JP6081207B2 - Contactless power supply system, power receiving device, power supply stand, contactless power supply method - Google Patents

Description

  The present invention relates to a non-contact power feeding system, a power receiving device, a power feeding base, and a non-contact power feeding method in which a power transmission coil and a power receiving coil are arranged close to each other so as to be electromagnetically coupled, About.

  A contactless power feeding method has been developed in which a power receiving device with a built-in power receiving coil is set on a power feeding base with a built-in power transmitting coil, and power is transferred from the power transmitting coil to the power receiving coil (see Patent Document 1). In this non-contact power supply method, for example, as shown in FIG. 12, a power receiving device 260 such as a mobile phone is placed on a charging surface 221 of a non-contact power supply base 220, and power is transferred from the power supply base 220 to the power receiving device 260. Then, the secondary battery built in the power receiving device 260 is charged. In order to realize such non-contact power transmission, the power receiving coil 261 of the mobile phone is brought close to the power transmitting coil 251 of the power supply stand 220 and power is transmitted from the power transmitting coil 251 to the power receiving coil 261. As a result, the internal battery is charged with the electric power induced in the power receiving coil 261. This power transmission method does not require the mobile phone to be connected to the power supply base via the connector, and has the advantage that power can be transferred to the mobile phone in a contactless manner.

  By the way, power receiving devices in recent years are required to have higher output due to demands such as a larger screen and longer battery driving time, and the capacity of built-in secondary batteries tends to be increased. As a result, the power required for charging also increases, and the charging time tends to be longer if the transmission power is the same as in the past. On the other hand, there is a strong demand for shortening the charging time as much as possible, and there is a demand for higher output of the power supply stand.

  On the other hand, standardization of the contactless power feeding method is being promoted so that different models and manufacturers of power receiving devices can be charged with a common charging stand. For example, in the WPC (Wireless Power Consortium), which is one of standardization organizations, the power supply base 1310 supplies power to the power reception apparatus 1350 while performing unidirectional communication from the power reception apparatus 1350 to the power supply base 1310 as shown in FIG. A specification has been established for this purpose.

  In order to charge a high-output power receiving device in a short time, it is conceivable to increase the power supply stand as described above. Accordingly, it is conceivable that charging with high output is possible in a combination of a power receiving device and a power supply base that is compatible with charging with high output outside the standard while enabling charging according to the standard.

  However, if you prepare an electrical device that can supply power at a non-standard high output, if you place it on a power supply stand that does not support non-standard high-output power supply, As a result of seeking power supply, the current value of the power supply base rises and generates heat, or the current value and temperature increase, and it is erroneously detected that a foreign object exists between the power supply base and the power receiving device. There was also a problem that power supply was stopped.

JP 2008-17562 A

  The present invention has been made in view of such conventional problems. An object of the present invention is to provide a non-contact power supply system, a power receiving device, a power supply stand, and a non-contact power supply method capable of charging with a large current without adding hardware for new communication. It is in.

  On the other hand, in the conventional charging method using a wired connection, a dedicated charger is often prepared for each model or manufacturer, and it is generally possible to use only a specific combination. On the other hand, in contactless power transmission, since there is no need to mechanically connect terminals and connectors, the combination of the power receiving device and the power supply stand can be used without being between specific models or manufacturers. It is desirable to do. Therefore, as described above, standardization of power receiving devices and power supply bases used for contactless power transmission is underway. For example, in WPC, as shown in FIG. 13, specifications for the power supply base 1310 to supply power to the power receiving device 1350 are established while performing unidirectional communication from the power receiving device 1350 to the power supply base 1310.

  On the other hand, if a foreign object exists between the contactless power supply base and the power receiving device, the foreign object may generate heat. For example, as shown in the schematic diagram of FIG. 14, when a metal foreign object FO (Foreign Object) such as a clip is inserted between the power transmission coil 4103 and the power receiving coil 4104, an induced current flows through the metal foreign object, resulting in Joule heat. Fever. Therefore, it is conceivable that the power receiving device has a foreign object detection function for detecting that a foreign material is placed between the contactless power supply base and the power receiving device. The foreign object detection function determines whether a foreign object exists based on, for example, charging efficiency. Specifically, the target value of the current required for charging is transmitted from the power receiving device to the power supply base, and the charging efficiency is calculated by comparing with the actual power transmitted from the power supply base and received by the power receiving device. Is compared with a predetermined threshold value (foreign substance threshold value), and when the charging efficiency is lower than the foreign substance threshold value, it is determined that a foreign object exists. When the power receiving device determines that there is a foreign object, it sends a foreign object detection signal to the power transmission device and takes necessary measures on the power transmission device side. For example, measures such as stopping power transmission or reducing the power transmission current to continue charging can be cited. As described above, in order to realize the foreign object detection function, it is necessary to support the foreign object detection function not only on the power receiving device side but also on the power supply stand side.

  In this case, for example, when a power receiving device having a foreign object detection function is set on a power supply stand that does not support the foreign object detection function and power transmission is attempted, the power reception device detects the foreign material and sends the foreign object detection signal to the power supply base. Even if it is sent out, this signal cannot be properly processed on the power supply stand side, and as a result, even if a foreign object is present, an appropriate measure is not executed, for example, a metal foreign object generates heat and becomes high temperature. It is done.

  In such a case, if power can be transmitted in a state in which the transmission current transmitted from the power supply side to the power receiving device is limited, heat generation due to foreign matter can be reduced. However, as described above, in the unidirectional communication such as the WPC standard, it is impossible to determine whether the power receiving device side is the type of the power supply stand, that is, the power supply stand corresponding to the foreign object detection function. Only on the other hand, it is impossible to control to limit the transmission current.

  For this reason, only uniform control can be performed for all the power supply bases. For example, when the transmission current is controlled at a high current value, there is a possibility that the power supply base without the foreign object detection function may become hot when foreign objects exist. . Conversely, if the control is performed so that the power transmission current is low for all the power supply bases, the temperature can be kept low even when foreign objects are present, so that there is a problem that the charging time until the battery is fully charged becomes long. It was.

  The present invention has been made in view of such conventional problems. Another object of the present invention is to provide a non-contact power supply system, a power receiving device, a power supply that can transmit power without suppressing power transmission current while suppressing power transmission current when foreign material is present. It is to provide a power stand and a contactless power supply method.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above-described problem, according to the contactless power feeding system of the present invention, the power receiving device includes an electric load, and a power feeding base that transmits power to the power receiving device. A contactless power supply system capable of transmitting power by transmitting power without contact, wherein the power receiving device receives the electric load, a power receiving coil for receiving power transmitted from the power supply base, and power received by the power receiving coil Power receiving side control means for controlling driving of the electric load with power, power receiving amount acquiring means for acquiring the amount of power actually obtained on the power receiving apparatus side, and power transmission transmitted from the power supply base to the power receiving apparatus Request signal generating means for generating a power transmission request signal for instructing the quantity, and the power supply base is generated by the power transmission coil for electromagnetically coupling with the power receiving coil and transmitting power, and the request signal generating means A request signal receiving means for receiving a power transmission request signal, and a power control means for controlling the amount of power transmitted from the power transmission coil based on the power transmission request signal received by the request signal receiving means, The power supply base has a first current mode in which power can be transmitted with a first target current value as a rated current, and a second current mode in which power can be transmitted with a second target current value larger than the first target current value as a rated current. The power control means can be switched, and the request signal generating means, as a power transmission request signal, a first power transmission request signal for requesting a first transmission power necessary for power transmission in the first current mode, It is possible to transmit a second transmission request signal for requesting second transmission power required for power transmission in the two-current mode. With the above configuration, it is possible to increase the power transmission energy and to perform charging in a short time.

  Moreover, according to the power receiving device of the present invention, the power receiving device can be driven in a contactless manner with the power transmitted through the power transmission coil built in the power supply stand, and transmits the electric load and the electric load. In order to receive power, a power receiving coil that can be electromagnetically coupled to a power transmitting coil, power receiving side control means for controlling the driving of the electric load with power received by the power receiving coil, and actually obtained on the power receiving device side A received power amount acquisition means for acquiring the received power value, and a request signal generating means for generating a power transmission request signal for instructing a power transmission amount transmitted from the power supply base to the power receiving device, the request signal generating means, As a power transmission request signal, a first power transmission request signal for requesting a first transmission power required for power transmission in a first current mode capable of power transmission with a first target current value as a rated current, and larger than the first target current value Two target current value may enable transmitting a second transmission request signal requesting the second transmission power required for transmission of the second current mode can be transmitting a rated current. With the above configuration, it is possible to increase the power transmission energy and to perform charging in a short time.

