governor unstable running condition

Hydro turbine governor knowledge–governor unstable running condition.

What is the cause of hydropower turbine governor unstable running?

In addition to improper design, manufacturing, governor item selection, governor installation and maintenance and debugging etc. there are also other reason cause unstable running of the hydro turbine governor, it also caused by running water pressure pulsation of the unit pressure system, unit running maintenance and the improper management, the possible reasons are below:

1. For common water diversion pipe or parallel operation hydro turbine units in the same surge tank, due to the adjacent hydro turbine units taking big adjustment, it cause water diversion system of hydraulic pulsation, finally make the turbine speed unstable running; Hydropower station of low head and large flow on upstream and downstream water level changing sharply condition can also cause periodic fluctuation of the turbine regulating system.
2. For a too long penstock hydropower station, when the pipe pressure changing cycle close to the governor natural vibration cycle, it may be caused unstable running of the governor by resonance.
3. Low head micro hydropower unit deviating from the optimal working conditions, to produce cavity vortex in the draft tube, finally cause speed instability; Or turbine with strong cavitations cause instability.
4. The hydropower system load cycle oscillation or system power oscillation will cause the speed fluctuation.
5. Dirty pressure oil will affect buffer working, also can induce governor unstable running.
6. Air into the governor oil pipeline and relay, or oil spill between relay stop oil leakage unit and the main pressure valve.