JP2014068413A - Power transmission and non-contact power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission apparatus and non-contact power transmission device having the same, capable of eliminating each noise generated by switching each switching element with a simple configuration.SOLUTION: A non-contact power transmission device 10 includes a ground apparatus 11 installed on the ground and a vehicle apparatus 21 installed on a vehicle. On the ground apparatus 11, a high-frequency power supply 12 for outputting high-frequency power is installed. The high-frequency power supply 12 includes an AC-DC converter 12a with a switching element 12aa for AC-DC switching periodically and a DC-RF converter 12b with a switching element 12bb for DC-RF switching periodically. Meanwhile, a switching frequency of each of the switching elements 12aa, 12bb is set at the same.

Description

  The present invention relates to a power transmission device and a contactless power transmission device including the power transmission device.

  2. Description of the Related Art Conventionally, as a non-contact power transmission device that does not use a power cord or a power transmission cable, for example, a device using magnetic field resonance is known. For example, the non-contact power transmission device of Patent Literature 1 includes a power transmission device having an AC power source and a primary coil to which AC power is input from the AC power source. The non-contact power transmission apparatus includes a power receiving device having a primary side coil and a secondary side coil capable of magnetic field resonance. Then, when the primary side coil and the secondary side coil perform magnetic field resonance, AC power is transmitted from the power transmitting device to the power receiving device, and the AC power is rectified to DC power by a rectification unit provided in the power receiving device. Input to the load.

JP 2010-70048 A

  Here, the AC power source includes, for example, a first conversion unit that converts system power into DC power, and a second conversion unit that converts the DC power into AC power having a frequency at which each coil can transmit power. There may be. In this case, for example, each of the first conversion unit and the second conversion unit is provided with a switching element that periodically switches, and each conversion unit operates by switching of each switching element.

  In such a configuration, noise may be generated by switching of each switching element provided in each conversion unit. In this case, it is conceivable that a plurality of noise removal units having different cutoff frequencies are provided in the power receiving device in correspondence with the frequency of each noise generated from each switching element. However, there is a concern that the configuration is complicated in the configuration in which such a plurality of noise removing units are provided.

  The present invention has been made in view of the above-described circumstances, and power transmission equipment capable of removing each noise generated by switching of each switching element with a simple configuration and non-contact power provided with the power transmission equipment An object is to provide a transmission apparatus.

  In order to achieve the above object, an invention according to claim 1 is a power receiving device including an AC power supply capable of outputting AC power and a primary coil to which the AC power is input, and having a secondary coil. In the power transmission device capable of transmitting the AC power in a non-contact manner, the AC power source includes a first switching element that periodically switches, and the system power is changed to DC power by switching the first switching element. An AC power having a frequency corresponding to a switching frequency of the second switching element by switching the second switching element; A second conversion unit for converting to a switching frequency of the first switching element and a switching frequency of the second switching element. The ring frequency, characterized in that it is set the same or close to.

  According to this invention, since the switching frequency of each switching element is the same or close, the frequency of each noise generated by the switching of each switching element is the same or close. Thereby, the noise generated by the switching of the first switching element and the noise generated by the switching of the second switching element can be removed by the same noise removing unit. Therefore, simplification of the configuration related to noise removal provided in the power receiving device can be achieved.

  The invention according to claim 2 is a non-contact power transmission device including the power transmission device according to claim 1 and the power receiving device, wherein the power receiving device is received by the secondary coil. A rectifying unit that rectifies AC power, a load to which DC power rectified by the rectifying unit is input, and a noise in a predetermined specific frequency range provided between the rectifying unit and the load. And a switching frequency of the first switching element and a switching frequency of the second switching element are set so as to be included in the specific range. According to this invention, since the switching frequency of each switching element is set to be included in the specific range, each noise generated by switching of each switching element can be removed by the same noise removing unit.

