JP2018198493A - Non-contact power transmission system - Google Patents

Abstract

To provide a non-contact power transmission system in which positioning of a primary coil and a secondary coil can be further accurately performed.SOLUTION: A storage device 70 stores voltage value-position deviation amount information In indicative of the correspondence between a horizontal position deviation amount A2 obtained when a vertical position deviation amount A1 of a secondary coil 44 relative to a primary coil 28 is 0, and a voltage value V_LPE corresponding to the horizontal position deviation amount A2. A maximum value determination unit 64 determines a maximum value V_LPEmax of LPE voltage which varies in accordance with traveling of an electric vehicle 40. A deviation amount estimation unit 66 estimates the horizontal position deviation amount A2 corresponding to the maximum value V_LPEmax on the basis of the voltage value-position deviation amount information In and the maximum value V_LPEmax.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-contact power transmission system that transmits power between a primary coil and a secondary coil, and in particular, weak power from a power transmission side to a power reception side in order to align the primary coil and the secondary coil. And an LPE (Low Power Excitation) voltage generated at both ends of the resistor when receiving weak power.

  Along with the development of electric vehicles such as electric vehicles and hybrid vehicles, a technology related to non-contact charging for charging the battery of the electric vehicle in a non-contact manner has also been developed. In order to efficiently perform non-contact charging, it is necessary to accurately align the primary coil provided in the charging station and the secondary coil provided in the electric vehicle.

  Regarding the alignment of the primary coil and the secondary coil, for example, there is a technique as disclosed in Patent Document 1. Patent Document 1 discloses an apparatus that detects the position of a wheel with a plurality of proximity sensors provided on the charging station side when aligning a primary coil and a secondary coil. This device changes the lighting state of the traffic light provided in the charging station depending on whether the proximity sensor detects the wheel of the electric vehicle or not. The occupant operates the electric vehicle while observing the lighting state of the traffic light, and aligns the primary coil and the secondary coil.

JP 2014-099964 A (paragraphs [0024]-[0031])

  In the apparatus of Patent Document 1, the positional deviation amount of the secondary coil with respect to the primary coil is not taken into account when the primary coil and the secondary coil are aligned. For this reason, it is difficult for the occupant to accurately align the primary coil and the secondary coil.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a non-contact power transmission system that can more accurately align the primary coil and the secondary coil.

The present invention
In a state where the longitudinal direction of the charging station is substantially parallel to the vehicle length direction of the electric vehicle and the lateral direction of the charging station is substantially parallel to the vehicle width direction of the electric vehicle, the primary coil is changed to the secondary coil. A non-contact power transmission system that transmits power in a non-contact manner,
A voltage detector for detecting a voltage generated by the weak power transmitted from the primary coil and received by the secondary coil;
Correspondence between the lateral displacement amount when the longitudinal displacement amount of the secondary coil with respect to the primary coil is 0 and the voltage value according to the lateral displacement amount A storage device for storing voltage value-position error information indicating the relationship;
A maximum value determination unit that determines the maximum value of the voltage that varies with the traveling of the electric vehicle;
The lateral displacement amount corresponding to the maximum value is estimated based on the voltage value-position displacement amount information stored in the storage device and the maximum value determined by the maximum value determination unit. And a deviation amount estimation unit.

  According to the above configuration, the lateral displacement amount of the secondary coil with respect to the primary coil is determined based on the voltage value-position displacement amount information stored in the storage device and the maximum value of the voltage detected by the voltage detector. Can be easily estimated. Further, since the amount of lateral displacement of the secondary coil relative to the primary coil can be estimated, the primary coil and the secondary coil can be more accurately aligned.

In the present invention,
You may further provide the alerting | reporting control part which alert | reports the amount of positional deviation of the said horizontal direction estimated by the said deviation | shift amount estimation part with an alerting | reporting apparatus.

  According to the above configuration, it is possible to notify the occupant of the amount of lateral displacement of the secondary coil with respect to the primary coil. For this reason, the occupant can easily align the primary coil and the secondary coil.

