Reliability Evaluation of STATCOM Based on the k-out-of-n: G Model

The reliability level of STATCOM devices is a key issue concerned by all the design department, manufacturing sector and application department. A k-out-of-n: G system model of STATCOM and the basic analysis method for it are proposed in this paper. The k-out-of-n: G system can be used to quantify the reliability benefit of redundancy units in main circuit of STATCOM. Utilizing the basic reliability indices of IGCT, GTO and IGBT provided by literatures, the reliability value and MTTF of an applied 50 MVA STATCOM device are evaluated. And the optimal redundant unit count is analyzed basing on the indices obtained in forenamed study. Finally the dynamic model is proposed to evaluate the reliability of the k-out-of-n: G system when component failure induces higher failure rates in survivors.