JP3042119B2 - Plasma ignition power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma ignition power supply for a plasma torch used for igniting an aircraft engine, igniting an automobile engine, or welding, cutting or spraying.

[0002]

2. Description of the Related Art Conventionally, a plasma torch has been used for igniting an aircraft engine or an automobile engine or for welding, cutting, thermal spraying and the like.

FIG. 3 shows an example of a plasma torch 17 in which a working fluid 3 is supplied at a high pressure from a working fluid supply pipe 1 via a control valve 2 and a cooling fluid is supplied from a supply pipe 4 via a control valve 5. The fluid 6 is supplied, and the high-pressure working fluid 3 supplied from the working fluid supply pipe 1 cools the cathode rod 9 while passing through the ring-shaped supply passage 8 from the passage 7. 10 to the cathode rod 9
And plasma generated by passing through an arc generating electrode 12 composed of an injection nozzle 11 forming an anode.
3 is accelerated and ejected by the nozzle port 14. The cooling fluid 6 supplied from the supply pipe 4 is supplied to the injection nozzle 11
Is guided to the tip through the introduction flow path 15 in the
After cooling, the cooling fluid 1 is discharged to the outside through the cooling fluid discharge passage 16.

The above-described conventional plasma torch 17 is shown in FIG.
As shown in the figure, a plasma ignition power supply device having one power supply device 18 for one plasma torch 17 is constituted. In the case of an apparatus provided with a plurality of plasma torches 17, it is possible to simplify the equipment if the power supply 18 is shared, but it is difficult to distribute the current even if the power supply 18 is simply shared. As a result, a current flows only to one of the plasma torches 17, and therefore, no conventional power supply is shared.

[0005]

For this reason, when the above-mentioned conventional plasma ignition power supply device is applied to a facility provided with a large number of plasma torches 17 such as an aircraft engine, for example, the large power supply device 18 becomes a plasma torch. 17 is required, the configuration is complicated, the size is increased, and a very large occupied area is required. In addition, there is an arrangement problem that the large power supply 18 cannot be arranged near the plasma torch 17. Was. In addition, since the weight increases, it is a particularly important problem in an aircraft engine or the like that requires a reduction in weight.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and allows a plurality of plasma torches to be ignited by a single main power supply, thereby simplifying the apparatus and reducing the weight. The purpose is to:

[0007]

The basic structure of the present invention comprises a main power supply section and a plurality of sub-power supply sections of the same number as the torch. The main power supply section is provided with a high-frequency transformer to reduce the arc load of each torch. Irrespective of whether the current can be supplied evenly to each sub power supply unit and the sub power supply unit controls the supply current according to the arc load of each torch, the main power supply unit A power rectifier for rectifying an AC power supply to a DC power supply, a main current controller for outputting a setting / synchronization signal, and a DC power supply from the power rectifier for inputting a setting / synchronization signal from the main current controller. A high-frequency AC power supply, a high-frequency transformer unit that insulates the high-frequency AC power supply from the transistor switching unit from an arc load and converts the voltage into a voltage suitable for the arc load. A high-frequency rectifier for converting high-frequency AC power from the high-frequency transformer to DC power; and a sub-power supply receiving the DC power from the high-frequency rectifier of the main power supply. And a sub-current control unit that inputs a setting / synchronization signal from the main current control unit and controls switching timing and output current in the switching unit. A plasma ignition power supply device,
It is related to.

[0008]

The AC power supply is rectified into a DC power supply by a power supply rectification unit of the main power supply unit in order to reduce the size of a transformer unit installed behind, and then converted into a high-frequency AC power supply by a transistor switching unit. The transistor switching unit receives the setting / synchronization signal from the main current control unit (the setting current signal to the sub-current control unit and the synchronization signal for simultaneous ignition of each torch). A switching operation for converting a DC power supply to a high-frequency AC power supply and an output current setting are performed. The high-frequency AC power from the transistor switching unit is guided to the high-frequency transformer, insulated from the arc load, and converted into a voltage suitable for the arc load. The high-frequency AC power from the high-frequency transformer is guided to the high-frequency rectifier and converted back into a DC power.

