Analysis of a Transformer Time-Varying Outage Model for Operational Risk Assessment

Firstly, the operating mechanism in developing process of transformer internal latent fault and external accessory fault is analyzed. Then, dissolved gas analysis (DGA) outcome and average degree of polymerization (DP) are used as an indicator to classify transformers operating condition, the multi-state Markov process model based transformers operating condition is proposed to estimate the internal failure rate. According to the method of weather condition classification, the external accessory failure rate model is proposed by considering the influence of weather change. A time-varying transformer outage model for operational risk assessment is proposed by using the multi-state Markov process to estimate the time-varying failure probability. Finally, a numerical is presented.