  The invention according to claim 3 is characterized in that the power receiving device is mounted on a vehicle. According to this invention, the power receiving device is mounted on the vehicle. Here, various driving devices used for traveling and a control device for controlling them are mounted on the normal vehicle, and these are arranged close to each other. For this reason, each noise generated by switching of each switching element can propagate to other devices in the vehicle. For this reason, removal of each said noise is desired. However, it is not preferable that the configuration related to noise removal is large because of the characteristics of a vehicle having a limited installation space.

  On the other hand, according to the present invention, by making the switching frequency of each switching element the same or close to each other, each of the above-mentioned noises can be suitably removed, and the configuration relating to noise removal can be simplified. it can. As a result, both noise removal and downsizing can be achieved.

  According to the present invention, each noise generated by switching of each switching element can be removed with a simple configuration.

The block diagram which shows the electric constitution of a non-contact electric power transmission apparatus.

Hereinafter, a non-contact power transmission device (non-contact power transmission system) including a power transmission device according to the present invention will be described.
As shown in FIG. 1, the non-contact power transmission apparatus 10 includes a ground side device 11 provided on the ground and a vehicle side device 21 mounted on the vehicle. The ground side device 11 corresponds to a power transmission device (primary side device), and the vehicle side device 21 corresponds to a power receiving device (secondary side device).

  The ground side device 11 includes a high frequency power source 12 (AC power source) capable of outputting high frequency power (AC power) having a predetermined frequency. The high frequency power supply 12 is configured to convert the system power into the high frequency power and change the power value of the high frequency power. Specifically, the high-frequency power source 12 includes an AC / DC converter 12a as a first conversion unit that converts system power into DC power, and DC / RF conversion as a second conversion unit that converts the DC power into high-frequency power. And a container 12b.

  The AC / DC converter 12a includes an AC / DC switching element 12aa as a first switching element that periodically switches, and the system power is converted to a desired voltage value by switching of the AC / DC switching element 12aa. Convert to DC power. In this case, the voltage value of the DC power output from the AC / DC converter 12a is determined by the duty ratio of on / off (switching) of the AC / DC switching element 12aa. The power value of the high frequency power output from the high frequency power supply 12 is determined by the voltage value of the direct current power output from the AC / DC converter 12a. For this reason, the duty ratio of the AC / DC switching element 12aa determines the power value of the high-frequency power output from the high-frequency power source 12.

  The DC / RF converter 12b has a DC / RF switching element 12bb as a second switching element that periodically switches, and corresponds to the switching frequency by switching of the DC / RF switching element 12bb. A high frequency power having the same frequency as the switching frequency is output.

  As a specific configuration of the DC / RF converter 12b, for example, a class D amplifier or the like can be considered, and as a specific configuration of the DC / RF switching element 12bb, for example, a power MOSFET or IGBT can be considered. It is done.

  The high-frequency power output from the high-frequency power source 12 is transmitted to the vehicle-side device 21 in a non-contact manner and used for charging the vehicle battery 22 provided in the vehicle-side device 21. Specifically, the non-contact power transmission device 10 is provided in the vehicle-side device 21 and the power transmitter 13 provided in the ground-side device 11 as a device that performs power transmission between the ground-side device 11 and the vehicle-side device 21. The power receiver 23 is provided.

  The power transmitter 13 and the power receiver 23 are configured to be capable of magnetic field resonance. Specifically, the power transmitter 13 includes a resonance circuit having a primary coil 13a and a primary capacitor 13b connected in parallel. The power receiver 23 includes a resonance circuit having a secondary coil 23a and a secondary capacitor 23b connected in parallel. Both resonance frequencies are the same.

  According to this configuration, when high-frequency power is input from the high-frequency power source 12 to the power transmitter 13 (primary coil 13a), the power transmitter 13 and the power receiver 23 (secondary coil 23a) magnetically resonate. As a result, the power receiver 23 receives a part of the energy of the power transmitter 13. That is, the power receiver 23 receives high-frequency power from the power transmitter 13 in a contactless manner.

