arithmetic logic circuit 341 may be configured with a programmable logic device (PLD) such as a field programmable gate array (FPGA).

In the computer system of the drive control circuit 34a including the arithmetic logic circuit 341 shown in FIG. 2, the transmission data storage device 342a is appropriately selected from a group including a plurality of registers, a plurality of cache memories, a main storage device, and an auxiliary storage device. It is also possible to use any combination of Further, the cache memory may be a combination of a primary cache memory and a secondary cache memory, or may have a hierarchy including a tertiary cache memory. When part or all of the arithmetic logic circuit 341 is configured by a PLD, the transmission data storage device 342a can be configured as a memory element such as a memory block included in a part of the logic blocks that configure the PLD. Further, the arithmetic logic circuit 341 may have a structure in which a CPU core-like array and a PLD-like programmable core are mounted on the same chip. This CPU core-like array includes a hard macro CPU pre-installed inside the PLD and a soft macro CPU configured using the logic blocks of the PLD. In other words, a configuration in which software processing and hardware processing are mixed within the PLD may be used.

The calculation sequence control circuit 344 is a computer software program that executes each processing procedure of the primary side current measurement control circuit 345, the secondary side voltage measurement control circuit 346, the coupling coefficient calculation circuit 347, and the transmission condition setting circuit 348. Control is performed according to the synchronous resonance type transmission control program. In FIG. 2, a configuration is illustrated in which a primary side switching element drive circuit 340a, a secondary side switching element drive circuit 340b, and a transmission interval control circuit 340c are connected to the A bus 349a. On the other hand, although a configuration is illustrated in which a transmission data storage device 342a, a program storage device 342b, and an output device 343 are connected to the B bus 349b, the configuration is not limited to the configuration shown in FIG. 2. The program storage device 342b stores a synchronous resonant transmission control program that executes an algorithm equivalent to the process flow of the synchronous resonant transmission control method shown in FIG.

The primary side current measurement control circuit 345, the secondary side voltage measurement control circuit 346, the coupling coefficient calculation circuit 347, and the transmission condition setting circuit 348 as hardware resources constituting the arithmetic logic circuit 341 shown in FIG. It is a formal expression of hardware resources focusing on functions, and does not necessarily mean functional blocks that exist independently as physical areas on a semiconductor chip. This does not negate the actually existing configurations such as programmable logic components mounted on semiconductor chips such as "logic blocks". When part or all of the arithmetic logic circuit 341 is configured with a PLD such as an FPGA, the program counter of the arithmetic sequence control circuit 344 shown in FIG. 2 and data buses such as the A bus 349a and the B bus 349b can be omitted.

The input element _Q1 inputs an intermittent DC voltage from the DC power supply 5 in steps, generates electromagnetic energy that decays in a wavelet shape in the primary LC circuit 2b, and transfers this electromagnetic energy to the secondary LC circuit 3b. This is a circuit element that enables contactless power transmission through synchronous resonance with the In the configuration in which the power transmission control element _{Q2 is} connected in series with _the power transmission coil _L1 as illustrated in FIG. This assists in realizing wavelet-like damped vibration in the primary side LC circuit 2b. The DC power supply 5 may be a pseudo constant voltage source, or may be a DC power supply with a simple structure that is simply rectified, and may include a large ripple component, so that the control circuit and peripheral circuits are simple, hard to break, and easy to design. Furthermore, an inexpensive DC power source 5 can be used.

A load side diode _D2 and a load 6, which are connected in series with each other, are connected in parallel to a power receiving side capacitor _C2 . As the load 6, for example, a rechargeable battery such as a lithium (Li) ion battery mounted on the vehicle 31c can be adopted. Lithium-ion batteries include resistors in the current collector and electrolyte, and an electrical double layer capacitor and resistor that forms at the interface within the battery. As shown in FIG. 3, the load side diode _D2 is connected so that its anode faces the secondary LC circuit 3b side and its cathode faces the load 6 side, and limits the direction in which the charging current _IC flows to one direction. There is. In FIG. 3, the floating resistance including the on-resistance of the load 6 is indicated by _r2 .

