Oltc Mechanical Properties Of The Online Monitoring System

With fast development of electric power industry, the capacity of electric equipment and the scale of power network are extending in the meantime. Potential power system faults will result in large economical losses and social impacts, therefore, some measures must be taken to enhance the quality of power supply and ensure the safety of power systems. Condition-based maintenance diagnosis will present a preferable solution for the above issues.On-load tap changers (OLTC) of power transformers play very important role in the power delivery to adjust voltage levels. Statistics shows that the ratio of OLTC accidents and faults among all the 110kV-500kV transformers faults is 18% and 12% respectively, and the faults ratio is also growing with time.An OLTC is composed of a selector, a tap-changer and a motor-controlled mechanical drive system. OLTC's performance is characterized in both electric and mechanical aspects, with the mechanical one being the prominent fault source. Further, the electric faults are normally caused by mechanical reasons. So on-line monitoring of OLTC's mechanical conditions can present critical indications of potential faults.An on-line monitoring system for condition assessment and fault diagnosis of OLTC is developed, which incorporates some new technologies such as mechanical sensors, data acquisition system, virtual instruments, network monitoring and diagnosis and so on. The system is the first of its kind developed in China, which presents a boost for condition monitoring applications to guarantee reliability, economy and stability of power systems.