JP4453810B2 - Step-up transformer - Google Patents

Description

  The present invention relates to a step-up transformer for high-frequency and high-voltage, and more particularly to a step-up transformer for high-frequency and high-voltage applied to an excimer discharge lamp lighting circuit.

  In general, in a step-up transformer for high voltage, a high potential difference is generated between a primary winding and a secondary winding. Therefore, in order to sufficiently absorb this potential difference, an insulating layer is provided between the primary winding and the secondary winding, or the number of winding layers forming the secondary winding is increased, and the voltage applied to each layer is increased. Is lowered.

  Further, in a step-up transformer for high frequency and high voltage, it is necessary not only to increase the withstand voltage but also to take measures to prevent corona discharge induced in the insulating layer. Conventionally, in order to cope with this, for example, ten sheets of Nomex (registered trademark of DuPont) having a dielectric constant of 2.5 have been used as insulating paper. Moreover, the whole transformer was immersed in oil and the insulation was ensured, or the method of insulating with a mold was performed. However, such a method has problems such as an increase in size of the transformer and a decrease in conversion efficiency.

  In addition, the secondary winding is formed by overlapping a plurality of winding layers wound in a coil shape, but a potential difference is generated between the winding start and the winding end of the coil of each layer. Therefore, insulating paper is inserted between a certain winding layer and the next winding layer to ensure insulation between the layers. However, when the interlayer insulating paper is inserted in this way, there is a problem that the transformer is further increased in size.

  In Japanese Patent Laid-Open No. 3-34643, a winding method called block winding or bank winding is adopted as a winding method of a choke coil or a transformer, thereby reducing interlayer insulating materials interposed between layers of the winding. Technology is disclosed.

  In Japanese Patent Laid-Open No. 5-13247, in order to reduce the proximity effect and skin effect in high-frequency and high-voltage transmission, the secondary winding of the step-up transformer is bundled with a plurality of insulated wires called litz wires. A technique that employs an electric wire coated with an insulator is disclosed.

  Japanese Patent Application Laid-Open No. 8-96766 discloses an excimer discharge lamp in which an output voltage from a switching inverter as a power feeding device is boosted by a step-up transformer (transformer 18) and is passed through an LC series resonance circuit (coil 19 and capacitor 20). A circuit for supplying and lighting (dielectric barrier discharge lamps T1 to T4) is disclosed.

JP-A-3-34643 JP-A-5-13247 Japanese Patent Application Laid-Open No. 8-96766

  By the way, when an insulating layer is interposed between the layers of the secondary winding in the step-up transformer, stray capacitance is generated in the secondary winding. Therefore, when trying to boost the high frequency high voltage, there arises a problem that the rise time of the high frequency high voltage is dulled. In particular, in a discharge lamp such as an excimer discharge lamp that discharges and charges a dielectric charged between electrodes in a short period of time, the luminous efficiency decreases when the rise time of the high-frequency voltage is dull. Cause problems.

  In order to solve such a problem, it is necessary to reduce the stray capacitance in the high-frequency high-voltage step-up transformer for the excimer discharge lamp by reducing the number of interlayer insulating materials interposed between the layers of the secondary winding. Therefore, it is conceivable to employ a winding method called block winding or bank winding as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 3-34643. However, if a block winding or a bank winding is simply adopted for the secondary winding, a large potential difference is generated between the primary winding and the secondary winding, and this is not applicable to a high frequency high voltage step-up transformer. Can not.

  Further, in a step-up transformer having a high frequency and a sharp rise for an excimer discharge lamp, it is necessary to reduce the proximity effect and the skin effect. Therefore, it is conceivable to improve the transmission efficiency by adopting a litz wire as disclosed in the above-mentioned JP-A-5-13247. However, even if a litz wire is simply used, in order to avoid creeping corona discharge between the primary winding and the secondary winding, the insulating material must be put above the actual withstand voltage, resulting in floating There is a problem that the capacity increases and the conversion efficiency decreases.

