JP5099475B2 - Abnormality diagnosis device for high power millimeter wave transmission system - Google Patents

Description

  The present invention relates to a high-frequency heating device for a nuclear fusion device, and more particularly to an abnormality diagnosis device for a high power millimeter transmission system.

  In particular, the present invention provides a high-frequency transmission line that can accurately detect abnormalities and abnormal points in a fusion apparatus, accurately detecting abnormal phenomena in a high-frequency transmission path to a vacuum vessel where high-frequency waves purified by an oscillation tube reach plasma. It is an abnormality diagnosis device. In addition, this device is useful for diagnosing abnormalities that occur in long transmission lines of several tens to 100 meters. It is used in radiation control areas, high-voltage entry-prohibited areas, narrow places where humans cannot approach, and high places. Anomaly diagnosis that can identify the anomaly and occurrence location, and can determine the transmission efficiency of the high frequency until the millimeter wave generated from the high frequency oscillation tube is incident on the plasma, or the transmission efficiency between specific transmission systems Device.

  A high-frequency heating device has one purpose of heating a super-high temperature of 100 million degrees or higher where high-power high-frequency waves are incident on high-temperature plasma and a nuclear fusion reaction occurs efficiently. The MW class high-frequency generated by the oscillation tube and amplifier passes through the waveguide and various high-frequency components that are the high-frequency transmission path before reaching the plasma, and the direction of the MW-class high-frequency beam changes in it. In order to evacuate the inside of the waveguide without leaking high frequencies outside the waveguide, the waveguide is finely processed and exhausted through countless grooves of about 0.5 mm. A special waveguide with a mouth, a polarization converter that adjusts the polarization angle and ellipticity, a vacuum window that cuts off impurities such as tritium in a vacuum by passing high frequency with low loss, and high frequency in the open state A combination of multiple devices such as a high-frequency vacuum gate valve that transmits low-loss and shuts off the vacuum when closed, and a waveguide switch that changes the direction of high-frequency beam travel (0 °, 90 °). Yes. In these places, there may occur a malfunction such as a breakdown of a breakdown voltage of a component device or a sudden abnormality, for example, a damage of the device due to a discharge due to an increase in the degree of vacuum. If a small abnormality cannot be detected, the arc can be further propagated by arc marks and protrusions generated by the discharge, and can develop into a new discharge, leading to the breakage of the equipment.

  In the conventional apparatus, the abnormality detection of the high-frequency transmission path is performed by the following methods (1), (2), and (3).

  (1) A method of detecting abnormalities in the high-frequency transmission line by making a small hole that leaks high-frequency waves in the reflector at the 90 ° bend of the transmission line and measuring the high-frequency traveling power and the reverse power leaking from it. .

  (2) A method of detecting anomalies by selecting a device that may develop into a large abnormal event when a discharge occurs, among other high-frequency components, and installing a sensor that detects discharge light.

  (3) A method in which the degree of vacuum in the transmission line is measured and detected based on the abnormally changed degree of vacuum.

In a high-frequency power measuring device, a high-frequency wave propagating in a waveguide is passed through a dielectric of a detection unit, and the high-frequency power converted into heat is measured there (Patent Document 1). It has not been done until the abnormal equipment in the wave tube is selected and the location is specified. In addition, papers describing the losses of the various components in the high-power millimeter-wave transmission system, such as waveguides and reflectors, and their principles have been published (Non-Patent Documents 1, 2, 3, and 4).
JP 2006-132960 A Manfred Thumm, Walter Kasparek; Recent advanced technology in electron cyclotron heating systems.Fusion Engineering and Design 26 (1995) 291-317 JPCrenn; Optical propagation of the HE11 mode and Gaussian beams in hollow circular waveguides.International Journal of Infrared and Millimeter Waves, vol.14, No.10, 1993 JLDoane, CPMoeller; HE11 mitre bends and gaps in a circular corrugated waveguide.INT.J.ELECTRONICS, 1994, vol.77, No.4, 489-509 IA Gorelov et al; Calorimetric Power Measurements of the DIII-D Gyrotron System, Bull. Am Phys. Soc. 46, p.302 (2001)

The problem of the background technology (1) is
1) Since the amount of power changes due to changes in the polarization of high-frequency waves and unnecessary modes, it is difficult to accurately capture abnormal phenomena.

  2) Use a detector to detect the minute high frequency leaking from the hole. Therefore, it depends on the performance inherent to the detector. 100 GHz band detectors are easily affected by aging and environmental conditions, and are subject to level fluctuations.

