Contactless power supply system and lighting system

Abstract

The objective of this disclosure is to improve security. [Solution] The non-contact power supply system A1 comprises a power transmission device 1 that transmits power non-contact via a power transmission coil 10, and a power receiving device 2 that receives power non-contact via a power receiving coil 20. The power receiving device 2 includes a power receiving coil 20, a lighting circuit unit 21 that lights up a lighting load 3 using the power received via the power receiving coil 20, a power receiving side control unit 22 that controls the lighting circuit unit 21, and an abnormality detection unit 23 that detects abnormalities occurring in the lighting circuit unit 21. The power transmission device 1 includes a power transmission coil 10 and a power supply circuit unit 11 that supplies current to the power transmission coil 10. The power receiving side control unit 22 performs protective operations to protect at least one of the power receiving device 2 and the power transmission device 1 when the abnormality detection unit 23 detects an abnormality.

Description

Technical Field

[0001] The present disclosure relates to a non-contact power supply system and a lighting system. More specifically, the present disclosure relates to a non-contact power supply system in which a power receiving device that is non-contact power-supplied from a power transmission device lights a lighting load, and a lighting system having the non-contact power supply system and the lighting load.

Background Art

[0002] As a conventional example, a lighting device (lighting system) described in Patent Document 1 will be exemplified. The lighting device (hereinafter referred to as a conventional example) described in Patent Document 1 includes a power supply unit and a light emitting unit having a light source that is lit by the supply of power from the power supply unit. The power supply unit includes a primary coil. The light emitting unit includes a secondary coil that electromagnetically induces with the primary coil and is detachably attached to the power supply unit. The conventional example is configured to be able to supply power from the power supply unit to the light emitting unit by electromagnetic induction between the primary coil and the secondary coil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the conventional example, when some abnormality occurs in the light emitting unit, for example, a short circuit failure of the light source, etc., for example, it is not desirable from the viewpoint of safety that the power supply to the light emitting unit continues.

[0005] An object of the present disclosure is to provide a non-contact power supply system and a lighting system capable of improving safety.

Means for Solving the Problems

[0006] A contactless power supply system according to one aspect of the present disclosure comprises a power transmission device that transmits power in a contactless manner via a power transmission coil, and a power receiving device that receives power in a contactless manner via a power receiving coil. The power receiving device includes the power receiving coil, a lighting circuit section that lights up a lighting load using the power received via the power receiving coil, a power receiving side control section that controls the lighting circuit section, and an abnormality detection section that detects abnormalities occurring in the lighting circuit section. The power transmission device includes the power transmission coil and a power supply circuit section that supplies current to the power transmission coil. The power receiving side control section performs a protective operation to protect at least one of the power receiving device and the power transmission device when the abnormality detection section detects the abnormality.

[0007] A lighting system according to one aspect of this disclosure comprises the contactless power supply system and the lighting load. [Effects of the Invention]

[0008] The contactless power supply system and lighting system disclosed herein have the effect of improving safety. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram of a contactless power supply system and a lighting system according to an embodiment of the present disclosure. [Figure 2] Figure 2 is a partially abbreviated block diagram showing a modified example 1 of the same contactless power supply system. [Figure 3] Figure 3 is a partially abbreviated block diagram showing a modified example 2 of the same contactless power supply system. [Figure 4] Figure 4 is a perspective view showing a third modified example of the same lighting system. [Modes for carrying out the invention]

[0010] Hereinafter, a contactless power supply system A1 and a lighting system B1 according to embodiments of this disclosure will be described in detail with reference to the drawings. However, the configurations described in the following embodiments are merely examples of this disclosure. This disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of this disclosure can be achieved.

[0011] (1) Overview The contactless power supply system A1 according to this embodiment comprises a power transmission device 1 that transmits power contactlessly via a power transmission coil 10, and a power receiving device 2 that receives power contactlessly via a power receiving coil 20 (see Figure 1).

[0012] Furthermore, the lighting system B1 according to the embodiment comprises a contactless power supply system A1 according to the embodiment and a lighting load 3 (see Figure 1). The lighting load 3 has, for example, one or more LEDs. The LEDs are preferably, for example, white LEDs for illumination. However, the lighting load 3 may have multiple types of LEDs with different light colors, for example, two LEDs of warm white and daylight color. Alternatively, the lighting load 3 may have three or more LEDs, including red LEDs, green LEDs, and blue LEDs.

