WO2015198602A1

WO2015198602A1 - Non-contact power supply device, non-contact power-receiving device, and non-contact power supply system

Info

Publication number: WO2015198602A1
Application number: PCT/JP2015/003182
Authority: WO
Inventors: 稔博秋山; 豊彦辻本; 弘士小原; 秀明安倍
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-06-27
Filing date: 2015-06-24
Publication date: 2015-12-30
Also published as: JP6347389B2; JP2016012975A

Abstract

　A power supply device (20), provided with an excitation circuit (22) and a power supply coil (23). The excitation circuit (22) inverts the polarity of an input voltage from a rectifying and smoothing circuit (21) in response to a PWM signal in which the duty ratio repeatedly increases and decreases at a period of an AC voltage to be applied from a power-receiving device (30) to a load (40), thereby generating an excitation current applied to the power supply coil (23). The power-receiving device (30) is provided with a power-receiving coil (31) and a filter circuit (32). The filter circuit (32) attenuates, from an AC waveform generated by electromagnetic induction in the power-receiving coil (31), frequency components corresponding to a frequency higher than that of the AC voltage to be applied to the load (40).

Description

Non-contact power feeding device, non-contact power receiving device and non-contact power feeding system

The present invention relates to a noncontact power feeding device, a noncontact power receiving device, and a noncontact power feeding system, and more particularly, to a noncontact power feeding device, a noncontact power receiving device, and a noncontact power feeding device each configured to transmit power in a noncontact manner. The present invention relates to a noncontact power feeding system.

Conventionally, a non-contact power supply configured to non-contactly supply power from the primary side unit to the secondary side unit has been proposed (for example, Japanese Patent Application Publication No. 2004-96853 (hereinafter "Document 1"). ))).

The secondary side unit included in the non-contact power supply device includes a rectifying and smoothing circuit configured to rectify and smooth an induced current flowing through a secondary winding of the coupling transformer, and a sine wave output voltage of the rectifying and smoothing circuit. And an inverter circuit configured to convert into an alternating voltage and to supply the load.

In the non-contact power supply described in Document 1, a rectifying and smoothing circuit converts an induced current flowing through a secondary winding of a coupling transformer into a DC voltage. Therefore, in order to supply an AC voltage to the load, an inverter circuit is required to convert the DC voltage output from the rectifying and smoothing circuit into an AC voltage, and the size of the device is increased by the provision of the inverter circuit. Also, in the secondary side unit, after the rectifying and smoothing circuit converts the alternating current output of the secondary side of the coupling transformer into direct current, the inverter circuit converts the direct current output of the rectifying and smoothing circuit into alternating current, so conversion between direct current and alternating current The loss occurs twice, which causes the power loss in the entire apparatus to increase.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a noncontact power feeding apparatus, a noncontact power receiving apparatus, and a noncontact power feeding system in which downsizing is achieved while suppressing power loss in the whole noncontact power feeding system. Do.

The non-contact power feeding device (20) of the present invention is electromagnetically coupled to the power receiving coil (31) of the non-contact power receiving device (30) to supply power to the power receiving coil (31) by electromagnetic induction. And a PWM (Pulse (Pulse)) in which the duty ratio is repeatedly increased and decreased at a cycle (T1) of an AC voltage (V2) to be applied from the non-contact power reception device (30) to the load (40). And an excitation circuit (22) configured to generate an excitation current to be applied to the feeding coil (23) by inverting the polarity of the input voltage according to a Width Modulation) signal (S3).

The non-contact power reception device (30) of the present invention is electromagnetically coupled to the feeding coil (23) included in the non-contact power feeding device (20), and configured to receive power from the feeding coil (23) by electromagnetic induction. The frequency component of a higher frequency than the frequency of the alternating voltage (V2) to be applied to the load (40) from the receiving coil (31) to be received and the alternating current waveform generated in the receiving coil (31) by electromagnetic induction And a filter circuit (32) configured as follows.

The non-contact power feeding system of the present invention includes the above-described non-contact power feeding device (20) and the above-described non-contact power receiving device (30).

According to the present invention, it is possible to realize a non-contact power feeding device, a non-contact power reception device, and a non-contact power feeding system in which miniaturization is achieved while suppressing power loss in the entire non-contact power feeding system.

