January 2, 2014
Study Shows Wind Power Can Cause Power Grid Problems, Offers Solution
Lee Rannals for redOrbit.com – Your Universe Online
Researchers from North Carolina State University and Johns Hopkins University found that increasing wind power generation makes the power grid more susceptible to disruptions. However, while the study revealed the potential problem wind power brings, the team also was able to offer a solution.
The team devised a way for coordinating wind power generation and energy storage in order to minimize the potential for power disruptions.
Power flowing through lines on a power grid sometimes suffers from small deviations after a disturbance. These oscillations are mitigated through controllers inside the power generators. However, if controls are not strong enough, then the oscillations may reduce the efficiency of power transfer and pose a threat to the stability of the grid.
According to the study, under certain circumstances, wind power generators can make small oscillations worse. This happens because wind farms produce power erratically, as the amount of power being produced depends on how hard the wind is blowing.
“To counteract this problem, we have designed a technique that coordinates the activity of controllers inside the wind turbines and battery management systems to even out the flow of power from wind farms into the grid,” Dr. Aranya Chakrabortty, an assistant professor of electrical engineering at NC State and senior author of a paper describing the work, said in a statement.
Chakrabortty and colleagues developed several algorithms that match control efforts between wind farms and energy storage facilities. If power output from these wind farms increases, the surplus can be siphoned off to charge batteries at the storage facility, instead of just giving the grid all the power. If the power output at the wind farm begins to decline, then the batteries can push power back onto the grid to help mitigate the changing surges.
“By matching the behavior of the two controllers, we can produce the desired damping effect on the power flow and restore stable grid behavior,” Chakrabortty said in a statement.
Wind energy production in the US has been increasing rapidly over the years due to government mandates and the goal of providing 20 percent of the nation’s power through wind by 2020. Understanding how wind energy will affect the power grid is crucial for a future where this power becomes a large chunk of US energy. Studies like this provide the information scientists need to continue integrating wind power into the existing power grid.