[0013] The power receiving device 2 includes a power receiving coil 20, a lighting circuit unit 21 that uses the power received via the power receiving coil 20 to light up the lighting load 3, a power receiving side control unit 22 that controls the lighting circuit unit 21, and an abnormality detection unit 23 that detects abnormalities occurring in the lighting circuit unit 21.

[0014] The power transmission device 1 includes a power transmission coil 10 and a power supply circuit unit 11 that supplies current to the power transmission coil 10. The power supply circuit unit 11 is configured to supply a high-frequency current of several tens of kHz to several tens of MHz to the power transmission coil 10. The power transmission coil 10 generates a high-frequency magnetic field (magnetic flux) when a high-frequency current flows through it. The power receiving coil 20 generates an induced electromotive force by linking with the high-frequency magnetic flux generated by the power transmission coil 10. In other words, the contactless power supply system A1 according to this embodiment can supply power from the power transmission device 1 to the power receiving device 2 without contact by utilizing electromagnetic induction.

[0015] Here, there is a possibility that some abnormality may occur in the power receiving device 2, for example, a short-circuit fault of the lighting load 3 or an open fault due to disconnection of the lighting load 3. When the lighting load 3 has a short-circuit fault, an excessive current (short-circuit current) flows from the lighting circuit section 21 of the power receiving device 2 to the lighting load 3. Alternatively, when the lighting load 3 is disconnected, the current does not flow from the lighting circuit section 21 of the power receiving device 2 to the lighting load 3.

[0016] Therefore, the abnormality detection unit 23 in the embodiment detects at least one of the output current and output voltage of the lighting circuit section 21, and detects an abnormality of the lighting circuit section 21 based on at least one of the detected current and voltage. Then, the power receiving side control unit 22 in the embodiment performs a protection operation for protecting at least one of the power receiving device 2 and the power transmission device 1 when the abnormality detection unit 23 detects an abnormality. The protection operation is, for example, an operation of reducing or stopping the output from the power receiving device 2 to the lighting load 3.

[0017] Thus, the non-contact power supply system A1 according to the embodiment and the lighting system B1 according to the embodiment cause the power receiving side control unit 22 to perform a protection operation when the abnormality detection unit 23 detects an abnormality, so that the safety can be improved as compared with the case where the abnormality is not detected and the protection operation is not performed.

[0018] (2) Details (2-1) Configuration of the non-contact power supply system according to the embodiment The non-contact power supply system A1 according to the embodiment (hereinafter abbreviated as the non-contact power supply system A1) includes a power transmission device 1 that performs non-contact power transmission via a power transmission coil 10, and a power receiving device 2 that performs non-contact power reception via a power receiving coil 20 (see FIG. 1).

[0019] The power transmission device 1 includes a power transmission coil 10, a power supply circuit section 11, and a power transmission side control unit 12. The power transmission device 1 further includes a transmission unit (power transmission side communication unit 13).

[0020] The power transmission coil 10 may be a cylindrical coil (solenoid) formed by winding a conducting wire in a tubular shape, or it may be a coil formed by winding a conducting wire in a spiral shape or the like.

[0021] The power supply circuit section 11 includes a full-wave rectifier that full-wave rectifies an AC voltage and an AC current supplied from an external AC power supply 5, a smoothing capacitor that smooths the pulsating DC voltage and pulsating DC current output from the full-wave rectifier, and an inverter circuit that converts the DC voltage and DC current smoothed by the smoothing capacitor into a high-frequency voltage and high-frequency current. The inverter circuit is preferably a half-bridge type inverter circuit having two semiconductor switching elements or a full-bridge type inverter circuit having four semiconductor switching elements. The inverter circuit is configured to convert the DC voltage and DC current smoothed by the smoothing capacitor into a high-frequency voltage and high-frequency current by switching two or four semiconductor switching elements and apply the converted voltage and current to the power transmission coil 10. Note that the frequency of the high-frequency voltage and high-frequency current output from the inverter circuit is preferably on the order of several tens of kHz to several tens of MHz.

[0022] The power transmission side control section 12 mainly consists of a microcontroller. The power transmission side control section 12 is configured to control the power supply circuit section 11 by causing the processor of the microcontroller to execute a program. Note that the power transmission side control section 12 may have a drive circuit (drive integrated circuit) that drives two or four semiconductor switching elements included in the inverter circuit of the power supply circuit section 11 separately from the microcontroller.