Although the drawings show one or more embodiments in accordance with the present teachings, they are not limiting and are merely exemplary. In the drawings, like numerals refer to like or similar elements.
It is a block diagram of this embodiment. It is a circuit diagram of this embodiment. It is a wave form diagram of the sine wave signal in the PWM signal generation circuit of this embodiment, a reference signal, and a PWM signal. It is a wave form diagram of the voltage impressed to the feed coil of this embodiment, and the exchange voltage outputted from a power receiving device. It is a circuit diagram showing another circuit composition of this embodiment.

Hereinafter, the non-contact power feeding system according to the present embodiment will be described with reference to the drawings.

FIG. 1 is a block diagram of the non-contact power feeding system 10 of the present embodiment, and FIG. 2 is a schematic circuit diagram of the non-contact power feeding system 10 of the present embodiment.

As shown in FIG. 1, the non-contact power feeding system 10 of the present embodiment includes a non-contact power feeding device 20 and a non-contact power receiving device 30. Hereinafter, the non-contact power feeding device and the non-contact power receiving device will be referred to as “power feeding device” and “power receiving device”, respectively. In the non-contact power feeding system 10 of the present embodiment, for example, the power feeding device 20 is disposed on the back side of a building material such as a floor or a wall, and the power receiving device 30 is disposed on the front side of the building material. In another example, the power feeding device 20 is disposed inside the window, and the power receiving device 30 is disposed outside the window. The power feeding device 20 is configured to contactlessly supply the power supplied from the AC power supply 100 to the power receiving device 30. The power receiving device 30 includes an outlet 33 to which the power plug 41 of the load 40 is detachably connected. The load 40 is configured to operate with a commercial AC power supply that supplies AC power of a predetermined voltage having a predetermined frequency. The load 40 is configured to operate with the AC power of a commercial AC power supply. For example, the load 40 is a general electric device such as a vacuum cleaner or a television receiver. The power receiving device 30 is configured to supply the power supplied contactlessly from the power feeding device 20 to the load 40 connected to the outlet 33. Therefore, if the power supply devices 20 are installed at a plurality of locations on the back side of the construction material, the power reception device 30 is disposed on the front side of the construction material at a position where power can be received from the power supply device 20 near the load 40. Power can be supplied from the power receiving device 30 to the load 40.

The feeding device 20 includes a DC power supply, an excitation circuit 22 (excitation unit), a feeding coil (transmission coil) 23, and a control circuit 24 (see FIG. 2). In the examples of FIGS. 1 and 2, the DC power supply is a rectifying and smoothing circuit 21, and the control circuit 24 includes a PWM signal generating circuit (PWM signal generating unit) 241.

For example, the rectifying and smoothing circuit 21 rectifies an AC voltage input from an AC power supply 100 such as a commercial AC power supply with a full-wave rectifier 211, smoothes the rectified voltage with a capacitor 212, and has a substantially constant voltage value. _Configured to convert to a DC voltage V.sub.DC.

Excitation circuit 22 receives DC voltage V input from rectifying and smoothing circuit 21 in accordance with a PWM signal whose duty ratio changes in the cycle of AC voltage (second AC voltage) V2 to be supplied from load receiving device 30 to load 40. By inverting (switching) the polarity of _DC , an excitation current to be applied to the feed coil 23 is generated.

The power feeding coil 23 is electromagnetically coupled (inductive coupling) to a power receiving coil (receiving coil) 31 included in the power receiving device 30, and configured to supply power to the power receiving coil 31 by electromagnetic induction.

The control circuit 24 is configured to control the operation of the excitation circuit 22.

The power receiving device 30 includes a power receiving coil 31 and a capacitor 321 as a filter element that constitutes the filter circuit 32 together with the power receiving coil 31. Further, the power receiving device 30 of the present embodiment further includes the outlet 33.

The power receiving coil 31 is electromagnetically coupled (inductively coupled) to the power feeding coil 23 included in the power feeding device 20, and configured to receive power from the power feeding coil 23 by electromagnetic induction.

The filter circuit 32 is configured to attenuate the frequency component of a higher frequency than the frequency of the AC voltage V2 to be supplied to the load 40 from the AC waveform generated in the power receiving coil 31 by electromagnetic induction. The output voltage (second AC voltage V 2) of the filter circuit 32 is applied to the load 40 connected to the outlet 33 through the outlet 33.

Next, specific configurations of the excitation circuit 22, the control circuit 24, and the filter circuit 32 will be described with reference to the circuit diagram of FIG.

