Active power control of wind turbines can improve power grid reliability

Jan 28, 2014

The Energy Department's National Renewable Energy Laboratory (NREL), along with partners from the Electric Power Research Institute and the University of Colorado have completed a comprehensive study to understand how wind power technology can assist the power grid by controlling the active power output being placed onto the system. The rest of the power system's resources have traditionally been adjusted around wind to support a reliable and efficient system. The research that led to this report challenges that concept.

The study, "Active Power Controls from Wind Power: Bridging the GapsPDF", finds that wind can support the power system by adjusting its power output to enhance system reliability. Additionally, the study finds that it often could be economically beneficial to provide active power control , and potentially damaging loads on turbines from providing this control is negligible. Active power control helps balance load with generation at various times, avoiding erroneous power flows, involuntary load shedding, machine damage, and the risk of potential blackouts.

"Utilities and independent system operators are all seeking strategies to better integrate wind and other variable generation into their electric systems," NREL Analyst Erik Ela said. "Few have considered using wind power to support power system reliability."

The study included a number of different power system simulations, control simulations, and field tests using turbines at NREL's National Wind Technology Center (NWTC). The study developed proposals for new ancillary services designs in U.S. wholesale electricity markets, studied how wind power affects system frequency in the western U.S. with and without active power control, and tested the use of active power control at the NWTC to better understand the performance and structural impacts on wind turbines when providing active power control to the electric system.

"Although many of the control strategies have been proven technically feasible and are used in many regions of the world, only a limited number of wind turbines in the United States are currently providing active power control," Ela said. "The reason is that the stakeholders – system operators, manufacturers, regulators and the plant owners – all have different goals and perspectives. This report covers many different aspects of the topic in order to address the diverse viewpoints throughout the wind industry."

Wind is one of the fastest growing sources of power generation – supplying up to 20% of electricity in many areas of the world. In some regions of the U.S., wind sometimes provides more than 50% of the electric power. The challenge with integrating high concentrations of wind power into electric systems is that it is a variable, uncertain resource, commonly considered "non-dispatchable."

The forms of active power control considered in this study are synthetic inertial control, primary frequency control (PFC), and automatic generation control (AGC) regulation. For wind power to provide active power control services, three things must happen:

  • The wind power response needs to improve power system reliability; not impair it
  • It must be economically viable for wind power plants as well as electricity consumers. Because power plants may incur additional capital costs for the controls and reduce the amount of energy it sells to the market, there must be an incentive to provide the service
  • Active power control should not have negative impacts on the turbine loading or induce structural damage that could reduce the life of the turbine.

The comprehensive study, funded by the Energy Department's Office of Energy Efficiency and Renewable Energy, analyzed timeframes ranging from milliseconds to the lifetime of , spatial scopes ranging from turbine components to entire regions, and study types ranging from economics to power systems engineering, to control design.

"The study's key takeaway is that can act in an equal or superior manner to conventional generation when providing control, supporting the system frequency response and improving reliability," Ela said.

Explore further: Improving energy conversion processes

More information: Study: www.nrel.gov/docs/fy14osti/60574.pdf

Related Stories

Using fluctuating wind power

Mar 25, 2013

Incorporating wind power into existing power grids is challenging because fluctuating wind speed and direction means turbines generate power inconsistently. Coupled with customers' varying power demand, many ...

Improving energy conversion processes

Dec 03, 2013

(Phys.org) —Renewable energy sources such as wind-powered generators can be more reliable and efficient by better controlling the process of getting electricity onto the power grid, according to a United ...

Renewable sources can provide stable power

Dec 02, 2013

Renewable energy sources - an area in which Germany is a leader - are becoming increasingly important for the worldwide power mix. Nevertheless, experts are still deliberating which market model is best for ...

Recommended for you

Seoul to provide smartphone-charging down by the stream

Aug 29, 2014

Seoul's mobile users will be able to make use of outdoor charging stations at a popular downtown stream, powered by mini-hydroelectric turbines that use the stream's current. The city is building the recharging ...

Tesla, Chinese firm plan 400 charging stations

Aug 29, 2014

Tesla Motors Co. and a state-owned Chinese phone carrier announced plans Friday to build 400 charging stations for electric cars in a new bid to promote popular adoption of the technology in China.

Cool roofs in China can save energy and reduce emissions

Aug 28, 2014

(Phys.org) —Working with Chinese researchers, the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has conducted the first comprehensive study of cool roofs in China and concluded ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

nagar
not rated yet Mar 11, 2014
That's good new as it helps a lot in saving more percentage of power generation which in turns helps to increase power efficiency

http://www.servo-...izer.net