JP2016007107A - Non-contact power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission device capable of suitably determining whether or not power transmission is performed between respective coils.SOLUTION: A power transmission apparatus 11 includes an AC power supply 12 capable of outputting AC power whose power values are different from each other and a transmitter 13 into which AC power output from the AC power supply 12 is input. The power reception apparatus 21 includes a receiver 23 capable of receiving AC power input into the transmitter 13 in a non-contact mode, and a first load 25 and a second load 26 with different impedance, in which reception power of AC power received by the receiver 23 is input.

Description

  The present invention relates to a contactless power transmission device.

  As a non-contact power transmission device that does not use a power cord or a power transmission cable, for example, an AC power source that outputs AC power, and a power transmission device that has a primary coil to which the AC power is input, and a non-contact from the primary coil. What is provided with the power receiving apparatus which has the secondary side coil which can receive alternating current power by contact is known (for example, refer patent document 1). In such a non-contact power transmission device, AC power is transmitted from a power transmitting device to a power receiving device in a non-contact manner, for example, by magnetic resonance between the primary side coil and the secondary side coil. Patent Document 1 describes that the power receiving device is mounted on a vehicle as a moving body.

JP 2009-106136 A

  Here, as a non-contact power transmission device, power transmission is performed between the coils using AC power having a relatively small power value in a stage before performing power transmission of AC power having a relatively large power value. There is a case where it is desired to determine whether or not. In this case, if it is erroneously determined that power transmission is performed between the coils even though power transmission is not performed between the coils, a relatively large AC power is erroneously detected from the AC power source. May be output. Further, from the viewpoint of suppressing erroneous determination, there is a case where it is desired to determine whether or not power transmission is performed between the coils in both the power transmitting device and the power receiving device.

  This invention is made | formed in view of the situation mentioned above, The objective is to provide the non-contact electric power transmission apparatus which can determine suitably whether electric power transmission is performed between each coil.

  The non-contact power transmission device that achieves the above object includes an AC power source capable of outputting a plurality of types of AC power having different power values, a power transmission device having a primary coil to which the AC power is input, and the primary A secondary coil that can receive the AC power input to the side coil in a contactless manner, and AC power received by the secondary coil or DC power obtained by converting the AC power is input. A power receiving device having a first load and a second load, wherein the power receiving device is an AC power received by the secondary coil or an output destination of a DC power obtained by converting the AC power. In the situation where the switching unit that switches to the first load or the second load, the output destination is the first load, and the first AC power is output from the AC power source, the 2 First determining whether or not power transmission is performed between the primary coil and the secondary coil based on a voltage value detected from the power transmission path from the side coil to the first load. A first transmission determination unit that performs transmission determination, and the non-contact power transmission device performs power transmission between the primary coil and the secondary coil by the first transmission determination unit. A switching control unit for controlling the switching unit so that the output destination is switched from the first load to the second load having an impedance lower than the impedance of the first load when the determination is made; The power transmission device detects from the power transmission path from the AC power source to the primary coil in a situation where the output destination is the second load and the second AC power is output from the AC power source. The A second transmission determination unit that performs a second transmission determination for determining whether or not power transmission is performed between the primary side coil and the secondary side coil based on a current value of When it is determined by the second transmission determination that power transmission is performed between the primary side coil and the secondary side coil, the power value is higher than the first AC power and the second AC power. A large third AC power is output.

  According to such a configuration, it is possible to uniquely determine whether or not power transmission is performed between the coils in both the power transmitting device and the power receiving device by the first transmission determination and the second transmission determination. In addition, since the second transmission determination is performed when the first transmission determination is affirmative, the first transmission determination is erroneously affirmative when the power transmission is not performed between the coils. Even in this case, the second transmission determination is a negative determination. Therefore, it can be suitably determined whether or not power transmission is performed between the coils.

  Here, when performing 1st transmission determination and 2nd transmission determination using the 1st alternating current power and 2nd alternating current power with comparatively small electric power value, the voltage value and electric current according to the presence or absence of electric power transmission between each coil The amount of change in value tends to be small. For this reason, erroneous determination is likely to occur in each transmission determination.

  On the other hand, according to this configuration, since the output destination when the first transmission determination is performed is the first load having a relatively high impedance, it corresponds to the presence or absence of power transmission between the coils. The amount of change in voltage value is large. Thereby, the first abnormality determination can be performed with high accuracy. On the other hand, since the output destination when the second transmission determination is performed is the second load having a relatively low impedance, the amount of change in the current value according to the presence or absence of power transmission between the coils increases. Yes. Thereby, the second transmission determination can be performed with high accuracy.

From the above, both the first transmission determination and the second transmission determination can be suitably performed by using the first AC power and the second AC power, which have smaller power values than the third AC power.
About the said non-contact electric power transmission apparatus, the said 2nd transmission determination part is from the said AC power supply in the situation where the said output destination is the said 2nd load, and the said 2nd AC power is output from the said AC power supply. When the current value detected from the power transmission path to the primary side coil or a parameter calculated from the current value is equal to or greater than a predetermined threshold value, the primary side coil and the secondary side It may be determined that power transmission is performed between the coils. According to such a configuration, when the amount of change in the current value according to the presence or absence of power transmission between the coils is small, it is difficult to set the threshold value, or erroneous determination is likely to occur in the second transmission determination. On the other hand, as described above, since the amount of change in the current value can be increased by switching the output destination, the threshold value can be easily set to a value that is unlikely to cause erroneous determination. Thereby, the second transmission determination can be easily and accurately performed.

  With respect to the non-contact power transmission device, the power receiving device includes an AC / DC converter that converts AC power received by the secondary coil into DC power, and the DC power that is converted by the AC / DC converter. The first load and the second load are provided separately from the battery and are fixed loads with a constant impedance, and the switching unit includes the output destination, The AC / DC conversion unit, the first load, or the second load may be switched. According to this configuration, it is possible to improve the determination accuracy of the second transmission determination as compared with a configuration in which a battery that is a variable load whose impedance varies is used as the second load.