The excitation circuit 22 includes four switching elements 221-224. The switching elements 221 to 224 are, for example, field effect transistors, and the switching elements 221 to 224 are controlled by the control circuit 24 to be turned on / off. In the example of FIG. 2, the series circuit of the

switching elements

221 and 222 and the series circuit of the

switching elements

223 and 224 are connected in parallel between the output terminals of the rectifying and smoothing circuit 21. That is, the excitation circuit 22 is configured by an inverter circuit of a full bridge configuration. The feeding coil 23 is electrically connected between a connection point P1 of the

switching elements

221 and 222 and a connection point P2 of the

switching elements

223 and 224.

The control circuit 24 includes a PWM signal generation circuit 241 and a NOT gate 242.

The PWM signal generation circuit 241 is configured to generate a PWM signal S3 whose duty ratio repeatedly increases and decreases in the cycle of the AC voltage V2 to be supplied from the power reception device 30 to the load 40. The duty ratio of the PWM signal S3 periodically repeats increase and decrease in a cycle of the AC voltage V2 in accordance with a fixed change pattern.

The PWM signal generation circuit 241 includes a sine wave generation circuit 243, a triangular wave generation circuit 244, and a comparator 245.

The sine wave generation circuit 243 is configured to generate a sine wave signal S1 having substantially the same frequency as the AC voltage V2. For example, the frequency of the sine wave signal S1 is 50 Hz or 60 Hz, which is the frequency of a commercial AC power supply.

The triangular wave generation circuit 244 is configured to generate a reference signal S2 which is a triangular wave signal whose frequency is higher than that of the sine wave signal S1 and whose peak value is slightly larger than that of the sine wave signal S1. The frequency of the reference signal S2 may be at least twice the frequency of the sine wave signal S1, and is set to about five times in the present embodiment.

The comparator 245 compares the signal level of the sine wave signal S1 with the signal level of the reference signal S2 that is a triangular wave signal, and outputs a PWM signal S3 whose level changes according to the comparison result. In the example of FIG. 2, the sine wave signal S1 is input to the negative input terminal (inverting input terminal) of the comparator 245, and the reference signal S2 is input to the positive input terminal (non-inverting input terminal) of the comparator 245. Therefore, as shown in FIG. 3, the signal level of the PWM signal S3 output from the comparator 245 is low during the period in which the signal level of the sine wave signal S1 is higher than the signal level of the reference signal S2. During a period in which the signal level of the sine wave signal S1 is lower than the signal level of the reference signal S2, the signal level of the PWM signal S3 is high. Therefore, the PWM signal S3 is a duty signal whose duty ratio repeatedly increases and decreases at the cycle T1 of the sine wave signal S1, and the ratio of the on period is larger as the difference between the reference signal S2 and the sine wave signal S1 is larger. Becomes a duty signal that

The PWM signal S3 output from the comparator 245 is input to control electrodes of the switching

elements

221 and 224, respectively. The PWM signal S3 is input to the NOT gate 242, and the output signal of the NOT gate 242 is input to control electrodes of the switching

elements

222 and 223, respectively. That is, a signal obtained by inverting high / low of the PWM signal S3 is input to the control electrodes of the switching

elements

222 and 223 via the NOT gate 242.

While the signal level of the PWM signal S3 is high, the switching

elements

221 and 224 are turned on, and the switching

elements

222 and 223 are turned off. As a result, current flows from the positive terminal of the rectifying and smoothing circuit 21 to the negative terminal of the rectifying and smoothing circuit 21 through the path of the switching element 221, the feeding coil 23, and the switching element 224. On the other hand, while the signal level of the PWM signal S3 is low, the switching

elements

221 and 224 are turned off, and the switching

elements

222 and 223 are turned on. As a result, current flows from the positive terminal of the rectifying and smoothing circuit 21 to the negative terminal of the rectifying and smoothing circuit 21 via the path of the switching element 223, the feeding coil 23, and the switching element 222. Therefore, by alternately turning on / off the pair of switching

elements

221 and 224 and the pair of switching

elements

222 and 223, an alternating current by the alternating voltage V1 flows through the feeding coil 23, and around the feeding coil 23. Generates a magnetic flux corresponding to the time change of the excitation current.

