Disturbance analysis in TNB transmission system

With deregulation, a utility such as Tenaga Nasional Berhad (TNB) recognises the need to examine the key indicators of reliability in order to be competitive. To examine the reliability needs, TNB has embarked on an extensive programme of installing disturbance recorders on all its 275 kV substations and important 132 kV substations. This enables TNB to monitor and evaluate protective relay equipment which is essential to the system reliability. Prior to the application of the disturbance recorder, monitoring and fault analysis relied mainly on the relay operation. This at times led to inaccuracies in the fault analysis due to uncertainty of correct relay operation. This paper describes the application and field experience over the last five years including the problem of circuit transmission of data by modem to the analysis centre and the future move towards transmission by Internet Protocol.