  In the non-contact power transmission apparatus, the power receiving device is mounted on a mobile body, and the first transmission determination by the first transmission determination unit is performed while the mobile body is moving, and the second transmission determination The second transmission determination by the unit may be performed when the moving body is stopped. According to such a configuration, the moving body can be positioned based on the determination result of the first transmission determination. In addition, after the positioning of the moving body is performed based on the determination result of the first transmission determination, it is possible to confirm whether the positioning of the moving body has been normally performed by performing the second transmission determination.

  According to this invention, it can be suitably determined whether or not power transmission is performed between the coils.

The block diagram which shows the electric constitution of a non-contact electric power transmission apparatus. The flowchart which shows a charge control process. (A), (b) is a schematic diagram which shows a mode that a vehicle is parked. (A) is a graph which shows the time change of the voltage value detected by a secondary side detection part, (b) is a graph which shows the time change of a power factor.

Hereinafter, an embodiment of a non-contact power transmission device (non-contact power transmission system) and a power transmission device (power transmission device) will be described.
As shown in FIG. 1, the non-contact power transmission device 10 includes a power transmission device 11 (ground side device, primary side device) and a power receiving device 21 (vehicle side device, secondary side device) capable of non-contact power transmission. It has. The power transmission device 11 is provided on the ground, and the power reception device 21 is mounted on the vehicle 100.

  The power transmission device 11 includes an AC power supply 12 that can output AC power having a predetermined frequency. The AC power source 12 is, for example, a voltage source, and when system power as external power is input from the system power source E as infrastructure, the system power can be converted into AC power and the converted AC power can be output. It is configured.

  Specifically, the AC power supply 12 receives an AC / DC converter 12a as a first conversion unit that converts system power input from the system power supply E into DC power, and DC power input from the AC / DC converter 12a. And a DC / AC converter 12b as a second converter that converts the DC power into AC power and outputs the converted AC power.

  The AC / DC converter 12a of the present embodiment is configured such that the power value of the DC power output from the AC / DC converter 12a is variable. Thereby, the AC power supply 12 can output a plurality of types of AC power having different power values.

  As illustrated in FIG. 1, the power transmission device 11 includes a power transmission-side controller 14 that controls an AC power supply 12, specifically, an AC / DC converter 12 a and a DC / AC converter 12 b. The power transmission side controller 14 performs ON / OFF control of AC power from the AC power source 12 and power value control of AC power output from the AC power source 12.

  The AC power output from the AC power supply 12 is transmitted to the power receiving device 21 in a non-contact manner, and used for charging the vehicle battery 22 (power storage device) provided in the power receiving device 21. Specifically, the non-contact power transmission apparatus 10 performs power transmission between the power transmission device 11 and the power reception device 21, and the AC power provided in the power transmission device 11 and output from the AC power source 12 is converted into the impedance converter 15. And a power receiver 23 provided in the power receiving device 21. The impedance converter 15 will be described later.

  The power transmitter 13 and the power receiver 23 have the same configuration, and both are configured to be capable of magnetic field resonance. Specifically, the power transmitter 13 includes a resonance circuit including a primary coil 13a and a primary capacitor 13b that are connected in series or in parallel to each other. The power receiver 23 has a resonance circuit including a secondary coil 23a and a secondary capacitor 23b connected in series or in parallel. The resonant frequencies of both resonant circuits are set to be the same.

  According to such a configuration, AC power is input to the power transmitter 13 (primary coil 13a) via the impedance converter 15 in a situation where the relative position of the power transmitter 13 and the power receiver 23 is at a position where magnetic field resonance is possible. In such a case, the power transmitter 13 and the power receiver 23 (secondary coil 23a) magnetically resonate. As a result, the power receiver 23 receives part of the energy from the power transmitter 13. That is, the power receiver 23 receives AC power from the power transmitter 13.

  Incidentally, the frequency of the AC power output from the AC power supply 12 is set corresponding to the resonance frequency of the power transmitter 13 and the power receiver 23 so that power transmission is possible between the power transmitter 13 and the power receiver 23. Yes. For example, the frequency of AC power is set to be the same as the resonance frequency of the power transmitter 13 and the power receiver 23. However, the present invention is not limited thereto, and the frequency of the AC power and the resonance frequency of the power transmitter 13 and the power receiver 23 may be deviated within a range where power transmission is possible.

  The power receiving device 21 according to the present embodiment has a plurality (specifically three) of output destinations of AC power received by the power receiver 23. Specifically, the power receiving device 21 includes a rectifier 24 as an AC / DC conversion unit, a first load 25, and a second load 26, and receives power by the power receiver 23. A switching relay 27 is provided as a switching unit that switches the output destination of the AC power thus switched to the rectifier 24, the first load 25, or the second load 26. Note that “the output destination of the AC power received by the power receiver 23” can be said to be the connection destination of the power receiver 23. In the following description, “AC power received by the power receiver 23” is simply referred to as received power.

  The rectifier 24 converts received power into DC power. When the DC power rectified by the rectifier 24 is input to the vehicle battery 22, the vehicle battery 22 is charged.

  The first load 25 and the second load 26 are fixed loads having a constant impedance regardless of the input power value or the like. The impedance (resistance) of the first load 25 is set higher than the impedance (resistance) of the second load 26. Note that the impedance of the vehicle battery 22 is lower than the impedance of the first load 25.

  The power receiving device 21 includes a secondary side detection unit 28 that detects the voltage value V of the received power. The secondary side detection unit 28 detects the voltage value V of AC power from the power receiver 23 toward the switching relay 27 and transmits the detection result to the power reception side controller 29 provided in the power receiving device 21. Based on the voltage value V, the power receiving side controller 29 determines whether or not the vehicle 100 is disposed at a position where the power transmitter 13 can transmit power, or controls the switching relay 27.