In the synchronous resonant transmission system according to one embodiment, only four power semiconductor elements are required as the input element Q ₁ , the power transmission control element Q ₂ , the power reception control element Q ₃ , and the load transfer control element Q ₄ . A cooling structure that prevents heat generation can be easily designed, and stray resistance, stray capacitance, and stray inductance can also be minimized. Moreover, since only simple control is required to turn on/off the input element Q ₁ and the power transmission control element Q ₂ , it is possible to easily design a design that increases the voltage of the drive control circuit 34 a and suppresses the generation of Joule heat.

Further, the first freewheeling diode _FWD1 is connected between the source and drain of the MOSFET serving as the input element _Q1 , the second freewheeling diode FWD2 is connected between the source and drain of the MOSFET serving as the power transmission control element Q2, and the third freewheeling diode _FWD1 is connected between the source and drain of the MOSFET serving as the power transmission control element _Q2 . The freewheeling diode FWD ₃ is connected in parallel between the source and drain of the MOSFET as the power reception control element _Q3 , and the fourth freewheeling diode _FWD4 is connected in parallel between the source and drain of the MOSFET as the load transfer control element _Q4 , respectively, as a protection element. has been done. The third freewheeling diode FWD ₃ is provided in the direction in which the freewheeling current from the power receiving coil L ₂ flows, and therefore is provided in the opposite direction to the second freewheeling diode FWD ₂ . Further, in order to prevent the return current from the power transmission side coil _L1 from flowing back to the DC power supply 5, a power supply side diode _D1 is connected in series between the DC power supply 5 and the input element _Q1 . In the mounted circuit shown in FIG. 1 as well, the equivalent impedance X _Leq of the load 6 is approximated and expressed by the charging capacity C _s .

The power transmission side coil L ₁ and the power reception side coil L ₂ of the synchronous resonance type transmission system according to one embodiment can be spiral planar coils as schematically shown in FIG. 8, for example. FIG. 8 is a schematic diagram in which the physical structures of the power transmitting coil L ₁ and power receiving coil L ₂ in FIG. 3 are enlarged and exaggerated to make it easier to imagine, and the actual dimensions and ratios differ . In the synchronous resonance type transmission system according to one embodiment, for example, a wiring cable with a conductor cross-sectional area of 16 mm ² is wound nine times each to form a spiral planar coil with a diameter of about 30 cm. These two spiral planar coils each having a diameter of about 30 cm are arranged parallel to each other without contact, with a gap of d between them. The transmission efficiency from the primary side LC circuit 2b to the secondary side LC circuit 3b due to transient response mutual induction between the primary side LC circuit 2b and the secondary side LC circuit 3b is determined by the coupling coefficient K _AC defined in AC theory. depends on the value of the degree of magnetic coupling. The degree of magnetic coupling varies depending on the distance d between the two spiral plane coils, and it is necessary to control the distance d between the two spiral plane coils.

The degree of magnetic coupling can be determined by mechanically adjusting the positional relationship between the two spiral planar coils, inserting a magnetic material between the two spiral planar coils, or inserting a magnetic material around the two spiral planar coils. Adjustments can be made by, for example, attaching to a pre-shaped coupling using the attraction or repulsion force acting between two spiral planar coils.

(Operation flow)
The power receiving circuit 27b of the synchronous resonant transmission system according to one embodiment is in a loosely coupled state (equivalent coupling coefficient k<0.08) where the distance d between the power transmitting coil _L1 and the power receiving coil _L2 is 300 mm or more. In order to make it possible to transmit sufficient power with one synchronous resonance, the current flowing through the power transmitting coil _L1 reaches its peak after the voltage amplitude on the power receiving side exceeds a predetermined value, according to the process shown in the flowchart shown in FIG. Selecting the momentary timing shown, power is supplied from the DC power supply 5 by synchronous resonance. The power supply operation with this synchronization timing selected is repeated periodically, that is, until the voltage amplitude on the receiving side reaches the maximum. Here, the "power receiving side voltage amplitude" means the amplitude of the voltage between the terminals of the power receiving side capacitor _C2 . By selecting the instantaneous timing when the current flowing through _L1 peaks and repeating the operation of supplying power from the DC power source 5, resonance due to parasitic resistance of the circuit can be avoided even if the time from the start of resonance to the maximum transmission timing becomes long. Since voltage attenuation can be recovered, the power that can be transmitted with one synchronous resonance can be significantly improved compared to the case without synchronous resonance.

