JP5256557B2 - Power supply - Google Patents

Description

  The present invention relates to a power supply device. More specifically, the present invention relates to a power supply device that supplies power having two different frequencies to a load such as an induction heating coil.

  A technique is known in which AC power having two different frequencies is supplied to an induction load such as an induction heating coil, and an object to be heated such as a gear or a screw is uniformly heated by the induction heating coil. In this case, since the permeation depth of the high frequency AC power is shallow, the vicinity of the surface of the object to be heated is heated by the high frequency AC power. On the other hand, since the low frequency AC power has a deep penetration depth, the inside of the object to be heated is heated by the low frequency AC power. Therefore, by induction heating the object to be heated at two different frequencies, it is possible to simultaneously heat the region from the surface of the object to be heated to the depth of the penetration depth of the low frequency. As two different frequencies, for example, a high frequency is about 100 kHz to 2 MHz, and a low frequency is about 1 kHz to 50 kHz.

  Patent Document 1 discloses a two-frequency induction heating apparatus including a high-frequency oscillator and a low-frequency oscillator. AC power from the high-frequency oscillator is output to the first matching circuit unit. The first matching circuit unit matches the impedance of the load composed of the induction heating coil and the object to be heated to the high frequency output impedance, and supplies high frequency AC power to the induction heating coil. At the same time, the AC power from the low frequency oscillator is output to the second matching circuit unit, and the impedance of the load is matched with the low frequency output impedance in the second matching circuit unit, and the AC power of the low frequency is induced by the induction heating coil To supply.

FIG. 5 is a circuit diagram illustrating an example of an induction heating apparatus using two frequencies disclosed in Patent Document 1. In FIG. The first matching circuit unit is composed of a capacitor 107. The capacitor 107 prevents AC power having a low frequency from flowing into the AC power side having a high frequency.
On the other hand, the second matching circuit unit is composed of a series resonance circuit of a capacitor 112 and an inductance 119, and the series resonance circuit prevents the high frequency AC power from flowing into the low frequency AC power side. ing.

Patent Document 2 discloses a circuit for connecting a dual frequency power source to an induction heating coil as a dual frequency power source melting furnace power circuit.
FIG. 6 is a circuit diagram showing an example of a power supply circuit for a dual frequency power melting furnace disclosed in Patent Document 2. Current source inverter section A of the low frequency _{(f L)} is is connected to the parallel resonant circuit 113L of the resonance frequency _{f L,} via a series resonance circuit of the resonance frequency _{f L} to a capacitor _{C 2L} and an inductance _{L 1} derived It is connected to the heating coil 120.
On the other hand, the high frequency (f _H ) current source inverter section A is connected to the parallel resonance circuit 113H having the resonance frequency f _H and is connected to the induction heating coil via the capacitor C _2H .

In Patent Document 2, in the power circuit for the dual-frequency power melting furnace, the low-frequency current component that tends to flow from the low-frequency side toward the high-frequency side current source inverter A is the capacitor C _2H and the frequency f of the high-frequency circuit. It is described that it is absorbed by the parallel resonance circuit 113H having a low impedance value in the vicinity of _L and does not flow into the current source inverter section A on the high frequency side.

On the other hand, the high-frequency current component that tends to flow out from the high-frequency current source inverter A toward the low-frequency current source inverter A is in the vicinity of the inductance L ₁ and the capacitor C _2L of the low-frequency circuit and the frequency f _H. It is described that it is absorbed by the parallel resonant circuit 113L having a low impedance value and does not flow into the current source inverter section A on the low frequency side.

Japanese Patent No. 3150968 (for example, FIGS. 3 and 4) JP-A-11-288780 (for example, FIG. 2)

  In the technique disclosed in Patent Document 1, in order to prevent high frequency AC power from entering a low frequency oscillator, it is necessary to connect an inductance 119 to a matching circuit unit connected to the low frequency oscillator. . According to Patent Document 1, the inductance 119 must be at least four times larger than the inductance of the inductive load. Therefore, it is necessary to provide a very large inductance 113 in the matching circuit unit.

  The technique disclosed in Patent Document 2 has a circuit configuration in which a parallel resonant circuit is provided in each of the high-frequency and low-frequency current source inverter units, and an inductance L1 is connected to the low-frequency current inverter unit. An inductance L1 connected to the low-frequency current inverter unit is provided to prevent high-frequency components from entering the low-frequency side. Therefore, as in Patent Document 1, it is necessary to provide a very large inductance L1 in the matching circuit.