  In view of the above-described problems, an object of the present invention is to provide a step-up transformer that is small and excellent in rising characteristics of a high-frequency high-voltage induced on the secondary side without generating creeping corona discharge. In particular, in order to improve luminous efficiency in excimer discharge lamps, it has excellent high-frequency and high-voltage rise characteristics induced on the secondary side, low heat generation, and excellent power transfer efficiency from the primary side to the secondary side. The object is to provide a step-up transformer.

The present invention employs the following means in order to solve the above problems.
A first means is a step-up transformer for supplying a high frequency high voltage for lighting an excimer discharge lamp, wherein the step-up transformer has a frequency of the high frequency high voltage supplied from the secondary side of 10 kHz to 1 MHz and a secondary voltage. Is a step-up transformer having a voltage of 2 kVp-p to 15 kVp-p, and a plurality of wall-like bodies made of an insulating material are provided between the primary winding and the secondary winding of the step-up transformer, and air is interposed between the wall-like bodies. A composite dielectric constant obtained by synthesizing the relative permittivity of the wall-shaped body and the relative permittivity of the air layer is 1 to 4, and the secondary winding travels parallel to the wall-shaped body. The first winding mode in which the first winding is wound in the direction, and the first winding that has been wound each time the first winding is wound by one winding in the first winding mode. A second winding mode in which the second winding connected to the first winding is wound between the other windings. Becomes the first of said winding manner to the second winding mode are repeated alternately winding is wound in the direction of travel, said primary winding a metal wire constituting the winding with wire diameter of a φ0.03 to Fai0.08, a step-up transformer, characterized in that it constitutes a composite litz wire of the metal wire plurality of bundled.

According to the first aspect of the present invention, in a step-up transformer that supplies a high-frequency high voltage that requires a rapid rise in order to light an excimer discharge lamp,
(1) Since a plurality of wall-like bodies made of an insulating material are provided between the primary winding and the secondary winding of the step-up transformer and an air layer is provided between the wall-like bodies, compared with the conventional step-up transformer. Thus, the gap between the primary winding and the secondary winding can be narrowed, the transfer efficiency of electromagnetic energy from the primary winding to the secondary winding can be improved, and the secondary winding The rise characteristic of the secondary voltage of the high frequency and high voltage induced by can be improved, and the luminous efficiency of the excimer discharge lamp can be improved.
(2) Since the combined relative dielectric constant obtained by combining the relative permittivity of the wall-like body and the relative permittivity of the air layer is 1 to 4, a plurality of conventional insulators such as Nomex are provided. Compared with the wound one, the voltage applied to the wall-like body with the air layer interposed therebetween can be increased, preventing creeping corona discharge generated between the wall-like body and the primary or secondary winding. can do.
(3) The secondary winding is a first winding mode in which the first winding is wound in a traveling direction parallel to the wall-like body, and the first winding mode is a first winding mode. Each time one of the windings is wound, the second winding connected to the one winding is wound between the wound first windings by the second winding. Since the first winding mode and the second winding mode are alternately repeated and the winding is wound in the traveling direction, the conventional secondary winding Compared with the winding method, the potential difference between adjacent windings is small, so there is no need to interpose an insulating layer, the stray capacitance in the secondary winding can be reduced, and the high frequency voltage induced in the secondary winding can be reduced. The rise characteristic can be improved. In particular, this is extremely effective when the excimer discharge lamp is lit with a steep pulsed high-frequency voltage.
(4) Further, since the wire diameter of the metal wire constituting the winding is φ0.03 to φ0.08 in the primary winding, the skin effect in high-frequency voltage transmission is reduced, and the power transmission efficiency is improved. While improving, the heat_generation | fever in a step-up transformer can be suppressed.
(5) Furthermore, the wire diameter of the metal wire constituting the winding is φ0.03 to φ0.08, and a high-frequency voltage transmission is made up of a composite litz wire in which a plurality of the metal wires are bundled. In addition to reducing the proximity effect, the power transmission efficiency can be improved, and heat generation in the step-up transformer can be suppressed.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a front view showing a step-up transformer used in a lighting device for an excimer discharge lamp according to the invention of this embodiment.
In the figure, 1 is a ferrite core of a step-up transformer, 2 is a secondary winding wound in a plurality of layers, 3 is a transformer holding plate A, 4 is a transformer holding plate B, and 5 is a cooling fluid for cooling the step-up transformer. A cooling hose made up of a Teflon (registered trademark) tube or the like provided to supply the battery, 6 is a high voltage (HV) cable, and 7 is a ground (E) cable.

