JP7180534B2 - Contactless power supply system and its control method - Google Patents

Description

The present disclosure relates to technology for contactlessly supplying power to a mobile body.

Patent Document 1 discloses a power supply device that supplies electric power to a vehicle, which is a mobile object that travels in a predetermined direction, in a contactless manner. It is disclosed that power is supplied continuously by switching in accordance with the movement of the . Specifically, when even a part of the power receiving coil intrudes into the coil plane of the power transmitting coil, the power transmitting coil is switched, and power is transmitted by the power transmitting coil that has penetrated. Further, it is disclosed that by enlarging the coil surface area of the power transmission coil in a direction other than a predetermined direction, a decrease in power supply efficiency is suppressed when the traveling direction of the vehicle deviates.

Japanese Patent No. 6221460

However, in the switching method of the power transmission coil, the power transmission coil may be switched even when the power reception coil does not directly face the power transmission coil. There is a problem that the power demanded by the body is not met and the power control of the mobile body is adversely affected.

According to one aspect of the present disclosure, a power supply device (100) and a power receiving device (205) mounted on a mobile body (200) and whose position relative to the power supply device varies, A contactless power supply system is provided in which power is supplied from a power supply device to the power receiving device in a contactless manner. In this contactless power supply system, the power receiving device includes a power receiving resonance circuit (210) including at least one power receiving coil (212). The power supply device includes a plurality of segments (Seg) having a power transmission resonance circuit (110) including at least one power transmission coil (112) that transmits power to the power reception device via the power reception coil, and power transmission to the power reception device. By comparing the information about the power supplied to the power transmitting coil in the segment for transmitting the a control device (140) for controlling an operation, wherein the control device controls the operation according to a result of comparing the information about the power in the segment where the power transmission is continued and the information about the power in the segment where the power transmission is stopped. estimating the relative positional relationship between the power transmitting coil of the segment for continuing power transmission and the power receiving coil of the power receiving device, and determining the switching timing between the segment for stopping power transmission and the segment for starting power transmission according to the estimation result; decide .
According to this contactless power supply system, by comparing the information about the power supplied to the power transmission coil in the segment that transmits power to the power receiving device, the segment that continues power transmission to the power receiving device and the segment that stops power transmission. The segment and the operation of the segment that initiates transmission can be controlled. As a result, for example, in a state in which the power receiving coil faces the power transmitting coil, it is possible to appropriately switch between a segment for stopping power transmission and a segment for starting power transmission. can be suppressed.

According to another aspect of the present disclosure, power is supplied from a power supply device (100) to a power receiving device (205) that is mounted on a mobile body (200) and whose position relative to the power supply device changes in a non-contact manner. A control method for a contactless power supply system to which is supplied is provided. The power receiving device comprises a power receiving resonant circuit (210) including at least one power receiving coil (212). The power supply device comprises a plurality of segments (Seg) having a power transmission resonant circuit (110) including at least one power transmission coil (112) for power transmission to the power reception device via the power reception coil. In the control method for the contactless power supply system, a segment for continuing power transmission to the power receiving device by comparing information about power supplied to the power transmission coil in a segment for power transmission to the power receiving device; According to the result of comparing the information about the power in the segment in which the power transmission is to be continued and the information about the power in the segment in which the power transmission is to be stopped, estimating a relative positional relationship between the power transmitting coil of the segment for continuing the power transmission and the power receiving coil of the power receiving device, and switching timing between the segment for stopping the power transmission and the segment for starting the power transmission according to the estimation result; to decide .
According to this control method of the contactless power supply system, by comparing the information on the power supplied to the power transmission coil in the segment for transmitting power to the power receiving device, the segment for continuing power transmission to the power receiving device and the power transmission coil are compared. It is possible to control the operation of the segment that stops transmission and the segment that starts transmission. As a result, for example, in a state in which the power receiving coil faces the power transmitting coil, it is possible to appropriately switch between a segment for stopping power transmission and a segment for starting power transmission. can be suppressed.