The DC power from the high-frequency rectifier of the main power supply is guided to the respective switching units of the plurality of sub-power supplies and converted into a high-frequency AC power. At this time, the switching timing and the output current of the switching unit are controlled by the sub-current control unit to which the setting / synchronization signal from the main current control unit is input.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of the plasma ignition power supply 22 of the present invention. In the illustrated example, one main power supply 19 and two sub-power supplies 20 connected to two plasma torches 17 are shown. , 21.

As described above, in order for one main power supply unit 19 to share the ignition of a plurality of plasma torches 17, it is necessary to simultaneously and stably supply the same voltage current to each plasma torch 17. .

For this reason, the main power supply section 19 has a potential insulating action between the power supply and the arc load, and the sub power supply sections 20 and 2
1 as a primary DC power supply for the sub-power supply units 20 and 21, and functions such as overall sequence control.

That is, the main power supply section 19 includes a power supply rectification section 24 for rectifying the AC power supply 23 into a DC power supply, a smoothing section 25 for smoothing the power supply ripples (irregularities) of the DC power supply and reducing the ripples, and a transistor half. A transistor switching unit 26 configured by a bridge to convert the DC power from the smoothing unit 25 to a high-frequency AC power; and insulate the high-frequency AC power converted by the transistor switching unit 26 from the load and generate an arc load (arc generation). A high-frequency transformer section 27 for converting to a required voltage, a high-frequency AC power supply from the high-frequency transformer section 27 is non-rectified, and a high-frequency rectification section 28 for once rectifying the power and reconverting it into a DC power supply; , 21 are matched,
And a load matching section 29 for reducing high frequency ripples.

Further, the main power supply section 19 is provided with a sequence control section 30.
A start / stop signal from the stop switch 31 and an output current setting signal from the output current setting unit 32 are input, and a control signal 33 including an output current setting and a switching control operation command is calculated and output. At the same time, the output of the command signal 35 to the gas control unit 34 and the input of the gas shortage signal 36 from the gas control unit 34 are performed to perform the ignition control and the gas control.

Upon receiving a control signal 33 consisting of two commands, an output current setting and a switching control operation command from the sequence control unit 30, the transistor switching unit 26 performs a switching operation of converting the DC power supply into a high-frequency AC power supply. Setting and synchronization signal 3 for setting the output current
7 is provided. The main current control unit 38 is connected to a power supply voltage detection unit 40 that detects excess or deficiency of the power supply voltage and inputs a voltage abnormality signal 39 for protecting the inverter circuit of the transistor switching unit 26.

On the other hand, the two sub power supply units 20 and 21 are respectively
The main power supply unit 19 is constituted by one transistor.
Switching units 41 and 42 for converting the DC power supply from the load matching unit 29 into a high-frequency AC power supply, and load matching units 43 and 44 for impedance-matching the high-frequency AC power supply from the switching units 41 and 42 to a target arc load. Current detection units 45 and 46 for detecting an output current by DCCT (DC current conversion);
High-frequency superimposing units 49 and 50 for superimposing 48 on the output voltage;
High-frequency oscillating units 52 and 53 for generating high-voltage high-frequency power supplies 47 and 48 to be applied to the high-frequency superimposing units 49 and 50 by high-frequency oscillation of about 1 MHz in response to a command signal 51 from the sequence control unit 30 are provided.

Further, a setting / synchronization signal 37 from the main current control unit 19 is input to each of the sub power supply units 20 and 21 to control a switching timing and an output current in the switching units 41 and 42. Control units 54 and 55 are provided. At this time, the sub-current control units 54 and 55 output the current feedback signals 56 and 5 from the current detection units 45 and 46, respectively.
7, the output current is controlled to a predetermined value. In the figure, 58 and 59 indicate output power supplies.

