JP2006340541A - Method for power supply to electric vehicle using microwave - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply method by which power is efficiently supplied in correspondence with a variation in conditions on an electric vehicle side with respect to a power supply that supplies power from a road surface to an electric vehicle using a microwave. <P>SOLUTION: The power supply on the road surface side receives vehicle information including vehicle model of an electric vehicle. Based on the received vehicle information, the power supply controls power for the transmission of a microwave from an antenna so as to optimize it using the relation between transmission power and power supply efficiency stored beforehand in the road surface-side power supply in the form of map. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of supplying electric power to a traveling vehicle from an infrastructure side such as a road surface outside the vehicle.

  As a method of improving transmission efficiency in microwave power transmission, conventionally, a method of increasing the power of a rectenna as disclosed in Patent Document 1 below, or a structure of a power feeding system disclosed in Patent Document 2 below is disclosed. A method for reducing loss due to microwave scattering has been studied. In particular, the following method is disclosed for the latter efficiency improvement. The rectenna is a microwave receiving device including a microwave receiving antenna and a rectifier circuit.

  As a power receiving system for a traveling vehicle, a system described in Patent Document 2 below is disclosed. The basic configuration of this power receiving system is formed by a power supply device embedded in a road surface on the infrastructure side and a receiving device mounted on a vehicle on the power receiving side. The power supply device is composed of a waveguide as a power transmission system for power transmitted in the form of microwaves, and a slot antenna that emits microwave power, and has a certain degree of directionality to microwaves. In addition, a transmission reflector made of a conductive material for efficiently supplying power to the receiving side and a microwave transmitting cover for protecting the power supply device are attached.

  The receiving device mounted on the vehicle side is composed of a rectenna, which is a microwave receiving device that receives and rectifies microwaves, and a rechargeable battery that charges the electric power received by the rectenna. A receiving reflector made of a conductive material for efficiently receiving the incoming microwave is attached. With this configuration, the power receiving system has improved power receiving efficiency.

  The former method of increasing power requires high power transmission in anticipation of loss when the relative positional relationship between the power transmitting side and the receiving side constantly changes as in the case of an electric vehicle. Further, in the latter method of improving efficiency structurally, although there is an improvement in efficiency for a specific vehicle type, there is a fluctuation in power supply efficiency depending on the relative position of the antenna on the transmission side and the reception side, and also depending on the vehicle type There was also a problem that it could not respond sufficiently to fluctuations in required power.

Patent No. 385472 Japanese Laid-Open Patent Publication No. 2002-152996

  As described above, a transmission-side reflector is installed on the road surface (infrastructure) side, a reception-side reflector is installed on the vehicle side, and the width region of the reception-side reflector is covered so as to cover the entire width region of the transmission-side reflector. By setting it wider than that of the side reflector, it is considered that microwave leakage to the outside of the vehicle between the road surface and the vehicle, that is, between transmission and reception is reduced, and it is possible to improve the efficiency of power reception.

  However, since it is necessary to install reflectors on both the road surface side and the vehicle side, system setting and installation on the road surface side are particularly large. In addition, for example, when the vehicle has a corner portion or the vehicle is disposed obliquely with respect to the traveling direction of the road, when the traveling direction of the road surface does not coincide with the longitudinal direction of the vehicle when viewed from above, specifically the transmission In situations where the side reflector and the receiver reflector are not parallel, it is difficult to provide a certain degree of directivity for the microwave on the power transmission side with respect to the power reception side. There was a problem that it was difficult to improve the performance. Therefore, an object of the present invention is to provide a method for solving such problems and receiving microwave power with high efficiency.

  In order to achieve the above object, in the present invention, when power is supplied from the road surface side power supply device to the electric vehicle, the road surface side power supply device first receives vehicle information such as receivable power based on the vehicle type and rectenna configuration from the electric vehicle side. Receive. A relationship between transmission power and power supply efficiency mapped in advance to each vehicle type is set in the road surface side power supply device, and the transmission power between the road surface side power supply device and the electric vehicle becomes the optimum power supply efficiency using this relationship. The way to control is as follows.

  According to the present invention, the electric power required according to the type of the electric vehicle on the power receiving side and the configuration of the rectenna is supplied, and the electric power supplied by the road surface side power supply device and the electric vehicle and the power supply efficiency are monitored. The power supply efficiency can be increased because the supplied power can be controlled from moment to moment.

Hereinafter, the present invention will be described with reference to the drawings.
(Embodiment 1)
Embodiment 1 of a method for supplying power to an electric vehicle using microwaves is shown in FIG. FIG. 1A is a system configuration diagram when the configuration of the first embodiment is viewed from above. Similarly, FIG. 1B is a system configuration diagram when the configuration of the first embodiment is viewed from the side. .

  The road surface side power supply device (microwave transmission equipment) 20 basically includes a road surface (infrastructure) side power line 21, a microwave generation unit 22, a microwave transmission antenna group 23, a transmitter / receiver 24, and a microwave transmission antenna control circuit 25. Consists of. The microwave generation unit 22 converts the electrical energy supplied from the infrastructure side power supply line 21 into microwaves.

  The microwave transmission antenna group 23 is a set of microwave transmission antennas having a mechanism for transmitting microwaves. The microwave transmission antenna group 23 is a means for transmitting microwaves to space. The microwave transmission antenna group 22 converts the microwaves converted by the microwave generation unit 22. The microwaves are emitted toward the rectenna 27 that is a microwave receiver installed above the road surface, that is, at the lower part of the vehicle body of the electric vehicle 26.

  In the microwave transmission antenna control circuit 25, the “transmission power-feeding efficiency relationship” shown in FIG. For example, as shown by vehicle type A or vehicle type B in FIG. 2, the transmission power is set so as to obtain the maximum power supply efficiency for each vehicle type. Thereby, the road surface (infrastructure) side power supply device 20 is configured to optimally control the transmission power according to the vehicle type of the electric vehicle 26 to be supplied with power.

  Next, the power reception system on the reception side, that is, the electric vehicle 26 side will be described. Although not shown, the rectenna 27 includes a microwave receiving antenna and a rectifier circuit. The microwave receiving antenna (not shown) functions as means for receiving microwaves transmitted from the microwave transmitting antenna group 23 set on the road surface side.