In the present invention,
A distance sensor for detecting a travel distance of the electric vehicle;
The maximum value determination unit is configured to determine the value of the voltage with respect to a minute travel distance based on the voltage value detected by the voltage detector and the travel distance of the electric vehicle detected by the distance sensor. A position differential value that is a change amount may be calculated, and the voltage value when the position differential value becomes 0 may be determined as the maximum value.

  According to the above configuration, the maximum value of the voltage can be calculated by an easy method such as calculating the position differential value of the voltage value. For this reason, alignment of a primary coil and a secondary coil can be performed easily.

  According to the present invention, the amount of lateral displacement of the secondary coil with respect to the primary coil can be estimated, so that the primary coil and the secondary coil can be more accurately aligned.

FIG. 1 is a system configuration diagram showing a non-contact power transmission system according to the present embodiment. FIG. 2 is an explanatory diagram for explaining the lateral displacement of the secondary coil with respect to the primary coil. FIG. 3 is a graph showing the voltage value-horizontal distance characteristic. FIG. 4 is a flowchart showing processing performed in the electric vehicle. 5A and 5B are explanatory views for explaining the parking operation of the electric vehicle with respect to the charging station.

  Hereinafter, preferred embodiments of the non-contact power transmission system according to the present invention will be described in detail with reference to the accompanying drawings.

[1 Configuration of contactless power transmission system 10]
The structure of the non-contact electric power transmission system 10 which concerns on 1st Embodiment is demonstrated using FIG. The non-contact power transmission system 10 includes a primary (power feeding side) charging station 20 provided on the ground (installation surface) and a secondary (power receiving side) electric vehicle 40. In FIG. 1, the component below the two-dot chain line indicates the charging station 20, and the component above the two-dot chain line indicates the electric vehicle 40. In the non-contact power transmission system 10, the battery 56 mounted on the electric vehicle 40 is charged by the charging station 20 in a non-contact manner.

  The charging station 20 mainly includes a power transmission circuit 22, a primary side control device 34, and a primary side communication device 36. The power transmission circuit 22 includes an AC power source 24, a power converter 26 that converts AC power supplied from the AC power source 24 into transmitted power, and a primary capacitor for resonance (not shown) and a primary coil 28. . The primary coil 28 is covered with the primary pad 30 and disposed on the ground (installation surface).

  The primary side control device 34 functions as a predetermined operation unit when a processor (not shown) such as a CPU reads and executes a program stored in a storage device (not shown). In the first embodiment, the primary-side controller 34 transmits weak power for positioning the primary coil 28 and the secondary coil 44 and charging power for charging the battery 56 to the primary coil 28. Functions as a power transmission control unit.

  The primary side communication device 36 is connected to the primary side control device 34 by a communication line. The primary side communication device 36 performs wireless communication with the secondary side communication device 74 of the electric vehicle 40. For example, wireless communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark) can be used.

  The electric vehicle 40 mainly includes a power receiving circuit 42, a battery 56, a secondary side control device 60, a secondary side communication device 74, a display device 76, an acoustic device 78, a distance sensor 80, and a traveling device 90. .

  The power receiving circuit 42 includes a secondary capacitor (not shown) for resonance and a secondary coil 44, a rectifier 50 that rectifies received power that is AC power received by the secondary coil 44, and a power receiving circuit 42 and a battery 56. And a contactor 54 for switching electrical connection / disconnection. The secondary coil 44 is covered with the secondary pad 46 and disposed on the lower surface of the electric vehicle 40.

  The power receiving circuit 42 further includes a voltage detector 52 that can be connected between the rectifier 50 and the contactor 54. The voltage detector 52 includes, for example, a parallel circuit (not shown) of a predetermined resistance and a voltage sensor as disclosed in Japanese Patent No. 5937663. The voltage sensor detects a voltage generated at both ends of the resistor when receiving weak power. This voltage is called LPE voltage. When a switching device (not shown) receives a control instruction from the secondary side control device 60 and receives a weak power, the voltage detector 52 is connected to the power receiving circuit 42. In this embodiment, the LPE voltage is detected using the power receiving circuit 42 used at the time of charging. However, a circuit for detecting the LPE voltage is provided separately from the power receiving circuit 42, and a rectifier is provided there. And a voltage detector 52 may be provided.

  The battery 56 is composed of a lithium ion battery or the like, and is charged via the power receiving circuit 42 when the contactor 54 is in a connected state and the primary coil 28 and the secondary coil 44 are magnetically coupled.