  Furthermore, according to the power supply stand of the present invention, it is a power supply stand that can be driven by transmitting power without contact to a power receiving device having an electrical load, and electromagnetically coupled to a power receiving coil built in the power receiving device, A power transmission coil for transmitting power to the power receiving device; a request signal receiving means for receiving a power transmission request signal transmitted from the power receiving device and instructing the amount of power transmitted from the power supply to the power receiving device; and the request Power control means for controlling the amount of power transmitted from the power transmission coil based on the power transmission request signal received by the signal receiving means, wherein the power control means transmits the first target current value as a rated current. It is possible to switch between a possible first current mode and a second current mode in which power can be transmitted with a second target current value larger than the first target current value as a rated current. With the above configuration, it is possible to increase the power transmission energy and to perform charging in a short time.

Furthermore, according to the non-contact power feeding method of the present invention, a non-contact power feeding method for driving a power receiving device having an electric load by transmitting power from a power feeding base in a non-contact manner, the power receiving coil of the power receiving device In a state in which power is transmitted from the power transmission coil to the power receiving coil in an electromagnetically coupled state to the power transmission coil of the power supply stand, and the power receiving device receives the electric power by the power received by the power receiving coil. Starting the power transmission to the load and detecting the power reception value, and based on the detected power reception value, the power transmission request signal instructing the increase or decrease in the amount of power transmitted from the power supply base to the power receiving device. wherein the step of transmitting the electric board, according to the power transmission request signal, and a step in which the power control means for adjusting the transmission amount of power to the power receiving coil from the transmitting coil, the power receiving device, the power transmission request signal A first transmission request signal for requesting a first transmission power required for power transmission in a first current mode in which transmission can be performed with the first target current value as a rated current, and a second target current larger than the first target current value The second transmission request signal for requesting the second transmission power required for power transmission in the second current mode in which the value can be transmitted as the rated current can be transmitted to the power supply stand together. As a result, it is possible to increase the power transmission energy and realize charging in a short time.

1 is a block diagram showing a contactless charging system according to Embodiment 1. FIG. It is a block diagram which shows the non-contact charge system which concerns on Embodiment 2. FIG. FIG. 6 is a block diagram showing a contactless charging system according to a third embodiment. It is a schematic diagram which shows a mode that electric power receiving equipment provided with a feed stand discrimination | determination function is transmitted with a feed stand provided with a foreign material detection function. It is a schematic diagram which shows a mode that it is a power supply stand provided with a foreign material detection function, and is transmitting power receiving apparatus without a power supply stand discrimination | determination function. It is a schematic diagram which shows a mode that electric power receiving equipment provided with a feed stand discrimination | determination function is transmitted with a feed stand without a foreign material detection function. It is a flowchart which shows the operation | movement which transmits the power receiving apparatus provided with a feed stand discrimination | determination function with the feed stand corresponding to an original control. It is a flowchart which shows operation | movement of the power receiving apparatus corresponding to an original control. It is a flowchart which shows operation | movement of the electric power feeding stand corresponding to an original control. It is a flowchart which shows operation | movement of the feed stand corresponding to a standard. It is a timing chart which shows the timing which a power receiving apparatus transmits two types of power transmission request signals to a feed stand. It is a perspective view which shows the conventional non-contact charging stand and a mobile phone. It is a schematic diagram which shows a mode that a battery built-in apparatus is charged with the charging stand according to the standard which performs non-contact charge. It is a schematic diagram which shows the case where a foreign material exists between a power transmission coil and a receiving coil.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below exemplify a non-contact power supply system, a power receiving device, a power supply stand, and a non-contact power supply method for embodying the technical idea of the present invention. The system, power receiving device, power supply stand, and contactless power supply method are not specified as follows. In particular, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the embodiments are referred to as “claims” and “means for solving the problems”. However, the members shown in the claims are not limited to the members in the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.

According to the non-contact power feeding system according to an embodiment of the present invention, the power feeding base further includes foreign matter detection means for detecting the presence of foreign matter between the power transmission coil and the power receiving coil, When the presence of a foreign object is detected by the foreign object detection means, the power supply stand can be controlled not to shift to the second current mode even when the second power transmission request signal is received. With the configuration described above, it is possible to increase safety by increasing the power transmission energy and realizing charging in a short time, but not shifting to the second current mode when detecting a foreign object.

  According to the non-contact power feeding system according to an embodiment of the present invention, the power feeding base may be configured to receive the second power transmission request signal when the foreign matter detecting unit detects the presence of the foreign matter. It can be controlled to transmit power in one current mode. With the above configuration, it is possible to increase safety by increasing the power transmission energy and realizing charging in a short time and reducing the amount of power transmission when detecting a foreign object.

Moreover, according to the non-contact power feeding system according to another embodiment of the present invention, the amount of power received can be a current value.

Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the amount of received power can be set to a power value.

  Furthermore, according to the contactless power supply system according to another embodiment of the present invention, the first current mode is a power supply corresponding to a standardized standard, and the second current mode is a charging stand discrimination function. The power receiving side control means determines that the power supply base has responded to the second power transmission request signal, determines that the power supply base responds to the charging base determination function compatible type, and outputs the second power transmission request signal. It can be configured to determine that it has responded to the first power transmission request signal and not to respond to the standard specification type.

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the power receiving side control means detects that the second transmission power corresponding to the second power transmission request signal is received from the power feeding stand. Then, it is determined that the charging base discriminating function is compatible, detects that the first transmission power corresponding to the first transmission request signal has been received without reacting to the second transmission request signal, Can be configured to discriminate.

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, when the request signal receiving unit receives the second power transmission request signal and the first power transmission request signal from the power receiving device, According to the power transmission request signal, the second power transmission is transmitted by the power control means, while the first power transmission request signal is ignored.

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the standardized standard is a WPC standard, and the first power transmission request signal can be a control error signal.

  Furthermore, according to the non-contact power feeding system according to another embodiment of the present invention, the second power transmission request signal is stored in the header included in the WPC standard proprietary packet signal with information on the charging stand determination function. it can.

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the foreign object detection means detects a received current value in the power receiving device, calculates a transmission efficiency based on the received current value, By comparing the transmission efficiency with a predetermined efficiency threshold value, it can be determined that foreign matter exists when the transmission efficiency is smaller than the efficiency threshold value, and it can be determined that no foreign matter exists when the transmission efficiency is larger than the efficiency threshold value. .

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the electrical load is a secondary battery, the power feeding base is a charging base for charging the secondary battery, and the power receiving Electric power is transmitted to the device without contact from the power supply base, and the power receiving side control means controls the charging current of the secondary battery with the received power received by the power receiving coil. The secondary battery can be charged.

  Furthermore, according to the contactless power supply system according to another embodiment of the present invention, the first target current value can be a current value according to a standardized contactless charging method.

  Furthermore, according to the contactless power feeding system according to another embodiment of the present invention, the first target current value can be set to 700 mA and the second target current value can be set to 900 mA.

  Furthermore, according to the non-contact power feeding system according to another embodiment of the present invention, the request signal generating means can transmit the first power transmission request signal and the second power transmission request signal at a rate of d / minute. it can.

  Furthermore, according to the contactless power supply system according to another embodiment of the present invention, the power supply base further includes a moving mechanism for moving the power transmission coil within a mounting surface on which the power receiving device is mounted. Can be provided.

  Furthermore, according to the non-contact power feeding system according to another embodiment of the present invention, the power transmission coil of the power feeding base can be fixed.

Furthermore, according to the power receiving device according to another embodiment of the present invention, when the power feeding stand detects that a foreign object exists between the power transmitting coil and the power receiving coil, the power receiving device does not shift to the second current mode. it can be so. With the above-described configuration, it is possible to increase safety by increasing the power transmission energy to achieve charging in a short time and the like so as not to shift when detecting a foreign object.

Furthermore, according to the power supply stand according to the embodiment of the present invention, the power supply stand further includes foreign matter detection means for detecting the presence of foreign matter between the power transmission coil and the power receiving coil. When the presence of the power is detected, the power control means can perform control so as not to shift to the second current mode even when the power transmission request signal requesting power transmission in the second current mode is received. With the above-described configuration, it is possible to increase safety by increasing the power transmission energy to achieve charging in a short time and the like so as not to shift when detecting a foreign object.