  Here, when the output destination of the power receiver 23 is the first load 25 by the switching relay 27, the secondary side detection unit 28 determines the voltage on the power transmission path from the power receiver 23 to the first load 25. It can be said that the value V is detected. Similarly, when the output destination of the power receiver 23 is the rectifier 24 by the switching relay 27, the secondary side detection unit 28 determines the voltage value V on the power transmission path from the power receiver 23 to the vehicle battery 22. It can be said that it is detected.

  As shown in FIG. 1, the power transmission device 11 includes an impedance converter 15 that is provided between an AC power source 12 (specifically, a DC / AC converter 12b) and a power transmitter 13 and performs impedance conversion. The impedance converter 15 is composed of, for example, a transformer or an LC circuit.

  Here, the power supply load from the input terminal of the impedance converter 15 (the output terminal of the DC / AC converter 12b) to the vehicle battery 22 is defined as one power load. The impedance converter 15 supplies power to the power load when the charging power as the third AC power is output from the AC power source 12 and the relative position between the power transmitter 13 and the power receiver 23 is a predetermined reference position. The input impedance of the power transmitter 13 (primary coil 13a) is converted so that the power factor λ of the generated power approaches (preferably matches) “1”. That is, the impedance converter 15 of this embodiment is a power factor correction circuit.

  In addition, the power transmission device 11 includes a primary side detection unit 16 that detects a current value on a power transmission path from the AC power supply 12 to the power transmitter 13. The primary side detection unit 16 detects the output current value Iout of the DC / AC converter 12b as the current value. Moreover, the primary side detection part 16 detects the input current value Iin of the DC / AC converter 12b, and transmits the detection result of the input current value Iin and the output current value Iout to the power transmission side controller 14. The power transmission side controller 14 calculates, for example, the power factor λ based on the detection result of the primary side detection unit 16, and controls the AC power source 12 according to the calculation result.

  The power factor λ is a quotient of the input current value Iin of the DC / AC converter 12b with respect to the output current value Iout of the DC / AC converter 12b. Further, the input current value Iin and the output current value Iout of the DC / AC converter 12b are, for example, effective values.

  The power transmission side controller 14 and the power reception side controller 29 are configured to be capable of wireless communication. In this case, the range in which wireless communication can be performed between the controllers 14 and 29 is greater than the range in which contactless power transmission is performed between the power transmitter 13 (power transmission device 11) and the power receiver 23 (power reception device 21). wide. Note that a specific method of wireless communication between the controllers 14 and 29 is arbitrary. For example, Zigbee (registered trademark), Bluetooth (registered trademark), and the like are conceivable.

  Each controller 14 and 29 executes a charge control process for charging the vehicle battery 22 while exchanging information based on the fact that wireless communication can be performed with each other. The charge control process will be described in detail below.

  Incidentally, “the controllers 14 and 29 can perform wireless communication with each other” means that the power receiving device 21 having the power receiving side controller 29 is mounted within the range where the power transmitting side controller 14 can perform wireless communication. This is a case where the vehicle 100 has entered. In this case, it is assumed that vehicle 100 is moving at the start timing of the charging control process.

  In FIG. 2, for convenience of illustration, a charging control process executed by the power transmission side controller 14 and a charging control process executed by the power receiving side controller 29 are shown together. In this case, dotted arrows indicate the state of signals exchanged between the controllers 14 and 29.

  The charging control process basically includes a positioning phase in which the power receiving side controller 29 positions the vehicle 100 based on the detection result of the secondary side detection unit 28, and the power transmission side controller 14 detects the primary side detection unit 16. It consists of a confirmation phase for confirming that power transmission is possible based on the result, and a charging phase for actually charging.

  First, the positioning phase will be described. As shown in FIG. 2, when the charging control process is started, the power transmission side controller 14 stands by until a request signal for positioning power is received in step S101.

  On the other hand, in step S201, the power receiving side controller 29 sets the switching relay 27 so that the output destination of the received power is the first load 25, specifically, the power receiver 23 and the first load 25 are connected. Control. Thereafter, the power receiving side controller 29 transmits a positioning power request signal to the power transmitting side controller 14 in step S202.

  When the power transmission side controller 14 receives the positioning power request signal, the power transmission side controller 14 proceeds to step S102 and starts the output of the positioning power as the first AC power. The converter 12a and the DC / AC converter 12b) are controlled. The positioning power is AC power having a smaller power value than the charging power. Thereafter, the power transmission side controller 14 stands by until a positioning completion signal is received in step S103.

  In step S <b> 203, the power receiving side controller 29 determines whether or not the positioning is completed in a situation where positioning power is output from the AC power supply 12. Specifically, the power receiving side controller 29 determines whether or not the voltage value V detected by the secondary side detection unit 28 is equal to or higher than a predetermined threshold voltage value Vth. The process of step S203 corresponds to “first transmission determination”, and the function of the power receiving controller 29 executing the process of step S203 corresponds to “first transmission determination unit”.

  Here, when the power transmitter 13 and the power receiver 23 are not arranged at a position where magnetic field resonance is possible, AC power is not received by the power receiver 23. In this case, the voltage value V detected by the secondary side detection unit 28 is 0 (V).

  On the other hand, when the power transmitter 13 and the power receiver 23 are arranged at a position where magnetic field resonance is possible, AC power is received by the power receiver 23. In this case, the voltage value V detected by the secondary side detection unit 28 is higher than 0 (V).