  In addition, the rectifier circuit (not shown) is composed of a plurality of filters and rectifier diodes, and functions as means for directly extracting DC power from the microwaves received by the microwave receiving antenna. Therefore, the electric vehicle 26 converts the microwave received from the road surface into electric energy by setting the rectenna 27 at the lower part of the vehicle body, and stores it in the power storage mechanism 28 or directly supplies it to the motor generator 29.

  The motor generator 29 can travel the electric vehicle 26 by converting the electric energy stored in the power storage mechanism 28 or directly supplied from the rectenna 27 into a driving force. Alternatively, the electric energy supplied from the rectenna 27 is converted into an in-vehicle electric system voltage by the DC / DC converter 30 in accordance with the power consumption state (the presence or absence of an air conditioner, a light, etc.) in the electric vehicle 26, and the vehicle electric equipment It is supplied to the in-vehicle electrical unit via the system storage battery 31.

  In addition, the electric vehicle 26 is provided with a transmitter / receiver 32 similar to the transmitter / receiver 24 in the road surface side power supply device (microwave transmission facility) 20, and microwave transmission power from the road surface side power supply device 20 to the electric vehicle 26 side. Information necessary for optimal control of the vehicle, specifically, the vehicle type (vehicle grade) of the vehicle, the setting of the microwave power receiving system (configuration of the rectenna 27), the amount of charge SOC (State of Charge) information of the power storage mechanism 28 Is exchanged in parallel with the power feeding operation.

With reference to the flowcharts shown in FIGS. 3 and 4, a method for supplying power to the electric vehicle using the microwave according to the first embodiment in the configuration of the power supply system described above will be described.
First, the process until the road surface side power supply apparatus 20 determines the electric vehicle 26 to be supplied and starts power supply based on the determination result will be described with reference to the flowchart of FIG. In the present invention, when power is supplied from the road surface side power supply apparatus 20 to the electric vehicle 26 by microwaves, the second transmitter / receiver installed in the road surface side power supply apparatus 20 from the first transmitter / receiver 32 mounted on the electric vehicle 26. Vehicle information such as the vehicle type of the electric vehicle 26 is transmitted to the transmitter / receiver 24, and “transmission power-feeding efficiency” set in advance by mapping to the microwave transmission antenna control circuit 25 built in the road-side power feeding device 20 Using the relationship, the power supply method controls the transmission power so as to be within the transmission power range in which the optimum power supply efficiency unique to the vehicle information is maintained.

  In step S01, the power feeding device 20 reads the vehicle information of the electric vehicle 26 to be fed using the transceivers 24 and 32 shown in FIG. At this time, as the vehicle information, the vehicle type (vehicle grade) of the electric vehicle 26, the area of the rectenna 27, the maximum power that can be received, and the storage amount SOC of the power storage mechanism 28 are read. Most of these pieces of information are information necessary for wireless power transmission by microwaves between the road surface side power feeding device 20 and the electric vehicle 26 in FIG. If there is more necessary information, it is assumed that the transmitters and receivers 24 and 32 that are the same information transmission path are used in a form that is appropriately added.

In step S02, the power supply target set in advance on the road surface side power supply device 20 based on the vehicle type (vehicle size) information of the electric vehicle 26 read in step S01 and mapped from the “transmission power-power supply efficiency relationship” The “optimum power supply efficiency” region of the electric vehicle 26 is determined. An example of this “transmission power-feeding efficiency relationship” is shown in FIG. Here, in order to improve the power supply efficiency, the rectenna 27 may be increased in power. As a method of increasing the power, 1) the diode used in the rectifier circuit portion of the rectenna 27 is increased in power. 2) rectenna 27 3) Connect a number of diodes used in the rectifier circuit section in series and in parallel. 3) Divide the microwaves obtained from one receiving antenna equally to multiple transmission lines, and rectify and smoothly output each of the transmission paths. The rectification circuit is provided (see Patent Document 1), but in any case, the conversion efficiency as shown in FIG. 5 tends to be “convex upward” (FIG. 5: Patent Document). 1 of FIG. 2). As shown in FIG. 5, when trying to increase the power in the rectenna 27, the property of RF-DC conversion efficiency (efficiency for converting microwaves to DC power) with respect to the input power to the rectenna 27 is different for each set power. . If the power region in which the RF-DC conversion efficiency is maintained near the maximum value as in 11, 12, 13, and 14 in FIG. 5 is defined as the “optimal power supply efficiency” region, this optimal power supply efficiency is determined from the transmission side. It changes with the input power by the microwave. The “RF-DC conversion efficiency” can be handled equivalently to “feed power efficiency (received power / transmitted power)” in the present invention. If this property is used, the relationship between transmission power and power supply efficiency corresponding to a plurality of properties corresponding to FIG. 5 is set in the road surface side power supply device 20 in advance as calculation means, and is set for the electric vehicle that is the power supply target. By grasping the setting of the microwave reception system (configuration of the rectenna 27) with the road surface side power supply device 20, it is possible to supply power to the electric vehicle 26 with transmission power corresponding to the region in which the optimum power supply efficiency is maintained. It becomes. As a result, loss due to leakage waves in the wireless transmission region can be minimized, and the power supply efficiency from the power supply device to the electric vehicle can be increased. A specific example of the relationship between transmission power and power supply efficiency in the present invention is shown in FIG. As shown in FIG. 2, the relationship between transmission power and power feeding efficiency corresponding to a plurality of vehicle types is mapped in advance, and then set in the road surface side power feeding device 20 as calculation means.

  In FIG. 2, the “optimum power supply efficiency” area is hatched with an upward slanting line for “vehicle type A” (assuming a relatively small vehicle that can be driven with low power), B ″ (assuming a vehicle driven by a large power with a normal to large vehicle size) is indicated by a hatched area with a diagonal line rising to the left.

  As a result, the “optimum feeding efficiency” of the electric vehicle 26 to be fed in the road surface side feeding device 20 is grasped in advance, and the electric vehicle is fed with the transmission power that maintains the optimum feeding efficiency value. Therefore, loss due to leakage waves in the wireless transmission region can be minimized, and the power supply efficiency from the road surface side power supply device 20 to the electric vehicle 26 can be increased.

