Using process data in condition based maintenance

Electricity plays a major role in today’s society and it is being taken for granted. For Electricity Network Company it is important that distribution of electricity is safe and disturbance free. Networks components faults will cause costs because compensation of disturbances is paid for the customers. For this reason it is important to minimize unplanned interruptions and optimize equipment performance. Network assets condition monitoring has an important role in the whole electricity network company’s operations so that investments timing and network assets lifetime can be optimize. The objective in maintenance is to maintain electricity network performance as high as possible. Its purpose is maintaining reliability, guarantee safety, prevent disturbances and repair noticed failures as fast as possible with optimal costs. Maintenance can be divided into preventative maintenance and corrective maintenance. In preventative maintenance the aim is to prevent failures and it can be performed either time based or condition based. Efficient maintenance is based on condition inspections when condition monitoring of components can be used to optimize its lifetime and maintenance costs. Networks components can be also overhauled in certain time intervals but then unnecessary investments are possible. The objective of this thesis is to clarify how condition based maintenance can be implemented more efficiently by using available network information. Appropriate would be that the resources could be used to necessary overhauls and not to inspections. For this purpose failure development is explained. Also insights are given on how to improve maintenance. The primary substations transformer, circuit breakers and protection relays has presented manners how their condition could be estimated without visiting the substation. The basis has been conveying data from primary substation and modern numeric relay possibilities to operate as data collectors. Today ICT-technology enables gathering of diverse data from the electricity networks. Telecommunications make it possible to transmit information however for this purpose it is necessary to develop a system which can analyse and restore this data. This thesis presents potential structures for system infrastructure and database which could be practical. Intention is that system would not only serve maintenance but would also make possible to implement future smart grid technologies. /Kir1