Automatic calibrating system for ultrahigh-frequency partial discharge tester and method thereof

Abstract

The invention discloses an automatic calibrating system for an ultrahigh-frequency partial discharge tester and a method thereof. The system comprises a calibrating signal generator, an UHF partial discharge sensor and a calibrated ultrahigh-frequency partial discharge tester. The ultrahigh-frequency partial discharge tester is connected with the UHF partial discharge sensor. The high-frequency signal output end of the calibrating signal generator is connected with a signal input coaxial joint of a GTEM small chamber. The UHF partial sensor is placed at the central part of the GTEM small chamber. The middle part of the GTEM small chamber is provided with a field strength probe. The field strength probe is connected with an oscilloscope which is arranged outside the GTEM small chamber. Theoutput signal of the oscilloscope is connected with a controller. The controller is connected with the calibrating signal generator. The automatic calibrating system performs real-time hardware part controlling, data acquisition and displaying processing on the ultrahigh-frequency partial discharge tester. The system has advantages of high reliability, real-time measurement and effective calibrating efficiency improvement. A feasible method is supplied for automatic calibration of the ultrahigh-frequency partial discharge tester. The automatic calibrating system further has advantages of highcalibration precision and simple control method.

Description

technical field [0001] The invention relates to an automatic calibration system and method for a UHF partial discharge instrument, which is an automatic calibration system and method for an UHF partial discharge instrument based on real-time control, data acquisition, processing and display of a C# platform. Background technique [0002] For the calibration of UHF PD instruments under laboratory conditions using UHF sensors, there is no unified evaluation standard at home and abroad, and there is no widely recognized performance test method. At present, the most widely used is to place the sensor directly on the transformer or GIS model installed with various partial discharge defects to evaluate the detection effectiveness of the UHF partial discharge instrument, including signal-to-noise ratio, sensitivity and gain, etc., but the partial discharge The inherent differentiation of the defect model itself leads to a large dispersion of test results. The British DMA company t...

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Problems solved by technology

At present, the most widely used is to place the sensor directly on the transformer or GIS model installed with various partial discharge defects to evaluate the detection effectiveness of the UHF partial discharge instrument, including signal-to-noise ratio, sensitivity and gain, etc., but the partial discharge The inherent differentiation of the defect model itself leads to a large dispersion of test results

The British DMA company tests the equivalent height of the sensor by injecting a standard pulse signal into the GTEM cell and performing Fourier decomposition on the pulse signal received from the sensor. The energy of the frequency band is weak, especially the signal strength above 500 MHz is insufficient. Under the influence of background noise, the measurement error caused by the transfer function of the output / input system itself will be too large, and it is difficult to meet the accuracy and reproducibility requirements of the test. Require

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