  In step S03, the maximum power supply efficiency in the optimum power supply efficiency region determined in step S02 is set as the predicted maximum power supply efficiency from the relationship between the transmission power and the power supply efficiency in the vehicle type corresponding to the electric vehicle 26 to be supplied with power. The transmission power value is determined as an expected transmission power value, and power supply from the road surface side power supply apparatus 20 to the electric vehicle 26 is started at the predicted transmission power value.

The case of “vehicle type A” will be described as an example using the map of FIG. 2. The point at which the power supply efficiency becomes maximum in the above-mentioned “optimal power supply efficiency” region (hatched portion of the right-upward oblique line) is “η _max ”. The transmission power value (power) corresponding to this is set to “P _in _0”. Using this transmission power value “P _{in —} 0” as a default transmission power value, power supply from the road surface side power supply apparatus 20 to the electric vehicle 26 is started.

Next, in step S04, the electric power value that the electric vehicle 26 that has received the microwaves converted into DC power is transmitted to the road surface side power feeding device 20 through the transceivers 24 and 32 as “P _{out —} 0”. In response to this, in step S05, the road surface side power supply apparatus 20 uses “P _in _0” calculated in step S03 and “P _out _0” received from the electric vehicle in step S04, thereby supplying a default power supply. Efficiency “η_0” is calculated (step S05).

  Here, in the present invention, the power feeding efficiency “η_0” is set using the transmission power from the road surface side power feeding device 20 for each setting of the microwave receiving system (configuration of the rectenna 27) that is changed in advance depending on the type of the electric vehicle 26. At the time of calculation, the setting of the microwave receiving system including the configuration of the rectenna 27 in the electric vehicle 26 is determined from the vehicle information such as the vehicle type of the electric vehicle 26 to be fed, and within the transmission power range obtained from the determination result The power supply method is to transmit power to the electric vehicle 26 with the calculated maximum value of the power supply efficiency as the optimal power supply efficiency.

  In addition, when the electric power is supplied from the road surface side power supply device 20 to the electric vehicle 26, the range of the optimum electric power supply efficiency set in advance is maintained in consideration of the variation of each electric vehicle 26 and the amount of stored electricity (SOC). Power is supplied at the maximum power value in the transmission power region. Thereby, the power feeding efficiency from the road surface side power feeding apparatus 20 to the electric vehicle 26 can be increased, and rapid power feeding is also possible.

In step S06, it is determined whether or not the calculated power supply efficiency “η_0” corresponds to the maximum power supply efficiency value “η _max ” set in the power supply apparatus 20 as shown in FIG. That is, it is determined whether or not the power supply efficiency “η_0” is equal to the maximum power supply efficiency value “η _max ”. However, in consideration of the effects of variations in individual vehicles in the electric vehicle 26, the impedance of the power storage mechanism 28 in FIG. 1, deterioration with time, etc., a specified width S [%] is given as shown in FIG. The difference (“η_0” − “η _max ”) only needs to be within the specified width S that is the variation.

The value of the specified width S [%] is expected to vary depending on the setting of the microwave receiving system on the electric vehicle 26 side (particularly, the configuration of the rectenna 27 and the performance variation of the rectenna 27 alone), but is generally 3 to 10 [ %]. If the power supply efficiency “η_0” does not fall within S [%] with respect to the maximum power supply efficiency “η _max ” in step S06 (step S06; No), it is determined that the vehicle is defective and power supply is stopped (step S061). .

  Next, a process of deriving a transmission power value most suitable for the electric vehicle 26 in consideration of individual variation for each electric vehicle 26 to be fed will be described with reference to a flowchart of FIG. Here, when power is supplied from the road surface side power supply device 20 to the electric vehicle 26, the vehicle information of the vehicle type is transmitted from the electric vehicle 26 to be supplied to the road surface side power supply device 20, and the road surface side power supply device 20 A microwave is transmitted with transmission power capable of maintaining “optimum power supply efficiency” based on vehicle information. Since this vehicle information includes information on the configuration of the rectenna 27, the radiation range of the microwave can be determined.

  The electric vehicle 26 that has received the transmitted microwave transmits the received power value to the road surface side power supply device 20 via the first transmitter / receiver 32 and the second transmitter / receiver 24 built in the electric vehicle 26 side, The road surface side power feeding device 20 calculates power feeding efficiency from the transmission power value transmitted by the road surface side power feeding device 20 and the received power value received from the electric vehicle 26, and the calculated power feeding efficiency value becomes the optimum power feeding efficiency value. On the other hand, the transmission power is controlled so that the power region falls within a predetermined range.

Hereinafter, it demonstrates with a figure. For the first task only, in step S07 in FIG. 3, the power supply apparatus 20 sets the transmission power value “P _in —0” set as default in step S03 and the power supply efficiency value “η_0” calculated in step S05 to “ _{P in _0 → P in _n-} 1 ", it performs the initialization as" η_0 → η_n-1 ".

In step S08, the transmission power is set to “P _in _L”, and the electric power is supplied to the electric vehicle 26 by reducing the transmission power value “P _in _n−1” of the immediately preceding task by ΔP _in . The power feeding apparatus 20 obtains the received power value information “P _out _L” in the electric vehicle 26 when the transmission power value “P _in _L” is transmitted via the transceivers 24 and 32 in FIG. 1 (step S09). From these values (P _in _L and P _out _L), the power supply efficiency “η_L” during power reduction is calculated (step S10).

The value of the reduced amount ΔP _in is expected to vary depending on the setting of the microwave reception system on the electric vehicle side 26 (particularly the configuration of the rectenna 27 and the performance of the rectenna 27 alone), the setting variable width in the power supply device 20, and the like. The Of course, finer transmission power accuracy can be obtained by setting the reduced amount ΔP _in to a smaller value. For example, when ΔP _in is set to about 1 [%] of “P _{in —} 0” which is the transmission power (power) corresponding to the power supply efficiency maximum point “η _max ” in FIG. 2, the transmission power is the reciprocal thereof, that is, 100 It is thought that it becomes possible to control with the accuracy of the level.

