Hydro-Electric Series

The objective of this course is to present and discuss types of equipment used to monitor and control the operation of the hydro turbine. Typical examples of mechanical hydraulic and electro hydraulic actuators are demonstrated plus monitoring and protection devices.

Upon completion of this course, you should have an understanding of the following concepts:

• The need for turbine controls, monitoring systems, alarm and annunciators, and protection devices
• Methods for controlling the flow of water through the turbine
• The effect of control action before the generator is synchronized, and after the generator is synchronized
• Operation of the mechanical hydraulic actuator for control of wicket gates
• Force amplification through the servo mechanism. The need for reset action to stabilize actuator operation
• Operation of the hydraulic oil system, including pressurized oil tank, oil pumps, and compressors
• Automatic governor operations using the “flyball” type governor head
• The purpose of the PMG, “Permanent Magnet Generator”
• The function of the governor speeder set point control, i.e. speed or load adjustment
• Response of the turbine governor to frequency (speed) changes
• The function of the speed droop characteristic, i.e. sharing of load changes between generators in parallel
• The effect of changes in speed droop setting
• The function of the gate limiter
• The use of the gate limiter for manual control during start-up or power output control
• The function of reset signal damping, i.e. the dash pot in older machines
• Requirements for monitoring turbine conditions, i.e. critical measuring points
• The implications of high bearing temperatures, excessive vibration, and shaft misalignment
• Abnormal turbine conditions which necessitate shutdown of the unit, i.e. overspeed
• The turbine generator trip (shut-down) circuit
• Types of overspeed trip devices
• Operation of the electro hydraulic actuator and governor system
• Operation of the electronic SSG (Speed Signal Generator) in place of the PMG
• The nature of digital control systems versus analog
• Pre-programming turbine operations through microprocessor control
• Using the SCADA system for remote operation from the energy control center
• Monitoring and control of the turbine through the operator CRT interface in the powerhouse