JP2015050888A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy installation work of a non-contact power supply device on site in a state of power supply efficiency raised to the maximum by the adjustment of a resonance frequency.SOLUTION: A resonance circuit 13 connected to a power reception coil 12 includes a capacitor 15 and a resonance coil 16. The inductance L3 of the resonance coil 16 is set sufficiently larger than the inductance L2 of the power reception coil 12, so that the inductance L2 of the power reception coil 12 is almost negligible in regard to an inductance value that determines a resonance frequency in relation to the capacitance C of the capacitor 15. Thus, by the adjustment of the capacitance C of the capacitor 15 only in relation to the inductance L3 of the resonance coil 16 before an operator goes to a site, the setting of a necessary resonance frequency can be set in order to raise the power supply efficiency to the maximum.

Description

  The present invention relates to a non-contact power supply device, and is particularly suitable for use in a non-contact power supply device that supplies power using electromagnetic induction by a power transmission coil and a power reception coil installed concentrically.

  In monitoring and control of rotating machines such as turbines and motors, it is necessary to measure stress and temperature of a rotating rotor and transmit the measurement data to a control and monitoring device in real time. In the case of a rotating body such as a rotor, conventionally, a contact type of a slip ring or a trolley type has been mainly used for supplying electric power. However, these types of systems are expensive, and there is a problem of mechanical wear of the contact portion. In recent years, a non-contact type power feeding method using electromagnetic induction has been used.

  In general, a non-contact power supply device that supplies electric power to a rotating body using electromagnetic induction is configured as shown in FIG. That is, the conventional general non-contact power feeding apparatus includes a power transmission coil 101 and a power receiving coil 102 that are concentrically installed on the outer periphery of the rotating body 100, and a power transmission oscillator 103 that supplies AC power to the power transmission coil 101. A resonance circuit 104 including a capacitor having a capacity that is tuned to the inductance of the power receiving coil 102; a rectifying circuit 105 that rectifies AC power supplied from the power receiving coil 102 through the resonance circuit 104 and converts the AC power into DC power; It has. In addition, there is one in which a tuning capacitor is connected to the power transmission coil 101 (see, for example, Patent Document 1).

JP 2000-14053 A

  In a non-contact power feeding apparatus using electromagnetic induction, in order to supply power as efficiently as possible, the frequency of the AC power supplied to the power transmission coil 101, the inductance of the power receiving coil 102, and the capacitor included in the resonance circuit 104 It is necessary to adjust so that the value of the resonance frequency determined by the capacitance is the same or close to it. For this purpose, it is important to adjust the capacitance of the capacitor included in the resonance circuit 104 to an appropriate value.

  However, when the non-contact power supply apparatus is installed in a huge facility such as a large turbine or motor, the power transmission coil 101 or the power receiving coil 102 is wound around the rotating body 100 at the site where the turbine or motor is present, and the capacitance of the capacitor is measured at the site. The value of C must also be adjusted. In this case, the value of the resonance frequency varies depending on many factors such as the diameter of the power receiving coil 102 wound around the rotating body 100, the inductance value of the power receiving coil 102, and the permeability of the iron core used. End up.

  Therefore, in order to adjust the capacitance of the capacitor to the value necessary to obtain the maximum efficiency of power supply, trial and error work such as connecting the capacitors of various capacities and measuring the resonance frequency is required. There is a problem that the installation work of the non-contact power feeding apparatus on the site becomes very complicated.

  The present invention has been made to solve such a problem, and easily performs an operation of installing a non-contact power feeding apparatus on site in a state where the resonance frequency is adjusted and the power feeding efficiency is maximized. The purpose is to be able to.

  In order to solve the above-described problem, a contactless power supply device of the present invention includes a power transmission coil and a power reception coil that are installed concentrically, and a resonance circuit connected to the power reception coil. And a resonance coil that resonates, and the inductance of the resonance coil is set to a sufficiently large value with respect to the inductance of the power receiving coil.

  According to the present invention configured as described above, since the inductance of the resonance coil is set to a sufficiently large value relative to the inductance of the power receiving coil, the resonance frequency is set in relation to the capacitance of the capacitor in the resonance circuit. Regarding the inductance to be determined, the inductance of the receiving coil can be almost ignored. That is, the resonance frequency does not change under the influence of the diameter of the receiving coil, the inductance value of the receiving coil, the magnetic permeability of the iron core, etc. The inductance of the resonance coil provided separately from the receiving coil The resonance frequency is determined by the capacitance of the capacitor.