1 is a block diagram showing the overall configuration of a contactless power supply system; FIG. FIG. 2 is a block diagram showing one segment of a power feeder and a power receiver. FIG. 2 is an explanatory diagram showing an example of a positional relationship between a power feeding device and a power receiving device; FIG. 4 is an explanatory diagram showing the amount of power fluctuation according to the position of the power receiving coil with respect to the power transmitting coil; FIG. 5 is an explanatory diagram showing fluctuations in received power when the first position in FIG. 4 is the switching position; FIG. 5 is an explanatory diagram showing fluctuations in received power when the second position in FIG. 4 is the switching position; FIG. 4 is an explanatory diagram showing a comparison between the current of a segment for which power transmission is stopped and the current of a segment for which power transmission is continued; FIG. 5 is an explanatory diagram showing an example of switching timing determination processing; FIG. 9 is an explanatory diagram showing another example of the switching timing determination process; FIG. 9 is an explanatory diagram showing an example of the positional relationship between the power supply device and the power receiving device according to the second embodiment; FIG. 11 is an explanatory diagram showing an example of a positional relationship between a power feeding device and a power receiving device according to the third embodiment; FIG. 4 is an explanatory diagram showing a comparison between the current of a segment where power transmission is stopped and the current of a segment where power transmission is started; FIG. 4 is an explanatory diagram showing an example of switching timing correction processing; FIG. 5 is an explanatory diagram showing a specific example of switching timing correction; The block diagram which shows the whole structure of the non-contact electric power feeding system containing the electric power feeding apparatus of other embodiment.

A. First embodiment:
As shown in FIG. 1, the contactless power feeding system includes a power feeding device 100 installed on a road RS, and a power receiving device 205 mounted on a vehicle 200 running on the road RS as a moving body. It is a system capable of supplying electric power to the vehicle 200 for a period of time. Vehicle 200 is configured as, for example, an electric vehicle or a hybrid vehicle. In FIG. 1, the x-axis direction indicates the traveling direction of the vehicle 200, the y-axis direction indicates the width direction of the vehicle 200, and the z-axis direction indicates the vertically upward direction. The directions of the x, y, and z axes in other drawings to be described later are the same directions as in FIG.

The power supply device 100 includes a plurality of segments Seg, a power supply circuit 130 that supplies DC power to the plurality of segments Seg, and a control device 140 that controls operations of the plurality of segments Seg. Each segment Seg includes a power transmission resonance circuit 110 and a power transmission circuit 120 that supplies AC power to the power transmission resonance circuit 110 .

The power transmission resonance circuit 110 has a power transmission coil 112 installed on or in the road surface of the road RS, and a resonance capacitor (not shown). The power transmission coil 112 of each segment Seg is installed along the direction of travel of the vehicle 200 (also referred to as the "extending direction of the road RS").

The power transmission circuit 120 is a circuit that converts the DC power supplied from the power supply circuit 130 into high-frequency AC power and supplies the power transmission coil 112 of the power transmission resonance circuit 110 . A specific configuration example of the power transmission circuit 120 will be described later. The power supply circuit 130 is a circuit that supplies DC power to the power transmission circuit 120 . For example, the power supply circuit 130 is configured as an AC/DC converter circuit that rectifies an AC voltage of an external power supply and outputs a DC voltage.

Note that FIG. 1 shows four segments, the first segment Seg1 to the fourth segment Seg4, among a plurality of segments Seg. A state in which the receiving coil 212 of 205 is positioned is shown as an example.

The control device 140 controls the operation of the power transmitting circuit 120 of each segment Seg according to the position of the power receiving coil 212 with respect to the power transmitting coil 112 to control the switching of the segment for power transmission. The positional relationship of the power receiving coil 212 with respect to the power transmitting coil 112 is estimated, for example, based on the current measurement information DI supplied from the power transmitting circuit 120 to the power transmitting coil 112 in each segment Seg. The control device 140 supplies control information SD for controlling the operating state to the power transmission circuit 120 of each segment Seg so that the power transmission circuit 120 of each segment Seg is in the operating state suitable for the estimated positional relationship. Note that FIG. 1 shows a state in which measurement information DI1 to DI4 of the current supplied to each power transmission coil 112 from each power transmission circuit 120 of each of the first to fourth segments Seg1 to Seg4 is supplied to the control device 140. It is shown. Also, a state in which control information SD1 to SD4 is supplied to each power transmission circuit 120 is shown. The control device 140 controls switching of segments to which power is transmitted. The segment switching operation under the control of the control device 140 will be described later.

Vehicle 200 includes a power receiving device 205, a main battery 230, a motor generator 240, an inverter circuit 250, a DC/DC converter circuit 260, an auxiliary battery 270, an auxiliary device 280, and a control device 290. there is The power receiving device 205 has a power receiving resonance circuit 210 and a power receiving circuit 220 .

