阅读说明：本技术 对在高压仪表的绝缘介质中溶解的气体的分析 (Analysis of gases dissolved in the insulating medium of a high-voltage instrument ) 是由 M·克林克特 P·鲁夫 于 2019-09-04 设计创作，主要内容包括：本发明涉及一种用于分析在高压仪表(HG)的绝缘介质(IM)中溶解的气体(GG)的方法,所述方法包括借助于分析设备将所溶解的气体(GG)转化为气相。将生成的分析气体混合物(AG)运输到分析传感器(AS)并且根据所述分析气体混合物(AG)的成分产生传感器信号。基于干扰参量的传感器信号产生第一中间参量。基于所述第一中间参量和所述分析设备的特定参量来确定第二中间参量。基于所述第二中间参量确定用于所述绝缘介质(IM)中的所溶解的气体(GG)的浓度的值。(The invention relates to a method for analyzing a gas (GG) dissolved in an Insulating Medium (IM) of a high-voltage meter (HG), comprising converting the dissolved gas (GG) into a gas phase by means of an analysis device. The generated analysis gas mixture (AG) is transported to an Analysis Sensor (AS) and a sensor signal is generated AS a function of the composition of the analysis gas mixture (AG). A first intermediate variable is generated on the basis of the sensor signal of the disturbance variable. A second intermediate variable is determined on the basis of the first intermediate variable and a specific variable of the evaluation device. Determining a value for the concentration of the dissolved gas (GG) in the Insulating Medium (IM) on the basis of the second intermediate variable.)

1. Method for analyzing a gas (GG) dissolved in an Insulating Medium (IM) of a high voltage meter (HG), the method comprising:

-converting the dissolved gas (GG) into the gas phase by means of an analysis device in order to obtain an analysis gas mixture (AG);

-transporting the analysis gas mixture (AG) to an Analysis Sensor (AS) of the analysis apparatus;

-generating a sensor signal AS an output signal of the Analysis Sensor (AS) AS a function of a composition of the analysis gas mixture (AG);

-determining a first intermediate variable on the basis of the sensor signal and at least one disturbance variable;

-determining a second intermediate quantity on the basis of the first intermediate quantity and at least one specific quantity of the analysis device;

-determining a value for the concentration of the dissolved gas (GG) in the Insulating Medium (IM) based on the second intermediate quantity.

2. Method according to claim 1, wherein said at least one specific parameter of the analytical device influences the conversion of the dissolved gas (GG) into the gas phase or the performance of the Analytical Sensor (AS).

3. Method according to any one of claims 1 or 2, wherein the conversion of the dissolved gas (GG) into the gas phase is carried out by means of a semipermeable membrane (M) of the analytical device, and the at least one specific parameter of the analytical device comprises a property of the membrane (M), in particular the porosity of the membrane (M).

4. Method according to any one of claims 1 to 3, wherein said at least one specific parameter of said analytical device comprises a characteristic of said Analytical Sensor (AS), in particular a sensitivity, an action time or a response time of said Analytical Sensor (AS).

5. Method according to any one of claims 1 to 4, wherein the at least one disturbance variable influences the performance of the evaluation sensor (AS).

6. Method according to any one of claims 1 to 5, wherein said at least one disturbance variable comprises the temperature or pressure or humidity of the environment of said Analysis Sensor (AS).

7. Method according to any one of claims 1 to 6, wherein the determination of the value for the concentration is carried out additionally on the basis of at least one further disturbance variable.

8. The method according to claim 7, wherein the at least one further disturbance variable influences the conversion of the dissolved gas (GG) into the gas phase.

9. Method according to any one of claims 8 or 9, wherein the at least one further disturbance variable comprises the temperature, pressure or humidity or flow speed of the Insulating Medium (IM).

10. Method according to one of claims 1 to 9, wherein the determination of the second intermediate variable is additionally carried out on the basis of a specific variable of the Insulating Medium (IM).

11. Method according to claim 10, wherein the specific parameter of the Insulating Medium (IM) influences the conversion of the dissolved gas (GG) into the gas phase.

12. Method according to any one of claims 10 or 11, wherein the specific parameter of the Insulating Medium (IM) comprises the solubility of the dissolved gas (GG) in the Insulating Medium (IM).