[0023] The power transmission side communication section 13 is configured to transmit and receive wireless signals using electromagnetic waves including light (visible light or infrared light) and radio waves as a medium. Note that the power transmission side communication section 13 can transmit and receive wireless signals via the power transmission coil 10 by using radio waves having the same frequency as the frequency of the high-frequency current flowing through the power transmission coil 10 by the power supply circuit section 11 as a medium. Such wireless communication is preferably performed in accordance with a standard called NFC (Near Field Communication), for example.

[0024] The power transmission side communication unit 13 transmits a wireless signal containing data provided by the power transmission side control unit 12. The data provided by the power transmission side control unit 12 is, for example, the dimming level of the lighting load 3. The dimming level is a ratio of the current value when the lighting load 3 is lit at its rated capacity (rated current value) is set to 100%. For example, a dimming level of 50% means a current value that is half of the rated current value. The power transmission side control unit 12 receives a signal transmitted from, for example, a remote controller and provides the power transmission side communication unit 13 with dimming level data according to the command contained in the received signal.

[0025] The power receiving device 2 includes a power receiving coil 20, a lighting circuit unit 21, a power receiving side control unit 22, and an abnormality detection unit 23. Preferably, the power receiving device 2 also includes a receiving unit (power receiving side communication unit 24).

[0026] The receiving coil 20 may be a solenoid or a coil with a wire wound in a spiral. However, it is preferable that the receiving coil 20 has the same shape as the transmitting coil 10. The receiving coil 20 generates an induced electromotive force by linking with the high-frequency magnetic flux generated by the transmitting coil 10.

[0027] The lighting circuit section 21 includes, for example, a full-wave rectifier with both ends of the power receiving coil 20 electrically connected to the AC input terminal, a smoothing capacitor electrically connected to the pulsating output terminal of the full-wave rectifier, and a DC conversion circuit with both ends of the smoothing capacitor electrically connected to the input terminal. The DC conversion circuit is composed of, for example, a buck-boost converter (step-up / step-down chopper). The DC conversion circuit steps up or steps down the DC voltage smoothed by the smoothing capacitor and applies it to the lighting load 3.

[0028] The power receiving control unit 22 primarily consists of a microcontroller. The power receiving control unit 22 is configured to control the lighting circuit unit 21 by having the microcontroller's processor execute a program. In addition to the microcontroller, the power receiving control unit 22 may also have a drive circuit (driving integrated circuit) that drives the semiconductor switching elements in the DC conversion circuit of the lighting circuit unit 21.

[0029] The power receiving control unit 22 uses PWM control to control the DC conversion circuit of the lighting circuit unit 21 so that the current flowing to the lighting load 3 (output current of the lighting circuit unit 21) matches a predetermined target value. The power receiving control unit 22 can adjust the output current of the lighting circuit unit 21 and dim the lighting load 3 by changing the target value according to the dimming level.

[0030] The receiving-side communication unit 24 is configured to receive a wireless signal transmitted from the transmitting-side communication unit 13, acquire data (such as dimming level) contained in the received wireless signal, and pass the acquired data to the receiving-side control unit 22.

[0031] The abnormality detection unit 23 includes a current detection circuit that detects the output current of the lighting circuit unit 21, and a determination circuit that determines whether or not an abnormality has occurred based on the value detected by the current detection circuit. The current detection circuit detects the current flowing through the semiconductor switching element of the DC conversion circuit of the lighting circuit unit 21 as the output current of the lighting circuit unit 21. The determination circuit includes, for example, a comparator that compares the detected value of the current detected by the current detection circuit with a threshold value. The comparator is a window comparator, and the output becomes low level when the detected value of the current detection circuit is greater than the upper threshold or less than the lower threshold, and the output becomes high level when the detected value is less than or equal to the upper threshold and greater than or equal to the lower threshold. However, the abnormality detection unit 23 may also have a voltage detection circuit that detects the output voltage of the lighting circuit unit 21 instead of the current detection circuit, or together with the current detection circuit.

