JPH06109685A - Method and device for monitoring blend ratio of impregnated resin - Google Patents

Abstract

PURPOSE:To obtain a method and device for monitoring blend ratio of impregnated resin which can measure the blend ratio easily, does not require any technical knowledge, can reduce the measurement time, and can achieve continuous monitoring. CONSTITUTION:In a method for monitoring the change in blend ratio during repeated use of an impregnated resin where a liquid resin and a curing agent are blended in a specific ratio, a constant temperature liquid bath 1 at a specific temperature, a dielectric characteristic measurement electrode 3, and a dielectric characteristic measuring device 5 are used to measure dielectric characteristics of a sample impregnated resin 9 which is sampled at a measurement container 2, the obtained characteristic value is collated with the dielectric characteristic versus blend ratio characteristic data obtained at a specific temperature for the impregnated resin with a previously known blend ratio, thus obtaining the blend ratio of the sample impregnated resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin impregnating apparatus, and more particularly to a method and apparatus for monitoring changes in the compounding ratio of impregnating resin contained in a resin impregnating apparatus of a high voltage rotating electric machine.

[0002]

2. Description of the Prior Art Thermosetting impregnating resins such as epoxy impregnating resins and polyester impregnating resins are solvent-free, and by impregnating a fibrous base material in a vacuum and heat-curing it, mechanical and thermal , It is widely used in various fields because it provides a reinforced plastic material having excellent electrical and chemical properties. In an electric device, especially in a high-voltage rotating electric machine, an assembled mycatep is wound to a predetermined thickness on the surface of an armature coil conductor, and this tape layer is impregnated with an epoxy-based impregnating resin at a predetermined temperature under vacuum pressure, After that, the insulating layer obtained by heating the whole to a predetermined temperature and heat-curing the impregnated resin does not contain defects such as voids in the insulating layer, and therefore, it is difficult for void discharge deterioration to occur, and long-term withstand voltage life characteristics It is widely used because it provides an excellent armature coil.

Further, as a resin impregnating method for a rotary electric machine,
There are two methods, one is to store a single coil in the vacuum impregnation tank and impregnate with resin, and the other is to wind the unimpregnated coil around the iron core and then store the whole in the vacuum impregnation tank to impregnate resin. Since a large amount of impregnating resin is used at one time in an electric machine, it is necessary to repeatedly use the impregnating resin compounded in a predetermined weight ratio while adding a shortage. Therefore, there is a problem that the compounding ratio of the impregnating resin gradually changes during repeated use, which adversely affects the curing characteristics of the impregnating resin and the properties after curing. We need to understand the changes.

For example, a chemical method has been conventionally used as a method for monitoring the change with time of the compounding ratio in an impregnated resin obtained by mixing a mixed buffer A type epoxy resin and an acid anhydride type curing agent in a predetermined weight ratio. A method of measuring a certain acid value and a method of measuring a saponification value are known. Among them, the acid value is measured by adding a predetermined amount of water to the sample impregnated resin collected in a predetermined amount and boiling it, and then measuring the acid value of the curing agent dissolved in water by titration with sodium hydroxide, and preparing in advance. The curing agent concentration in the aqueous solution is compared with the acid value characteristic data obtained above to obtain the curing agent concentration in the aqueous solution, and the compounding ratio of the curing agent and the epoxy resin is calculated based on this value. Be seen. The same applies to the measurement of saponification value.

[0005]

In the conventional method of measuring the chemical compounding ratio, it takes 4 to 5 hours until the compounding ratio of the test impregnated resin is determined by a series of procedures. Therefore, the blending ratio of the impregnating resin to be supplied is calculated based on the obtained blending ratio, and the blended resin is mixed with the impregnating resin in the impregnating device,
When an attempt is made to restore the mixing ratio of the impregnated resin in the impregnating device having the changed mixing ratio to a predetermined mixing ratio, it takes time to measure the mixing ratio, resulting in a problem that work efficiency becomes extremely poor. In addition, when performing the titration operation manually, there is a problem that expert knowledge is required for the titration operation.

