Five important tests to run on wind turbines

Wind turbines use wind to make electricity. The wind turns the turbine’s propeller-like blades around a rotor, which spins a generator. This creates electricity. Each of these segments in the operating process of a wind turbine are essential in creating energy and require many parts and components to function properly. If one part fails, the wind turbine will not work. That is why regular inspection and maintenance are important to keep things running smoothly and uninterrupted.

By regularly performing these five important tests, your wind turbine should run effectively and efficiently for years.

1. Electric motor and generator testing

The generator is essential in creating power with a wind turbine. If the generator is not working properly, it will not produce enough electricity to reach a voltage high enough to produce useable electricity - it may even overheat and stop working all together. That is why static motor testers, such as MTR105, should be used to perform routine testing on a wind turbine’s generator.

The MTR105 is a particularly good for this as it is a handheld dedicated static motor tester that can perform multiple tests, including insulation resistance tests, which can determine if there is moisture or other contaminants in the generator that may be a reason for concern.

The MTR105 can also perform motor rotation tests to look for shorted connections, loose connections, and broken conductors, or resistive connections problems that could cause the motor to fail. Other tests it can perform include low resistance tests, inductance tests, diode tests, as well as inductance and capacitance tests. Diode testing is particularly important as they are used in generators to ensure that energy flows in one direction. If just one of the diodes fail, then there will be a loss in energy output.

2. Contact resistance testing

Busbar and cable joints, as well as high-voltage circuit breakers located in or new the tower need to be tested to eliminate potential hazards caused by induced voltages. Contact resistance testing of circuit breakers is a very important safety test. Poor contact resistance leads to poor circuit breaker performance, and this can lead to electrical damage.

Cable joints can be tested with a 10A DLRO, but circuit breakers need up to 200A testing and that needs to be performed using a MOM2.

Circuit breakers are vital safety devices that ensure disconnection in the event of a fault. The MOM2 is a high current micro-ohmmeter that can conduct a full day’s worth of testing in locations where no power supply is available, making it the ideal tool for this kind of turbine maintenance. 

3. Insulation resistance testing

Testing the insulation resistance of high-voltage power cables and buses, large motor/generator windings, and transformers is extremely important to ensure the integrity of the generator’s winding insulation and the likelihood of developing a ground.

The MIT1525 has been specifically engineered to perform this test while ensuring the highest accuracy possible. It can be used at altitudes as high as 3,000 meters (9,800 feet) above sea level and is uniquely designed to charge while operating and will continue to take measurements when connected to a line power with a fully discharged battery. This feature is particularly important when working out in the field on a wind turbine.

4. Earth/ground resistance testing

Ground resistance testing can help prevent a rise in voltage caused by a fault current, surges, and lightning strikes in earth/ground systems.

To ensure turbine cables are able to deal with these sudden voltage increases, use a DET24C earth/ground digital clamp-on resistance tester. It allows for the easy access and testing of cables found in wind turbines as it can clamp around the cable and measures ground resistance. Measuring the ground resistance of turbines under IEEE 81 standard, requires the use of test reels and a special instrument like the DET2/3. The Fall of Potential value can be measured with this excellent diagnostic tool when there is a problem with a turbine, and they can be used to test grounding and lightning protection.

5. Low resistance testing

Measuring low resistance is an important electrical test because it helps identify components where the resistance has exceeded acceptable values. Lightning strikes cause a great deal of downtime and power loss for wind turbines. As towers become taller, the number of strikes continue to increase. Because of this, the need for lightning protection testing is important. Several spots on a wind turbine, like the weather mast, roof cooler, control panels, nacelle-tower junction, nacelle-hub junction, and machine support can be tested using the DLRO10X, DLRO2, and KC-C test leads to ensure low resistance.

Wind turbines are an excellent source of power, they don’t release emissions that can pollute the air or water, and they don’t require water for cooling. However, wind turbines do require preventative maintenance check-ups two or three times per year and may need to be increased as a turbine ages. Performing the tests listed above will help with the life of your turbine.