Furthermore, according to the non-contact power feeding method according to the embodiment of the present invention, when the presence of a foreign object is detected, even when the power feeding base receives the second power transmission request signal, the second current mode is set. You can control not to go . Accordingly, it is possible to increase safety by increasing the power transmission energy to realize charging in a short time and the like so as not to shift the foreign object detection.
(Embodiment 1)

  FIG. 1 is a block diagram showing a non-contact power feeding system 100 according to Embodiment 1 of the present invention. The power supply stand 10 shown in this figure conveys power to the power receiving device 50 by a non-contact power supply method. In the figure, a state is shown in which the power receiving device 50 is placed on the power supply stand 10 and power is transmitted from the power supply stand 10 to the power receiving device 50. In this embodiment, the power supply base 10 is a charging base, the power receiving device 50 is a battery built-in device, and power is transmitted from the charging stand to the battery built-in device to charge the secondary battery 52 of the battery built-in device. .

  The present invention does not specify the power supply stand as a charging stand or the power receiving device as a battery built-in device. The power receiving device can be, for example, a lighting fixture, a charging adapter, or the like, and can transmit power from the power supply stand to the power receiving device to drive the power receiving device. For example, when the power receiving device is a lighting device, the light source is turned on with power transmitted from the power supply base. When the power receiving device is a charging adapter, the battery connected to the charge adapter with power transmitted from the power supply base. Supply the battery charging power to the internal device to charge the battery of the internal battery device. The power receiving device may be a battery pack.

  In the power supply stand 10, an upper surface plate 21 on which the power receiving device 50 is set and placed at a fixed position is provided on the upper surface of the case 20, and the power transmission coil 11 is disposed inside the upper surface plate 21. The power transmission coil 11 is connected to an AC power source 12 and controls the AC power source 12 by a power control means 13.

  The power control unit 13 controls the AC power supply 12 with a power transmission request signal transmitted from the power receiving device 50 to adjust the power supplied to the power transmission coil 11. The power control means 13 increases the output power from the AC power supply 12 to the power transmission coil 11 with the increase request signal input from the request signal reception means 14, and decreases the output to the power transmission coil 11 with the decrease request signal. The requested power requested from the device 50 is transmitted. The power control means 13 adjusts the output of the AC power supply 12 to the maximum output as follows, or adjusts it below the preset set power. The power control means 13 increases the output of the AC power supply 12 by the increase request signal. In the state where the output of the AC power supply 12 is increased to the maximum power or the set power, even if the increase request signal is detected, The output of the AC power supply 12 is not increased.

  The power supply base 10 electromagnetically couples the power transmission coil 11 to the power reception coil 51, and carries power from the power transmission coil 11 to the power reception coil 51, that is, transmits power. The power supply base 10 that charges the secondary battery 52 by setting the power receiving device 50 at a free position on the top plate 21 incorporates a moving mechanism 16 that moves the power transmission coil 11 so as to approach the power reception coil 51. . In the power supply base 10, the power transmission coil 11 is disposed below the upper surface plate 21 of the case 20, and is moved along the upper surface plate 21 by the moving mechanism 16 to be brought closer to the power receiving coil 51. The moving mechanism 16 moves the power transmission coil 11 within the XY plane of the top plate 21. As such a moving mechanism 16, a motor or the like that moves the power transmission coil 11 in the XY directions can be used.

The power supply base 10 and the power receiving device 50 can be provided with a positioning unit mechanism that sets the power receiving device 50 at a fixed position of the power supply stand 10, and the power receiving device 50 can be set at a fixed position of the power supply stand 10. The positioning unit mechanism sets the power receiving device 50 at a fixed position of the power supply base 10 so that the power receiving coil 51 approaches the power transmitting coil 11. The power receiving coil 51 approaching the power transmitting coil 11 carries power from the power transmitting coil 11 to the power receiving coil 51 for electromagnetic transmission by electromagnetic induction.
(Embodiment 2)

  In the above example, the configuration in which the power transmission coil 11 is moved in the horizontal plane by the moving mechanism 16 on the inner surface of the upper surface plate 21 has been described. However, it is also possible to use a power supply stand with a fixed power transmission coil. Such an example is shown in FIG. The non-contact power feeding system 200 shown in this figure includes a power feeding base 10 ′ and a power receiving device 50. The power supply base 10 ′ uses a fitting structure in which the power receiving device 50 is set at a fixed position of the power supply base 10 ′ as the positioning unit mechanism 22 for electromagnetically coupling the power transmission coil 11 to the power reception coil 51. The fitting structure of FIG. 2 is provided with a fitting recess 23 into which the power receiving device 50 is fitted on the upper surface of the power supply base 10 ′, and the power receiving device 50 is put in the fitting recess 23 and set at a fixed position. Although not shown, the positioning unit mechanism can also set the power receiving device at a fixed position of the power supply base by providing concavity and convexity of the fitting structure on the opposing surface of the power supply base and the power receiving device. The fitting structure can prevent displacement of the power receiving device.

  The power transmission coil 11 is a planar coil wound in a spiral shape on a surface parallel to the upper surface plate 21, and radiates an alternating magnetic flux above the upper surface plate 21. The power transmission coil 11 radiates an alternating magnetic flux orthogonal to the upper surface plate 21 above the upper surface plate 21. The power transmission coil 11 is supplied with AC power from the AC power source 12 and radiates AC magnetic flux above the upper surface plate 21. The power transmission coil 11 can increase the inductance by winding a wire around a core (not shown) made of a magnetic material. The power transmission coil with the core can concentrate the magnetic flux to a specific part and efficiently transmit power to the power reception coil. However, the power transmission coil does not necessarily need to be provided with a core, and may be an air-core coil. Since the air-core coil is light, the moving mechanism can be simplified in the structure in which the power transmission coil is moved on the inner surface of the top plate. The power transmission coil 11 is substantially equal to the outer diameter of the power reception coil 51 and efficiently conveys power to the power reception coil 51.

  The AC power supply 12 adjusts the power supplied to the power transmission coil 11 by the power control means 13 and supplies, for example, high frequency power of 20 kHz to 1 MHz to the power transmission coil 11. The power supply stand 10 that moves the power transmission coil 11 so as to approach the power reception coil 51 connects the AC power supply 12 to the power transmission coil 11 via a flexible lead wire. The AC power supply 12 includes an oscillation circuit and a power amplifier that amplifies the AC output from the oscillation circuit.

  The power supply base 10 supplies AC power to the power transmission coil 11 with the AC power supply 12 in a state where the power transmission coil 11 is brought close to the power reception coil 51. The AC power of the power transmission coil 11 is transmitted to the power reception coil 51 to charge the secondary battery 52. The power supply base 10 stops the power supply to the power transmission coil 11 by a signal transmitted from the power receiving device 50 in a state in which the secondary battery 52 is fully charged, foreign matter is detected, or abnormality is determined. The charging of the battery 52 is stopped.

  The power receiving device 50 in FIGS. 1 and 2 is a battery built-in device 5 and includes a power receiving coil 51 that is electromagnetically coupled to the power transmitting coil 11 of the power supply base 10. The secondary battery 52 is charged with the received power induced by the power receiving coil 51. Accordingly, the power receiving device 50 in FIG. 1 includes a secondary battery 52, a power receiving coil 51, a rectifier circuit 56 that converts alternating current induced in the power receiving coil 51 into direct current, and a direct current that is output from the rectifier circuit 56. The power receiving side control means 53 for adjusting the charging current and voltage for charging the secondary battery 52, the transmission circuit 54 for transmitting the information signal of the power receiving device 50 to the power supply base 10, and the amount of received power received from the output of the rectifier circuit 56. A request for generating a power transmission request signal by comparing the power reception amount detected by the power reception amount acquisition unit 58 to be detected and the power reception amount detected by the power reception amount acquisition unit 58 with power required for charging the secondary battery 52. A signal generating means 57 is provided.

  The secondary battery 52 is a lithium ion battery or a lithium polymer battery. However, the battery can be any rechargeable battery such as a nickel metal hydride battery or a nickel cadmium battery. The power receiving device 50 includes one or a plurality of secondary batteries 52. The plurality of secondary batteries 52 are connected in series or in parallel, or connected in series and in parallel.

  The rectifier circuit 56 full-wave rectifies the alternating current induced in the power receiving coil 51 with a diode bridge, and smoothes the pulsating current with a smoothing capacitor. The rectifier circuit rectifies alternating current with a diode bridge, but a synchronous rectifier circuit can be used for the rectifier circuit in which an FET is connected to the bridge and the FET is switched on and off in synchronization with the alternating current. The synchronous rectification circuit of the FET has a small on-resistance, reduces the heat generation of the rectification circuit, and can reduce the increase in the temperature inside the case of the power receiving device 50. Further, the smoothing capacitor is not always necessary, and the battery can be charged by the output of the diode bridge or the synchronous rectifier circuit.

