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.

热、热和热电联产（CHP）的机组组合（UC）是电力系统的关键问题之一，对电力系统的经济性能具有重要作用。热电联产机组中热能和电能的相互依赖增加了 UC 问题的复杂性。在这项研究工作中，采用了两种模式的热电联产装置，抽取和背压，这两种模式相互比较具有灵活性。热电联产机组运行模式在 UC 问题中的附加值处于起步阶段。之后，优化技术被应用于解决 CHP UC 问题。二元粒子群优化用于更新机组状态，并采用搜索最优发电计划优先级列表的方法。该方法已被应用于解决热电联供问题的经济和利润模型。已进行的一套测试系统由十台常规热力机组、一台热电联产机组和一台纯热机组组成。获得的经济和利润模型结果揭示了热电联产机组在不同模式下的重要性。