Study on Communication Strategy in Triple Module Redundant ETS System

A triple module redundant turboset emergent trip system (ETS) based on triple modular redundancy fault-tolerance technology is discussed in this paper, which is used for safety protection of large steam turbine. The system consists of input modules, main controllers, bus controllers and output modules, in which the 2-out-of-3 (2oo3) vote mechanism is adopted to enhance the reliability and safety of system. In the mean time, the communication strategy among different function modules based on control right (CR) is illustrated in detail. It is attested that the asynchronism of input data on three buses in one control right rotate cycle has no influence on the system vote results. The system running flow is given through analyzing the system data flow. The field running proves the system reliability.