  For this reason, by adjusting the capacitance of the capacitor only in relation to the inductance of the resonance coil, it is possible to set the resonance frequency necessary to maximize the power supply efficiency. As a result, if the resonance frequency is set by adjusting the capacitance of the capacitor provided in the resonance circuit and the inductance of the resonance coil before the worker goes to the site, the resonance circuit is simply connected to the receiving coil at the site. This is all you need to do. Therefore, it is possible to easily perform the work of installing the non-contact power feeding apparatus on site with the resonance frequency adjusted to maximize the power feeding efficiency.

It is a figure which shows the structural example of the non-contact electric power feeder by this embodiment. It is a figure which shows the structural example of the conventional non-contact electric power supply.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration example of the contactless power feeding device according to the present embodiment. In addition, the non-contact electric power feeder shown in FIG. 1 shows the structure typically, and does not reflect a magnitude | size and a shape correctly.

  As shown in FIG. 1, the contactless power feeding device of the present embodiment is connected to the power receiving coil 12 and the power transmitting coil 11 and the power receiving coil 12 that are installed concentrically on the outer periphery of a rotating body 100 such as a rotor of a turbine. And a rectifier circuit 14 that rectifies AC power supplied from the power receiving coil 12 through the resonance circuit 13 and converts the AC power into DC power.

  A power transmission oscillator 20 for supplying AC power to the power transmission coil 11 is connected to the power transmission coil 11. The power transmission coil 11 supplies power to the power receiving coil 12 using electromagnetic induction. The power receiving coil 12 receives power from the power transmitting coil 11 using electromagnetic induction. The power receiving coil 12 is wound around the outer peripheral surface of the rotating body 100, for example, and the resonance circuit 13 and the rectifier circuit 14 are installed on the outer peripheral surface of the rotating body 100, for example.

  The resonance circuit 13 is a circuit for generating, on the power receiving coil 12 side, a resonance frequency that substantially matches the frequency of the AC power supplied from the power transmission oscillator 20 to the power transmission coil 11, and resonates with the capacitor 15. And a resonance coil 16.

  In this embodiment, the resonance coil 16 is constituted by a toroidal coil. The toroidal coil is provided with two sets of connection terminals, one set is connected to the power receiving coil 12 via the capacitor 15, and the other set is connected to the rectifier circuit 14.

  Further, in the present embodiment, by setting the number of turns of the resonance coil 16 to a sufficiently large value with respect to the number of turns of the power receiving coil 12, the inductance L 3 of the resonance coil 16 is sufficiently larger than the inductance L 2 of the power receiving coil 12. Is set to a large value. For example, the number of turns of the power receiving coil 12 is 1, and the number of turns of the resonance coil 16 is n (n >> 1).

  With this configuration, the inductance L2 of the power receiving coil 12 is almost the same as the inductance L3 of the resonance coil 16 with respect to the inductance value that determines the resonance frequency in relation to the capacitance C of the capacitor 15 in the resonance circuit 13. Can be ignored.

  That is, the resonance frequency of the resonance circuit 13 may change due to the influence of the size of the receiving coil 12 wound around the outer periphery of the rotor, the value of the inductance L2 of the receiving coil 12, the magnetic permeability of the iron core, and the like. The resonance frequency is determined by the value of the inductance L3 of the resonance coil 16 provided separately from the power receiving coil 12 and the value of the capacitance C of the capacitor.

For this reason, by adjusting the capacitance C of the capacitor 15 only by the relationship with the inductance L3 of the resonance coil 16, it is possible to set the resonance frequency necessary to maximize the power supply efficiency. For example, when the frequency of the AC power supplied to the power transmission coil 11 is f ₁ [kHz], the resonance frequency f ₂ [kHz] determined by the inductance L3 of the resonance coil 16 and the capacitance C of the capacitor 15 is abbreviated as f _1. What is necessary is just to adjust the capacity | capacitance C of the capacitor | condenser 15 so that it may correspond.

  As a result, before the operator goes to the site, if the resonance frequency is set by adjusting the capacitance C of the capacitor 15 provided in the resonance circuit 13 and the inductance L3 of the resonance coil 16, the resonance circuit 13 is set on the site. Only the work of connecting to the power receiving coil 12 is sufficient. Therefore, it is possible to easily perform the work of installing the non-contact power feeding apparatus on site with the resonance frequency adjusted to maximize the power feeding efficiency. Moreover, in this embodiment, since the winding number of the receiving coil 12 is set to 1 time, the operation | work which winds the receiving coil 12 around the outer periphery of a rotor on the spot can also be performed very easily.

  Here, the larger the ratio between the inductance L2 of the power receiving coil 12 and the inductance L3 of the resonance coil 16, the less the resonance frequency of the resonance circuit 13 is affected by the inductance fluctuation of the power receiving coil 12. For example, it is desirable to set the inductance L3 of the resonance coil 16 to a value that is approximately 10 times or more the inductance L2 of the power receiving coil 12.

