Hydroelectric power, the single greatest source of renewable energy around the world, is derived from moving water through the use of dams and hydroelectric power plants. Since no fuel is burned to create hydroelectric energy, it does not produce greenhouse gas emissions like more traditional fossil fuel power plants. The cost of running a hydroelectric plant is much lower, as water is provided by nature in the form of precipitation, so no additional fuel is needed.
How Hydroelectric Energy Works
Although hydroelectric power system configurations may differ based on the location and water source, the operating principle is the same. A hydroelectric power plant is built on a river, stream, or other moving body of water.
In order to create enough energy to generate electricity, the water must move with adequate speed and volume to turn the turbine blades within the dam. Openings in the dam barrier, also known as penstocks or floodgates, allow operators to control the water flow past the free-spinning turbine blades, which are in turn attached to a rotor. Coils on the rotor create an electromagnetic field when they move past stationary coils in the system’s generator, converting the rotary motion into electricity.
Repairs for Hydroelectric Generators
Hydroelectric generators transform mechanical energy from the spinning turbines into electrical energy using electromagnetic coils. The harsh operating environment and sheer amount of energy flowing through the hydroelectric system places enormous stress on the components within the generator. Coil winding failures and mechanicals failures are the two most common issues faced by operators of hydroelectric generators.
Coil Winding Failure
When one of the stationary or rotary windings coils in a hydroelectric generator fails due to damage or the effects of thermal aging, theycoil must be rewound. The rewinding process involves taking detailed as-found data and measurements of the existing windings to enable new coils to be reverse engineered. The original windings are then stripped from the generator and further measurements of these coils are taken to ensure that the correct geometry is maintained for the new coils.
Rewinding a hydroelectric generator also provides an ideal opportunity to enhance the performance of the generator by utilizing conductors having an increased cross-sectional area over the original coils. Using larger conductors will reduce I2R losses in the winding and thereby improve the overall efficiency of the generator.
Mechanical failure of a hydroelectric generator can be caused by a number of underlying issues. If any part of the system is misaligned or unbalanced, the hydroelectric equipment may experience high levels of vibration that can damage the overall system. A vibration analysis conducted while the generator is operating allows technicians to detect the location and nature of balance or alignment issues to facilitate correction at the source. Imbalance and misalignments can be caused by anything from a loose fastener or bearing to broken welds and rotors.
Other common repairs and maintenance for hydroelectric generators include the repair and replacement of bearings, slip rings, brush rigging, rotors, and flanges, as well as cleaning of stators and rotors. The size and weight of a hydroelectric generator can make repairs and maintenance difficult, but seasoned technicians are capable of conducting many repairs on location.
The Importance of Electric Motor and Generator Repairs
Electric motors and generators require regular repairs and maintenance to ensure safe and reliable operation. With critical power generation applications, it is essential that downtime be minimized as much as possible to ensure that the power supply is not interrupted. The best way to save time and money in hydroelectric operations is to conduct repairs as soon as a problem is detected. Left untreated, electrical and mechanical issues will only grow in severity, resulting in more expensive repairs, longer downtime, and greater safety risks.
To ensure that every aspect of the system stays in optimal operating condition, it is especially important to conduct regularly scheduled maintenance. A maintenance plan will provide you with a reliable overview of your system’s components, current operating condition, and expected service life. This allows you to plan for repairs and replacements, thereby further reducing the potential for excessive downtime and expensive last-minute repairs.
Electric Motor and Generator Repairs by Renown Electric
At Renown Electric, we are pleased to offer a variety of services for our customers in the hydroelectric industry and beyond. Our specialties include industrial electric motor repair, generator rebuilding, rewinding, on-site electric motor repair, and contract maintenance services. With more than 30 years of experience with industrial electric motors, Renown has the knowledge and expertise necessary to ensure that your hydroelectric system operates with the highest degree of safety and efficiency.
To learn more about our electric motor and generator solutions, contact our experts today.