Composition of partial discharge monitoring diagnosis system
Sensor
Composed of Airborne-Acoustic sensor(AA), Airborne-Emission sensor(AE), and TEV(Transient Earth Voltage)sensor, and detects abnormal signals about the insulation status of the switchgear generated by partial discharge.
TEV(Transient Earth Voltage) sensor
- When a partial discharge occurs, the instantaneous transient earth voltage signal of the electric field induced on the surface of the switchgear is a frequency
component of 1 MHz~30 MHz. It is a method of detecting the charge induced in a conductor having a surface resistance value
- Use to detect partial discharge of transformers, circuit breakers, switch, busbars, etc in switchgear.
Airborne-Acoustic Sensor
- A sensor device that can detect whether partial discharge is occurring in the switchgear by detecting ultrasonic waves in the 40 kHz band among the sound pressure
generated by the partial discharge
- When 40 kHz sound pressure is above a certain level, partial discharge is detected
Acoustic-Emission Sensor
- Detecting vibrations caused by acoustic emission, in which 150 kHz band radiation emitted when a partial discharge inside the switchgear is transmitted to the
exterior.
- Sensor unit used to detect partial discharges occurring inside molds and oil-immersed transformers, and GIS
Partial discharge detection devices
Receiving the ultrasonic signal and transient earth voltage signal detected by the sensor unit, diagnoses the partial discharge status with an intelligent artificial neural network algorithm, and notifies the administrator of the alarm signal
Sensor receiver unit : As a DAQ board, it receives the partial discharge signal data measured by the sensor and removes noise by digital filtering.
Setting unit: A device that sets values such as alarm and on-off criteria
Abnormality decision unit: Determining the insulation status of the partial discharge signal of the switchgear using the frequency spectrum
- Signal conversion unit: Converts ultrasonic signal and TEV voltage pulse signal into digital signal
- Noise removal unit : Appling filter to remove circuit noise and other impulses included in the partial discharge signal
- Discharge detection unit : Amplifing the partial discharge signal and diagnose whether or not partial discharge has occurred through an artificial intelligent neural
network algorithm
- Control unit : Remotely reporting the deterioration status of the switchgear by the detection result of the artificial intelligent neural network algorithm