  In view of the above problems, an object of the present invention is to provide a power supply device that can reduce inductance used to prevent AC power having a high frequency from entering a low frequency circuit.

To achieve the above object, a power supply device of the present invention, in the power supply apparatus for supplying AC power with a first frequency and a AC power having a second frequency to the induction heating coil, and outputs the AC power of the first frequency A first oscillator; a first matching circuit connected to the first oscillator; a second oscillator that outputs AC power having a second frequency higher than the first frequency; and a second matching circuit connected to the second oscillator A transformer connected to the first matching circuit and the second matching circuit, and an induction heating coil connected to the secondary side of the transformer, the first matching circuit being connected to the first oscillator A first matching transformer, a first capacitor connected to the first matching transformer, and a T-type filter connected in series to the first capacitor, the T-type filter comprising a first reactor and a second Consists of a reactor and a second capacitor. One end of the capacitor is connected to the secondary winding of the first matching transformer, the other end of the first capacitor is connected to the input end of the T-type filter, and the output end of the T-type filter is connected to the primary winding of the transformer. The first reactor and the second reactor are connected in series, one end of the second capacitor is connected to the connection point between the first reactor and the second reactor, and the second matching circuit is connected to the second oscillator. A second matching transformer connected to the second matching transformer, and a capacitor for blocking the first frequency connected to the second matching transformer, wherein one end of the capacitor blocking the first frequency is a secondary winding of the second matching transformer. The other end of the capacitor connected to the line and blocking the first frequency is connected to the primary winding of the transformer, and the first matching circuit allows the first frequency to pass and the second frequency to pass While the second matching circuit prevents It passed through a second frequency, and wherein the blocking first frequency.

  The T-type filter preferably allows a fundamental wave of the second oscillator and a harmonic having at least one frequency of the fundamental wave to pass.

  The first oscillator is preferably smoothed by a first forward conversion unit that converts AC power into DC power, a first smoothing capacitor that smoothes DC power output from the first forward conversion unit, and a first smoothing capacitor. A first reverse conversion unit that converts the DC power into AC power of the first frequency, and the second oscillator outputs the second forward conversion unit that converts the AC power into DC power and the second forward conversion unit. A second smoothing capacitor that smoothes the DC power that has been smoothed, and a second inverse conversion unit that converts the DC power smoothed by the second smoothing capacitor into AC power of the second frequency.

  Preferably, further comprising a forward converter that converts AC power output from one AC power source into DC power, the first oscillator includes a first smoothing capacitor that smoothes the DC power output from the forward converter and a first smoothing capacitor A first reverse conversion unit that converts DC power smoothed by one smoothing capacitor into AC power of a first frequency, and the second oscillator includes a second smoothing capacitor that smoothes the DC power output from the forward conversion unit; And a second inverse converter that converts the DC power smoothed by the second smoothing capacitor into AC power of the second frequency.

  The first inverse conversion unit and the second inverse conversion unit are preferably voltage source inverse conversion units.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power supply apparatus which can apply the alternating current power of a 1st frequency and a 2nd frequency to an induction heating coil efficiently by the structure of a simple matching circuit can be provided.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a circuit diagram showing a configuration of a power supply device 1 according to the first embodiment. In FIG. 1, the power supply device 1 includes a first oscillator 2 for low frequency, a first matching circuit 3 for low frequency connected to the first oscillator 2, a second oscillator 4 for high frequency, A high-frequency second matching circuit 5 connected to the oscillator 4, a transformer 6 to which the first matching circuit 3 and the second matching circuit 5 are connected, and an induction heating coil 7 connected to the transformer 6. It is prepared for.
Incidentally, the first oscillator 2 and the frequency of the second oscillator 4 for high frequency for the low frequency, respectively, (referred to as f _L) first frequency, referred to as the second frequency (referred to as f _H). The second frequency is a higher frequency than the first frequency.

  As the first oscillator 2, an oscillator composed of a so-called voltage source inverter can be used. Similarly, the second oscillator 4 can also be an oscillator composed of a voltage source inverter.

  The transformer 6 includes an input side primary winding 6A and an output side secondary winding 6B. A first frequency AC power and a second frequency AC power are applied to the primary winding 6 </ b> A of the transformer 6 via the first matching circuit 3 and the second frequency matching circuit 5. An induction heating coil 7 is connected to the secondary winding 6B of the transformer 6, and an object to be heated (not shown) is inserted.