In the synchronous resonance type transmission system according to the embodiment, a signal from the power transmission side detector 28 provided on the power transmission side is transmitted to the secondary side communication unit 22 via the secondary side switching element drive circuit 340b to the primary side communication 21. The primary side communication unit 21 transmits the received signal from the power transmission side detector 28 to the arithmetic logic circuit 341. Changes in the current flowing through the power transmission coil _L1 are input to the arithmetic logic circuit 341 via the primary switching element drive circuit 340a. The arithmetic logic circuit 341 detects the timing at which the current flowing through the power transmitting coil _L1 reaches its peak, and also detects the voltage between the terminals of the power receiving capacitor _C2 by the power receiving side detector 29 provided on the power receiving side. Then, after the voltage between the terminals of the power receiving capacitor _C2 exceeds a predetermined value and before reaching the maximum, the arithmetic logic circuit 341 generates a direct current from the DC power source 5 at a timing when the current flowing through the power transmitting coil _L1 reaches its peak. A control signal is output to the control terminal of the input element _Q1 so that the voltage (driving voltage) is periodically and repeatedly supplied. Hereinafter, an example of the operation flow of the synchronous resonant transmission system according to one embodiment will be described with reference to FIG. 4.

First, in step S1, the power transmission control element Q ₂ , the power reception control element Q ₃ , and the load transfer control element Q ₄ are turned off, and only the input element Q ₁ is turned on. The inter-terminal voltage V _C1 of the power transmission side capacitor C ₁ is charged to a constant voltage while ringing. The voltage V _C2 between the terminals of the power receiving side capacitor C ₂ is a negative value. Here, since the power transmission control element Q ₂ is in the off state, no current flows to the power transmission side coil L ₁ side, and electric charge is stored in the power transmission side capacitor C ₁ more effectively. After applying an initial voltage to the power transmission side capacitor C ₁ to store charge, the input element Q ₁ is turned off.

Next, in step S2, the input element Q ₁ is turned off, and after a certain period of time, the power transmission control element Q ₂ and the power reception control element Q ₃ are simultaneously turned on. Load transfer control element _Q4 is in an off state. When the power transmission control element _Q2 is turned on, the electromagnetic energy stored in the power transmission side capacitor _C1 is stored in the power transmission side coil _L1 , and furthermore, the electromagnetic energy stored in the power transmission side capacitor C1 is stored in the power transmission side coil L1. Transient response mutual induction occurs. When the electromagnetic energy stored in the power transmission capacitor C ₁ moves to the power transmission coil L ₁ , the voltage V _C1 between the terminals of the power transmission capacitor C ₁ reaches a negative maximum value and then becomes 0V. Due to transient response mutual induction from the primary side LC circuit 34b to the secondary side LC circuit 27b, the electromagnetic energy transmitted to the power receiving side coil L ₂ is transmitted to the power receiving side capacitor C ₂ since the power receiving control element Q ₃ is in the ON state. Charge. At this time, since the load transfer control element _Q4 is in the off state, no current flows to the load 6 side, and charge is stored in the power receiving capacitor _C2 more effectively.