The power receiving resonance circuit 210 includes a power receiving coil 212 installed on the bottom surface of the vehicle 200 and a resonance capacitor (not shown). It is a device that obtains The coil surface of the power receiving coil 212 facing the power transmitting coil 112 side and the coil surface of the power transmitting coil 112 facing the power receiving coil 212 side have substantially the same size in the advancing direction. The coil surface is a surface surrounded by a loop-shaped wire and functioning as a loop-shaped coil. In FIG. 1, it is basically a surface along the xy plane. The power receiving circuit 220 is a circuit that converts AC power output from the power receiving resonance circuit 210 into DC power. A specific configuration example of the power receiving circuit 220 will be described later. The DC power output from power receiving circuit 220 can be used to charge main battery 230 as a load. The DC power output from power receiving circuit 220 can also be used to charge auxiliary battery 270 , drive motor generator 240 , and drive auxiliary device 280 .

Main battery 230 is a secondary battery that outputs DC power for driving motor generator 240 . Motor generator 240 operates as a three-phase AC motor and generates driving force for running vehicle 200 . Motor generator 240 operates as a generator during deceleration of vehicle 200 and generates three-phase AC power. Inverter circuit 250 converts the DC power of main battery 230 into three-phase AC power to drive motor generator 240 when motor generator 240 operates as a motor. When motor generator 240 operates as a generator, inverter circuit 250 converts the three-phase AC power output from motor generator 240 into DC power and supplies the DC power to main battery 230 .

DC/DC converter circuit 260 converts the DC voltage of main battery 230 into a lower DC voltage and supplies it to auxiliary battery 270 and auxiliary device 280 . Auxiliary battery 270 is a secondary battery that outputs DC power for driving auxiliary device 280 . Auxiliary device 280 is a peripheral device such as an air conditioner or an electric power steering device.

Control device 290 controls each part in vehicle 200 . Control device 290 controls power receiving circuit 220 to receive power when receiving contactless power supply while the vehicle is running.

One segment Seg of the power supply device 100 and the power receiving device 205 of the vehicle 200 are configured by the circuit shown in FIG. 2, for example. FIG. 2 shows an example of a state in which power is transmitted between the second segment Seg2 and the power receiving device 205 .

The power transmission resonance circuit 110 has a power transmission coil 112 and a resonance capacitor 116 connected in series. Similarly to the power transmission resonance circuit 110, the power reception resonance circuit 210 also has a power reception coil 212 and a resonance capacitor 216 connected in series. A primary-series-secondary-series capacitor system (also called “SS system”) is applied to the power transmission resonant circuit 110 and the power reception resonant circuit 210 . Further, a power transmitting side single-phase-power receiving side single phase non-contact power feeding system is applied in which the power transmitting side is configured with a single-phase power transmitting coil 112 and the power receiving side is configured with a single-phase power receiving coil 212 .

The power transmission circuit 120 includes an inverter circuit 122 that converts the DC power from the power supply circuit 130 into AC power, and a filter circuit 124 that reduces high frequency components higher than the fundamental frequency component of the AC power to be transmitted. As the filter circuit 124, a filter circuit such as an immittance conversion circuit, a low-pass filter circuit, or a band-pass filter circuit is used. Note that the filter circuit 124 can be omitted.

A current sensor SA for measuring the current flowing through the power transmission coil 112 is provided on one of a pair of wirings connecting the filter circuit 124 and the power transmission resonance circuit 110, and the result of measurement by the current sensor SA is provided as measurement information DI2. It is fed to controller 140 (FIG. 1). A voltage sensor SV that measures the voltage applied to the power transmission coil 112 is provided across the power transmission coil 112, and the result measured by the voltage sensor SV is supplied to the control device 140 as measurement information DV2. .

As will be described later, the control device 140 determines the operating conditions of the inverter circuits 122 of the segments Seg related to power transmission to the power receiving coil 212 based on the measurement information DV and DI acquired in the segments Seg related to power transmission to the power receiving coil 212 . Then, the control device 140 supplies control information SD for controlling the operating state of the inverter circuit 122 to the inverter circuit 122 of each segment Seg. Switching of the power transmission state of each segment Seg is executed depending on whether the inverter circuit 122 is in an operating state or in a stopped state.

The power receiving circuit 220 includes a filter circuit 224 that reduces frequency components higher than the fundamental frequency component of the received AC power, a rectifier circuit 226 that converts the AC power from the filter circuit 224 into DC power, and a main battery 230 for charging. A DC/DC converter circuit 228 is provided as a power conversion circuit that converts power to a suitable DC voltage. Similar to the filter circuit 124, the filter circuit 224 also uses a filter circuit such as an immittance conversion circuit, a low-pass filter circuit, or a band-pass filter circuit. Note that the filter circuit 224 can be omitted.

