Estimated Solution to Economic Dispatch Problem with Multiple Fuel Types and Power Losses

Economic dispatch problem with multiple fuel types is complex because the objective function is nonconvex and piecewise. It is proposed a simple but effective solution strategy to estimate the economic dispatch solution by using the concept of loading ratio and fuel switching point. The proper fuel of each generating unit can be identified when the system load is known, prior to obtain the economic dispatch solution. As a result, the proposed method is superior to the existing methods that identify the proper fuel type as part of the economic dispatch solution. The proposed method is capable of solving the economic dispatch problem with consideration of power losses. A two-unit model is provided as an illustrative example. The proposed method is also tested with a ten-unit model which has been widely used in the literature for validation.