Aim. An approach for quantifying the reliability of the wired duplicated control channel with common and separate cable jackets is developed. Method. Reliability block diagrams and dynamic fault trees are used to formalize reliability. To describe the specifics of the damage processes to cores and cable jackets, logical conditions are formed in the failure tree. States and transition diagrams of the control channel are formed for carrying out stationary and dynamic analyzes. Stationary analysis is performed on the basis of logical and probabilistic expressions for states. Dynamic analysis is performed by forming and calculating a Markov model. Results. Stationary analysis is performed using a complete factorial experiment on the selected point parameters. It is shown that from the point of view of reliability, the protection of the cores of the control channel by separate cable jackets has an advantage over the protection by a common cable jacket. This advantage is especially evident for unreliable cores, which are quickly damaged after the destruction of the cable jacket. Dynamic analysis is performed for the parameters specified in relative units. It is shown that the reliability of the control channel depends on the ratio of the intensity of damage to the cable jacket and the intensity of damage to the core. If the intensity of damage to the cable jacket is higher than the intensity of damage to the core, the reliability of the control channel is determined by the reliability of two parallel cores. If the damage intensity of the cable jacket is equal to or lower than the intensity of the core damage, then the control channel with separate cable jackets should be preferred. Scientific novelty. An approach to modeling the reliability of control channels that connect process equipment to controls based on the use of dynamic failure trees has been improved. Practical significance. The proposed approach is recommended to be used to assess the reliability during the equipment design, the operation of which may endanger the life and health of service personnel. The obtained results are a mathematical basis for studying the reliability of the leading duplicate control channels with additional reinforcement and multiple protections of the cores.
[1] M.H. Faber, S. Engelund, R. Rackwitz. "Aspects of parallel wire cable reliability," in Structural Safety, vol. 25, no 2, pp. 201-225, 2003.
https://doi.org/10.1016/S0167-4730(02)00057-7
[2] M. Kikuchi, Y. Yamada, J. Kawataka, H. Izumita and K. Katayama, "3-D Measurement of Rollable Fiber Ribbons in 1000-Fiber Cable and Calculated Fiber Reliability," in IEEE Photonics Technology Letters, vol. 30, no. 17, pp. 1519-1522, 1 Sept.1, 2018.
https://doi.org/10.1109/LPT.2018.2855203
[3] M. Buhari, V. Levi and S. K. E. Awadallah, "Modelling of Ageing Distribution Cable for Replacement Planning," in IEEE Transactions on Power Systems, vol. 31, no. 5, pp. 3996-4004, Sept. 2016.
https://doi.org/10.1109/TPWRS.2015.2499269
[4] T. Bdour, C. Guiffaut and A. Reineix, "Use of Adaptive Kriging Metamodeling in Reliability Analysis of Radiated Susceptibility in Coaxial Shielded Cables," in IEEE Transactions on Electromagnetic Compatibility, vol. 58, no. 1, pp. 95-102, Feb. 2016.
https://doi.org/10.1109/TEMC.2015.2501899
[5] J. Guo, Z. Liu, H. Che and S. Zeng, "Reliability Model of Consecutive (2, k) -Out-of-(2, n) :F Systems With Local Load-Sharing," in IEEE Access, vol. 6, pp. 8178-8188, 2018.
https://doi.org/10.1109/ACCESS.2018.2802319
[6] T. Stefanovych, S. Shcherbovskykh, "Modeling the influence of short-term mode of component for non-reserved system on its reliability," in Industrial Process Automation in Engineering and Instrumentation, vol. 53, pp.66-72.
https://doi.org/10.23939/istcipa2019.53.066