  Incidentally, the threshold voltage value Vth is set to a value indicating that the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power. For example, when a permissible range that allows a positional deviation between the power transmitter 13 and the power receiver 23 with respect to the reference position is determined, the permissible range is obtained under the condition that positioning power is output from the AC power supply 12. The relative position between the power transmitter 13 and the power receiver 23 at which the voltage value V detected by the secondary side detection unit 28 is minimum is defined as the first specific relative position. In this case, the threshold voltage value Vth is such that positioning power is output from the AC power supply 12 in a situation where the relative position between the power transmitter 13 and the power receiver 23 is the first specific relative position, and the output destination of the received power is the first. This is the voltage value V detected by the secondary side detection unit 28 when the load is one. That is, the threshold voltage value Vth is such that positioning power is output from the AC power supply 12 and the output destination of the received power is the first in a situation where the power transmitter 13 and the power receiver 23 are disposed within the allowable range. This is the minimum value of the voltage value V detected by the secondary side detection unit 28 when the load 25 is used.

  The allowable range is arbitrary as long as it is a predetermined range. For example, the AC power supply 12 may be set as a range in which AC power (charging power) having a desired power value can be output. Specifically, the output power value of the AC power supply 12 depends on the impedance from the output terminal of the AC power supply 12 to the vehicle battery 22. The impedance depends on the relative positions of the power transmitter 13 and the power receiver 23. For this reason, even if the relative position fluctuates within the permissible range and the impedance fluctuates, the permissible range is the rating (drive) of the AC power supply 12 so that the charging power can be output. It is good to set it according to (capability).

  When the voltage value V detected by the secondary side detection unit 28 is equal to or higher than the threshold voltage value Vth, the power receiving side controller 29 makes an affirmative determination in step S203 and proceeds to step S204, while the voltage value V is equal to the threshold value. If it is less than the voltage value Vth, the voltage value V is grasped again after a predetermined time, and the voltage value V is compared with the threshold voltage value Vth. That is, the power receiving side controller 29 periodically grasps the voltage value V, and the voltage value V and the threshold voltage value until the voltage value V detected by the secondary side detection unit 28 becomes equal to or higher than the threshold voltage value Vth. The comparison with Vth is repeatedly executed.

  In step S <b> 204, the power receiving side controller 29 executes a vehicle stop process for stopping the vehicle 100. In the vehicle stop process, the power receiving controller 29 uses a display monitor, a speaker, or the like mounted on the vehicle 100 at the current position (that is, a position where the power receiver 23 can receive AC power from the power transmitter 13). Notify to stop. When the vehicle 100 has an automatic driving function, the vehicle 100 may be forcibly stopped using the automatic driving function.

  Thereafter, the power receiving side controller 29 transmits a positioning completion signal to the power transmitting side controller 14 in step S205, and waits until a switching request signal is received in step S206.

  As described above, in the situation where positioning power is output from the AC power supply 12 and the output destination of the received power is the first load 25, it is detected from the power transmission path from the power receiver 23 to the first load 25. Based on the voltage value V, the vehicle 100 is positioned. Each controller 14 and 29 executes a confirmation phase when the positioning is completed.

  Next, the confirmation phase will be described. As shown in FIG. 2, when the power transmission side controller 14 receives the positioning completion signal, the power transmission side controller 14 proceeds to step S104 and controls the AC power supply 12 so that the output of the positioning power is stopped. In subsequent step S <b> 105, the power transmission side controller 14 transmits a switching request signal requesting that the output destination of the received power is switched from the first load 25 to the second load 26. Thereafter, the power transmission controller 14 stands by until a switch completion signal is received in step S106.

  When the power receiving side controller 29 receives the switching request signal, the power receiving unit 23 and the second load 26 are connected in detail so that the output destination of the received power is the second load 26 in step S207. The switching relay 27 is controlled as described above. Then, the power receiving side controller 29 transmits a switching completion signal to the power transmission side controller 14 in step S208 and waits until a chargeable signal is received in step S209. The function of executing the processing of step S105, step S206, and step S207 in cooperation with the controllers 14 and 29 corresponds to the “switching control unit”.

  When the power transmission side controller 14 receives the switching completion signal, the power transmission side controller 14 proceeds to step S107 and controls the AC power supply 12 so that the confirmation power as the second AC power is output. The confirmation power is AC power having a smaller power value than the charging power. Then, in step S108, the power transmission side controller 14 acquires the detection result of the primary side detection unit 16, calculates the power factor λ based on the detection result, and the calculated power factor λ is determined in advance. It is determined whether the power factor is equal to or greater than the threshold power factor λth. In the present embodiment, the power value of the positioning power and the power value of the confirmation power are the same.

  Here, the input impedance of the power transmitter 13 varies depending on whether or not the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power. When the input impedance varies, the power factor λ also varies. Specifically, the power factor λ increases when the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power. For this reason, it can be said that the process of step S108 is a process of determining whether or not the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power.

  The threshold power factor λth is set to a value indicating that the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power. For example, the threshold power factor λth is such that the confirmation power is output from the AC power supply 12 and the output destination of the received power is the first in a situation where the power transmitter 13 and the power receiver 23 are disposed within the allowable range. This is the minimum power factor when there are two loads 26. More specifically, the relative position between the power transmitter 13 and the power receiver 23 at which the power factor λ is minimized within the allowable range under the condition where the confirmation power is output from the AC power supply 12 is the second specific relative position. And In this case, the threshold power factor λth is output from the AC power supply 12 in a situation where the relative position between the power transmitter 13 and the power receiver 23 is the second specific relative position, and the output destination of the received power is the first This is the power factor λ when there are two loads 26. Note that the first specific relative position and the second specific relative position may be the same position or different.

  As already described, the power factor λ is calculated based on the output current value Iout of the AC power supply 12 as a kind of current value detected from the power transmission path from the AC power supply 12 to the power transmitter 13. . Further, in the situation where the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power, when the confirmation power is output from the AC power supply 12, power transmission is performed between the power transmitter 13 and the power receiver 23. Yes. For this reason, the process of step S108 is based on the electric current value detected from the power transmission path | route from AC power supply 12 to the power transmission device 13, whether power transmission is performed between the power transmission device 13 and the power receiving device 23. It can be said that this is a process for determining. The process of step S108 corresponds to “second transmission determination”, and the function of the power transmission side controller 14 executing the process of step S108 corresponds to “second transmission determination unit”.

