Method and device for determining and/or monitoring the breakdown voltage of a transformer oil

Abstract

The invention relates to a method for determining and / or monitoring the breakdown voltage of a transformer oil, comprising the following steps: a) carrying out an acoustic impedance measurement of thetransformer oil, wherein the impedance of a medium, which is arranged partially or completely in the transformer oil and which is suitable for vibrating itself and / or transmitting vibration to the transformer oil, is determined in at least one frequency band of a defined frequency width; b) calculating a resonator quality factor for the frequency band based on the determining carried out in stepa); c) calculating an acoustic imbalance of the transformer oil based on the calculation carried out in step b); and d) determining the breakdown voltage of the transformer oil based on the calculation carried out in step c). The invention also relates to a device (100, 200) for determining and / or monitoring the breakdown voltage of a transformer oil.

Description

technical field [0001] The invention relates to a method and a device for determining and / or monitoring the breakdown voltage of transformer oil according to the preambles of the independent claims. Background technique [0002] Devices from high-voltage technology, such as transformers, capacitors, crowbars and / or switches, are known from the prior art and are used in particular, but by no means exclusively, to ensure a continuous power supply. Among these installations, transformers are among the most important and most expensive equipment in the electrical energy supply. In order to ensure a continuous and fault-free supply of electrical energy and to avoid economic losses, it is important to detect faults that potentially occur in the operation of transformers and may cause interruptions in time to be able to initiate appropriate measures for correction. [0003] Usually, a combination of liquid insulation and solid insulation is used as insulation in transformers. For...

AI Technical Summary

Problems solved by technology

It is therefore not surprising that a large number of different methods and devices are known from the prior art for determining the breakdown voltage of transformer oils, which determine the dissolved gas and / or water content in transformer oils, since both are known to have a significant effect on breakdown voltage. Voltage has a substantial effect and thus indirectly affects the lifetime and / or utilization time of the transformer

The reason for this is that the water in the transformer leads to hydrolysis of the solid insulating substance and thus to a reduction in its degree of polymerization

However, all these methods and devices have the disadvantage that sampling is required and the breakdown voltage of the transformer oil is not determined and / or monitored permanently and off-line

Another problem is that transformer oil is highly hygroscopic, which means that sampling itself will distort measurements

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