[0032] For example, if lighting load 3 experiences a short-circuit failure, the output current of the lighting circuit 21 increases, causing the detected value of the current detection circuit (and the detected value of the voltage detection circuit) to exceed the upper threshold. Also, if lighting load 3 experiences an open-circuit failure, the output current of the lighting circuit 21 becomes zero, causing the detected value of the current detection circuit (and the detected value of the voltage detection circuit) to fall below the lower threshold. In other words, the determination circuit determines that an abnormality has occurred if the detected value of the current detection circuit (and the detected value of the voltage detection circuit) is greater than the upper threshold or less than the lower threshold, and outputs a low-level detection signal (abnormality detection signal) to the power receiving control unit 22. On the other hand, if the detected value is less than or equal to the upper threshold and greater than or equal to the lower threshold, the determination circuit determines that no abnormality has occurred and does not output an abnormality detection signal by setting the output to a high level.

[0033] (2-2) Configuration of the lighting system according to the embodiment The lighting system B1 according to the embodiment (hereinafter referred to as lighting system B1) comprises the contactless power supply system A1 described above and a lighting load 3.

[0034] The lighting load 3 preferably has LEDs, but may also have other light-emitting elements, such as organic electroluminescent elements or semiconductor laser elements. The lighting load 3 may be configured integrally with the power receiving device 2, or it may be configured separately and detachably from the power receiving device 2. The lighting load 3 emits light (lights up) when a direct current output from the lighting circuit section 21 of the power receiving device 2 flows through it, and the light intensity is adjusted (dimmed) by increasing or decreasing the value of the direct current. Furthermore, if the lighting load 3 has multiple types of LEDs with different light colors, a direct current is individually supplied to each LED of each light color from the lighting circuit section 21 of the power receiving device 2. The color of the illumination light emitted from the lighting load 3 is then adjusted (color-tuned) by changing the ratio of the current values ​​of the direct currents flowing through each LED of each light color.

[0035] (2-3) Operation of the contactless power supply system and lighting system Next, the operation of the contactless power supply system A1 and the lighting system B1 will be explained. As a prerequisite, the power transmission device 1 is installed in a location where it can be powered by an external power source (AC power supply 5), and the power receiving device 2 is installed in a location where it can receive power from the power transmission device 1 at all times or at any time.

[0036] The power transmission control unit 12 of the power transmission device 1 intermittently operates the power supply circuit unit 11 and intermittently transmits wireless signals from the power transmission communication unit 13. The power transmission control unit 12 continues to operate the power supply circuit unit 11 intermittently unless the power transmission communication unit 13 receives a reply wireless signal including an ACK (acknowledgment) from the power receiving communication unit 24 of the power receiving device 2. If the power transmission control unit 13 receives a reply wireless signal including an ACK from the power receiving communication unit 24 of the power receiving device 2, the power transmission control unit 12 operates the power supply circuit unit 11 continuously and starts supplying power to the power receiving device 2. In other words, the contactless power supply system A1 determines whether the power receiving device 2 is located in a place where it can receive power from the power transmission device 1 by sending and receiving wireless signals between the power transmission device 1 and the power receiving device 2, and operates the power supply circuit unit 11 intermittently if it determines that the power receiving device 2 is not located there. As a result, the contactless power supply system A1 can suppress unnecessary power consumption of the power transmission device 1 while preventing malfunctions (such as temperature rise of foreign objects) that occur when foreign objects (conductors) are present near the power transmission coil 10.

[0037] When the power transmission control unit 12 keeps the power supply circuit unit 11 running continuously, a high-frequency current flows through the power transmission coil 10, generating a magnetic flux. The magnetic flux generated in the power transmission coil 10 links with the power receiving coil 20, inducing an electromotive force in the power receiving coil 20, allowing the power receiving device 2 to receive power. The power receiving device 2 uses the power supplied from the power transmission device 1 to light the lighting load 3 using the lighting circuit unit 21.

[0038] Furthermore, the power transmission control unit 12 receives signals transmitted from the remote controller and provides dimming level data to the power transmission communication unit 13 according to the commands included in the received signals. The power transmission communication unit 13 transmits a wireless signal containing the dimming level data provided by the power transmission control unit 12. If the lighting load 3 has multiple types of LEDs with different light colors, the power transmission control unit 12 causes the power transmission communication unit 13 to transmit color adjustment data, including the dimming level for each LED of each light color, via a wireless signal.

