Modeling, Simulation, and Control of a Supercritical Coal-Fired Power Plant for Smart Grid Applications

Modeling, Simulation and Control of a Supercritical Coal-fired Power Plant for Smart Grid Applications

Jacob Douglas, Xin He, and Fernando V. Lima

Submitted to Topical Area: Computing and Process Control

Modern smart grid programs rely on the combustion reaction of fossil fuels such as coal and natural gas to supplement energy produced by renewable resources. These programs utilize several different sources of energy such as wind, solar, and fossil fuels. In a smart grid program, the power required from fossil fuel power plants has to change quickly in response to the available renewable energy. Therefore a fossil fuel power plant has to be able to ramp up or ramp down power generation instantaneously to account for the intermittent deficits of renewable energy. Several different power plant designs have been proposed to try to solve the problems associated with the implementation of a smart grid program. One of these designs is the supercritical coal-fired power plant. An advantage of this design is that the power plant runs at a constant pressure. Thus, if the temperature entering the turbine cycle is kept constant as well, the power produced by the design can be cycled by changing the flow rates of the water and coal entering the process. With this design, the power produced from the combustion of hydrocarbons can be manipulated quickly to account for a change in the energy produced by renewable techniques.

In this presentation, the conditions of turbines and a boiler used in the supercritical coal-fired power plant design are manipulated by using proportional-integral-derivative (PID) controllers to show how this plant design could be incorporated into a smart grid program. In the control scheme for the developed power plant model, the pressure and temperature of the steam entering the turbines are kept constant at specified set points. The implemented control scheme allows for the inlet conditions of the solid coal and water flow rates to be cycled in order to obtain a desired power output. Preliminary results indicate that a cycling range of ± 25% is achievable by the current power plant design. These results show that using this controller design, it is possible to make changes to the plant model to accommodate energy produced by renewable sources.