Then, in step S3, a signal from the power transmission side detector 28 provided on the power transmission side is transmitted to the arithmetic logic circuit 341 via the secondary side switching element drive circuit 340b, the secondary side communication section 22, and the primary side communication section 21. is input. In step S3, the arithmetic logic circuit 341 determines whether the power receiving side voltage amplitude (=amplitude of the voltage between the terminals of the power receiving side capacitor _C2 ) exceeds a predetermined value. If the arithmetic logic circuit 341 determines in step S3 that the power receiving side voltage amplitude exceeds the predetermined value, the process proceeds to step S4. In step S4, information on changes in the current flowing through the power transmission coil _L1 is input from the power transmission side detector 28 to the arithmetic logic circuit 341 via the primary switching element drive circuit 340a. In step S4, the arithmetic logic circuit 341 determines the timing when the power transmission side voltage decreases to zero, that is, the zero cross time when the voltage between the terminals of the power transmission side capacitor _C1 becomes 0V, and the timing when the current flowing through the power transmission side coil _L1 reaches its peak. Determine as. In step S4, when the arithmetic logic circuit 341 confirms the timing at which the current flowing through the power transmitting coil _L1 reaches its peak, the process immediately proceeds to step S5. In step S5, the arithmetic logic circuit 341 sends a command to the primary side switching element drive circuit _340a , and momentarily turns on the input element _Q1 while keeping the power transmission control element Q2 and the power reception control element _Q3 in the on state. state. In step S5, when the DC voltage is supplied from the DC power supply 5 to the power transmission side capacitor _C1 under the control of the primary side switching element drive circuit 340a, the process returns to step S2. The arithmetic logic circuit 341 periodically performs the voltage supply operation along the loop of steps S2 → S3 → S4 → S5 → S2, that is, the voltage amplitude on the power receiving side detected by the power receiving side detector 29 (=power receiving side capacitor C ₂ control is repeated until the amplitude of the voltage between the terminals of

For example, as shown in the wavelet-like attenuation waveform shown by the solid line _{in FIG} . It will be held twice. That is, after the power receiving side _voltage amplitude shown by the broken line in _FIG . Since it is performed twice, power is supplied from the DC power supply 5 to the power transmission side capacitor _C1 at this timing. In this case, the time it takes for the voltage amplitude on the receiving side to reach its maximum (the time it takes for one cycle to turn off resonance), shown by the broken line, becomes longer, but the amount of power transmitted in one cycle can be significantly improved. As a result, compared to the case without synchronous resonance, the amount of power transmitted in a predetermined period of time can be increased and the time for transmitting the predetermined amount of power can be shortened.

Returning to the operation flow in FIG. 4, in step S3, when the power receiving side detector 29 detects the timing P _max at which the power receiving side voltage amplitude becomes maximum, the process proceeds to step S6. In step S3, the timing P _max at which the power receiving side voltage amplitude detected by the power receiving side detector 29 becomes maximum is transmitted from the secondary side communication unit 22 to the primary side communication unit via the primary side switching element drive circuit 340a. 21. The primary side communication unit 21 transmits information to the arithmetic logic circuit 341 at the timing P _max when the received power reception side voltage amplitude becomes maximum. When the load transfer control element _Q4 is turned on at the timing of step S6, the charging current _ICS starts flowing to the load 6. In step S6, the power transmission control element _Q2 and the power reception control element _Q3 are turned off at the timing when the load transfer control element _Q4 is turned on. When the power transmission control element Q ₂ and the power reception control element Q ₃ are in the OFF state, the voltage V _C2 between the terminals of the power reception side capacitor C ₂ increases due to transient response mutual induction between the primary side LC circuit 34b and the secondary side LC circuit 27b. This is the time when the voltage V _C1 between the terminals of the capacitor C ₁ on the power transmission side reaches 0V. At this time, since the power receiving control element _Q3 is in the off state, the charging current _ICS is transferred to the load 6 more effectively. The charging current _ICS increases even after the power transmission control element _Q2 and the power reception control element _Q3 are turned off, reaches a peak value, and then decreases to zero.

Next, after the charging current I _C becomes 0A, the power transmission control element Q ₂ and the power reception control element Q ₃ are simultaneously turned on again while the load transfer control element Q ₄ remains on. Charging of the side capacitor _C2 is started. Due to the electromagnetic coupling between the primary side LC circuit 34b and the secondary side LC circuit 27b, the voltage V _C1 between the terminals of the power transmission side capacitor _C1 starts to decrease from 0V to a negative value. Furthermore, in step S7, when the load transfer control element _Q4 is turned off and the power receiving capacitor _C2 starts discharging, the reflux due to the transient response mutual induction between the primary side LC circuit 34b and the secondary side LC circuit 27b occurs. arise. In the synchronous resonance type transmission system according to one embodiment, since the load transfer control element _Q4 is in the off state, no current flows to the load 6 side, and current flows more effectively to the power receiving side coil _L2 . The return current flowing through the power transmitting coil _L1 due to mutual induction between the power receiving coil _L2 and the power transmitting coil _L1 charges the power transmitting capacitor _C1 , and the terminal voltage V _C1 changes from a negative maximum value to a positive value. becomes the value of , and begins to increase. Further, the inter-terminal voltage V _C2 starts to decrease, reaches a maximum negative value, and then becomes 0V.