In step S11, it determines whether the power supply efficiency "η_L" when the reducer only [Delta] P _in, feed efficiency "η_n-1" in the previous immediately preceding task decreased [Delta] P _in power is greater than. If η_L is larger (S11; Yes), the “maximum power supply efficiency η _max ” is set on the ΔP _in power reduction side, that is, on the transmission power side smaller than the transmission power “P _in _n−1” set in the immediately preceding task. There should be. As described above, the power conversion efficiency of the microwave power receiving element (rectenna) 27 is qualitatively expressed as “input power-RF / DC conversion efficiency” shown in FIG. Based on the grounds of showing a tendency to “convex upward”. Therefore, the transmission power “P _in _n” _in the current task is corrected to “P _in _L”, and the power supply efficiency “η_n” is corrected to “η_L” (step S12). Thereafter, it is determined whether or not the charged amount SOC of the power storage mechanism 28 in the electric vehicle 26 has reached a specified value “Cp” that is an operable range (step S13). In addition, since it is considered that there is a feeding power point corresponding to “maximum feeding efficiency η _max ” on the power reducing side with respect to the feeding power in the current task, the sequence of steps S08 to S131 is performed until the maximum feeding efficiency point is reached. Move to the repeating phase. However, in step S13 in the process, when the stored amount SOC of the power storage mechanism 28 becomes equal to or greater than the specified value “Cp”, it is determined that the power supply is completed and ends (END). The specified value “Cp” is set in the range of 0 to 100% depending on the state of the electric vehicle from moment to moment.

In the step S11, if [Delta] P _in is the power supply efficiency "η_L" when the reduced power only was powered efficiency "η_n-1" or less before the immediately preceding task decreased [Delta] P _in force (S11; No), In step S111, the transmission power is set to “P _in _H”, and the transmission power value “P _in _n−1” of the immediately preceding task is increased by ΔP _in to supply power to the electric vehicle 26. The power feeding device 20 reads the received power value information “P _out _H” in the electric vehicle 20 when transmitting the increased transmission power “P _in _H” via the transceivers 24 and 32 (step After S112), the power supply efficiency “η_H” at the time of power reduction is calculated from these values (P _in _H and P _out _H) (step S113). Here, the definition of ΔP _in is the same as in the case of the reduction.

Then it determines in step S114, is the feed efficiency "η_H" when the energizing only [Delta] P _in, whether power supply efficiency "η_n-1" or more in the [Delta] P _in energizing just before the preceding tasks. If any η_H is η_n-1 or more (step S114; Yes), energizing side of the [Delta] P _in, i.e. the set "maximum power the larger transmission power side of the transmission power" P _in _n-1 "in immediately preceding task An efficiency η _max ”should exist. As described above, this means that “the power conversion efficiency of the microwave power receiving element (rectenna) 27 qualitatively shows a tendency of“ upwardly convex ”as shown in FIG. 5 with respect to the input power”. Based on evidence. Accordingly, the transmission power “P _in _n” _in the current task is corrected to “P _in _H”, and the power supply efficiency “η_n” is corrected to “η_H” (step S115). Thereafter, it is determined whether or not the storage amount SOC of the power storage mechanism 28 in the electric vehicle 26 has reached the specified value “Cp” (step S116), and the stored amount SOC is less than the specified value “Cp” (step S116; No). If it is, it is considered that there is a transmission power point corresponding to the “maximum power supply efficiency η _max ” on the power increase side with respect to the transmission power in the current task, and therefore the maximum power supply efficiency point (η _max ). The process proceeds to a phase in which the sequence of steps S111 to S1161 is repeated until the value reaches. However, in step S116 in the process, when the storage amount SOC of the power storage mechanism 28 is equal to or more than the specified value “Cp” (step S116; Yes), it is determined that the power supply is completed and ends (END). The specified value “Cp” is set in the range of 0 to 100% depending on the state of the electric vehicle from moment to moment.

In the foregoing step S114, if the power supply efficiency when the energizing only [Delta] P _in "η_H" is In the case of below the feed efficiency "η_n-1" in the [Delta] P _in energizing just before the preceding tasks (step S114; No) at the same time, there also; (No step S11) in step S11, said power supply efficiency "η_L" when the reducer only [Delta] P _in, if not more than feed efficiency "η_n-1" in the previous immediately preceding task decreased [Delta] P _in force Therefore, this means that the power supply efficiency “η_n−1” in the immediately preceding task has reached the value corresponding to “maximum power supply efficiency η _max ”.

Accordingly, since the transmission power “P _in _n−1” of the immediately preceding task becomes the optimal transmission power, power is supplied from the power supply device 20 to the electric vehicle 26 as the transmission power “P _in _n” of the current task (step S1141). The process proceeds to a phase in which the sequence of steps S1141 to S11451 is repeated. In step S1145 in the process, when the stored amount SOC of the power storage mechanism 28 is equal to or greater than the specified value “Cp” (step S1145; Yes), it is determined that the power supply is completed and ends (END).

In this phase, the transmission power basically remains unchanged at “P _in _n”, but in order to ensure safety at the time of power supply, the power supply device 20 uses the electric vehicle 26 at the time of transmission of the transmission power “P _in _n”. the "P _out _n" received power value information in, read via the transceiver 24 and 32 in FIG. 1 (step S1142) after calculating the power supply efficiency "η_n" during the reduced power from these values (step S1143 It is monitored whether or not the power supply efficiency value “η_n” is within the range of the specified value S [%] with respect to the “maximum power supply efficiency η _max ” specified in FIG. S1144). If in step S1144 the power supply efficiency is still lower than the specified value variation range, it is determined that some trouble has occurred on the electric vehicle 26 side, power supply is stopped (step S11441), and the process is terminated.

  In this way, paying attention to the property of the setting of the microwave power receiving system mounted on the electric vehicle 26 (particularly the configuration of the rectenna 27 and the performance of the rectenna 27 alone), the corresponding transmission power within the “optimum power supply efficiency” region. By performing optimal control at, loss due to leakage waves in the wireless transmission region can be kept to a minimum, and the power supply efficiency from the power supply device 20 to the electric vehicle 26 can be increased.