  When the calculated power factor λ is less than the threshold power factor λth, there is a high probability that incorrect positioning has been performed for some reason. In this case, the power transmission side controller 14 determines that power transmission is not performed between the power transmitter 13 and the power receiver 23, and executes an abnormality handling process in step S109. In the abnormality handling process, the power transmission side controller 14 transmits, for example, a notification that an abnormality has occurred to the power reception side controller 29, and ends this charging control process. When the power receiving side controller 29 receives the notification, it determines that an abnormality has occurred, stops the subsequent processing, and ends the charging control processing.

  Note that the specific configuration of the abnormality handling process is not limited to the above. For example, the controllers 14 and 29 may be configured to sequentially perform steps S101 and S201 again.

  On the other hand, when the calculated power factor λ is equal to or greater than the threshold power factor λth, it means that the power transmission side controller 14 has also confirmed that the power receiver 23 is disposed at a position where the power transmitter 13 can transmit power. . In other words, the power transmission side controller 14 determines that power transmission is being performed between the power transmitter 13 and the power receiver 23. In this case, each controller 14 and 29 performs processing for charging the vehicle battery 22.

Specifically, first, the power transmission side controller 14 transmits a chargeable signal to the power reception side controller 29 in step S110.
When the power receiving side controller 29 receives the charge enable signal, the power receiving side controller 29 makes a positive determination in step S209 and proceeds to step S210. In step S210, the power receiving side controller 29 controls the switching relay 27 so that the power receiver 23 and the rectifier 24 are connected in detail so that the output destination of the received power is the rectifier 24.

  Then, each controller 14 and 29 shifts to a charging phase. In the charging phase, the power transmission controller 14 continues to output charging power having a power value larger than both the positioning power and the confirmation power until a predetermined charging termination condition is satisfied. The charging termination condition is arbitrary. For example, in the configuration in which the charging state (SOC) of the vehicle battery 22 is terminated or when the power transmission device 11 is provided with a stop switch, the stop switch It is conceivable that has been operated.

  Next, the operation of this embodiment will be described with reference to FIGS. For convenience of explanation, it is assumed that the power transmitter 13 is installed on the ground and the power receiver 23 is provided at the bottom of the vehicle 100.

  As shown in FIGS. 3A and 3B, the vehicle 100 on which the power receiver 23 (power receiving device 21) is mounted enters the wireless communication range of the power transmission side controller 14, and the power receiver 23 is When arranged within the allowable range, as shown in FIG. 4A, the voltage value V detected by the secondary side detection unit 28 rises from 0 (V), and the voltage value V becomes the threshold voltage value Vth. That's it. Then, as shown in FIG. 4A, the positioning of the vehicle 100 is completed by stopping the vehicle 100 in a state where the voltage value V is equal to or higher than the threshold voltage value Vth at the timing t1. As shown in FIG. 4B, the power factor λ slightly increases when the power receiver 23 is disposed within the allowable range.

  As shown in FIG. 4A and FIG. 4B, when the output destination of the received power is switched from the first load 25 to the second load 26 having a lower impedance than the first load 25 at the timing t2. While the voltage value V decreases, the power factor λ increases. In this case, when power transmission between the power transmitter 13 and the power receiver 23 is normally performed, the power factor λ is equal to or greater than the threshold power factor λth.

  Here, as shown in FIG. 4A, the voltage value V when the vehicle 100 does not exist is set to the first voltage value V1, the positioning of the vehicle 100 is completed, and the output destination of the received power is the first. The voltage value V when the load is 1 is the second voltage value V2, the positioning of the vehicle 100 is completed, and the voltage value V when the output destination of the received power is the second load is the third voltage value. V3. In this case, since the impedance of the first load 25 is higher than the impedance of the second load 26, the second voltage value V2 is equal to the third voltage value V3 under the same relative position between the power transmitter 13 and the power receiver 23. Higher than. In other words, the difference δV1 between the second voltage value V2 and the first voltage value V1 is larger than the difference δV2 between the third voltage value V3 and the first voltage value V1. The threshold voltage value Vth is set to be relatively high in correspondence with the second voltage value V2 being higher than the third voltage value V3. Specifically, the threshold voltage value Vth is a value between the third voltage value V3 and the second voltage value V2. The first voltage value V1 is 0 (V).

  Similarly, as shown in FIG. 4B, the power factor λ when the vehicle 100 is not present is the first power factor λ1, the positioning of the vehicle 100 is completed, and the output destination of the received power is the first power factor λ1. The power factor λ when the load is 1 is the second power factor λ2, the positioning of the vehicle 100 is completed, and the power factor λ when the output destination of the received power is the second load is the third power factor. Let λ3. In this case, since the impedance of the second load 26 is lower than the impedance of the first load 25, the third power factor λ3 is equal to the second power factor λ2 under the same relative positions of the power transmitter 13 and the power receiver 23. Higher than. In other words, the difference δλ2 between the third power factor λ3 and the first power factor λ1 is larger than the difference δλ1 between the second power factor λ2 and the first power factor λ1. The threshold power factor λth is set to be relatively high in correspondence with the third power factor λ3 being higher than the second power factor λ2. Specifically, the threshold power factor λth is a value between the second power factor λ2 and the third power factor λ3.