13. Analytical device for analyzing a gas (GG) dissolved in an insulating medium of a high voltage meter (HG), the analytical device comprising:

-a separation unit arranged for converting the dissolved gas (GG) into the gas phase in order to obtain an analysis gas mixture (AG);

-an Analysis Sensor (AS) arranged to generate a sensor signal, an output signal, depending on a composition of the analysis gas mixture (AG);

-a pump device (P1, P2) arranged for transporting the analysis gas mixture (AG) from the separation unit to the Analysis Sensor (AS);

-an analysis processing unit (AE) arranged for:

-determining a first intermediate variable on the basis of the sensor signal and at least one disturbance variable;

-determining a second intermediate quantity on the basis of the first intermediate quantity and at least one specific quantity of the analysis device;

-determining a value for the concentration of the dissolved gas (GG) in the Insulating Medium (IM) based on the second intermediate quantity.

14. An analytical device according to claim 13, wherein the separation unit comprises a semipermeable membrane (M) through which the dissolved gas (GG) can pass from the high-pressure meter (HG) into the analytical device.

15. Analytical device according to one of claims 13 or 14, wherein the analytical processing unit (AE)

-comprising a processor unit and a measuring device for determining a temperature of the processor unit; and is

-is arranged for determining a temperature in the environment of the Analysis Sensor (AS) based on the temperature of the processor unit.

Technical Field

The invention relates to a method and an analysis device for analyzing a gas dissolved in an insulating medium of a high-voltage instrument.

Background

The determined concentration of dissolved gas in the high-voltage meter, e.g. an insulating medium, e.g. insulating oil, of a transformer or a tap changer may be used as an indicator for a fault or an impending fault of the high-voltage meter. In this connection, for example, hydrogen and carbon monoxide are of great importance and can indicate electrical faults or defects in the insulation material. The analysis, in particular the continuous online monitoring, of the gas concentration in the insulating medium enables an early detection of possible problematic developments.

Existing methods or devices for analyzing dissolved gases in the insulating medium of high-voltage meters do not take into account product or production fluctuations, for example, due to material, and therefore only achieve limited accuracy.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved solution for analyzing gases dissolved in the insulating medium of a high-voltage instrument, which leads to an improved accuracy of the analysis.

The object is achieved by the corresponding solution of the independent claims. Other embodiments are the subject matter of the dependent claims.

The improvement is based on the following concept: a multi-stage method for the evaluation of sensor signals is carried out, and the different influences of the installation and the environment on the sensor signals are taken into account in the individual stages. The individual stages are independent of one another. The particular performance mode of the instrument can thus be observed and compensated differently.

According to the improvement, a method for analyzing a gas dissolved in an insulating medium of a high-voltage instrument is provided. The dissolved gas is converted into the gas phase by means of an analysis device, in particular a separation unit of an analysis device, in order to obtain an analysis gas mixture. Transporting the analysis gas mixture to an analysis sensor of an analysis device. A sensor signal is generated as an output signal of the evaluation sensor as a function of the composition of the evaluation gas mixture, in particular the concentration of the gas converted into the gas phase in the evaluation gas mixture. A first intermediate variable is generated on the basis of the sensor signal and at least one disturbance variable. A second intermediate variable is determined on the basis of the first intermediate variable and at least one specific variable of the evaluation device. Determining the concentration of the dissolved gas in the insulating medium on the basis of the second intermediate quantity.

The analysis gas mixture may contain, in addition to the gas converted into the gas phase, a carrier gas, for example air. The carrier gas can be introduced into the analysis device, for example, by means of a pump device.

In this case, the at least one disturbance variable reflects, for example, external influences or states which in particular do not originate from product fluctuations, for example from analytical sensors or other components of the analytical device.

In contrast, the at least one specific variable of the analysis device reflects the performance of the analysis device itself, for example, on the basis of product or production fluctuations, in particular material-dependent fluctuations. In particular, at least one specific variable of the evaluation device is independent of external influences or states.

The separate consideration of the at least one disturbance variable and the at least one specific variable of the evaluation device allows a differential consideration of the behavior of the evaluation device itself, for example in the case of the shaping of the gas concentration in the insulating medium.

According to at least one embodiment, the insulating medium is an insulating liquid, in particular an insulating oil, such as transformer oil, or alternatively an insulating liquid, such as a synthetic ester.

In at least one embodiment, the high-voltage instrument relates to a transformer, in particular a power transformer, a choke valve or a tap changer, for example an on-load tap changer, for switching between different winding taps of the transformer or the choke valve.

In at least one embodiment, the dissolved gas comprises hydrogen or carbon monoxide.

According to at least one embodiment, the at least one specific parameter of the analysis device influences the conversion of the dissolved gas into the gas phase.

In particular, the gas concentration of the gas phase in the interior of the analysis device is dependent on the concentration of the dissolved gas in the insulating medium and on the at least one specific variable of the analysis device.