(Embodiment 2)
The system configuration in the second embodiment is the same as that in the first embodiment, and therefore FIGS. 1A and 1B are used. Further, the second embodiment differs from the first embodiment mainly in the process until the power supply device 20 determines the vehicle type of the electric vehicle 26 to which power is supplied and starts power supply based on the determination result. Therefore, the process will be described with reference to the flowchart of FIG. Further, as a vehicle type (vehicle grade) in the electric vehicle 26 to be supplied with power, “vehicle type A” shown in FIG. 2 is assumed, and this will be described as an example.

  In the second embodiment, the power feeding method is based on the following procedure. That is, when power supply is started, the electric vehicle 20 to be supplied with power supplies the road surface side power supply device 20 with the optimum power supply efficiency value of the electric vehicle 26 from the first transceiver 32 shown in FIG. To the second transceiver. The road-side power supply device 20 determines the vehicle type of the electric vehicle 26 and the setting of the microwave reception system, that is, the receivable power based on the configuration of the rectenna 27, based on the transmitted optimal power supply efficiency value. A microwave is transmitted with transmission power based on.

  The electric vehicle 26 that has received the microwave transmits the received power value to the second transmitter / receiver installed in the road surface side power feeding device 20 via the first transmitter / receiver. In the road surface side power feeding device 20, the power feeding efficiency is calculated from the power value transmitted from the road surface side power feeding device 20 and the received power value transmitted from the first transmitter / receiver of the electric vehicle 26, and the calculated power feeding efficiency value is obtained. The transmission power is controlled so as to be in a power region that falls within a range of a preset optimum power supply efficiency value.

This procedure will be specifically described below with reference to the flowchart of FIG.
In step T01, the power feeding device 20 reads the maximum power feeding efficiency value η_P of the electric vehicle 26 preset in the electric vehicle 26 to be fed using the transceivers 24 and 32 shown in FIG. This η_P is a value that has been clarified in advance by, for example, measurement during the production process for each electric vehicle 26, that is, individual variations in the vehicle are included.

  In step T02, the road surface side power feeding device 20 uses the “transmission power-power feeding efficiency relationship” (FIG. 2) stored in the power feeding device 20 in advance from the maximum power feeding efficiency value η_P, and the vehicle type of the electric vehicle 26 to be fed. (Vehicle size) and setting of the microwave receiving system, that is, the receivable power based on the configuration of the rectenna 27 is determined.

Next, _{in order} to determine the default transmission power “P _in _P” from the road surface side power supply device 20 to the electric vehicle 26, the maximum power supply efficiency value η_P and a vehicle (vehicle case) corresponding to the electric vehicle 26 in advance in FIG. Is compared with the maximum power supply efficiency value η _max in the “optimal power supply” region set for (step T03). FIG. 7 shows an enlargement of the “optimum power supply efficiency” area of “vehicle type A” in FIG. In step T03, when η_P is equal to or greater than η _max (the power feeding efficiency of the electric vehicle 26 is superior to the level of the maximum power feeding efficiency value), “η_P = η _max ” as shown in FIG. Instead, power supply to the electric vehicle 26 is started with the transmission power value P _{in —} 0 corresponding to η _max on the maps of FIG. 2 and FIG. 7 as the default transmission power (transmission power) P _{in —} P of the power feeding device (step T04). . When the η_P is less than the η _max (the power feeding efficiency of the electric vehicle 26 is lower than the level), the transmission power values P _in _a and P _in _b corresponding to the η_P as shown in FIG. Then, power supply to the electric vehicle 26 is started with P _in _a on the low power side as default transmission power P _in _P (step T031).

In step T05, as in step S04 (see FIG. 3) in the first embodiment, the transmitter / receiver 24 and 32 are set with the power value converted into DC power by the electric vehicle 26 receiving the microwave as “P _{out —} 0”. To the road surface side power supply device 20. In response to this, in step T06, the road surface side power supply apparatus 20 receives the default transmission power “P _in _P” calculated in step T04 or step T031, and “P _out _0” received from the electric vehicle 26 in step T05. Is used to calculate the default power supply efficiency “η_0” (step T06).

In Step T07, it is determined whether or not the calculated default power supply efficiency “η_0” corresponds to the maximum power supply efficiency value “η _max ” set in the power supply apparatus 20 as shown in FIG. However, in consideration of the influence of the individual vehicle variation in the electric vehicle 26, the impedance of the power storage mechanism 28 in FIG. 1 or the deterioration with time, etc., as shown in FIGS. As long as it is within the specified width S. The value of the specified width “S” is expected to vary depending on the setting of the microwave reception system on the electric vehicle 26 side (particularly, the configuration of the rectenna 27 and the performance of the rectenna 27 alone), but about 3 to 10%. it is conceivable that.

If the power supply efficiency “η — 0” does not fall within S [%] with respect to the maximum power supply efficiency “η _max ” in step T07 (step T07; No), it is determined that the vehicle is defective and power supply is stopped by warning processing ( Step T071). By this processing, it is possible to inspect and confirm whether or not the configuration of the rectenna 27 mounted on the electric vehicle 26 is functioning at the maximum power supply efficiency “η_P” preset in the electric vehicle 26.

  Following this process, the process of deriving the transmission power value most suitable for the electric vehicle 26 in consideration of individual variations in the electric vehicle 26 to be fed is the same as that of the first embodiment, and is similar to that of FIG. It operates by connecting from step T08 to step S08 of FIG.

In this way, by paying attention to the property of the setting of the microwave receiver mounted on the electric vehicle (the configuration of the rectenna 27), optimal control is performed with the corresponding transmission power within the “optimum power supply efficiency” region. The loss due to the leakage wave in the wireless transmission area can be minimized, and the power supply efficiency from the power supply device 20 to the electric vehicle 26 can be increased.
In addition, after the start of power supply, the power supply efficiency is calculated every moment by obtaining the received power value information from the electric vehicle 26, and the road surface side power supply apparatus is compared with the calculated power supply efficiency value and the optimum power supply efficiency value. Therefore, it is possible to optimally control the transmission power from 20 to the electric vehicle 26, so that loss due to leakage waves in the wireless transmission region can be minimized and the power supply efficiency from the power supply device to the electric vehicle can be increased. it can.