  The vehicle-side device 21 includes a rectifier 24 (rectifying unit) that rectifies high-frequency power received by the power receiver 23 into DC power, and a DC that converts the voltage value of the DC power rectified by the rectifier 24 into a different voltage value. / DC converter 25 is provided. The DC / DC converter 25 includes a DC / DC switching element 25a as a third switching element that periodically switches. In this case, the impedance from the input end of the DC / DC converter 25 to the vehicle battery 22 is determined by the duty ratio of on / off (switching) of the DC / DC switching element 25a.

  The DC power output from the DC / DC converter 25 is applied to the vehicle via a noise removal circuit 26 as a noise removal unit provided in the vehicle side device 21 and a sensor circuit 27 provided in the vehicle side device 21. Input to the battery 22. Thereby, the battery 22 for vehicles is charged.

  The sensor circuit 27 detects the charge amount of the vehicle battery 22 and the power value (voltage value and current value) of the DC power input to the vehicle battery 22, and the detection result is provided in the vehicle-side device 21. Output to the vehicle controller 28. Thereby, the vehicle-side controller 28 can grasp the charge amount of the vehicle battery 22 and the power value of the DC power input to the vehicle battery 22.

  In addition, the ground side device 11 is provided with a power source side controller 14 capable of wireless communication with the vehicle side controller 28. The power supply side controller 14 and the vehicle side controller 28 control power transmission by exchanging information with each other.

  For example, when the charge amount of the vehicle battery 22 reaches the full charge amount (the charge amount that triggers the end of charge), the vehicle side controller 28 transmits a notification to that effect to the power supply side controller 14. The power supply side controller 14 stops the output of the high frequency electric power from the high frequency power supply 12, when the said notification is received.

  Further, for example, the vehicle-side controller 28 determines whether or not the power value of the DC power input to the vehicle battery 22 is a power value suitable for charging based on the detection result of the sensor circuit 27, and charging. When it is determined that the power value is not suitable for the power supply, a power value change command is transmitted to the power supply controller 14.

  When receiving the change command, the power supply side controller 14 controls the high frequency power supply 12 so that the power value of the high frequency power output from the high frequency power supply 12 is changed. Specifically, the power supply side controller 14 includes an AC / DC switching control unit 14a that performs switching control (on / off control) of the AC / DC switching element 12aa of the AC / DC converter 12a. The AC / DC switching control unit 14a is output from the high-frequency power source 12 by controlling the on / off duty ratio of the AC / DC switching element 12aa based on a power value change command from the vehicle-side controller 28 or the like. Change the power value of the high frequency power.

  The power supply side controller 14 includes a DC / RF switching control unit 14b that performs switching control (on / off control) of the DC / RF switching element 12bb of the DC / RF converter 12b. The DC / RF switching control unit 14b performs switching control of the DC / RF switching element 12bb so that high-frequency power having a frequency suitable for power transmission is output from the DC / RF converter 12b. For example, the DC / RF switching control unit 14b switches the DC / RF switching element 12bb so that the DC / RF switching element 12bb switches at the same frequency as or close to the resonance frequency of the power transmitter 13 and the power receiver 23. Control.

  The vehicle-side controller 28 includes a DC / DC switching control unit 28 a that performs switching control of the DC / DC switching element 25 a of the DC / DC converter 25. The DC / DC switching control unit 28a controls the on / off duty ratio of the DC / DC switching element 25a in accordance with the fluctuation of the impedance of the vehicle battery 22.

  More specifically, the vehicle battery 22 is a load whose impedance varies according to the power value of the input DC power. For this reason, for example, when the power value of the DC power input to the vehicle battery 22 is changed by changing the power value of the high-frequency power output from the high-frequency power source 12, the impedance of the vehicle battery 22 changes, and the DC Impedance from the input terminal of DC / DC converter 25 to vehicle battery 22 may vary. On the other hand, the DC / DC switching control unit 28a controls the duty ratio in accordance with the fluctuation of the impedance of the vehicle battery 22, so that the vehicle battery 22 from the input end of the DC / DC converter 25 is controlled. Until the impedance is constant.