The problem of the background technology (2) is
1) A light quantity detection method that detects light with a light-receiving diode and outputs a signal at a certain light quantity level is common, but if the sensitivity is increased, malfunctions occur due to changes in the light quantity in the background environment. difficult.

  2) Abnormal light emission generated in a part of the transmission line reacts with multiple sensors installed at several locations, making it difficult to identify abnormal locations.

  3) Transmits the light emitted by the optical fiber, receives it with the control light receiver, converts the light amount into an electrical signal, generates a device interlock signal, installs the light source necessary for sensitivity adjustment, and adjusts the sensitivity to the controller Since a mechanism is required, the production cost of the equipment constituting the system becomes expensive.

  4) In normal light sources other than abnormal light emission, such as a fusion experimental device, it may be detected by light such as plasma, and it may be difficult to distinguish between abnormal light emission and normal light emission.

The problems of the background art (3) are as follows: 1) The reaction is slow, and an abnormal phenomenon may progress when detected.

  2) When high-frequency waves are transmitted to the transmission path, there is a case where gas is released from the reflector or the inner wall of the waveguide that is directly in contact with the high-frequency beam. Many.

  3) Emissions from the transmission system increase due to problems with the vacuum exhaust system, installation of high-frequency equipment that emits large amounts of gas, and long-term release to the atmosphere. The degree of vacuum increases from the steady state, and further increases due to high-frequency transmission. In many cases, it is difficult to accurately capture abnormal phenomena.

  In the present invention, if the high frequency output from the oscillation tube is normal, it is installed at a certain ratio (resistance loss in the waveguide as a transmission line or transmission line) from the oscillation tube side to the plasma side. This is a device for diagnosing an abnormality by capturing the phenomenon that these ratios change when an abnormality occurs. In addition, an accelerometer is installed at an appropriate position in the transmission system to select and diagnose the maximum and fastest received waves of several abnormal vibration waves generated by discharge, etc. This device has the effect of improving the identification accuracy.

  That is, the present invention is a high-frequency beam reflector, a temperature sensor (thermocouple), an acceleration sensor (piezoelectric element), an electric heater that facilitates heat conversion provided on the reflector, and signal selection control. This is a high-power millimeter-wave transmission system abnormality diagnosis device that consists of a detector, a measurement calculation display, and an abnormal output control display, and is used to heat the high-frequency beam reflector installed in the transmission system as one of high-frequency devices. Measure the converted high-frequency power with a temperature sensor, find the high-frequency power from a predetermined relationship with the measured temperature, compare the power loss during normal transmission and power loss during abnormal transmission, and perform abnormality diagnosis Judgment and / or location of abnormal equipment, plus fastest received wave and maximum received wave from abnormal vibration wave signal measured from acceleration sensor installed as one of high frequency equipment in transmission system By selecting and performing an abnormality diagnosis to determine the location and / or location of the abnormal device, and comparing it with the abnormal transmission power loss location by the temperature sensor, the abnormality installed in the transmission system based on the abnormality that matches both diagnosis It is a device that identifies and / or identifies the location of equipment. In addition, transmission loss of the transmission line can be determined on a regular basis, monitoring abnormal changes in the power output from the oscillation tube and abnormalities in the transmission system, and high-power millimeter-wave transmission equipped with an interlock signal output for device protection System abnormality diagnosis device.

  The fastest received wave or the maximum received wave is a signal from an acceleration sensor (14 here, see FIGS. 2 and 3) attached to an arbitrary place in the transmission system. The signal detected at the earliest time is the fastest received wave. (T min), the largest signal is the maximum received wave (E max).

  The abnormality diagnosis device for a high-power millimeter-wave transmission system in the high-frequency heating device according to the present invention is one of the high-frequency components constituting the transmission system, and temperature information by high-frequency loss obtained from a high-frequency beam reflector of a bend or matching device. The abnormal vibration wave obtained from the acceleration sensor (piezoelectric element) has the feature that the transmission efficiency of the transmission system and the identification of the abnormal place can be identified. The characteristic effects are shown below.

  (1) An abnormal vibration wave signal exceeding the threshold value outputs an interlock signal for device protection, and the oscillation of the oscillation tube is stopped.

  (2) By comparing the high-frequency power loss during normal transmission and high-frequency power loss during abnormal transmission, in addition, selecting the fastest received wave and the maximum received wave of the abnormal vibration wave signal, matching the high-frequency power loss due to abnormal transmission It is possible to determine an abnormal part in the transmission system.

  (3) The transmission efficiency of high-frequency transmission systems with different polarizations and modes can be steadily determined.

