Reliable hydraulic cylinder position indication
Hydroelectric power stations depend on reliable hydraulic cylinder position signals to safely and efficient control the flow of water through and around the plant. Balluff has decades of experience developing and deploying precise yet robust cylinder sensors for continuous position feedback or end-of-stroke detection. Other Balluff sensor technologies such as inclination / angle sensors can simplify controls systems by directly reporting the angular position of mechanisms.
To ensure that the turbines run smoothly, the position of the guide blades in Kaplan turbines is adjusted as needed. Balluff's externally mounted aluminum profile magnetostrictive linear position sensors enable ganged control of blade angle with a single feedback device.
By adapting the rotor blades to the water volume, the efficiency of Kaplan turbines is optimized. Balluff's magnetostrictive linear position sensors are directly integrated into the shaft for direct position monitoring at the impeller.
In Pelton turbines, the speed of the impeller, and thus the power produced, is controlled via nozzles in the water jet. At several inlet nozzles there is high pressure of up to 200 bar, which has to be adjusted quickly and smoothly. Balluff's magnetostrictive linear position sensors are installed in the hydraulic cylinder that operates the nozzles, providing precise position feedback for accurate control.
To implement remote, automated control of water levels at dams means that the position of water level and flood control gates must be measured electronically. Balluff's inclination / angle sensors can be mounted direction to the moving portion of the gate itself.
Accumulated debris at the infeed screen of hydroelectric power plants resulted in reduced pressure head and flow volume, reducing plant efficiency. Automatic debris rakes are operated periodically to clean flotsam from the inlet screens. Balluff's pressure-rated inductive proximity sensors detect and report the end-of-stroke positions of the screen actuating cylinder.