  The transformer 6 may be provided with a primary side voltage tap 6C on the primary winding 6A side as shown in the figure. By switching the primary side voltage tap 6C of the transformer 6, the secondary side voltage of the transformer 6 can be changed.

The first matching circuit 3 will be described.
The first matching circuit 3 for low frequency includes a first matching transformer 10 connected to the first oscillator 2, a first capacitor 11 connected to the first matching transformer 10, and a first capacitor 11 connected in series. And a T-type filter 12. The first matching transformer 10 includes an input-side primary winding 10 </ b> A connected to the first oscillator 2 and an output-side secondary winding 10 </ b> B. One end of the first capacitor 11 is connected to one end of the secondary winding 10 </ b> B of the first matching transformer 10, the other end of the first capacitor 11 is connected to the input end 12 </ b> A of the T-type filter 12, and the T-type filter 12. Is connected to one end of the primary winding 6 </ b> A of the transformer 6.

  The first matching transformer 10 may be provided with a primary side voltage tap 10C on the primary winding 10A side as illustrated. The primary side voltage tap 10C may be provided on the secondary winding 10B side. By switching the primary side voltage tap 10C of the first matching transformer 10, the secondary side voltage of the first matching transformer 10 can be changed. By providing the primary side voltage tap 10C, the voltage of the first frequency input from the first oscillator 2 to the first matching circuit 3 can be adjusted.

  The capacitance value of the first capacitor 11 may be set to such a value that the capacitive reactance becomes small with respect to the first frequency output from the first oscillator 2.

  The T-type filter 12 includes a first reactor 14 and a second reactor 15 connected to the other end of the first capacitor 11, and a second capacitor 16 for the T-type filter.

  In the T-type filter 12, a first reactor 14 and a second reactor 15 are connected in series, and one end of a second capacitor 16 is connected to a connection point between the first reactor 14 and the second reactor 15. The other end of the second capacitor 16 is connected to the other end of the secondary winding 10B of the first matching transformer 10 and the other end (low potential side) of the primary winding 6A of the transformer 6. That is, the other end of the second capacitor 16 is grounded to the low potential side that becomes the common wiring 17 including the other end of the secondary winding 10B of the first matching transformer 10 and the other end of the primary winding 6A of the transformer 6. Has been.

  The other end of the second reactor 15 serving as the output end 12 </ b> A of the T-type filter 12 is connected to one end (high potential side) of the primary winding 6 </ b> A of the transformer 6.

The T-type filter 12 has a low-pass filter characteristic that allows the first frequency to pass but does not allow the second frequency to pass. The T-type filter 12 has an effect of efficiently transmitting the output of the first oscillator 2 to the transformer 6 and preventing the output of the second oscillator 4 from flowing into the first oscillator 2 side.
Here, the 1st reactor 14 and the 2nd reactor 15 may have the same inductance value.

  On the other hand, when the output waveform of the first oscillator 2 is a rectangular wave, it contains harmonic frequency components in addition to the fundamental frequency. The cutoff characteristic of the T-type filter 12 for efficiently transmitting the output of the first oscillator 2 to the transformer 6 may be different from that in the case of a sine wave.

FIG. 2 is a diagram schematically illustrating the transfer characteristics of the T-type filter 12. In the figure, the horizontal axis represents frequency, and the vertical axis represents attenuation.
When the output waveform of the second oscillator 4 is a rectangular wave, the T-type filter 12 passes the first frequency (f _L ) of the fundamental frequency, and at least the fundamental frequency or less so as to improve the power transmission characteristics. One or more harmonic components, preferably the harmonic components up to the seventh order, may be passed, and a low-pass filter characteristic that does not pass the second high frequency (f _H ) may be provided. An example of the transfer characteristic of the T-type filter 12 as shown in FIG. 2, so that the power transmission characteristics of the induction heating coil 7 from the second oscillator 4 is improved, 7th harmonic from the fundamental frequency f _L (7f _L ).

The output of the second oscillator 4 is input to a series connection circuit of the second reactor 15 and the second capacitor 16 via a third capacitor 19 of the second matching circuit 5 described later. Therefore, it is sufficient that the transfer characteristic of the T-type filter as shown in FIG. 2 has a sufficient attenuation effect on the second frequency (f _H ).

  The inductance values of the first reactor 14 and the second reactor 15 used in the T-type filter 12 can be values on the order of μH when the first frequency is about 1 kHz to 50 kHz. What is necessary is just to select the capacity | capacitance of the 2nd capacitor | condenser 16 to the value from which a desired low-pass filter characteristic is acquired with the value of the said inductance.

