A simplified dual-redundancy digital electro-hydraulic servo control system for steam turbine

A dual-redundancy servo loop of digital electro-hydraulic control system for steam turbine is built up, through the way that the electro-hydraulic servo valve with two parallel current inputs. Dynamic responses of the dual-redundancy structure in various operation conditions are analyzed on the basic of dynamically modeling of the whole redundant servo loop. The analytical results show that, compared with conventional irredundant system, the new system still maintains good dynamic characters while the reliability improved notably.