  The secondary side control device 60 is an ECU and manages the power receiving process. The secondary-side control device 60 reads and executes a program stored in the storage device 70 by a processor such as a CPU (not shown), whereby the overall unit 62, the maximum value determination unit 64, the deviation amount estimation unit 66, and notification control It functions as the unit 68.

  The supervision unit 62 supervises and manages power reception processing. Maximum value determination unit 64 is based on LPE voltage value V_LPE (hereinafter referred to as voltage value V_LPE) detected by voltage detector 52 and travel distance X of electric vehicle 40 detected by distance sensor 80. Then, a change amount of the voltage value V_LPE with respect to a minute travel distance X (travel distance X per unit time), that is, a position differential value dV / dX related to the LPE voltage is calculated. When the calculated value becomes 0, the voltage value V_LPE detected by the voltage detector 52 is determined as the maximum value (peak value) V_LPEmax. The deviation amount estimation unit 66 is based on a later-described voltage value-position deviation amount information In stored in the storage device 70 and the maximum value V_LPEmax determined by the maximum value determination unit 64, and corresponds to the maximum value V_LPEmax. A direction misalignment amount A2 is estimated. The notification control unit 68 outputs a command signal corresponding to the lateral displacement amount A2 estimated by the displacement amount estimation unit 66, and causes the display device 76 and the acoustic device 78 to notify the lateral displacement amount A2.

  The storage device 70 stores voltage value-position shift amount information In in addition to predetermined values and predetermined values used in various programs and various calculations. The voltage value-position displacement amount information In is the amount of lateral displacement A2 when the amount of longitudinal displacement A1 of the secondary coil 44 with respect to the primary coil 28 is 0, and the amount of displacement in the lateral direction. This is information indicating a correspondence relationship with the voltage value V_LPE corresponding to A2. The voltage value-position shift amount information In will be further described in [2] below.

  The secondary side communication device 74 is connected to the secondary side control device 60 via a communication line. The secondary side communication device 74 performs wireless communication with the primary side communication device 36 of the charging station 20 as described above.

  The display device 76 displays information indicating the positional deviation amount A2 between the primary coil 28 and the secondary coil 44 in accordance with a command signal output from the secondary side control device 60. For example, a bird's-eye view showing the positions of the primary coil 28 and the secondary coil 44 in a simulated manner and a positional deviation amount A2 between the primary coil 28 and the secondary coil 44 are displayed on the screen. The acoustic device 78 outputs information indicating the positional deviation amount A2 between the primary coil 28 and the secondary coil 44 from the speaker in response to the command signal output from the secondary side control device 60.

  The traveling device 90 includes a driving device that generates a driving force in response to an accelerator pedal operation performed by an occupant, a steering device that performs steering in response to an operation of a steering wheel performed by the occupant, and an operation of a brake pedal performed by the occupant. And a braking device that generates a braking force in response. The driving force device includes an electric motor to which electric power is supplied from a battery 56 as a driving source.

[2 Voltage Value-Position Deviation Information In]
A scene in which the electric vehicle 40 moves horizontally in a state where the longitudinal direction of the charging station 20 and the vehicle length direction of the electric vehicle 40 are substantially parallel and the secondary coil 44 is separated from the primary coil 28 in the vertical direction. Is assumed. At this time, as shown in FIG. 2, it is assumed that the lateral displacement A2 of the secondary coil 44 with respect to the primary coil 28 is zero. In this scene, the horizontal distance D between the primary coil 28 and the secondary coil 44 and the voltage value V_LPE detected by the voltage detector 52 are in a relationship as shown by a curve B1 in FIG.

