Partial Discharge Assessment with Ultrasound and TEV (Transient Earth Voltage) in Medium Voltage Substation for Power Distribution Systems Reliability of 18th Asian Games 2018

Abstract

The medium voltage equipment is an important key in power distribution systems reliability in Jakarta. Having the chance to host the 18th Asian Games 2018, PLN (Perusahaan Listrik Negara) must be prepared for electrical reliability in Jakarta.In 2017, medium voltage cubicle breakdown failure contributed as much as 40% is a factor causing incoming 20 kV transformertrip. From the observations after breakdown, there are several physical signs around the point of breakdown, the presence of white powder and wound at termination cable. These physical signs reinforce that failure of the cubicle material has an indication of partial discharge as the root cause.Preventing from partial discharge with TBM (Time Based Maintenance) is not enough. TBM only performs periodic maintenance of the cubicle without taking into a priority if an anomaly occurs in the cubicle. Partial discharge assessment which is included in CBM (Condition Based Maintenance) is one method for online monitoring and diagnosing malfunctions that occur in cubicles.Partial discharge assessment will focus on two methods of measurement. First, measurement with ultrasonic sound wave propagation to detect surface discharge and second, the measurement of TEV (Transient Earth Voltage) to detect internal discharge.Assessment with partial discharge measurements is considered to be able to prevent from failure or breakdown of medium voltage substation. Partial discharge assessment will be a sustainable business process in PLN that has a vision to periodically display health index so that the condition of each cubicle in medium voltage substation can be monitored continuously.