The following description is for the case where the vehicle 200 is running along the x direction, which is the traveling direction, and the power receiving coil 212 is passing over the power transmitting coil 112-2 of the second segment Seg2, as shown in FIG. will be described as an example. Further, while the second segment Seg2 is in the power transmission continuous state, the first segment Seg1 is switched from the power transmission state to the power transmission stopped state, and the third segment Seg3 is switched from the power transmission stopped state to the power transmission state. Also, the position where this switching is performed is referred to as a "switching position".

As shown in FIG. 4, the fluctuation amount of the power received by the power receiving device 205 changes depending on the position of the power receiving coil 212 in the traveling direction with respect to the second power transmitting coil 112-2. The amount of variation is the smallest when the center position of the coil surface of power receiving coil 212 coincides with the center position Pc of the coil surface of power transmitting coil 112-2. On the other hand, the center position of the coil surface of power receiving coil 212 is the front side (also referred to as “back side”) or rear side (“front side”) in the direction of travel from center position Pc of the coil surface of power transmission coil 112-2. ), the amount of fluctuation in the received power increases. In addition, below, the center position of the coil surface of a coil is also called simply "the center position of a coil." Further, the fact that the center position of power receiving coil 212 coincides with the center position Pc of power transmitting coil 112-2 corresponds to "power receiving coil 212 directly faces power transmitting coil 112-2". Note that “matching” includes a state in which the center position of power receiving coil 212 is within range R described below.

For example, as shown in FIG. 4, the switching position is a first position Ps1 on the front side of the traveling direction of a certain range R indicating a range equal to or less than the allowable fluctuation amount Pla preset as the allowable value of the electric power fluctuation amount. In this case, as shown in FIG. 5, the received power fluctuates greatly. In addition, the same applies when a position on the far side of the certain range R in the traveling direction is set as the switching position. On the other hand, if the second position Ps2 within a certain range R is set as the switching position, as shown in FIG. 6, fluctuations in received power can be reduced. The fixed range R is the range from the position (Pc-R/2) to the position (Pc+R/2) in the traveling direction (see FIG. 4).

When the center position of power receiving coil 212 is within a certain range R in the coil plane of power transmitting coil 112-2 in the traveling direction, the determination of the switching timing with that position as the switching position is performed, for example, as follows. is performed.

In the second segment Seg2 where the center position of power receiving coil 212 is above the coil surface of its own power transmitting coil 112-2 and power transmission continues (see FIG. 3), current I2 flowing through power transmitting coil 112-2 is , varies depending on the center position of the receiving coil 212, as shown in the lower part of FIG. That is, when the center position of power receiving coil 212 is nearer to range R in the direction of travel, it becomes larger as it approaches range R, and is the largest state within range R, more specifically, the largest state at center position Pc. becomes. Also, the current I2 decreases as the center position of the receiving coil 212 moves away from the range R.

On the other hand, the center position of the power receiving coil 212 moves away from the coil surface of its own power transmitting coil 112-1, and in the first segment Seg1 where power transmission is stopped (see FIG. 3), the current flowing in the power transmitting coil 112-1 As shown in the upper part of FIG. 7, I1 decreases as the center position of power receiving coil 212 in the traveling direction moves away. However, for the current I1 shown in the upper part of FIG. 7, in order to explain how the current flowing through the power transmitting coil 112-1 changes, the case where the power transmission of the first segment Seg1 is continued without being stopped is taken as an example. It is shown.

Therefore, focusing on the current I2 of the second segment Seg2 where power transmission is continued and the current I1 of the first segment Seg1 where power transmission is stopped, and comparing them, the central position of the power receiving coil 212 is is at a position within the range R or not. Then, at the timing when the center position of the receiving coil 212 is at the switching position within the range R, the first segment Seg1 is switched from the power transmission state to the stopped state, and the third segment Seg3 is switched from the stopped state to the power transmission state. can be done.

For example, by repeatedly executing the switching timing determination process shown in FIG. 8, the control device 140 can switch the operation of the first segment Seg1 for stopping power transmission and the third segment Seg3 for stopping power transmission. can. First, the current I2 of the second segment Seg2 that continues power transmission and the current I1 of the first segment Seg1 that stops power transmission are measured (step S12). Then, it is determined whether or not the absolute value |I2−I1| of the difference between the currents I2 and I1 is greater than the threshold value Td (step S14). Threshold Td is a value corresponding to the boundary of range R of the coil surface of power transmitting coil 112-2 at the center position of power receiving coil 212, and is set in advance by actual measurement or the like.