Next, the second matching circuit 5 will be described.
The second high-frequency matching circuit 5 includes a second matching transformer 18 connected to the second oscillator 4 and a third capacitor 19 for high-frequency coupling connected to the second matching transformer 18. As illustrated, the second matching transformer 18 includes a primary winding 18A connected to the output terminal of the second oscillator 4 and an output-side secondary winding 18B.

  One end (high potential side) of the secondary winding 18B of the second matching transformer 18 is connected to one end (high potential side) of the primary winding 6A of the transformer 6 via the third capacitor 19. On the other hand, the other end (low potential side) of the secondary winding 18B of the second matching transformer 18 is connected to the other end (low potential side) of the primary winding 6A of the transformer 6.

  The second matching transformer 18 may be provided with a primary side voltage tap 18C on the primary winding 18A side as illustrated. The primary voltage tap 18C may be provided on the secondary winding 18B side. By switching the primary side voltage tap 18C of the second matching transformer 18, the secondary side voltage of the second matching transformer 18 can be changed. By providing the primary side voltage tap 18C, the voltage of the second frequency input from the second oscillator 4 to the second matching circuit 5 can be adjusted.

The capacitance value of the third capacitor 19 is set to such a value that the capacitive reactance becomes small with respect to the second frequency (f _H ) output from the second oscillator 4, and the first value output from the first oscillator 2. The value is set such that the capacitive reactance increases with respect to one frequency (f _L ).

The point where the first oscillator 2 and the second oscillator 4 are separated from each other will be described in more detail.
When the first oscillator 2 is viewed from the second oscillator 4, a T-type filter 12 is inserted in the first matching circuit 3 for low frequency. By making the second frequency output from the second oscillator 4 out of the pass frequency band of the T-type filter 12, power leakage from the second oscillator 4 to the first oscillator 2 can be effectively prevented.

  The inductance value of the first reactor 14 and the second reactor 15 of the T-type filter 12 can be set to a small value as compared with the case where the leakage of power from the second oscillator 4 is prevented with only the conventional coil. The first matching circuit 3 for frequency can be reduced in size.

In the second matching circuit 5 connected to the second oscillator 4, the capacitive reactance X _C3 (where X _C3 = 1 / (2πf _H C3)) by the third capacitor (C3) 19 is a low frequency (f _L ). Then it becomes a big value. For this reason, power leakage from the first oscillator 2 to the second oscillator 4 is prevented by the large capacitive reactance X _C3 at the low frequency (f _L ) of the third capacitor 19. That is, the third capacitor 19 is a low frequency blocking capacitor, a so-called decoupling capacitor.

  In the power supply device 1 of the present invention, the first matching circuit 3 is connected to the first matching transformer 10 connected to the first oscillator 2 and the first matching circuit 3 so that the output of the second oscillator 4 does not flow into the first oscillator 2. It comprises a first capacitor 11 connected to the secondary winding 10B of the matching transformer 10 and a T-type filter 12, whereby induction outputs of different frequencies from the first oscillator 2 and the second oscillator 4 are induced. The first matching circuit 3 can be reduced in size because the first matching circuit 3 includes the T-type filter 12.

Next, a circuit configuration example of the first oscillator and the second oscillator will be described.
FIG. 3 is a circuit diagram showing a modification of the power supply device 1. In the power supply device 30, the first oscillator 2 for low frequency includes a first forward conversion unit 26 that converts AC power output from an AC power source 25 using a commercial power source or the like into DC power, and a first forward conversion unit. A first smoothing capacitor 27 that smoothes the DC power output from the first smoothing capacitor 27, and a voltage-type first inverse converter (low frequency) that converts the DC power smoothed by the first smoothing capacitor 27 into AC power of the first frequency. Reverse conversion unit) 28.

  The first forward conversion unit 26 includes a bridge rectifier circuit. The first inverse conversion unit 28 includes a so-called inverter and incorporates a plurality of switching elements composed of transistors and the like, and controls the conduction state (ON) and the cutoff state (OFF) of the plurality of switching elements to control the direct current. The electric power is converted into AC power having a first frequency. The first frequency is a frequency of about 1 kHz to 50 kHz, for example.

  The second oscillator 4 for high frequency includes a second forward conversion unit 36 that converts AC power output from an AC power source 35 using a commercial power source or the like into DC power, and a DC output from the second forward conversion unit 36. A second smoothing capacitor 37 for smoothing the power; a voltage-type second reverse conversion unit (high frequency reverse conversion unit) 38 for converting the DC power smoothed by the second smoothing capacitor 37 into AC power of the second frequency; It has.