  (4) By using the reflector attached to the bend, which is indispensable for millimeter wave transmission systems, it is possible to use various bends, and it is necessary to add equipment for measurement and change the prescribed transmission system equipment configuration. There is no.

  (5) Diagnosis of abnormalities can be made especially in restricted areas or narrow places where humans cannot approach.

  (6) It is effective in transmission lines with long transmission distances that are complex and composed of many high-frequency devices.

  (7) High-frequency high-frequency loss measurement is possible by making the high-frequency beam reflector a heat-insulating structure and unifying the shape and material.

  (8) By attaching a sheet-like electric heater excellent in heat transfer to the high-frequency beam reflector and calibrating the conversion coefficient, it is possible to calculate the high-frequency loss of each bend portion having a different specific heat capacity.

  The conversion coefficient calibration has the following meaning. This abnormality diagnosis device uses a reflector at the bend and a matching unit reflector, which is one of the high-frequency components, to measure the heat generated by the high-frequency beam and diagnose the abnormality. Therefore, there is a conversion coefficient for calculating the high-frequency loss from the generated heat. is important. Since this reflector is connected to a waveguide or other fixed fixture, and the heat capacities of the reflectors installed in various parts of the transmission system are different, calibration of all the reflectors is required. Therefore, in the apparatus of the present invention, by attaching a sheet-like electric heater with clear transmission power to each reflector, the power supplied to the reflector can be determined from the energized voltage and current, and the rising temperature of the reflector at this time is determined. By measuring, the relationship between the supplied power and the rising temperature is known, and the high frequency loss is calculated from the temperature rise when the high frequency passes through the reflector by using the calibration value of the conversion coefficient. The operation necessary for the calculation of the high frequency loss is the conversion coefficient calibration.

  If a reflector having a certain structure, shape, and material can be used with a bend or the like, the temperature difference in each bend is proportional to the high-frequency loss by using a heat insulating structure. By unifying the reflectors in this way, there is an advantage that the high-frequency loss measurement accuracy is improved. However, if the time is long for MW-class high-power transmission, the heat-insulating structure may increase the heat generation of the reflector, necessitating a heat removal structure, and the bend and waveguide including the reflector, the fixed holding The loss of each part is calculated by calibrating the specific heat at each location.

A typical millimeter-wave high-frequency heating device in a fusion experimental device is about 50-100m from the oscillator to the vacuum vessel that generates plasma, the transmission power is about 1MW, about 1-30 seconds, and the number of components in the transmission system is one system. It is composed of about 20 pieces. The diameter of the waveguide is evacuated at about 3~6cm (10 ^-3 P _a or less), it has been treated to reduce the abnormal discharge or the like in the transmission path. The high-frequency loss of the high-power millimeter-wave transmission system in the high-frequency heating device is designed to be about 10-20% or less at about 50 m, and the high-frequency loss is about 1% when the waveguide diameter is about 3 cm bend. Arise.

  Here, the best mode required for this abnormality diagnosis apparatus is to arrange a high-frequency beam reflector for detecting high-frequency loss and an acceleration sensor for detecting abnormal vibration waves in a well-balanced manner in a long transmission system. In order to maintain the specified performance even in the arrangement of the above, the highest received wave order 1 to 3 and the fastest received wave order 1 to 3 are selected from the abnormal vibration wave of each part, and the high frequency power lost by the reflector of each part is selected. It is an abnormality diagnosis device that can identify an abnormal part by calculating and comparing with a loss in a normal state.

  An embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG. FIG. 1 shows an embodiment in which an abnormality diagnosis device is mounted on a typical transmission system of a high-power millimeter-wave high-frequency heating device. The main components are the high-frequency beam reflectors 1 to 6 shown in FIG. 1, thermocouples 9a to 9f that measure high-frequency loss in each reflector, piezoelectric elements 10a to 10q that detect abnormal vibration waves, and FIG. Signal selection controller 25 that amplifies and corrects abnormal vibration wave to select fastest received wave and maximum received wave, abnormal output control indicator 26 that displays interlock signal output and abnormal position judgment, and temperature change of reflector Is converted to a high-frequency loss amount, and a measurement calculation control display unit 27 for comparing and displaying a loss change at normal time and abnormal time is constituted. Many high-power millimeter-wave transmission systems use a number of reflectors for changing the direction of the high-frequency beam. In this example, an abnormality diagnosis device using six reflectors for transmission system equipment was shown. .