The power receiving side control means 53 charges a lithium ion battery, a lithium polymer battery or the like at a constant voltage / constant current, and charges a nickel metal hydride battery or a nickel cadmium battery at a constant current. Further, the power receiving side control means 53 detects the full charge of the secondary battery 52 and transmits a full charge signal to the power supply base 10 via the transmission circuit 54. The power supply stand 10 detects the full charge signal transmitted from the transmission circuit 54 and the information signal of the power receiving device 50 by the request signal receiving unit 14. The power supply stand 10 detects an information signal from the power receiving device 50 and controls the AC power supply 12 by the power control means 13. When the power supply stand 10 detects the full charge signal, the power supply stand 10 stops the power supply to the power transmission coil 11.
(Embodiment 3)

In the example of FIGS. 1 and 2, the example in which the secondary battery 52 is charged using the charge control unit as the power receiving side control unit has been described. However, the present invention is not limited to the example in which the received power is used for charging the secondary battery, and can also be used as power for driving the electric load of the power receiving device. An example of such a non-contact power feeding system is shown in FIG. In the non-contact power feeding system 300 shown in this figure, the power receiving device 50 includes load drive control means 53B that supplies power for driving an electric load instead of the charge control means as the power receiving side control means. Other members can use the same configuration as in the first and second embodiments described above. The load drive control unit 53B converts the electric power to drive the electric load LD of the power receiving device 50. For example, a mobile phone, kitchenware, or a lighting device can be used as the electrical load of the power receiving device 50. In this way, the received power can be directly used for driving power of the electric load in addition to charging the secondary battery. If a secondary battery is used as the electrical load, the configuration of the first or second embodiment described above is obtained. Moreover, the structure which utilizes the received electric power for both driving of the electric load and charging of the secondary battery can also be adopted.
(Transmission circuit 54)

  The transmission circuit 54 sends a power transmission request signal including an increase request signal and a decrease request signal for increasing or decreasing the output of the power supply base 10 from the power receiving device 50 to the power supply base 10, a full charge signal of the secondary battery 52, and charging. Various information signals such as the voltage of the secondary battery 52, the charging current, the battery temperature, the battery serial number, the allowable charging current for specifying the charging current of the battery, the battery information such as the allowable temperature for controlling the charging of the battery, etc. It is transmitted to the power supply stand 10. The transmission circuit 54 changes various load impedances of the power reception coil 51 and transmits various information signals to the power transmission coil 11. Although not shown, the transmission circuit 54 has a modulation circuit connected to the power receiving coil 51. The modulation circuit connects a load such as a capacitor or a resistor and a switching element in series, controls on / off of the switching element, and transmits various information signals to the power supply base 10.

  The request signal receiving means 14 of the power supply stand 10 detects an information signal transmitted from the transmission circuit 54 by detecting an impedance change, a voltage change, a current change and the like of the power transmission coil 11. When the load impedance of the power receiving coil 51 changes, the impedance, voltage, and current of the power transmitting coil 11 that is electromagnetically coupled to the power receiving coil 51 change. Therefore, the request signal receiving unit 14 detects these changes and receives the power receiving device 50. It is possible to detect the information signal.

However, the transmission circuit may be a circuit that modulates and transmits a carrier wave, that is, a transmitter. The request signal receiving means for the information signal transmitted from the transmission circuit is a receiver that receives the carrier wave and detects the information signal. The transmission circuit and the request signal receiving means can have all circuit configurations capable of transmitting an information signal from the power receiving device to the power supply base.
(Received power acquisition means 58)

The received power acquisition means 58 acquires the received power of the received power output from the rectifier circuit 56 at a predetermined cycle. Further, the request signal generation means 57 generates a power transmission request signal by comparing the received power amount with the required power. Furthermore, the power receiving device can also include a determination function for determining foreign object detection based on a power transmission request signal. Further, the foreign object detection determination can be performed not on the power receiving device side but on the power supply stand side. In this case, for example, the voltage and charging current of the secondary battery are notified from the power receiving device side to the power supply stand, and when the transmission efficiency is lower than the reference value compared to the transmission power on the power supply stand side, it is determined that there is a foreign object. Then stop power transmission.
(Request signal generation means 57)

  The request signal generation unit 57 detects the amount of received power by the received amount acquisition unit 58 from the product of the output voltage and current of the rectifier circuit 56 and compares the detected amount of received power with the required power for power transmission. Generate and output a request signal. The received power acquisition means 58 detects the power required for charging the secondary battery 52 as the required power. The power reception amount acquisition unit 58 detects the power necessary for charging the secondary battery 52, that is, the required power, by detecting the type of the secondary battery 52, the battery voltage, the current to be charged, and the like. Since the lithium ion battery and the lithium polymer battery are charged with constant voltage / constant current characteristics, the charging current decreases as the secondary battery 52 approaches full charge. Therefore, the required power is reduced as the secondary battery 52 approaches full charge. In the example of FIGS. 1 and 2, the power receiving device 50 is used as a battery built-in device, and the secondary battery 52 is charged with power consumption. The power receiving device 50 uses the required power as charging power for the secondary battery 52, but the power receiving device is not necessarily limited to a battery built-in device. A power receiving device that is not a battery built-in device detects the required power as load power consumption or rated power.

  The power transmission request signal is an increase request signal for increasing the output of the power supply base 10 and a decrease request signal for decreasing the output. The request signal generation unit 57 detects that the received power amount is smaller than the required power and outputs an increase request signal, detects that the received power amount is larger than the required power, and outputs a decrease request signal. Further, the request signal generating unit 57 compares the received power amount with the required power so as to supply the optimum power to the electric load, and outputs a power transmission request signal composed of an increase request signal or a decrease request signal.

Here, how the power supply base 10 performs power transmission control on the power receiving device 50 will be described with reference to the block diagram of FIG. 4. The power supply stand 10 shown in this figure includes a power transmission coil 11 for electromagnetically coupling with the power reception coil 51 to transmit power, a request signal receiving means 14 for receiving a power transmission request signal transmitted from the request signal generating means 57, and Power control means 13 for controlling the amount of power transmitted from the power transmission coil 11 based on the power transmission request signal received by the request signal receiving means 14 is provided.
(Power receiving device 50)

On the other hand, the power receiving device 50 includes a power receiving coil 51, an electric load LD, a power reception amount acquiring unit 58, and a request signal generating unit 57. The electric load LD includes, for example, a secondary battery 52 and a power receiving side control unit 53 that controls a charging current for charging the secondary battery 52. The power reception amount acquisition unit 58 detects a power reception value actually obtained on the power receiving device 50 side. The request signal generation unit 57 transmits a power transmission request signal instructing the power transmission amount transmitted from the power supply base 10 to the power receiving device 50 to the power supply base 10 side based on the power reception value detected by the power reception amount acquisition means 58. . The request signal generation means 57 can use the transmission circuit 54 shown in FIGS. In the example of FIG. 4, the received power acquisition means 58 and the request signal generation means 57 are separate members, but they can also be configured with a single IC or the like. The power transmission request signal is transmitted to the power supply base 10 via the power receiving coil 51 in accordance with an instruction from the request signal generation unit 57.
(Power receiving side control means 53)

The power receiving side control means 53 of the power receiving device 50 shown in FIG. 4 has a first current mode in which the first current value can be transmitted to the electric load LD as a rated current, and a second current value larger than the first current value. It is possible to switch the second current mode in which power can be transmitted with the rated current as.
(Request signal generation means 57)

  The request signal generation unit 57 compares the power reception value detected by the power reception amount acquisition unit 58 with a predetermined value. If the power reception value value is lower than the predetermined value, the request signal generation unit 57 outputs a power increase request signal instructing to increase the transmission power. It transmits to the power supply stand 10 as a power transmission request signal. On the other hand, if it is higher than this predetermined value, a power reduction request signal instructing to reduce the transmission power is transmitted to the power supply base 10 as a power transmission request signal. This makes it possible to charge appropriately according to the transmitted power that is actually transmitted. As such a power transmission request signal, a standardized signal can be preferably used. For example, in the case of the Qi standard, a control error (CE) signal for 5 W can be used. Thereby, the secondary battery according to the Qi standard can be charged.