Here, the frequency of the AC / DC switching element 12aa and the switching frequency of the DC / RF switching element 12bb are set to be the same.
By the way, depending on the resonance frequency of the power transmitter 13 and the power receiver 23, the minimum value of the switching frequency of the AC / DC switching element 12aa for operating the AC / DC converter 12a (hereinafter referred to as the minimum operating frequency) is: In some cases, the switching frequency is lower than the switching frequency (frequency of high-frequency power transmitted) of the DC / RF switching element 12bb. In this case, it can be said that the switching frequency of the AC / DC switching element 12aa is set higher than the minimum operating frequency so as to be the same as the switching frequency of the DC / RF switching element 12bb. In the present embodiment, the minimum operating frequency of the AC / DC switching element 12aa is lower than the switching frequency of the DC / RF switching element 12bb, and the switching frequency of the AC / DC switching element 12aa is DC / RF. The switching frequency is set to be the same as the switching frequency of the switching element 12bb.

  Here, focusing on the fact that the minimum operating frequency is the frequency at which the switching loss of the AC / DC switching element 12aa is minimized within the range in which the AC / DC converter 12a can operate, the minimum operating frequency is AC It can be said that this is a frequency at which the efficiency of the / DC converter 12a is increased, that is, a predetermined frequency suitable for operation. Then, in this embodiment, it can be said that the switching frequency of the AC / DC switching element 12aa is set closer to the switching frequency of the DC / RF switching element 12bb than the predetermined frequency.

  Next, the noise removal circuit 26 provided in the vehicle side device 21 will be described. The noise removal circuit 26 is provided at a subsequent stage of the DC / DC converter 25, specifically between the DC / DC converter 25 and the sensor circuit 27. The noise removal circuit 26 removes noise having a predetermined range of frequencies. Specifically, the noise removal circuit 26 is configured by a low-pass filter circuit that removes high-frequency power equal to or higher than the switching frequency of the switching elements 12aa and 12bb. In other words, it can be said that the frequency range (specific range) that can be removed by the noise removal circuit 26 is equal to or higher than the switching frequency of each of the switching elements 12aa and 12bb. In this case, it can be said that the switching frequency of each switching element 12aa, 12bb is set so as to be included in the range of frequencies that can be removed by the noise removal circuit 26. The specific configuration of the noise removal circuit 26 is arbitrary, but for example, an LC circuit or an integration circuit is conceivable.

Next, the operation of this embodiment will be described.
Since the switching frequency of the AC / DC switching element 12aa and the DC / RF switching element 12bb is the same, the frequency of each noise generated when the switching elements 12aa and 12bb are switched is the same. And since the switching frequency of each switching element 12aa and 12bb is set so that it may be included in the range (specific range) of the frequency which the noise removal circuit 26 can remove, each said noise is removed in the noise removal circuit 26. The As a result, DC power from which each noise has been removed is input to the sensor circuit 27 and the vehicle battery 22. Therefore, the power value of the DC power input to the vehicle battery 22 is stable with the fluctuation of the power value caused by each noise reduced.

According to the embodiment described in detail above, the following excellent effects are obtained.
(1) The high frequency power supply 12 includes an AC / DC converter 12a having an AC / DC switching element 12aa that periodically switches, and a DC / RF converter 12b having a DC / RF switching element 12bb that periodically switches. It has. In this configuration, the switching frequencies of the switching elements 12aa and 12bb are set to be the same. Thereby, each noise accompanying switching of each switching element 12aa and 12bb can be removed with one noise removal circuit 26.

  Specifically, when the switching frequencies of the switching elements 12aa and 12bb are different, noise corresponding to each switching frequency is generated. In this case, in order to remove each noise, it may be necessary to provide a plurality of noise removal circuits corresponding to each noise frequency. In particular, since the vehicle battery 22 is required to have a large charge amount as compared with a battery such as a mobile phone, the power value of the DC power input to the vehicle battery 22 is relatively high. In order to handle such a relatively high power value, a high-breakdown-voltage element is required as a noise removal circuit. As a result, there is a concern about an increase in size of the element and an improvement in cost.