According to the embodiment described above in detail, the following effects are obtained.
(1) The power transmission device 11 includes an AC power source 12 capable of outputting AC power having different power values, and a power transmitter 13 (primary coil 13a) to which AC power output from the AC power source 12 is input. ing. The power receiving device 21 receives a power receiver 23 (secondary coil 23 a) capable of receiving AC power input to the power transmitter 13 in a contactless manner, and received power that is AC power received by the power receiver 23. A first load 25 and a second load 26 having different impedances are provided. The power receiving device 21 includes a switching relay 27 that switches the output destination of the received power to the first load 25 or the second load 26.

  The power receiving side controller 29 of the power receiving device 21 transmits power from the power receiver 23 to the first load 25 in a situation where the output destination of the received power is the second load 26 and positioning power is output from the AC power supply 12. Based on the voltage value V of the received power detected from the path, a first transmission determination is performed to determine whether power transmission is being performed between the power transmitter 13 and the power receiver 23. Each controller 14, 29, when the first transmission determination is an affirmative determination, that is, when it is determined by the first transmission determination that power transmission is being performed between the power transmitter 13 and the power receiver 23, Is switched from the first load 25 to the second load 26 having a lower impedance than the first load 25. And the power transmission side controller 14 is the electric power transmission path | route from the alternating current power supply 12 to the power transmission device 13 in the condition where the output destination of received electric power is the 2nd load 26, and the electric power for confirmation is output from the alternating current power supply 12. Based on the power factor λ calculated from the current value detected from above, second transmission determination is performed to determine whether or not power transmission is being performed between the power transmitter 13 and the power receiver 23. When the second transmission determination is an affirmative determination, that is, when it is determined by the second transmission determination that power transmission is being performed between the power transmitter 13 and the power receiver 23, the AC power supply 12 The charging power having a power value larger than the confirmation power is output.

  According to such a configuration, it is possible to uniquely determine whether or not power transmission is performed between the power transmitter 13 and the power receiver 23 in both the power transmitting device 11 and the power receiving device 21 by the first transmission determination and the second transmission determination. . In addition, the second transmission determination is performed when the first transmission determination is affirmative. Thereby, even if the power transmission is not performed between the power transmitter 13 and the power receiver 23, even if the first transmission determination is erroneously affirmative, the second transmission determination is negative. Therefore, it can suppress that the electric power for charge is output accidentally.

  Further, the first transmission determination and the second transmission determination are performed with positioning power and confirmation power having a power value smaller than the charging power. Thereby, power loss required for each transmission determination can be reduced, and the burden on the AC power supply 12 can be reduced.

  Here, when performing the first transmission determination and the second transmission determination using the positioning power and the confirmation power with relatively small power values, the voltage according to the presence or absence of power transmission between the power transmitter 13 and the power receiver 23. The amount of change in value V and power factor λ tends to be small. For this reason, erroneous determination is likely to occur in each transmission determination.

  On the other hand, in this embodiment, since the output destination of the received power when the first transmission determination is performed is the first load 25 having a relatively high impedance, the voltage value V corresponding to the presence or absence of the power transmission. (The difference δV1 between the first voltage value V1 and the second voltage value V2) is large. Thereby, the first abnormality determination can be performed with high accuracy.

  On the other hand, since the output destination of the received power when the second transmission determination is performed is the second load 26 having a relatively low impedance, the change amount of the power factor λ according to the presence or absence of the power transmission (first power factor) The difference δλ2) between λ1 and the third power factor λ3 is large. Thereby, the second transmission determination can be performed with high accuracy.

From the above, it is possible to suitably perform both the first transmission determination and the second transmission determination using the positioning power and the confirmation power with relatively small power values.
In addition, when the power transmission is not performed between the power transmitter 13 and the power receiver 23, the case where the first transmission determination is erroneously determined as affirmative is, for example, after the voltage value V becomes equal to or higher than the threshold voltage value Vth. A case where the vehicle 100 stops at a position where the voltage value V becomes less than the threshold voltage value Vth by moving the vehicle 100 during the time lag until the vehicle 100 stops can be considered.

  (2) When the power factor λ calculated from the detection result of the primary side detection unit 16 is greater than or equal to a predetermined threshold power factor λth in the second transmission determination, the power transmission side controller 14 transmits the power transmitter 13. Then, it is determined that power transmission is performed between the power receivers 23. When the change amount of the power factor λ according to the presence or absence of power transmission between the power transmitter 13 and the power receiver 23 is relatively small, it may be difficult to set the threshold power factor λth. Even if the threshold power factor λth can be set, erroneous determination is likely to occur. For example, when the output destination of the received power is the first load 25, it is necessary to set the threshold power factor λth to a value between the first power factor λ1 and the second power factor λ2. In this case, erroneous determination is likely to occur due to the influence of noise or the like.

  On the other hand, according to the present embodiment, the threshold power factor λth can be easily set to the extent that the amount of change can be increased. Further, since the threshold power factor λth can be set to a value relatively far from the first power factor λ1, the influence of noise and the like can be suppressed. From the above, the second transmission determination can be performed relatively easily and accurately.

  (3) The first load 25 and the second load 26 are provided separately from the rectifier 24 and the vehicle battery 22 and are fixed loads having a constant impedance. The switching relay 27 switches the output destination of the received power to the rectifier 24, the first load 25, or the second load 26. Thereby, compared with the structure which uses the battery 22 for vehicles as a 2nd load, the improvement of the determination precision of 2nd transmission determination can be aimed at.

  More specifically, the vehicle battery 22 is a variable load whose impedance varies according to the state of charge, the input power value, and the like. The power factor λ varies according to the impedance of the vehicle battery 22. For this reason, if the vehicle battery 22 is used as the second load, the power factor λ varies depending on both the presence / absence of power transmission between the power transmitter 13 and the power receiver 23 and the impedance of the vehicle battery 22. As a result, the determination accuracy of the second transmission determination decreases. On the other hand, according to the present embodiment, since the second transmission determination is performed using the second load 26 of the fixed load provided separately from the vehicle battery 22, the fluctuation of the impedance of the vehicle battery 22 is changed. The impact can be avoided.