  Many high-frequency devices are arranged in the high-frequency transmission path, and the high-power millimeter wave output from the oscillation tube 11 shapes the high-frequency distribution through the vacuum window 12 of the oscillation tube and guides the transmission system. Matching device 14 (consisting of two planar reflectors and two concave reflectors) that matches the high-frequency electric field distribution corresponding to the wave tube, and vacuum waveguides 13a to 13g (inner walls were processed into corrugated shapes to reduce loss) Things are generally transmitted). The bends 15a to 15d include a bend with only a reflector, a bend with a directional coupler that measures traveling waves and reflected waves, and a bend that includes an optical fiber that detects arc discharge light in a vacuum window. A polarization converter for adjusting the ellipticity is connected.

  In addition, the transmission system is a special evacuation waveguide 16 for evacuating the inside of the waveguide to a high vacuum, a waveguide switch 17 that can move the reflection plate in a horizontal / vertical direction, Calorimeter-type power meter 18 that measures the transmitted high-frequency power, torus vacuum window 19 that shuts off tritium etc. from the fusion device in a vacuum, vacuum cuts off the high-frequency transmission line with the fusion vacuum vessel, In addition, it is composed of high-frequency equipment such as the high-frequency vacuum gate valve 20 that has a structure that reduces high-frequency transmission loss as much as possible in the open state, and each has special functions, so power durability performance deteriorates due to abnormalities such as thermal deformation and increased vacuum. In many cases, abnormalities that induce discharge are generated.

The detection of the abnormality is performed by analyzing the high frequency loss of the reflector installed in the transmission system and the abnormal vibration wave from the piezoelectric element arranged at the specified position of the transmission system. 2 and 3, the positional relationship between the object to be measured and the acceleration sensor for detecting abnormality (piezoelectric elements 1 to 14 for detecting minute abnormal vibrations such as discharge) is as follows. They are placed at equal intervals (1 in Fig. 2) in the waveguide. In order to reduce the transmission vibration error due to the material or mass of the measurement point, the outer surface of the waveguide having the same structure is suitable for the location of the acceleration sensor from the measured object. The abnormal vibration waves 1 to 14 shown in FIG. 3 are passed through the isolation amplifier, delay corrector, and level corrector, and the signal selection controller 25 gives the highest signal level rankings 1 to 3 (E _max : 1 to 3), the highest. Signal ranks 1 to 3 (t _min : 1 to 3) received fast are selected. FIG. 2 shows the abnormality diagnosis detector, its arrangement example, and the transmission efficiency (P a _-f ) with respect to the oscillation tube output power (P ₀ ) at the arrangement location.

  Further, a protective interlock signal based on an abnormal vibration wave from the piezoelectric elements 1 to 4 is output through an OR circuit and a threshold setting circuit. The vibration wave of each part (position of the piezoelectric elements 1 to 14) gives a reference signal in a steady state without any abnormality, is adjusted by an insulation amplifier, a delay corrector, and a level corrector, and the input signal to the signal selection controller 25 is Unify.

  Further, assuming several different types of bends with high-frequency reflectors as objects to be measured, heat generation due to high-frequency loss is detected by thermocouples a to f, respectively. If possible, only the reflector is thermally insulated, and if a reflector with the same shape and the same material can be used, calibration can be performed easily and high-frequency loss can be measured with high accuracy. However, in reality, a device that uses a reflector incorporated in a bend suitable for each application is generally used, and this abnormality diagnosis device is a device having an abnormality diagnosis function that allows an existing device to be used without modification. did. Measure the high frequency power converted into heat with a high frequency beam reflector, with a thermometer, find the high frequency power from a predetermined relationship with the measured temperature, compare the loss during normal transmission and the loss during abnormal transmission, In addition, the fastest received wave and the maximum received wave of the abnormal vibration wave signal are selected and matched with the abnormal transmission loss location, thereby diagnosing abnormalities in the transmission system and selecting the abnormal equipment and specifying the location. In order to calculate the high-frequency loss in the reflector, calibration is performed using a sheet-like electric heater with clear transmission power.

The heat capacity C _i for each time change of each reflector, the temperature change dT _i / dt of the reflector per unit time, and the heat transfer coefficient α _i are evaluated by the following equations. (I: Reflector a, b, c ... f of each part)

Based on the calibration result in an electric heater, to evaluate the high-frequency loss P _i at each reflector unit in data computing unit. In addition, when the reflector is thermally insulated, the term α _i (T _i −T _{∞ i} ) is deleted, and evaluation can be performed by simple calibration.