Further, a temperature signal 60 which detects the temperature of the power rectifier 24, the transistor switching unit 26, the high-frequency transformer 27, the high-frequency rectifier 28, the switching units 41 and 42, etc. is input to the sequence control unit 30. The abnormality is managed, and when an abnormality occurs, all operations other than the cooling fluid 6 in FIG. 2 are stopped.

The operation will be described below.

The sequence control unit 30, which has received the start signal of the start / stop switch 31, sends a control valve 2, 5 for the working fluid 3 and the cooling fluid 6 shown in FIG.
Is output. Plasma torch 1
After a lapse of time (after the preflow time) at which the flow rate of the working fluid 3 at the tip 7 is sufficiently obtained, the sequence control unit 30
Outputs a control signal 33 including an output current setting and a switching control operation command to the main current control unit 38. The main current controller 19 controls the control signal 3 from the sequence controller 30.
In step 3, PWM control (pulse width adjustment control) for outputting the setting / synchronization signal 37 is started. The pulse generated by the PWM control is frequency-synchronized and divided into a positive pulse and a negative pulse. These positive and negative pulses are both divided into two systems, one is sent as sub-information to the sub-current control units 54 and 55 of the sub-power supply units 20 and 21, and the other is power-amplified and transistor-switched unit 26. Is output as a drive signal of the transistor of. The transistor switching section 26 has a two-bridge half-bridge configuration,
A DC power supply is converted into a high-frequency AC power supply having a frequency of about 8 KHz by alternately applying positive and negative pulses to the transistor. The high-frequency AC power from the transistor switching unit 26 passes through the high-frequency transformer unit 27 and is converted back to a DC power by the high-frequency rectification unit 28.

The high-frequency transformer section 27 is provided for insulation between a power supply and an arc load and for setting a voltage suitable for the arc load. The reconverted DC power is sent to the next stage load matching section 29 to match with the arc and reduce the ripple, to compensate for the loss in the transmission path to the sub power sections 20 and 21 and to reduce the inverter current. Radiation noise is reduced.

The sequence control section of the main power supply section includes: B. Inverter protection / inappropriate power supply voltage. Prevents damage from spreading due to inverter failure. It has an abnormality management function to stop all operations other than the cooling gas in order to prevent failure of the inverter unit, and to overheat the transformers and transistors due to lack of cooling gas and plasma gas and excess usage rate.

The current control of the two sub-power supply units 20 and 21 is performed by transmitting an output current setting command and switching sub-information based on the setting / synchronization signal 37 sent from the main current control unit 38 of the main power supply unit 19, respectively. The sub-current controllers 54 and 55 receive these signals and the current feedback signal 5 detected by the current detectors 45 and 46.
The PWM control (pulse width adjustment control) for keeping the output currents of the switching units 41 and 42 constant is performed by the control units 6 and 57. The sub information is a synchronization signal that synchronizes the switching operation of the main power supply unit 19 and the switching operation of the sub power supply units 20 and 21. Now, when the switching of one sub power supply unit 20 is operated in synchronization with the positive half wave of the high frequency AC power supply of the main power supply unit 19, the other sub power supply unit 21 operates in synchronization with the negative half wave. This is the signal that was made. This synchronization signal prevents the two systems of the sub power supply units 20 and 21 from mutually interfering with each other, and as a result, the outputs of the sub power supply units 20 and 21 can operate at different voltages.

The load matching section 43 at the next stage of the switching sections 41 and 42 has two purposes. One is to match the timing of the output voltage between the sub power supply sections 20 and 21. Another is to improve the ignition and holding properties for arc loads. Since the switching start timing between the sub power supply units 20 and 21 is shifted by a half-wave, each output is delayed, and L and L are adjusted to match the output voltage timing at the time of ignition and to the ignition and holding of the arc.
The purpose is to obtain a stable arc by C, R (reactance, capacitor, resistance).

