Partial Discharge Monitoring and Analysis using Phase Resolve Partial Discharge Pattern

Motors and generators like other machineries, experience wear and ageing. The materials and components will deteriorate over time if nothing is done, and they will ultimately fail. Fortunately, most form of failures may be avoided with proper maintenances. To successfully schedule the maintenance, the plant operator must have reliable information on the current state of their machineries. This paper presents a technique and measuring system for PD monitoring of rotating machines using Phase Resolve Partial Discharge pattern. With this technique, the maintenance strategy and planning can be considerably improved. The proposed method was tested on asynchronous motor with 6.6 kV rated voltage. The measuring approach is based on the decoupling of PD pulses using inductive sensors mounted on terminals of the item to be tested and the handling of the sensor signals, which results in a measurement of the PD level in the test object. Since one of the most essential responsibilities of PD monitoring is to identify insulation degradation early, analyzing PRPD patterns is helpful for assessing the state of high voltage rotating machines so they may work reliably for a known period of time. The paper evaluates a case scenario of a machine and the PRPD results show the current condition of the inspected machine which is in good running condition.