On the other hand, the filter circuit 32 included in the power receiving device 30 is configured by an LC filter circuit, and includes a power receiving coil 31 and a capacitor 321 connected between both ends of the power receiving coil 31. The LC filter circuit using the power receiving coil 31 and the capacitor 321 is a low pass filter circuit, and is configured to attenuate frequency components higher in frequency than the frequency of the AC voltage V2 to be applied to the load 40. In the present embodiment, the inductor of the LC filter circuit is also used as the power receiving coil 31. However, the LC filter circuit may be configured with an inductor and a capacitor 321 provided separately from the power receiving coil 31. Further, the filter circuit 32 is not limited to the LC filter circuit, but may be an RC series circuit using a resistor and a capacitor, as long as it is a filter circuit that attenuates frequency components higher than the frequency of the AC voltage V2. Other filter circuits may be used.

The terminals on both sides of the capacitor 321 are electrically connected to both terminals of the outlet 33, and the voltage across the capacitor 321 (that is, the output voltage of the filter circuit 32) is applied to the load 40 via the outlet 33. .

Next, the operation of the non-contact power feeding system 10 of the present embodiment will be described. The power receiving device 30 is disposed at a position where the power receiving coil 31 is magnetically coupled (inductively coupled) to the power feeding coil 23 and can receive power supply from the power feeding device 20 in a noncontact manner.

The rectifying and smoothing circuit 21 rectifies and smoothes an AC voltage (input voltage) input from the AC power supply 100, thereby converting the input voltage into a DC voltage V _DC having a substantially constant voltage value and exciting the DC voltage V _DC It outputs to the circuit 22. In the PWM signal generation circuit 241, the sine wave signal S1 is input to the negative input terminal of the comparator 245, and the reference signal S2 is input to the positive input terminal of the comparator 245. The comparator 245 periodically changes the duty ratio in the cycle of the AC voltage V2 by switching the signal level of the output to high or low according to the comparison result of the level of the sine wave signal S1 and the level of the reference signal S2. To generate a PWM signal S3 that repeats. The PWM signal S3 is input to control electrodes of the switching

elements

221 and 224, and a signal (output signal of the NOT gate 242) obtained by inverting the high / low of the PWM signal S3 is input to the switching

elements

222 and 223.

While the signal level of the PWM signal S3 is high, the switching

elements

221 and 224 are turned on and the switching

elements

222 and 223 are turned off. As a result, current flows from the connection point P1 to the connection point P2 in the feed coil 23. On the other hand, while the signal level of the PWM signal S3 is low, the switching

elements

221 and 224 are turned off and the switching

elements

222 and 223 are turned on. As a result, current flows from the connection point P2 to the connection point P1 in the feed coil 23. As shown in FIG. 3, the PWM signal S3 is a signal that repeats increase and decrease in the same cycle T1 as the cycle of the AC voltage V2 and in accordance with the change pattern of the same duty ratio. Therefore, as shown in FIG. 4, the voltage (first alternating voltage) V1 applied from the excitation circuit 22 to the feeding coil 23 becomes a constant positive voltage while the PWM signal S3 is high, and the PWM signal S3 is low. During this period, the pulse voltage of the rectangular wave becomes a negative constant voltage. At this time, the current flowing through the feeding coil 23 changes in accordance with the voltage V1, and a magnetic flux corresponding to the change in current is generated around the feeding coil 23.

Here, if the power receiving coil 31 of the power receiving device 30 is present in the vicinity of the power feeding coil 23, a magnetic flux is generated around the power feeding coil 23, and a current flows in the power receiving coil 31 by electromagnetic induction. The AC waveform generated in the power receiving coil 31 has a frequency component (frequency component of the PWM signal S3) having a frequency higher than that of the AC voltage V2. This high frequency component is constituted by the power receiving coil 31 and the capacitor 321. Attenuated by a low pass filter. Therefore, as shown in FIG. 4, the AC voltage V 2 output from the filter circuit 32 becomes a sine wave AC voltage after the high frequency component is attenuated, and this AC voltage V 2 is applied to the load 40. That is, since the AC voltage V2 similar to the power supply voltage of the commercial AC power supply is applied to the load 40, it is possible to operate the load 40 that operates by receiving the supply of the commercial AC power.

By the way, although the exciting circuit 22 is comprised by the full bridge inverter circuit in the non-contact electric power feeding system of the said embodiment, as shown in FIG. 5, the exciting circuit 22 may be comprised with a half bridge inverter circuit. Further, the power supply apparatus 20 shown in FIG. 5 includes a battery 25 and a smoothing circuit 26 instead of the rectifying and smoothing circuit 21 for converting an alternating voltage input from the alternating current power supply 100 into a direct voltage. The configuration other than the excitation circuit 22, the battery 25, and the smoothing circuit 26 is the same as that of the non-contact power feeding system 10 shown in FIG. 2, so the same components are denoted by the same reference numerals and the description thereof is omitted. .