  That is, the electric vehicle 40 approaches the primary coil 28 from a distance, and the position {horizontal distance D = D1 (position shift amount A1 = D1)} where the secondary coil 44 can receive the weak power transmitted from the primary coil 28. When reaching, the voltage value V_LPE starts to rise from the first predetermined value V_LPE1. As the electric vehicle 40 travels and the horizontal distance D decreases, the voltage value V_LPE gradually increases and reaches a maximum value V_LPE2 at the position of the horizontal distance D = D2 (position shift amount A1 = D2). Further, as the electric vehicle 40 travels and the horizontal distance D decreases, the voltage value V_LPE gradually decreases, and reaches a minimum value V_LPE3 at the position of the horizontal distance D = D3 (position shift amount A1 = D3). Further, as the electric vehicle 40 travels and the horizontal distance D decreases, the voltage value V_LPE gradually increases, and the position of the horizontal distance D = 0 (the positional deviation amount A1 = 0), that is, the center 44c of the secondary coil 44 is the primary. When the upper position of the center 28c of the coil 28 is reached, the maximum value V_LPEmax1 is obtained.

  Next, it is assumed that the electric vehicle 40 travels in a state shifted in the lateral direction. For example, as shown in FIG. 2, when the lateral displacement A2 = a (> 0) of the secondary coil 44 with respect to the primary coil 28, the voltage value V_LPE is expressed by the curve B2 in FIG. It becomes lower than the curve B1 in the case of the positional deviation amount A2 = 0. The maximum value V_LPEmax2 when the amount of positional deviation A1 = 0 in the vertical direction of the secondary coil 44 with respect to the primary coil 28 is lower than the maximum value V_LPEmax1. Further, as shown in FIG. 2, when the lateral displacement amount A2 = b (> a) of the secondary coil 44 with respect to the primary coil 28, the voltage value V_LPE is expressed as a curve B3 in FIG. It becomes lower than the curve B2 when the positional deviation amount A2 = a. The maximum value V_LPEmax3 when the amount of positional deviation A1 = 0 in the vertical direction of the secondary coil 44 with respect to the primary coil 28 is lower than the maximum value V_LPEmax1 and the maximum value V_LPEmax2. As described above, the maximum value V_LPEmax detected when the vertical displacement A1 = 0 becomes smaller as the lateral displacement A2 of the secondary coil 44 with respect to the primary coil 28 becomes larger. The storage device 70 stores the correspondence relationship between the maximum value V_LPEmax and the lateral displacement A2 such as A2 = 0 and V_LPE = V_LPEmax1, A2 = a and V_LPE = V_LPEmax2, A2 = b and V_LPE = V_LPEmax3. , Stored as voltage value-position error information In.

[3 Positioning process]
In the present embodiment, by detecting the maximum value V_LPEmax of the voltage value V_LPE, it is assumed that the amount of vertical displacement A1 of the secondary coil 44 with respect to the primary coil 28 is 0, and the primary coil 28 at that time The amount of displacement A2 in the lateral direction of the secondary coil 44 is estimated.

  The alignment process performed on the electric vehicle 40 side according to the present embodiment will be described with reference to FIG. The process described below is performed when an occupant of the electric vehicle 40 turns on a parking start switch (not shown). As shown in FIGS. 2 and 5A, for example, the charging station 20 is partitioned by a line 150. The occupant turns on the parking start switch at a position P1 away from the charging station 20 and causes the electric vehicle 40 to travel toward the charging station 20. The operation signal of the parking start switch is transmitted to the secondary side control device 60.

  Note that the occupant is such that the longitudinal direction of the charging station 20 and the vehicle length direction of the electric vehicle 40 are substantially parallel, and the lateral direction of the charging station 20 and the vehicle width direction of the electric vehicle 40 are substantially parallel. The electric vehicle 40 is operated. Then, the electric vehicle 40 is caused to travel substantially straight so that the primary coil 28 and the secondary coil 44 are aligned.

  In step S <b> 1, the overall unit 62 instructs the secondary side communication device 74 to transmit a weak power. The secondary side communication device 74 performs pairing such as authentication with the primary side communication device 36 and transmits a transmission request signal of weak power. The primary side control device 34 controls the power converter 26 according to the transmission request signal received by the primary side communication device 36 to start power transmission. The power converter 26 converts AC power supplied from the AC power source 24 into predetermined weak power and supplies it to the primary coil 28. Then, weak power for alignment is transmitted from the primary coil 28 to the outside.

