PUBLICATIONS

The multi-channel (MC) back-to-back voltage source inverter (VSI)-fed doubly fed induction machine (DFIM) is emerging as a highly

interesting topic in large-rated variable speed pumped-storage power plants (PSPP) in view of cost, optimal efficiency, and space

requirements. Although the VSI is the fundamental part of the drive controlling the active/reactive power of the plant, redundancy

is presently not adopted in practice causing the unit as a whole to shut down upon a failure in the converter and control circuit. This

paper evaluates a large-rated (250 MW) DFIM-fed variable-speed unit of a PSPP in terms of its reliability and availability. A Markov

model is developed to assess the reliability of the drive based on a number of factors including survivability and annual failure rate

(FIT). Further, the Markov model is applied to different PSPPs for comparison of reliability among them.