In at least one embodiment, the at least one specific variable of the evaluation device influences the behavior of the evaluation sensor, in particular the generation of the output signal.

In particular, the sensor signal is dependent on the concentration of the dissolved gas in the insulating medium and on the at least one specific variable of the evaluation device.

According to at least one embodiment, the conversion of the dissolved gas into the gas phase is carried out by means of a semipermeable membrane, in particular a separation unit, of the analytical device. The at least one specific parameter of the analysis device comprises a property of the membrane, in particular a porosity of the membrane.

In at least one embodiment, the at least one specific variable of the evaluation device comprises a property of the evaluation sensor, in particular a sensitivity of the evaluation sensor, an actuation time of the evaluation sensor or a response time of the evaluation sensor.

In at least one embodiment, the at least one disturbance variable influences the performance of the evaluation sensor. In particular, the output signal is dependent on the input signal of the evaluation sensor and on the at least one disturbance variable.

According to at least one embodiment, the at least one disturbance variable includes a temperature of an environment of the evaluation sensor, a pressure of the environment and/or a humidity of the environment. The environment can in particular relate to an interior of a detection unit of the analysis device, in which interior an analysis sensor is arranged.

According to at least one embodiment, the method comprises purging the analysis device with a purge gas and determining the purge result, in particular the quality and completeness of the purge. The at least one disturbance variable may then comprise a variable for determining the result of the cleaning.

In at least one embodiment, the determination of the value for the concentration is carried out additionally on the basis of at least one further disturbance variable.

According to at least one embodiment, the at least one further disturbance variable influences the conversion of the dissolved gas into the gas phase. In particular, the concentration of the gas in the gas phase in the interior of the analysis device is then dependent on the concentration of the dissolved gas in the insulating medium and on the at least one further disturbance variable.

According to at least one embodiment, the at least one further disturbance variable comprises a temperature of the insulation medium, a humidity of the insulation medium and/or a pressure of the insulation medium and/or a flow velocity of the insulation medium.

In at least one embodiment, the determination of the second intermediate variable is additionally carried out on the basis of a specific variable of the insulating medium. In this case, the material parameters of the insulating medium are involved. The material parameter, while possibly related to environmental conditions, does not by itself represent such environmental conditions.

According to at least one embodiment, the specific parameters of the insulating medium influence the conversion of the dissolved gas into the gas phase.

According to at least one embodiment, the specific parameter of the insulating medium comprises the solubility of the dissolved gas in the insulating medium.

In at least one embodiment, the first intermediate variable is determined on the basis of a first model, in particular a regression model. The second intermediate variable is determined on the basis of a second model, in particular a regression model. The value for the concentration of the dissolved gas is determined based on a third model, in particular a regression model. The three models are independent of one another, which allows special consideration and compensation of the disturbance variable, the other disturbance variables and/or specific variables of the evaluation device and thus leads to improved accuracy.

According to the further development, an analysis device for analyzing gases dissolved in an insulating medium of a high-voltage instrument is also specified. In particular, the analysis device is suitable for carrying out a method according to the development.

The analysis device comprises a separation unit, an analysis sensor, a pump device and an analysis processing unit. The separation unit is arranged for converting the dissolved gas into a gas phase in order to obtain an analysis gas mixture. The pump device is provided for transporting the aforementioned analysis gas mixture from the analysis unit to the analysis sensor. The analytical sensor is arranged to generate a sensor signal, an output signal, in accordance with a composition of the analytical gas mixture.

The evaluation unit is provided for determining a first intermediate variable on the basis of the sensor signal and at least one disturbance variable, and for determining a second intermediate variable on the basis of the first intermediate variable and at least one specific variable of the evaluation device. Furthermore, the evaluation unit is provided for determining a value for the concentration of the dissolved gas in the insulating medium on the basis of the second intermediate variable.

In accordance with at least one embodiment of the analysis device, the separation unit comprises a semipermeable membrane through which the dissolved gas can pass from the high-pressure meter into the analysis device.

In at least one embodiment, the analytical sensor includes a metal-oxide-semiconductor-field effect transistor, MOSFET.

According to at least one embodiment, the sensor signal is dependent on the resistance of the MOSFET, in particular on the drain-source resistance. In particular, the greater the concentration of the gas in the analysis gas mixture, the lower the resistance.

According to at least one embodiment, the sensor signal is related to the resistance of the MOSFET as a function of the saturation duration. The saturation duration is equal to the time period between the end of the washing and the moment at which the value of the resistance no longer changes significantly, for example.