  (4) The power receiving device 21 is mounted on the vehicle 100 as a moving body. The first transmission determination is performed while the vehicle 100 is moving, while the second transmission determination is performed when the vehicle 100 is stopped. Thereby, the vehicle 100 can be positioned based on the determination result of the first transmission determination. Moreover, after positioning of the vehicle 100 is performed based on the determination result of the first transmission determination, it is possible to confirm whether or not the positioning of the vehicle 100 has been normally performed by performing the second transmission determination. Therefore, it is possible to suppress the charging power from being output from the AC power supply 12 while the vehicle 100 is stopped at the wrong position.

In addition, you may change the said embodiment as follows.
○ The second load 26 may be omitted. In this case, the switching relay 27 switches the output destination of the received power to the first load 25 or the rectifier 24. In such a configuration, the second transmission determination may be performed in a situation where the output destination of the received power is the rectifier 24 (vehicle battery 22). Even in this case, since the impedance of the vehicle battery 22 is lower than the impedance of the first load 25, the second transmission determination can be performed. However, from the viewpoint of a decrease in the determination accuracy of the second transmission determination due to the fluctuation of the impedance of the vehicle battery 22, it is preferable that the second load 26 is provided separately. In this example, the vehicle battery 22 corresponds to the “second load”.

  In the embodiment, a plurality of output destinations of received power are provided. However, the present invention is not limited to this. For example, a plurality of output destinations of DC power output from the rectifier 24 may be provided. Specifically, the power receiving device 21 may include a switching unit that switches the connection destination of the rectifier 24 to the first load 25, the second load 26, or the vehicle battery 22. In short, the switching unit only needs to switch the received power or the output destination of the DC power obtained by converting the received power to the first load or the second load. Moreover, the 1st load 25 and the 2nd load 26 should just receive DC power obtained by converting received power or the said received power.

  In the other example, the secondary side detection unit 28 may detect the output voltage value of the rectifier 24 or the input voltage value of the first load 25. That is, the detection target of the secondary side detection unit 28 may be an AC voltage value or a DC voltage value. In short, the secondary side detection unit 28 only needs to detect a voltage value on the power transmission path from the power receiver 23 to the first load 25, and the first transmission determination is performed based on the voltage value. It's fine.

  The power value of the positioning power used in the first transmission determination may be different from the power value of the confirmation power used in the second transmission determination. In short, the positioning power (first AC power) used in the first transmission determination and the confirmation power (second AC power) used in the second transmission determination are from the charging power (third AC power). As long as the power value is small. The threshold voltage value Vth may be set in correspondence with the positioning power, and the threshold power factor λth may be set in correspondence with the confirmation power.

  The second transmission determination is performed based on the power factor λ, but is not limited thereto. For example, the second transmission determination may be performed based on the output current value Iout of the DC / AC converter 12b, or may be performed based on the input current value Iin of the power transmitter 13. The second transmission determination may be made based on the difference between the output current value Iout of the DC / AC converter 12b and the input current value Iin, or the output current value Iout of the DC / AC converter 12b and the output You may perform based on the active power value etc. which are the values which multiplied the voltage value. In short, the second transmission determination may be performed based on the current value detected from the power transmission path from the AC power supply 12 to the power transmitter 13, and in detail, a parameter relating to the current value is a predetermined threshold value. What is necessary is just to determine whether it is above. The parameter relating to the current value includes the current value itself and various parameters calculated using the current value.

  The power receiving device 21 may include a load to which AC power is input instead of the rectifier 24 and the vehicle battery 22. That is, the AC power received by the power receiver 23 may be used for purposes other than charging the vehicle battery 22.

  The specific aspect of the first transmission determination is not limited to that of the embodiment, but is arbitrary. For example, the power receiving side controller 29 grasps in advance the voltage value V when the AC power is not received from the power transmitter 13 as the reference voltage value, and is detected by the secondary side detection unit 28 in the second transmission determination. It may be determined whether or not the difference between the measured voltage value V and the reference voltage value is greater than or equal to a predetermined threshold value.

  Similarly, the power transmission side controller 14 grasps in advance the first power factor λ1, which is the power factor λ when the vehicle 100 (power receiver 23) does not exist at a position where the power transmitter 13 can transmit power, and performs the second transmission. In the determination, it may be determined whether or not the difference between the power factor λ calculated from the detection result of the primary side detection unit 16 and the first power factor λ1 is equal to or greater than a predetermined threshold value.

  The threshold power factor λth is arbitrary as long as it is higher than the first power factor λ1, but it is preferable that the threshold power factor λth is closer to the third power factor λ3 in view of the fact that the influence of noise and the like can be suppressed. Similarly, the threshold voltage value Vth is arbitrary as long as it is higher than 0 (V).

  A configuration in which the first transmission determination is performed after the vehicle 100 stops may be used. In this case, it may be adopted that the vehicle 100 is stopped in a state where the power transmission side controller 14 and the power reception side controller 29 can perform wireless communication as an execution trigger of the charging control process.

  The power transmission side controller 14 may control the alternating current power supply 12 so that it may become a desired output electric power value based on 3rd power factor (lambda) 3. Thereby, direct-current power of a desired power value can be input to the vehicle battery 22.

  ○ When the vehicle 100 enters the wireless communication range of the power transmission side controller 14 as a trigger for executing the charging control process, the communication establishment state in which the controllers 14 and 29 are authenticated as communication partners with each other You may adopt the case. The communication established state is a state in which communication with an authenticated controller is performed, but communication with a controller other than the authenticated controller is restricted.

  A plurality of impedance converters 15 may be provided. Further, the power receiving device 21 may be provided with an impedance converter. Further, the impedance converter 15 may be omitted.