  Furthermore, in the second embodiment, the maximum power supply efficiency value is stored in the electric vehicle 26 to be supplied with power, so it is considered that the power supply efficiency is quite good with the default transmission power, and the optimum transmission power is reached. It is considered that there is a merit that the number of tasks up to and the control response is improved as a result.

(Embodiment 3)
Since the mechanical configuration of the third embodiment is the same as that of the first and second embodiments, the description will be made with reference to FIG. 1 as it is, with a focus on differences from the first and second embodiments. To do. That is, FIG. 1A is a schematic view of the third embodiment viewed from above, and similarly, FIG. 1B is a schematic view of the third embodiment viewed from the side.

  The power supply method according to the third embodiment uses the following procedure as a basic method. When the road surface power supply device 20 supplies power to the electric vehicle 26, first, the electric vehicle 26 is mounted on the electric vehicle 26 with the optimal power supply efficiency value of the electric vehicle 26 from the electric vehicle 26 to be supplied to the road surface power supply device 20. Is transmitted from the transmitter / receiver 32 to the second transmitter / receiver 24 installed in the road surface side power supply device 20. Next, the road surface side power feeding device 20 determines the vehicle type of the electric vehicle 26 and the setting of the microwave receiving device, that is, the receivable power according to the configuration of the rectenna 27 based on the transmitted optimum power feeding efficiency value. The power feeding device 20 transmits microwaves with transmission power based on the determination result, and at the same time, the road surface side power feeding device 20 transmits the transmission power value to the first transmission / reception device 26 mounted on the electric vehicle 26 via the second transceiver 24. To the device 32.

  In the electric vehicle 26 that has received the microwave, the power supply efficiency value is calculated from the transmission power value from the road surface side power supply device 20 and the actual received power value of the transmitted microwave, and the calculation result is used as the road surface side power supply device. Power to the second transmitter / receiver installed at 20 via the first transmitter / receiver, and the road surface side power supply device 20 supplies power as a calculation result transmitted from the first transmitter / receiver of the electric vehicle 26. In this method, the transmission power is controlled so that the efficiency value falls within a predetermined power range with respect to the optimum power supply efficiency value.

Hereinafter, flowcharts of a method for supplying power to the electric vehicle 26 using the microwave based on the third embodiment are shown in FIGS. 8 and 9, and will be described.
First, the process until the road surface side power supply apparatus 20 determines the electric vehicle 26 to be supplied and starts power supply based on the determination result will be described with reference to the flowchart of FIG. In addition, as a vehicle type (vehicle grade) in the electric vehicle 26 to be supplied with power, a “vehicle type A” shown in FIG. 2 is assumed and described.

  In step U01, the road surface side power feeding apparatus 20 reads the maximum power feeding efficiency value η_P preset in the electric vehicle 26 to be fed using the transceivers 24 and 32 shown in FIG. This η_P is a value that is clarified by, for example, measurement in the production process for each electric vehicle 26, that is, an individual variation for each electric vehicle 26 is taken into consideration.

  In Step U02, the road surface side power feeding device 20 uses the maximum power feeding efficiency value “η_P” preset in the electric vehicle 26 to store the “transmission power-feeding efficiency relationship” (FIG. 2) stored in the road surface side power feeding device 20 in advance. It is used to determine the type (vehicle grade) of the electric vehicle 26 to be fed and the setting of the microwave reception system (receivable power based on the configuration of the rectenna 27).

Next, _{in order} to determine the default transmission power “P _in _P” from the power supply device 20 to the electric vehicle 26, the maximum power supply efficiency value “η_P” preset in the electric vehicle 26 and the electric vehicle 26 corresponding to FIG. The maximum power supply efficiency value η _max in the region of “optimum power supply efficiency” stored in advance for the vehicle type (vehicle grade) is compared (step U03). FIG. 7 shows an enlargement of the “optimum power supply efficiency” area of “vehicle type A” in FIG. In step U03, when “η_P” is equal to or greater than “η _max ”, that is, the power supply efficiency of the electric vehicle 26 is superior to the level of the maximum power supply efficiency value in the region of the optimum power supply efficiency) 7, the transmission power value “P _{in —} 0” corresponding to “η _max ” on the map of FIG. 2 and FIG. 7 is replaced with the default transmission power P _in of the road surface side power supply device 20 by replacing “η_P = η _max ”. Power supply to the electric vehicle 26 is started as _P (step U04).

When the “η_P” is less than the “η _max ” (the power supply efficiency of the electric vehicle is lower than the above level), the transmission power value P _in _a corresponding to the η_P as shown in FIG. of P _in _b, the starts feeding to the electric vehicle 26 to P _in _a a low power side as the default transmission power P _in _P (step U031). At the same time, the road surface side power supply apparatus 20 transmits the default transmission power value P _in _P information to the electric vehicle 26 using the transceivers 24 and 32 shown in FIG. 1 (step U05). The electric vehicle 26 that has received the microwave calculates a power supply efficiency value “η — 0” using the power value converted into DC power, and transmits the power supply efficiency value “η_0” to the road surface side power supply device 20 via the transceivers 24 and 32 (step U06). ).

  In step U07, it is determined whether or not the power supply efficiency value “η_0” calculated by the electric vehicle 26 and received by the road surface side power supply device 20 is equivalent to the maximum power supply efficiency value “η_P” stored in the electric vehicle 26. . However, in consideration of the influence of individual variations in the electric vehicle 26, the impedance of the power storage mechanism 28 in FIG. 1 or the deterioration with time, etc., S [%] is given as the specified width as shown in FIGS. As long as it is within this variation.

As in the first and second embodiments, the value of the specified width “S” is different depending on the setting of the microwave reception system on the electric vehicle 26 side (particularly, the configuration of the rectenna 27 and the performance of the rectenna 27 alone). Although expected, it is considered to be about 3 to 10%. If the power supply efficiency “η_0” does not fall within S [%] with respect to the maximum power supply efficiency “η _max ” stored in the electric vehicle 26 in step U07 (step U07; No), it is determined that the vehicle is defective. Then, power supply is stopped in the warning process (step U071). By this processing, it is possible to inspect and confirm whether or not the power reception system (the configuration of the rectenna 27) of the electric vehicle 26 is functioning at the maximum power supply efficiency “η_P” preset in the electric vehicle 26. .