If |I2−I1|≦Td (step S14: NO), it is estimated that power receiving coil 212 is not at the switching position within range R, so the process returns to step S12 to repeat the process. On the other hand, if |I2−I1|>Td (step S14: YES), it is estimated that the power receiving coil 212 is at the switching position within the range R, so the first segment Seg1 is stopped from the power transmission state. state, and the third segment Seg3 is switched from the stop state to the power transmission state (step S16). Then, the process returns to step S12 to repeat the process.

By repeating the above process, the first segment Seg1 is switched from the power transmission state to the stop state at the timing when the center position of the power reception coil 212 is at the switching position within the range R of the second power transmission coil 112-2. At the same time, the third segment Seg3 can be switched from the stop state to the power transmission state.

In addition, the control device 140 switches the operation of the first segment Seg1 for stopping power transmission and the third segment Seg3 for stopping power transmission, for example, by repeatedly executing the switching timing determination process shown in FIG. be able to. FIG. 9 is different in that the determination process of step S14 of FIG. 8 is replaced with the determination process of step S14b. In step S14b, it is determined whether or not the absolute value |I1/I2| of the ratio of the current I1 to the current I2 is greater than the threshold value Tr (step S14). Threshold Tr is a value corresponding to the boundary of range R of the coil surface of power transmitting coil 112-2 at the center position of power receiving coil 212, and is set in advance by actual measurement or the like.

If |I1/I2|≧Tr (step S14b: NO), it is estimated that the power receiving coil 212 is not at the switching position within the range R, so the process returns to step S12 to repeat the process. On the other hand, if |I1/I2|<Tr (step S14b: YES), it is estimated that the power receiving coil 212 is at the switching position within the range R, so the first segment Seg1 is stopped from the power transmission state. state, and the third segment Seg3 is switched from the stop state to the power transmission state (step S16).

In the case of this process as well, at the timing when the center position of the power receiving coil 212 is at the switching position within the range R of the second power transmitting coil 112-2, the first segment Seg1 is switched from the power transmitting state to the stopped state. , the third segment Seg3 can be switched from the stop state to the power transmission state.

8 and 9, for ease of explanation, the state shown in FIG. Although the case where the center position of 212 is present has been described as an example, the same applies when the center position of power receiving coil 212 is on the coil surface of power transmitting coil 112 of another segment. For example, when power transmission of the third segment Seg3 is started, the third segment Seg3 is set to the second segment Seg2, the second segment Seg2 is set to the first segment Seg1, and the fourth segment Seg4 is set to the above Similar processing may be performed for the third segment Seg3.

As described above, in the power supply device 100 of the contactless power supply system, by comparing the current supplied to the power transmission coil 112 of the segment Seg, it is possible to appropriately switch between the segment where power transmission is stopped and the segment where power transmission is started. It is possible to obtain appropriate timing, and switch between a segment for starting power transmission and a segment for stopping power transmission at the obtained appropriate timing. As a result, power is effectively supplied from the segment where power transmission is continued, and the balance between the power that is no longer supplied from the segment that power transmission is stopped and the power that is supplied from the segment where power transmission is started is balanced. It is possible to plan appropriately. As a result, it is possible to effectively suppress a decrease in power received by the power receiving device 205 caused by segment switching. Further, as described above, the segments can be switched by comparing the current supplied to the power transmitting coil 112 of the power feeding device 100 side, so the position information of the power receiving coil 212 can be acquired by communication with the vehicle 200 or the like. It does not have to be, and it is possible to suppress a decrease in the power to be received, and it is possible to simplify the equipment configuration on the power supply device 100 side.

B. Second embodiment:
In the first embodiment, as described above (see FIG. 8 or 9), the current I2 of the second segment Seg2 where power transmission is continued and the current I1 of the first segment Seg1 where power transmission is stopped are compared. Thus, it is determined whether or not the center position of the power receiving coil 212 is within the range R indicating the permissible switching position. However, it is not limited to this, and for example, it may be as follows. The configuration of the contactless power supply system of the second embodiment is the same as that of the contactless power supply system of the first embodiment (see FIG. 1).

