The Calibration System Research Of TEV Partial Discharge Detection Device

The Transient Earth Voltage(TEV)method is one of the main methods of switch cubicle partial discharge monitoring at the transformer substation.In recent years,based on the TEV method of partial discharge detection instrument in electric power system has been more and more widely used.This paper will be on the switchgear partial discharge based on the research of the characteristics of typical defects,put forward a set of TEV method of partial discharge detection instrument calibration method and the device,as well as the method for the measurement of the calibration device,promote TEV partial discharge test equipment calibration work.It can be used to check the instrument when selecting the instrument,and the instrument can be calibrated regularly to ensure the accuracy of the instrument and improve the validity of the charged test.The main research contents and results are as follows.Through the analysis of TEV signal and TEV sensor,the TEV signal amplitude of the sensor output is determined not only with the amplitude of the signal source itself,but also with the rise time of TEV signal.The measurement of TEV signal is mainly measured by amplitude and pulse count.TEV signals occur with built-in module combined with external pulse generator,the difference between inner and outer TEV signal amplitude generated inside can be up to 25 v,and external pulse signal generator is the most substantial value to 5 v,so that we can through the built-in TEV signal to measure amplitude measurement precision of the subjects.At the same time,the voltage calibrator is equipped with the TEV pulse signal with multiple standard amplitude and standard pulse frequency,which can be called by the keyboard,which is easier to use than the external pulse generator.Built-in TEV signal generator output pulse signal of the rise and fall time is relatively fixed,while the external the rise time of pulse signal of pulse signal generator and a flexible time control,so that we can through the external pulse signal generator to measure the frequency response characteristics of subjects to taste,to complete the TEV sensors and TEV measurement equipment calibration.Combining with the calibration work,formulated the TEV partial discharge detector calibration specifications.The test rules are put forward,and the content and requirements of the test are clarified.This specification can be used as the laboratory calibration test and the actual test of the actual switch cabinet defect,and provide certain technical support for the selection and purchase of this kind of equipment.