より異常が発生した位置を判定し、異常振動波選別結果と合致した場所の表示を行う。 The transmission efficiency at the measurement objects 1 to 6 can be obtained by the ratio P _i / P ₀ of the oscillation power P ₀ and the loss power at the points a to f. When an abnormality such as discharge occurs in any part of the transmission system, high frequency loss increases at the abnormal part, and the transmission path after the abnormal part has a state in which the transmission power decreases from the steady state. Can do. The criterion is that when the oscillation power is stable and constant, the loss ratio P _i / P _i0 at each reflector (af) in the normal state (P _i0 ) and abnormal state (P _i ), Loss ratio corrected by oscillation power (P ₀₀ , P ₀ ) when the oscillation power in abnormal state is different

The position where the abnormality has occurred is further determined, and the location that matches the abnormal vibration wave selection result is displayed.

  The abnormality diagnosis device for millimeter-wave transmission systems in this high-frequency heating device detects abnormal vibration waves by attaching a piezoelectric element to the transmission system equipment with high probability of abnormality and the waveguides before and after that, and abnormal vibration waves at each part To select the maximum received wave and the fastest received wave. In addition, the high frequency power lost by the high frequency mirror of the transmission system is measured, and the abnormal part is identified by comparing the loss in the normal state and the loss in the abnormal state. Furthermore, this device is a device that can constantly determine the transmission efficiency of a transmission line, monitors abnormal oscillations in a high power millimeter wave and abnormalities in the transmission system, and is equipped with an output of an interlock signal for device protection.

  The abnormality diagnosis device for a high power millimeter wave transmission system of the present invention is composed of a fusion device, a large accelerator device, an industry using a high power millimeter wave, a transmission system in which a waveguide and a high-frequency beam reflector are installed. It can be used in high-frequency transmission equipment.

These are the transmission system and abnormality diagnosis apparatus of the high-power millimeter-wave high-frequency heating apparatus of one embodiment of the present invention. These are the abnormality diagnosis detectors of one embodiment of the present invention and their arrangement examples. FIG. 2 is a schematic diagram of an abnormality diagnosis function of the abnormality diagnosis apparatus according to an embodiment of the present invention.

Explanation of symbols

1 ... High-frequency beam reflector 1
2 ... High-frequency beam reflector 2
3 ... High-frequency beam reflector 3
4 ... High-frequency beam reflector 4
5 ... High-frequency beam reflector 5
6 ... High-frequency beam reflector 6
7 ... High-frequency beam reflector 7
8 ... High-frequency beam reflector 8
9a ~ 9f ... Thermocouple
10a ~ 10q ・ ・ ・ Piezoelectric element
11 ... Oscillator tube
12 ... Oscillator tube vacuum window
13a ~ 13g ・ ・ ・ Waveguide
14 ... matching unit
15a-15d ... 90 ° bend
16 ... Vacuum waveguide for evacuation
17 ... Waveguide switch
18 ... Power meter
19 ... Torus vacuum window
20 ... High frequency vacuum gate valve
21 ... Vacuum container for plasma generation
22 ... Plasma
23 ・ ・ ・ High frequency beam
24 ... Vacuum exhaust system
25 ... Signal selection controller
26: Abnormal output control indicator
27 ・ ・ ・ Measurement calculation control display

Claims (2)

  A plurality of reflecting mirrors that reflect the high-power millimeter-wave power along the transmission path of the high-power millimeter-wave power, and a thermocouple that is provided in the plurality of reflecting mirrors and measures high-frequency loss heat generated by each as a temperature change When the output of the thermocouple is normal, the heat generated by the reflector installed decreases with the transmission distance (position). However, when the abnormality occurs, the heat generation increases near the location where the abnormality occurred, and further, the heat generation decreases significantly beyond the location where the abnormality occurred. And a measurement calculation control indicator for detecting a local abnormality of the transmission line by a heat generation abnormality of the reflecting mirror and determining a generation area thereof. Transmission system abnormality diagnosis device.   A signal selection controller for identifying a piezoelectric element installed at a plurality of locations in the transmission path of the high power millimeter wave power, a piezoelectric element that detects the signal first and a piezoelectric element that detects the signal having the largest amplitude; An abnormality occurrence region of the transmission path is specified based on a detection result of a measurement calculation control indicator and the signal selection controller, and based on an abnormal vibration wave from the piezoelectric element, a transmission path from a discharge occurrence due to dielectric breakdown The abnormality diagnosis apparatus for a high-power millimeter-wave transmission system according to claim 1, further comprising: an abnormality output control indicator that generates a protection interlock signal for protecting the power.

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