[0039] The receiving-side communication unit 24 receives a wireless signal transmitted from the transmitting-side communication unit 13, acquires the data contained in the wireless signal, and passes it to the receiving-side control unit 22. The receiving-side control unit 22 controls the lighting circuit unit 21 so that the current value of the DC current supplied to the lighting load 3 matches the dimming level of the received data. Specifically, the receiving-side control unit 22 adjusts the DC current output from the lighting circuit unit 21 by PWM control of the DC conversion circuit of the lighting circuit unit 21 to dim the lighting load 3. In addition, the receiving-side control unit 22 adjusts the color of the illumination light emitted from the lighting load 3 by adjusting the DC current output from the lighting circuit unit 21 for each LED of each light color according to the color adjustment data received by the receiving-side communication unit 24.

[0040] As described above, the contactless power supply system A1 transmits a wireless signal including a dimming level from the power-transmitting communication unit 13 to the power-receiving communication unit 24, and causes the power-receiving control unit 22 to control the lighting circuit unit 21 according to the dimming level included in the wireless signal. This allows for dimming of the lighting load 3 while providing contactless power, thereby improving usability.

[0041] By the way, the abnormality detection unit 23 of the power receiving device 2 detects the output current of the lighting circuit unit 21. However, the abnormality detection unit 23 may also detect the current (switching current) flowing through the semiconductor switching elements that constitute the inverter circuit of the lighting circuit unit 21 as the output current of the lighting circuit unit 21.

[0042] If any abnormality occurs in the power receiving device 2, the abnormality detection unit 23 outputs an abnormality detection signal to the power receiving side control unit 22. When the power receiving side control unit 22 receives an abnormality detection signal from the abnormality detection unit 23, it determines that the abnormality detection unit 23 has detected an abnormality and starts a protective operation to protect at least one of the power receiving device 2 and the power transmitting device 1. After starting the protective operation, the power receiving side control unit 22 either stops the lighting circuit unit 21 or controls the lighting circuit unit 21 to reduce the output current. As a result, the contactless power supply system A1 and the lighting system B1 can improve safety compared to when abnormality detection and protective operation are not performed by setting the power supplied from the power receiving device 2 to the lighting load 3 to zero or a very small value.

[0043] (2-4) Modifications of contactless power supply systems Next, several modifications of the contactless power supply system A1 and the lighting system B1 will be described. However, the basic configuration of each modification described below is the same as the basic configuration of the embodiment. Therefore, components that are common to or substantially common with the basic configuration of the embodiment will be denoted by the same reference numerals, and their illustration and description will be omitted as appropriate. In the following description, "substantially common configuration" means a configuration that differs slightly in shape, size, etc., but has the same function.

[0044] (2-4-1) Variation 1 The contactless power supply system A1 in Modification Example 1 employs a magnetic resonance method (also called magnetic resonance method), which is a type of non-radiative method similar to the electromagnetic induction method, as a contactless power supply method from the power transmission device 1 to the power receiving device 2.

[0045] In Modification 1, the transmitting coil 10, together with the capacitor 141, constitutes a resonator (hereinafter referred to as the transmitting side resonator 14) (see Figure 2). Also, in Modification 1, the receiving coil 20, together with the capacitor 251, constitutes a resonator (hereinafter referred to as the receiving side resonator 25) (see Figure 2).

[0046] However, the non-contact power supply system A1 of Modified Example 1 can supply power from the power transmission device 1 to the power receiving device 2 without contact by causing the power transmission side resonator 14 and the power receiving side resonator 25 to resonate (magnetic field resonance). Furthermore, since the non-contact power supply system A1 of Modified Example 1 performs non-contact power supply from the power transmission device 1 to the power receiving device 2 using the magnetic field resonance method, it is possible to increase the transmission distance (distance between the power transmission coil 10 and the power receiving coil 20) through non-contact power supply compared to the electromagnetic induction method.

[0047] (2-4-2) Modification example 2 The non-contact power supply system A1 of Modified Example 2 is characterized in that the power transmission device 1 is equipped with multiple power transmission coils 10. In Modified Example 2, the power transmission device 1 may supply high-frequency current from a single power supply circuit unit 11 to multiple power transmission coils 10, or it may be equipped with multiple power supply circuit units 11 that correspond one-to-one with multiple power transmission coils 10.

[0048] As shown in Figure 3, the power transmission device 1 in Modified Example 2 has a plurality (for example, two) of power transmission coils 10A and 10B. The power transmission device 1 in Modified Example 2 is configured to supply high-frequency current to each power transmission coil 10A and 10B from a single power supply circuit unit 11. However, the power transmission device 1 in Modified Example 2 may have three or more power transmission coils 10A, 10B, ... Also, the power transmission device 1 in Modified Example 2 may have a plurality of power supply circuit units 11 that correspond one-to-one with the plurality of power transmission coils 10A and 10B, and may be configured to supply high-frequency current individually to each power transmission coil 10A, 10B, ... from the plurality of power supply circuit units 11.