  Further, the request signal generation means 57, according to the first current mode and the second current mode, as a power transmission request signal, a first power transmission request signal for requesting the first transmission power required for power transmission in the first current mode, A second transmission request signal for requesting second transmission power required for power transmission in the second current mode can be transmitted. For example, let us consider a case where charging to the secondary battery is performed by the Qi standard and original control capable of charging at a higher output than that for power transmission to the electric load LD. At the time of charging in the first current mode, the first current value is set to 700 mA and charging is performed below this current. Further, the secondary battery can be charged to a predetermined voltage. The predetermined voltage is about 7V because 5 W is rated according to the low power specification (Volume I: Low Power) of the Qi standard, for example. In the second current mode, the secondary battery is charged to a predetermined voltage with the second current value set to 900 mA.

The request signal generation unit 57 simultaneously sends the first power transmission request signal and the second power transmission request signal to the power supply base 10. Preferably, as shown in FIG. 11, the first power transmission request signal and the second power transmission request signal are transmitted in a time division manner. Thereby, since one request signal generation means 57 can transmit two types of power transmission request signals, the transmission mechanism is shared and the configuration is simplified without separately preparing transmitters for transmitting the respective power transmission request signals. Can be achieved. The first power transmission request signal and the second power transmission request signal are updated every 250 ms, for example.
(Power control means 13)

  On the other hand, when the request signal receiving unit 14 receives the first power transmission request signal, the power supply base 10 transmits power to the power receiving device 50 with the first transmitted power. When receiving the second transmission request signal, the second transmission power is transmitted. Switching between these transmission powers is performed by the power control means 13. Here, the first transmission power is 5 W corresponding to the Qi standard.

  As described above, the request signal generation means 57 of the power receiving device 50 always sends the second power transmission request signal and the first power transmission request signal together as shown in FIG. And when the power supply stand 10 respond | corresponds to 2nd transmitted power, if the request signal receiving means 14 receives a 2nd power transmission request signal and a 1st power transmission request signal, according to a 2nd power transmission request signal, 2nd transmitted power Is transmitted by the power control means 13, while the first transmission request signal is ignored. In this way, power transmission in the second current mode with higher output becomes possible.

On the other hand, even when one or both of the power supply base 10 and the power receiving device 50 does not support such power transmission in the second current mode, power transmission in the first current mode can be performed and used safely. It becomes possible. In addition, this method can be easily applied to existing non-contact charging, so that an advantage that it can be mounted at low cost without adding a new member can be obtained.
(First transmission request signal)

The first power transmission request signal can be a standardized power transmission request signal. Such a power transmission request signal is a signal for increasing or decreasing the output from the power supply base so as to reduce the difference when there is a difference from the target value. For example, in the case of the Qi standard, a 5 W control error (control error) signal can be used. Thereby, the secondary battery according to the Qi standard can be charged.
(Power supply discriminating means 59)

  Further, the power receiving device 50 illustrated in FIG. 4 includes a power supply table discriminating unit 59 that determines the type of the power supply table 10. If a function for bidirectionally communicating between the power receiving device and the power supply base is provided, it is possible to determine the type of each other through communication. On the other hand, when there is no communication from the power supply stand to the power receiving device, the type of the power supply stand cannot be recognized on the power receiving device side. For example, according to the Qi standard low power specification (Volume I: Low Power) established by WPC (Wireless Power Consortium), which is widely used as a standard for contactless charging, communication from the power receiving device to the power supply stand However, communication from the power supply stand to the power receiving device is not specified. As a result, the power receiving device compliant with the WPC standard cannot know what power supply is used for power transmission. In particular, a power receiving device that is not compatible with WPC 1.0 and that is based on an original standard, such as a foreign object detection function or charging with a large current, is not compatible with such a charging stand discrimination function. When mixing with a power base, it is necessary for the power receiving device to know whether or not the power supply base supports the charging base discrimination function.

  Therefore, a power transmission request signal is transmitted from the power receiving device 50 to the power supply base 10, and whether or not the power supply base 10 corresponds to the charging base discrimination function with the power transmitted from the charging device is received. A power supply stand discriminating function for discriminating on the device 50 side is provided on the power receiving device 50 side. In the example of FIG. 4, the power supply base discriminating means 59 of the power receiving device 50 sends two types of power transmission request signals corresponding to the standard and the charging base discriminating function to the power supply base 10 and reacts to any of the signals. The function of the power supply base 10 is determined by determining whether or not to perform. Specifically, by transmitting two types of power transmission request signals with different target values of current from the power receiving device 50 to the power supply base 10, and determining which power transmission request signal the power supply base 10 reacts to, The power supply stand 10 is determined. Here, the first power transmission request signal for requesting the current required for power transmission in the first current mode in which power transmission is performed using the first target current value compliant with the standard as the rated current, and the charging base determination Corresponding to the function, a second power transmission request signal for requesting the power supply base 10 side for a current necessary for power transmission in the second current mode in which power transmission is performed using a second target current value larger than the first target current value as a rated current. And generate and send. Then, by determining whether the power supply base 10 responds to the first power transmission request signal or the second power transmission request signal on the power receiving device 50 side, either the first target current value or the second current target value is determined. To decide.

  As described above, in the case where the second power transmission request signal corresponding to the charging stand discriminating function is also transmitted from the power receiving device 50 side in addition to the first power transmission request signal according to the standard, the second power transmission request is transmitted on the power feeding base 10 side. If the signal can be received, the first power transmission request signal is ignored or the processing defined by the signal is not performed. As a result, in a combination of a power receiving device and a power supply stand that supports the charging stand determination function, when the power supply stand receives the second transmission request signal, the first transmission request signal corresponding to the standard is not executed. Only high-power compatible power transmission according to the function is executed. On the other hand, in the case of a power supply stand that supports only the standard, the first power transmission request signal can be interpreted, and power transmission is performed accordingly, while the second power transmission request signal can be processed because it does not support the charging stand discrimination function. As a result, only standard transmission is performed.

  With this method, power can be appropriately transmitted by each power transmission method, regardless of whether the power supply table is compatible only with the standard or both the standard and the charging table discrimination function. In addition, there is no need to add a new member such as a facility for communication from the power supply stand side to the power receiving device side, and it is only necessary to perform communication from the existing power receiving device side to the power supply stand side. Therefore, it can be easily applied to the device, and the advantage that it can be mounted at low cost is obtained.

In this example, a WPC 1.0 that does not have a foreign object detection function is adopted as a standard, while a non-contact charging method in which a foreign object detection function and a charging function with a large current are implemented as independent control will be described. However, according to the present invention, only one of the foreign object detection function and the large current charging function can be implemented as the unique control. Alternatively, or in addition to these, other functions such as charging at a high output of 5 W or more can be provided.
(Foreign matter detection means 15B)

  On the other hand, the power supply stand 10 includes foreign matter detection means 15B for determining whether or not a metal foreign matter is interposed between the power supply stand 10 and the power receiving device 50. Specifically, the power supply base 10 calculates the power transmission efficiency and compares this power transmission efficiency with a predetermined threshold set in advance. When the difference between the calculated power transmission efficiency and the predetermined threshold is small, in other words, when the power transmission efficiency is low, the foreign object detection means 15B determines that there is a high possibility that a foreign object has been inserted. In this case, control is performed such that the target current is switched to the first target current to limit the transmission current. Thereby, the power transmission current can be suppressed and the heat generation of the foreign matter can be reduced. Further, as shown in FIG. 5, the power supply stand 10 </ b> B can perform appropriate power transmission even when a power receiving device 50 </ b> A that does not support unique control is set.

  On the other hand, when the power supply base 10A is not compatible with the charging base discrimination function and does not have foreign matter detection means, for example, is compliant with WPC 1.0, as shown in FIG. 6, it corresponds to the charging base discrimination function. Even if the power receiving device 50B is set, the second power transmission request signal transmitted from the power receiving device 50B cannot be interpreted. Therefore, the second target current is not increased and the power is not transmitted. Power will be transmitted. Therefore, as a result of power transmission with the first target current with the current value suppressed from the beginning, even if there is a foreign object, the amount of heat generation can be suppressed. As described above, there is an advantage that heat generation due to foreign matter can be suppressed regardless of whether the power receiving device is placed on the power supply base 10B having a foreign matter detection function or placed on the power supply base 10A not having the foreign matter detection function. can get.

  Also in WPC, WPC1.1 employs a foreign object detection (FOD) function. However, the FOD function is not employed in WPC 1.0, and there are many products that conform to the WPC 1.0 specification at present, and there are almost no products that conform to the WPC 1.1 specification having the FOD function. In view of such a situation, the present invention is useful when combining a power supply base of WPC 1.0 specifications and a power receiving device which are not provided with a widely used FOD function.