  2A is a partial cross-sectional view of the step-up transformer as viewed from a cut surface parallel to the paper surface, passing through the center of the ferrite core 1 shown in FIG. 1, and FIG. FIG. 3 is an enlarged cross-sectional view of the primary winding 11 shown in FIG.

  In these drawings, 8 is a wall-like body made of a low dielectric constant material made of, for example, a glass fiber material, and 9 is formed between the wall-like bodies 8 and is made of, for example, air or N 2. A gas layer having a thickness of 0.4 to 0.8 mm provided so as to be able to flow in and out, 10 is a spacer provided to secure a gas layer 9 formed between the wall-like bodies 8, and 11 is 1 The primary winding 12 wound by layers is an insulating layer formed by overlapping a plurality of Nomex (registered trademark) having a thickness of 0.13 mm, for example. Other configurations correspond to the configurations of the same reference numerals shown in FIG.

  As shown in FIGS. 2A and 2B, in the step-up transformer according to the invention of the present embodiment, a secondary is provided via a gas layer 9 formed between the wall-like bodies 8 on the primary winding 11. Winding 2 is wound. Therefore, the primary winding is conventionally compared to the case where a plurality of (eg, 10) insulators such as Nomex (registered trademark) are wound around the primary winding and then the secondary winding is wound. The gap between the wire 11 and the secondary winding 2 can be reduced. As a result, the step-up transformer can be reduced in size, the transfer efficiency of electromagnetic energy from the primary winding 11 to the secondary winding 2 can be improved, and the high frequency induction induced in the secondary winding 2 can be improved. The rising characteristic of the secondary voltage of the voltage can be improved, and the luminous efficiency of the excimer discharge lamp can be improved. In addition, the composite dielectric constant formed by the wall-like body 8 and the gas layer 9 is reduced to 1 to 4, thereby making it possible to reduce the air in comparison with a conventional winding of a plurality of insulators such as Nomex (registered trademark). The voltage applied to the wall-like body 8 with the layer 9 interposed can be increased, and creeping corona discharge generated between the wall-like body 8 and the primary winding 11 or the secondary winding 2 can be prevented. .

  Further, as shown in FIG. 2B, the secondary winding 2 is wound in a bank winding on a wall-like body 8 that secures the gas layer 9. That is, the first turn is wound on the wall-shaped body 8, the second turn is then wound in the traveling direction parallel to the wall-shaped body 8, and the third turn is then turned on the first and second turns. Wound over the gap between the eyes, then, after the 4th turn, the 2nd turn and the 3rd turn winding method was repeated, and finally two layers parallel to the wall 8 on the wall 8 The secondary winding 2 is wound. In other words, the secondary winding 2 has a first winding mode in which the winding is wound in a traveling direction parallel to the wall-like body 8, and each time a winding is formed by the first winding mode. In addition, a second winding mode in which a new winding is wound on a gap between existing windings, and the first winding mode and the second winding mode are alternately repeated to form a winding. It is comprised by winding in the said advancing direction. In the winding method in which the secondary winding 2 is wound by the winding method as described above, and the conventional secondary winding is wound by stacking the next layer every layer, Since it is necessary to interpose an insulating layer between the layers, the stray capacitance in the secondary winding increases. However, according to the winding method of the present invention, the potential difference between adjacent windings can be reduced. Therefore, it is not necessary to interpose an insulating layer. As a result, the stray capacitance in the secondary winding 2 can be reduced, and the rising characteristics of the high frequency high voltage induced in the secondary winding 2 can be improved. In particular, it is extremely effective when the excimer discharge lamp is lit with a steep pulsed high frequency high voltage.