  On the other hand, according to this embodiment, by making the switching frequency of each switching element 12aa, 12bb the same, the frequency of each noise generated by the switching of each switching element 12aa, 12bb can be made the same, The noise removal circuit 26 that removes these noises can be shared. Therefore, the configuration can be simplified, and the contactless power transmission device 10, specifically the vehicle-side device 21 can be downsized.

  (2) The vehicle-side device 21 provided with the secondary coil 23a, the rectifier 24, the DC / DC converter 25, and the vehicle battery 22 is mounted on the vehicle. Here, various driving devices used for traveling and a control device for controlling them are mounted on the normal vehicle, and they are arranged close to each other. For this reason, each noise generated by switching of each switching element 12aa, 12bb can propagate to other devices in the vehicle. For this reason, removal of each noise which generate | occur | produces in the vehicle side apparatus 21 is desired. However, it is not preferable that the vehicle-side device 21 becomes large in order to remove each noise because of the characteristic of a vehicle having a limited installation space.

  On the other hand, according to this embodiment, by using the noise removal circuit 26 in common, noise removal can be suitably performed, and the configuration related to noise removal can be simplified. Thereby, both removal of each noise and size reduction of the vehicle side apparatus 21 can be aimed at.

  (3) A sensor circuit 27 for detecting the power value of the DC power input to the vehicle battery 22 is provided. In such a configuration, if erroneous detection of the sensor circuit 27 occurs due to the influence of noise, it is possible to accurately grasp whether or not DC power having a power value suitable for charging is input to the vehicle battery 22. Therefore, charging may be hindered. In particular, in the configuration in which the power value of the high-frequency power output from the high-frequency power source 12 is controlled based on the detection result by the sensor circuit 27, erroneous control is performed due to erroneous detection of the sensor circuit 27. Cases can arise.

  On the other hand, according to the present embodiment, since the noise removal circuit 26 is provided, each noise is removed from the DC power to be detected by the sensor circuit 27. Thereby, the erroneous detection of the sensor circuit 27 can be suppressed, and the inconvenience can be avoided.

  (4) The noise removal circuit 26 is configured by a low-pass filter circuit that removes a frequency equal to or higher than the switching frequency of each of the switching elements 12aa and 12bb. Thereby, not only the noise of the switching frequency of each switching element 12aa and 12bb but the harmonic noise with respect to the said switching frequency can be removed. Therefore, noise removal from DC power can be performed more suitably.

  (5) The power value of the high-frequency power output from the high-frequency power source 12 is determined by the on / off duty ratio of the AC / DC switching element 12aa. Thus, by controlling the ON / OFF duty ratio of the AC / DC switching element 12aa, it is possible to output high-frequency power having a desired power value from the high-frequency power source 12.

  In this case, since the control target is the ON / OFF duty ratio of the AC / DC switching element 12aa, the switching frequency of the AC / DC switching element 12aa can be set relatively freely. In other words, even if the switching frequency of the AC / DC switching element 12aa is changed in order to make the switching frequencies of the switching elements 12aa and 12bb the same, the above-described effects can be obtained and transmission efficiency can be improved. It is difficult to adversely affect. Thereby, it is possible to preferably achieve both the common use of the noise removal circuit 26 and the change of the power value of the high-frequency power output from the high-frequency power supply 12.

In addition, you may change the said embodiment as follows.
In the embodiment, the switching frequencies of the switching elements 12aa and 12bb are set to be the same, but it is not necessary to be completely the same, and a configuration in which both are set close to each other may be used.

  In the embodiment, the noise removal circuit 26 is provided between the DC / DC converter 25 and the vehicle battery 22, but is not limited thereto, and is provided between the rectifier 24 and the DC / DC converter 25. It may be. In this case, malfunction of the DC / DC converter 25 caused by each noise can be suppressed. In short, the noise removal circuit 26 may be provided between the rectifier 24 and the vehicle battery 22.