As described above, according to the present embodiment, it is possible to transmit power with a large current and enable quick charging, etc. It is possible to suppress and increase safety. Hereinafter, such an operation will be described with reference to the flowcharts of FIGS.
(Power transmission using a power supply stand and power receiving equipment that supports unique control)

  The flowchart of FIG. 7 shows the operation in the non-contact power transmission between the power supply base 10 and the power receiving device 50 corresponding to the charging base discrimination function. The flowchart of FIG. 8 shows the operation of the power supply base 10 corresponding to the charging base discrimination function, FIG. 9 shows the operation of the power receiving device corresponding to the charging base discrimination function, and FIG. The operation of the power receiving device that only complies with is shown. First, the overall operation flow will be described with reference to the flowchart of FIG. Here, a case will be described in which a charging stand is used as the power supply stand 10 and a smartphone is used as the power receiving device 50, and a battery pack attached to the smartphone is contactlessly charged with the charging stand.

  First, in step S701, the power receiving device 50 is set on the power feeding base 10, and power transmission with the first target current is started in a state where the power transmission coil of the power feeding base 10 and the power receiving coil of the power receiving device 50 are electromagnetically coupled. Here, a first power transmission request signal for starting charging is sent from the power receiving device 50 side to the power supply base 10. For example, the first target current is set to 700 mA in accordance with the WPC standard.

  Next, in step S702, it is determined whether the power receiving device 50 has passed a predetermined time from the start of power transmission. If not, step S702 is repeated, and if it has elapsed, the process proceeds to step S703. This step can be omitted.

  Next, in step S703, transmission of a plurality of power transmission request signals is started from the power receiving device 50 side to the power supply base 10. Here, two types of power transmission request signals, the first power transmission request signal and the second power transmission request signal, are generated by the request signal generation means 57 of the power receiving device 50 and transmitted to the power supply base 10. Such transmission can be sent to the power supply stand side without providing a separate communication means by modulation such as changing the load impedance of the power receiving coil electromagnetically coupled to the power transmitting coil as described above. On the power supply stand side, the power transmission request signal is analyzed by the request signal receiving means.

  The first power transmission request signal is a power transmission request signal compliant with the standard. Here, a control error (control error value (CE)) based on the Qi standard standardized by WPC is transmitted as a standard. The control error value is an output increase request signal or an output decrease request signal transmitted from the power receiving device 50 side to the power supply base 10 side for output control of the power supply base 10. The second power transmission request signal can be a signal such as a control signal or an information signal that can be uniquely defined by the manufacturer. For example, the second power transmission request signal is set as a control error value of the charging stand discriminating function using a proprietary packet signal compliant with the WPC standard. In this case, information that can be arbitrarily specified can be added as a proprietary packet to the header of a packet used for communication in the WPC standard. Power transmission control can be realized with a current value corresponding to the power base.

  Further, these two types of power transmission request signals are transmitted in a time division manner. For example, as shown in the timing chart of FIG. 11, WPC_CE and unique CE are alternately transmitted at predetermined time intervals. Here, the period for simultaneously sending the CE for the unique control and the CE for the WPC and the period for sending only the CE for the WPC are alternately repeated. As a result, the WPC CE is always sent, and the WPC-compliant power supply base receives the WPC CE and performs control in accordance with the WPC standard. On the other hand, when the power supply stand corresponding to the charging stand discriminating function receives the original control CE, it is switched to the operation mode (second current mode) of the charging stand discriminating function. Ignore and receive only CE with unique control. However, if the WPC CE is not received twice or more within a predetermined time, the second current mode is canceled and the operation mode is shifted to the first current mode, that is, the operation mode based on WPC. In this example, the power transmission request signal is switched every 250 ms according to the CE value in the WPC, but the switching timing can be any timing.

  Next, in step S704 in FIG. 7, it is determined whether or not the transmission times of the plurality of power transmission request signals have passed a predetermined time set in advance. If not, the process returns to step S703 to continue transmission. If so, the process proceeds to step S705. Here, although it is set to 10 seconds, it is needless to say that it can be set to an arbitrary time.

  Next, in step S705, it is determined whether or not it is a combination of a power receiving device compatible with unique control and a power supply stand. Here, the type of the set power receiving device 50 is determined on the power supply stand 10 side. In other words, the power supply base 10 determines whether the power receiving device conforms to the standard or the power receiving device having the charging stand determination function based on the CE sent from the power receiving device. That is, if the power supply stand 10 receives the charging stand determination function CE, the power supply stand 10 determines that the power receiving device is compatible with the charging stand determination function, while the power supply stand 10 does not receive the charging stand determination function CE. If only the CE of the standard is received, the power supply side detection circuit 15 determines that the power receiving device is compliant with the standard. Further, the power supply side detection circuit 15 is not limited to the configuration in which the power receiving device CE is determined to be a power receiving device that supports unique control as soon as it receives the charging stand discrimination function CE. When it is received, it is determined that the power receiving device is compatible with the charging stand determination function. Otherwise, it is preferable to determine that the power receiving device is not compatible with the charging stand determination function, that is, a standard-compliant power receiving device. As a result, erroneous detection caused by noise or the like can be avoided. For example, the power supply side detection circuit 15 determines that the power receiving device is compatible with the charging base determination function if it receives the CE of the charging base determination function twice or more in 10 seconds, and determines that the power receiving device conforms to the standard otherwise. In this way, the power supply side detection circuit 15 functions as the power receiving device determination unit 15A. Note that step S704 and step S705 can be performed simultaneously.

  In this way, when it is confirmed that the combination of the power receiving device and the power supply stand corresponding to the charging stand discriminating function is reached, the process proceeds to step S706, and if not, the process proceeds to step S713. In addition, if the power supply stand is not compatible with the charging stand discriminating function and conforms to the standard, since there is no power receiving device discriminating function in the first place, such a process does not exist and the step is performed regardless of the type of the power receiving device. The process proceeds to S713. In step S713, contactless charging control based on WPC is executed. That is, output control is performed on the power supply stand side according to WPC_CE, and the process proceeds to step S715 to set the first transmission current (700 mA in this case) to perform normal contactless power transmission control.

  On the other hand, if it is confirmed that the combination of the power supply stand and the power receiving device of the charging stand discrimination function, foreign matter determination is performed next. Specifically, first, in step S706, whether or not the difference between the efficiency and the foreign substance threshold is equal to or larger than a predetermined value is determined on the power supply base 10 side. If it is equal to or less than the predetermined value, it is determined that the efficiency is low, that is, there is a foreign object, and the process proceeds to step S713 to maintain contactless charging with the target current set to the first transmission current. Here, the efficiency is set to 62%, and the predetermined value is set to 5%.

  On the other hand, if the difference is equal to or larger than the predetermined value, the process proceeds to step S707, and output control is performed on the power supply base 10 side according to the CE of the charging base determination function. Here, the target current value is switched by outputting a control error value of 900 mA control to WPC_CE. Next, it progresses to step S708, and if it corresponds to a charging stand discrimination | determination function, it will wait until the charging current will be stabilized. Specifically, first, in step S708, it is determined whether or not a predetermined time has elapsed. If not, the process in step S708 is repeated. When a predetermined time (for example, 10 s) elapses, the process proceeds to step S709, and the power supply stand discriminating unit 59 of the power receiving device 50 determines whether or not the power transmission current has changed more than a predetermined value set in advance. When it has changed, it progresses to step S711, it determines with the electric power receiving apparatus 50 side that the electric power feeding base 10 is following the change of an electric current value, ie, the electric power feeding base 10 respond | corresponds to an independent control, and further step In S712, the power receiving device 50 sets the target current to a second target transmission current (for example, 900 mA) larger than the first target transmission current, and performs contactless power transmission control with a large current.

  On the other hand, if it is determined in step S709 that the change in the transmission current does not reach the predetermined value, the process proceeds to step S710 and the determination is continued until a predetermined time elapses. That is, if a predetermined time (for example, 15 seconds) has not elapsed, the process returns to step S709 to repeat the process of determining the amount of change in the transmission current. If the amount of change in the transmission current does not reach the predetermined value even after the predetermined time has elapsed, the process proceeds to step S714, and the power receiving device 50 determines that the power supply base 10 is a power supply base that does not support independent control. In step S715, the power receiving device 50 sets the first target transmission current (700 mA in this example) and performs power transmission control.

  As described above, in a contactless power supply system that combines a power supply base and a power receiving device that both support the charging base discrimination function, while achieving power transmission at a large current, a foreign object detection function is also added, If it exists, it is possible to reduce power transmission current and perform power transmission more safely.