  The second forward conversion unit 36 includes a known bridge rectifier circuit. Similarly to the first inverse conversion unit 28, the second inverse conversion unit 38 is composed of an inverter and incorporates a plurality of switching elements composed of transistors and the like. The conduction state (ON) and the cutoff state of the plurality of switching elements. By controlling (off), DC power is converted into AC power of the second frequency. The second frequency is a frequency of about 100 kHz to 2 MHz, for example.

  Furthermore, the first oscillator 2 and the second oscillator 4 include a control unit that controls the magnitude of electric power, heating time, and the like (not shown).

An example of induction heating of an object to be heated using the power supply device 30 will be described.
When power is supplied to an induction heating system (not shown) including the power supply device 30, AC power is supplied from the AC power supply 25 to the first oscillator 2, and from the AC power supply 35 to the second oscillator 4. AC power is supplied. In the first oscillator 2, AC power supplied from the AC power supply 25 is converted into DC power by the first forward conversion unit 26, and the DC power output from the first forward conversion unit 26 is smoothed by the first smoothing capacitor 27. The input DC power is converted into AC power having a first frequency of 1 kHz to 50 kHz, for example, by the first inverse conversion unit 28. The converted AC power is output to the first matching circuit 3.

  On the other hand, in the second oscillator 4, the AC power supplied from the AC power supply 35 is converted into DC power by the second forward conversion unit 36, and the DC power output from the second forward conversion unit 36 is converted into the second smoothing capacitor 37. And is input to the second inverse conversion unit 38. The input DC power is converted by the second inverse conversion unit 38 into AC power having a second frequency of 100 kHz to 2 MHz, for example. The converted AC power is output to the second matching circuit 5.

The transformer 6 is supplied with the first frequency AC power output from the first oscillator 2 and the second frequency AC power output from the second oscillator 4. An alternating current of the first frequency alternating current flows through the induction heating coil 7 through the transformer 6, and an eddy current is induced in the heated object by the alternating current of the first frequency to heat the heated object.
Here, since the T-type filter 12 is disposed in the first matching circuit 3, the second frequency AC power output from the second oscillator 4 cannot enter the first oscillator 2.

An alternating current of the second frequency alternating current flows through the induction heating coil 7 via the transformer 6, and an eddy current is induced in the heated object by the alternating current of the second frequency, thereby heating the heated object.
Here, the second matching circuit 5, the third capacitor 19 is arranged, the capacitive reactance X _C3 of the third capacitor 19, since a large value for the first frequency of the low-frequency, first The first frequency AC power output from the oscillator 2 does not enter the second oscillator 4.

In the first oscillator 2 and the second oscillator 4 of the power supply device 30 illustrated in FIG. 3, the first forward conversion unit 26 and the second forward conversion unit 36 that are independent of each other are provided, and AC power having different frequencies is supplied to the first forward conversion unit 26 and the second forward conversion unit 36. Although it has input into the reverse conversion part 28 and the 2nd reverse conversion part 38, the electric power supply apparatus 40 of another structure is further demonstrated with reference to FIG.
In the power supply device 40 in FIG. 4, AC power is input from one AC power supply 45 to one forward conversion unit 46, and the first reverse conversion unit 46 and the first reverse conversion unit 28 and the second reverse conversion unit 38 are input from this one forward conversion unit 46. DC power is output.

  According to the power supply device 40 shown in FIG. 4, unlike the power supply devices 1 and 30 shown in FIGS. 1 and 3, only one AC power supply 45 and one forward conversion unit 46 are required, and the configuration is simple. can do.

  In the power supply device 40 illustrated in FIG. 4, AC power is input from one AC power supply 45 to one forward conversion unit 46, and the first reverse conversion unit 28 and the second reverse conversion unit 38 are transmitted from the single forward conversion unit 46. Except for outputting direct current power to the power supply device 30, the object to be heated can be heated by applying alternating current power of the first frequency and the second frequency to the induction heating coil 7 in the same manner as the power supply device 30.

  As described above, in the power supply devices 30 and 40, the second frequency AC power output from the second oscillator 4 is blocked by the T-type filter 12 of the first matching circuit 3. Therefore, a conventional coil having a large inductance is not necessary.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included in the scope of the present invention. Absent. In the above-described embodiment, the transfer characteristics of the T-type filter 12 are appropriately designed according to the first and second frequencies, such as the inductance of the first reactor 14 and the second reactor 15 and the value of the second capacitor 16. It is possible.