  In the embodiment, the external power is system power, but is not limited thereto, and may be DC power. In this case, the AC / DC converter 12a may be omitted, or a DC / DC converter may be provided in place of the AC / DC converter 12a.

The resonance frequency of the power transmitter 13 and the resonance frequency of the power receiver 23 are set to be the same. However, the present invention is not limited to this, and they may be different within a range where power transmission is possible.
The power transmitter 13 and the power receiver 23 have the same configuration, but are not limited to this, and may have different configurations.

Each capacitor 13b, 23b may be omitted. In this case, magnetic field resonance is performed using the parasitic capacitances of the coils 13a and 23a.
○ The power receiving device 21 may be mounted on any object, and may be mounted on, for example, a robot or an electric wheelchair. Alternatively, the power receiving device 21 may be mounted on a mobile phone and the mobile phone battery may be charged using non-contact power transmission.

In the embodiment, magnetic field resonance is used in order to realize non-contact power transmission. However, the present invention is not limited to this, and electromagnetic induction may be used.
The power transmitter 13 may include a resonance circuit including a primary side coil 13a and a primary side capacitor 13b, and a primary side coupling coil that is coupled to the resonance circuit by electromagnetic induction. Similarly, the power receiver 23 may include a resonance circuit including a secondary coil 23a and a secondary capacitor 23b, and a secondary coupling coil coupled to the resonance circuit by electromagnetic induction.

Next, a preferable example that can be grasped from the embodiment and another example will be described below.
(B) The AC power supply is a voltage source. The contactless power transmission device according to any one of claims 1 to 4.

  (B) AC power that can output AC power, a power transmission device having a primary coil to which the AC power is input, and the AC power that is input to the primary coil can be received without contact. A secondary coil, and a power receiving device having a first load and a second load to which AC power received by the secondary coil or DC power obtained by converting the AC power is input. In the non-contact power transmission apparatus, the power receiving device receives the first load or the alternating current power received by the secondary coil or the output destination of direct current power obtained by converting the alternating current power. In a situation where the switching unit for switching to the second load, the output destination is the first load, and the AC power is output from the AC power source, the secondary load causes the first load to 1st transmission which performs the 1st transmission judgment which judges whether electric power transmission is performed between the primary side coil and the secondary side coil based on the voltage value detected from the power transmission path in A non-contact power transmission device, wherein when the first transmission determination unit determines that power transmission is performed between the primary side coil and the secondary side coil, An output destination includes a switching control unit that controls the switching unit to switch from the first load to the second load having an impedance lower than the impedance of the first load, and the power transmission device includes the output destination Is the second load, and in the situation where the AC power is output from the AC power source, based on the current value detected from the power transmission path from the AC power source to the primary coil, Above Non-contact power transmission apparatus characterized in that it comprises a second transmission determination unit that performs second transmission determination determines whether power transfer is being performed between the following side coil and the secondary coil.

  DESCRIPTION OF SYMBOLS 10 ... Non-contact electric power transmission apparatus, 11 ... Power transmission apparatus, 12 ... AC power supply, 13a ... Primary side coil, 14 ... Power transmission side controller, 16 ... Primary side detection part, 21 ... Power receiving apparatus, 22 ... Battery for vehicles, 23a ... secondary coil, 24 ... rectifier (AC / DC converter), 25 ... first load, 26 ... second load, 27 ... switching relay, 28 ... secondary side detection unit, 29 ... power receiving side controller.

Claims (4)

AC power supply capable of outputting a plurality of types of AC power having different power values, and a power transmission device having a primary coil to which the AC power is input,
A secondary coil that can receive the AC power input to the primary coil in a contactless manner, and an AC power received by the secondary coil or a DC power obtained by converting the AC power A power receiving device having a first load and a second load,
A non-contact power transmission device comprising:
The power receiving device is:
A switching unit that switches the AC power received by the secondary coil or the output destination of DC power obtained by converting the AC power to the first load or the second load;
The voltage detected from the power transmission path from the secondary coil to the first load in the situation where the output destination is the first load and the first AC power is output from the AC power source. A first transmission determination unit that performs a first transmission determination to determine whether power transmission is performed between the primary side coil and the secondary side coil based on a value;
With
In the non-contact power transmission device, when the first transmission determination unit determines that power transmission is performed between the primary coil and the secondary coil, the output destination is the first A switching control unit for controlling the switching unit to switch from the load to the second load having an impedance lower than the impedance of the first load;
In the situation where the output destination is the second load and the second AC power is output from the AC power source, the power transmission device is on the power transmission path from the AC power source to the primary coil. A second transmission determination unit that performs a second transmission determination to determine whether power transmission is performed between the primary side coil and the secondary side coil based on the detected current value;
When the AC power supply is determined by the second transmission determination that power transmission is performed between the primary coil and the secondary coil, the AC power supply is based on the first AC power and the second AC power. A non-contact power transmission device that outputs third AC power having a large power value.   In the situation where the output destination is the second load and the second AC power is output from the AC power source, the second transmission determination unit is configured to supply power from the AC power source to the primary coil. When the current value detected from the transmission path or the parameter calculated from the current value is greater than or equal to a predetermined threshold value, power is transmitted between the primary side coil and the secondary side coil. The contactless power transmission device according to claim 1, wherein the contactless power transmission device is determined to be The power receiving device is:
An AC / DC converter that converts AC power received by the secondary coil into DC power;
A battery to which the DC power converted by the AC / DC converter is input;
With
The first load and the second load are provided separately from the battery and are fixed loads having a constant impedance,
The non-contact power transmission apparatus according to claim 1, wherein the switching unit is configured to switch the output destination to the AC / DC conversion unit, the first load, or the second load. The power receiving device is mounted on a moving body,
The first transmission determination by the first transmission determination unit is performed while the mobile body is moving,
The non-contact power transmission apparatus according to claim 1, wherein the second transmission determination by the second transmission determination unit is performed when the moving body is stopped.