In this example, the example in which 700 mA, which is a normal rated charging current, is increased to 900 mA as the second current mode in which power transmission is performed with a large current has been described. The charging at 900 mA is a charging method according to WPC. However, in the present invention, the second charging current is not limited to charging in accordance with a standard such as the WPC standard, and can be a non-standard charging current.
(Power transmission operation on the power receiving device side)

  This power receiving device is combined with a power supply stand having a large-current power transmission function so as to correspond to unique control such as shortening the charging time of the battery pack. Further, as shown in FIG. 6, the power receiving device 50B does not have a large-current power transmission function based on unique control. In other words, even if the power receiving device 50B is set on the power supply base 10A that does not support unique control and only supports the standard, It becomes possible to receive power transmission correctly. Hereinafter, the power transmission operation on the power receiving device 50B side will be described based on the flowchart of FIG. The number of each step is the same as the number of the corresponding step in the flowchart of FIG. 7, and detailed description will be omitted as appropriate.

  First, in step S <b> 801, the power receiving device 50 requests the power supply base 10 to start charging. This is the same as step S701 described above, and here, the first power transmission request signal is transmitted, and the first target current is set to 700 mA.

  Next, in step S802, similarly to step S702, it is determined whether or not a predetermined time has elapsed since the start of power transmission. If not, step S802 is repeated, and if it has elapsed, the process proceeds to step S803.

  Next, in step S803, the first power transmission request signal and the second power transmission request signal are transmitted from the power receiving device 50 side to the power supply base 10 for a predetermined time (for example, 10 s). This step is also the same as step S703 described above.

  In the subsequent step, first, in step S804, it is determined whether or not a predetermined time (for example, 10 s) has elapsed. If not, the process in step S804 is repeated.

  When a predetermined time has elapsed, in step S809, based on whether or not the power supply base 10 follows the change in the current value, whether or not the power supply base 10 corresponds to the charging base determination function is determined. The determination is made at 59. Here, it is checked whether or not the transmission current has changed more than a predetermined value set in advance, and if it has changed, the feeding base changes the transmission current, that is, corresponds to the charging stand discrimination function. (Step S811), the target current is set to the second target transmission current (for example, 900 mA), and contactless power transmission control with a large current is performed (step S812).

  On the other hand, if it is determined that the change in the transmission current does not reach the predetermined value, the process proceeds to step S810, and the determination in step S809 is repeated until a predetermined time (for example, 15 s) elapses. If the change amount of the power supply is less than the predetermined value, it is determined that the power supply stand is a power supply stand that does not support the charging stand discrimination function (step S814), and the first target transmission current is set to perform power transmission control ( Step S815).

As described above, the power receiving device can request a large transmission current to the power supply base that supports the charging base discrimination function, and can request a transmission current that conforms to the standard if it is not compatible. It is also possible to carry out appropriate power transmission.
(Power transmission operation on the power supply stand side)

  On the other hand, the power supply base 10B is not limited to the case where the power receiving device is compatible with the charging stand determination function, and as shown in FIG. Appropriate power transmission can be performed according to the type of the power receiving device on the power supply stand 10B side corresponding to the discrimination function. Hereinafter, the operation on the power supply stand 10 side will be described with reference to FIG. Here, the number of each step is made to correspond to the number of the corresponding step in the flowchart of FIG. 7, and detailed description will be omitted as appropriate. In the example of FIG. 9, the case where the power receiving device 50 is compatible with the charging stand determination function is described.

  First, in step S <b> 901, in response to a request from the power receiving device 50 side to start power transmission at the first target current to the power supply base 10, power transmission from the power supply base 10 side to the power receiving device 50 side is started. This is the same as step S701 described above. Here, the first power transmission request signal set to 700 mA as the first target current from the power receiving device 50, that is, the CE of the WPC, is received and electromagnetically coupled from the power transmission coil. Power transmission to the receiving coil.

  Next, in step S905, it is determined whether the combination of the power receiving device corresponding to the charging stand determination function and the power supply stand. Here, it is determined on the power supply stand side whether or not the power receiving device is compatible with the original control. Specifically, the power supply base 10 receives two types of power transmission request signals transmitted from the power receiving device side corresponding to the charging base discrimination function. In the example shown in FIG. 4, since the power supply base 10 also supports the charging base determination function, the second power transmission request signal according to the charging base determination function can be correctly received. That is, the power supply base 50 recognizes that the power receiving device 50 is compatible with the original control, and, for example, ignores the first power transmission request signal while receiving the second power transmission request signal. Can be processed.

  On the other hand, if the power supply base 10A does not support the charging base discriminating function as shown in FIG. 6, since it cannot be interpreted even if the second power transmission request signal is received, only the CE of the WPC that is the first power transmission request signal is obtained. In step S913, output control is performed in accordance with the CE of the WPC. Note that if the power receiving device side does not support the charging stand determination function, step S905 itself does not exist.

  In this way, when it is confirmed that the combination of the power receiving device and the power supply stand compatible with the charging stand discrimination function, the process proceeds to step S906, and foreign matter determination is performed. Here, whether or not the difference between the efficiency and the foreign substance threshold is equal to or greater than a predetermined value is determined on the power supply stand 10 side. If it is less than or equal to the predetermined value, it is determined that the efficiency is poor, that is, there is a foreign substance, and the process proceeds to step S913. Here, the efficiency is set to 62%, and the predetermined value is set to 5%.

  On the other hand, if the difference is equal to or larger than the predetermined value, the process proceeds to step S907, and output control is performed on the power supply base 10 side according to the CE of the charging base discrimination function. Further, the process proceeds to step S908, where it is determined whether or not a predetermined time has elapsed. If not, the process of step S908 is repeated. When a predetermined time (for example, 10 s) elapses, the process proceeds to step S913 to perform output control according to the WPC CE.

  As described above, the power supply stand corresponding to the charging stand discriminating function can discriminate whether or not the set power receiving device is compatible with the charging stand discriminating function, and can detect foreign matter.

  Note that power can be transmitted not only when the power receiving device is set to the power supply stand corresponding to the charging stand determination function but also to the power supply stand 10A not compatible with the charging stand determination function as shown in FIG. The operation of the power supply stand in this case is shown in the flowchart of FIG. This power supply base 10A is a power supply base that does not support the charging base determination function and conforms to the standard. First, in step S1001, power transmission is started in accordance with the CE of the WPC that is the power transmission request signal transmitted from the power receiving device 50B. The power supply base 10A receives this WPC_CE signal (step S1005), and performs output control according to this (step S1013). If the power receiving device 10B is of a type that supports the charging base determination function, in step S1005, not only the WPC_CE but also the charging base determination function CE is transmitted to the power supply base 10A, but the power supply base 10A does not support the charging base determination function. Therefore, the charging stand discriminating function CE cannot be interpreted, and only WPC_CE is received and processed for output control. On the other hand, when the power receiving device 50A does not support the charging stand discrimination function, only the WPC_CE that is the first power transmission request signal is transmitted, so that the power feeding stand receives the WPC_CE as described above. As described above, the power supply base 10A compliant with the standard can perform power transmission according to the standard regardless of whether the power receiving device to be set is the charging base discrimination function compatible type or the non-compatible type.

  As described above, the power supply side detection circuit 15 also functions as the foreign matter detection means 15B. In WPC, the foreign object detection function is defined in the WPC 1.1 specification as described above, but in WPC 1.0, the foreign object detection function is not defined. Most do not implement the foreign object detection function. For this reason, there may be many scenes where power receiving devices and power supply stands having the foreign object detection function as described above are mixed. The foreign object detection function employed in this embodiment is based on unique control, but it goes without saying that the present invention can also be applied to a foreign object detection function based on a standardized standard such as WPC 1.1. Nor.

  In the above example, communication according to the standard has been described as the Qi standard standardized by WPC. However, the present invention is not limited to this, and communication standardized with respect to other contactless charging methods. Even if the system is not standardized, a practically standard communication system that is widely adopted can be appropriately employed.

  Furthermore, in the above example, in order to simplify the explanation, the transmission power is set to 5 W at the maximum according to the WPC standard low power specification standard (Volume I: Low Power). However, in the present invention, the power value is not limited to 5 W, and may be a power supply stand or a power receiving device that can transmit power with high power of 10 W, 15 W, 20 W or more, for example. In addition, the standard for contactless charging is not limited to the Qi standard, and the present invention can be applied to a charging stand and a battery built-in device corresponding to other contactless charging standards. Furthermore, as a contactless (wireless) charging method, a magnet attraction type, a coil array type, and the like can be used as appropriate in addition to a movable coil type.

