When hydraulic motor with great inertia breaks at high-speed, the high pressure in returning line will be brought, this would demolish equipment, engender fearful accident.

Simulation results reveal that equivalent rotational inertia, damping factor, fluctuating loading pressure and loading torque has comparatively large influence on control properties.

The effect of the model's nonlinearity on the system is mainly reflected by changes of fuel command corresponding to pressure increments in front of the turbine and heat storage inertia of the boiler.