The MOSFET or further MOSFETs may for example also be used to determine or evaluate the cleaning result.

In at least one embodiment, the evaluation unit comprises a processor unit and a measuring device for determining a temperature of the processor unit. The evaluation unit is provided for determining a temperature in the environment of the evaluation sensor, for example inside the detection unit, based on the temperature of the processor unit. For this purpose, the processor unit can be located in the vicinity of the evaluation sensor, for example.

In this case, an additional temperature sensor in the detection unit can advantageously be dispensed with in order to determine the temperature of the environment of the evaluation sensor.

In at least one embodiment, the evaluation unit is provided to determine the temperature in the environment of the evaluation sensor on the basis of the temperature of the processor unit and other influencing variables, in particular other heat sources, such as relays or insulating media.

Further embodiments and embodiments of the analysis device according to the development are obtained directly from the different embodiments of the method according to the development and vice versa.

Drawings

The invention is explained in detail below with the aid of exemplary embodiments with reference to the drawings.

In the drawings:

fig. 1 shows a schematic configuration of an exemplary embodiment of an analysis apparatus according to the modification;

fig. 2 shows a flow chart of an exemplary embodiment of the method according to the improvement.

Detailed Description

Fig. 1 shows a schematic configuration of an exemplary embodiment of an analysis device according to the above-described modification. Fig. 2 shows an associated flow diagram of an exemplary embodiment of the method according to the refinement.

Fig. 1 shows a high-voltage meter HG, for example a power transformer or an on-load tap changer, having a storage tank or container which is at least partially filled with an insulating medium IM, for example transformer oil. Different gases may be present dissolved in the insulating medium. The identified dissolved gas GG, such as hydrogen or carbon monoxide, is discussed below. However, the analysis device may analyze a plurality of different gases, in particular hydrogen and carbon monoxide, in different embodiments. Thus, the following embodiments are similarly applicable to different gases.

The analysis device comprises a separation unit which is in direct contact with the insulating medium. For this purpose, the separation unit can be guided at least partially into the interior of the high-pressure instrument via a corresponding connection of the high-pressure instrument. In the example shown, the separation unit comprises a semipermeable membrane M.

The evaluation device comprises a detection unit DE, which has, for example, a measurement chamber MK. An evaluation sensor AS is arranged in the interior of the detection unit DE, in particular in the measurement chamber MK.

Furthermore, the analysis device comprises an inlet E for a carrier gas TG, a gas outlet a and optionally a filter F for filtering the carrier gas TG flowing in through the inlet E.

The analysis device comprises a pump device, for example comprising a first pump P1 and a second pump P2.

The analysis device comprises a line system L which interconnects the separation unit, optionally the membrane M, the detection unit DE, in particular the measurement chamber MK, the inlet E, the outlet a and the pump device.

Optionally, the detection device DE comprises a temperature control device TE, for example a Peltier element, for controlling the temperature of the interior of the detection device DE, in particular of the measuring chamber MK and the environment of the evaluation sensor AS.

Optionally, the detection device DE comprises a pressure sensor (not shown) for determining the environment of the interior of the detection device DE, in particular of the measurement chamber MK and of the evaluation sensor AS.

The evaluation device comprises an evaluation unit AE, which is coupled to an evaluation sensor AS.

If necessary, the evaluation unit AE can also be coupled to the temperature control device TE for controlling the latter, if present. Alternatively, a separate control unit (not shown) for controlling the thermostat TE may be provided. In this case, the control unit may also be used to control the pump device.

In operation of the analysis device, in step 200 of fig. 2, the dissolved gas GG passes through the membrane M into the interior of the analysis device, in particular into the line system L, where it is present in the gas phase. On the other hand, the liquid insulating medium IM cannot pass through the membrane M. Furthermore, the pump device transports the carrier gas TG into the line system, so that the carrier gas forms an analysis gas mixture AG with the gas arriving through the membrane M.

This process of diffusion can be run by concentration drop or chemical potential. For example, dynamic equilibrium is formed on the membrane M with respect to the gas concentration. This equilibrium is for example related to the temperature of the insulating medium IM, the concentration of the dissolved gas GG in the insulating medium IM and/or the solubility of the gas in the insulating medium IM.

The process speed increases with increasing temperature. Thereby also possibly affecting the level of the equilibrium state. The concentration gradient is changed via the gas concentration in the insulating medium IM. Here, the gas concentration in the insulating medium IM can be varied locally. Thus, in the absence of convection of the insulating medium IM, a depletion zone of the dissolved gas GG surrounding the membrane M may be formed. The convection aids in supporting the surface healing of the gas on the membrane M. The solubility of the gas GG in the insulating medium IM is related to the sum of the dissolved substances in the insulating medium M. Thus, for example, the proportion of water dissolved in the insulating medium M influences the extent to which hydrogen can be dissolved.