  Further, as shown in FIG. 3, the primary winding 11 has a strand diameter φ0.03 to φ0.08. By using such a wire, the skin effect in high-frequency voltage transmission can be reduced, the power transmission efficiency can be improved, and heat generation in the step-up transformer can be suppressed.

  Further, as shown in FIG. 3, the primary winding 11 uses a litz wire technique to bundle seven strands having a wire diameter of φ0.03 to φ0.08, and further bundle a bundle of seven strands. Six bundles arranged around a dummy wire 13 made of a metal material are used. By configuring the primary winding 11 in this way, the proximity effect in high-frequency voltage transmission can be reduced, the power transmission efficiency can be improved, and heat generation in the step-up transformer can be suppressed. By adopting such a winding as the primary winding 11, the AC resistance count (Fac) could be reduced by 20%.

  As an actual method for assembling the step-up transformer, a wall-like body 8 on which a primary winding 11, a secondary winding 2, and a gas layer 9 formed in advance are prepared and the ferrite core 1 is provided. After the insulating layer 12 is wound, the primary winding 11, the wall 8 on which the gas layer 9 is formed, and the secondary winding 2 are arranged in this order.

  In the step-up transformer according to the present embodiment, the frequency of the applied high-frequency high voltage is 10 kHz to 1 MHz, and the step-up transformer has a step-up ratio of 7 to 20 times, and the input voltage on the primary side is 50 to 400 V, The maximum input current is 150 Ap, the output voltage is 2 kVp-p to 15 kVp-p, and the output current is 500 mA to 5 A. In this case, the rising characteristic of the secondary side voltage of the conventional step-up transformer is 4 kV0-p / μs as shown in FIG. 4B, whereas according to the step-up transformer of the present invention, FIG. As shown in a), it is 12 kV0-p / μs, and a step-up transformer with extremely excellent rising characteristics can be obtained.

It is a front view which shows the step-up transformer used for the lighting device of the excimer discharge lamp which concerns on this invention. FIG. 2 is a partial cross-sectional view seen from a cut surface passing through the center of the ferrite core 1 of the step-up transformer shown in FIG. 1 and parallel to the paper surface, and an enlarged view of a portion A of the partial cross-sectional view. It is a cross-sectional enlarged view of the primary winding 11 shown in FIG. It is a figure which shows the rise characteristic of the high frequency high voltage of the step-up transformer which concerns on this invention, and the rise characteristic of the high frequency high voltage of the step-up transformer which concerns on a prior art.

Explanation of symbols

1 Ferrite core 2 Secondary winding 3 Transformer holding plate A
4 Transformer holding plate B
5 Cooling hose 6 HV cable 7 E cable 8 Wall body 9 Gas layer 10 Spacer 11 Primary winding 12 Insulating layer 13 Dummy wire

Claims (1)

In a step-up transformer that supplies a high frequency high voltage for lighting an excimer discharge lamp,
The step-up transformer is a step-up transformer in which the frequency of the high frequency high voltage supplied from the secondary side is 10 kHz to 1 MHz, and the secondary side voltage is 2 kVp-p to 15 kVp-p,
A plurality of wall-like bodies made of an insulating material are provided between the primary winding and the secondary winding of the step-up transformer, an air layer is provided between the wall-like bodies, and the relative permittivity of the wall-like body and the air layer And a relative dielectric constant of 1 to 4,
The secondary winding includes a first winding mode in which the first winding is wound in a traveling direction parallel to the wall-like body, and the first winding mode is 1 in the first winding mode. From the second winding mode in which the second winding connected to the first winding is wound around the wound first winding every time the winding is wound. And the first winding mode and the second winding mode are alternately repeated to wind the winding in the traveling direction ,
The primary winding is that the wire diameter of the metal wires constituting the windings with a φ0.03 to Fai0.08, constitute a composite litz wire of the metal wire plurality of bundled A step-up transformer characterized.

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