Next, the process of deriving the transmission power value most suitable for the vehicle in consideration of individual variations in the electric vehicle 26 to be fed will be described with reference to the flowchart of FIG.
Only first task, the road-side power supply device 20 in step U08, the step U04, or step transmission power value defaults by U031, respectively "P _in _P → P _in the calculated power supply efficiency value in step S07 _n-1 "and" η_0 → η_n-1 "are initialized.

In step U09, the transmission power of the road surface side power supply apparatus 20 is set to “P _in _H”, and the electric power is supplied to the electric vehicle 26 by increasing the transmission power value “P _in _n−1” of the immediately preceding task by ΔP _in . At the same time, the road surface side power supply apparatus 20 transmits the transmission power value P _in _H information to the electric vehicle 26 using the transceivers 24 and 32 shown in FIG. 1 (step U10). The electric vehicle 26 that has received the microwave calculates a power supply efficiency value “η_H” using the power value converted into DC power, and transmits the power supply efficiency value “η_H” to the road surface side power supply device 20 via the transceivers 24 and 32 (step U11). ). The definition of ΔP _{in is} the same as that _in the first embodiment.

Then determines in step U12, said power supply efficiency "η_H" when the energizing only [Delta] P _in, whether power supply efficiency "η_n-1" or more in the [Delta] P _in energizing just before the preceding tasks. If if "η_H" is "η_n-1" or more (U12; Yes), ΔP _in energizing side, that is, greater transmission power side of the transmission power set at just before the task "P _in _n-1", " There should be a “maximum feed efficiency η _max ”. This is because, as described above, “the power conversion efficiency of the microwave power receiving element (rectenna 27) qualitatively shows a tendency of“ upwardly convex ”as shown in FIG. 5 with respect to the input power”. Based on evidence. Accordingly, the transmission power “P _in _n” _in the current task is corrected to “P _in _H”, and the power supply efficiency “η_n” is corrected to “η_H” (step U13). Thereafter, it is determined whether or not the storage amount SOC of the power storage mechanism 28 in the electric vehicle 26 has reached a specified value “Cp” as the storage amount that the electric vehicle 26 can be operated (step U14). (Step U14; No) Further power feeding is required, and it is considered that there is a transmission power point corresponding to the “maximum power feeding efficiency η _max ” on the boost side from the transmission power in the current task. The process proceeds to a phase in which the sequence of step U09 to step U141 is repeated until it reaches. However, in step U14 in the process, when the charged amount SOC of the power storage mechanism 28 becomes equal to or more than the specified value “Cp” (step U14; Yes), it is determined that the power supply is completed and ends (END).

When in the foregoing step U12, if the power supply efficiency when the energizing only [Delta] P _in "η_H" was less than the feed efficiency "η_n-1" in the [Delta] P _in energizing just before the preceding tasks (step U12; No), the power supply Even if the transmission power is increased for the purpose of shortening the time or the like, the power supply efficiency is decreased. As a result, the reception power in the electric vehicle 26 is decreased or the leakage wave of the microwave outside the vehicle is increased. To do. Accordingly, the transmission power “P _in _n−1” of the immediately preceding task is determined as the optimum transmission power, and is set to the transmission power “P _in _n” of the current task to supply power to the electric vehicle 26 from the power supply device 20 ( Step U121). The process proceeds to a phase in which the sequence of steps U121 to U1251 is repeated. In step U125 in the process, when the charged amount SOC of the power storage mechanism 28 is equal to or greater than the specified value “Cp” (step U125; Yes), it is determined that the power supply is completed and ends (END). The definition of Cp is the same as described above.

In this phase, the transmission power basically remains unchanged at “P _in _n”, but in order to ensure safety during power supply, the electric vehicle 26 determines the power supply efficiency for each task from the received power value in the vehicle. It is calculated and transmitted as “η_n” to the road surface side power supply device 20 via the transceivers 24 and 32 (step U123), and this power supply efficiency value “η_n” is defined as “maximum power supply efficiency η _max ”Is monitored whether it is less than the specified width S [%] (step U124). If the power supply efficiency falls below the specified value in step U124 (step U124; No), it is determined that some trouble has occurred on the electric vehicle 26 side, and power supply is stopped (step U1241).

  In this way, paying attention to the characteristics of the setting of the microwave power receiving system mounted on the electric vehicle 26 (the configuration of the rectenna 27 and the performance of the rectenna 27 alone), the transmission power corresponding in the “optimum power supply efficiency” region. By performing optimal control, loss due to leakage waves in the wireless transmission region can be minimized, and the power supply efficiency from the road surface side power supply device 20 to the electric vehicle 26 can be increased. Further, in the third embodiment, since each electric power supply target electric power vehicle 26 stores the maximum power supply efficiency value, it is considered that the power supply efficiency is considerably good with the default transmission power, and transmission is performed as shown in FIG. Control logic is simplified by performing optimal power control only on the booster side. In addition, in the third embodiment, since it is possible to calculate the power supply efficiency by obtaining the transmission power value information from the road surface side power supply device 20 on the electric vehicle 26 side, the power supply efficiency is also grasped on the electric vehicle 26 side. There is a merit that it can be done.

  In the first to third embodiments, the power to be received is optimized after determining the receivable power based on the vehicle type to be fed and the configuration of the rectenna 27 in advance. It is possible to supply power to multiple vehicle types with just the device. Furthermore, “optimum power supply efficiency” is calculated from the vehicle type (vehicle case) information, and after the start of power supply, the received power value information is obtained from the electric vehicle 26 to calculate the power supply efficiency every moment, and the calculated power supply efficiency value and By comparing the optimum power feeding efficiency values, it becomes possible to optimally control the transmission power from the road surface side power feeding device to the electric vehicle 26. Therefore, the loss due to the leakage wave in the radio transmission region is minimized, and the power feeding is performed. Power supply efficiency from the device to the electric vehicle can be increased. As described above, in the present invention, control is performed so as to minimize loss due to leakage waves in the radio transmission region due to microwaves, and therefore, safety against exposure of microwaves to human bodies and living organisms outside the vehicle is also particularly high. improves.