[0049] However, the non-contact power supply system A1 of the modified example 2 can supply power to two power receiving devices 2 simultaneously from one power transmitting device 1, thereby improving usability. Furthermore, the non-contact power supply system A1 of the modified example 2 can improve usability by increasing the flexibility of the installation location of the power receiving devices 2 by installing multiple power transmitting coils 10A and 10B in different locations.

[0050] (2-4-3) Modification 3 The lighting system B1 of Modification 3 comprises a contactless power supply system A1 and a lighting fixture 6 (see Figure 4). The power transmission device 1 of the contactless power supply system A1 in Modification 3 is installed on the underside of the tabletop 40 of the table 4. However, the multiple (for example, four) power transmission coils 10A, 10B, 10C, and 10D of the power transmission device 1 in Modification 3 are arranged vertically and horizontally with spacing between them on the surface (top) of the tabletop 40 of the table 4.

[0051] The lighting fixture 6 comprises a base 60 that houses the power receiving device 2 and the power receiving coil 20 and is placed on the upper surface of the deck 40, a cylindrical main body 61 that protrudes upward from the base 60, and a lamp body 62 that is rotatably connected to the tip (upper end) of the main body 61. In other words, the lighting fixture 6 is a so-called LED desk lamp. The power receiving coil 20 is provided on the lower surface of the base 60. The lighting load 3 is provided on the lamp body 62.

[0052] In Modification 3, the power transmission device 1 supplies power to the power receiving device 2 via one of the multiple power transmission coils 10A, 10B, 10C, and 10D, which overlaps with the base 60 of the lighting fixture 6. In other words, the lighting system B1 of Modification 3 can be used by placing the lighting fixture 6 at any location on the upper surface of the deck 40 (where the multiple power transmission coils 10A, 10B, 10C, and 10D are located), so there is no need to provide a power cord to the lighting fixture 6, and the installation location can be freely selected, improving usability.

[0053] (3) Summary A non-contact power supply system (A1) according to a first aspect of this disclosure comprises a power transmission device (1) that transmits power non-contact via a power transmission coil (10) and a power receiving device (2) that receives power non-contact via a power receiving coil (20). The power receiving device (2) includes a power receiving coil (20), a lighting circuit unit (21) that lights up a lighting load (3) using the power received via the power receiving coil (20), a power receiving side control unit (22) that controls the lighting circuit unit (21), and an abnormality detection unit (23) that detects abnormalities occurring in the lighting circuit unit (21). The power transmission device (1) includes a power transmission coil (10) and a power supply circuit unit (11) that supplies current to the power transmission coil (10). The power receiving side control unit (22) performs protective operations to protect at least one of the power receiving device (2) and the power transmission device (1) when the abnormality detection unit (23) detects an abnormality.

[0054] In the first embodiment of the contactless power supply system (A1), when the abnormality detection unit (23) detects an abnormality, the power receiving side control unit (22) is instructed to perform a protective action, thereby improving safety compared to the case where abnormality detection and protective action are not performed.

[0055] A contactless power supply system (A1) according to a second aspect of this disclosure can be realized in combination with the first aspect. In the contactless power supply system (A1) according to the second aspect, it is preferable that the power receiving control unit (22) controls the lighting circuit unit (21) to reduce the current flowing to the lighting load (3) as a protective operation.

[0056] The non-contact power supply system (A1) according to the second embodiment can further improve safety by reducing the current supplied to the lighting load (3), thereby preventing overcurrent from flowing to the power receiving device (2).

[0057] A contactless power supply system (A1) according to a third aspect of this disclosure can be realized in combination with the first or second aspect. In the contactless power supply system (A1) according to the third aspect, it is preferable that the power receiving control unit (22) controls the lighting circuit unit (21) so as a protective operation that current does not flow to the lighting load (3).

[0058] The third aspect of the contactless power supply system (A1) can further improve safety by preventing overcurrent from flowing to the power receiving device (2) by not supplying current to the lighting load (3).

