US researchers have designed a wind turbine that uses rotor inertia to smooth the power fluctuations caused by varying wind speeds.
Current solutions include using batteries or capacitors to store electricity on days when the wind is at the right speed and release it on days when the wind is too slow, or so fast the turbine has to be shut down. Turbines also incorporate technology to smooth the power supply and prevent blackouts due to the tripping of safety switches when electricity frequency deviates.
In research published in the International Journal of Power Electronics, engineers from Wisconsin-Milwaukee University propose a novel solution to allow wind turbines to supply more consistent electricity to the power grid.
The researchers’ method mitigates power fluctuations using the inertia of the wind turbine’s rotor as an energy storage component. They developed a braking control algorithm that adjusts the rotor speed so that when incoming wind power is greater than the average power, the rotor is allowed to speed up so that it can store the excess energy as kinetic energy rather than generating electricity. This energy is then released when the wind power falls below average.
This approach means no external energy storage is needed. It also captures wind energy more effectively and improves the overall efficiency of a wind farm, which could reduce the number of turbines required at any given site.