The system block diagram by this invention, (a) A figure is the top view seen from upper direction, (b) The figure is a side view seen from the side. Transmission power-power supply efficiency relationship diagram. FIG. 3 is a flowchart showing the first embodiment. FIG. 4 is a flowchart showing the first embodiment following FIG. 3. Input-RF / DC conversion efficiency relationship diagram. FIG. 5 is a flowchart showing Embodiment 2. The enlarged view of the optimal electric power feeding efficiency area | region of the vehicle type A. FIG. FIG. 9 is a flowchart showing Embodiment 3. FIG. 9 is a flowchart showing the third embodiment following FIG.

Explanation of symbols

20: Road surface side power supply device 21: Infrastructure side power supply line 22: Microwave generation unit 23: Microwave transmission antenna group 24: Transceiver 25: Microwave transmission antenna control circuit 26: Electric vehicle 27: Rectenna 28: Power storage mechanism 29: Motor generator 30: DC / DC converter 31: Storage battery for vehicle electrical system 32: Transmitter / receiver 33: Control circuit

Claims (7)

Used in a microwave power transmission system equipped with a microwave transmission antenna that radiates microwaves from a road-side power supply device that is a power supply source toward an electric vehicle that is supplied with power by microwaves received via a reception antenna A method for supplying power to the electric vehicle,
When supplying power to the electric vehicle from the road surface side power supply device,
The road surface side power supply device receives vehicle information from the electric vehicle,
Based on the vehicle information, the transmission power from the microwave transmission antenna of the road surface side power supply apparatus is optimally controlled using the “transmission power-power supply efficiency” relationship that is set in advance in the road surface side power supply apparatus. To do,
A method for supplying power to an electric vehicle using microwaves. In the electric power feeding method to the electric vehicle using the microwave according to claim 1,
The road surface side power feeding device receives vehicle information of the electric vehicle to be fed,
Controlling the transmission power to the electric vehicle so as to be within a transmission power range in which the optimum power supply efficiency inherent to the vehicle information is maintained;
A method for supplying power to an electric vehicle using microwaves. In the electric power feeding method to the electric vehicle using the microwave according to claim 2,
When calculating the power supply efficiency using the transmission power from the road surface side power supply device,
The configuration of the rectenna that is the microwave receiving system in the electric vehicle is determined from the vehicle information of the electric vehicle to be supplied with power, and the calculated maximum value of the power supply efficiency within the transmission power range obtained from the determination result The optimal power supply efficiency,
The method for feeding power to an electric vehicle using the microwave according to claim 2. In the electric power feeding method to the electric vehicle using the microwave according to claim 3,
When supplying electric power to the electric vehicle with the road surface side power supply device, the maximum electric power value in the transmission power region that maintains the predetermined range of the “optimum electric power supply efficiency” in consideration of individual variation of the electric vehicle and the amount of stored electricity To supply power at
A method for feeding power to an electric vehicle using the microwave according to claim 3. In the electric power feeding method to the electric vehicle using the microwave according to claim 4,
When supplying power to the electric vehicle from the road surface side power supply device,
Transmitting vehicle information of the vehicle type from the electric vehicle to be fed to the road surface side feeding device,
The road surface side power supply device transmits a microwave with transmission power capable of maintaining the "optimum power supply efficiency" based on the vehicle information,
The electric vehicle that has received the microwave transmits a received power value to a second transmitter / receiver built in the road surface side power feeding device via a built-in first transmitter / receiver,
The road surface side power supply device calculates power supply efficiency from the transmission power value transmitted by the road surface side power supply device and the received power value transmitted from the electric vehicle, and the calculated power supply efficiency value is the optimum power supply efficiency value. In contrast, the transmission power is controlled to be in a power region that falls within a predetermined range;
A method for supplying power to an electric vehicle using microwaves. In the electric power feeding method to the electric vehicle using the microwave according to claim 4,
When supplying power to the electric vehicle with the road surface side power supply device,
The electric vehicle to be fed transmits the optimum power feeding efficiency value of the electric vehicle to the road surface side power feeding device via the first transceiver mounted on the electric vehicle,
The road surface side power supply device determines the vehicle type of the electric vehicle and the setting of the microwave receiving system from the transmitted optimal power supply efficiency value,
The road surface side power supply device transmits a microwave with transmission power based on the determination result,
The electric vehicle that has received the microwave transmits the received power value to the second transmitter / receiver installed in the road surface side power feeding device via the first transmitter / receiver,
The road surface side power supply device calculates the power supply efficiency from the transmission power value in the road surface side power supply device and the received power value transmitted from the first transceiver of the electric vehicle,
Controlling the transmission power so that the calculated power supply efficiency value falls within a predetermined power range with respect to the optimum power supply efficiency value;
The power feeding method to the electric vehicle using the microwave according to claim 4. In the electric power feeding method to the electric vehicle using the microwave according to claim 4,
When supplying power to the electric vehicle with the road surface side power supply device,
The optimal power supply efficiency value of the electric vehicle is transmitted from the electric vehicle to be supplied to the road surface side power supply device by the first transmitter / receiver mounted on the electric vehicle,
The road surface side power supply device determines the vehicle type of the electric vehicle and the setting of the microwave receiving system from the optimum power supply efficiency value,
The road surface side power feeding device transmits a microwave with transmission power based on the determination result, and at the same time, the road surface side power feeding device transmits the transmission power value via the second transmitter / receiver installed in the road surface side power feeding device. To the first transceiver on the vehicle,
The electric vehicle that has received the microwave calculates a power supply efficiency value from the transmission power value from the road surface side power supply device and the received power value of the microwave that has been transmitted, and the calculation result is used as the road surface. To the second transmitter / receiver installed in the side power supply device,
The road surface side power supply device is a power region in which a power supply efficiency value as the calculation result transmitted from the first transmitter / receiver of the electric vehicle falls within a predetermined range with respect to the optimum power supply efficiency value. Controlling the transmission power as follows:
A method for supplying power to an electric vehicle using microwaves.

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