JPH04101648A - Anomaly detecting method for electric machine - Google Patents

Abstract

PURPOSE:To detect any anomaly in an early stage due to overheat or partial discharge of an electric rotary machine such as turbine generator, by installing an odor sensor being capable of detecting an odor of ambient gases within a sealed electric machine and of sending an output having a frequency signal corresponding to the odor and also by generating an alarm when said output signal exceeds a predetermined standard value. CONSTITUTION:A hydrogen gas-cooled turbine generator 1 comprises an outer frame 2, a rotor 3, stator core 4, an armature winding 5 and others; and its inside 6 is filled with oxygen gas tightly sealed. An odor sensor 7 is mounted inside the generator; and the frequency of a crystal oscillator built in the sensor is measured by a frequency counter 8 located outside of the generator. If this measured value becomes lower than a preset standard value, then a discriminating circuit 9 operates and an alarm 10 such as buzzer is activated in this electric circuit. This method is able to detect an odor and an abnormal state, so that it is able to detect not only an overheat but also slot discharge or discharge at the end of windings, thereby comprehensively detecting all kinds of abnormal states where abnormal odor substances are generated by discharge.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for detecting abnormalities in windings and cores of electrical equipment such as sealed rotating electric machines, particularly turbine generators. It is something.

(Prior Art) If an electrical device, such as a large turbine generator, which performs an important function in industry and social life should break down, it would cause a great deal of damage.

In particular, failures such as ground faults, short circuits, and melting of the windings or core due to dielectric breakdown of the windings must be avoided at all costs, as they require a long time to repair. Many of these failures can be prevented if the abnormality is detected early before it becomes a major accident.

For this reason, it has been common practice to attach temperature detectors to important parts of the windings and iron cores to monitor the presence or absence of overheating.

The presence or absence of slot discharge is monitored using a partial discharge meter.

In particular, in the case of turbine generators, the following abnormality detection method is known.

U.S. Pat. No. 3,427,880 discloses that thermal decomposition products consisting of submicron particles in a cooling gas are ionized by alpha rays, and the ultrafine particles are charged, resulting in a decrease in electric current on the downstream side. A method is described for detecting overheating of a rotating electrical machine from this current reduction rate.

In Japanese Patent Publication No. 54-10081, U.S. Patent No. 342
After detecting an abnormality using the method according to No. 7880, a method is described in which a region of local overheating is determined by mass spectrometry or gas chromatography analysis.

Furthermore, Japanese Patent Publication No. 56-17610 describes a method of detecting overheating of a rotating electric machine by charging a cooling gas by corona discharge and detecting an ionic current.

In addition, Japanese Patent Publication No. 60-31179 discloses that by measuring the free oxygen concentration in the cooling gas in a hydrogen gas-cooled turbine generator and detecting a decrease from the free oxygen concentration in the normal state, It describes how to detect failures.

(Problems to be Solved by the Invention) The conventional methods described above have the following drawbacks.

The method of attaching a temperature sensor has a limit on the part where the detector can be attached, and it is not possible to detect abnormalities in the part where the detector is not attached.

U.S. Patent No. 3427880, Japanese Patent Publication No. 10081/1986
No., Special Publication No. 56-17610, Special Publication No. 60-3117
In the method disclosed in Publication No. 9, the detection device is generally large and expensive, and requires specialized knowledge for operation and judgment.

It cannot be attached to any electrical equipment. Furthermore, although these methods can detect abnormalities due to overheating of the rotating electrical machine, it is difficult to detect other abnormalities such as slot discharge.

Therefore, in the present invention, it is possible to quickly detect abnormalities caused by overheating or partial discharge in electric equipment, especially rotating electric machines such as turbine generators, using small and inexpensive equipment without requiring specialized knowledge in operation or at low cost. The purpose is to provide a method of detection.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention installs an odor sensor that detects the odor of atmospheric gas in a sealed electrical device and outputs a frequency signal corresponding to the odor, An alarm is issued when this sensor output signal exceeds a predetermined reference value.

Further, a conduit is installed that communicates from the inside of the electrical equipment to the outside of the equipment, and the odor of the atmospheric gas inside the electrical equipment guided by this conduit is measured by the odor sensor.

A similar effect can be obtained by issuing an alarm when this output exceeds the reference value.

(Operation) The abnormality detection method of the present invention is configured as described above,
Insulation in the windings or core may be damaged due to overheating due to wire-to-wire short circuits in the windings, inter-winding shorts, ground faults, or short circuits between the laminates of the core, or due to slot discharge or partial discharge on the surface of the windings. When an object decomposes and gas is released into the atmosphere, an odor sensor detects the odor emitted by the decomposed gas, and if the odor exceeds a preset reference value, a discrimination circuit issues an alarm.