It is a circuit diagram which shows the structure of the electric power supply apparatus of this invention. It is a figure which illustrates typically the transfer characteristic of a T type filter. It is a circuit diagram which shows the modification of an electric power supply apparatus. It is a circuit diagram which shows another modification of an electric power supply apparatus. It is a circuit diagram which shows an example of the induction heating apparatus by the well-known 2 frequency currently disclosed by patent document 1. FIG. It is a circuit diagram which shows an example of the power supply circuit for well-known dual frequency power melting furnaces disclosed by patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,30,40: Electric power supply apparatus 2: 1st oscillator 3: 1st matching circuit 4: 2nd oscillator 5: 2nd matching circuit 6: Transformer 6A: Primary winding 6B: Secondary winding 6C: Primary Side voltage tap 7: Induction heating coil 10: First matching transformer 10A: Primary winding 10B: Secondary winding 10C: Primary side voltage tap 11: First capacitor 12: T-type filter 12A: Input terminal 12B: Output End 14: first reactor 15: second reactor 16: second capacitor 17: common wiring 18: second matching transformer 18A: primary winding 18B: secondary winding 18C: primary side voltage tap 19: third capacitor 25, 35, 45: AC power supply 26: first forward conversion unit 27: first smoothing capacitor 28: first reverse conversion unit 36: second forward conversion unit 37: second smoothing capacitor 38: second reverse conversion unit 46: Forward conversion part

Claims (5)

In the power supply apparatus that supplies the AC power of the first frequency and the AC power of the second frequency to the induction heating coil,
A first oscillator that outputs AC power of the first frequency;
A first matching circuit connected to the first oscillator;
A second oscillator that outputs AC power of the second frequency higher than the first frequency;
A second matching circuit connected to the second oscillator;
A transformer to which the first matching circuit and the second matching circuit are connected;
An induction heating coil connected to the secondary side of the transformer;
With
The first matching circuit includes a first matching transformer connected to the first oscillator, a first capacitor connected to the first matching transformer, and a T-type filter connected in series to the first capacitor. Consists of
The T-type filter includes a first reactor, a second reactor, and a second capacitor,
One end of the first capacitor is connected to the secondary winding of the first matching transformer, and the other end of the first capacitor is connected to the input end of the T-type filter.
The output end of the T-type filter is connected to the primary winding of the transformer,
The first reactor and the second reactor are connected in series, and one end of the second capacitor is connected to a connection point between the first reactor and the second reactor,
The second matching circuit comprises a second matching transformer connected to the second oscillator, and a capacitor for blocking a first frequency connected to the second matching transformer,
One end of a capacitor blocking the first frequency is connected to the secondary winding of the second matching transformer, and the other end of the capacitor blocking the first frequency is connected to the primary winding of the transformer;
The first matching circuit is passed through the first frequency, and prevents the second frequency, said second matching circuit is passed through the second frequency, and you prevent the first frequency A power supply device characterized by that. 2. The power supply device according to claim 1 , wherein the T-type filter passes a fundamental wave of the second oscillator and a harmonic having at least one frequency of the fundamental wave. The first oscillator includes a first forward conversion unit that converts AC power into DC power;
A first smoothing capacitor for smoothing the DC power output from the first forward conversion unit;
A first inverse converter that converts the DC power smoothed by the first smoothing capacitor into AC power of the first frequency,
The second oscillator includes a second forward conversion unit that converts AC power into DC power;
A second smoothing capacitor for smoothing the DC power output from the second forward conversion unit;
Wherein the second inverse transformation unit for converting the DC power smoothed by said second smoothing capacitor into AC power of the second frequency, in that it consists of, the power supply device according to claim 1 or 2. Furthermore, a forward conversion unit for converting AC power output from one AC power source into DC power is provided,
The first oscillator includes a first smoothing capacitor that smoothes the DC power output from the forward conversion unit, and a first reverse conversion that converts the DC power smoothed by the first smoothing capacitor into AC power of the first frequency. And consists of
The second oscillator includes a second smoothing capacitor that smoothes the DC power output from the forward conversion unit, and a second reverse conversion that converts the DC power smoothed by the second smoothing capacitor into AC power of the second frequency. characterized in that comprising the parts, the power supply device according to claim 1 or 2. The first inverse transformation unit and the second inverse transform unit is characterized by a voltage-inverse transform unit, the power supply device according to claim 3 or 4.

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