As shown in FIG. 10, when the power receiving coil 212 is above the coil surface of the power transmitting coil 112-1 (see FIG. 3) of the first segment Seg1, not the second segment Seg2, the power transmitting coil 112 At the switching position Sp1 corresponding to −1, power transmission of the 0th segment Seg0 (not shown in FIG. 3) is stopped and power transmission of the second segment Seg2 is started. At this switching position Sp1, the current flowing through the first segment Seg1 can be handled in the same manner as the current I2 of the second Seg2 at the switching position Sp2 corresponding to the power transmission coil 112-2 of the second segment Seg2. Therefore, the current I1c of the first segment Seg1 at the switching position Sp1 is measured and recorded. Then, by comparing the current I1c and the current I1, it is determined whether or not the center position of the power receiving coil 212 is within the range R indicating the permissible switching position in the power transmitting coil 112-2 of the second segment Seg2. You may make it Even in this way, as in the first embodiment, at the timing when the center position of the power receiving coil 212 is at the switching position within the range R of the second power transmitting coil 112-2, the first segment Seg1 is switched to the power transmitting state. to the stop state, and the third segment Seg3 can be switched from the stop state to the power transmission state.

C. Third embodiment:
In the third embodiment, as shown in FIG. 11, the position P2 in the traveling direction of the power transmission coil 112-2 of the second segment Seg2 is set as the switching position, and as described in the first embodiment, the segment for transmitting power is Correction of the switching timing will be described by taking the case of switching as an example. The configuration of the contactless power supply system of the third embodiment is the same as that of the contactless power supply system of the first embodiment (see FIG. 1).

As shown in the upper and lower parts of FIG. 12, when the switching position P2 coincides with the center position Pc of the power transmission coil 112-2, basically the current I1 of the first segment Seg1 for stopping power transmission is , the current I3 of the third segment Seg3 where power transmission is started is the same. On the other hand, the more the switching position P2 shifts to the front side of the traveling direction from the center position Pc and the more to the front side than the range R, the larger the current I1 and the smaller the current I3. As the switching position P2 shifts forward in the traveling direction of the center position Pc and shifts further forward than the range R, the current I1 decreases and the current I3 increases. Note that the current I1 in the upper part of FIG. 11 shows, as an example, the case where the power transmission of the first segment Seg1 continues without switching, in order to explain how the current flowing through the power transmission coil 112-1 changes. there is Similarly, for the current I3 in the lower part of FIG. 11, in order to explain how the current flowing through the power transmission coil 112-3 changes, the case where the power transmission in the third segment Seg3 continues without switching is taken as an example. ing.

Therefore, as described below, according to the comparison result of comparing the current I1 and the current I3, the center position of the receiving coil 212 with respect to the switching timing at the switching position P2 is the transmitting coil 112- of the next segment Seg3. 3, the switching timing indicating the switching position may be corrected. Note that hereinafter, the switching timing indicating the switching position when the center position of the power receiving coil 212 is above the power transmitting coil 112-3 of the next segment Seg3 is, for example, "the timing of switching off the next segment Seg3". may also be described in

The control device 140 (see FIG. 1) can determine the switching positions after the switching position P2, for example, by repeatedly executing the switching timing correction process shown in FIG. First, the current I1 of the first segment Seg1 immediately before power transmission is stopped by switching at the switching position P2 is measured (step S21), and the current I3 of the third segment Seg3 immediately after power transmission is started is measured (step S22). and the difference [|I1|-|I3|] between the absolute value |I1| of the current I1 and the absolute value |I3| of the current I3 is greater than or equal to −S and less than or equal to S (S is a constant positive value). It is determined whether or not (step S23). If not -S≤|I1|-|I3|≤S (step S23: NO), it is determined whether the difference [|I1|-|I3|] is greater than S (step S24). . The range from -S to S is the range of the difference [|I1|-|I3|] corresponding to the range R (see FIG. 4) allowed for the switching position P2, and the value of S is determined by actual measurement. preset.

Therefore, if -S≤|I1|-|I3|≤S (step S23: YES), it is estimated that the switching position P2 is within the range R. Therefore, in this case, the center position of the receiving coil 212 does not correct the switching timing indicating the switching position in the power transmission of the next segment Seg3, and the switching timing is the same as the switching position P2 (step S25). If S<|I1|-|I3| (step S23: NO and step S24: YES), the switching position P2 is on the far side (also referred to as the “front side”) of the range R with respect to the traveling direction. It is estimated that the position is shifted to Therefore, in this case, the switching timing indicating the switching position of the next segment Seg is corrected forward in the traveling direction (step S26). In the case of |I1|-|I3|<-S (step S23: NO and step S24: NO), the switching position P2 is on the near side (also referred to as the "rear side") with respect to the traveling direction from the range R. It is estimated that the position is shifted to Therefore, in this case, the switching timing indicating the switching position of the next segment Seg is corrected to the rear side in the traveling direction (step S27). As a result, the switching timing of the segment Seg3 next to the switching position P2 can be corrected with respect to the switching timing corresponding to the switching position P2, and the switching position of the next segment Seg3 can be determined.