An object of the present invention is to provide a method for monitoring the compounding ratio of an impregnating resin and an apparatus therefor, which has a simple method for measuring the compounding ratio, does not require specialized knowledge, and has a short measuring time and can be continuously monitored.

[0007]

In order to solve the above-mentioned problems, according to the present invention, the change of the compounding ratio during repeated use of the impregnated resin in which a liquid resin and a curing agent are compounded in a predetermined weight ratio is used. A method of monitoring, in which the dielectric properties of the test impregnated resin are measured at a predetermined temperature, and the obtained characteristic values are obtained at the predetermined temperature for the impregnated resin having a known mixing ratio in advance. The mixing ratio of the test impregnated resin is determined by collating with the data.

Further, the impregnated resin is a mixed buffer A
The system epoxy resin and the acid anhydride curing agent are mixed at a predetermined mixing ratio. Furthermore, it is assumed that the predetermined temperature is a constant temperature including the impregnation treatment temperature of the impregnating resin. Furthermore, it is assumed that the dielectric characteristic is any one of the dielectric loss tangent, the relative dielectric constant, and the inter-electrode capacitance.

On the other hand, the resin impregnating device is provided with an electrode for measuring a dielectric characteristic, which is disposed in an impregnating resin of a predetermined temperature which is contained in the resin impregnating device, and the characteristic value obtained by this electrode is used in advance for the impregnating resin having a known mixing ratio. Is compared with the dielectric characteristic-compounding ratio characteristic data obtained at the above-mentioned predetermined temperature, and the time-dependent change of the compounding ratio of the impregnated resin in the resin impregnating apparatus is monitored.

[0010]

In the constitution of the present invention, the dielectric characteristics of the test impregnated resin are measured at a predetermined temperature, and the obtained characteristic values are obtained at the predetermined temperature for the impregnated resin having a known mixing ratio in advance. Dielectric property measuring electrode with a constant electrode constant (constant capacitance in air) by configuring the compounding ratio monitoring method so as to obtain the compounding ratio of the impregnated resin under test by comparing with the characteristic data By using a measuring device such as a digital LCR meter which is easy to measure, and utilizing the dependency of the compounding ratio on the dielectric characteristics, the compounding ratio of the impregnating resin or its change with time can be performed easily without requiring specialized knowledge. The function that can be found in a short time can be obtained.

Further, the impregnating resin is a mixed buffer A
When a system epoxy resin and an acid anhydride-based curing agent are mixed at a prescribed blending ratio, a clear correlation is observed between the blending ratio and the dielectric properties, and this is used to measure the blending ratio. A function of accurately monitoring the compounding ratio can be obtained. Further, if the predetermined temperature is set to a constant temperature including the impregnation resin impregnation temperature, it is possible to monitor the compounding ratio of the impregnating resin contained in the impregnation device and kept at the impregnation temperature without taking a sample. You can get the function.

Furthermore, if the dielectric characteristic is any one of the dielectric loss tangent, the relative permittivity, or the capacitance between the electrodes, the measurement can be performed by one digital LCR meter in any case, and the expert knowledge is required. A function that facilitates measurement is obtained without the need. On the other hand, a dielectric property measuring electrode is provided in the impregnating resin contained inside the impregnating device and maintained at a predetermined temperature, and the property value obtained by this electrode is collated with the dielectric property-compounding ratio property data for impregnation. If it is formed so as to monitor changes over time in the compounding ratio of the resin, it will be possible to continuously monitor changes in the compounding ratio.
It is possible to obtain the function of facilitating the related work such as the work of adjusting the blending ratio by the supplementary resin.