  In step S2, the overall unit 62 determines whether or not the voltage value V_LPE detected by the voltage detector 52 is equal to or higher than the first predetermined value V_LPE1, that is, the secondary coil 44 receives weak power as shown in FIG. 5A. It is determined whether or not a possible range R (horizontal distance D = D1) has been entered. When the value is equal to or greater than the first predetermined value V_LPE1, that is, when the secondary coil 44 enters a range R in which weak power can be received (step S2: YES), the process proceeds to step S3. On the other hand, when it is less than the first predetermined value V_LPE1, that is, when the secondary coil 44 is not in the range R in which the weak power can be received (step S2: NO), the process of step S2 is repeatedly performed.

  When the process proceeds from step S2 to step S3, the maximum value determination unit 64 determines the position differential value based on the voltage value V_LPE detected by the voltage detector 52 and the travel distance X per unit time detected by the distance sensor 80. dV / dX is calculated.

  In step S4, the maximum value determination unit 64 determines the voltage value V_LPE and the position differential value dV / dX. As shown in FIG. 3, for example, in the curve B1 indicating the characteristic of the positional deviation amount A2 = 0, the voltage value V_LPE becomes the maximum value V_LPE2 at the position of the horizontal distance D = D2 and 0, and the position differential value dV / dX is 0. In the present embodiment, in order to correctly determine the maximum value V_LPEmax, in other words, in order not to determine the position of the horizontal distance D = D2 as the position of the vertical displacement A1 = 0, the voltage value V_LPE is The maximum value V_LPE2 detected at the position of the horizontal distance D = D2 in the largest curve B1 is stored in the storage device 70 as the second predetermined value. When the voltage value V_LPE is larger than the second predetermined value V_LPE2 and the position differential value dV / dX is 0 (step S4: YES), the voltage value V_LPE is the maximum value V_LPEmax and the positional deviation amount A1 in the vertical direction. = 0 and the process proceeds to step S5. On the other hand, if the voltage value V_LPE is equal to or smaller than the second predetermined value V_LPE2 or the position differential value dV / dX is not 0 (step S4: NO), the voltage value V_LPE is not the maximum value V_LPEmax but the vertical position shift. It is estimated that the position is not at the amount A1 = 0, and the process returns to step S3.

  In step S5, the shift amount estimation unit 66 refers to the voltage value-position shift amount information In stored in the storage device 70, and the position shift corresponding to the voltage value V_LPE when the position differential value dV / dX is 0. The amount A2 is estimated.

  In step S <b> 6, the notification control unit 68 outputs a command signal that instructs the display device 76 and the acoustic device 78 to perform notification based on the positional deviation amount A <b> 2 estimated by the deviation amount estimation unit 66. The display device 76 displays a positional deviation amount A2 or a bird's eye view of the primary coil 28 and the secondary coil 44 on the screen. The acoustic device 78 outputs a sound for notifying the positional deviation amount A2 and a signal sound corresponding to the positional deviation amount A2 from the speaker. For example, the interval between the output of the signal sound and the stop is changed according to the positional deviation amount A2.

  The driver grasps the positional deviation amount A <b> 2 by notification from the display device 76 and / or the acoustic device 78. As shown in FIG. 5B, when the positional deviation amount A2 of the secondary coil 44 with respect to the primary coil 28 becomes 0, the driver parks the electric vehicle 40 and starts charging. On the other hand, when the driver redoes the alignment operation, the processes after step S2 are executed again.

[4 Summary of Embodiments]
In the non-contact power transmission system 10 according to the above-described embodiment, the longitudinal direction of the charging station 20 and the vehicle length direction of the electric vehicle 40 are substantially parallel, and the lateral direction of the charging station 20 and the vehicle width direction of the electric vehicle 40 are. Are transmitted in a non-contact manner from the primary coil 28 to the secondary coil 44. The non-contact power transmission system 10 includes a voltage detector 52 that detects an LPE voltage generated by the weak power transmitted from the primary coil 28 and received by the secondary coil 44, and the longitudinal direction of the secondary coil 44 relative to the primary coil 28. A voltage value-position error information In indicating a correspondence relationship between the position error A2 in the horizontal direction when the position error A1 in the direction is 0 and the voltage value V_LPE corresponding to the position error A2 in the horizontal direction. A storage device 70 that stores data, a maximum value determination unit 64 that determines a maximum value V_LPEmax of an LPE voltage that varies as the electric vehicle 40 travels, a voltage value-position shift amount information In that is stored in the storage device 70, and a maximum A displacement amount estimation unit 66 that estimates a lateral displacement amount A2 corresponding to the maximum value V_LPEmax based on the maximum value V_LPEmax determined by the value determination unit 64; Obtain.