After the processing of steps S25, S26, and S27, the process returns to step S21 to repeat the processing. As a result, the switching timing of each segment Seg after the switching position P2 can be sequentially corrected, and the switching position of each segment Seg after the switching position P2 can be determined.

In the switching timing correction process of FIG. 13, for ease of explanation, the state shown in FIG. A case has been described as an example in which the first and third segments Seg1 and Seg3 are set to be switched at the switching position P2. The same is true when the center position of power receiving coil 212 is on the coil surface after power transmitting coil 112-3 of third segment Seg3. For example, when the vehicle 200 moves and the power transmission of the third segment Seg3 is started, the segment Seg3 is set as the second segment Seg2, the second segment Seg2 is set as the first segment Seg1, and the fourth segment Seg3 is set as the second segment Seg2. A similar process may be executed with the segment Seg4 as the third segment Seg3.

Here, the correction of the switching timing in steps S26 and S27 can be performed, for example, as follows. As shown in FIG. 14, Vn is the vehicle speed at the switching position Pn (n is the number of the segment), d is the distance between the power transmission coils 112 of each segment, and the distance between the current switching position Pn and the next switching position Pn+1 is Let tn be the time interval for switching between , and α be the correction value of the interval. In this case, the interval tn is represented by the following formula (1). For example, the interval t2 from the switching position P2 to the next switching position P3 is given by the following formula (2).
tn=tn−1·(1±α)+(Vn−1−Vn)/d (1)
t2=t1·(1±α)+(V1−V2)/d (2)

As shown in the above formula (1), the correction in steps S26 and S27 can be performed by increasing or decreasing the interval tn to the switching position of the next segment by the correction value α. Specifically, in step S26, the correction value α is used to reduce the interval tn (t2 in the example of FIG. 13), and in step S27, the correction value α is used to increase the interval tn (t2 in the example of FIG. 13). do Note that the correction value α is a predetermined constant value. However, it is not limited to this, and the correction value α is the absolute value of the current of the segment to stop (current I1 in the example of FIG. 13) and the current of the segment to start (current I3 in the example of FIG. 13). It may be a variable corresponding to the difference in absolute value ([|I1|-|I3|] in the example of FIG. 13).

Further, the correction of switching timing in steps S26 and S27 can also be performed as follows. That is, the threshold Td used in the determination process of step S14 in FIG. 8 is corrected by the correction value αd as shown in the following expression (3), and the threshold Tr used in the determination process of step S14b in FIG. Correction may be performed using the correction value αr as shown in equation (4).
Tdn=Tdn−1·(1±αd) (3)
Trn=Trn−1·(1±αr) (4)
Note that Tdn and Trn are thresholds at the switching position Pn. Further, the correction values αd and αr may be constant values or variables, like the correction value α.

D. Other embodiments:
(1) As shown in FIG. 1, the power supply device 100 of the contactless power supply system of the above embodiment has a power transmission circuit 120 whose power transmission operation is controlled by the control device 140 for each segment Seg. explained to However, it is not limited to this. For example, a contactless power supply system including a power supply device 100C shown in FIG. 15 may be used.

Unlike the power supply device 100 (see FIG. 1), the power supply device 100C is provided with one power transmission circuit 120 common to each segment Seg. Each segment Seg is provided with a switch circuit 128 that opens and closes the connection with the power transmission circuit 120 between its own power transmission resonance circuit 110 and the power transmission circuit 120 . Opening and closing of each switch circuit 128 is executed according to control information SD supplied from the control device 140 to each switch circuit 128 . Thereby, switching of the power transmission state of each segment Seg is controlled. Also in this configuration, the segment switching position can be controlled in the same manner as in the above-described embodiment.

(2) In the above embodiment, an example of a configuration in which switching of the segment Seg for power transmission is controlled by using the current flowing through the power transmission coil 112 of the power transmission resonance circuit 110 as "information on the power supplied to the power transmission coil" will be described. However, the input current or output current of the inverter circuit 122 may be used as "information on power supplied to the power transmission coil". Alternatively, the voltage applied between the power transmission coils 112 may be used as information about power to control switching of the segment Seg for power transmission.