  In the embodiment, the switching frequency of the DC / RF switching element 12bb and the resonance frequency of the power transmitter 13 and the power receiver 23 are the same. However, the present invention is not limited to this, and within the range where power can be transmitted. It may be shifted.

  The switching frequency of the DC / RF switching element 12bb may be changed in accordance with the switching frequency of the AC / DC switching element 12aa so that the switching frequencies of the switching elements 12aa and 12bb are the same. In this case, the resonance frequency of the power transmitter 13 and the power receiver 23 may be changed in accordance with the change of the switching frequency of the DC / RF switching element 12bb in order to increase the transmission efficiency.

  The switching frequency of the DC / DC switching element 25a of the DC / DC converter 25 may be the same as or close to the switching frequency of each of the switching elements 12aa and 12bb. In short, the switching frequency of the DC / DC switching element 25a may be set so as to be included in the range in which the noise removal circuit 26 can be removed.

  In the embodiment, the frequency of the high-frequency power output from the high-frequency power source 12 is the same as the switching frequency of the DC / RF switching element 12bb, but is not limited to this, for example, a frequency obtained by multiplying or dividing the switching frequency It may be.

  In the embodiment, the sensor circuit 27 detects the charge amount of the vehicle battery 22 and the power value of the DC power input to the vehicle battery 22, but detects at least one of the both. It may be a thing.

  In the embodiment, the noise removal circuit 26 is configured by a low-pass filter circuit that removes a frequency equal to or higher than the switching frequency of each switching element 12aa, 12bb. However, the present invention is not limited to this, and a band-pass filter or the like may be used. . In short, in order to be able to remove each noise with a single noise removing unit, the switching frequency of each switching element 12aa, 12bb may be set so as to be included in the range of frequencies that can be removed by the noise removing unit.

  A converter that converts impedance may be provided in at least one of the ground side device 11 and the vehicle side device 21. For example, the secondary side converter that performs impedance conversion between the power receiver 23 and the rectifier 24 so that the impedance from the output terminal of the power receiver 23 to the vehicle battery 22 becomes an impedance that relatively increases transmission efficiency. May be provided. Further, for example, a primary side converter may be provided between the high frequency power source 12 and the power transmitter 13. In this case, the primary-side converter may be configured to perform impedance conversion so that high-frequency power having a desired power value (a predetermined specific power value) is output from the high-frequency power source 12, or the power factor. You may comprise so that may be improved. Moreover, you may comprise a primary side converter so that a power factor may be improved, obtaining the high frequency electric power of a desired electric power value.

The voltage waveform of the high-frequency power output from the high-frequency power source 12 is arbitrary such as a pulse waveform or a sine wave.
In the embodiment, the capacitors 13b and 23b are provided, but these may be omitted. In this case, magnetic field resonance is performed using the parasitic capacitances of the coils 13a and 23a.

In the embodiment, the resonance frequency of the power transmitter 13 and the resonance frequency of the power receiver 23 are set to be the same. However, the present invention is not limited to this, and may be different within a range in which power transmission is possible.
In embodiment, although the structure of the power transmission device 13 and the power receiving device 23 was the same, it is not restricted to this, The structure from which both differ may be sufficient.

In the embodiment, magnetic field resonance is used in order to realize non-contact power transmission. However, the present invention is not limited to this, and electromagnetic induction may be used.
The power transmitter 13 may be composed of a resonance circuit including a primary side coil 13a and a primary side capacitor 13b, and a primary side coupling coil that is coupled to the resonance circuit by electromagnetic induction. In this case, the resonant circuit is configured to receive high frequency power from the primary side coupling coil by electromagnetic induction. Similarly, the power receiver 23 includes a resonance circuit including a secondary side coil 23a and a secondary side capacitor 23b, and a secondary side coupling coil coupled to the resonance circuit by electromagnetic induction. The high-frequency power may be extracted from the resonance circuit of the power receiver 23 by using it.

