Short Answer:

Governing of turbines refers to the system used to control the speed and output of a hydraulic turbine. It adjusts the flow of water entering the turbine to maintain a constant speed, even when the load on the generator changes. This ensures smooth and safe operation.

It is necessary to prevent fluctuations in power supply, avoid damage to the equipment, and ensure synchronization with the grid. Governing systems are crucial for stable power generation and automatic adjustment to load variations.

Detailed Explanation:

Governing of turbines

In hydroelectric power stations, the demand for electricity can vary continuously. These changes affect the load on the turbine, and as a result, the speed of the turbine runner can fluctuate. But turbines must rotate at a constant speed to generate electricity at a stable frequency. This is where governing of turbines comes into play.

Governing is the method of controlling water flow into the turbine to maintain constant speed and output, regardless of load variations. The governing system monitors the turbine speed and adjusts the guide vanes or nozzle opening accordingly. This keeps the turbine stable and synchronized with the rest of the electrical system.

Working of Governing System

The basic components of a turbine governing system include:

• Speed sensing mechanism (e.g., centrifugal governor)
• Control unit (mechanical, hydraulic, or electronic)
• Actuator or servomotor
• Guide vanes or nozzle control system

When the load on the generator increases, it slows down the turbine. The governor detects this and increases the water flow to bring the speed back up. Similarly, if the load decreases, the turbine speeds up. The governor then reduces water flow to slow it down. This automatic adjustment maintains a steady turbine speed.

Importance of Governing

1. Maintains constant speed
   Governing ensures that the turbine speed remains steady, which is essential for stable power generation and maintaining the frequency of electricity (usually 50 Hz or 60 Hz depending on the region).
2. Prevents mechanical damage
   Sudden changes in load can cause the turbine to overspeed or underspeed, leading to mechanical stress. Governing reduces these effects and protects the turbine and generator.
3. Ensures grid synchronization
   Hydroelectric generators work in parallel with other power sources. Any speed change may disturb synchronization. Governing keeps the turbine in sync with the national or local grid.
4. Improves efficiency
   By controlling water usage, governing systems help in using water more efficiently and avoiding wastage during low demand.
5. Automatic and reliable
   Modern governing systems are automatic and precise, using sensors and computer controls to quickly react to load changes. This ensures continuous and uninterrupted power supply.

Types of Governing in Turbines

• Mechanical Governing: Uses mechanical linkages and centrifugal governors.
• Hydraulic Governing: Uses oil pressure and hydraulic systems to move control elements.
• Electronic Governing: Modern system using sensors, PLCs, and automatic control logic.

Each method serves the same purpose but differs in speed, accuracy, and application suitability.

Conclusion:

Governing of turbines is a critical control process in hydroelectric power stations. It keeps the turbine speed constant by regulating water flow based on load demand. This ensures safe operation, efficient energy conversion, and grid stability. Without governing, turbines would operate erratically, leading to equipment damage and power supply problems.