Then, in step S8, the arithmetic logic circuit 341 determines whether the amount of power received by the load 6 has reached a predetermined value. In step S8, when the arithmetic logic circuit 341 determines that the amount of power received by the load 6 has reached the predetermined value, the process of the flow shown in FIG. 4 is ended. If it is determined in step S8 that the amount of power received by the load 6 has not reached the predetermined value, the process returns to step S1 and continues until the amount of power received by the load 6 reaches the predetermined value as determined in step S8 → S1 → S2 →... ...→Repeat the loop operation of S8.

The process flow of the series of synchronous resonant transmission control methods shown in FIG. 4 can be executed by controlling the drive control circuit 34a shown in FIG. 2 using a synchronous resonant transmission control program with an algorithm equivalent to that in FIG. . This synchronous resonance type transmission control program may be stored in the program storage device 342b of the computer system that constitutes the drive control circuit 34a of the present invention. Further, this synchronous resonance type transmission control program is stored in a computer-readable recording medium, and by reading this recording medium into the program storage device 342b of the drive control circuit 34a, a series of deterioration operations of the present invention are executed. can do. Here, the term "computer-readable recording medium" refers to a medium on which a program can be recorded, such as a computer's external memory device, semiconductor memory, magnetic disk, optical disk, magneto-optical disk, or magnetic tape. do.

Specifically, "computer-readable recording media" include flexible disks, CD-ROMs, MO disks, HDDs, and the like. For example, the main body of the drive control circuit 34a can be configured to have a flexible disk device (flexible disk drive) and an optical disk device (optical disk drive) built-in or externally connected. By inserting a flexible disk into a flexible disk drive or a CD-ROM into an optical disk drive, and performing the specified reading operation, the programs stored on these recording media can be run. It can be installed in the program storage device 342b that constitutes the control circuit 34a. Further, this program can be stored in the program storage device 342b via an information processing network such as the Internet.

As described above, according to the synchronous resonant transmission system, the synchronous resonant transmission control method, and the synchronous resonant transmission control program according to the embodiment, even in a loosely coupled state, a single synchronous resonance can generate enough power. That is, it is possible to transmit power equivalent to that without the parasitic resistance of the circuit, and it is possible to supply power to a longer distance without contact and in a shorter time. For example, when transmitting a predetermined amount of electric power, it took 32 msec with the reference technology that does not take synchronization into consideration, but according to an embodiment of the present invention, it takes 32 msec to transmit a predetermined amount of power. In this case, it is possible to perform the process in 10.6 msec, which is about 1/3.

Specifically, in the reference technology that the inventors originally considered that does not take synchronization into account, as the time from the start of resonance to the maximum transmission timing becomes longer, the resonant voltage is attenuated by the parasitic resistance of the circuit, The transmission voltage decreases when the resonance is temporarily cut off, making it impossible to transmit sufficient power in one contactless power transmission, and it takes a long time to transmit a predetermined amount of power. In other words, as shown in Fig. 6, if parasitic resistance is not assumed, the voltage amplitude on the power receiving side indicated by the broken line should reach a maximum voltage of 25V at point P _max , but in reality, the voltage amplitude on the receiving side shown by the broken line should reach the maximum voltage of 25V, but in reality, the amplitude at the point when resonance is turned off due to parasitic resistance (Resonance time: 3 msec) At _XR , only 12.5V can be stored in the power receiving capacitor _C2 . On the other hand, in the synchronous resonant transmission system according to one embodiment _, as _shown in FIG. Because of this, although the time from the start of resonance to the maximum transmission timing P _max is longer than in the reference technology that does not consider synchronization, the resonant voltage attenuated by the parasitic resistance of the circuit can be recovered by power supply. Therefore, the amount of power that can be transmitted in one synchronous resonance can be significantly increased. That is, with a resonance time of 5.6 msec, 25V can be stored in the power receiving capacitor _C2 .

