An Efficient Approach to Schedule Generating Units of Combined Heat and Power (CHP) Generating System

The unit commitment (UC) of thermal, heat and combined heat and power (CHP) is one of the critical issues of power systems which have an essential role in the economic performance of power systems. The mutual dependency of heat and power in the CHP unit has increased the complexity of the UC problem. In this research work, two modes of CHP units, extraction and back-pressure, have been undertaken, which offers flexibility as compared to each other. The added value of operating modes of CHP units in the UC problem is in the infancy stage. Afterwards, the optimization technique has been applied to solve the CHP UC problem. The binary particle swarm optimization is used to to update unit status, and to search optimal generation schedule priority list method has been employed. This method has been applied to solve economic and profit models of CHP-UC problem. One test system that has been undertaken consists of ten conventional thermal units, one CHP, and one heat only unit. The obtained results of economic and profit models reveal the importance of the CHP unit under different modes.