The purpose of the power station governor is to regulate the hydraulic energy input to the turbine unit in order to achieve the desired rotational speed or power output of the generator. In speed control mode, for black start or island generation, the governor ensures a constant rotational speed of the generator under varying loads or hydraulic pressures by regulating flow through the turbine.

In power control mode the governor will attempt to maintain the contracted power delivery to the grid but will allow the power house to respond to grid conditions in order to maintain stability of the grid, as mandated by applicable grid connection codes, or the balancing mechanism contracts that are in place.

The governor’s role is critical, not least in preventing potentially catastrophic damage from a freewheeling turbine and generator should the design load fall significantly, or from substantial pressure loss which could be due to a restriction in the hydraulic system.

One of the biggest problems for asset owners is unstable running reducing efficiency. Assuming there’s no design, manufacturing or installation fault, and the maintenance schedule has been maintained, a deeper examination of potential causes may be required. Causes may include frantic oscillations in the load cycle, a cavity vortex in the supply penstock, a hydraulic pulsation, even air or dirt getting into any of the controlling hydraulic pipelines.

Fortunately for owners and operators, KGAL’s mechanical, electrical and hydraulic engineers have the knowledge, skill and experience to provide professional consultancy services to manage every aspect of a HPP including governors. We can manage your suppliers and contractors, and control and inspect services to ensure a timely, safe and profitable solution to power house problems or to an entire new or refurbishment project.

The images show the HMI screen and the control panel of the managing system for one of the Woodward hydraulic / mechanical turbine governors at Fasnakyle HPP in Scotland where we provided project management and consultancy services for an asset life assessment (plant condition study).