High frequency superimposing sections 49, 5 connected to the last stage
At 0, the high-voltage high-frequency power supplies 47 and 48 generated by the high-frequency starting units 52 and 53 are coupled to the output circuit by a coupling coil, so that the output power supplies 58 and 59 are superimposed on the high-frequency AC power supply and are connected to the high-frequency AC power supply in FIG. The plasma 13 is output to the plasma torches 17 and ignited to generate plasma 13. Since the high-voltage high-frequency power supplies 47 and 48 start in synchronization with a half-wave of the high-frequency AC power supply,
It is possible to prevent misalignment of ignition between the two.

Upon receiving the stop signal of the start / stop switch 31, the sequence control unit 30 stops all operations except for the supply of the cooling fluid 6. The cooling fluid 6 is stopped after a certain time. The cooling fluid 6 includes the plasma torch 17, the transistor switching unit 26, and the high-frequency transformer unit 2.
It is used to sufficiently cool 7 and the like.

It should be noted that the present invention is not limited to the above-described embodiment, but that a main power supply unit may be provided with three or more sub-power supply units, and that the present invention does not depart from the gist of the present invention. Of course, various changes can be made within the range.

[0029]

According to the plasma ignition power supply of the present invention described above, the power supply comprises a main power supply and a plurality of sub-power supplies, insulates a power supply from an arc load, and comprises a main power supply and a plurality of sub-power supplies. By synchronizing the output currents of the sub-power units, the main power unit can be shared to enable plasma ignition of a plurality of plasma torches, thereby simplifying the configuration and reducing the installation area and weight. The power supply can be reduced, and the sub-power supply can be made very small, so that it can be easily installed near the plasma torch, and the sub-power supply is installed near the plasma torch away from the main power supply. By doing so, various excellent effects can be achieved, such as the effect of the high-frequency oscillator on other components can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of the present invention.

FIG. 3 is a schematic explanatory view showing an example of a conventional plasma ignition power supply device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 19 Main power supply part 20 Sub power supply part 21 Sub power supply part 22 Plasma ignition power supply 23 AC power supply 24 Power supply rectifier 26 Transistor switching part 27 High frequency transformer part 28 High frequency rectification part 37 Setting / synchronization signal 38 Main current control part 41 Switching part 42 Switching Unit 54 Sub-current control unit 55 Sub-current control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F23D 14/38 F23D 14/38 Z (72) Inventor Toshio Irisawa 1 Shinnakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima-Harima Heavy Industries, Ltd. Inside the Technical Research Institute (72) Inventor Masami Sayama 3-5-1 Mukodai-cho, Tanashi-shi, Tokyo Ishikawashima-Harima Heavy Industries, Ltd. Inside the Tanashi Plant (72) Inventor Katsuo Yonezawa 3-5-1 Mukodai-cho, Tanashi-shi, Tokyo No. Ishikawashima Harima Heavy Industries, Ltd. Tanashi Factory (56) References JP-A-58-59376 (JP, A) JP-A-57-151072 (JP, A) (58) Fields studied (Int. Cl. ⁷ , (DB name) H05H 1/36 B23K 10/00 F02P 3/01 F02P 15/02

Claims (1)

(57) [Claims] 1. A power supply comprising: a main power supply unit; and a sub-power supply unit having the same number as the number of plasma torches, wherein the main power supply unit rectifies an AC power supply to a DC power supply, and a main current which outputs a setting / synchronization signal. A control unit, a transistor switching unit that inputs a setting / synchronization signal from the main current control unit and converts DC power from the power rectification unit to high-frequency AC power, and arcs the high-frequency AC power from the transistor switching unit. A sub-power supply unit having a configuration including a high-frequency transformer unit that insulates from a load and converts the voltage into a voltage suitable for an arc load, and a high-frequency rectification unit that converts a high-frequency AC power supply from the high-frequency transformer unit to a DC power supply; A switching unit that receives a DC power supply from a high-frequency rectification unit of the main power supply unit and converts it into a high-frequency AC power supply, and inputs a setting / synchronization signal from the main current control unit and A plasma ignition power supply device having a configuration including a switching timing in a switching unit and a sub-current control unit for controlling an output current.