  The contactless power supply system, the power receiving device, the power supply stand, and the contactless power supply method according to the present invention are a method for charging a battery by transferring power from a power supply stand such as a charging stand to a power receiving device such as a battery built-in device by electromagnetic coupling action. It can be used optimally. Further, the present invention can be used not only for a charger but also for a system for supplying electric power to an electric load of a power receiving device and driving it, for example, a kitchen product such as a lighting fixture or a mixer, or a method for transmitting power to a charging adapter without contact.

DESCRIPTION OF SYMBOLS 100, 200, 300 ... Non-contact electric power feeding system 10, 10 '... Feeding stand; 10A ... Standard-compatible charging stand; 10B ... Original control-compatible charging stand 11 ... Power transmission coil 12 ... AC power supply 13 ... Power control means 14 ... Request signal receiving means 15 ... power feeding side detection circuit; 15A ... power receiving device discriminating means; 15B ... foreign matter detection means 16 ... moving mechanism 20 ... case 21 ... top plate 22 ... positioning portion mechanism 23 ... insertion recess 50 ... power receiving device; Power receiving device compliant with standard specification; 50B ... Power receiving device 51 corresponding to original control ... Power receiving coil 52 ... Secondary battery 53 ... Power receiving side control means; 53B ... Load drive control means 54 ... Transmission circuit 56 ... Rectifier circuit 57 ... Request signal generation Means 58... Received power acquisition means 59... Power feeding base discriminating means 220... Power feeding base 221... Charging surface 251. 0 ... charging stand 1350 ... power receiving device 4103 ... power transmission coil 4104 ... power receiving coil LD ... electric load

Claims (18)

A power receiving device having an electrical load;
A power supply base for transmitting power to the power receiving device,
A non-contact power supply system capable of transmitting power by transmitting power from the power supply base without contact to the power receiving device,
The power receiving device is:
The electrical load;
A power receiving coil for receiving power from the power supply base;
Power receiving side control means for controlling driving of the electric load with the received power received by the power receiving coil;
A power receiving amount acquisition means for acquiring a power receiving amount actually obtained on the power receiving device side;
Request signal generating means for generating a power transmission request signal for instructing the amount of power transmitted from the power supply to the power receiving device,
The power supply stand is
A power transmission coil for electromagnetically coupling with the power receiving coil to transmit power;
Request signal receiving means for receiving the power transmission request signal generated by the request signal generating means;
Based on the power transmission request signal received by the request signal receiving means, power control means for controlling the amount of power transmitted from the power transmission coil,
With
The power supply stand is
A first current mode capable of transmitting power with the first target current value as a rated current;
The power control means can switch between a second current mode in which a second target current value larger than the first target current value can be transmitted as a rated current,
The request signal generation means, as a power transmission request signal,
A first transmission request signal for requesting first transmission power required for power transmission in the first current mode;
A contactless power feeding system capable of transmitting a second transmission request signal for requesting second transmission power required for power transmission in the second current mode. The contactless power supply system according to claim 1, wherein the power supply base further includes:
Foreign matter detecting means for detecting the presence of foreign matter between the power transmission coil and the power receiving coil,
The power feeding base is controlled so as not to shift to the second current mode even when the second power transmission request signal is received when the presence of the foreign matter is detected by the foreign matter detecting means. Contact power supply system. The contactless power supply system according to claim 2,
The power supply base is configured to control power transmission in the first current mode even when the second power transmission request signal is received when the foreign object detection means detects the presence of the foreign object. Contactless power supply system. The contactless power supply system according to any one of claims 1 to 3,
The non-contact power supply system, wherein the amount of power received is a current value. The contactless power supply system according to claim 1,
The contactless power supply system, wherein the amount of received power is a power value. The contactless power supply system according to claim 2,
The foreign object detection means detects a received current value in the power receiving device, calculates a transmission efficiency based on the received current value, compares the transmission efficiency with a predetermined efficiency threshold,
When the transmission efficiency is smaller than the efficiency threshold, it is determined that there is a foreign object,
A non-contact power feeding system that determines that there is no foreign object when transmission efficiency is greater than an efficiency threshold. It is a non-contact electric power feeding system as described in any one of Claims 1-6,
The electrical load is a secondary battery;
The power supply base is a charging base for charging the secondary battery;
For the power receiving device, power is transmitted from the power supply without contact, and the power receiving side control means controls the charging current of the secondary battery with the received power received by the power receiving coil, A non-contact power supply system capable of charging the secondary battery. It is a non-contact electric power feeding system as described in any one of Claims 1-7,
A contactless power supply system, wherein the first target current value is a current value according to a standardized contactless charging method. It is a non-contact electric power feeding system according to claim 8,
The first target current value is 700 mA,
A non-contact power feeding system, wherein the second target current value is 900 mA. A contactless power feeding system according to any one of claims 1 to 9,
The non-contact power feeding system according to claim 1, wherein the request signal generating unit is capable of transmitting the first power transmission request signal and the second power transmission request signal in a time division manner. The contactless power supply system according to any one of claims 1 to 10, wherein the power supply base further includes:
A contactless power feeding system comprising: a moving mechanism for moving the power transmission coil within a mounting surface on which the power receiving device is mounted. It is a non-contact electric power feeding system according to any one of claims 1 to 10,
The non-contact power feeding system according to claim 1, wherein the power feeding stand has a fixed power transmission coil. A power receiving device that can be driven in a contactless manner with electric power transmitted through a power transmission coil built in the power supply stand,
Electrical load,
In order to receive the power transmitted to the electrical load, a power receiving coil that can be electromagnetically coupled to the power transmitting coil,
Power receiving side control means for controlling driving of the electric load with the received power received by the power receiving coil;
A power receiving amount acquisition means for acquiring a power receiving value actually obtained on the power receiving device side;
Request signal generating means for generating a power transmission request signal for instructing the amount of power transmitted from the power supply to the power receiving device,
The request signal generation means, as a power transmission request signal,
A first transmission request signal for requesting a first transmission power necessary for power transmission in a first current mode in which transmission can be performed with a first target current value as a rated current;
A second transmission request signal for requesting a second transmission power required for power transmission in a second current mode in which a second target current value larger than the first target current value can be transmitted as a rated current can be transmitted. Power receiving equipment characterized by The power receiving device according to claim 13,
The power receiving device according to claim 1, wherein when the power supply base detects that a foreign object exists between the power transmission coil and the power reception coil, the power supply device does not shift to the second current mode. A power supply stand that can be driven by transmitting electric power to a power receiving device having an electric load without contact,
A power transmission coil for electromagnetically coupling with a power receiving coil incorporated in the power receiving device to transmit power to the power receiving device;
A request signal receiving means for receiving a power transmission request signal for instructing a power transmission amount transmitted from the power supply device to the power receiving device, transmitted from the power receiving device;
Based on the power transmission request signal received by the request signal receiving means, power control means for controlling the amount of power transmitted from the power transmission coil,
With
The power control means includes
A first current mode capable of transmitting power with the first target current value as a rated current;
A power supply stand that is switchable between a second current mode in which power can be transmitted with a second target current value larger than the first target current value as a rated current. The power supply stand according to claim 15, further comprising:
A foreign object detection means for detecting the presence of a foreign object between the power transmission coil and the power receiving coil;
When the presence of a foreign object is detected by the foreign object detection unit, the power control unit does not shift to the second current mode even when receiving the power transmission request signal requesting power transmission in the second current mode. A power supply stand that is controlled. A non-contact power supply method for driving by transmitting power from a power supply stand without contact to a power receiving device having an electrical load,
A step of transmitting power from the power transmission coil to the power reception coil in a state where the power reception coil of the power reception device is electromagnetically coupled to the power transmission coil of the power supply base;
The power receiving device starts power transmission to the electric load with the received power received by the power receiving coil, and detects a power reception value;
A step of transmitting a power transmission request signal instructing increase / decrease in the amount of power transmitted from the power supply base to the power receiving device based on the detected power reception value;
Wherein in accordance with transmission request signal, and a step in which the power control means for adjusting the transmission amount of power to the power receiving coil from the transmitting coil,
The power receiving device, as a power transmission request signal,
A first transmission request signal for requesting a first transmission power necessary for power transmission in a first current mode in which transmission can be performed with a first target current value as a rated current;
Combined with the second power transmission request signal for requesting the second transmission power required for power transmission in the second current mode in which the second target current value larger than the first target current value can be transmitted as the rated current. A non-contact power feeding method characterized by comprising: The contactless power supply method according to claim 17,
A contactless power feeding method, wherein, when the presence of a foreign object is detected, control is performed so as not to shift to the second current mode even when the power feeding base receives the second power transmission request signal.

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