[0013]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a schematic diagram of a measuring device for explaining a method for monitoring a compounding ratio of an impregnated resin according to an embodiment of the present invention. In the figure, the dielectric property measuring container 2 is provided with a dielectric property measuring electrode 3 having a constant electrode constant therein, and a sample impregnating resin 9 is housed in the measuring container 2 at a predetermined temperature (eg, impregnation temperature). It is stored in the constant temperature liquid tank 1 kept at. When the impregnated resin 9 under test stabilizes at a predetermined temperature, a dielectric characteristic, for example, a dielectric loss tangent (tan δ) is calculated by using a digital LCR meter 5 as a dielectric characteristic measuring device, or the capacitance is measured. To obtain the relative permittivity (ε).

FIG. 2 is a characteristic diagram of a dielectric property versus a compounding ratio obtained for an epoxy-based impregnated resin having a known compounding ratio, and the curve is a Buphenol A-based epoxy resin (manufactured by Dow Chemical Co., model number DER332). It was obtained by measuring the dielectric loss tangent at 70 ° C in consideration of the impregnation temperature, using the impregnating resin in which the compounding ratio (wt%) of the acid anhydride curing agent (Hitachi Chemical Co., Ltd., model number HN2200) was variously changed. The curve 10 shows a downward sloping characteristic in proportion to the compounding ratio of the curing agent. Although the dielectric constant-mixing ratio characteristic curve is not shown, it has been confirmed that the characteristic shows a downward sloping characteristic like the curve 10.

The change in the compounding ratio of the impregnated resin having the above compounding ratio during repeated use was measured by measuring the dielectric properties of the sample impregnated resin sampled from the resin impregnating apparatus described later, and the measured value was shown as curve 10 in FIG. By comparing, the compounding ratio of the epoxy resin (monomer) and the compounding ratio of the curing agent can be determined by the curve 10
Can be read immediately from. In this example, it was found that the time required for a series of operations from the collection of the test impregnated resin from the impregnation device to the determination of the compounding ratio can be shortened to about 1/10 of that in the conventional chemical method. .

FIG. 3 is a schematic diagram showing a monitoring device in which the compounding ratio monitoring method according to the embodiment of the present invention is applied to a resin impregnation device. In the figure, the resin impregnation device is a vacuum pressure impregnation tank 11
And an impregnating resin heat-retaining tank 12 for holding the impregnating resin 19 at its impregnating temperature (for example, about 70 ° C. in the case of an epoxy resin resin), and both tanks are connected by a pipe having a recovery pump 14 and a pressure pump 15. In addition, the inside of the impregnation tank 11 kept at the impregnation temperature can be evacuated by the vacuum pump 13. The mixing ratio monitoring device is, for example, a dielectric characteristic measuring electrode 3 arranged in a state of being immersed in the impregnating resin insulation tank 12 in the impregnating resin keeping tank 12, and a digital LCR meter as a dielectric characteristic measuring device connected thereto. 5 and
It is composed of an arithmetic unit 6 for converting the obtained dielectric characteristic measured value into a mixture ratio using, for example, the curve 10 as a judgment curve, and further a recording unit 7 for the arithmetic result.

In the resin impregnation apparatus equipped with the blending ratio monitoring apparatus configured as described above, for example, the impregnated rotary electric machine 20 is housed in the vacuum pressure impregnation tank 11 and evacuated to impregnate the impregnated resin under vacuum pressure. If the dielectric characteristics of the impregnating resin 19 are continuously or periodically measured by a compounding ratio monitor in the process of repeating the operation, the change in the compounding ratio of the impregnating resin 19 with time can be easily monitored. By using it to determine and adjust the mixing ratio of the replenishing resin, the work of adjusting the mixing ratio of the impregnating resin 19 can be performed efficiently, and a large fluctuation in the curing characteristics of the impregnating resin is prevented, and stable rotation performance is achieved. The advantage is that an insulation system for an electric machine can be formed.