(3) In the above embodiment, the power transmitting coil 112 on the power transmitting side and the power receiving coil 212 on the power receiving side are both single-phase. However, it is not limited to this. The power transmission side may be configured with multi-phase power transmission coils. Also, the power receiving side may be configured with a multi-phase power receiving coil. For example, the power transmitting side may be configured with a single-phase conductive coil, and the power receiving side may be configured with a multi-phase power receiving coil of two or three or more phases. Further, the power transmission side may be configured with a two-phase or multi-phase power transmission coil of three or more phases, and the power reception side may be configured with a single-phase or multi-phase power reception coil. Even in the case of a configuration of multi-phase power transmission coils or power reception coils, as described in the embodiment, it is possible to control switching of the segment Seg for power transmission using information about power such as the current flowing in the power transmission coils. . When the power transmission side has multiple phases, using the input current or the output current of the inverter circuit 122 as the information about the power facilitates the determination of the switching position and the control for correction.

(4) In the above embodiments, the power transmitting resonant circuit and the power receiving resonant circuit using series resonance have been described as examples, but the present invention is not limited to this, and the power transmitting resonant circuit and power receiving resonant circuit using parallel resonance can also be used. Well, one of them may be a resonant circuit using series resonance and the other using parallel resonance.

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in the respective modes described in the Summary of the Invention column may be used to solve some or all of the above problems, or Substitutions and combinations may be made as appropriate to achieve some or all. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

REFERENCE SIGNS LIST 100, 100C power supply device 110 power transmission resonance circuit 112 power transmission coil 140 control device 200 vehicle 205 power reception device 210 power reception resonance circuit 212 power reception coil Seg segment

Claims (5)

A power supply device (100) and a power receiving device (205) mounted on a moving body (200) and whose position relative to the power feeding device varies, wherein the power feeding device is connected to the power receiving device in a non-contact manner. A contactless power supply system powered by
The power receiving device comprises a power receiving resonant circuit (210) including at least one power receiving coil (212),
The power supply device
a plurality of segments (Seg) having a power transmitting resonant circuit (110) including at least one power transmitting coil (112) for transmitting power to the power receiving device via the power receiving coil;
A segment for continuing power transmission to the power receiving device, a segment for stopping the power transmission, and the power transmission are performed by comparing information about the power supplied to the power transmission coil in the segment for power transmission to the power receiving device. a controller (140) for controlling the operation of the segment that initiates the
The control device controls the power transmission coil in the segment where power transmission is continued and the power receiving device according to a result of comparing the information on the power in the segment where the power transmission is continued and the information on the power in the segment where the power transmission is stopped. relative positional relationship with the power receiving coil, and determines switching timing of a segment to stop power transmission and a segment to start power transmission according to the estimation result. The contactless power supply system according to claim 1 ,
The comparison of the power information is performed using the absolute value of the difference or the absolute value of the ratio between the value of the power information in the segment in which the power transmission is continued and the value of the power information in the segment in which the power transmission is stopped. A contactless power supply system. The contactless power supply system according to claim 1 ,
The comparison of the information about the power is performed by comparing the value of the information about the power in the segment in which power transmission is stopped and the value of the information in the segment other than the segment in which power transmission is stopped before the switching timing of the segment in which power transmission is stopped. The absolute value of the difference or the absolute value of the ratio between the value of the information regarding the power supplied to the power transmission coil when the power transmission is switched and the segment for which the power transmission is stopped is in the state of continuing the power transmission. , contactless power supply system. The contactless power supply system according to claim 2 or claim 3 ,
The switching timing of the segments is determined by comparing the value of the information on the power of the segment for which the power transmission is to be stopped and the value of the information on the power to be supplied to the power transmission coil of the segment for which the power transmission is to be started. estimating a relative positional relationship between the power transmitting coil of the segment for continuing the power transmission and the power receiving coil of the power receiving device, and determining switching timing between the segment for stopping the power transmission and the segment for starting the power transmission according to the estimation result; Correction, contactless power supply system. A method for controlling a contactless power supply system in which electric power is supplied from a power supply device (100) to a power receiving device (205) mounted on a mobile body (200) and whose position relative to the power supply device varies in a non-contact manner. and
The power receiving device comprises a power receiving resonant circuit (210) including at least one power receiving coil (212),
The power supply device includes a plurality of segments (Seg) having a power transmission resonance circuit (110) including at least one power transmission coil (112) that transmits power to the power reception device via the power reception coil,
A segment for continuing power transmission to the power receiving device, a segment for stopping the power transmission, and the power transmission are performed by comparing information about the power supplied to the power transmission coil in the segment for power transmission to the power receiving device. and according to the result of comparing the information about the power in the segment to continue power transmission and the information about the power in the segment to stop power transmission, the power transmission coil of the segment to continue power transmission and estimating the relative positional relationship between the power receiving device and the power receiving coil, and determining the switching timing of the segment to stop power transmission and the segment to start power transmission according to the estimation result. control method.

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