  In embodiment, the non-contact electric power transmission apparatus 10 was applied to the vehicle, However, It is not restricted to this, You may apply to another apparatus. For example, it may be applied to charge a battery of a mobile phone.

In the embodiment, the load is the vehicle battery 22, but is not limited thereto, and may be another device.
In addition, although the vehicle battery 22 whose impedance varies according to the power value of the input DC power is used as the load, the present invention is not limited to this, and the same impedance is obtained regardless of the power value of the input DC power. You may use what has.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The contactless power transmission device according to claim 2 or 3, further comprising a sensor that detects a power value of the DC power input to the load.

  (B) A low-pass filter circuit for removing noise having a frequency equal to or higher than a switching frequency of each switching element is provided between the rectifying unit and the load in the power receiving device. , 3 and the technical idea (A).

  (C) The power transmission device according to claim 1, wherein the power value of the AC power output from the AC power supply is determined by an on / off duty ratio of the first switching element.

  (D) The switching frequency of the first switching element is such that the switching frequency of the second switching element is higher than the frequency at which the switching loss of the first switching element is minimized. 2. The power transmission device according to claim 1, wherein the power transmission device is set equal to or closer to a switching frequency of the second switching element than a frequency at which a switching loss of the first switching element is minimized.

(E) an AC power source capable of outputting AC power and a power transmission device having a primary coil to which the AC power is input;
A secondary coil that can receive the AC power in a non-contact manner from the primary coil, a rectifier that rectifies the AC power received by the secondary coil, and a DC power that is rectified by the rectifier A power receiving device having an input load;
In a non-contact power transmission device comprising:
The AC power supply is
A first converter that has a first switching element that periodically switches, and converts system power into DC power by switching of the first switching element;
A second converter that has a second switching element that periodically switches, and that converts the DC power into AC power having a frequency corresponding to a switching frequency of the second switching element by switching of the second switching element; ,
With
Between the rectifying unit and the load in the power receiving device, a noise removing unit that removes noise of a predetermined frequency range is provided,
The contactless power transmission device, wherein the switching frequency of the first switching element and the switching frequency of the second switching element are set to be included in the specific range.

  DESCRIPTION OF SYMBOLS 10 ... Non-contact electric power transmission apparatus, 11 ... Ground side apparatus (power transmission apparatus), 12 ... High frequency power supply (AC power supply), 12a ... AC / DC converter (1st conversion part), 12aa ... Switching element for AC / DC ( First switching element), 12b ... DC / RF converter (second conversion unit), 12bb ... DC / RF switching element (second switching element), 13a ... Primary coil, 21 ... Vehicle side device (power receiving device) ), 22 ... Vehicle battery (load), 24 ... rectifier, 25 ... DC / DC converter, 26 ... noise removal circuit.

Claims (3)

AC power supply capable of outputting AC power,
A primary coil to which the AC power is input;
In a power transmission device capable of transmitting the AC power in a contactless manner with respect to a power receiving device having a secondary side coil,
The AC power supply is
A first converter that has a first switching element that periodically switches, and converts system power into DC power by switching of the first switching element;
A second converter that has a second switching element that periodically switches, and that converts the DC power into AC power having a frequency corresponding to a switching frequency of the second switching element by switching of the second switching element; ,
With
The power transmission device, wherein the switching frequency of the first switching element and the switching frequency of the second switching element are set to be the same or close to each other. A power transmission device according to claim 1;
The power receiving device;
A non-contact power transmission device comprising:
The power receiving device is:
A rectifying unit that rectifies AC power received by the secondary coil;
A load to which DC power rectified by the rectifier is input;
A noise removing unit that is provided between the rectifying unit and the load and removes noise having a predetermined frequency range;
With
The contactless power transmission device, wherein the switching frequency of the first switching element and the switching frequency of the second switching element are set to be included in the specific range.   The non-contact power transmission device according to claim 2, wherein the power receiving device is mounted on a vehicle.