The power supply device 20 shown in FIGS. 1 and 2 obtains power from the external AC power supply 100, but the power supply device 20 shown in FIG. 5 obtains power from the built-in battery 25. The battery 25 may be a primary battery or a secondary battery such as a lead storage battery, a nickel hydrogen battery, or a lithium ion battery, and a battery having a storage amount corresponding to the amount of power supplied to the load 40 may be used.

Smoothing circuit 26, the output voltage of the battery 25 smoothes and generates a DC voltage V _DC, configured to apply a DC voltage V _DC to the excitation circuit 22. That is, in the example of FIG. 5, the battery 25 and the smoothing circuit 26 constitute a DC power supply, and the smoothing circuit 26 is optional (not a requirement).

The excitation circuit 22 is a half bridge inverter circuit including two switching

elements

225 and 226 and two

capacitors

227 and 228. A series circuit of two switching

elements

225 and 226 and a series circuit of two

capacitors

227 and 228 are connected in parallel between the output terminals of the smoothing circuit 26 (DC power supply). The feed coil 23 is connected between a connection point P3 of the switching

elements

225 and 226 and a connection point P4 of the

capacitors

227 and 228. The switching

elements

225 and 226 are, for example, field effect transistors, and the switching

elements

225 and 226 are controlled by the control circuit 24 to be on / off. The PWM signal S3 generated by the PWM signal generation circuit 241 is input to the control electrode of the switching element 225 on the high potential side. A signal obtained by inverting high / low of the PWM signal S3 by the NOT gate 242 is input to the control electrode of the switching element 226 on the low potential side.

While the PWM signal S3 is high, the switching element 225 is turned on and the switching element 226 is turned off. As a result, current flows from the positive terminal of the smoothing circuit 26 to the negative terminal of the smoothing circuit 26 through the path of the switching element 225, the feeding coil 23 and the capacitor 228. During this time, a current flows in the feeding coil 23, and the capacitor 228 is charged. While the PWM signal S3 is low, the switching element 225 is turned off and the switching element 226 is turned on. As a result, the capacitor 228 is discharged, and a current flows from the high potential side of the capacitor 228 to the low potential side of the capacitor 228 through the path of the feeding coil 23 and the switching element 226. During this time, current flows in the feeding coil 23.

Therefore, alternating current due to alternating voltage V1 flows through feeding coil 23 by switching

elements

225 and 226 alternately turned on / off according to the high / low of PWM signal S3, and excitation current around feeding coil 23 Magnetic flux is generated according to the time change of Thereby, power is supplied from the feeding coil 23 to the power receiving coil 31 by electromagnetic induction, and power is supplied from the power receiving device 30 to the load 40.

As described above, the feed device 20 according to the present embodiment is characterized by including the feed coil 23 and the excitation circuit 22. The power feeding coil 23 is electromagnetically coupled (inductively coupled) to the power receiving coil 31 included in the power receiving device 30, and supplies power to the power receiving coil 31 by electromagnetic induction. The exciting circuit 22 reverses (switches) the polarity of the DC voltage V _DC in accordance with the PWM signal S 3 whose duty ratio repeatedly increases and decreases in a cycle of the AC voltage V 2 to be applied from the power receiving device 30 to the load 40. The excitation current is generated by the AC voltage V1 to supply the excitation current to the feeding coil 23.

As described above, the excitation circuit 22 performs excitation by the AC voltage V1 by inverting (switching) the polarity of the DC voltage V _DC according to the PWM signal S3 whose duty ratio repeatedly increases and decreases in the cycle of the AC voltage V2. It is generating current. As a result, an excitation current whose polarity is reversed according to the high / low state of the PWM signal S3 flows through the feeding coil 23, and an alternating current according to the excitation current flows through the power receiving coil 31 by electromagnetic induction. become. Therefore, in the power receiving device 30, the frequency component corresponding to the frequency of the sine wave signal S1 is obtained by attenuating the frequency component higher than the frequency of the AC voltage V2 from the AC component generated in the power receiving coil 31 by the filter circuit 32. AC voltage V2 can be obtained, and power can be supplied contactlessly. Therefore, as in the conventional power receiving device, there is no need to perform the operation of converting the AC output of the power receiving coil 31 into DC once and then converting it into AC voltage V2 of a desired frequency. Power loss can be reduced as a whole system. Further, since it is not necessary to provide the power receiving device 30 with a conversion circuit for converting the AC output of the power receiving coil 31 into DC once and then converting it into an AC voltage V2 of a desired frequency, There is also the advantage of being able to