[0059] A contactless power supply system (A1) according to a fourth aspect of this disclosure can be realized in combination with any of the first to third aspects. In the contactless power supply system (A1) according to the fourth aspect, it is preferable that the abnormality detection unit (23) detects an abnormality based on the output current of the lighting circuit unit (21) or the output voltage of the lighting circuit unit (21).

[0060] The non-contact power supply system (A1) according to the fourth embodiment can improve the accuracy of anomaly detection by the anomaly detection unit (23).

[0061] A contactless power supply system (A1) according to a fifth aspect of this disclosure can be realized in combination with any of the first to fourth aspects. In the contactless power supply system (A1) according to the fifth aspect, the power transmission device (1) preferably further comprises a transmission unit (power transmission side communication unit 14) that transmits a wireless signal including the dimming level of a lighting load (3). The power receiving device (2) preferably further comprises a receiving unit (power receiving side communication unit 24) that receives a wireless signal. The power receiving side control unit (22) preferably controls the lighting circuit unit (21) according to the dimming level included in the wireless signal received by the receiving unit.

[0062] The fifth aspect of the contactless power supply system (A1) allows for dimming of the lighting load (3) while providing contactless power, thereby improving usability.

[0063] A contactless power supply system (A1) according to a sixth aspect of this disclosure can be realized in combination with any of the first to fifth aspects. In the contactless power supply system (A1) according to the sixth aspect, the power transmission device (1) preferably further has a resonator (power transmission side resonator 15) including a power transmission coil (10). The power receiving device (2) preferably further has a resonator (power receiving side resonator 24) including a power receiving coil (20).

[0064] The contactless power supply system (A1) according to the sixth embodiment performs contactless power supply from the power transmission device (1) to the power receiving device (2) using a magnetic field resonance method, and therefore, compared to the electromagnetic induction method, it is possible to extend the transmission distance by contactless power supply.

[0065] A lighting system (B1) according to the seventh aspect of this disclosure comprises a contactless power supply system (A1) according to any of the first to sixth aspects and a lighting load (3).

[0066] The lighting system (B1) according to the seventh embodiment can improve safety compared to the case in which abnormality detection and protective action are not performed. [Explanation of symbols]

[0067] A1 Contactless power supply system B1 Lighting System 1. Power transmission equipment 2. Power receiving device 3. Lighting load 10 Power transmission coil 11 Power supply circuit section 12 Power transmission side control unit 13. Power transmission side communication unit (transmitter) 14 Power transmission side resonator (resonator) 20 Power receiving coil 21 Lighting circuit section 22 Power receiving side control unit 23 Anomaly detection unit 24. Receiving side communication unit (receiving unit) 25. Receiving side resonator (resonator)

Claims

1. A power transmission device that transmits power without contact via a power transmission coil, A power receiving device that receives power non-contact via a power receiving coil, Equipped with, The power receiving device is The aforementioned power receiving coil, A lighting circuit unit that uses the power received via the aforementioned power receiving coil to light up a lighting load, A power receiving side control unit that controls the aforementioned lighting circuit section, An abnormality detection unit for detecting an abnormality occurring in the lighting circuit section, It has, The aforementioned power transmission device is The aforementioned power transmission coil, A power supply circuit section that supplies current to the aforementioned power transmission coil, It has, The power receiving control unit performs a protective operation to protect at least one of the power receiving device and the power transmitting device when the abnormality detection unit detects the abnormality. Contactless power supply system.

2. The power receiving control unit controls the lighting circuit to reduce the current flowing to the lighting load as a protective action. The contactless power supply system according to claim 1.

3. The power receiving control unit controls the lighting circuit section so as a protective action, that the current does not flow to the lighting load. The contactless power supply system according to claim 2.

4. The abnormality detection unit detects the abnormality based on the output current of the lighting circuit or the output voltage of the lighting circuit. A contactless power supply system according to any one of claims 1 to 3.

5. The power transmission device further comprises a transmitting unit that transmits a wireless signal including the dimming level of the lighting load, The power receiving device further comprises a receiving unit for receiving the wireless signal, The power receiving control unit controls the lighting circuit unit according to the dimming level included in the wireless signal received by the receiving unit. A contactless power supply system according to any one of claims 1 to 3.

6. The power transmission device further includes a resonator containing the power transmission coil, The power receiving device further comprises a resonator including the power receiving coil. A contactless power supply system according to any one of claims 1 to 3.

7. A contactless power supply system according to any one of claims 1-3, The aforementioned lighting load and, Equipped with, Lighting system.

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