Examples of the time of one cycle and the amount of power that can be transmitted in one cycle are shown below.
[1 cycle time]
When the time other than resonance is set to 5 msec, one cycle of the synchronous non-consideration system that the inventors originally considered is 3.0 msec + 5 msec = 8 msec, whereas the synchronous resonant transmission system according to one embodiment, the synchronous In the resonance type transmission control method and the synchronous resonance type transmission control program, 5.6 msec+5 msec=10.6 msec. That is, in the present invention, the time for one cycle is approximately 1.3 times that of the reference technology, which is a system that does not consider synchronization.
[Transmission power amount for one cycle]
Since the transmission power amount W is expressed as W = (1/2) CV ² , the transmission voltage of the system without consideration of synchronization is 12.5V, whereas the transmission voltage of the present invention is 25V, which is twice that. This means that in the present invention, the amount of transmitted power per cycle is approximately four times as much as that of the reference technology, which is a system that does not take synchronization into consideration.

From the above, the present invention can transmit about 4 times the amount of power in about 1.3 times the time compared to the reference technology and non-synchronization system originally considered by the inventors. I understand. That is, according to the present invention, even in a loosely coupled state (equivalent coupling coefficient k<0.08) where the power transmitting side coil and the power receiving side coil are separated by 300 mm or more, sufficient power can be generated with one synchronous resonance. Since it can be transmitted, it becomes possible to supply power to a longer distance without contact and in a shorter time.

(Other embodiments)
As mentioned above, although the present invention has been described with reference to the above-described exemplary embodiment, the discussion and drawings forming a part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, implementations, and operational techniques will be apparent to those skilled in the art from this disclosure. For example, in the description of the synchronous resonant transmission system according to the above embodiment, for convenience, a circuit including an input element Q ₁ , a power transmission control element Q ₂ , a power reception control element Q ₃ , and a load transfer control element Q ₄ and four switching elements is used. Although the configuration has been described, a circuit configuration having three switching elements without the load transfer control element _Q4 may be used. In short, after the power receiving side detector 29 detects that the resonance amplitude voltage on the side of the secondary side LC circuit 3b exceeds a predetermined value, the power transmitting side determines the timing at which the current flowing through the primary side LC circuit 2b reaches its peak. Any configuration is sufficient as long as the arithmetic logic circuit 341 controls the primary side switching element drive circuit 340a so that the DC voltage is supplied from the DC power supply 5 when the detector 28 detects the detection.

From the same point of view, a circuit configuration having two switching elements may be used in which the power reception control element Q ₃ and the load transfer control element Q ₄ are omitted from the circuit configuration illustrated in FIG. 3 . Further, as explained above, the power transmission control element Q ₂ , the power reception control element Q ₃ and the load transfer control element Q ₄ may be omitted from the circuit configuration illustrated in FIG. 3, and the circuit configuration may include only the input element Q ₁ . It can be understood from the purpose of

Furthermore, for example, even when the distance between the power transmitting coil _L1 and the power receiving coil _L2 is 300 mm or more, sufficient power can be transmitted. By embedding a plurality of power transmission coils continuously along the travel route, power can be supplied to the vehicle without contact even when the vehicle is in motion. Of course, if further infrastructure is developed, it will be possible to supply electricity to vehicles on public roads without contact. As described above, the present invention includes various embodiments not described in the specification and drawings, and the technical scope of the present invention is determined by the matters specifying the invention in the claims that are reasonable from the above description. only.

