Solution for Over-speed Protection Misoperation Under 115% Rated Speed in Hydraulic Generator

The over-speed protection misoperation under 115% rated speed in hydraulic turbine generator is introduced.The reason for the above problem is analyzed.Traditional tripping approach about the main pressure valve is described.The unit over-speed protection control solutions under 115% rated speed are discussed.Meanwhile,a new kind of over-speed protection logic control strategy is put forward: using the rising edge of 115% rated speed with valves position to judge the mis operation of speed governor's main control valve.At present,the method has been applied in the Shanxi Power Plant with good results.And the disoperation of the protection and optimization of the system structure has been solved.