Steam turbine governing valve redundancy control system and control method thereof

The invention discloses a steam turbine governing valve redundancy control system and a control method thereof. Redundant distributed control units and redundant valve positioner modules are combined to control steam turbine governing valves. The distributed control units are arranged in pairs, the current valve position instruction signals of the steam turbine governing valves are calculated in real time to be sent to the valve positioner modules. The valve positioner modules are arranged in pairs, feedback signals of two different steam turbine governing valves are collected at the same time, the valve position instruction signals sent by the distributed control units are combined with the feedback signals, the instruction signals of a current governing valve servo valve are calculated and output to drive two coils of hydraulic servo-motor servo valves corresponding to the two governing valves, closed loop control over the steam turbine governing valves is achieved, the two coils of the hydraulic servo-motor servo valves corresponding to each steam turbine governing valve are respectively controlled by adopting the two valve positioner modules which are arranged in pairs, safety of valve control of a steam turbine is improved greatly, and on-line non-stop and interference-free renewing of the valve positioner modules can be achieved.