Alternatively to the membrane M, the separation unit may comprise other devices capable of facilitating the separation of the dissolved gas GG from the insulating medium IM. For example, the separation can be carried out by means of a vacuum process or a headspace process. The latter two methods are known to the person skilled in the art.

In step 300, the analysis gas mixture AG is transported into the interior of the detection unit DE and thus to the analysis sensor AS by means of a pump device.

In step 400, a sensor signal is generated by means of the evaluation sensor AS, which sensor signal corresponds, for example, to a saturation value of the resistance of the evaluation sensor AS. The sensor signal is related to the concentration of the gas to be analyzed in the analysis gas mixture AG and thus to the concentration of the dissolved gas GG in the insulating medium.

Optionally, the line system L and the detection unit DE, in particular the measurement chamber MK, can be cleaned with carrier gas TG by means of a pump device before the sensor signal is generated. This makes it possible to: the analysis gas mixture AG first consists essentially of carrier gas AG and, after the cleaning, the concentration of the gas to be analyzed increases until an equilibrium state. The sensor signal can thus be normalized in that it corresponds, for example, to the difference between the output signal of the evaluation sensor AS directly after the cleaning and after reaching equilibrium or saturation.

The sensor signals are detected by an evaluation unit AE. In step 500, evaluation unit AE determines a first intermediate variable on the basis of the sensor signal and at least one disturbance variable, which influences, for example, the performance of evaluation sensor AS. The at least one disturbance variable may comprise, for example, a temperature, a pressure or a humidity in the interior of the detection unit DE or in the measurement chamber MK. The at least one disturbance variable may be detected, for example, in step 400 by an evaluation unit AE. For this purpose, the evaluation device may comprise further sensors (not shown) coupled to the evaluation unit AE for determining the at least one disturbance variable. For determining the first intermediate variable, a first regression model may be used, for example.

The evaluation unit AE then determines a second intermediate variable in step 600 on the basis of the first intermediate variable and at least one specific variable of the evaluation device, which influences the conversion of the dissolved gas GG into the gas phase and/or the performance of the evaluation sensor AS. In the first case, the at least one specific parameter of the analytical device may comprise a property of the separation unit, for example of the membrane M, for example the porosity of the membrane M. In a second case, the at least one specific parameter of the analysis device may comprise a characteristic of the analysis sensor AS, for example, a sensitivity of the analysis sensor AS. The at least one specific variable of the analysis device can be determined during the method according to the development or before the analysis device is put into operation. Thus, for example, material-related or process-related product fluctuations can be taken into account and compensated differently. For the determination of the second intermediate variable, a second regression model may be used, for example.

In step 700, the evaluation unit AE determines a value for the concentration of the dissolved gas GG in the insulating medium IM on the basis of the second intermediate variable and optionally additionally on the basis of at least one further disturbance variable. In this case, the at least one further disturbance variable influences the conversion of the dissolved gas GG into the gas phase. The at least one further value may comprise, for example, the temperature, the humidity and/or the flow speed of the insulating medium IM. They can be detected, for example, by the evaluation unit AE in step 200. For this purpose, the evaluation device or the high-voltage meter HG may comprise a further sensor (not shown) coupled to the evaluation unit AE for determining the at least one further disturbance variable. For determining the value for the concentration, a third regression model can be used here, for example.

In an optional step 800, the evaluation unit AE can generate process instructions or information, for example warning signals or the like, based on the values for the concentration.

With the method or the analysis device according to the described development, an analysis of the gas dissolved in the insulating medium of the high-voltage instrument can be carried out with improved analytical accuracy in the described manner.

Dividing the analysis into separate stages also allows: a linearized model for correcting the analysis device is used in production. The model can be set up instrument-specifically, for example, via a simple two-point calibration. In-situ single point tuning (e.g., degraded insulating oil has a different gas solubility than fresh insulating oil) can be applied in the field.

List of reference numerals

HG high-voltage instrument

IM insulating medium

Gas dissolved in GG

M semipermeable membranes

L pipeline system

AE analysis processing unit

DE detection unit

MK measures chamber

AS analysis sensor

AG analysis gas mixture

TE temperature adjusting device

P1, P2 pump

E inlet

A outlet

TG carrier gas

And F, filtering.