  According to the above configuration, the secondary coil 44 with respect to the primary coil 28 based on the voltage value-position shift amount information In stored in the storage device 70 and the maximum value V_LPEmax of the LPE voltage detected by the voltage detector 52. The lateral displacement A2 can be easily estimated. Further, since the lateral displacement A2 of the secondary coil 44 with respect to the primary coil 28 can be estimated, the primary coil 28 and the secondary coil 44 can be more accurately aligned.

  The non-contact power transmission system 10 includes a notification control unit 68 that notifies the lateral position deviation amount A2 estimated by the deviation amount estimation unit 66 using a display device 76 and an acoustic device 78 as a notification device. According to the above configuration, the occupant can be notified of the lateral displacement A2 of the secondary coil 44 with respect to the primary coil 28. Therefore, the occupant can easily align the primary coil 28 and the secondary coil 44.

  The non-contact power transmission system 10 includes a distance sensor 80 that detects a travel distance X of the electric vehicle 40. The maximum value determination unit 64 determines the voltage value V_LPE for a minute travel distance X based on the voltage value V_LPE detected by the voltage detector 52 and the travel distance X of the electric vehicle 40 detected by the distance sensor 80. A position differential value dV / dX that is a change amount is calculated, and the voltage value V_LPE when the position differential value dV / dX becomes 0 is determined as the maximum value V_LPEmax. According to the above configuration, the maximum value V_LPEmax of the LPE voltage can be calculated by an easy method such as calculating the position differential value dV / dX of the voltage value V_LPE. For this reason, the primary coil 28 and the secondary coil 44 can be easily aligned.

  Note that the non-contact power transmission system according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention. For example, a non-contact power transmission system according to the present invention includes a parking assistance device or an automatic parking device (Japanese Patent Laid-Open No. 2015-074266, etc.) that automatically performs at least one of steering, driving, and braking. Can also be used.

DESCRIPTION OF SYMBOLS 10 ... Non-contact electric power transmission system 20 ... Charging station 28 ... Primary coil 34 ... Primary side control apparatus 40 ... Electric vehicle 44 ... Secondary coil 52 ... Voltage detector 64 ... Maximum value determination part 66 ... Deviation amount estimation part 68 ... Notification control unit 70 ... Storage device 76 ... Display device 78 ... Sound device 80 ... Distance sensor

Claims (3)

In a state where the longitudinal direction of the charging station is substantially parallel to the vehicle length direction of the electric vehicle and the lateral direction of the charging station is substantially parallel to the vehicle width direction of the electric vehicle, the primary coil is changed to the secondary coil. A non-contact power transmission system that transmits power in a non-contact manner,
A voltage detector for detecting a voltage generated by the weak power transmitted from the primary coil and received by the secondary coil;
Correspondence between the lateral displacement amount when the longitudinal displacement amount of the secondary coil with respect to the primary coil is 0 and the voltage value according to the lateral displacement amount A storage device for storing voltage value-position error information indicating the relationship;
A maximum value determination unit that determines the maximum value of the voltage that varies with the traveling of the electric vehicle;
The lateral displacement amount corresponding to the maximum value is estimated based on the voltage value-position displacement amount information stored in the storage device and the maximum value determined by the maximum value determination unit. A non-contact power transmission system comprising: a deviation amount estimation unit. The contactless power transmission system according to claim 1,
A contactless power transmission system, further comprising: a notification control unit that notifies a notification device of the amount of lateral displacement estimated by the displacement amount estimation unit. The contactless power transmission system according to claim 1 or 2,
A distance sensor for detecting a travel distance of the electric vehicle;
The maximum value determination unit is configured to determine the value of the voltage with respect to a minute travel distance based on the voltage value detected by the voltage detector and the travel distance of the electric vehicle detected by the distance sensor. A non-contact power transmission system, wherein a position differential value that is a change amount is calculated, and the value of the voltage when the position differential value becomes 0 is determined as the maximum value.

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