Further, the power supply device 20 of the present embodiment may include the PWM signal generation circuit 241 for generating the PWM signal S3. The PWM signal generation circuit 241 has a signal level of the sine wave signal S1 having the same cycle as the AC voltage V2 to be applied from the power receiving device 30 to the load 40, and a signal level of the reference signal S2 whose frequency is higher than that of the sine wave signal S1. And generate a PWM signal S3 whose level changes in accordance with the comparison result. Thus, the PWM signal generation circuit 241 can generate the PWM signal S3 whose duty ratio repeatedly increases and decreases in the cycle of the AC voltage V2 to be applied to the load 40. The exciting circuit 22 inverts (switches) the polarity of the DC voltage V _DC in accordance with the PWM signal S 3 to supply an exciting current whose polarity is inverted in accordance with high / low of the PWM signal S 3 to the feeding coil 23 be able to.

The power receiving device 30 of the present embodiment is characterized by including a power receiving coil 31 and a filter circuit 32 (filter unit). In the examples of FIGS. 2 and 5, the power receiving coil 31 functions as part of the filter circuit 32. In other words, the power receiving device 30 includes the power receiving coil 31 and the capacitor 321 as a filter element that constitutes the filter circuit 32 together with the power receiving coil 31. The power receiving coil 31 is electromagnetically coupled (inductively coupled) to the power feeding coil 23 included in the power feeding device 20, and configured to receive power from the power feeding coil 23 by electromagnetic induction. The filter circuit 32 attenuates the frequency component of a higher frequency than the frequency of the AC voltage V2 to be applied to the load 40 from the AC waveform generated in the power receiving coil 31 by electromagnetic induction.

In this manner, the filter circuit 32 attenuates the frequency component of a frequency higher than the frequency of the AC voltage V2 from the AC waveform generated in the power receiving coil 31, thereby obtaining an AC voltage having a frequency corresponding to the frequency of the sine wave signal S1. V2 can be applied to the load 40. Further, since the power receiving device 30 does not perform the operation of converting the AC output of the power receiving coil 31 into DC once after converting the AC output of the power receiving coil 31 into DC as in the conventional example, conversion loss of DC and AC occurs. As a result, power loss can be reduced as a whole system.

In the power receiving device 30 of the present embodiment, the filter circuit 32 may be an LC filter circuit including the power receiving coil 31 and the capacitor 321. In the examples of FIGS. 2 and 5, the power receiving device 30 includes only the filter circuit 32 including the power receiving coil 31, and converts the AC output of the power receiving coil 31 into DC once and then converts it into AC voltage V2 of a desired frequency. Since it is not provided, there is also an advantage that the power receiving device 30 can be made smaller by the amount of conversion circuit.

Further, since the inductor of the LC filter circuit is shared by the power receiving coil 31, the number of parts can be reduced, and the overall size can be reduced.

Moreover, the non-contact power feeding system of the present embodiment is characterized by including any of the above-described power feeding devices 20 and any of the above-described power receiving devices 30, and a compact non-contact power feeding with reduced power loss as a whole system. The system can be realized.

In one example, the non-contact power feeding system includes the non-contact power feeding device 20 and the non-contact power receiving device 30 physically separated from the non-contact power feeding device 20. The non-contact power feeding apparatus 20 converts a DC voltage V _DC into a first AC voltage V 1 by converting a DC power supply (21 or 25 and 26) configured to generate the DC voltage V _DC , the transmission coil 23, and the first AC voltage V 1. And an excitation circuit 22 configured to apply an AC voltage V1 to the transmission coil 23. The non-contact power reception device 30 is configured such that the power supply plug 41 of the load 40 is detachably mounted, and the reception coil 31 that is inductively coupled to the transmission coil 23 to form a transformer. And a circuit (32) including The circuit (32) is configured to obtain the second AC voltage V 2 from the receiving coil 31 and apply the second AC voltage V 2 to the load 40 via the outlet 33.

