Gas pressure monitoring system and gas-insulated electric apparatus

Abstract

In a conventional gas pressure monitoring system that detects a gas leak inside the hermetic container using temperatures measured by the temperature sensor provided outside the hermetic container, there exist uncertain temperature differences between actual temperatures inside the hermetic container and measured temperatures. Thus it is difficult to obtain from a pressure measured inside the hermetic container, an equivalent pressure converted to one at a predetermined temperature, so that it is not possible to early detect a gas leak. By removing the influence of the uncertain differences between temperatures inside and outside the hermetic container, from characteristic-curve slopes obtained from time-series measurements in pressure and temperature during predetermined periods at intervals of 24 hours, it becomes possible to obtain an equivalent pressure inside the hermetic container with a high accuracy, to detect a gas leak at early stages.

Description

technical field [0001] The present invention relates to, for example, an air pressure monitoring device for monitoring the leakage of gas enclosed in a gas insulated electrical equipment such as a gas insulated switchgear, and a gas insulated electrical equipment equipped with the air pressure monitoring device. Background technique [0002] The existing air pressure monitoring device is provided with an air pressure sensor and a temperature sensor in the airtight container of the gas-insulated electrical equipment, using the pressure value and temperature value measured by these sensors, according to the gas state equation or Betty-Bridgeman (Beattie-Bridgeman) ) formula or the like to calculate the converted pressure corresponding to a predetermined temperature, and monitor the change of the converted pressure to grasp the gas leakage of the gas-insulated electrical equipment (for example, refer to Patent Document 1). [0003] The temperature in the airtight container incl...

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Problems solved by technology

[0007] However, since the above-mentioned converted pressure calculated from the temperature value and pressure value at a predetermined time varies greatly from day to day, there is a problem in the reproduction accuracy of this measurement.

In addition, even if you want to improve the accuracy by using the trend of the converted pressure, for example, it will take three months to accumulate the converted pressure 100 times, so it is impossible to grasp the air leakage at an early stage

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