(Example) An embodiment of the present invention will be described with reference to the drawings.

As shown in Fig. 1, an outer frame 2, a rotor 3, a stator core 4,
, an odor sensor 7 (SF-101 (manufactured by Mutsuyakudama)) is installed in the hydrogen gas-sealed atmosphere 6 of the hydrogen gas-cooled turbine generator 1, which is composed of an armature winding 5, etc.
The frequency of the crystal oscillator built into the sensor is measured by a frequency counter 8 located outside the machine. The electric circuit was configured so that when this measured value became lower than a preset reference value, the discrimination circuit 9 was activated and an alarm device IO such as a buzzer sounded.

However, the odor sensor may be installed within the conduit leading to the generator main body.

Sensor 5 attached to hydrogen gas cooled turbine generator
F-101 (manufactured by Sogo Yakuko) is a product in which a synthetic lipid bilayer membrane is formed on the electrode of a crystal oscillator (9 MHz) as a model material for nasal olfactory cells.

This membrane is a bilayer membrane consisting of an ion complex of dialkyl ammonium salts (2G, N''2C) and polystyrene sulfonic acid, and has a bilayer membrane lamellar structure parallel to the electrode surface.

Acids such as formaldehyde, acetaldehyde, benzyl acetate, phenethyl acetate, citral, anethole, p-anisaldehyde, and undecanol, alcohols, aromatic components, and odor substances such as ozone contained in gases generated by thermal decomposition and electric discharge enter this lipid membrane. When adsorbed, the weight of the membrane increases and the frequency of the crystal oscillator decreases, and the odorant can be quantified from this frequency change.

The detection limit of this sensor is approximately 1 ng (corresponding to frequency changes of IHz in air), and measurement is possible in both gas phase and liquid phase (aqueous solution). Both reproducibility and response time (90% response time is about 30 seconds) are good.

FIG. 2 shows an example of odor measurement by an odor sensor using this lipid bilayer membrane-coated crystal oscillator when an insulator used in a turbine generator is heated. It can be seen that one frequency decreases as the temperature increases.

Conventional methods could only detect abnormalities due to overheating, but this method detects abnormalities by detecting odors, so it is not only possible to detect overheating, but also to generate odorous substances such as abnormalities caused by discharge such as slot discharge and discharge at the end of the winding. It is possible to comprehensively detect all kinds of abnormalities that occur.

Odor sensors are small and do not require much space for installation, so they can be installed anywhere in the aircraft, and the scent sensors and frequency counters are cheaper than conventional abnormality detection devices. There are advantages.

As another example, in this example, an odor sensor using a crystal resonator coated with a lipid bilayer membrane was used, but an odor sensor based on another principle may be used. For example, a semiconductor gas sensor using tin dioxide can be used. however,
In this case, since the amount of chemical reaction between the odorant and the semiconductor surface is detected, the output of the sensor increases as the amount of the odorant increases.

〔Effect of the invention〕

The method for detecting an abnormality in electrical equipment using the odor sensor of the present invention can comprehensively detect not only overheating but also abnormalities that generate odorants due to discharge or the like.

Furthermore, the device is small and can be easily handled without any restrictions on the mounting position. Furthermore, the cost of the equipment is significantly lower than that of conventional methods.

Therefore, it is possible to attach various electrical devices to which it was impossible to attach using conventional methods.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of a rotating electric machine for explaining an embodiment of the abnormality detection method according to the present invention, and FIG. 2 shows lipid bimolecules when an insulator used in a turbine generator is heated. FIG. 3 is a diagram showing an example of odor measurement using an odor sensor using a membrane-coated crystal oscillator. 1... Turbine generator 2... Outer frame 3... Rotor 4... Stator core 5... Armature winding 6... Atmosphere 7... Odor sensor
8...Frequency counter 9...Discrimination circuit
10... Alarm device Figure 1

Claims (3)

[Claims] (1) An odor sensor that detects the odor of atmospheric gases and outputs a frequency signal corresponding to the odor is installed in a sealed electrical device, and an alarm is issued when this sensor output signal exceeds a predetermined reference value. A method for detecting an abnormality in an electrical device, characterized by emitting a signal. (2) A conduit is provided that communicates from the inside of the sealed electrical equipment to the outside of the machine, and the odor of the atmospheric gas of the electrical equipment guided through this conduit is measured by an odor sensor that outputs a frequency signal corresponding to the odor. A method for detecting an abnormality in electrical equipment, characterized in that an alarm is issued when a sensor output signal exceeds a predetermined reference value. (3) The method for detecting an abnormality in an electrical device according to claim 1 or 2, wherein the odor sensor is a lipid bilayer membrane-coated crystal oscillator or a semiconductor gas sensor.