[0018]

As described above, according to the present invention, the dielectric characteristics of the impregnated resin are measured at a predetermined temperature, and the obtained characteristic values are calculated in advance at a predetermined temperature for the impregnated resin having a known mixing ratio. A method of monitoring the compounding ratio was constructed so as to obtain the compounding ratio by collating with the compounding ratio characteristic data. As a result, a dielectric characteristic measuring electrode with a constant electrode constant and a digital LCR
By using a dielectric property measuring device such as a meter that is easy to measure, and by utilizing the dielectric property dependence of the compounding ratio, the compounding ratio of the impregnated resin or its change with time can be easily performed without requiring special expertise. Therefore, it is possible to provide a method for monitoring the compounding ratio of the impregnated resin, which can reduce the time required for a series of operations, which has been a problem in the conventional chemical monitoring method, of 4 to 5 hours to about 1/10 of that time. . Further, when the blending ratio of the replenishing resin is determined or adjusted by utilizing the blending ratio obtained by this method, there is an advantage that the efficiency of the adjusting work can be significantly improved by shortening the measurement time.

On the other hand, a dielectric characteristic measuring electrode is provided inside the resin impregnating device which is encapsulated at a predetermined temperature in the impregnating resin, and the characteristic value obtained by this electrode is collated with the dielectric characteristic / mixing ratio characteristic data, If a composition ratio monitoring device is configured to monitor changes in the composition ratio of the impregnated resin over time, continuous changes in the composition ratio can be monitored, and the work of adjusting the composition ratio by the replenishment resin can be made more efficient and the composition ratio can be improved. It is possible to prevent a change in the curing characteristics of the impregnated resin caused by the change and to provide an advantage that, for example, a high-voltage insulation system having excellent withstand voltage life characteristics can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a measuring device for explaining a method for monitoring a compounding ratio of impregnated resin according to an embodiment of the present invention.

[Fig. 2] Dielectric characteristic vs. compounding ratio characteristic diagram obtained for epoxy-impregnated resin having a known compounding ratio.

FIG. 3 is a schematic diagram showing a monitoring device in which a compounding ratio monitoring method according to an embodiment of the present invention is applied to a resin impregnation device.

[Explanation of symbols]

 1 Constant Temperature Liquid Tank 2 Measuring Container 3 Dielectric Property Measuring Electrode 5 Digital LCR Meter 6 Computing Device 7 Recording Device 9 Test Impregnation Resin 10 Dielectric Loss Tangent-Compounding Ratio Characteristic Curve 11 Vacuum Pressurization Impregnation Tank 12 Impregnation Resin Insulation Tank 13 Vacuum Pump 14 Recovery pump 15 Pressurizing pump 20 Impregnated rotary electric machine

Claims (5)

[Claims] 1. A method for monitoring a change in a compounding ratio of an impregnated resin, in which a liquid resin and a curing agent are compounded in a predetermined weight ratio, during repeated use. In order to obtain the compounding ratio of the test impregnating resin, the obtained characteristic value is collated with the dielectric property-compounding ratio characteristic data obtained at the predetermined temperature for the impregnating resin having a known compounding ratio in advance. A characteristic method for monitoring the compounding ratio of impregnated resin. 2. The impregnating resin according to claim 1, wherein the impregnating resin is a mixture of mixed phenol A type epoxy resin and an acid anhydride type curing agent in a predetermined compounding ratio. Mixing ratio monitoring method. 3. The method for monitoring the blending ratio of an impregnating resin according to claim 1, wherein the predetermined temperature is a constant temperature including the impregnating treatment temperature of the impregnating resin. 4. The method for monitoring the compounding ratio of an impregnating resin according to claim 1, wherein the dielectric property is any one of dielectric loss tangent, relative permittivity, and electrostatic capacitance between electrodes. 5. A resin impregnating apparatus is provided with an electrode for measuring a dielectric characteristic, which is disposed in an impregnating resin of a predetermined temperature, which is contained in the resin impregnating apparatus, and the characteristic value obtained by this electrode is an impregnating resin having a known mixing ratio in advance. And the mixing ratio characteristic data obtained at the above-mentioned predetermined temperature, and is formed so as to monitor the change with time of the mixing ratio of the impregnating resin. .