Thermal Unit Commitment Using Fuzzy Logic

The Unit Commitment Problem is to determine a minimal cost turn-on and turn-off schedule of a set of electrical power generating units to meet a load demand while satisfying a set of operational constraints such as power generation-load balance, spinning reserve, operating constraints, minimum up time & minimum down time, etc. The production cost includes fuel, startup, shutdown, and no-load costs. Several conventional methods are available to solve the unit commitment problem. This paper describes the application of fuzzy logic algorithm for determining short term commitment of thermal units in electrical power generation. This method allows a qualitative description of the behavior of the system, the system characteristics and response without the need for exact mathematical formulations. It is demonstrated through a numerical example that a fuzzy logic based approach achieves a logical and feasible economic cost of operation of the power system, which is the major object of Unit commitment. The results obtained from fuzzy logic based approach are compared with the priority list method solution to unit commitment problem