That is, if the combined inductance of the power receiving coil 12 and the resonance coil 16 in the power receiving side is L = (L2 + L3), the resonant frequency _{f r} of the power receiving side,
f _r = 1 / 2π√ (LC) (1)
It is. When the resonance frequency f _r of the power receiving side is matched with the transmission side of the oscillation frequency f _{o (corresponding} to the frequency f ₁ of the AC power to power transmitting coil 11 described above), the power receiving gain is maximized.

In contrast, the resonance frequency f _r is a deviation with respect to the oscillation frequency f _o, the power receiving gain is decreased in accordance with the magnitude of the deviation. Since the Q value of the inductance is affected by the difference in the arrangement of the magnetic material around the power receiving coil 12 and the resonance coil 16, the method of reducing the power receiving gain can vary depending on the installation state of the device. Experiments have confirmed that the power reception gain is about ½ of the maximum value.

Assuming that the decrease in the power receiving gain is up to 1/2, and applying the combined inductance L on the power receiving side to the equation (1), if L3 ≧ 10 * L2, the power receiving side inductance is L = ( L2 + L3) deviation becomes less than 5% of the resonance frequency f ₂ at the resonance frequency f _r and L = L3 when the, it is possible to use in a practical range without adjustment of the resonance frequency in the field.

Here, it is assumed when the deviation with respect to the oscillation frequency f _o of the resonance frequency f _r is 5% or less as a practical range, this number is merely an example. In a case where more strict control is desired or in an environment where the Q value is high, the ratio between the inductance L2 of the power receiving coil 12 and the inductance L3 of the resonance coil 16 may be set larger than 10 times. Conversely, the deviation of the tolerance is greater than 5% or if Q is lower value environment for the oscillation frequency f _o of the resonant frequency f _r, the ratio of the inductance L2 of the power reception coil 12 and the inductance L3 resonance coil 16 10 It is possible to set it smaller than twice.

  In the above-described embodiment, the example in which the number of turns of the power receiving coil 12 is one has been described, but the present invention is not limited to this. That is, if the inductance L3 of the resonance coil 16 is sufficiently large with respect to the inductance L2 of the receiving coil 12 so that the value of the inductance L2 of the receiving coil 12 is almost negligible compared to the inductance L3 of the resonance coil 16. In addition, the number of turns of the power receiving coil 12 may be plural.

  Incidentally, the magnitude of the inductance of the coil is proportional to the square of the number of turns of the coil and proportional to the cross-sectional area of the coil. Here, when the power receiving coil 12 is wound around a huge facility such as a rotor of a turbine, the cross-sectional area of the power receiving coil 12 inevitably increases. On the other hand, the cross-sectional area of the resonance coil 16 is reduced. Therefore, in order to make the inductance L3 of the resonance coil 16 sufficiently large with respect to the inductance L2 of the power reception coil 12, the number of turns of the power reception coil 12 is reduced while the number of turns of the resonance coil 16 is increased. Therefore, it is necessary to satisfy L2 << L3 due to the difference in the number of turns.

  Moreover, although the said embodiment demonstrated the example which installs a non-contact electric power feeder in the rotor of a turbine, the apparatus and installation which install a non-contact electric power feeder may be other than this. In that case, the device or facility for installing the non-contact power feeding device may be a rotating body or may not be a rotating body. However, it is usually most useful when installed in equipment or facilities where installation is complicated and difficult.

  Moreover, although the said embodiment demonstrated the example which uses a toroidal coil as an example of the coil 16 for resonance, this invention is not limited to this. However, the toroidal coil is characterized in that the generated magnetic flux does not leak to the outside, so that the coil efficiency is very good and the inductance is stable. Therefore, it is preferable to use a toroidal coil in that the resonance frequency can be easily set to a more accurate value.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 11 Power transmission coil 12 Power receiving coil 13 Resonance circuit 14 Rectifier circuit 15 Capacitor 16 Resonance coil (toroidal coil)

Claims (3)

A power transmission coil and a power reception coil installed concentrically;
A resonance circuit connected to the power receiving coil,
The resonance circuit includes a capacitor and a resonance coil that resonates with the capacitor.
A non-contact power feeding apparatus, wherein an inductance of the resonance coil is set to a sufficiently large value with respect to an inductance of the power receiving coil.   2. The non-contact power feeding apparatus according to claim 1, wherein the number of turns of the resonance coil is set to a sufficiently large value with respect to the number of turns of the power receiving coil.   The non-contact power feeding apparatus according to claim 2, wherein the resonance coil is configured by a toroidal coil.

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