In the above example, the non-contact power feeding device 20 is configured to generate the PWM signal S3 obtained from the sine wave signal S1 having a period T1 equal to the period of the second AC voltage V2 to be applied to the load 40 The circuit further includes a PWM signal generation circuit 241. The excitation circuit 22 includes an inverter, which includes a plurality of switching elements (221 to 224 or 225 and 226), and inverts the polarity of the DC voltage V _DC in accordance with the PWM signal S 3 to generate the first DC voltage V _DC It is configured to convert into an alternating voltage V1. The filter circuit 32 configured to obtain the second AC voltage V2 by removing or reducing a frequency component higher than the frequency of the second AC voltage V2 from the induction voltage of the receiving coil 31. including.

For example, the PWM signal generation circuit 241 is configured to generate a sine wave generation circuit 243 configured to generate a sine wave signal S1, and generate a triangular wave signal S2 having a frequency higher than that of the sine wave signal S1. And a comparator (245). The comparator 245 is configured to generate the PWM signal S3 by receiving the sine wave signal S1 and the triangular wave signal S2.

For example, the filter circuit 32 includes a capacitor 321 that constitutes an LC circuit together with the receiving coil 31.

Having described what is believed to be the best mode and / or other embodiments described above, various modifications may be made and the subject matter disclosed herein may be practiced in various forms and embodiments. And they may be applied to a large number of applications, some of which are described herein. The following claims are to claim any and all modifications and variations that fall within the true scope of the present teachings.

Claims

A feeding coil that is electromagnetically coupled to a receiving coil included in the non-contact power receiving apparatus and configured to supply power to the receiving coil by electromagnetic induction;
An excitation current to be applied to the feeding coil is generated by reversing the polarity of the input voltage in accordance with a PWM signal whose duty ratio repeatedly increases and decreases in a cycle of AC voltage to be applied to the load from the non-contact power reception device. A non-contact power supply device comprising: an excitation circuit configured to:
The signal level of the sine wave signal having the same cycle as the AC voltage to be applied to the load from the non-contact power reception device is compared with the signal level of the triangular wave signal having a frequency higher than that of the sine wave signal. The non-contact power feeding device according to claim 1, further comprising a PWM signal generation circuit configured to generate the PWM signal whose level changes in response.
A power receiving coil that is electromagnetically coupled to a power feeding coil included in the non-contact power feeding device, and configured to receive power from the power feeding coil by electromagnetic induction;
And a filter circuit configured to attenuate a frequency component higher than the frequency of the AC voltage to be applied to the load from the AC waveform generated in the power receiving coil by electromagnetic induction. Power receiving device.
The receiving coil also serves as part of the filter circuit.
The non-contact power reception device according to claim 3, wherein the filter circuit is an LC filter circuit, and the filter circuit includes the power receiving coil and a capacitor.
A non-contact power supply system comprising the non-contact power supply device according to any one of claims 1 and 2 and the non-contact power reception device according to any one of claims 3 and 4.
A DC power supply configured to generate a DC voltage, a transmission coil, and an excitation circuit configured to convert the DC voltage into a first AC voltage and apply the first AC voltage to the transmission coil. A non-contact power feeding device comprising
And a receiving coil configured to be detachably mounted to a power plug of a load, and a receiving coil configured to be inductively coupled to the transmitting coil to form a transformer, the second AC voltage from the receiving coil A non-contact power reception device comprising: a circuit configured to apply the second alternating voltage to the load via the outlet unit;
The non-contact power feeding device further comprises a PWM signal generating circuit configured to generate a PWM signal obtained from a sine wave signal having a period equal to the period of the second alternating voltage to be applied to the load;
The excitation circuit includes an inverter, which is configured to convert the DC voltage to the first AC voltage by inverting a polarity of the DC voltage according to the PWM signal, and including a plurality of switching elements.
A filter configured to obtain the second alternating voltage by removing or reducing a frequency component higher than the frequency of the second alternating voltage from an induced voltage of the receiving coil, the circuit including the receiving coil being removed A contactless power supply system characterized by including a circuit.
The PWM signal generation circuit
A sine wave generator circuit configured to generate the sine wave signal;
A triangular wave generation circuit configured to generate a triangular wave signal having a frequency higher than that of the sine wave signal;
The contactless power supply system according to claim 6, further comprising: a comparator configured to receive the sine wave signal and the triangular wave signal to generate the PWM signal.
The non-contact power feeding system according to claim 6, wherein the filter circuit includes a capacitor which constitutes an LC circuit together with the receiving coil.