Hydroelectric Power

Power Needle Operation Controlling the power needle is critical to any hydroelectric plant with an impulse turbine configuration. Operating head ranges are between 20-2000 meters where the water is converted to a high velocity jet stream when released from the nozzle’s orifice. As part of the nozzle for an impulse turbine, the power needle controls the water jet that impinges on a series of buckets rotating the runner.  There are two types of impulse turbines – Pelton and Turgo. A Pelton turbine power needle is in-line with the buckets of the runner that splits the water jet in half for maximum efficiency. The water impinges on the buckets from an incline, releasing it to the other side of the buckets with a Turgo turbine. Orientation can either be vertical or horizontal. Single and multi-jet power needles can also be utilized for a system. A deflector or other method of redirecting the water jet can be used both for more control and safety. The use of either turbines or configuration can vary depending on plant strategy.  Literature Download the Power Needle Application Spotlight to read more! Download

Wicket Gates Background Wicket gates are a series of adjustable vanes controlling the flow of water to a reaction turbine. Each vane, mechanically in parallel, is attached to an adjustable gate ring. Actuating the gate ring either clockwise or counterclockwise positions the wicket gates to regulate water flow to the turbine. Variations of operating the wicket gates are dependent on many factors including axis of the turbine, available head, physical space and turbine type.  A Hydraulic Power Unit (HPU) is one of the most common methods of actuating wicket gates. This allows the supply of pressurized oil to a servomotor, adjusting the wicket gates to a desired position. An HPU system usually includes an oil pressure tank (or accumulator), oil sump, air compressor, oil filtration/condition system, and an oil pump/motor – all coupled with a governor mechanism.  Problem The degradation of hydraulic fluid can cause problems in the HPU. This can lead to sluggish performance or entirely disable the oil pressure system, therefore causing an increase in downtime and cost.  Another problem lies in the growing concern and awareness on environmental impact. With governments enforcing strict regulations to reduce the hydroelectric industry’s environmental impact, HPU systems are under heavy scrutiny. Protecting waterways is top priority and unfortunately, HPU systems pose higher risk as they contain hundreds (and sometimes thousands) of gallons of oil – increasing the potential discharge into waterways. The consequences of this can be severe, resulting in hefty fines and potential incarceration.  Literature Download the Wicket Gate Operation for Reaction Turbines Application Spotlight! Download