Design and reliability analysis of the electrical control system of the subsea control module

The subsea control module is the core equipment of the subsea production system, and its electrical control system plays a large role in the failure modes of the subsea control module. Based on a traditional nonredundant programmable logic controller system, a parallel cross-redundancy system is proposed, designed and tested for the electrical control system of the subsea control module to enhance the reliability of the subsea control module within the given space. A success-oriented system decomposition method is proposed on the basis of the reliability block diagram and system logical relationship that effectively reduces the system dimension and solves the problem of the system state-space explosion caused by the number of system components in the Markov model, and the system reliability and mean time to failure models are created. The reliability model is solved by a Markov model successfully. Finally, the redundancy of the system is tested to validate the logical relationship in the reliability model. The reliability and mean time to failure of the system are analyzed in MATLAB. The tests and analysis show that the proposed parallel cross-redundancy system is better than the double hot-standby system, as demonstrated by a higher reliability and longer mean time to failure, and the module failure rate effects have been minimized.