2b...Primary side LC circuit, 3b...Secondary side LC circuit, 5...DC power supply, 6...Load, 21...Primary side communication section, 22...Secondary side communication section, 23...Secondary side operation section, 27b ...Power receiving circuit, 28...Detector (power transmitting side detector), 29...Detector (power receiving side detector), 29b...Power feeding circuit, 30...Flat surface, 31c...Vehicle, 33...Primary side operation section, 34a... Drive control circuit, 340a...Primary side switching element drive circuit, 340b...Secondary side switching element drive circuit, 340c...Transmission interval control circuit, 341...Arithmetic logic circuit, 342a...Transmission data storage device, 342b...Program storage device, 343... Output device, 344... Arithmetic sequence control circuit, 345... Primary side current measurement control circuit, 346... Secondary side voltage measurement control circuit, 347... Coupling coefficient calculation circuit, 348... Transmission condition setting circuit, 349a... A bus , 349b...B bus

Claims (3)

a primary side LC circuit having a power transmission side capacitor, a power transmission side coil connected in parallel to the power transmission side capacitor, and a power transmission side detector that detects a change in the current flowing through the power transmission side coil;
an excitation circuit having a DC power source and an input element for stepwise inputting a DC voltage supplied from the DC power source between one terminal and the other terminal of the power transmission side capacitor;
a secondary side LC circuit including a power receiving side coil facing the power transmitting side coil, a power receiving side capacitor connected in parallel to the power receiving side coil, and a power receiving side detector that detects a change in voltage between terminals of the power receiving side capacitor; ,
a load circuit having a load connected between terminals of the power receiving capacitor and receiving electrostatic energy accumulated in the power receiving capacitor from the power receiving capacitor;
a primary side switching element drive circuit that sends a control signal for the step input to a control terminal of the input element;
After the power receiving side detector detects that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value, when the power transmitting side detector detects a timing at which the current flowing through the power transmitting side coil reaches a peak, an arithmetic logic circuit that controls the primary side switching element drive circuit so as to supply the DC voltage from the DC power supply;
A synchronous resonant transmission system characterized by comprising: A primary LC circuit including a power transmission side capacitor, a power transmission side coil connected in parallel to the power transmission side capacitor, and a power transmission side detector that detects a change in the current flowing through the power transmission side coil, a DC power supply, and a DC power supply supplied from the DC power supply. an excitation circuit having an input element that inputs a DC voltage between one terminal and the other terminal of the power transmission side capacitor in a stepwise manner; a power reception side coil facing the power transmission side coil; and a power reception side coil connected in parallel to the power reception side coil. a secondary side LC circuit having a power receiving side capacitor and a power receiving side detector that detects a change in the voltage between the terminals of the power receiving side capacitor; and a circuit connecting between the terminals of the power receiving side capacitor; A synchronous resonant transmission control method for controlling the operation of a synchronous resonant transmission system comprising a load that receives electrostatic energy stored in a side capacitor, the method comprising:
a step in which the power receiving side detector detects that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value;
A synchronous resonance type transmission control method comprising: supplying the DC voltage from the DC power supply when the power transmission side detector detects a timing at which the current flowing through the power transmission side coil reaches a peak. A primary LC circuit including a power transmission side capacitor, a power transmission side coil connected in parallel to the power transmission side capacitor, and a power transmission side detector that detects a change in the current flowing through the power transmission side coil, a DC power supply, and a DC power supply supplied from the DC power supply. an excitation circuit having an input element that inputs a DC voltage between one terminal and the other terminal of the power transmission side capacitor in a stepwise manner; a power reception side coil facing the power transmission side coil; and a power reception side coil connected in parallel to the power reception side coil. a secondary side LC circuit having a power receiving side capacitor and a power receiving side detector that detects a change in the voltage between the terminals of the power receiving side capacitor; and a circuit connecting between the terminals of the power receiving side capacitor; A synchronous resonant transmission control program that controls the operation of a synchronous resonant transmission system including a load that receives electrostatic energy accumulated in a side capacitor,
a command to cause the power receiving side detector to detect that the voltage between the terminals of the power receiving side capacitor exceeds a predetermined value;
When the power transmission side detector detects a timing at which the current flowing through the power transmission side coil reaches a peak, the computer system is caused to execute a series of instructions including an instruction to cause the DC power source to supply the DC voltage. A program for controlling synchronous resonant transmission.

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